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   722篇
  免费   50篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   40篇
妇产科学   3篇
基础医学   56篇
口腔科学   18篇
临床医学   84篇
内科学   185篇
皮肤病学   8篇
神经病学   16篇
特种医学   82篇
外科学   75篇
综合类   68篇
预防医学   58篇
眼科学   8篇
药学   45篇
肿瘤学   32篇
  2022年   5篇
  2021年   7篇
  2020年   5篇
  2019年   4篇
  2018年   8篇
  2017年   11篇
  2016年   10篇
  2015年   19篇
  2014年   13篇
  2013年   19篇
  2012年   14篇
  2011年   19篇
  2010年   24篇
  2009年   35篇
  2008年   20篇
  2007年   28篇
  2006年   40篇
  2005年   11篇
  2004年   22篇
  2003年   8篇
  2002年   16篇
  2001年   24篇
  2000年   11篇
  1999年   16篇
  1998年   43篇
  1997年   34篇
  1996年   42篇
  1995年   19篇
  1994年   23篇
  1993年   23篇
  1992年   11篇
  1991年   15篇
  1990年   8篇
  1989年   20篇
  1988年   34篇
  1987年   10篇
  1986年   12篇
  1985年   22篇
  1984年   11篇
  1983年   4篇
  1982年   7篇
  1981年   5篇
  1980年   4篇
  1979年   5篇
  1978年   3篇
  1977年   5篇
  1976年   5篇
  1975年   3篇
  1968年   6篇
  1965年   2篇
排序方式: 共有779条查询结果,搜索用时 15 毫秒
71.
Culture-based preemptive therapy with ganciclovir was shown to reduce the incidence of cytomegalovirus (CMV) disease after bone marrow transplantation (BMT). Culture techniques did not detect CMV in 12% to 13% of patients before the onset of CMV disease. In a prospective study, 71 patients either received preemptive therapy based on polymerase chain reaction (PCR) technique (37 patients) or on culture assays (34 patients). In both groups, therapy was continued until clinical signs disappeared and PCR negativity was documented. Twenty- two patients in the PCR group and 15 patients in the culture group received antiviral therapy. PCR allowed detection of the virus (median day, +32 v day +49; P = .006) and introduction of antiviral therapy (median day, +44 v day +54; P = .02) earlier than did culture assays. The incidences of CMV disease (2 of 37 v 8 of 34 in PCR group v culture group, respectively; P = .02) and CMV-associated mortality (0 of 37 v 5 of 34 in PCR group v culture group, respectively; P = .02) were decreased, and the duration of ganciclovir therapy (P < .001) was shorter in the PCR-monitored group. Incidence and median duration of severe neutropenia (less than 500/microL) were lower in the PCR group (two v eight episodes, P = .02; median duration, 1.5 v 5 days, P = .04), as was the incidence of nonviral infections during/after antiviral therapy (2 of 37 v 9 of 34; P = .012). Thus, preemptive therapy based on more sensitive detection methods such as the PCR assay reduces the incidence of CMV disease and CMV-related mortality. Additionally, stopping and withholding antiviral therapy in a PCR- negative patient is safe and allows reduction of the duration and side effects of antiviral therapy.  相似文献   
72.
Dyspepsia is most optimally defined as pain or discomfort centred in the upper abdomen. The symptom complex may be caused by peptic ulcer disease, gastro-oesophageal reflux, or gastric cancer but is most often due to functional (or non-ulcer) dyspepsia. While upper endoscopy is the method of choice to determine the underlying cause of dyspepsia, it is expensive. A more pragmatic approach is needed in the Asia-Pacific region where health services are limited. A detailed treatment algorithm is given for managing patients presenting with new-onset dyspepsia and documented functional dyspepsia after endoscopy, and evidence to support this approach is reviewed. Prompt endoscopy is recommended for patients with alarm features. In patients without alarm features, treatment for 2–4 weeks with an empirical anti-secretory or prokinetic agent, followed by investigation using non-invasive Helicobacter pylori testing and treatment for patients who do not respond or relapse, is recommended. Trials of management strategies are now needed to establish the efficacy and cost-effectiveness of the approaches recommended.  相似文献   
73.
The effects of recombinant canine stem cell factor (rcSCF) on hematopoiesis were studied in normal dogs and in dogs given otherwise lethal total body irradiation (TBI) without marrow transplant. Results were compared with previous and concurrent data with recombinant granulocyte colony-stimulating factor (rG-CSF). Four normal dogs received 200 micrograms rcSCF per kilogram body weight daily either by continuous intravenous infusion for 28 days (n = 2) or by subcutaneous (SC) injection in two divided doses for 20 days (n = 2). All dogs showed at least a twofold increase in peripheral blood neutrophil counts starting approximately 7 days after the initiation of treatment. Hematocrit level and monocyte, lymphocyte, eosinophil, reticulocyte, and platelet counts were not elevated. Marrow sections after rcSCF treatment showed panhyperplasia. The only toxicity was facial edema during the first few days of rcSCF administration, presumably caused by mast cell stimulation. Ten dogs were given 400 cGy TBI at 10 cGy/min from two opposing 60Co sources. They were given no marrow infusion and received 200 micrograms/kg/d rcSCF SC in two divided doses for 21 days starting within 2 hours of TBI. Five of the 10 dogs showed complete and sustained hematopoietic recovery and survived as compared with 1 of 28 control dogs not receiving growth factor (P < .005). RcSCF treatment allowed for hematopoietic recovery in two of seven dogs administered 500 cGy of TBI but in none of five dogs given 600 cGy of TBI. Results with rcSCF are similar to those obtained with rG-CSF. The rate of neutrophil recovery in rcSCF-treated dogs after 400 cGy TBI was not different from that of rG-CSF-treated dogs (P = .65), but the rate of platelet recovery was faster (P = .06) in the rcSCF-treated animals. Combined treatment with rcSCF and rcG-CSF after 500 cGy TBI did not result in strongly improved survival as compared with results obtained with either factor alone.  相似文献   
74.
A 12‐year‐old child presented with recurrent respiratory infections and was diagnosed with Scimitar syndrome. Drainage of IVC and course of aberrant arterial supply from aorta were not clear by echocardiogram, and hence, additional imaging was planned. CT unraveled the presence of a rare combination of anomalous pulmonary venous connection (APVC) to IVC, with near‐atresia/severe stenosis of IVC, superior to the drainage of scimitar vein. There was a prominent azygos vein with preferential contrast opacification on lower limb injection.  相似文献   
75.
76.
Cross‐matching of records between Singapore's tuberculosis and HIV registries showed that 3.3% of individuals with tuberculosis (TB) were coinfected with HIV (2000?2014), the TB incidence among individuals with HIV infection was 1.65 per 100 person‐years, and 53% of coinfections were diagnosed within 1 month of each other. The findings supported joint prevention programmes for early diagnosis and treatment.  相似文献   
77.
K M Tillotson  A K Burton 《Spine》1991,16(1):29-33
The use of flexicurves to measure lumbar sagittal mobility was subjected to a series of reliability and validation experiments. Appropriate statistical methods were described and used to quantify intraobserver and intrasubject variability and to determine limits of agreement with measurements from radiographs. It was shown that the traditional use of correlation coefficients can produce misleading or inadequate information. The flexicurve technique had an intraobserver variability of 3-4 degrees of movement, was not significantly influenced by intrasubject variability, and provided measurements typically within 6 degrees of radiographic measurements. The data suggest that the flexicurve technique is less biased than the inclinometric method. These results demonstrate the use of suitable statistical methods to assess the clinical usefulness, or level of interchangeability, of spinal measurement instruments.  相似文献   
78.
Abstract: In hemodialysis, a certain degree of bacterial contamination on the dialysate side is a regular finding. Concern has been growing that this contamination may lead to a chronic inflammatory response in the patient. Ultrafiltration of dialysate can be used to reduce bacterial content and levels of cytokine-inducing substances upstream of the patient's dialyzer. The aim of this study was to test in vitro the rejection capacity of a polysulfone hollow-fiber ultrafilter (ETF 609, NISSHO Co., Osaka, Japan) challenged with bacterial filtrates derived from Pseudomonus aeruginosa PA 103. Results showed a reduction of interleukin-Iβ-inducing activity (measured on peripheral blood mononuclear cells) from 5,035 ± 394 pg/ml prefilter to nondetectable levels postfilter and endotoxin levels (limulus amebocyte lysate assay) of 4,167 ± 1,079 versus 12 ± 2 pg/ml, respectively. In conclusion, ultrafiltration of dialysate with the polysulfone ultrafilter ETF 609 leads to a potent reduction of cytokine-inducing activity.  相似文献   
79.
Karkouti  K  Beattie  WS  Dattilo  KM  McCluskey  SA  Ghannam  M  Hamdy  A  Fedorko  L  Yau  TM 《Journal canadien d'anesthésie》2005,52(1):A64-A64
Canadian Journal of Anesthesia/Journal canadien d'anesthésie -  相似文献   
80.
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