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排序方式: 共有1472条查询结果,搜索用时 15 毫秒
1.
Jincy Joy Jessica Pereira Rachida Aid‐Launais Graciela Pavon‐Djavid Alok R Ray Didier Letourneur Anne Meddahi‐Pell Bhuvanesh Gupta 《Polymer International》2019,68(7):1367-1377
The work reported involved the fabrication of an electrospun tubular conduit of a gelatin and polycaprolactone (PCL) blend as an adventitia‐equivalent construct. Gelatin was included as the matrix for increased biocompatibility with the addition of PCL for durability. This is contrary to most of the literature available for biomaterials based on blends of gelatin and PCL where PCL is the major matrix. The work includes the assiduous selection of key electrospinning parameters to obtain smooth bead‐free fibres with a narrow distribution of pore size and fibre diameter. Few reports elucidate the optimization of all electrospinning parameters to fabricate tubular conduits with a focus on obtaining homogeneous pores and fibres. This stepwise investigation would be unique for the fabrication of gelatin–PCL electrospun tubular constructs. The fabricated microfibrous gelatin–PCL constructs had pores of size ca 50–100 μm reportedly conducive for cell infiltration. The measured value of surface roughness of 57.99 ± 17.4 nm is reported to be favourable for protein adhesion and cell adhesion. The elastic modulus was observed to be similar to that of the tunica adventitia of the native artery. Preliminary in vitro and in vivo biocompatibility tests suggest safe applicability as a biomaterial. Minimal cytotoxicity was observed using MTT assay. Subcutaneous implantation of the scaffold demonstrated acute inflammation which decreased by day 15. The findings of this study could enable the fabrication of smooth bead‐free microfibrous gelatin–PCL tubular construct as viable biomaterial which can be included in a bilayer or a trilayer scaffold for vascular tissue engineering. © 2019 Society of Chemical Industry 相似文献
2.
Kumari Asha Neeraj Kumar Biswas Sakshi Saxena Vibha Rani Satsangi Rohit Shrivastav Rama Kant Sahab Dass 《International Journal of Hydrogen Energy》2021,46(40):20858-20870
The present study attempts quantitative determination of changes in the morphological surface features viz. fractal dimension, lower and upper cut off length scale through Power Spectral Density analysis prior to and after irradiation of 100 KeV Ar+ ion beam at incidence angles of 0°, 40° and 60° on ZnO thin films. All the unirradiated and irradiated samples are subjected to photoelectrochemical characterization and a correlation between photoelectrochemical performance and morphological parameters is established. Sample irradiated at 40° angle at the fluence of 5 × 1016 ions/cm2 is found to possess maximum fractal dimension of 2.72, lower and upper cut off length scale of 3.16 nm and 63.00 nm respectively. This sample exhibits maximum photocurrent density of 3.19 mA/cm2 and applied bias photon-to-current efficiency of 1.12% at 1.23 V/RHE. Hydrogen gas collected for duration of 1 h for the same sample was ~4.83 mLcm?2. 相似文献
3.
Sintering and grain growth of nano-crystalline undoped ZnO has been studied in detail over a wide range of temperature and holding time. Below 800 °C, sintering of over 70% theoretical density is not observed, irrespective of particle size. At 900 °C for 6 h, the nano-crystalline sample sinters to 99% of theoretical density whereas the density for as received sample is 93% of theoretical density. However, at 1300 °C or higher, the densification is found to be much faster and after a few hours becomes independent of holding time. Grain growth studies reveal a similar feature of attaining saturation over holding time. The average saturated grain size is found to be ∼1.5 and ∼2.2 μm at 800 and 900 °C, respectively, while at 1300 °C or higher, it is in between 12 and 13 μm. 相似文献
4.
In a prospective study of layered versus mass closure of abdominal incisions in infants and children, 34 cases underwent wound closure by layered and mass closure technique on an alternate basis. All the patients were assessed for their nutritional status and haemoglobin level pre-operatively, and wound complications were compared with respect to closure technique, nutritional status and normal haemoglobin level. Presence of protein energy malnutrition and anaemia did not increase the risk of wound complications with either of the technique. 相似文献
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The present study was aimed at understanding the response of 2014 Al alloy dispersed with graphite particles in various corrosive environments. Marine (sodium chloride) as well as acidic media were selected for the purpose with a view to widen the range of utility of the composite for applications where such environments may be encountered. Studies were also extended to characterize the corrosion resistance of the composite in fresh as well as used lubricating oils to explore the possibilities of using it in bearing, bushing and such other applications. The corrosion behaviour of the base alloy processed under identical conditions was also examined in the above media to see the influence of graphite addition in the alloy. In order to assess the role of the matrix microstructure, the composite as well as the base alloy was subjected to corrosion in heat-treated as well as-cast conditions. It was observed that the specimens suffered from the maximum rate of corrosion in acid, while sodium chloride produced the minimum corrosion rate. Oil in both used and fresh conditions revealed a negligibly small extent of corrosion. The composite was found to show a higher rate of corrosion than the base alloy under identical test conditions. This was attributed to the dispersoid/matrix interfacial corrosion in the case of the graphitic aluminium alloy. Heat treatment of the composite and the base alloy was found to lower the rate of corrosion in the environments tested. Microstructural modifications of the matrix and possible relief of residual stresses were thought to be responsible for the lower rate of corrosion in the heat-treated condition. 相似文献
7.
K. Chatty T. P. Chow R. J. Gutmann E. Arnold D. Alok 《Journal of Electronic Materials》2002,31(5):356-360
Hall measurements have been used to compare the properties of 4H-SiC inversion-mode MOSFETs with “wet” and “dry” gate oxides.
While the field-effect mobilities were approximately 3–5 cm2/Vs, the Hall mobilities in 4H-SiC MOSFETs in the wet and dry oxide samples were approximately 70–80 cm2/Vs. The dry-oxidized metal oxide semiconductor field effect transistors (MOSFETs) had a higher transconductance, improved
threshold voltage, improved subthreshold slope, and a higher inversion carrier concentration compared to the wet-oxidized
MOSFETs. The difference in characteristics between the wet- and the dry-oxidized MOSFETs is attributed to the larger fixed
oxide charge in the dry oxide sample and a higher interface trap density in the wet oxide sample. 相似文献
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We analyze and numerically study the code-matching logic module that is the central element in a proposed soliton-based ring network system running at peak rates of 100 Gb/s. The proposed network is packet-switched, and fast logic is required to route each packet. That is the function of the code-matching logic module, and four soliton logic gates that can perform fast logic are the key devices in its design. The behavior of the code-matching logic module is governed by a large set of parameters, and we simulate it by varying many of these parameters. The physical effects that occur in these devices and their significance are analyzed. The results indicate that the logic module will work but within a restricted parameter range 相似文献
10.