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排序方式: 共有452条查询结果,搜索用时 15 毫秒
71.
Haran Burri 《Indian pacing and electrophysiology journal》2015,15(2):110-112
Vein stenosis or occlusion is a frequent finding in patients with previously-implanted transvenous leads. This editorial describes the different techniques that may be used to overcome this hurdle in case a new lead needs to be implanted, and discusses two case reports in this issue of the journal. 相似文献
72.
73.
The objective of the study was the construction of a generic curriculum development model for the use of biomedical physics (BMP) educators teaching the non-physics healthcare professions (HCP) in Europe. A comprehensive, qualitative cross-sectional Europe-wide survey of the curricula delivered by BMP in Faculties of Medicine and Health Sciences (FMHS) was carried out. Curricular content was collected from faculty web-sites, curricular documents and textbooks. The survey data was supplemented with semi-structured interviews and direct observation during onsite visits. The number of faculties studied was 118 from 67 universities spread all over Europe, whilst the number of onsite visits/interviews was 15 (geographically distributed as follows: Eastern Europe 6, North Western Europe 5, and South Western Europe 4). EU legislation, recommendations by European national medical councils, educational benchmark statements by higher education quality assurance agencies, research journals concerning HCP education and other documents relevant to standards in clinical practice and undergraduate education were also analyzed. Best practices and BMP learning outcomes were elicited from the curricular materials, interviews and documentation and these were subsequently used to construct the curriculum development model. A structured, comprehensive BMP learning outcomes inventory was designed in the format required by the European Qualifications Framework (EQF). The structures of the inventory and curriculum development model make them ideally suited for use by BMP involved in European curriculum development initiatives for the HCP. 相似文献
74.
ThuyTien Nguyen I. Ricardo Argueta-Morales Stephen Guimond William Clark Andres Ceballos Ruben Osorio 《Computer methods in biomechanics and biomedical engineering》2016,19(7):789-799
Stroke is the most devastating complication after ventricular assist device (VAD) implantation with a 19% incidence and 65% mortality in the pediatric population. Current pediatric VAD technology and anticoagulation strategies alone are suboptimal. VAD implantation assisted by computational methods (CFD) may contribute reducing the risk of cerebral embolization. Representative three-dimensional aortic arch models of an infant and a child were generated. An 8 mm VAD outflow-graft (VAD-OG) anastomosed to the aorta was rendered and CFD was applied to study blood flow patterns. Particle tracks, originating in the VAD, were computed with a Lagrangian phase model and the percentage of particles entering the cerebral vessels was calculated. Eight implantation configurations (infant = 5 and child = 3) and 5 particle sizes (0.5, 1, 2, 3, and 4 mm) were considered. For the infant model, percentage of particles entering the cerebral vessels ranged from 15% for a VAD-OG anastomosed at 90° to the aorta, to 31% for 30° VAD-OG anastomosis (overall percentages: X2 = 10,852, p < 0.0001). For the child model, cerebral embolization ranged from 9% for the 30° VAD-OG anastomosis to 15% for the 60° anastomosis (overall percentages: χ2 = 10,323, p < 0.0001). Using detailed CFD calculations, we demonstrate that the risk of stroke depends significantly on the VAD implantation geometry. In turn, the risk probably depends on patient-specific anatomy. CFD can be used to optimize VAD implantation geometry to minimize stroke risk. 相似文献
75.
Enhanced photoluminescence properties of electrospun Dy3+‐doped ZnO nanofibres for white lighting devices
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Chaitali Niranjan Pangul Shyamkant Wasudeorao Anwane Subhash Baburao Kondawar 《Luminescence》2018,33(6):1087-1093
Dy3+‐doped ZnO nanofibres with diameters from 200 to 500 nm were made using an electrospinning technique. The as‐fabricated amorphous nanofibres resulted in good crystalline continuous nanofibres through calcination. Dy3+‐doped ZnO nanofibres were characterized using scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), ultraviolet–visible (UV–vis) light spectroscopy, Fourier transform infrared spectroscopy (FTIR), and photoluminescence (PL). XRD showed the well defined peaks of ZnO. UV–vis spectra showed a good absorption band at 360 nm. FTIR spectra showed a Zn–O stretching vibration confirming the presence of ZnO. Photoluminescence spectra of Dy3+‐doped ZnO nanofibres showed an emission peak in the visible region that was free from any ZnO defect emission. Emissions at 480 nm and 575 nm in the Dy3+‐doped ZnO nanofibres were the characteristic peaks of dopant Dy3+ and implied efficient energy transfer from host to dopant. Luminescence intensity was found to be increased with increasing doping concentration and reduction in nanofibre diameter. Colour coordinates were calculated from photometric characterizations, which resembled the properties for warm white lighting devices. 相似文献
76.
Qiu Jiang Narendra Kurra Mohamed Alhabeb Yury Gogotsi Husam N. Alshareef 《Liver Transplantation》2018,8(13)
2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, in particular in electrochemical energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high‐rate pseudocapacitive energy storage in MXene electrodes. However, symmetric MXene supercapacitors have a limited voltage window of around 0.6 V due to possible oxidation at high anodic potentials. In this study, the fact that titanium carbide MXene (Ti3C2Tx) can operate at negative potentials in acidic electrolyte is exploited, to design an all‐pseudocapacitive asymmetric device by combining it with a ruthenium oxide (RuO2) positive electrode. This asymmetric device operates at a voltage window of 1.5 V, which is about two times wider than the operating voltage window of symmetric MXene supercapacitors, and is the widest voltage window reported to date for MXene‐based supercapacitors. The complementary working potential windows of MXene and RuO2, along with proton‐induced pseudocapacitance, significantly enhance the device performance. As a result, the asymmetric devices can deliver an energy density of 37 µW h cm?2 at a power density of 40 mW cm?2, with 86% capacitance retention after 20 000 charge–discharge cycles. These results show that pseudocapacitive negative MXene electrodes can potentially replace carbon‐based materials in asymmetric electrochemical capacitors, leading to an increased energy density. 相似文献
77.
Corrugation Architecture Enabled Ultraflexible Wafer‐Scale High‐Efficiency Monocrystalline Silicon Solar Cell
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Rabab R. Bahabry Arwa T. Kutbee Sherjeel M. Khan Adrian C. Sepulveda Irmandy Wicaksono Maha Nour Nimer Wehbe Amani S. Almislem Mohamed T. Ghoneim Galo A. Torres Sevilla Ahad Syed Sohail F. Shaikh Muhammad M. Hussain 《Liver Transplantation》2018,8(12)
Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large‐scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon‐based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor‐based integration strategy where corrugation architecture enables ultraflexible and low‐cost solar cell modules from bulk monocrystalline large‐scale (127 × 127 cm2) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 µm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon‐based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 µm of the back contacts is shown that carries the solar cells segments. 相似文献
78.
Ternary Organic Solar Cells With 12.8% Efficiency Using Two Nonfullerene Acceptors With Complementary Absorptions
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Bin Kan Yuan‐Qiu‐Qiang Yi Xiangjian Wan Huanran Feng Xin Ke Yanbo Wang Chenxi Li Yongsheng Chen 《Liver Transplantation》2018,8(22)
A new small‐molecule acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐(4,4,10,10‐tetrakis(4‐hexylphenyl)‐5,11‐diocthylthieno[3′,2′:4,5]cyclopenta[1,2‐b]thieno[2″,3″:3′,4′]cyclopenta[1′,2′:4,5]thieno[2,3‐f][1]benzothiophene) (NNBDT) based on naphthyl‐fused indanone ending units is reported. This molecule shows a narrow optical bandgap of 1.43 eV and effective absorption in the range of 700–870 nm. The devices based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T):NNBDT yield a power conversion efficiency of 11.7% with a low energy loss of 0.55 eV and a high fill factor (FF) of 71.7%. Another acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐4,4,7,7,12,12‐hexaoctyl‐4H‐cyclopenta[2″,1″:5,6;3″,4″:5′,6′]diindeno[1,2‐b:1′,2′‐b′]dithiophene (FDNCTF) is introduced as the third component to fabricate ternary devices. The two acceptors (NNBDT and FDNCTF) possess complementary absorption, same molecular orientation, and well‐miscible behavior. It is found that there exists a nonradiative energy transfer process from FDNCTF to NNBDT. The fullerene‐free ternary cells based on PBDB‐T:NNBDT:FDNCTF achieve a high efficiency of 12.8% with an improved short circuit current near 20 mA cm?2 in contrast to the binary devices. The result represents the best performance for fullerene‐free ternary solar cells reported to date and highlights the potential of ternary solar cells. 相似文献
79.
Myoungsoo Shin Woo‐Jin Song Hye Bin Son Seungmin Yoo Sungho Kim Gyujin Song Nam‐Soon Choi Soojin Park 《Liver Transplantation》2018,8(23)
With the emergence of stretchable electronic devices, there is growing interest in the development of deformable power accessories that can power them. To date, various approaches have been reported for replacing rigid components of typical batteries with elastic materials. Little attention, however, has been paid to stretchable separator membranes that can not only prevent internal short circuit but also provide an ionic conducting pathway between electrodes under extreme physical deformation. Herein, a poly(styrene‐b‐butadiene‐b‐styrene) (SBS) block copolymer–based stretchable separator membrane is fabricated by the nonsolvent‐induced phase separation (NIPS). The diversity of mechanical properties and porous structures can be obtained by using different polymer concentrations and tuning the affinity among major components of NIPS. The stretchable separator membrane exhibits a high stretchability of around 270% strain and porous structure having porosity of 61%. Thus, its potential application as a stretchable separator membrane for deformable energy devices is demonstrated by applying to organic/aqueous electrolyte–based rechargeable lithium‐ion batteries. As a result, these batteries manifest good cycle life and stable capacity retention even under a stretching condition of 100%, without compromising the battery's performance. 相似文献
80.
Jabuticaba‐Inspired Hybrid Carbon Filler/Polymer Electrode for Use in Highly Stretchable Aqueous Li‐Ion Batteries
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Woo‐Jin Song Jeonghwan Park Dong Hyup Kim Sohyun Bae Myung‐Jun Kwak Myoungsoo Shin Sungho Kim Sungho Choi Ji‐Hyun Jang Tae Joo Shin So Youn Kim Kwanyong Seo Soojin Park 《Liver Transplantation》2018,8(10)
Stretchable electronics are considered as next‐generation devices; however, to realize stretchable electronics, it is first necessary to develop a deformable energy device. Of the various components in energy devices, the fabrication of stretchable current collectors is crucial because they must be mechanically robust and have high electrical conductivity under deformation. In this study, the authors present a conductive polymer composite composed of Jabuticaba‐like hybrid carbon fillers containing carbon nanotubes and carbon black in a simple solution process. The hybrid carbon/polymer (HCP) composite is found to effectively retain its electrical conductivity, even when under high strain of ≈200%. To understand the behavior of conductive fillers in the polymer matrix when under mechanical strain, the authors investigate the microstructure of the composite using an in situ small‐angle X‐ray scattering analysis. The authors observe that the HCP produces efficient electrical pathways for filler interconnections upon stretching. The authors develop a stretchable aqueous rechargeable lithium‐ion battery (ARLB) that utilizes this HCP composite as a stretchable current collector. The ARLB exhibits excellent rate capability (≈90 mA h g?1 at a rate of 20 C) and outstanding capacity retention of 93% after 500 cycles. Moreover, the stretchable ARLB is able to efficiently deliver power even when under 100% strain. 相似文献