Thermal properties of nylon 6 fibres grafted with acrylic monomers

Thermal Properties of methyl methacrylate (MMA), ethyl methacrylate (EMA) and n-butyl methacrylate (n-BMA) grafted onto nylon 6 fibre with various graft levels were investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) and the results compared with that of parent nylon 6 fibre. It was found that the initial decomposition temperatures (IDT) of the grafted samples were lower than that of the parent nylon 6 fibre. On the other hand with all the three monomers, there was an increase in overall thermal stability followed by subsequent decrease with increase in the graft level. Among the grafted samples both the IDT and IPDT (initial procedural decomposition temperature) followed the order MMA-g nylon > EMA-g nylon < n-BMA-g nylon Differential thermal analysis shows a depression in glass transition temperature (T_g) as well as in melting temperature (T_m). In the case of the MMA and EMA grafted samples, the depression is small over a wide range of graft level. In the case of the n-BMA grafted samples, the depression is higher. A wide melting range was obtained in the grafted samples. Flammability studies also showed that with an increase in the graft level as well as an increase in the alkyl chain the ease of flammability increased as expressed by limiting oxygen index (LOI) values. The possible reasons for the phenomena occurred have been discussed.     

Development of a method employing reversed‐phase thin‐layer chromatography for establishing milk fat purity with respect to adulteration with vegetable oils

A systematic study was conducted using reversed‐phase thin‐layer chromatography wherein unsaponifiable matter of samples namely, pure cow and buffalo milk fats, vegetable oils (groundnut oil, soya bean oil and sunflower oil) and milk fats adulterated with vegetable oils (≥1%) were run along with the reference standards using two new solvent systems to detect adulteration in milk fat. The results of the study revealed that adulteration at even a 1% level could easily be detected using this rapid, reliable and reproducible method based on the presence of β‐sitosterol as a marker and some additional spots ascribable to their occurrence in vegetable oils only.     

Essential oil nanoemulsions: antibacterial activity in contaminated fruit juices

Many human acid tolerant bacterial and fungal pathogens can be transmitted through the consumption of the contaminated fruit juices. We aim to formulate essential oil nanoemulsions (basil, black seed, turmeric, clove & cinnamon), determine their ability to clear contamination by food borne bacterial pathogens from fruit juices. The antibacterial activity of the optimised formulations was tested in the fruit juices against bacterial pathogens causing gastrointestinal tract infections. The minimum bactericidal concentration (MBC) of clove emulsions ranged from 15.6 to 25 μL mL⁻¹. Cinnamon oil emulsion had an MBC ranging between 15 and 31 μL mL⁻¹. At MBC, cinnamon oil emulsions caused a 6log₁₀ decrease in viable counts by 8 h and maintained the sterility of fruit juices for 7 days at ambient temperature. Thus, clove and cinnamon microemulsions can be used as juice additives to control food borne bacterial pathogens and maintain the bacterial sterility of fruit juices.     

Antibiotic susceptibility profiles of new probiotic Lactobacillus and Bifidobacterium strains

The antimicrobial susceptibilities and presence of plasmids in four new probiotic lactic acid bacteria (LAB) strains, Lactobacillus rhamnosus HN001 (DR20) HN067, Lactobacillus acidophilus HN017 and Bifidobacterium lactis HN019 (DR10), were determined. Resistance to 18 commonly used antibiotics was assessed by disk diffusion. The three Lactobacillus strains had similar antibiotic susceptibility profiles to those of Lactobacillus plantarum strain HN045 and two commercial probiotic Lactobacillus strains, GG and LA-1. The B. lactis strain HN019 had a similar profile to three commercial probiotic B. lactis strains (Bb12, HN049 and HN098). All 10 strains were sensitive to the Gram-positive spectrum antibiotics erythromycin and novobiocin, the broad-spectrum antibiotics rifampicin, spectinomycin, tetracycline and chloramphenicol and the beta-lactam antibiotics penicillin, ampicillin and cephalothin. By contrast, most strains were resistant to the Gram-negative spectrum antibiotics fusidic acid, nalidixic acid and polymyxin B and the aminoglycosides neomycin, gentamicin, kanamycin and streptomycin. All three L. rhamnosus strains (HN001, HN067 and GG) were resistant to vancomycin and several strains were also resistant to cloxacillin. Of the four new probiotic strains, only L. rhamnosus HN001 contained plasmids; however, a plasmid-free derivative of HN001 had the same antibiotic susceptibility profile as the parent strain.     

Cytochrome P450 inhibitory potential of selected Indian spices — possible food drug interaction

Spices constitute an important group of food which is virtually indispensable in the culinary art. In a view, these spices feared to pose a probability to affect the disposition of conventional pharmaceuticals through inhibition of human cytochrome P450 (CYPs) enzymes. In the present study an approach has been made to evaluate the possible CYP inhibition potential with some Indian spices (Capsicum annuum, Murraya koenigii, Zingiber officinale) and their major bioactive compounds, in combination with pooled microsome; as well as commercially available recombinant human CYP3A4, CYP2D6, CYP2C9 and CYP1A2. Quantification of the bioactive compound was determined through RP-HPLC, in order to standardize the plant material. CYP–carbon monoxide (CYP–CO) complex assay result indicated that all the plants and their bioactive compounds have an interaction potential with CYPs. Fluoregenic assay results indicated that the spice extracts have higher inhibition potential comparing to their single bioactive molecule. The higher enzyme inhibition potential by the extracts may be related to the synergistic effects due to the presence of other constituents in the extract. Capsaicin and C. annuum showed the lowest IC₅₀ value and 6-gingerol and Z. officinale extract showed the highest IC₅₀ value among the entire sample tested. The entire sample showed significantly less (P < 0.001, P < 0.01) interaction potential than known inhibitors. These findings indicate that selected spices are unlikely to cause clinically relevant drug interactions involving the inhibition of major CYP isozymes.     

An apparatus for quantitative measurement of interparticulate friction in a non-compacted powder mass

This paper describes a new test apparatus developed for measuring interparticulate friction. The results obtained using this apparatus are compared with Hausner ratio as well as the angle of repose results made on identical powders and under identical environmental conditions. The resistance to flow of a mass of uncompacted power is determined by measuring the torque needed to prevent the rotation of a vane shaft embedded in the powder while the powder column is rotated at a constant speed. The vane shaft, located at the center of the apparatus, is coupled to a load cell and the force developed is recorded on a strip chart. The load cell is capable of measuring forces up to 500 gf with a limit of resolution of about 0.5 gf. Results obtained for a number of different particulate materials are presented.     

Managing the Topological Expansion of Computer Networks in an Optimal Way

This article describes a subgradient-based near-optimal heuristic algorithm designed for minimizing the search of links that need to be added to an existing telecommunications network to enhance the survivability and routability of the network.     

Soluble activated charcoal

Reduction of activated charcoal by lithium in liquid ammonia yields charcoal salts that can be reacted with dodecyl iodide to yield soluble dodecylated activated charcoal. Atomic force microscopy images reveal a heterogeneous size distribution of nearly spherical nanoparticles. High-resolution transmission electron microscopy images show a layered microcrystalline arrangement that becomes separated to form mostly single layered disordered structures after dodecylation. A ¹H-¹³C cross polarization magic angle spinning spectrum of the charcoal revealed a broad, featureless signal from sp² carbons and a much weaker broad signal from aliphatic carbons.     

Recent studies on electrospinning preparation of patterned,core–shell,and aligned scaffolds

Electrospinning is one of the most important ways to prepare continuous, high porosity, large specific surface area, and uniform diameter micro‐ and nanoscale fibers. So, it has been widely used in the preparation of micro/nano‐sized polymer scaffolds for tissue engineering in recent years. In addition to the versatility in material selection and the processing variables, electrospinning also provides a lot of methods to regulate fiber structure and scaffolds morphology. For example, the near‐field electrospinning can provide a method to solve the problem of uncontrollable fiber path; the melt electrospinning eliminates the risk of solvent residue in the construct; the addition of different auxiliary electrodes can make the fiber patterned. This review introduces the underlying principle and characteristics of above electrospinning applied in biomedicine. Herein, we highlight a comprehensive understanding of the technical aspect of this technology for versatile fibers with patterned, core–shell and aligned morphology. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46570.