全文获取类型
收费全文 | 1952篇 |
免费 | 132篇 |
出版年
2023年 | 11篇 |
2022年 | 22篇 |
2021年 | 41篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 38篇 |
2017年 | 32篇 |
2016年 | 61篇 |
2015年 | 101篇 |
2014年 | 107篇 |
2013年 | 120篇 |
2012年 | 142篇 |
2011年 | 135篇 |
2010年 | 80篇 |
2009年 | 86篇 |
2008年 | 117篇 |
2007年 | 111篇 |
2006年 | 98篇 |
2005年 | 93篇 |
2004年 | 80篇 |
2003年 | 79篇 |
2002年 | 75篇 |
2001年 | 28篇 |
2000年 | 18篇 |
1999年 | 24篇 |
1998年 | 25篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 17篇 |
1990年 | 15篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1986年 | 8篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1970年 | 6篇 |
1965年 | 5篇 |
1964年 | 8篇 |
1960年 | 4篇 |
1955年 | 5篇 |
排序方式: 共有2084条查询结果,搜索用时 15 毫秒
71.
72.
PurposeTo compare intraocular pressure (IOP) reduction and to develop a predictive surgery calculator based on the results between trabectome-mediated ab interno trabeculectomy in pseudophakic patients versus phacoemulsification combined with trabectome-mediated ab interno trabeculectomy in phakic patients.MethodsThis observational surgical cohort study analyzed pseudophakic patients who received trabectome-mediated ab interno trabeculectomy (AIT) or phacoemulsification combined with AIT (phaco-AIT). Follow up for less than 12 months or neovascular glaucoma led to exclusion. Missing data was imputed by generating 5 similar but non-identical datasets. Groups were matched using Coarsened Exact Matching based on age, gender, type of glaucoma, race, preoperative number of glaucoma medications and baseline intraocular pressure (IOP). Linear regression was used to examine the outcome measures consisting of IOP and medications.ResultsOf 949 cases, 587 were included consisting of 235 AIT and 352 phaco-AIT. Baseline IOP between groups was statistically significant (p≤0.01) in linear regression models and was minimized after Coarsened Exact Matching. An increment of 1 mmHg in baseline IOP was associated with a 0.73±0.03 mmHg IOP reduction. Phaco-AIT had an IOP reduction that was only 0.73±0.32 mmHg greater than that of AIT. The resulting calculator to determine IOP reduction consisted of the formula -13.54+0.73 × (phacoemulsification yes:1, no:0) + 0.73 × (baseline IOP) + 0.59 × (secondary open angle glaucoma yes:1, no:0) + 0.03 × (age) + 0.09 × (medications).ConclusionsThis predictive calculator for minimally invasive glaucoma surgery can assist clinical decision making. Only a small additional IOP reduction was observed when phacoemulsification was added to AIT. Patients with a higher baseline IOP had a greater IOP reduction. 相似文献
73.
74.
75.
Nils Pilotte Marina Papaiakovou Jessica R. Grant Lou Ann Bierwert Stacey Llewellyn James S. McCarthy Steven A. Williams 《PLoS neglected tropical diseases》2016,10(3)
BackgroundThe soil transmitted helminths are a group of parasitic worms responsible for extensive morbidity in many of the world’s most economically depressed locations. With growing emphasis on disease mapping and eradication, the availability of accurate and cost-effective diagnostic measures is of paramount importance to global control and elimination efforts. While real-time PCR-based molecular detection assays have shown great promise, to date, these assays have utilized sub-optimal targets. By performing next-generation sequencing-based repeat analyses, we have identified high copy-number, non-coding DNA sequences from a series of soil transmitted pathogens. We have used these repetitive DNA elements as targets in the development of novel, multi-parallel, PCR-based diagnostic assays.Conclusions/SignificanceThe utilization of next-generation sequencing-based repeat DNA analysis methodologies for the identification of molecular diagnostic targets has the ability to improve assay species-specificity and limits of detection. By exploiting such high copy-number repeat sequences, the assays described here will facilitate soil transmitted helminth diagnostic efforts. We recommend similar analyses when designing PCR-based diagnostic tests for the detection of other eukaryotic pathogens. 相似文献
76.
Adam Rick Bessa-Silva Marcelo Vallinoto Davidson Sodré Divino Bruno da Cunha Dante Hadad Nils Edvin Asp Iracilda Sampaio Horacio Schneider Fernando Sequeira 《PloS one》2016,11(4)
The Amazonian coast has several unique geological characteristics resulting from the interaction between drainage pattern of the Amazon River and the Atlantic Ocean. It is one of the most extensive and sedimentologically dynamic regions of the world, with a large number of continental islands mostly formed less than 10,000 years ago. The natural distribution of the cane toad (Rhinella marina), one of the world’s most successful invasive species, in this complex Amazonian system provides an intriguing model for the investigation of the effects of isolation or the combined effects of isolation and habitat dynamic changes on patterns of genetic variability and population differentiation. We used nine fast-evolving microsatellite loci to contrast patterns of genetic variability in six coastal (three mainlands and three islands) populations of the cane toad near the mouth of the Amazon River. Results from Bayesian multilocus clustering approach and Discriminant Analyses of Principal Component were congruent in showing that each island population was genetically differentiated from the mainland populations. All FST values obtained from all pairwise comparisons were significant, ranging from 0.048 to 0.186. Estimates of both recent and historical gene flow were not significantly different from zero across all population pairs, except the two mainland populations inhabiting continuous habitats. Patterns of population differentiation, with a high level of population substructure and absence/restricted gene flow, suggested that island populations of R. marina are likely isolated since the Holocene sea-level rise. However, considering the similar levels of genetic variability found in both island and mainland populations, it is reliable to assume that they were also isolated for longer periods. Given the genetic uniqueness of each cane toad population, together with the high natural vulnerability of the coastal regions and intense human pressures, we suggest that these populations should be treated as discrete units for conservation management purposes. 相似文献
77.
78.
79.
80.
PTPRN2 and PLCβ1 promote metastatic breast cancer cell migration through PI(4,5)P2‐dependent actin remodeling 下载免费PDF全文
Caitlin A Sengelaub Kristina Navrazhina Jason B Ross Nils Halberg Sohail F Tavazoie 《The EMBO journal》2016,35(1):62-76
Altered abundance of phosphatidyl inositides (PIs) is a feature of cancer. Various PIs mark the identity of diverse membranes in normal and malignant cells. Phosphatidylinositol 4,5‐bisphosphate (PI(4,5)P2) resides predominantly in the plasma membrane, where it regulates cellular processes by recruiting, activating, or inhibiting proteins at the plasma membrane. We find that PTPRN2 and PLCβ1 enzymatically reduce plasma membrane PI(4,5)P2 levels in metastatic breast cancer cells through two independent mechanisms. These genes are upregulated in highly metastatic breast cancer cells, and their increased expression associates with human metastatic relapse. Reduction in plasma membrane PI(4,5)P2 abundance by these enzymes releases the PI(4,5)P2‐binding protein cofilin from its inactive membrane‐associated state into the cytoplasm where it mediates actin turnover dynamics, thereby enhancing cellular migration and metastatic capacity. Our findings reveal an enzymatic network that regulates metastatic cell migration through lipid‐dependent sequestration of an actin‐remodeling factor. 相似文献