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   109335篇
  免费   7530篇
  国内免费   3222篇
耳鼻咽喉   544篇
儿科学   2501篇
妇产科学   1972篇
基础医学   15437篇
口腔科学   1254篇
临床医学   13702篇
内科学   16090篇
皮肤病学   959篇
神经病学   7024篇
特种医学   3792篇
外国民族医学   7篇
外科学   7459篇
综合类   17246篇
现状与发展   6篇
预防医学   8177篇
眼科学   1365篇
药学   10786篇
  86篇
中国医学   8025篇
肿瘤学   3655篇
  2024年   156篇
  2023年   1408篇
  2022年   1993篇
  2021年   3838篇
  2020年   3672篇
  2019年   3127篇
  2018年   3043篇
  2017年   3383篇
  2016年   3413篇
  2015年   3550篇
  2014年   6554篇
  2013年   7065篇
  2012年   5913篇
  2011年   6567篇
  2010年   5133篇
  2009年   4900篇
  2008年   4975篇
  2007年   5065篇
  2006年   4505篇
  2005年   4037篇
  2004年   3570篇
  2003年   3305篇
  2002年   2815篇
  2001年   2687篇
  2000年   2284篇
  1999年   2005篇
  1998年   1900篇
  1997年   1917篇
  1996年   1694篇
  1995年   1666篇
  1994年   1586篇
  1993年   1264篇
  1992年   1243篇
  1991年   1075篇
  1990年   901篇
  1989年   840篇
  1988年   784篇
  1987年   636篇
  1986年   586篇
  1985年   861篇
  1984年   737篇
  1983年   469篇
  1982年   588篇
  1981年   463篇
  1980年   410篇
  1979年   320篇
  1978年   260篇
  1977年   227篇
  1976年   206篇
  1975年   101篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
目的:探讨益气通脉饮治疗气虚血瘀型冠心病心绞痛的临床疗效。方法:选取2017年10月—2019年2月烟台业达医院收治的气虚血瘀型冠心病心绞痛的患者90例作为研究对象,根据随机数字表法将所选患者均分为两组,每组各45例,两组的一般资料经统计学方法,差异无统计学意义(P>0.05),因此具有可比性。对照组给予常规西药进行治疗,观察组在对照组治疗基础上给予益气通脉饮治疗,1个月后比较两组临床的疗效,评估治疗前后中医证候、心绞痛症状分级和血脂水平。临床检测的数据通过统计产品与服务解决方案(Statistical Product and Service Solutions,SPSS) 19.0软件进行分析和处理,计量的数据使用平均数±标准差(x±s)表示,采用双侧t检验,计数的数据采用χ~2检验,以%表示,以P<0.05为差异有统计学意义。结果:治疗后,对照组和观察组都有一定疗效,但观察组的改善中医证候总有效率95.56%(43/45),高于对照组的82.22%(37/45),两组比较具有统计学意义(P<0.05);心绞痛的症状总有效率观察组为93.33%(42/45),对照组为77.78%(35/45),两组比较差异有统计学意义(P<0.05);与治疗前相比较,两组治疗后的三酰甘油(Triglyceride,TG)、血清总胆固醇(Serum Total Cholesterol,TC)、高密度脂蛋白胆固醇(High Density Liptein Cholesterol,HDL-C)水平均降低(P<0.05),且观察组治疗后低于对照组(P<0.05),两组治疗后的HDL-C升高(P<0.05),组间比较,差异无统计学意义(P>0.05)。结论:益气通脉饮治疗气虚血瘀型冠心病心绞痛的疗效显著,值得临床进一步研究与推广应用。  相似文献   
23.
《Vaccine》2021,39(45):6601-6613
AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain.  相似文献   
24.
25.
Food-grade titanium dioxide (E171) is widely used as a food additive, and it is known that after oral consumption, E171 is translocated into the bloodstream reaching the highest titanium level at 6 h. E171 is accumulated in some organs triggering toxicity, but the effects on the blood parameters after oral consumption have been less studied. Recently, evidence shows that oral exposure to E171 induces behavioral signs of anxiety and depression. The relation between blood alterations and psychiatric disorders has been previously demonstrated. However, the oral exposure to E171 effects on alterations in blood parameters and effects linked to alterations in animal behavior has not been explored. In this short communication, we aimed to investigate the effects of E171 on specific blood parameters (hematocrit, hemoglobin, number of erythrocytes, and leukocytes) and anxiety and compulsive-like behavior in males and females orally exposed to ~5 mg/kg for 4 weeks. The results showed that E171 decreased hematocrit and hemoglobin in male but not in female mice while leukocyte and erythrocyte count remained unaltered. Oral consumption of E171 decreased the levels of anxiety-like behavior in females but not in male mice, while compulsive-like behavior was increased in both male and female mice.  相似文献   
26.
The current literature suggests that the antibacterial effect of leukocyte- and platelet-rich plasma (L-PRP) is directly related to platelet and leukocyte concentrations. The aim of this study was twofold: first, to evaluate the antimicrobial effect of L-PRP against selected bacterial strains in vitro, and second, to correlate this effect with leukocyte and platelet content in the final concentration. Blood was collected from 20 healthy males, and L-PRP, acellular plasma (AP), and autologous thrombin were consecutively prepared. Flow cytometry analysis of the blood, L-PRP, and AP was performed. The L-PRP gel, liquid L-PRP, and thrombin samples were tested in vitro for their antibacterial properties against seven selected bacterial strains using the Kirby–Bauer disk-diffusion method. There was notable antimicrobial activity against selected bacterial strains. No statistically significant correlations between antimicrobial activities and the platelet concentration in L-PRP were observed. Statistically significant positive correlations between selected leukocyte subtypes and antimicrobial activity were noted. A negative correlation was found between elevated monocyte count and antimicrobial activity of L-PRP against one bacterial strain studied. L-PRP possesses antimicrobial activity and can be potentially useful in the fight against certain postoperative infections. The bactericidal effect of L-PRP is caused by leukocytes, and there exists a relationship among selected leukocyte subtypes and L-PRP antimicrobial activity.  相似文献   
27.
Most vaccines approved by regulatory bodies are administered via intramuscular or subcutaneous injections and have shortcomings, such as the risk of needle-associated blood infections, pain and swelling at the injection site. Orally administered vaccines are of interest, as they elicit both systemic and mucosal immunities, in which mucosal immunity would neutralize the mucosa invading pathogen before the onset of an infection. Hence, oral vaccination can eliminate the injection associated adverse effects and enhance the person's compliance. Conventional approaches to manufacturing oral vaccines, such as coacervation, spray drying, and membrane emulsification, tend to alter the structural proteins in vaccines that result from high temperature, organic and toxic solvents during production. Electrohydrodynamic processes, specifically electrospraying, could solve these challenges, as it also modulates antigen release and has a high loading efficiency. This review will highlight the mucosal immunity and biological basis of the gastrointestinal immune system, different oral vaccine delivery approaches, and the application of electrospraying in vaccines development.  相似文献   
28.
《Vaccine》2019,37(31):4302-4309
Influenza A virus (IAV) vaccines in pigs generally provide homosubtypic protection but fail to prevent heterologous infections. In this pilot study, the efficacy of an intradermal pDNA vaccine composed of conserved SLA class I and class II T cell epitopes (EPITOPE) against a homosubtypic challenge was compared to an intramuscular commercial inactivated whole virus vaccine (INACT) and a heterologous prime boost approach using both vaccines. Thirty-nine IAV-free, 3-week-old pigs were randomly assigned to one of five groups including NEG-CONTROL (unvaccinated, sham-challenged), INACT-INACT-IAV (vaccinated with FluSure XP® at 4 and 7 weeks, pH1N1 challenged), EPITOPE-INACT-IAV (vaccinated with PigMatrix EDV at 4 and FluSure XP® at 7 weeks, pH1N1 challenged), EPITOPE-EPITOPE-IAV (vaccinated with PigMatrix EDV at 4 and 7 weeks, pH1N1 challenged), and a POS-CONTROL group (unvaccinated, pH1N1 challenged). The challenge was done at 9 weeks of age and pigs were necropsied at day post challenge (dpc) 5. At the time of challenge, all INACT-INACT-IAV pigs, and by dpc 5 all EPITOPE-INACT-IAV pigs were IAV seropositive. IFNγ secreting cells, recognizing vaccine epitope-specific peptides and pH1N1 challenge virus were highest in the EPITOPE-INACT-IAV pigs at challenge. Macroscopic lung lesion scores were reduced in all EPITOPE-INACT-IAV pigs while INACT-INACT-IAV pigs exhibited a bimodal distribution of low and high scores akin to naïve challenged animals. No IAV antigen in lung tissues was detected at necropsy in the EPITOPE-INACT-IAV group, which was similar to naïve unchallenged pigs and different from all other challenged groups. Results suggest that the heterologous prime boost approach using an epitope-driven DNA vaccine followed by an inactivated vaccine was effective against a homosubtypic challenge, and further exploration of this vaccine approach as a practical control measure against heterosubtypic IAV infections is warranted.  相似文献   
29.
目的 分析乌司他丁与连续性血液净化联用对热射病患者所产生的影响。方法 选取2017年5月—2019年2月在海南医学院第二附属医院进行治疗的88例热射病患者作为研究对象,将其分为研究组和常规组,常规组患者接受常规治疗,研究组患者在常规治疗基础上,将乌司他丁与连续性血液净化联用。分析两种治疗措施的效果。结果 治疗前两组患者的IL-17、TNF-α、cTnⅠ、β2-MG、PT、D-D、ET和TM水平,差异无统计学意义(P>0.05)。经治疗两组患者的上述指标水平都表现出下降的趋势,相对于常规组,研究组患者下降水平更明显,差异具有统计学意义(P<0.05)。研究组治疗的总有效率为95.5%,高于常规组的72.7%,差异具有统计学意义(P<0.05)。结论 运用乌司他丁与连续性血液净化联用的疗法对热射病患者进行治疗,可获得十分理想的治疗效果,可在临床工作中推广。  相似文献   
30.
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