全文获取类型
收费全文 | 326篇 |
免费 | 24篇 |
专业分类
儿科学 | 8篇 |
妇产科学 | 7篇 |
基础医学 | 52篇 |
口腔科学 | 12篇 |
临床医学 | 75篇 |
内科学 | 31篇 |
皮肤病学 | 11篇 |
神经病学 | 17篇 |
特种医学 | 22篇 |
外科学 | 12篇 |
综合类 | 1篇 |
预防医学 | 56篇 |
眼科学 | 20篇 |
药学 | 16篇 |
中国医学 | 1篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 13篇 |
2014年 | 7篇 |
2013年 | 20篇 |
2012年 | 16篇 |
2011年 | 22篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 15篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 19篇 |
2000年 | 3篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有350条查询结果,搜索用时 15 毫秒
1.
In a prospective, randomized study of insemination with donor semen,
intracervical insemination by straw was compared with insemination using a
cervical cap with an intracervical reservoir. A total of 91 patients
completed 486 treatment cycles. There were no significant differences in
age, parity, indication for insemination by donor, or method of cycle
monitoring between women who became pregnant and those who did not conceive
with either insemination method. In 236 standard intracervical insemination
cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients
conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude
pregnancy rates and the cumulative pregnancy rates calculated by the
Kaplan-Meier life-table method were significantly different (chi(2)-test, P
< 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates
in artificial insemination with cryopreserved donor semen may be improved
by the use of a cervical cap when compared to cervical insemination by
straw. The use of the cervical cap may prolong the exposure of the
spermatozoa to the cervical mucus and prevent the backflow of semen into
the vagina.
相似文献
2.
Low-artifact intravascular devices: MR imaging evaluation 总被引:2,自引:0,他引:2
Teitelbaum GP; Ortega HV; Vinitski S; Stern H; Tsuruda JS; Mitchell DG; Rifkin MD; Bradley WG Jr 《Radiology》1988,168(3):713-719
Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible. 相似文献
3.
4.
Complement activation by malignant B cells from patients with chronic lymphocytic leukaemia (CLL).
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H V Marquart K Grnbaek B E Christensen S E Svehag R G Leslie 《Clinical and experimental immunology》1995,102(3):575-581
It has previously been reported that the expression of the complement receptors CR1 (CD35) and CR2 (CD21) on malignant B cells in CLL is reduced compared with the expression on normal B cells, while deposition of complement C3 fragments, as a consequence of alternative pathway (AP) activation of complement, is observed on mononuclear cells from patients with B CLL. Following our demonstration that normal B cells are capable of activating the AP of complement in a CR2-dependent fashion, we have chosen to re-examine the complement-activating ability of B CLL cells in relation to their altered phenotype with respect to CR2 and the complement regulatory membrane proteins, CR1, decay accelerating factor (DAF) (CD55) and membrane cofactor protein (MCP) (CD46). Flow cytometry was used to measure expression of complement receptors and regulatory proteins on CD5+ B cells from CLL patients, as well as the deposition of C3 fragments occurring both in vivo and after in vitro AP activation. We have confirmed the reduced expression of CR1 and CR2 on CLL cells and have shown that AP activation in the presence of homologous, normal serum was reduced on B CLL cells compared with normal B cells. The degree of AP activation correlated directly with CR2 expression. In addition, we observed that CLL cells bear in vivo-deposited C3d,g, although at a significantly lower level than normal B cells. 相似文献
5.
Karl-Horst Marquart 《Virchows Archiv : an international journal of pathology》1981,391(3):309-313
Summary Crystalline arrays of coated parallel tubules (CPT) were observed by electron microscopy within dilated cisternae of the rough endoplasmic reticulum of pleomorphic mononuclear cells in a human osteosarcoma. The wall of the peculiar intracisternal tubules consisted of an electron-dense thin membrane-like envelope which appeared to be composed of granular subunits. The electron-lucent tubular core together with the limiting envelope was approximately 15 nm in diameter. A coat of fuzzy material, approximately 10 nm thick, tightly surrounded the membrane-like wall of the tubules. Cross sections of accumulations of CPT showed the tubules to be arranged in a hexagonal crystalline array. The nature and significance of the intracisternal CPT are unknown. 相似文献
6.
7.
Dr. Karl-Horst Marquart 《Calcified tissue international》1976,21(1):219-223
Intracisternal type A particles were detected by electron microscopy in cells of normal trabecular bone tissue from the mouse strains C57BL, NMRI, C3H, 101, and (C3H×101)F1. The relatively small numbers of particles observed in all five strains were roughly equivalent. About 10% of the bone cell profiles examined in specimens from each animal contained a single particle. The intracisternal type A particles occurred predominantly in osteoblasts and rarely in osteoprogenitor cells and osteocytes. They were not found in osteoclasts. 相似文献
8.
对发展中国家改善用药的10点建议 总被引:2,自引:0,他引:2
WHO建议改善药品管理的工作要在国家药物政策保障之下.在许多国家,执行国家药物政策的机制是实施国家基本药物计划,其要点是强调公共领域的药品选择、采购、流通与使用的合理性.不适当的处方使医疗质量降低并导致资源浪费.本文以探讨在国家药物政策范畴内鼓励更合理地使用药品的问题为重点,在已有证据的基础上,详细阐明基本药物计划内容中的合理用药问题.本文评述了在发展中国家改善用药状况的有效策略及最新知识,并为决策者与管理者提出达到改善用药目标的建议. 相似文献
9.
Morten Tulstrup Thomas L. Frandsen Jonas Abrahamsson Bendik Lund Kim Vettenranta Olafur Gisli Jonsson Hanne Vibeke Hansen Marquart Birgitte Klug Albertsen Mats Heyman Kjeld Schmiegelow On behalf of the Nordic Society of Paediatric Haematology Oncology 《European journal of haematology》2018,100(1):53-60
Objectives
This randomized controlled trial tested the hypothesis that children with non‐high‐risk acute lymphoblastic leukemia could benefit from individualized 6‐mercaptopurine increments during consolidation therapy (NCT00816049). Primary and secondary end points were end of consolidation minimal residual disease (MRD) positivity and event‐free survival.Methods
392 patients were randomized to experimental and 396 to standard therapy. Patients allocated to standard therapy received oral 6‐mercaptopurine (25 mg/m2/day) from days 30 to 85, while the experimental arm received stepwise increments of additional 25 mg/m2/day beginning on days 50 and/or 71 unless dose‐limiting myelosuppression had occurred.Results
In the experimental arm, 166 patients (42%) received one dose increment, and 62 (16%) received two. Fifty‐seven of 387 (15%) patients in the experimental arm were MRD positive at end of consolidation vs 77 of 389 (20%) in the control arm (P = .08). Five‐year probability of event‐free survival was 0.89 (95% CI: 0.85‐0.93) in the experimental arm vs 0.93 (0.90‐0.96) in the control arm (P = .13). The median accumulated length of 6‐mercaptopurine treatment interruptions was 7 (IQR 2‐12) in the experimental arm vs 4 (IQR 0‐10) in the control arm (P = .002).Conclusion
This study found no benefit from individualized 6‐mercaptopurine increments compared to standard therapy. 相似文献10.