全文获取类型
收费全文 | 19320篇 |
免费 | 1514篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 140篇 |
儿科学 | 726篇 |
妇产科学 | 546篇 |
基础医学 | 2438篇 |
口腔科学 | 321篇 |
临床医学 | 2148篇 |
内科学 | 3618篇 |
皮肤病学 | 312篇 |
神经病学 | 2074篇 |
特种医学 | 415篇 |
外国民族医学 | 5篇 |
外科学 | 2066篇 |
综合类 | 153篇 |
一般理论 | 67篇 |
预防医学 | 2866篇 |
眼科学 | 286篇 |
药学 | 1233篇 |
1篇 | |
中国医学 | 39篇 |
肿瘤学 | 1419篇 |
出版年
2024年 | 44篇 |
2023年 | 284篇 |
2022年 | 492篇 |
2021年 | 928篇 |
2020年 | 562篇 |
2019年 | 766篇 |
2018年 | 876篇 |
2017年 | 633篇 |
2016年 | 650篇 |
2015年 | 704篇 |
2014年 | 930篇 |
2013年 | 1185篇 |
2012年 | 1643篇 |
2011年 | 1662篇 |
2010年 | 846篇 |
2009年 | 690篇 |
2008年 | 1177篇 |
2007年 | 1245篇 |
2006年 | 1017篇 |
2005年 | 939篇 |
2004年 | 839篇 |
2003年 | 763篇 |
2002年 | 576篇 |
2001年 | 102篇 |
2000年 | 90篇 |
1999年 | 93篇 |
1998年 | 127篇 |
1997年 | 99篇 |
1996年 | 48篇 |
1995年 | 59篇 |
1994年 | 50篇 |
1993年 | 51篇 |
1992年 | 49篇 |
1991年 | 34篇 |
1990年 | 41篇 |
1989年 | 57篇 |
1988年 | 24篇 |
1987年 | 32篇 |
1986年 | 36篇 |
1985年 | 30篇 |
1984年 | 30篇 |
1983年 | 15篇 |
1982年 | 20篇 |
1981年 | 26篇 |
1980年 | 24篇 |
1979年 | 14篇 |
1978年 | 15篇 |
1976年 | 18篇 |
1975年 | 18篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Bonnie L. Green Lisa A. Goodman Janice L. Krupnick Carole B. Corcoran Rachel M. Petty 《Journal of traumatic stress》2000,13(4):743-744
Note
Acknowledgment of Ad Hoc Reviewers for Volume 13 相似文献82.
83.
Mitchell Maiman M.D. Rachel G. Fruchter Ph.D. Alexander Sedlis M.D. Joseph Feldman Dr.P.H. Patrick Chen M.D. Robert D. Burk M.D. Howard Minkoff M.D. 《Gynecologic oncology》1998,68(3):233-239
Objectives.The objective was to evaluate the sensitivity and specificity of cervical cytology in women infected with the human immunodeficiency virus (HIV), risk factors for abnormal cytology in HIV-infected and uninfected women, and risk factors for histologic diagnosis of cervical intraepithelial neoplasia (CIN) in HIV-infected women.Methods.Methods included a cross-sectional analysis of cervical cytology, colposcopic impression, and histology in 248 HIV-infected women and multivariate analyses of risk factors for abnormal cytology in 253 HIV-infected and 220 uninfected women and risk factors for CIN in 186 HIV-infected women.Results.The sensitivity and specificity of cytology for all CIN grades were 0.60 and 0.80 and, for high-grade CIN, 0.83 and 0.74. The prevalence of abnormal cytology was 32.9% in HIV-infected and 7.6% in HIV-negative women. Independent risk factors for abnormal cytology were immunodeficiency [odds ratio (OR) 8–17,P< 0.001] and human papillomavirus (HPV) infection (OR = 5,P< 0.001). The prevalence of CIN on histology was 32% in HIV-infected women, and the only independent risk factor for CIN was oncogenic HPV type (OR = 5,P= 0.005).Conclusion.Given the high prevalence of abnormal cytology and CIN in HIV-infected women, cytologic screening has significant limitations. Both immunodeficiency and type of HPV infection are important risk factors. 相似文献
84.
Kramer HK Andria ML Kushner SA Esposito DH Hiller JM Simon EJ 《Brain research. Molecular brain research》2000,79(1-2):55-66
Opioid receptors are known for their ability to activate diverse second messenger systems. Previously, we showed that selective delta-opioid agonists were able to induce the rapid tyrosine phosphorylation of delta-opioid receptors (delta-ORs) through Src. Src-dependent tyrosine phosphorylation of delta-ORs appears to be important for activation of the mitogen-activated protein kinase cascade and for receptor sequestration into clathrin-coated endosomes, as the Src antagonist, PP1, inhibited both. In an attempt to clarify the role of tyrosine phosphorylation in delta-OR signalling and regulation, we constructed a mutant receptor in which the tyrosine located in the conserved NPXXY motif of the C-terminus was replaced by a phenylalanine (Y318F-delta-OR). Mutation of Y318 resulted in a receptor that was comparable to the wild type in its expression level in HEK-293 cells and in its affinity for opioid ligands. Both receptors showed effective coupling to G proteins and were capable of inhibiting forskolin-stimulated cAMP accumulation with similar potencies. However, the mutant receptor was able to stimulate (35)S-GTPgammaS binding with a lower EC(50) than the wild type receptor. The stimulation of tyrosine phosphorylation in delta-ORs by [D-Thr(2)]-Leu-enkephalin-Thr (DTLET) was significantly less in cells expressing the Y318F-delta-OR than in cells expressing the wild type. In addition, both rapid receptor internalization and down-regulation were markedly attenuated in the mutant. Finally, the mutant receptor was unable to induce a robust activation of the MAPK pathway, suggesting that tyrosine phosphorylation of the delta-OR protein is important for this signalling pathway. These findings implicate tyrosine phosphorylation of Y318 in receptor signalling and agonist-mediated regulation. 相似文献
85.
86.
Rachel L. Harrington Dima M. Qato James W. Antoon Rachel N. Caskey Glen T. Schumock Todd A. Lee 《Pediatric blood & cancer》2019,66(6)
Early survivors of pediatric cancer are at increased risk of experiencing chronic conditions; however, little is known about the morbidity burden in this population. In this observational cohort study of commercially insured pediatric cancer survivors in the United States (2009–2014), we find that 22.5% of survivors had one chronic condition, and 36.3% had multiple. Compared with survivors without chronic conditions, the presence of multiple conditions significantly increased the odds of an emergency department visit by 70% (odds ratios [OR], 1.7; 95% confidence interval [CI], 1.4–2.1) and of a hospitalization almost four‐fold (OR, 3.8; 95% CI], 2.5–5.5). Findings are important for informing pediatric survivorship care plans in the years following completion of therapy. 相似文献
87.
Rachel L. W. Hanson Heidi A. Baseler Archana Airody Antony B. Morland Richard P. Gale 《Investigative ophthalmology & visual science》2022,63(5)
PurposeThe aim of this study was to assess both retinal and cortical structure in a cohort of patients with long-term acquired central retinal disease in order to identify potential disease biomarkers and to explore the relationship between the anterior and posterior visual pathways.MethodsFourteen participants diagnosed with long-term central retinal disease underwent structural assessments of the retina using spectral-domain optical coherence tomography, including macular ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (pRNFL) thickness. Structural magnetic resonance imaging was used to measure visual cortex, including cortical volume of the entire occipital lobe and cortical thickness of the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively.ResultsMean thickness was significantly reduced in both the macular GCL and the inferior temporal pRNFL across patients. Cortical thickness was significantly reduced in both the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively. Disease duration significantly correlated with GCL thickness with a large effect size, whereas a medium effect size suggests the possibility that cortical thickness in the occipital pole may correlate with visual acuity.ConclusionsLong-term central retinal disease is associated with significant structural changes to both the retina and the brain. Exploratory analysis suggests that monitoring GCL thickness may be a sensitive biomarker of disease progression and reductions in visual cortical thickness may be associated with reduced visual acuity. Although this study is limited by its heterogeneous population, larger cohort studies would be needed to better establish some of the relationships detected between disease dependent structural properties of the anterior and posterior visual pathway given the effect sizes reported in our exploratory analysis. 相似文献
88.
Simon P. Jochems Karin de Ruiter Carla Solrzano Astrid Voskamp Elena Mitsi Elissavet Nikolaou Beatriz F. Carniel Sherin Pojar Esther L. German Jesús Rein Alessandra Soares-Schanoski Helen Hill Rachel Robinson Angela D. Hyder-Wright Caroline M. Weight Pascal F. Durrenberger Robert S. Heyderman Stephen B. Gordon Hermelijn H. Smits Britta C. Urban Jamie Rylance Andrea M. Collins Mark D. Wilkie Lepa Lazarova Samuel C. Leong Maria Yazdanbakhsh Daniela M. Ferreira 《The Journal of clinical investigation》2022,132(11)
89.
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
90.
Stephen Sameroff Rafal Tokarz Marko Vucelja Komal Jain Alexandra Oleynik Marko Boljfeti Linda Bjedov Rachel A. Yates Josip Margaleti Christopher A. L. Oura Walter Ian Lipkin Lidija Cvetko Krajinovi Alemka Markoti 《Viruses》2022,14(5)
Tick-borne diseases are a serious threat to both public and veterinary health. In this study, we used high-throughput sequencing to characterize the virome of three tick species implicated in the spread of vector-borne disease throughout Croatia. Ten viruses were identified, including seven potential novel species within the viral families Flaviviridae, Nyamiviridae, Rhabdoviridae, Peribunyaviridae, Phenuiviridae, and Nairoviridae. 相似文献