全文获取类型
收费全文 | 20155篇 |
免费 | 1725篇 |
国内免费 | 501篇 |
专业分类
耳鼻咽喉 | 206篇 |
儿科学 | 376篇 |
妇产科学 | 542篇 |
基础医学 | 2709篇 |
口腔科学 | 417篇 |
临床医学 | 2296篇 |
内科学 | 3787篇 |
皮肤病学 | 371篇 |
神经病学 | 1370篇 |
特种医学 | 803篇 |
外国民族医学 | 3篇 |
外科学 | 2514篇 |
综合类 | 1206篇 |
一般理论 | 4篇 |
预防医学 | 1509篇 |
眼科学 | 521篇 |
药学 | 1700篇 |
4篇 | |
中国医学 | 348篇 |
肿瘤学 | 1695篇 |
出版年
2024年 | 36篇 |
2023年 | 221篇 |
2022年 | 489篇 |
2021年 | 727篇 |
2020年 | 408篇 |
2019年 | 531篇 |
2018年 | 560篇 |
2017年 | 488篇 |
2016年 | 495篇 |
2015年 | 674篇 |
2014年 | 814篇 |
2013年 | 930篇 |
2012年 | 1483篇 |
2011年 | 1551篇 |
2010年 | 897篇 |
2009年 | 748篇 |
2008年 | 1141篇 |
2007年 | 1130篇 |
2006年 | 1069篇 |
2005年 | 1026篇 |
2004年 | 945篇 |
2003年 | 808篇 |
2002年 | 704篇 |
2001年 | 504篇 |
2000年 | 423篇 |
1999年 | 423篇 |
1998年 | 185篇 |
1997年 | 174篇 |
1996年 | 196篇 |
1995年 | 170篇 |
1994年 | 130篇 |
1993年 | 114篇 |
1992年 | 215篇 |
1991年 | 199篇 |
1990年 | 178篇 |
1989年 | 149篇 |
1988年 | 138篇 |
1987年 | 120篇 |
1986年 | 120篇 |
1985年 | 119篇 |
1984年 | 103篇 |
1983年 | 86篇 |
1982年 | 76篇 |
1981年 | 77篇 |
1980年 | 65篇 |
1979年 | 75篇 |
1978年 | 63篇 |
1977年 | 43篇 |
1975年 | 38篇 |
1974年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
A series of 6-fluoro-7-substituted-1-ethyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acids were prepared. The substituents at the 7-position included five- and six-membered heterocyclic rings such as oxazoline and oxazine as well as five-membered heteroaromatic rings such as oxazoles and imidazoles. The structure--activity relationships (SAR) of these compounds indicated that oxazole substituents containing a 2-methyl group had the greatest in vitro potency. The compounds showed greater in vitro antibacterial activity against Gram-positive organisms than against Gram-negative organisms. 相似文献
83.
84.
Dina Vivian Janet E. Fischel Robert M. Liebert 《Journal of behavior therapy and experimental psychiatry》1986,17(4):301-303
The case study reported in this paper focuses on the relationship between bedwetting and misconduct after the implementation of behavior therapy for both problems. A 6
-year-old girl was treated for enuresis and subsequently for conduct problems (lying, aggressiveness). After both bedwetting and misconduct displayed substantial and stable improvement, it was found that occasional nightly relapses in bedwetting were strongly associated with the occurence of misconduct the following day. Implications of this finding are discussed. 相似文献
85.
经左颈静脉肝内门腔静脉支架分流术(附12例报告) 总被引:4,自引:0,他引:4
为解决肝硬变门脉高压患者在经颈静脉肝内门腔静脉支架分流术中右颈静脉窄或闭的难题,我们做了经左颈静脉途径完成肝内门腔分流术的尝试。自1993年7月至1995年8月,共178例TIPSS操作中发现12例右颈静脉狭窄或闭塞。其方法为经左颈内静脉穿刺、插管入路。 相似文献
86.
Vivian Khamis 《Journal of traumatic stress》1993,6(4):555-559
The current study aimed to assess the prevalence of PTSD among Palestinians who sustained serious bodily injuries during theintifada, as well as to delineate factors having an effect on the development and attenuation of PTSD symptomatology. Results indicated evidence of high prevalence of PTSD among the injured. No significant differences in PTSD prevalence for demographic, situational, and trauma-related variables were found except for the age factor. Prevalence of PTSD among adolescents was significantly higher than among adults. It seemed that the injury itself was so intensely overwhelming that the other variables were overshadowed. Implications for further research and stress management techniques were discussed. 相似文献
87.
Tissue distribution metabolism and excretion of 2,2′,4,4′, 5-pentachlorodiphenyl ether in the rat 总被引:1,自引:0,他引:1
E. Komsta I. Chu D. C. Villeneuve F. M. Benoit D. Murdoch 《Archives of toxicology》1988,62(4):258-262
The tissue distribution, metabolism and excretion of 14C-2,2,4,4,5-pentachlorodiphenyl ether (PCDE) were studied in the rat. Radioactivity was distributed in all tissues examined, with the highest concentrations being found in the fat followed by the skin, liver, kidney and muscle. Most of the radioactivity found in the tissues was due to unchanged PCDE. Decay of PCDE in the blood was fitted to a four-compartment pharmacokinetic model, and the last compartment had a half-life of 5.8 days. A total of 55% and 1.3% of an orally administered dose was excreted in feces and urine, respectively, in 7 days. More than 64% of the fecal radioactivity was due to unchanged PCDE, while hydroxylated PCDE accounted for 23%. 相似文献
88.
二氧化硅活化巨噬细胞中早期生长反应因子-1及其信号转导通路的研究 总被引:3,自引:0,他引:3
目的 探讨早期生长反应因子(Egr-1)及其信号转导在矽肺发生发展中的作用。方法用细胞免疫荧光、原位杂交方法检测二氧化硅(SiO2)刺激后Egr-1的表达定位,用报道质粒及EMSA检测其活性改变;用激酶活性分析法检测si0:刺激巨噬细胞后ERK1/2活性改变,进一步用激酶抑制剂初步探讨SiO2活化Egr-1的信号转导通路。结果SiO2刺激RAW264.7细胞短时间Egr-1核蛋白表达及转录因子明显增加;且在处理后30~60min,Egr-1核蛋白结合活性明显升高(为未处理组的20倍);在刺激后15min ERK1/2活性开始升高,30min达高峰(活性为对照组的29倍)而后渐降至基础水平;进一步用激酶阻断发现,Egr-1 mRNA及蛋白表达均减少。结论SiO2能激活巨噬细胞中Egr-1,且此过程可能由ERK1/2、p38介导,提示SiO2-ERK1/2、p38-Egr-1通路可能在矽肺发生发展过程中起重要作用。 相似文献
89.
A two decade survey of respiratory adenovirus in Taiwan: the reemergence of adenovirus types 7 and 4 总被引:3,自引:0,他引:3
Lin KH Lin YC Chen HL Ke GM Chiang CJ Hwang KP Chu PY Lin JH Liu DP Chen HY 《Journal of medical virology》2004,73(2):274-279
From November 1999 to December 2001, three outbreaks of adenovirus (Ad) respiratory infection occurred in southern Taiwan. To determine the circulating serotypes and molecular epidemiology, a total of 524 virus strains were randomly selected from 1,064 strains isolated from 1981 to 2001, and were studied using restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-RFLP. The major subgenus found was subgenus B (45%), followed by subgenus E (29%) and subgenus C (25%). Ad3 and Ad7 were the major types found during the 1st outbreak, which occurred from November 1999 to March 2000, while Ad4 was found mainly during the 2nd and 3rd outbreaks in October 2000 and September 2001, respectively. Both Ad7 and Ad4 were reemerged serotypes, whereas Ad3 was consistently isolated during the survey, although it declined drastically from 36 to 2% in 2001. Genotype analysis in this study showed that the only strain of Ad7 found in 1983 was Ad7a, but all randomly selected strains of Ad7 isolated during 1999-2000 were Ad7b. The clinical features of 217 patients were analyzed during the 1999-2000 outbreaks. About 79% of the total cases were less than 7 years old. The ratio of male to female was 2:1. Severe infections, such as pneumonia and acute bronchitis, accounted for nearly half of the cases (43%). These results show the reemergence and changing of serotypes, the clinical association of respiratory adenovirus infections, and the molecular epidemiology of Ad7 genotypes in Taiwan during the past two decades. 相似文献
90.
Chu PH Yeh HI Jung SM Chien LY Cheng NF Wu HH Chu JJ Hsueh C Lee YS 《Virchows Archiv : an international journal of pathology》2004,444(4):383-386
Cardiac hamartomas are very rare and are demarcated masses of enlarged, hypertrophied, mature myocytes and collagen tissue. Cardiac hamartomas are generally circumscribed in the right ventricle or atrium, but not reported in the crista terminalis (CRT). The CRT is crucial in electrophysiology, is related to arrhythmogenesis, and is targeted by radiofrequency catheter procedures. Previous works only described the benign natures of prominent CRT using non-invasive methods. This study describes an unusual cardiac hamartoma originating from the CRT and extending toward the tricuspid valve. Microscopically, this hamartoma comprised dense collagen and adipose tissue, mixed with hypertrophy, but with disarrayed cardiomyocytes. An irregular gap junction, connexin43, was demonstrated in this cardiac hamartoma. 相似文献