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   6835篇
  免费   421篇
  国内免费   52篇
耳鼻咽喉   123篇
儿科学   151篇
妇产科学   130篇
基础医学   968篇
口腔科学   826篇
临床医学   485篇
内科学   1364篇
皮肤病学   153篇
神经病学   412篇
特种医学   121篇
外科学   772篇
综合类   15篇
一般理论   3篇
预防医学   834篇
眼科学   130篇
药学   483篇
中国医学   71篇
肿瘤学   267篇
  2024年   6篇
  2023年   70篇
  2022年   154篇
  2021年   314篇
  2020年   196篇
  2019年   257篇
  2018年   320篇
  2017年   220篇
  2016年   257篇
  2015年   261篇
  2014年   358篇
  2013年   376篇
  2012年   578篇
  2011年   681篇
  2010年   382篇
  2009年   259篇
  2008年   437篇
  2007年   388篇
  2006年   320篇
  2005年   290篇
  2004年   218篇
  2003年   210篇
  2002年   193篇
  2001年   89篇
  2000年   89篇
  1999年   68篇
  1998年   28篇
  1997年   16篇
  1996年   13篇
  1995年   11篇
  1994年   11篇
  1993年   15篇
  1992年   29篇
  1991年   25篇
  1990年   19篇
  1989年   20篇
  1988年   14篇
  1987年   15篇
  1986年   14篇
  1985年   9篇
  1984年   10篇
  1983年   7篇
  1982年   9篇
  1981年   4篇
  1979年   6篇
  1978年   4篇
  1977年   5篇
  1970年   3篇
  1969年   7篇
  1968年   3篇
排序方式: 共有7308条查询结果,搜索用时 250 毫秒
11.
12.
This study aimed to investigate whether endothelial cells are damaged and to evaluate fibrinolytic system function in patients with type 2 diabetes. For this proposal, plasma levels of von Willebrand factor (an endothelial marker of injury), homocysteine (an inductor of endothelial injury), D-dimer (a marker of coagulation cascade activation) and plasminogen activator inhibitor-1 (a fibrinolysis marker) were measured in individuals with both type 2 diabetes and high blood pressure, with type 2 diabetes, with high blood pressure and in healthy control individuals. No significant differences among groups were observed for von Willebrand factor and homocysteine plasma levels. The type 2 diabetes and high blood pressure group presented a significant difference to the other groups for D-dimer and also presented high values for plasminogen activator inhibitor-1. The high blood pressure group and type 2 diabetes group presented separately higher values of plasminogen activator inhibitor-1 compared with the control group. High levels of D-dimer and plasminogen activator inhibitor-1 in patients with type 2 diabetes and high blood pressure with normoalbuminuria therefore indicate a state of hypercoagulability and hypofibrinolysis, despite no evident microvascular injury supported by normal levels of von Willebrand factor and homocysteine.  相似文献   
13.
OBJECTIVE: The objective of this study was to assess the efficiency of topical applications of podophyllin resin (25%) (P) versus podophyllin resin (25%) together with acyclovir cream (5%) (PA) in the treatment of oral hairy leukoplakia (OHL) in accordance with the following criteria: (1) number of applications necessary for the total clinical resolution of OHL; (2) correlation between the decrease of lesion size and the number of applications; (3) total clinical resolution of OHL; and (4) clinical reevaluation 12 months after the end of treatment. STUDY DESIGN: Forty-six OHLs were treated with P (P group) or with PA (PA group). Applications were performed weekly. Student t, Fisher exact, and Pearson correlation tests were used for statistical analysis. RESULTS: All 24 lesions from the PA group presented total clinical resolution while 4 lesions from the P group did not. The P group required up to 25 applications performed weekly while the PA group required up to 18. Observed was a negative significant association between the size of the lesions and the number of applications performed weekly in the PA group. CONCLUSIONS: The present study demonstrated the following: (1) P and PA topical treatments presented a similar average number of applications performed weekly; (2) both groups showed the same clinical response at 12 months post-therapy; and (3) PA presented a 100% clinical resolution and a continuous decrease in OHL size over the course of weekly applications.  相似文献   
14.
OBJECTIVE: To evaluate the efficacy of oral moisturizing gel (Oral Balance) in xerostomic patients with primary Sj?gren's syndrome (SS). METHOD AND MATERIALS: Twenty-one xerostomic patients with primary SS were subjected to a single-blind trial in which the efficacy of Oral Balance gel in reducing xerostomia and xerostomia-related oral symptoms was compared with that of a placebo. Both gels were packaged identically and were indiscernible in appearance and taste. Xerostomia was confirmed for all the patients through measurement of stimulated whole saliva. Patients began using the Oral Balance gel three times a day for 90 days, and were then switched to a gel placebo to be used in the same way for the same length of time. Clinical response was evaluated through the patients' subjective assessment (improved, worsened, or unaltered) of both gels. RESULTS: Neither the Oral Balance gel nor the gel placebo affected the salivary output of the patients. The Oral Balance gel presented a substantial statistically significant advantage in the control of burning mouth, mastication, and swallowing. No statistically significant relief of the isolated sensation of oral dryness was established. CONCLUSION: Oral Balance is a useful tool in the management of dryness-related oral symptoms in primary SS, but there is room for enhancing the overall properties of topical preparations designed to reduce oral complaints in xerostomic patients.  相似文献   
15.
16.
17.
18.
The authors report data collected prospectively on 551 cases of head injury in New Delhi, India, and 822 cases in Charlottesville, Virginia. The mortality rate, adjusted for initial severity of injury, was 11.0% in New Delhi versus 7.2% in Charlottesville (p less than 0.02). There was a striking similarity in mortality rates at both centers when comparing patients with the least severe head injuries and those with the most severe injuries according to the motor score of the Glasgow Coma Scale (GCS M). However, in the group with an abnormal but purposeful motor response (GCS M = 5), the mortality rate was 12.5% in New Delhi versus 4.8% in Charlottesville (p less than 0.01). The relative absence of prehospital emergency care and the delay in admission after head injury in New Delhi are cited as two possible causes for the differences in mortality rates in this subgroup of patients with "moderate" head injuries.  相似文献   
19.
The promoter region of the human GSTP1 gene contains a polymorphic short tandem repeat (STR) locus consisting of pentanucleotide repeat units (ATAAA). In this work we report the existence of a total of 26 alleles in a Caucasian population. While differences in size (ranging from one to five base pairs) were responsible for the major variation, in five size-defined classes, two alternative sequences were found. Automatic fragment sizing and sequencing analysis revealed that this polymorphism is of a highly complex nature in contrast with previous reports. A genetic population study was carried out on a random sample from Portugal showing no deviation from Hardy-Weinberg equilibrium. Somatic instability studies were also performed on gastric and thyroid tumours using this STR: no instability was detected in thyroid tumour tissues when compared with their normal counterpart but in gastric tumour tissues microsatellite instability (MSI) was detected in 9.6% of the cases and loss of heterozygosity (LOH) also in 9.6% of the cases studied. The results obtained with GSTP1 in gastric cancer were compared with previously reported data on MSI using BAT-26 and several dinucleotide repeat markers.  相似文献   
20.
Wilson disease (WD) is a rare inherited autosomal recessive disorder caused by a defect in a metal transporting P-type ATPase, resulting in copper overload in various tissues and cells. The aim was to assess both the phenotype in Brazilian WD patients and the corresponding ATP7B genotype. Sixty subjects belonging to 46 pedigrees diagnosed as WD were included in this study. Direct sequencing of all 21 exons within ATP7B and their flanking introns was performed. Demographic, clinical, laboratory and histopathological data at the time of diagnosis were obtained. We identified twenty-five mutations, twelve of them reported for the first time. The c.3402delC mutation had the highest allelic frequency (30.8%), followed by the c.2123T>C (p.L708P) (16.7%). Exons 8 and 15 were the site of 62.5% of the mutations. The common European mutation c.3207C>A (p.H1069Q) was not present at all. Phenotype varied greatly among individuals with the same ATP7B genotype. Our data confirm the heterogeneity of ATP7B genotype in Brazilian WD patients. The mutational spectrum is compatible with the Brazilian history of Mediterranean immigration; however, new mutations, and different frequencies and phenotype associated with the previously known mutations characterize this population. Exons 8 and 15 should be preferentially screened in WD cases from Brazil. Phenotype variation among subjects with the same ATP7B genotype suggests that modifying factors play an additional role in the pathogenesis of WD.  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