首页 | 官方网站   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   23436篇
  免费   1158篇
  国内免费   123篇
医药卫生   24717篇
  2021年   415篇
  2020年   253篇
  2019年   285篇
  2018年   400篇
  2017年   309篇
  2016年   369篇
  2015年   377篇
  2014年   541篇
  2013年   662篇
  2012年   1014篇
  2011年   1105篇
  2010年   602篇
  2009年   537篇
  2008年   1037篇
  2007年   1091篇
  2006年   1033篇
  2005年   970篇
  2004年   970篇
  2003年   952篇
  2002年   982篇
  2001年   891篇
  2000年   930篇
  1999年   796篇
  1998年   290篇
  1997年   210篇
  1996年   173篇
  1995年   177篇
  1994年   155篇
  1993年   138篇
  1992年   597篇
  1991年   624篇
  1990年   532篇
  1989年   539篇
  1988年   520篇
  1987年   497篇
  1986年   426篇
  1985年   428篇
  1984年   314篇
  1983年   241篇
  1979年   232篇
  1978年   132篇
  1977年   136篇
  1974年   128篇
  1973年   119篇
  1972年   137篇
  1971年   127篇
  1970年   114篇
  1969年   137篇
  1968年   110篇
  1967年   128篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
Objectives: To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD).

Methods: Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n?=?93, Study 2: n?=?99) were retrospectively analyzed.

Results: In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p?r2: 0.088, p?=?.02). While average sCa of the patients was 9.2?mg/dL before treatment, it increased time-dependently to 9.6?mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike’s information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3?mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3?mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3?mg/dL (0.8%, p?=?.038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed.

Conclusion: sCa was associated with an increased LS-BMD by BPs with aVD.  相似文献   
5.
6.
Early onset periodontitis is rarely seen in infants, though often leads to an acute and serious clinical course when encountered in such patients. Autoimmune neutropenia presents systemic and dental symptoms, as depressed resistance to bacterial infection is caused by a disorder that reduces the number of neutrophils. This disease can result in not only gingival inflammation but also destruction of periodontal tissues, such as attachment loss, alveolar bone absorption, and early tooth loss in primary as well as mixed dentition. Here, we report treatment of a child with marginal periodontitis from the age of 3 years–7 years 9 months. No systemic manifestations were noted until 3 years of age, thus the patient had never received a detailed examination or medication related to the disease. Following examinations at our department, we referred the patient to a pediatrician at our university hospital for possible systemic disease, who made a diagnosis of autoimmune neutropenia. Although administration of antibiotics and professional dental care were continued, neutrophil count was not increased and progressive periodontal destruction was observed. Extraction of teeth with poor prognosis was performed and a prosthetic strategy for the missing teeth developed. It is important to recognize that periodontitis along with autoimmune neutropenia can appear in infants, even though the incidence is quite low. Early detection and early treatment of this disease is necessary for delaying progression of periodontitis and optimal occlusal induction of permanent teeth.  相似文献   
7.
8.
9.
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN.  相似文献   
10.
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-23

京公网安备 11010802026262号