全文获取类型
收费全文 | 13311篇 |
免费 | 755篇 |
国内免费 | 288篇 |
专业分类
耳鼻咽喉 | 148篇 |
儿科学 | 424篇 |
妇产科学 | 446篇 |
基础医学 | 931篇 |
口腔科学 | 212篇 |
临床医学 | 1485篇 |
内科学 | 1575篇 |
皮肤病学 | 105篇 |
神经病学 | 987篇 |
特种医学 | 245篇 |
外科学 | 1197篇 |
综合类 | 2400篇 |
预防医学 | 1560篇 |
眼科学 | 166篇 |
药学 | 1295篇 |
13篇 | |
中国医学 | 283篇 |
肿瘤学 | 882篇 |
出版年
2024年 | 16篇 |
2023年 | 255篇 |
2022年 | 456篇 |
2021年 | 656篇 |
2020年 | 631篇 |
2019年 | 498篇 |
2018年 | 531篇 |
2017年 | 454篇 |
2016年 | 529篇 |
2015年 | 507篇 |
2014年 | 1220篇 |
2013年 | 1105篇 |
2012年 | 972篇 |
2011年 | 1016篇 |
2010年 | 747篇 |
2009年 | 665篇 |
2008年 | 653篇 |
2007年 | 539篇 |
2006年 | 466篇 |
2005年 | 342篇 |
2004年 | 275篇 |
2003年 | 208篇 |
2002年 | 191篇 |
2001年 | 167篇 |
2000年 | 145篇 |
1999年 | 130篇 |
1998年 | 103篇 |
1997年 | 65篇 |
1996年 | 79篇 |
1995年 | 77篇 |
1994年 | 69篇 |
1993年 | 53篇 |
1992年 | 55篇 |
1991年 | 57篇 |
1990年 | 43篇 |
1989年 | 36篇 |
1988年 | 44篇 |
1987年 | 35篇 |
1986年 | 21篇 |
1985年 | 34篇 |
1984年 | 26篇 |
1983年 | 26篇 |
1982年 | 23篇 |
1981年 | 15篇 |
1980年 | 21篇 |
1979年 | 27篇 |
1978年 | 20篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 562 毫秒
71.
Barbara Lowenthal 《Early child development and care》1998,142(1):43-52
Recently, the number of young children who have suffered from the traumas of abuse and neglect has increased. There are negative cognitive, neurological, and psychological effects from this maltreatment which is described in this article. Interventions which can prevent neglect and abuse and further resiliency in the young victims are discussed. As concerned individuals, we need to advocate for preventive and therapeutic efforts which promote resiliency in maltreated children. 相似文献
72.
L. J. Dowie J. E. Smith A. J. MacGilchrist R. Fraser J. W. Honour J. L. Reid C. J. Kenyon 《European journal of clinical pharmacology》1988,35(6):625-629
Summary The site of omeprazole inhibition of adrenal steroidogenesis has been sought in vivo by analyzing the patterns of urinary steroid metabolite excretion after 6 days of treatment with placebo/omeprazole.Excretion rates of androsterone, aetiocholanolone, dehydroepiandrosterone, 11 hydroxyandrosterone, tetrahydrocortisone, tetrahydrocortisol and cortolone were reduced, indicating a block at an early step in steroidogenesis, possibly cholesterol side-chain cleavage. In vitro studies have confirmed this finding by measuring conversion of added precursors to cortisol in isolated bovine adrenocortical cells. Cortisol synthesis from added 20 hydroxycholesterol was inhibited by 83% in the presence of 100 µg omeprazole/ml. Conversion from pregnenolone and progesterone and their 17 hydroxylated derivatives was inhibited by 20–40% whereas cortisol production from added 11 deoxycortisol was not affected.These data suggest that omeprazole primarily inhibits cholesterol cleavage and does not inhibit 3 hydroxysteroid dehydrogenase, 17 hydroxylase or 11 hydroxylation; 21 hydroxylase activity may be marginally attenuated. 相似文献
73.
背景 主观认知下降(SCD)是阿尔茨海默病(AD)早期预防的目标阶段,AD与慢性病共病关系密切,但二者间相关性尚不十分明确。目的 探究老年人SCD与慢性病共病的相关性,为AD早期预防和干预提供理论依据。方法 于2021年1月至2022年6月,在广州市城市生活小区和养老机构以便利抽样法抽取≥60岁的老年人612例。采用基础版蒙特利尔认知评估量表(MoCA-B)、临床痴呆量表(CDR)、Hachinski缺血指数量表(HIS)评定客观认知功能水平,通过SCD标准诊断框架和SCD问卷(SCD-Q9)进行分组,将整体客观认知水平无异常、符合SCD标准诊断框架和SCD-Q9≥5分的老年人分入SCD组,将整体客观认知功能无异常和SCD-Q9<5分的老年人为认知无异常(CN)组。采用一般资料问卷收集老年人的社会人口学(性别、年龄、居住地、受教育年限、婚姻状况、退休前职业类型、月收入)和健康相关资料[体质指数、腰围、吸烟习惯、饮酒习惯、饮茶习惯、锻炼频率、午觉习惯及平均时长、睡眠质量、抑郁及焦虑症状、日常生活活动能力(ADL)],其中睡眠质量、抑郁症状、焦虑症状及ADL分别采用匹兹堡睡眠指数量表... 相似文献
74.
ONO—802阴道给药抗早孕50例临床效果观察 总被引:2,自引:0,他引:2
本文报告了停经56天以内的早孕妇女应用ONO-802阴道栓剂抗早孕的临床观察及效果。50例早孕妇女住院观察24小时,阴道投药1枚(1mg/枚),5枚为一疗程。用药后1周、2周、4~6周门诊随访,复查尿HCG、血红蛋白。在第二周随访时判断用药效果。临床结果:总有效率82%,其中完全流产76%,不全流产6%,失败率18%。ONO-802使用方便,副反应轻,是深受广大妇女欢迎的一种非手术终止妊娠的方法。本项试验结果通过与国内PG 联合用药的结果和研究资料对比,ONO-802如果能与丙睾、R2323、天花粉等联合应用,将会提高其抗早孕的有效率。 相似文献
75.
目的评估AO肩锁钢板钩治疗重型肩锁关节脱位的手术疗效.方法回顾性分析两年来27例手术病人的手术治疗和疗效.结果手术方法符合生理结构,手术时间平均30分钟,内固定牢靠.根据Murley和Constant[1]评分,优良率94%.结论 AO肩锁钢板钩治疗重型肩锁关节脱位,手术方法简单,疗效可靠,允许病人术后早期功能锻炼. 相似文献
76.
The Modality Specificity of the Slow Negative Wave 总被引:1,自引:0,他引:1
Event-related potentials were recorded in a simple reaction time task using a 3-sec interval between S1 and S2. The sensory modalities of S1 and S2 were varied across 4 conditions to yield all possible combinations of tones and flashes. A negative component which peaked between 600 and 800 msec after S1 was specific in scalp distribution to the modality of S1 but not S2. It was concluded that this negative component is a response to S1 and not related to processes associated with anticipation of S2. A slow negative shift which peaked at S2 was largest at the vertex in all conditions, suggesting its motor origin. A trend for the latter activity to be more negative in posterior recordings when S2 was visual than auditory leaves open the possibility that the terminal CNV is a combination of motor activities and anticipation of the sensory modality of S2. 相似文献
77.
目的建立分泌抗EPF(Early pregnancy factor,早孕因子)单克隆抗体的杂交瘤细胞株,纯化单抗并鉴定.方法用本实验室已纯化的早孕和肿瘤源性EPF作为抗原刺激Balb/c小鼠,用免疫后的小鼠脾细胞与同系小鼠骨髓瘤细胞(NS-1)融合,经4次克隆化,获得可稳定分泌抗EPF单克隆抗体的细胞株,注入Balb/c小鼠腹腔制备腹水型单抗,Protein-A亲和层析纯化,SDS电泳和Western-blot等方法分析纯化结果.结果融合后获得一株稳定分泌抗EPF抗体的细胞株(C3D11),克隆化后,获得稳定分泌抗EPF单克隆抗体的细胞株,将增殖后的细胞注射Balb/c小鼠腹腔获得腹水型单抗,以亲和层析法纯化,SDS-PAGE分析显示纯化后去掉了大部分杂蛋白,免疫印迹分析抗体纯度较高,与抗原匹配性良好.结论本研究制备的EPF单克隆抗体为特异性抗EPF抗体. 相似文献
78.
C. Garcia Castro J. M. Gonzalez-Posada V. Castro Lopez-Tarruella E. C. Salido Ruiz 《Diagnostic cytopathology》1993,9(2):174-178
We have analyzed 245 transplant aspirative cytologies (TACs) from 96 renal allograft patients. TACs were divided in two chronological groups: Early (TACs performed during the first 3-mo post-transplantation) and late (TACs performed after the third month post-transplantation), in order to assess the effect of allograft tolerance on TAC features. Both morphological and immunocytochemical aspects were evaluated, including CD4, CD8, IL2-R, and HLA-DR immunolabeling. A final diagnosis for each case of allograft dysfunction was achieved by other independent diagnostic means. Four diagnostic groups were considered in the present study: acute rejection (AR), chronic rejection (CR), acute tubular necrosis (ATN), and Cyclosporin A toxicity (CsA-T). In addition, a control group (C) was established from patients with stable allograft function. We found that immunocytochemical analysis of TACs is particularly helpful in the diagnosis of late allograft dysfunction, a time period when the simple cytological study of renal infiltrate is not informative enough to help take therapeutic decisions. 相似文献
79.
早期干预对高危儿智能发育影响的研究 总被引:1,自引:0,他引:1
周宇芳 《中国优生与遗传杂志》2008,16(4):100-101
目的探讨定期随访高危儿,进行早期发育评价及干预,对高危儿智能发育的影响。方法将82例高危儿随机分成干预组42例和常规组40例,干预组接受早期干预,两组患儿定期随访,以中国婴幼儿发育量表(CDCC)和《Ge-sell发育诊断量表》进行智能发育评估。结果3、6、9月龄时干预组患儿智力发育指数(MD I)和运动发育指数(PD I)均显著高于常规组;1岁时Gesell智能检查,干预组除大运动能区与常规组有显著性差异外(P〈0.05),其他四大能区均存在非常显著性差异(P〈0.01)。结论早期干预可促进高危儿的智能发育,改善其预后。 相似文献
80.
Larsen MV Lundegaard C Lamberth K Buus S Brunak S Lund O Nielsen M 《European journal of immunology》2005,35(8):2295-2303
Reverse immunogenetic approaches attempt to optimize the selection of candidate epitopes, and thus minimize the experimental effort needed to identify new epitopes. When predicting cytotoxic T cell epitopes, the main focus has been on the highly specific MHC class I binding event. Methods have also been developed for predicting the antigen-processing steps preceding MHC class I binding, including proteasomal cleavage and transporter associated with antigen processing (TAP) transport efficiency. Here, we use a dataset obtained from the SYFPEITHI database to show that a method integrating predictions of MHC class I binding affinity, TAP transport efficiency, and C-terminal proteasomal cleavage outperforms any of the individual methods. Using an independent evaluation dataset of HIV epitopes from the Los Alamos database, the validity of the integrated method is confirmed. The performance of the integrated method is found to be significantly higher than that of the two publicly available prediction methods BIMAS and SYFPEITHI. To identify 85% of the epitopes in the HIV dataset, 9% and 10% of all possible nonamers in the HIV proteins must be tested when using the BIMAS and SYFPEITHI methods, respectively, for the selection of candidate epitopes. This number is reduced to 7% when using the integrated method. In practical terms, this means that the experimental effort needed to identify an epitope in a hypothetical protein with 85% probability is reduced by 20-30% when using the integrated method.The method is available at http://www.cbs.dtu.dk/services/NetCTL. Supplementary material is available at http://www.cbs.dtu.dk/suppl/immunology/CTL.php. 相似文献