全文获取类型
收费全文 | 464篇 |
免费 | 43篇 |
国内免费 | 1篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 24篇 |
2020年 | 22篇 |
2019年 | 34篇 |
2018年 | 26篇 |
2017年 | 19篇 |
2016年 | 17篇 |
2015年 | 32篇 |
2014年 | 34篇 |
2013年 | 41篇 |
2012年 | 46篇 |
2011年 | 28篇 |
2010年 | 18篇 |
2009年 | 17篇 |
2008年 | 18篇 |
2007年 | 18篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有508条查询结果,搜索用时 31 毫秒
41.
Yousefi Fatemeh Najafi Hadi Behmanesh Mehrdad Soltani Bahram M. 《Molecular biology reports》2022,49(5):3377-3387
Molecular Biology Reports - Aberrant activation of the Wnt signaling pathway is observed in most colorectal cancers (CRC). OCC-1D is a splice variant of OCC-1 gene which is considered as a long... 相似文献
42.
Inhibitory Effect of Hsa‐miR‐590‐5p on Cardiosphere‐derived Stem Cells Differentiation Through Downregulation of TGFB Signaling 下载免费PDF全文
43.
Temporal variation of Bistorta vivipara‐associated ectomycorrhizal fungal communities in the High Arctic 下载免费PDF全文
Sunil Mundra Mohammad Bahram Leho Tedersoo Håvard Kauserud Rune Halvorsen Pernille Bronken Eidesen 《Molecular ecology》2015,24(24):6289-6302
Ectomycorrhizal (ECM) fungi are important for efficient nutrient uptake of several widespread arctic plant species. Knowledge of temporal variation of ECM fungi, and the relationship of these patterns to environmental variables, is essential to understand energy and nutrient cycling in Arctic ecosystems. We sampled roots of Bistorta vivipara ten times over two years; three times during the growing‐season (June, July and September) and twice during winter (November and April) of both years. We found 668 ECM OTUs belonging to 25 different ECM lineages, whereof 157 OTUs persisted throughout all sampling time‐points. Overall, ECM fungal richness peaked in winter and species belonging to Cortinarius, Serendipita and Sebacina were more frequent in winter than during summer. Structure of ECM fungal communities was primarily affected by spatial factors. However, after accounting for spatial effects, significant seasonal variation was evident revealing correspondence with seasonal changes in environmental conditions. We demonstrate that arctic ECM richness and community structure differ between summer (growing‐season) and winter, possibly due to reduced activity of the core community, and addition of fungi adapted for winter conditions forming a winter‐active fungal community. Significant month × year interactions were observed both for fungal richness and community composition, indicating unpredictable between‐year variation. Our study indicates that addressing seasonal changes requires replication over several years. 相似文献
44.
45.
Reza Heidari Hossein Niknahad Akram Jamshidzadeh Negar Azarpira Mandana Bazyari Asma Najibi 《Journal of biochemical and molecular toxicology》2015,29(4):173-181
Liver injury is a deleterious adverse effect associated with methimazole administration, and reactive intermediates are suspected to be involved in this complication. Glyoxal is an expected reactive intermediate produced during methimazole metabolism. Current investigation was undertaken to evaluate the role of carnosine, metformin, and N‐acetyl cysteine as putative glyoxal (carbonyl) traps, against methimazole‐induced hepatotoxicity. Methimazole (100 mg/kg, intraperitoneally) was administered to intact and/or glutathione (GSH)?depleted mice and the role of glyoxal trapping agents was investigated. Methimazole caused liver injury as revealed by an increase in serum alanine aminotransferase and aspartate aminotransferase. Moreover, lipid peroxidation and protein carbonylation occurred significantly in methimazole?treated animals’ liver. Hepatic GSH reservoirs were decreased, and inflammatory cells infiltration was observed in liver histopathology. Methimazole?induced hepatotoxicity was severe in GSH‐depleted mice and accompanied with interstitial hemorrhage and necrosis of the liver. Glyoxal trapping agents effectively diminished methimazole‐induced liver injury both in intact and/or GSH?depleted animals. 相似文献
46.
Fine root foraging strategies in Norway spruce forests across a European climate gradient 总被引:1,自引:0,他引:1
Ivika Ostonen Heljä‐Sisko Helmisaari Werner Borken Leho Tedersoo Mai Kukumägi Mohammad Bahram Antti‐Jussi Lindroos Pekka Nöjd Veiko Uri Päivi Merilä Endla Asi Krista Lõhmus 《Global Change Biology》2011,17(12):3620-3632
Fine root acclimation to different environmental conditions is crucial for growth and sustainability of forest trees. Relatively small changes in fine root standing biomass (FRB), morphology or mycorrhizal symbiosis may result in a large change in forest carbon, nutrient and water cycles. We elucidated the changes in fine root traits and associated ectomycorrhizal (EcM) fungi in 12 Norway spruce stands across a climatic and N deposition gradient from subarctic‐boreal to temperate regions in Europe (68°N–48°N). We analysed the standing FRB and the ectomycorrhizal root tip biomass (EcMB, g m?2) simultaneously with measurements of the EcM root morphological traits (e.g. mean root length, root tissue density (RTD), N% in EcM roots) and frequency of dominating EcM fungi in different stands in relation to climate, soil and site characteristics. Latitude and N deposition explained the greatest proportion of variation in fine root traits. EcMB per stand basal area (BA) increased exponentially with latitude: by about 12.7 kg m?2 with an increase of 10° latitude from southern Germany to Estonia and southern Finland and by about 44.7 kg m?2 with next latitudinal 10° from southern to northern Finland. Boreal Norway spruce forests had 4.5 to 11 times more EcM root tips per stand BA, and the tips were 2.1 times longer, with 1.5 times higher RTD and about 1/3 lower N concentration. There was 19% higher proportion of root tips colonized by long‐distance exploration type forming EcM fungi in the southern forests indicating importance of EcM symbiont foraging strategy in fine root nutrient acquisition. In the boreal zone, we predict ca. 50% decrease in EcMB per stand BA with an increase of 2 °C annual mean temperature. Different fine root foraging strategies in boreal and temperate forests highlight the importance of complex studies on respective regulatory mechanisms in changing climate. 相似文献
47.
Reproductive or neotenic soldiers of the Archotermopsid Zootermopsis nevadensisnevadensis (Hagen) are compared to sterile soldiers and primary male reproductives. Several head capsule morphometrics correlate significantly with gonad size across all forms and both sexes of soldiers. The easily observed field character of ratio of mandible length to labrum length is a consistent and reliable feature of head capsule external morphology for predicting gonad development and reproductive potential of soldier forms regardless of age, sex, or live weight. 相似文献
48.
Song X Rampitsch C Soltani B Mauthe W Linning R Banks T McCallum B Bakkeren G 《Proteomics》2011,11(5):944-963
Puccinia triticina (Pt) is a representative of several cereal-infecting rust fungal pathogens of major economic importance world wide. Upon entry through leaf stomata, these fungi establish intracellular haustoria, crucial feeding structures. We report the first proteome of infection structures from parasitized wheat leaves, enriched for haustoria through filtration and sucrose density centrifugation. 2-D PAGE MS/MS and gel-based LC-MS (GeLC-MS) were used to separate proteins. Generated spectra were compared with a partial proteome predicted from a preliminary Pt genome and generated ESTs, to a comprehensive genome-predicted protein complement from the related wheat stem rust fungus, Puccinia graminis f. sp. tritici (Pgt) and to various plant resources. We identified over 260 fungal proteins, 16 of which matched peptides from Pgt. Based on bioinformatic analyses and/or the presence of a signal peptide, at least 50 proteins were predicted to be secreted. Among those, six have effector protein signatures, some are related and the respective genes of several seem to belong to clusters. Many ribosomal structural proteins, proteins involved in energy, general metabolism and transport were detected. Measuring gene expression over several life cycle stages of ten representative candidates using quantitative RT-PCR, all were shown to be strongly upregulated and four expressed solely upon infection. 相似文献
49.
50.
Gerami S Jahromi KT Ashouri A Rasoulian G Heidari A 《Communications in agricultural and applied biological sciences》2005,70(4):779-785
In this study we report the sublethal effects of recommended concentrations of imidacloprid and pymetrozine on cotton aphid's reproduction. Fecundity life table parameters for AG were studied on cucumber under conditions of 25+/-1 degrees C, 70+/-5% RH and photoperiod of 16:8 (L:D). Leaf discs of cucumber immersed in the recommended concentrations of the above mentioned insecticides and controls and the new born female was released on the lower surface of leaf discs. Values of parameters such as adult longevity and daily fecundity rate were recorded. Standard error of population growth parameter was calculated using the Jacknife method. The results show that these two insecticides significantly reduce life table parameters compared with control. 相似文献