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101.
Laccase‐containing ureasil–polymer composite as the sensing layer of an amperometric biosensor
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Taras Kavetskyy Oleh Smutok Mykhailo Gonchar Olha Demkiv Halyna Klepach Yuliia Kukhazh Ondrej Šauša Tamara Petkova Victor Boev Vania Ilcheva Plamen Petkov Andrey L. Stepanov 《应用聚合物科学杂志》2017,134(36)
Innovative amperometric biosensors for monitoring the level of wastewater pollution have been constructed on the surface of the gold planar electrodes C220AT “DropSens” by using the organic–inorganic ureasil‐based composites as host matrixes and immobilized commercial laccase from Trametes versicolor . It was found that the biosensor based on the ureasil–chalcogenide glass composite is characterized by a very high sensitivity (67,540 А M?1 m?2) that is 38.3 times higher than for pure ureasil (the sensitivity of the bioelectrode was calculated as 1762 А M?1 m?2). On the other hand, application of the ureasil–chalcogenide glass composite with incorporated silver nanoparticles (NPs) synthesized by high‐dose (1.0 × 1017 Ag+/cm2) 30 keV Ag+ ion implantation results in decreasing the biosensor sensitivity up to 2390 times (the sensitivity of the bioelectrode was 28.3 А M?1 m?2). The role of additives (chalcogenide glass and silver NPs) in the ureasil matrix on the biofunctionality of the biosensors produced is considered. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45278. 相似文献
102.
Influence of acceleration setting reaction by halogen light‐curing on GIC–dentin interface: Qualitative analysis by SEM
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Laysa Yoshioka Tamara Kerber Tedesco Ana Flávia Bissoto Calvo Sabrina Sun Ha Kim Anna Paula Vieira Ferreira Prado Malagrana Daniela Prócida Raggio 《Microscopy research and technique》2017,80(4):374-377
The aim of this study was to evaluate by scanning electron microscope (SEM) photomicrographs the influence of application of halogen light‐curing for fastening the set reaction of high‐viscosity glass ionomer cements (GIC) by assessing the material/dentin interface. Twelve human primary canines were assigned in four groups (n = 3) according to the GIC (Fuji IX, GC or Maxxion R, FGM) and application of halogen light‐curing (60 sec or control—no external energy). Blocks with approximately 6 mm of height were buildup on previously pre‐treated dentin surface in according to the experimental group. After storage at 37 °C, 100% humidity for 48 h, the specimens were then sectioned in slices with 1‐mm thick. The slices were qualitative analyzed using SEM to evaluate possible structural changes. Two examiners independently evaluated the images in order to observe the spherical hollow spaces of each tooth. The photomicrographs revealed the presence of spherical hollow spaces in all experimental groups. However, in both groups that received halogen light‐curing application, it was possible to observe that the presence of these hollow spaces decreased in size and quantity. It can be concluded that the halogen light‐curing application positively decreases in size and quantity in the presence of spherical hollow spaces in GIC. 相似文献
103.
Russo A Maccaferri S Djakovac T Precali R Degobbis D Deserti M Paschini E Lyons DM 《The Science of the total environment》2005,353(1-3):24-38
Mucilage events (formation of very large organic aggregates and gelatinous surface layers) have been documented several times during the past two centuries in the northern Adriatic Sea (NA), while their frequency has significantly increased since 1988. In this work, meteorological and oceanographic conditions in the NA during the period June 1999-July 2002 are described and their relation to the outbreak and fate of the mucilage phenomenon was investigated. Salinity and temperature data were collected during approximately monthly cruises along three transects in the NA. Relevant meteorological situations (air temperature, rainfall, wind) were selected from large-scale ECMWF analyses and from the Local Analysis and Prediction System (LAPS; Emilia Romagna Meteorological Service), while sea conditions (waves) were analysed by means of the Wave Adriatic Model (WAM). Data for air temperature, rainfall, and wind from several meteorological stations in the region were used. Average seasonal cycles of sea temperature and salinity simulated with statistical models, based on historical data collected in the NA since 1972, were used to determine thermal and haline anomalies. The monthly anomaly variability of maximum and minimum air temperatures, rainfall amount and number of rainy days did not appear to be relevant for the mucilage phenomenon outbreak. In contrast, both vertical and horizontal thermohaline gradients in the region were more developed during late spring and summer of 2000 and particularly of 2002, when the mucilage events were of greatest extent in space and time, compared to 2001 (short-lived event) and 1999 (no event). These more pronounced gradients were due to a combination of several unusual conditions: sharp heating of the sea surface in May-June, domination of eastwards transport of freshened waters formed in the Po Delta area, and intrusion of very high salinity intermediate waters originating in the eastern Mediterranean. Moreover, in winter of both 2000 and 2002 very dense and cold water formed and remained in the bottom layer until spring, contributing to increase the stratification degree of the water column. The duration of the mucilage events and their spatial distribution in the region depend strongly on meteorological changes. Recurrent anticyclonic conditions, characterized by low wind and calm sea, favour extended events in time (up 2 months in 2002). In contrast, highly perturbed weather, particularly due to strong "bora" wind, can be determined in sharp decay of the event (e.g. in July 2000). 相似文献
104.
Bekka S. Brodie Tamara Babcock Regine Gries Arlan Benn Gerhard Gries 《Journal of chemical ecology》2016,42(1):40-50
We investigated foraging decisions by adult females of the common green bottle fly, Lucilia sericata, in accordance with their physiological state. When we gave female flies a choice between visually occluded, fresh canine feces (feeding site) and a CO2-euthanized rat (carrion oviposition site), 3-d-old “protein-starved” females responded equally well to feces and carrion, whereas protein-fed gravid females with mature oocytes responded only to carrion, indicating resource preferences based on a fly’s physiological state. Dimethyl trisulfide (DMTS) is known to attract gravid L. sericata females to carrion. Therefore, we analyzed headspace from canine feces by gas chromatographic-electroantennographic detection (GC-EAD) and GC/mass spectrometry. In bioassays, of the 17 fecal odorants that elicited GC-EAD responses from fly antennae, a blend of indole and one or more of the alcohols phenol, m-/p-cresol and 1-octen-3-ol proved as attractive to flies as canine feces. Unlike young females, gravid females need to locate carrion for oviposition and distinguish between fresh and aging carrion, the latter possibly detrimental to offspring. Gravid female L. sericata accomplish this task, in part, by responding to trace amounts of DMTS emanating from fresh carrion and by discriminating against carrion as soon it begins to produce appreciable amounts of indole, which is also the second-most abundant semiochemical in fresh canine feces, and apparently serves as an indicator of food rather than oviposition resources. Our results emphasize the importance of studying foraging choices by flies in accordance with their physiological stage. 相似文献
105.
106.
Boris?MonchevEmail author Tamara?Petkova Plamen?Petkov Sasho?Vassilev 《Journal of Materials Science》2007,42(23):9836-9840
Novel bulk glassy samples of the pseudoternary chalcohalide Ge–S–AgI system have been prepared. Glasses have been obtained
by monotemperature synthesis in evacuated ampoules and standard melt-quenching technique. The glass-forming region in the
system determined by X-ray diffraction is situated in the S-rich region on the Ge–S side (S/Ge = 1.2, 1.5, 2 and 3) with AgI
content up to 20 mol.%. Some physicochemical properties of the amorphous materials and their compositional dependence have
been investigated. In addition, the theoretical average coordination number (Z), the total constraints per atom (Nco), the radial (Na) and axial (Nb) strength of the bonds have been calculated and related to the experimental results. 相似文献
107.
Geng Y Dalhaimer P Cai S Tsai R Tewari M Minko T Discher DE 《Nature nanotechnology》2007,2(4):249-255
Interaction of spherical particles with cells and within animals has been studied extensively, but the effects of shape have received little attention. Here we use highly stable, polymer micelle assemblies known as filomicelles to compare the transport and trafficking of flexible filaments with spheres of similar chemistry. In rodents, filomicelles persisted in the circulation up to one week after intravenous injection. This is about ten times longer than their spherical counterparts and is more persistent than any known synthetic nanoparticle. Under fluid flow conditions, spheres and short filomicelles are taken up by cells more readily than longer filaments because the latter are extended by the flow. Preliminary results further demonstrate that filomicelles can effectively deliver the anticancer drug paclitaxel and shrink human-derived tumours in mice. Although these findings show that long-circulating vehicles need not be nanospheres, they also lend insight into possible shape effects of natural filamentous viruses. 相似文献
108.
109.
Rimma V. Golovnya Margarita B. Terenina Natalya I. Krikunova Vladimir P. Yuryev Tamara A. Misharina 《Starch - St?rke》2001,53(6):269-277
The binding absorption of individual alcohols, ketones, alkyl acetates and their mixtures — used as aroma compounds — from aqueous solutions by corn starch cryotextures was studied by capillary gas chromatography at different starting concentrations of the odourants (1—25 mmol/L). The amount of compound sorbed by the cryotextures increases with concentration of this compound in the initial sol and increasing length of the alkyl chain in the corresponding compound. Linear equations describing the concentration dependence were proposed. The presence of octanol in the mixture increases the binding of hexanol as compared to hexanol alone. The methods of scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy, differential scanning microcalorimetry (DSC) and scanning tunneling microscopy (STM) were used for estimation of the microstructure of sols, and cryotextures, and for the determination of supramolecular complex formation in the systems odourant/cryotexture and odourant/sol. It was shown that waxy corn cryotextures do not form supramolecular complexes with aroma compounds. 相似文献
110.
Louise Jank Magda Targa Martins Juliana Bazzan Arsand Tanara Magalhães Campos Motta Tiago Corrêa Feijó Tamara dos Santos Castilhos Rodrigo Barcellos Hoff Fabiano Barreto Tânia Mara Pizzolato 《Food Analytical Methods》2017,10(7):2152-2164
A screening method for analysis of 46 antibiotics residues, belonging to different classes, such as tetracyclines, sulfonamides, fluoroquinolones, β-lactams, cephalosporins, macrolides and other minority groups was developed and validated for application in bovine milk and bovine, swine, poultry, equine, fish and shrimp meat samples. Sample preparation consists in solvent extraction followed by clean up with C18 bulk and low temperature purification. Instrumental analysis was performed using liquid chromatography coupled to tandem mass spectrometry system. Chromatographic separation was achieved using a C18 column. Mobile phase was composed by methanol and water. The method was validated according to Commission Decision 2002/657/EC criteria. Validation parameters such as specificity and detection capability (CCβ) were determined and considered suitable to the established criteria. Values of CCβ ranged from 1.0 to 50.0 μg L?1 or μg Kg?1, depending on the compound and the matrix. The proposed method has been applied into Brazilian National Residue Control Plan since 2013 for the determination of antibiotic residues. A total of 3833 samples were analyzed until the current date and 13 samples showed positive results with concentrations above the permitted. The method is fast, easy and adequate for high throughput analysis in routine laboratories. 相似文献