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   3119篇
  免费   164篇
  国内免费   3篇
耳鼻咽喉   47篇
儿科学   125篇
妇产科学   49篇
基础医学   337篇
口腔科学   53篇
临床医学   187篇
内科学   522篇
皮肤病学   57篇
神经病学   222篇
特种医学   116篇
外科学   385篇
综合类   91篇
预防医学   224篇
眼科学   245篇
药学   359篇
中国医学   13篇
肿瘤学   254篇
  2023年   17篇
  2022年   57篇
  2021年   70篇
  2020年   32篇
  2019年   57篇
  2018年   59篇
  2017年   49篇
  2016年   70篇
  2015年   67篇
  2014年   82篇
  2013年   123篇
  2012年   229篇
  2011年   213篇
  2010年   106篇
  2009年   96篇
  2008年   138篇
  2007年   149篇
  2006年   143篇
  2005年   135篇
  2004年   128篇
  2003年   113篇
  2002年   102篇
  2001年   67篇
  2000年   75篇
  1999年   80篇
  1998年   35篇
  1997年   19篇
  1996年   22篇
  1995年   17篇
  1993年   18篇
  1992年   67篇
  1991年   57篇
  1990年   56篇
  1989年   52篇
  1988年   27篇
  1987年   38篇
  1986年   38篇
  1985年   33篇
  1984年   31篇
  1983年   31篇
  1981年   14篇
  1980年   17篇
  1979年   24篇
  1978年   21篇
  1976年   14篇
  1974年   20篇
  1973年   35篇
  1972年   14篇
  1971年   15篇
  1970年   18篇
排序方式: 共有3286条查询结果,搜索用时 0 毫秒
81.
82.
83.
Myasthenic gravis (MG) is an autoimmune disease associated with acetylcholine receptor deficiency. Patients with MG exhibit increased sensitivity to non-depolarising muscle relaxants. In an attempt to avoid neuromuscular blockers, we used sevoflurane in two myasthenic patients undergoing trans-sternal thymectomy. Inhalation of 8% sevoflurane in oxygen using vital capacity technique produced rapid, pleasant and smooth induction and provided good tracheal intubating conditions. In both patients anaesthesia was maintained with 1.5-2% end-tidal concentration of sevoflurane and nitrous oxide in oxygen without adjunctive neuromuscular blocking agents. There were minimal changes in cardiovascular variables and recovery was faster. It is suggested that sevoflurane may be the main anaesthetic for both induction and maintenance in myasthenic patients undergoing trans-sternal thymectomy.  相似文献   
84.
85.
The purpose of this study was to determine whether tumor necrosis factor (TNF) contributes to airway hyperresponsiveness (AHR) and migration of polymorphonuclear leukocytes (PMN) into the airways following exposure to ozone (O(3)). Wild-type mice, TNF p55 or p75 receptor knockout mice (p55 TNFR -/- and p75 TNFR -/-), as well as double receptor knockout mice (p55/p75 TNFR -/-), were exposed to O(3). Three hours after cessation of O(3), airway responses to inhaled methacholine were determined by whole body plethysmography using changes in enhanced pause (Penh) as an index of airway narrowing. In wild-type mice, O(3) exposure (0.5 ppm, 3 h) caused a significant increase in airway responsiveness as indicated by a 1.2 log leftward shift in the methacholine dose- response curve. In contrast, in p55/p75 TNFR -/- mice, O(3) caused only a 0.5 log shift in the dose-response curve (p < 0.05 compared with wild-type). Similar results were obtained in p75 TNFR -/- mice. In contrast, O(3)-induced airway hyperresponsiveness was not different in WT and p55 TNFR -/- mice. During O(3) exposure (1 pm, 3 h), minute ventilation (V E) decreased by 64 +/- 4% in wild-type, but only 24 +/- 5% in p55/p75 TNFR -/- mice, indicating that despite their reduced O(3)-induced AHR, the TNFR-deficient mice actually inhaled a greater dose of O(3). Similar results were obtained in p75 -/- mice, whereas changes in V E induced by O(3) were the same in wild-type and p55 -/- mice. PMN numbers in bronchoalveolar lavage fluid recovered 21 h after cessation of exposure to O(3) (2 ppm, 3 h) were significantly increased compared with after air exposure but were not different in wild-type and p55/p75 TNFR -/- mice. Our results indicate that TNF contributes to the AHR but not the PMN emigration induced by acute O(3) exposure. Keywords: whole body plethysmography; polymorphonuclear leukocytes; minute ventilation; knockout mice; methacholine  相似文献   
86.
87.
88.
Parathyroid hormone (PTH) has been a major contributor to the anabolic therapy for osteoporosis, but its delivery to bone without losing activity and avoiding adverse local effects remain a challenge. Being the natural component of bone, use of hydroxyapatite for this purpose brings a major breakthrough in synergistic anabolism. This study focuses on synthesis, characterization and evaluation of in vitro and in vivo efficacy of PTH (1-34) adsorbed hydroxyapatite nanocarrier for synergistic enhancement in the anabolic activity of PTH for bone regeneration. The negative zeta potential of this nanocarrier facilitated its affinity to the Ca2+ rich bone tissue and solubilization at low pH enhanced specific delivery of PTH to the resorption pits in osteoporotic bone. In this process, PTH retained its anabolic effect and at the same time an increase in bone mineral content indicated enhancement of the net formative effect of the PTH anabolic therapy.  相似文献   
89.
Back pain is a significant health service issue in Australia and internationally. Back pain sufferers can draw upon a range of health care providers including complementary and alternative medicine (CAM) practitioners. Women are higher users of health services than men and tend to use CAM frequently for musculoskeletal conditions. However, there remain important gaps in our understanding of women’s consultation patterns with CAM practitioners for back pain. The objective of this study is to examine the prevalence of use and characteristics of women who use CAM practitioners for back pain. The method used was a survey of a nationally representative sample of women aged 60–65 years from the Australian Longitudinal Study on Women’s Health. Women consulted a massage therapist (44.1 %, n?=?578) and a chiropractor (37.3 %, n?=?488) more than other CAM practitioners for their back pain. Consultations with a chiropractor for back pain were lower for women who consulted a General Practitioner (GP) (OR, 0.56; 95 % CI 0.41, 0.76) or a physiotherapist (OR, 0.53; 95 % CI 0.39, 0.72) than for those who did not consult a GP or a physiotherapist. CAM practitioner consultations for back pain were greater for women who visited a pharmacist (OR, 1.99; 95 % CI 1.23, 3.32) than for women who did not visit a pharmacist. There is substantial use of CAM practitioners alongside conventional practitioners amongst women for back pain, and there is a need to provide detailed examination of the communication between patients and their providers as well as across the diverse range of health professionals involved in back pain care.  相似文献   
90.
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