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51.
The relationship between cardiac activity and sensory acuity suggested by Lacey and Lacey was tested by recording heart rates of Ss attempting to detect a threshold-level visual stimulus. Heart rate decelerations during a warning tone preceding the threshold stimulus were found in be greater on hit trials than on miss trials, supporting the suggested relationship. 相似文献
52.
多参数信息融合实现非脑电的睡眠结构分期 总被引:7,自引:3,他引:7
目前临床睡眠分析的主要手段是多导睡眠图(Polysomnograph,PSG),用仪器记录被测者整晚的脑电、眼动电和颏肌电等生理参数,计算机进行自动睡眠分期,再由技术人员依据国际标准进行校正.几十年来PSG保持着睡眠分期金标准的地位.提出在不使用脑电的条件下,利用较易获得的心动周期、呼吸、体动等基本生理参数,提取其中与睡眠过程及其变化有关的规律和信息,建立知识规则库,采用不确定推理的证据理论进行多参数睡眠信息融合计算,实现睡眠结构分期.50余例与PSG对照试验结果表明:醒睡的平均符合率达90%以上,基本睡眠结构的平均符合率达75%以上,证明该技术达到了应用的要求. 相似文献
53.
The main purpose of the study was to compare the efficiency of the Fishbein and Ajzen and the Triandis models to predict (1) the intention to participate regularly in some physical activities during free time within a 3-week period and (2) the exercise behavior within these 3 weeks among a group of 166 subjects, aged 22 to 65 years. Our results show that the Triandis model was as efficient as the Fishbein and Ajzen model in predicting the exercise behavior. However, the results obtained from the Triandis model demonstrate the importance of the habit of exercising in predicting the exercise behavior. Moreover, the Triandis model was superior to the Fishbein and Ajzen model in explaining behavioral intention. Of particular interest was the salience of the affective, social, and personal belief components of the Triandis model. In addition, from a practical perspective, this comparative study showed that (1) to exercise regularly is perceived as hard work, and (2) individuals believe that it is their own responsibility to exercise or not to exercise. 相似文献
54.
The prognostic significance of nucleolar organizer regions (NORs) in renal cell carcinoma (RCC) was evaluated. NORs were quantified in a series of 182 cases of RCC using the silver-colloid method. The cases were staged according to Robson's method (48 stage I, 26 stage II, 33 stage III, 75 stage IV) and mean NOR numbers for each tumour were correlated with survival over a 5-year period. Localized tumours (stages I and II) with low NOR numbers had an almost 100 per cent 5-year survival. Those patients with clinical evidence of metastases at presentation showed a high mortality, although those with low numbers of NORs had a significantly increased disease-free interval. Statistical analysis using the log rank test indicated NORs to be a significant predictor of survival over the whole series (P = 0.0001) and within each of Robson's stages (P = 0.0008 stage I, P = 0.0154 stage II, P = 0.0009 stage III, P = 0.0001 stage IV). Analysis of data using Cox's proportional hazard model showed mean NOR numbers to be independent of stage as a predictor of survival. 相似文献
55.
Sowiska-Klencka D Klencki M Dedecjus M Lewiski A Pawlikowski M 《Endocrine pathology》2000,11(2):173-178
Nucleolar organizer regions (NORs) are segments of DNA, encoding for ribosomal RNA. They are associated with argyrophilic
proteins and, thus, they can be localized through silver staining. A correlation has been shown between the number, the size,
or the intranuclear localization of AgNORs, and the proliferative activity of cells. The aim of this study was to examine
numerous features of AgNORs in pituitary adenomas and to relate them to immunohistochemical typing of tumor. Histologic slides
from 32 pituitary tumors and one normal pituitary were silver-stained and analyzed with a computerized system for microscopic
image analysis, supported by an AgNORmeter95 program. All the tumors were also immunocyto chemically characterized. We have
found that gonadotropinomas, when compared with plurihormonal adenomas, revealed a lower proportion of nuclei with a single
AgNOR and a higher percentage of marginal dots. Recurrent adenomas, when compared with primary adenomas, showed a higher proportion
of nuclei with three AgNOR dots, a larger total area of dots in the nuclei, and a higher standard deviation of the AgNOR dot
area in the nucleus. Adenomas immunopositive for prolactin, when compared with immunonegative ones, showed a larger mean area
of the AgNOR dot, a larger area of the biggest dot in the nucleus, and a higher proportion of nuclei within a single dot.
These results suggest that the estimated parameters of AgNOR dots differ according to tumor aggressiveness and to the hormone
immunopositivity of pituitary adenomas. 相似文献
56.
Nucleolar organizer regions in uterine sarcomas 总被引:3,自引:0,他引:3
L. L. V. Boquist 《Virchows Archiv : an international journal of pathology》1992,420(4):353-358
Summary Nucleolar organizer regions demonstrable by silver staining technique (AgNORs) are loops of nucleolar DNA transcribing to ribosomal RNA. This report quantifies AgNORs in normal endometrium and myometrium, and in leiomyomas and homologous sarcomas of the uterus. The mean AgNOR number in leiomyosarcomas was significantly higher than that in normal myometrium and that in leiomyomas, whereas no significant difference was observed between normal myometrium and leiomyomas. The mean AgNOR count in low-grade endometrial stromal sarcomas was significantly higher than that in normal endometrial stroma, and significantly lower than that in the high-grade variant of the same tumour. The epithelial component of malignant mixed müllerian tumours exhibited a significantly higher mean AgNOR number than normal endometrial epithelium, and the stromal component of these tumours showed a significantly higher mean AgNOR count than normal endometrial stroma and normal myometrium, respectively. The AgNOR count was significantly correlated with the mitotic rate in leiomyosarcomas, in high-grade endometrial stromal sarcomas, and in the epithelial and mesenchymal portions of mixed müllerian tumours, whereas no statistically significant correlation was observed in low-grade endometrial stromal sarcomas. Increased AgNOR counts have been reported for some kinds of malignant tumours in various organs, compared with normal tissues and benign tumours. This study demonstrates a similar increase when homologous uterine sarcomas are compared with histogenetically related normal and neoplastic tissues. AgNOR counting might be a useful adjunct in the classification and grading of uterine tumours. 相似文献
57.
The effect of a series of fixatives on the AgNOR technique 总被引:6,自引:0,他引:6
With increasing interest being shown in nucleolar organizer regions (NORs) in pathology, it was considered of great importance to evaluate the effect of some of the more commonly used and more specialized fixatives on the demonstration of these moieties. NORs can be demonstrated in paraffin sections by a silver technique (AgNOR method) which was developed from a method used by cytogeneticists for the demonstration of NORs in chromosome spreads. The degree of staining is dependent on the fixation regime employed and results may vary greatly from one fixative to another. The fixative schedules and post-treatments used in this study were based on standard sequences from the literature. We have shown that, in general, alcohol-based fixatives give optimal results, Carnoy's fluid being especially recommended. Mercurial and dichromate-containing fixatives were found to have highly detrimental effects on NOR staining. 'Routine' 10 per cent formol saline fixation gave adequate results whereas 10 per cent neutral buffered formalin gave optimal staining, similar to alcohol-based fixation. 相似文献
58.
J Rüschoff K H Plate H Contractor S Kern R Zimmermann C Thomas 《The Journal of pathology》1990,161(2):113-118
This study summarizes our experiences with the silver staining of nucleolus organizer regions (AgNORs) in a total of 580 tumours from ten different tissues. In contrast to other investigators, we made use of automatic image analysis for the evaluation of AgNORs. This provided good reproducibility as determined by the standard cumulative means technique and intra-observer (r1) and inter-observer (r2) agreement in 30 benign (r1 = 0.83-0.95, r2 = 0.76-0.92) and 50 malignant tissue samples (r1 = 0.72-0.85, r2 = 0.51-0.78). By using a series of staining times on sections from 30 tissue blocks taken from the ten types of tissue investigated, considerable variation in the argyrophilic staining of NORs in different tissues and in different blocks from one tumour was shown. The mean AgNOR area of resting lymphocytes or connective tissue cells within tissue blocks of the same organ system varied up to four-fold, even though identical staining times had been used. The most suitable silver reaction time which rendered a good diagnostic difference in the AgNOR content of benign and malignant tissue ranged, for example, in the breast cancer specimens, from 23 to 35 min. We therefore conclude that the staining time has to be adjusted to the individual silver-binding characteristics of each tissue block or even each section. The use of internal staining standards like lymphocytes or connective tissue cells in the same tissue section is mandatory. This, in turn, is most precisely controlled by morphometry. 相似文献
59.
Robert L. Rubinstein 《Journal of cross-cultural gerontology》1987,2(1):1-14
Almost nothing is concretely known about childless elderly in cross-cultural perspective. Few published papers have appeared on this social category in the West, although childless elders make up (at least) 20% of the population of elderly in many Western nations. Little is known about childless elderly in the Third World. This paper provides some theoretical background to the study of childless elderly and articulates some social policy concerns about them. It suggests that there are five important questions to examine concerning the lives of childless elderly. These include, how childless aged are or are not provided for in societies in which a great deal of the care of the aged is undertaken by children; how kinship functions as a matrix for care; how the increasingly common phenomenon of voluntary childless may give meaning to childlessness in late life; how childlessness fits with such social science models such as the developmental cycle; and, the relationship of this phenomenon to changing opportunities for women. The paper further examines how factors such as fertility, systems of caregiving, the social meaning of childlessness, alternatives to childlessness such as adoption, and educational and economic opportunities may affect the lives of childless elders. 相似文献
60.
Radiographic quantification of alveolar bone level changes 总被引:3,自引:0,他引:3
Jasim M. Albandar Jostein Rise Per Gjermo Jan R. Johansen 《Journal of clinical periodontology》1986,13(3):195-200
The "random burst" theory has recently been proposed as an explanation of the pattern of periodontal disease progression. The theory predicts that the progression of bone loss at individual sites is not dependent upon previous bone loss and age. A longitudinal radiographic study was designed to test this hypothesis, and to describe the changes in bone level over 2 years in a group of 180 subjects (18-68 years of age) who were not under systematic periodontal treatment. The results indicated that 94% of the sites did not show significant changes in the alveolar bone level during the observation period. The mean annual bone loss for the total population was 0.11 mm. By regressing longitudinal bone loss upon age, it was shown that the rate of bone loss increased rapidly between 33 and 56 years of age while a different pattern was shown for the age intervals 18-32 and 57-68 years. Also, the rate of bone loss increased with increasing initial bone loss. This was less evident in the oldest age group. It was concluded that the progression of bone loss in the present material is consistent with a "burst" theory. However, the progression did not occur randomly with regard to previous loss of alveolar bone and time. 相似文献