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   620篇
  免费   51篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   32篇
妇产科学   1篇
基础医学   71篇
口腔科学   6篇
临床医学   72篇
内科学   94篇
皮肤病学   11篇
神经病学   30篇
特种医学   184篇
外科学   24篇
综合类   7篇
预防医学   43篇
眼科学   5篇
药学   68篇
  1篇
中国医学   13篇
肿瘤学   18篇
  2021年   10篇
  2020年   7篇
  2019年   4篇
  2018年   16篇
  2017年   7篇
  2016年   3篇
  2015年   8篇
  2014年   9篇
  2013年   19篇
  2012年   20篇
  2011年   28篇
  2010年   22篇
  2009年   23篇
  2008年   19篇
  2007年   20篇
  2006年   24篇
  2005年   13篇
  2004年   19篇
  2003年   17篇
  2002年   15篇
  2001年   21篇
  2000年   16篇
  1999年   16篇
  1998年   24篇
  1997年   17篇
  1996年   30篇
  1995年   18篇
  1994年   23篇
  1993年   17篇
  1992年   8篇
  1991年   7篇
  1990年   6篇
  1989年   18篇
  1988年   15篇
  1987年   22篇
  1986年   14篇
  1985年   15篇
  1984年   10篇
  1983年   14篇
  1982年   11篇
  1981年   11篇
  1980年   9篇
  1979年   9篇
  1978年   3篇
  1977年   6篇
  1976年   9篇
  1975年   6篇
  1974年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有681条查询结果,搜索用时 140 毫秒
1.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml ̄(-1)诱导HL-60细胞发生凋亡,而阻断HR20细胞于G_1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml ̄(-1)处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G_1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关  相似文献   
2.
Hydrolysis of peptides within lumen of small intestine   总被引:2,自引:0,他引:2  
  相似文献   
3.
4.
Guinea pig basophils, cloned mouse mast cells, and cloned mouse granule-containing lymphoid cells were found to utilize a vesicular transport system to internalize eosinophil peroxidase (EPO) added in vitro. Kinetic analysis indicated that EPO internalization involved the binding of EPO to the plasma membrane, the formation of complex surface invaginations, and the movement of EPO-laden vesicles, tubules, and vacuoles toward the center of the cells. EPO became associated with multivesicular bodies in granule-containing lymphoid cells and mast cells, with immature granules in mast cells, and with mature granules in basophils. In other cells, the endogenous production of granule peroxidases (neutrophils and eosinophils) or the prior uptake of exogenous peroxidatic substances (some basophils) precluded cytochemical analysis of granules for EPO. Vesicular transport of EPO provides a possible explanation for the variable detection of peroxidase activity in mast cells or basophils. It also provides a mechanism for sequestration of this potentially toxic material or for its storage for possible future use.  相似文献   
5.
Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation  相似文献   
6.
Differential pattern of DNA-aneuploidy in human malignancies   总被引:5,自引:0,他引:5  
The differential pattern of DNA-aneuploidy, detected by flow cytometry (FCM) regarding its frequency, grade and multiclonality, was investigated and correlated to tumor type, malignancy grade, tumor stage and prognosis in a multi-institutional study at the University of Münster. High resolution measurements using admixed normal blood reference cells were undertaken in 2413 cases of 13 different malignant diseases and in 776 benign lesions or samples. The incidence of DNA-aneuploidy was highest in melanomas, carcinomas, testicular tumors, sarcomas (75%-95%) and myelomas (65%). Acute leukemias showed an intermediate DNA-aneuploidy rate of 40% with special subgroups represented by common ALL (44%), p less than 0.05) and myelomonocytic/monocytic AML (47%, p less than 0.01). The lowest DNA-aneuploidy-rate was found in basal cell skin carcinomas (19%) and congenital melanocytic nevi (9%). No case of DNA-aneuploidy was observed in the 776 benign lesions or samples.--DNA-indices giving the grade of DNA-aneuploidy with 1.0 for normal diploid G1/0 cells were found distributed predominantly between 1.0 and 2.0 in the solid tumors, except testicular tumors, clustering around a triploid maximum at 1.5. DNA-indices of myelomas and acute leukemias generally ranged below 1.25 with lower DNA-aneuploidy grades in AML than in ALL (p less than 0.01).--In melanomas the aneuploidy rate was higher (86%) in metastases than in the primary tumors (54%, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.
8.
Osteosarcomatosis   总被引:10,自引:0,他引:10  
A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.  相似文献   
9.
Uses an empirical investigation based on a survey of junior doctors in five NHS trust hospitals, to examine their attitudes towards both the general principle of clinical involvement in hospital management and the particular prospect of exercising such a role themselves. Finds that junior doctors, with few exceptions and irrespective of grade, were very positive towards clinical management roles in NHS trusts and were almost universally keen to assume management responsibilities when they were more senior. At the same time, finds junior doctors to have little concept of the doctor manager role or the recognized and demanded specific preparation for assuming management responsibilities.  相似文献   
10.
Given the increasing advocacy for the use of inhaled corticosteroids as a treatment of choice for persistent asthma, growing numbers of children are being exposed to the possible growth-suppressing effects of glucocorticoids. Recent evidence strongly suggests that, when consistently administered at moderate doses, inhaled corticosteroids (IC) are capable of slowing growth in children. Whether such growth suppression would persist and ultimately affect final adult height remains unknown. Therapeutic goals which aim for uninterrupted inflammatory disease control rather than periodic symptom control may increase the occurrence of growth failure in children treated with IC. In this article, current information about the mechanisms of growth suppression by glucocorticoids and the effects of IC on growth is reviewed, and recommendations for designing studies to investigate the effects of drugs on growth are presented.  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