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   1871篇
  免费   146篇
  国内免费   8篇
耳鼻咽喉   2篇
儿科学   90篇
妇产科学   83篇
基础医学   260篇
口腔科学   27篇
临床医学   235篇
内科学   295篇
皮肤病学   41篇
神经病学   93篇
特种医学   84篇
外科学   258篇
综合类   51篇
预防医学   232篇
眼科学   31篇
药学   106篇
中国医学   4篇
肿瘤学   133篇
  2023年   13篇
  2021年   28篇
  2020年   28篇
  2019年   33篇
  2018年   45篇
  2017年   31篇
  2016年   35篇
  2015年   30篇
  2014年   36篇
  2013年   68篇
  2012年   92篇
  2011年   89篇
  2010年   76篇
  2009年   52篇
  2008年   70篇
  2007年   73篇
  2006年   80篇
  2005年   49篇
  2004年   66篇
  2003年   67篇
  2002年   53篇
  2001年   36篇
  2000年   39篇
  1999年   48篇
  1998年   39篇
  1997年   27篇
  1996年   27篇
  1995年   31篇
  1994年   20篇
  1993年   18篇
  1992年   38篇
  1991年   41篇
  1990年   28篇
  1989年   45篇
  1988年   36篇
  1987年   38篇
  1986年   40篇
  1985年   53篇
  1984年   34篇
  1983年   25篇
  1982年   20篇
  1980年   15篇
  1979年   17篇
  1976年   12篇
  1975年   12篇
  1974年   20篇
  1973年   13篇
  1972年   14篇
  1971年   13篇
  1969年   12篇
排序方式: 共有2025条查询结果,搜索用时 31 毫秒
1.
2.
Our understanding of the causes of male infertility and our ability to develop an appropriate range of diagnostic tests are both dependent upon a knowledge of the cellular mechanisms responsible for the regulation of human sperm function. This review examines the intra- and extracellular factors regulating four separate components of human sperm function: sperm transport, sperm-egg recognition, the acrosome reaction and sperm-oocyte fusion. Within each of these areas the fundamental nature of the process, the control mechanisms involved, the availability of appropriate diagnostic tests and the relationship with human infertility have been considered.  相似文献   
3.
A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development.  相似文献   
4.
We describe a 15-y-old girl with Fechtner-like syndrome, who is the first Chinese reported to have this rare syndrome. She presented with left homonymous hemianopia and neuroimaging revealed haemorrhage in both parietal and occipital lobes. Peripheral blood smear showed macrothrombocytopenia and intracytoplasmic inclusion bodies inside leucocytes. Thrombocytopenia and proteinuria responded to intravenous immunoglobulin and pulsed methylprednisolone. This case illustrates that life-threatening haemorrhage can occur in patients with Fechtner syndrome. Although there was no effective treatment reported in the literature, high dose steroid and immunoglobulin seemed to be useful in our patient. Our patient also had nephritic-nephrotic syndrome with renal insufficiency, which is unusual in adolescent female patients.  相似文献   
5.
The Edinburgh Rehabilitation Status Scale (ERSS) was applied to 129 attenders at a day center for physical disability. All of the attenders had significant neurological impairment dating from birth or from infancy. Fifty-nine of the subjects (46%) had been diagnosed on conventional grounds as having mental handicap as well as physical disability. ERSS scores were compared with Barthel Index scores in all subjects and with PULSES profile in 50 subjects (27 physical disability alone, 23 combined with mental handicap). The ERSS scores clearly demonstrated significant differences in the level of disablement between the two groups in all four subscales as well as in total scores; the Barthel scores showed differences in self-care and total scores, and, to a lesser extent, in mobility. PULSES failed to differentiate the groups except in one of its subscales. The ERSS is a sensitive index of overall function and is useful in highlighting the additive effect of mental handicap and physical disability, a difference which may not be apparent when other assessment scales are used.  相似文献   
6.
7.
A synchronous occurrence of large bowel adenocarcinoma and extragenital malignant mixed mesodermal tumour (MMMT) is reported. This case represents the sixth extragenital MMMT reported in the literature.  相似文献   
8.
The efficacy of metronidazole and doxycycline in preventing recurrent periodontitis was studied in 23 patients. After treatment in the previous 7 months with either bimonthly scaling and 3 weeks of systemic doxycycline (11 subjects) or scaling and placebo (12 subjects), patients were monitored for recurrent periodontitis and were scaled every 2 months. When either a periodontal abscess or greater than 2 mm loss of gingival attachment was observed, metronidazole was administered (250 mg every 8 hours) for 10 days. In the placebo plus metronidazole group, 5 patients (42%) exhibited recurrent periodontitis after the metronidazole regimen compared with only one (9%) in the doxycycline plus metronidazole group (P less than 0.096). Subgingival plaque samples at study and healthy control sites were screened for the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, and Fusobacterium nucleatum by immunofluorescence and for spirochetes using Ryu's stain. Presence/absence analysis of the sum of scores of the 6 individual pathogens demonstrated large reductions (P less than 0.005) in the frequency of detection of pathogens in the former doxycycline compared with the placebo plus metronidazole group at both study and control sites before and one month after metronidazole. By 7 months after metronidazole, there was no detectable difference between groups. These results indicate that prevention of recurrent periodontitis with metronidazole may be enhanced by previous treatment with doxycycline.  相似文献   
9.
A randomized, double-blind, placebo-controlled study was performed to assess the analgesic efficacy of intramuscular nefopam hydrochloride after upper abdominal surgery. Patients received either 20 mg nefopam (n = 23) or matching placebo (n = 26), 90 min before surgery, immediately after surgery, and 6, 12 and 18 h after the end of surgery. The 24-h morphine requirements were measured using a patient-controlled analgesia system delivering on-demand intravenous bolus doses of morphine. Pain was assessed using visual analogue scales. Patients receiving nefopam had a mean (+/- s.e.m.) cumulative morphine consumption of 4.1 +/- 0.8 mg in the first hour, compared with 8.5 +/- 0.8 mg in the control group (P less than 0.01). After 24 h the consumptions were 44.1 +/- 7.2 mg and 62.5 +/- 6.9 mg respectively (P less than 0.05). The pain scores in both groups were similar. This study confirms that nefopam hydrochloride has significant analgesic effects and would be a useful supplement to morphine in the management of postoperative pain.  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