全文获取类型
收费全文 | 93945篇 |
免费 | 6352篇 |
国内免费 | 1814篇 |
专业分类
耳鼻咽喉 | 1152篇 |
儿科学 | 1768篇 |
妇产科学 | 1682篇 |
基础医学 | 12101篇 |
口腔科学 | 3065篇 |
临床医学 | 8610篇 |
内科学 | 21188篇 |
皮肤病学 | 1879篇 |
神经病学 | 7633篇 |
特种医学 | 2544篇 |
外国民族医学 | 24篇 |
外科学 | 11940篇 |
综合类 | 4252篇 |
现状与发展 | 5篇 |
一般理论 | 38篇 |
预防医学 | 7668篇 |
眼科学 | 1915篇 |
药学 | 7144篇 |
12篇 | |
中国医学 | 1529篇 |
肿瘤学 | 5962篇 |
出版年
2024年 | 126篇 |
2023年 | 817篇 |
2022年 | 1159篇 |
2021年 | 2361篇 |
2020年 | 1557篇 |
2019年 | 1998篇 |
2018年 | 2968篇 |
2017年 | 2019篇 |
2016年 | 2110篇 |
2015年 | 3180篇 |
2014年 | 3421篇 |
2013年 | 4156篇 |
2012年 | 7870篇 |
2011年 | 7902篇 |
2010年 | 3932篇 |
2009年 | 2985篇 |
2008年 | 6395篇 |
2007年 | 6589篇 |
2006年 | 6769篇 |
2005年 | 6344篇 |
2004年 | 5576篇 |
2003年 | 5161篇 |
2002年 | 4914篇 |
2001年 | 2170篇 |
2000年 | 2638篇 |
1999年 | 1564篇 |
1998年 | 529篇 |
1997年 | 497篇 |
1996年 | 437篇 |
1995年 | 414篇 |
1994年 | 331篇 |
1993年 | 265篇 |
1992年 | 327篇 |
1991年 | 287篇 |
1990年 | 235篇 |
1989年 | 187篇 |
1988年 | 163篇 |
1987年 | 156篇 |
1986年 | 141篇 |
1985年 | 158篇 |
1984年 | 149篇 |
1983年 | 94篇 |
1982年 | 103篇 |
1981年 | 88篇 |
1980年 | 89篇 |
1979年 | 81篇 |
1978年 | 57篇 |
1977年 | 53篇 |
1976年 | 42篇 |
1974年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的观察和评价外剥、内扎硬化注射术治疗混合痔的近期疗效.方法作者采用外剥、内扎硬化注射术治疗混和痔800例.结果近期治愈788例,治愈率98.5%,好转12例,好转率1.5%.治愈天数10~21天.结论外剥、内扎硬化注射术治疗混合痔简单实用,手术时间短,术后痛苦小,伤面愈合快,并发症少,无后遗症,复发率低,是治疗混合痔的较好方法. 相似文献
62.
63.
64.
René Schwendimann Hugo Bühler Sabina De Geest Koen Milisen 《BMC health services research》2006,6(1):69
Background
Patient falls in hospitals are common and may lead to negative outcomes such as injuries, prolonged hospitalization and legal liability. Consequently, various hospital falls prevention programs have been implemented in the last decades. However, most of the programs had no sustained effects on falls reduction over extended periods of time. 相似文献65.
目的:了解包头市初次吸毒者与复吸者戒毒期间的生活质量。方法:用QOL-DA2.0量表对戒毒人员的生活质量进行调查。结果:初次吸毒者与复吸者各纬度进行t检验显示躯体功能纬度(t=10.51)、心理功能纬度(t=5.94)、症状及毒副作用纬度(t=6.41)、社会功能纬度(t=10.47)和总分(t=10.48)均有统计学意义(P<0.001),表明戒毒期间初次吸毒者的生活质量高于复吸者。结论:在戒毒期间初次吸毒者的生活质量较复吸者易改善。 相似文献
66.
BMP-2 gene polymorphisms and osteoporosis: the Rotterdam Study. 总被引:7,自引:0,他引:7
Marco Medici Joyce Bj van Meurs Fernando Rivadeneira HongYan Zhao Pascal P Arp Albert Hofman Huibert Ap Pols André G Uitterlinden 《Journal of bone and mineral research》2006,21(6):845-854
After reported associations of variations in the BMP-2 gene with osteoporosis in small populations, we studied the association of the BMP-2 gene polymorphisms Ser37Ala and Arg190Ser with osteoporosis in 6353 men and women from the Rotterdam Study. We did not observe an association of these variants with BMD, bone loss, hip structural analysis parameters, and fracture risk. INTRODUCTION: Bone morphogenetic protein 2 (BMP-2) plays a role in osteoblast differentiation. BMP-2 gene variation has previously been associated with osteoporosis in various small populations, but current evidence remains inconclusive about the exact association with osteoporosis. Therefore, we studied the association of two polymorphisms located in the BMP-2 gene (Ser37Ala and Arg190Ser) and haplotypes defined by these polymorphisms with BMD, rates of bone loss, parameters of hip structural analysis (HSA), and fractures in the Rotterdam Study, a large prospective cohort study of diseases in the elderly. MATERIALS AND METHODS: Databases were searched for polymorphisms and haplotype blocks in the BMP-2 gene region. Allele frequencies for Ser37Ala and Arg190Ser were determined in 60 blacks and 110 Chinese from Coriell panels. Genotype data on Ser37Ala and Arg190Ser were available for 6353 individuals from the Rotterdam Study population. Haplotype alleles defined by Ser37Ala and Arg190Ser were inferred using PHASE software. Genotype and haplotype analyses for BMD (measured at the lumbar spine and femoral neck), bone loss per year (measured at the femoral neck), and HSA were performed using AN(C)OVA. Fractures were analyzed using a Cox proportional-hazards model and logistic regression. All outcomes were adjusted for age, height, and weight. RESULTS: Allele frequencies were 2.5% for Ala37 and 40.2% for Ser190, whereas haplotype allele frequencies were 57.28% (Ser37Arg190), 40.19% (Ser37Ser190), 2.50% (Ala37Arg190), and 0.02% (Ala37Ser190). For BMD, bone loss, HSA outcomes, and (incident) fractures, no differences could be seen between genotype and haplotype groups. Conclusions: In this large population-based cohort of Dutch whites, we conclude that the BMP-2 Ser37Ala and Arg190Ser polymorphisms or haplotypes thereof are not associated with parameters of osteoporosis. 相似文献
67.
目的 获得丙型肝炎病毒 (HCV) H株包膜糖蛋白的重组杆状病毒 ,在昆虫细胞中稳定表达包膜糖蛋白 E1和 E2 ,并初步应用于丙型肝炎患者血清抗体的检测。方法 用 PCR方法自 HCV H株扩增出包膜蛋白 E基因 ,构建重组杆状病毒 ,并在昆虫细胞中稳定表达包膜糖蛋白 E1和 E2。免疫荧光及 Western blot方法鉴定表达产物。用表达的 E1和 E2蛋白与 35例丙型肝炎患者血清反应。结果 昆虫细胞中表达的 E蛋白呈现 3种分子大小 ,E1的相对分子量为 2 1× 10 3和 33× 10 3 ,E2的相对分子量为 6 0× 10 3。在 35份感染者血清中 ,有 4例 E1抗体阳性 ,其中 1例检出 E2抗体。在 9例 PCR检测 HCV RNA阳性而抗 HCV检测阴性的血清中 ,有 3例血清与表达的 E蛋白反应。结论 HCV E蛋白基因可在昆虫细胞中稳定表达 ,表达的 E1和 E2蛋白可用于 HCV患者的血清学诊断 相似文献
68.
中国汉坦病毒H82O5株G2糖蛋白基因的克隆及在真核细胞中的瞬时表达 总被引:2,自引:1,他引:1
从感染病毒乳鼠脑组织提取总RNA,采用RT-PCR和分子克隆技术将扩增到的G2糖蛋白基因插入含CMV启动子的pcDNA3.1/His质粒载体中,通过脂质体介导转染COS-7细胞,用SDS-PAGE、Western-blot及IFIA方法分别测定表达产物的相对分子量及特异性。结果证明获得正向插入的G2-pcDNA3.1/His重组表达质粒,表达产物的相对分子量为56ku,与理论预期大小一致,并且可与汉坦病毒H8205株的腹水抗体起特异反应。表明构建的G2-pcDNA3.1/His重组质粒所表达的蛋白为中国汉坦病毒株特有,能在哺乳动物细胞中表达并具有抗原性,重组质粒可应用于汉坦病毒的DNA疫苗研究。 相似文献
69.
Is colonic electrical activity a similar phenomena to small-bowel electrical activity? 总被引:4,自引:0,他引:4
Dr. José A. S. Medeiros M.D. Ph.D. Fausto A. Pontes M.D. Ph.D. Octávio A. R. O. Mesquita 《Diseases of the colon and rectum》1997,40(1):93-99
PURPOSE: This study was designed to investigate colonic spike bursts regarding 1) their migration behavior, 2) their pressure correlates, and 3) comparing colonic short spike bursts with spike bursts from migrating myoelectric complex from the small bowel. METHODS: Rectosigmoid electromyography and manometry were recorded simultaneously in seven normal volunteers and electromyography alone in five others during two hours of fasting and for two hours after one 2,100-kJ meal. One patient with an ileostomy was also studied by the same method to record the migrating myoelectric complex from the terminal ileum during fasting. RESULTS: Three kinds of spike bursts were observed in the pelvic colon: rhythmic short spike bursts, migrating long spike bursts, and nonmigrating long spike bursts. The meal significantly increased the number of migrating and nonmigrating long spike bursts (from 25 to 38.7 percent of the recording time;
P
<0.01). These bursts of potentials showed a peak 15 minutes after the meal, which may be caused by the gastrocolic reflex. Migrating long spike bursts started anywhere along the rectosigmoid and migrated from there aborad 82 percent of the time and orad or in both directions in 10 or 7 percent of the time, respectively. They originated pressure waves 99 percent of the time. Short spike bursts were more frequent before the meal (15.1 percent before and 9.6 percent after the meal), but the difference was not significant; they neither propagated nor initiated pressure waves detected by the miniballoon. CONCLUSIONS: Migrating long spike bursts were the only potentials that migrated, sometimes for short distances. Short spike bursts are a different phenomenon from the small-bowel migrating myoelectric complex because they do not migrate; they can occur during the postprandial period and never originated intraluminal pressure waves.Supported by a grant from the Instituto Nacional de Investigação Científica, Proc. DBI-22086.Presented at the meeting of the Portuguese Congress of Gastrenterology, Vila Moura, Portugal, June 2 to 5, 1993. 相似文献
70.
老年充血性心衰患者地高辛药代动力学研究 总被引:3,自引:0,他引:3
目的 :探讨老年心衰患者地高辛维持量的合理应用。 方法 :用荧光偏振免疫分析法测定了 14例老年心衰患者血清地高辛浓度 ,并计算出药代动力学参数。 结果 :14例老年心衰患者地高辛 t1/ 2 β,β和 Vd分别为 72 .769± 2 9.768h、0 .0 11± 0 .0 0 6h-1和 3.190± 3.30 0 L/ kg,与非老年心衰患者 ( t1/ 2 β 36.1± 2 .0 h,56.3± 12 h,β 0 .0 19± 0 .0 0 1h-1,Vd 7.37± 1.65L / kg)相比差异显著。 结论 :老年心衰患者地高辛维持量以小量分次给药为宜 ,且更应注意个体化 相似文献