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1.
A method for measuring K, the coefficient of thermal conductivity, for a variety of dog tissues is described. The values of K for muscle and liver are larger than that for water, the value of K for lung is smaller than that for water and the values of K for brain, plasma, and blood are about the same as that of water. The values found for K are given in a table.  相似文献   

2.
目的:探讨死胎的病因及终止妊娠的方式。方法:收集我院住院分娩的死胎病例23 例,对孕妇一般资料、死胎发生原因、终 止妊娠方式进行统计分析。结果:①死胎发生孕妇中,年龄>36 岁者最多,共8 例,占34.8%,孕周在28-36+6 周的孕妇数最多,共 10 例,占43.5%,初产妇17 例,占73.9%,有流产史孕妇9 例,占39.1%;②在所有病因中,脐带因素占比最大,共11 例,占47.8%, 其次为胎盘因素和母体因素,各5 例,各占21.7%,胎儿原因与不明原因各2 例,各占8.7%;③在对终止妊娠方式的选择上,施行 羊膜腔穿刺引产例数最多,共13 例,占56.5%,其次为剖宫产,共5 例,占21.7%,米索流产3 例,占13.0%,自娩患者2 例,占 8.7%。结论:脐带因素为造成死胎发生的主要原因,其次为胎盘因素及母体因素,应对孕妇进行全面的孕期检查及孕期健康教育, 以减少死胎的发生,并选择合适的终止妊娠方式以减轻孕妇痛苦。  相似文献   

3.
Biofuels composed by fatty acid methyl esters are widely used as partly substituting fuels for diesel fossil fuels. Additionally, it is expected that the diesel biofuel norms will be extended to ethyl esters produced from bioethanol in the upcoming years. A precise knowledge of the standard enthalpy of formation is necessary for the calculation of some parameters useful for the analysis of the combustion process and emissions of a diesel engine operating with different fuels, such as the heating value, the adiabatic flame temperature or the kinetic mechanisms. However, experimental data for this property are scarce, and only available for short-chain, saturated methyl esters. In this work, four estimation methods for the calculation of the enthalpy of formation are examined and compared. Three of them are simple methods based on groups or bonds contribution, and another one is a computational method (with Gaussian 03 software). After presenting the implementation rules for each of them, conclusions are stated based on the results attained. Gaussian and Benson-Groups methods seem to be more accurate in predicting the actual values of the enthalpy of formation, both methods considering the separation between double bonds and the edge effects in the molecule. However, only the Gaussian method considers the effect of the position of the double bond in the molecule for all the unsaturated esters.  相似文献   

4.
Population genetic characteristics were estimated in the Alatyr' raion (administrative district) of the Republic of Chuvashia, which has long been populated by three ethnic groups. The ethnic assortativeness values in the town of Alatyr' and the rural area of the district were 1.17 and 1.21, respectively, for Russians; 1.14 and 4.82, respectively, for Chuvashes; and 1.33 and 2.45, respectively, for Mordovians. Wright's statistics were as follows: Fst = 0.00358, Fit = 0.00178, and Fis = 0.00134. The migration indices were 0.0264 for Alatyr' and 0.0178 for the district. The endogamy indices for the total and the Russian populations of Alatyr' were 0.47 and 0.53, respectively. The parameters of isolation by distance were a = 0.000189 and b = 0.00959 for the urban and a = 0.000318 and b = 0.00919 for the rural area. Schemes of the genetic landscape were constructed. The influence of the polyethnic composition on the genetic structure of the population is discussed.  相似文献   

5.
The methods used for the sparing inactivation of highly concentrated R. prowazekii biomass and for the decrease of its infectious activity are described. These methods are recommended for use in experiments in the field of molecular biology, as well as for disinfection of different materials contaminated with rickettsiae. As conditions for complete inactivation, incubation at 50 degrees C for 1 hour without chemical disinfectants, treatment with 0.5% phenol solution at 30 degrees C for 12 hours and with 0.1% formaldehyde solution at 4 degrees C for 24 hours have been selected. Treatment with 0.5% phenol solution at 36 degrees C for 1 hour or incubation at 45 degrees C without the use of disinfectants ensures an essential decrease in the infectivity of the material if the work with viable infective agents is necessary. Ultraviolet irradiation for 1.5 hours and exposure to the action of 0.1-0.5% sodium azide are less effective.  相似文献   

6.
The EU Tissues and Cells Directive (2004/23/EC, 2006/17/EC, 2006/86/EC) (EUTCD) provides standards for quality and safety for all aspects of banking of tissues and cells for clinical applications. Commission Directive 2006/17/EC stipulates that the complete donor record with all the medical information is assessed for suitability before releasing tissues for clinical use. The aim of this study was to investigate the medical reasons for post-procurement donor exclusion, to identify the various potential sources for gathering information about donors’ medical and behavioural history and to evaluate their contribution to maximising the safety of donations. Information was collected from the Tissue Services (TS) records of 1000 consecutive deceased donors submitted to National Health Service Blood and Transplant (NHSBT) medical officers for authorisation for release for subsequent tissue processing and then for transplantation. Of the 1000 donors 60 (6%) were excluded because they did not fulfil the donor selection requirements of the EUTCD and NHSBT donor selection guidelines. The main reasons for medical exclusion were the presence of significant local or systemic infection in 32 donors (53% of those excluded for medical reasons) and a history of past or occult malignancy in 9 donors (15% of those excluded for medical reasons) which was not identified prior to procurement. The information leading to post-procurement exclusion was obtained from autopsy reports in 35 of the 60 excluded donors for medical reasons (58%) and from the general practitioner for 10 donors (17% of those excluded for medical reasons). In summary, careful evaluation of complete donor records reduces the potential risk of disease transmission by tissue allografts and ensures compliance with regulations and guidelines. The findings may lead to changes in donor selection policies with the aim of improving efficiency without compromising safety.  相似文献   

7.
D. S. Suh  T. Mukai 《Genetics》1991,127(3):545-552
Eight hundred second chromosomes were extracted from the Ishigakijima population, one of the southernmost populations of Drosophila melanogaster in Japan. Half of them were extracted in Native cytoplasm (P-type), and half in Foreign cytoplasm (M-type). Various population-genetic parameters, including the frequency of lethal-carrying second chromosomes (Q = 0.235 for the Native; 0.218 for the Foreign), the allelism rate of lethal second chromosome (Ic = 0.0217 for the Native; 0.0134 for the Foreign), the homozygous detrimental and lethal loads (D = 0.179 for the Native; 0.270 for the Foreign; L = 0.262 for the Native; 0.240 for the Foreign), the average degree of dominance of mildly deleterious mutations (?E = 0.244 for the Native; 0.208 for the Foreign), and the components of genetic variance for viability [additive (sigma A2) and dominance (sigma D2)](?igma A2 = 0.0187 for the Native; 0.0172 for the Foreign; ?igma D2 = 0.0005 for the Native; 0.0009 for the Foreign) were estimated. The data indicate that D was significantly larger and hE was significantly smaller in the Foreign cytoplasm. However, the estimates of additive and dominance variances were not significantly different between the two cytoplasms. The additive genetic variance for viability in the Ishigakijima population was greater than expected on the basis of mutation-selection balance confirming previous studies on papers of D. melanogaster in warm climates.  相似文献   

8.
三角梅属(Bougainvil lea)属于紫茉莉科(Nyctaginaceae), 有14个种。该文综述了三角梅属植物的生物学特性, 展望了该属植物在增进人类健康、丰富精神生活以及保护环境等方面的应用前景。三角梅属植物因其苞片的形态色彩以及植株形态的变化而具有独特的观赏价值。三角梅属植物不仅作为花卉备受关注, 近年来, 有关三角梅其它应用价值的研究使人们对其有了新的认识。从三角梅叶片中分离得到具有类胰岛素功能的松醇(D-pini tol )对替代胰岛素治疗糖尿病以及减轻胰岛素疗法带来的副作用具有重要意义。研究还表明, 三角梅叶片和根中至少含有2种抗病毒蛋白——BAPI和 Bouganin, 它们对于多种植物病毒具有不同程度的抑制作用。这些研究结果对于开发低毒高效的生物农药具有十分积极的意义。三角梅还是研究甜菜色素代谢的重要模式植物之一, 其甜菜色素的种类和含量之丰富为开发安全的天然食用色素开辟了广阔的前景。这些相关研究展示了三角梅作为资源植物的多元价值, 为进一步开发三角梅的观赏、医药、生物农药价值和作为天然食用色素以及发挥环境修复作用提供了充分的科学依据。  相似文献   

9.
The mode of action of aphidicolin on DNA synthesis catalysed by the DNA polymerase of Methanococcus vannielii is competitive for dCTP, noncompetitive for dATP, dGTP and dTTP and uncompetitive for activated DNA. The kinetic data are accounted for by a mechanism in which dCTP and aphidicolin compete for the dCTP-specific binding site on the DNA polymerase. The dissociation constant for the aphidicolin--DNA-polymerase complex is 0.04-0.07 microM. Similar modes of inhibition of DNA synthesis exist for DNA polymerase alpha of higher eucaryotes but not for eubacteria or viruses and suggests a close functional relationship between the DNA polymerase of eucaryotes and of the archaebacterium M. vannielii.  相似文献   

10.
【目的】蝗虫血细胞的研究以及不同血细胞类型间的演化关系,是蝗虫细胞免疫学的依据,也是防蝗治蝗的重要依据。【方法】本研究通过Wright-Giemsa对黑翅痂蝗Bryodema nigroptera Zheng血细胞进行了混合染色,并使用光学显微镜进行了观察。【结果】发现黑翅痂蝗血细胞包括原血胞、浆血胞、粒血胞、类绛色血细胞、囊血胞、脂血胞、蠕形细胞和巨核血细胞8种类型。【结论】在成虫体内,原血胞占细胞总数的1%,浆血胞占32.2%,粒血胞占57.3%,类绛色血细胞占1%,囊血胞占6%,脂血胞占1%,蠕形细胞占1%,巨核细胞占细胞总数的0.5%,粒血胞数量最多,巨核细胞最少。  相似文献   

11.
We propose Metropolis-Hastings sampling methods for estimating the exact conditional p-value for tests of goodness of fit of log-linear models for mortality rates and standardized mortality ratios. We focus on two-way tables, where the required conditional distribution is a multivariate noncentral hypergeometric distribution with known noncentrality parameter. Two examples are presented: a 2 x 3 table, where the exact results, obtained by enumeration, are available for comparison, and a 9 x 7 table, where Monte Carlo methods provide the only feasible approach for exact inference.  相似文献   

12.
Communality indices for rates of elongation of diaphyses of short bones of the hand were computed from serial data for children with Down syndrome, 7 to 14 years of age. Communalities were larger for adjacent than for nonadjacent bones and also larger for bones grouped in rows rather than rays of the hand. This pattern is similar to that reported for normal children. Communality indices for rates of diaphyseal elongation for girls with Down syndrome were lower than those of boys with Down syndrome and normal children.  相似文献   

13.
It is established that, for a Maxwellian plasma in a monochromatic pump field, the phenomenon of bifurcation of the degree of circular polarization of the field harmonics is of a universal nature. A general equation determining the thresholds for this phenomenon for arbitrary harmonics is derived, and a set of its solutions is presented for illustrative purposes.  相似文献   

14.
We model the recombination process of fungal systems via chromatid exchange in meiosis, which accounts for any type of bivalent configuration in a genetic interval in any specified order of genetic markers, for both random spore and tetrad data. First, a probability model framework is developed for two genes and then generalized for an arbitrary number of genes. Maximum likelihood estimators (MLEs) for both random and tetrad data are developed. It is shown that the MLE of recombination for tetrad data is uniformly more efficient over that from random spore data by a factor of at least 4 usually. The MLE for the generalized probability framework is computed using the expectation-maximization (EM) algorithm. Pearson's chi-squared statistic is computed as a measure of goodness of fit using a product-multinomial setup. We implement our model with genetic marker data on the whole genome of Neurospora crassa. Simulated annealing is used to search for the best order of genetic markers for each chromosome, and the goodness of fit value is evaluated for model assumptions. Inferred map orders are corroborated by genomic sequence, with the exception of linkage groups I, II, and V.  相似文献   

15.
KOLOTKIN, RONETTE L, SUSAN HEAD, ALAN BROOKHART. Construct validity of the Impact of Weight on Quality of Life questionnaire. The Impact of Weight on Quality of Life questionnaire (IWQOL) is a 74-item self-report, condition-specific instrument that (1) assesses the effect of weight on quality of life in eight key areas, and (2) may be used as a treatment outcome measure and/or an evaluation tool for healthcare policy makers and third-party payers. This study explores IWQOL construct validity and provides new information on internal consistency, treatment effects, and differences between men and women. IWQOL total scores correlated highly with other measures of overall quality of life, and subscale scores correlated well with counterparts in the assessment battery. Internal consistency estimates for the IWQOL scales generally were high. For the women, 4-week participants, and the total sample, pretreatment-posttreatment differences were significant for all IWQOL scales and total score. For men, treatment differences were significant for the total score and all subscales except for Work and Mobility. Treatment differences for 2-week participants were significant for all scales except for Work. Consistent with previous IWQOL study results, the Comfort With Food scale scores reflected more discomfort at posttreatment as compared with pretreatment. The IWQOL, already translated into French and Italian, currently is demonstrating clinical and research utility as a quality-of-life outcome measure for clinical trials of antiobesity drugs and surgical treatments for patients with obesity.  相似文献   

16.
The possibilities of using the DNA copies of different genes of influenza A virus for the detection of virus-specific RNa by molecular dot hybridization have been studied. High specificity and sensitivity of the RNA determination techniques have been demonstrated, as well as the efficacy of using DNA probes with the sequences of conservative genes (polymerase, nucleoprotein and matrix genes) for the detection of influenza A virus subtypes H1N1, H2N2, H3N2 and probes with the copies of the corresponding hemagglutinin genes for the differential determination of subtypes H3N2 and H1N1. The complex analysis of nasopharyngeal washings has confirmed the efficacy of the dot hybridization method for epidemiological investigations, particularly for deciphering influenza outbreaks, especially those of mixed etiology.  相似文献   

17.
A method for assessment of integral biological toxicity of carbon-based nanomaterials (CBN) using a bacterial luminescent biosensor was developed, which accounted for the properties of the objects under study. The proposed approach includes a special procedure for the preparation of the analyzed CBN samples aimed at obtaining highly dispersed suspensions, an extended period of dynamic monitoring of the luminescence of the contacting sensor microorganism, and the special algorithm for quantification of the results of the bioluminescence analysis, in order to exclude the effect of the optical properties of CBN on the results of investigation. This method was used for assessment of the biological toxicity of a broad spectrum of CBN, such as single- and multi-walled nanotubes, nanofibres, and C60- and C70-fullerenes, in order to compare them in this respect to amorphous (nonstructured) carbon.  相似文献   

18.
目的了解实验所用常见致病真菌能否在常用医用原材料上生存及生存时间。方法选择8种常见致病真菌,活化后将它们分别接种在5种常用的医用原材料上,接种后及以后的每24h将接种有真菌的医用材料放入巯基乙酸盐液体培养基中并观察能否生存,记录存活时间。结果红色毛癣菌和须癣毛癣菌在棉布、纸板、铁皮、玻璃表面存活25~28d,在地板胶表面存活14~15d;新生隐球菌在棉布、纸板、铁皮表面存活24~27d,在玻璃和地板胶表面存活14~18d;茄病镰刀菌在上述5种材料上存活22~27d;石膏样小孢子菌在棉布、纸板、铁皮和玻璃表面存活20~27d,在地板胶表面存活8d;申克孢子丝菌在棉布、纸板、玻璃和地板胶表面存活17~24d,在铁皮表面存活10d;白念珠菌在棉布、纸板、铁皮和地板胶表面存活15~20d,在玻璃表面存活4d;犬小孢子菌在棉布、纸板、铁皮、玻璃和地板胶上存活时间分别为10d、9d、3d、2d和1d。结论实验所用各种真菌在医用原材料上都能存活,其时间长短不仅与菌种有关,还与所存在的材料有关。真菌在吸水性强、表面粗糙的材料(棉布、纸板)上的平均存活时间长于在吸水性差、表面光滑的材料(玻璃、铁皮和地板胶)。  相似文献   

19.
An accurate and high-throughput assay for collagen is essential for collagen research and development of collagen products. Hydroxyproline is routinely assayed to provide a measurement for collagen quantification. The time required for sample preparation using acid hydrolysis and neutralization prior to assay is what limits the current method for determining hydroxyproline. This work describes the conditions of alkali hydrolysis that, when combined with the colorimetric assay defined by Woessner, provide a high-throughput, accurate method for the measurement of hydroxyproline.  相似文献   

20.
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