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   660篇
  免费   68篇
  国内免费   1篇
耳鼻咽喉   5篇
儿科学   46篇
妇产科学   4篇
基础医学   70篇
口腔科学   29篇
临床医学   147篇
内科学   83篇
皮肤病学   9篇
神经病学   58篇
特种医学   14篇
外科学   68篇
综合类   3篇
一般理论   1篇
预防医学   77篇
眼科学   5篇
药学   60篇
肿瘤学   50篇
  2023年   2篇
  2022年   7篇
  2021年   13篇
  2020年   13篇
  2019年   24篇
  2018年   20篇
  2017年   22篇
  2016年   21篇
  2015年   20篇
  2014年   25篇
  2013年   43篇
  2012年   38篇
  2011年   35篇
  2010年   25篇
  2009年   28篇
  2008年   49篇
  2007年   48篇
  2006年   42篇
  2005年   54篇
  2004年   43篇
  2003年   40篇
  2002年   36篇
  2001年   7篇
  2000年   2篇
  1999年   4篇
  1998年   5篇
  1997年   7篇
  1996年   6篇
  1995年   4篇
  1994年   6篇
  1993年   5篇
  1992年   6篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1971年   3篇
  1970年   2篇
  1969年   1篇
排序方式: 共有729条查询结果,搜索用时 0 毫秒
61.
Melanoma is the most lethal skin cancer. Most deaths from melanoma result from metastases. Semaphorins have been shown to inhibit neuronal and endothelial cell migration, but the effects of semaphorins on tumor metastasis have not been documented. We found that semaphorin 3F (SEMA3F) was markedly downregulated in highly metastatic human cell lines in vitro and in vivo, which suggested that it may be a metastasis inhibitor. Metastatic human melanoma cells were transfected with SEMA3F and implanted into mice; the resultant tumors did not metastasize. Rather, the primary tumors resembled benign nevi characterized by large areas of apoptosis, diminished vascularity, inhibition of hyperplasia in overlying epidermal cells, and encapsulated tumor borders delineated by thick layers of fibroblasts and collagen matrix. This phenotype is in stark contrast to highly invasive, vascular mock-transfected tumors. In vitro, tumor cells expressing SEMA3F had a diminished capacity to adhere and migrate on fibronectin. Consistent with semaphorin-mediated chemorepulsion of neurons, tumor cells expressing SEMA3F were chemorepulsive for vascular and lymphatic endothelial cells expressing neuropilin-2 (NRP2), a novel mechanism for a tumor angiogenesis inhibitor. The repulsive activity was abrogated by NRP2 RNA interference. Together these results indicate that SEMA3F is a potent metastasis inhibitor that targets both tumor and stromal cells and raise the possibility of SEMA3F having therapeutic potential.  相似文献   
62.
63.
64.
65.
This article discusses conceptions of sexuality and the satisfaction of sexual needs in a sample of aged home nursing patients (N = 50) in a small rural town in Finland. The purpose of the study, which was carried out as part of a nursing development project in the form of action research, was to gain a deeper understanding of the satisfaction of basic human needs and problems of need-satisfaction in aged people, particularly in the domain of sexual needs. The data were collected using a semi-structured questionnaire, which was designed primarily on the basis of the need theories of Yura & Walsh and Orem. Negative attitudes towards sexual needs were found in more than half of the aged respondents; they did not consider it proper for aged people to have an active sex life. One-quarter felt that sexual needs and desires were shameful and sinful. Only less than one-quarter had positive attitudes towards sex. The majority of the respondents felt that they could freely and confidently talk about sex with the nursing staff, but only less than one-quarter were willing to do so. Almost all had some need to show affection to another person. The majority accepted their own self-image, but half were not satisfied with their physical appearance.  相似文献   
66.
The extent of rehabilitation services is adequate, but little feedback is available on these services and service users. This paper is based on a client feedback survey of physiotherapy services conducted in Spring 2000. The purpose of the paper is to compare patients' perceptions of the physiotherapy instruction they received in a private outpatient facility and in a public physiotherapy facility. The results of the study showed that physiotherapy clients were satisfied with the therapy and instruction they received. They felt they received an adequate amount of instructions and advice. The rehabilitee's strong commitment to care, high motivation and a support network are important to independent rehabilitation in the future. As for the point of contact, the majority of clients in the private physiotherapy facility were gainfully employed while the health centre had almost as many retired clients. Client instruction was not dependent on the point of contact.  相似文献   
67.
This study examines sociodemographic differences in myocardial infarction (MI) risk perceptions among people with coronary heart disease (CHD) (N = 3130). Two variables for comparative risk perceptions were computed: (1) own risk compared to that of an average person; and (2) own risk compared to that of an average person with CHD. Comparative optimism in MI risk perceptions was common, particularly among men and those with higher education. CHD severity and psychosocial resources mediated these sociodemographic differences. These results suggest challenges for secondary prevention in CHD, particularly regarding psychosocial interventions for communicating risk information and supporting lifestyle adjustments.  相似文献   
68.
69.
ES remains an important cause of morbidity and mortality in children undergoing auto‐HCT. Glucocorticoid use in ES is an area of debate. We retrospectively analyzed single‐institution experience from September 2000 through December 2012 to evaluate the use of glucocorticoids in auto‐HCT patients. ES was defined by the occurrence of new onset of non‐infectious fever plus diarrhea, rash, or pulmonary infiltrates 24‐h before or within five days after neutrophil engraftment. Sixty‐five pediatric patients (<21 yr) with different solid tumors underwent auto‐HCTs in the study period. Fifteen patients (23%) fulfilled criteria for ES, of which 13 received methylprednisolone (2 mg/kg IV for 3–5 days). Clinical improvement occurred in all patients within 48 h without significant complications. In the non‐ES group, 11 patients received glucocorticoid without significant complications as well. MEL‐based regimens were found to be significant factor for ES (p < 0.05). Fever, edema, non‐infectious diarrhea, and serum albumin concentration were statistically different between the two groups. Median hospital length of stay was higher in the ES group. Conclusion: ES is a common complication in children after auto‐HCT and short‐course glucocorticoid therapy is an effective and well‐tolerated treatment, even in those who did not completely fulfill diagnostic criteria.  相似文献   
70.
Aim : To compare the neuromuscular function and balance of blind prepuberty- and puberty-aged boys to those with normal sight. Methods : Thirty-three prepubertal (aged 9–13 y) and pubertal (aged 15–18 y) blind and sighted boys were tested for muscle mass thickness, electromyography and maximal isometric strength, dynamic explosive actions, and balance. Results : There was no difference in the muscle mass thickness, maximal strength or vertical jump between the blind and sighted boys. However, fitness-ball throwing and five-jump distances were significantly shorter in both blind groups compared to the sighted groups. One-leg stance of the prepuberty-aged sighted boys was 109 (67) s and in blind boys 32 (12) s, and in the puberty-aged boys 120 (57) s and 31 (8) s, respectively. When vision was blocked in the sighted boys, differences between the blind and sighted boys disappeared.
Conclusion : The results showed comparable performance between prepubertal and pubertal blind and sighted boys in the static physical fitness tests. However, balance and performance in dynamic multi-joint tests did not improve similarly in the blind groups compared to sighted groups, indicating that maturation, learning and experience by themselves cannot compensate for the loss of sight.  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