全文获取类型
收费全文 | 2886334篇 |
免费 | 252487篇 |
国内免费 | 12853篇 |
专业分类
耳鼻咽喉 | 39882篇 |
儿科学 | 91504篇 |
妇产科学 | 72860篇 |
基础医学 | 477289篇 |
口腔科学 | 77551篇 |
临床医学 | 259500篇 |
内科学 | 493172篇 |
皮肤病学 | 82381篇 |
神经病学 | 248860篇 |
特种医学 | 113197篇 |
外国民族医学 | 88篇 |
外科学 | 455626篇 |
综合类 | 88423篇 |
现状与发展 | 23篇 |
一般理论 | 2097篇 |
预防医学 | 248050篇 |
眼科学 | 66104篇 |
药学 | 195519篇 |
22篇 | |
中国医学 | 8541篇 |
肿瘤学 | 130985篇 |
出版年
2022年 | 22704篇 |
2021年 | 54347篇 |
2020年 | 34689篇 |
2019年 | 57614篇 |
2018年 | 69661篇 |
2017年 | 52967篇 |
2016年 | 58196篇 |
2015年 | 72903篇 |
2014年 | 106912篇 |
2013年 | 171863篇 |
2012年 | 74786篇 |
2011年 | 72914篇 |
2010年 | 112066篇 |
2009年 | 117579篇 |
2008年 | 60673篇 |
2007年 | 61522篇 |
2006年 | 73178篇 |
2005年 | 68939篇 |
2004年 | 71276篇 |
2003年 | 62597篇 |
2002年 | 52892篇 |
2001年 | 73953篇 |
2000年 | 66045篇 |
1999年 | 71566篇 |
1998年 | 61900篇 |
1997年 | 60390篇 |
1996年 | 58192篇 |
1995年 | 53680篇 |
1994年 | 47840篇 |
1993年 | 44798篇 |
1992年 | 47890篇 |
1991年 | 46251篇 |
1990年 | 43860篇 |
1989年 | 43862篇 |
1988年 | 40734篇 |
1987年 | 39918篇 |
1986年 | 37958篇 |
1985年 | 38851篇 |
1984年 | 38520篇 |
1983年 | 36069篇 |
1982年 | 38096篇 |
1981年 | 36342篇 |
1980年 | 34350篇 |
1979年 | 30918篇 |
1978年 | 29747篇 |
1977年 | 27751篇 |
1976年 | 25487篇 |
1975年 | 24148篇 |
1974年 | 23868篇 |
1973年 | 22652篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Jennifer J. Schoch Reesa L. Monir Kerrie G. Satcher Jessica Harris Eric Triplett Josef Neu 《Pediatric dermatology》2019,36(5):574-580
Recent focus on the neonatal intestinal microbiome has advanced our knowledge of the complex interplay between the intestinal barrier, the developing immune system, and commensal and pathogenic organisms. Despite the parallel role of the infant skin in serving as both a barrier and an interface for priming the immune system, large gaps exist in our understanding of the infantile cutaneous microbiome. The skin microbiome changes and matures throughout infancy, becoming more diverse and developing the site specificity known to exist in adults. Delivery method initially determines the composition of the cutaneous microbiome, though this impact appears transient. Cutaneous microbes play a critical role in immune system development, particularly during the neonatal period, and microbes and immune cells have closely intertwined, reciprocal effects. The unique structure of newborn skin influences cutaneous microbial colonization and the development of dermatologic pathology. The development of the infantile skin barrier and cutaneous microbiome contributes to future skin pathology. Atopic dermatitis flares and seborrheic dermatitis have been linked to dysbiosis, while erythema toxicum neonatorum is an immune response to the establishment of normal bacterial skin flora. Physicians who care for infants should be aware of the impact of the infantile skin microbiome and its role in the development of pathology. A better understanding of the origin and evolution of the skin microbiome will lead to more effective prevention and treatment of pediatric skin disease. 相似文献
993.
994.
995.
996.
Saisanjana Kalagara Adam E.M. Eltorai J. Mason DePasse Alan H. Daniels 《The spine journal》2019,19(1):182-185
BACKGROUND
Online physician rating websites are increasingly used by patients to evaluate their doctors. The purpose of this investigation was to evaluate factors associated with better spine surgeon ratings.METHODS
Orthopedic spine surgeons were randomly selected from the North American Spine Society directory utilizing a random number generator. Surgeon profiles on three physician rating websites, namely, www.HealthGrades.com, www.Vitals.com, and www.RateMDs.com, were analyzed to gather qualitative and quantitative data on patients’ perceptions of the surgeons. Independent variables from the websites were analyzed in relation to overall physician or patient satisfaction rating. Comments were coded by subject into following three categories: professional competence, bedside manner, and practice characteristics.RESULTS
A total of 250 surgeons were evaluated, and 92% (n=230) of these doctors had at least one rating among the three websites. The surgeons with a higher average rating had significantly better trust (p<.01), scheduling (p<.01), staff (p<.01), helpfulness (p<.01), and punctuality (p<.01) scores but significantly less experience (p<.05). A linear regression model for the average rating of each surgeon (R2 value=0.754) yielded only following three significant variables: trustworthiness (p<.01), experience match (p<.05), and the average number of negative comments on surgeon's professional competence (p<.05). Trustworthiness (β=0.749) was the strongest predictor variable of physician rating, followed by the number of negative professional competence comments (β=?0.132) and experience match (β=?0.112).CONCLUSIONS
This investigation assessed spine surgeon online patient ratings and categorized factors that patients associate with quality care. Trustworthiness was the most significant predictor of positive ratings, whereas ease of scheduling, quality of staff, helpfulness, and punctuality were also associated with higher patient ratings. Understanding what patients value may help optimize care of spine surgery patients. 相似文献997.
J.A. Hannam S.J. Mitchell D. Cumin C. Frampton A.F. Merry M.R. Moore C.J. Kruger 《British journal of anaesthesia》2019,122(2):198-205
Background
Etomidate is frequently selected over propofol for induction of anaesthesia because of a putatively favourable haemodynamic profile, but data confirming this perception are limited.Methods
Patients undergoing cardiac surgery were randomised to induction of anaesthesia with propofol or etomidate. Phase I (n=75) was conducted as open-label, whereas Phase II (n=75) was double blind. Mean arterial blood pressure (MAP) and boluses of vasopressor administered after induction were recorded. The primary endpoint was the area under the curve below baseline MAP (MAP-time integral) during the 10 min after induction. Secondary endpoints were the use of vasopressors over the same period, and the effect of blinding on the aforementioned endpoints. Groups were compared using regression models with phase and anaesthetist as factors.Results
The mean difference between etomidate and propofol in the MAP-time integral below baseline was 2244 mm Hg s (95% confidence interval, 581–3906; P=0.009), representing a 34% greater reduction with propofol. Overall, vasopressors were used in 10/75 patients in the etomidate group vs 21/75 in the propofol group (P=0.38), and in 20/74 patients during the blinded phase vs 11/76 during the open-label phase (P=0.31). The interaction between randomisation and phase (open-labelled or blinded) was not significant for either primary (P=0.73) or secondary endpoints (P=0.90).Conclusions
Propofol caused a 34% greater reduction in MAP-time integral from baseline after induction of anaesthesia than etomidate, despite more frequent use of vasopressors with propofol, confirming the superior haemodynamic profile of etomidate in this context. The proportion of patients receiving vasopressors increased slightly, albeit not significantly, in both groups in the blinded phase.Clinical trial registration
Australian and New Zealand Clinical Trials Registry, ACTRN12614000717651. 相似文献998.
Lee Mi Jung Romero Sergio Velozo Craig A. Gruber-Baldini Ann L. Shulman Lisa M. 《Quality of life research》2019,28(6):1595-1603
Quality of Life Research - This study investigated the PROMIS Self-Efficacy Measure for Managing Chronic Conditions (PROMIS-SE) domain distributions and examined the factor structure of the... 相似文献
999.
Hend Kothayer Samy M. Ibrahim Moustafa K. Soltan Samar Rezq Shireen S. Mahmoud 《Drug development research》2019,80(3):343-352
In light of the pharmacophoric structural requirements for achieving anticonvulsant activity, a series of N-(1-methyl-4-oxo-2-un/substituted-1,2-dihydroquinazolin-3[4H]-yl)benzamide (4a-g) and N-(1-methyl-4-oxo-2-un/substituted-1,2-dihydroquinazolin-3[4H]-yl)-2-phenylacetamide (4h-n) derivatives were synthesized in two steps starting from the reaction of N-methyl isatoic anhydride with the appropriate hydrazide and followed by condensation with the appropriate aldehyde. The anticonvulsant activities of the synthesized compounds were evaluated according to the anticonvulsant drug development (ADD) programme protocol. Among the synthesized compounds, 4n showed promising activity in both the maximal electroshock (MES) and pentylenetetrazole (PTZ) tests with median effective dose (ED50) values of 40.7 and 6 mg/kg, respectively. The six most promising derivatives, 4b , 4a , 4c , 4f , 4j , and 4i , showed very low ED50 values in the PTZ test (3.1, 4.96, 8.68, 9.89, 12, and 13.53 mg/kg, respectively). All the tested compounds showed no to low neurotoxicity in the rotarod test with a wide therapeutic index. Docking studies of compound 4n suggested that GABAA binding could be the mechanism of action of these derivatives. The in silico drug likeliness parameters indicated that none of the designed compounds violate Lipinski's rule of five and that they are able to cross the blood–brain barrier.
相似文献
Hit, Lead & Candidate Discovery |
1000.
Éktova L. V. Goryunova O. V. Eremina V. A. Tikhonova N. I. Medvedeva L. A. 《Pharmaceutical Chemistry Journal》2019,53(7):604-609
Pharmaceutical Chemistry Journal - Use of formylindolylacetic acid as a reagent at the stage of preparing the glycosides of bis(indolyl)furan-2,5-diones and dioxane as solvent increased yields from... 相似文献