首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   525篇
  免费   12篇
耳鼻咽喉   2篇
儿科学   53篇
妇产科学   6篇
基础医学   41篇
口腔科学   10篇
临床医学   33篇
内科学   122篇
皮肤病学   23篇
神经病学   45篇
特种医学   2篇
外科学   76篇
综合类   2篇
预防医学   9篇
眼科学   1篇
药学   51篇
肿瘤学   61篇
  2022年   3篇
  2021年   7篇
  2016年   4篇
  2015年   9篇
  2014年   6篇
  2013年   5篇
  2012年   6篇
  2011年   7篇
  2010年   8篇
  2009年   8篇
  2007年   8篇
  2006年   29篇
  2005年   12篇
  2004年   16篇
  2003年   11篇
  2002年   6篇
  2001年   4篇
  2000年   3篇
  1999年   6篇
  1998年   25篇
  1997年   24篇
  1996年   30篇
  1995年   31篇
  1994年   20篇
  1993年   23篇
  1992年   17篇
  1991年   9篇
  1990年   10篇
  1988年   7篇
  1987年   9篇
  1986年   22篇
  1985年   19篇
  1984年   7篇
  1983年   4篇
  1982年   5篇
  1981年   9篇
  1980年   8篇
  1979年   8篇
  1978年   6篇
  1970年   2篇
  1969年   3篇
  1967年   2篇
  1960年   2篇
  1959年   2篇
  1958年   15篇
  1957年   15篇
  1956年   13篇
  1955年   10篇
  1954年   9篇
  1948年   2篇
排序方式: 共有537条查询结果,搜索用时 15 毫秒
61.
62.
This report deals with a comparative study on the expression of alpha B crystallin, ubiquitin, stress-response protein 27 (srp 27), srp 72 and phosphorylated neurofilament protein (pNFP) by ballooned neurons in Pick's disease, Creutzfeldt-Jakob disease (CJD), amyotrophic lateral sclerosis (ALS), leptomeningeal carcinomatosis, anterior spinal artery syndrome and pellagra. Immunohistochemical techniques were used. alpha B Crystallin was expressed by the majority of ballooned neurons of Pick's disease and CJD, but not by those of the other disorders. Ubiquitin and srp 27 expression was also restricted to abnormal neurons of Pick's disease and CJD, but the proportion of stained cells was less than that expressing alpha B-crystallin. There was no evidence of ballooned neurons expressing srp 72. Except for those of pellagra patients, phosphorylated neurofilament protein (pNFP) was detected in most abnormal neurons. Our results suggest that the mechanisms involved in formation and maintenance of swollen neurons in Pick's disease and CJD may be different than those of ballooned neurons in the other entities studied.  相似文献   
63.
Background: Since the prevalence of atrial fibrillation (AF) increases progressively with aging, especially in men, we hypothesized that testosterone might affect the occurrence of AF.
Methods and Results: We examined the electrophysiological properties of the atria in isolated-perfused hearts of sham-operated male (SM), female (SF), orchiectomized male with and without administration of testosterone (ORCH-T and ORCH), and ovariectomized female (OVX) Sprague-Dawley rats. An electrophysiological study revealed that repetitive atrial responses induced by electrical stimuli significantly increased in ORCH rats without changes in other electrophysiological properties and were abolished by administration of testosterone. To investigate the underlying mechanisms, we evaluated the expression level of calcium-handling proteins. In ORCH rats, the immunoreactive protein level of ryanodine receptor type 2 (RyR2) and sodium–calcium exchanger significantly increased as compared with SM and ORCH-T rats without alterations in the level of FK506-binding protein (FKBP12.6), sarcoendoplasmic reticulum Ca-ATPase, and phospholamban. Immunoprecipitation analysis demonstrated decreased binding of FKBP12.6 to RyR2 in ORCH rats, which was prevented by testosterone. In contrast, the expression levels of these proteins showed no significant differences between SF and OVX rats.
Conclusion: Deficiency of testosterone was arrhythmogenic in rat atria possibly through less binding of FKBP12.6 to RyR2, which could induce feasible calcium leakage from the sarcoendoplasmic reticulum. These results would explain, at least in part, the increase in the prevalence of AF in accordance with the decline of testosterone particularly in elderly men.  相似文献   
64.
65.
NOGAMI, A., et al. : Enhancement of J–ST-Segment Elevation by the Glucose and Insulin Test in Brugada Syndrome. The effects of glucose and insulin on J–ST-segment elevation were evaluated in seven men   (mean age 45 ± 10 years)   with Brugada syndrome. Six patients had been reanimated from VF and one patient had experienced syncope. The effects of intravenous (1) pilsicainide 50 mg, (2) glucose 50 g, and (3) glucose 50 g plus regular insulin 10 IU on the precordial ECG leads were examined. Pilsicainide significantly enhanced J-ST elevation in all patients and induced VF in 1 patient. A significant accentuation of the abnormal J-ST configuration was observed in all patients at a mean of   51 ± 40   minutes after glucose and insulin infusion. Changes in blood glucose and serum potassium concentration were   111 ± 158 mg/dL   and   −0.30 ± 0.48 mEq/L   , respectively. These changes were not directly related to the ECG changes. Glucose infusion without insulin caused a subtle increase in J-ST elevation. In conclusion, the administration of glucose and insulin safely unmasked or accentuation the J–ST-segment elevation in Brugada syndrome. Blood glucose and insulin concentrations may be factors modulating the circadian or day-to-day ECG variations in this syndrome. (PACE 2003; 26[Pt. II]:332–337)  相似文献   
66.
Abstract: To estimate the distribution of Helicobacter pylori in human gastric mucosa in vivo, the phenol red dye spraying endoscopy lias been successfully developed and is performed after an oral and/or intravenous premedication of famotidine 20mg. This technique was conducted on 25 patients with chronic, atrophic gastritis, on 21 patients with a gastric ulcer and on 14 patients with duodenal ulcers. The red color changes which occurred on the gastric mucosa were classified into three types; the diffuse staining type, the regional staining type and the patchy staining type. In the chronic gastritis group, the diffuse staining type, the regional staining type and the patchy staining type occurred in 11 patients (44%), 7 patients (28%) and 2 patients (8%), respectively. The remainder of the patients' mucosa was unstained. In addition, the regional staining type occurred most frequently in the gastric ulcer group, while the diffuse staining type was dominant in the duodenal ulcer group. Notably, a recurrent and intractable ulcer was surrounded by regional staining fields in the stomach, and showed a diffuse staining at the antrum of the duodenum. These facts suggest that Helicobacter pylori prevented ulcer healing. This concurs with the results of our previous experimental study which found that the low concentration NH3 solution, produced by Helicobacter pylori, prevented an acetic acid ulcer healing in rats and resulted from the suppression of the cell kinetics of the regenerative epithelial cells and the fibroblasts in the connective tissues at the ulcer margins.  相似文献   
67.
AIM: Microalbuminuria is typically observed in renal transplant recipients with systemic hypertension. The effects of angiotensin II type 1 receptor antagonist (losartan) on the hypertensive recipients have been evaluated. However, the clinical background of normotensive recipients with microalbuminuria and the effect of losartan administration in those subjects have not been clarified. One of the two purposes for the present study was to investigate the clinical characteristics of normotensive recipients with microalbuminuria. The other was to evaluate the effect of losartan on urinary excretion of albumin in these patients. METHODS: The clinical data and the change of the single kidney glomerular filtration rate (GFR) for the graft by radionuclide study were assessed in 13 normotensive recipients with microalbuminuria. These were compared with the data of 13 normotensive patients without microalbuminuria. The 13 recipients with microalbuminuria were treated with losartan for one year and urine excretion of albumin, N-acetyl-beta-D-glucosaminidase (NAG) and serum creatinine (S-Cr) levels were measured. RESULTS: The GFR of the grafts from donors to recipients significantly increased (30.9 to 55.2 mL/min) in microalbuminuric recipients, but did not significantly increase in the non-microalbuminuric recipients. Decreases of the urinary excretion rate of albumin (351 +/- 261 at baseline to 158 +/- 14 mg/gCr at 12 months), NAG (13 +/- 5 to 10 +/- 3 IU/gCr) and S-Cr (1.7 +/- 0.6 to 1.5 +/- 0.4 mg/DL) were observed in the microalbuminuric recipients with losartan administration. CONCLUSIONS: The present study suggests that an increased single kidney GFR of the graft from the donor in situ to the recipient might be a cause of microalbuminuria in normotensive recipients. The one-year effects of losartan were observed in terms of the decrease in urinary excretion of albumin, NAG and S-Cr levels.  相似文献   
68.
69.
Background: The present paper describes a patient with a right temporal lobe variant (RTLV) of frontotemporal lobar degeneration (FTLD). Methods: The study was undertaken when the patient was completely independent in her environment and had not complained of any cognitive problems. Results: Under general neuropsychological assessment, the patient showed no notable deficit other than a difficulty in recognizing famous people by looking at photographs of their faces. Subsequent in‐depth evaluation indicated prosopagnosia: the patient presented with an impaired ability to recognize the faces of famous people and family members, whereas her visuospatial abilities were intact. Because the patient was able to recognize familiar people by their voices, the impairment was not a general loss of knowledge about people, but an inability to access this knowledge from visual stimuli (i.e. via the visual modality). The patient also exhibited a ‘within‐category’ learning deficit; however, her ability to learn from ‘across‐category’ visual stimuli remained intact. Conclusions: Overall, the results of the present study support the proposed model of RTLV of FTLD, where the first sign would be the disruption of face recognition components, leading to a selective form of associative prosopagnosia. Further, the co‐occurrence of face and ‘within‐category’ object learning deficits favor an interpretation in which a more generalized deficit occurs ‘earlier’ in the sequence of events associated with the object recognition process.  相似文献   
70.
Abstract: To study reflux esophagitis in the general population, we reviewed the records of 64,171 apparently healthy Japanese adults, 48, 706 men and 15,465 women, who had undergone automated multiphasic health testing and services (AMHTS), a comprehensive routine medical health check, that includes double-contrast upper gastrointestinal roentgenograms. All subjects suspected of having gastrointestinal disease underwent a flexible fiberscopy as indicated. Reflux esophagitis was thus confirmed in 101 subjects. The prevalence of refla esophugitis was 0.20% among men and 0.04% among women (men vs. women p<0.001) and its frequency increased with age in both men (p<0.001) and women (p<0.05). Endoscopic classification according to the Savary-Miller criteria yielded 48, 27, 23, and patients in Stage I, II, III and IV, respectively. In this series, 49/101 (48.5%) of the esophagitis patients had concurrent upper gastrointestinal abnormalities. The incidence of heavy smoking and excessive drinking of alcohol was significantly higher in the patients with reflux esophagitis (p<0.001 and p<0.005, respectively) as compared with the normal population.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号