全文获取类型
收费全文 | 26001篇 |
免费 | 1975篇 |
国内免费 | 79篇 |
专业分类
耳鼻咽喉 | 237篇 |
儿科学 | 616篇 |
妇产科学 | 625篇 |
基础医学 | 3956篇 |
口腔科学 | 838篇 |
临床医学 | 3028篇 |
内科学 | 5243篇 |
皮肤病学 | 464篇 |
神经病学 | 2454篇 |
特种医学 | 765篇 |
外科学 | 2930篇 |
综合类 | 312篇 |
一般理论 | 16篇 |
预防医学 | 2614篇 |
眼科学 | 406篇 |
药学 | 1930篇 |
中国医学 | 119篇 |
肿瘤学 | 1502篇 |
出版年
2023年 | 216篇 |
2022年 | 285篇 |
2021年 | 583篇 |
2020年 | 352篇 |
2019年 | 617篇 |
2018年 | 816篇 |
2017年 | 584篇 |
2016年 | 617篇 |
2015年 | 808篇 |
2014年 | 937篇 |
2013年 | 1315篇 |
2012年 | 1939篇 |
2011年 | 1981篇 |
2010年 | 970篇 |
2009年 | 811篇 |
2008年 | 1516篇 |
2007年 | 1523篇 |
2006年 | 1481篇 |
2005年 | 1389篇 |
2004年 | 1329篇 |
2003年 | 1237篇 |
2002年 | 1194篇 |
2001年 | 445篇 |
2000年 | 411篇 |
1999年 | 362篇 |
1998年 | 208篇 |
1997年 | 159篇 |
1996年 | 180篇 |
1995年 | 134篇 |
1994年 | 125篇 |
1993年 | 126篇 |
1992年 | 242篇 |
1991年 | 242篇 |
1990年 | 233篇 |
1989年 | 216篇 |
1988年 | 187篇 |
1987年 | 206篇 |
1986年 | 200篇 |
1985年 | 200篇 |
1984年 | 175篇 |
1983年 | 121篇 |
1982年 | 90篇 |
1981年 | 94篇 |
1980年 | 85篇 |
1979年 | 98篇 |
1978年 | 74篇 |
1977年 | 72篇 |
1975年 | 80篇 |
1974年 | 75篇 |
1973年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jo?o R. Mesquita Inês Delgado Veronica Costantini Kristin Heenemann Thomas W. Vahlenkamp Jan Vinjé Maria S. J. Nascimento 《Clinical and Vaccine Immunology : CVI》2014,21(6):898-900
To investigate the prevalence of the recently described genogroup VI canine noroviruses (CNVs) in dogs in Europe, we tested 510 serum samples from dogs in 14 European countries for anti-IgG CNV antibodies. Seropositive dogs were found throughout Europe. Dogs with antibodies against human noroviruses were also found. 相似文献
992.
Feng Liu Hui Zheng Yuanyuan Qi Xue Wang Jianjun Yang Miaomiao Han Hart Zhang Hong Jiang 《Cellular & molecular immunology》2014,11(2):169-174
We have shown that Hsp6Osp-loaded immature dendritic cells (DC/sp) can protect mice from the induction of experimental allergic encephalomyelitis (EAE) by inducing Qa-l-restricted CD8+ T regulatory (Treg) cells. The binding half-life between Qa-1 and Hsp6Osp is particularly short and leads to an unstable Qa- l/peptide complex that significantly decreases the efficacy of this vaccination. To prevent Qa-l/Hsp6Osp complex dissociation, we utilized paraformaldehyde (PFA) fixation to stabilize the formation of the Qa-l/Hsp6Osp complex and maximize the function of DC/sp as a vaccine to control autoimmune diseases. Compared with the non-fixed DC/sp, the fixed DC/sp (FDC/sp) showed an enhanced ability to activate Qa-l-restricted Hsp6Osp-specific CD8+T cells in vitro and prevented EAE in vivo. Importantly, the FDC/sp maintained immune activity following cryopreservation for I week or after storage for 72 h at 4 ~C. These results indicate that PFA fixation can sustain or increase the efficacy of DC/sp by improving the stability of the Qa-l/Hsp6Osp complex on the surface of the DC/sp. In addition, PFA fixation creates a time window for DC/sp storage, transport and application. Our d~tn ~u~p__~t ~ nnt~nti~l clinic~l ..~e nf FDCI~n ~ ~ vnccine fnr the nr~v~ntinn and treatment of autnimm.n~_ di_~_~__ 相似文献
993.
Pedro Carreiro-Martins João Viegas Ana Luisa Papoila Daniel Aelenei Iolanda Caires José Araújo-Martins João Gaspar-Marques Maria Manuela Cano Ana Sofia Mendes Daniel Virella José Rosado-Pinto Paula Leiria-Pinto Isabella Annesi-Maesano Nuno Neuparth 《European journal of pediatrics》2014,173(8):1041-1049
Poor ventilation at day care centres (DCCs) was already reported, although its effects on attending children are not clear. This study aimed to evaluate the association between wheezing in children and indoor CO2 (a ventilation surrogate marker) in DCC and to identify behaviours and building characteristics potentially related to CO2. In phase I, 45 DCCs from Lisbon and Oporto (Portugal) were selected through a proportional stratified random sampling. In phase II, 3 months later, 19 DCCs were further reassessed after cluster analysis for the greatest difference comparison. In both phases, children’s respiratory health was assessed by ISAAC-derived questionnaires. Indoor CO2 concentrations and building characteristics of the DCC were evaluated in both phases, using complementary methods. Mixed effect models were used to analyze the data. In phase I, which included 3,186 children (mean age 3.1?±?1.5 years), indoor CO2 concentration in the DCC rooms was associated with reported wheezing in the past 12 months (27.5 %) (adjusted odds ratio (OR) for each increase of 200 ppm 1.04, 95 % CI 1:01 to 1:07). In phase II, the association in the subsample of 1,196 children seen in 19 out of the initial 45 DCCs was not significant (adjusted OR 1.02, 95 % CI 0.96 to 1.08). Indoor CO2 concentration was inversely associated with the practices of opening windows and internal doors and with higher wind velocity. A positive trend was observed between CO2 and prevalence of reported asthma (4.7 %). Conclusion: Improved ventilation is needed to achieve a healthier indoor environment in DCC. 相似文献
994.
995.
Lack of association between MDM2 promoter SNP309 and clinical outcome in patients with neuroblastoma
Ali Rihani MSc Tom Van Maerken MD PhD Bram De Wilde MD Fjoralba Zeka MSc Geneviève Laureys MD PhD Koen Norga MD PhD Gian Paolo Tonini PhD Simona Coco PhD Rogier Versteeg PhD Rosa Noguera MD PhD Johannes H. Schulte MD PhD Angelika Eggert MD PhD Raymond L. Stallings PhD Frank Speleman PhD Jo Vandesompele PhD 《Pediatric blood & cancer》2014,61(10):1867-1870
996.
Holly McKnight W. Patrick Kelsey Deborah A. Hooper Thomas C. Hart Angelo Mariotti 《Journal of periodontology》2014,85(6):810-818
Background: Although human gingival fibroblasts (hGFs) and human periodontal ligament fibroblasts (hPDLFs) exhibit numerous phenotypic similarities, it has been suggested that the secretory and behavioral differences, which exist between these cell types, are a result of the membrane protein composition of these cells. Methods: Four matched pairs of hGFs and hPDLFs were cultured. Before confluence, membrane‐bound and ‐associated proteins from cells of the fourth passage were extracted. The processed protein samples were evaluated using capillary‐liquid chromatography‐nanospray tandem mass spectrometry. Global protein identification was performed on an orbitrap mass spectrometer equipped with a microspray source operated in positive ion mode. Proteome software was used to validate protein identifications derived from tandem mass spectrometry sequencing results. Results: Four hundred fifty proteins were common to both hGFs and hPDLFs. Of the proteins identified, 214 were known membrane‐bound or ‐associated proteins, and 165 proteins were known nuclear‐associated proteins. Twenty‐seven proteins, identified from the 450 proteins, common to both hGFs and hPDLFs, were detected in statistically significant greater quantities in either hGFs or hPDLFs. More specifically, 13 proteins were detected in significantly greater quantities in hGFs, whereas 14 proteins were detected in significantly greater quantities in hPDLFs. Conclusions: Distinct differences in the cellular protein catalog may reflect the dynamic role and high energy requirements of hGFs in extracellular matrix remodeling and response to inflammatory challenge as well as the role of hPDLFs in monitoring mechanical stress and maintaining tissue homeostasis during regeneration and remineralization. 相似文献
997.
Nicolette Nabukeera-Barungi Jo Wilmshurst Muloiwa Rudzani James Nuttall 《African health sciences》2014,14(1):143-149
Background
Diagnosis of tuberculous meningitis (TBM) is complicated and outcome is poor especially in resource limited settings. Early diagnosis and prompt treatment are vital in effective treatment. We set out to describe experiences in the management and immediate outcome of TBM a tertiary-level children''s hospital in a high HIV and tuberculosis co-infection setting.Methods
This retrospective study included children who were diagnosed with TBM in the year 2009. A pre-coded questionnaire was used to extract data on presentation, diagnostics, treatment and outcome at the time of hospital discharge. Data was analyzed using STATA statistical package (StataCorp, Version 11).Results
Of the 40 children diagnosed with TBM, 6 (15%) had definitive TBM, 17 (42.5%) had probable TBM and 17 (42.5%) had possible TBM. The cerebrospinal fluid (CSF) chemistry and cells were abnormal in 39/40 (98%). Mantoux test was reactive in 16/29 (55%) and 17/30 (57%) had Chest X-rays suggestive of tuberculosis. Only 3/21 (14%) had positive sputum tuberculosis culture and 89% (32/36) had neuro-imaging abnormalities. Outcome at discharge was; 8% died, 49% improved with neurological sequelae and 43% improved without sequelae. Having TBM stage 3 at admission was associated with mortality (p=0.001).Conclusions
Most children had early diagnosis of TBM and mortality was lower than in previous studies. We recommend a larger prospective study to further understand the outcome of TBM. 相似文献998.
Adriano Fernandes Jo?o Ettinger Fabiano Amaral Maria José Ramalho Rodrigo Alves Norma Sueli Pinheiro Módolo 《Clinics (S?o Paulo, Brazil)》2014,69(10):655-659
OBJECTIVES:
Video laparoscopic bariatric surgery is the preferred surgical technique for treating morbid obesity. However, pneumoperitoneum can pose risks to the kidneys by causing a decrease in renal blood flow. Furthermore, as in other surgical procedures, laparoscopic bariatric surgery triggers an acute inflammatory response. Neutrophil gelatinase-associated lipocalin is an early and accurate biomarker of renal injury, as well as of the inflammatory response. Anesthetic drugs could offer some protection for the kidneys and could attenuate the acute inflammatory response from surgical trauma. The objective of this study was to compare the effects of two types of anesthetics, propofol and sevoflurane, on the serum levels of neutrophil gelatinase-associated lipocalin during the perioperative period in laparoscopic bariatric surgery.METHODS:
Sixty-four patients scheduled for laparoscopic bariatric surgery were randomized into two anesthesia groups and were administered either total intravenous anesthesia (propofol) or inhalation anesthesia (sevoflurane). In the perioperative period, blood samples were collected at three time points (before anesthesia, 6 hours after pneumoperitoneum and 24 hours after pneumoperitoneum) and urine output was measured for 24 hours. Acute kidney injuries were evaluated by examining both the clinical and laboratory parameters during the postoperative period. The differences between the groups were compared using non-parametric tests. ReBEC (http://www.ensaiosclinicos.gov.br/rg/recruiting/): RBR-8wt2fyRESULTS:
None of the patients developed an acute kidney injury during the study and no significant differences were found between the serum neutrophil gelatinase-associated lipocalin levels of the groups during the perioperative period.CONCLUSION:
The choice of anesthetic drug, either propofol or sevoflurane, did not affect the serum levels of neutrophil gelatinase-associated lipocalin during the perioperative period in laparoscopic bariatric surgery. 相似文献999.
1000.
Rodrigo Guedes de Amorim Soraya Coelho Leal Jan Mulder Nico H. J. Creugers Jo E. Frencken 《Clinical oral investigations》2014,18(1):117-124