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  • 3901.
    Abdelamer, Liena
    Karlstad University, Faculty of Social and Life Sciences.
    Den stressade eleven: En enkätstudie om stressorer som utsätter barnen för stress2011Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Researchers claim that stress has become a word of fashion and is now frequently used. They also state that there is no accepted definition that can easily describe the concept. In this essay, I have examined children and stress. The aim of the diploma work is to illustrate stress more closely the stress concept, the underlying reasons that can influence children and how teachers and school staff support children in their stress handling. My three issues are: What is stress? What stressors put children, at home and at school, in a stress situation? How can teachers help children to manage their stress? The diploma work is based on a literature study in order to find out what has been written on the subject in earlier research. Moreover, the work is based on four interviews with three class teachers and a school nurse in order to illustrate their experiences of what stresses children at school. In order to get a good base for the work the children's participation was of utmost importance to get a good base for the work, therefore questionnaires were given to 89 children in class 4 and 5. The results of the questionnaires showed that children had little or no knowledge of the stress concept. They associate it most often with lack of time and having to hurry. Children can be stressed just like adults. In addition, stress levels differ greatly between them, which means that some children feel more stress-tolerant than others. The conclusion that can be drawn from this study is that the child's environment affects the child, school and home being the greatest stress factors.

                                                                                             

    Keywords: Children under stress, stress, stressor, stress handling.

  • 3902. Abdel-Aty, M A
    et al.
    Radwan, A E
    Developing crash predictive models for a principal arterial2000Report (Other (popular science, discussion, etc.))
  • 3903. Abdel-Aty, M.
    et al.
    Larson, Jonas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Eleuch, H.
    Obada, A. S. F.
    Multi-particle entanglement of charge qubits coupled to a nanoresonator2011In: Physica. E, Low-Dimensional systems and nanostructures, ISSN 1386-9477, E-ISSN 1873-1759, Vol. 43, no 9, p. 1625-1630Article in journal (Refereed)
    Abstract [en]

    The dynamics of charge qubits coupled to a nanomechanical resonator under the influence of both a phonon bath in contact with the resonator and irreversible decay of the qubits is considered. The focus of our analysis is devoted to multi-particle entanglement and the effects arising from the coupling to the reservoir. Even in the presence of the reservoirs, the inherent entanglement is found to be rather robust. Due to this fact, together with control of system parameters, the system may, therefore, be especially suited for quantum information processing. Our findings also shed light on the evolution of open quantum many-body systems. For instance, due to intrinsic qubit-qubit couplings our model is related to a driven XY spin model.

  • 3904. Abdel-Aty, MA
    et al.
    As-Saidi, AH
    Using GIS to locate the high risk driver population2000Report (Other (popular science, discussion, etc.))
  • 3905.
    Abdelaziz, Ahmed
    et al.
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Ang, Tanfong
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Sookhak, Mehdi
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Khan, Suleman
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Vasilakos, Athanasios
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Liew, Cheesun
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Akhunzada, Adnan
    Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur.
    Survey on network virtualization using openflow: Taxonomy, opportunities, and open issues2016In: KSII Transactions on Internet and Information Systems, ISSN 1976-7277, Vol. 10, no 10, p. 4902-4932Article in journal (Refereed)
    Abstract [en]

    The popularity of network virtualization has recently regained considerable momentum because of the emergence of OpenFlow technology. It is essentially decouples a data plane from a control plane and promotes hardware programmability. Subsequently, OpenFlow facilitates the implementation of network virtualization. This study aims to provide an overview of different approaches to create a virtual network using OpenFlow technology. The paper also presents the OpenFlow components to compare conventional network architecture with OpenFlow network architecture, particularly in terms of the virtualization. A thematic OpenFlow network virtualization taxonomy is devised to categorize network virtualization approaches. Several testbeds that support OpenFlow network virtualization are discussed with case studies to show the capabilities of OpenFlow virtualization. Moreover, the advantages of popular OpenFlow controllers that are designed to enhance network virtualization is compared and analyzed. Finally, we present key research challenges that mainly focus on security, scalability, reliability, isolation, and monitoring in the OpenFlow virtual environment. Numerous potential directions to tackle the problems related to OpenFlow network virtualization are likewise discussed

  • 3906.
    Abdeldaim, Guma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Korsgaard, J.
    Köpenhamns Universitet.
    Olcén, P.
    Örebro Universitet, klinisk mikrobiologi.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Strålin, Kristoffer
    Örebro Universitet, klinisk mikrobiologi.
    Is quantitative PCR for the pneumolysin (ply) gene useful for detection of pneumococcal lower respiratory tract infection?2009In: Clinical Microbiology and Infection, ISSN 1198-743X, E-ISSN 1469-0691, Vol. 15, no 6, p. 565-570Article in journal (Refereed)
    Abstract [en]

    The pneumolysin (ply) gene is widely used as a target in PCR assays for Streptococcus pneumoniae in respiratory secretions. However, false-positive results with conventional ply-based PCR have been reported. The aim here was to study the performance of a quantitative ply-based PCR for the identification of pneumococcal lower respiratory tract infection (LRTI). In a prospective study, fibreoptic bronchoscopy was performed in 156 hospitalized adult patients with LRTI and 31 controls who underwent bronchoscopy because of suspicion of malignancy. Among the LRTI patients and controls, the quantitative ply-based PCR applied to bronchoalveolar lavage (BAL) fluid was positive at >/=10(3) genome copies/mL in 61% and 71% of the subjects, at >/=10(5) genome copies/mL in 40% and 58% of the subjects, and at >/=10(7) genome copies/mL in 15% and 3.2% of the subjects, respectively. Using BAL fluid culture, blood culture, and/or a urinary antigen test, S. pneumoniae was identified in 19 LRTI patients. As compared with these diagnostic methods used in combination, quantitative ply-based PCR showed sensitivities and specificities of 89% and 43% at a cut-off of 10(3) genome copies/mL, of 84% and 66% at a cut-off of 10(5) genome copies/mL, and of 53% and 90% at a cut-off of 10(7) genome copies/mL, respectively. In conclusion, a high cut-off with the quantitative ply-based PCR was required to reach acceptable specificity. However, as a high cut-off resulted in low sensitivity, quantitative ply-based PCR does not appear to be clinically useful. Quantitative PCR methods for S. pneumoniae using alternative gene targets should be evaluated.

  • 3907.
    Abdeldaim, Guma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Mölling, Paula
    Holmberg, Hans
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Olcén, Per
    Strålin, Kristoffer
    Usefulness of real-time PCR for lytA, ply, and Spn9802 on plasma samples for the diagnosis of pneumococcal pneumonia2010In: Clinical Microbiology and Infection, ISSN 1198-743X, E-ISSN 1469-0691, Vol. 16, no 8, p. 1135-1141Article in journal (Refereed)
    Abstract [en]

    In the present study, we evaluated rapid real-time PCR assays for ply, Spn9802, and lytA applied to plasma samples for the detection of Streptococcus pneumoniae in patients with community-acquired pneumonia (CAP). In a prospective study of CAP aetiology, an EDTA plasma sample was collected together with blood culture in 92 adult CAP patients and 91 adult controls. Among the 92 CAP patients, lytA PCR was positive in eight (9%), Spn9802 PCR was positive in 11 (12%) and ply PCR was positive in 19 (21%) cases. Of 91 controls, the ply PCR was positive in eight cases (9%), but no positive cases were noted by Spn9802 or lytA PCRs. Ten CAP patients had pneumococcal bacteraemia. Compared to blood culture, PCR for lytA, Spn9802 and ply had sensitivities of 70% (7/10), 60% (6/10) and 70% (7/10), and specificities of 96% (79/82), 94% (77/82) and 85% (70/82) respectively. With blood culture and/or culture of representative sputum, and/or urinary antigen detection, S. pneumoniae was identified in 31 CAP patients. Compared to these tests in combination, PCR for lytA, Spn9802 and ply showed sensitivities of 26% (8/31), 32% (10/31) and 42% (13/31), and specificities of 100% (61/61), 98% (60/61) and 90% (55/61) respectively. We conclude that Spn9802 and lytA PCRs may be useful for the rapid detection of bacteraemic pneumococcal pneumonia, whereas ply PCR is not specific enough for routine use and blood PCR with small plasma volumes is not useful for the detection of nonbacteraemic pneumococcal pneumonia.

  • 3908.
    Abdeldaim, Guma M. K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    PCR detection of Streptococcus pneumoniae and Haemophilus influenzae in pneumonia patients2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    PCR is a rapid, reproducible method for nucleic acid detection. However, this technology displays significant deficiencies when applied in clinical microbiology. This work’s aim was to improve current diagnostics and provide sensitive and quantitative real-time PCRs.

    Paper I describes the development of a sensitive and specific quantitative real-time PCR for the detection of Streptococcus pneumoniae, based on the Spn9802 DNA fragment. Applied to nasopharyngeal aspirates from 166 pneumonia patients, Spn9802 PCR had a sensitivity of 94% and a specificity of 98%.

    In Paper II the performance of a ply gene PCR for identification of pneumococcal lower respiratory tract infection (LRTI) was evaluated on bronchoalveloar lavage fluids. At the detection limit 103 genome copies/mL, 89% sensitivity but only 43% specificity was achieved.

    Paper III shows that S. pneumoniae DNA is detectable in plasma from acutely febrile patients. Sensitivities were low (26-42%) for detection of pneumococcal pneumonia, for bacteraemic pneumococcal pneumonia they were 60-70%.

    Paper IV describes evaluation of four PCR targets for Haemophilus influenzae detection. A real-time PCR based on the P6 gene was developed and applied to 166 CAP patients, using cut-off of 104 genome copies/mL the assay had a sensitivity of 97% and a specificity of 96%.

    In paper V, the two real-time PCRs presented in papers I and IV were combined with a PCR for detection of Neisseriae meningitidis. The analytical sensitivity of this multiplex real-time PCR was not affected by using a mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae) in single tubes. Applied to 156 LRTI patients, this PCR had sensitivities over 90% for S. pneumoniae and H. influenzae, and specificities of 89% and 96%, respectively.

    In conclusion, real-time PCR assays are useful for the diagnosis of S. pneumoniae and H. influenzae. They enable detection after antibiotic installation, and quantification increases the etiological specificity of pneumonia.

  • 3909.
    Abdeldaim, Guma M. K.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology.
    PCR detection of haemophilus influenzae from respiratory specimens2013In: PCR Detection of Microbial Pathogens / [ed] Mark Wilks, Humana Press, 2013, 2, p. 115-123Chapter in book (Refereed)
    Abstract [en]

    The detection of Haemophilus influenzae by conventional methods like culture is time-consuming and may give false-negative results, especially during ongoing antibiotic treatment. Therefore, non-culture based methods that are sensitive, specific, and rapid are valuable for early diagnosis and effective therapy. Here we describe a quantitative real-time PCR assay based on the outer membrane P6 gene omp6, to detect H. influenzae and its application on respiratory tract specimens.

  • 3910.
    Abdeldaim, Guma M. K.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology.
    Stralin, Kristoffer
    Olcen, Per
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Virology.
    Molling, Paula
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology.
    Quantitative fucK gene polymerase chain reaction on sputum and nasopharyngeal secretions to detect Haemophilus influenzae pneumonia2013In: Diagnostic microbiology and infectious disease, ISSN 0732-8893, E-ISSN 1879-0070, Vol. 76, no 2, p. 141-146Article in journal (Refereed)
    Abstract [en]

    A quantitative polymerase chain reaction (PCR) for the fucK gene was developed for specific detection of Haemophilus influenzae. The method was tested on sputum and nasopharyngeal aspirate (NPA) from 78 patients with community-acquired pneumonia (CAP). With a reference standard of sputum culture and/or serology against the patient's own nasopharyngeal isolate, H. influenzae etiology was detected in 20 patients. Compared with the reference standard, fucK PCR (using the detection limit 10(5) DNA copies/mL) on sputum and NPA showed a sensitivity of 95.0% (19/20) in both cases, and specificities of 87.9% (51/58) and 89.5% (52/58), respectively. In a receiver operating characteristic curve analysis, sputum fucK PCR was found to be significantly superior to sputum P6 PCR for detection of H. influenzae CAP. NPA fucK PCR was positive in 3 of 54 adult controls without respiratory symptoms. In conclusion, quantitative fucK real-time PCR provides a sensitive and specific identification of H. influenzae in respiratory secretions.

  • 3911.
    Abdeldaim, Guma M. K.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Strålin, Kristoffer
    Department of Infectious Diseases, Örebro University Hospital.
    Kirsebom, Leif A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Detection of Haemophilus influenzae in respiratory secretions from pneumonia patients by quantitative real-time polymerase chain reaction2009In: Diagnostic microbiology and infectious disease, ISSN 0732-8893, E-ISSN 1879-0070, Vol. 64, no 4, p. 366-373Article in journal (Refereed)
    Abstract [en]

    A quantitative real-time polymerase chain reaction (PCR) based on the omp P6 gene was developed to detect Haemophilus influenzae. Its specificity was determined by analysis of 29 strains of 11 different Haemophilus spp. and was compared with PCR assays having other target genes: rnpB, 16S rRNA, and bexA. The method was evaluated on nasopharyngeal aspirates from 166 adult patients with community-acquired pneumonia. When 104 DNA copies/mL was used as cutoff limit for the method, P6 PCR had a sensitivity of 97.5% and a specificity of 96.0% compared with the culture. Of 20 culture-negative but P6 PCR-positive cases, 18 were confirmed by fucK PCR as H. influenzae. Five (5.9%) of 84 nasopharyngeal aspirates from adult controls tested PCR positive. We conclude that the P6 real-time PCR is both sensitive and specific for identification of H. influenzae in respiratory secretions. Quantification facilitates discrimination between disease-causing H. influenzae strains and commensal colonization.

  • 3912.
    Abdeldaim, Guma M. K.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Strålin, Kristoffer
    Olcén, Per
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Toward a quantitative DNA-based definition of pneumococcal pneumonia: a comparison of Streptococcus pneumoniae target genes, with special reference to the Spn9802 fragment2008In: Diagnostic microbiology and infectious disease, ISSN 0732-8893, E-ISSN 1879-0070, Vol. 60, no 2, p. 143-150Article in journal (Refereed)
    Abstract [en]

    The current shift from phenotypically toward genotypically based microbial diagnosis is not unproblematic. A novel quantitative real-time polymerase chain reaction (PCR) assay based on the Spn9802 DNA fragment was therefore developed for detection of Streptococcus pneumoniae. Out of 44 bacterial species, only S. pneumoniae and Streptococcus pseudopneumoniae were positive in Spn9802 PCR. In an evaluation on nasopharyngeal aspirates from 166 patients with community-acquired pneumonia, the assay was positive in 49 of 50 culture-positive cases. Of 19 culture-negative but Spn9802 PCR-positive cases, 12 were confirmed as S. pneumoniae by rnpB sequence analysis. With an expanded reference standard, including culture and rnpB sequencing, Spn9802 had a sensitivity of 94% and a specificity of 98%. A cutoff for clinically significant positivity was 10(4) DNA copies/mL, giving 71% sensitivity and 100% specificity. In conclusion, Spn9802 real-time PCR is highly sensitive and specific. The quantification it provides enables differentiation between pneumococcal pathogenicity and commensalism.

  • 3913.
    Abdeldaim, Guma M. K.
    et al.
    Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden; Department of Clinical Mycobacteriology, National Center for Diseases Control, Benghazi, Libyan Arab Jamahiriya.
    Strålin, Kristoffer
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden; Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.
    Olcén, Per
    Department of Laboratory Medicine, Örebro University Hospital, Örebro, Sweden.
    Blomberg, Jonas
    Section of Clinical Virology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
    Mölling, Paula
    Örebro University Hospital. Department of Laboratory Medicine.
    Herrmann, Björn
    Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
    Quantitative fucK gene polymerase chain reaction on sputum and nasopharyngeal secretions to detect Haemophilus influenzae pneumonia2013In: Diagnostic microbiology and infectious disease, ISSN 0732-8893, E-ISSN 1879-0070, Vol. 76, no 2, p. 141-146Article in journal (Refereed)
    Abstract [en]

    A quantitative polymerase chain reaction (PCR) for the fucK gene was developed for specific detection of Haemophilus influenzae. The method was tested on sputum and nasopharyngeal aspirate (NPA) from 78 patients with community-acquired pneumonia (CAP). With a reference standard of sputum culture and/or serology against the patient's own nasopharyngeal isolate, H. influenzae etiology was detected in 20 patients. Compared with the reference standard, fucK PCR (using the detection limit 10(5) DNA copies/mL) on sputum and NPA showed a sensitivity of 95.0% (19/20) in both cases, and specificities of 87.9% (51/58) and 89.5% (52/58), respectively. In a receiver operating characteristic curve analysis, sputum fucK PCR was found to be significantly superior to sputum P6 PCR for detection of H. influenzae CAP. NPA fucK PCR was positive in 3 of 54 adult controls without respiratory symptoms. In conclusion, quantitative fucK real-time PCR provides a sensitive and specific identification of H. influenzae in respiratory secretions.

  • 3914.
    Abdeldaim, Guma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Strålin, Kristoffer
    Department of Infectious Diseases, Örebro University Hospital, Örebro.
    Korsgaard, Jens
    Department of Chest Diseases, Aarhus University Hospital, Aalborg, Denmark.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Bacteriology.
    Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis2010In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 10, p. 310-Article in journal (Refereed)
    Abstract [en]

    Background. Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR) for detection of S. pneumoniae (9802 gene fragment), H. influenzae (omp P6 gene) and N. meningitidis (ctrA gene). The method was evaluated on bronchoalveolar lavage (BAL) samples from 156 adults with lower respiratory tract infection (LRTI) and 31 controls, and on 87 cerebrospinal fluid (CSF) samples from meningitis patients.

    Results. The analytical sensitivity was not affected by using a combined mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae/N. meningitidis) in single tubes. By blood- and BAL-culture and S. pneumoniae urinary antigen test, S. pneumoniae and H. influenzae were aetiological agents in 21 and 31 of the LTRI patients, respectively. These pathogens were identified by qmPCR in 52 and 72 of the cases, respectively, yielding sensitivities and specificities of 95% and 75% for S. pneumoniae, and 90% and 65% for H. influenzae, respectively. When using a cut-off of 105 genome copies/mL for clinical positivity the sensitivities and specificities were 90% and 80% for S. pneumoniae, and 81% and 85% for H. influenzae, respectively. Of 44 culture negative but qmPCR positive for H. influenzae, 41 were confirmed by fucK PCR as H. influenzae. Of the 103 patients who had taken antibiotics prior to sampling, S. pneumoniae and H. influenzae were identified by culture in 6% and 20% of the cases, respectively, and by the qmPCR in 36% and 53% of the cases, respectively. In 87 CSF samples S. pneumoniae and N. meningitidis were identified by culture and/or 16 S rRNA in 14 and 10 samples and by qmPCR in 14 and 10 samples, respectively, giving a sensitivity of 100% and a specificity of 100% for both bacteria.

    Conclusions. The PCR provides increased sensitivity and the multiplex format facilitates diagnosis of S. pneumoniae, H. influenzae and N. meningitidis and the assay enable detection after antibiotic treatment has been installed. Quantification increases the specificity of the etiology for pneumonia.

  • 3915.
    Abdeldaim, Guma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology. Benghazi Univ, Fac Med, Dept Med Microbiol & Parasitol, Benghazi, Libya..
    Svensson, Erik
    Statens Serum Inst, Int Reference Lab Mycobacteriol, Copenhagen, Denmark..
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Virology.
    Herrmann, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Bacteriology.
    Duplex detection of the Mycobacterium tuberculosis complex and medically important non-tuberculosis mycobacteria by real-time PCR based on the rnpB gene2016In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 124, no 11, p. 991-995Article in journal (Refereed)
    Abstract [en]

    A duplex real-time PCR based on the rnpB gene was developed for Mycobacterium spp. The assay was specific for the Mycobacterium tuberculosis complex (MTB) and also detected all 19 tested species of non-tuberculous mycobacteria (NTM). The assay was evaluated on 404 clinical samples: 290 respiratory samples and 114 from tissue and other nonrespiratory body sites. M. tuberculosis was detected by culture in 40 samples and in 30 samples by the assay. The MTB assay showed a sensitivity similar to Roche Cobas Amplicor MTB-PCR (Roche Molecular Systems, Pleasanton, CA, USA). There were only nine samples with non-tuberculous mycobacteria detected by culture. Six of them were detected by the PCR assay.

  • 3916. Abdelfatah Possnert, Heba
    Detection of Thymidine Kinase 1 Activity in Whole Blood Using an Oligonucleotide System2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today’s medical science studies, many tumor markers are being used to monitor cancer cell proliferation, but the number of assays for analysis of these markers are few. The aim of this study was to find an easier and more time-efficient way to measure the activity of a specific tumor marker called tymidine kinase 1 (TK1). This tumor marker is an important enzyme involved in cell proliferation and is a key enzyme in the salvage pathway. TK1 activity is related to the occurrence of hematological malignancies and cell activity and therefore have been used as a marker when monitoring this group of patients in treatment. Measurement of the enzyme activity in this study was performed by using an oligonucleotide assay. Detection of the enzyme activity in whole blood and in plasma has not previously been shown. The TK1 activity measured in whole blood and plasma correlated with TK1 activity measured in serum (R2=0,8651 and R2 =0,9845, respectively). It was found that it is possible to determine the TK1 activity in whole blood but only if the activity was measured on the same day as the blood samples were taken. The results shows that the activity measurement of TK1 in plasma and whole blood can be used as a marker to verify patients' therapy in cancer care. This study is only the beginning and further investigations should be made in the future to determine if the method that is subject to this study has the requested effects.

  • 3917.
    Abdelfattah, Ahmed
    et al.
    Univ Mediterranea Reggio Calabria, Italy.
    Malacrinò, Antonino
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wisniewski, Michael
    USDA ARS, WV 25430 USA.
    Cacciola, Santa O.
    Univ Catania, Italy.
    Schena, Leonardo
    Univ Mediterranea Reggio Calabria, Italy.
    Metabarcoding: A powerful tool to investigate microbial communities and shape future plant protection strategies2018In: Biological control (Print), ISSN 1049-9644, E-ISSN 1090-2112, Vol. 120Article in journal (Refereed)
    Abstract [en]

    Microorganisms are the main drivers shaping the functioning and equilibrium of all ecosystems, contributing to nutrient cycling, primary production, litter decomposition, and multi-trophic interactions. Knowledge about the microbial assemblies in specific ecological niches is integral to understanding the assemblages interact and function the function, and becomes essential when the microbiota intersects with human activities, such as protecting crops against pests and diseases. Metabarcoding has proven to be a valuable tool and has been widely used for characterizing the microbial diversity of different environments and has been utilized in many research endeavors. Here we summarize the current status of metabarcoding technologies, the advantages and challenges in utilizing this technique, and how this pioneer approach is being applied to studying plant diseases and pests, with a focus on plant protection and biological control. Current and future developments in this technology will foster a more comprehensive understanding of microbial ecology, and the development of new, innovative pest control strategies.

  • 3918.
    Abdelfattah, Ahmed
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Università Mediterranea di Reggio Calabria, Italy.
    Ruano-Rosa, David
    Cacciola, Santa Olga
    Nicosia, Maria G. Li Destri
    Schena, Leonardo
    Impact of Bactrocera oleae on the fungal microbiota of ripe olive drupes2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 11, article id e0199403Article in journal (Refereed)
    Abstract [en]

    The olive fruit fly (OFF), Bactrocera oleae is the most devastating pest affecting olive fruit worldwide. Previous investigations have addressed the fungal microbiome associated with olive drupes or B. oleae, but the impact of the insect on fungal communities of olive fruit remains undescribed. In the present work, the fungal microbiome of olive drupes, infested and non-infested by the OFF, was investigated in four different localities and cultivars. Olive fruit fly infestations caused a general reduction of the fungal diversity, a higher quantity of the total DNA and an increase in taxa that remained unidentified or had unknown roles. The infestations led to imbalanced fungal communities with the growth of taxa that are usually outcompeted. While it was difficult to establish a cause-effect link between fly infestation and specific fungi, it is clear that the fly alters the natural microbial balance, especially the low abundant taxa. On the other hand, the most abundant ones, were not significantly influenced by the insect. In fact, despite the slight variation between the sampling locations, Aureobasidium, Cladosporium, and Alternaria, were the dominant genera, suggesting the existence of a typical olive fungal microbiome.

  • 3919.
    Abdelfattah, Ahmed
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Università Mediterranea di Reggio Calabria, Italy.
    Sanzani, Simona M.
    Wisniewski, Michael
    Berg, Gabriele
    Cacciola, Santa O.
    Schena, Leonardo
    Revealing Cues for Fungal Interplay in the Plant-Air Interface in Vineyards2019In: Frontiers in Plant Science, ISSN 1664-462X, E-ISSN 1664-462X, Vol. 10, article id 922Article in journal (Refereed)
    Abstract [en]

    Plant-associated microorganisms play a crucial role in plant health and productivity. Belowground microbial diversity is widely reported as a major factor in determining the composition of the plant microbiome. In contrast, much less is known about the role of the atmosphere in relation to the plant microbiome. The current study examined the hypothesis that the atmospheric microbiome influences the composition of fungal communities of the aboveground organs flowers, fruit, and leaves) of table grape and vice versa. The atmosphere surrounding grape plantings exhibited a significantly higher level of fungal diversity relative to the nearby plant organs and shared a higher number of phylotypes 5,536 OTUs, 40.3%) with the plant than between organs of the same plant. Using a Bayesian source tracking approach, plant organs were determined to be the major source of the atmospheric fungal community 92%). In contrast, airborne microbiota had only a minor contribution to the grape microbiome, representing the source of 15, 4, and 35% of the fungal communities of leaves, flowers, and fruits, respectively. Moreover, data indicate that plant organs and the surrounding atmosphere shared a fraction of each other's fungal communities, and this shared pool of fungal taxa serves as a two-way reservoir of microorganisms. Microbial association analysis highlighted more positive than negative interactions between fungal phylotypes. Positive interactions were more common within the same environment, while negative interactions appeared to occur more frequently between different environments, i. e., atmosphere, leaf, flower, and fruit. The current study revealed the interplay between the fungal communities of the grape phyllosphere with the surrounding air. Plants were identified as a major source of recruitment for the atmospheric microbiome, while the surrounding atmosphere contributed only a small fraction of the plant fungal community. The results of the study suggested that the plant-air interface modulates the plant recruitment of atmospheric fungi, taking a step forward in understanding the plant holobiont assembly and how the atmosphere surrounding plants plays a role in this process. The impact of plants on the atmospheric microbiota has several biological and epidemiological implications for plants and humans.

  • 3920.
    Abdelgadir, M
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Elbagir, M
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Eltom, A
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Eltom, M
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Berne, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Factors affecting perinatal morbidity and mortality in pregnanciescomplicated by diabetes mellitus in Sudan.2003In: Diabetes Res Clin Pract, Vol. 60, p. 41-Article in journal (Refereed)
  • 3921.
    Abdelgadir, M
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Elbagir, M
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Eltom, M
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Berne, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Ahren, B
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Reduced leptin concentrations in subjects with type 2 diabetes mellitus in Sudan.2002In: Metabolism, Vol. 51, p. 304-Article in journal (Refereed)
  • 3922.
    Abdelgadir, Moawia
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Clinical and Biochemical Features of Adult Diabetes Mellitus in Sudan2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The high prevalence of diabetes mellitus among the Sudanese population is linked to obesity, poor glycaemic control and a high rate of complications. This study investigated 1/ Leptin hormone and its correlations with different biochemical characteristics in Sudanese diabetic subjects, 2/ The impact of glycaemic control on pregnancy outcome in pregnancies with diabetes, 3/ The glycaemic response to Sudanese traditional carbohydrate foods, 4/ The influence of glucose self-monitoring on the glycaemic control among this population, 5/ The health related quality of life in Sudanese subjects with diabetes-related lower limb amputation.

    Leptin was significantly lower in diabetic subjects compared with controls of same BMI in both females (P =0.0001) and males (P =0.019). In diabetic subjects, serum leptin correlated positively with the homeostatic assessment (HOMA) of both beta-cell function (P =0.018) and insulin resistance (P =.038). In controls, leptin correlated only with insulin resistance. Pregnancy complications were higher among diabetic compared with control women (P<0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (P<0.0001). In six Sudanese traditional carbohydrate meals over all differences in incremental AUCs were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). Millet porridge and wheat pancakes displayed significantly lower post-prandial glucose and insulin responses, whereas maize porridge induced a higher post-prandial glucose and insulin response. In type 2 diabetic subjects SMBG or SMUG was not related to glycaemic control. In type 1 diabetic subjects, SMBG was significantly associated with better glycaemic control, as assessed by HbA1c (P=0.02) and blood glucose at clinic visits (P=<0.0001), similar associations were found for SMUG respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level. Diabetic subjects with LLA had significantly poorer HRQL compared to a reference diabetic group (P=<0.0001). Duration of diabetes and amputation had negative impact on HRQL in subjects with LLA (P=<0.0001) respectively. Diabetic subjects with LLA had decreased sense of coherence and high presence of symptoms. Improving health services at the primary level is important to reduce the complications and burden of disease in the Sudanese population.

  • 3923.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences. Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Abbas, M
    Jarvi, A
    Elbagir, M
    Eltom, M
    Berne, Christian
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences. Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Glycaemic and insulin responses of six traditional Sudanese carbohydrate-rich meals in subjects with Type 2 diabetes mellitus.2005In: Diabet Med, ISSN 0742-3071, Vol. 22, no 2, p. 213-217Article in journal (Refereed)
  • 3924.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Abbas, Mazahir
    Järvi, Anette
    Elbagir, Murtada
    Eltom, Mohamed
    Berne, Christian
    Glycaemic and insulin responses of six traditional Sudanese carbohydrate-rich meals in subjects with Type 2 diabetes mellitusArticle in journal (Refereed)
  • 3925.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Elbagir, Murtada
    Eltom, Aboud
    Eltom, Mohamed
    Berne, Christian
    Factors affecting perinatal morbidity and mortality in pregnancies complicated by diabetes mellitus in Sudan2003In: Diabetes Res Clin Pract, Vol. 60, no 1, p. 41-7Article in journal (Refereed)
  • 3926.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Elbagir, Murtada
    Eltom, Mohamed
    Berne, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    The influence of glucose self-monitoring on glycaemic control in patients with diabetes mellitus in Sudan2006In: Diabetes Research and Clinical Practice, ISSN 0168-8227, E-ISSN 1872-8227, Vol. 74, no 1, p. 90-94Article in journal (Refereed)
    Abstract [en]

    Objective: To investigate the influence of self-monitoring of glucose on the glycaemic control in Sudanese diabetic subjects.

    Subjects and methods: A group of 193 consecutive type 2 and type I diabetic subjects (95 men, 98 women) were studied. In 104 subjects with type 2 diabetes fasting blood glucose was measured using a glucose meter and blood was obtained for serum glucose measurement in the laboratory. In the remaining 89 diabetic subjects random blood glucose was measured using the same glucose meter and a whole blood sample was drawn for laboratory assessment of HbA1c. Data on self-monitoring and other clinical and personal characteristics were recorded.

    Results: More than 75% of either type I and type 2 diabetic patients never self-monitored blood or urine glucose. In type 2 diabetic subjects self-monitoring of blood or urine glucose was not related to glycaemic control. In type I diabetic subjects, however, self-monitoring of blood glucose was significantly associated with better glycaemic control, as assessed by HbA1c (P = 0.02) and blood glucose at clinic visits (P < 0.0001), and similar associations were found for urine glucose self-monitoring (P = 0.04 and 0.02) respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level.

    Conclusions: Self-monitoring of blood glucose was not found to be associated to better glycaemic control in Sudanese subjects with type 2 diabetes. In contrast, self-monitoring of both blood and urine glucose was significantly associated with glycaemic control in subjects with type I diabetes. Self-monitoring of urine glucose could be useful where measurement of blood glucose is not available or affordable.

  • 3927.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Sciences.
    Elbagir, Murtada
    Eltom, Mohamed
    Berne, Christian
    Ahren, Bo
    leptin concentrations in subjects with type 2 diabetes mellitus in Sudan2002In: Metabolism, Vol. 51, no 3, p. 304-6Article in journal (Refereed)
  • 3928.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Endocrinology, Diabetes and Metabolism.
    Karlsson, Anders F.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Endocrinology, Diabetes and Metabolism.
    Berglund, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Berne, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Endocrinology, Diabetes and Metabolism.
    Low serum adiponectin concentrations are associated with insulin sensitivity independent of obesity in Sudanese subjects with type 2 diabetes mellitus2013In: Diabetology and Metabolic Syndrome, ISSN 1758-5996, E-ISSN 1758-5996, Vol. 5, p. 15-Article in journal (Refereed)
    Abstract [en]

    Aims: Prevalence of Type 2 diabetes mellitus among Sudanese population was found to be 3.4% and associated with high rates of complications and obesity. Different adipocytokines are secreted from adipose tissues, among them adiponectin, which was shown to have insulins ensitizing properties and anti-inflammatory, anti-atherogenic effect. The aim of this study was to characterize type 2 diabetes in Sudanese diabetic subjects and controls in respect to hormones influencing or influenced by glucose metabolism. Methods: 104 type 2 diabetic patients (45 men and 59 women), and 75 matched control subjects (34 men and 41 women) were studied. Fasting serum samples were used to measure adiponectin, leptin, insulin, proinsulin, ghrelin and glucose. Body mass index, insulin/proinsulin ratio and (HOMA) insulin resistance and beta cell function were also calculated. Results: Adiponectin serum concentrations were significantly lower in subjects with type 2 diabetes compared with controls subjects (P = 0.002), comparison between males and females did not reach significant levels in both diabetic (P = 0.06) or controls (P = 0.16) groups. In the diabetic group adiponectin correlated positively with serum glucose, negatively with serum proinsulin and HOMA beta cell function (P = 0.03) respectively and serum ghrelin (P = 0.003), but not with BMI, HOMA insulin resistance, insulin or leptin. In controls serum adiponectin correlated negatively with BMI (P = 0.002) but not with other variables. Conclusions: The findings of this study suggest that, adiponectin concentrations independent on BMI as a measure of adiposity, were mostly linked to insulin sensitivity and not to insulin resistance in Sudanese type 2 diabetic subjects, where race specific regulation mechanisms or different type 2 diabetes phenotype suggested being a major contributory factor in clarification the findings of this study.

  • 3929.
    Abdelgadir, Moawia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Shebeika, Wafaa
    Eltom, Mohamed
    Berne, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Wikblad, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Health related quality of life and sense of coherence in Sudanese diabetic subjects with lower limb amputation2009In: Tohoku journal of experimental medicine, ISSN 0040-8727, E-ISSN 1349-3329, Vol. 217, no 1, p. 45-50Article in journal (Refereed)
    Abstract [en]

    Quality of life is an important outcome measure in diabetic patients with lower limb amputation (LLA). The aim of this study was to investigate the influence of lower limb amputation on health-related quality of life (HRQOL) in Sudanese diabetic subjects. Additionally the Sense of Coherence scale (SOC-13) and a symptom check list was used in subjects with LLA. A total of 60 (M/F; 40/20) diabetic subjects with LLA and 60 (M/F; 23/37) diabetic reference subjects without LLA, were studied. For both groups HRQOL was measured using The Medical Outcomes Study questionnaire (MOS). Subjects with LLA had significantly poorer HRQOL compared to the reference group in most HRQOL domains (p < 0.0001). Duration of diabetes had the greatest negative impact on HRQOL in both groups, those with LLA (p < 0.0001), and in those without LLA (p < 0.0001), although subjects who were amputated earlier had poorer HRQOL than recently amputated (p < 0.0001). Higher SOC scores were recorded in LLA patients who have greater ratings of positive feelings, family satisfaction and sleep in the HRQOL examination (p < 0.0001). In conclusion, Sudanese diabetic subjects with LLA have a poor quality of life. The triad of diabetes duration, symptoms and amputations, has turned to be important risk factor for poorer HRQOL. Functional and mobility status were suggested to be an important determinant of HRQOL among this population. As the Sudanese population has coherent social relationships, this poor performance of the diabetic subjects will certainly increase the burden on the whole family, in both integrity and economical status. Nevertheless, these deep-rooted social interrelations together with increasing diabetes awareness have substantially improved the family satisfaction among our patients.

  • 3930.
    Abdel-Hafiez, Mahmoud
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China;Harvard Univ, Lyman Lab Phys, Cambridge, MA 02138 USA;Natl Univ Sci & Technol MISiS, Moscow 119049, Russia.
    Thiyagarajan, R.
    Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China.
    Majumdar, Arnab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Luo, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Vasiliev, A. N.
    Natl Univ Sci & Technol MISiS, Moscow 119049, Russia;Natl Res South Ural State Univ, Chelyabinsk 454080, Russia;Moscow MV Lomonosov State Univ, Moscow 119991, Russia.
    Maarouf, A. A.
    Imam Abdulrahman Bin Faisal Univ, Inst Res & Med Consultat, Dept Phys, Dammam 31441, Saudi Arabia.
    Zybtsev, S. G.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pokrovskii, V. Ya
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    V-Zaitsev-Zotov, S.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pavlovskiy, V. V.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pai, Woei Wu
    Natl Taiwan Univ, Ctr Condensed Matter Sci, Taipei 106, Taiwan;Natl Taiwan Univ, Dept Phys, Taipei 10610, Taiwan.
    Yang, W.
    Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China.
    Kulik, L. , V
    Pressure-induced reentrant transition in NbS3 phases: Combined Raman scattering and x-ray diffraction study2019In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 99, no 23, article id 235126Article in journal (Refereed)
    Abstract [en]

    We report the evolution of charge density wave states under pressure for two NbS3 phases: triclinic (phase I) and monoclinic (phase II) at room temperature. Raman and x-ray diffraction (XRD) techniques are applied. The x-ray studies on the monoclinic phase under pressure show a compression of the lattice at different rates below and above similar to 7 GPa but without a change in space group symmetry. The Raman spectra of the two phases evolve similarly with pressure; all peaks almost disappear in the similar to 6-8 GPa range, indicating a transition from an insulating to a metallic state, and peaks at new positions appear above 8 GPa. The results suggest suppression of the ambient charge-density waves and their subsequent recovery with new orderings above 8 GPa.

  • 3931. Abdelhai, Rehab
    et al.
    Yassin, Sahar
    Ahmad, Mohamad F.
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    An e-learning reproductive health module to support improved student learning and interaction: a prospective interventional study at a medical school in Egypt2012In: BMC Medical Education, ISSN 1472-6920, E-ISSN 1472-6920, Vol. 12, p. 11-Article in journal (Refereed)
    Abstract [en]

    Background: The Public Health (PH) course at the medical college of Cairo University is based on traditional lectures. Large enrollment limits students' discussions and interactions with instructors. Aim: Evaluate students' learning outcomes as measured by improved knowledge acquisition and opinions of redesigning the Reproductive Health (RH) section of the PH course into e-learning and assessing e-course utilization. Methods: This prospective interventional study started with development of an e-learning course covering the RH section, with visual and interactive emphasis, to satisfy students' diverse learning styles. Two student groups participated in this study. The first group received traditional lecturing, while the second volunteered to enroll in the e-learning course, taking online course quizzes. Both groups answered knowledge and course evaluation questionnaires and were invited to group discussions. Additionally, the first group answered another questionnaire about reasons for non-participation. Results: Students participating in the e-learning course showed significantly better results, than those receiving traditional tutoring. Students who originally shunned the e-course expressed eagerness to access the course before the end of the academic year. Overall, students using the redesigned e-course reported better learning experiences. Conclusions: An online course with interactivities and interaction, can overcome many educational drawbacks of large enrolment classes, enhance student's learning and complement pit-falls of large enrollment traditional tutoring.

  • 3932. Abdel-Halim, S M
    et al.
    Ostenson, C-G
    Andersson, A
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Cell Biology.
    Andersson, A
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Cell Biology.
    Andersson, A
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Cell Biology.
    Jansson, L
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Cell Biology.
    Efendic, S
    A defective stimulus-secretion coupling rather than glucotoxicity mediates the impaired insulin secretion in the mildly diabetic F1 hybrids of GK-Wistar rats.1995In: Diabetes, Vol. 44, p. 1280-Article in journal (Refereed)
  • 3933.
    Abdelhamid, Hani Nasser
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Lanthanide Metal-Organic Frameworks and Hierarchical Porous Zeolitic Imidazolate Frameworks: Synthesis, Properties, and Applications2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents the synthesis, properties, and applications of two important classes of metal-organic frameworks (MOFs); lanthanide MOFs and hierarchical porous zeolitic imidazolate frameworks (ZIFs). The materials have been characterized using a wide range of techniques including diffraction, imaging, various spectroscopic techniques, gas sorption, dynamical light scattering (DLS) and thermogravimetric analysis (TGA).

    In Chapter 1, the unique features of MOFs and ZIFs as well as their potential applications are summarized. In Chapter 2, different characterization techniques are presented.

    Chapter 3 describes a family of new isoreticular lanthanide MOFs synthesized using tri-topic linkers of different sizes, H3L1-H3L4, denoted SUMOF-7I-IV (Ln) (SU; Stockholm University, Ln = La, Ce, Pr, Nd, Sm, Eu and Gd, Paper I). The SUMOF-7I-III (Ln) contain permanent pores and exhibit exceptionally high thermal and chemical stability. The luminescence properties of SUMOF-7IIs are reported (Paper II). The influences of Ln ions and the tri-topic linkers as well as solvent molecules on the luminescence properties are investigated. Furthermore, the potential of SUMOF-7II (La) for selective sensing of Fe (III) ions and the amino acid tryptophan is demonstrated (Paper III). 

    Chapter 4 presents a simple, fast and scalable approach for the synthesis of hierarchical porous zeolitic imidazolate framework ZIF-8 and ZIF-67 using triethylamine (TEA)-assisted approach (Paper IV). Organic dye molecules and proteins are encapsulated directly into the ZIFs using the one-pot method. The photophysical properties of the dyes are improved through the encapsulation into ZIF-8 nanoparticles (Paper IV). The porosity and surface area of the ZIF materials can be tuned using the different amounts of dye or TEA. To further simplify the synthesis of hierarchical porous ZIF-8, a template-free approach is presented using sodium hydroxide, which at low concentrations induces the formation of zinc hydroxide nitrate nanosheets that serve as in situ sacrificial templates (Chapter 5, Paper V). A 2D leaf-like ZIF (ZIF-L) is also obtained using the method. The hierarchical porous ZIF-8 and ZIF-L show good performance for CO2 sorption.

  • 3934.
    Abdelhamid, Hani Nasser
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Assiut University, Egypt.
    Surfactant assisted synthesis of hierarchical porous metal-organic frameworks nanosheets2019In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 30, no 43, article id 435601Article in journal (Refereed)
    Abstract [en]

    Two-dimensional metal-organic frameworks show increasing research attention due to their unique properties including tunable thickness, simple packing into a film and membrane, and high surface-to-volume atom ratios. A bottom-up synthesis strategy using cetyltrimethylammonium bromide for the synthesis of copper-benzenedicarboxylate (Cu(BDC)) nanosheets is reported. The method offers the synthesis of hierarchical porous Cu(BDC) lamellae with micrometer lateral dimensions, and nanometer thickness (100-150 nm). Electron microscope (scanning and transmission), and N-2 adsorption isotherms confirm the formation of lamellae Cu(BDC) with mesopore size of 5-80 nm. The material has thermal stability up to 400 degrees C with good chemical stability in several organic solvents. However, the material transforms to another phase (Cu(BDC)(H2O)(2)) when soaked in water and alcohols. The transformation reduces crystal size and offers the formation of hydrogen bond resulting in an increase in the sorption of CO2 by similar to 10% compared to the pristine material Cu(BDC).

  • 3935.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bermejo-Gómez, Antonio
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    A water-stable lanthanide metal-organic framework for fluorimetric detection of ferric ions and tryptophan2017In: Microchimica Acta, ISSN 0026-3672, E-ISSN 1436-5073, Vol. 184, no 9, p. 3363-3371Article in journal (Refereed)
    Abstract [en]

    The preparation of a highly water stable and porous lanthanide metal-organic framework (MOF) nanoparticles (denoted SUMOF-7II; SU refers to Stockholm University) is described. SUMOF-7II was synthesized starting from the tritopic linker of 2,4,6-tri-p-carboxyphenyl pyridine (H3L2) and La(III) as metal clusters. SUMOF-7II forms a stable dispersion and displays high fluorescence emission with small variation over the pH range of 6 to 12. Its fluorescence is selectively quenched by Fe(III) ions compared to other metal ions. The intensity of the fluorescene emission drops drops linearly in 16.6–167 μM Fe(III) concentration range, and Stern-Volmer plots are linear. The limit of detection (LOD) is 16.6 μM (at an S/N ratio of >3). This indicator probe can also be used for selective detection of tryptophan among several amino acids. Compared to the free linker H3L2, SUMOF-7II offers improved sensitivity and selectivity of the investigated species.

  • 3936.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.;Assiut Univ, Dept Chem, Adv Multifunct Mat Lab, Assiut 71515, Egypt..
    El-Zohry, Ahmed M.
    Uppsala Univ, Dept Chem, Angstrom Labs, POB 523, S-75120 Uppsala, Sweden..
    Cong, Jiayan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Thersleff, Thomas
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Karlsson, Karl Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Kloo, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Zou, Xiaodong
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Towards implementing hierarchical porous zeolitic imidazolate frameworks in dye-sensitized solar cells2019In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 6, no 7, article id 190723Article in journal (Refereed)
    Abstract [en]

    A one-pot method for encapsulation of dye, which can be applied for dye-sensitized solar cells (DSSCs), and synthesis of hierarchical porous zeolitic imidazolate frameworks (ZIF-8), is reported. The size of the encapsulated dye tunes the mesoporosity and surface area of ZIF-8. The mesopore size, Langmuir surface area and pore volume are 15 nm, 960-1500 m(2). g(-1) and 0.36-0.61 cm(3). g(-1), respectively. After encapsulation into ZIF-8, the dyes show longer emission lifetimes (greater than 4-8-fold) as compared to the corresponding non-encapsulated dyes, due to suppression of aggregation, and torsional motions.

  • 3937.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Huang, Zhehao
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    El-Zhory, Ahmed M.
    Haoquan, Zheng
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules2017In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 15, p. 9139-9146Article in journal (Refereed)
    Abstract [en]

    A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic imidazolate framework ZIF-8 nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim). Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300–2500 m2/g), and large pore volumes (0.5–1.0 cm3/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3–27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIF (dye@ZIF-67).

  • 3938.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Huang, Zhehao
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Zheng, Haoquan
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules2017In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 15, p. 9139-9146Article in journal (Refereed)
    Abstract [en]

    A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic, imidazolate framework ZIF-8, nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were, tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim): Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300-2500 m(2)/g), and large pore Volatiles (0.5-1.0 cm(3)/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled Up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3-27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIP (dye@ZIF-67).

  • 3939.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;Assiut Univ, Dept Chem, Assiut 71515, Egypt.
    Wilk-Kozubek, Magdalena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;PORT Polish Ctr Technol Dev, Dept Nanotechnol, 147 Stablowicka St, PL-54066 Wroclaw, Poland.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Gomez, Antonio Bermejo
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Valiente, Alejandro
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Martin-Matute, Belen
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Mudring, Anja-Verena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Luminescence properties of a family of lanthanide metal-organic frameworks2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 279, p. 400-406Article in journal (Refereed)
    Abstract [en]

    Two isostructural series of lanthanide metal-organic frameworks denoted as SUMOF-7II (Ln) and SUMOF-7IIB (Ln) (Ln = La, Ce, Pr, Nd, Sm, Eu, and Gd) were synthesized using4,4',4 ''-(pyridine-2,4,6-triyl)tris(benzoic acid) (H(3)L2) and a mixture of H(3)L2 and 4,4',4 ''-(benzene-1,3,5-triyl)tris(benzoic acid) (H3BTB) as linkers, respectively. Both series were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal analysis (TGA), and photoluminescence spectroscopy. Photoluminescence measurements show that Eu-MOFs demonstrate a red emission while Pr- and Nd-MOFs display an emission in the near-infrared (NIR) range. On the other hand, La-, Ce-, Sm- and Gd-MOFs exhibit only a ligand-centered emission. The average luminescence lifetimes in the SUMOF-7IIB series are 1.3-1.4-fold longer than the corresponding ones in the SUMOF-7II series. SUMOF-7IIs show a good photo- and thermal stability. Altogether, the properties of SUMOF-7II and SUMOF-7IIB render them promising materials for applications including sensing, biosensing, and telecommunications.

  • 3940.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Assiut University, Egypt.
    Wilk-Kozubek, Magdalena
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). PORT Polish Center for Technology Development, Poland.
    El-Zohry, Ahmed M.
    Gómez, Antonio Bermejo
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Valiente, Alejandro
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Mudring, Anja-Verena
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Luminescence properties of a family of lanthanide metal-organic frameworks2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 279, p. 400-406Article in journal (Refereed)
    Abstract [en]

    Two isostructural series of lanthanide metal-organic frameworks denoted as SUMOF-7II (Ln) and SUMOF-7IIB (Ln) (Ln = La, Ce, Pr, Nd, Sm, Eu, and Gd) were synthesized using4,4',4 ''-(pyridine-2,4,6-triyl)tris(benzoic acid) (H(3)L2) and a mixture of H(3)L2 and 4,4',4 ''-(benzene-1,3,5-triyl)tris(benzoic acid) (H3BTB) as linkers, respectively. Both series were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal analysis (TGA), and photoluminescence spectroscopy. Photoluminescence measurements show that Eu-MOFs demonstrate a red emission while Pr- and Nd-MOFs display an emission in the near-infrared (NIR) range. On the other hand, La-, Ce-, Sm- and Gd-MOFs exhibit only a ligand-centered emission. The average luminescence lifetimes in the SUMOF-7IIB series are 1.3-1.4-fold longer than the corresponding ones in the SUMOF-7II series. SUMOF-7IIs show a good photo- and thermal stability. Altogether, the properties of SUMOF-7II and SUMOF-7IIB render them promising materials for applications including sensing, biosensing, and telecommunications.

  • 3941.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Assuit University, Egypt .
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Template-free and room temperature synthesis of hierarchical porous zeolitic imidazolate framework nanoparticles and their dye and CO2 sorption2018In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 20, no 5, p. 1074-1084Article in journal (Refereed)
    Abstract [en]

    Hierarchical porous zeolitic imidazolate framework ZIF-8 nanoparticles have been synthesized using zinc nitrate, 2-methylimidazole (Hmim), and sodium hydroxide. Zinc hydroxide nitrate nanosheets were formed as intermediates that further transformed to hierarchical porous ZIF-8 after the addition of Hmim. These intermediates serve as in situ sacrificial templates and promote the formation of hierarchical porous ZIF-8 without the need for any other templates. The surface area and mesoporosity of the materials can be tuned by adjusting the concentration of NaOH. This method offers a fast and template-free approach for the synthesis of pure hierarchical porous ZIF-8 at room temperature with tunable porosity. The approach has been applied to synthesize two-dimensional ZIF leaf-like materials, ZIF-L. The synthesis of ZIF-8 and ZIF-L can be scaled up with high yields (>80%). The resulting ZIF-8 and ZIF-L materials show very good CO2 sorption properties. ZIF-8 nanoparticles show fast (<5 min), selective, and high efficiency (>95%) uptake of methyl blue in aqueous solution both without and in the presence of other dyes. The results open a new avenue for the understanding of the self-assembly and the formation of hierarchical porous ZIFs.

  • 3942.
    Abdelhamid, Hani
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Wilk-Kozubek, Magdalena
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Ahmed, M. El-Zohry
    Valiente, Alejandro
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Bermejo-Gomez, Antonio
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Mudring, Anja-Verena
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Luminescence Properties for a Family of Highly Stable Lanthanide Metal-Organic FrameworksManuscript (preprint) (Other academic)
  • 3943.
    Abdelhamid, Hani
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Template-Free Synthesis of Hierarchical Porous Zeolitic Imidazole Frameworks Nanoparticles and their CO2 SorptionManuscript (preprint) (Other academic)
  • 3944. Abdel-Hamid, Mohammed K
    et al.
    Macgregor, Kylie A
    Odell, Luke R
    Chau, Ngoc
    Mariana, Anna
    Whiting, Ainslie
    Robinson, Phillip J
    McCluskey, Adam
    1,8-Naphthalimide derivatives: new leads against dynamin I GTPase activity.2015In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, no 29Article in journal (Refereed)
    Abstract [en]

    Fragment-based in silico screening against dynamin I (dynI) GTPase activity identified the 1,8-naphthalimide framework as a potential scaffold for the design of new inhibitors targeting the GTP binding pocket of dynI. Structure-based design, synthesis and subsequent optimization resulted in the development of a library of 1,8-naphthalimide derivatives, called the Naphthaladyn™ series, with compounds 23 and 29 being the most active (IC50 of 19.1 ± 0.3 and 18.5 ± 1.7 μM respectively). Compound 29 showed effective inhibition of clathrin-mediated endocytosis (IC50(CME) 66 μM). The results introduce 29 as an optimised GTP-competitive lead Naphthaladyn™ compound for the further development of naphthalimide-based dynI GTPase inhibitors.

  • 3945.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Nonparametric structural damage detection algorithm for ambient vibration response: utilizing artificial neural networks and self-organizing maps2016In: Journal of Architectural Engineering, ISSN 1076-0431, E-ISSN 1943-5568, Vol. 22, no 2Article in journal (Refereed)
    Abstract [en]

    This study presentes a new nonparametric structural damage detection algorithm that integrates self-organizing maps with a pattern-recognition neural network to quantify and locate structural damage. In this algorithm, self-organizing maps are used to extract a number of damage indices from the ambient vibration response of the monitored structure. The presented study is unique because it demonstrates the development of a nonparametric vibration-based damage detection algorithm that utilizes self-organizing maps to extract meaningful damage indices from ambient vibration signals in the time domain. The ability of the algorithm to identify damage was demonstrated analytically using a finite-element model of a hot-rolled steel grid structure. The algorithm successfully located the structural damage under several damage cases, including damage resulting from local stiffness loss in members and damage resulting from changes in boundary conditions. A sensitivity study was also conducted to evaluate the effects of noise on the computed damage indices. The algorithm was proved to be successful even when the signals are noise-contaminated.

  • 3946.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Active vibration control of flexible cantilever plates using piezoelectric materials and artificial neural networks2016In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 363, p. 33-53Article in journal (Refereed)
    Abstract [en]

    The study presented in this paper introduces a new intelligent methodology to mitigate the vibration response of flexible cantilever plates. The use of the piezoelectric sensor/actuator pairs for active control of plates is discussed. An intelligent neural network based controller is designed to control the optimal voltage applied on the piezoelectric patches. The control technique utilizes a neurocontroller along with a Kalman Filter to compute the appropriate actuator command. The neurocontroller is trained based on an algorithm that incorporates a set of emulator neural networks which are also trained to predict the future response of the cantilever plate. Then, the neurocontroller is evaluated by comparing the uncontrolled and controlled responses under several types of dynamic excitations. It is observed that the neurocontroller reduced the vibration response of the flexible cantilever plate significantly; the results demonstrated the success and robustness of the neurocontroller independent of the type and distribution of the excitation force.

  • 3947.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Optimization of chiral lattice based metastructures for broadband vibration suppression using genetic algorithms2016In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 369, p. 50-62Article in journal (Refereed)
    Abstract [en]

    One of the major challenges in civil, mechanical, and aerospace engineering is to develop vibration suppression systems with high efficiency and low cost. Recent studies have shown that high damping performance at broadband frequencies can be achieved by incorporating periodic inserts with tunable dynamic properties as internal resonators in structural systems. Structures featuring these kinds of inserts are referred to as metamaterials inspired structures or metastructures. Chiral lattice inserts exhibit unique characteristics such as frequency bandgaps which can be tuned by varying the parameters that define the lattice topology. Recent analytical and experimental investigations have shown that broadband vibration attenuation can be achieved by including chiral lattices as internal resonators in beam-like structures. However, these studies have suggested that the performance of chiral lattice inserts can be maximized by utilizing an efficient optimization technique to obtain the optimal topology of the inserted lattice. In this study, an automated optimization procedure based on a genetic algorithm is applied to obtain the optimal set of parameters that will result in chiral lattice inserts tuned properly to reduce the global vibration levels of a finite-sized beam. Genetic algorithms are considered in this study due to their capability of dealing with complex and insufficiently understood optimization problems. In the optimization process, the basic parameters that govern the geometry of periodic chiral lattices including the number of circular nodes, the thickness of the ligaments, and the characteristic angle are considered. Additionally, a new set of parameters is introduced to enable the optimization process to explore non-periodic chiral designs. Numerical simulations are carried out to demonstrate the efficiency of the optimization process.

  • 3948.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Boashash, Boualem
    Qatar University, Qatar; The University of Queensland, Herston, Australia.
    Sodano, Henry
    University of Michigan, USA.
    Inman, Daniel
    University of Michigan, USA.
    1-D CNNs for structural damage detection: verification on a structural health monitoring benchmark data2018In: Neurocomputing, ISSN 0925-2312, E-ISSN 1872-8286, Vol. 275, p. 1308-1317Article in journal (Refereed)
    Abstract [en]

    Structural damage detection has been an interdisciplinary area of interest for various engineering fields. While the available damage detection methods have been in the process of adapting machine learning concepts, most machine learning based methods extract “hand-crafted” features which are fixed and manually selected in advance. Their performance varies significantly among various patterns of data depending on the particular structure under analysis. Convolutional neural networks (CNNs), on the other hand, can fuse and simultaneously optimize two major sets of an assessment task (feature extraction and classification) into a single learning block during the training phase. This ability not only provides an improved classification performance but also yields a superior computational efficiency. 1D CNNs have recently achieved state-of-the-art performance in vibration-based structural damage detection; however, it has been reported that the training of the CNNs requires significant amount of measurements especially in large structures. In order to overcome this limitation, this paper presents an enhanced CNN-based approach that requires only two measurement sets regardless of the size of the structure. This approach is verified using the experimental data of the Phase II benchmark problem of structural health monitoring which had been introduced by IASC-ASCE Structural Health Monitoring Task Group. As a result, it is shown that the enhanced CNN-based approach successfully estimated the actual amount of damage for the nine damage scenarios of the benchmark study.

  • 3949.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Gabbouj, Moncef
    Tampere University of Technology, Finland.
    Inman, Daniel
    University of Michigan, USA.
    Real-time vibration-based structural damage detection using one-dimensional convolutional neural networks2017In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 388, p. 154-170Article in journal (Refereed)
    Abstract [en]

    Structural health monitoring (SHM) and vibration-based structural damage detection have been a continuous interest for civil, mechanical and aerospace engineers over the decades. Early and meticulous damage detection has always been one of the principal objectives of SHM applications. The performance of a classical damage detection system predominantly depends on the choice of the features and the classifier. While the fixed and hand-crafted features may either be a sub-optimal choice for a particular structure or fail to achieve the same level of performance on another structure, they usually require a large computation power which may hinder their usage for real-time structural damage detection. This paper presents a novel, fast and accurate structural damage detection system using 1D Convolutional Neural Networks (CNNs) that has an inherent adaptive design to fuse both feature extraction and classification blocks into a single and compact learning body. The proposed method performs vibration-based damage detection and localization of the damage in real-time. The advantage of this approach is its ability to extract optimal damage-sensitive features automatically from the raw acceleration signals. Large-scale experiments conducted on a grandstand simulator revealed an outstanding performance and verified the computational efficiency of the proposed real-time damage detection method.

  • 3950.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Optimization of linear zigzag insert metastructures for low-frequency vibration attenuation using genetic algorithms2017In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 84, no Part A, p. 625-641Article in journal (Refereed)
    Abstract [en]

    Vibration suppression remains a crucial issue in the design of structures and machines. Recent studies have shown that with the use of metamaterial inspired structures (or metastructures), considerable vibration attenuation can be achieved. Optimization of the internal geometry of metastructures maximizes the suppression performance. Zigzag inserts have been reported to be efficient for vibration attenuation. It has also been reported that the geometric parameters of the inserts affect the vibration suppression performance in a complex manner. In an attempt to find out the most efficient parameters, an optimization study has been conducted on the linear zigzag inserts and is presented here. The research reported in this paper aims at developing an automated method for determining the geometry of zigzag inserts through optimization. This genetic algorithm based optimization process searches for optimal zigzag designs which are properly tuned to suppress vibrations when inserted in a specific host structure (cantilever beam). The inserts adopted in this study consist of a cantilever zigzag structure with a mass attached to its unsupported tip. Numerical simulations are carried out to demonstrate the efficiency of the proposed zigzag optimization approach.

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