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1.
草履虫的运动与摄食   总被引:2,自引:0,他引:2  
描述了草履虫的形态结构及不同细胞器的主要功能,进而结合示意图详细叙述了草履虫是如何进行运动和摄食的.  相似文献   

2.
在病理技术工作中,组织固定是最基础,也是最关键的步骤。因固定不当造成切片困难、着色不良而延误诊断,严重影响临床治疗。我科通过长期实践对固定液进行改良,收到满意效果。材料和方法1.组织来源日常送检淋巴结、诊刮的子宫内膜、子宫肌瘤组织各60例,每一实验组20例。2.固定液  相似文献   

3.
本文利用激光扫描共聚焦显微技术(Laserscanningconfocalmicroscopy,LSCM)对大草履虫(Parameciumcaudatum)口胞器及消化胞器进行了再观察,通过连续断层扫描和三维重建技术,清晰地显示出草履虫口胞器中前庭、口腔、内口膜、四分膜、背咽膜、腹咽膜等结构,它们的位置和形态与前人的工作结果基本一致,并给出口胞器结构的三维立体构象。观察了虫体内的食物泡及其形成过程。看到胞咽在摄食并形成食物泡时其直径变大的现象,表明Allen(1974)有关消化后期食物泡产生的微小泡回到胞咽处与胞咽膜融合的时间应该是在胞咽直径扩大时,此时微小泡参与到胞咽膜上,进而再参与到新食物泡膜的形成过程中,由此完成膜的循环再利用。在样品制备中采用KMnO4替代了免疫荧光技术中传统的固定剂,固定效果很好,清楚地显示了胞咽膜、纤毛以及食物泡膜的结构  相似文献   

4.
本研究对传统的骨折内固定材料进行了分析,对其存在的问题进行了总结。提出了利用复合材料之间可以取长补短的优势来克服单纯的聚乳酸材料所存在的问题这一研究设想。本研究通过在聚乳酸中加入少量的β-磷酸三钙,使二者之间达到有机的结合,以得到一种新的性能优异的复合骨折内固定材料。对研究结果的分析表明所得到的复合材料能基本满足骨折内固定的要求。  相似文献   

5.
通过对安徽省6家不同所有制、不同规模、不同经营方式的药品流通企业的实地调研,了解药品流通企业及药品配送工作的基本情况,剖析了药品招标配送中存在的问题,对实施药品集中招标采购配送工作提出政策建议。  相似文献   

6.
植物原生质体的制备与活力检测研究进展   总被引:3,自引:0,他引:3  
原生质体是进行植物遗传改良和细胞各种生理生化特性研究的平台.本文对近些年制备原生质体的材料选择、预处理、游离、纯化和活力检测等方面的研究进展进行了综述,分析了影响原生质体的分离和纯化的有关因素,并根据相关文献讨论了今后原生质体重点研究方向.  相似文献   

7.
本文介绍一种简便快捷提纯猪生长激素的方法。通过杂交瘤技术,首次获得抗猪生长激素的单克隆抗体,并讨论和比较从腹水纯化单克隆抗体的各种方法。  相似文献   

8.
为利用基因工程技术获得重组Maxadilan(RMMAX), 根据Maxadilan的氨基酸序列, 设计并人工合成了在原核表达的基因。克隆到表达载体pKYB, 重组质粒pKYB-MAX转化表达宿主菌Escherichia coli strain ER2566, 构建表达工程菌。用诱导剂IPTG诱导由目的多肽、内含肽和几丁质结合域(Chitin binding domain, CBD)组成的“三元”融合蛋白表达; 用几丁质珠亲和层析纯化了裂解液中的融合蛋白, 用b-巯基乙醇切割融合蛋白, 获得目的蛋白。所得的多肽经激光飞行质谱测定分子量结果与理论值相符, 生物活性分析表明, 重组Maxadilan有显著的提升血糖的作用。  相似文献   

9.
目的:从手足口病的管理探讨医院对传染病的归口管理与集中收治的相关问题.方法:2011年9月至2012年6月期间,共收治传染624例,占所有就诊患者的3.6%,其中手足口病患者66例,占所有传染病患者的10.58%,占所有就诊患者的3.81‰.积极相应我地区卫生管理部门的号召,召开全体员工大会,从思想上保证所有成员都全身心地投入到防止工作中去.根据卫生部门的相关要求,学校及幼儿园、车站、码头等人流密集地区也安排专业的医疗人员对过往行人进行检查,一旦发现疑似及确诊为手足口病的患者则马上加以隔离,并进行相关治疗.结果:经4-12周的治疗,所有患者均符合临床痊愈的标准,手足口病的传染源也得到了有效的控制.除此之外,本地未见其他手足口病被传染患者.结论:要健全并完善传染病的归口管理和集中收治体系,必须从法律、行政及执行多个层面共同入手,提升整个社会对于传染病的防范意识和救治能力,进而保证社会和谐化发展,人民的健康得到有效的保障.  相似文献   

10.
护士规范化培训是指在完成医学院校基础教育后,接受规范的护理专业培训[1].新毕业护士规范化培训是现代医学发展的要求,是护理人才选拔和培养的基础,也是病人安全和舒适的保证[2].  相似文献   

11.
Summary The combination of using15N for determining the amount of nitrogen fixed by a legume crop in field experiments and the labelling of only one treatment at a time in each treatment combination is shown to be conceptually and experimentally valid for determining the effect of cultural practices on the amount of nitrogen fixed by a legume crop.  相似文献   

12.
Workflows in urinary proteomics studies are often complex and require many steps to enrich, purify, deplete, and separate the complex mixture. Many of these methods are laborious, are time-consuming, and have the potential for error. Although individual steps of these methods have been previously studied, their downstream compatibilities with fractionation technologies such as off-gel electrophoresis have not been investigated. We developed a one-step sample preparation workflow that simultaneously (i) concentrates proteins, (ii) purifies by removing salts and other low molecular weight compounds, and (iii) depletes (albumin) from urine samples. This simple and robust workflow can be multiplexed and is compatible with a diverse range of downstream multidimensional separation technologies. Additionally, because of its high reproducibility and flexibility in processing samples with different volumes and concentrations, it has the potential to be used for standardization of urinary proteomics studies, as well as for studying other body fluids of similar complexity.  相似文献   

13.
A simple method for rapid evaluation of bull and ram sperm concentration is described. In this technique, a sample from an undiluted specimen was placed in a special 10-mum counting chamber and examined either by an ordinary or a phase-contrast microscope. The pattern distribution of the observed spermatozoa was matched as closely as possible with one of five pictures of a standard scale. This scale was prepared from serial photomicrographs that ranged from 100 to 1500 million per ml. The number that appeared at the corresponding photograph immediately indicated the sperm concentration of the tested specimen. In this way values up to 1500 million per ml could be determined rapidly with no further procedures. More concentrated specimens needed slight dilution to make them suitable for direct evaluation. Accuracy and reliability were statistically evaluated; the mean deviation from the conventional method was less than 15.2% with confidence level of 95%.  相似文献   

14.
A new method for obtaining Anabaena-free Azolla   总被引:1,自引:1,他引:0  
  相似文献   

15.
16.
Scientists often need to test hypotheses and construct corresponding confidence intervals. In designing a study to test a particular null hypothesis, traditional methods lead to a sample size large enough to provide sufficient statistical power. In contrast, traditional methods based on constructing a confidence interval lead to a sample size likely to control the width of the interval. With either approach, a sample size so large as to waste resources or introduce ethical concerns is undesirable. This work was motivated by the concern that existing sample size methods often make it difficult for scientists to achieve their actual goals. We focus on situations which involve a fixed, unknown scalar parameter representing the true state of nature. The width of the confidence interval is defined as the difference between the (random) upper and lower bounds. An event width is said to occur if the observed confidence interval width is less than a fixed constant chosen a priori. An event validity is said to occur if the parameter of interest is contained between the observed upper and lower confidence interval bounds. An event rejection is said to occur if the confidence interval excludes the null value of the parameter. In our opinion, scientists often implicitly seek to have all three occur: width, validity, and rejection. New results illustrate that neglecting rejection or width (and less so validity) often provides a sample size with a low probability of the simultaneous occurrence of all three events. We recommend considering all three events simultaneously when choosing a criterion for determining a sample size. We provide new theoretical results for any scalar (mean) parameter in a general linear model with Gaussian errors and fixed predictors. Convenient computational forms are included, as well as numerical examples to illustrate our methods.  相似文献   

17.
JINLIANG WANG 《Molecular ecology》2009,18(10):2148-2164
Equations for the effective size ( Ne ) of a population were derived in terms of the frequencies of a pair of offspring taken at random from the population being sibs sharing the same one or two parents. Based on these equations, a novel method (called sibship assignment method) was proposed to infer Ne from the sibship frequencies estimated from a sibship assignment analysis, using the multilocus genotypes of a sample of offspring taken at random from a single cohort in a population. Comparative analyses of extensive simulated data and some empirical data clearly demonstrated that the sibship assignment method is much more accurate [measured by the root mean squared error, RMSE, of 1/(2 Ne )] than other methods such as the heterozygote excess method, the linkage disequilibrium method, and the temporal method. The RMSE of 1/(2 Ne ) from the sibship assignment method is typically a small fraction of that from other methods. The new method is also more general and flexible than other methods. It can be applied to populations with nonoverlapping generations of both diploid and haplodiploid species under random or nonrandom mating, using either codominant or dominant markers. It can also be applied to the estimation of Ne for a subpopulation with immigration. With some modification, it could be applied to monoecious diploid populations with self-fertilization, and to populations with overlapping generations.  相似文献   

18.
A fully automated liquid chromatographic method was developed for the determination of Ro 28-2653, a new synthetic inhibitor of matrix metalloproteinases (MMPs), in ovine serum and plasma. The method was based on the coupling of a pre-column packed with restricted access material, namely LiChrospher RP-8 ADS (alkyl diol silica), for sample clean-up to an analytical column containing octyl silica stationary phase. One hundred microl of biological sample, to which 2-propanol was automatically added, were injected onto the ADS pre-column, which was then washed with a washing liquid consisting of a mixture of 25 mM phosphate buffer (pH 7.0) and acetonitrile (90:10; v/v) for 10 min. By rotation of the switching valve, the analyte was then eluted in the back-flush mode with the LC mobile phase composed of a mixture of acetonitrile and 25 mM phosphate buffer (pH 7.0) (57:43; v/v). The UV detection was performed at 395 nm. The main parameters likely to influence the sample preparation technique were investigated. The method was then validated over a concentration range from 17.5 to 1950 ng/ml, the first concentration level corresponding to the lower limit of quantitation. At this concentration level, the mean bias and the R.S.D. value for intermediate precision were -2.4% and 4.2%, respectively.  相似文献   

19.
In many cases before a protein sample can be subjected to analysis by gel filtration, electrophoresis, or immunoelectrophoresis, concentration may be necessary. Some of the commonly used techniques for sample concentration are adsorption on columns, ultrafiltration through cellophane membranes, evaporation of water, absorption by hydrophilic gels, precipitation by salts or organic solvents, and rechromatography. Except for evaporation, all of the other procedures are practical only when the sample size exceeds a few milliliters. Although there is no lower limit on the sample size when evaporation is employed, the resulting increase in salt concentration of the final product is a problem.In this communication we describe a simple technique that is capable of concentrating, severalfold, samples of proteins 25–250 μl in volume. The technique is based on the same principle as ultrafiltration through cellophane membranes.  相似文献   

20.
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