全文获取类型
收费全文 | 767篇 |
免费 | 66篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 37篇 |
妇产科学 | 57篇 |
基础医学 | 124篇 |
口腔科学 | 5篇 |
临床医学 | 61篇 |
内科学 | 164篇 |
皮肤病学 | 9篇 |
神经病学 | 31篇 |
特种医学 | 21篇 |
外科学 | 86篇 |
综合类 | 31篇 |
预防医学 | 37篇 |
眼科学 | 3篇 |
药学 | 39篇 |
中国医学 | 7篇 |
肿瘤学 | 122篇 |
出版年
2023年 | 13篇 |
2022年 | 16篇 |
2021年 | 36篇 |
2020年 | 21篇 |
2019年 | 27篇 |
2018年 | 34篇 |
2017年 | 25篇 |
2016年 | 22篇 |
2015年 | 32篇 |
2014年 | 45篇 |
2013年 | 46篇 |
2012年 | 61篇 |
2011年 | 64篇 |
2010年 | 35篇 |
2009年 | 29篇 |
2008年 | 35篇 |
2007年 | 45篇 |
2006年 | 36篇 |
2005年 | 34篇 |
2004年 | 26篇 |
2003年 | 26篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1974年 | 4篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1968年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有837条查询结果,搜索用时 15 毫秒
91.
Intractable maximum likelihood problems can sometimes be finessed with aMonte Carlo implementation of the EM algorithm. However, there appears to be little theory governing when Monte Carlo EM (MCEM) sequences converge. Consequently, in some applications, convergence is assumed rather than proved. Motivated by this problem in the context of modeling market penetration of new products and services over time, we develop (i) high-level conditions for rates of almost-sure convergence and convergence in distribution of any MCEM sequence and (ii) primitive conditions for almost-sure monotonicity and almost-sure convergence of an MCEM sequence when Monte Carlo integration is carried out using independent Gibbs runs. We verify the main primitive conditions for the Bass product diffusion model and apply the methodology to data on wireless telecommunication services. 相似文献
92.
Background
Knee braces are considered to be extremely useful tools in reducing the shear force of knee joints for non-contact anterior cruciate ligament (ACL) injury prevention. However, the effectiveness of sports knee braces and sleeves remains to be identified. Therefore, the purpose of this study was to evaluate the effectiveness of wearing commercialized sports knee braces and sleeves on knee kinematics, kinetics, and ACL force during drop jumps using musculoskeletal modeling analysis.Methods
Musculoskeletal modeling analysis was conducted on 19 male alpine skiers who performed drop jump motions from a 40-cm box under three conditions: without a brace/sleeve, with a brace, and while wearing a neoprene sleeve.Results
The physical performance (i.e., the center of mass of the jumping height) was not affected by the type of brace or sleeve. However, wearing a brace or sleeve during drop jump tasks reduced the knee joint's maximum flexion, abduction angles, and adduction moment. The knee joint shear force when wearing the brace or sleeve exhibited no statistical differences. Further, the ACL load estimated in this study did not exhibit any statistical differences in relation to wearing a brace or sleeve.Conclusions
The knee braces and sleeves reduced flexion and abduction movement, and adduction moment but did not reduce the knee joint shear force, internal rotation moment, or the ACL force. Therefore, if a sports knee brace that controls the knee joint's shear force and internal rotation moment is developed, it may aid in preventing ACL injuries. 相似文献93.
Cousins not twins: intratumoural and intertumoural heterogeneity in syndromic neuroendocrine tumours 下载免费PDF全文
Aidan Flynn Trisha Dwight Diana Benn Siddhartha Deb Andrew J Colebatch Stephen Fox Jessica Harris Emma L Duncan Bruce Robinson Annette Hogg Jason Ellul Henry To Cuong Duong Julie A Miller Christopher Yates Paul James Alison Trainer Anthony J Gill Roderick Clifton‐Bligh Rodney J Hicks Richard W Tothill 《The Journal of pathology》2017,242(3):273-283
Hereditary endocrine neoplasias, including phaeochromocytoma/paraganglioma and medullary thyroid cancer, are caused by autosomal dominant mutations in several familial cancer genes. A common feature of these diseases is the presentation of multiple primary tumours, or multifocal disease representing independent tumour clones that have arisen from the same initiating genetic lesion, but have undergone independent clonal evolution. Such tumours provide an opportunity to discover common cooperative changes required for tumourigenesis, while controlling for the genetic background of the individual. We performed genomic analysis of synchronous and metachronous tumours from five patients bearing germline mutations in the genes SDHB, RET, and MAX. Using whole exome sequencing and high‐density single‐nucleotide polymorphism arrays, we analysed two to four primary tumours from each patient. We also applied multi‐region sampling, to assess intratumoural heterogeneity and clonal evolution, in two cases involving paraganglioma and medullary thyroid cancer, respectively. Heterogeneous patterns of genomic change existed between synchronous or metachronous tumours, with evidence of branching evolution. We observed striking examples of evolutionary convergence involving the same rare somatic copy‐number events in synchronous primary phaeochromocytoma/paraganglioma. Convergent events also occurred during clonal evolution of metastatic medullary thyroid cancer. These observations suggest that genetic or epigenetic changes acquired early within precursor cells, or pre‐existing within the genetic background of the individual, create contingencies that determine the evolutionary trajectory of the tumour. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
94.
Atasi De Chatterjee Tavis L. Mendez Sukla Roychowdhury Siddhartha Das 《Infection and immunity》2015,83(5):2030-2042
Although encystation (or cyst formation) is an important step of the life cycle of Giardia, the cellular events that trigger encystation are poorly understood. Because membrane microdomains are involved in inducing growth and differentiation in many eukaryotes, we wondered if these raft-like domains are assembled by this parasite and participate in the encystation process. Since the GM1 ganglioside is a major constituent of mammalian lipid rafts (LRs) and known to react with cholera toxin B (CTXB), we used Alexa Fluor-conjugated CTXB and GM1 antibodies to detect giardial LRs. Raft-like structures in trophozoites are located in the plasma membranes and on the periphery of ventral discs. In cysts, however, they are localized in the membranes beneath the cyst wall. Nystatin and filipin III, two cholesterol-binding agents, and oseltamivir (Tamiflu), a viral neuraminidase inhibitor, disassembled the microdomains, as evidenced by reduced staining of trophozoites with CTXB and GM1 antibodies. GM1- and cholesterol-enriched LRs were isolated from Giardia by density gradient centrifugation and found to be sensitive to nystatin and oseltamivir. The involvement of LRs in encystation could be supported by the observation that raft inhibitors interrupted the biogenesis of encystation-specific vesicles and cyst production. Furthermore, culturing of trophozoites in dialyzed medium containing fetal bovine serum (which is low in cholesterol) reduced raft assembly and encystation, which could be rescued by adding cholesterol from the outside. Our results suggest that Giardia is able to form GM1- and cholesterol-enriched lipid rafts and these raft domains are important for encystation. 相似文献
95.
Ian S. Hagemann MD PhD Siddhartha Devarakonda MD Christina M. Lockwood PhD David H. Spencer MD PhD Kalin Guebert MS CCRP Andrew J. Bredemeyer PhD Hussam Al‐Kateb MS PhD TuDung T. Nguyen MD PhD Eric J. Duncavage MD Catherine E. Cottrell PhD Shashikant Kulkarni MS PhD Rakesh Nagarajan MD PhD Karen Seibert PhD Maria Baggstrom MD Saiama N. Waqar MD John D. Pfeifer MD PhD Daniel Morgensztern MD Ramaswamy Govindan MD 《Cancer》2015,121(4):631-639
96.
Siddhartha Ganguly Trisha Home Abdulraheem Yacoub Suman Kambhampati Huidong Shi Prasad Dandawate Subhash Padhye Ashok K. Saluja Joseph McGuirk Rekha Rao 《Oncotarget》2015,6(31):31767-31779
CLL is a disease characterized by chromosomal deletions, acquired copy number changes and aneuploidy. Recent studies have shown that overexpression of Heat Shock Factor (HSF) 1 in aneuploid tumor cells can overcome deficiencies in heat shock protein (HSP) 90-mediated protein folding and restore protein homeostasis. Interestingly, several independent studies have demonstrated that HSF1 expression and activity also affects the chaperoning of HSP90 kinase clients, although the mechanism underlying this observation is unclear. Here, we determined how HSF1 regulates HSP90 function using CLL as a model system. We report that HSF1 is overexpressed in CLL and treatment with triptolide (a small molecule inhibitor of HSF1) induces apoptosis in cultured and primary CLL B-cells. We demonstrate that knockdown of HSF1 or its inhibition with triptolide results in the reduced association of HSP90 with its kinase co-chaperone cell division cycle 37 (CDC37), leading to the partial depletion of HSP90 client kinases, Bruton''s Tyrosine Kinase (BTK), c-RAF and cyclin-dependent kinase 4 (CDK4). Treatment with triptolide or HSF1 knockdown disrupts the cytosolic complex between HSF1, p97, HSP90 and the HSP90 deacetylase- Histone deacetylase 6 (HDAC6). Consequently, HSF1 inhibition results in HSP90 acetylation and abrogation of its chaperone function. Finally, tail vein injection of Mec-1 cells into Rag2−/−IL2Rγc−/− mice followed by treatment with minnelide (a pro-drug of triptolide), reduced leukemia, increased survival and attenuated HSP90-dependent survival signaling in vivo. In conclusion, our study provides a strong rationale to target HSF1 and test the activity of minnelide against human CLL. 相似文献
97.
Akela A Nandi SK Banerjee D Das P Roy S Joardar SN Mandal M Das PK Pradhan NR 《International wound journal》2012,9(5):505-516
A study was conducted to evaluate the potential of autologous bone marrow-derived cells in comparison with buffy coat of autologous blood for rapid cutaneous wound healing in rabbit model. Three square full-thickness skin excisional wounds were created in 15 selected experimental animals (rabbit) divided randomly into three groups. The wound was treated with autologous bone marrow cells in plasma (group 1), buffy coat of blood in plasma (group 2) and autologous plasma as control (group 3). Wounds were observed for 30 days for granulation tissue formation, biochemical, histomorphological and histochemical evaluation. In this study, granulation tissue appeared significantly lesser in wounds of group 3 animals followed by group 2 and 1 animals. Neovascularisation, granulation tissue formation, denser, thicker and better arranged collagen fibres, reticulin fibres and elastin fibres formation was more in group 1 as compared with other groups. It was concluded that the application of bone marrow-derived nucleated cells into the wound margins resulted in early and significantly faster rate of complete healing as compared with buffy coat of autologous blood and autologous plasma (control). This approach may be beneficial in various surface wounds that heal at a slower rate and recommended for healing of various complicated wound in future. 相似文献
98.
99.
100.
Summary A study of red cell membrane polypeptide and lipid profiles in G-6-PD deficient subjects has been made. High membrane spectrin and lipid content was demonstrated in the red cells of drug sensitive G-6-PD deficient individuals, while it was normal in non-sensitive G-6-PD deficient subjects. An inverse relationship was observed between GSH level and spectrin content in the former group. Possible mechanism of increased spectrin content in relation to hemolysis is discussed. 相似文献