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排序方式: 共有613条查询结果,搜索用时 671 毫秒
101.
Gustavious Williams Patrick Sawyer Richard Venedam Veronica E. Wannberg 《Canadian Metallurgical Quarterly》2011,15(1):26-36
This paper compares three current state-of-the-practice models, ALOHA, EPICode, and SCIPUFF for use in safety evaluations using data from a unique full-scale field experiment under low-wind speed conditions. The experiment included the release and transport of three gases: ammonia (buoyant), ethylene (neutral buoyant), and propylene (dense) in low-wind speed (diffusion) conditions, less than 2 m/s. In total there were 30 releases ranging from 6 to 30 min in duration. The diagnostics included nine meteorology stations on 100-m centers and 36 photo ionization detectors in a radial pattern. Diffusive conditions are difficult to model, and all of the models had difficulty replicating the field measurements. However, the work does show that these models, if used correctly, are conservative (overpredict concentrations) and can be used for safety and emergency planning. 相似文献
102.
Veronica M.T. Lattanzio Biancamaria Ciasca Valeria Terzi Roberta Ghizzoni Susan P. McCormick Michelangelo Pascale 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2015,32(10):1647-1655
This paper reports a new method for the determination of T-2 and HT-2 toxins and their glucosylated derivatives in cereals, and some survey data aimed at obtaining more comprehensive information on the co-occurrence of T-2 and HT-2 toxins and their glucosylated derivatives in naturally contaminated cereal samples. For these purposes, barley samples originating from a Northern Italian area were analysed by LC-HRMS for the presence of T-2, HT-2 and relevant glucosyl derivatives. Quantitative analysis of T-2 and HT-2 glucosides was performed for the first time using a recently made available standard of T-2 glucoside. The glucosyl derivative of HT-2 was detected at levels up to 163 µg kg–1 in 17 of the 18 analysed unprocessed barley grains, whereas the monoglucosyl derivative of T-2 toxin was detected in only a few samples and at low µg kg–1 levels. The ratio between glucosylated toxins (sum of T-2 and HT-2 glucosides) and native toxins (sum of T-2 and HT-2) ranged from 2% to 283%. Moreover, taking advantage of the possibility of retrospective analysis of full-scan HRMS chromatograms, samples were also screened for the presence of other type-A trichothecenes, namely neosolaniol, diacetoxyscirpenol and their monoglucosyl derivatives, which were detected at trace levels. A subset of nine different samples was subjected to micro-maltation in order to carry out a preliminary investigation on the fate of T-2, HT-2 and relevant glucosides along the malting process. Mycotoxin reduction from cleaned barley to malt was observed at rates ranging from 4% to 87%. 相似文献
103.
Antonella Virgilio Daniela Benigno Annalisa Pecoraro Annapina Russo Giulia Russo Veronica Esposito Aldo Galeone 《International journal of molecular sciences》2021,22(13)
In this paper, we report our investigations on five analogues, prepared by replacing sequence thymidines with abasic sites (S) one at a time, in comparison to their natural counterpart in order to evaluate their antiproliferative potential and the involvement of the residues not belonging to the central core of stacked guanosines in biological activity. The collected NMR (Nuclear Magnetic Resonance), CD (Circular Dichroism), and PAGE (Polyacrylamide Gel Electrophoresis) data strongly suggest that all of them adopt G-quadruplex (G4) structures strictly similar to that of the parent aptamer with the ability to fold into a dimeric structure composed of two identical G-quadruplexes, each characterized by parallel strands, three all-anti-G-tetrads and four one-thymidine loops (one bulge and three propeller loops). Furthermore, their antiproliferative (MTT assay) and anti-motility (wound healing assay) properties against lung and colorectal cancer cells were tested. Although all of the oligodeoxynucleotides (ODNs) investigated here exhibited anti-proliferative activity, the unmodified T30175 aptamer showed the greatest effect on cell growth, suggesting that both its characteristic folding in dimeric form and its presence in the sequence of all thymidines are crucial elements for antiproliferative activity. This straightforward approach is suitable for understanding the critical requirements of the G-quadruplex structures that affect antiproliferative potential and suggests its application as a starting point to facilitate the reasonable development of G-quadruplexes with improved anticancer properties. T30175相似文献
104.
Justin Kurian Veronica Bohl Michael Behanan Sadia Mohsin Mohsin Khan 《International journal of molecular sciences》2021,22(13)
Metabolism has emerged as a regulator of core stem cell properties such as proliferation, survival, self-renewal, and multilineage potential. Metabolites serve as secondary messengers, fine-tuning signaling pathways in response to microenvironment alterations. Studies show a role for central metabolite acetyl-CoA in the regulation of chromatin state through changes in histone acetylation. Nevertheless, metabolic regulators of chromatin remodeling in cardiac cells in response to increasing biological age remains unknown. Previously, we identified novel cardiac-derived stem-like cells (CTSCs) that exhibit increased functional properties in the neonatal heart (nCTSC). These cells are linked to a unique metabolism which is altered with CTSC aging (aCTSC). Here, we present an in-depth, RNA-sequencing-based (RNA-Seq) bioinformatic with cluster analysis that details a distinct epigenome present in nCTSCs but not in aCTSCs. Gene Ontology (GO) and pathway enrichment reveal biological processes, including metabolism, gene regulation enriched in nCTSCs, and STRING analysis that identifies a network of genes related to acetyl-CoA that can potentially influence chromatin remodeling. Additional validation by Western blot and qRT-PCR shows increased acetyl-CoA signaling and histone acetylation in nCTSCs compared to aCTSCs. In conclusion, our data reveal that the link between metabolism and histone acetylation in cardiac cells is altered with the aging of the cardiac tissue. 相似文献
105.
106.
Song J Chen M Olesen MB Wang C Havelund R Li Q Xie E Yang R Bøggild P Wang C Besenbacher F Dong M 《Nanoscale》2011,3(12):4966-4971
Core-sheath silver nanowire/polyvinylpyrrolidone (AgNW/PVP) nanocables have been fabricated via an efficient single-spinneret electrospinning method. The core-sheath structure is revealed by combining several characterization methods. A possible formation mechanism of the AgNW/PVP nanocable involving a strong stretching during the electrospinning process is proposed. Further, electrical measurements were performed on AgNW/PVP nanocables as well as bare AgNWs, which indicated the nanocables became insulating due to the isolation of highly conductive AgNWs by insulating PVP sheath. Therefore, the described fabrication method holds potential for the fabrication of low-cost metal/polymer composite materials for nanoelectronic applications in general. 相似文献
107.
Claudio Colleoni Maria Rosaria Massafra Veronica Migani Giuseppe Rosace 《应用聚合物科学杂志》2011,120(4):2122-2129
Textile finishing includes all processes that help to maintain the value or increase the value of the textile material. It encompasses dyeing, printing, and all the finishing treatments to realize durable press, soil release, flame retardant, antistatic, antimicrobial, or water/oil repellency properties. When these properties are realized on dyed textile fabric, one effect could be ascribed to the color change induced by finishing operations. This research focuses on the assessment of color alterations occurring on the dyed cotton/polyester blended fabrics due to the nanoparticle‐sized dendrimer (DWR), dendrimer–fluorocarbon (DWOR), and fluorocarbon (FWOR) finishing onto their surfaces. The dependence of color on the surface state of treated textiles is calculated in the context of spectrophotometric measurements. Modification of the surface roughness by reflectance spectrum and the absorbance of finishes in visible range were investigated to determine color changes between the original (control fabric, dyed but not treated) and treated fabrics. As a result of color matching calculated by CIE‐Lab values, color change is related to the surface roughness associated with absorbance values of applied finishes. In addition, fabrics mechanical properties were evaluated to estimate if finishing agents application gives rise to other changes, besides color alterations. The fabrics mechanical properties have been found not significantly altered by the aforementioned finishing treatments. These results could be applied for industrial needs (quality control), or in the artistic field of conservation, or restoration (to follow the color of paintings). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
108.
Emilio Fortunato Campana Giampaolo Liuzzi Stefano Lucidi Daniele Peri Veronica Piccialli Antonio Pinto 《Optimization and Engineering》2009,10(4):533-555
The aim of this paper is to solve optimal design problems for industrial applications when the objective function value requires
the evaluation of expensive simulation codes and its first derivatives are not available. In order to achieve this goal we
propose two new algorithms that draw inspiration from two existing approaches: a filled function based algorithm and a Particle
Swarm Optimization method. In order to test the efficiency of the two proposed algorithms, we perform a numerical comparison
both with the methods we drew inspiration from, and with some standard Global Optimization algorithms that are currently adopted
in industrial design optimization. Finally, a realistic ship design problem, namely the reduction of the amplitude of the
heave motion of a ship advancing in head seas (a problem connected to both safety and comfort), is solved using the new codes
and other global and local derivative-free optimization methods. All the numerical results show the effectiveness of the two
new algorithms. 相似文献
109.
Crystallite regions within a hydrogel network contribute to its mechanical strength, which is crucial for use in load-bearing applications. However, high amounts of crystallinity can negatively impact the ability for hydrogels to be injected, an attractive property that could replace the need for highly invasive surgical procedures. The reversibility of crystallinity and its lasting impact on the injectability of poly(vinyl alcohol) and poly(ethylene glycol) hydrogels was evaluated in this paper. The relative percent crystallinity in hydrogels was evaluated after storage and autoclaving in syringes in weekly intervals using X-ray diffraction. Results indicate that crystallinity increased over time and significantly decreased after autoclaving for all samples, where postautoclaved samples contained comparable crystallinity percentages to freshly made gels (p > 0.05). Injectability was evaluated using calculated viscosity. Aged samples were able to be injected after autoclaving, yet there was no determination established between viscosity and storage times based on the data. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48706. 相似文献
110.
Anna Paola Carreca Veronica Maria Pravat Danilo DApolito Simone Bonelli Matteo Calligaris Elisa Monaca Stephan A. Müller Stefan F. Lichtenthaler Simone Dario Scilabra 《International journal of molecular sciences》2021,22(5)
Ectodomain shedding is a key mechanism of several biological processes, including cell-communication. Disintegrin and metalloproteinases (ADAMs), together with the membrane-type matrix metalloproteinases, play a pivotal role in shedding transmembrane proteins. Aberrant shedding is associated to several pathological conditions, including arthritis. Tissue inhibitor of metalloproteases 3 (TIMP-3), an endogenous inhibitor of ADAMs and matrix metalloproteases (MMPs), has been proven to be beneficial in such diseases. Thus, strategies to increase TIMP-3 bioavailability in the tissue have been sought for development of therapeutics. Nevertheless, high levels of TIMP-3 may lead to mechanism-based side-effects, as its overall effects on cell behavior are still unknown. In this study, we used a high-resolution mass-spectrometry-based workflow to analyze alterations induced by sustained expression of TIMP-3 in the cell surfaceome. In agreement with its multifunctional properties, TIMP-3 induced changes on the protein composition of the cell surface. We found that TIMP-3 had differential effects on metalloproteinase substrates, with several that accumulated in TIMP-3-overexpressing cells. In addition, our study identified potentially novel ADAM substrates, including ADAM15, whose levels at the cell surface are regulated by the inhibitor. In conclusion, our study reveals that high levels of TIMP-3 induce modifications in the cell surfaceome and identifies molecular pathways that can be deregulated via TIMP-3-based therapies. 相似文献