全文获取类型
收费全文 | 47667篇 |
免费 | 3422篇 |
国内免费 | 177篇 |
专业分类
耳鼻咽喉 | 701篇 |
儿科学 | 1105篇 |
妇产科学 | 727篇 |
基础医学 | 5857篇 |
口腔科学 | 763篇 |
临床医学 | 5286篇 |
内科学 | 9151篇 |
皮肤病学 | 629篇 |
神经病学 | 4208篇 |
特种医学 | 1810篇 |
外国民族医学 | 2篇 |
外科学 | 8314篇 |
综合类 | 791篇 |
现状与发展 | 1篇 |
一般理论 | 32篇 |
预防医学 | 3900篇 |
眼科学 | 1019篇 |
药学 | 3614篇 |
1篇 | |
中国医学 | 76篇 |
肿瘤学 | 3279篇 |
出版年
2023年 | 311篇 |
2022年 | 471篇 |
2021年 | 1226篇 |
2020年 | 649篇 |
2019年 | 1203篇 |
2018年 | 1419篇 |
2017年 | 1029篇 |
2016年 | 1051篇 |
2015年 | 1282篇 |
2014年 | 1874篇 |
2013年 | 2387篇 |
2012年 | 3636篇 |
2011年 | 3880篇 |
2010年 | 2134篇 |
2009年 | 1794篇 |
2008年 | 3127篇 |
2007年 | 3453篇 |
2006年 | 3279篇 |
2005年 | 3127篇 |
2004年 | 2759篇 |
2003年 | 2738篇 |
2002年 | 2446篇 |
2001年 | 385篇 |
2000年 | 267篇 |
1999年 | 373篇 |
1998年 | 504篇 |
1997年 | 350篇 |
1996年 | 307篇 |
1995年 | 318篇 |
1994年 | 275篇 |
1993年 | 225篇 |
1992年 | 189篇 |
1991年 | 167篇 |
1990年 | 165篇 |
1989年 | 171篇 |
1988年 | 156篇 |
1987年 | 146篇 |
1986年 | 123篇 |
1985年 | 149篇 |
1984年 | 166篇 |
1983年 | 142篇 |
1982年 | 176篇 |
1981年 | 151篇 |
1980年 | 163篇 |
1979年 | 86篇 |
1978年 | 97篇 |
1977年 | 69篇 |
1976年 | 55篇 |
1975年 | 52篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
PURPOSE: The use of systemic corticosteroids for the management of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) was studied. METHODS: Medical charts of patients admitted to the hospital between July 2002 and November 2003 with a primary diagnosis of AECOPD were retrospectively reviewed. The primary objective was to characterize the drug, dosage, route, frequency, and duration of systemic corticosteroids prescribed for the management of AECOPD. The secondary objective was to compare the mean length of stay (LOS) and 30-day relapse rate between patients who received lower and higher dosages of corticosteroids. RESULTS: One hundred forty-five admissions (123 patients) for AECOPD (mean +/- S.D. age, 65 +/- 11 years) were evaluated. Higher dosages of systemic corticosteroids (>80 mg of prednisone equivalent [PE] per day) were prescribed for 51% and i.v. therapy for 56% of admissions. The mean +/- S.D. total systemic corticosteroid exposure during hospitalization for all admissions was 759 +/- 971 mg of PE (mean +/- S.D. daily exposure = 134 +/- 111 mg of PE per day). The mean LOS was significantly longer for the higher-dosage group than for the lower-dosage group (6.1 versus 4.2 days, p = 0.0004). A tapered regimen was prescribed for 79% of discharges. Twenty-seven percent of the discharges with routine follow-up care had a relapse of disease within 30 days. CONCLUSION: This retrospective observational study confirmed a wide variability in the dosages of systemic corticosteroids for the inpatient management of AECOPD, including the use of higher dosages and tapered regimens. Prospective randomized studies are needed to determine the most effective regimen of systemic corticosteroids in patients with AECOPD. 相似文献
82.
83.
84.
Brian Bonnar 《The British journal of general practice》2004,54(509):945-945; author reply 946
85.
86.
87.
Nancy J Keuthen Nikos Makris John E Schlerf Brian Martis Cary R Savage Katherine McMullin Larry J Seidman Jeremy D Schmahmann David N Kennedy Steven M Hodge Scott L Rauch 《Neuropsychopharmacology》2007,61(3):374-381
BACKGROUND: Limited knowledge exists regarding the neurobiology of trichotillomania (TTM). Cerebellum (CBM) volumes were explored, given its role in complex, coordinated motor sequences. METHODS: Morphometric magnetic resonance imaging (MRI) scans were obtained for 14 female subjects with DSM-IV diagnoses of TTM and 12 age-, education-, and gender-matched normal control (NC) participants. Parcellation was performed utilizing a recently developed methodology to measure subterritory volumes of the CBM. Regions were defined based on knowledge of the structural and functional subunits of the CBM. RESULTS: As predicted, significant group differences were reported for CBM raw cortical volumes (p = .008) that survived correction for total brain volume (TBV; p = .037) and head circumference (HC; p = .011). A priori and post hoc group raw volume comparisons for CBM subterritories and functional clusters revealed many significant differences. However, most differences failed to withstand correction for total CBM volumes (TCV). Smaller volumes were consistently reported for the TTM versus NC cohorts. Total Massachusetts General Hospital Hair Pulling Scale (MGHHPS) scores were significantly inversely correlated with left primary sensorimotor cluster volumes (p = .008), with smaller volumes associated with more severe TTM symptoms. CONCLUSIONS: These findings implicate the CBM in the neurobiology of TTM, with reduced subterritory volumes reported for the TTM versus NC groups. 相似文献
88.
89.
90.
Stacey M Pollock-Barziv Anne I Dipchand Brian W McCrindle Nadya Nalli Lori J West 《The Journal of heart and lung transplantation》2005,24(2):190-194
BACKGROUND: While Tacrolimus (Tac) and Cyclosporine (Cya) immunosuppression are used after cardiac transplantation (tx), few studies have evaluated their use in pediatric patients. METHODS: We randomized 26 heart transplant recipients (pts) in a prospective, open-label trial to Tac (n = 14) or Cya (n = 12) to compare their efficacy and side-effects. Mean age at tx was 4.2 years for Tac and 5.8 years for Cya. Mean follow-up was 26 months (range: 11-39 months) for Tac and 24 months for Cya (range: 33-13 months). RESULTS: Our data suggest that both regimens are efficacious in the pediatric population. Conversion from Cya to Tac was useful for dealing with persistent rejection, although this sample did not suggest lower incidence of acute cellular rejection in the Tac group. CONCLUSIONS: Further studies are required to establish pharmacokinetic parameters to enhance therapeutic monitoring of these patients to minimize side effects and enhance outcomes. 相似文献