全文获取类型
收费全文 | 7279篇 |
免费 | 475篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 222篇 |
妇产科学 | 105篇 |
基础医学 | 1030篇 |
口腔科学 | 962篇 |
临床医学 | 522篇 |
内科学 | 1530篇 |
皮肤病学 | 152篇 |
神经病学 | 456篇 |
特种医学 | 312篇 |
外科学 | 694篇 |
综合类 | 66篇 |
预防医学 | 800篇 |
眼科学 | 147篇 |
药学 | 453篇 |
中国医学 | 64篇 |
肿瘤学 | 191篇 |
出版年
2023年 | 68篇 |
2022年 | 171篇 |
2021年 | 237篇 |
2020年 | 192篇 |
2019年 | 232篇 |
2018年 | 319篇 |
2017年 | 187篇 |
2016年 | 221篇 |
2015年 | 266篇 |
2014年 | 336篇 |
2013年 | 410篇 |
2012年 | 554篇 |
2011年 | 630篇 |
2010年 | 324篇 |
2009年 | 305篇 |
2008年 | 380篇 |
2007年 | 433篇 |
2006年 | 325篇 |
2005年 | 268篇 |
2004年 | 201篇 |
2003年 | 160篇 |
2002年 | 167篇 |
2001年 | 130篇 |
2000年 | 114篇 |
1999年 | 110篇 |
1998年 | 67篇 |
1997年 | 58篇 |
1996年 | 56篇 |
1995年 | 49篇 |
1994年 | 44篇 |
1993年 | 41篇 |
1992年 | 47篇 |
1991年 | 55篇 |
1990年 | 38篇 |
1989年 | 61篇 |
1988年 | 46篇 |
1987年 | 48篇 |
1986年 | 49篇 |
1985年 | 39篇 |
1984年 | 35篇 |
1983年 | 34篇 |
1982年 | 24篇 |
1981年 | 21篇 |
1980年 | 17篇 |
1979年 | 19篇 |
1977年 | 24篇 |
1976年 | 22篇 |
1975年 | 17篇 |
1970年 | 20篇 |
1968年 | 20篇 |
排序方式: 共有7783条查询结果,搜索用时 15 毫秒
21.
22.
Daniela de Queiroz Moura Ramon Rawache Marília Ferreira Gomes Garcia Nathalia Farias Vasconcelos Priscila Santos Gustavo Rego Coelho Thiago Luis da Paz Santos Duílio Reis da Rocha Filho Sonia Leite da Silva Eliana Regia Barbosa de Almeida Paula F.C.B.C. Fernandes João Batista Cerqueira José Huygens Parente Garcia Claudia Maria Costa de Oliveira 《Transplantation proceedings》2021,53(4):1345-1349
Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation. 相似文献
23.
Sérgio Soares Tiago Mota Gomes Gustavo Campos Filipe Medeiros João Bragança Xavier Martin Oliva 《Foot and Ankle Surgery》2021,27(5):567-576
BackgroundVascular injury after hallux valgus surgery is a rare condition but serious complications can ensue.MethodsWe performed an anatomical study using 26 cadaveric lower extremities. We enhanced first metatarsal bone’s (FMB) vascularization by injecting latex. Each specimen was classified according to the severity of hallux valgus deformity (HVD). Then we measured two distances: one between the first tarsometatarsal joint (FTMJ) to the first dorsal branch’s origin, the other between the first metatarsophalangeal joint (MTP) to the dorsal plexus’s origin.ResultsThe distance between the FTMJ and the first dorsal branch to the FMB ranges from 10 mm in normal feet to 15 mm in severe deformed feet. The distance between the MTP and the dorsal plexus’ origin ranges from 20 mm in normal feet to 25 mm in severe deformed feet.ConclusionsUnderstanding the foot’s vascular anatomy has allowed us to adapt surgical landmarks to the severity of the HVD and to avoid post-operative complications. 相似文献
24.
Shyrar Tanussiya Ramu Madushika Dissanayake Chandima Jeewandara Farha Bary Michael Harvie Laksiri Gomes Ayesha Wijesinghe Dinuka Ariyaratne Graham S. Ogg Gathsaurie Neelika Malavige 《Immunology》2023,170(1):47-59
To further understand the role of NS1-specific antibodies (Abs) in disease pathogenesis, we compared neutralizing antibody levels (Nabs), NS1-Ab levels, IgG antibody subclass profiles and NS1-specific memory B-cell responses (Bmems) in individuals, with varying severity of past dengue. Nabs (Neut50 titres) were assessed using the Foci Reduction Neutralization Test (FRNT) and in-house ELISAs were used to assess NS1-Abs and NS1-Ab subclasses for all four DENV serotypes in individuals with past DF (n = 22), those with past DHF (n = 14) and seronegative (SN) individuals (n = 7). B-cell ELISpot assays were used to assess NS1-specific Bmem responses. 15/22 (68.18%) individuals with past DF and 9/14 (64.29%) individuals with past DHF had heterotypic infections. Neut50 titres were found to be significantly higher for DENV1 than DENV2 (p = 0.0006) and DENV4 (p = 0.0127), in those with past DHF, whereas there was no significant difference seen in titres for different DENV serotypes in those with past DF. Overall NS1-Ab to all serotypes and NS1-specific IgG1 responses for DENV1, 2 and 4 serotypes were significantly higher in those with past DHF than individuals with past DF. Those with past DHF also had higher IgG1 than IgG3 for DENV1 and DENV3, whereas no differences were seen in those with past DF. Over 50% of those with past DF or DHF had NS1-specific Bmem responses to >2 DENV serotypes. There was no difference in the frequency of Bmem responses to any of the DENV serotypes between individuals with past DF and DHF. Although the frequency of Bmem responses to DENV1 correlated with DENV1-specific NS1-Abs levels (Spearman r = 0.35, p = 0.02), there was no correlation with other DENV serotypes. We found that those with past DF had broadly cross-reactive Nabs, while those with past DHF had higher NS1-Ab responses possibly with a different functionality profile than those with past DF. Therefore, it would be important to further evaluate the functionality of NS1-specific antibody and Bmem responses to find out the type of antibody repertoire that is associated with protection against severe disease. 相似文献
25.
To find out the efficacy of sucralfate in preventing gastrointestinal side effects of non-steroidal anti-inflammatory drugs (NSAIDs) a prospective, randomised single blind study was conducted from 1989 to 1992. Patients with osteoarthritis, rheumatoid arthritis and other long standing painful conditions, who were expected to receive NSAIDs for over three months, were recruited into the study. All medicines were discontinued for a period of 10–15 days prior to initial endoscopic assessment. NSAID therapy was started and the patients were randomised to receive either placebo (group A) or sucralfate (group B) in addition. Patient were reassessed clinically every week and an endoscopic examination was repeated after 6–8 weeks of follow-up. A total of 176 patients were studied in group A (n=91) and group B (n=85). At the end of 8 weeks gastrointestinal symptoms were present in 30.6% and 26.4% patients of group A and B respectively. Endoscopic assessment showed superficial lesions in 36.5% and 18.7% while endoscopic ulcer in 2.4% and 1.1% patients of groups A and B respectively. Thus in patients receiving chronic NSAID therapy, simultaneous administration of sucralfate reduces the incidence of superficial gastric lesions but has no significant effect on symptoms or ulcer formation.KEY WORDS: Gastropathy, Sucralfate, Nonsteroidal anti-inflammatory drugs 相似文献
26.
27.
Nakamura-Palacios EM de Oliveira RW Gomes CF 《Progress in neuro-psychopharmacology & biological psychiatry》1999,23(8):1369-1388
1. Effects of diazepam (DZP) or haloperidol (HAL) on convulsions and behavioral responses (locomotion, circling, spying and head shaking) induced by bilateral electrical stimulation in the medial prefrontal cortex (mPFC) were examined. 2. Male Wistar rats were electrically stimulated (ten 30-sec trains, 60 Hz, 80-100 microA) bilaterally in the mPFC and their behavior was simultaneously observed in an open field in daily session. 3. DZP and HAL dose-response curves (0, 0.5, 1.25, 2.5 and 5 mg/kg, i.p., 30 min before electrical stimulation session) were determined after a baseline of behavioral responses was established. 4. DZP dose-dependently decreased head shaking and convulsions, had no effect in circling and spying behaviors, and increased locomotion except at the highest dose. HAL reduced locomotion, circling and spying behaviors in a dose-dependent manner, but did not affect convulsions or head shaking. 5. These results demonstrated that convulsion and behavioral responses induced by electrical activation of the mPFC were modified by DZP or HAL. Therefore, the mPFC is involved in the mediation of neural and/or behavioral activity that may be implicated in some central effects of psychoactive drugs. 相似文献
28.
A quartz crystal microbalance has been used to check the purity of glycerol. The experimental procedure involves no derivatization or other preliminary step except determination of water content. The protocol consists of the direct reading of the frequency of a quartz crystal with one face in contact with an aqueous solution of the glycerol to be tested. The method is inexpensive, simple, rapid, and highly sensitive; diethylene glycol contamination at the 3.61% level could be detected. 相似文献
29.
A. Dolei C. Serra A. Biolchini S. Curreli P. Marongiu E. Gomes F. Ameglio 《Perspectives in Drug Discovery and Design》1996,5(1):93-102
Summary HIV-1 is a polytropic virus that, apart from hematopoietic cells, can replicate in several cells from solid tissues. Virus yields vary widely, closely resembling differences in HIV binding to the cells; the latter phenomenon appears mainly related to the extent of CD4 expression, even though other molecules have been implied in virus-cell interactions, the expression of which on the cell membrane can be modulated by several stimuli. During the course of HIV replication, a series of cytokines is produced and released in parallel to virus growth, particularly IL-6 and TNF-. In fact, exposure of fibroblasts or epithelial cells to these HIV-in-duced cytokines causes an increase of CD4 expression, HIV adsorption to uninfected cells, and release of infectious virions by infected cells. In cells exposed to interferon-, IL-6 and TNF- allow the virus to bypass interferon inhibition of virus release. The fact that HIV-1 adsorption and spread can be mediated by HIV-induced cytokines may be relevant in AIDS pathogenesis, accelerating virus transmission both within the organ and to infiltrating cells, activating a self-maintaining mechanism of infection. 相似文献
30.
We are concerned in this paper with learning classification procedures from known cases. More precisely, we provide a diagnostic model that discriminate between cerebellum-pontine angle (CPA) tumors and otorhinolaryngological (ENT) disorders. Usually, in order to distinguish between CPA tumors and ENT disorders one must perform clinical-neurological examination together with expensive radiological imagery (CT and MRI). The proposed model was obtained through artificial intelligence methods and presented a good accuracy level (88.4%) when tested against new cases, considering only clinical examination without radiological imagery results. 相似文献