全文获取类型
收费全文 | 2343篇 |
免费 | 257篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 36篇 |
妇产科学 | 28篇 |
基础医学 | 309篇 |
口腔科学 | 44篇 |
临床医学 | 190篇 |
内科学 | 355篇 |
皮肤病学 | 15篇 |
神经病学 | 147篇 |
特种医学 | 63篇 |
外科学 | 256篇 |
综合类 | 254篇 |
一般理论 | 1篇 |
预防医学 | 246篇 |
眼科学 | 95篇 |
药学 | 214篇 |
中国医学 | 80篇 |
肿瘤学 | 382篇 |
出版年
2023年 | 9篇 |
2022年 | 50篇 |
2021年 | 44篇 |
2020年 | 27篇 |
2019年 | 14篇 |
2018年 | 28篇 |
2017年 | 14篇 |
2016年 | 24篇 |
2015年 | 36篇 |
2014年 | 40篇 |
2013年 | 61篇 |
2012年 | 82篇 |
2011年 | 272篇 |
2010年 | 193篇 |
2009年 | 166篇 |
2008年 | 129篇 |
2007年 | 123篇 |
2006年 | 111篇 |
2005年 | 129篇 |
2004年 | 255篇 |
2003年 | 174篇 |
2002年 | 96篇 |
2001年 | 76篇 |
2000年 | 71篇 |
1999年 | 43篇 |
1998年 | 27篇 |
1997年 | 25篇 |
1996年 | 24篇 |
1995年 | 11篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 37篇 |
1991年 | 19篇 |
1990年 | 20篇 |
1989年 | 18篇 |
1988年 | 14篇 |
1987年 | 27篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1972年 | 10篇 |
1971年 | 7篇 |
1968年 | 9篇 |
1966年 | 7篇 |
排序方式: 共有2726条查询结果,搜索用时 15 毫秒
61.
62.
Genome-wide array analysis of normal and malformed human hearts 总被引:1,自引:0,他引:1
63.
硒对鸡胚脑发育的影响 总被引:1,自引:5,他引:1
目的观察补硒对正常鸡胚脑谷胱甘肽过氧化物酶(GPx)、Ⅱ型脱碘酶(IDⅡ)活性和生长相关蛋白(GAP-43)表达的影响,探讨硒对正常动物脑发育的作用。方法对孵育8 d的鸡胚分别注射不同剂量的MSeC(含0、1、5、10、20、40 μg硒),孵育至第20天时处死。测定脑组织中硒、GPx活性、IDⅡ活性,检测GAP-43蛋白的表达。结果对正常鸡胚补硒,可提高脑硒水平、脑GPx活性及GAP-43的表达,补硒量与脑硒、脑GPx活性显著相关(P< 0.01),而与脑IDⅡ活性无相关性。结论MSeC可有效提高鸡胚脑组织硒水平、脑GPx活性和GAP-43的表达,对脑IDⅡ活性没有影响。对正常鸡胚适量补硒可能会促进神经系统的生长和发育。 相似文献
64.
Acquired factor VII (FVII) deficiency in the absence of vitamin K deficiency, oral anticoagulant therapy, synthetic liver dysfunction, or DIC is rare, with only a handful of cases thus far reported. In the period from 1990 to 1996 we identified eight patients with acquired FVII deficiency, all of whom presented with prolongation of the prothrombin time (PT) in the first 2 weeks following stem cell transplantation (SCT). The mean plasma FVII clotting activity (FVII:c) was 22% (range 8-35%) with an approximately equivalent reduction in FVII antigen (FVII:Ag) level. Mean plasma levels of fibrinogen and factors II, V, IX, and X were normal. Protein C activity was significantly depressed in only one of the three patients in whom it was measured. Several patients experienced bleeding complications, and hemorrhage directly accounted for death in two cases. Veno-occlusive disease of the liver developed in three patients. We conclude that FVII deficiency should be considered in the differential diagnosis of prolonged PT in patients who have recently undergone SCT. The mechanism of this acquired deficiency state remains to be defined. 相似文献
65.
Frank D. Gilliland Thomas M. Becker Jonathan M. Samet Charles R. Key 《Alcoholism, clinical and experimental research》1995,19(6):1572-1577
Reduction of alcohol-related mortality is a national goal for health promotion and disease prevention. We conducted this analysis to determine whether trends in New Mexico's Hispanics, non-Hispanic Whites, and American Indians were consistent with national trends in alcohol-related mortality, and whether differences in drinking patterns could account for racial and ethnic differences in rates. Age-adjusted, race-specific, and ethnic-specific alcohol-related mortality rates and 95% confidence intervals were calculated for 5-year periods for 1958–1991 using New Mexico vital statistics data. We estimated the prevalence of acute and chronic at-risk drinking behaviors and abstinence from data collected by the Behavioral Risk Factor Surveillance System (BRFSS) for the period 1986–1992. We found that alcohol-related mortality rates varied substantially by race, ethnicity, sex, age, and calendar period. American Indians had the highest rates for both sexes. Rates increased sharply from the period 1958–1962 until the late 1970s and the early 1980s, and then began to decrease rapidly. However, during the most recent decade, the rates have followed contrasting trends in the three ethnic and racial groups. Although rates have continued to decline among non-Hispanic Whites, rates for Hispanics and American Indians have not declined, and still remain substantially higher than rates during the 1958–1962 period. Differences in at-risk drinking behaviors reported to the BRFSS do not explain the contrast in race-specific and ethnic-specific mortality rates. Although progress has been made in reducing national per capita alcohol consumption and alcohol-related mortality, certain high-risk racial and ethnic groups may not be sharing in the progress. 相似文献
66.
67.
Given the rarity of haemophilic pseudotumours, consensus on management is lacking. We describe the clinical features and management of haemophilic pseudotumours by retrospectively reviewing the medical records of haemophilia patients with a diagnosis of pseudotumour seen at our Hemophilia Center from 1981 to 2011. We recorded the following data: type and severity of haemophilia, documented aetiological antecedent, localization of the pseudotumour, presenting symptoms, management and outcome. We identified 12 pseudotumours in 11 patients over a 30‐year period. Six patients had known inhibitors or a history of inhibitor. An aetiological antecedent leading to the development of pseudotumour was reported in nine cases. Localization of the pseudotumour was confined to soft tissue (n = 3) and bone (n = 8). Six of the 12 pseudotumours (50%) were not diagnosed at the time of initial presentation, with a delay ranging from 6 weeks to 6 years. In eight cases, surgical intervention (surgical drainage, n = 2; excision, n = 4; limb amputation, n = 2) was the initial treatment choice, with complete resolution in six cases. Conservative management with close monitoring occurred in three cases, with one case subsequently requiring surgical resection. We conclude that haemophilic pseudotumours still occur sporadically, and the diagnosis is frequently delayed. Surgical intervention is generally a safe and effective treatment, although conservative management may be appropriate in selected cases. 相似文献
68.
Serkan ?zkul Akif Turna Ahmet Demirkaya Burcu Aksoy Kamil Kaynak 《Journal of thoracic disease》2014,6(12):1731-1735
Background
Chemical pleurodesis can be palliative for recurrent, symptomatic pleural effusions in patients who are not candidate for a thoracic surgical procedure. We hypothesized that effective pleurodesis could be accomplished with a rapid method of pleurodesis as effective as the standard method.Methods
A prospective randomized ‘non-inferiority’ trial was conducted in 96 patients with malignant pleural effusion (MPE) who are not potentially curable and/or not amenable to any other surgical intervention. They were randomly allocated to group 1 (rapid pleurodesis) and to group 2 (standard protocol). In group 1, following complete fluid evacuation, talc slurry was instilled into the pleural space. This was accomplished within 2 h of thoracic catheter insertion, unless the drained fluid was more than 1,500 mL. After clamping the tube for 30 min, the pleural space was drained for 1 h, after which the thoracic catheter was removed. In group 2, talc-slurry was administered when the daily drainage was lower than 300 mL/day.Results
No-complication developed due to talc-slurry in two groups. Complete or partial response was achieved in 35 (87.5%) and 33 (84.6%) patients in group 1 and group 2 respectively (P=0.670). The mean drainage time was 40.7 and 165.2 h in group 1 and group 2 respectively (P<0.001).Conclusions
Rapid pleurodesis with talc slurry is safe and effective and it can be performed in an outpatient basis. 相似文献69.
Alexandra P Key Dorita Jones Elisabeth M Dykens 《Journal of Neurodevelopmental Disorders》2013,5(1):7
Background
People with Prader-Willi syndrome (PWS) demonstrate social dysfunction and increased risk of autism spectrum disorder, especially those with the maternal uniparental disomy (mUPD) versus paternal deletion genetic subtype. This study compared the neural processing of social (faces) and nonsocial stimuli, varying in emotional valence, across genetic subtypes in 24 adolescents and adults with PWS.Methods
Upright and inverted faces, and nonsocial objects with positive and negative emotional valence were presented to participants with PWS in an oddball paradigm with smiling faces serving as targets. Behavioral and event-related potential (ERP) data were recorded.Results
There were no genetic subtype group differences in accuracy, and all participants performed above chance level. ERP responses revealed genetic subtype differences in face versus object processing. In those with deletions, the face-specific posterior N170 response varied in size for face stimuli versus inverted faces versus nonsocial objects. Persons with mUPD generated N170 of smaller amplitude and showed no stimulus differentiation. Brain responses to emotional content did not vary by subtype. All participants elicited larger posterior and anterior late positive potential responses to positive objects than to negative objects. Emotion-related differences in response to faces were limited to inverted faces only in the form of larger anterior late positive potential amplitudes to negative emotions over the right hemisphere. Detection of the target smiling faces was evident in the increased amplitude of the frontal and central P3 responses but only for inverted smiling faces.Conclusion
Persons with the mUPD subtype of PWS may show atypical face versus object processes, yet both subtypes demonstrated potentially altered processing, attention to and/or recognition of faces and their expressions. 相似文献70.
艾灸预处理对大鼠应激性胃黏膜损伤增殖修复相关因子的影响 总被引:1,自引:0,他引:1
目的:观察艾灸预处理对应激性胃黏膜损伤大鼠血清和胃黏膜表皮生长因子(EGF)、转化生长因子-α(TGF-α)、胃黏膜三叶因子家族-1(TFF1)、增殖细胞核抗原(PCNA)的影响,探讨艾灸预处理促进胃黏膜损伤增殖修复的作用机制.方法:将48只健康SD大鼠随机分为4组,即空白组、模型组、艾灸穴位组、艾灸非穴组.束缚冷应激法制作大鼠应激性胃黏膜损伤模型.造模之前,艾灸组选取足三里、中脘、脾俞和胃俞等穴位行艾灸预处理8d,艾灸非穴组选取非穴对照点进行预处理.以Guth法计算胃黏膜损伤指数,光镜下观察大鼠胃黏膜组织学改变,放射免疫法测定血清EGF与TGF-α的含量,酶免法检测胃黏膜组织中EGF、TGF-α、TFF1和PCNA的含量.结果:与模型组和艾灸非穴组比较,艾灸足三里、中脘等穴位可使应激性胃黏膜损伤大鼠胃黏膜损伤指数明显下降(14.667±5.710vs27.250±7.448,24.750±7.300,P<0.01),血清EGF、TGF-α含量升高(2.167±0.756vs1.147±0.983,1.358±0.962,P<0.05;11.170±1.315vs4.585±0.720vs5.118±0.659,P<0.01),胃黏膜EGF、TGF-α和PCNA含量升高(343.560±27.644vs269.610±45.119,279.590±58.890,P<0.05;147.470±17.784vs115.530±24.319,116.620±14.908,P<0.01;191.910±37.262vs154.580±18.910,152.450±20.333,P<0.05);与模型组比较,艾灸穴位组胃黏膜TFF1含量明显升高(4.573±0.121vs3.654±0.507,P<0.05).结论:艾灸足三里、中脘等穴位预处理可减轻束缚水浸应激所造成大鼠胃黏膜损伤、促进胃黏膜损伤组织增殖修复,可能是通过上调胃黏膜损伤增殖修复相关因子(EGF、TGF-α、TFF1和PCNA)而达到其促胃黏膜损伤修复的作用. 相似文献