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   19700篇
  免费   2151篇
  国内免费   352篇
耳鼻咽喉   102篇
儿科学   431篇
妇产科学   508篇
基础医学   960篇
口腔科学   1183篇
临床医学   2587篇
内科学   3635篇
皮肤病学   435篇
神经病学   1506篇
特种医学   216篇
外国民族医学   2篇
外科学   1845篇
综合类   1239篇
现状与发展   1篇
预防医学   2055篇
眼科学   229篇
药学   2249篇
  7篇
中国医学   1179篇
肿瘤学   1834篇
  2024年   84篇
  2023年   643篇
  2022年   797篇
  2021年   1329篇
  2020年   1146篇
  2019年   1169篇
  2018年   1112篇
  2017年   1007篇
  2016年   842篇
  2015年   778篇
  2014年   1458篇
  2013年   1812篇
  2012年   1000篇
  2011年   1022篇
  2010年   824篇
  2009年   855篇
  2008年   886篇
  2007年   831篇
  2006年   770篇
  2005年   697篇
  2004年   546篇
  2003年   419篇
  2002年   365篇
  2001年   260篇
  2000年   209篇
  1999年   200篇
  1998年   168篇
  1997年   118篇
  1996年   114篇
  1995年   89篇
  1994年   80篇
  1993年   51篇
  1992年   60篇
  1991年   46篇
  1990年   49篇
  1989年   39篇
  1988年   35篇
  1987年   36篇
  1986年   32篇
  1985年   40篇
  1984年   36篇
  1983年   24篇
  1982年   15篇
  1981年   20篇
  1980年   22篇
  1979年   16篇
  1978年   9篇
  1977年   10篇
  1976年   8篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Vaccine》2022,40(27):3721-3726
We initiated a randomized, placebo-controlled, phase 1/2 trial to evaluate the safety and immunogenicity of the S-268019-b recombinant protein vaccine, scheduled as 2 intramuscular injections given 21 days apart, in 60 randomized healthy Japanese adults. We evaluated 2 regimens of the S-910823 antigen (5 μg [n = 24] and 10 μg [n = 24]) with an oil-in-water emulsion formulation and compared against placebo (n = 12). Reactogenicity was mild in most participants. No serious adverse events were noted. For both regimens, vaccination resulted in robust IgG and neutralizing antibody production at days 36 and 50 and predominant T-helper 1-mediated immune reaction, as evident through antigen-specific polyfunctional CD4+ T-cell responses with IFN-γ, IL-2, and IL-4 production on spike protein peptides stimulation. Based on the interim analysis, the S-268019-b vaccine is safe, produces neutralizing antibodies titer comparable with that in convalescent serum from COVID-19-recovered patients. However, further evaluation of the vaccine in a large clinical trial is warranted.  相似文献   
3.
《Vaccine》2021,39(42):6333-6339
Px563L is a next-generation anthrax vaccine candidate consisting of a protein subunit, mutant recombinant protective antigen SNKE167-ΔFF-315-E308D (mrPA), and liposome-embedded monophosphoryl lipid A (MPLA) adjuvant. Px563L has the potential to deliver an improved safety and immunogenicity profile relative to the currently licensed vaccine, which is produced from filtered B. anthracis culture supernatants.We conducted a Phase 1, double–blind, placebo–controlled, dose–escalation study in 54 healthy subjects to evaluate Px563L at 3 dose levels of mrPA (10, 50, and 80 mcg). For each dose level, 18 subjects were randomized in an 8:8:2 ratio to Px563L (mrPA with adjuvant), RPA563 (mrPA only) or placebo (saline). Each subject received an intramuscular (IM) injection on Day 0 and Day 28. Primary safety and immunogenicity analysis was conducted after all subjects completed the Day 70 visit, a duration deemed clinically relevant for post-exposure prophylaxis. Long-term safety was assessed through Day 393.Vaccinations with Px563L at all dose levels were well-tolerated. There were no serious adverse events or adverse events (AE) leading to early withdrawal. In all treatment groups, most AEs were due to injection site reactions, and all AEs at the 10 and 50 mcg dose levels were mild. For the primary immunogenicity endpoint (protective toxin neutralizing antibody 50% neutralization factor [TNA NF50]), titers started to increase significantly after the second administration of Px563L, from Day 35 through Day 70, with the geometric mean and lower bound of the 95% confidence interval exceeding 0.56, a threshold correlating with significant survival in animal models of anthrax exposure.In conclusion, Px563L, administered as two IM doses 28 days apart, was well-tolerated and elicited a protective antibody response starting at seven days after the second vaccination. These findings support the continued development of Px563L in a two-dose regimen for anthrax post-exposure prophylaxis. ClinicalTrials.gov identifier NCT02655549.  相似文献   
4.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
5.
6.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
7.
目的 系统评价中药治疗哮喘-慢阻肺(ACO)的疗效与安全性。方法 全面检索PubMed、Cochrane Library、Web of Science、中国知网、万方、维普、中国医学文献数据库,纳入有关中医药治疗ACO的随机对照试验(RCT),运用Cochrane手册对纳入研究的方法学质量进行评估,采用Review Manager 5.3进行Meta分析。结果 共纳入32项RCT,包括2688例ACO患者,其中试验组1361例,对照组1327例。Meta分析结果显示,中医药可以显著改善ACO患者的中医证候疗效[RR=1.19,95% CI(1.13,1.25),P<0.00001]、CAT评分[MD=-3.62,95% CI(-4.37,-2.87),P<0.00001]、ACT评分[MD=3.42,95% CI(2.23,4.62),P<0.00001],、中医证候总积分[MD=-3.61,95% CI(-4.83,-2.39),P<0.00001]、FEV1[MD=0.59,95% CI(0.08,1.10),P=0.02]、FEV1%[MD=8.61,95% CI(5.20,12.1),P<0.00001]、FEV1/FVC[MD=6.52,95% CI(4.24,8.80),P<0.00001]、6 min步行实验[MD=41.18,95% CI(22.15,60.21),P<0.0001]、急性发作次数[MD=-2.46,95% CI(-3.62,-1.13),P<0.0001]。所有研究均未报道严重不良反应。结论 中药治疗ACO,可以显著提高临床疗效,改善患者的肺功能且具有较好安全性,但是需要更高质量、多样本、多中心的随机对照试验进一步确认。  相似文献   
8.
Introduction: Collaborative interactions between several diverse biological processes govern the onset and progression of breast cancer. These processes include alterations in cellular metabolism, anti-tumor immune responses, DNA damage repair, proliferation, anti-apoptotic signals, autophagy, epithelial-mesenchymal transition, components of the non-coding genome or onco-mIRs, cancer stem cells and cellular invasiveness. The last two decades have revealed that each of these processes are also directly regulated by a component of the cell cycle apparatus, cyclin D1.

Area covered: The current review is provided to update recent developments in the clinical application of cyclin/CDK inhibitors to breast cancer with a focus on the anti-tumor immune response.

Expert opinion: The cyclin D1 gene encodes the regulatory subunit of a proline-directed serine-threonine kinase that phosphorylates several substrates. CDKs possess phosphorylation site selectivity, with the phosphate-acceptor residue preceding a proline. Several important proteins are substrates including all three retinoblastoma proteins, NRF1, GCN5, and FOXM1. Over 280 cyclin D3/CDK6 substrates have b\een identified. Given the diversity of substrates for cyclin/CDKs, and the altered thresholds for substrate phosphorylation that occurs during the cell cycle, it is exciting that small molecular inhibitors targeting cyclin D/CDK activity have encouraging results in specific tumors.  相似文献   

9.
10.
Potential for widespread transmission of HIV/AIDS among American Indian (AI) adolescents exists, yet no evidence-based interventions (EBIs) have been adapted and evaluated with this population. Intensive psychoeducation may improve knowledge and decision-making which could potentially translate to reductions in HIV risk behaviors. A peer group randomized controlled comparison of an adapted EBI vs. control was delivered over an eight-day summer basketball camp in one reservation-based tribal community to adolescents ages 13–19. Outcome data were gathered immediately post-camp and at 6 and 12 months follow-up. Self-selected peer groups were randomized to intervention (n = 138) or control (n = 129) conditions for a total sample of 267 participants (56.2% female), mean age 15.1 years (SD = 1.7). Intervention participants had better condom use self-efficacy post-camp (Adjusted Mean Difference [AMD] = ?0.75, p < 0.005) and at 6 (AMD = ?0.44, p < 0.005) and 12 months (AMD = ?0.23, p < 0.05) follow-up. Intervention participants also had higher HIV prevention and transmission knowledge (post-camp: AMD = 0.07, p < 0.01; 6 months: AMD = 0.06, p < 0.01) were more likely to believe condoms prevent sexually transmitted infections (post-camp: RR = 1.41, p < 0.005; 6 months: RR = 1.34, p < 0.05), to talk with an adult about HIV/AIDS (post-camp: RR=1.78, p < 0.005; 6 months: RR = 1.14, p < 0.005), had higher partner negotiation efficacy related to substance use during sex (post-camp: AMD = 0.37, p < 0.01), and were more likely to intend to use a condom (post-camp: RR = 1.39, p < 0.01). The adapted intervention had short- and medium-term impacts on AI adolescent risk for HIV/AIDS, but attenuated at 12 months. Intervention delivery through a community-based camp is feasible and acceptable with strong retention. Additional study is needed to evaluate the adapted intervention's impact on sexual risk behaviors and if booster sessions and parent involvement translate to long-term impacts.  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