全文获取类型
收费全文 | 3009篇 |
免费 | 172篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 189篇 |
妇产科学 | 45篇 |
基础医学 | 437篇 |
口腔科学 | 58篇 |
临床医学 | 260篇 |
内科学 | 680篇 |
皮肤病学 | 44篇 |
神经病学 | 121篇 |
特种医学 | 515篇 |
外科学 | 266篇 |
综合类 | 33篇 |
一般理论 | 2篇 |
预防医学 | 142篇 |
眼科学 | 24篇 |
药学 | 150篇 |
中国医学 | 6篇 |
肿瘤学 | 228篇 |
出版年
2023年 | 10篇 |
2022年 | 30篇 |
2021年 | 31篇 |
2020年 | 28篇 |
2019年 | 33篇 |
2018年 | 63篇 |
2017年 | 41篇 |
2016年 | 60篇 |
2015年 | 70篇 |
2014年 | 86篇 |
2013年 | 117篇 |
2012年 | 136篇 |
2011年 | 119篇 |
2010年 | 127篇 |
2009年 | 124篇 |
2008年 | 106篇 |
2007年 | 104篇 |
2006年 | 86篇 |
2005年 | 82篇 |
2004年 | 69篇 |
2003年 | 64篇 |
2002年 | 61篇 |
2001年 | 42篇 |
2000年 | 66篇 |
1999年 | 58篇 |
1998年 | 148篇 |
1997年 | 129篇 |
1996年 | 129篇 |
1995年 | 95篇 |
1994年 | 87篇 |
1993年 | 87篇 |
1992年 | 35篇 |
1991年 | 35篇 |
1990年 | 29篇 |
1989年 | 74篇 |
1988年 | 53篇 |
1987年 | 55篇 |
1986年 | 52篇 |
1985年 | 56篇 |
1984年 | 35篇 |
1983年 | 41篇 |
1982年 | 40篇 |
1981年 | 25篇 |
1980年 | 39篇 |
1979年 | 19篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 27篇 |
1975年 | 29篇 |
1966年 | 5篇 |
排序方式: 共有3206条查询结果,搜索用时 0 毫秒
1.
Michelle L. DeOliveira Timothy M. Pawlik Ana L. Gleisner Lia Assumpcaom Gaspar J. Lopes-Filho Michael A. Choti 《Journal of gastrointestinal surgery》2007,11(8):970-976
Survival after resection of colorectal liver metastases has traditionally been associated with clinicopathologic factors.
We sought to investigate whether echogenicity of colorectal liver metastasis as assessed by intraoperative ultrasound (IOUS)
was a prognostic factor after hepatic resection. Prospective data on tumor IOUS appearance were collected in 84 patients who
underwent hepatic resection for colorectal liver metastasis. Images were digitally recorded, blindly reviewed, and scored
for echogenicity (hypo-, iso-, or hyperechoic). The median tumor number was 1 and the median tumor size was 5.0 cm. At the
time of surgery, the IOUS appearance of the colorectal liver metastases were hypoechoic in 35 (41.7%) patients, isoechoic
in 37 (44.0%) patients, and hyperechoic in 12 (14.3%) patients. Traditional clinicopathologic prognostic factors were similarly
distributed among the three echogenicity groups (all p > 0.05). Patients with a hypoechoic lesion had a significantly shorter median survival (30.2 months) compared with patients
who had either an isoechoic (53.2 months) or hyperechoic (42.3 months) lesion (p = 0.005). The 5-year survival after hepatic resection of colorectal liver metastasis was also associated with the echogenic
appearance of the lesion (hypoechoic 14.4 vs isoechoic 37.4 vs hyperechoic 46.2%) (p < 0.05). Intraoperative ultrasound echogenicity should be considered a prognostic factor after hepatic resection of metastatic
colorectal cancer.
This study was presented at the 47th annual meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, CA, USA,
22 May 2006. 相似文献
2.
Susi Elaine Dal''Belo Lorena Rigo Gaspar Patrícia Maria Berardo Gonçalves Maia Campos 《Skin research and technology》2006,12(4):241-246
BACKGROUND/PURPOSE: The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques. METHODS: Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.10%, 0.25% or 0.50% (w/w) of freeze-dried Aloe vera extract and applied to the volar forearm of 20 female subjects. Skin conditions in terms of the water content of the stratum corneum and of transepidermal water loss (TEWL) (Corneometer CM 825 and Tewameter TM 210) were analysed before and after a single and 1- and 2-week period of daily application. RESULTS: After a single application, only formulations supplemented with 0.25% and 0.50% (w/w) of Aloe vera extract increased the water content of the stratum corneum, while after the 2-week period application, all formulations containing the extract (0.10%, 0.25% and 0.50%) had the same effect, in both cases as compared with the vehicle. TEWL was not modified after a single and after 1- and 2-week period of application, when compared with the vehicle. CONCLUSION: Our results show that freeze-dried Aloe vera extract is a natural effective ingredient for improving skin hydration, possibly through a humectant mechanism. Consequently, it may be used in moisturizing cosmetic formulations and also as a complement in the treatment of dry skin. 相似文献
3.
4.
5.
6.
Michelle Lucinda DeOliveira M.D. Tarcisio Triviño M.D. Ph.D. Gaspar de Jesus Lopes Filho M.D. Ph.D. 《Journal of gastrointestinal surgery》2006,10(8):1140-1143
Carcinoma of the papilla of Vater is classified as periampullary cancer representing 5% of all gastrointestinal tract malignancies.
Early and accurate diagnosis is important for those patients with a tumor of the papilla, as the prognosis is more favorable
than in other periampullary neoplasms. Endoscopically obtained biopsies from suspicious papillae can detect an early tumor,
although even for skilled pathologists it is often difficult to differentiate carcinomas from noninvasive lesions on the basis
of forceps biopsies. The purpose of this study was to assess the preoperative diagnostic accuracy of duodenoscopy appearance
and biopsy in all cases with suspicion of tumor. Thirty patients with suspicion of carcinoma of the papilla of Vater and with
final diagnosis established by pancreatoduodenectomy were included in this retrospective study. In each case, a comparison
was made between endoscopic biopsy and duodenoscopic appearance. Duodenoscopic appearance sensitivity and accuracy for malignancy
were 86% and 83%, respectively, whereas endoscopic biopsy sensitivity and accuracy were 65% and 67%, respectively. Although
preoperative diagnosis of carcinoma of the papilla of Vater is useful for making therapeutic decisions, the diagnostic value
of the endoscopic appearance was superior to endoscopic biopsy in this series.
Presented at the 2003 American Hepato-Pancreato-Biliary Association Congress, Miami, Florida, February 27-March 3, 2003.
Supported by FADA-CAPES/PROP 200J (M.L.D.). 相似文献
7.
J.Martinez Calatayud C.Gomez Benito D.Gaspar Gimenez 《Journal of pharmaceutical and biomedical analysis》1990,8(8-12):667-670
A flow injection-fluorimetric determination of thiamine is reported. The procedure is based on the oxidation of the analyte with potassium hexacyanoferrate(III) immobilized on an anionic exchange resin; the fluorescence is monitored in aqueous basic solution. Concentrations of the vitamin of 0.1–4 ppm have been determined; the relative standard deviation was 1.8%. The injection rate was 28 samples/h. The influence of other substances and the determination of the drug in a pharmaceutical formulation are also reported. 相似文献
8.
We report an adult female with a rare giant choledochal cyst. The patient presented following a normal pregnancy with the classical triad of an abdominal mass associated with jaundice and right upper quadrant abdominal pain. The cyst was excised using an intramural technique and biliary reconstruction achieved with a Roux-en-Y hepaticojejunostomy. Our patient has remained well with no evidence of malignancy over a 12 year review period. The aetiology and current management of this condition are discussed. 相似文献
9.
10.
Na+ dependence of in vitro pancreatic amylase release 总被引:1,自引:0,他引:1