全文获取类型
收费全文 | 545篇 |
免费 | 22篇 |
国内免费 | 22篇 |
专业分类
儿科学 | 30篇 |
妇产科学 | 2篇 |
基础医学 | 66篇 |
口腔科学 | 10篇 |
临床医学 | 56篇 |
内科学 | 85篇 |
皮肤病学 | 3篇 |
神经病学 | 13篇 |
特种医学 | 183篇 |
外科学 | 29篇 |
综合类 | 4篇 |
预防医学 | 28篇 |
眼科学 | 7篇 |
药学 | 45篇 |
肿瘤学 | 28篇 |
出版年
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 16篇 |
2010年 | 16篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 27篇 |
2006年 | 11篇 |
2005年 | 19篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 1篇 |
2001年 | 12篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 32篇 |
1997年 | 44篇 |
1996年 | 25篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 19篇 |
1988年 | 26篇 |
1987年 | 16篇 |
1986年 | 19篇 |
1985年 | 23篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 16篇 |
1981年 | 7篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 14篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有589条查询结果,搜索用时 15 毫秒
91.
92.
CT模拟结肠镜在结肠病灶诊断中的应用 总被引:2,自引:0,他引:2
结肠癌是常见的消化道肿瘤,上海等地区的发病率有明显增高的趋势。在发达国家,结肠癌占肿瘤死亡率第二位,且与大肠腺瘤关系密切。如能早期发现有恶变先兆的息肉并切除之,可以预防结肠癌发生。目前,对结肠癌发病高危人群并未作大规模普查,部分由于患者缺乏早期主诉,或是由于现有普查手段不够有效。大便隐血试验只能发现30%~40%结肠肿瘤,乙状结肠镜不能进入近端结肠,并有10%~15%乙状结肠肿瘤漏诊。钡剂灌肠和结肠镜能检查全结肠,但有10%~15%患者行结肠镜检查失败,并且结肠镜可能使10%~20%病灶遗漏,尚… 相似文献
93.
94.
95.
GTA Jombo EM Mbaawuaga AN Gyuse MNO Enenebeaku EE Okwori EJ Peters S Akpan F Odey EA Etukumana JT Akosu 《Asian Pacific journal of tropical medicine》2010,3(5):402-406
ObjectiveTo ascertain the socio-cultural factors influencing the rate of utilization of insecticide treated bed nets (ITNs) in a malaria endemic city of Makurdi, north central Nigeria.MethodsThe study was cross-sectional in nature using systematic sampling method to identify households. Both quantitative and qualitative data was generated from adult women using structured and semi structured questionnaires, and focused group discussions (FGDs) to obtain information on rate and patterns of utilization of ITNs. Information such as age, educational level, marital status, awareness or otherwise of the existence of malaria, and factors influencing rate of ownership and utilization of ITNs were obtained. FGDs were used to obtain qualitative information on rate of utilization of ITNs not captured in the questionnaires. Data obtained was analysed using Epi Info 6 statistical software.ResultsAmong the respondents interviewed, 97.0% (2 013/2 075) were aware of existence of malaria and 87.0% of these (1 751/2 013) would associate it with mosquitoes. The rate of ownership of any bed net, ITNs and untreated bed nets (UTNs) was 25.1%, 17.0% and 8.3%, respectively. Utilization of ITNs among children was 30.0% (112/373) and UTNs 12.9% (48/373). Positive contributors to ITNs utilization were literacy, enhanced economy, experience of marriage, and being gainfully employed (P<0.05); while negative contributors were ignorance, poverty and some cultural beliefs and values.ConclusionsA more synchronized advocacy should be carried out on the potential benefits of ITNs utilization and sustained. Also ITNs should be made available to the people of the community at minimal or no cost. 相似文献
96.
97.
Marleen?J?NahuisEmail author Nienke?S?Weiss Fulco?van der Veen Ben?Willem?J?Mol Peter?G?Hompes Jur?Oosterhuis Nils?B?Lambalk Jesper?MJ?Smeenk Carolien?AM?Koks Ron?JT?van Golde Joop?SE?Laven Ben?J?Cohlen Kathrin?Fleischer Angelique?J?Goverde Marie?H?Gerards Nicole?F?Klijn Lizka?CM?Nekrui Ilse?AJ?van Rooij Diederik?A?Hoozemans Madelon?van Wely 《BMC women's health》2013,13(1):42
Background
Clomiphene citrate (CC) is first line treatment in women with World Health Organization (WHO) type II anovulation and polycystic ovary syndrome (PCOS). Whereas 60% to 85% of these women will ovulate on CC, only about one half will have conceived after six cycles. If women do not conceive, treatment can be continued with gonadotropins or intra-uterine insemination (IUI). At present, it is unclear for how many cycles ovulation induction with CC should be repeated, and when to switch to ovulation induction with gonadotropins and/or IUI.Methods/Design
We started a multicenter randomised controlled trial in the Netherlands comparing six cycles of CC plus intercourse or six cycles of gonadotrophins plus intercourse or six cycles of CC plus IUI or six cycles of gonadotrophins plus IUI.Women with WHO type II anovulation who ovulate but did not conceive after six ovulatory cycles of CC with a maximum of 150 mg daily for five days will be included.Our primary outcome is birth of a healthy child resulting from a pregnancy that was established in the first eight months after randomisation. Secondary outcomes are clinical pregnancy, miscarriage, multiple pregnancy and treatment costs. The analysis will be performed according to the intention to treat principle. Two comparisons will be made, one in which CC is compared to gonadotrophins and one in which the addition of IUI is compared to ovulation induction only. Assuming a live birth rate of 40% after CC, 55% after addition of IUI and 55% after ovulation induction with gonadotrophins, with an alpha of 5% and a power of 80%, we need to recruit 200 women per arm (800 women in total).An independent Data and Safety Monitoring Committee has criticized the data of the first 150 women and concluded that a sample size re-estimation should be performed after including 320 patients (i.e. 80 per arm).Discussion
The trial will provide evidence on the most effective, safest and most cost effective treatment in women with WHO type II anovulation who do not conceive after six ovulatory cycles with CC with a maximum of 150 mg daily for five days. This evidence could imply the need for changing our guidelines, which may cause a shift in large practice variation to evidence based primary treatment for these women.Trial registration number
Netherlands Trial register NTR144998.
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
99.
Mood and menopause: findings from the Study of Women's Health Across the Nation (SWAN) over 10 years
Women are twice as likely as men to suffer from depressive symptoms/disorder. Research has focused on physiologic and psychosocial differences between men and women; an important target of study has been periods of reproductive changes. Controversy has existed regarding the extent to which the menopausal transition or postmenopause increases the risk for depressive symptoms/disorders. This paper presents findings from analyses of data from the SWAN study and an ancillary study on mental health. We found that risk for high depressive symptoms and disorder is greater during and possibly after the menopausal transition. Other factors contribute to risk for depression. 相似文献
100.
The membrane mucin MUC4 is elevated in breast tumor lymph node metastases relative to matched primary tumors and confers aggressive properties to breast cancer cells
下载免费PDF全文
![点击此处可从《Breast cancer research : BCR》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Heather C Workman Jamie K Miller Ellen Q Ingalla Rouminder P Kaur Diane I Yamamoto Laurel A Beckett Lawrence JT Young Robert D Cardiff Alexander D Borowsky Kermit L Carraway Colleen Sweeney Kermit L Carraway III 《Breast cancer research : BCR》2009,11(5):R70