全文获取类型
收费全文 | 413篇 |
免费 | 19篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 18篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 36篇 |
2012年 | 50篇 |
2011年 | 41篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 23篇 |
2007年 | 15篇 |
2006年 | 20篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2003年 | 13篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 4篇 |
1983年 | 2篇 |
1977年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有432条查询结果,搜索用时 15 毫秒
11.
12.
Filomena Sica Andrea Pica Antonello Merlino Irene Russo Krauss Carmine Ercole Delia Picone 《FEBS letters》2013
Bovine seminal ribonuclease (BS-RNase) acquires an interesting anti-tumor activity associated with the swapping on the N-terminal. The first direct experimental evidence on the formation of a C-terminal swapped dimer (C-dimer) obtained from the monomeric derivative of BS-RNase, although under non-native conditions, is here reported. The X-ray model of this dimer reveals a quaternary structure different from that of the C-dimer of RNase A, due to the presence of three mutations in the hinge peptide 111–116. The mutations increase the hinge peptide flexibility and decrease the stability of the C-dimer against dissociation. The biological implications of the structural data are also discussed. 相似文献
13.
Letizia Antonilli Anna Rita Togna Giovanna Sabatini Alessandro Venditti Laura Guarcini Giuseppina I. Togna Rosario Nicoletti Filomena Sanasi Armandodoriano Bianco Paolo Nencini 《Bioorganic & medicinal chemistry》2013,21(24):7955-7963
We have previously found that phenanthrenic opioids, including codeine, modulate morphine glucuronidation in the rat. Here codeine and five of its derivatives were compared in their effects on the synthesis of morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) from morphine by rat liver microsomal preparations, and by primary cultures of rat hepatocytes previously incubated for 72 h with either codeine or its derivatives. Acetylcodeine and pivaloylcodeine shared the capability of the parent compound of inhibiting the synthesis of M3G by liver microsomes through a noncompetitive mechanism of action. Their IC50 were 3.25, 2.27, and 4.32 μM, respectively. Dihydrocodeine, acetyldihydrocodeine, and lauroylcodeine were ineffective. In all the experimental circumstances M6G was undetectable in the incubation medium. In primary hepatocyte cultures codeine only inhibited M3G formation, but with a lower efficacy than that observed with microsomes (IC50 20.91 vs 4.32 μM). Preliminary results show that at micromolar concentrations codeine derivatives exhibit a low rate of affinity for μ opiate receptors. In conclusion, acetyl and pivaloyl derivatives of codeine noncompetitively inhibit liver glucuronidation of morphine interacting with microsomes. This study further strengths the notion that phenanthrenic opioids can modulate morphine glucuronidation independently from their effects on μ opiate receptors. 相似文献
14.
15.
GbEXPATR,a species‐specific expansin,enhances cotton fibre elongation through cell wall restructuring
下载免费PDF全文
![点击此处可从《Plant biotechnology journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yang Li Lili Tu Filomena A Pettolino Shengmei Ji Juan Hao Daojun Yuan Fenglin Deng Jiafu Tan Haiyan Hu Qing Wang Danny J. Llewellyn Xianlong Zhang 《Plant biotechnology journal》2016,14(3):951-963
Cotton provides us the most important natural fibre. High fibre quality is the major goal of cotton breeding, and introducing genes conferring longer, finer and stronger fibre from Gossypium barbadense to Gossypium hirsutum is an important breeding strategy. We previously analysed the G. barbadense fibre development mechanism by gene expression profiling and found two homoeologous fibre‐specific α‐expansins from G. barbadense, GbEXPA2 and GbEXPATR. GbEXPA2 (from the DT genome) is a classical α‐expansin, while its homoeolog, GbEXPATR (AT genome), encodes a truncated protein lacking the normal C‐terminal polysaccharide‐binding domain of other α‐expansins and is specifically expressed in G. barbadense. Silencing EXPA in G. hirsutum induced shorter fibres with thicker cell walls. GbEXPA2 overexpression in G. hirsutum had no effect on mature fibre length, but produced fibres with a slightly thicker wall and increased crystalline cellulose content. Interestingly, GbEXPATR overexpression resulted in longer, finer and stronger fibres coupled with significantly thinner cell walls. The longer and thinner fibre was associated with lower expression of a number of secondary wall‐associated genes, especially chitinase‐like genes, and walls with lower cellulose levels but higher noncellulosic polysaccharides which advocated that a delay in the transition to secondary wall synthesis might be responsible for better fibre. In conclusion, we propose that α‐expansins play a critical role in fibre development by loosening the cell wall; furthermore, a truncated form, GbEXPATR, has a more dramatic effect through reorganizing secondary wall synthesis and metabolism and should be a candidate gene for developing G. hirsutum cultivars with superior fibre quality. 相似文献
16.
Vilizzi Lorenzo Copp Gordon H. Adamovich Boris Almeida David Chan Joleen Davison Phil I. Dembski Samuel Ekmekçi F. Güler Ferincz Árpád Forneck Sandra C. Hill Jeffrey E. Kim Jeong-Eun Koutsikos Nicholas Leuven Rob S. E. W. Luna Sergio A. Magalhães Filomena Marr Sean M. Mendoza Roberto Mourão Carlos F. Neal J. Wesley Onikura Norio Perdikaris Costas Piria Marina Poulet Nicolas Puntila Riikka Range Inês L. Simonović Predrag Ribeiro Filipe Tarkan Ali Serhan Troca Débora F. A. Vardakas Leonidas Verreycken Hugo Vintsek Lizaveta Weyl Olaf L. F. Yeo Darren C. J. Zeng Yiwen 《Reviews in Fish Biology and Fisheries》2019,29(3):529-568
Reviews in Fish Biology and Fisheries - The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11... 相似文献
17.
Pedro Naves Helena Bragana Filomena Nbrega Carlos Valente 《Journal of Applied Entomology》2019,143(10):1200-1204
Eucalypts are among the most widely planted forest trees in the world, and outside their native Australian range, the main arthropod pests are sap‐sucking insects, defoliators, gall‐making insects and xylophagous beetles. We report on a new association between a polyphagous wood‐boring beetle and Tasmanian blue gum (Eucalyptus globulus Labill.) in Central Portugal. Unidentified wood‐boring insects were found attacking two three‐year‐old E. globulus trees showing signs of decline among otherwise healthy trees in a commercial plantation, in June 2018. Declining trees presented dead twigs and branches, and recently developed epicormic sprouts evident on the trunks. Insects emerging from logs were identified as Ambrosiodmus rubricollis (Eichhoff), a species native to eastern and southern Asia, with the taxonomic identification validated by molecular analysis. To our knowledge, this is the first record of A. rubricollis associated with a eucalypt species worldwide. It is not clear whether the beetles played any significant role on the decline of the trees, but Ambrosiodmus may be potential pests for several tree and shrub species in Europe, as these beetles can transport pathogenic fungi. 相似文献
18.
Eva Raquel Neves Stephan Schäfer Alan Phillips João Canejo Maria Filomena Macedo 《International biodeterioration & biodegradation》2009,63(3):267-272
With many important artistic works and documents made of paper, and thus susceptible to biodeterioration by fungi, research is required in an effort to replace toxic chemical products with other more benign ones. In this work the antifungal effect of methyl and propyl paraben mixtures at different concentrations was evaluated. The fungi used in the experiments were a Cladosporium species and Penicillium corylophilum, both of which are well known as paper-biodeteriorating fungi. The results demonstrate that a mixture of 0.5% methyl paraben and 1% propyl paraben, in 85% ethanolic solution, is the lowest concentration necessary to provide an efficient antifungal action. A deacidification agent, 5% calcium propionate, was added to this mixture to produce a multi-purpose formulation to treat acidification and fungal contamination of paper documents. Tests carried out on paper samples before and after application of this mixture showed only a minor increase in yellowing and a slight decrease in tensile strength, while substantially raising the pH, and thus the alkaline reserve, and also a slight increase in the percentage of deformation. 相似文献
19.
Filomena D’Amato Barbara Noli Laura Angioni Efisio Cossu Michela Incani Irene Messana Barbara Manconi Paola Solinas Raffaella Isola Stefano Mariotti Gian-Luca Ferri Cristina Cocco 《PloS one》2015,10(11)
To address the possible involvement of VGF peptides in obesity and diabetes, we studied type 2 diabetes (T2D) and obese patients, and high-fat diet induced obese mice. Two VGF peptides (NAPP-19 and QQET-30) were identified in human plasma by HPLC-ESI-MS. The VGF C-terminus, the above two cleaved peptides, and the TLQP-21 related peptide/s were studied using ELISA and immunohistochemistry. In euglycemic patients, plasma NAPPE and TLQP like peptides were significantly reduced with obesity (74±10 vs. 167±28, and 92±10 vs. 191±19 pmol/ml, mean+SEM, n = 10 and 6, obese vs. normal BMI, respectively, p<0.03). Upon a standard glucose load, a distinct response was shown for VGF C-terminus, TLQP and QQET-like (ERVW immunoreactive) peptides in euglycemic normal BMI patients, but was virtually abolished in euglycemic obese, and in T2D patients independently of BMI. High-fat diet induced obese mice showed reduced plasma VGF C-terminus, NAPPE and QQET-like (ERVW) peptide/s (3±0.2 vs. 4.6±0.3, 22±3.5 vs. 34±1.3, and 48±7 vs. 100±7 pmol/ml, mean+SEM, n = 8/group, obese vs. slim, respectively, p<0.03), with a loss of the response to glucose for all VGF peptides studied. In immunohistochemistry, TLQP and/or VGF C-terminus antibodies labelled VGF containing perikarya in mouse celiac ganglia, pancreatic islet cells and thin beaded nerve fibres in brown adipose tissues, with fewer in white adipose tissue. Upon the glucose load, tyrosine hydroxylase and VGF C-terminus immunoreactive axons became apparent in pancreatic islets of slim animals, but not in obese animals. Alltogether, a significant loss of VGF peptide immunoreactivity and/or their response to glucose was demonstrated in obese patients, with or without T2D, in parallel with a similar loss in high-fat diet induced obese mice. An involvement of VGF in metabolic regulations, including those of brown and/or white adipose tissues is underlined, and may point out specific VGF peptides as potential targets for diagnosis and/or treatment. 相似文献
20.
Daniele Amadio Filomena Fezza Giuseppina Catanzaro Ottaviano Incani Guus van Zadelhoff Alessandro Finazzi Agrò Mauro Maccarrone 《Biochimie》2010
The biological activity of endocannabinoids like anandamide (AEA) and 2-arachidonoylglycerol (2-AG) is subjected in vivo to a “metabolic control”, exerted mainly by catabolic enzymes. AEA is inactivated by fatty acid amide hydrolase (FAAH), that is inhibited competitively by hydroxyanandamides (HAEAs) generated from AEA by lipoxygenase activity. Among these derivatives, 15-HAEA has been shown to be an effective (Ki ∼0.6 μM) FAAH inhibitor, that blocks also type-1 cannabinoid receptor (CB1R) but not other components of the “endocannabinoid system (ECS)”, like the AEA transporter (AMT) or CB2R. Here, we extended the study of the effect of 15-HAEA on the AEA synthetase (NAPE-PLD) and the AEA-binding vanilloid receptor (TRPV1), showing that 15-HAEA activates the former (up to ∼140% of controls) and inhibits the latter protein (down to ∼70%). We also show that 15-HAEA halves the synthesis of 2-AG and almost doubles the transport of this compound across the membrane. In addition, we synthesized methyl and acetyl derivatives of 15-HAEA (15-MeOAEA and 15-AcOAEA, respectively), in order to check their ability to modulate FAAH and the other ECS elements. In fact, methylation and acetylation are common biochemical reactions in the cellular environment. We show that 15-MeOAEA, unlike 15-AcOAEA, is still a powerful competitive inhibitor of FAAH (Ki ∼0.7 μM), and that both derivatives have negligible interactions with the other proteins of ECS. Therefore, 15-MeOAEA is a FAAH inhibitor more selective than 15-HAEA. Further molecular dynamics analysis gave clues to the molecular requirements for the interaction of 15-HAEA and 15-MeOAEA with FAAH. 相似文献