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   1293113篇
  免费   99499篇
  国内免费   3150篇
耳鼻咽喉   18499篇
儿科学   44513篇
妇产科学   35176篇
基础医学   183927篇
口腔科学   33857篇
临床医学   113358篇
内科学   260486篇
皮肤病学   28144篇
神经病学   101205篇
特种医学   51798篇
外国民族医学   673篇
外科学   197625篇
综合类   29586篇
现状与发展   5篇
一般理论   380篇
预防医学   96619篇
眼科学   28284篇
药学   96255篇
  22篇
中国医学   3395篇
肿瘤学   71955篇
  2019年   9657篇
  2018年   13714篇
  2017年   10476篇
  2016年   11353篇
  2015年   13067篇
  2014年   18035篇
  2013年   26939篇
  2012年   37077篇
  2011年   39244篇
  2010年   23557篇
  2009年   22402篇
  2008年   37436篇
  2007年   39961篇
  2006年   40216篇
  2005年   39155篇
  2004年   38087篇
  2003年   36911篇
  2002年   36208篇
  2001年   64301篇
  2000年   66851篇
  1999年   56742篇
  1998年   15324篇
  1997年   13951篇
  1996年   14371篇
  1995年   13608篇
  1994年   12906篇
  1993年   11891篇
  1992年   44647篇
  1991年   43532篇
  1990年   42300篇
  1989年   40168篇
  1988年   36936篇
  1987年   36283篇
  1986年   33653篇
  1985年   32307篇
  1984年   24161篇
  1983年   20283篇
  1982年   11731篇
  1981年   10695篇
  1979年   21343篇
  1978年   14825篇
  1977年   12533篇
  1976年   11696篇
  1975年   12630篇
  1974年   14663篇
  1973年   14125篇
  1972年   12948篇
  1971年   11731篇
  1970年   11052篇
  1969年   10026篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
OBJECTIVE: A safe entry zone to tegmental lesions was identified based on intraoperative electrophysiological findings, the compound muscle action potentials (CMAP) from the extraocular muscles, and anatomic considerations. This entry zone is bordered caudally by the intramesencephalic path of the trochlear, laterally by the spinothalamic tract, and rostrally by the caudal margin of the brachium of the superior colliculus. METHODS: Four intrinsic midbrain lesions were operated upon via the safe entry zone using the infratentorial paramedian supracerebellar approach. All lesions involved the tegmentum and included an anaplastic astrocytoma, a metastatic brain tumor, a radiation necrosis, and a cavernous angioma. CMAP were bilaterally monitored from the inferior recti (for oculomotor function) and superior oblique (for trochlear nerve function) muscles. RESULTS: In three of four cases, CMAP related to the oculomotor nerve were obtained upon stimulation at the cavity wall after removal of the tumor. Stimulation at the surface of the quadrigeminal plate, however, did not cause any CMAP response. Using this monitoring as an indicator, the lesions were totally removed. CONCLUSIONS: In the surgery of tegmental lesions, CMAP monitoring from extraocular muscles is particularly helpful to prevent damage to crucial neural structures during removal of intrinsic lesions, but less so to select the site of the medullary incision. The approach via the lateral part of the colliculi is considered to be a safe route to approach the tegmental lesions.  相似文献   
95.
96.
97.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population.  相似文献   
98.
Zusammenfassung Dieser Artikel stellt eine Übersetzung der im Jahr 2006 herausgegebenen Empfehlungen zur Behandlung von Patienten mit spontaner intrazerebraler Blutung der Europäischen Schlaganfallinitiative (EUSI) für das Europäische Schlaganfall-Council (ESC), die Europäische Neurologische Gesellschaft (ENS) und die Europäische Förderation Neurologischer Gesellschaften (EFNS) dar.Diese EUSI-Empfehlungen werden von dem European Stroke Council (ESC), der European Neurological Society (ENS) und der European Federation of Neurological Societies (EFNS) unterstützt.  相似文献   
99.
OBJECTIVES: To pilot the acceptability and feasibility of clinical audit in free and pedicled flap reconstruction. To establish a baseline flap failure rate in participating units, so that a sample size calculation could be performed for future national audit. METHODS: A proforma was piloted over a 3-month period in four participating units, during which time data on 93 reconstructive procedures involving free and pedicled flaps was collected. The patients included those where large transfers of tissue were required such as for coverage of grade IIIb compound tibial fractures and breast reconstruction after mastectomy, and also smaller flap transfers such as after skin cancer excision. RESULTS: The proforma was found to be acceptable to clinicians and the feasibility of the data collection process was established. Overall there was a total flap survival of 89% and secondary operations to the donor or recipient sites were required in 11% of patients. CONCLUSIONS: This study demonstrates the feasibility of comparative audit for free and pedicled flap procedures using the methods proposed. Based on the incidence of flap failure observed in this pilot study, at least 18 months of prospective data collection on consecutive patients is required to fulfil the statistical requirements of comparative audit. The establishment of a routinely collected minimum dataset is proposed as one means of meeting these requirements.  相似文献   
100.
Abstract Migraine without aura is typically considered a female condition. The purpose of this study was to determine if there have been any changes in the female-to-male ratio of the disease over time. We included in the study all patients with migraine without aura (n=3457) referred to the Parma University Headache Centre between 1976 and 1995. They were divided into subgroups with respect to gender and year-range of onset of migraine (before 1960, in the 1960s, in the 1970s, in the 1980s, and between 1990 and 1995). Gender ratio ranged from 3.6:1 (in patients with onset before 1960) to 2.8:1 (in patients with onset in the 1980s), with no statistically significant changes during the observation period.  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