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1.
Skin conductance and heart rate in women with premenstrual syndrome   总被引:1,自引:0,他引:1  
This study investigated the effects of the menstrual cycle phase on certain components of autonomic arousal and task performance. Premenstrual syndrome (PMS) women and matched controls (non-PMS) were tested both premenstrually and postmenstrually. The conditions selected were a) the presentation of 10 tones, b) a proofreading performance task, and c) a word-association learning task. Skin conductance and heart rate were continuously monitored. No significant effects were found on baseline physiological measures, or on proofreading or word-association performance. A significant point in cycle effect for skin conductance and HR orienting response to the tones was found showing smaller HR and skin conductance responses postmenstrually. Several significant PMS classifications by point in menstrual cycle interactions were found. These indicated that, paradoxically, the non-PMS subjects showed higher spontaneous skin conductance responding during the word association task and higher skin conductance responses to tones prior to menses. While in contrast, PMS subjects yielded higher responding on the same measures postmenstrually. On stress ratings, PMS subjects reported experiencing more stress postmenstrually. Results are discussed in terms of the possible role of expectancy factors and inaccurate self-monitoring.  相似文献   
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On-line radiotherapy imaging with an array of fiber-optic image reducers   总被引:1,自引:0,他引:1  
In the optical approach for on-line radiotherapy imaging, a large metal sheet-fluorescent screen combination is used to convert the radiation intensity distribution into a visible light image. Data are then captured via a mirror with a camera located out of the beam. Although usable portal images can be acquired, presence of the large mirror renders the system impractical in many treatment geometries. We have overcome this limitation by replacing the mirror with an array of 16 by 16 bundles of plastic fiber-optic image reducers. Each bundle, in turn, is made up of 16 by 16 individual optical fibers. The total of 256 by 256 fibers spans an input area of 40 cm by 40 cm with each individual fiber viewing an area of 1.6 mm by 1.6 mm. Within a height of 12 cm, each fiber is reduced to an area of 0.1 mm by 0.1 mm. The reduced portal image is then turned and "piped" to a final 3.0 cm by 3.0 cm output area. For data acquisition and digitization, the fiber output is directly coupled to the sensor of a TV camera interfaced to a small computer via a 512 by 512 frame grabber. In this initial evaluation, the imaging system has been characterized in terms of its line spread function, noise and resistance to radiation damage. Adequate phantom and patient images are presented.  相似文献   
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Observations made in an investigation of the diurnal variation of the serum iron concentration suggested that the diurnal variations of serum iron can be explained as a phenomenon secondary to the diurnal variation of the hemoglobin metabolism. This hypothesis is supported by parallel changes in the bilirubin and serum iron values.  相似文献   
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Objective

The goal of this study is to review our series of head and neck paragangliomas to identify factors that may help in predicting malignancy.

Study Design

Case series with chart review.

Setting

Academic medical center.

Subjects and Methods

Subjects with head and neck paragangliomas at our institution from 1976 to current were reviewed. In addition to statistical comparisons of epidemiologic factors, pathologic and radiographic characteristics were reviewed.

Results

Of the 84 subjects, there were seven malignant paragangliomas (8%). Age was found to be significantly different between the benign and malignant subgroups, with an average age of 54 ± 16 and 40 ± 12 years, respectively (P = 0.02). Pain was a presenting complaint in five patients with benign disease (6%), and five of the seven malignant patients (71%) presented with pain, showing a significant association between pain and disease type (P < 0.0001). The odds ratio for a patient with pain having a malignant tumor was 36 (95% CI: 5.5-234). Enlarging neck mass was noted in all cases of malignant disease, but only in 31 percent of cases of benign disease (P < 0.0001). In a secondary analysis of carotid body tumors alone, enlarging neck mass was not found to be significant between benign and malignant disease (P = 0.14). However, pain continued to be significantly different, with 67 percent of malignant lesions demonstrating pain, compared with only 11 percent of benign lesions (P = 0.01).

Conclusion

This study suggests that pain, a rapidly enlarging neck mass, and younger age are predictive factors of underlying malignancy, which should prompt one to consider an aggressive diagnostic and management approach.  相似文献   
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