全文获取类型
收费全文 | 1695648篇 |
免费 | 123331篇 |
国内免费 | 3777篇 |
专业分类
耳鼻咽喉 | 21730篇 |
儿科学 | 55637篇 |
妇产科学 | 46151篇 |
基础医学 | 241209篇 |
口腔科学 | 48739篇 |
临床医学 | 151362篇 |
内科学 | 333505篇 |
皮肤病学 | 38652篇 |
神经病学 | 131145篇 |
特种医学 | 63868篇 |
外国民族医学 | 242篇 |
外科学 | 257221篇 |
综合类 | 38945篇 |
现状与发展 | 4篇 |
一般理论 | 531篇 |
预防医学 | 124230篇 |
眼科学 | 40211篇 |
药学 | 123593篇 |
7篇 | |
中国医学 | 4475篇 |
肿瘤学 | 101299篇 |
出版年
2021年 | 12782篇 |
2019年 | 13525篇 |
2018年 | 19950篇 |
2017年 | 15214篇 |
2016年 | 16615篇 |
2015年 | 18957篇 |
2014年 | 26214篇 |
2013年 | 37943篇 |
2012年 | 52728篇 |
2011年 | 55420篇 |
2010年 | 32770篇 |
2009年 | 30697篇 |
2008年 | 51520篇 |
2007年 | 54799篇 |
2006年 | 55260篇 |
2005年 | 52540篇 |
2004年 | 50744篇 |
2003年 | 48156篇 |
2002年 | 46370篇 |
2001年 | 91792篇 |
2000年 | 93608篇 |
1999年 | 76964篇 |
1998年 | 19721篇 |
1997年 | 17269篇 |
1996年 | 17392篇 |
1995年 | 16743篇 |
1994年 | 15289篇 |
1993年 | 14071篇 |
1992年 | 57384篇 |
1991年 | 55271篇 |
1990年 | 52972篇 |
1989年 | 50749篇 |
1988年 | 46131篇 |
1987年 | 44940篇 |
1986年 | 42226篇 |
1985年 | 39988篇 |
1984年 | 29349篇 |
1983年 | 24908篇 |
1982年 | 13898篇 |
1979年 | 25529篇 |
1978年 | 17574篇 |
1977年 | 14906篇 |
1976年 | 13874篇 |
1975年 | 14563篇 |
1974年 | 17630篇 |
1973年 | 16944篇 |
1972年 | 15673篇 |
1971年 | 14453篇 |
1970年 | 13431篇 |
1969年 | 12517篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
I. Fouzas C. Papanikolaou G. Katsanos N. Antoniadis N. Salveridis K. Karakasi S. Vasileiadou A. Fouza E. Mouloudi G. Imvrios V. Papanikolaou 《Transplantation proceedings》2019,51(2):416-420
Aims
Variations of the anatomy of donor hepatic arteries increase the number of arterial anastomoses during liver transplantation and, possibly, the incidence of hepatic artery thrombosis (HAT). In this study, we describe the arterial anatomic variations in liver grafts procured and transplanted by a single center in Greece, the techniques of arterial anastomosis, and their effect on the incidence of early HAT.Materials and Methods
From January 2013 to December 2017, the arterial anatomy of 116 grafts procured for liver transplantation were recorded, as well as the technique of arterial anastomosis and the incidence of early hepatic artery thrombosis (HAT <30 days).Results
A single hepatic artery was recorded in 72.41% of the procured grafts, an aberrant left hepatic artery (accessory or replaced) in 18 grafts (15.52%), and an aberrant right hepatic artery (accessory or replaced) in 17 grafts (14.66%), while other variations were observed in less than 1% of the procured livers. Of the 116 primary liver transplantations, 6 patients (5.17%) developed early HAT <30 days. Two of these patients (1.72%) had 1 anastomosis of the hepatic artery and 4 (3.45%) had 2 anastomoses due to anatomic variations.Conclusions
Anatomic variations of the hepatic artery in liver grafts is a common finding and increase the incidence of early HAT but not to a degree to make these grafts unusable. 相似文献162.
163.
164.
Lara Feulner Hamed S. Najafabadi Simon Tanguay Janusz Rak Yasser Riazalhosseini 《Urologic oncology》2019,37(2):166-175
Background
Clear cell renal cell carcinoma (ccRCC) is known to occur across the adult lifetime traversing the spectrum of age-related organismal changes. Little is known as to how the aging process may affect the course of renal cell carcinoma (RCC) and the repertoire of genes involved.Methods
Using The Cancer Genome Atlas (n?=?436) and Cancer Genomics of the Kidney (n?=?89) datasets, we applied regression analysis to examine associations between patient age and gene expression profiles in ccRCC tumors and normal kidney tissues. Pathway enrichment analysis was performed to identify cellular process that is affected by aging in ccRCC. Moreover, connectivity mapping analysis was used to predict age-dependent response to drug treatments.Results
Our analysis revealed different age-dependent gene expression spectra in ccRCC and normal kidney tissues. These findings were significant and independently reproducible in both datasets examined. Age up-regulated genes, showing higher expression in older patients, were significantly enriched (false discovery rate <0.05) in normal tissues for pathways associated with immune response and extracellular matrix organization, whereas age up-regulated genes in tumors were enriched for metabolism and oxidation pathways. Strikingly, age down-regulated genes in normal cells were also enriched for metabolism and oxidation, while those in tumors were enriched for extracellular matrix organization. Further in silico analysis of potential drug targets predicted preferential efficacy of Phosphoinositide 3-kinase inhibitor or immunotherapy in association with age.Conclusion
We report on previously unrecognized associations between age and molecular underpinnings of RCC, including age-associated expression of genes implicated in RCC development or treatment. 相似文献165.
Hend Kothayer Samy M. Ibrahim Moustafa K. Soltan Samar Rezq Shireen S. Mahmoud 《Drug development research》2019,80(3):343-352
In light of the pharmacophoric structural requirements for achieving anticonvulsant activity, a series of N-(1-methyl-4-oxo-2-un/substituted-1,2-dihydroquinazolin-3[4H]-yl)benzamide (4a-g) and N-(1-methyl-4-oxo-2-un/substituted-1,2-dihydroquinazolin-3[4H]-yl)-2-phenylacetamide (4h-n) derivatives were synthesized in two steps starting from the reaction of N-methyl isatoic anhydride with the appropriate hydrazide and followed by condensation with the appropriate aldehyde. The anticonvulsant activities of the synthesized compounds were evaluated according to the anticonvulsant drug development (ADD) programme protocol. Among the synthesized compounds, 4n showed promising activity in both the maximal electroshock (MES) and pentylenetetrazole (PTZ) tests with median effective dose (ED50) values of 40.7 and 6 mg/kg, respectively. The six most promising derivatives, 4b , 4a , 4c , 4f , 4j , and 4i , showed very low ED50 values in the PTZ test (3.1, 4.96, 8.68, 9.89, 12, and 13.53 mg/kg, respectively). All the tested compounds showed no to low neurotoxicity in the rotarod test with a wide therapeutic index. Docking studies of compound 4n suggested that GABAA binding could be the mechanism of action of these derivatives. The in silico drug likeliness parameters indicated that none of the designed compounds violate Lipinski's rule of five and that they are able to cross the blood–brain barrier.
相似文献
Hit, Lead & Candidate Discovery |
166.
Gregers Mads Christian Tofte Mikkelsen Søren Lindvig Katrine Prier Brøchner Anne Craveiro 《Neurocritical care》2020,33(1):273-282
Neurocritical Care - For years, the use of ketamine as an anesthetic to patients suffering from acute brain injury has been debated because of its possible deleterious effects on the cerebral... 相似文献
167.
Heidi J Kalkwarf John A Shepherd Didier Hans Elena Gonzalez Rodriguez Joseph M Kindler Joan M Lappe Sharon Oberfield Karen K Winer Babette S Zemel 《Journal of bone and mineral research》2022,37(4):776-785
Trabecular bone score (TBS) is used for fracture prediction in adults, but its utility in children is limited by absence of appropriate reference values. We aimed to develop reference ranges for TBS by age, sex, and population ancestry for youth ages 5 to 20 years. We also investigated the association between height, body mass index (BMI), and TBS, agreement between TBS and lumbar spine areal bone mineral density (aBMD) and bone mineral apparent density (BMAD) Z-scores, tracking of TBS Z-scores over time, and precision of TBS measurements. We performed secondary analysis of spine dual-energy X-ray absorptiometry (DXA) scans from the Bone Mineral Density in Childhood Study (BMDCS), a mixed longitudinal cohort of healthy children (n = 2014) evaluated at five US centers. TBS was derived using a dedicated TBS algorithm accounting for tissue thickness rather than BMI. TBS increased only during ages corresponding to pubertal development with an earlier increase in females than males. There were no differences in TBS between African Americans and non-African Americans. We provide sex-specific TBS reference ranges and LMS values for calculation of TBS Z-scores by age and means and SD for calculation of Z-scores by pubertal stage. TBS Z-scores were positively associated with height Z-scores at some ages. TBS Z-scores explained only 27% and 17% of the variance of spine aBMD and BMAD Z-scores. Tracking of TBS Z-scores over 6 years was lower (r = 0.47) than for aBMD or BMAD Z-scores (r = 0.74 to 0.79), and precision error of TBS (2.87%) was greater than for aBMD (0.85%) and BMAD (1.22%). In sum, TBS Z-scores provide information distinct from spine aBMD and BMAD Z-scores. Our robust reference ranges for TBS in a well-characterized pediatric cohort and precision error estimates provide essential tools for clinical assessment using TBS and determination of its value in predicting bone fragility in childhood and adolescence. © 2022 American Society for Bone and Mineral Research (ASBMR). 相似文献
168.
Renal Denervation for Treatment of Cardiac Arrhythmias: State of the Art and Future Directions
下载免费PDF全文
![点击此处可从《Journal of cardiovascular electrophysiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
JEDRZEJ KOSIUK M.D. SEBASTIAN HILBERT M.D. EVGENY POKUSHALOV M.D. GERHARD HINDRICKS M.D. Ph.D. JONATHAN S. STEINBERG M.D. ANDREAS BOLLMANN M.D. Ph.D. 《Journal of cardiovascular electrophysiology》2015,26(2):233-238
Renal Denervation for Treatment of Cardiac Arrhythmias . It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future. 相似文献
169.