全文获取类型
收费全文 | 683篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 16篇 |
妇产科学 | 5篇 |
基础医学 | 61篇 |
口腔科学 | 6篇 |
临床医学 | 36篇 |
内科学 | 77篇 |
皮肤病学 | 1篇 |
神经病学 | 179篇 |
特种医学 | 97篇 |
外科学 | 14篇 |
综合类 | 32篇 |
预防医学 | 13篇 |
药学 | 122篇 |
中国医学 | 1篇 |
肿瘤学 | 56篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 6篇 |
2007年 | 18篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 14篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1992年 | 26篇 |
1991年 | 31篇 |
1990年 | 33篇 |
1989年 | 40篇 |
1988年 | 50篇 |
1987年 | 32篇 |
1986年 | 60篇 |
1985年 | 40篇 |
1984年 | 30篇 |
1983年 | 21篇 |
1982年 | 17篇 |
1981年 | 18篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1977年 | 13篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1966年 | 1篇 |
排序方式: 共有717条查询结果,搜索用时 93 毫秒
131.
L Han D A Nielsen N E Rosenthal K Jefferson W Kaye D Murphy M Altemus J Humphries G Cassano A Rotondo M Virkkunen M Linnoila D Goldman 《Neuropsychopharmacology》1999,45(5):615-619
BACKGROUND: The goal of this study was to evaluate the role of genetic variation in the coding sequence of tryptophan hydroxylase (TPH) in the pathogenesis of several psychiatric diseases in which altered serotonin function has been implicated: bipolar affective disorder (BP), obsessive-compulsive disorder (OCD), anorexia nervosa (AN), seasonal affective disorder (SAD), panic disorder (PD), and alcoholism (Alc). METHODS: Ninety-three percent of the TPH coding sequence was screened by polymerase chain reaction single-strand conformation polymorphism (SSCP) for DNA sequence variations in 128 AN, 88 OCD, 72 SAD, 45 PD, and 36 BP patients and 142 normal volunteers. Also included in the screening were 61 Alc randomly selected from a Finnish alcoholic population in which an association of a TPH intron 7 polymorphism with suicidality was previously observed. Polymorphisms detected by SSCP were characterized by DNA sequencing and by allele-specific restriction enzyme digestion. Genotyping was then performed in 34 Finnish alcoholic suicide attempters. RESULTS: A rare silent mutation was identified in exon 10 and is designated T1095C. The C1095 allele was found in 1 OCD and in 2 AN subjects; all 3 individuals were heterozygous (C1095/T1095) for the variant allele. No association was observed between this TPH T1095C variant with either OCD, AN, Alc, or suicidality. CONCLUSION: These results suggest that the coding sequence of the TPH gene does not contain abundant variants, and may not play a major role in vulnerability to several psychopathologies in which reduced serotonin turnover has been implicated. 相似文献
132.
First rotavirus vaccine licensed: Is there really a need? 总被引:6,自引:0,他引:6
RI Glass JS Bresee UD Parashar RC Holman JR Gentsch 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(S426):2-8
The first rotavirus vaccine was licensed in the United States on 31 August 1998 for the prevention of severe rotavius diarrhea in children. Despite this landmark in new vaccines, many pediatricians and public health professionals in Europe are uncertain of the need for this vaccine for the routine immunization of infants. In Europe, ample evidence suggests that rotavirus is the most common cause of hospitalizations for severe diarrhea among children, but proper studies documenting the disease burden of rotavirus or th cost-effectiveness of a rotavirus immunization program have only been conducted in the United Kingdom following epidemiologic models used in the United States. All children are infected with rotavirus during their first few years of life, 30-50% of diarrheal hospitalizations among children <5 years are due to this agent, and, by the age of 5 years, between 1 in 40 and 1 in 77 children in Europe and the United States may be hospitalized for rotavirus. The first vaccine is a live, oral preparation combining four different serotypes of rotavirus and administered in three doses with other childhood immunizations. The good efficacy against severe rotavirus diarrhea, the low risk of adverse side effects and the positive costeffectiveness equation have led the two major immunization advisory groups in the U.S. to recommend this vaccine for routine use in American infants. European physicians and policymakers should re-examine the epidemiology and disease burden of rotavirus diarrhea now that an effective method of prevention is at hand. □ Childhood immunization, diseases, rotavirus, vaccination . 相似文献
133.
K B Zajicek C S Price S E Shoaf P T Mehlman S J Suomi M Linnoila J D Higley 《Neuropsychopharmacology》2000,22(3):240-250
Seasonal changes in cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) concentrations were assessed on multiple occasions in 103 free-ranging male rhesus macaques (Macaca mulatta). At the time of sampling subjects ranged between the ages of 2 and 6 years. CSF samples were collected between the hours of 0900 and 1600 throughout the Fall, Winter, and Spring from 1990 through 1994. Data were analyzed in a general linear mixed model with random intercepts. Results indicated that CSF 5-HIAA concentrations decreased with age. CSF 5-HIAA concentrations were significantly increased in the Fall (October and November), which is the height of the breeding season, with no evidence of differences between Winter and Spring. There was also some evidence that the seasonal variation in CSF 5-HIAA concentrations was blunted in younger, more immature subjects. 相似文献
134.
A relationship between serotonin transporter genotype and in vivo protein expression and alcohol neurotoxicity. 总被引:22,自引:0,他引:22
A Heinz D W Jones C Mazzanti D Goldman P Ragan D Hommer M Linnoila D R Weinberger 《Neuropsychopharmacology》2000,47(7):643-649
BACKGROUND: Genetic variation of the promoter for the serotonin transporter (5-HTT) gene has been associated with its functional capacity. In vitro, carriers of a short allele (s-carriers) of the 5-HTT promoter display significant reduction in 5-HTT capacity. Dysfunction of 5-HTT has been observed in alcoholic individuals. We assessed whether the allelic constitution of the 5-HTT gene is associated with reduced serotonin transporter availability among alcoholic individuals. METHODS: We genotyped the 5-HTT promoter region and measured the availability of serotonin transporter protein with [I-123]beta-CIT SPECT in the raphe area in 14 abstinent male alcoholic subjects and 8 age-matched control subjects of European American descent. RESULTS: Among control subjects, the ratio of in vivo 5-HTT availability for ll-homozygous individuals relative to s-carriers was comparable to serotonin uptake ratios measured in vitro. There was a significant interaction of diagnosis and 5-HTT promoter genotype on 5-HTT availability (p <.01). Among controls, ll-homozygous individuals displayed a significant increase as compared with s-carriers. The availability of raphe 5-HTT was significantly reduced in ll-homozygous alcoholic individuals and was negatively correlated with their amount of alcohol consumption. Among s-carriers, 5-HTT availability did not differ significantly between control and alcoholic subjects. CONCLUSIONS: Our preliminary findings suggest an association between 5-HTT allelic constitution and in vivo measurements of human serotonin transporter availability, and a potentially selective susceptibility of ll-homozygous individuals to the neurotoxic effects of chronic excessive alcohol consumption. 相似文献
135.
136.
137.
Maier CR Hollander MC Hobbs EA Dogan I Linnoila RI Dennis PA 《Cancer prevention research (Philadelphia, Pa.)》2011,4(11):1743-1751
Smoking is the leading cause of preventable cancer deaths in the United States. Nicotine replacement therapies (NRT) have been developed to aid in smoking cessation, which decreases lung cancer incidence. However, the safety of NRT is controversial because numerous preclinical studies have shown that nicotine enhances tumor cell growth in vitro and in vivo. We modeled NRT in mice to determine the effects of physiologic levels of nicotine on lung tumor formation, tumor growth, or metastasis. Nicotine administered in drinking water did not enhance lung tumorigenesis after treatment with the tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Tumors that develop in this model have mutations in K-ras, which is commonly observed in smoking-related, human lung adenocarcinomas. In a transgenic model of mutant K-ras-driven lung cancer, nicotine did not increase tumor number or size and did not affect overall survival. Likewise, in a syngeneic model using lung cancer cell lines derived from NNK-treated mice, oral nicotine did not enhance tumor growth or metastasis. These data show that nicotine does not enhance lung tumorigenesis when given to achieve levels comparable with those of NRT, suggesting that nicotine has a dose threshold, below which it has no appreciable effect. These studies are consistent with epidemiologic data showing that NRT does not enhance lung cancer risk in former smokers. 相似文献
138.
139.
Xiao-Yang Wang Luiz OF Penalva Hongyan Yuan R Ilona Linnoila Jiachun Lu Hideyuki Okano Robert I Glazer 《Molecular cancer》2010,9(1):221
Background
Musashi1 (Msi1) is a conserved RNA-binding protein that regulates the Notch and Wnt pathways, and serves as a stem cell marker in the breast and other tissues. It is unknown how Msi1 relates to other breast cancer markers, whether it denotes tumor initiating cells (TICs), and how it affects gene expression and tumor cell survival in breast cancer cells. 相似文献140.
MA Islam RI Chowdhury N Chakraborty W Bari HH Akhter 《The European journal of contraception & reproductive health care》2013,18(4):203-213
Objectives There are only a few studies on maternal morbidity, delivery complications and maternal mortality in Bangladesh. This study analyzes data from a follow-up study conducted by the Bangladesh Institute of Research for Health and Technologies (BIRPERHT) on maternal morbidity in rural Bangladesh in 1993. Methods A total of 1020 pregnant women were interviewed in the follow-up component of the study. The survey collected information on socioeconomic and demographic characteristics, pregnancy-related care and practice, morbidity during the period of follow-up as well as in the past, information concerning complications at the time of delivery and during the postpartum period. For the purpose of this study, we selected 993 pregnant women with at least one antenatal follow-up. Both bivariate and multivariate analyses were conducted to identify the potential risk factors for complication during delivery and duration of labor. Results and conclusions It appears that complications during the antenatal period can result in various complications at the time of delivery. Some of the important findings are: hemorrhage during the antenatal period increases the risk of excessive hemorrhage during delivery, the risk of obstructed labor increases significantly if abdominal pain is observed during the antenatal period, prolonged labor appears to be significantly higher for the first pregnancy, and pregnancies suffering from abdominal pain during pregnancy tend to have a higher risk of prolonged labor during delivery. The duration of labor appears to be negatively associated with the number of previous pregnancies, being longest for the first pregnancies. The duration of labor pain is significantly higher for the respondents who reported the index pregnancy as undesired, and, similarly, the respondents who were reported to be involved with gainful employment would have a shorter duration of labor pain than those having no involvement with gainful employment. 相似文献