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   7685篇
  免费   521篇
  国内免费   32篇
耳鼻咽喉   46篇
儿科学   268篇
妇产科学   164篇
基础医学   1272篇
口腔科学   99篇
临床医学   763篇
内科学   1505篇
皮肤病学   183篇
神经病学   705篇
特种医学   179篇
外国民族医学   1篇
外科学   954篇
综合类   109篇
一般理论   3篇
预防医学   731篇
眼科学   134篇
药学   482篇
中国医学   40篇
肿瘤学   600篇
  2023年   41篇
  2022年   89篇
  2021年   180篇
  2020年   114篇
  2019年   152篇
  2018年   174篇
  2017年   132篇
  2016年   155篇
  2015年   184篇
  2014年   214篇
  2013年   304篇
  2012年   502篇
  2011年   499篇
  2010年   288篇
  2009年   306篇
  2008年   466篇
  2007年   504篇
  2006年   541篇
  2005年   473篇
  2004年   471篇
  2003年   421篇
  2002年   407篇
  2001年   143篇
  2000年   111篇
  1999年   92篇
  1998年   117篇
  1997年   89篇
  1996年   78篇
  1995年   84篇
  1994年   56篇
  1993年   62篇
  1992年   44篇
  1991年   51篇
  1990年   51篇
  1989年   37篇
  1988年   39篇
  1987年   35篇
  1986年   46篇
  1985年   51篇
  1984年   33篇
  1983年   39篇
  1982年   26篇
  1981年   22篇
  1980年   30篇
  1979年   26篇
  1978年   21篇
  1976年   14篇
  1975年   15篇
  1974年   21篇
  1973年   18篇
排序方式: 共有8238条查询结果,搜索用时 15 毫秒
101.
102.
The purpose of this retrospective study was to evaluate the influence of axillary disease on patients' survival after neoadjuvant chemotherapy and to assess patient and tumor characteristics associated with post-chemotherapy axillary involvement.After six induction cycles, 277 patients with operable breast cancer (stage II–III) underwent surgery with axillary dissection, followed by radiotherapy (n = 267) or additional chemotherapy (n = 63) and adjuvant tamoxifen therapy (n = 138). At a median follow-up of 8.5 years, overall survival (OS) and disease-free survival (DFS) were analyzed as a function of node involvement.The differences in OS and DFS according to the number of positive nodes were highly statistically significant with a decreased survival associated with the increasing number of nodes (p = 5 × 10–6 and 9 × 10–7, respectively). Upon multivariate analysis, the node number after chemotherapy appeared as the most significant prognostic factor (p = 7 × 10–4 for OS and p = 3 × 10–5 for DFS). All the other classical prognostic factors were insignificant, except post-chemotherapy Scarff–Bloom–Richardson (SBR) grading for OS (p = 8 × 10–4) and adjuvant hormonotherapy for DFS (p = 1 × 10–2).Although constituting a different parameter from primary surgery data, the number of positive nodes after chemotherapy could still remain a valuable prognostic factor at secondary surgery, raising the question for high risk patients of a second non-cross-resistant adjuvant regimen, or high dose chemotherapy with peripheral blood stem cells support.  相似文献   
103.
104.
Type 2 diabetes mellitus (T2DM) is a genetically influenced disease, but few studies have been performed to investigate the genetic basis of T2DM in Vietnamese subjects. Thus, the potential associations of KCNJ11 and ABCC8 single nucleotide polymorphisms (SNPs) with T2DM were investigated in a Kinh Vietnamese population. A cross-sectional study consisting of 404 subjects including 202 T2DM cases and 202 non-T2DM controls was designed to examine the potential associations of 4 KCNJ11 and ABCC8 SNPs (rs5219, rs2285676, rs1799859, and rs757110) with T2DM. Genotypes were identified based on restriction fragment length polymorphism and tetra-primer amplification refractory mutation system polymerase chain reaction. After statistically adjusting for age, sex, and BMI, rs5219 was found to be associated with an increased risk of T2DM under 2 inheritance models: codominant (OR = 2.15, 95% confidence intervals [CI] = 1.09–4.22) and recessive (OR = 2.08, 95%CI = 1.09–3.94). On the other hand, rs2285676, rs1799859, and rs757110 were not associated with an increased risk of T2DM. Haplotype analysis elucidated a strong linkage disequilibrium between the 3 SNPs, rs5219, rs2285676, and rs757110. The haplotype rs5219(A)/rs2285676(T)/rs757110(G) was associated with an increased risk of T2DM (OR = 1.42, 95%CI = 1.01–1.99). The results show that rs5219 is a lead candidate SNP associated with an increased risk of developing T2DM in the Kinh Vietnamese population. Further functional characterization is needed to uncover the mechanism underlying the potential genotype-phenotype associations.  相似文献   
105.
Epidemiological studies reported that resilience, generally regarded as the ability to manage stress in the face of adversity, correlates with mental health in middle-aged and older adults. Currently, there is limited information on eating habits that affect resilience. Therefore, this cross-sectional study investigated the relationship between vitamin intake and resilience based on sex in community-dwelling middle-aged and older individuals in Shika town, Ishikawa Prefecture, Japan. A total of 221 participants (106 men and 115 women) aged 40 years or older were included in the analysis. We assessed vitamin intake and resilience using a brief-type self-administered diet history questionnaire (BDHQ) and the resilience scale (RS), respectively. A two-way analysis of covariance (ANCOVA) revealed that higher intakes of β-carotene and vitamin K were associated with higher RS in women, but not in men. Furthermore, a multiple logistic regression analysis stratified by sex showed that β-carotene and vitamin K were significant independent variables for RS only in women. The present study suggests that higher intakes of β-carotene and vitamin K were associated with higher resilience among middle-aged and older women. The results obtained demonstrate that β-carotene and vitamin K intakes may enhance resilience by strengthening stress tolerance.  相似文献   
106.
107.
Exonucleasic domain POLE (edPOLE) mutations, which are responsible for a hypermutated tumor phenotype, occur in 1–2% of colorectal cancer (CRC) cases. These alterations represent an emerging biomarker for response to immune checkpoint blockade. This study aimed to assess the molecular characteristics of edPOLE‐mutated tumors to facilitate patient screening. Based on opensource data analysis, we compared the prevalence of edPOLE mutations in a control group of unselected CRC patients (n = 222) vs a group enriched for unusual BRAF/RAS mutations (n = 198). Tumor mutational burden (TMB) and immune infiltrate of tumors harboring edPOLE mutations were then analyzed. In total, 420 CRC patients were analyzed: 11 edPOLE‐mutated tumors were identified, most frequently in microsatellite (MMR)‐proficient young (< 70 years) male patients, with left‐sided tumors harboring noncodon 12 KRAS mutation. The prevalence of edPOLE‐mutated tumors in the control vs the experimental screening group was, respectively, 0.45% (n = 1) vs 5.0% (n = 10). Among the 11 edPOLE‐mutated cases, two had a low TMB, three were hypermutated, and six were ultramutated. EdPOLE‐mutated cases had a high CD8+ tumor‐infiltrating lymphocyte (TIL) infiltration. These clinicopathological and molecular criteria may help to identify edPOLE mutations associated with a high TMB in CRC, and improve the selection of patients who could benefit from immunotherapy.  相似文献   
108.
Health-related concerns about cyanobacteria-laden sludge of drinking water treatment plants (DWTPs) have been raised in the past few years. Microscopic taxonomy, shotgun metagenomic sequencing, and microcystin (MC) measurement were applied to study the fate of cyanobacteria and cyanotoxins after controlled sludge storage (stagnation) in the dark in a full-scale drinking water treatment plant within 7 to 38 days. For four out of eight dates, cyanobacterial cell growth was observed by total taxonomic cell counts during sludge stagnation. The highest observed cell growth was 96% after 16 days of stagnation. Cell growth was dominated by potential MC producers such as Microcystis, Aphanocapsa, Chroococcus, and Dolichospermum. Shotgun metagenomic sequencing unveiled that stagnation stress shifts the cyanobacterial communities from the stress-sensitive Nostocales (e.g., Dolichospermum) order towards less compromised orders and potential MC producers such as Chroococcales (e.g., Microcystis) and Synechococcales (e.g., Synechococcus). The relative increase of cyanotoxin producers presents a health challenge when the supernatant of the stored sludge is recycled to the head of the DWTP or discharged into the source. These findings emphasize the importance of a strategy to manage cyanobacteria-laden sludge and suggest practical approaches should be adopted to control health/environmental impacts of cyanobacteria and cyanotoxins in sludge.  相似文献   
109.
目的 观察五丹散治疗2 型糖尿病合并牙周炎患者的临床效果.方法 将86 例2 型糖尿病合并牙周炎患者按随机数表法分为2 组,对照组采用牙周基础治疗,实验组采用五丹散煎汤含漱治疗,7d 为1 个疗程,共连续治疗3 个疗程,观察治疗前后2 组病人牙周指标的变化.结果 2 组病人治疗前菌斑指数(PLI)、牙龈指数(GI)、探诊出血(BOP)、探诊深度(PD)及牙齿松动指数(TM)均无明显差异(P>0.05),2 组病人治疗后菌斑指数(PLI)、牙龈指数(GI)、探诊出血(BOP)、探诊深度(PD)比较差异有显著性(t=4.468~6.735,P<0.05).结论 五丹散对2 型糖尿病合并牙周炎患者的牙周治疗有良好的效果.  相似文献   
110.
Purpose This work characterizes the interactions between efavirenz (EFV) and P-glycoprotein (P-gp/ABCB1) at the blood–brain barrier (BBB) and predicts the possible consequences on the brain uptake of coadministered P-gp substrates. Methods The uptake of EFV was measured in whole brains of rat and mdr1a−/− and mdr1a+/+ mice, and in GPNT cells (rat brain endothelial cell line) with and without P-gp inhibitors (PSC833, S9788, Quinidine). The effect of a single dose or multiple doses of EFV on the P-gp functionality was evaluated in vivo and in vitro by measuring the brain and cell uptake of digoxin, completed by the analysis of the P-gp expression at the rat BBB after repeated administrations of EFV. Results Inhibition of P-gp did not alter the uptake of EFV in rat brain and GPNT cells. The EFV brain/plasma ratio in mdr1a−/− mice, lacking the expression of P-gp, was not different from that in mdr1a+/+ mice. Moreover, a single dose of EFV did not modify the uptake of digoxin in rat brain and GPNT cells. Finally, the 3-day exposure of GPNT cells to EFV did not have any effect on the uptake of digoxin. Similarly, the 7-day treatment with EFV did not change the uptake of digoxin in rat brain nor the expression of P-gp at the BBB. Conclusion EFV is strongly distributed in the brain, but is neither a substrate nor an inhibitor of the P-gp at the blood–brain barrier. On the other hand, EFV did not induce P-gp, allowing to sustain the brain accumulation of associated P-gp substrates such as protease inhibitors. These findings make EFV suitable for combinations circumventing the brain HIV-1 residency.  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