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   2426篇
  免费   128篇
  国内免费   14篇
耳鼻咽喉   9篇
儿科学   74篇
妇产科学   20篇
基础医学   308篇
口腔科学   74篇
临床医学   159篇
内科学   789篇
皮肤病学   24篇
神经病学   100篇
特种医学   46篇
外科学   447篇
综合类   6篇
预防医学   89篇
眼科学   83篇
药学   116篇
中国医学   5篇
肿瘤学   219篇
  2023年   17篇
  2022年   24篇
  2021年   70篇
  2020年   20篇
  2019年   51篇
  2018年   47篇
  2017年   58篇
  2016年   44篇
  2015年   57篇
  2014年   94篇
  2013年   77篇
  2012年   141篇
  2011年   158篇
  2010年   78篇
  2009年   76篇
  2008年   115篇
  2007年   115篇
  2006年   108篇
  2005年   128篇
  2004年   113篇
  2003年   126篇
  2002年   81篇
  2001年   67篇
  2000年   68篇
  1999年   73篇
  1998年   24篇
  1997年   9篇
  1996年   11篇
  1995年   12篇
  1994年   17篇
  1993年   10篇
  1992年   52篇
  1991年   53篇
  1990年   37篇
  1989年   45篇
  1988年   37篇
  1987年   31篇
  1986年   26篇
  1985年   16篇
  1984年   13篇
  1983年   15篇
  1979年   20篇
  1978年   16篇
  1977年   17篇
  1976年   9篇
  1975年   10篇
  1973年   11篇
  1972年   10篇
  1970年   8篇
  1969年   8篇
排序方式: 共有2568条查询结果,搜索用时 301 毫秒
51.
At present, vancomycin (VCM) and metronidazole (MNZ) are used for the first-line standard treatment of Clostridioides difficile infection (CDI). However, their differential use has not been sufficiently investigated. In this study, a meta-analysis on differences in the efficacy for CDI between VCM and MNZ was performed. Reports of randomized controlled studies using VCM or MNZ to treat CDI were surveyed. Meta-analysis was performed using the Mantel-Haenszel method and random-effects model, and the risk ratio and 95% confidence interval were calculated. Excluding overlapping reports, 1043 reports were extracted and 5 randomized controlled studies were extracted. There was no difference in therapeutic effects for CDI between VCM and MNZ (RR = 1.08, 95% CI (0.99–1.17), p = 0.09, I2 = 37%). On subgroup analysis by the severity, there was no difference in the clinical effects for CDI between VCM and MNZ in non-severe cases (risk ratio: 1.09, 95% confidence interval: 1.00–1.19, p = 0.06), but the clinical effects of VCM were significantly higher than those of MNZ in severe cases (risk ratio: 1.19, 95% confidence interval: 1.02–1.39, p = 0.03). No significant difference was noted in the recurrence rate, incidence of adverse event, time to exhibit therapeutic effects, or judgment of the bacteriological effects. As the therapeutic effects of VCM were superior in severe CDI cases, VCM should be considered first in severe cases.  相似文献   
52.
Summary We developed a new adsorbent utilizing hydrophobic amino acids in order to treat severe rheumatoid arthritis patients with extracorporeal adsorption therapy. In in vitro experiment, the new adsorbent selectively removed immune complexes and rheumatoid factors from RA plasma presumably due to hydrophobic adsorption. Six out of elevent patients markedly improved in clinical as well as laboratory parameters of disease activities, particularly in their extra-articular manifestations. We recommend preferential use of this treatment since it can spare the replacement protein solution and is expected to give similar efficacy to simple plasma exchange therapy.  相似文献   
53.
54.
A phase I dose-escalation study of multicyclic, ifosfamide, carboplatin, and etoposide (ICE) with sequential reinfusion of peripheral blood stem cells (PBSCs) was conducted to determine the maximum-tolerated dose (MTD) of ICE. Twenty-four patients with SCLC (LD: 6, ED: 18) were treated with ifosfamide (3000-9000 mg/m2, 24-h infusion), carboplatin (300-400 mg/m2), and etoposide (300 mg/m2) followed by subcutaneous filgrastim (75 microg/day) from day 4 to the day of PBSC collection. PBSC were harvested when the WBC count reached >/=5 x 109/l. The leukapheresis product was cryopreserved and reinfused on day 4 of the next cycle, which was started 48 h after the last PBSC collection. The ifosfamide dose was escalated as follows: 3000 mg/m2 (level 1), 5000 mg/m2 (level 2), 7000 mg/m2 (level 3), 9000 mg/m2 (level 4). Patients with LD were treated with concurrent radiotherapy at 1.5 Gy twice daily for the initial 3 weeks to a total dose of 45 Gy and MTD, defined separately. Patients were evaluated for hematologic and non-hematologic toxicity, actual dose intensities, as well as response to therapy. The maximum-tolerated dose (MTD) was defined as the dose level at which more than 5 days of grade 4 myelo- suppression or non-hematologic toxicity greater than grade 3 developed in two thirds of the patients. For ED cases, MTD was level 4 and the recommended dose of ifosfamide was 7000 mg/m2. For LD cases, the recommended dose of ifosfamide was 5000 mg/m2. The dose limiting toxicity of multicyclic ICE was hemato- logic toxicity and CNS toxicity which manifested as ataxia. Tumor responses were seen in all patients, with 14 patients showing a complete response. The actual total dose-intensity at the recommended dose level was 2.2 and 1.74, for ED and LD, respectively, compared with previously reported ICE regimens. PBSC support for dose-intensive ICE regimen permitted dose escalation of ifosfamide with a mean interval of 16-17 days. We conclude that this regimen is well tolerated, with acceptable hematological and non-hematological toxicity. Bone Marrow Transplantation (2000) 25, 5-11.  相似文献   
55.
The cell-cycle status of hematopoietic stem and progenitor cells (HSPCs) becomes activated following chemotherapy-induced stress, promoting bone marrow (BM) regeneration; however, the underlying molecular mechanism remains elusive. Here we show that BM-resident group 2 innate lymphoid cells (ILC2s) support the recovery of HSPCs from 5-fluorouracil (5-FU)–induced stress by secreting granulocyte-macrophage colony-stimulating factor (GM-CSF). Mechanistically, IL-33 released from chemo-sensitive B cell progenitors activates MyD88-mediated secretion of GM-CSF in ILC2, suggesting the existence of a B cell–ILC2 axis for maintaining hematopoietic homeostasis. GM-CSF knockout mice treated with 5-FU showed severe loss of myeloid lineage cells, causing lethality, which was rescued by transferring BM ILC2s from wild-type mice. Further, the adoptive transfer of ILC2s to 5-FU–treated mice accelerates hematopoietic recovery, while the reduction of ILC2s results in the opposite effect. Thus, ILC2s may function by “sensing” the damaged BM spaces and subsequently support hematopoietic recovery under stress conditions.  相似文献   
56.
Primary biliary cirrhosis (PBC) is characterized by portal inflammation and immune-mediated destruction of intrahepatic bile ducts that often result in liver failure. Toll-like receptor (TLR) 4 recognizes lipopolysaccharides of Gram-negative bacteria. Infectious agents have been suspected to play a crucial role in PBC pathogenesis since TLR4 expression was found in bile duct epithelial cells and periportal hepatocytes in liver tissues of PBC. To assess the potential contribution of TLR4 SNPs to the development of this disease, we genotyped five SNPs in TLR4 in 261 PBC patients and 359 controls using a TaqMan assay. No significant positive associations with either PBC susceptibility or progression were uncovered. These results indicate that TLR4 polymorphisms do not play a prominent role in the development of PBC in Japanese patients.  相似文献   
57.
ObjectivesThe Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a promising tool for the evaluation of stroke expansion to determine suitability for reperfusion therapy. The aim of this study was to validate deep learning-based ASPECTS calculation software that utilizes a three-dimensional fully convolutional network-based brain hemisphere comparison algorithm (3D-BHCA).Materials and MethodsWe retrospectively collected head non-contrast computed tomography (CT) data from 71 patients with acute ischemic stroke and 80 non-stroke patients. The results for ASPECTS on CT assessed by 5 stroke neurologists and by the 3D-BHCA model were compared with the ground truth by means of region-based and score-based analyses.ResultsIn total, 151 patients and 3020 (151 × 20) ASPECTS regions were investigated. Median time from onset to CT was 195 min in the stroke patients. In region-based analysis, the sensitivity (0.80), specificity (0.97), and accuracy (0.96) of the 3D-BHCA model were superior to those of stroke neurologists. The sensitivity (0.98), specificity (0.92), and accuracy (0.97) of dichotomized ASPECTS > 5 analysis and the intraclass correlation coefficient (0.90) in total score-based analysis of the 3D-BHCA model were superior to those of stroke neurologists overall. When patients with stroke were stratified by onset-to-CT time, the 3D-BHCA model exhibited the highest performance to calculate ASPECTS, even in the earliest time period.ConclusionsThe automated ASPECTS calculation software we developed using a deep learning-based algorithm was superior or equal to stroke neurologists in performing ASPECTS calculation in patients with acute stroke and non-stroke patients.  相似文献   
58.
Radish mosaic virus (RaMV) is a crucifer-infecting comovirus that has been detected worldwide. Here, we report the successful construction of a full-length infectious cDNA clone of RaMV. The full-length cDNA clones corresponding to RNA1 and RNA2 of a Japanese isolate of RaMV were cloned into the pBlueScript plasmid or the binary vector pCAMBIA1301 downstream of the cauliflower mosaic virus 35S promoter. Mechanical inoculation or agroinoculation of Nicotiana benthamiana with these vectors resulted in systemic RaMV infections causing symptoms similar to those caused by the wild-type parental virus. The presence of progeny virus was verified by western blot analysis and electron microscopy.  相似文献   
59.
60.
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