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   3036篇
  免费   230篇
  国内免费   15篇
耳鼻咽喉   30篇
儿科学   95篇
妇产科学   76篇
基础医学   505篇
口腔科学   66篇
临床医学   250篇
内科学   649篇
皮肤病学   128篇
神经病学   406篇
特种医学   59篇
外科学   226篇
综合类   12篇
一般理论   1篇
预防医学   260篇
眼科学   38篇
药学   233篇
中国医学   4篇
肿瘤学   243篇
  2024年   8篇
  2023年   64篇
  2022年   109篇
  2021年   182篇
  2020年   97篇
  2019年   140篇
  2018年   123篇
  2017年   93篇
  2016年   102篇
  2015年   131篇
  2014年   156篇
  2013年   154篇
  2012年   270篇
  2011年   265篇
  2010年   133篇
  2009年   111篇
  2008年   173篇
  2007年   152篇
  2006年   145篇
  2005年   162篇
  2004年   101篇
  2003年   127篇
  2002年   96篇
  2001年   27篇
  2000年   19篇
  1999年   20篇
  1998年   12篇
  1997年   13篇
  1996年   10篇
  1995年   11篇
  1994年   9篇
  1993年   8篇
  1992年   3篇
  1991年   6篇
  1990年   9篇
  1989年   5篇
  1988年   4篇
  1987年   2篇
  1985年   2篇
  1984年   2篇
  1982年   2篇
  1980年   3篇
  1978年   3篇
  1971年   1篇
  1964年   1篇
  1932年   1篇
  1931年   2篇
  1930年   2篇
  1929年   5篇
  1903年   1篇
排序方式: 共有3281条查询结果,搜索用时 31 毫秒
61.
62.
ObjectiveWomen with early-stage, ER + breast cancer are recommend to receive genomic profiling tests, such as the 21-gene Recurrence Score (RS) test, to guide treatment decisions. We examined test- and treatment-related information discussed and the associations between RS categories and aspects of communication during patient-oncologist clinical encounters.MethodsAs part of a larger trial, clinical encounters (N = 46) were audiorecorded and coded for 1) RS- and treatment-related information, 2) shared decision making, 3) patient active participation, and 4) oncologist patient-centered communication. We examined differences by RS category using mixed models, adjusting for nesting within oncologist.ResultsPatients with a high RS were more likely to receive a chemotherapy recommendation (p < .01), hear about the risks/side effects of chemotherapy (p < .01), and offer their preferences (p = .02) than those with intermediate or low RS. Elements of shared decision making increased with RS. Oncologist patient-centered communication (M = 4.09/5, SD = .25) and patient active participation (M = 3.5/4, SD = 1.0) were high across RS.ConclusionFindings suggest that disease severity, rather than clinical uncertainty, impact treatment recommendations and shared decision making.Practice implicationsOncologists adjust test- and treatment-related information and shared decision making by disease severity. This information provides a framework to inform decision making in complex cancer and genomics settings.  相似文献   
63.
IntroductionMaternal apical periodontitis (AP) is associated with insulin resistance (IR) in adult offspring. Oxidative stress has been linked to IR. This study investigated insulin sensitivity (IS) and oxidative stress in the gastrocnemius muscle (GM) of adult offspring of rats with AP.MethodsFifteen female Wistar rats were distributed into a control group, a group with 1 tooth with AP, and a group with 4 teeth with AP. Thirty days after AP induction, female rats were mated with healthy male rats. When male offspring reached 75 days of age, glycemia, insulinemia, and IS were determined. In the GM, the oxidative damage products (thiobarbituric acid reactive substances and carbonyl protein) and activities of enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) and nonenzymatic (glutathione and total antioxidant capacity) antioxidants were quantified. Analysis of variance was performed followed by the Tukey post hoc test (P < .05).ResultsMaternal AP was associated with decreased IS and changes in antioxidant activities (reduced superoxide dismutase and increased catalase, glutathione peroxidase, and glutathione) and decreased thiobarbituric acid reactive substance concentration in the GM of their adult offspring. However, maternal AP does not appear to affect glycemia, carbonyl protein concentration, and the nonenzymatic total antioxidant capacity in the GM of this offspring.ConclusionsMaternal AP modulates the antioxidant defense system in the GM of their adult offspring, attenuating lipid peroxidation in this tissue. This reflects part of an adaptive response of the offspring to the stimulation of the maternal chronic oral inflammatory process in which the organism acts by decreasing oxidative tissue damage in the postnatal stage. The present study improves knowledge about the impact of maternal oral inflammation on healthy offspring.  相似文献   
64.
65.

Objective:

To evaluate quantitative measurements of background parenchymal enhancement (BPE) on breast MRI and compare them with observer-based scores.

Methods:

BPE of 48 patients (mean age: 48 years; age range: 36–66 years) referred to 3.0-T breast MRI between 2012 and 2014 was evaluated independently and blindly to each other by two radiologists. BPE was estimated qualitatively with the standard Breast Imaging Reporting and Data System (BI-RADS) scale and quantitatively with a semi-automatic and an automatic software interface. To assess intrareader agreement, MRIs were re-read after a 4-month interval by the same two readers. The Pearson correlation coefficient (r) and the Bland–Altman method were used to compare the methods used to estimate BPE. p-value <0.05 was considered significant.

Results:

The mean value of BPE with the semi-automatic software evaluated by each reader was 14% (range: 2–79%) for Reader 1 and 16% (range: 1–61%) for Reader 2 (p > 0.05). Mean values of BPE percentages for the automatic software were 17.5 ± 13.1 (p > 0.05 vs semi-automatic). The automatic software was unable to produce BPE values for 2 of 48 (4%) patients. With BI-RADS, interreader and intrareader values were κ = 0.70 [95% confidence interval (CI) 0.49–0.91] and κ = 0.69 (95% CI 0.46–0.93), respectively. With semi-automated software, interreader and intrareader values were κ = 0.81 (95% CI 0.59–0.99) and κ = 0.85 (95% CI 0.43–0.99), respectively. BI-RADS scores correlated with the automatic (r = 0.55, p < 0.001) and semi-automatic scores (r = 0.60, p < 0.001). Automatic scores correlated with the semi-automatic scores (r = 0.77, p < 0.001). The mean percentage difference between automatic and semi-automatic scores was 3.5% (95% CI 1.5–5.2).

Conclusion:

BPE quantitative evaluation is feasible with both semi-automatic and automatic software and correlates with radiologists'' estimation.

Advances in knowledge:

Computerized BPE quantitative evaluation is feasible with both semi-automatic and automatic software. Computerized BPE quantitative scores correlate with radiologists'' estimation.  相似文献   
66.
67.
68.
69.
70.
Phospholipases catalyze the cleavage of membrane phospholipids into smaller bioactive molecules. The lysosomal phospholipase A2 (LPLA2) is specifically expressed in macrophages. LPLA2 gene deletion in mice causes lysosomal phospholipid accumulation in tissue macrophages leading to phospholipidosis. This phenotype becomes most prominent in alveolar macrophages where LPLA2 contributes to surfactant phospholipid degradation. High expression of LPLA2 in alveolar macrophages prompted us to investigate its role in host immunity against the respiratory pathogen Mycobacterium tuberculosis, the causative agent of tuberculosis. Here we report that adaptive immune responses to M. tuberculosis were impaired in LPLA2 deficient mice. Upon aerosol infection with M. tuberculosis, LPLA2 deficient mice showed enhanced mycobacterial counts but less lung immunopathology and pulmonary inflammatory responses. Compromised T‐cell priming in the lymph nodes was associated with impaired pulmonary T‐cell recruitment and activation. Together with reduced Th1 type cytokine production, these results indicate that LPLA2 is indispensable for the induction of adaptive T‐cell immunity to M. tuberculosis. Taken together, we identified an unexpected and novel function of a lysosomal phospholipid‐degrading enzyme.  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