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   2269篇
  免费   235篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   77篇
妇产科学   30篇
基础医学   220篇
口腔科学   199篇
临床医学   193篇
内科学   508篇
皮肤病学   21篇
神经病学   75篇
特种医学   169篇
外科学   309篇
综合类   51篇
一般理论   14篇
预防医学   164篇
眼科学   7篇
药学   178篇
中国医学   2篇
肿瘤学   286篇
  2023年   16篇
  2021年   24篇
  2020年   19篇
  2019年   12篇
  2018年   32篇
  2017年   27篇
  2016年   32篇
  2015年   41篇
  2014年   64篇
  2013年   76篇
  2012年   66篇
  2011年   88篇
  2010年   81篇
  2009年   82篇
  2008年   111篇
  2007年   104篇
  2006年   80篇
  2005年   77篇
  2004年   78篇
  2003年   81篇
  2002年   79篇
  2001年   75篇
  2000年   68篇
  1999年   74篇
  1998年   34篇
  1997年   55篇
  1996年   71篇
  1995年   51篇
  1994年   39篇
  1993年   50篇
  1992年   40篇
  1991年   48篇
  1990年   45篇
  1989年   59篇
  1988年   35篇
  1987年   58篇
  1986年   57篇
  1985年   41篇
  1984年   36篇
  1983年   28篇
  1982年   38篇
  1981年   23篇
  1980年   18篇
  1979年   20篇
  1977年   27篇
  1976年   19篇
  1975年   16篇
  1974年   11篇
  1972年   14篇
  1970年   13篇
排序方式: 共有2512条查询结果,搜索用时 31 毫秒
1.
Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment.  相似文献   
2.
目的:观察开道散合扶正和胃合剂治疗上消化道癌性狭窄的临床疗效。方法:对40例患者采用口服开道散、扶正和胃合剂联合胃镜下癌灶内注射5-氟脲嘧啶注射液及鸦胆子乳剂方法治疗上消化道癌性狭窄。结果:治疗后无瘤灶消失病例,34例患者肿瘤缩小达50%以上,完全缓解0例,部分缓解34例,稳定4例,进展2例,有效率为85.0%。治疗后患者吞咽困难有了较明显的改善,显效7例,有效31例,无效2例,总有效率95.0%。治疗后所有患者的卡氏评分均有所升高,与治疗前比较,差异有显著性意义(P〈0.05),提示治疗后患者的生活质量有所改善。结论:开道散合扶正和胃合剂治疗上消化道癌性狭窄疗效满意,能使实体瘤缩小、吞咽困难改善、生活质量提高。  相似文献   
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.
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   
5.
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.
9.
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   
10.
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.  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