3,422 research outputs found
Recommended from our members
Access to Care for VA Dialysis Patients During Superstorm Sandy.
Introduction: This study examines the use of dialysis services by end-stage renal disease (ESRD) patients following the Superstorm Sandy-related, months-long closure of the New York campus of the US Department of Veterans Affairs (VA) New York Harbor VA Healthcare System (NYHHS, Manhattan VAMC). Methods: Outpatient visits, dialysis care, emergency department visits, and hospitalizations at VA and non-VA facilities for 47 Manhattan VAMC ESRD patients were examined 12 months pre- and post-Sandy using VA administrative and clinical data. Results: The Brooklyn campus of NYHHS, which is within ten miles of Manhattan VAMC, experienced the largest increase in the number of dialysis encounters after the closure. Dialysis encounters for VA patients also increased at non-VA facilities, rising on average, to 106 per month. For the James J Peters Bronx VAMC, the number of total dialysis encounters for Manhattan VAMC patients fluctuated between 39 and 43 per month, dropping to less than 30 after the Manhattan VAMC dialysis unit reopened. Conclusion: Manhattan VAMC ESRD patients used nearby alternate VA sites and non-VA clinics for their care during the closure of the Manhattan VAMC dialysis unit. The VA electronic health records played an important role in ensuring continuity of care for patients who exclusively used VAMC facilities post-Sandy because patient information was immediately accessible at other VA facilities. The events related to Superstorm Sandy highlight the need for dialysis providers to have a comprehensive disaster plan, including nearby alternate care sites that can increase service capacity when a dialysis facility is closed because of a disaster
Plastic Deformation in Laser-Induced Shock Compression of Monocrystalline Copper
Copper monocrystals were subjected to shock compression at pressures of 10–60 GPa by a short (3 ns initial) duration laser pulse. Transmission electron microscopy revealed features consistent with previous observations of shock-compressed copper, albeit at pulse durations in the µs regime. The results suggest that the defect structure is generated at the shock front. A mechanism for dislocation generation is presented, providing a realistic prediction of dislocation density as a function of pressure. The threshold stress for deformation twinning in shock compression is calculated from the constitutive equations for slip, twinning, and the Swegle-Grady relationship
Modelling of a thin film thermoelectric micro-Peltier module
A micro Peltier cooler/heater module has been modelled. The module consists of n-type bismuth telluride and p-type antimony telluride thermoelectric materials. The commercial software package CFD-ACE+ has been used to implement and analyse the model. A two-dimensional coupled electrical and thermal simulation was performed. This software includes the possibility to incorporate the Peltier effect. The temperature, electric field intensity and wall heat flux distributions were simulated for different applied potentials. The variation in temperature difference with respect to the Seebeck coefficient of the material was calculated and analysed
A layered SAW device based on ZnO/LiTaO3 for liquid media sensing applications
Surface Acoustic Wave (SAW) sensors comprising a zinc oxide guiding layer deposited on a 36°-YX lithium tantalate substrate were developed. They were found to have greater mass sensitivity than other LiTaO3 based SAW sensors, such as the -SiO2/LiTaO3 configuration. In this paper, the fabrication of the ZnO/LiTaO3 sensor is described and micro-characterisation of the deposited films is presented. Sensitivity of these devices to surface mass and dielectric perturbations is then presented, followed by an analysis of temperature stability
ZnO nanobelt based conductometric H2 and NO2 gas sensors
Conductometric H2 and NO2 gas sensors based on single-crystalline ZnO nanobelt sensitive layers have been developed. These layers were deposited using a rf magnetron sputterer. TEM and SEM characterization methods were employed to study the morphology of the nanobelts. These sensors were exposed to H2 and NO2 gases at operating temperatures between 225degC and 420degC. Study showed that sensors responded with highest magnitude at above 300degC. The fastest response and recovery times, with greater repeatability occurred at 385degC and 350degC for H2 and NO2 gases, respectively. Sensor with ZnO nanobelts has a much lower optimum operational temperature than that of conductometric sensors with other forms of ZnO crystal layers
Palladium nanowire hydrogen sensor based on a SAW transducer
Palladium (Pd) nanowires were synthesized by electro chemical deposition technique. Pd nanowires were transferred onto a ZnO/36deg LiTaO3 surface acoustic wave (SAW) transducer with an approximate operating frequency of 100 MHz. This operational frequency approximately corresponds to the device's highest conductometric sensitivity. These devices were investigated for hydrogen (H2) sensing at the room temperature. It was observed that the device exposure to the H2 gas resulted to a measurable increase in the device operating frequenc
In situ nanoindentation: probing nanoscale multifunctionality
Nanoindentation is the leading technique for evaluating nanoscale mechanical properties of materials. Consistent developments in instrumentation and their capabilities are transforming nanoindentation into a powerful tool for characterization of multifunctionality at the nanoscale. This review outlines the integration of nanoindentation with real-time electron imaging, high temperature measurements, electrical characterization, and a combination of these. In situ nanoindentation measurements have enabled the real-time study of the interplay between mechanical, thermal, and electrical effects at the nanoscale. This review identifies previous reviews in this area, traces developments and pinpoints significant recent advances (post-2007), with emphasis on the applications of in situ nanoindentation techniques to materials systems, and highlighting the new insights gained from these in situ techniques. Based on this review, future directions and applications of in situ nanoindentation are identified, which highlight the potential of this suite of techniques for materials scientists from all disciplines
Development of nano-structured titanium oxide thin films using a gas carving technique
A method is developed for producing nano-structured titanium oxide thin films using H2 gas interaction with titanium thin film at a high temperature. These nano-structured thin films have been formed on a quartz crystal substrate. Titanium (Ti) thin films were deposited on the quartz crystal using a RF magnetron sputterer. The samples were placed in the oven at 500-800°C for 5 hours. The gas mixture of 1% H2 in N2 was introduced in the oven. The process of Ti annealing in the presence of H2 carves Ti films into nano-structure shapes. The process is a gas-solid interaction. Thin films were characterised using Scanning Electron Microscopes (SEM) and X-Ray Diffraction (XRD) technique. The nano structures formed have dimensions in a range of 25nm - 150nm obtained after gas carving
Genetic risk factors in patients with deep venous thrombosis, a retrospective case control study on Iranian population
Background: Venous thromboembolism (VTE) could be manifested as deep venous thrombosis (DVT) or pulmonary embolism (PE). DVT is usually the more common manifestation and is usually formation of a thrombus in the deep veins of lower extremities. DVT could occur without known underlying cause (idiopathic thrombosis) which could be a consequence of an inherited underlying risk factor or could be a consequence of provoking events, such as trauma, surgery or acute illness (provoked thrombosis). Our aim in this study was to assess the impact of some previously reported genetic risk factors including, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, plasminogen activator inhibitor-1(PAI-1) 4G/5G, prothrombin 20210 and FV Leiden on occurrence of DVT in a population of Iranian patients. Methods: This long-term study was conducted on 182 patients with DVT and also 250 age and sex matched healthy subjects as control group. The diagnosis of DVT was based on patient's history, clinical findings, D-dimer test, and confirmed by Doppler ultrasonography. After confirmation of DVT, both groups were assessed for the five mentioned mutations. The relationship between mutations and predisposition to DVT was calculated by using logistic regression and expressed as an OR with a 95 confidence interval (CI). Results: Our results revealed that FV Leiden (OR 6.7; 95 CI = 2.2 to 20.3; P = 0.001), MTHFR C677T (OR 6.0; 95 CI = 2.2 to 16.4; P < 0.001), MTHFR A1298C (OR 8.3; 95 CI = 4.4 to 15.8; P < 0.001), and PAI-1 4G/5G (OR 3.8; 95 CI = 2.1 to 7.2; P < 0.001) mutations were all significantly associated with an increased risk of DVT. Prothrombin 20210 was found in none of the patients and controls. Conclusion: Our findings suggest that genetic risk factors have a contributory role on occurrence of DVT. © 2015 Hosseini et al
- …