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   2133篇
  免费   236篇
  国内免费   63篇
耳鼻咽喉   8篇
儿科学   59篇
妇产科学   21篇
基础医学   229篇
口腔科学   174篇
临床医学   226篇
内科学   464篇
皮肤病学   16篇
神经病学   74篇
特种医学   103篇
外科学   315篇
综合类   61篇
一般理论   14篇
预防医学   161篇
眼科学   10篇
药学   205篇
中国医学   2篇
肿瘤学   290篇
  2023年   16篇
  2021年   25篇
  2020年   16篇
  2018年   31篇
  2017年   28篇
  2016年   34篇
  2015年   44篇
  2014年   56篇
  2013年   74篇
  2012年   72篇
  2011年   89篇
  2010年   69篇
  2009年   71篇
  2008年   95篇
  2007年   138篇
  2006年   86篇
  2005年   83篇
  2004年   74篇
  2003年   76篇
  2002年   83篇
  2001年   74篇
  2000年   68篇
  1999年   75篇
  1998年   36篇
  1997年   55篇
  1996年   52篇
  1995年   44篇
  1994年   27篇
  1993年   39篇
  1992年   39篇
  1991年   52篇
  1990年   42篇
  1989年   69篇
  1988年   32篇
  1987年   50篇
  1986年   42篇
  1985年   36篇
  1984年   37篇
  1983年   28篇
  1982年   24篇
  1981年   21篇
  1980年   24篇
  1979年   21篇
  1978年   12篇
  1977年   19篇
  1976年   16篇
  1975年   12篇
  1974年   12篇
  1972年   15篇
  1970年   13篇
排序方式: 共有2432条查询结果,搜索用时 15 毫秒
1.
The initial management of bladder outflow obstruction typically related to benign prostatic hyperplasia (BPH) falls to a large extent within the remit of general practice. Referral onwards to secondary care typically arises following the failure to respond to conservative measures or when complications have supervened; the most significant of which is urinary retention. In the hospital setting, anaesthesia, constipation and immobility are the common precipitants. What follows is a practical guide to the management of these situations and provides an overview of the conservative, medical, minimally invasive and surgical treatments available.  相似文献   
2.
3.
OBJECTIVE: The aim of this study was to determine whether the survival of patients with untreated synchronous liver metastases after resection of a colorectal cancer was associated with any features of the primary tumour. METHODS: Information for 398 consecutive patients with unresected liver metastases in the period 1971-2001 was examined by multivariate survival analysis. RESULTS: Of 19 clinical and pathological variables considered, survival was independently associated only with residual tumour in a line of resection (hazard ratio (HR) 1.95), venous invasion (HR 1.87), right colonic tumour (HR 1.68), lymph node metastasis (HR 1.54), and extra-hepatic metastasis (HR 1.16); 8.3% of patients had none of these adverse features. Their 2-year overall survival rate was 39.2%, compared with only 16.5% (P < 0.001) in those with one or more adverse features. CONCLUSIONS: These findings may assist in selecting patients most likely to benefit from treatment of hepatic metastases and in counselling patients and their relatives.  相似文献   
4.
5.
Radiological sign of chronic anterior cruciate ligament deficiency   总被引:1,自引:0,他引:1  
An early radiological sign of anterior cruciate ligament deficiency is described. A retrospective study of the radiographs of 38 patients with chronic anterior cruciate ligament deficiency was performed. In 36 patients from this group an osteophyte was present on the medial femoral condyle adjacent to the medial tibial spine. This was best seen on a 30 ° notch view and was the earliest radiographic sign of chronic anterior cruciate ligament deficiency.  相似文献   
6.
7.
Variant von Willebrand disease designated as type I New York or type Malmö is characterized by enhanced ristocetin-induced platelet agglutination with normal von Willebrand factor multimeric distribution in plasma. We have studied four such patients belonging to three unrelated families and found in all of them a unique cytosine-to-thymine transition changing the codon for Pro503 (CCG) to Leu (CTG). In three patients the mutant allele also had a silent mutation in the codon for Ser500 (TCG-->TCA). Both nucleotide changes are present in the von Willebrand factor pseudogene; however, the characterization of distinctive markers where the gene and pseudogene differ, as well as the examination of amplified cDNA derived from platelet mRNA, confirmed that the abnormality occurs in the von Willebrand factor gene of the patients. Moreover, recombinant expression of the isolated glycoprotein Ib-binding domain of von Willebrand factor provided direct evidence that the Pro503-->Leu mutation is responsible for enhanced platelet reactivity to lower ristocetin concentrations. These results define a new structural element affecting the affinity of von Willebrand factor for glycoprotein Ib and establish the molecular basis of a variant form of von Willebrand disease.  相似文献   
8.
Surgical staging of gastric carcinoma: sources and consequences of error   总被引:2,自引:0,他引:2  
Macroscopic 'TNM' staging was performed during 78 consecutive operations for gastric carcinoma and compared with subsequent pathological staging. Surgical assessment was correct for tumour (T) in 60 per cent when depth of invasion was assessed, for nodes (N) in 61 per cent, for liver metastases (M) in 92 per cent but for all aspects in only 21 per cent. Curability (conservatively defined as T1-3, N0-1, M0) was correct in 8 of 18 patients thus assessed at surgery and incurability was pathologically correct in 58 of 60 patients. Despite inaccurate surgical staging, no patient was denied a resection although 10 patients had unduly radical procedures for their stage and 2 had inappropriately conservative procedures for their stage (but without evidence of residual disease). Staging errors did not jeopardize conventional surgical management substantially and use of intra-operative microscopic sampling of nodes would have improved surgical treatment only minimally.  相似文献   
9.
10.
OBJECTIVE: To determine whether the presence of tumour at a free serosal surface was independently associated with pelvic recurrence or survival in patients who had a resection for clinicopathological stage B or stage C rectal cancer and who had not received adjuvant therapy. METHOD: Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1971 to December 1998 with follow up to December 2003. Statistical analysis employed the chi(2) test or Fisher's exact probability, Kaplan-Meier estimation and proportional hazards regression, with a significance level of < or =0.05 and 95% confidence intervals (CI). RESULTS: In 665 patients with stages B or C tumour, 35 (5.3%; CI 3.7-7.2%) had tumour at a free serosal surface. These comprised 6/332 (1.8%; CI 0.8-3.7%) patients with stage B tumour and 29/333 (8.7%; CI 6.1-12.2%) with stage C tumour. After adjustment for other relevant variables, involvement of a free serosal surface was significantly associated with pelvic recurrence [hazard ratio (HR) 2.7; CI 1.3-5.5] and diminished survival (HR 1.6; CI 1.1-2.4) but not with systemic (only) recurrence. CONCLUSION: This study has confirmed that direct tumour spread to a free serosal surface independently predicts pelvic recurrence and diminished survival after resection of clinicopathological stage B and C rectal cancer. This feature should always be sought by the pathologist and reported when present, and noted by the surgeon and oncologist. Serosal involvement should be evaluated further for its utility in selecting patients for adjuvant therapy.  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