全文获取类型
收费全文 | 35002篇 |
免费 | 2719篇 |
国内免费 | 123篇 |
专业分类
耳鼻咽喉 | 339篇 |
儿科学 | 1140篇 |
妇产科学 | 699篇 |
基础医学 | 4180篇 |
口腔科学 | 555篇 |
临床医学 | 4316篇 |
内科学 | 7298篇 |
皮肤病学 | 466篇 |
神经病学 | 3268篇 |
特种医学 | 900篇 |
外国民族医学 | 2篇 |
外科学 | 4720篇 |
综合类 | 679篇 |
一般理论 | 55篇 |
预防医学 | 3419篇 |
眼科学 | 861篇 |
药学 | 2314篇 |
中国医学 | 55篇 |
肿瘤学 | 2578篇 |
出版年
2023年 | 226篇 |
2022年 | 330篇 |
2021年 | 668篇 |
2020年 | 469篇 |
2019年 | 695篇 |
2018年 | 738篇 |
2017年 | 571篇 |
2016年 | 593篇 |
2015年 | 701篇 |
2014年 | 955篇 |
2013年 | 1489篇 |
2012年 | 2214篇 |
2011年 | 2216篇 |
2010年 | 1262篇 |
2009年 | 1128篇 |
2008年 | 1994篇 |
2007年 | 2139篇 |
2006年 | 2137篇 |
2005年 | 2072篇 |
2004年 | 1933篇 |
2003年 | 1784篇 |
2002年 | 1743篇 |
2001年 | 453篇 |
2000年 | 380篇 |
1999年 | 463篇 |
1998年 | 414篇 |
1997年 | 336篇 |
1996年 | 350篇 |
1995年 | 294篇 |
1994年 | 241篇 |
1993年 | 231篇 |
1992年 | 300篇 |
1991年 | 265篇 |
1990年 | 299篇 |
1989年 | 226篇 |
1988年 | 261篇 |
1987年 | 239篇 |
1986年 | 224篇 |
1985年 | 228篇 |
1984年 | 244篇 |
1983年 | 242篇 |
1982年 | 245篇 |
1981年 | 237篇 |
1980年 | 245篇 |
1979年 | 224篇 |
1978年 | 182篇 |
1977年 | 145篇 |
1976年 | 152篇 |
1974年 | 164篇 |
1973年 | 137篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Xingguang Luo Henry R Kranzler Lingjun Zuo Shuang Wang Joel Gelernter 《Neuropsychopharmacology》2007,61(5):599-608
BACKGROUND: Personality traits are associated with substance dependence (SD); genetic factors may influence both. Strong associations between ADH4 variation and SD have been reported. We aimed to investigate the relationship between ADH4 variation and personality traits in the present study. METHODS: We assessed dimensions of the five-factor model of personality in 243 subjects with SD (175 European Americans [EAs] and 68 African Americans [AAs]) and 296 healthy control subjects (256 EAs and 40 AAs). We also genotyped 7 ADH4 markers (spanning the locus) and 38 unlinked ancestry-informative markers in these subjects. The relationships between the diplotypes, alleles, and genotypes at ADH4 and personality traits were examined using multivariate analysis of covariance (MANCOVA), controlling for potential confounders. RESULTS: Generally, SD patients, older individuals, and male subjects scored higher on neuroticism and lower on other personality factors. Personality factors were associated with the diplotypes. The allele A or genotype A/A of single nucleotide polymorphism (SNP)6 (rs1800759 at the gene promoter) was significantly associated with agreeableness scores. There were associations between extraversion and SNP1 (hcv2033010 at the 3' end) and SNP2 (rs1042364 in exon 9) in subjects with higher conscientiousness scores. CONCLUSIONS: The personality traits of agreeableness and extraversion are related to ADH4 polymorphism. Among the ADH4 markers that appear to predispose to certain personality traits, the functional variant rs1800759 (SNP6) in the promoter region is most important. We conclude that personality traits and SD have a partially overlapping genetic basis. 相似文献
52.
Heather J Baer Graham A Colditz Walter C Willett Joanne F Dorgan 《Cancer epidemiology, biomarkers & prevention》2007,16(9):1880-1888
Greater body fatness during childhood is associated with reduced risk of premenopausal breast cancer, but few studies have addressed the relation of adiposity with sex hormones in girls. We prospectively examined associations between adiposity and circulating levels of sex hormones and sex hormone-binding globulin (SHBG) among 286 girls in the Dietary Intervention Study in Children. Participants were 8 to 10 years old at baseline and were followed for an average of 7 years. Anthropometric measurements were taken at baseline and at subsequent annual visits, and blood samples were collected every 2 years. Concentrations of dehydroepiandrosterone sulfate (DHEAS) during follow-up were higher among girls with greater body mass index (BMI) at baseline. The mean for the lowest BMI quartile was 63.0 microg/dL compared with 78.8 microg/dL for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with a 4.3% increase (95% confidence interval, 1.6-7.0%) in DHEAS levels during follow-up (P(trend) = 0.002). Concentrations of SHBG during follow-up were lower among girls with greater BMI at baseline. The mean for the lowest BMI quartile was 94.8 nmol compared with 57.5 nmol for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with an 8.8% decrease (95% confidence interval, 7.0-10.6%) in SHBG levels during follow-up (P(trend) < 0.0001). Estrogen and progesterone concentrations were similar across BMI quartiles. These findings suggest that adiposity may alter DHEAS and SHBG levels in girls. Whether and how these differences affect breast development and carcinogenesis requires further research. 相似文献
53.
54.
The climbing fibre projection from the motor cortex to the cerebellar cortical C1 zone in the posterior lobe of the rat cerebellum was investigated using a combination of physiological, anatomical and neuropharmacological techniques. Electrical stimulation of the ipsilateral fore- or hindimbs or somatotopically corresponding parts of the contralateral motor cortex evoked climbing fibre field potentials at the same cerebellar recording sites. Forelimb-related responses were located in the C1 zone in the paramedian lobule or lobulus simplex and hindlimb-related responses were located in the C1 zone in the copula pyramidis. Microinjections of anterograde axonal tracer (Fluoro-Ruby or Fluoro-Emerald) were made into the fore- or hindlimb parts of the motor cortex where stimulation evoked the largest cerebellar responses. After a survival period of 7–10 days, the neuraxis was examined for anterograde labelling. No terminal labelling was ever found in the inferior olive, but labelled terminals were consistently found in a well-localized site in the dorso-medial medulla, ventral to the gracile nucleus, termed the matrix region. Pharmacological inactivation of the matrix region (2 mm caudal to the obex) selectively reduced transmission in descending (cerebro-olivocerebellar) but not ascending (spino-olivocerebellar) paths targeting fore- or hindlimb-receiving parts of the C1 zone. Transmission in spino-olivocerebellar paths was either unaffected, or in some cases increased. The identification of a novel pre-olivary relay in cerebro-olivocerebellar paths originating from fore- and hindlimb motor cortex has implications for the regulation of transmission in climbing fibre pathways during voluntary movements and motor learning. 相似文献
55.
56.
57.
Reduced virulence of Candida albicans mutants affected in multidrug resistance. 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Disruption of a multidrug resistance gene (CaMDR1) in Candida albicans resulted in mutant strains that colonized mouse kidneys to very high levels but were markedly reduced in their virulence. No obvious differences in several properties related to colonization and dissemination were noted among MDR+ or mdr- strains. These results suggest that specific fungal efflux pumps play a role in fungal pathogenicity. 相似文献
58.
59.
Joanne F. Berson Robert W. Doms Deborah Long 《Perspectives in Drug Discovery and Design》1996,5(1):169-180
Summary The glycosphingolipid galactosylceramide (GalCer) has been identified as an alternate receptor for the human immunodeficiency virus type 1 (HIV-1). Here we review a liposome flotation assay used to study the interaction of the HIV-1 envelope glycoprotein (env) with artificial membrane vesicles containing GalCer. The properties of binding, the nature of the env binding site for GalCer, and the implications of this interaction for HIV-1 infection are discussed. 相似文献
60.
Camphor and m-cresol mixtures are used in antiseptic and anti-itching creams. No compendial method exists for these preparations. This paper reports a capillary gas chromatographic method using FID detection with 2,6-di-tert-butyl-4-methylphenol as internal standard on a 30 m×0.32 mm Supelcowax®-10 column (0.25 μm film) with helium as carrier gas. Ramped temperature programming was applied. The method allows simultaneous quantitation of camphor and m-cresol in the presence of o- and p-cresols, calamine and zinc oxide. Overall percent recoveries (±SD, n=9) of camphor, o-, p- and m-cresol from spiked placebo creams, at a labeled amount of 10 (w/w)% were 96.9±0.6, 98.2±0.6, 99.2±0.5 and 101.0±0.9%, respectively, and at a labeled amount of 1% were 96.7±0.6, 97.8±0.9, 97.8±0.6, and 100.3±1.0%, respectively. The recovery studies were carried out at ±30% of the labeled amounts. Linear peak area or height ratios were obtained (r>0.999) for camphor, o-, p- and m-cresol covering a concentration range of 10–200% of the labeled amount. Linearity (r>0.999) was also obtained for m-cresol when the relative concentration of o- and p-cresol was varied from 5 to 100% of the m-cresol concentration. The resolution between the ‘critical pair’ of p- and m-cresol was ≥1.1. The limit of quantitation was 23 pg for m-cresol and 9.3 pg for camphor using an injection split of 1:50. The repeatability (%RSD) for all compounds were <2% for peak area and <1.4% for peak height ratios. System suitability and robustness of the method were established. The method was successively applied to the assay of available commercial products and allows assay of camphor and the three cresol isomers. 相似文献