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1.
家兔胫骨前肌肌纤维型的分布研究   总被引:2,自引:0,他引:2  
根据家兔胫骨前肌的肌纤维起止、排列和神经支配特征,将该肌分为前、后两个亚体。利用家兔8例16侧胫骨前肌,按上述两个亚体分别取材,作恒冷箱冰冻横切,肌球蛋白ATP酶染色,将肌纤维分为Ⅰ型、ⅡA型、ⅡB型,检测各亚体的肌纤维型构成比例,肌束内肌纤维的分布特征,并用图象分析仪测量各亚体肌纤维横切面积和直径。结果发现,前、后亚体以Ⅱ型纤维居多,前亚体ⅡA型纤维高达35.4%,后亚体Ⅰ型纤维多达24.5%,两者的ⅡB型纤维均达50%左右。而左、右侧之间无差异,肌束周边部内Ⅰ型纤维仅占12.7~13.3%,ⅡB型纤维高达59.9~60.0%,说明受肌束膜压迫影响,ⅡB型肌纤维血供少,以适应无氧酵解的功能。各亚体的Ⅰ型纤维较细,Ⅱ型纤维较Ⅱ粗,A型与ⅡB型二者相似。作者认为,前亚体主要参与快速有力的足背屈运动,后亚体则维持踝关节的稳定,保持足弓的形状和弹性,以便适应该肌的站立、跑动和跳跃的功能。  相似文献   

2.
Intracellular microelectrodes were used to record action potentials from fibres of the isolated rabbit right ventricle and the areas of the action potentials were measured. The action potential area was found to depend in a reproducible way on the preceding pattern of stimulation. A mathematical model reproducing all the observed changes in the action potential area was developed. In the model the action potential area is taken as a linear function of the product of two time and stimulation dependent variables, M and N. The behaviour of each variable between action potentials is described by the solution of a second order differential equation. During each action potential the variables are assumed to change discontinuously, the magnitudes of the discontinuous changes being given by a set of subsidiary equations. It was found that the behaviour of all the fibres tested was described by the same set of equations, each single fibre being characterized by a set of ten independent constants.  相似文献   

3.
Zone Precipitation Chromatography is useful tech-nique for the initial isolation of the different colla-gen types in their native configuration. Small quan-tities of collagen mixtures can be rapidly separated into different collagen types with relatively high degree of purity, based upon stained protein patterns on sodium dodecyl sulfate polyacrylamide gel electro-phoresis (SDS-PAGE) slab gels. Tn the commonly used bulk salt preparative method for isolating the different collagens, 50 mg of starting material was needed. Three days were required to complete the procedure. The stained protein patterns on SDS-PAGE slab gels showed about 25% contamination with the bulk purified Type III fraction and 20% contamination with the bulk purified type AB collagen. With Zone Precipitation Chromatography 5 mg of starting material was used and in less than 4 hours the mixture was separated with Types III and AB fractions showing less than 10% contamination from other collagen types. The technique is patterned after the Zone Precinitation method reported by Porath seventeen years ago and utilizes a step-wise sodium chloride gradient to precipitate and redissolve the collagens, eluting from the interbead spaces of a molecular sieve column.  相似文献   

4.
Based on percentages of Pinus pollen in surface samples and that of Pinto vegetation, the data indicates that, in Pinus forest its pollen is more then 90% of total tree pollen, while in non-pine area it is usually less than 30%. The factors influencing dispersal of the Pinus pollen, besides production, are air currents and landform. In the Pinus mixed forest the behavior of associate tree pollen has great effect on statistical result of Pin,ts pollen percentage. To estimate quantitatively the relationship between Pinus plant and its pollen, two curves are fitted by powet regression. Although Pinus pollen has great productivity and complex dispersal characteristics, the relationships between Pinus trees and Pinus pollen shown in our data are relatively consistant.  相似文献   

5.
Quantitative relationship between phycobiliprotein (PBP) andPS II contents was compared for 10 cyanobacterial and 3 redalgal strains. Following results were obtained: (1) contentof PBP per PS II was always equal to that of one phycobilisome(PBS) when PBS was hemidiscoidal type, (2) unusually high ratiosbetween antenna PBP [phycoerythrin (PE) and phycocyanin (PC)]and allophycocyanin contents were found in the PE-containingcyanobacteria Phormidium persicinum, Phormidium sp. NIBB 1052and Synechococcus sp. NIBB 1059 and the red alga Porphyra yezoensissuggesting that PBS in these organisms is not ordinary hemidiscoidaltype, and (3) the PBP content per PS II in Synechococcus NIBB1059 and P. yezoensis was as small as 14 to 13 of that of onePBS similarly to the case of Porphyridium cruentum. Resultssuggest that (1) hemidiscoidal PBS is the antenna for only onePS II, but (2) in some of organisms containing non-hemidiscoidalPBS, one PBS becomes a common antenna for plural PS II (around4), and (3) such PBS occurs not only in red algae but also incyanobacteria. 1 Present address: Department of Biology, Faculty of Science,Toho University, Funabashi, Chiba 274, Japan. 1219 (Received April 15, 1987; Accepted July 11, 1987)  相似文献   

6.
7.
目的:探讨不同疼痛患者的焦虑、抑郁和患病行为的关系,为疼痛患者临床心理诊断及心理干预提供必要的参考依据.方法:采用多中心合作的方式,抽取北京、西安、重庆等10家医疗单位的513例疼痛患者进行门诊问卷调查,采用医院焦虑抑郁量表(HADS)和患病行为问卷(IBQ)分别进行测量,对不同疾病种类疼痛患者焦虑、抑郁症状差异和患病行为的差异进行比较,并对焦虑、抑郁和患病行为各维度进行相关和多元逐步回归分析.结果:(1)不同疾病种类疼痛患者HADS总分差异有显著性(F=3.20,P<0.05),其中焦虑因子得分差异无统计学意义(F=1.28,P>0.05),抑郁因子得分差异有统计学意义(F=4.45,P<0.01),癌症患者得分[(9.67±4.70)分]显著高于其他疾病种类;不同疾病种类疼痛患者IBQ总分差异有显著性(F=5.44,P<0.01),其中负性情绪因子得分(F=3.11,P<0.05)和患病角色因子得分(F=9.28,P<0.01)差异有统计学意义,癌症患者得分最高[分别为(9.50±3.68)分和(8.10±1.82)分],显著高于其他疾病种类,行为反应因子得分差异无统计学意义(F=0.80,P>0.05);(2)负性情绪和行为反应因子均与焦虑和抑郁因子呈显著正相关(rmax=0.517,P<0.01;rmin=0.305,P<0.05),多元逐步回归分析发现:焦虑和抑郁的首要影响因素为行为反应因子(分别为Beta=0.323和Beta=0.368),患病角色在抑郁维度上未进入回归方程.结论:不同疾病种类疼痛患者焦虑、抑郁和患病行为存在差异,患病行为对疼痛患者焦虑及抑郁症状具有正向预测作用.  相似文献   

8.
本文阐述了海南岛尖峰岭各植被类型特征及分布,其分布是决定海拔与水热状况的变化。文中试用气候指标确立我国热带地区植被类型随海拔变化的模式,建立了指数、线性方程。本研究的目的在于加深对我国热带植被类型生境特点的认识,对合理利用和经营,起到应有的作用。  相似文献   

9.

Background

Strategic leadership is an important organizational capability and is essential for quality improvement in hospital settings. Furthermore, the quality of leadership depends crucially on a common set of shared values and mutual trust between hospital management board members. According to the concept of social capital, these are essential requirements for successful cooperation and coordination within groups.

Objectives

We assume that social capital within hospital management boards is an important factor in the development of effective organizational systems for overseeing health care quality. We hypothesized that the degree of social capital within the hospital management board is associated with the effectiveness and maturity of the quality management system in European hospitals.

Methods

We used a mixed-method approach to data collection and measurement in 188 hospitals in 7 European countries. For this analysis, we used responses from hospital managers. To test our hypothesis, we conducted a multilevel linear regression analysis of the association between social capital and the quality management system score at the hospital level, controlling for hospital ownership, teaching status, number of beds, number of board members, organizational culture, and country clustering.

Results

The average social capital score within a hospital management board was 3.3 (standard deviation: 0.5; range: 1-4) and the average hospital score for the quality management index was 19.2 (standard deviation: 4.5; range: 0-27). Higher social capital was associated with higher quality management system scores (regression coefficient: 1.41; standard error: 0.64, p=0.029).

Conclusion

The results suggest that a higher degree of social capital exists in hospitals that exhibit higher maturity in their quality management systems. Although uncontrolled confounding and reverse causation cannot be completely ruled out, our new findings, along with the results of previous research, could have important implications for the work of hospital managers and the design and evaluation of hospital quality management systems.  相似文献   

10.
新疆莫索湾垦区啮齿动物群落分布与生境类型关系的研究   总被引:3,自引:0,他引:3  
为探索沙漠开垦为绿洲后,啮齿动物群落的生态分布格局及变迁规律,2004年6~8月对莫索湾垦区150团场啮齿动物进行了调查.结果表明:荒漠开垦为林地,红尾沙鼠占据主导地位;开垦为农田,鼠类群落表现出较大差异:棉田中柽柳沙鼠占主导地位,麦田中小家鼠为优势鼠种,苜蓿地则以小林姬鼠为主,白菜地中灰仓鼠占据优势地位;城镇居民区“伴人”鼠种褐家鼠居于绝对优势.结论:在荒漠开垦为林地、农田和变为居民区的过程中,鼠类群落也相应地由荒漠鼠类向人工景观鼠类演变.然而对于从沙漠腹地开垦出来的绿洲,虽然人类已开垦经营了半个世纪,但啮齿动物群落的原始荒漠特征仍较完善地保存着,这与当地极端的地理特征相一致.  相似文献   

11.
As a first step toward developing the methodology for screening large numbers of heterocyst-forming freshwater cyanobacteria strains for the presence of various types of nitrogenases and hydrogenases, we surveyed the distribution of these genes and their activities in 14 strains from culture collections. The nitrogenase genes include nif1 encoding a Mo-type nitrogenase expressed in heterocysts, nif2 expressed in vegetative cells and heterocysts under anaerobic conditions, and vnf encoding a V-type nitrogenase expressed in heterocysts. Two methods proved to be valuable in surveying the distribution of nitrogenase types. The first method was Southern blot hybridization of DNA digested with two different endonucleases and hybridized with nifD1, nifD2, and vnfD probes. The second method was ethane formation from acetylene to detect the presence of active V-nitrogenase. We found that all 14 strains have nifD1 genes, and eight strains also have nifD2 genes. Four of the strains have vnfD genes, in addition to nifD2 genes. It is curious that three of these four strains had similar hybridization patterns with all of the nifD1, nifD2, and vnfD probes, suggesting that there could be some bias in strains used in the present study or in strains held in culture collections. This point will need to be assessed in the future. For surveying the distribution of hydrogenases, Southern blot hybridization was an effective method. All strains surveyed had hup genes, with the majority of them also having hox genes.  相似文献   

12.
A Study of the Relationship between Root and Shoot Metabolism   总被引:2,自引:0,他引:2  
The influence of light and dark on the respiration rate, sugarlevel, and rubidium uptake of the roots of young sunflower andbarley plants has been investigated. The rate of root respirationwas found to be closely correlated with the rate of carbohydratetransport from the shoots. This enabled the energy requiredfor root growth to be calculated. A period of darkness causeda reduction in rubidium uptake and transport which appearedto be due to the reduced rate of root metabolism in the dark.The experiments of some earlier workers on the effect of transpirationon rubidium uptake by young sunflower and barley plants wererepeated. The results indicated that they were studying themetabolic effect of light and dark on salt uptake as well asthe effect of transpiration.  相似文献   

13.
The changes in the mechanical integrity of the cervix during pregnancy have implications for a successful delivery. Cervical collagens are known to remodel extensively in mice with progressing gestation leading to a soft cervix at term. During this process, mature crosslinked collagens are hypothesized to be replaced with immature less crosslinked collagens to facilitate cervical softening and ripening. To determine the mechanical role of collagen crosslinks during normal mouse cervical remodeling, tensile load-to-break tests were conducted for the following time points: nonpregnant (NP), gestation day (d) 6, 12, 15, 18 and 24 hr postpartum (PP) of the 19-day gestation period. Immature crosslinks (HLNL and DHLNL) and mature crosslinks (DPD and PYD) were measured using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). There were no significant changes in the total immature crosslink density (HLNL+DHLNL mol per collagen mol) throughout normal mouse gestation (range: 0.31–0.49). Total mature crosslink density (PYD+DPD mol per collagen mol) decreased significantly in early softening from d6 to d15 (d6: 0.17, d12: 0.097, d15: 0.026) and did not decrease with further gestation. The maturity ratio (total mature to total immature crosslinks) significantly decreased in early softening from d6 to d15 (d6: 0.2, d15: 0.074). All of the measured crosslinks correlated significantly with a measure of tissue stiffness and strength, with the exception of the immature crosslink HLNL. This data provides quantitative evidence to support the hypothesis that as mature crosslinked collagens decline, they are replaced by immature collagens to facilitate increased tissue compliance in the early softening period from d6 to d15.  相似文献   

14.
目的:建立A型肉毒毒素抑制剂的定量构效关系模型。方法:应用分子全息定量构效关系(HQSAR)技术,研究了14种A型肉毒毒素抑制剂的抑制活性与其二维分子结构之间的关系,讨论了碎片区分参数及碎片长度对模型质量的影响。结果:最佳全息条件下产生的模型相关系数r2为0.780,交叉验证相关系数q2LOO为0.583。所建模型具有良好的拟和效果和较高的预测能力,HQSAR模型贡献图显示抑制剂分子中的噻吩环及羟胺对活性有较大贡献。结论:本研究对新抑制剂的设计具有一定的指导作用。  相似文献   

15.
不同类型森林石灰土的团聚体组成及其有机碳分布特征   总被引:5,自引:0,他引:5  
选取中国西南喀斯特石灰土人工林、次生林、原生林3个主要森林类型的6个代表性群落,建立18个20m×20m的样方,按梅花型5点法采集各样方的原状土壤,基于团聚体的干湿筛2种分组方法,研究不同类型森林石灰土机械性、水稳性团聚体组成及全土、各粒级团聚体的有机碳分布特征。结果显示:(1)3类森林石灰土干湿筛团聚体均以>2mm粒径为主,分别为67.93%~81.24%和30.49%~76.81%,1~10mm粒径的干湿筛优势团聚体分别高达78.18%~88.67%和43.41%~84.00%。(2)团聚体的整体稳定性很好,干湿筛平均重量直径(MWD)为4.82~5.77和0.75~2.13,平均几何直径(GMD)为2.87~4.17和1.45~2.85;>0.25mm和>2mm粒径的团聚体破坏率(PAD)分别仅为6.15~20.91和2.04~52.79。(3)石灰土的有机碳含量很高,全土和干、湿筛团聚体的有机碳含量分别为17.28~58.85、19.12~91.47、17.16~78.86g/kg,其中干筛以<2mm粒径团聚体的有机碳含量较高,湿筛反之,但干湿筛均以>2mm粒径团聚体的有机碳贮量最高。研究表明,中国西南喀斯特石灰土林区土壤沿人工林、次生林、原生林土壤扰动递减梯度,石灰土的团聚化作用越来越强,稳定性越来越好,有机碳含量也越来越丰富。  相似文献   

16.
家兔供体细胞的发育周期与重构胚发育的关系   总被引:3,自引:0,他引:3  
采用血清饥饿法处理体外培养的兔子胎儿成纤维细胞,并将其作为供体细胞移入去核卵母细胞内构建重构胚胎。检查供体细胞的细胞周期对重构胚的融合率、分裂率和着床率的影响。实验结果表明:培养基中血清含量在0.5%的情况下,G0/G1期的细胞比例由正常培养条件下(培乔液中含有10%FCS)的73.2%明显地增加到86%以上。饥饿1~3天的细胞作为供体细胞构建重构胚时,可明显提高重构胚的融合率,但是不同的饥饿时间其融合率并无显著的差异。饥饿处理可明显增加重构胚的分裂率,以饥饿处理3天为最佳。  相似文献   

17.
Cyclic AMP levels in rabbit carotid bodies incubated under control conditions, 100% O2- or 95% O2/5% CO2- equilibrated medium, are close to 1 pmol/mg wet tissue (range 0.4-2.43 pmol/mg). Isobutylmethylxanthine (0.5 mM) increases cyclic AMP levels by a factor of 14 and 8 in HEPES- and CO2/CH3O(-)-buffered medium, respectively. Forskolin (0.5-10 microM) applied during 30 min increases cyclic AMP levels in a dose-dependent manner. Incubation of carotid bodies at low O2 tensions resulted in an elevation of cyclic AMP levels both in the absence and in the presence of isobutymethylxanthine. In the latter conditions cyclic AMP increase was maximum at an O2 tension of 46 mm Hg and tended to decrease at extremely low PO2. In isobutylmethylxanthine-containing Ca2(+)-free medium, cyclic AMP increased linearly with decreasing PO2 from 66 to 13 mm Hg; the absolute cyclic AMP levels attained in Ca2(+)-free medium were smaller than those observed in Ca2(+)-containing medium at any PO2. The differences between Ca2(+)-free and Ca2(+)-containing media appear to be due to the action of released neurotransmitters in the latter conditions, because dopamine and norepinephrine, which are known to be released by hypoxia in a Ca2(+)-dependent manner, increase cyclic AMP in the carotid body. Low pH/high PCO2 and high [K+]e increase cyclic AMP levels only in Ca2(+)-containing medium. Forskolin potentiates the release of catecholamines induced by low PO2. These results suggest that cyclic AMP plays an important role in the modulation of the chemoreception process.  相似文献   

18.
从斑块信息的角度分析了四川冶勒的红豆杉种群分布格局与坡度的关系。结果表明:1) 红豆杉种群在冶勒的分布格局与坡度存在密切关系: 0°~50°的坡度范围内红豆杉种群均为聚集分布, 50°以上的坡度范围内红豆杉种群为随机分布。2) 红豆杉种群的聚集强度均与坡度和坡度的空间形状有关: 30°~50°坡度内的种群聚集强度远远高于0°~10°间坡度, 而10°~30°坡度的聚集强度介于二者之间; 在一定范围内, 空间形状越复杂, 其种群的聚集指数越高。  相似文献   

19.
A novel procedure was developed for direct quantitative isolation of microbial DNA from soil. This technique was used to evaluate microbial DNA pools in soils of contrasting types (chernozems and brown forest soils) under different anthropogenic loads. A strong correlation was found between microbial biomass and DNA contents in soils of different types (R 2= 0.799). The ratio of soil CO2 emission rate to the amount of extractable DNA in the soil was shown to reflect the physiological state of the soil microbial community; this ratio can be used as an ecophysiological parameter similarly to the metabolic quotient qCO2.  相似文献   

20.
5个不同形态类型龙葵的同工酶研究   总被引:11,自引:0,他引:11  
同工酶作为基因表达的产物 ,在一定程度上可以帮助鉴别一些外部形态难以区别的遗传差异 [1 ] 。目前利用同工酶进行分类学研究已有不少报道 ,其中将过氧化物酶及酯酶同工酶作为探讨亲缘关系、种和品种的鉴定比较多[2 7] 。但中国产龙葵同工酶方面的研究还未见报道。笔者对中国产龙葵 5个不同形态类型的酯酶及过氧化物酶同工酶进行了测定、分析 ,试图从分子水平探讨其亲缘关系 ,为龙葵等级分类提供生化依据。表 1  供试材料名称及特征Table1  The name and character of the materials used编号No.中文名称Chinesename学 名Scientific n…  相似文献   

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