全文获取类型
收费全文 | 1034篇 |
免费 | 69篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 45篇 |
妇产科学 | 45篇 |
基础医学 | 144篇 |
口腔科学 | 8篇 |
临床医学 | 109篇 |
内科学 | 210篇 |
皮肤病学 | 32篇 |
神经病学 | 61篇 |
特种医学 | 15篇 |
外科学 | 139篇 |
综合类 | 14篇 |
一般理论 | 2篇 |
预防医学 | 146篇 |
眼科学 | 5篇 |
药学 | 65篇 |
中国医学 | 4篇 |
肿瘤学 | 58篇 |
出版年
2022年 | 17篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 27篇 |
2014年 | 43篇 |
2013年 | 49篇 |
2012年 | 70篇 |
2011年 | 82篇 |
2010年 | 47篇 |
2009年 | 35篇 |
2008年 | 66篇 |
2007年 | 51篇 |
2006年 | 60篇 |
2005年 | 47篇 |
2004年 | 53篇 |
2003年 | 42篇 |
2002年 | 39篇 |
2001年 | 16篇 |
2000年 | 17篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1938年 | 4篇 |
1936年 | 4篇 |
1934年 | 5篇 |
1925年 | 3篇 |
排序方式: 共有1104条查询结果,搜索用时 15 毫秒
1.
2.
Differentiation of pancreatic epithelial progenitor cells into hepatocytes following transplantation into rat liver 下载免费PDF全文
Mariana D. Dabeva Seong-Gyu Hwang Srinivasa Rao G. Vasa Ethel Hurston Phyllis M. Novikoff Douglas C. Hixson Sanjeev Gupta David A. Shafritz 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(14):7356-7361
The ability to identify, isolate, and transplant progenitor cells from solid tissues would greatly facilitate the treatment of diseases currently requiring whole organ transplantation. In this study, cell fractions enriched in candidate epithelial progenitor cells from the rat pancreas were isolated and transplanted into the liver of an inbred strain of Fischer rats. Using a dipeptidyl dipeptidase IV genetic marker system to follow the fate of transplanted cells in conjunction with albumin gene expression, we provide conclusive evidence that, after transplantation to the liver, epithelial progenitor cells from the pancreas differentiate into hepatocytes, express liver-specific proteins, and become fully integrated into the liver parenchymal structure. These studies demonstrate the presence of multipotent progenitor cells in the adult pancreas and establish a role for the liver microenvironment in the terminal differentiation of epithelial cells of foregut origin. They further suggest that such progenitor cells might be useful in studies of organ repopulation following acute or chronic liver injury. 相似文献
3.
Medical records of 170 patients who had undergone thymectomy for myasthenia gravis were reviewed from the point of view of respiratory disturbances. In the group of patients requiring mechanical ventilation for over 24 hours after operation the incidence of high preoperative cholinesterase inhibitor intake, severe bulbar symptoms and severe myasthenia gravis with anamnestic respiratory crisis and cardiorespiratory disease were much higher than in the group of patients who could have their trachea extubation within 24 hours. The presence of a thymic tumour, patients' age over 50 years and the so-called precrisis have revealed differences between the two groups, while the patient groups were identical in mean age, duration of myasthenia gravis and sex distribution. The above clinical data are recommended to be considered in the evaluation of the need for postoperative mechanical ventilation or extubation and preparation of preventive tracheotomy. 相似文献
4.
5.
6.
Reed Jon A.; Nador Roland G.; Spaulding David; Tani Yoichi; Cesarman Ethel; Knowles Daniel M. 《Blood》1998,91(10):3825-3832
7.
Ventral spondylodesis or ventrofixation is the most important surgical method for the treatment of severe cervical spine injuries accompanied by instability. Its wide indications include fracture-dislocations, compression fractures of the vertebral body, injuries to the disc, luxations, 'tear drop fractures' as well as "hangman's fractures". The essential parts of its technique: previous reduction by traction, anterior cervical approach, removal of the injured parts of vertebral body and disc(s), replacement by corticocancellous bone graft with subsequent plate-screw fixation. The authors performed in their Institute nearly 100 operations of this type, in a 10-year period of which; detailed account is given. Good results of surgery can be expected only by ensuring adequate technical conditions and professional knowledge, performing the operations in centres having sufficient experience. 相似文献
8.
A human myeloma immunoglobulin G binding four moles of calcium associated with asymptomatic hypercalcemia 总被引:3,自引:0,他引:3
Giampaolo Merlini Lorraine A. Fitzpatrick Ethel S. Siris John P. Bilezikian Steven Birken Sherman Beychok Elliott F. Osserman 《Journal of clinical immunology》1984,4(3):185-196
A calcium-binding immunoglobulin G (IgGIRUP) was identified in the serum of a patient with multiple myeloma, asymptomatic hypercalcemia, and a normal ionized serum calcium. Calcium binding by IgGRUP was confirmed by two-dimensional electrophoresis with calcium-45 and equilibrium dialysis. Amino acid analyses indicated an unusually high number of glutamic (or glutamine) residues in the L chain and Fab fragment but no detectable -carboxyglutamic acid. As determined by equilibrium dialysis with45Ca, the intact IgGRUP and its Fab fragments bound calcium at an optimum pH of 7.4. There was minimal binding of calcium to H chains and no binding by L chains or the Fc fragment. Recombination of H and L chains partially restored the binding activity. By Scatchard analysis, the binding affinity (K
d) of IgGRUP was 1.7×10–3
M and the binding capacity was 4 mol of calcium/mol of IgG. The binding of 4 mol of calcium/mol of IgG is twice that reported previously for two other calcium-binding myeloma proteins and suggests unique properties of IgGRUP. 相似文献
9.
Sputum Cytokine Levels in Patients with Pulmonary Tuberculosis as Early Markers of Mycobacterial Clearance 下载免费PDF全文
Rodrigo Ribeiro-Rodrigues Tatiana Resende Co John L. Johnson Fabiola Ribeiro Moises Palaci Ricardo T. S Ethel L. Maciel Fausto E. Pereira Lima Valderio Dettoni Zahra Toossi W. Henry Boom Reynaldo Dietze Jerrold J. Ellner Christina S. Hirsch 《Clinical and Vaccine Immunology : CVI》2002,9(4):818-823
Sputum and serum from patients with active pulmonary tuberculosis (TB), healthy purified protein derivative-positive adults, and patients with bacterial pneumonia were collected to simultaneously assess local immunity in the lungs and peripheral blood. To determine whether cytokine profiles in sputum from TB patients and control subjects were a reflection of its cellular composition, cytospin slides were prepared in parallel and assessed for the presence of relative proportions of epithelial cells, neutrophils, macrophages, and T cells. Gamma interferon (IFN-γ) in sputum from TB patients was markedly elevated over levels for both control groups. With anti-TB therapy, IFN-γ levels in sputum from TB patients decreased rapidly and by week 4 of treatment were comparable to those in sputum from controls. Further, IFN-γ levels in sputum closely followed mycobacterial clearance. Although detected at fourfold-lower levels, IFN-γ immunoreactivities in serum followed kinetics in sputum. TNF-α, interleukin 8 (IL-8) and IL-6 also were readily detected in sputum from TB patients at baseline and responded to anti-TB therapy. In contrast to IFN-γ, however, TNF-α and IL-8 levels also were elevated in sputum from pneumonia controls. These data indicate that sputum cytokines correlate with disease activity during active TB of the lung and may serve as potential early markers for sputum conversion and response to anti-TB therapy. 相似文献
10.
Herschel Sidransky Ethel Verney Challakonda N. Murty 《Experimental and molecular pathology》1981,35(1):124-136
Female inbred Buffalo rats bearing intrahepatically transplanted hepatoma 5123 were subjected intraperitoneally to the acute administration of hypertonic NaCl or CCl4 followed by a tube-feeding of l-tryptophan. The responses in terms of changes in polyribosomal aggregation and protein synthesis (in vitro) of host liver and hepatoma were evaluated. While treatment with hypertonic NaCl or CCl4 caused disaggregation of polyribosomes and inhibition of protein synthesis in both host liver and hepatoma, the subsequent administration of tryptophan caused some improvement in both parameters in host liver but not in hepatoma. Administration of hypertonic NaCl alone caused a decrease in [14C]orotate incorporation into poly(A)-mRNA of host liver and hepatoma, whereas administration of tryptophan after hypertonic NaCl caused a significant improvement in host liver alone. Following the tryptophan administration, the activities of nuclear DNA-dependent RNA polymerases I and II, and of nuclear-envelope nucleoside triphosphatase, as well as labeled nuclear RNA release in vitro were slightly elevated in host liver but not in hepatoma. Tryptophan-related compounds, 5-hydroxy-dl-tryptophan, 5-fluorotryptophan, indole, and 3-hydroxyanthranilic acid, when administered in place of l-tryptophan, did not appreciably affect polyribosomal aggregation or protein synthesis in vitro in host liver or hepatoma. 相似文献