Miracle-dz/UniFAR-FTUs huggingface dataset:
Effects of chitosan on quality attributes fresh meat slices stored at 40C

The present study was conducted to evaluate the effect of natural substances as chitosan, thyme oil, lactic acid and acetic acid on microbial, chemical and sensorial quality of fresh meat slices during 18 day of storage at 4C and periodically analysed for total mould counts, pH, surface colour (Hunter L*, a* and b* values), 2-thiobarbituric acid reactive substance and Total Volatile Nitrogen were measured on days 0, 3, 6, 9, 12, 15 and 18 day of storage. The obtained results showed that addition of tested antifungal and antioxidants, individually, affected colour, lipid stability and sensory attributes of the meat slices compared to control during storage. Chitosan (1.5, 1.0 and 0.5 % w/v) showed the most intense red colour than other tested antifungal and antioxidants (thyme essential oil, lactic acid and acetic acid) when compared to the control. Also, the results showed that the initial total count (day 0) value for the fresh meat slices was 1x10 CFU /g, then decrease gradually until 9 day not detected any colony by using chitosan 1.5%. While in treated samples with thyme oil 1.5% and lactic acid 1.5% ,the total mould values was 5.6x10 ±5.5x10 CFU /g at 15 days and 9.4x10 ±3.9x10 CFU /g at 12 days. Based on the results obtained in this study, the application of natural substances as chitosan, thyme oil, lactic acid and acetic acid were effective in preserving quality of fresh meat slices and is recommended in meat products.
Free radical scavenging activity of hydroalcoholic extracts of dried flowers of Nymphaea stellata Willd.

The free radical scavenging potential of the dried flower of plant Nymphaea stellata Willd was studied by using different in vitro antioxidant models of screening. The hydroalcoholic extract at 500 2g/ml showed maximum scavenging of the in vitro riboflavin NBT assay (26.22%), hydroxyl radical scavenging activity (26.06%), DPPH (25.70%) and nitric oxide radicals (25.11%). However, the extract
An Experimental and Computational Study of a Swirl-Stabilized Premixed Flame

An unconfined strongly swirled flow is investigated for different Reynolds numbers using particle image velocimetry (PIV) and Large Eddy Simulation (LES) with a Thickened Flame (TF) model. Both reacting and non-reacting flow results are presented. In the LES-TF approach, the flame front is resolved on the computational grid through artificial thickening and the individual species transport equations are directly solved with the reaction rates specified using Arrhenius chemistry. Good agreement is found when comparing predictions with the experimental data for the non-reacting cases studied. For the reacting flows, the mean axial velocity profiles are in good agreement with measurements at lower Re; at high Re, the computations show a more compact and attached flame whereas experimental observations show a slightly lifted flame. Tangential velocity predictions consistently show the peak at the flame front location while measurements show greater radial spreading of the tangential momentum. The predicted RMS fluctuations exhibit a double-peak profile with one peak in the burnt and the other in the unburnt region. The measured and predicted heat release distributions are in qualitative agreement with each other and exhibit the highest values along the inner edge of the shear layer. The precessing vortex core (PVC) is clearly observed in both the non-reacting and reacting cases. However, it appears more axially-elongated for the reacting cases.Copyright © 2009 by ASME
Cycloadditions of 1‐Aza‐2‐azoniaallene Salts derived from coumarin and camphor

The 1-aza-2-azoniaallene salt 8 prepared from 3-acetyl coumarin via the hydrazone 6 and the (chloroalkyl)azo derivative 7 reacts with nitriles to afford the 3-(3-chromenyl)-1,2,4-triazolium salts 11a–d. With diisopropylcarbodiimide the triazolium salt 13 and with norborene a tricyclic pyrazolium salt 14 are obtained. Concurrent to these cycloadditions the by-product 12 is formed by intramolecular cyclization of the cumulene 8. Similarly, the intramolecular cyclization product 18 is isolated as the sole product when the 1-aza-2-azoniaallene salt 17a (prepared from the ethyl carbazone of camphor by chlorination and treatment of the product 16a with SbCl5) was treated with nitriles, carbodiimides or alkenes. In contrast, 1,2,4-triazolium salts 20a–c, 23c, respectively pyrazolium salts 20d–f, and 1,3,4-thiadiazolium salts 23a,b are obtained by reaction of the 1-aza-2-azoniaallene salt 17b with nitriles, respectively alkenes, alkynes, diisopropylcarbodiimide, and isothiocyanates. The constitutions of two of these products (20e, 23a) were secured by X-ray structural analysis.
Preparation of Hydrophobic Viscose Fabric Using Nitrogen DBD and Copper Ions Sorption

Plasma treatment of viscose cellulose fabric was performed using the atmospheric pressure dielectric barrier discharge (DBD) in nitrogen. Samples were treated using nonthermal plasma, and change of sorption properties with plasma energy density was investigated. It was found that using low energy of discharge, modified viscose samples become less hydrophilic and their wettability is significantly reduced. The observed hydrophobic effect was investigated and confirmed throughout series of experiments, by measuring a change in wetting time and in the level of aqueous liquid repellency. Structural changes were monitored using SEM, AFM, and XPS. It was established that increase of roughness combined with removal of hydrophilic polar groups from the surface of cellulose using plasma represents a novel approach to impart hydrophobicity onto hydrophilic textile. An additional binding of copper ions to nitrogen DBD treated cellulose produces a cross-linking effect, i.e., an occupation of remaining hydrophilic groups on the fabric surface and provides so called “petal effect” where drops of water stick to the fabric surface when the fabric is tilted for 180°. This novel procedure for obtaining hydrophobic cellulose could be used for a preparation of special protective textile materials with cost and time effective methods and chemicals.
Study of cryostructuration of polymer systems. XI. The formation of PVA cryogels by freezing–thawing the polymer aqueous solutions containing additives of some polyols

The influence of the presence of some polyols in initial poly(vinyl alcohol) aqueous solutions on rheological and thermal properties of the cryogels, which were produced by the freezing–thawing method, was investigated. The polyol additives (cosolvents) were as follows: glycerol, propylene glycol, mono-, di-, and triethylene glycols, and oligoethylene glycols (PEG-400 and PEG-1000). It was shown that the introduction of glycerol, propylene, or ethylene glycols into the polymer solution resulted in a decrease of cryogel's shear modulus and fusion temperature, whereas the use of triethylene and higher ethylene glycol oligomers as cosolvents gave rise to an increase in the gel's strength and thermostability, and diethylene glycol exhibited a transitional influence. The possible mechanism of the action of reinforcing cosolvents is discussed. © 1995 John Wiley & Sons, Inc.
Stress Engineering by Controlling Sapphire Substrate Thickness in 520 nm GaN-Based Light-Emitting Diodes

Controlling the compressive stress in 520 nm GaN-based light-emitting diodes (LEDs) prepared on sapphire substrates with different thicknesses was investigated. As the sapphire substrate thickness is reduced, the compressive stress in the GaN layer is released, resulting in wafer bowing. The wafer bowing-induced mechanical stress alters the piezoelectric fields, which in turn reduces the quantum-confined Stark effect in the InGaN/GaN active region of the LED. Thus, the electroluminescence spectral peak wavelength was blue-shifted, and the internal quantum efficiency was improved by about 11% at an injection current of 20 mA. The LED with an 80-µm-thick sapphire substrate exhibited the highest light output power of 11.5 mW.
Application of Different Lipases as Pretreatment in Anaerobic Treatment of Wastewater

Wastewater from a swine and bovine meat industry with high content of oil and grease was treated in batch anaerobic reactors with and without an enzymatic pretreatment. Two different lipases were tested: a commercial lipase (Lipolase 100T, Novozymes) and a lipase obtained by solid state fermentation (Lipase SEP). Meat industry wastewater with different oil and grease concentrations (250 to 3,000 mg · L−1) was treated with two amounts of enzyme preparations [0.1 and 5.0% (w/v)], in batch anaerobic bioreactors, corresponding to partial and complete hydrolysis of oil and grease. A control anaerobic bioreactor fed with raw wastewater was compared to an anaerobic reactor fed with prehydrolyzed effluent (test reactor). Although a high amount of enzyme maximizes hydrolysis of oil and grease, it decreases biodegradation, mainly when Lipolase 100T is used, probably due to inhibition caused by excess of free acids. However, the benefits of the enzymatic prehydrolysis became evident when the wastewater was treated w.
Rheology of dilute suspensions of red blood cells: experimental and theoretical approaches

Shear viscosity measurements with dilute suspensions of red blood cells are interpreted using a microrheological model that relates the bulk measurements to the physical properties of the suspended cells. It is thus possible to quantify the average deformability of a RBC population in terms of a mean value of the membrane shear elastic modulus E s . The values obtained for normal cells are in good agreement with those given in the literature. The method allows to discriminate between normal and altered (diamide or glutaraldehyde treated) cells or pathological cells (scleroderma). The predictions of the microrheological model, based on analytic calculations, are also compared with the numerical results of Ramanujan and Pozrikidis (JFM 361, 1998) for dilute suspensions of capsules in simple shear flow.
ELECTROCATALYTIC OXIDATION OF CYSTEINE BY INDIGO CARMINE MODIFIED GLASSY CARBON ELECTRODE

The electrocatalytic oxidation of L-Cysteine (L-Cys) has been studied by Indigo carmine (IND) at the glassy carbon electrode (GCE). Cyclic voltammetry and chronoamperometry techniques were used to investigate the suitability of IND as a mediator in aqueous solution with various pHs. It has been found that under the optimum conditions (pH 8.0) the oxidation of L-Cys occurs at a potential of about 290 mV less positive than that of an unmodified GCE. The heterogeneous electron transfer rate constant between IND and the GCE and the diffusion coefficient of IND were estimated to be about 2.62×10 -3 cm s -1 and 4.10×10 -6 cm 2 s -1 , respectively. The diffusion coefficient of L-Cys (D= 1.8×10 -6 cm 2 s -1 ), and its kinetic parameters such as electron transfer coefficient, (α = 0.41) and the catalytic reaction rate constant, (k=5.9×10 4 M -1 s -1 ) were also determined using electrochemical approaches. The voltammetric response of the modified electrode was linear against the concentration of L-Cys in the ranges of 1.0×10 -4 M- 1.5×10 -2 M with cyclic voltammetry method. The detection limit (3σ) was determined as 5.1×10 -5
Novel Use of Kaolin Wastes in Blended Cements

This paper describes the influence of different thermally activated clay wastes (ACW) on the hydration phases in cement pastes containing two percentages of addition (10% and 20%). Results show that the main products obtained during hydration of cement pastes containing ACW were portlandite, calcium aluminate hydrates, calcium silicate hydrates, and hydrotalcite-type compounds. Portlandite formation decreases when addition percentage is 20%, contrary to tetracalcium aluminate hydrate, which increases in similar conditions. The ACW that showed the most portlandite consumption was ACW1 (700°C, 2 h) according to thermogravimetric data.
Synthesis and characterization of graft copolymers able to form polymersomes and worm-like aggregates

Poly(glycerol adipate)-graft-(poly(e-caprolactone)-block-poly(ethylene oxide)) (PGA-g-(PCL-b-PEO)) is synthesized by ring opening polymerization of e-caprolactone initiated by the hydroxyl groups of PGA. This is followed by grafting of poly(ethylene oxide) monomethylether mPEO-N3 onto the PCL blocks using copper-catalyzed azide–alkyne cycloaddition (CuAAC, “click” reaction). All polymers form micelles of radii in the range of 10 nm after dissolving in acetone and dialysis against water. Micelles formed by PGA-g-(PCL-b-PEO) show smaller critical micelle concentration (cmc) and higher stability against temperature increase compared to micelles formed by PCL-b-PEO with an identical chemical composition to the grafted segments. Additionally, PGA17-g-(PCL24-b-PEO44) forms worm-like aggregates prepared by the cosolvent/evaporation method. The resulting worm-like aggregates are visualized by transmission electron and confocal laser scanning microscopy and show shape persistent behaviour over their entire contour length. It is suggested that these worm-like aggregates are formed by partially fused polymersomes under the influence of shear flow. They have the potential for simultaneous delivery of hydrophobic and hydrophilic drugs.
Selective Ligands for the μ, δ, and κ Opioid Receptors Identified from a Single Mixture Based Tetrapeptide Positional Scanning Combinatorial Library*

A combinatorial library of 6,250,000 tetrapeptides in the mixture based positional scanning format was screened in binding assays for the three opioid receptors, μ, δ, and κ. Three different binding profiles were found. Individual peptides were synthesized representing all possible combinations of the active amino acids identified from the screening data. New, highly active peptides selective for each of the three receptors were chosen. This study demonstrates the power of mixture-based combinatorial libraries to identify distinctly different ligands for closely related receptors.
RP-HPLC/ELSD METHOD DETERMINATION OF TOPIRAMATE IN PHARMACEUTICAL PRODUCTS

Topiramate is chemically sulfamate-substituted monosaccharide group drug. It is used to prevent the seizures of epilepsy. The present work describes RP-HPLC/ELSD method for estimation of topiramate in bulk samples and formulations. Best peak shape was achieved with the mobile phase having composition of acetonitrile and buffer (1.0gm of ammonium acetate in 1000ml of HPLC water) in the ratio 35:65v/v, Xterra C18, 150 x4.6mm, 5µ column, 20µL injection volume, column oven temperature 40°C, 1.0mL per min flow rate and ELS detector conditions are 90°C drift tube temperature, 22psi gas pressure, 100 is the gain for sample and standard detection was used. The linearity response of the HPLC system was obtained over the range of 500-3000ppm with a correlation coefficient of 0.983. The result of recovery analysis showed excellent recoveries ranging from 98.0% to 102.0%. Specificity study indicated that no interference due to common excipients and diluent was observed with the developed method.
A New Molecular Probe Method To Study Surface Topography of Carbonaceous Solid Surfaces

Adsorption on a heterogeneous surface of flexible molecules composed of a number of mers, like n-alkanes for instance, is strongly affected by topography of surface adsorption sites. Therefore, fitting to experimental adsorption isotherms, theoretical expressions developed for multi site-occupancy adsorption on heterogeneous surfaces characterized by random and patchwise topography should make it possible to distinguish whether a studied solid surface is characterized by random or by patchwise topography. For certain fundamental but also practical reasons, we took into consideration carbonaceous adsorbents. Following the general approach to multisite-occupancy adsorption published recently by Rudzinski and Everett, we have developed here a generalized form of the Dubinin-Astakhov isotherm equation, taking into account surface topography and the interactions between the adsorbed molecules. The developed isotherm equation has been used successfully by us to study the nature of surface topography of a number of carbonaceous adsorbents.
Immobilization of the Glucose-Galactose Receptor Protein onto a Au Electrode Through a Genetically Engineered Cysteine Residue

Studies by electrochemical impedance spectroscopy demonstrate that the wild-type glucose-galactose receptor (GGR) protein does not interact significantly with a Au surface, even through nonspecific interactions. Only the GGR A1C mutant, where alanine is replaced by a cysteine residue at the N-terminus, can form a protein film on Au suitable for creating an impedance biosensor. Impedance measurements of glucose binding at equilibrium allow estimation of the dissociation constant (K d ) as approximately 6.6 (1.5) μM, about 32 times higher than that for the native protein in solution. This change likely arises from surface immobilization rather than from cysteine introduction.
STUDY ON CATIONIC RING-OPENING POLYMERIZATION MECHANISM OF 3-ETHYL-3-HYDROXYMETHYL OXETANE

ABSTRACT Cationic ring-opening polymerization of 3-ethyl-3-hydroxylmethyl oxetane was carried out using BF3·O(C2H5)2 as initiator, and a branched polyether was formed. Typical SEC curves show that the polymer consists of two fractions: one has higher molecular weight (11.7×104∼ 9.2×104) and the other has lower molecular weight (3.8×103∼4.0×103). This probably resulted from the chain-tran sfer reaction of two propagating polymer chains. The structure of the polyEHMO formed was characterized by 1H and 13C NMR spectra. The degree of branching is mainly affected by the propagation mechanism. As the molar ratio of [I]0/[EHMO]0 in feed increased, the degree of branching also increased.
Thermo-responsive adhesion properties of composite hydrogel microcapsules

The present work describes the synthesis and characterisation of thermo-responsive microcapsules consisting of poly-N-isopropylacrylamide (PNIPAM) hydrogel, hydrophilic citrate-stabilized super-paramagnetic iron oxide nanoparticles (SPIONs) that perform the function of a local heat source and hydrophobic nanoparticles (either SiO2 or oleic acid-coated SPIONs) that stabilize the microcapsule surface. The microcapsules have been synthesized by the inverse Pickering emulsion polymerisation method. The effect of iron oxide concentration in the hydrogel on the shape, size, shrinkage ratio and heating rate of the microcapsules has been systematically investigated. The adhesion properties of the composite microcapsules towards a range of substrates have been characterised in a microfluidic flow cell and it was found that the temperature-induced change of the microcapsule size is an effective way of controlling adhesion. The induction heating of the embedded SPIONs makes it possible to control adhesion remotely in environments where macroscopic heating is not possible.
Application of Cloud Dynamics to Dosimetry of Cigarette Smoke Particles in the Lungs

Clinical data suggest a relationship between in vivo deposition patterns of cigarette smoke particles and the occurrence of tumors in the lung. Traditional dosimetry models fail to predict the preferential proximal deposition of cigarette smoke in the human airways, which resembles deposition of aerosol with a larger mass median aerodynamic diameter (MMAD) than that representative of cigarette smoke. Previous work has shown that accounting for the so-called cloud effect leads to enhanced proximal deposition and to better agreement with clinical and experimental data. This work presents an improved model of transport and deposition of cigarette smoke in the airways of smokers, accounting for possible particle-particle interactions (cloud effect) and their effect on the mobility of individual particles and on the deposition profile. Brinkman's effective medium approach is used for modeling the flow through and around the cloud, with the cloud's permeability changing according to the cloud's solid volume fraction. Although the weakest of all interparticle hydrodynamic interactions is considered, it significantly alters the deposition pattern along the respiratory tract, both alone and simultaneously with other synergistic processes (coagulation, hygroscopic growth) that dynamically modify the particle size distribution. Model results compare favorably with clinical data available on CSP deposition in the lungs and indicate that a combination of cloud behavior, hygroscopic growth, and coagulation may explain the preferential proximal deposition of smoke particles in the tracheobronchial region.
Monoclonal antibodies against serogroup B salmonellae: production, characterisation and use in a sandwich ELISA

Abstract Ten monoclonal antibodies (MAbs) against serogroup B salmonellae were obtained after immunisation of BALB/c mice with outer membrane proteins (OMPs) from Salmonella enterica serovar Typhimurium. Affinity constants, measured by enzyme-linked immunosorbent assay (ELISA), ranged from 8×05 to 6×07 l mol−1. Additivity ELISA demonstrated that most MAbs recognise different epitopes. ELISA determined the antigen specificity of the MAbs. The MAbs were more reactive with live Salmonella Typhimurium than with heat-treated cells. Two MAbs were used to develop a sandwich ELISA for rapid detection of Salmonella Typhimurium in experimentally contaminated meats. Its detection limit was 105 CFU ml−1 and it was able to detect 1–10 CFU in post-enrichment broth from 25 g of beef and chicken meat samples. The sandwich ELISA developed was shown to be specific and sensitive for the detection of Salmonella Typhimurium in meat, and produced results comparable to the culture methods in 57 h.
Spray Drying of Casein Aggregates Loaded with β-Carotene: Influences of Acidic Conditions and Storage Time on Surface Structure and Encapsulation Efficiencies

Spray-dried casein-encapsulated β-carotene powders were prepared for encapsulation efficiency studies with respect to structural changes in casein aggregates prior to drying. The use of casein aggregates as shell matrix materials for encapsulation is of interest in encapsulation research; however, the relationship between process conditions and casein aggregation is not completely understood. Here, we report the investigation of the influence of solution pH and storage time on casein aggregate structural changes, in addition to encapsulation efficiency after spray drying. Total β-carotene loading quantities observed were higher when a solution with lower pH was employed in the dried powder preparation. Specimens obtained from a solution with pH 5.5 gave the highest total loading efficiency. Loading efficiencies were largely improved when the solutions were stored for 5 days prior to spray drying. Small-angle X-ray scattering analysis confirmed that surface structures and particle sizes were correlated to the solution pH used, as well as to storage time. At lower pH conditions (pH 5.5), particle sizes greatly increased over the entire storage duration, with a rough surface formed in the first 6 h, followed by a gradual surface smoothing. At higher pH conditions (pH 6.0–7.0), a rough surface formed accompanied by an increase in the particle size in the first 24 h, after which the size gradually decreased with the smoothed surface formation. The encapsulation efficiencies could be correlated with these structural changes during storage. The results obtained provide important insights into the encapsulation process and are expected to improve applications involving casein aggregation.