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1. Tissue sections eight microns thick were exposed to various experimental conditions used in histochemistry, and the effect upon the activities of esterase, the phosphatases, leucine aminopeptidase, β-glucuronidase, and arylsulfatase was determined colorimetrically. 2. Significant differences were found in the amounts of the lyo and desmo fractions of these enzymes. The desmo components were found to be for esterase, alkaline phosphatase, leucine aminopeptidase, acid phosphatase, β-glucuronidase, and arylsulfatase, ⅓, 2/3, 2/3, ½, ⅛, and ⅛ of the total enzymatic activity respectively. 3. Variations in the time and in the temperature at which diffusion was studied and of the pH and salt concentration of the solution into which the sections were placed, resulted in differences in the amount of enzymatic activity which remained in the tissue section. Some enzyme loss by diffusion was noted even after fixation of the tissue section. 4. The significance of the findings with respect to some of the concepts of localization of enzymes in tissue sections was discussed.  相似文献   

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Recent studies comparing magnitude estimation to other scaling methods have been criticized for failure to submit the data to logarithmic transformation before statistical analysis, a procedure which can improve the ability of magnitude estimation scaling to differentiate among products. Data from one of these studies was available for re-analysis, which was conducted both with and without logarithmic transformation of magnitude estimation, category scales and line scales. The ability of magnitude estimation to differentiate among products was improved by log transformation, while the other methods were not. Improvements were associated in pan with reductions in positive skew and improved approximation of the normal distribution. In spite of this improvement, magnitude estimation remained slightly inferior to the other methods especially in the hands of an untrained consumer sample.  相似文献   

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Three methods of standardizing magnitude estimation data, external calibration, modulus normalization, and equalization were examined using a sensory evaluation data set arising from an incomplete block experiment testing five gels of varying firmness. Both the original data and a logarithmic transformation of the data were analyzed. Instrumental data were also collected. When untransformed data were analyzed the method of standardization profoundly affected tests of significance, coefficients of variation (%CV), and estimation of the power function relating the sensory data to the concentration of the underlying gel. The logarithmically transformed data lead to results independent of the standardizing technique and with higher F-ratios, lower %CV's and normally distributed errors.  相似文献   

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The use of linear time series, as a psychophysical method ofassessing self-adaptation and carryover effects in olfactoryintensity judgments, is illustrated for eugenol and acetophenone.Data from series of 60 successive magnitude estimation judgmentsby 11 subjects show consistent within-subject and between-subjectdifferences. The two substances used do not show the same self-adaptationpatterns.  相似文献   

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目的探讨吸烟患慢性阻塞性肺疾病(chronic obstructive pul monary disease,COPD)者与吸烟不患COPD者肺组织中白介素-18(interleukin-18,IL-18)表达水平的差异。方法不吸烟不患COPD(Control组)、吸烟不患COPD(Smoker组)和吸烟患COPD(COPD组)患者各10例,性别、年龄相匹配,均为因肺部占位病变行肺叶切除术患者,取材尽量远离病变组织,采用HE染色观察各组肺组织形态学变化,用免疫组织化学染色方法,检测IL-18在肺组织的表达。结果1.HE染色显示正常对照组与吸烟不患COPD组无明显炎症变化;COPD组肺组织有明显的肺泡结构破坏和炎症细胞浸润,炎性细胞较Control组和Smoker组明显增加。2.免疫组化染色图像分析显示,Control组IL-18的平均光密度值为0.472±0.134,Smoker组为0.622±0.090,COPD组为0.897±0.193,COPD组与Control组和Smoker组之间有显著统计学差异(n均为10,P0.01),并且Smoker组和Control组之间也存在统计学差异(P0.05)。将30例受试者作为整体分析,肺组织中IL-18表达(平均光密度值表示)分别与肺功能指标FEV1/FVC、FEV1(%pred)之间存在显著的负的直线相关关系(n=30,r=-0.778,P0.01和n=30,r=-0.520,P0.01)。结论吸烟患COPD者肺组织中IL-18的表达较不患COPD者明显增加,IL-18在肺部的表达量与气流受限程度具有显著相关性,提示IL-18在吸烟致COPD的发病机制中可能起重要作用。  相似文献   

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Differential inductive capacities among liver tissues of several animals were examined by anticipating the correlation between the capacity and the completness of perisinusoidal basement membrane.
The reacting tissue was competent ectoderm of gastrula of Triturus pyrrhogaster , and the inductive effects of livers on the ectoderm were tested by explantation method. The inductive effect of livers being devoid of the membrane (chick and guinea pig) was neural and the tissues having the dense well-developed membrane (reptiles) produced an assembly of neural and meso-dermal tissues, such as notochord and somite or muscle. The livers with the membrane being of intermediate grade of development ( calf, Triturus and mouse) induce mesodermal tissues, but not frequently, together with neural tissue or alone. The liver tissue was more active in mesodermal induction in proportion to the completeness of the perisinusoidal basement membrane.
On the basis of these data the difference in inductive capacity among liver tissues from different kinds of animals were discussed.  相似文献   

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1. Detmer''s solution and a modified Knop''s solution are unfavorable culture media for the growth of Spirodela polyrhiza. 2. When the modified Knop''s solution was diluted to 10 times its volume, Spirodela polyrhiza and Lemna valdiviana grew and reproduced for periods of 26 months and 21 months, respectively. 3. Growth in the dilute Knop''s solution, which alone can support the growth of Spirodela indefinitely, was considerably stimulated over a period of 23 days by adding to every liter the water-soluble material of 0.4 gm. autolyzed yeast, or the material of 2.5 gm. peat soluble in a 1 per cent solution of NaHCO3. 4. The nature of the stimulus or of the protection afforded by the organic material is as yet unknown. 5. The necessity of organic accessory foods (auximones) in the nutrition of green plants cannot be accepted as an established fact.  相似文献   

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The formation from hemoglobin of split products not precipitable by trichloracetic acid is taken as a measure of tryptic activity. The split products are estimated colorimetrically. Many measurements of tryptic activity can be made in a short time and different samples of hemoglobin yield the same results.  相似文献   

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《Chronobiology international》2013,30(6):1189-1205
There is a strong association between metabolic syndrome (MS) and increased risk of end-organ damage, cardiovascular disease, stroke, and cardiovascular mortality. Moreover, non-dipping (<?10% decline in the asleep relative to the awake blood pressure [BP] mean) and elevated ambulatory pulse pressure (PP), among other factors related to the circadian BP pattern, have also been associated with increased cardiovascular morbidity and mortality. This cross-sectional study investigated the circadian BP pattern in 2,045 non-diabetic untreated patients with uncomplicated essential hypertension (941 men/1,099 women), 48.7?±?11.9 yrs of age, classified by the presence or absence of MS. BP was measured by ambulatory monitoring for 48 consecutive hours to substantiate reproducibility of the dipping pattern. Physical activity was simultaneously monitored every min by wrist actigraphy to accurately calculate mean BP when awake and asleep for each subject. MS was present in 40.7% of the patients. Patients with MS were characterized by a significantly higher 24?h mean of systolic BP and a lower diastolic BP compared to patients without MS. Accordingly, ambulatory PP was significantly elevated the entire 24?h in MS patients. The prevalence of an altered non-dipper BP profile was significantly higher in MS patients (48.4 vs. 36.1% in patients without MS, p?<?0.001). MS patients were characterized, among other risk factors, by significantly higher uric acid, fibrinogen, leukocyte count, hemoglobin and globular sedimentation velocity, plus lower estimated glomerular filtration rate. Apart from corroborating the significant increased prevalence of a blunted nocturnal BP decline in MS, this study documents ambulatory PP is higher in MS, without differences between groups in mean arterial pressure. This elevated PP might reflect increased arterial stiffness in MS. MS patients were also characterized by elevated values of relevant markers of cardiovascular risk, including fibrinogen and globular sedimentation velocity. These collective findings indicate that MS should be included among the clinical situations in which ambulatory BP monitoring is recommended. (Author correspondence: )  相似文献   

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The analysis of multiple components is often used to modelbiological variables that show nonsinusoidal predictable changes of knownperiods. In general, to anticipate the periods is not easy, and even in caseswhen we have some a priori information, it is advisable to have a statisticaltool to test the chosen periods. In this work, we introduce a statisticalprocedure to estimate periods of longitudinal series by applying nonlinearregression techniques to the multiple sinusoidal model, as well as to thegeneral linear model. Approximate inferences about the parameters of the modelare carried out under the usual hypothesis of normality, independence, andconstant variance of the errors. Confidence intervals (CIs) for each individualparameter, as well as for the amplitude-acrophase pair or for any other subgroupof parameters of interest, can be computed. As in the linear analysis of multiplecomponents, it is possible to check the existence of rhythm by means of azero-amplitude test. The method also allows statistical testing of severalhypotheses related to the periods. For example, it is possible to test ifthe periods are equal to certain values of chronobiologic interest and tocheck if some components included in the model are harmonically related. Onthe other hand, when the fitted components have proximal periods, the methodallows one to verify if they are modeling the same or different spectral peaks.The method, which was validated by a simulation study for a model of two componentsand is illustrated by an example of modeling the diastolic blood pressureof two subjects, represents a new step in the development of statistical proceduresin chronobiology. (Chronobiology International, 18(2),285–308, 2001)  相似文献   

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Age-specific mortality is measured to characterize the costs of reproduction in the beetle Callosobruchus maculatus, providing explicit details of the timing, duration, magnitude, and acceleration of mortality. We experimentally manipulated reproductive effort in four cohorts of 200 individually housed females by controlling exposure to males and to an artificial oviposition substrate. We demonstrate that (1) early reproduction produces long-term increases in age-specific mortality; (2) egg-laying effort affects the onset of age-specific mortality but not its shape or rate of change; and (3) mating with subsequent reproduction increases the rate of change in age-specific mortality relative to virgins. Accelerated senescence is defined demographically as an increase in the rate of change of age-specific mortality. Our results challenge the hypothesis that reproductive effort accelerates senescence but provides evidence that mating itself may have this effect.  相似文献   

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本文考虑到育种过程数量性状间的遗传相关和环境相关,我们把单性状的F2代有效因子模型推广到了多性状,并讨论了相关参数的辨识问题,其结果优于不考虑相关时的情况,更优于Castle-Wright公式.  相似文献   

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