883 resultados para Glass fosfo-borates with titanium


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The major problem with durability of asphalt cement concrete (ACC) overlays to rehabilitate jointed portland cement concrete (PCC) pavement comes from reflective cracking. The objective of this research was to evaluate the effectiveness of Glasgrid in regard to preventing reflection cracking. Glasgrid is a glass fiber mesh with 1/2 inch by 1 inch openings (Figure 1). Each strand is composed of many small glass fibers. After the grid is formed, it is coated with a polymer modified asphalt cement. In 1986, four experimental Glasgrid test sections were incorporated into Polk County project IR-35-2(191)67--12-77 on Interstate 35 from IA 5 to the west 1-80 interchange on the west edge of Des Moines, Single and double layers of Glasgrid were placed over transverse cracks and joints of the existing PCC pavement. The Glasgrid was placed on the PCC pavement for one section and between lifts of the ACC resurfacing on the other three sections. The four Glasgrid sections were compared to two sections without Glasgrid for four years. The sections were reviewed annually to determine how many cracks or joints had reflected through the resurfacing. Glasgrid placed on the PCC pavement was more effective at preventing reflection cracking than Glasgrid between lifts of AC resurfacing. In general, Glasgrid yielded a small reduction or retardation in the amount of reflection cracking, but not sufficient to justify additional expense for the use of Glasgrid.

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Per Maria-Mercè Marçal, la poeta no es pot trobar, no es pot veure, en el «mirall del bell», que sempre han fomentat els discursos dominants. El seu és una altra mena de mirall trencat que reflecteix un ésser complex, híbrid i contaminat que lluita «entre un jo que es vol fer i els múltiples personatges que, des del mirall, li retornen una imatge múltiple». En aquest article, per explorar el tema de l’imaginari femení i el llenguatge poètic, hem escollit dialogar amb Maria- Mercè Marçal i examinar tres dels múltiples bocins que conformen la seva imatge en el mirall. Conversem amb dues mares i un pare simbòlics de l’altre cantó del seu espill, tots tres proveïdors de material ideològic i eixos vertebradors dels assaigs marçalians. Es tracta d’intel·lectuals ben diversos: l’escriptora anglesa Virginia Woolf, el filòsof francès Jacques Derrida i la poeta catalana Maria-Antònia Salvà. En definitiva, dividim la investigació en tres apartats, que volen coincidir amb el diàleg que Marçal suposem que hi mantingué. De primer, amb Virginia Woolf, explorem la necessitat de la poeta de descobrir el sentiment de «fúria» que porta a dins per tal d’assumir la irracionalitat del seu llenguatge. Després, ens endinsem en les teories derridianes sobre la dona i l’escriptura, en un intent de demostrar que ambdues són espècies híbrides que viuen en el llindar, en un espai d’entremig. A l’últim, amb Maria-Antònia Salvà, revisem la imatge de la dona-monstre amb la certesa que «el salvatge» i «l’incert » són el motor del llenguatge poètic femení.

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In order to improve the efficacy and safety of treatments, drug dosage needs to be adjusted to the actual needs of each patient in a truly personalized medicine approach. Key for widespread dosage adjustment is the availability of point-of-care devices able to measure plasma drug concentration in a simple, automated, and cost-effective fashion. In the present work, we introduce and test a portable, palm-sized transmission-localized surface plasmon resonance (T-LSPR) setup, comprised of off-the-shelf components and coupled with DNA-based aptamers specific to the antibiotic tobramycin (467 Da). The core of the T-LSPR setup are aptamer-functionalized gold nanoislands (NIs) deposited on a glass slide covered with fluorine-doped tin oxide (FTO), which acts as a biosensor. The gold NIs exhibit localized plasmon resonance in the visible range matching the sensitivity of the complementary metal oxide semiconductor (CMOS) image sensor employed as a light detector. The combination of gold NIs on the FTO substrate, causing NIs size and pattern irregularity, might reduce the overall sensitivity but confers extremely high stability in high-ionic solutions, allowing it to withstand numerous regeneration cycles without sensing losses. With this rather simple T-LSPR setup, we show real-time label-free detection of tobramycin in buffer, measuring concentrations down to 0.5 μM. We determined an affinity constant of the aptamer-tobramycin pair consistent with the value obtained using a commercial propagating-wave based SPR. Moreover, our label-free system can detect tobramycin in filtered undiluted blood serum, measuring concentrations down to 10 μM with a theoretical detection limit of 3.4 μM. While the association signal of tobramycin onto the aptamer is masked by the serum injection, the quantification of the captured tobramycin is possible during the dissociation phase and leads to a linear calibration curve for the concentrations over the tested range (10-80 μM). The plasmon shift following surface binding is calculated in terms of both plasmon peak location and hue, with the latter allowing faster data elaboration and real-time display of the results. The presented T-LSPR system shows for the first time label-free direct detection and quantification of a small molecule in the complex matrix of filtered undiluted blood serum. Its uncomplicated construction and compact size, together with the remarkable performances, represent a leap forward toward effective point-of-care devices for therapeutic drug concentration monitoring.

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The quantitative chemical analysis of the Brazilian sugar cane spirit distilled from glass column packaged with copper, stainless steel, aluminum sponge, or porcelain balls is described. The main chemical compounds determined by gas chromatography coupled with flame ionization (FID) and flame photometric (FPD) detectors and liquid chromatography coupled with diode array detector are aldehydes, ketones, carboxylic acids, alcohols, esters and dimethylsulfite (DMS). The spirits produced either in columns filled with copper or aluminum pot still exhibits the lowest DMS contents but the higher sulfate and methanol contents, whereas spirits produced in stainless steel or porcelain showed higher DMS concentration and lower teors of sulfate ion and methanol. These observations are coherent with DMS oxidation to sulfate, with methanol as by product, in the presence of either copper or aluminum.

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Photodegradation of the PAHs anthracene, chrysene and benzo[k]fluoranthane on silica gel impregnated with TiO2 and over glass plates holding TiO2 was studied. Silica gel plates holding these substances were exposed to solar radiation, developed with hexane and photographed under ultra-violet light. The plates containing benzo[k]fluoranthene were also analysed by both diffuse reflectance and laser induced fluorescence. Diffuse reflectance spectra of the fluorescent spot from non irradiated plates showed small differences when compared with those obtained from irradiated plates. These spectral differences are compatible with formation of less conjugated compounds during irradiation. Fluorescence and time resolved fluorescence spectra observed after irradiation were identical to those obtained with benzo[k]fluoranthene in methanol. On plates holding silica, PAH degradation requires longer periods of solar irradiation when compared with those plates containing silica impregnated with TiO2. Glass plates impregnated with TiO2 also showed very rapid PAH degradation.

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Glass ionomer cements (GICs) are products of the acid-base setting reaction between an finely fluoro-alumino silicate glass powder and poly(acrylic acid) in aqueous solution. The sol gel method is an adequate route of preparation of the glasses used to obtain the GICs. The objective of this paper was to compare two powders: a commercial and an experimental and to investigate the structural changes during hardening of the cements by FTIR and Al MAS NMR. These analyses showed that the experimental glass powder reacted with organic acid to form the GICs and it is a promising material to manufacture dental cements.

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Polyurethane/multi-walled carbon nanotube (MWCNT) nanocomposites have been prepared with nanotube concentrations between 0.01 wt% and 1 wt%. MWCNT as-synthesized samples with ~74 nm diameter and ~7 μm length were introduced by solution processing in the polyurethane matrix. Scanning electron microscopy (SEM) images demonstrated good dispersion and adhesion of the CNTs to the polymeric matrix. The C=O stretching band showed evidence of perturbation of the hydrogen interaction between urethanic moieties in the nanocomposites as compared to pure TPU. Differential scanning calorimetry and positron anihilation lifetime spectroscopy measurements allowed the detection of glass transition displacement with carbon nanotube addition. Furthermore, the electrical conductivity of the nanocomposites was significantly increased with the addition of CNT.

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Ruzigrass (Brachiaria ruziziensis, syn. Urochloa ruziziensis) is used as a cover crop in tropical regions because it has a high yield potential, is widely adapted and has a vigorous root system. However, it may affect early growth of the next crop due to allelopathy and competition for soil nitrate. A greenhouse experiment was conducted in glass-walled pots with soil to determine the effect of ruzigrass residues on the initial growth and mineral nutrition of common bean (Phaseolus vulgaris). Ruzigrass was grown in the pots for 50 days and chemically desiccated. Then, common bean was grown: without ruzigrass residues; with ruzigrass shoots placed on the soil surface; with ruzigrass roots left in the soil; and with ruzigrass shoots and roots left undisturbed. Root growth of common bean was decreased by ruzigrass residues, but shoot biomass was not affected when it was grown in the presence of ruzigrass shoots or roots alone. In pots where ruzigrass residues were undisturbed, common bean biomass yield was decreased. Nitrogen concentration in common bean shoot was not affected by ruzigrass shoot on the soil surface, an evidence that the observed decrease in common bean growth probably was due to allelopathic effects rather than competition for nitrogen.

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In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.

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Wear particles are phagocytosed by macrophages and other inflammatory cells, resulting in cellular activation and release of proinflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty failure. During this pathological process, tumor necrosis factor-alpha (TNF-α) plays an important role in wear-particle-induced osteolysis. In this study, recombination adenovirus (Ad) vectors carrying both target genes [TNF-α small interfering RNA (TNF-α-siRNA) and bone morphogenetic protein 2 (BMP-2)] were synthesized and transfected into RAW264.7 macrophages and pro-osteoblastic MC3T3-E1 cells, respectively. The target gene BMP-2, expressed on pro-osteoblastic MC3T3-E1 cells and silenced by the TNF-α gene on cells, was treated with titanium (Ti) particles that were assessed by real-time PCR and Western blot. We showed that recombinant adenovirus (Ad-siTNFα-BMP-2) can induce osteoblast differentiation when treated with conditioned medium (CM) containing RAW264.7 macrophages challenged with a combination of Ti particles and Ad-siTNFα-BMP-2 (Ti-ad CM) assessed by alkaline phosphatase activity. The receptor activator of nuclear factor-κB ligand was downregulated in pro-osteoblastic MC3T3-E1 cells treated with Ti-ad CM in comparison with conditioned medium of RAW264.7 macrophages challenged with Ti particles (Ti CM). We suggest that Ad-siTNFα-BMP-2 induced osteoblast differentiation and inhibited osteoclastogenesis on a cell model of a Ti particle-induced inflammatory response, which may provide a novel approach for the treatment of periprosthetic osteolysis.

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La phosphorylation est une modification post-traductionnelle omniprésente des protéines Cette modification est ajoutée et enlevée par l’activité enzymatique respective des protéines kinases et phosphatases. Les kinases Erk1/2 sont au cœur d’une voie de signalisation importante qui régule l’activité de protéines impliquées dans la traduction, le cycle cellulaire, le réarrangement du cytosquelette et la transcription. Ces kinases sont aussi impliquées dans le développement de l’organisme, le métabolisme du glucose, la réponse immunitaire et la mémoire. Différentes pathologies humaines comme le diabète, les maladies cardiovasculaires et principalement le cancer, sont associées à une perturbation de la phosphorylation sur les différents acteurs de cette voie. Considérant l’importance biologique et clinique de ces deux kinases, connaître l’étendue de leur activité enzymatique pourrait mener au développement de nouvelles thérapies pharmacologiques. Dans ce contexte, l’objectif principal de cette thèse était de mesurer l’influence de cette voie sur le phosphoprotéome et de découvrir de nouveaux substrats des kinases Erk1/2. Une étude phosphoprotéomique de cinétique d’inhibition pharmacologique de la voie de signalisation Erk1/2 a alors été entreprise. Le succès de cette étude était basé sur trois technologies clés, soit l’enrichissement des phosphopeptides avec le dioxyde de titane, la spectrométrie de masse haut débit et haute résolution, et le développement d’une plateforme bio-informatique nommée ProteoConnections. Cette plateforme permet d’organiser les données de protéomique, évaluer leur qualité, indiquer les changements d’abondance et accélérer l’interprétation des données. Une fonctionnalité distinctive de ProteoConnections est l’annotation des sites phosphorylés identifiés (kinases, domaines, structures, conservation, interactions protéiques phospho-dépendantes). Ces informations ont été essentielles à l’analyse des 9615 sites phosphorylés sur les 2108 protéines identifiées dans cette étude, soit le plus large ensemble rapporté chez le rat jusqu’à ce jour. L’analyse des domaines protéiques a révélé que les domaines impliqués dans les interactions avec les protéines, les acides nucléiques et les autres molécules sont les plus fréquemment phosphorylés et que les sites sont stratégiquement localisés pour affecter les interactions. Un algorithme a été implémenté pour trouver les substrats potentiels des kinases Erk1/2 à partir des sites identifiés selon leur motif de phosphorylation, leur cinétique de stimulation au sérum et l’inhibition pharmacologique de Mek1/2. Une liste de 157 substrats potentiels des kinases Erk1/2 a ainsi été obtenue. Parmi les substrats identifiés, douze ont déjà été rapportés et plusieurs autres ont des fonctions associées aux substrats déjà connus. Six substrats (Ddx47, Hmg20a, Junb, Map2k2, Numa1, Rras2) ont été confirmés par un essai kinase in vitro avec Erk1. Nos expériences d’immunofluorescence ont démontré que la phosphorylation de Hmg20a sur la sérine 105 par Erk1/2 affecte la localisation nucléocytoplasmique de cette protéine. Finalement, les phosphopeptides isomériques positionnels, soit des peptides avec la même séquence d’acides aminés mais phosphorylés à différentes positions, ont été étudiés avec deux nouveaux algorithmes. Cette étude a permis de déterminer leur fréquence dans un extrait enrichi en phosphopeptides et d’évaluer leur séparation par chromatographie liquide en phase inverse. Une stratégie analytique employant un des algorithmes a été développée pour réaliser une analyse de spectrométrie de masse ciblée afin de découvrir les isomères ayant été manqués par la méthode d’analyse conventionnelle.

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A review. 6-Substituted fulvenes are interesting and easily accessible starting materials for the synthesis of novel substituted titanocenes via reductive dimerization, carbolithiation or hydridolithiation reactions, which are followed by a transmetallation reaction with titanium tetrachloride in the latter two cases. Depending on the substitution pattern, these titanocenes prove to be bioorganometallic anticancer drugs, which have significant potential against advanced or metastatic renal-cell cancer. Patients bearing these stages of kidney cancer have a poor prognosis so far and therefore real progress in the area of metal-based anticancer drugs may come from this simple and effective synthetic approach. This tutorial review provides an insight into the synthesis of fulvene-derived titanocenes and their activity in preclin. expts.

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Using 6-benzo[1,3]dioxolefulvene (1a), a series of benzodioxole substituted titanocenes was synthesized. The benzyl-substituted titanocene bis[(benzo[1,3]dioxole)-5-methylcyclopentadienyl] titanium (IV) dichloride (2a) was synthesized from the reaction of Super Hydride with 1a. An X-ray determined crystal structure was obtained for 2a. The ansa-titanocene (1,2-di(cyclopentadienyl)1,2-di-(benzo[1,3]dioxole)-ethanediyl) titanium(IV) dichloride (2b) was synthesized by reductive dimerisation of la with titanium dichloride. The diarylmethyl substituted titanocene bis(di(benzo[1,3]dioxole)-S-methylcyclopentadienyl) titanium(IV) dichloride (20 was synthesized by reacting la with the para-lithiated benzodioxole followed by transmetallation with titanium tetrachloride. When titanocenes 2a-c were tested against pig kidney (LLC-PK) cells inhibitory concentrations (IC50) of 2.8 X 10(-4), 1.6 x 10(-4) and 7.6 x 10(-5) m, respectively, were observed. These values represent improved cytotoxicity against LLC-PK, when compared with unsubstituted titanocene dichloride, but are not as impressive as values obtained for titanocenes previously synthesized using the above methods. Copyright (c) 2006 John Wiley & Sons, Ltd.

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From the reaction of Super Hydride (LiBEt3H) with 6-(furyl)fulvene (1a), 6-(thiophenyl)fulvene (1b) or 6-(N-methyl-pyrrole)fulvene (1c) the corresponding lithium cyclopentadienide intermediates (2a-c) were obtained. These intermediates were reacted with titanium tetrachloride and bis-[(furyl-2-cyclopentadienylmethane)] titanium(IV) dichloride (3a) and bis-[(thiophenyl-2-cyclopentadienylmethane)] titanium(IV) dichloride (3b) and bis-[(N-methylpyrrole-2-cyclopentadienylmethane)] titanium(IV) dichloride (3c) were obtained and subsequently characterised by X-ray crystallography. When titanocenes 3a-c were tested against pig kidney (LLC-PK) cells inhibitory concentrations (IC50) of 1.6 x 10(-4) M, 1.5 x 10(-4) M and 9.1 x 10(-5) M, respectively, were observed. These values represent improved cytotoxicity against LLC-PK, when compared to their corresponding ansa substituted analogues and also in comparison to unsubstituted titanocene dichloride. (c) 2006 Elsevier Inc. All rights reserved.

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From the reaction of tert-butyl lithium or n-butyl lithium with N-methylpyrrole (1a), furan (1b) or 2-bromo-thiophen (1c), 2-N-methylpyrrolyl lithium (2a), 2-furyl lithium (2b) or 2-thiophenyl lithium (2c), respectively, was obtained. When reacted with 6-(2-N-methylpyrrolyl) fulvene (3a), 6-(2-furyl) fulvene (3b) or 6-(2-thiophenyl) fulvene (3c), the corresponding lithiated intermediates were formed (4a-c). Titanocenes (5a-c) were obtained through transmetallation with titanium tetrachloride. When these titanocenes were tested against pig kidney epithelial (LLC-PK) cells, inhibitory concentrations (IC50) of 32 mu M, 140 mu M, and 240 mu M, respectively, were observed. These values represent improved cytotoxicity against LLC-PK, compared to their ansa-analogues. (c) 2006 Elsevier B.V. All rights reserved.