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   639篇
  免费   64篇
耳鼻咽喉   3篇
儿科学   16篇
妇产科学   16篇
基础医学   75篇
口腔科学   13篇
临床医学   64篇
内科学   121篇
皮肤病学   32篇
神经病学   36篇
特种医学   23篇
外科学   133篇
综合类   4篇
预防医学   30篇
眼科学   13篇
药学   61篇
中国医学   3篇
肿瘤学   60篇
  2024年   2篇
  2023年   18篇
  2022年   36篇
  2021年   55篇
  2020年   41篇
  2019年   41篇
  2018年   46篇
  2017年   41篇
  2016年   34篇
  2015年   36篇
  2014年   38篇
  2013年   43篇
  2012年   52篇
  2011年   55篇
  2010年   28篇
  2009年   12篇
  2008年   22篇
  2007年   30篇
  2006年   21篇
  2005年   11篇
  2004年   7篇
  2003年   7篇
  2002年   10篇
  2001年   2篇
  1999年   2篇
  1998年   1篇
  1996年   1篇
  1992年   3篇
  1991年   1篇
  1989年   2篇
  1974年   2篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有703条查询结果,搜索用时 15 毫秒
41.
42.
43.
T staging of gastric cancer: role of multi-detector row CT   总被引:16,自引:0,他引:16  
PURPOSE: To evaluate retrospectively the accuracy of multi-detector row computed tomography (CT) in the assessment of serosal invasion in patients with gastric cancer. MATERIALS AND METHODS: The Ethics Committee does not require approval or informed consent for retrospective studies. Forty-one consecutive patients (24 men, 17 women; mean age, 68 years) with gastric cancer were included in this study. All patients were given 600 mL of tap water to drink and were positioned prone or supine on the scanning table. The detector row configuration included four detector rows, a section thickness of 1.25 mm, a pitch of 6, and a reconstruction interval of 0.63 mm. Transverse and multiplanar reconstruction images were simultaneously evaluated by two independent observers to assess the depth of tumor invasion in the gastric wall (ie, T stage). T staging at multi-detector row CT was compared with T staging at histologic evaluation (reference standard), which was performed by means of surgical or histologic examination of the resected specimen. We also calculated the sensitivity, specificity, and accuracy of multi-detector row CT for each observer in the assessment of serosal invasion. RESULTS: Analysis of interobserver agreement showed substantial or almost perfect agreement (nonweighted kappa value of 0.78 and weighted kappa value of 0.85). Correct assessment of gastric wall invasion was 80% and 85% for observers 1 and 2, respectively. The sensitivity, specificity, and accuracy of multi-detector row CT in the assessment of serosal invasion were 90%, 95%, and 93%, respectively, for observer 1 and 80%, 97%, and 93%, respectively, for observer 2. Overstaging occurred in six patients, and understaging occurred in five patients. All understaged tumors were scirrhous subtype gastric cancer. CONCLUSION: Multi-detector row CT scanning of patients with gastric cancer gave 93% accuracy in the assessment of serosal invasion in patients with gastric cancer.  相似文献   
44.
45.
Paul S  Sodhi A 《Immunology letters》2002,82(3):171-182
In continuation with the earlier and ongoing studies on Thymosin-alpha-1 (Talpha1) exerting its immunomodulatory effects on various components of the immune system including T-cells, NK-cells, blood lymphocytes and macrophages, the role of Talpha1 in normal bone-marrow haematopoiesis has been investigated in the present study. The haematopoietic alterations associated with the growth of murine T-cell lymphoma, Dalton's Lymphoma (DL) and subsequently its restoration by Talpha1 was also investigated. It is observed that the non-adherent bone-marrow cells from normal mice (N-BMCs) exhibited enhanced proliferation on in vitro treatment with Talpha1 (dose range of 1-100 ng/ml) with maximal response at 100 ng/ml of Talpha1. In vitro stimulation with 100 ng/ml of Talpha1 also resulted in increased myeloid colony formation, as manifested by the rise in total number of colonies, frequency of the individual colony types and their size. This response was further upregulated in the presence of various colony stimulating factors (CSFs) like MCSF, GMCSF, GCSF and IL-3. Similarly, in vivo administration of Talpha1 (a single intraperitoneal injection of 10 microg per mouse) to normal mice also resulted in enhanced proliferation and colony formation by BMCs as compared with BMCs obtained from untreated mice. On the contrary, the progressive growth of T-cell lymphoma in mice led to suppressed myelogenesis, with marked reduction in the total colony numbers and their size. The BMCs from DL-bearing mice (DL-BMCs) displayed a preferential lineage-restricted differentiation towards the granulocytic-type colonies with maximum numbers of CFU-Gs and CFU-GMs, followed by CFU-Ms. However, incubation of DL-BMCs with 100 ng/ml of Talpha1, in vitro restored their suppressed proliferation and colony forming ability (CFA) with significantly enhanced total number of colonies and individual colony types, which further increased in the presence of CSFs. In vivo studies with BMCs from DL-bearing mice treated with single intraperitoneal injection of 10 microg Talpha1/mouse also resulted in significant enhancement in their proliferative as well as colony forming ability in comparison to that of untreated DL-mice. The present observations suggest that Talpha1 can positively modulate the haematopoietic functions of normal murine BMCs, in addition to its myelorestorative role in tumour-bearing mice showing suppressed myelopoiesis.  相似文献   
46.
47.
To develop a malaria treatment policy for children with Plasmodium falciparum, an in vivo and in vitro chloroquine (CQ) sensitivity study was conducted in C?te d'Ivoire in September 1986. The efficacy of a single dose of CQ (10 mg base kg-1, C10) was tested with assessment of subjects on Days 2 and 7 after treatment; 108 (99%) of 109 children were aparasitaemic on Day 7. Of 33 isolates of P. falciparum tested in vitro, two (6%) were resistant to CQ. Although C10 appeared effective clinically and parasitologically in C?te d'Ivoire, a treatment dose of 25 mg of CQ base kg-1 (C25), over three days, was recommended as first-line therapy for malaria. This was because in vivo CQ-resistance will soon spread into other West African countries including C?te d'Ivoire, the C25 dose still retains clinical effectiveness in most partially-immune persons living in areas with low-level chloroquine resistance, and alternate drugs are more expensive.  相似文献   
48.
Previous research suggests that protein intake, particularly plant protein, may benefit blood pressure control. However, very little has been published regarding protein sources in diets of US adults and factors influencing these choices. The purpose of this report is to describe specific sources of animal and plant proteins in diets of PREMIER clinical trial participants at baseline and how the PREMIER intervention, along with participant demographics, affected protein sources. Adult participants (n=809) who completed the 18-month PREMIER lifestyle intervention trial and had at least one diet recall at each of three study visits were included. Participants were recruited from four clinical centers in the Eastern, Southern, and Northeastern regions of United States. The PREMIER trial, conducted from 1999 to 2002, compared the impact on blood pressure of two structured behavioral interventions focusing on the traditional lifestyle modifications for blood pressure control with or without the Dietary Approaches to Stop Hypertension dietary pattern. Protein sources were assessed by two unannounced 24-hour recalls at each of three study visits. Differences in protein sources were mainly related to participant demographics, with relatively moderate impact of the intervention. The top four protein sources for all the study participants were poultry, dairy, refined grains and beef, each contributing approximately 10% to 17% in descending order to the total protein intake at baseline. Animal and plant protein each comprised approximately 66% and 34%, respectively, to the total daily protein intake at baseline, and such overall contribution pattern remained relatively constant over time. However, sex, race, age, and body weight status all influenced contribution patterns from different food groups significantly. These influences significantly impact choice and are essential elements to consider when designing intervention programs to alter protein contributions from animal vs plant sources.  相似文献   
49.

Background  

Intense and long-standing problems in burn centers in Tehran have led nurses to burnout. This phenomenon has provoked serious responses and has put the nurses, patients and the organization under pressure. The challenge for managers and nurse executives is to understand the factors which would reduce or increase the nurses' responses to burnout and develop delivery systems that promote positive adaptation and facilitate quality care. This study, as a part of more extensive research, aims to explore and describe the nurses' perceptions of the factors affecting their responses to burnout.  相似文献   
50.

Purpose

Older age (>?60) has been considered a relative contraindication for bariatric surgery due to increased complication risk. This study examined the risks and benefits of bariatric surgery for patients older than 60 years in Canadian population.

Methods

This was a retrospective cohort study of the Ontario Bariatric Registry: a database recording peri-operative and post-operative outcomes of publicly funded bariatric surgeries across the province. Patients who completed 1 year follow-up, who underwent laparoscopic gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) between January 2010 and May 2013, were divided into older (>?60) and younger (>?60) cohorts, and outcomes were compared.

Results

Between January 2010 and May 2013, 3166 registry patients underwent LRYGB or LSG and completed 1-year follow-up. Of these, 204 (6.5%) were older than 60 years, with 175 (85.8%) undergoing LRYGB and 29 (14.2%) LSG. Demographics were similar, except for a higher number of males in the older group (59 (28.9%) versus 452 (15.3%) (p?<?0.001)). No significant difference in complication rate was noted (15% for younger cohort versus 13.8% (p?=?0.889)). The average percentage of excess weight loss was significantly higher in the younger population (60.72% versus 56.25% (p?<?0.05)) overall, however not significantly in the LSG group. Reduction in medication use post-surgery for management of co-morbidities was significantly higher in the older patients (??0.91 versus ??2.03 (p?<?0.001)).

Conclusion

The older cohort who underwent LRYGB or LSG was at no greater risk for intra-operative and post-operative complications and showed greater reduction in medication use post-surgery when compared to the younger cohort.
  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