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排序方式: 共有3207条查询结果,搜索用时 281 毫秒
1.
F.T. Munna Vidhya Selvanathan K. Sobayel Ghulam Muhammad Nilofar Asim Nowshad Amin Kamaruzzaman Sopian Md. Akhtaruzzaman 《Ceramics International》2021,47(8):11003-11009
In this study, dilute chemical bath deposition technique has been used to deposit CdZnS thin films on soda-lime glass substrates. The structural, morphological, optoelectronic properties of as-grown films have been investigated as a function of different Zn2+ precursor concentrations. The X-ray diffractogram of CdS thin-film reveals a peak corresponding to (002) plane with wurtzite structure, and the peak shift has been observed with the increase of the Zn2+ concentration upon formation of CdZnS thin film. From morphological studies, it has been revealed that the diluted chemical bath deposition technique provides homogeneous distribution of film on the substrate even at a lower concentration of Zn2+. Optical characterization has shown that the transparency of the film is influenced by Zn2+ concentration and when the Zn2+ concentration is varied from 0 M to 0.0256 M, bandgap values of resulting films range from 2.42 eV to 3.90 eV while. Furthermore, electrical properties have shown that with increasing zinc concentration the resistivity of the film increases. Finally, numerical simulation validates and suggests that CdZnS buffer layer with composition of 0.0032 M Zn2+ concentration would be a promising candidate in CIGS solar cell. 相似文献
2.
Mohammed Amin Salih Venkatachalam K. Hubálovský S. Trojovský P. Prabu P. 《Mobile Networks and Applications》2022,27(3):1050-1059
Mobile Networks and Applications - 5G/6G communication are first generation high speed wireless communication network which integrates the aerial data, terrestrial data and maritime data via... 相似文献
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Wireless Personal Communications - Current mobile communications technology relies heavily on efficient design of antennas, where the operational characteristics of the wireless communication... 相似文献
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MA Nowak AL Lloyd GM Vasquez TA Wiltrout LM Wahl N Bischofberger J Williams A Kinter AS Fauci VM Hirsch JD Lifson 《Canadian Metallurgical Quarterly》1997,71(10):7518-7525
Mathematical modeling of viral replication dynamics, based on sequential measurements of levels of virion-associated RNA in plasma during antiretroviral treatment, has led to fundamental new insights into human immunodeficiency virus type 1 pathogenesis. We took advantage of the simian immunodeficiency virus (SIV)-infected macaque model to perform detailed measurements and mathematical modeling during primary infection and during treatment of established infection with the antiretroviral drug (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA). The calculated clearance half-life for productively infected cells during resolution of the peak viremia of primary infection was on the order of 1 day, with slightly shorter clearance half-lives calculated during PMPA treatment. Viral reproduction rates upon discontinuation of PMPA treatment after 2 weeks were approximately twofold greater than those obtained just prior to initiation of treatment in the same animals, likely reflecting accumulation of susceptible target cells during treatment. The basic reproductive ratio (R0) for the spread of SIV infection in vivo, which represents the number of productively infected cells derived from each productively infected cell at the beginning of infection, was also estimated. This parameter quantifies the extent to which antiviral therapy or vaccination must limit the initial spread of virus to prevent establishment of chronic disseminated infection. The results thus provide an important guide for efforts to develop vaccines against SIV and, by extension, human immunodeficiency virus. 相似文献
7.
OBJECTIVE: To study the effects of an aldose reductase inhibitor (ARI-509, Wyeth-Ayerst, Princeton, NJ) and aminoguanidine (AMG), agents that have been reported to prevent or delay diabetic retinopathy, on retinal vascular abnormalities and the immunocytochemical expression in the retina of vascular endothelial growth factor (VEGF) in rats maintained for up to 2 years on a 50% galactose diet. METHODS: Albino rats were placed on a control diet, a diet containing 50% galactose, or the 50% galactose diet containing either ARI-509 or AMG. Treatment with ARI-509 or AMG was initiated at the beginning of the experiment or after 12 months of galactose feeding. After 22 to 24 months, the rats were killed and the retinal vasculature from half of one eye was isolated by trypsin-elastase digestion for semiquantitative evaluation of retinal vascular lesions. The other half of the retina was prepared for immunocytochemistry and stained for the presence of VEGF, factor VIII, vimentin, and glial fibrillary acidic protein. Red blood cells, sciatic nerves, and a portion of the retina from the second eye were assayed for glucose, galactose, fructose, sorbitol, galactitol, and myo-inositol. Red blood cells were also assayed for galactosylated hemoglobin. RESULTS: Galactose-fed animals developed a vascular retinopathy characterized by severe cellular loss in the retinal capillaries and intensification of periodic acid-Schiff staining of the vascular basement membranes. Some animals also displayed dilation and hypercellularity of vessels in the posterior retina. These changes were substantially reduced in animals receiving ARI-509 from the beginning of the galactose diet, but were unaffected in all of the other treatment groups. None of the rats receiving ARI-509 or AMG treatment, whether initiated from the onset or after 12 months of galactosemia, demonstrated VEGF immunoreactivity. With the exception of the animals receiving ARI-509 from the beginning of the experiment, all of the galactose-fed animals developed dense cataracts within 6 weeks of the beginning of the galactose diet. Galactitol levels in animals receiving ARI-509 were 86% to 93% lower in red blood cells, retina, and sciatic nerve than those in the other galactose-fed groups. CONCLUSIONS: Although ARI-509 and AMG have different abilities to delay or prevent the diabetic-like retinopathy in galactosemic rats, even when substantial retinal microvascular acellularity occurs, both drugs prevent the immunocytochemical expression of VEGF. These results suggest that factors other than hypoxia may be responsible for VEGF expression in the retina, and that aldose reductase inhibitors and AMG have potential roles in preventing such expression and, thus, perhaps preventing retinal neovascularization. 相似文献
8.
SA Khotimchenko VM Kodentsova IA Alekseeva SG Vlaskina OA Vrzhesinskaia AA Sokol''nikov LA Kharitonchik IP Aleshko-Ozhevskií LV Sheviakova 《Canadian Metallurgical Quarterly》1997,43(3):158-164
Gamma delta T-Cells represent a minor subpopulation of T-lymphocytes in man and their role in normal and diseased human skin is unknown. This article is a comprehensive review of T-lymphocytes bearing the gamma delta T-cell receptor in normal and pathological human skin. Firstly, we have documented the occurrence of gamma delta T-cells in normal skin and in a range of reactive and malignant skin conditions. We have then discussed the experimental findings regarding the repertoire used by gamma delta T-cells in normal human skin and in cutaneous disorders with an increased percentage of gamma delta T-cells. 相似文献
9.
The accuracies of ultrasonography (US) and computed tomography (CT) for determining tumor invasion of the chest wall in lung cancer were compared in a retrospective study of 120 patients. US findings were evaluated preoperatively according to the following criteria: disruption of pleura, extension through the chest wall, and fixation of tumor during breathing. CT findings were evaluated with the following criteria: obtuse angle of the mass to the pleural surface, more than 3 cm contact with the pleural surface, and visible pleural thickening associated with the mass. Chest wall invasion was judged as positive when at least two of the three findings were present with either technique. Nineteen of the 120 patients had chest wall invasion by tumor. The sensitivity of US was 100% and the specificity was 98%. The sensitivity of CT was 68% and the specificity was 66%. The accuracy of US and CT were 98% and 67%, respectively. 相似文献
10.
Cypriano G da Trindade Neto Ana LP Fernandes Ana IB Santos Waldenice A Morais Marcos VM Navarro Tereza NC Dantas Mrcia R Pereira Jos LC Fonseca 《Polymer International》2005,54(4):659-666
Complexation of chitosan in aqueous solutions by low molecular weight electrolytes is one of the simplest methods for the preparation of aqueous chitosan dispersions. In this work, the influence of storage time, sulfate concentration, method of preparation and surfactant content on some properties of the resultant chitosan dispersions (turbidity, viscosity and zeta potential) was analyzed. Turbidimetry was adequate to monitor the formation of particles, while viscometry was suitable to monitor changes in the dispersing phase. An analysis of the properties of these systems, mainly in terms of particle–particle and macromolecule–macromolecule interactions was carried out. Copyright © 2004 Society of Chemical Industry 相似文献