全文获取类型
收费全文 | 22458篇 |
免费 | 1505篇 |
国内免费 | 316篇 |
学科分类
医药卫生 | 24279篇 |
出版年
2023年 | 143篇 |
2022年 | 233篇 |
2021年 | 828篇 |
2020年 | 425篇 |
2019年 | 593篇 |
2018年 | 691篇 |
2017年 | 524篇 |
2016年 | 791篇 |
2015年 | 1011篇 |
2014年 | 1153篇 |
2013年 | 1377篇 |
2012年 | 2027篇 |
2011年 | 1944篇 |
2010年 | 1119篇 |
2009年 | 917篇 |
2008年 | 1410篇 |
2007年 | 1363篇 |
2006年 | 1216篇 |
2005年 | 1114篇 |
2004年 | 952篇 |
2003年 | 828篇 |
2002年 | 728篇 |
2001年 | 435篇 |
2000年 | 410篇 |
1999年 | 343篇 |
1998年 | 168篇 |
1997年 | 143篇 |
1996年 | 123篇 |
1995年 | 105篇 |
1994年 | 83篇 |
1993年 | 72篇 |
1992年 | 106篇 |
1991年 | 103篇 |
1990年 | 83篇 |
1989年 | 86篇 |
1988年 | 81篇 |
1987年 | 70篇 |
1986年 | 51篇 |
1985年 | 56篇 |
1984年 | 38篇 |
1983年 | 42篇 |
1982年 | 26篇 |
1981年 | 19篇 |
1980年 | 25篇 |
1979年 | 38篇 |
1978年 | 19篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1972年 | 15篇 |
1969年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
42.
Keuk Shun Shin M.D. Seum Chung M.D. Hye Kyung Lee M.D. Jae Duk Lew M.D. 《Aesthetic plastic surgery》1996,20(1):69-76
Reduction mammaplasty was performed in 30 patients by combining the central pedicle flap method with the short submammary scar (3-S) technique to avoid the common drawbacks of currently popular dermoglandular procedures. Reduction was accomplished by using perforating vascular branches from the pectoralis major muscle and its fascia supplying the nipple and breast parenchyme instead of the subdermal plexus. The central vascular pedicle supplying the nipple-areola complex was preserved. Only the periphery of the breast parenchyme was resected circumferentially, with the exception of the inferolateral portion, so as not to injure the sensory nerve. The remaining breast parenchyme was preserved in an inverted cone shape. The nipple-areola complex was safely transposed with great freedom, and the amount of resection was accurately adjusted for symmetry. No cases of nipple-areola complex sensory change occurred postoperatively, and lactation is possible because of preservation of the lactiferous ducts. The length of postoperative scars was reduced by using the short submammary scar technique. We believe this combined method is ideal in patients requiring resections ranging from 200 to 600 g per breast with good skin elasticity and moderate degree of ptosis.Presented at the Sixth Asian Pacific Congress of the International Confederation for Plastic and Reconstructive Surgery, in Seoul, Korea, October 1993. 相似文献
43.
44.
Hyun-Min Shin Chul-Jong Park Jong-Yuk Yi Tae-Yoon Kim Chung-Won Kim 《Pediatric dermatology》1996,13(2):146-147
Abstract: Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before. 相似文献
45.
无环鸟苷亲脂性前体药物脂质体的制备及体外抗病毒活性(英文) 总被引:2,自引:0,他引:2
本文通过将无环鸟苷(acyclovir,简称ACV)2’位羟基分别与月桂酰氯或棕榈酰氯进行酯化反应,制得亲脂性前体药物无环鸟苷月桂酸酯和无环鸟苷棕榈酸酯(分别简称为C12-ACV和C16-ACV),使脂质体包封率从ACV的29.9%提高到C12-ACV的95.6%和C16-ACV的97.1%;漏泄实验表明在4℃透析60h后,一半以上的ACV从脂质体中漏泄,而C12-ACV和C16-ACV的滞留率分别为70%和80%;体外抗疱疹病毒的试验中,在最低试验浓度0.044μmol/L时,ACV不显示抗病毒活性,而C16-ACV脂质体抑制细胞病变率达75%,说明前体药物通过与脂质体脂膜的结合增加了药物的进入细胞能力,从而提高了ACV的抗病毒能力。 相似文献
46.
Georgios Amoiridis Ludwig Gutmann Dennis E. Wilkins Raja Sawaya Alain Lagueny Roger Marthan Philippe Schuermans Philippe Le Collen Xavier Ferrer Jean Julien Reha Kuruoglu Shin J. Oh Brian Thompson A. Aggarwal L. Gutmann A. Gutierrez Okifumi Nakazato Russel Johnsen Philip Morling B. A. Kakulas 《Muscle & nerve》1994,17(2):245-253
47.
Suk Hee Heo Yong Yeon Jeong Sang Soo Shin Tae Woong Chung Heoung Keun Kang 《Korean journal of radiology》2007,8(2):180-183
We report an uncommon case of solitary, small hepatic angiosarcoma that was initially considered as a hemangioma. We present the imaging findings, with an emphasis on the initial and follow-up CT and MR findings, as well as report on the more suggestive findings of angiosarcoma than those of a hemangioma. 相似文献
48.
Production of tumor necrosis factor and other cytokines by astrocytes stimulated with lipopolysaccharide or a neurotropic virus. 总被引:39,自引:4,他引:35
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A P Lieberman P M Pitha H S Shin M L Shin 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(16):6348-6352
Rat astrocytes, immunologically competent glial cells of the central nervous system (CNS), released a variety of cytokines after activation. Lipopolysaccharide-stimulated astrocytes produced tumor necrosis factor (TNF) as demonstrated by Northern blot analysis using a mouse TNF probe and by functional assay. Biological activity of rat astrocyte-derived TNF was neutralized by rabbit antiserum against recombinant murine TNF. Stimulation of astrocytes by lipopolysaccharide also activated the interleukin 1 and interleukin 6 genes. We have also investigated whether a neurotropic paramyxovirus, Newcastle disease virus, triggers cytokine production by astrocytes. This virus induced astrocytes to produce TNF, lymphotoxin, interleukin 6, and alpha- and beta-interferons. Thus, stimulation by endotoxin and virus activated distinct, yet overlapping, sets of cytokine genes. We propose that astrocytes and the cytokines they produce may play a significant role in the pathogenesis of immunologically and/or virally mediated CNS disease, in CNS intercellular communication, and in the interactions between the nervous and immune systems. 相似文献
49.
David R. Young Lih-Yuann Shin Michael G. Rock Frank J. Frassica Petri Virolainen Edmund Y. S. Chao 《Journal of orthopaedic research》1997,15(5):773-780
The reconstruction of large bone and joint defects after the resection of malignant tumors remains a major challenge. Chemotherapy has significantly lowered the risk of metastasic disease, but complications associated with reconstructive techniques continue to result in late morbidity. In the present study, biomechanical torsion testing, gait analysis, and histomorphometric and scanning electron microscopic evaluations of 24 dogs were used to examine the effects of preoperative and postoperative administration of cisplatin on the biologic fixation of a porous-coated segmental replacement prosthesis. The chemotherapy consisted of four cycles of cisplatin administered at a dosage of 75 mg/m:2 preoperatively or postoperatively. The healing was enhanced by use of an autogenous corticocancellous bone graft. The graft was placed evenly around the prosthesis and the adjacent femoral cortex. Mechanical analyses of torsional stiffness, yield strength, and maximum strength revealed no statistically significant differences between the groups at 12 weeks. Such lack of difference was mainly due to the penetration of highly organized fibrous tissue into the porous surface; this provided strong fixation of the implant to bone even in the absence of bone ingrowth. Although bone ingrowth into the prostheses was not affected, electron microscopic, histomorphometric, and radiologic analyses showed a clear difference in the formation of new bone around the prosthesis. Preoperative chemotherapy did not alter the formation of new bone, but specimens from animals treated postoperatively with cisplatin showed significantly less bone graft resorption and less new bone formation. Hence, the effect of cisplatin administration caused only a temporary delay, not a permanent effect, on extracortical capsule formation. The formation of extracortical bone and soft tissue might prevent debris-incised osteolysis and, therefore, prevent late complications by forming a tight capsule around the bone-prosthetic interface. 相似文献
50.
J D Lee K H Shin S N Cho J S Shin M G Lee W I Yang C Y Park H S Yoo J T Lee O D Awh 《European journal of nuclear medicine》1992,19(12):1011-1015
Immunoscintigraphy with radiolabelled monoclonal antibodies is widely used to detect solid tumours, but only a few trials have been carried out concerning the specific in vivo localization of an inflammatory process. The purpose of this study was to investigate the detectability of tuberculous foci utilizing this method with radiolabelled bacillus Calmette-Guérin (BCG)-specific F(ab')2 in rabbits. All of the tuberculous lesions (n = 8) were clearly visualized on serial scintigraphy for up to 48 h after injection of the antibody. Immunohistochemical and Ziel-Neelson staining of the tuberculous lesions confirmed the presence of the tuberculous antigens and bacilli. It failed to demonstrate any sustained retention of the BCG-specific antibody fragment in the control group with syphilitic orchitis (n = 2). Therefore, the specific in vivo localization of tuberculosis is feasible by immunoscintigraphy. 相似文献