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排序方式: 共有403条查询结果,搜索用时 187 毫秒
21.
鸦胆子联合角膜缘干细胞移植治疗翼状胬肉 总被引:1,自引:0,他引:1
目的 :探讨鸦胆子在翼状胬肉联合手术中的安全性和有效性。方法 :在 41只眼的角膜缘干细胞移植联合翼状胬肉切除术中 ,用鸦胆子仁糊状粉末剂搽抹在巩膜创面的表面上 ,过五分钟后 ,使用注射用水将鸦胆子仁粉末从抹过的巩膜创面上冲洗掉。结果 :41例 (41只眼 )随访期间无复发 ,未见副作用及并发症。结论 :以鸦胆子仁技术行翼状胬肉切除角膜缘干细胞移植联合手术安全有效 ;术中应用鸦胆子可防止术后复发。 相似文献
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D. V. Schoon H. Enomoto M. P. Harris 《Documenta ophthalmologica. Advances in ophthalmology》1989,71(3):329-340
Visual evoked potentials were obtained from 112 subjects (215 eyes) aged 5 to 79 years with fast random stimuli. The stimulus (the presence or absence of the initiation of a reversal) and response (voltage measurements) were used in calculating the first order Wiener kernels to obtain the visual evoked potentials. Five check sizes were used to stimulate each eye. The implicit time of the major negative wave showed a significant increase with age for each check size used. Regression lines for the implicit time vs age data for male subjects were significantly different from those of females. The y-intercepts were lower and the slope of the regression lines were consistently steeper for males. Thus the rate of increase in implicit time was higher in males. The relationship of the amplitude of the major wave to age did not appear to be linear. The data suggested that a second-order polynomial curve might be an appropriate representation of the relationship. 相似文献
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Solving chance constrained optimal control problems in aerospace via kernel density estimation
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J.‐B. Caillau M. Cerf A. Sassi E. Trélat H. Zidani 《Optimal control applications & methods.》2018,39(5):1833-1858
The goal of this paper is to show how nonparametric statistics can be used to solve some chance constrained optimization and optimal control problems. We use the kernel density estimation method to approximate the probability density function of a random variable with unknown distribution from a relatively small sample. We then show how this technique can be applied and implemented for a class of problems including the Goddard problem and the trajectory optimization of an Ariane five‐like launcher. 相似文献
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Zhang J Gu HD Zhang L Tian ZJ Zhang ZQ Shi XC Ma WH 《Food and chemical toxicology》2011,49(12):3136-3141
The present study was undertaken to evaluate the potential cardioprotective effects of apricot kernel oil (AO) on the myocardial ischemia–reperfusion (IR) of rat model in vivo. The rats were divided into five groups: sham-operated, IR, low dose AO-treated IR (LD-AO + IR), medium dose AO-treated IR (MD-AO + IR) and high dose AO-treated IR (HD-AO + IR). All rats were provided with food and water ad libitum. The LD-AO + IR, MD-AO + IR and HD-AO + IR groups were given a daily dose of 2, 6 and 10 ml kg−1 BW−1 of AO, respectively, for 14 days prior to the IR operation. Tetrazolium chloride staining revealed that infarct size and the ratio of infarct weight to the total heart weight were decreased significantly in the three AO-treated groups compared to the IR group. The serum creatine kinase and aspartate aminotransferase activities also demonstrated similar beneficial effects. Myocardial catalase, superoxide dismutase, glutathione peroxidase, and constitutive nitric oxide synthase activities, as well as NO concentrations, were all increased, whereas malondialdehyde content and inducible nitric oxide synthase were decreased in AO-treated rats. These findings suggest that apricot kernel oil has potent cardioprotective effects, and could be developed as a nutriment for the treatment and prevention of myocardial infarcts. 相似文献
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利用小波支持向量回归,实现了遥感多光谱图像分辨率的增强。首先采用非下采样Contourlet变换对低分辨率的多光谱图像和高分辨率的全色图像进行多分辨率分解,再利用小波支持向量回归对分解系数进行学习和预测,获得分辨率初步提高的多光谱图像,最后再与传统的插值方法得到的结果进行融合来实现多光谱图像分辨率增强。实验结果表明:此方法借遥感全色图像的辅助获得丰富的高频细节信息,使得分辨率增强结果无论是最小均方误差还是峰值信噪比都要优于仅依靠原图像本身放大的传统方法以及其他的分辨率增强方法。 相似文献
27.
Lerman G Shakhnovich BE 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(27):11334-11339
Although rigorous measures of similarity for sequence and structure are now well established, the problem of defining functional relationships has been particularly daunting. Here, we present several manifold embedding techniques to compute distances between Gene Ontology (GO) functional annotations and consequently estimate functional distances between protein domains. To evaluate accuracy, we correlate the functional distance to the well established measures of sequence, structural, and phylogenetic similarities. Finally, we show that manual classification of structures into folds and superfamilies is mirrored by proximity in the newly defined function space. We show how functional distances place structure-function relationships in biological context resulting in insight into divergent and convergent evolution. The methods and results in this paper can be readily generalized and applied to a wide array of biologically relevant investigations, such as accuracy of annotation transference, the relationship between sequence, structure, and function, or coherence of expression modules. 相似文献
28.
Anurag Sharma 《Health care management science》2009,12(1):38-55
This paper empirically investigates the resource distribution dynamics across Diagnosis Related Groups (DRGs) of elective
surgery patients, in a continuing Prospective Payment System (PPS). Existing econometric literature has mainly focussed on
the impact of PPS on average Length of Stay (LOS) concluding that the average LOS has declined post PPS. There is little literature
on the distribution of this decline across DRGs, in a PPS. The present paper helps fill this gap. It models the evolution over time of the empirical
distribution of LOS across DRGs. The empirical distributions are estimated using a non parametric “stochastic kernel approach”
based on Markov Chain theory. The results for inlier episodes suggest that resource redistribution will increase capacity
and expected number of admissions for DRGs having increasing waiting times. In addition, adjustments in relative cost weights
are perceived as price signals by hospitals leading to a change in their casemix. The results for high outlier patients reveal
that improved quality of care is one of the factors causing reduction in high outlier episodes.
相似文献
Anurag SharmaEmail: |
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