全文获取类型
收费全文 | 6541篇 |
免费 | 318篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 127篇 |
儿科学 | 192篇 |
妇产科学 | 154篇 |
基础医学 | 704篇 |
口腔科学 | 547篇 |
临床医学 | 365篇 |
内科学 | 1771篇 |
皮肤病学 | 95篇 |
神经病学 | 456篇 |
特种医学 | 100篇 |
外科学 | 963篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 612篇 |
眼科学 | 199篇 |
药学 | 309篇 |
中国医学 | 14篇 |
肿瘤学 | 269篇 |
出版年
2024年 | 10篇 |
2023年 | 67篇 |
2022年 | 169篇 |
2021年 | 266篇 |
2020年 | 136篇 |
2019年 | 169篇 |
2018年 | 243篇 |
2017年 | 172篇 |
2016年 | 171篇 |
2015年 | 220篇 |
2014年 | 314篇 |
2013年 | 331篇 |
2012年 | 604篇 |
2011年 | 605篇 |
2010年 | 307篇 |
2009年 | 265篇 |
2008年 | 419篇 |
2007年 | 462篇 |
2006年 | 398篇 |
2005年 | 345篇 |
2004年 | 313篇 |
2003年 | 264篇 |
2002年 | 224篇 |
2001年 | 44篇 |
2000年 | 51篇 |
1999年 | 31篇 |
1998年 | 28篇 |
1997年 | 21篇 |
1996年 | 14篇 |
1995年 | 22篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 15篇 |
1990年 | 14篇 |
1989年 | 19篇 |
1988年 | 5篇 |
1987年 | 11篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1974年 | 4篇 |
1971年 | 4篇 |
1967年 | 4篇 |
1962年 | 4篇 |
排序方式: 共有6895条查询结果,搜索用时 31 毫秒
41.
Cornelius Schüle Flavia di Michele Thomas Baghai Elena Romeo Giorgio Bernardi Peter Zwanzger Frank Padberg Augusto Pasini Rainer Rupprecht 《Neuropsychopharmacology》2003,28(3):577-581
There is evidence from preclinical and clinical studies that concentrations of neuroactive steroids are altered in depression and normalize after antidepressant pharmacotherapy. However, no data are available concerning the impact of sleep deprivation on the concentrations of neuroactive steroids. A total of 29 drug-free patients (12 men, 17 women) suffering from major depression according to DSM-IV criteria were treated with partial sleep deprivation (PSD). Response to PSD was defined as a reduction of at least 30% according to the six-item version of the Hamilton depression scale (6-HAMD). Plasma samples were taken the day before and after PSD (days 0 and 1) and after one night of recovery sleep (day 2) at 8:00 am. The samples were quantified for neuroactive steroids by means of a highly sensitive and specific combined gas chromatography/mass spectrometry analysis. There was no influence of PSD on the concentrations of neuroactive steroids either in PSD responders (n=20) or in nonresponders (n=9). However, nonresponders showed significantly higher concentrations of 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP), 3alpha,5beta-tetrahydroprogesterone (3alpha,5beta-THP), and dehydroepiandrosterone (DHEA) before or after PSD compared to responders. In contrast to antidepressant drugs, which correct the dysequilibrium of neuroactive steroids in major depression within several weeks, PSD does not affect the concentrations of neuroactive steroids either in responders or in nonresponders. 相似文献
42.
43.
Waleska Teixeira Caiaffa Francisco Incio Bastos Fernando Augusto Proietti ngela Cristina Maia Reis Sueli Aparecida Mingoti Denise Gandolfi Denise Doneda AjUDE-Brasil II Project 《The International journal on drug policy》2003,14(5-6):365
The study describes practices relating to syringe acquisition and disposal by Syringe Exchange Programme (SEP) participants. A cross-sectional multi-city study enrolled 857 injection drug users (IDUs) from six SEPs in different Brazilian regions, and assessed self-reported acquisition and disposal behaviours. Seven hundred and nine males (82.9%) and 146 females (17.1%) were recruited through outreach and interviewed, most from the streets or their neighbourhoods (54.1%). The average age was 28.5 years; 76.4% reported injecting cocaine in the past 6 months. Sources for acquiring new syringes differed significantly between time of injection drug use debut and the 6 months prior to interview. Fifty-three percent of IDUs reported acquiring their syringes in pharmacies when they initiated injection drug use, whereas most reported acquiring new syringes in the 6 months before interview from several simultaneous sources: 69% through SEPs; 58% through pharmacies; 36% from friends and/or sexual partners; and 17% from other health services. Across SEPs, acquisition and disposal varied widely. Most interviewees discarded their syringes on the streets, in open fields, or in the garbage or sewage. Restrictions on syringe availability and unsafe practices may be functioning as barriers to the public health recommendation of one-time use of sterile syringes for IDUs and discouraging community support to SEPs. Further increase in access to legal, inexpensive and timely sterile syringes, as well as counselling about the merits of one-time use and safer disposal must be reinforced as part of efforts to minimise high-risk behaviours and curb the spread of blood-borne infections. 相似文献
44.
Augusto Ferrari MD Luigi Frigerio MD 《American journal of obstetrics and gynecology》1997,177(6):1426-1431
OBJECTIVE: We describe an alternative sling procedure that permits concomitant correction of urethral hypermobility and urinary incontinence through a single surgical exposure. STUDY DESIGN: Fifteen women with severe urinary stress incontinence and urethral hypermobility underwent a sling procedure by creation of a simple triangular patch from the anterior vaginal wall. RESULTS: The mean operative time for the vaginal sling procedure was 38 minutes (range 29 to 65 minutes) in addition to other operations. The mean postoperative hospital stay was 7.7 days (range 5 to 13 days) and all patients were routinely discharged with an indwelling Foley catheter. Spontaneous micturition occurred in 12 patients after a mean period of 25 days (range 13 to 36 days). In three cases long-term catheterization was necessary. By subjective and objective evaluations, all the patients were cured of their stress incontinence. CONCLUSION: The triangular vaginal patch with the single sutures on each side provides an alternative approach for bladder neck stabilization that may permit a more anatomic suspension of a hypermobile urethra.(Am J Obstet Gynecol 1997;177:31) 相似文献
45.
Jednak R Schimke CM Barroso U JR Barthold JS González R 《The Journal of urology》2000,164(6):2045-2049
PURPOSE: We report our continuing experience with seromuscular colocystoplasty lined with urothelium. This procedure is designed to preserve the urothelium and potentially decrease the incidence of complications associated with standard bladder augmentation. MATERIALS AND METHODS: We retrospectively reviewed the charts of 32 patients who underwent seromuscular colocystoplasty lined with urothelium between April 1994 and July 1999. Data were collected on patient demographics, surgical indications, previous and adjunctive surgical procedures, preoperative and postoperative urinary continence, upper urinary tract changes, urodynamic parameters, surgical complications and histological findings. RESULTS: Mean patient age at surgery plus or minus standard deviation was 11.1 +/- 4.8 years. Mean followup was 1.6 +/- 1 years. A mean of 1.5 +/- 0.9 years postoperatively urodynamic studies available in 28 cases showed that total and safe bladder capacity increased by 1.8 and 2.4-fold, respectively. Continence was achieved in 71% of patients after the initial procedure, increasing to 81% after secondary procedures. Hourglass deformity developed in 7 cases (22%), augmentation failed in 4 (12.5%) and there were bladder calculi in 2 (6%). New onset or increased hydronephrosis and reflux were present in 6 of 62 (10%) and 9 of 60 (15%) evaluated renal units, respectively. Of the 7 interpretable biopsies 5 revealed various degrees of repeat colonic mucosal growth. There was no bladder perforation or metabolic abnormalities, and mucous production was not clinically significant. CONCLUSIONS: Seromuscular colocystoplasty lined with urothelium is a viable alternative to standard bladder augmentation. The 2 procedures have a similar overall complication rate. Comparatively there appears to be a low incidence of bladder calculi, mucous production has not been clinically significant, metabolic disturbances have not developed and perforation has not occurred during short-term followup. We are enthusiastic about this technique and continue to apply it in select patients. 相似文献
46.
Socorro Vanesca Frota Madeira Angela de Castro Resende Dayane Teixeira Ognibene Marcelo Augusto Vieira de Sousa Roberto Soares de Moura 《Pharmacological research》2005,52(4):321-327
An alcohol-free grape-skin extract (GSE) obtained from skins of Vitis labrusca has significant anti-hypertensive, antioxidant and vasodilator effects. According to our previous results, the vasodilator effect of GSE in the isolated mesenteric vascular bed (MVB) of the rat is dependent on endothelium and partially dependent on nitric oxide (NO). In the MVB of the rat pre-contracted with norepinephrine (NE), bolus injections of GSE induced a long-lasting dose-dependent vasodilation that is significantly reduced after the treatment with 1H-[1,2,3] oxadiazolo [4,4-a] quinoxalin-1-one (ODQ). Additionally, in vessels pre-contracted with norepinephrine and depolarized with KCl (25 mM) or treated with Ca(2+)-dependent K(+)-channel blockers charybdotoxin (ChTx) plus apamin, the vasodilator effect of GSE was significantly reduced and almost abolished by ChTx plus apamin plus L-NAME. However, the vasodilator effect of GSE was unaffected by D-Arg[Hyp(3),Thi(5),D-Tic(7),Oic(8)]bradykinin (HOE-140), atropine, yohimbine, pyrilamine and 4-aminopyridine (4-AP). The vasoconstriction response elicited by bolus injection of KCl was not affected by GSE, whereas the vasoconstrictor response induced by NE was dose-dependently and completed inhibited by GSE in the presence but not in the absence of endothelium. However, NE-induced vasoconstriction in calcium-free condition or without endothelium was not reduced by GSE. The present results demonstrate that GSE induces a vasodilator effect in the rat MVB, which is dependent on NO in combination with endothelium-derived hyperpolarizing factor (EDHF). Additionally, our results indicated that extracellular Ca(2+) has an important role on the endothelium-dependent vasodilator effect induced by GSE. 相似文献
47.
David E. Barroso Terezinha M.P.P. Casti?eiras Fernanda S. Freitas Jane W. Marsh Mary G. Krauland Mary M. Tulenko érica L. Fonseca Ana C.P. Vicente Maria C. Rebelo Elaine O. Cerqueira Adriano C. Xavier Ana P.C.M. Cardozo Simone E.M. da Silva Lee H. Harrison 《Emerging infectious diseases》2013,19(11):1847-1850
During 2003–2012, 8 clusters of meningococcal disease were identified in Rio de Janeiro State, Brazil, all caused by serogroup C Neisseria meningitidis. The isolates were assigned to 3 clonal complexes (cc): cc11, cc32, and cc103. These hyperinvasive disease lineages were associated with endemic disease, outbreaks, and high case-fatality rates. 相似文献
48.
49.
50.