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   103913篇
  免费   7814篇
  国内免费   4124篇
耳鼻咽喉   478篇
儿科学   2379篇
妇产科学   1085篇
基础医学   18520篇
口腔科学   908篇
临床医学   8506篇
内科学   26612篇
皮肤病学   1337篇
神经病学   4742篇
特种医学   1622篇
外国民族医学   9篇
外科学   6078篇
综合类   13309篇
现状与发展   21篇
预防医学   12611篇
眼科学   1272篇
药学   9282篇
  22篇
中国医学   2801篇
肿瘤学   4257篇
  2023年   1068篇
  2022年   2518篇
  2021年   3565篇
  2020年   3023篇
  2019年   3447篇
  2018年   3389篇
  2017年   3238篇
  2016年   3490篇
  2015年   4009篇
  2014年   6305篇
  2013年   6877篇
  2012年   6126篇
  2011年   6877篇
  2010年   5622篇
  2009年   5210篇
  2008年   4999篇
  2007年   5392篇
  2006年   4724篇
  2005年   4179篇
  2004年   3540篇
  2003年   3160篇
  2002年   2599篇
  2001年   2341篇
  2000年   1948篇
  1999年   1797篇
  1998年   1513篇
  1997年   1524篇
  1996年   1167篇
  1995年   1192篇
  1994年   1068篇
  1993年   839篇
  1992年   703篇
  1991年   590篇
  1990年   509篇
  1989年   472篇
  1988年   425篇
  1987年   326篇
  1986年   302篇
  1985年   796篇
  1984年   772篇
  1983年   599篇
  1982年   553篇
  1981年   515篇
  1980年   441篇
  1979年   391篇
  1978年   336篇
  1977年   248篇
  1976年   284篇
  1975年   258篇
  1974年   211篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
内生菌由细菌、真菌、古菌和原生生物组成,它们生活在植物的活体组织中,具有丰富的次级代谢产物多样性。人参内生菌在人参的生长发育、次级代谢产物的生成和环境适应等方面均有重要的促进作用,对人参的产量和品质有较大影响。随着人们在微生物领域研究的深入,高通量测序技术已经成为研究植物内生菌的重要方法。文章主要从人参内生菌分离与鉴定研究方法、人参内生菌的多样性、人参内生菌及其次级代谢产物的活性、人参内生菌对宿主的影响等4个方面对人参内生菌近年来的研究进展进行讨论,并对其发展方向提出展望,以期为药用植物内生菌研究和品质改良提供新思路、新方法。  相似文献   
3.
《Molecular therapy》2022,30(5):1885-1896
  1. Download : Download high-res image (90KB)
  2. Download : Download full-size image
  相似文献   
4.
The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus, and it synchronizes the peripheral clocks in other tissues. Circadian clock genes and clock-controlled genes exist in almost all cell types. They have an essential role in many physiological processes, including lipid metabolism in the liver, regulation of the immune system, and the severity of infections. In addition, circadian rhythm genes can stimulate the immune response of host cells to virus infection. Hepatitis B virus (HBV) infection is the leading cause of liver disease and liver cancer globally. HBV infection depends on the host cell, and hepatocyte circadian rhythm genes are associated with HBV replication, survival, and spread. The core circadian rhythm proteins, REV-ERB and brain and muscle ARNTL-like protein 1, have a crucial role in HBV replication in hepatocytes. In addition to influencing the virus’s life cycle, the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines. Therefore, it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment. For these reasons, understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy. Therefore, this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.  相似文献   
5.
6.
[摘要]?目的?结合环介导等温扩增技术(loop-mediated isothermal amplification, LAMP)和微流控芯片技术,建立一种适合现场快速检测登革病毒的方法。方法?利用RT-LAMP,针对登革病毒基因组中3’非编码区中特异性序列进行扩增,建立基于微流控芯片技术的LAMP检测方法,优化检测体系,并对该方法的灵敏性和特异性进行评估。结果?基于LAMP 和微流控芯片技术的登革病毒检测方法,通过对病毒模板进行扩增,发现与其他病毒无交叉反应,特异性良好;同时,结果显示该方法对登革病毒检测灵敏性可达61.2 pg/μl,与实时荧光定量PCR仪所达到的检测灵敏性一致。结论?基于LAMP和微流控芯片技术的登革病毒检测方法具有操作简单、快速、对设备要求低等优势,并且灵敏性、特异性均较好,是一种便于开展现场快速检测的方法。  相似文献   
7.
《Vaccine》2022,40(16):2370-2378
Porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae (M. hyopneumoniae, Mhp) are two of the most common pathogens involved in the porcine respiratory disease complex (PRDC) resulting in significant economic losses worldwide. Vaccination is the most effective approach to disease prevention. Since PRRSV and Mhp co-infections are very common, an efficient dual vaccine against these pathogens is required for the global swine industry. Compared with traditional vaccines, multi-epitope vaccines have several advantages, they are comparatively easy to produce and construct, are chemically stable, and do not have an infectious potential. In this study, to develop a safe and effective vaccine, B cell and T cell epitopes of PRRSV-GP5, PRRSV-M, Mhp-P46, and Mhp-P65 protein had been screened to construct a recombinant epitope protein rEP-PM that has good hydrophilicity, strong antigenicity, and high surface accessibility, and each epitope is independent and complete. After immunization in mice, rEP-PM could induce the production of high levels of antibodies, and it had good immunoreactivity with anti-rEP-PM, anti-PRRSV, and anti-Mhp antibodies. The anti-rEP-PM antibody specifically recognizes proteins from PRRSV and Mhp. Moreover, rEP-PM induced a Th1-dominant cellular immune response in mice. Our results showed that the rEP-PM protein could be a potential candidate for the development of a safe and effective multi-epitope peptide combined vaccine to control PRRSV and Mhp infections.  相似文献   
8.
《Vaccine》2022,40(7):1001-1009
Vaccination guidelines for dogs and cats indicate that core vaccines (for dogs, rabies, distemper, adenovirus, parvovirus; for cats, feline parvovirus, herpes virus-1, calicivirus) are essential to maintain health, and that non-core vaccines be administered according to a clinician’s assessment of a pet’s risk of exposure and susceptibility to infection. A reliance on individual risk assessment introduces the potential for between-practice inconsistencies in non-core vaccine recommendations. A study was initiated to determine non-core vaccination rates of dogs (Leptospira, Borrelia burgdorferi, Bordetella bronchiseptica, canine influenza virus) and cats (feline leukemia virus) in patients current for core vaccines in veterinary practices across the United States. Transactional data for 5,531,866 dogs (1,670 practices) and 1,914,373 cats (1,661 practices) were retrieved from practice management systems for the period November 1, 2016 through January 1, 2020, deidentified and normalized. Non-core vaccination status was evaluated in 2,798,875 dogs and 788,772 cats that were core-vaccine current. Nationally, median clinic vaccination rates for dogs were highest for leptospirosis (70.5%) and B. bronchiseptica (68.7%), and much lower for canine influenza (4.8%). In Lyme-endemic states, the median clinic borreliosis vaccination rate was 51.8%. Feline leukemia median clinic vaccination rates were low for adult cats (34.6%) and for kittens and 1-year old cats (36.8%). Individual clinic vaccination rates ranged from 0 to 100% for leptospirosis, B. bronchiseptica and feline leukemia, 0–96% for canine influenza, and 0–94% for borreliosis. Wide variation in non-core vaccination rates between clinics in similar geographies indicates that factors other than disease risk are driving the use of non-core vaccines in pet dogs and cats, highlighting a need for veterinary practices to address gaps in patient protection. Failure to implement effective non-core vaccination strategies leaves susceptible dogs and cats unprotected against vaccine-preventable diseases.  相似文献   
9.
陈红亮 《中医学报》2016,(6):910-912
目的:观察理筋通督手法治疗颈性眩晕的临床疗效。方法:将120例颈性眩晕患者随机分成3组,理筋通督组、传统手法组及安慰剂组。理筋通督组采用理筋通督手法;传统手法组采用传统手法;安慰剂组口服维生素C。结果:理筋通督手法可显著减缓患者基底动脉舒张期最低血流速度(P0.05)。理筋通督组有效率为93.67%,传统手法组有效率为67.5%,安慰剂组有效率为17.5%,3组比较差异有统计学意义(P0.05),理筋通督组明显优于其他两组。结论:理筋通督手法治疗颈性眩晕临床疗效显著。  相似文献   
10.
目的探讨微信平台延续性护理对老年腰椎间盘突出症术后患者康复及生活质量的影响。方法选取2015年6月—2018年5月在郑州市骨科医院接受手术治疗的老年腰椎间盘突出症患者96例进行研究。对照组行常规延续性护理,观察组行微信平台延续性护理。对比两组康复效果、治疗依从性及生活质量。计数资料采用卡方检验分析,计量资料采用t检验分析。结果观察组有效率为95.83%,明显高于对照组的81.25%。观察组总依从率为91.67%,明显高于对照组的77.08%。干预前两组生活质量量表得分相当,治疗后两组生活质量均有明显改善,但观察组改善程度更为明显。结论微信平台延续性护理相比传统延续性护理可明显提高老年腰椎间盘突出症患者康复效果、提高治疗依从性和改善生活质量。  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