112 research outputs found
Mechanical Properties and Morphological Characterization of PLA/Chitosan/Epoxidized Natural Rubber Composites
Poly (lactic acid) (PLA)/chitosan (CS) natural polymer/epoxidised natural rubber (ENR) composites were successfully prepared through a solution casting method. The morphological characteristics of fabricated composites were investigated by scanning electron microscopy (SEM) and optical microscopy. The microstructure of PLA/ENR was significantly altered with the addition of CS. SEM analysis of composites fractured surfaces revealed smooth and homogeneous texture and good dispersion of CS. However for 15 wt% CS composites, the phase segregation and poor adhesion between the polymers were observed. Fourier transform infrared spectroscopy revealed some levels of attractive interaction between CS, PLA, and ENR in the composites. The mechanical properties of composites in terms of tensile strength and tensile modulus were significantly improved with the addition of CS into the matrix while the percent elongation at break decreased. The tensile strength increased up to 5 wt% CS loading for both PLA/CS and PLA/ENR/CS and thereafter decreased while Young’s modulus increased up to 10 wt%. However, when the CS content was increased to 15 wt%, the tensile strength and tensile modulus were slightly decreased. These improvements were attributed to good dispersion of CS at the optimum filler levels and attractive interaction between the composites components.</jats:p
Clinico-epidemiological study of childhood psoriasis
The clinico-epidemiological data of 276 childhood psoriasis were studied. The mean age was 7.64 years (range 1 day to 15 years). There was no complain of any discomfort in 198 cases. Itching was present in 67 cases and burning in 11 cases. Plaque psoriasis was the most common type (68.8%) followed by guttate (18.8%). Erythrodermic and pustular psoriasis were found in 2.2% and 1.5% cases. Scalp was the most frequently affected site (75.36%) followed by extensors of extremities (41.3%), trunk (37.7%), palm and/or sole (13.0%) and diaper area (11.6%). Nail involvement was found only in 8%, joint was affected in 3.6% and only 2.2% children with psoriasis were erythrodermic. In Bangladeshi children with psoriasis, plaque is the most common type and scalp is the mostly affect site. Nail and joint involvement is less common. Pustular and erythrodermic psoriasis is rare
Novel Adsorbent For Industrial Wastewater Treatment Applications
In this study, the hydroxyapatite powder is investigated for both of methylene blue and thymol blue in aqueous solution. The physical and chemical properties of the adsorbent were evaluated systematically using the different techniques including Microsoft Excel programming, linear regression model and also the coefficient of determination. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial dye concentrations, and also the adsorbent dosage on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model for both of methylene blue and thymol blue. The isotherm data of methylene blue and thymol blue could be well described by the Freundlich isotherm model which means the adsorption is multilayer adsorption with non-uniform distribution of adsorption heat and affinities over the heterogeneous surface. The maximum adsorption capacity (KF) of methylene blue and thymol blue is found to be 0.2736 (L/mg) and 11.18407 (L/mg) respectively. The high specific surface area and the porous structure with some acidic functional groups on the surface were obviously responsible for high dyes adsorption onto hydroxyapatite (HA). Adsorption kinetics data were modeled with the application of Pseudo first order, Pseudo second order and Intraparticle diffusion models. The results revealed that the Pseudo second order model was the best fitting model. Which means that, the adsorption mechanism followed two stages in which the first one was fast and the other was slower step. Which means the adsorption of dye molecules was limited by intra particle diffusion and film diffusion, as well as the adsorption rate in both of adsorption system are depends only on the slower step. The Boyd plot exposed that the intra-particle diffusion was the rate controlling step of the adsorption process of both of methylene blue and thymol blue molecules by HA powder. However, the adsorption of methylene blue molecules (basic solution) using of HA as adsorbent particles is found to be extremely preferable than thymol blue molecules
(E)-4-Octyloxybenzaldehyde thiosemicarbazone
In the title compound, C16H25N3OS, the thiosemicarbazone group adopts an E configuration with respect to the C=N bond and is almost coplanar with the benzene ring, forming a dihedral angle of 9.3 (1)°. In the crystal packing, the molecules lie along the a axis in an antiparallel arrangement and are held in place by van der Waals interactions. As a consequence, there is relatively low anisotropic thermal motion in the terminal atoms of the n-octyl chain
Bis[benzyl N′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2 N′,S]zinc(II)
In the title ZnII complex, [Zn(C17H15N2S2)2], the ZnII atom lies on a twofold rotation axis. It exists in a tetrahedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Molecules are connected by weak C—H⋯S intermolecular interactions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π interactions involving the phenyl ring of the 3-phenylprop-2-enylidene unit
Occurrence, Phenotypic and Molecular Characteristics of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Healthy Turkeys in Northern Egypt
Poultry is one of the most important reservoirs for zoonotic multidrug-resistant pathogens. The indiscriminate use of antimicrobials in poultry production is a leading factor for development and dissemination of antimicrobial resistance. This study aimed to describe the prevalence and antimicrobial resistance of E. coli isolated from healthy turkey flocks of different ages in Nile delta region, Egypt. In the current investigation, 250 cloacal swabs were collected from 12 turkey farms in five governorates in the northern Egypt. Collected samples were cultivated on BrillianceTM ESBL agar media supplemented with cefotaxime (100 mg/L). The E. coli isolates were identified using MALDI-TOF-MS and confirmed by a conventional PCR assay targeting 16S rRNA-DNA. The phenotypic antibiogram against 14 antimicrobial agents was determined using the broth micro-dilution method. DNA-microarray-based assay was applied for genotyping and determination of both, virulence and resistance-associated gene markers. Multiplex real-time PCR was additionally applied for all isolates for detection of the actual most relevant Carbapenemase genes. The phenotypic identification of colistin resistance was carried out using E-test. A total of 26 E. coli isolates were recovered from the cloacal samples. All isolates were defined as multidrug-resistant. Interestingly, two different E. coli strains were isolated from one sample. Both strains had different phenotypic and genotypic profiles. All isolates were phenotypically susceptible to imipenem, while resistant to penicillin, rifampicin, streptomycin, and erythromycin. None of the examined carbapenem resistance genes was detected among isolates. At least one beta-lactamase gene was identified in most of isolates, where blaTEM was the most commonly identified determinant (80.8%), in addition to blaCTX-M9 (23.1%), blaSHV (19.2%) and blaOXA-10 (15.4%). Genes associated with chloramphenicol resistance were floR (65.4%) and cmlA1 (46.2%). Tetracycline- and quinolone-resistance-associated genes tetA and qnrS were detected in (57.7%) and (50.0%) of isolates, respectively. The aminoglycoside resistance associated genes aadA1 (65.4%), aadA2 (53.8%), aphA (50.0%), strA (69.2%), and strB (65.4%), were detected among isolates. Macrolide resistance associated genes mph and mrx were also detected in (53.8%) and (34.6%). Moreover, colistin resistance associated gene mcr-9 was identified in one isolate (3.8%). The class 1 integron integrase intI1 (84.6%), transposase for the transposon tnpISEcp1 (34.6%) and OqxB -integral membrane and component of RND-type multidrug efflux pump oqxB (7.7%) were identified among the isolates. The existing high incidence of ESBL/colistin-producing E. coli identified in healthy turkeys is a major concern that demands prompt control; otherwise, such strains and their resistance determinants could be transmitted to other bacteria and, eventually, to people via the food chain
Efficacy and safety of intralesional triamcinolone acetonide in the treatment of chronic hand eczema
This randomized controlled clinical trial was conducted to assess the efficacy and safety of intralesional triamcinolone acetonide in the treatment of chronic hand eczema comparing with topical clobetasol propionate. A total 60 patients of chronic hand eczema were recruited in the study. Thirty patients (Group A) were treated with intralesional triamcinolone acetonide and the rest 30 (Group B) with topical clobetasol propionate. Severity and improvement were assessed using Hand Eczema Severity Index (HECSI) score. The patients of both groups were followed up at 4th week and 12th week. In Group A, median HECSI score at baseline, 4th week and 12th week were 3, 20 and 20 respectively; whereas these scores were 54, 10 and 8 in Group B. In both groups, HECSI score was decreased gradually but the rate was higher in Group B than Group A (p0.05). The result of this study demonstrates that intralesional triamcinolone acetonide is effective and safe in treating chronic hand eczema but less effective than the topical clobetasol
Dynamic Crushing Response of Closed-cell Aluminium Foams during Shock Loading
Understanding the impact response of aluminium foams is essential for assessing their energy absorption capacity under dynamic loading. In this paper, the dynamic compaction behavior of closed-cell aluminium foam (CYMAT ™) has been tested using the plate-impact technique. Post-impacted samples have been examined using optical microscopy to observe the microstructural changes with the objective of elucidating the pore-collapse mechanism.The authors
also gratefully acknowledge UNSW Canberra’s Defence Related Research program that part-funded this work
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