全文获取类型
收费全文 | 1549篇 |
免费 | 108篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 31篇 |
妇产科学 | 9篇 |
基础医学 | 253篇 |
口腔科学 | 21篇 |
临床医学 | 129篇 |
内科学 | 275篇 |
皮肤病学 | 48篇 |
神经病学 | 78篇 |
特种医学 | 61篇 |
外科学 | 273篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 114篇 |
眼科学 | 59篇 |
药学 | 75篇 |
中国医学 | 3篇 |
肿瘤学 | 143篇 |
出版年
2022年 | 13篇 |
2021年 | 14篇 |
2019年 | 14篇 |
2018年 | 35篇 |
2017年 | 18篇 |
2016年 | 25篇 |
2015年 | 18篇 |
2014年 | 22篇 |
2013年 | 50篇 |
2012年 | 78篇 |
2011年 | 66篇 |
2010年 | 41篇 |
2009年 | 42篇 |
2008年 | 67篇 |
2007年 | 83篇 |
2006年 | 82篇 |
2005年 | 72篇 |
2004年 | 71篇 |
2003年 | 60篇 |
2002年 | 44篇 |
2001年 | 52篇 |
2000年 | 54篇 |
1999年 | 48篇 |
1998年 | 15篇 |
1996年 | 11篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 21篇 |
1991年 | 27篇 |
1990年 | 29篇 |
1989年 | 17篇 |
1988年 | 23篇 |
1987年 | 20篇 |
1986年 | 20篇 |
1985年 | 28篇 |
1984年 | 22篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 18篇 |
1980年 | 10篇 |
1979年 | 18篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1975年 | 9篇 |
1973年 | 12篇 |
1971年 | 19篇 |
1969年 | 11篇 |
1933年 | 13篇 |
1932年 | 9篇 |
1931年 | 10篇 |
排序方式: 共有1658条查询结果,搜索用时 8 毫秒
1.
Several studies have reported that core body temperature decreases with age and has greater variability in older populations. Furthermore, oral measurement, the most frequently used clinical method for determining fever, may not accurately reflect core body temperature. This study was designed to compare accurate measurements of oral and core body temperatures in a group of 93 healthy subjects, aged 62-96, under controlled conditions. Increasing age, presence of dentures, and type of thermometer were examined to determine if they affect body temperature measurements. Core temperatures did not show a negative relationship with advancing age (r = -0.02) nor did variation in temperatures increase with age. Neither the type of thermometer nor the presence of dentures significantly affected the measurement of temperature. 相似文献
2.
Transient occurrence of extrachromosomal DNA of an Arabidopsis thaliana transposon-like element, Tat1. 总被引:5,自引:1,他引:4
J Peleman B Cottyn W Van Camp M Van Montagu D Inzé 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(9):3618-3622
Analysis of 11 genomic clones containing the S-adenosylmethionine synthetase 1 gene (sam1) of Arabidopsis thaliana revealed the presence of a 431-base-pair (bp) insertion in the 3' end of sam1 in one of these clones. The inserted sequence, called Tat1, shows structural features of a transposon. It is flanked by a 5-bp duplication of the target site DNA and has 13-bp inverted repeats at its termini. Two highly homologous elements situated in a different genomic context were isolated from a genomic library. Genomic Southern analysis indicates that there are at least four copies of Tat1 present in the A. thaliana ecotype Columbia genome. Different hybridization patterns are observed with DNAs derived from different ecotypes of Arabidopsis thaliana, indicating that the element has moved since the divergence of these ecotypes. In two populations of A. thaliana, linear extrachromosomal Tat1-homologous DNA has been observed. The presented data are consistent with the hypothesis that Tat1 is an active transposable element. 相似文献
3.
Camp S. J. Stevenson V. L Thompson A. J. 《世界核心医学期刊文摘》2006,2(6):58-59
有关多发性硬化症患者认知功能的纵向研究很少,并且上述研究的结果也不明确,迄今尚无专门关于原发进行性多发性硬化症(PPMS)病例系列的连续神经心理学资料。横断面分析揭示,PPMS患者的认知功能与磁共振成像(MRI)参数之间显著相关。本研究持续2年时间对来源于5个欧洲中心的99例PPMS患者的认知功能和MRI改变进行探讨。采用简易可重复问卷(一种推理能力测试)和抑郁量表每隔12个月对患者进行评估,同时在每个时间点对T1低信号负荷、T2损伤负荷和部分脑体积的MRI参数进行测算。基线和2年时患者的平均认知功能得分间无显著差异。然而,1/3患者的单独测试得分表现出绝对的认知功能下降。研究结果提示,纳入研究时的初始认知状态是2年后认知能力的一个可靠预测指标。认知功能改变和MRI改变间仅有少数几项指标显著相关,值得一提的是T1低信号负荷与2项注意力测试任务相关(r=-0.266,P=0.017;r=-0.303,P=0.012),可能是由多种因素造成认知功能和MRI参数间的这种弱相关。 相似文献
4.
5.
B A Faraj F H Schmidt R Sarper V M Camp E Malveaux 《The Journal of pharmacology and experimental therapeutics》1987,241(1):42-47
Tyramine induces coma in phenelzine-treated dogs with liver disease. The objective of the present investigation was to examine the influence of tyramine in these monoamine oxidase-inhibited dogs on the kinetics of Tc-99m-diethylenetriamine penta-acetic acid (Tc-99m-DTPA) during its first passage through the brain by nuclear imaging techniques. The study began with anesthetized mongrel dogs (n = 10) in a supine position over the camera detector. Data acquisition was started simultaneously after the rapid intracarotid injection of Tc-99m-DTPA (5 mCi) and 60 0.5-sec images of the brain were taken. Tyramine induced increased uptake with a concomitant impairment in the elimination of Tc-99m-DTPA from the brain of these phenelzine-treated animals with hepatic injury (n = 5) as compared to pretreated animals serving as a control group or phenelzine-treated animals without liver disease. This was accompanied by an appreciable reduction in hemispheric cerebral blood flow (50.5 +/- 19.3 vs. 110 +/- 16 ml/100 g/min), respectively. Increased cerebrovascular permeability of Tc-99m-DTPA and decreased cerebral blood flow occurred concomitantly with increased cerebrospinal fluid pressure and elevation in cerebrospinal fluid catecholamines of monoamine oxidase-inhibited animals with hepatic injury. 相似文献
6.
Cryogenic burns are uncommon. We present two patients who presented to a Regional Burns Unit on consecutive days with almost identical burn injuries caused by exposure to a unique source of sub-zero temperature, the spray from an aerosol deodorant. The clinical features and management of the cases are outlined, and we discuss the mechanism of a cryogenic burn. 相似文献
7.
8.
Many women in medical training want to combine a family life and a career. Of major interest to these women is determining the most desirable time for pregnancy during their medical education and career. The results of a study on women physicians' timing of pregnancy are reported. A 53 percent response rate was obtained in a randomized national survey of women physicians who had completed residency training and were less than 50 years of age. Their first pregnancies (of which 77 percent were planned) occurred as follows: prior to medical school, 4 percent; during medical school, 7 percent; in first year as house officer, 11 percent; in other residency year, 32 percent; in fellowship year(s), 13 percent; in practice, 28 percent, on leave or other, 5 percent. Seventy percent of the respondents considered "after completion of residency" to be the best time to become pregnant. Sixty percent of the respondents' maternity leaves were six weeks or less in duration. Seventeen percent required some medical leave before delivery, although only 5 percent required more than eight weeks of medical leave. Only a third reported that their training or work sites had maternity leave policies. Ninety-one percent of the respondents reported satisfaction in their careers. 相似文献
9.
H. Fujiwara M. Emi H. Nagai T. Nishimura N. Konishi Y. Kubota T. Ichikawa S. Takahashi T. Shuin T. Habuchi O. Ogawa K. Inoue M. H. Skolnick J. Swensen N. J. Camp S. V. Tavtigian 《Journal of human genetics》2002,47(12):0641-0648
The recently identified prostate cancer susceptibility gene ELAC2 (HPC2) harbors two common missense variants, a serine to leucine substitution at residue 217 (Leu217) and an alanine to threonine
substitution at residue 541 (Thr541). We genotyped the two variants in a Japanese cohort consisting of 350 prostate cancer
patients 242 male population controls, and 114 male low-risk controls. Both missense alleles, Leu217 and Thr541, were carried
at higher frequency in Japanese patients than in the controls (Leu217, P = 0.0012; Thr541, P = 0.0145), and the odds ratios associated with carrying these sequence variants were higher in Japanese than in Caucasians.
Although the Leu217 and Thr541 variants of ELAC2 are less common in Japanese than in Caucasians, both variants confer significantly increased risk of prostate cancer in Japanese.
Carriage of these variants was not associated with age at diagnosis, tumor stage, or tumor grade in these Japanese prostate
cancer patients. The allele-specific pattern of risk observed in Japanese and familial Caucasian patients was qualitatively
similar; however, the magnitude of that risk was considerably greater in Japanese than in Caucasians.
Received: September 3, 2002 / Accepted: October 2, 2002 相似文献
10.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献