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   553篇
  免费   32篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   11篇
妇产科学   1篇
基础医学   70篇
口腔科学   19篇
临床医学   39篇
内科学   179篇
皮肤病学   31篇
神经病学   31篇
特种医学   4篇
外科学   79篇
综合类   1篇
预防医学   24篇
眼科学   3篇
药学   53篇
中国医学   4篇
肿瘤学   35篇
  2023年   9篇
  2022年   10篇
  2021年   14篇
  2020年   13篇
  2019年   17篇
  2018年   24篇
  2017年   15篇
  2016年   19篇
  2015年   15篇
  2014年   17篇
  2013年   23篇
  2012年   30篇
  2011年   32篇
  2010年   15篇
  2009年   19篇
  2008年   32篇
  2007年   36篇
  2006年   32篇
  2005年   33篇
  2004年   22篇
  2003年   17篇
  2002年   23篇
  2001年   11篇
  2000年   6篇
  1999年   11篇
  1998年   10篇
  1997年   7篇
  1996年   3篇
  1995年   6篇
  1994年   1篇
  1993年   5篇
  1992年   9篇
  1991年   4篇
  1990年   6篇
  1989年   3篇
  1988年   7篇
  1987年   4篇
  1986年   3篇
  1985年   6篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1981年   3篇
  1980年   1篇
  1979年   4篇
  1978年   4篇
  1977年   2篇
  1974年   1篇
  1970年   2篇
排序方式: 共有593条查询结果,搜索用时 0 毫秒
21.
Hepatitis C virus (HCV) infection is associated with lymphoproliferative disorders. HCV infection of B cells is a predictive factor for lymphoproliferative disorders in patients with chronic hepatitis C, although its molecular mechanisms remain unknown. Epstein-Barr virus (EBV) is a B cell-tropic virus with the potential to cause lymphoproliferative disorders, and its reactivation is induced by several viruses and cytokines. The possibility that HCV infection triggers reactivation of EBV and induces lymphoproliferative disorders were investigated. Expression of EBV mRNAs was analyzed by RT-PCR in patients infected with HCV and control subjects, and correlations between reactivation of EBV and markers for lymphoproliferative disorders were investigated. BZLF1 mRNA, a starter molecule of reactivation, was detected in peripheral blood mononuclear cells from 12 of 52 (23%), patients infected with HCV and the frequency was higher than in healthy subjects [3 of 43 (9%), P = 0.032]. But the presence of the BZLF1 mRNA was not associated with an abnormality of markers for lymphoproliferative disorders. This study on BZLF1 mRNA expression among lymphoid cell subsets showed that reactivation of EBV was observed specifically in B cells. The BZLF1 mRNA disappeared following anti-viral therapy and remained negative after eradication of HCV in patients with a sustained viral response, while the EBER1 RNA, a marker for persistence of EBV, was detected throughout the therapy. Infection with HCV induces reactivation of EBV in B cells, but this reactivation was not associated directly with lymphoproliferative disorders triggered by HCV.  相似文献   
22.
The criterion tumor volume (TV) for clinically insignificant prostate cancer has been reported, but it differs from study to study: some have reported TV < 200 mm3; others, < 500 mm3. The aim of the present study was to distinguish clinically insignificant cancers from significant ones using molecular biological methods. A total of 184 microscopic cancers (MC) defined as limited within a 3 mm circle and 82 main tumor (MT) nodules were selected. Thirteen microsatellite loci at 6q22, 8p23.2–23, 13q14 and 13q33 were evaluated for loss of heterozygosity (LOH). MT were subgrouped as TV ≥ 500 mm3 or <500 mm3; TV ≥ 200 mm3 or < 200 mm3; and TV < 200 mm3, 200 mm3 ≤ TV < 500 mm3 or TV ≥ 500 mm3; and frequencies of LOH were compared between these three groups. Frequencies of LOH at 6q16–21, 6q22, 8p23.1, 8p23.2, 13q14 were significantly lower in MC (1.0%, 2.7%, 1.9%, 1.1% and 5.4%) than in MT (30.9%, 40.4%, 12%, 8.7% and 20.6%), but no significant differences in LOH frequency were found within each of the three TV groups, between each cut-off. When insignificant tumor is defined as TV < 200 mm3 or < 500 mm3, it should include tumors with malignant potential equivalent to larger tumors. It is suggested that in order to identify insignificant tumor within a strict safety range, TV should be set lower.  相似文献   
23.
24.
We investigated positive rate of lupus anticoagulant (LA) according to the each understanding disease in our hospital. 596 cases (F/M 477/149, 7-87 y.o.) were examined from 2003 to 2004 years. LA tests were performed using 2 methods such as kaolin clotting time (KCT) mixing test and dilute Russell's viper venom time (dRVVT). The LA tests were most frequently ordered in dermatology, and the most common purpose of LA test was the check of existence of antiphospholipid (aPL) in patients with collagen diseases. The LA positive rate was the highest in patients with SLE among the collagen diseases, and in patients with cerebral infarction among the thrombotic diseases. The LA positive rate exceeded 40% in ITP and livedo reticularis. Moreover, LA positive rate was 16% in preoperative tests of the orthopedic patients without any physical diseases. Thus, it was suggested that there were considerable numbers of the asymptomatic LA positive persons. The LA positive cases based on KCT only accounted for about 60% of all the LA positive cases. Among the thrombotic patients, there were not the DVT/PE patients with only KCT positive. On the other hands, the KCT positive rate was higher than the dRVVT positive rate in patients with cerebral infarction. There were not dRVVT single positive cases in patients with recurrent abortion and ITP, but KCT single positive case accounted for about 90%. From these results, it is suggested that there is a difference in KCT and dRVVT about detecting aPL, and that care should be taken to interpret the LA test.  相似文献   
25.
26.
Learning and memory of early postnatal protein malnourished rats were investigated in the Morris water maze. During the lactation period (21 days) each litter (mother plus six male and two female pups) was provided with 16% (well-nourished) or 6% (malnourished) protein diets. After weaning, rats remained on the same diet until 49 days of age. From day 50 on all animals were fed a commercial lab chow. Experiments started on day 70. In experiment I (proximal cue version) the animals were trained to escape from water to a visible platform (3 cm above the water level) in six trials daily for four consecutive days, completing 24 trials. In experiment II (distal cue version) the animals were trained to escape from water to a submerged platform using the same procedure as in experiment II. After the 24th trial, the platform was removed and the animals were submitted to a 60-s trial (probe trial). Seven and twenty-eight days after training, the retention test was conducted in one 180-s trial. The results showed no impairment of the learning or memory of malnourished animals tested in the proximal cue version but an increased latency and distance traveled to find the submerged platform in the distal cue version of the procedure. In the distal cue version the malnourished animals also showed increased latency to find the platform 7 and 28 days after the test training. No difference due to diet was found in the probe trial test indicating that, once the task is acquired, malnourished rats can manage extra-maze cues as easily as well-nourished rats. It is suggested that the present results can be due to alterations produced by protein malnutrition in the hippocampal formation or also to reflect the higher emotionality of rats following early malnutrition, specially considering the fact that postnatally malnourished animals are more reactive to unpleasant or aversive stimuli as cold water.  相似文献   
27.
Two patients with amyopathic dermatomyositis complicated by interstitial lung lesions were effectively treated with a combination of corticosteroids and cyclosporine and/or cyclophosphamide. A 48-year-old female patient was treated with pulse methylprednisolone and cyclosporine 2 months after onset of dermal symptoms. A 45-year-old male patient was treated with oral prednisolone and pulse cyclophosphamide 2 1/2 months after onset of dermal symptoms. Early evaluation of interstitial lung lesions and early extensive therapy may improve prognosis of interstitial lung lesions in patients with amyopathic dermatomyositis.  相似文献   
28.
(Received for publication on Oct. 19, 1998; accepted on Nov. 11, 1999)  相似文献   
29.
The aim of the study was to evaluate quality of life (QOL) prospectively in women who undergo tension-free vaginal tape (TVT) operation for stress urinary incontinence. Sixty-six women who completed QOL questionnaires and a 2-year follow-up examination were included. Improvement of health-related QOL was assessed by the Incontinence Impact Questionnaire-7 (IIQ-7), the Urogenital Distress Inventory-6 (UDI-6), and two questions regarding patient satisfaction and de novo urge incontinence. Prior to surgery, patients complained most of stress symptoms followed by physical activities and emotional health. Postoperatively IIQ-7 and UDI-6 as a whole and all seven domains improved significantly (p<0.001). Scores of IIQ-7, UDI-6, and seven domains did not differ between the adult and the elderly groups. Of the patients 88% were much satisfied or satisfied with surgical outcomes. Incidence of de novo urge incontinence was 12%. It is concluded that the TVT procedure significantly improved health-related quality of life.The authors listed above wrote this contribution on behalf of the Tension-free Vaginal Tape Trial GroupEditorial Comment: This study adds to the body of literature on the efficacy of the TVT procedure. Using quality of life instruments 88% of the patients were much satisfied or satisfied with surgical outcomes. Incidence of de novo urge incontinence was 12%. The biggest deficiency of the study was that follow-up was only available on 66 of 161 women  相似文献   
30.
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