Antioxidant and Prooxidant Effects of Metal Dafonates on the NADPH-Dependent Lipid Peroxidation in the Murine Hepatic Microsomal System

Dafone inhibits the lipid peroxidation significantly in a concentration dependent manner. The inhibition was found to be an uncompetitive type with the inhibition constant (Ki) of 62.5muM On the other hand complexation with metal ions results in a significant reversal from antioxidant to pro-oxidant properties for the resulting complexes which are cationic and with associated halometallate anions. The nature of the potentiation in case of the ferric compound was of competitive type with activation constant (Ka) having the value 32.5muM. The neutral copper-dafonate complex, however, inhibits lipid peroxidation with increase in concentration.     

YAG激光治疗慢性鼻炎264例疗效观察

慢性鼻炎,临床上常见的有:①慢性单纯性鼻炎,②慢性肥厚性鼻炎,③变应性鼻炎,门诊率高,药物及其他治疗,疗效不佳。有些患者,由于严重鼻塞,流涕,头昏,头痛,影响正常工作和学习,不得不进行手术治疗。二年来,我院对各种慢性鼻炎采取了YAG激光治疗,,取得为较了满意的效果。     

新一代CAD／CAM集成系统的探讨

论述了新一代的ＣＡＤ／ＣＡＭ集成系统应具备的特点及实现的关键技术，并提出了一个系统结构的设想，为系统的具体实现提供了有力的支持     

The direct measurement of embryogenic volume and nucleo-cytoplasmic ratio during mouse pre-implantation development

Stringent selection mechanisms, in both internal and external fertilisation systems, reject all but a significant minority of the spermatozoa released at ejaculation. Sperm competition theory provides circumstantial evidence that the selection process involves mechanisms by which the quality of the fertilising spermatozoon is controlled, thereby ensuring that females and their offspring receive high quality genetic material. In this review we examine some of these selection processes to see whether they could be exploited for the improvement of laboratory tests of sperm quality. Such tests are not only required for clinical and agricultural purposes, but are increasingly needed in fields such as reproductive and environmental toxicology where the species requirement is much broader. Despite many years of research, sperm quality assessment methods continue to provide imprecise data about fertility; here we suggest that this may be a consequence of using tests that focus on the spermatozoa that would normally be unable to fertilise under natural conditions. To achieve fertilisation a spermatozoon must be capable of responding appropriately to external signalling stimuli; those involving protein kinase-regulated flagellar function seem especially influential in governing effects ranging from non-Mendelian inheritance in mammals to sperm chemotaxis in sea urchins. Examination of the elicited responses reveals considerable heterogeneity in all species. Here we propose that this level of heterogeneity is meaningful both in terms of understanding how spermatozoa from some individuals possess fertility advantages over spermatozoa from their rivals in sperm competition, and in that the heterogeneity should be exploitable in the development of more accurate laboratory tests.     

Verification of point-spread-function-based modeling of an extreme-ultraviolet photoresist

A crucial component of lithographic modeling is the resist. Resists typically used at extreme-ultraviolet (EUV) wavelengths are derivatives of deep-ultraviolet chemically amplified resists. Models that describe these resists are often very complicated and are dependent on a large number of free parameters. Point-spread-function-based resist modeling serves as a simple alternative. I show this type of modeling to be a viable technique at EUV wavelengths by directly comparing modeling results with a variety of printing metrics, including process windows and isodense bias.     

Measurement of 40k as an indicator of body potassium: implication for diabetes and other disease conditions

Potassium (K) content in 408 male workers of a rare earths processing plant was estimated using a shadow shield whole body counter. The average K content in the non-vegetarian and vegetarian group was found to be 1.5 g kg(-1) and 2.1 g kg(-1) respectively. The absorbed dose due to 40K is determined as 0.18 +/- 0.02 mGy. While the K content was found to be proportional to body build index, it is inversely proportional to slenderness. Body K was maximum in the middle aged group (35-45 y) and a minimum in younger and older persons. The correlation of potassium content with some disease patterns was also studied. Diabetes mellitus patients were observed to have low K content of 0.9 +/- 0.2 g kg(-1) and those who suffer from cardiovascular disorders were found to have high K content 2.7 +/- 0.3 g kg(-1). The studies showed that the depletion of body K content takes place a few years prior to the clinical detection of diabetes and it builds up a few years before the clinical detection of cardiovascular disorders. It is stressed that the medical information is preliminary as the number of subjects studied was not very large. Wider and in depth study by various groups can hopefully strengthen the observation.     

Use of triethylcitrate plasticizer in the production of poly-L-lactic acid implants with different degradation times

Bioabsorbable materials have been widely used in the repair of damaged tissue as well as in the controlled release of drugs and as a supports for cultured cells. The degradation time of poly-L-(lactic acid) (PLLA) may be controlled by altering the polymer porosity through the addition of the plasticizer triethylcitrate. This in turn influences the extent cellular infiltration. In this study, we examined the degradation of PLLA membranes containing different concentrations of plasticizer. PLLA discs were implanted subcutaneouly in rats and withdrawn 2, 14 and 60 days after implantation. The samples were processed for light microscopy and scanning electron microscopy (SEM). Polymer degradation was proportional to the concentration of plasticizer, indicating that triethylcitrate could affect the degradation time of the implants, without damaging the polymer biocompatibility.     

Sampling properties of the spectrum and coherency of sequences of action potentials

The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This article begins with a review of these quantities, their interpretation, and how they may be estimated. A discussion of how to assess the statistical significance of features in these measures is included. In addition, new work is presented that builds on the framework established in the review section. This work investigates how the estimates and their error bars are modified by finite sample sizes. Finite sample corrections are derived based on a doubly stochastic inhomogeneous Poisson process model in which the rate functions are drawn from a low-variance gaussian process. It is found that in contrast to continuous processes, the variance of the estimators cannot be reduced by smoothing beyond a scale set by the number of point events in the interval. Alternatively, the degrees of freedom of the estimators can be thought of as bounded from above by the expected number of point events in the interval. Further new work describing and illustrating a method for detecting the presence of a line in a point process spectrum is also presented, corresponding to the detection of a periodic modulation of the underlying rate. This work demonstrates that a known statistical test, applicable to continuous processes, applies with little modification to point process spectra and is of utility in studying a point process driven by a continuous stimulus. Although the material discussed is of general applicability to point processes, attention will be confined to sequences of neuronal action potentials (spike trains), the motivation for this work.     

Analysis and characterization of photo-plethysmographic signal

Qualitative assessment of the overall clinical status of the subject and characterization of complex cardiovascular dynamics from digital blood volume pulsations measured noninvasively using a photo-plethysmographic device is addressed. A novel concept is employed to detect the dominant nonsinusoidal periodicity embedded in the data series and to extract the associated periodic component. The detection and the extraction of periodic component is performed with moving window to accommodate the variations of the physiological oscillations. The covariance matrix formed by the gradually varying pattern is used as a simple measure of qualitative assessment. Further, the characterization of the underlying system in the light of nonlinear dynamical analysis is also presented. The stable subjects are shown to behave as a low-dimensional system whereas the diseased subjects exhibit comparatively high dimensional activity.