大桑菊合剂的提取工艺研究

目的:大桑菊合剂为医院制剂,由桑叶、菊花、薄荷、连翘、鱼腥草等中药经乙醇提取制成,为完善大桑菊合剂的制备工艺,对该制剂的制备工艺进行初步的研究。方法:①实验设计:以加水量、提取时间、提取次数和醇沉浓度为考察因素,各因素均取3水平,采用正交试验L(934)优选制备工艺。②含量测定方法:以大桑菊饮合剂中总黄酮的含量为指标,以芦丁为标准品,利用紫外分光光度计于503nm下测定吸光值,计算样品中总黄酮的含量,以此作为筛选大桑菊合剂最佳制备工艺的重要指标。结果:最佳制备工艺为不浸泡,加8倍水,提取3次,每次1小时。结论:经正交设计优化的大桑菊合剂的中药制备工艺合理、可行。     

蛋白质聚集的三种途径和控制策略

蛋白质聚集在生物医药生产中是一个关键问题。在蛋白质的生产、运输和储存的过程中,多种因素都能导致蛋白质发生聚集。随着对蛋白质聚集这一现象的深入研究,发现蛋白质聚集的产生存在不同途径和各种影响因素,如理化因素、翻译修饰和蛋白质结构等。由于蛋白质的聚集对于蛋白质的活性和均一性具有重大影响,因此了解蛋白质聚集的途径以及研究如何控制聚集对获得均质蛋白是十分有意义的。本文主要阐述了3D结构域交换、盐桥的形成、氧化应激3种蛋白质的聚集途径,以及在蛋白质生产、运输、储存过程中控制蛋白质聚集的方法,这有助于减少由于蛋白质聚集体形成而造成的损失,并提高实验研究和商业生产中的蛋白质纯度和均质性。     

Identifying the environmental factors that determine the genetic structure of populations

The study of population genetic structure is a fundamental problem in population biology because it helps us obtain a deeper understanding of the evolutionary process. One of the issues most assiduously studied in this context is the assessment of the relative importance of environmental factors (geographic distance, language, temperature, altitude, etc.) on the genetic structure of populations. The most widely used method to address this question is the multivariate Mantel test, a nonparametric method that calculates a correlation coefficient between a dependent matrix of pairwise population genetic distances and one or more independent matrices of environmental differences. Here we present a hierarchical Bayesian method that estimates F(ST) values for each local population and relates them to environmental factors using a generalized linear model. The method is demonstrated by applying it to two data sets, a data set for a population of the argan tree and a human data set comprising 51 populations distributed worldwide. We also carry out a simulation study to investigate the performance of the method and find that it can correctly identify the factors that play a role in the structuring of genetic diversity under a wide range of scenarios.     

Modes of Explanation in Anthropological Population Theory: Biological Determinism vs. Self-Regulation in Studies of Population Growth in Third World Countries

Anthropological theories of population growth in underdeveloped countries are considered and it is argued that most studies have concentrated exclusively on either deterministic or self-regulatory factors in population growth without regard to their probable interaction. A research strategy is proposed in which self-regulatory factors, especially the decision-making activities of individual parents, provide a primary focus of study but with careful attention to deterministic factors which constrain and influence the decision process . [population, underdevelopment, biology and self-regulation in population theory]     

Eukaryotic translation initiation factor 4E (eIF4E) expression in the brain tissue is induced by infusion of nerve growth factor into the mouse cisterna magnum: an in vivo study

In many cell types translation can be regulated by an expression of the translation initiation factor. Eukaryotic translation initiation factor eIF4E, which binds to the 5′ cap structure of mRNA, plays an important role in translation regulation and it has been suggested that it is implicated in increased protein synthesis promoted by growth factors. In this study the effects of nerve growth factor (NGF) infusion into the cerebrospinal fluid (CSF) on eIF4E expression and phosphorylation in mouse brain tissue have been investigated. We investigated NGF as it is one of the most important growth factors and it is an important factor in cerebral cortical development, stimulating neuronal precursor proliferation. eIF4E level is also increased in response to infusion of NGF into the CSF. The present study shows that eIF4E is phosphorylated in the brain tissues treated with NGF. It is concluded that NGF regulates protein synthesis in the nervous tissue by enhancing expression and phosphorylation of eIF4E.     

Mechanisms of repression and derepression of artificial transformation of pigmented epithelium into retina inXenopus laevis

Summary The present study shows that pigmented epithelium of tadpoles and adult frogs ofXenopus laevis, like that of the other Anurans and the Cyprinid fishes, cannot transform into retina without the action of retinal factors. Transformation of pigmented epithelium into retina occurs when a sheet of it is implanted into the lensless eye. Transformation of pigmented epithelium also occurs when a sheet of it is wrapped in Bruch's membrane of the adult frog and afterwards implanted into a lensless eye, thus suggesting that Bruch's membrane is permeable to the inducing factors. Bruch's membrane was shown to play a polarizing role in the newly formed retina. Artificial transformation is based on a mechanism involving both the elimination of the repressive action of membranes adjacent to pigmented epithelium and the influence of retinal factors.     

Economics of the lemon industry

Contrary to most articles in this periodical, this one is not a study in economic botany but in agricultural economics. As such, it is concerned primarily with business factors and only incidentally with lemon products.     

Mutation modulating activity in human serum factors induced after parabolic flight

We have reported that human interferon, one of cytokines present in serum, can confer hypomutability on various human cells. On the contrary, we have also reported that serum factors from cancer patients can enhance cell mutability. Therefore, it seems likely that cell mutability is changed by cytokine-like serum factors in our body. It is one of important space problems whether the mutability of human cells is regulated in response to microgravity and hypergravity (gravitational stress). However, there is little information about cell mutability during such stress. In this study, we investigated whether the mutability is changed by exposing cells to human serum factors after gravitational stress.     

MATCHING THE SHAPE OF TIME-INTENSITY CURVES1

Time-Intensity Curves are often summarized by average curves. From these curves TI-parameters are inferred. In this paper a different method is proposed in which the shape of the curves is the central concept. Isotropic scaling factors are computed for each curve. These factors can be tabled and inspected. Often a large number of scaling factors will be computed, which makes it hard to study them in a table. In such cases they can be represented in a plot, for which in this paper PCA is suggested. In this plot a structure in the scaling factors for the different TI-curves may become visible. It is also possible to make a plot in which the homogeneity of the panel of subjects can be studied.     

灵长类相互理毛的影响因素、功能及其利益分析

理毛行为是动物行为学研究的主要内容之一,根据理毛的对象可分为自我理毛(Autogrooming)和相互理毛(Allogrooming),其中相互理毛是灵长类重要的社会行为。现在认为相互理毛可能与社会参量(亲缘关系、性别、年龄、等级制度、繁殖状况等)有联系,并且有一定的社会功能。本文论述了理毛行为的分类、影响相互理毛的因素、相互理毛功能假说及其相互理毛的投入-收益分析,以便人们对相互理毛的行为进行更深入的研究。     

"Closing-in" phenomenon in Alzheimer's disease and subcortical vascular dementia

Background  

The 'closing-in' phenomenon is defined as a tendency to close in on a model while copying it. This is one of several constructional apraxia observed in dementia, particularly in Alzheimer's disease (AD). The aim of this study was to investigate the usefulness of it in the differential diagnosis of AD and subcortical vascular dementia (SVD) and to clarify the factors associated with it.     

Possible virulence factors of Staphylococcus sciuri

Staphylococcus sciuri is an opportunistic pathogen of controversial clinical significance. The factors that contribute to colonization and/or infection caused by this bacterium have not been studied intensively so far. The present research was carried out in order to study the presence of potential virulence factors in 121 human and animal isolates of this bacterium. Isolates were examined for biofilm formation, hemagglutination, presence of clumping factor, production of spreading factors and exotoxins, cytotoxicity and capacity to stimulate nitric oxide production. The results showed that S. sciuri is highly capable of biofilm production, that it displays strong proteolytic and DNase activities, produces hemolysins and stimulates nitric oxide production by rat macrophages. Although the present study showed existence of a wide spectrum of possible virulence determinants of S. sciuri, their exact contribution to virulence of this bacterium in vivo remains to be determined.     

Parametric analysis of a novel semi-circular microfluidic CD-ELISA valve

CD-ELISA uses the microfluidic ranking method and centrifugal force to control the testing solution as it flows into the reaction region. The most challenging part of CD-ELISA is controlling the flow process for different biological testing solutions, i.e. the controlling sequence for the microfluidic channel valves. The microfluidic channel valve is therefore the most important fluid channel structure for CD-ELISA. In this study, we propose a valve design suitable for a wide range rotational speeds which can be applied for mass production (molding). Together with supporting experiments, simulation based on two-phase flow theory is used in this study, and the feasibility of this novel valve design is confirmed. Influencing design factors for the microfluidic channel valves in CD-ELISA are investigated, including various shapes of the arc, distance d, radius r, the location of the center of the circle, and the contact angle. From both the experimental results and the simulated results, it is evident that the narrowest channel width and the contact angle are the primary factors influencing valve burst frequency. These can be used as the main controlling factors during the design.     

A review of the use of uncertainty factors in the health risk assessment of some metals

Because metals can produce health risks, standards for regulating metal exposure are necessary. The purpose of this chapter is to review the application of uncertainty factors to mercury, arsenic, and cadmium. By the conventional method, uncertainty factors are often applied to animal studies to establish the reference dose (RfD) in humans. However, with the availability of a better database from improved study designs, it was demonstrated that uncertainty factors can be decreased. Incorporation of more pharmacokinetic and mechanistic data into the risk assessment process, as well as discussions between risk assessors and the research community to identify research needs are essential in reducing uncertainty factors.     

A two years' survey of the potato aphides in the Northern Agricultural Advisory Province

The role of aphis vectors in the deterioration of potato stocks is well known, and any effort to maintain healthy (virus-free) stocks of potatoes depends on the degree of their isolation from these vectors. In practice this isolation depends on geographical, climatic, and biological factors; of these the biological factors are fundamental, as it is only from their study that the significant geographical and climatic factors can be determined.
The present work consists of a survey made during 1942 and 1943, in the Northern Agricultural Advisory Province. Special attention is paid to overwintering, and the prevailing weather conditions at the time of the spring migration.     

Causes of biological differences among social classes

The following research attempts to find biological differences among social classes is of interest, because it paves the way for practical applications and differs from the usual I.Q. polemics. In addition to well-known socio-cultural factors, this study provides a proof of the inhibitory effects of four other factors: matrimonial choices, consanguinity, natal prematurity and perturbations in growth rhythm, all of which are found more frequently in certain social classes.     

Framing pictures: A conceptual framework to identify and correct for biases in detection probability of camera traps enabling multi‐species comparison

Obtaining reliable species observations is of great importance in animal ecology and wildlife conservation. An increasing number of studies use camera traps (CTs) to study wildlife communities, and an increasing effort is made to make better use and reuse of the large amounts of data that are produced. It is in these circumstances that it becomes paramount to correct for the species‐ and study‐specific variation in imperfect detection within CTs. We reviewed the literature and used our own experience to compile a list of factors that affect CT detection of animals. We did this within a conceptual framework of six distinct scales separating out the influences of (a) animal characteristics, (b) CT specifications, (c) CT set‐up protocols, and (d) environmental variables. We identified 40 factors that can potentially influence the detection of animals by CTs at these six scales. Many of these factors were related to only a few overarching parameters. Most of the animal characteristics scale with body mass and diet type, and most environmental characteristics differ with season or latitude such that remote sensing products like NDVI could be used as a proxy index to capture this variation. Factors that influence detection at the microsite and camera scales are probably the most important in determining CT detection of animals. The type of study and specific research question will determine which factors should be corrected. Corrections can be done by directly adjusting the CT metric of interest or by using covariates in a statistical framework. Our conceptual framework can be used to design better CT studies and help when analyzing CT data. Furthermore, it provides an overview of which factors should be reported in CT studies to make them repeatable, comparable, and their data reusable. This should greatly improve the possibilities for global scale analyses of (reused) CT data.