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   2533篇
  免费   184篇
  国内免费   10篇
耳鼻咽喉   5篇
儿科学   65篇
妇产科学   49篇
基础医学   344篇
口腔科学   14篇
临床医学   247篇
内科学   708篇
皮肤病学   30篇
神经病学   301篇
特种医学   48篇
外科学   186篇
综合类   21篇
一般理论   3篇
预防医学   236篇
眼科学   16篇
药学   196篇
中国医学   13篇
肿瘤学   245篇
  2024年   6篇
  2023年   38篇
  2022年   55篇
  2021年   92篇
  2020年   58篇
  2019年   81篇
  2018年   84篇
  2017年   68篇
  2016年   66篇
  2015年   85篇
  2014年   103篇
  2013年   136篇
  2012年   213篇
  2011年   211篇
  2010年   118篇
  2009年   101篇
  2008年   163篇
  2007年   172篇
  2006年   165篇
  2005年   151篇
  2004年   156篇
  2003年   127篇
  2002年   122篇
  2001年   15篇
  2000年   12篇
  1999年   13篇
  1998年   14篇
  1997年   13篇
  1996年   7篇
  1995年   5篇
  1994年   5篇
  1992年   3篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1987年   4篇
  1986年   4篇
  1984年   3篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   2篇
  1976年   2篇
  1975年   2篇
  1972年   6篇
  1970年   2篇
  1969年   3篇
  1968年   4篇
  1967年   3篇
排序方式: 共有2727条查询结果,搜索用时 78 毫秒
951.
The disorder is described as a size distortion involving the side of space. We report the case of a woman with an ipsilateral hyperschematia without neglect after a right frontal lesion. The patient has exhibited a disproportionate enlargement of the right-hand side of objects and added more left-sided petals to the drawn daisy. This pathologic behavior is independent from spatial neglect and from classic frontal perseverations. Our data support the presence of a spatial component to the perception of object size and a specific sub-component of space distortion.  相似文献   
952.
953.
954.
955.
956.
The aim of this study was to determine the efficacy, safety, and immunosuppressant adherence in 125 stable liver transplant (LT) patients converted from twice‐daily tacrolimus (TAC BID) to once‐daily TAC (TAC OD). Tacrolimus trough levels, laboratory parameters, metabolic disorders, selected patient reported outcomes, and adverse events were assessed. Mean TAC trough level concentration was 6.1 ± 2.3 ng/ml at study entry, decreased to 5.5 ± 2.1 ng/ml (P = 0.016) and 5.5 ± 2.2 ng/ml (P = 0.019) after 1 and 2 weeks, respectively, and tended to equal the baseline value during further follow‐up. At week 1, TAC concentrations were lower in 62.4% of patients and higher in 36.0% when compared with baseline. Renal and cardiovascular risk factors remained stable and no rejection episodes occurred over 12 months. Adverse events were consistent with the safety profile known from previous studies with TAC BID. Nonadherence measured by the “Basel Assessment of Adherence Scale to Immunosuppressives” was evident in 66.4% at study entry and decreased to 30.9% postconversion (P < 0.0001). Prevalence of nonadherence at baseline was significantly higher in patients converted >2 years after LT and in those ≤60 years of age. Conversion to TAC OD is safe, enhances immunosuppressant adherence and should be accompanied by a close TAC level monitoring during the initial period.  相似文献   
957.
Obesity disproportionately affects Latina women. Common genetic variants are convincingly associated with body mass index (BMI) and may be used to create genetic risk scores (GRS) for obesity that could define genetically influenced forms of obesity and alter response to clinical trial interventions. The objective of this study was (1) to identify the frequency and effect size of common obesity genetic variants in Latina women; (2) to determine the clinical utility of a GRS for obesity with Latina women participating in a community-based clinical trial. DNA from 85 Latina women was genotyped for eight genetic variants previously associated with BMI in Caucasians, but not yet assessed in Latina populations. The main outcome measure was the correlation of GRS (sum of eight risk alleles) with BMI, waist circumference, and percent body fat. A majority (83%) of participants had a BMI ≥25. Frequency of loci near FTO, MC4R, and GNPDA2 were lower in Latinas than Caucasians. Association of each locus with BMI was lower in Latinas compared to Caucasians with no significant correlations with BMI. We conclude that an eight locus GRS has no clinical utility for explaining obesity or predicting response to intervention in Latina women participating in a clinical trial.  相似文献   
958.
Given that TP53 alterations predict prognosis and response to therapy in chronic lymphocytic leukemia (CLL), screening for TP53 mutations has an increasing role in patient management. TP53 direct sequencing is a time-consuming method, while the AmpliChip p53 Research Test is a novel non time-consuming microarray-based resequencing assay and queries Exons 2-11. We evaluated the impact of TP53 mutations on clinical outcome by analyzing 98 untreated CLL using the AmpliChip p53 Research Test and direct sequencing and performed microarrays analysis on TP53 mutated and/or deleted cases. The AmpliChip p53 Research Test detected 17 mutations in 14 patients (17.3%); a significant association between TP53 mutations and del(17p) was recorded. From a clinical standpoint, a higher percentage of mutation was found in CLL with unfavorable outcome (17.2% vs. 7.1% in progressive vs. stable cases). Detection of TP53 mutations by the AmpliChip p53 Research Test was associated with a significantly worse survival (P = 0.0002). Comparison of the array and direct sequencing tests showed that the p53 Research Test detected more mutations, although it failed to identify two microdeletions. Finally, microarrays analysis showed a more distinctive signature associated with del(17p) than with TP53 mutations, likely due to a concomitant gene dosage effect. The AmpliChip p53 Research Test is a straightforward method that bears prognostic value. This study confirms a high percentage of TP53 mutations in CLL with unfavorable outcome and a significant association between TP53 aberrations and del(17p). Finally, specific gene expression profiles are recognized for TP53 alterations.  相似文献   
959.
The acceleration of chronic obstructive pulmonary disease (COPD) by cigarette smoke (CS) in individuals with severe genetic deficiency of α(1)-antitrypsin (Z-AT [Glu342Lys]) exemplifies the critical importance of gene-environmental interactions to the development of COPD. We investigated the molecular basis for the interaction between Z-AT and CS. Female mice (8-10 wk old) transgenic for normal (M-AT) or Z-AT on CBA background were exposed to four 1R3F cigarettes daily for 5 days. Age and sex matched littermates not exposed to CS were used as controls. Bronchoalveolar lavage fluid and lung homogenates were assessed for inflammatory cells, neutrophil elastase, and AT conformers. Z-AT was purified from plasma, exposed to CS extract, and assessed for the development and temporal relationship between AT conformers. Mice transgenic for Z-AT developed a significant increase in pulmonary polymers after acute CS exposure (P = 0.001). There were also increased neutrophils in CS-Z lungs versus controls (P < 0.001), which were tightly correlated with polymer concentrations (r(2) = 0.93). Oxidation of human plasma Z-AT by CS or N-chlorosuccinimide greatly accelerated polymerization (P = 0.004), which could be abrogated by antioxidants (P = 0.359 versus Z control). Our data show that CS accelerates polymerization of Z-AT by oxidative modification, which, in so doing, further reduces pulmonary defense and increases neutrophil influx into the lungs. These novel findings provide a molecular explanation for the striking observation of premature emphysema in ZZ homozygotes who smoke. Further work is required to assess whether antioxidant therapy may be beneficial in Z-AT-related COPD.  相似文献   
960.
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