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排序方式: 共有3931条查询结果,搜索用时 15 毫秒
91.
Jeanne Fvre Elena Leveille Aurlie Jeanson Sabine Santucci-Darmanin Valrie Pierrefite-Carle Georges F. Carle Christophe Den Auwer Christophe Di Giorgio 《International journal of molecular sciences》2022,23(9)
In case of an incident in the nuclear industry or an act of war or terrorism, the dissemination of plutonium could contaminate the environment and, hence, humans. Human contamination mainly occurs via inhalation and/or wounding (and, less likely, ingestion). In such cases, plutonium, if soluble, reaches circulation, whereas the poorly soluble fraction (such as small colloids) is trapped in alveolar macrophages or remains at the site of wounding. Once in the blood, the plutonium is delivered to the liver and/or to the bone, particularly into its mineral part, mostly composed of hydroxyapatite. Countermeasures against plutonium exist and consist of intravenous injections or inhalation of diethylenetetraminepentaacetate salts. Their effectiveness is, however, mainly confined to the circulating soluble forms of plutonium. Furthermore, the short bioavailability of diethylenetetraminepentaacetate results in its rapid elimination. To overcome these limitations and to provide a complementary approach to this common therapy, we developed polymeric analogs to indirectly target the problematic retention sites. We present herein a first study regarding the decontamination abilities of polyethyleneimine methylcarboxylate (structural diethylenetetraminepentaacetate polymer analog) and polyethyleneimine methylphosphonate (phosphonate polymeric analog) directed against Th(IV), used here as a Pu(IV) surrogate, which was incorporated into hydroxyapatite used as a bone model. Our results suggest that polyethylenimine methylphosphonate could be a good candidate for powerful bone decontamination action. 相似文献
92.
Alexander Aleksandrov Elena Aleksandrova Alexey Zhabko 《Circuits, Systems, and Signal Processing》2016,35(10):3531-3554
This paper examines certain classes of multiconnected (complex) systems with time-varying delay. Delay-independent stability conditions and estimates of the convergence rate of solutions to the origin for those systems are derived. It is shown that the exponents in the obtained estimates depend on the parameters of Lyapunov functions constructed for the corresponding isolated subsystems. The problem of computing parameter values that provide the most precise estimates is investigated. Some examples are presented to demonstrate the effectiveness of the proposed approaches. 相似文献
93.
Birzabith Mendoza-Novelo Diego I. Alvarado-Castro José L. Mata-Mata Juan V. Cauich-Rodríguez Arturo Vega-González Eduardo Jorge-Herrero Francisco J. Rojo Gustavo V. Guinea 《Materials science & engineering. C, Materials for biological applications》2013,33(4):2392-2398
The present study investigates the potential use of non-catalyzed water-soluble blocked polyurethane prepolymer (PUP) as a bifunctional cross-linker for collagenous scaffolds. The effect of concentration (5, 10, 15 and 20%), time (4, 6, 12 and 24 h), medium volume (50, 100, 200 and 300%) and pH (7.4, 8.2, 9 and 10) over stability, microstructure and tensile mechanical behavior of acellular pericardial matrix was studied. The cross-linking index increased up to 81% while the denaturation temperature increased up to 12 °C after PUP crosslinking. PUP-treated scaffold resisted the collagenase degradation (0.167 ± 0.14 mmol/g of liberated amine groups vs. 598 ± 60 mmol/g for non-cross-linked matrix). The collagen fiber network was coated with PUP while viscoelastic properties were altered after cross-linking. The treatment of the pericardial scaffold with PUP allows (i) different densities of cross-linking depending of the process parameters and (ii) tensile properties similar to glutaraldehyde method. 相似文献
94.
95.
Capillary zone electrophoresis (CZE) has been applied to separation and characterisation of enzymatic (tryptic) hydrolysates of water-soluble proteins from Bacillus thuringiensis (Bt)-transgenic (Aristis-Bt) and two native non-transgenic (Aristis and Coventry) maize varieties. Water-soluble proteins were extracted from the flour of these maize species and digested by bovine pancreatic trypsin immobilised on agarose gel in 100 mM ammonium hydrocarbonate buffer, pH 7.9. The yielded tryptic digests of proteins were analysed by CZE in four acidic background electrolytes (BGEs) (100 mM H3PO4, 50 mM Tris, pH 2.25; 500 mM acetic acid, pH 2.54; 200 mM formic acid, 200 mM acetic acid, pH 2.05; and 200 mM iminodiacetic acid, pH 2.26) using a lab-made CZE apparatus equipped with bare fused silica capillary and UV-absorption detector operating at 206 nm. Among the tested BGEs, the best resolution of the tryptic peptides of extracted proteins of the above three maize species was obtained in isoelectric BGE, 200 mM iminodiacetic acid, pH 2.26. Selected resolved tryptic peptides of proteins were characterised by effective electrophoretic mobilities and corrected (migration times normalised) peak areas. Some significant relative qualitative and quantitative differences in CZE-UV profiling of tryptic protein digests were found, which can be potentially used to differentiate transgenic Aristis Bt and non-transgenic Aristis varieties or two native non-transgenic varieties, Aristis and Coventry. 相似文献
96.
Natalia D. Lenenko Elena N. Semina Vladimir I. Zaikovskii Alexandre S. Golub 《Materials Chemistry and Physics》2013
Microstructure of layered nanocomposite compound consisting of molybdenum disulfide single layers and the layers of octadecyltrimethylammonium molecules as well as the structure of destruction products of this hybrid compound were studied by high resolution transmission electron microscopy (HRTEM) and powder X-ray diffraction (XRD) techniques. Changes in composition, ordering and morphology of the host and guest layers of the compound occurring due to release of organic guest from the interlayer space of MoS2 on heating or on action of electronic beam have been revealed. Removal of the guest was found to initiate formation in the initial layered structure of the packets consisting of a few MoS2 layers which come close together within the distances of ca. 1–1.5 nm and 0.6–0.7 nm after heating at 250 °C and 400 °C, respectively. Leaving the guest also causes deformations of MoS2 layers resulting in their non-flat geometry. At 400 °C, strong bending of a part of the sulfide layers with the radius as small as 3–4 nm was observed. 相似文献
97.
Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species 下载免费PDF全文
Elena Bartkiene Vadims Bartkevics Janis Rusko Vytaute Starkute Daiva Zadeike Grazina Juodeikiene 《International Journal of Food Science & Technology》2016,51(9):2049-2056
The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin. 相似文献
98.
Guillermo Rodrigo Mark P. Zwart Santiago F. Elena 《Journal of the Royal Society Interface》2014,11(98)
The cornerstone of today''s plant virology consists of deciphering the molecular and mechanistic basis of host–pathogen interactions. Among these interactions, the onset of systemic infection is a fundamental variable in studying both within- and between-host infection dynamics, with implications in epidemiology. Here, we developed a mechanistic model using probabilistic and spatio-temporal concepts to explain dynamic signatures of virus systemic infection. The model dealt with the inherent characteristic of plant viruses to use two different and sequential stages for their within-host propagation: cell-to-cell movement from the initial infected cell and systemic spread by reaching the vascular system. We identified the speed of cell-to-cell movement and the number of primary infection foci in the inoculated leaf as the key factors governing this dynamic process. Our results allowed us to quantitatively understand the timing of the onset of systemic infection, describing this global process as a consequence of local spread of viral populations. Finally, we considered the significance of our predictions for the evolution of plant RNA viruses. 相似文献
99.
Yury I. Lyakhovetsky Elena A. Shilova Boris L. Tumanskii Alexander V. Usatov Era A. Avetisyan Sergei R. Sterlin 《Fullerenes, Nanotubes and Carbon Nanostructures》2013,21(2):263-287
Abstract Both [60]- and [70]fullerene react with either the Scherer radical (perfluorodiisopropylethylmethyl, C9F19), a mixture of branched perfluorononenes (C9F18, the product of hexafluoropropene trimerization), or β-fluorosulphatotetrafluoroethyldiheptafluoroisopropylmethyl radical (C9F18OSO2F) in the ionization chamber of a mass spectrometer to give the positive parent ions of trifluoromethylation products, the reaction being accompanied by hydrogen addition. The reaction occurs at least partly on the walls of the ionization chamber, by a radical mechanism employing CF3 radicals formed from the radical reactants both thermally and under electron impact; only the latter route occurs with the perfluorononenes. 相似文献
100.