全文获取类型
收费全文 | 513029篇 |
免费 | 33976篇 |
国内免费 | 612篇 |
专业分类
耳鼻咽喉 | 6892篇 |
儿科学 | 16830篇 |
妇产科学 | 13521篇 |
基础医学 | 84999篇 |
口腔科学 | 14471篇 |
临床医学 | 44299篇 |
内科学 | 93484篇 |
皮肤病学 | 12153篇 |
神经病学 | 36172篇 |
特种医学 | 18454篇 |
外国民族医学 | 63篇 |
外科学 | 77029篇 |
综合类 | 8467篇 |
一般理论 | 118篇 |
预防医学 | 38931篇 |
眼科学 | 12128篇 |
药学 | 40508篇 |
中国医学 | 1006篇 |
肿瘤学 | 28092篇 |
出版年
2018年 | 4923篇 |
2015年 | 4509篇 |
2014年 | 6062篇 |
2013年 | 9544篇 |
2012年 | 12867篇 |
2011年 | 14272篇 |
2010年 | 8300篇 |
2009年 | 7770篇 |
2008年 | 13693篇 |
2007年 | 14699篇 |
2006年 | 14939篇 |
2005年 | 14357篇 |
2004年 | 14049篇 |
2003年 | 13387篇 |
2002年 | 13268篇 |
2001年 | 24069篇 |
2000年 | 25079篇 |
1999年 | 20556篇 |
1998年 | 5426篇 |
1997年 | 4705篇 |
1996年 | 5041篇 |
1995年 | 4625篇 |
1994年 | 4318篇 |
1993年 | 4135篇 |
1992年 | 15725篇 |
1991年 | 16309篇 |
1990年 | 16422篇 |
1989年 | 15796篇 |
1988年 | 14575篇 |
1987年 | 14419篇 |
1986年 | 13597篇 |
1985年 | 12975篇 |
1984年 | 9627篇 |
1983年 | 8247篇 |
1982年 | 4559篇 |
1981年 | 4229篇 |
1979年 | 9418篇 |
1978年 | 6855篇 |
1977年 | 5772篇 |
1976年 | 5602篇 |
1975年 | 6396篇 |
1974年 | 7634篇 |
1973年 | 7130篇 |
1972年 | 6960篇 |
1971年 | 6685篇 |
1970年 | 6173篇 |
1969年 | 5888篇 |
1968年 | 5559篇 |
1967年 | 5012篇 |
1966年 | 4450篇 |
排序方式: 共有10000条查询结果,搜索用时 300 毫秒
111.
112.
113.
J. F. Trotter J. Campsen T. Bak M. Wachs L. Forman G. Everson I. Kam 《American journal of transplantation》2006,6(8):1882-1889
The purpose of this study is to determine the role of liver biopsy and outcome of patients undergoing donor evaluation for adult-to-adult right hepatic lobe living donor liver transplantation (LDLT). Records of patients presenting for a comprehensive donor evaluation between 1997 and February 2005 were reviewed. Liver biopsy was performed only in patients with risk factors for abnormal histology. Two hundred and sixty patients underwent a comprehensive donor evaluation and 116 of 260 (45%) were suitable for donation, 14 of 260 (5.4%) did not complete evaluation and 130 of 260 (50%) were rejected. Four patients underwent unsuccessful hepatectomy surgery due to discovery of intraoperative abnormalities. Between 1997 and 2001, the acceptance rate of donor candidates (63%) was higher than 2002-2005 (36%), p < 0.0001. Sixty-six of the 150 eligible patients (44%) fulfilled criteria for liver biopsy and 28 of 66 (42%) had an abnormal finding. Less than half of the patients undergoing donor evaluation were suitable donors and the donor acceptance rate has declined over time. A large proportion of the patients undergoing liver biopsy have abnormal findings. Our evaluation process failed to identify 4 of 103 who had aborted donor surgeries. 相似文献
114.
OBJECTIVE: Gelastic seizures are a frequent and well established manifestation of the epilepsy associated with hypothalamic hamartomas. The scalp EEG recordings very seldom demonstrate clear spike activity and the information about the ictal epilepsy dynamics is limited. In this work, we try to isolate epileptic rhythms in gelastic seizures and study their generators. METHODS: We extracted rhythmic activity from EEG scalp recordings of gelastic seizures using decomposition in independent components (ICA) in three patients, two with hypothalamic hamartomas and one with no hypothalamic lesion. Time analysis of these rhythms and inverse source analysis was done to recover their foci of origin and temporal dynamics. RESULTS: In the two patients with hypothalamic hamartomas consistent ictal delta (2-3 Hz) rhythms were present, with subcortical generators in both and a superficial one in a single patient. The latter pattern was observed in the patient with no hypothalamic hamartoma visible in MRI. The deep generators activated earlier than the superficial ones, suggesting a consistent sub-cortical origin of the rhythmical activity. CONCLUSIONS: Our data is compatible with early and brief epileptic generators in deep sub-cortical regions and more superficial ones activating later. SIGNIFICANCE: Gelastic seizures express rhythms on scalp EEG compatible with epileptic activity originating in sub-cortical generators and secondarily involving cortical ones. 相似文献
115.
116.
I García-Rubio C Martínez-Cócera T Robledo Echarren S Vázquez Cortés 《Journal of investigational allergology & clinical immunology》2006,16(4):264-265
Eye drops contain several ophthalmic medications which can produce allergic reactions. We report the case of a patient with contact dermatitis from neomycin and a probable fixed exanthema after parenteral administration of tobramycin who tolerated topical tobramycin and other aminoglycosides. 相似文献
117.
Alexander Stoff MD ; Angel A. Rivera PhD ; N. S. Banerjee PhD ; J. Michael Mathis PhD ; Antonio Espinosa-de-los-Monteros MD ; Long P. Le PhD ; Jorge I. De la Torre MD ; Luis O. Vasconez MD ; Thomas R. Broker PhD ; Dirk F. Richter MD ; Mariam A. Stoff-Khalili MD ; David T. Curiel MD PhD 《Wound repair and regeneration》2006,14(5):608-617
Genetically modified keratinocytes and fibroblasts are suitable for delivery of therapeutic genes capable of modifying the wound healing process. However, efficient gene delivery is a prerequisite for successful gene therapy of wounds. Whereas adenoviral vectors (Ads) exhibit superior levels of in vivo gene transfer, their transductional efficiency to cells resident within wounds may nonetheless be suboptimal, due to deficiency of the primary adenovirus receptor, coxsackie-adenovirus receptor (CAR). We explored CAR-independent transduction to fibroblasts and keratinocytes using a panel of CAR-independent fiber-modified Ads to determine enhancement of infectivity. These fiber-modified adenoviral vectors included Ad 3 knob (Ad5/3), canine Ad serotype 2 knob (Ad5CAV-2), RGD (Ad5.RGD), polylysine (Ad5.pK7), or both RGD and polylysine (Ad5.RGD.pK7). To evaluate whether transduction efficiencies of the fiber-modified adenoviral vectors correlated with the expression of their putative receptors on keratinocytes and fibroblasts, we analyzed the mRNA levels of CAR, alpha upsilon integrin, syndecan-1, and glypican-1 using quantitative polymerase chain reaction. Analysis of luciferase and green fluorescent protein transgene expression showed superior transduction efficiency of Ad5.pK7 in keratinocytes and Ad5.RGD.pK7 in fibroblasts. mRNA expression of alpha upsilon integrin, syndecan-1 and glypican-1 was significantly higher in primary fibroblasts than CAR. In keratinocytes, syndecan-1 expression was significantly higher than all the other receptors tested. Significant infectivity enhancement was achieved in keratinocytes and fibroblasts using fiber-modified adenoviral vectors. These strategies to enhance infectivity may help to achieve higher clinical efficacy of wound gene therapy. 相似文献
118.
JM Martín† L Calduch† C Monteagudo‡ I Molina† D Ramón† V Alonso† E Jordᆠ《Journal of the European Academy of Dermatology and Venereology》2006,20(4):428-431
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified. 相似文献
119.
Christine E. Marx William T. Trost Lawrence J. Shampine Robert D. Stevens Christine M. Hulette David C. Steffens John F. Ervin Marian I. Butterfield Daniel G. Blazer Mark W. Massing Jeffrey A. Lieberman 《Neuropsychopharmacology》2006,60(12):1287-1294
BACKGROUND: Few data are currently available investigating neurosteroids (NS) in Alzheimer's disease (AD). The NS allopregnanolone may be decreased in serum and plasma in patients with AD, but it is unclear if allopregnanolone is also reduced in brain. Because a number of NS exhibit neuroprotective effects and impact cognitive performance in rodent models, these molecules may be relevant to the pathophysiology of neurodegenerative disorders. We therefore investigated prefrontal cortex (PFC) NS levels in AD. METHODS: Neurosteroid levels (allopregnanolone, pregnenolone, dehydroepiandrosterone [DHEA]) were determined in postmortem PFC in 14 male subjects with AD and 15 cognitively intact male control subjects by gas chromatography/mass spectrometry preceded by high-performance liquid chromatography purification. RESULTS: Subjects with AD exhibit significant reductions in allopregnanolone compared with cognitively intact control subjects (median levels = 2.50 ng/g vs. 5.59 ng/g, respectively; p = .02). Allopregnanolone levels are inversely correlated with neuropathological disease stage (Braak), r = -.49, p = .007. Median DHEA levels are elevated in subjects with AD (p = .01). CONCLUSIONS: Subjects with AD demonstrate significant reductions in PFC allopregnanolone levels, a finding that may be relevant to neuropathological disease stage severity. Neurosteroids may have utility as candidate biomarkers in AD. 相似文献
120.