全文获取类型
收费全文 | 96670篇 |
免费 | 10137篇 |
国内免费 | 6151篇 |
专业分类
耳鼻咽喉 | 796篇 |
儿科学 | 1539篇 |
妇产科学 | 778篇 |
基础医学 | 9405篇 |
口腔科学 | 1504篇 |
临床医学 | 12657篇 |
内科学 | 12569篇 |
皮肤病学 | 998篇 |
神经病学 | 4424篇 |
特种医学 | 3664篇 |
外国民族医学 | 49篇 |
外科学 | 8786篇 |
综合类 | 19742篇 |
现状与发展 | 21篇 |
一般理论 | 16篇 |
预防医学 | 8725篇 |
眼科学 | 2515篇 |
药学 | 10700篇 |
145篇 | |
中国医学 | 7211篇 |
肿瘤学 | 6714篇 |
出版年
2024年 | 423篇 |
2023年 | 1495篇 |
2022年 | 3759篇 |
2021年 | 4781篇 |
2020年 | 3834篇 |
2019年 | 3058篇 |
2018年 | 3067篇 |
2017年 | 3222篇 |
2016年 | 2967篇 |
2015年 | 4368篇 |
2014年 | 5755篇 |
2013年 | 5790篇 |
2012年 | 8084篇 |
2011年 | 8662篇 |
2010年 | 6600篇 |
2009年 | 5466篇 |
2008年 | 6000篇 |
2007年 | 5879篇 |
2006年 | 5551篇 |
2005年 | 4749篇 |
2004年 | 3360篇 |
2003年 | 3228篇 |
2002年 | 2716篇 |
2001年 | 2058篇 |
2000年 | 1681篇 |
1999年 | 1254篇 |
1998年 | 714篇 |
1997年 | 747篇 |
1996年 | 522篇 |
1995年 | 452篇 |
1994年 | 369篇 |
1993年 | 244篇 |
1992年 | 298篇 |
1991年 | 227篇 |
1990年 | 212篇 |
1989年 | 184篇 |
1988年 | 154篇 |
1987年 | 143篇 |
1986年 | 133篇 |
1985年 | 110篇 |
1984年 | 51篇 |
1983年 | 50篇 |
1982年 | 34篇 |
1981年 | 30篇 |
1979年 | 53篇 |
1974年 | 38篇 |
1973年 | 30篇 |
1969年 | 31篇 |
1967年 | 30篇 |
1966年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
R Assan G Feutren J Sirmai C Laborie C Boitard P Vexiau H Du Rostu M Rodier M Figoni P Vague 《Diabetes》1990,39(7):768-774
Remission from insulin dependency in insulin-treated recent-onset type I (insulin-dependent) diabetic patients can result from a partial recovery of insulin secretion, an improvement in tissue sensitivity to insulin, or both. The same hypothesis must be analyzed when remission occurs in cyclosporin A (CsA)-treated patients. In this study, plasma C-peptide levels were serially measured in the basal state and after stimulation in 219 recent-onset type I diabetic patients; 129 received CsA, and all patients were similarly monitored and insulin treated. The results were analyzed in view of the occurrence of remission. Remission was defined as good metabolic control in the absence of hypoglycemic treatment for greater than or equal to 1 mo. Remission occurred in 44% of the CsA-treated group and lasted for mean +/- SE 10.0 +/- 0.9 mo vs. 21.6% in the non-CsA-treated group with a duration of 4.4 +/- 0.8 mo. Plasma C-peptide levels were initially dramatically lower than normal in both groups in the basal and stimulated states. C-peptide levels increased significantly later, at 3 and 6 mo, in both groups. C-peptide values were proportional to the rates of remission in both groups. In the non-CsA-treated group, C-peptide levels later decreased, and these patients inexorably relapsed to insulin dependency. In contrast, in the CsA-treated group, the initial recovery in insulin secretory capacity was maintained over the 18-24 mo of the study. Furthermore, higher remission rates and longer-lasting remission were obtained in patients who reached higher C-peptide levels at the 3rd mo of treatment.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
52.
Dr. James Hui Ph.D. Dr. Yow-Ming C. Wang Ph.D. Dr. Appavu Chandrasekaran Ph.D. Dr. Douglas R. Geraets Pharm.D. Dr. James H. Caldwell M.D. Dr. Larry W. Robertson Ph.D. Dr. Richard H. Reuning Ph.D. 《Pharmacotherapy》1994,14(5):607-612
Study Objective . To compare digoxin tablets and liquid-filled capsules with respect to excretion of the drug and its metabolites in urine and feces at steady state. Design . A randomized, crossover trial, each period lasting 3 weeks, with no washout period. Setting . A university hospital. Patients . Six patients, five of whom were elderly, with histories of gastrointestinal disorders, such as hypochlorhydria, intestinal bacterial overgrowth, and inflammatory bowel disease. Interventions . The patients received digoxin once/day in either tablet or capsule form for 3 weeks, and then were switched to the other formulation. Total urinary and fecal excretion from the last 3 days of each regimen were analyzed for the drug and metabolites. Measurements and Main Results . No statistically significant differences were found between tablets and capsules in recovery of digoxin or its metabolites in urine or feces (p=0.05). One subject had a 4-fold increase in urinary drug excretion and 50% decrease in fecal excretion after taking the capsules compared with tablets. Intersubject variability in extent and type of metabolite excretion was greater than intrasubject variability. Conclusions . Fecal analyses may be an accurate way to classify patients as formers of digoxin reduction products. 相似文献
53.
本文应用计算机辅助的角膜地形图系统TMS-1和角膜曲率计TOPCONOM-4同时测定了200例(278眼)的角膜地形图和中央角膜屈光状态。比较了角膜地形图的模拟角膜曲率SIMK值和角膜曲率计的垂直和水平屈光度。结果显示,白内障术前组116例150眼的SIMK平均值分别为44.22D(垂直轴)和44.26D(水平轴),角膜曲率计的中央屈光度垂直轴平均为44.16D,水平轴为44.23D。统计学处理表明,2种组方法的结果之间差异无显著性(P>0.05),第2种术后组67例90眼的SIMK平均值分别为46.37D(垂直轴)和43.06D(水平轴),角膜曲率计的中央屈光度垂直轴平均为46.09D,水平轴平均为42.88D,统计学处理二种方法的结果之间差异无显著性(P>0.05)。研究提示,角膜地形图系统的模拟角膜曲率SIMK值和角膜曲率计的屈光度无论在白内障手术前还是在手术后其结果是一致的,临床应用具有同等的价值。但是,当角膜中央屈光度异常范围小于3毫米,角膜混浊,角膜严重不规则散光时,角膜曲率计不能满足临床需要。而计算机辅助的角膜地形图系统则具有极大的诊断及检测价值。眼科学报 1994;10:85—89。 相似文献
54.
目的:研究中国汉族群体中α艾杜糖苷酶基因D4S111位点的遗传多态性。方法:采用扩增片段长度多态性(AmpFLP)分析技术,检测了广州地区汉族无血缘关系健康个体97名。结果:D4S111位点,在97名无关个体中发现5个等位基因和9种基因型,等位基因片段长度为830~510bp,基因频率为00052~03608,PIC为05966,杂合性为078。结论:中国汉族群体中D4S111位点具有高度多态性,并与其它种族间存在差异性。 相似文献
55.
56.
Objective. To study the characteristics of changes of LDH enzyme patterns of mice under slight hypoxia.Methods. Mice treated with artificial hypoxia, various tissues were made for the test of LDH enzymatic activity by the specific staining technique. LDH (1 -5) relative percentage enzymatic activity (RPEA) were measured with CS-910 dual-wavelength thin layer chromatography scanner.Results. The RPEA of LDH isozymes of various tissues after slight hypoxia shifted to the isozymes LDH1 and LDH2, whose principal subunits are H subunits, and the RPEA of LDH,(H4), LDH2(H3M) increased, while RPEA of LDH5(M4) in various tissues decreased prominently except the cardiac muscle, and that of LDH4(HM3) decreased as well. After polyacrylamide gel electrophoresis (PAGE) of the hypoxia treated cardiac muscle specimen was made, activity subbands originated regularly in the isozyme patterns of LDH, with the regularity of LDH1 (0 subband), LDH2 (0-1 subbands), LDH3 (0-2 subbands), LDH4 (1-3 subbands), LDH5 (2-4 subbands). 相似文献
57.
Hsiu Hui Chiu Hsiao Hui Chou Wen Dar Jean Wung Yang Shieh 《Journal of microbiology, immunology, and infection》2007,40(1):14-23
BACKGROUND AND PURPOSE: Marine luminous bacteria were isolated and identified from samples in shallow coastal waters of Taiwan during the relatively warm seasons. METHODS: Identification of the luminous isolates was performed based on differences of phenotypic and genotypic characteristics together with data from phylogenetic analysis. RESULTS: Twenty seven strains of marine luminous bacteria were isolated. They were divided into five types based on differences of phenotypic characteristics. However, they could be clustered into only two genotypes according to the analysis of restriction patterns of polymerase chain reaction-amplified 16S rRNA genes digested with various restriction enzymes. The characterization data together with the 16S rRNA gene-based phylogenetic analysis revealed that the isolates included in phenotype I (seven isolates) could be Photobacterium leiognathi, and those included in phenotypes II-V (twenty isolates) might be classified as Vibrio harveyi. However, phylogeny based on gyrB sequences indicated that phenotypes II-V could be classified into two species, V. harveyi and Vibrio campbellii. CONCLUSION: Culturable luminous bacteria in the shallow coastal waters of Taiwan during the sampling period are dominated by V. harveyi/campbellii and P. leiognathi, and the former species appeared to be more prevalent and numerous than the latter species in general. 相似文献
58.
云南金铁锁的生物学特性及其保护的初步研究 总被引:12,自引:0,他引:12
对金铁锁的生物学特征、适应性及其机理进行探讨。结果表明:金铁锁具有旱生植物的结构和特征,耐旱、耐贫瘠能力较细。同时提出了相应的保护措施。为合理的开发、利用和保护金铁锁提供了依据。 相似文献
59.
目的 了解本社区高血压患者的危险因素现状,探讨干预对策。方法 采用分层整群抽样的方法,随机抽取社区4个里委2级、3级高血压患者402例作为研究对象,收集各项危险因素如性别、年龄、血脂、血糖、吸烟、饮食、体育锻炼、体重等,并进行统计分析。结果402例高血压患者1年内进行所有相关辅助检查者有14例,占3.48%;1年内进行相关辅助检查一项者306例,占76.12%。饮食控制及进行体育锻炼有300例,占74.43%;吸烟62例,占15.42%。结论 高血压患者对饮食控制及体育锻炼、吸烟有害的知晓率明显提高,而对相关辅助检查认识不足。 相似文献
60.