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51.
Suska F Källtorp M Esposito M Gretzer C Tengvall P Thomsen P 《Journal of materials science. Materials in medicine》2001,12(10-12):939-944
Machined, commercially pure titanium (Ti) disks were coated with approximately 400 nm copper (Cu) by physical vapor deposition or left uncoated. The kinetics of inflammatory cell recruitment, distribution and viability was evaluated around Ti, Cu, and in sham sites after 1, 3, 12, 18, 24, and 48 h in a rat subcutaneous (s.c.) model. Further analysis of the cells on implant surfaces was performed by ex vivo incubation of the disks. Ti and Cu stimulated an increased recruitment of inflammatory cells in comparison with sham sites. A markedly higher amount of cells, predominantly polymorpho-nuclear granulocytes (PMN), was detected around Cu after 18 h and onwards. More cells were found at the implant surfaces than in the surrounding exudates after 18 h. The total amount of lactate dehydrogenase (LDH), an indicator of plasma membrane injury, was higher in Cu exudates after 18 h in comparison with Ti and sham. In contrast, no differences in the proportion of dead cells (trypan blue dye uptake) were detected in the exudates. Further, LDH levels were higher around Ti than Cu during the initial 18 h of ex vivo incubation. The results of this study indicate that the early inflammatory process associated with a cytotoxic material in soft tissues is largely attributed to the induction of a markedly strong and prolonged chemotactic response. In contrast, this process is characterized by a higher amount of inflammatory cells around a biocompatible material than in sham sites, but with a transient course and total LDH similar to sham sites. 相似文献
52.
J. Jakobsen E. Bozhevolnaya O.T. Thomsen 《Composites Science and Technology》2007,67(15-16):3378-3385
The paper addresses the damage tolerance of sandwich structures, where the prevention and limitation of delamination failure are highly important design issues. Due to the layered composition of sandwich structures, face–core interface delamination is a commonly observed failure mode, often referred to as peeling failure. Peeling between the sandwich face sheets and the core material drastically diminishes the structural integrity of the structure. This paper presents a new peel stopper concept for sandwich structures. Its purpose is to effectively stop the development of debonding/delamination by rerouting the delamination, and to confine it to a predefined zone in the sandwich structure. The suggested design was experimentally tested for different material compositions of sandwich beams subjected to three-point bending loading. For all the tested sandwich configurations the suggested peel stopper was able to stop face–core delamination and to limit the delamination damage to restricted zones. 相似文献
53.
我们非常感激你对儿音响产品的关心,并且希望它能成为你家庭音响和家庭影院中的一部分。
当我们进入家庭音响市场的时候,我们公司承诺会以性能和品质的最高标准来创造产品。我们相信你会从Fathom@或者Gofham中的每个细节中看到儿音响对品质的承诺,但最重要的是,我们相信你会在每次欣赏电影和享受音乐的时候都会感受得到。 相似文献
54.
Nonresponse to surveys, which seems to plague work environment studies and studies of health care personnel in particular, may pose problems of generalizability and validity. The aim of this study was to provide an estimate of nonresponse error in a self-administered survey concerning the work environment of psychiatric health care personnel. A random sample of 10% of the original survey population (N?=?693) was selected to participate in a telephone follow-up of a postal survey that had a response rate of 51%. There were no differences between the responders and nonresponders to the postal survey on the exposure or outcome variables. There was no evidence of nonresponse bias in this study, although recall bias may have been a problem. In those cases in which generalizability is deemed important, it is recommended that nonresponse studies be regularly carried out when response rates are less than 100%. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
55.
技术改造项目的技术经济评价方法 总被引:1,自引:0,他引:1
分析比较了技术改造项目的经济评价的计算方法,利用“有无比较法”计算增量净收益,是技术改造项目经济效益计算的有效方法。 相似文献
56.
Digital dermatitis is a serious problem in dairy production in many countries. In many settings, it is important to evaluate the digital dermatitis status of individual cows or an entire dairy herd. Such an evaluation has traditionally been done in a hoof trimming chute. An evaluation in the milking parlor can take place without disturbing the cows to a large extent, it can be done using less labor compared with an evaluation in a hoof trimming chute, and is cheaper than using a chute. The objective was to evaluate the sensitivity and specificity of a rapid screening method for digital dermatitis in the milking parlor, without using any specialized tools and taking approximately 15 s/cow. All lactating cows in 3 commercial Danish dairy herds were included. Cows were first scored for the presence of digital dermatitis during milking and the next day all cows were scored during hoof trimming. A 6-point nominal scoring system based on a visual inspection of the digital dermatitis lesions was used. For the analysis, the scores were dichotomized (digital dermatitis positive or digital dermatitis negative). Additionally, lesions were classified as small (diameter ≤ 2 cm) or large (diameter >2 cm). Sensitivity and specificity were calculated using observations from the hoof trimming chute as the “gold standard” and observations during milking as the diagnostic test. Relatively large variation was found between herds with an overall sensitivity of 0.65 (95% confidence interval: 0.59 to 0.72) and a specificity of 0.84 (0.81 to 0.87). The sensitivity increased to 0.69 (0.62 to 0.76), when only large lesions were assessed. The method has several advantages compared with evaluation in a chute and may be a useful tool in the daily hoof health management in dairy herds. 相似文献
57.
Hans Erhorn Tomasz Mroz Ove Mørck Fritz Schmidt Lorenz Schoff Kirsten Engelund Thomsen 《Energy and Buildings》2008,40(4):419-428
Educational buildings such as kindergartens, schools and universities display many similar design, operation and maintenance features in most countries. The two most noteworthy similarities amongst these building types are the high energy consumption and the necessity for retrofitting many buildings within this sector. However, studies have shown that during retrofit, energy saving measures are only rarely applied, because the decision-makers lack knowledge of investments and the efficiency of potential energy saving measures. The main goal of the International Energy Agency ECBCS Annex 36 is to provide the educational building decision-makers with sufficient data, information and tools to improve their learning and teaching environments by improving the energy efficiency of their buildings. 相似文献
58.
A 27-year-old woman was admitted with an abdominal mass in the right hypochondrium. Ultrasound, intravenous urography and scintigraphy revealed a giant non-functioning hydronephrosis. Because she refused surgery, a percutaneous aspiration with instillation of doxycycline was performed. One year thereafter, the patient was still without recurrence of any symptoms or hydronephrosis. 相似文献
59.
60.
Late psychosocial improvement in a case of severe head injury with bilateral fronto-orbital lesions.
Describes the results of a 19-yr follow-up study of a head-injured female patient. At age 17 yrs, the S sustained a blunt head trauma with bilateral fronto-orbital lesions verified by late regional cerebral blood flow. The S presented an extreme state of regression for many months after injury. During the first posttraumatic years no behavioral disorders were reported, but after the 5th yr lack of control, including sexual disinhibition, and lack of motivation became severe problems. More than 10 yrs after the accident, a partner applied a simple program of behavioral modification to the S. After 2 yrs of rigid training, an unexpected improvement in psychosocial adaptation took place. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献