全文获取类型
收费全文 | 228577篇 |
免费 | 20814篇 |
国内免费 | 4759篇 |
专业分类
耳鼻咽喉 | 3376篇 |
儿科学 | 4346篇 |
妇产科学 | 3670篇 |
基础医学 | 20649篇 |
口腔科学 | 7600篇 |
临床医学 | 21808篇 |
内科学 | 20911篇 |
皮肤病学 | 2471篇 |
神经病学 | 17723篇 |
特种医学 | 6235篇 |
外国民族医学 | 11篇 |
外科学 | 21057篇 |
综合类 | 35727篇 |
现状与发展 | 12篇 |
一般理论 | 37篇 |
预防医学 | 28807篇 |
眼科学 | 2313篇 |
药学 | 21814篇 |
433篇 | |
中国医学 | 25992篇 |
肿瘤学 | 9158篇 |
出版年
2023年 | 4825篇 |
2022年 | 7044篇 |
2021年 | 11278篇 |
2020年 | 11232篇 |
2019年 | 12348篇 |
2018年 | 10868篇 |
2017年 | 9464篇 |
2016年 | 8420篇 |
2015年 | 7899篇 |
2014年 | 15482篇 |
2013年 | 16256篇 |
2012年 | 13802篇 |
2011年 | 14934篇 |
2010年 | 11955篇 |
2009年 | 10496篇 |
2008年 | 9869篇 |
2007年 | 9878篇 |
2006年 | 8510篇 |
2005年 | 7147篇 |
2004年 | 5939篇 |
2003年 | 5239篇 |
2002年 | 4065篇 |
2001年 | 3373篇 |
2000年 | 2971篇 |
1999年 | 2381篇 |
1998年 | 1829篇 |
1997年 | 1652篇 |
1996年 | 1332篇 |
1995年 | 1395篇 |
1994年 | 1229篇 |
1993年 | 1111篇 |
1992年 | 1012篇 |
1991年 | 911篇 |
1990年 | 793篇 |
1989年 | 748篇 |
1988年 | 718篇 |
1987年 | 617篇 |
1986年 | 577篇 |
1985年 | 1884篇 |
1984年 | 2148篇 |
1983年 | 1348篇 |
1982年 | 1776篇 |
1981年 | 1234篇 |
1980年 | 1058篇 |
1979年 | 944篇 |
1978年 | 768篇 |
1977年 | 596篇 |
1976年 | 731篇 |
1975年 | 501篇 |
1974年 | 435篇 |
排序方式: 共有10000条查询结果,搜索用时 136 毫秒
31.
目的:探讨脑出血对酵母沉默信息调节因子2(Sirt2)和炎症的影响。方法:将胶原酶Ⅳ注入SD大鼠右侧
纹状体中建立脑出血模型,通过免疫印迹和ELISA 等方法测定大鼠脑出血后48 h 的Sirt2 的表达及炎症变化。利
用Hemin 诱导PC12 细胞损伤模拟体外脑出血模型,并检测Sirt2 及炎症变化;采用短发夹RNA(shRNA)-Sirt2 沉
默Sirt2 在PC12 细胞中的表达及对炎症的影响。结果:手术后48 h 脑出血行为学评分最低。脑出血组Sirt2 的表达
显著高于假手术组。脑出血组IL-6、IL-1β 表达显著升高。结论:脑出血可以促进Sirt2 的表达和炎症反应,降低
Sirt2 的表达可减缓炎症反应。
关键词 脑出血;沉默信息调节 相似文献
32.
Defects of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein affect the homeostasis of chloride, bicarbonate, sodium, and water in the airway surface liquid, influencing the mucus composition and viscosity, which induces a severe condition of infection and inflammation along the whole life of CF patients. The introduction of CFTR modulators, novel drugs directly intervening to rescue the function of CFTR protein, opens a new era of experimental research. The review summarizes the most recent advancements to understand the characteristics of the infective and inflammatory pathology of CF lungs. 相似文献
33.
The research and development of penicillin started with difficulty before 1949 and achieved certain results. In 1951, after the founding of the People's Republic of China, Zhang Weishen, as the only Chinese scientist who had been trained and worked in a penicillin research and development center in the United States for many years, overcame many difficulties and returned to China. In 1953, with the efforts of Zhang Weishen and his colleagues, China realized the industrialized production of penicillin, alleviating the urgent needs of the masses. Antibiotics has also become the first discipline to achieve major scientific and technological achievements after the founding of the New China. In the mid-1950s, the technical breakthrough in the localization of lactose substitutes marked the localization of the raw materials of the penicillin-producing culture medium, which paved the way for the industrialized production of penicillin with Chinese characteristics. Antibiotics have become one of the most widely used and affordable drugs for hundreds of millions of patients in China, and China has since ended the humiliating history of the “Sick Man of East Asia". 相似文献
34.
35.
《Vaccine》2022,40(34):5010-5015
ObjectivesTo investigate the association between providing leaflets to support pediatricians in explaining the safety of the human papillomavirus (HPV) vaccine and mother’s decision to vaccinate their daughters in Japan.MethodsIn this cross-sectional study, we conducted a survey of mothers to evaluate the effect of leaflets that were created to support pediatricians in explaining the safety profile of the HPV vaccine. Mothers who provided consent for vaccination before receiving an explanation were excluded from the study. The primary outcome was the mother’s decision to vaccinate their daughters with the HPV vaccine after receiving an explanation from pediatricians using our leaflets.ResultsAmong 161 eligible mothers, 101 decided on HPV vaccination (decided group) and 60 did not (decided against group). There was no difference in the maternal background between the 2 groups. The decided group had a significantly more positive impression of the leaflets than the undecided group. In multivariable logistic regression analysis, a detailed explanation for possible adverse events and specific solutions to them was associated with the mother's decision to have their daughters vaccinated (odds ratio 2.35, 95% confidence interval 1.02–5.44), but not the pathology of cervical cancer and the HPV vaccination process.ConclusionLeaflets emphasizing an explanation of adverse events may contribute to mothers’ decision making for HPV vaccination. 相似文献
36.
《Vaccine》2022,40(6):904-911
BackgroundGSK initiated a Pregnancy Registry in the United States (US) for the reduced-antigen-content tetanus-diphtheria-acellular pertussis (Tdap; Boostrix, GSK) vaccine with the aim to detect and describe pregnancy outcomes in women vaccinated with Boostrix 28 days before estimated conception or during pregnancy.MethodsVoluntary reports of pregnancy exposure to Boostrix received from spontaneous and post-marketing surveillance sources in the US were assessed. Reports were classified as prospective or retrospective based on the knowledge of pregnancy outcomes at the time of reporting. For completeness, reports of exposure to Boostrix or to the Tdap-inactivated poliovirus vaccine (Boostrix-IPV, GSK) reported to the global safety database from countries outside the US were also evaluated.ResultsFrom May 2005 to August 2019, 1517 (1455 prospective and 62 retrospective) pregnancy reports were received in the Boostrix US Pregnancy Registry. Of the prospective reports, 250 had known outcomes: 244 live infants with no apparent birth defects (BDs), three live infants with BDs, and three spontaneous abortions with no apparent BDs. Of the retrospective reports, 55 had known outcomes: 33 live infants with no apparent BDs, 16 live infants with BDs, one spontaneous abortion with no apparent BDs, four stillbirths with no apparent BDs, and one stillbirth with BDs. Cumulatively, 1321 pregnancy reports (1006 for Boostrix; 315 for Boostrix-IPV) were received from countries outside the US. Of these, 163 prospective reports and 551 retrospective reports had known outcomes. Results were in line with those from the Boostrix US Pregnancy Registry.ConclusionsData currently available from the Boostrix US Pregnancy Registry and from countries outside the US suggested that exposure to Boostrix or Boostrix-IPV during pregnancy does not raise safety concerns related to adverse pregnancy outcomes or BDs. 相似文献
37.
《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
38.
《Vaccine》2022,40(33):4748-4763
This work identifies the innovations that made it possible for the Bio-Manguinhos/Fiocruz Immunobiological Technology Institute to engage in the entire production of the Oxford/AstraZeneca vaccine (ChAdOx1 nCov-19) in Brazil, just 1.8 years after the COVID-19 pandemic was declared. The results were summarized in a case-based innovation model composed of 11 workstreams, 32 stages, 22 gates, 11 innovations, and 38 events. In terms of research contributions, three were found: (i) the identification of firm and government-level innovations allowing the substantial reduction in the COVID-19 vaccine time-to-market in Brazil; (ii) the presentation of empirical evidence supporting the new Outbreak Paradigm for vaccine research, development, and production; and (iii) the proposition of a conceptual model for describing innovations through the vaccine value chain in pandemic contexts, particularly when technology transfer is involved. 相似文献
39.
40.