全文获取类型
收费全文 | 672篇 |
免费 | 27篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 38篇 |
妇产科学 | 37篇 |
基础医学 | 39篇 |
口腔科学 | 13篇 |
临床医学 | 92篇 |
内科学 | 79篇 |
皮肤病学 | 36篇 |
神经病学 | 22篇 |
特种医学 | 208篇 |
外科学 | 26篇 |
综合类 | 18篇 |
一般理论 | 8篇 |
预防医学 | 56篇 |
药学 | 20篇 |
1篇 | |
肿瘤学 | 15篇 |
出版年
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2013年 | 12篇 |
2012年 | 17篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 15篇 |
2008年 | 13篇 |
2007年 | 23篇 |
2006年 | 23篇 |
2005年 | 17篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 8篇 |
2001年 | 12篇 |
2000年 | 16篇 |
1999年 | 18篇 |
1998年 | 21篇 |
1997年 | 20篇 |
1996年 | 29篇 |
1995年 | 16篇 |
1994年 | 23篇 |
1993年 | 19篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 19篇 |
1989年 | 29篇 |
1988年 | 19篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1977年 | 7篇 |
1976年 | 13篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 5篇 |
1925年 | 5篇 |
排序方式: 共有709条查询结果,搜索用时 15 毫秒
1.
C M Misch C E Misch R R Resnik Y H Ismail 《The International journal of oral & maxillofacial implants》1992,7(3):360-366
Partially edentulous patients with alveolar defects contraindicating implant placement were treated with bone grafts obtained from the mandibular symphysis. Complications encountered were minor and uneventful. Evaluation 4 months after surgery revealed minimal graft resorption, thus implant placement was possible in all potential sites. Advantages of the symphysis graft include easy access, availability of greater quantities of bone over other intraoral donor sites, low morbidity, no hospitalization, minimal discomfort, no alteration in ambulation, and no cutaneous scar. Compared with other bone regenerative methods for implant placement, a superior quality of bone was found and a shorter healing period is required. Results of this preliminary clinical investigation demonstrate that chin grafts offer a viable alternative for reconstruction of alveolar defects prior to dental implant placement. 相似文献
2.
3.
We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantifications based on measurement of fluorescence intensity. We found that, for bands alpha and beta of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near pH 7-7.5 for copro- and uroporphyrin, respectively. For band gamma of the emission spectra there was a constant decrease of fluorescence with increasing alkalinity of the solution. The intensity of porphyrin fluorescence also depends on ionic strength, reaching sharp maxima at 0.1 mol/L (for uroporphyrin) and 1 mol/L (for coproporphyrin). The organic mixture ethyl acetate:acetic acid (4:1 by vol), commonly used to extract porphyrins from biological samples, markedly diminishes the fluorescence of both porphyrins as compared with the same concentration of each porphyrin in aqueous acidic solvent. Furthermore, when we measured different ratios of uro:copro mixture at three distinct pHs and buffers, we found that at pH 10.5 (in carbonate buffer) the measured units of fluorescence depend only on total porphyrin concentration and not on the composition of the mixture. 相似文献
4.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml ̄(-1)诱导HL-60细胞发生凋亡,而阻断HR20细胞于G_1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml ̄(-1)处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G_1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关 相似文献
5.
Hydrolysis of peptides within lumen of small intestine 总被引:2,自引:0,他引:2
6.
Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation 相似文献
7.
8.
Osteosarcomatosis 总被引:10,自引:0,他引:10
Hopper KD; Moser RP Jr; Haseman DB; Sweet DE; Madewell JE; Kransdorf MJ 《Radiology》1990,175(1):233-239
A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized. 相似文献
9.
The widespread availability and use of stapling devices have changed colorectal surgery. In 1980, Knight and Griffen developed the "double-staple" technique, using a circular stapler to transect a linear rectal staple line. This eliminated the need for a hand-sewn, distal purse string, which was sometimes difficult or even impossible to accurately place low in the pelvis. To evaluate this procedure, the authors have reviewed their results with the double-staple technique over the past 5 years. One hundred four patients underwent this procedure between 1985 and 1990 at Thomas Jefferson University Hospital (Philadelphia, PA). There were 60 men and 44 women, with a mean age of 62.4 years. Seventy-two patients underwent operation for carcinoma of the rectum or sigmoid. Thirty-five of these had preoperative radiation therapy. Other diagnoses included 1) diverticular disease, 2) rectal prolapse, 3) villous adenoma, 4) endometrial carcinoma, 5) fistula, 6) stricture, 7) Crohn's disease, 8) colonic endometriosis, 9) lymphoma, 10) ovarian carcinoma, and 11) ulcerative colitis. Incomplete "donuts" were observed in 5 patients. Diverting colostomies were performed in 23 patients, ileostomies in 3. Postoperative complications relating to the double-staple technique itself included a rectovaginal fistula in 1 patient. There were 3 clinical leaks (2.8%), all treated nonoperatively. No strictures were observed. As previously observed, the authors believe the double-staple technique offers certain advantages over traditional, hand-sewn and stapled anastomoses, for instance: 1) there is significantly less contamination, 2) the anastomosis is technically easier, and 3) bowel segments of different diameters can be easily anastomosed. 相似文献
10.