全文获取类型
收费全文 | 38472篇 |
免费 | 2635篇 |
国内免费 | 136篇 |
专业分类
耳鼻咽喉 | 529篇 |
儿科学 | 933篇 |
妇产科学 | 600篇 |
基础医学 | 4675篇 |
口腔科学 | 517篇 |
临床医学 | 4094篇 |
内科学 | 7906篇 |
皮肤病学 | 503篇 |
神经病学 | 3396篇 |
特种医学 | 1466篇 |
外科学 | 6537篇 |
综合类 | 501篇 |
一般理论 | 43篇 |
预防医学 | 3310篇 |
眼科学 | 622篇 |
药学 | 2897篇 |
中国医学 | 94篇 |
肿瘤学 | 2620篇 |
出版年
2023年 | 260篇 |
2022年 | 438篇 |
2021年 | 1166篇 |
2020年 | 714篇 |
2019年 | 1070篇 |
2018年 | 1291篇 |
2017年 | 900篇 |
2016年 | 915篇 |
2015年 | 1092篇 |
2014年 | 1648篇 |
2013年 | 2122篇 |
2012年 | 3079篇 |
2011年 | 3120篇 |
2010年 | 1642篇 |
2009年 | 1524篇 |
2008年 | 2616篇 |
2007年 | 2568篇 |
2006年 | 2409篇 |
2005年 | 2409篇 |
2004年 | 2274篇 |
2003年 | 2037篇 |
2002年 | 1889篇 |
2001年 | 365篇 |
2000年 | 301篇 |
1999年 | 368篇 |
1998年 | 352篇 |
1997年 | 281篇 |
1996年 | 255篇 |
1995年 | 197篇 |
1994年 | 196篇 |
1993年 | 154篇 |
1992年 | 165篇 |
1991年 | 192篇 |
1990年 | 137篇 |
1989年 | 106篇 |
1988年 | 100篇 |
1987年 | 82篇 |
1986年 | 67篇 |
1985年 | 78篇 |
1984年 | 77篇 |
1983年 | 73篇 |
1982年 | 87篇 |
1981年 | 59篇 |
1980年 | 49篇 |
1979年 | 38篇 |
1978年 | 38篇 |
1977年 | 27篇 |
1976年 | 23篇 |
1975年 | 28篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
994.
Protective immunization against inhalational anthrax: a comparison of minimally invasive delivery platforms 总被引:8,自引:0,他引:8
Mikszta JA Sullivan VJ Dean C Waterston AM Alarcon JB Dekker JP Brittingham JM Huang J Hwang CR Ferriter M Jiang G Mar K Saikh KU Stiles BG Roy CJ Ulrich RG Harvey NG 《The Journal of infectious diseases》2005,191(2):278-288
A new anthrax vaccine under clinical investigation is based on recombinant Bacillus anthracis protective antigen (rPA). Here, we investigated microneedle-based cutaneous and nasal mucosal delivery of rPA in mice and rabbits. In mice, intradermal (id) delivery achieved up to 90% seroconversion after a single dose, compared with 20% after intramuscular (im) injection. Intranasal (inl) delivery of a liquid formulation required 3 doses to achieve responses that were comparable with those achieved via the id or im routes. In rabbits, id delivery provided complete protection against aerosol challenge with anthrax spores; in addition, novel powder formulations administered inl provided complete protection, whereas a liquid formulation provided only partial protection. These results demonstrate, for the first time, that cutaneous or nasal mucosal administration of rPA provides complete protection against inhalational anthrax in rabbits. The novel vaccine/device combinations described here have the potential to improve the efficacy of rPA and other biodefense vaccines. 相似文献
995.
996.
Fibroblastic foci in usual interstitial pneumonia: idiopathic versus collagen vascular disease 总被引:3,自引:0,他引:3
Flaherty KR Colby TV Travis WD Toews GB Mumford J Murray S Thannickal VJ Kazerooni EA Gross BH Lynch JP Martinez FJ 《American journal of respiratory and critical care medicine》2003,167(10):1410-1415
A histologic feature of usual interstitial pneumonia is the presence of fibroblastic foci. As some patients with usual interstitial pneumonia and an underlying collagen vascular disease have a better prognosis, we hypothesized that they would have fewer fibroblastic foci. Pathologists reviewed surgical lung biopsies from 108 patients with usual interstitial pneumonia (nine with collagen vascular disease) and assigned a score (absent 0, mild 1, moderate 2, and marked 3) for fibroblastic foci. Patients with idiopathic usual interstitial pneumonia had a higher median profusion of fibroblastic foci (1.75 vs. 1.0, p = 0.003). Baseline characteristics were similar, although patients with a collagen vascular disease were younger, had a shorter duration of symptoms, and had a higher percentage of predicted total lung capacity. Profusion of fibroblastic foci was the most discriminative feature for separating idiopathic from collagen vascular disease-associated usual interstitial pneumonia (odds ratio 8.31; 95% confidence interval, 1.98, 59.42; p = 0.002 for a one-unit increase in fibroblastic foci score). No deaths were noted in the collagen vascular disease-associated usual interstitial pneumonia group; 52 deaths occurred in the idiopathic usual interstitial pneumonia group (log rank; p = 0.005). We conclude that patients with collagen vascular disease-associated usual interstitial pneumonia have fewer fibroblastic foci and improved survival. 相似文献
997.
In response to the HIV/AIDS pandemic, antiretroviral treatment is currently being implemented in sub-Saharan Africa, where malaria and HIV-1 co-infections are highly prevalent. The effectiveness and tolerability of antiretrovirals in patients with malaria and HIV-1 co-infection have not been investigated. Antiretrovirals decrease CD36 surface concentrations in vivo, which might impair receptor function and affect parasite-host interactions. Thus, we investigated the effects of these drugs on CD36-mediated cytoadherence and non-opsonic phagocytosis of Plasmodium falciparum parasitised erythrocytes in vitro. The protease-inhibitor class of antiretrovirals particularly impairs CD36-mediated cytoadherence and non-opsonic phagocytosis of parasitised erythrocytes by human macrophages. Such treatment might therefore contribute to altered malaria disease outcomes in co-infected patients. 相似文献
998.
The role of the resting zone in growth plate chondrogenesis 总被引:8,自引:0,他引:8
Abad V Meyers JL Weise M Gafni RI Barnes KM Nilsson O Bacher JD Baron J 《Endocrinology》2002,143(5):1851-1857
In mammals, growth of long bones occurs at the growth plate, a cartilage structure that contains three principal layers: the resting, proliferative, and hypertrophic zones. The function of the resting zone is not well understood. We removed the proliferative and hypertrophic zones from the rabbit distal ulnar growth plate in vivo, leaving only the resting zone. Within 1 wk, a complete proliferative and hypertrophic zone often regenerated. Next, we manipulated growth plates in vivo to place resting zone cartilage ectopically alongside the proliferative columns. Ectopic resting zone cartilage induced a 90-degree shift in the orientation of nearby proliferative zone chondrocytes and seemed to inhibit their hypertrophic differentiation. Our findings suggest that resting zone cartilage makes important contributions to endochondral bone formation at the growth plate: 1) it contains stem-like cells that give rise to clones of proliferative chondrocytes; 2) it produces a growth plate-orienting factor, a morphogen, that directs the alignment of the proliferative clones into columns parallel to the long axis of the bone; and 3) it may also produce a morphogen that inhibits terminal differentiation of nearby proliferative zone chondrocytes and thus may be partially responsible for the organization of the growth plate into distinct zones of proliferation and hypertrophy. 相似文献
999.
1000.
Tahereh Ghaziani Seyed-Moayed Alavian Mohammad R. Zali Saeid Shahraz Mohammdreza Agah Kevin P. Jensen Shahin Ansari Hossein Sendi Richard W. Lambrecht Jonathan Covault Herbert L. Bonkovsky 《Hepatology research》2007,37(3):172-178
Aim: We tested associations between HFE mutations and hepatitis B virus (HBV) infection. We also explored measures of total body iron status and their association with chronic HBV infection. Methods: Serum measures of iron status and HFE mutations (C282Y, H63D, and S65C) were assessed in 344 Iranian patients with chronic HBV infection (214 asymptomatic carriers, 130 patients with chronic progressive liver disease [CPLD]) and 302 controls. Results: Frequencies of HFE mutations did not differ between patients with chronic HBV infection and controls (C282Y: P=0.9, H63D: P= 0.8, S65C: P=0.9). By logistic regression, advanced hepatic fibrosis was associated with HFE H63D mutation (OR=13.1, P=0.006; 95% CI=2.0-84.1). Higher levels of serum ferritin and transferrin saturation were observed in patients with CPLD than in healthy controls (P=0.0001 and 0.01, respectively, adjusted for age and sex). None of the serum iron measures was related to liver fibrosis stage or necroinflammatory grade. Conclusion: Serum iron measures are associated with chronic progressive hepatitis B. Carriage of HFE mutations is not associated with the presence of chronic HBV infection or values of serum iron measures in this population, although HFE H63D is associated with more advanced hepatic fibrosis. 相似文献