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   4471篇
  免费   226篇
  国内免费   14篇
耳鼻咽喉   35篇
儿科学   243篇
妇产科学   109篇
基础医学   632篇
口腔科学   127篇
临床医学   332篇
内科学   762篇
皮肤病学   424篇
神经病学   256篇
特种医学   66篇
外科学   332篇
综合类   92篇
预防医学   283篇
眼科学   236篇
药学   451篇
中国医学   18篇
肿瘤学   313篇
  2023年   46篇
  2022年   167篇
  2021年   242篇
  2020年   117篇
  2019年   154篇
  2018年   165篇
  2017年   115篇
  2016年   152篇
  2015年   141篇
  2014年   191篇
  2013年   223篇
  2012年   303篇
  2011年   303篇
  2010年   181篇
  2009年   151篇
  2008年   214篇
  2007年   197篇
  2006年   203篇
  2005年   178篇
  2004年   155篇
  2003年   149篇
  2002年   161篇
  2001年   83篇
  2000年   96篇
  1999年   69篇
  1998年   28篇
  1997年   25篇
  1996年   29篇
  1995年   12篇
  1994年   20篇
  1993年   21篇
  1992年   38篇
  1991年   29篇
  1990年   49篇
  1989年   45篇
  1988年   35篇
  1987年   29篇
  1986年   26篇
  1985年   24篇
  1984年   16篇
  1983年   14篇
  1982年   11篇
  1981年   8篇
  1980年   11篇
  1979年   12篇
  1978年   10篇
  1977年   13篇
  1974年   6篇
  1972年   6篇
  1971年   7篇
排序方式: 共有4711条查询结果,搜索用时 31 毫秒
41.
The present study was undertaken to compare the efficacy and safety of thalidomide to that of oral prednisolone in the treatment of moderate to severe type 2 lepra reaction. Sixty patients with a histologically confirmed diagnosis of erythema nodosum leprosum with a clinical score of 4 or more (i.e. moderate to severe type 2 reaction) were randomly allocated to two groups comprising 30 patients each. Group 1 patients were given thalidomide at a dose of 300 mg/day for 1 week and the dose was gradually reduced, and Group 2 received prednisolone 40 mg daily for 2 weeks, which was tapered by 10 mg every 2 weeks. Thalidomide induced a faster clinical response (cutaneous as well as systemic) compared with prednisolone. Patients taking thalidomide had fewer relapses and a longer period of remission than those receiving prednisolone.  相似文献   
42.
43.
44.
45.

Objective

To assess the quality of facility-based active management of the third stage of labour in Ethiopia, Kenya, Madagascar, Mozambique, Rwanda and the United Republic of Tanzania.

Methods

Between 2009 and 2012, using a cross-sectional design, 2317 women in 390 health facilities were directly observed during the third stage of labour. Observers recorded the use of uterotonic medicines, controlled cord traction and uterine massage. Facility infrastructure and supplies needed for active management were audited and relevant guidelines reviewed.

Findings

Most (94%; 2173) of the women observed were given oxytocin (2043) or another uterotonic (130). The frequencies of controlled cord traction and uterine massage and the timing of uterotonic administration showed considerable between-country variation. Of the women given a uterotonic, 1640 (76%) received it within three minutes of the birth. Uterotonics and related supplies were generally available onsite. Although all of the study countries had national policies and/or guidelines that supported the active management of the third stage of labour, the presence of guidelines in facilities varied across countries and only 377 (36%) of 1037 investigated providers had received relevant training in the previous three years.

Conclusion

In the study countries, quality and coverage of the active management of the third stage of labour were high. However, to improve active management, there needs to be more research on optimizing the timing of uterotonic administration. Training on the use of new clinical guidelines and implementation research on the best methods to update such training are also needed.  相似文献   
46.
Water buffaloes are the principle source of milk in south Asia and Africa. Mammary gland repeatedly undergoes the cycles of growth and regeneration during pregnancy, lactation and involution. It is assumed that buffalo mammary gland has mammary stem and progenitor cells that regulate gland growth and regeneration. In the present study the authors analyzed percentage of cellular composition, proliferation status and putative mammary stem/progenitor cell population. Identification of putative buffalo mammary stem/progenitor cells was attempted using immunohistochemical staining with Musashi1 (MSI1), an adult stem cell marker and fibronectin type III domain containing 3B (FNDC3B), a mammary stem and cancer cell marker. Immunolocalization of MSI1 and FNDC3B showed nuclear and cytoplasmic staining of alveolar and ductal mammary epithelial cells (MEC) and a few stromal cells. The percentage of MSI1-positive MEC in non-lactating (3.31 ± 1.11 %), lactating (2.73 ± 0.78 %) and mastitic glands (3.30 ± 0.97 %) were equivalent, indicating that the proportion of putative stem/progenitor cell population did not differ during various physiological stages. Likewise, the percentage of FNDC3B-positive MEC in non-lactating (12.40 ± 3.22 %) tended to be higher than lactating (8.19 ± 2.71 %) and mastitic glands (4.88 ± 2.37 %). In some cases, expression of MSI1 and FNDC3B was exceptionally high with high proliferative indices (37.6 ± 2.4 %)-an indication of tumor cells. This is the first report on expression of MSI1 and FNDC3B in buffalo mammary gland. Identification of buffalo mammary stem cells using MSI1 and FNDC3B requires further studies and functional validation.  相似文献   
47.
Metabolic Brain Disease - Human diseases have always been a significant turf of concern since the origin of mankind. It is cardinal to know the cause, treatment, and cure for every disease...  相似文献   
48.
The rising prevalence of the chronic obstructive pulmonary disease (COPD) is generally attributed to smoking, since the role of other risk factors among non-smokers are not well established especially in low and middle income countries like India. This is also reflected by the limited literature available on non-smoking related COPD risk factors like indoor and outdoor air pollution. The present review is an attempt to assess the influence of non-smoking risk factors on COPD and its measures in Indian subcontinent. The most noteworthy factors among non-smokers appear to be the use of biomass fuel for cooking and heating purposes. We observed that the studies undertaken to evaluate the role of such risk factors are inconclusive due to weak methodologies and small sample sizes, may be due to limited financial resources. The present review suggests the need of a nationally representative study to estimate the effect of each of the potential modifiable risk factor (other than smoking) for framing impactful public health policies to prevent and manage COPD at community and population level in India.  相似文献   
49.
Enrichment for murine keratinocyte stem cells based on cell surface phenotype   总被引:54,自引:0,他引:54  
The identification and physical isolation of epithelial stem cells is critical to our understanding of their growth regulation during homeostasis, wound healing, and carcinogenesis. These stem cells remain poorly characterized because of the absence of specific molecular markers that permit us to distinguish them from their progeny, the transit amplifying (TA) cells, which have a more restricted proliferative potential. Cell kinetic analyses have permitted the identification of murine keratinocyte stem cells (KSCs) as slowly cycling cells that retain [(3)H]thymidine ([(3)H]Tdr) label, termed label-retaining cells (LRCs), whereas TA cells are visualized as rapidly cycling cells after a single pulse of [(3)H]Tdr, termed pulse-labeled cells (PLCs). Here, we report on the successful separation of KSCs from TA cells through the combined use of in vivo cell kinetic analysis and fluorescence-activated cell sorting. Specifically, we demonstrate that murine dorsal keratinocytes characterized by their high levels of alpha(6) integrin and low to undetectable expression of the transferrin receptor (CD71) termed alpha(6)(bri)CD71(dim) cells, are enriched for epithelial stem cells because they represent a minor ( approximately 8%) and quiescent subpopulation of small blast-like cells, with a high nuclear:cytoplasmic ratio, containing approximately 70% of label-retaining cells, the latter being a well documented characteristic of stem cells. Conversely, TA cells could be enriched in a phenotypically distinct subpopulation termed alpha(6)(bri)CD71(bri), representing the majority ( approximately 60%) of basal keratinocytes that are actively cycling, and importantly contain approximately 70% of [(3)H]Tdr pulse-labeled cells. Importantly, immunostaining of dorsal skin revealed the presence of CD71(dim) cells in the hair follicle bulge region, a well documented location for KSCs.  相似文献   
50.
We report a patient with splenic vein thrombosis (SVT) in whom splenectomy resulted in the unmasking of essential thrombocythemia (ET). He had portal hypertension with haematemesis, resulting in anaemia requiring repeated blood transfusions. Investigations revealed SVT. Following splenectomy, he suffered a transient ischaemic attack episode, associated with persistent thrombocytosis (> 2000 x 10(9)/l). Other myeloproliferative disorders were excluded and a diagnosis of ET was established. He responded to hydroxyurea but, due to financial constraints, he discontinued treatment and subsequently relapsed. The association of ET with SVT is rare and the diagnosis of ET was missed initially as the platelet count was normal prior to splenectomy.  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