全文获取类型
收费全文 | 727篇 |
免费 | 81篇 |
国内免费 | 36篇 |
出版年
2024年 | 5篇 |
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 19篇 |
2020年 | 26篇 |
2019年 | 17篇 |
2018年 | 20篇 |
2017年 | 27篇 |
2016年 | 23篇 |
2015年 | 15篇 |
2014年 | 32篇 |
2013年 | 49篇 |
2012年 | 17篇 |
2011年 | 39篇 |
2010年 | 23篇 |
2009年 | 51篇 |
2008年 | 43篇 |
2007年 | 42篇 |
2006年 | 31篇 |
2005年 | 23篇 |
2004年 | 21篇 |
2003年 | 23篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 19篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 16篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 4篇 |
排序方式: 共有844条查询结果,搜索用时 0 毫秒
841.
《Endocrine practice》2023,29(7):525-528
ObjectiveWhile surgical resection has been the traditional standard treatment for small (≤1 cm), differentiated thyroid cancers, active surveillance (AS) and radiofrequency ablation (RFA) are increasingly considered. The aim of this study was to explore patient preferences in thyroid cancer treatment using a series of clinical vignettes.MethodsThyroid cancer survivors and general population volunteers were recruited to rank experience-driven clinical vignettes in order of preference. Rankings were compared using Wilcoxon signed rank. Formative qualitative methods were used to develop and refine clinical vignettes that captured 4 treatments—thyroid lobectomy (TL), total thyroidectomy (TT), AS, and RFA—along with 6 treatment complications. Content was validated via interviews with 5 academic subspecialists.ResultsNineteen volunteers participated (10 survivors, 9 general population). Treatment complications were ranked lower than uncomplicated counterparts in 99.0% of cases, indicating excellent comprehension. Counter to our hypothesis, among uncomplicated vignettes, median rankings were 1 for AS, 2 for RFA, 3.5 for TL, and 5 for TT. Trends were consistent between thyroid cancer survivors and the general population. AS was significantly preferred over RFA (P = .02) and TT (P < .01). Among surgical options, TL was significantly preferred over TT (P < .01).ConclusionWhen treatments for low-risk thyroid cancer are described clearly and accurately through clinical vignettes, patients may be more likely to choose less invasive treatment options over traditional surgical resection. 相似文献
842.
Takumi Yamada H. Thomas McElderry James D Allred Harish Doppalapudi G. Neal Kay 《Indian pacing and electrophysiology journal》2010,10(3):152-155
An 83-year-old man underwent electrophysiological testing for focal atrial tachycardia (AT) exhibiting narrow P waves with negative deflections in the inferior leads. Catheter ablation at the cavo-tricuspid isthmus (CTI) successfully eliminated the AT. The propagation map during AT and pacing study from the successful ablation site demonstrated that the atrial activation throughout the CTI did not produce significant P wave deflections. Consequently, during AT, the left atrial activation time determined the P wave duration. This case demonstrates that AT originating from the CTI may exhibit narrow P waves which can be misinterpreted as AT originating from the inter-atrial septum. 相似文献
843.
Abstract Permanent oestrus was induced in 24, 61 and 100% of 2‐months old Wistar rats under conditions of continuous light exposure (LL) for 1, 2 and 6 months, respectively. After cessation of 2 months LL, rhythmic fluctuations of oestrus activity were observed. The weight of newborns produced by females under LL during pregnancy was increased by 7% as compared to controls (P < 0.05). LL before mating did not affect embryonic development. 20‐day old pups produced by females which were kept in LL for 1, 2 months and more were significantly heavier than controls by 5, 18 and 30%, respectively. The stimulatory effect of LL for 1 and 2 months on pre‐ and postnatal development was maintained in the subsequent reproduction cycle, when these females were transferred to normal conditions of LD 14:10. 相似文献
844.
Kevin H. Mayo Judith Haseman Elena Ilyina Beulah Gray 《Biochimica et Biophysica Acta (BBA)/General Subjects》1998,1425(1):81-92
Novel peptide 33mers have been designed by incorporating β-conformation stabilizing residues from the β-sheet domains of α-chemokines and functionally important residues from the β-sheet domain of human neutrophil bactericidal protein (B/PI). B/PI is known for its ability to kill bacteria and to neutralize the action of bacterial endotoxin (lipopolysaccharide, LPS) which can induce septic shock leading to eventual death. Here, the goal was to make short linear peptides which demonstrate good β-sheet folding and maintain bioactivity as in native B/PI. A library of 24 peptide 33mers (βpep-1 to βpep-24) were synthesized with various amino acid substitutions. CD and NMR data acquired in aqueous solution indicate that βpep peptides form β-sheet structure to varying degrees and self-associate as dimers and tetramers like the α-chemokines. Bactericidal activity toward Gram-negative Pseudomonas aeruginosa was tested, and βpep-19 was found to be only about 5-fold less potent (62% kill at 1.2×10?7 M) than native B/PI (80% kill at 2.9×10?8 M). At LPS neutralization, βpep-2 and -23 were found to be most active (66–78% effective at 1.2×10?6 M), being only about 50–100-fold less active than B/PI (50% at 1.5×10?8 M). In terms of structure–activity relations, β-sheet structural stability correlates with the capacity to neutralize LPS, but not with bactericidal activity. Although a net positive charge is necessary for activity, it is not sufficient for optimal activity. Hydrophobic residues tend to influence activities indirectly by affecting structural stability. Furthermore, results show that sequentially and spatially related residues from the β-sheet domain of native B/PI can be designed into short linear peptides which show good β-sheet folding and retain much of the native activity. This research contributes to the development of solutions to the problem of multiple drug-resistant, opportunistic microorganisms like P. aeruginosa and of agents effective at neutralizing bacterial endotoxin. 相似文献