全文获取类型
收费全文 | 318291篇 |
免费 | 29144篇 |
国内免费 | 5400篇 |
专业分类
耳鼻咽喉 | 3579篇 |
儿科学 | 6091篇 |
妇产科学 | 5264篇 |
基础医学 | 22895篇 |
口腔科学 | 11508篇 |
临床医学 | 38583篇 |
内科学 | 27793篇 |
皮肤病学 | 3200篇 |
神经病学 | 15279篇 |
特种医学 | 7050篇 |
外国民族医学 | 11篇 |
外科学 | 23965篇 |
综合类 | 50552篇 |
现状与发展 | 14篇 |
一般理论 | 138篇 |
预防医学 | 70113篇 |
眼科学 | 2450篇 |
药学 | 24832篇 |
611篇 | |
中国医学 | 27947篇 |
肿瘤学 | 10960篇 |
出版年
2023年 | 6652篇 |
2022年 | 8820篇 |
2021年 | 14840篇 |
2020年 | 15821篇 |
2019年 | 16329篇 |
2018年 | 14569篇 |
2017年 | 13089篇 |
2016年 | 12048篇 |
2015年 | 11492篇 |
2014年 | 22015篇 |
2013年 | 24347篇 |
2012年 | 19934篇 |
2011年 | 21491篇 |
2010年 | 17058篇 |
2009年 | 15214篇 |
2008年 | 14728篇 |
2007年 | 14670篇 |
2006年 | 12616篇 |
2005年 | 10352篇 |
2004年 | 8589篇 |
2003年 | 7453篇 |
2002年 | 5649篇 |
2001年 | 4895篇 |
2000年 | 4279篇 |
1999年 | 3248篇 |
1998年 | 2510篇 |
1997年 | 2204篇 |
1996年 | 1798篇 |
1995年 | 1737篇 |
1994年 | 1542篇 |
1993年 | 1334篇 |
1992年 | 1185篇 |
1991年 | 1121篇 |
1990年 | 979篇 |
1989年 | 902篇 |
1988年 | 868篇 |
1987年 | 741篇 |
1986年 | 698篇 |
1985年 | 1953篇 |
1984年 | 2195篇 |
1983年 | 1397篇 |
1982年 | 1822篇 |
1981年 | 1272篇 |
1980年 | 1110篇 |
1979年 | 965篇 |
1978年 | 810篇 |
1977年 | 633篇 |
1976年 | 758篇 |
1975年 | 529篇 |
1974年 | 436篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
《Vaccine》2022,40(6):904-911
BackgroundGSK initiated a Pregnancy Registry in the United States (US) for the reduced-antigen-content tetanus-diphtheria-acellular pertussis (Tdap; Boostrix, GSK) vaccine with the aim to detect and describe pregnancy outcomes in women vaccinated with Boostrix 28 days before estimated conception or during pregnancy.MethodsVoluntary reports of pregnancy exposure to Boostrix received from spontaneous and post-marketing surveillance sources in the US were assessed. Reports were classified as prospective or retrospective based on the knowledge of pregnancy outcomes at the time of reporting. For completeness, reports of exposure to Boostrix or to the Tdap-inactivated poliovirus vaccine (Boostrix-IPV, GSK) reported to the global safety database from countries outside the US were also evaluated.ResultsFrom May 2005 to August 2019, 1517 (1455 prospective and 62 retrospective) pregnancy reports were received in the Boostrix US Pregnancy Registry. Of the prospective reports, 250 had known outcomes: 244 live infants with no apparent birth defects (BDs), three live infants with BDs, and three spontaneous abortions with no apparent BDs. Of the retrospective reports, 55 had known outcomes: 33 live infants with no apparent BDs, 16 live infants with BDs, one spontaneous abortion with no apparent BDs, four stillbirths with no apparent BDs, and one stillbirth with BDs. Cumulatively, 1321 pregnancy reports (1006 for Boostrix; 315 for Boostrix-IPV) were received from countries outside the US. Of these, 163 prospective reports and 551 retrospective reports had known outcomes. Results were in line with those from the Boostrix US Pregnancy Registry.ConclusionsData currently available from the Boostrix US Pregnancy Registry and from countries outside the US suggested that exposure to Boostrix or Boostrix-IPV during pregnancy does not raise safety concerns related to adverse pregnancy outcomes or BDs. 相似文献
93.
This masterclass aims to provide an overview of the measurement of neck strength and the factors which can increase the ecological validity of the testing protocol within an athletic population. Adopting a ‘gold standard’ method for measuring neck strength is of vital importance when determining strength differences across sports, ages and sexes. Without a ‘gold standard’ method current variations in testing procedure and equipment have created challenges in establishing normative neck strength data. With encouraging evidence that higher neck strength can have a protective effect against sports-related head and neck injuries, including concussion, new injury prevention knowledge may be impeded by a lack of consensus on how to accurately measure neck strength, with a number of different methods available. This masterclass will outline the factors clinicians should consider when selecting a device and measurement protocol when measuring maximal neck strength as well as how to interpret the results. 相似文献
94.
《Patient education and counseling》2022,105(4):974-981
ObjectivesCancer can have long-term biopsychological impacts for young people that persist for years. To promote adjustment, it is essential to understand how young people cope, yet this is relatively understudied.MethodsThis study explored the coping strategies using semi-structured interviews with 16 young people with cancer aged 15–24 years. Eligible participants were diagnosed within the previous 24 months and recruited through Australian Youth Cancer Services. Transcribed interviews were analysed using content analysis.ResultsCoping strategies included: seeking support; controlling the focus; avoiding negatives and staying positive; meaning making and; changes with time. During treatment, seeking support, focussing on the present, distraction and avoidance were commonly applied. Following treatment, planning for the future, avoidance of re-traumatising situations and meaning making were used.ConclusionFindings support the concept of coping as a dynamic process where different strategies are used depending on the stressor, available resources and previous experiences.Practice ImplicationsComprehensive, developmentally appropriate psychosocial assessments, open communication, education and information provision, as well as appropriate referral for support are essential, particularly for young cancer survivors identified at risk. 相似文献
95.
Stephanie H. Ameis John D. Haltigan Rachael E. Lyon Amanda Sawyer Pat Mirenda Connor M. Kerns Isabel M. Smith Tracy Vaillancourt Joanne Volden Charlotte Waddell Lonnie Zwaigenbaum Teresa Bennett Eric Duku Mayada Elsabbagh Stelios Georgiades Wendy J. Ungar Anat Zaidman-Zait Meng-Chuan Lai Peter Szatmari for the Pathways in ASD Study Team 《Journal of child psychology and psychiatry, and allied disciplines》2022,63(5):553-562
96.
《Dental materials》2022,38(6):924-934
ObjectivesTo study the oxide layer stability of certified dental implants of system "P", made based on TiO2 alloy with carbon coating. To perform a comparative statistical analysis of the obtained data with the available data for the dental implants of systems "A" and "B".MethodsX-ray microtomography and X-ray fluorescence analysis were used to study soft tissue biopsy specimens. Supernatants were studied by dynamic light scattering and transmission electron microscopy when simulating free emission of nanoscale metal oxide particles from the surface of dental implants as well as when simulating physical loading. A comparative analysis of three parameters of nanoscale particles was performed by statistical data analysis. The surface of the "P" system dental implant with surface treatment was analyzed by scanning electron microscopy.ResultsBoth free emission of nanoscale oxide layer particles and yield of nano- and microscale particles during simulation of physical load were confirmed. Statistically significant differences were noted in a comparative analysis of the size and frequency of occurrence of these particles in the supernatants obtained from the surfaces of three dental implant systems. The elemental composition of the particles and the composition and structure of the "P" system dental implants themselves were analyzed.SignificanceThe developed method of dynamic light scattering can be used to compare the stability of the oxide layer of standardized medical products manufactured on the basis of the TiO2 alloy. 相似文献
97.
《Advances in medical sciences》2022,67(1):163-169
PurposeThe variation in the immune response to Bartonella spp. infection in humans remains unclear. The present study compares the expression of selected interleukins, cytokines and cathelicidin (LL-37) in rheumatology clinic patients suffering from musculoskeletal symptoms with healthy blood donors. The patients had previously been tested for the presence of Bartonella henselae antibodies.MethodsGene expression of LL-37, interleukin (IL)-2, IL-4, IL-6, IL-12, interferon-(IFN)-γ, and tumor necrosis factor (TNF-α)-α was determined in blood samples using quantitative Polymerase Chain Reaction (qPCR). Statistical analysis was prepared with STATISTICA.ResultsStatistically significant differences in the mRNA levels of the tested cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-12; p<0.0001) were observed between the healthy controls and patients; however, no difference was observed for LL37 mRNA (p ?= ?0.1974). No significant differences in mRNA expression were observed between IgG in anti-Bartonella seropositive and seronegative individuals (p>0.05). The only significant differences between the Bartonella spp. DNA positive and negative patients, indicated by PCR, were observed for TNF-α and IL-12 mRNA (p ?= ?0.0045 and p ?= ?0.0255, respectively).ConclusionA broadly similar immune response to the tested cytokines was observed among the participants irrespective of anti-Bartonella spp. IgG seropositivity. However, the Bartonella DNA-positive participants demonstrated significantly lower expression of IL-12 and TNF-α mRNA; this may indicate that these bacteria have a suppressive influence on the immune system. 相似文献
98.
99.
100.
Loren Saulsberry PhD Ankur Bhargava MD MPH Sharon Zeng BA Jason B. Gibbons PhD Cody Brannan MS Diane S. Lauderdale PhD Robert D. Gibbons PhD 《Health services research》2023,58(4):873-881