21 research outputs found
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Dynamic behavior assessment of public buildings in Syria using non-linear time-history analysis and ambient noise measurements: a case study
This study evaluates the dynamic behavior and performance of vital reinforced concrete (RC) public building [Ministry of Higher Education (MHE)] designed in compliance with the old Syrian (non-seismic) building code. The real non-linear dynamic behavior of the MHE building has been checked by detailed dynamic numerical analyses (finite elements methodâFEM) validated by a series of ambient noise measurements carried out on-site. The modeling approach for the thorough 3D dynamic analyses of the (RC) MHE building has been developed to be able to investigate the actual non-linear dynamic performance of widespread range of RC structures, providing the opportunity to set up a reliable detailed methodology to assess the real dynamic performance of the old vital structures designed according to the old Syrian (non-seismic) building code from the new seismic requirements perspective. The results of the frequency analyses, the nonlinear time history, and the experimental measurements have shown an excellent agreement. The study showed that the modeling approach by the FEM is reliable for predicting the actual dynamic behavior of RC structures, but it is very sensitive to the modeling assumptions. Furthermore, the dynamic performance analyses have revealed unsymmetrical behavior of the eastâwest wings about the Y-axis which could be attributed to the inefficient seismic rehabilitation executed in 2001
Investigation the nonlinear optical properties of silver nanoparticles using femtosecond laser
© 2020 Published under licence by IOP Publishing Ltd. In this research, the fabrication of silver nanoparticles and experimental nonlinear response (NLO). The fabrication of the silver nanoparticles has been done using E-Beam evaporation on a glass substrate (Ag-NPs) and investigation of their nonlinear optical response (NLO). The silver nanoparticles was evaluated by optical spectrum (UV-Vis) that shows localized surface Plasmon band at 375 nm. The experiment shows the nonlinear absorption and nonlinear refraction effect of silver nanoparticles, the silver nanoparticles is analysed by Z-Scan technique using a femtoseconds laser with 800 nm wavelength. The result shows the nonlinear absorption (NLA) is at 4.8710-4cmW-1, while (NLR) is at 7.9410-9cmW-1
Reprogramming of hepatic fat accumulation and 'browning' of adipose tissue by the short-chain fatty acid acetate
Background/Objectives:
Short-chain fatty acids, produced by microbiome fermentation of carbohydrates, have been linked to a reduction in appetite, body weight and adiposity. However, determining the contribution of central and peripheral mechanisms to these effects has not been possible.
Subjects/Methods:C57BL/6 mice fed with either normal or high-fat diet were treated with nanoparticle-delivered acetate, and the effects on metabolism were investigated.
Results:In the liver, acetate decreased lipid accumulation and improved hepatic function, as well as increasing mitochondrial efficiency. In white adipose tissue, it inhibited lipolysis and induced 'browning', increasing thermogenic capacity that led to a reduction in body adiposity.
Conclusions:This study provides novel insights into the peripheral mechanism of action of acetate, independent of central action, including âbrowningâ and enhancement of hepatic mitochondrial function
Estimated impact of maternal vaccination on global paediatric influenza-related in-hospital mortality: A retrospective case series
BACKGROUND: Influenza virus infection is an important cause of under-five mortality. Maternal vaccination protects children younger than 3 months of age from influenza infection. However, it is unknown to what extent paediatric influenza-related mortality may be prevented by a maternal vaccine since global age-stratified mortality data are lacking. METHODS: We invited clinicians and researchers to share clinical and demographic characteristics from children younger than 5 years who died with laboratory-confirmed influenza infection between January 1, 1995 and March 31, 2020. We evaluated the potential impact of maternal vaccination by estimating the number of children younger than 3 months with in-hospital influenza-related death using published global mortality estimates. FINDINGS: We included 314 children from 31 countries. Comorbidities were present in 166 (53%) children and 41 (13%) children were born prematurely. Median age at death was 8·6 (IQR 4·5-16·6), 11·5 (IQR 4·3-24·0), and 15·5 (IQR 7·4-27·0) months for children from low- and lower-middle-income countries (LMICs), upper-middle-income countries (UMICs), and high-income countries (HICs), respectively. The proportion of children younger than 3 months at time of death was 17% in LMICs, 12% in UMICs, and 7% in HICs. We estimated that 3339 annual influenza-related in-hospital deaths occur in the first 3 months of life globally. INTERPRETATION: In our study, less than 20% of children is younger than 3 months at time of influenza-related death. Although maternal influenza vaccination may impact maternal and infant influenza disease burden, additional immunisation strategies are needed to prevent global influenza-related childhood mortality. The missing data, global coverage, and data quality in this study should be taken into consideration for further interpretation of the results. FUNDING: Bill & Melinda Gates Foundation
Global respiratory syncytial virusârelated infant community deaths
Background
Respiratory syncytial virus (RSV) is a leading cause of pediatric death, with >99% of mortality occurring in low- and lower middle-income countries. At least half of RSV-related deaths are estimated to occur in the community, but clinical characteristics of this group of children remain poorly characterized.
Methods
The RSV Global Online Mortality Database (RSV GOLD), a global registry of under-5 children who have died with RSV-related illness, describes clinical characteristics of children dying of RSV through global data sharing. RSV GOLD acts as a collaborative platform for global deaths, including community mortality studies described in this supplement. We aimed to compare the age distribution of infant deaths <6 months occurring in the community with in-hospital.
Results
We studied 829 RSV-related deaths <1 year of age from 38 developing countries, including 166 community deaths from 12 countries. There were 629 deaths that occurred <6 months, of which 156 (25%) occurred in the community. Among infants who died before 6 months of age, median age at death in the community (1.5 months; IQR: 0.8â3.3) was lower than in-hospital (2.4 months; IQR: 1.5â4.0; Pâ
<â
.0001). The proportion of neonatal deaths was higher in the community (29%, 46/156) than in-hospital (12%, 57/473, Pâ
<â
0.0001).
Conclusions
We observed that children in the community die at a younger age. We expect that maternal vaccination or immunoprophylaxis against RSV will have a larger impact on RSV-related mortality in the community than in-hospital. This case series of RSV-related community deaths, made possible through global data sharing, allowed us to assess the potential impact of future RSV vaccines
New insight on the recent instrumental seismic activity along the Serghaya fault, Syria
En este trabajo se presentan observaciones y anĂĄlisis basados en datos instrumentales de actividad sĂsmica a lo largo de la falla Serghaya. La actividad sĂsmica registrada por estaciones de perĂodo corto entre 1995 y 2009, muestra una actividad significativa que se ha asociado con trazos superficiales conocidos de âsteps-overâ a lo largo de la falla Serghaya. Los enjambres espaciales podrĂan relacionarse con el âstep-overâ de la falla, por ejemplo en Deir el Acheir y Ham. Algunos enjambres se observaron en la regiĂłn de Hermel, pudiĂ©ndose relacionar con una posible extensiĂłn de la falla Serghaya en el NE de LĂbano. La zona sismogĂ©nica pudo coincidir con la supuesta localizaciĂłn de uniĂłn desde la falla Serghaya hasta las fallas de Jhar y Bishri. Esta evidencia completa los resultados de estudios anteriores que demostraron que el Ășltimo sismo destructivo se localizĂł en la falla Serghaya y pudo ser anterior a los sismos de la falla Yammouneh. La falla Serghaya es probablemente la fuente mĂĄs plausible de riesgo sĂsmico en Siria y LĂbano.
doi: https://doi.org/10.22201/igeof.00167169p.2017.56.3.181
Multiparametric MR imaging reveals early cartilage degeneration at 2 and 8 weeks after ACL transection in a rabbit model
Abstract
In this study, the rabbit model with anterior cruciate ligament transection (ACLT) was used to investigate early degenerative changes in cartilage using multiparametric quantitative magnetic resonance imaging (qMRI). ACLT was surgically induced in the knees of skeletally mature New Zealand White rabbits (nâ=â14). ACL transected and contralateral knee compartmentsâmedial femur, lateral femur, medial tibia, and lateral tibiaâwere harvested 2 (nâ=â8) and 8 weeks (nâ=â6) postsurgery. Twelve ageâmatched nonoperated rabbits served as control. qMRI was conducted at 9.4âT and included relaxation times Tâ, Tâ, continuousâwave T1p (CWT1p), adiabatic T1p (AdT1p), adiabatic T2p (AdT2p), and relaxation along a fictitious field (TRAFF). For reference, quantitative histology and biomechanical measurements were carried out. Posttraumatic changes were primarily noted in the superficial half of the cartilage. Prolonged Tâ, Tâ, CWT1p, and AdT1p were observed in the lateral femur 2 and 8 weeks postâACLT, compared with the corresponding control and contralateral groups (Pâ<â.05). Collagen orientation was significantly altered in the lateral femur at 2 weeks postâACLT compared with the corresponding control group. In the medial femur, all the studied relaxation time parameters, except TRAFF, were increased 8 weeks postâACLT, as compared with the corresponding contralateral and control groups (Pâ<â.05). Similarly, significant proteoglycan loss was observed in the medial femur at 8 weeks following surgery (Pâ<â.05). Multiparametric MRI demonstrated early degenerative changes primarily in the superficial cartilage with Tâ, Tâ, CWT1p, and AdT1p sensitive to cartilage changes at 2 weeks after surgery