98 research outputs found

    Robust Bain distortion in the premartensite phase of platinum substituted Ni2MnGa magnetic shape memory alloy

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    The premartensite phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite phase with preserved austenite phase symmetry. The thermodynamic stability of the premartensite phase and its relation to the martensitic phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite phase of 10% Pt substituted Ni2MnGa. We show that the robust Bain distorted premartensite (T2) phase results from another premartensite (T1) phase with preserved cubic-like symmetry through an isostructural phase transition. The T2 phase finally transforms to the martensite phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite phase should not be considered as a precursor state with the preserved symmetry of the cubic austenite phase

    Treatment of third-degree burn wounds in animal specimens: Acellular dermis or partial-thickness skin graft Traitement des brûlures du 3ème degré chez l�animal: Derme acel-lulaire ou greffe semi-épaisse

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    Several dermal products have been introduced to substitute dermal tissues. In this study we review the effects of these products on repairing third-degree burn wounds and managing complications in animal specimens. Using an interventional approach, rats were randomly assigned to four groups (G1 to G4). Two wounds were created on the back of each rat. An open wound was left on the back of rats in G1; in G2, wounds were covered with a thick rat derived-ADM product and overlying thin skin graft; on G3 rats, similar third degree ulcers were made with one ulcer covered with harvested thin skin graft. In G4, ulcers were covered with a thin rat derived-ADM product and thin graft. Factors such as take rate, histopathological score, wound contracture and graft contracture were compared on the 7th, 15th, 21st and 30th day. Mean graft take rate on the 30th day in the thick ADM, thin ADM and graft group showed a significant difference (p=0.015). Histopathological score on the 30th day in the thin ADM, thick ADM and graft group showed no considerable difference. Mean graft take rate was significantly better in the thin ADM and graft group than in the thick ADM group. Wound contracture was significantly more severe in the thick ADM and control group than in the thin ADM and graft group. © 2018, Mediterranean Club for Burns and Fire Disasters. All rights reserved

    Pressure tuning of the anomalous Hall effect in the chiral antiferromagnet Mn3Ge

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    We report on the pressure evolution of the giant anomalous Hall effect (AHE) in the chiral antiferromagnet Mn3_3Ge. The AHE originating from the non-vanishing Berry curvature in Mn3_3Ge can be continuously tuned by application of hydrostatic pressure. At room temperature, the Hall signal changes sign as a function of pressure and vanishes completely at p=1.53p=1.53 GPa. Even though the Hall conductivity changes sign upon increasing pressure, the room-temperature saturation value of 23 Ω1cm1{\rm \Omega^{-1}cm^{-1}} at 2.85 GPa is remarkably high and comparable to the saturation value at ambient pressure of about 40 Ω1cm1{\rm \Omega^{-1}cm^{-1}}. The change in the Hall conductivity can be directly linked to a gradual change of the size of the in-plane components of the Mn moments in the non-collinear triangular magnetic structure. Our findings, therefore, provide a route for tuning of the AHE in the chiral antiferromagnetic Mn3_3Ge.Comment: 5 pages, 4 figure

    The requirements and challenges in preventing of road traffic injury in Iran. A qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Road traffic injuries (RTIs) are a major public health problem, especially in low- and middle-income countries. Among middle-income countries, Iran has one of the highest mortality rates from RTIs. Action is critical to combat this major public health problem. Stakeholders involved in RTI control are of key importance and their perceptions of barriers and facilitators are a vital source of knowledge. The aim of this study was to explore barriers to the prevention of RTIs and provide appropriate suggestions for prevention, based on the perceptions of stakeholders, victims and road-users as regards RTIs.</p> <p>Methods</p> <p>Thirty-eight semi-structured interviews were conducted with informants in the field of RTI prevention including: police officers; public health professionals; experts from the road administrators; representatives from the General Governor, the car industry, firefighters; experts from Emergency Medical Service and the Red Crescent; and some motorcyclists and car drivers as well as victims of RTIs. A qualitative approach using grounded theory method was employed to analyze the material gathered.</p> <p>Results</p> <p>The core variable was identified as "The lack of a system approach to road-user safety". The following barriers in relation to RTI prevention were identified as: human factors; transportation system; and organizational coordination. Suggestions for improvement included education (for the general public and targeted group training), more effective legislation, more rigorous law enforcement, improved engineering in road infrastructure, and an integrated organization to supervise and coordinate preventive activities.</p> <p>Conclusion</p> <p>The major barriers identified in this study were human factors and efforts to change human behaviour were suggested by means of public education campaigns and stricter law enforcement. However, the lack of a system approach to RTI prevention was also an important concern. There is an urgent need for both an integrated system to coordinate RTI activities and prevention and a major change in stakeholders' attitudes towards RTI prevention. The focus of all activities should take place on road users' safety.</p

    Prevalence and risk factors for HBV and HCV in prisoners in Iran: a national bio-behavioural surveillance survey in 2015

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    Objectives: To provide more accurate estimates of the prevalence of Hepatitis B (HBV) and Hepatitis C (HCV) and their contributing factors among prisoners in Iran. Methods: Cross-sectional study of 6200 Iranian prisoners in 2015. Data were collected through questionnaires and interviews. HBV infection and HCV exposure status of the participants was determined by HBsAg and HCV antibodies blood tests using enzyme-linked immunosorbent assay (ELISA). Data were analysed in STATA-12. Result: Prevalence of HCV exposure was 9.48 (95 CI: 8.73�10.27), and prevalence of HBV was 2.48 (95 CI: 2.07�2.89) in the general prison population. In multivariate analysis, the most important risk factor for HBV was a history of drug use in lifetime (adjusted odds ratio, AOR: 1.8, 95 CI: 1.17�3.02). The main risk factors for HCV exposure were a history of drug use in lifetime (AOR: 4.08, CI: 2.56�6.27), age over 30 (AOR: 2.68, CI: 2.01�3.56), and having tattoos (AOR = 1.67, CI: 1.35�2.07). Conclusion: Although vaccination is used to control HBV among prisoners, prevalence of HCV exposure is alarming in the prison population of Iran, especially among people who inject drugs. Eliminating viral hepatitis in Iran by 2030 requires a national commitment and rapid measures for targeting this high-risk group. Given the increased efficiency of HCV treatment in recent years, prisons provide an opportunity to access patients for treatment. © 2018 John Wiley & Sons Lt

    Prevalence and risk factors for HBV and HCV in prisoners in Iran: a national bio-behavioural surveillance survey in 2015

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    Objectives: To provide more accurate estimates of the prevalence of Hepatitis B (HBV) and Hepatitis C (HCV) and their contributing factors among prisoners in Iran. Methods: Cross-sectional study of 6200 Iranian prisoners in 2015. Data were collected through questionnaires and interviews. HBV infection and HCV exposure status of the participants was determined by HBsAg and HCV antibodies blood tests using enzyme-linked immunosorbent assay (ELISA). Data were analysed in STATA-12. Result: Prevalence of HCV exposure was 9.48 (95 CI: 8.73�10.27), and prevalence of HBV was 2.48 (95 CI: 2.07�2.89) in the general prison population. In multivariate analysis, the most important risk factor for HBV was a history of drug use in lifetime (adjusted odds ratio, AOR: 1.8, 95 CI: 1.17�3.02). The main risk factors for HCV exposure were a history of drug use in lifetime (AOR: 4.08, CI: 2.56�6.27), age over 30 (AOR: 2.68, CI: 2.01�3.56), and having tattoos (AOR = 1.67, CI: 1.35�2.07). Conclusion: Although vaccination is used to control HBV among prisoners, prevalence of HCV exposure is alarming in the prison population of Iran, especially among people who inject drugs. Eliminating viral hepatitis in Iran by 2030 requires a national commitment and rapid measures for targeting this high-risk group. Given the increased efficiency of HCV treatment in recent years, prisons provide an opportunity to access patients for treatment. © 2018 John Wiley & Sons Lt

    Large-scale magnetic fields from inflation due to a CPTCPT-even Chern-Simons-like term with Kalb-Ramond and scalar fields

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    We investigate the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the CPTCPT-even dimension-six Chern-Simons-like effective interaction with a fermion current by taking account of the dynamical Kalb-Ramond and scalar fields in inflationary cosmology. It is explicitly demonstrated that the magnetic fields on 1Mpc scale with the field strength of 109\sim 10^{-9}G at the present time can be induced.Comment: 18 pages, 6 figures, version accepted for publication in Eur. Phys. J.

    Barriers and facilitators to provide effective pre-hospital trauma care for road traffic injury victims in Iran: a grounded theory approach

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    BACKGROUND: Road traffic injuries are a major global public health problem. Improvements in pre-hospital trauma care can help minimize mortality and morbidity from road traffic injuries (RTIs) worldwide, particularly in low- and middle-income countries (LMICs) with a high rate of RTIs such as Iran. The current study aimed to explore pre-hospital trauma care process for RTI victims in Iran and to identify potential areas for improvements based on the experience and perception of pre-hospital trauma care professionals. METHODS: A qualitative study design using a grounded theory approach was selected. The data, collected via in-depth interviews with 15 pre-hospital trauma care professionals, were analyzed using the constant comparative method. RESULTS: Seven categories emerged to describe the factors that hinder or facilitate an effective pre-hospital trauma care process: (1) administration and organization, (2) staff qualifications and competences, (3) availability and distribution of resources, (4) communication and transportation, (5) involved organizations, (6) laypeople and (7) infrastructure. The core category that emerged from the other categories was defined as "interaction and common understanding". Moreover, a conceptual model was developed based on the categories. CONCLUSIONS: Improving the interaction within the current pre-hospital trauma care system and building a common understanding of the role of the Emergency Medical Services (EMS) emerged as key issues in the development of an effective pre-hospital trauma care process

    Glycan Structures Contain Information for the Spatial Arrangement of Glycoproteins in the Plasma Membrane

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    Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro(-)5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells

    Spondylodiscitis following endovascular abdominal aortic aneurysm repair: imaging perspectives from a single centre's experience.

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    OBJECTIVE: Very few reports have previously described spondylodiscitis as a potential complication of endovascular aortic aneurysm repair (EVAR). We present to our knowledge the first case series of spondylodiscitis following EVAR based on our institution's experience over an 11-year period. Particular attention is paid to the key imaging features and challenges encountered when performing spinal imaging in this complex patient group. MATERIALS AND METHODS: Of 1,847 patients who underwent EVAR at our institution between January 2006 and January 2017, a total of 9 patients were identified with imaging features of spondylodiscitis (0.5%). All cross-sectional studies before and after EVAR were assessed by a Consultant Musculoskeletal Radiologist and a Musculoskeletal Radiology Fellow to evaluate for features of spondylodiscitis. RESULTS: All 9 patients had single-level spondylodiscitis involving lumbosacral levels adjacent to the aortic/iliac stent graft. Eight out of nine patients had an extensive anterior paravertebral phlegmon/abscess that was contiguous with the infected stent graft and native aneurysm sac ± anterior vertebral body erosion. Epidural disease was present in only 3 out of 9 patients and was a minor feature. MRI was non-diagnostic in 3 out of 9 patients owing to susceptibility artefact. 18F-FDG PET/CT accurately depicted the spinal level involved and adjacent paravertebral disease in patients with non-diagnostic MRI and was adopted as the follow-up modality in 3 out of 5 surviving patients. CONCLUSION: Spondylodiscitis is a rare complication post-EVAR. Imaging features of disproportionate anterior paravertebral disease and anterior vertebral body bony involvement suggest direct spread of infection posteriorly to the adjacent vertebral column. Use of MRI versus 18F-FDG PET/CT as the optimal imaging modality should be directed by the type of stent graft deployed
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