全文获取类型
收费全文 | 6102篇 |
免费 | 698篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 192篇 |
妇产科学 | 379篇 |
基础医学 | 690篇 |
口腔科学 | 106篇 |
临床医学 | 1208篇 |
内科学 | 1129篇 |
皮肤病学 | 236篇 |
神经病学 | 434篇 |
特种医学 | 329篇 |
外科学 | 813篇 |
综合类 | 73篇 |
预防医学 | 483篇 |
眼科学 | 65篇 |
药学 | 299篇 |
中国医学 | 5篇 |
肿瘤学 | 329篇 |
出版年
2023年 | 79篇 |
2022年 | 46篇 |
2021年 | 137篇 |
2020年 | 102篇 |
2019年 | 138篇 |
2018年 | 199篇 |
2017年 | 188篇 |
2016年 | 170篇 |
2015年 | 209篇 |
2014年 | 263篇 |
2013年 | 289篇 |
2012年 | 306篇 |
2011年 | 325篇 |
2010年 | 237篇 |
2009年 | 233篇 |
2008年 | 243篇 |
2007年 | 257篇 |
2006年 | 233篇 |
2005年 | 235篇 |
2004年 | 195篇 |
2003年 | 216篇 |
2002年 | 183篇 |
2001年 | 168篇 |
2000年 | 141篇 |
1999年 | 154篇 |
1998年 | 138篇 |
1997年 | 146篇 |
1996年 | 135篇 |
1995年 | 122篇 |
1994年 | 103篇 |
1993年 | 77篇 |
1992年 | 100篇 |
1991年 | 112篇 |
1990年 | 84篇 |
1989年 | 99篇 |
1988年 | 97篇 |
1987年 | 83篇 |
1986年 | 81篇 |
1985年 | 83篇 |
1984年 | 52篇 |
1983年 | 45篇 |
1982年 | 37篇 |
1981年 | 33篇 |
1980年 | 25篇 |
1979年 | 26篇 |
1978年 | 33篇 |
1977年 | 31篇 |
1976年 | 25篇 |
1975年 | 26篇 |
1972年 | 17篇 |
排序方式: 共有6825条查询结果,搜索用时 0 毫秒
61.
62.
Scorpionism is an endemic public health problem in Mexico [Hoffmann, C.C., 1936. La distribucion geografica de los alacranes peligrosos en la Republica Mexicana. Bol. Inst. Hygiene Mex. 2, 321; Hoffmann, C.C., Nieto, D.R., 1939. Segunda contribucion al conocimiento de los alacranes mexicanos. Anal. Inst. Biol. 10, 83-92; Mazzoti, L., Bravo-Becherelle, M.A., 1963. Scorpionism in the Mexican Republic. In: Keegan, H.L., McFarlane, W.V. (Eds.), Venomous and Poissonous Animals and Noxious Plants of the Pacific Area. Pergamon Press, London, pp. 119-131; Monroy-Velasco, J., 1961. Alacranes venenosos de Mexico. Rev. Mex. Cien. Med. Biol., Mex. 1, 1-23; Diaz-Najera, A., 1975. Listas y datos de distribucion geografica de los alacranes de Mexico. Rev. Inv. Salud. Publica. (Mex.) 35, 1; Velasco-Castrejon, O., Lara-Aguilera, R., Alatorre, H., 1976. Aspectos epidemiologicos y clinicos de la picadura de alacran en una area hiperendemica. Rev. Inv. Salud Publica. (Mex.) 36, 93-103; Dehesa-Davila, M., Possani, L.D., 1994. Scorpionism and serotherapy in Mexico. Toxicon 32 (9), 1015-1018]. In this prospective study, we assess cardiovascular disorders in children via electrocardiographic (ECG) recordings following envenomation by scorpion species Centruroides limpidus tecomanus found in the state of Colima, Mexico. We analyzed 113 cases between the ages of 5 and 14 years. Among the most frequent symptoms presented included local pain (99.1%) and paresthesia (75.2%), pruritus (36.3%), sialorrhoea (35.4%), and nystagmus (24.8%). Cardiovascular disorders were observed in 39.8% of cases, 71% of which were rhythm abnormalities. We find a significant association between the frequency of ECG alterations and age, whereby 8-9-year-old children are more likely to experience ECG alterations when compared with other tested age groups. 相似文献
63.
A saccular aneurysm of the posterior inferior cerebellar artery lying in the fourth ventricle and an arteriovenous malformation in the cerebellum fed by the same artery are reported. Clipping of the neck of the aneurysm and total removal of the arteriovenous malformation were performed successfully during one stage. Review of the pertinent literature indicates that the aneurysm of the posterior inferior cerebellar artery originates from the peripheral portion of the artery when associated with arteriovenous malformation. The treatment is often surgical with good results in more than 80% of cases. A one-stage operation is the method of choice. Embolization is not without risk and can be attempted when the PICA's course allows easy catheterization. 相似文献
64.
Naveenchandra Suryadevara Andrea R. Shiakolas Laura A. VanBlargan Elad Binshtein Rita E. Chen James Brett Case Kevin J. Kramer Erica C. Armstrong Luke Myers Andrew Trivette Christopher Gainza Rachel S. Nargi Christopher N. Selverian Edgar Davidson Benjamin J. Doranz Summer M. Diaz Laura S. Handal Robert H. Carnahan Michael S. Diamond Ivelin S. Georgiev James E. Crowe Jr. 《The Journal of clinical investigation》2022,132(11)
The protective human antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) focuses on the spike (S) protein, which decorates the virion surface and mediates cell binding and entry. Most SARS-CoV-2 protective antibodies target the receptor-binding domain or a single dominant epitope (“supersite”) on the N-terminal domain (NTD). Using the single B cell technology called linking B cell receptor to antigen specificity through sequencing (LIBRA-Seq), we isolated a large panel of NTD-reactive and SARS-CoV-2–neutralizing antibodies from an individual who had recovered from COVID-19. We found that neutralizing antibodies against the NTD supersite were commonly encoded by the IGHV1-24 gene, forming a genetic cluster representing a public B cell clonotype. However, we also discovered a rare human antibody, COV2-3434, that recognizes a site of vulnerability on the SARS-CoV-2 S protein in the trimer interface (TI) and possesses a distinct class of functional activity. COV2-3434 disrupted the integrity of S protein trimers, inhibited the cell-to-cell spread of the virus in culture, and conferred protection in human angiotensin-converting enzyme 2–transgenic (ACE2-transgenic) mice against the SARS-CoV-2 challenge. This study provides insight into antibody targeting of the S protein TI region, suggesting this region may be a site of virus vulnerability. 相似文献
65.
Changes in neuromuscular transmission of guinea pig vas deferens produced by decamethrin treatment 总被引:1,自引:0,他引:1
Responses of the isolated vas deferens of guinea pig to clonidine (inhibition of contractions to field stimulation at 2.5 Hz), tyramine (inhibition of contractions to field stimulation at 10 Hz), prostaglandin E2 (inhibition of contractions to field stimulation at 10 Hz), and noradrenaline (contraction of longitudinal muscle) were determined after administration of decamethrin (18 mg kg-1, ip) once a day for 3 consecutive days. Treatment with decamethrin produced a subsensitivity of the prejunctional alpha 2-adrenoceptor system as evidenced by the fact that the alpha 2-agonist clonidine was less effective in decreasing nerve-stimulated induced contractions of the vas deferens. In addition, the presynaptic action of tyramine on postganglionic motor transmission was impaired. However, no detectable changes in the inhibition by prostaglandin E2 of twitch responses were produced by decamethrin. Decamethrin treatment had a significant effect on noradrenaline responsiveness, causing an increase in the maximum contractile response, indicative of an enhanced postreceptor mechanism. The present results suggest that decamethrin treatment reduces peripheral presynaptic adrenoceptor sensitivity. This reduction will lead subsequently to increased noradrenaline release and postsynaptic adrenoceptor upregulation. 相似文献
66.
Lee TK Wang W O'Brien KF Johnke RM Wang T Allison RR Diaz AL 《Phytotherapy research : PTR》2008,22(12):1614-1622
To explore the radioprotective effect of a standardized North American ginseng extract (NAGE) on human peripheral blood lymphocytes (PBL), a micronuclei (MN) assay was conducted in PBL obtained from 12 volunteers. NAGE (50-1000 microg/mL) and WR-1065 (1 mM and 3 mM) were applied to PBL cultures at 0 h and 90 min post-irradiation. It was found that (1) the baseline MN yield of PBL ranged from 14.4 +/- 1.5 to 15.9 +/- 1.5 per 1000 binucleated cells (p > 0.05); after irradiation (1 Gy and 2 Gy), the MN yield increased sharply; (2) MN yields declined with increasing concentrations of NAGE and WR-1065. Even at 90 min post-irradiation of 1 Gy, the maximum level of MN reduction rate caused by NAGE and WR-1065 was 53.8% and 59.2%, respectively; after 2 Gy irradiation, it was 37.3% and 42%, respectively; (3) the MN distribution in PBL followed a non-Poisson distribution in all cases; and (4) both NAGE and WR-1065 showed no significant effect on the proliferation index of lymphocytes. The results indicate that NAGE is a relatively non-toxic natural product, which can be administered as a dietary supplement and has the potential to be a radiation countermeasure. 相似文献
67.
68.
In Argentina, the Pampa ecoregion has been almost completely transformed into agroecosystems. To evaluate the environmental (agricultural area, tree coverage, distance to the nearest water body and urban site) and biological (dove, cowbird, and sparrow abundance) effects on free-ranging bird exposure to St. Louis encephalitis virus (SLEV) and West Nile virus (WNV), we used generalized linear mixed models. For 1,019 birds sampled during 2017–2019, neutralizing antibodies were found against SLEV in samples from 60 (5.8%) birds and against WNV for 21 (2.1%). The best variable for explaining SLEV seroprevalence was agricultural area, which had a positive effect; however, for WNV, no model was conclusive. Our results suggest that agroecosystems in the La Pampa ecoregion increase the exposure of avian hosts to SLEV, thus potentially increasing virus activity. 相似文献
69.
70.