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   2465篇
  免费   136篇
  国内免费   15篇
耳鼻咽喉   88篇
儿科学   63篇
妇产科学   51篇
基础医学   346篇
口腔科学   47篇
临床医学   199篇
内科学   321篇
皮肤病学   140篇
神经病学   243篇
特种医学   238篇
外科学   298篇
综合类   12篇
预防医学   89篇
眼科学   70篇
药学   156篇
中国医学   12篇
肿瘤学   243篇
  2023年   8篇
  2022年   41篇
  2021年   46篇
  2020年   23篇
  2019年   58篇
  2018年   49篇
  2017年   63篇
  2016年   66篇
  2015年   122篇
  2014年   117篇
  2013年   143篇
  2012年   159篇
  2011年   172篇
  2010年   116篇
  2009年   115篇
  2008年   148篇
  2007年   115篇
  2006年   123篇
  2005年   109篇
  2004年   89篇
  2003年   65篇
  2002年   45篇
  2001年   44篇
  2000年   56篇
  1999年   38篇
  1998年   40篇
  1997年   35篇
  1996年   32篇
  1995年   28篇
  1994年   32篇
  1993年   24篇
  1992年   19篇
  1991年   21篇
  1990年   27篇
  1989年   28篇
  1988年   25篇
  1987年   19篇
  1986年   12篇
  1985年   18篇
  1984年   9篇
  1983年   11篇
  1982年   20篇
  1981年   14篇
  1980年   11篇
  1978年   4篇
  1977年   8篇
  1976年   14篇
  1975年   11篇
  1974年   6篇
  1973年   8篇
排序方式: 共有2616条查询结果,搜索用时 15 毫秒
1.
2.
3.
The selective cyclooxygenase-2 (COX-2) inhibitor has been reported to have antiinflammatory, neuroprotective, and antioxidant effects in ischemia models. In this study, the authors examined whether a selective COX-2 inhibitor (celecoxib) reduces cerebral inflammation and edema after intracerebral hemorrhage (ICH), and whether functional recovery is sustained with longer treatment. ICH was induced using collagenase in adult rats. Celecoxib (10 or 20 mg/kg) was administered intraperitoneally 20 minutes, 6 hours, and 24 hours after ICH and then daily thereafter. Seventy-two hours after ICH induction, the rats were killed for histologic assessment and measurement of brain edema and prostaglandin E2. Behavioral tests were performed before and 1, 7, 14, 21, and 28 days after ICH. The brain water content of celecoxib-treated rats decreased both in lesioned and nonlesioned hemispheres in a dose-dependent manner. Compared with the ICH-only group, the number of TUNEL-positive, myeloperoxidase-positive, or OX42-positive cells was decreased in the periphery of hematoma and brain prostaglandin E2 level was reduced in the celecoxib-treated group. Celecoxib-treated rats recovered better by the behavioral tests at 7 days after ICH throughout the 28-day period, and the earlier the drug was administered, the better the functional recovery. Evidence of similar effects in an autologous blood-injected model showed that direct collagenase toxicity was not the major cause of inflammation or cell death. These data suggest that celecoxib treatment after ICH reduces prostaglandin E2 production, brain edema, inflammation, and perihematomal cell death in the perihematomal zone and induces better functional recovery.  相似文献   
4.
Acute appendicitis: CT and US correlation in 100 patients   总被引:19,自引:1,他引:18  
  相似文献   
5.
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.  相似文献   
6.
7.
Recently, metastasis to N3 lymph nodes group was regarded as distant metastasis by the new TNM staging system due to poor overall survival. However, the 5-year overall survival rate of patients with metastasis to N3 groups was 34.5% after curative surgery. Moreover, in patients with metastasis to lymph node subgroups of #12, #13, #14, the overall 5-year survival rate increased upto 47.2% after curative resection and adjuvant chemotherapy. This was similar to that of the patients with metastasis to N1 and N2 lymph nodes groups. But in these highly tumor burden states, no survival benefit was found with the addition of immunotherapy to chemotherapy as we achieved in stage II and III. Therefore, we suggest that, at least, metastasis to #12, #13, #14 lymph nodes subgroups should not be categorized as a distant metastasis. And in these situations, active curative radical surgery with extended lymphadenectomy and adjuvant chemotherapy are recommended.  相似文献   
8.
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.  相似文献   
9.
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