全文获取类型
收费全文 | 1658篇 |
免费 | 98篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 151篇 |
妇产科学 | 17篇 |
基础医学 | 171篇 |
口腔科学 | 47篇 |
临床医学 | 158篇 |
内科学 | 365篇 |
皮肤病学 | 23篇 |
神经病学 | 55篇 |
特种医学 | 474篇 |
外科学 | 102篇 |
综合类 | 28篇 |
预防医学 | 44篇 |
眼科学 | 13篇 |
药学 | 52篇 |
中国医学 | 3篇 |
肿瘤学 | 72篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 10篇 |
2016年 | 22篇 |
2015年 | 29篇 |
2014年 | 28篇 |
2013年 | 56篇 |
2012年 | 21篇 |
2011年 | 20篇 |
2010年 | 72篇 |
2009年 | 56篇 |
2008年 | 31篇 |
2007年 | 23篇 |
2006年 | 27篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 13篇 |
2002年 | 20篇 |
2001年 | 16篇 |
2000年 | 21篇 |
1999年 | 25篇 |
1998年 | 133篇 |
1997年 | 118篇 |
1996年 | 125篇 |
1995年 | 92篇 |
1994年 | 77篇 |
1993年 | 81篇 |
1992年 | 24篇 |
1991年 | 30篇 |
1990年 | 17篇 |
1989年 | 66篇 |
1988年 | 45篇 |
1987年 | 49篇 |
1986年 | 46篇 |
1985年 | 48篇 |
1984年 | 26篇 |
1983年 | 33篇 |
1982年 | 34篇 |
1981年 | 20篇 |
1980年 | 36篇 |
1979年 | 14篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 23篇 |
1975年 | 25篇 |
1971年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有1778条查询结果,搜索用时 15 毫秒
101.
CT evaluation of complications of abdominal aortic surgery 总被引:5,自引:0,他引:5
102.
Arnstein NB; Shapiro B; Ekhauser FE; Dmuchowski CF; Knol JA; Strodel WE; Nakajo M; Swanson DP 《Radiology》1985,156(2):501-504
Mechanisms by which gastroplasty for morbid obesity causes weight loss are poorly understood. We studied the role of altered gastric emptying in 50 patients before surgery, 1-4 weeks after surgery, and 2-24 months after surgery using technetium-99m pentetate in water for liquid meals and a Tc-99m styrene divinylbenzene copolymer resin in oatmeal for semisolid meals. We determined the emptying half-times of the stomach before and after surgery in the proximal and distal compartments. The proximal compartment emptied promptly in the early and late postoperative periods. The distal compartment emptied liquids at rates similar to those before surgery, while the late postoperative emptying of semisolids was significantly faster. The stoma connecting the two compartments thus permits rapid transit of liquids and semisolids without delay of distal compartment emptying. No correlation was seen between the emptying half-times or changes thereof and eventual weight loss. Delayed gastric emptying is therefore not the mechanism for satiety and weight loss after gastroplasty has been performed. 相似文献
103.
104.
Gonzalez-Reyes S Fernandez-Dumont V Martinez-Calonge W Martinez L Hernandez F Tovar J 《Pediatric surgery international》2005,21(3):203-207
Rats with nitrofen-induced congenital diaphragmatic hernia (CDH) have heart hypoplasia and cardiovascular malformations. The mechanism of action of nitrofen involves changes in neural crest signaling. Pax3 function is required for cardiac neural crest cells to complete their migration to the developing heart. The aim of this study was to examine whether Pax3 expression is changed at two gestational endpoints in rat embryos or fetuses exposed to nitrofen. On day E9.5 of gestation, pregnant rats received either 100 mg of nitrofen (n=10) or vehicle alone (control, n=10). The fetuses were recovered on E15 or E21. Their hearts were dissected out and weighed. Pax3 mRNA expression was determined by real-time polymerase chain reaction. We used two-tailed Students t-tests to compare groups, with a threshold of significance of p<0.05. Compared with controls, nitrofen-exposed fetuses had heart hypoplasia in terms of heart/body weight ratio (0.62±0.10% vs. 0.77±0.17%, p<0.05). Pax3 mRNA expression in the heart was significantly decreased on E15 in nitrofen-treated embryos (32.94±17.11 U vs. 55.09±11.56 U, p<0.05), and it was still decreased, although not significantly, in the hearts of nitrofen-exposed fetuses recovered on E21 (15.67±5.56 U vs. 20.51±5.92 U, not significant). In conclusion, Pax3 is underexpressed in the hearts of nitrofen-exposed embryonal rats before the end of gestation. The mechanism of action of Pax3 should be further investigated because it could be one of the targets for future prenatal transplacental intervention.Paper presented at the XVIIth International Symposium of Pediatric Surgical Research, Liverpool, United Kingdom, 1–2 October, 2004. 相似文献
105.
McCullough JA Evoy D Sweeney KJ Meyers C Ravi N Keeling N Byrne PJ Reynolds JV 《Irish journal of medical science》2003,172(3):132-135
Background Gastric carcinoma is a significant cause of death in Ireland. Surgery offers the best option of cure, but the five-year survival
following resection remains dismal at 10–15%. Experience from Japan and from some Western units suggest that an extended (D2)
lymphadenectomy in association with gastrectomy increases the prospect of cure, but concern about the morbidity and mortality
of this operation and lack of evidence from randomised studies has limited its acceptance.
Aims This study reports the experience of a specialist upper gastrointestinal unit with D2 gastrectomy in a four-year audit.
Methods Sixty-two resections were performed for gastric cancer. Results Nineteen patients were deemed unsuitable for the D2 procedure
and underwent a more limited lymphadenectomy (DO or D1). Forty-three patients underwent D2 resection, 12 with an oesophagogastrectomy,
22 with total gastrectomy and nine with a sub-total distal resection. Eight patients undergoing D2 resection had extended
resections, five with splenectomy and three with a distal pancreatectomy. Post-operative complications occurred in 31% of
patients. Thirty-day and 90-day mortality were zero. Median survival was 822 days in the D2 group (range 120–1,320).
Conclusions These results show that a D2 gastrectomy can be performed with a low morbidity and mortality and a median survival of greater
than two years. 相似文献
106.
Post-operative lumbar spine: comparative study of TSE T2 and turbo-FLAIR sequences vs contrast-enhanced SE T1 总被引:2,自引:0,他引:2
Barrera MC Alústiza JM Gervás C Recondo JA Villanúa JA Salvador E 《Clinical radiology》2001,56(2):133-137
AIM: To compare turbo T2 weighted spin echo (TSE T2) and turbo-FLAIR (fluid attenuated inversion recovery) vs gadolinium enhanced T1 weighted spin echo (SE T1) sequence in the differential diagnosis between disc herniation and post-surgical fibrosis. MATERIALS AND METHODS: Sixty-four patients who underwent surgical treatment for lumbar disc herniation with persistent or recurrent post-surgical symptoms were studied with a 0.5 Tesla MR system. The sequences used were TSE T2, turbo-FLAIR and T1 SE with and without intravenous gadolinium DTPA. The enhanced T1 SE sequence was considered the gold standard. Sensitivity and specificity were calculated. RESULTS: The sensitivity was 100% for both TSE T2 and turbo-FLAIR sequences. The specificity was 94% for TSE T2 and 92% for turbo-FLAIR. Negative predictive value was 100% for both sequences and positive predictive value 84% and 80% for TSE T2 and turbo-FLAIR, respectively. CONCLUSION: Although both sequences show high sensitivity, TSE-T2 presents greater specificity than turbo-FLAIR as compared to enhanced T1 SE. TSE T2 also offers the advantage of myelographic effect. We consider that the use of rapid sequences may avoid the need for intravenous contrast medium in most cases, reserving gadolinium DTPA only to those where all the criteria for hernia or fibrosis are not fulfilled. 相似文献
107.
108.
MG Magaji JA Anuka I Abdu-Aguye AH Yaro I M Hussaini 《African journal of traditional, complementary, and alternative medicines》2008,5(2):147-153
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant. 相似文献
109.
Casanueva FF Molitch ME Schlechte JA Abs R Bonert V Bronstein MD Brue T Cappabianca P Colao A Fahlbusch R Fideleff H Hadani M Kelly P Kleinberg D Laws ED Marek J Scanlon M Sobrinho LG Wass JAH Giustina A 吴哲褒 张亚卓 《中华神经外科杂志》2008,24(8)
3.男性:高催乳素血症通常导致阳痿、不孕和性功能低下.男性患者通常为大腺瘤,有神经系统症状.其原因可能是对症状认识的延误或者肿瘤生物学行为的差异. 相似文献
110.
Volumetric rendering techniques: applications for three-dimensional imaging of the hip 总被引:1,自引:0,他引:1
Fishman EK; Drebin B; Magid D; Scott WW Jr; Ney DR; Brooker AF Jr; Riley LH Jr; St. Ville JA; Zerhouni EA; Siegelman SS 《Radiology》1987,163(3):737-738
Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images. 相似文献