全文获取类型
收费全文 | 878篇 |
免费 | 47篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 47篇 |
妇产科学 | 27篇 |
基础医学 | 84篇 |
口腔科学 | 38篇 |
临床医学 | 95篇 |
内科学 | 211篇 |
皮肤病学 | 16篇 |
神经病学 | 31篇 |
特种医学 | 116篇 |
外科学 | 118篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 63篇 |
眼科学 | 3篇 |
药学 | 59篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 50篇 |
出版年
2023年 | 8篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 23篇 |
2013年 | 42篇 |
2012年 | 23篇 |
2011年 | 25篇 |
2010年 | 24篇 |
2009年 | 23篇 |
2008年 | 15篇 |
2007年 | 46篇 |
2006年 | 25篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 20篇 |
1998年 | 48篇 |
1997年 | 52篇 |
1996年 | 62篇 |
1995年 | 47篇 |
1994年 | 30篇 |
1993年 | 33篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 19篇 |
1988年 | 29篇 |
1987年 | 26篇 |
1986年 | 15篇 |
1985年 | 18篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1975年 | 5篇 |
1971年 | 4篇 |
1968年 | 7篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有973条查询结果,搜索用时 0 毫秒
61.
62.
Sanna A Adani GL Anania G Donini A 《Journal of laparoendoscopic & advanced surgical techniques. Part A》2003,13(1):17-19
PURPOSE: In this report, we retrospectively evaluate the effect of a laparoscopic approach in the diagnosis and treatment of acute abdominal pain in patients with suspected peritonitis. PATIENTS AND METHODS: We evaluated the clinical records of patients admitted to our institution between January 1995 and July 2001 with a diagnosis of acute abdomen and suspected peritonitis. RESULTS: Ninety four of 229 patients underwent diagnostic laparoscopy. In this series, 83 (88.3%) of the cases were successfully treated by emergent laparoscopy for an acute abdomen. Eleven (11.7%) required conversion to an open laparotomy procedure. Overall, the preoperative diagnosis was confirmed by laparoscopy in 67 (71.27%) of the cases. It was not confirmed in 27 (28.73%). Postoperative mortality was 4.25%. Morbidity was 8.5%. DISCUSSION: Data reported in the literature establish that laparoscopy offers adequate visualization of the entire abdomen and pelvic cavity in the diagnosis of an abdomen acute secondary to peritonitis. In this series, laparoscopy confirmed the diagnosis in 97.8% of the patients, and minimally invasive treatment was achieved in 88.3% of the cases. Female patients with gynecologic disease particularly benefitted from a laparoscopic approach, which permitted the correct evaluation of this condition and may have prevented unnecessary laparotomy. We believe that laparoscopy is an accurate modality for the diagnosis and treatment of patients with an acute abdomen and suspected peritonitis when the diagnosis cannot be clearly made by physical examination and noninvasive methods. 相似文献
63.
64.
65.
Understanding diet and energy balance as risk factors for breast, colon,
and other cancers requires information on the contribution of each factor
and of interactions among factors to cancer risk. Rodent models for breast
cancer provide extensive data on effects of dietary fat and calories,
energy balance, body weight gain, and physical activity on tumor
development. Analyses of the combined data from many studies have shown
clearly that quality and quantity of dietary fat and energy balance
contribute independently to increased mammary gland tumorigenesis. These
findings were seen in female rats fed diets high in fat (35-40% of
calories) compared to rats fed control diets, with approximately 10% of
calories as fat (Fay and Freedman, 1997, Breast Cancer Res. Treat. 46,
215-223). The methods used permit comparison of experimental and
epidemiological data, and they may be useful in extrapolating between
species and developing public health recommendations. In addition to the
contributions of lifetime-diet composition, intake, energy balance, and
physical activity to cancer risk, there are questions about the timing and
duration of alterations in these factors and about the "dose-response"
characteristics of cancer risk to the factors. Endocrine mechanisms may be
significant in mammary gland tumor risk, but experimental and
epidemiological data indicate that cancers at other sites, such as colon
and liver, also are influenced by the factors listed. Other diet and
lifestyle factors that influence energy, or specifically fat, metabolism
may also affect risk for cancers that are promoted by increased intake of
fat and calories. Studies of separate and interactive effects of dietary
fat, black tea, weight gain, and mammary gland tumorigenesis (Rogers, et
al, 1998, Carcinogenesis 19, 1269-1273) have been analyzed. Using
adjustment of carcinogenesis endpoints for body weight, tumor burden, and
latency, they were found to be related to weight gain within treatment
groups in 2 of 3 experiments.
相似文献
66.
Background
Postal questionnaires are an economical and simple method of data collection for research purposes but are subject to non-response bias. Several studies have explored the effect of monetary and non-monetary incentives on response. Recent meta-analyses conclude that financial incentives are an effective way of increasing response rates. However, large surveys rarely have the resources to reward individual participants. Three previous papers report on the effectiveness of lottery incentives with contradictory results. This study aimed to determine the effect of including a lottery-style incentive on response rates to a postal health survey.Methods
Randomised controlled trial. Setting: North and West Birmingham. 8,645 patients aged 18 or over randomly selected from registers of eight general practices (family physician practices). Intervention: Inclusion of a flyer and letter with a health questionnaire informing patients that returned questionnaires would be entered into a lottery-style draw for £100 of gift vouchers. Control: Health questionnaire accompanied only by standard letter of explanation. Main outcome measures: Response rate and completion rate to questionnaire.Results
5,209 individuals responded with identical rates in both groups (62.1%). Practice, patient age, sex and Townsend score (a postcode based deprivation measure) were identified as predictive of response, with higher response related to older age, being female and living in an area with a lower Townsend score (less deprived).Conclusion
This RCT, using a large community based sample, found that the offer of entry into a lottery style draw for £100 of High Street vouchers has no effect on response rates to a postal health questionnaire. 相似文献67.
68.
69.
70.