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   1631篇
  免费   108篇
  国内免费   17篇
耳鼻咽喉   8篇
儿科学   20篇
妇产科学   10篇
基础医学   248篇
口腔科学   28篇
临床医学   111篇
内科学   519篇
皮肤病学   13篇
神经病学   77篇
特种医学   29篇
外科学   260篇
综合类   3篇
预防医学   52篇
眼科学   30篇
药学   71篇
中国医学   3篇
肿瘤学   274篇
  2024年   3篇
  2023年   16篇
  2022年   20篇
  2021年   59篇
  2020年   17篇
  2019年   38篇
  2018年   34篇
  2017年   30篇
  2016年   63篇
  2015年   53篇
  2014年   65篇
  2013年   64篇
  2012年   109篇
  2011年   143篇
  2010年   68篇
  2009年   58篇
  2008年   89篇
  2007年   118篇
  2006年   89篇
  2005年   83篇
  2004年   91篇
  2003年   93篇
  2002年   71篇
  2001年   20篇
  2000年   22篇
  1999年   29篇
  1998年   18篇
  1997年   10篇
  1996年   19篇
  1995年   21篇
  1994年   18篇
  1993年   4篇
  1992年   15篇
  1991年   14篇
  1990年   13篇
  1989年   6篇
  1988年   6篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1984年   7篇
  1983年   4篇
  1981年   4篇
  1979年   5篇
  1978年   8篇
  1977年   4篇
  1976年   5篇
  1975年   4篇
  1971年   3篇
  1966年   2篇
排序方式: 共有1756条查询结果,搜索用时 15 毫秒
1.
2.
Abstract:   A 19-year-old woman presented at our hospital with acute urinary retention in September 2005. She had experienced the same chief complaint twice previously. She had used non-steroidal anti-inflammatory drugs before acute urinary retention. The results of physical examinations were unremarkable, and her neurologic signs were not remarkable. The basic laboratory test values were all normal and a psychiatric assessment indicated that her symptoms were not psychogenic. Magnetic resonance imaging was carried out, but revealed only a slight bulging in the L3/L4/L5 disk. Water cystometry showed acontractile detrusor. We made a diagnosis of acute urinary retention as a result of non-steroidal anti-inflammatory drugs because of her use of such drugs before the development of symptoms on multiple occasions. This patient was regularly followed up as an outpatient, and she could void smoothly in February 2006. This is the first report which acute urinary retention associated with non-steroidal anti-inflammatory drugs in Japan.  相似文献   
3.
Skip mediastinal nodal metastases in non-small cell lung cancer   总被引:1,自引:0,他引:1  
Objective: To reveal the incidence and clinical significance of mediastinal nodal metastases without N1-station nodal metastases (‘skip-N2 metastases’) in non-small cell lung cancer (NSCLC). Methods: A total of 450 NSCLC patients who underwent tumor resection with a systemic mediastinal nodal dissection were retrospectively reviewed. p53 status and proliferative activity represented as proliferative index (PI) were also examined immunohistochemically. Results: Skip-N2 metastases were documented in 49 (13%) patients of all 450 patients; among 334 patients without N1-nodal involvement, 18% patients had skip-N2 metastases. The postoperative survival of skip-N2 patients was almost same as that for patients with metastases to both N1 and N2 nodes. Skip-N2 metastases were significantly more frequent in male patients and squamous cell carcinoma patients. In addition, the mean PI for tumor with skip-N2 metastases was significantly higher than that for any other pathologic nodal (pN)-status diseases. Combined with histologic type and PI, the incidences of skip-N2 metastases for adenocarcinoma showing lower PI were only 5% (7/137) of all patients and 7% (7/94) of patients without N1-nodal involvement. Conclusions: N1 nodal status is not a useful predictor of N2 nodal status in NSCLC, because skip-N2 metastases were documented in 18% patients showing no N1-nodal involvement. However, N1 node-guided dissection might be performed in patients with adenocarcinoma showing lower PI, because the incidence of skip-N2 metastases was extremely low.  相似文献   
4.
We report a patient manifesting seizures with bilateral symmetric tonic posturing, which were markedly reduced after resection of the left precuneus. A 16-year-old man had sudden onset, complex partial seizures with bilateral symmetric tonic posturing since the age of eight years. Magnetic resonance fluid-attenuated inversion-recovery imaging revealed a hyperintense lesion in left precuneus. In almost all focal seizures recorded during an invasive EEG evaluation, ictal onset was detected from the inferomesial aspect of the lesion, but fast paroxysmal discharges from the ipsilateral supplementary motor area (SMA) were observed just before the clinical onset. After surgical excision of the EEG onset zone, including the lesion, seizure frequency was markedly (> 95%) reduced. By the 20th month after surgery, there were only brief nocturnal seizures involving slight elevation of both shoulders and slight abduction of both arms, with preservation of consciousness occurring once every few days. Invasive EEG findings and surgical outcome suggested that the epileptic activity originating from the epileptogenic zone may have propagated to the symptomatogenic zone including mainly the ipsilateral SMA. In summary, we report an interesting case of bilateral symmetric tonic posturing suggesting propagation to the SMA. MRI and invasive EEG confirmed the epileptogenic focus as a precuneate cortical dysplasia lesion.[Published with video sequences].  相似文献   
5.
The efficacy and safety of a recombinant yeast-derived hepatitis B vaccine were evaluated in 209 subjects after three administrations at 0, 4 and 20 weeks. Subjects were divided into four groups given 5 micrograms vaccine subcutaneously, 10 micrograms subcutaneously, 10 micrograms intramuscularly and 20 micrograms subcutaneously to define the effective dose and to compare the effect of administration. Seroconversion of the antibody to hepatitis B surface antigen after the third vaccination reached 96.6% in the group given 5 micrograms vaccine subcutaneously and 100% in the other groups. The final geometric mean antibody titres were 700 IU/l in subjects given 5 micrograms subcutaneously, 2004 IU/l in those given 10 micrograms subcutaneously, 4674 IU/l in those given 10 micrograms intramuscularly and 3342 IU/l in those given 20 micrograms subcutaneously. In the groups given 10 micrograms, the early seroconversion rate of the antibody to hepatitis B surface antigen and the geometric mean antibody titres after the third vaccination were significantly higher in subjects administered intramuscularly than subcutaneously (P less than 0.05). No major adverse effects were observed and minor reactions were the same as, or less than, those reported for the plasma-derived vaccine. Before and after administration, no significant fluctuation in the yeast antibody titre was observed. These results demonstrate the efficacy and safety of the yeast-derived vaccine, and show that 10 micrograms was the effective dose.  相似文献   
6.
The effects of glucocorticoids on the proportion of lymphocytes in bronchoalveolar lavage (BAL) fluid in relation to humoral and cellular immunity were studied in 56 patients with steroid-dependent intractable asthma. To analyze the mechanism responsible for reduced numbers of BAL lymphocytes, we divided the subjects into 4 groups according to their BAL lymphocyte proportions: 0—4.9%, 5.0-9.9%, 10.0-14.9%, and 15.0-20.0%. Serum IgG levels and the peripheral lymphocyte count were significantly reduced in patients with a low proportion of BAL lymphocytes (less than 9.9%) than in those with more than 10% BAL lymphocytes. Delayed cutaneous reactivity to purified protein derivative was suppressed in patients with a low proportion of BAL lymphocytes (less than 4.9%). The mean proportion of BAL neutrophils tended to increase as the proportion of BAL lymphocytes decreased. These results show that the reduction in BAL lymphocytes produced by glucocorticoids is associated with suppressed humoral and cellular immunity, and that under such conditions the proportion of BAL neutrophils increases.  相似文献   
7.
8.
The effects of long-term glucocorticoid therapy on airway inflammation were examined in 84 asthma patients. The proportion of lymphocytes in bronchoalveolar lavage (BAL) fluid was significantly decreased in patients with steroid-dependent intractable asthma (SDIA) compared to results in non-SDIA patients, while BAL neutrophils were significantly increased in SDIA patients compared to results in non-SDIA patients. Regarding age, in patients under the age of 69 (except those between 30 and 39), BAL lymphocyte number was significantly decreased in SDIA compared with non-SDIA subjects, and in patients between 50 and 69, BAL neutrophils were significantly increased in SDIA compared with non-SDIA subjects. The number of BAL lymphocytes was significantly lower in patients with serum cortisol levels of less than 5.0 μg/dl than in those with levels of more than 5.1 μg/dl. BAL lymphocyte number was also significantly lower in patients who had received glucocorticoid therapy for more than 6 years than in those who had received such therapy for 2 years. These results show that long-term glucocorticoid therapy decreases the number of lymphocytes and increases neutrophil numbers in the airways.  相似文献   
9.
The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV-C virus (GBV-C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18-72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV-C/HGV RNA estimations were carried out by double-nested polymerase chain reaction (PCR) using primers from the 5'-untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5'-UTR primers and by PCR with type-specific 5'-UTR primers. GBV-C/HGV-RNA genotypes were determined by RFLP with specific 5'-UTR primers and phylogenetic trees were constructed using the Neighbour-Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 10(6) genome equivalents per millilitre (range 10(4)-10(9)/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV-C/HGV-RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV-C/HGV.  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