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41.
Carlo Bertucci Enrico Domenici Piero Salvadori 《Journal of pharmaceutical and biomedical analysis》1990,8(8-12):843-846
The application of a circular dichroism (c.d.) detection system in HPLC using a chiral stationary phase is presented. The simultaneous measurement of the absorbance and c.d. signal allows the evaluation of the anisotropy factor (g = Δ/) and thus the determination of the enantiomeric excess (e.e.) of the eluates. When this detection system is used in preparative chiral chromatography the collection of the enantiomeric fractions can be readily optimized. 相似文献
42.
Jen auo Hirschberg 《Early child development and care》1990,65(1):57-69
During a period of twenty years [1969-1988] the author has observed 614 cases of congenital malformations and noninflammatory diseases of the larynx in infants and young children, Budapest. He summarizes the most characteristic symptoms of laryngeal pathology in infants, and discusses the diagnostic possibilities. Among the latter, spectrographic analyses complemented by auditory evaluation of pathological cry and different breathing noises play an important role. Based on his investigation author differentiates 20 kinds of pathological crying sounds and 4 basic forms of stridor. He describes the acoustic attributes of different pathological sound phenomena and summarizes characteristic voice changes. 相似文献
43.
心理因素对小学生脑力工作能力影响的研究 总被引:4,自引:2,他引:2
采用横断面研究方法,对180名小学三年级学生脑力工作能力与其智力、性格、学习动机等心理因素和学习、睡眠时间等作息因素的关系进行分析研究。验证了学习、睡眠时间是影响学生脑力工作能力重要的外部因素;脑力工作能力与智力和学习成绩呈正相关。学生自身的心理因素中,学习动机对脑力工作能力有重要影响,所以激发和强化学生的学习动机,是保持和提高学生学习工作能力的有效手段;而性格内外向性、情绪稳定性等因素,对脑力工作能力的影响不明显。 相似文献
44.
放射性肝纤维化过程的定量研究 总被引:6,自引:0,他引:6
经^60Coγ线照射大鼠肝区,通过光镜、电镜和图像分析仪、宣研究了照后1年肝脏的病理改变。结果表明,30Gy组在照射后1年内逐渐发生了放射性肝纤维化病变。在肝纤维化发生过程中,肝细胞内糖原颗凿含量进行性减少,间质中胶原纤维含量进行性增加,网状纤维于照射1-3个月呈进行性增加。 相似文献
45.
Acute Immobilization Stress and Intraventricular Injection of CRF Suppress Naloxone-Induced LH Release in Ovariectomized Estrogen-Primed Rats 总被引:1,自引:0,他引:1
Tatsuo Akema Atsuhiko Chiba Reiji Shinozaki Morihiro Oshida Fukuko Kimura & Jun-ichi Toyoda 《Journal of neuroendocrinology》1996,8(8):647-652
The present study was undertaken to evaluate the role and possible interaction of the endogenous opioid peptide (EOP) and corticotropin-releasing factor (CRF) in the acute stress-induced suppression of gonadotropin secretion in ovariectomized estrogen-primed rats. An intravenous (i.v.) injection of naloxone (10 or 20 mg/kg), an EOP antagonist, significantly elevated serum luteinizing hormone (LH) levels within 10 min in non-stressed animals. The naloxone-induced LH release was completely eliminated when tested 30 min after the onset of acute immobilization. In a subsequent study, it was found that suppression of the naloxone-induced LH release occurred as early as 5 min after the stress onset, and was still evident 60 min after the end of a 30-min period of immobilization. The effect of naloxone was restored 3 h after liberation of the animal from the 30-min immobilization. An intraventricular (i.c.v.) injection of CRF (1 or 5 μg) also significantly suppressed, in a dose-related manner, the effect of a subsequent i.v. injection of naloxone. However, an i.c.v. injection of α -helical CRF(9-41) (25 or 50 μg), a CRF antagonist, prior to immobilization, could not interfere with the suppressive effect of stress on naloxone-induced LH release. These results suggest that both acute immobilization stress and CRF can inhibit the LH secretory activity without mediation by EOP neurons. However, the stress-related suppression may involve non-CRF mechanism(s). 相似文献
46.
为提供微波辐射安全标准必要的数据,研究了不同极化方向微波辐射能量对猕猴的影响。实验在医学微波无反射室中进行,分为电场,磁场和微波传输方向极化组,辐射频率1GHz,用红外热图技术,对暴露在三种极化方向电磁场中猕猴面部各解剖特片部位及胸部在辐射前后进行温度变化的定量分析。 相似文献
47.
J. de Pedro-Cuesta V. Abraira G.-X. Jiang G. Solders S. Fredrikson 《Acta neurologica Scandinavica》1996,93(2-3):175-183
Using hierarchical cluster analysis, applied to 47 cases of Guillain-Barre Syndrome (GBS) incident in South-West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 ± 6.7 years), recorded a peak incidence at ages 20–29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 ± 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.47; of cases, was older (61.1 ± 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time. 相似文献
48.
J. Rutenfranz W. Ottmann B. Neidhart W. Brockmann 《International archives of occupational and environmental health》1988,61(1-2):89-93
Summary A typical shiftwork experiment was chosen to prove the validity of an automated procedure for the analysis of free noradrenaline and adrenaline in urine. The method consists of a column switching technique with an adsorption/elution clean-up and a reversed phase high performance liquid chromatography followed by chemical reaction detection based on the trihydroxyindole method. The analysis of variance was performed using a second data set obtained by a semi-automated procedure for which the accuracy had already been confirmed. The analysis of covariance showed that for field studies, as well as for laboratory experiments in which the variances contributed by the experiments themselves are greater than 10% rel., the data sets of the two methods provide the same information.Dedicated to Prof. H. Hartkamp, University of Wuppertal, on the occasion of his 60th birthday 相似文献
49.
50.
笔者对13例良性小脑出血的患者,从起病、临床表现进行了具体分析.总结出中老年良性小脑出血的6个特点,供临床工作者参考. 相似文献