单参数对称广义特征值问题重特征值的灵敏度分析

研究了解析依赖于单参数的对称广义特征值问题重特征值的灵敏度分析，证明了重特征值及其相应特征向量的解析性，给出了特征值一阶导数的表达式，并以数值算例验证了所给结论的正确性。     

半夏采收加工标准探讨

目的:为制定半夏采收加工标准提供参考。方法:产地调查和实验室工作相结合。结果:半夏采收最佳时间应为秋分。鲜半夏块茎直径在1．2 cm以上的允许用来加工药材,鲜半夏块茎直径在1．2 cm以下的只能用来作繁殖材料。半夏药材含水量应控制在11％-13％。结论:半夏采收加工最佳时间应为秋分。     

阴道加德纳菌感染与男性不育的相关性研究

目的探讨精液中阴道加德纳菌(Gv)感染与男性不育的关系。方法采用套式PCR术进行Gv检测并与精液参数、精液白细胞含量、AsAb进行相关分析;383例男性不育就诊者精液中检出Gv阳性者设为阳性组;精液Gv阴性者设为阴性组。结果就诊者精液中检出Gv阳性者86例,阳性组精子密度、精子活率、a b活力、低渗肿胀率明显低于阴性组(P<0.05);而阳性组精子畸形率、精液pH值,白细胞精液症检出率、AsAb阳性率明显高于阴性组(P<0.05,P<0.01);两组精液量、精液黏度增高率差异无显著性(P>0.05)。结论精液中Gv感染可影响精液质量,是男性不育的重要原因之一。     

Motor planning: effect of directional uncertainty with discrete spatial cues

We investigated the effect of spatial uncertainty on motor planning by using the cueing method in a reaching task (experiment 1). Discrete spatial cues indicated the different locations in which the target could be presented. The number of cues as well as their direction changed from trial to trial. We tested the adequacy of two models of motor planning to account for the data. The switching model assumes that only one motor response can be planned at a time, whereas the capacity-sharing model assumes that multiple motor responses can be planned in parallel. Both models predict the same relation between average reaction time (RT) and number of cues, but they differ in their prediction of the shape of the distribution of the reaction time. The results showed that RT increased with the number of cues independently from their spatial dispersion. This relation was well described by the function predicted by both models, whereas it was poorly described by the Hick-Hyman law. In addition, the distribution of RT conformed to the prediction of the capacity-sharing model and not to that of the switching model. We investigated the role that the requirement of a spatially directed motor response might have had on this pattern of results by testing subjects in a simple RT task (experiment 2) with the same cueing presentation as in experiment 1. The results contrasted with those in experiment 1 and showed that RT was dependent on the spatial dispersion of the cues and not on their number. The results of the two experiments suggest that the mode of processing of potential targets is dependent on the spatial constraints of the task. The processing resources can be either divided relative to the spatial distribution of possible targets or across multiple independent discrete representations of these targets. Electronic Publication     

Short-term mobilization of processing resources is revealed in the event-related potential

This study investigates whether an occasional effortful improvement of performance, as asked for by a precue, is reflected in event-related potential (ERP) changes. To estimate the limits of possible effort-induced behavioral and ERP changes, we manipulated the time between precue and imperative stimulus (IS; precue interval, PCI). The subjects could, in fact, improve their performance in the effort trials, with all but the shortest PCI. The postcue ERP revealed a fronto-central contingent negative variation (CNV), which was preceded by a frontal positive/occipital negative wave (P2/N2). Both the P2/N2 and the CNV were larger for effort than for standard trials for all PCIs. For the shortest PCI (300 ms), the CNV increase was seen after the IS. The CNV increase for PCIs 600 and 300 began at about 400 ms postcue. The results suggest that effortful performance improvement is associated with prior increase of a frontocentral CNV and a preceding P2/N2. The CNV increase is thought to reflect the activity of a frontal executive process by which additional processing resources can be mobilized on a trial-to-trial basis within less than 500 ms.     

A Robust Time-Varying Identification Algorithm Using Basis Functions

We extend a recently developed time invariant (TIV) model order search criterion named the optimal parameter search algorithm (OPS) for identification of time varying (TV) autoregressive (AR) and autoregressive moving average (ARMA) models. Using the TV algorithm is facilitated by the fact that expanding each TV coefficient onto a finite set of basis sequences permits TV parameters to become TIV. Taking advantage of this TIV feature of expansion parameters exploits the features of the OPS, which has been shown to provide accurate model order selection as well as extraction of only the significant model terms. Another advantage of the new algorithm is its ability to discriminate insignificant basis sequences thereby reducing the number of expansion parameters to be estimated. Due to these features, the resulting algorithm can accurately estimate TV AR or ARMA models and determine their orders. Indeed, comparison via computer simulations of AR models between the proposed method and one of the well-known iterative methods, recursive least squares, shows the greater capability of the new method to track TV parameters. Furthermore, application of the new method to experimentally obtained renal blood flow signals shows that the new method provides higher-resolution time-varying spectral capability than does the short-time Fourier transform (STFT), concomitant with fewer spurious frequency peaks than obtained with the STFT spectrogram. © 2003 Biomedical Engineering Society. PAC2003: 8710+e, 8719Uv, 8780Tq     

On-line parameter identification of systemic circulation using the delta operator

To develop effective medical care with the artificial heart, we propose a new method, on-line parameter identification of the systemic circulation using the delta operator which can calculate the time-varying and unmeasured hemodynamics of the internal human body from some measured data: aortic pressure and total flow in real time. This method consists of first, a dynamic physiological model which is configured with the physiological parameters Ca (aortic compliance) and Rp (total peripheral resistance); and second, a system identification method using the delta operator. In the computer simulation study, we could confirm the effectiveness to identify the physiological parameters. In animal experiments with a left ventricular assist system, the physiological parameters, Ca = 1.8 (ml/mm Hg) and Rp = 0.8 (mm Hg s/ml), could be identified on-line.     

补肾壮骨颗粒的最佳成型处方筛选

以不同辅料与补肾壮骨方提取的稠膏按不同比例配伍制成药粉及颗粒后，以颗粒剂的制剂学参数为指标，筛出了补肾壮骨颗粒的最佳成型处方组成。并为成型及分装车间控制相对湿度提供了理论依据。     

蔓荆子古今炮制药用研究

经古今３０余篇中医药文献著作考证，蔓荆子历代炮制方法有酒蒸、酒炒、清炒等，其中炒制沿用至今。蔓荆子古代以生用为主，现代以炒制为众，并有炒焦、炒炭、微炒，不同炒制程度要求，微炒、炒焦居多，炒炭入药自古较少，蔓荆子临床应用范围颇为广泛     

不同地黄炮制品对增液汤的药效影响

目的比较地黄不同炮制品组方的增液汤在“润肠通便”方面的药效差异，筛选出临床用于“津亏便秘症”的增液汤中所用地黄的炮制品种。方法采用小鼠炭末推进试验和小鼠肠容量试验的模型及相关指标进行筛选研究。结果地黄4种炮制品所组成的增液汤在促进肠蠕动、增加肠容量之药效与空白对照组比较都具有著著性差异，但各给药组之间没有显著性差异；熟地黄和酒地黄在药效方面的作用，有强于其他两种地黄组方的趋势。结论以熟地黄或酒地黄用于治疗“津亏便秘症”的增液汤组方效果尤佳，可予以推荐应用。