全文获取类型
收费全文 | 2412篇 |
免费 | 175篇 |
出版年
2024年 | 2篇 |
2023年 | 34篇 |
2022年 | 63篇 |
2021年 | 111篇 |
2020年 | 87篇 |
2019年 | 101篇 |
2018年 | 86篇 |
2017年 | 80篇 |
2016年 | 118篇 |
2015年 | 177篇 |
2014年 | 154篇 |
2013年 | 191篇 |
2012年 | 179篇 |
2011年 | 172篇 |
2010年 | 108篇 |
2009年 | 79篇 |
2008年 | 117篇 |
2007年 | 119篇 |
2006年 | 102篇 |
2005年 | 101篇 |
2004年 | 74篇 |
2003年 | 68篇 |
2002年 | 56篇 |
2001年 | 25篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 18篇 |
1997年 | 12篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有2587条查询结果,搜索用时 43 毫秒
91.
92.
Jackson Fabio Preuss Carolina Lambertini Domingos da Silva Leite Luís Felipe Toledo Elaine Maria Lucas 《Studies on Neotropical Fauna and Environment》2016,51(1):68-77
The fungal infection caused by Batrachochytrium dendrobatidis (Bd) in amphibians is known to be lethal when infection intensity values exceed loads of 10,000 zoospores per individual. We investigated Bd infection intensity in 100 anurans of southern Brazil. Almost half of the individuals were infected and the intensity ranged from four to about 156,000 zoospore genomic equivalents. We found no clinical signs of chytridiomycosis and no evidence of mortality. However, we observed a reduction in the number of infected individuals with loads above 10,000 zoospores. This fact could be considered indirect evidence that individuals with high loads are removed from the population. 相似文献
93.
94.
95.
Enilson B. Silva Felipe G. Fonseca Luís R. F. Alleoni Sandra S. Nascimento Paulo H. Grazziotti Bárbara O. Nardis 《International journal of phytoremediation》2016,18(9):847-852
It is important to know the mechanisms for forage development, especially those related to the tolerance of potentially toxic elements, when considering their use in phytoremediation in heavy metal contaminated areas. In this study, we evaluated plant growth, concentration, and the availability of cadmium (Cd) for forage grasses (Panicum maximum Jacq. cv. Aruana and cv. Tanzânia; Brachiaria decumbens cv. Basilisk; Brachiaria brizantha cv. Xaraés and cv. Marandu) cultivated in Cd contaminated soils. The experiments were performed under greenhouse conditions over a 90-day evaluation period, and the Cd rates were 2, 4, and 12 mg/kg of soil. The relative growth rate of the forage grasses decreased as Cd rates increased, and the following descending order of susceptibility was observed: Marandu > Xaraés > Aruana > Tanzânia > Basilisk, with regard to phytotoxicity in these plants. The forage Cd concentration increased in line with increases in the Cd rates. Cd contents extracted by Mehlich-1 and by diethylenetriaminepentaacetic acid presented high positive correlation with forage relative growth. The forage plants did not block Cd entry into the food chain because they were not capable of limiting Cd absorption. 相似文献
96.
Leonardo da Costa Bastos Felipe Rodrigues de Souza Ana Paula Guimarães Mehdi Sirouspour Teobaldo Ricardo Cuya Guizado Pat Forgione 《Journal of biomolecular structure & dynamics》2016,34(10):2184-2198
In the present work, we propose to design drugs that target the enzyme dihydrofolate redutase (DHFR) as a means of a novel drug therapy against plague. Potential inhibitors of DHFR from Yersinia pestis (YpDHFR) were selected by virtual screening and subjected to docking, molecular dynamics (MD) simulations, and Poisson–Boltzmann surface area method, in order to evaluate their interactions in the active sites of YpDHFR and human DHFR (HssDHFR). The results suggested selectivity for three compounds that were further used to propose the structures of six new potential selective inhibitors for YpDHFR. 相似文献
97.
98.
99.
María N. Barrachina Aurelio M. Sueiro Vanessa Casas Irene Izquierdo Lidia Hermida‐Nogueira Esteban Guitin Felipe F. Casanueva Joaquín Abin Montserrat Carrascal María Pardo ngel García 《Proteomics》2019,19(1-2)
Plasma‐derived extracellular vesicles (EVs) have been extensively described as putative biomarkers in different diseases. Interestingly, increased levels of EVs subpopulations are well known to associate with obesity. The goal of this study is to identify EVs‐derived biomarkers in plasma from obese patients in order to predict the development of pathological events associated with obesity. Samples are obtained from 22 obese patients and their lean‐matched controls are divided into two cohorts: one for a 2D fluorescence difference gel electrophoresis (2D‐DIGE)‐based study, and the other one for a label free LC–MS/MS‐based approach. EVs are isolated following a serial ultracentrifugation protocol. Twenty‐two and 23 differentially regulated features are detected from 2D‐DIGE and label free LC–MS/MS, respectively; most of them involve in the coagulation and complement cascades. Remarkably, there is an upregulation of complement C4, complement C3, and fibrinogen in obese patients following both approaches, the latter two also validated by 2D‐western‐blotting in an independent cohort. These results correlate with a proinflammatory and prothrombotic state of those individuals. On the other hand, a downregulation of adiponectin leading to an increased risk of suffering cardiovascular diseases has been shown. The results suggest the relevance of plasma‐derived‐EVs proteins as a source of potential biomarkers for the development of atherothrombotic events in obesity. 相似文献
100.
Felipe Couñago Ana Aurora Díaz Gavela Gemma Sancho Irene Ortiz Francisco José Marcos Manuel Recio Julio Fernández Raquel Cano Mar Jiménez Israel J. Thuissard David Sanz-Rosa Juan Castro Nováis Eduardo Pardo Yolanda Molina Hugo Pérez García Elia del Cerro 《Reports of Practical Oncology and Radiotherapy》2019,24(5):472-480
AimTo analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.BackgroundMultiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).ResultsLocal, lymph node, and pelvic bone recurrence was observed in 13, 4 and 2 patients, respectively. PSA levels were significantly lower in patients with negative mpMRI (0.4 ng/mL [0.4]) vs. positive mpMRI (2.2 ng/mL [4.1], p = 0.003). Median planning target volume doses in patients with visible vs. non-visible recurrences were 76 Gy vs. 70 Gy. Overall, mean follow-up was 41 months (6–81). Biochemical relapse-free survival (bRFS) at 3 years was 82.3% and 82.5%, respectively, for the negative and positive mpMRI groups (p = 0.800). Three-year rates of late grade ≥2 urinary and rectal toxicity were 14.8% and 1.9%, respectively; all but one patient recovered without sequelae.ConclusionSRT to the macroscopic recurrence identified by mpMRI is a feasible and well-tolerated option. In this study, there were no differences in bRFS between MRI-positive and MRI-negative patients, indicating effective targeting of MRI-positive lesions. 相似文献