全文获取类型
收费全文 | 3662篇 |
免费 | 254篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 160篇 |
妇产科学 | 62篇 |
基础医学 | 258篇 |
口腔科学 | 79篇 |
临床医学 | 413篇 |
内科学 | 698篇 |
皮肤病学 | 55篇 |
神经病学 | 265篇 |
特种医学 | 753篇 |
外科学 | 564篇 |
综合类 | 131篇 |
一般理论 | 2篇 |
预防医学 | 263篇 |
眼科学 | 19篇 |
药学 | 94篇 |
中国医学 | 3篇 |
肿瘤学 | 130篇 |
出版年
2023年 | 18篇 |
2022年 | 13篇 |
2021年 | 38篇 |
2020年 | 26篇 |
2019年 | 43篇 |
2018年 | 64篇 |
2017年 | 54篇 |
2016年 | 58篇 |
2015年 | 51篇 |
2014年 | 114篇 |
2013年 | 137篇 |
2012年 | 118篇 |
2011年 | 125篇 |
2010年 | 131篇 |
2009年 | 132篇 |
2008年 | 127篇 |
2007年 | 181篇 |
2006年 | 141篇 |
2005年 | 143篇 |
2004年 | 121篇 |
2003年 | 105篇 |
2002年 | 95篇 |
2001年 | 117篇 |
2000年 | 95篇 |
1999年 | 97篇 |
1998年 | 99篇 |
1997年 | 84篇 |
1996年 | 91篇 |
1995年 | 73篇 |
1994年 | 68篇 |
1993年 | 67篇 |
1992年 | 95篇 |
1991年 | 71篇 |
1990年 | 90篇 |
1989年 | 96篇 |
1988年 | 98篇 |
1987年 | 89篇 |
1986年 | 94篇 |
1985年 | 79篇 |
1984年 | 54篇 |
1983年 | 43篇 |
1982年 | 25篇 |
1981年 | 19篇 |
1980年 | 25篇 |
1979年 | 30篇 |
1978年 | 44篇 |
1977年 | 31篇 |
1976年 | 33篇 |
1975年 | 33篇 |
1974年 | 22篇 |
排序方式: 共有3965条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Snuff use and smoking among senior high school students: effects of a snuff sales ban 总被引:1,自引:0,他引:1
OBJECTIVES: The popularity of snuff especially among adolescents is rising. The association between long-term snuff use and oral cancer discovered in epidemiological studies has prompted a variety of preventive measures to be taken to reduce snuff use and prevent adoption of the habit. In this study, the effect of a recent (I March, 1995) snuff sales ban introduced in Finland was investigated. Further, the rates of smoking, snuff use, alcohol use and drug experimenting were investigated before the introduction of the ban to characterize the study population.
DESIGN AND SUBJECTS: Two questionnaire studies were carried out. The first was carried out 3 months prior to the ban in 1994 and the second 9 months after the ban in 1995 in a senior high school population in southwestern Finland. The participants were 793 students (aged 15–22 years) in the first survey and 545 students (aged 16–23) in the second. Associations between variables were analyzed using cross-tabulation and stepwise logistic regression. The effects of the ban were determined on the basis of direct questions in the second questionnaire relating to the snuff sales ban.
RESULTS: Snuff was used by 9% of the students participating in the first study. The results of the second questionnaire indicate that the implementation of the snuff sales ban reduced the rate of snuff use by 1% in the study population. The majority of the snuff users (76%) reported that they had maintained their snuff habit. Of those reporting that they were snuff users before implementation of the snuff sales ban, 12% had switched to smoking and 5% to drugs.
CONCLUSIONS: The results of the present study suggest that the snuff sales ban in this population with a high rate of snuff use had little effect on snuff use rates and may have some short-term negative consequences as some snuff users switch to other substitutes, such as smoking, with known adverse health effects. 相似文献
DESIGN AND SUBJECTS: Two questionnaire studies were carried out. The first was carried out 3 months prior to the ban in 1994 and the second 9 months after the ban in 1995 in a senior high school population in southwestern Finland. The participants were 793 students (aged 15–22 years) in the first survey and 545 students (aged 16–23) in the second. Associations between variables were analyzed using cross-tabulation and stepwise logistic regression. The effects of the ban were determined on the basis of direct questions in the second questionnaire relating to the snuff sales ban.
RESULTS: Snuff was used by 9% of the students participating in the first study. The results of the second questionnaire indicate that the implementation of the snuff sales ban reduced the rate of snuff use by 1% in the study population. The majority of the snuff users (76%) reported that they had maintained their snuff habit. Of those reporting that they were snuff users before implementation of the snuff sales ban, 12% had switched to smoking and 5% to drugs.
CONCLUSIONS: The results of the present study suggest that the snuff sales ban in this population with a high rate of snuff use had little effect on snuff use rates and may have some short-term negative consequences as some snuff users switch to other substitutes, such as smoking, with known adverse health effects. 相似文献
7.
8.
Marwan SM Al-Nimer 《World journal of diabetes》2022,13(5):417-419
Hyperandrogenism and hyperinsulinemia have resulted from dysfunction of the theca cell of the ovary and adipose tissue and each one potentiates the other in patients with androgen excess disorders e.g., polycystic ovary disease and idiopathic hirsutism. Possible external and/or internal triggers can produce such cellular dysfunction. There is evidence that sodium valproate acts as a trigger of cellular dysfunction and produces both hyperinsulinemia and hyperandrogenism. Therefore, the elimination of these triggers can help the patients to recover from hyperinsulinemia, insulin resistance and hyperandrogenism. 相似文献
9.
Niveditha Girimaji Sakthivel Murugan SM Ritambhra Nada Ashish Sharma Manish Rathi Harbir S. Kohli Krishna L. Gupta Raja Ramachandran 《Nephrology (Carlton, Vic.)》2020,25(6):497-501
Alport syndrome (AS) is an inherited disorder of basement membranes caused by mutations affecting specific proteins of the type IV collagen family, presenting with nephropathy and extrarenal manifestations such as sensorineural deafness and ocular anomalies. Ten percentage to 15% of the patients with AS have autosomal recessive (ARAS) due to mutation in either COL4A3 or COL4A4 gene. We report a novel mutation in the COL4A3 gene in an Indian family with ARAS. The above‐mentioned genetic anomaly was a missense variation in exon 26 of the COL4A3 gene (chr2:228137797G>A; c.1891G>A) that resulted in the amino acid substitution of Arginine for Glycine at codon 631 (p.Gly631Arg) that was present in the heterozygous state in the asymptomatic parents and homozygous state in the male offspring who presented with early‐onset end‐stage renal disease, lenticonus and hearing loss. The patient (male offspring) underwent successful renal transplantation with his mother as a donor. 相似文献
10.