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   874篇
  免费   54篇
  国内免费   17篇
耳鼻咽喉   9篇
儿科学   36篇
妇产科学   27篇
基础医学   91篇
口腔科学   23篇
临床医学   90篇
内科学   290篇
皮肤病学   5篇
神经病学   56篇
特种医学   68篇
外科学   103篇
综合类   11篇
预防医学   31篇
眼科学   5篇
药学   27篇
中国医学   1篇
肿瘤学   72篇
  2023年   2篇
  2022年   8篇
  2021年   17篇
  2020年   15篇
  2019年   12篇
  2018年   18篇
  2017年   13篇
  2016年   13篇
  2015年   17篇
  2014年   27篇
  2013年   32篇
  2012年   41篇
  2011年   40篇
  2010年   35篇
  2009年   47篇
  2008年   33篇
  2007年   37篇
  2006年   37篇
  2005年   24篇
  2004年   31篇
  2003年   30篇
  2002年   28篇
  2001年   19篇
  2000年   33篇
  1999年   26篇
  1998年   36篇
  1997年   33篇
  1996年   24篇
  1995年   17篇
  1994年   23篇
  1993年   8篇
  1992年   11篇
  1991年   13篇
  1990年   10篇
  1989年   14篇
  1988年   13篇
  1987年   15篇
  1986年   22篇
  1985年   23篇
  1984年   7篇
  1983年   3篇
  1982年   11篇
  1981年   3篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1972年   3篇
  1968年   2篇
  1967年   2篇
  1963年   2篇
排序方式: 共有945条查询结果,搜索用时 554 毫秒
31.
We describe a 50-yr-old black laborer who presented with right lower chest pain, weight loss, and pedal edema. Ultrasonography and computed tomograms showed a large abscess cavity in the right lobe of the liver which extended very close to the inferior vena cava. The lumen of the adjacent inferior vena cava was partially occluded by thrombus, which could be traced up into the cavity of the right atrium. The hepatic veins were normally patent. Sterile blood-stained pus was aspirated from the abscess. Antibodies against Entamoeba histolytica were present in high titer in the patient's serum. Although propagation of hepatocellular carcinoma into the inferior vena cava and even up into the right atrium is well recognized, inferior vena caval thrombosis extending up into the right atrium has not hitherto been reported as a complication of amebic hepatic abscess.  相似文献   
32.
33.
34.
This study examined the relationship between childhood diarrhea prevalence and caregiver knowledge of the causes and prevention of diarrhea in a prospective cohort of 952 children < 5 years of age in Cochabamba, Bolivia. The survey of caregiver knowledge found that more than 80% of caregivers were unaware that hand washing with soap could prevent childhood diarrhea. Furthermore, when asked how to keep food safe for children to eat only 17% of caregivers reported hand washing before cooking and feeding a child. Lack of caregiver awareness of the importance of practices related to hygiene and sanitation for diarrhea prevention were significant risk factors for diarrheal disease in this cohort. The knowledge findings from this study suggest that health promotion in these communities should put further emphasis on increasing knowledge of how water treatment, hand washing with soap, proper disposal of child feces, and food preparation relate to childhood diarrhea prevention.  相似文献   
35.
36.

Aims/hypothesis  

Pancreatic islet microendothelium exhibits unique features in interdependent relationship with beta cells. Gastrointestinal products of the ghrelin gene, acylated ghrelin (AG), unacylated ghrelin (UAG) and obestatin (Ob), and the incretin, glucagon-like peptide-1 (GLP-1), prevent apoptosis of pancreatic beta cells. We investigated whether the ghrelin gene products and the GLP-1 receptor agonist exendin-4 (Ex-4) display survival effects in human pancreatic islet microendothelial cells (MECs) exposed to chronic hyperglycaemia.  相似文献   
37.

Purpose

Questions remain about the polysomnographic findings and the predictors for sleep desaturation in cystic fibrosis (CF) patients. Our study aimed to evaluate sleep parameters in a sample of adult CF patients comparing them with healthy controls and to determine the best predictors of sleep desaturation in CF patients with awake resting peripheral oxygen saturation (SpO2) ??90%.

Methods

In a cross-sectional study, with data collected prospectively, 51 clinically stable adult CF patients (mean age 25.1?±?6.7?years) and 25 age-matched controls underwent an overnight polysomnography and answered sleep questionnaires. CF patients had their pulmonary function, 6-min walk test, and echocardiography assessed.

Results

CF patients and control subjects had similar sleep architecture. However, CF patients had impaired subjective sleep quality and a higher arousal index than controls. The apnea?Chypopnea index was similar in both groups, and only two CF patients (3.9%) fulfilled the criteria for obstructive sleep apnea syndrome. Sleep desaturation was more common in CF patients (29.4% vs 0%; p?2 was the single best variable associated with sleep desaturation in CF population (p?2 <94% had a sensitivity, specificity, positive and negative predictive value for sleep desaturation of, respectively, 93.3%, 100%, 100%, and 97.3%.

Conclusions

CF patients had a worse subjective sleep quality and small changes in sleep architecture. In nonhypoxic, adult CF patients, sleep desaturation is common, is not associated with obstructive sleep events, and can be accurately predicted by awake resting SpO2 <94%.  相似文献   
38.
PurposeTo assess the toxicity and cosmetic results in breast cancer patients undergoing adjuvant partial breast irradiation (PBI) to a total dose of 40 Gy in 10 daily fractions (4 Gy/fraction).Methods and materialsPatients affected by early-stage breast cancer were enrolled in this phase II trial. Patients had to be 60 years old and treated with breast conservative surgery for early stage (pT1–T2 pN0–N1a) invasive ductal carcinoma.Results77 patients were enrolled. Median follow-up was 18 months. The proposed schedule was well tolerated. One patient reported Grade 3 pain at the site of irradiation. Four (5%) patients experience Grade 2 erythema. Late Grade 2 and 1 fibrosis was observed in 3 (4%) and 14 (18%) patients, respectively. Cosmesis was judged “good/excellent” and “poor” in 75 (97%) and in 2 (3%) patients, respectively.Conclusions40 Gy in 10 daily fractions, 4 Gy/fraction, is a well tolerated regimen to deliver PBI.  相似文献   
39.
The goal of this phase II multicenter clinical trial was to evaluate a new intensive chemotherapy program for adults with untreated acute lymphoblastic leukemia (ALL) and to examine prospectively the impact of clinical and biologic characteristics on the outcome. One hundred ninety-seven eligible and evaluable patients (16 to 80 years of age; median, 32 years of age) received cyclophosphamide, daunorubicin, vincristine, prednisone, and L-asparaginase; 167 patients (85%) achieved a complete remission (CR), 13 (7%) had refractory disease, and 17 (9%) died during induction. A higher CR rate was observed in younger patients (94% for those < 30 years old, 85% for those 30 to 59 years old, and 39% for those > or = 60 years old, P < .001) and in those who had a mediastinal mass (100%) or blasts with a T-cell immunophenotype. Eighty percent of B-lineage and 97% of T-cell ALL patients achieved a CR (P = .01). The coexpression of myeloid antigens did not affect the response rate or duration. Seventy percent of those with cytogenetic or molecular evidence of the Philadelphia (Ph) chromosome and 84% of those without such evidence achieved a CR (P = .11). Patients in remission received multiagent consolidation treatment, central nervous system prophylaxis, late intensification, and maintenance chemotherapy for a total of 24 months. After a median follow-up time of 43 months, the median survival for all 197 patients is 36 months; the median remission duration for the 167 CR patients is 29 months. Favorable pretreatment characteristics relative to remission duration or survival are younger age, the presence of a mediastinal mass or lymphadenopathy, a white blood cell count (WBC) less than 30,000/microL, L1 morphology, T or TMy immunophenotype, and the absence of the Ph chromosome. The estimates of the proportion surviving at 3 years are 69% for patients less than 30 years old, 39% for those 30 to 59 years old, 89% for those who had a mediastinal mass, 59% with WBC less than 30,000/microL, 63% with L1 morphology, 69% for T or TMy antigen expression, and 62% for those who lack the Ph chromosome. Fifteen patients (8%) had no unfavorable prognostic factors and have an estimated probability of survival at 5 years of 100% (95% confidence interval, 77% to 100%). This intensive chemotherapy regimen produces a high remission rate and a high proportion of durable remissions in adults with ALL.  相似文献   
40.
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