Peristaltically induced flow of nanomaterial through uniform porous space and gravitational aspects

Magneto peristaltic flows of nanofluids play a key role in magnetic drug transport systems. Therefore, peristalsis of a nanofluid through a uniform porous medium under the influence of a uniform magnetic force is studied here. Ohmic heating and Hall aspects are incorporated in the analysis. Three distinct types of nanoparticles (ie, silver, alumina, and copper) have been used for theoretical analysis. A large wavelength and a small Reynolds number scheme are adopted in mathematical modeling. The dimensionless nonlinear system is solved using the well‐known perturbation method, and physical analysis is done via graphs. A comparison of different nanoparticles is also presented. It is noticed that an increase in the Hall effects nullifies the variations, which are due to an increment in the Hartman number. The temperature of the nanofluid can be reduced by increasing the permeability of the porous medium.     

Wound dressing application of castor oil- and CAPA-based polyurethane membranes

Polymer Bulletin - The objective of this study was to investigate and compare the effects of two different types of polyols on properties of synthesized polyurethanes (PUs), to develop biomedical...     

Functional Identification of Serine Hydroxymethyltransferase as a Key Gene Involved in Lysostaphin Resistance and Virulence Potential of Staphylococcus aureus Strains

Gaining an insight into the mechanism underlying antimicrobial-resistance development in Staphylococcus aureus is crucial for identifying effective antimicrobials. We isolated S. aureus sequence type 72 from a patient in whom the S. aureus infection was highly resistant to various antibiotics and lysostaphin, but no known resistance mechanisms could explain the mechanism of lysostaphin resistance. Genome-sequencing followed by subtractive and functional genomics revealed that serine hydroxymethyltransferase (glyA or shmT gene) plays a key role in lysostaphin resistance. Serine hydroxymethyltransferase (SHMT) is indispensable for the one-carbon metabolism of serine/glycine interconversion and is linked to folate metabolism. Functional studies revealed the involvement of SHMT in lysostaphin resistance, as ΔshmT was susceptible to the lysostaphin, while complementation of the knockout expressing shmT restored resistance against lysostaphin. In addition, the ΔshmT showed reduced virulence under in vitro (mammalian cell lines infection) and in vivo (wax-worm infection) models. The SHMT inhibitor, serine hydroxymethyltransferase inhibitor 1 (SHIN1), protected the 50% of the wax-worm infected with wild type S. aureus. These results suggest SHMT is relevant to the extreme susceptibility to lysostaphin and the host immune system. Thus, the current study established that SHMT plays a key role in lysostaphin resistance development and in determining the virulence potential of multiple drug-resistant S. aureus.     

Structural and magnetic studies of Ce-Zn doped M-type SrFe12O19 hexagonal ferrite synthesized by sol-gel auto-combustion method

In the present work, the M-type Sr-hexagonal ferrites having chemical composition Sr_1-xCe_xFe_12-yZn_yO₁₉ (x?=?0.000, 0.025, 0.050, 0.075, 0.10, y?=?0.00, 0.25, 0.50, 0.75, 1.0) are prepared via sol-gel autocombustion technique. The Structural and magnetic properties of M-type Sr-hexagonal ferrites are studied and discussed thoroughly. The structural, micro graphical and magnetic particularities of the samples are calculated through X-Ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM) respectively. X-ray diffraction assured that all the synthesized composites possess a pure M-type hexaferrite structure and basic crystalline configuration of Sr-hexaferrite which does not alter by Ce-Zn substitution. It is observed that the Ce-Zn substitution has significant effect on its magnetic properties. VSM results reveal that pure sample has coercivity of 4.49?kOe, which shows the hard nature of the samples. It is perceived that values of remanence (M_r) and saturation magnetization (M_s) decline with increasing the Ce-Zn ions substitution. The reason behind the reduction in magnetic saturation (M_s) and remanence (M_r) might be spin canting and dilution phenomena with increasing the rare earth substituted ions. The large coercivity magnets may be valuable for permanent (stable) magnet applications. The prepared composites could be useful for applications in microwave absorbing materials.     

Kinetic modeling and optimization of parameters for biomass pyrolysis: A comparison of different lignocellulosic biomass

A primitive element for the development of sustainable pyrolysis processes is the study of thermal degradation kinetics of lignocellulosic waste materials for optimal energy conversion. The study presented here was conducted to predict and compare the optimal kinetic parameters for pyrolysis of various lignocellulosic biomass such as wood sawdust, bagasse, rice husk, etc., under both isothermal and non-isothermal conditions. The pyrolysis was simulated over the temperature range of 500–2400 K for isothermal process and for heating rate range of 25–165 K/s under non-isothermal conditions to assess the maximum pyrolysis rate of virgin biomass in both cases. Results revealed that by increasing the temperature, the pyrolysis rate was enhanced. However, after a certain higher temperature, the pyrolysis rate was diminished which could be due to the destruction of the active sites of char. Conversely, a decrease in the optimum pyrolysis rate was noted with increasing reaction order of the virgin biomass. Although each lignocellulosic material attained its maximum pyrolysis rate at the optimum conditions of 1071 K and 31 K/s for isothermal and non-isothermal conditions, respectively, but under these conditions, only wood sawdust exhibited complete thermal utilization and achieved final concentrations of 0.000154 and 0.001238 under non-isothermal and isothermal conditions, respectively.     

Characterization of semipurified enterocins produced by Enterococcus faecium strains isolated from raw camel milk

Food safety has become an issue of great interest worldwide. Listeria monocytogenes is a food-borne pathogen that causes listeriosis and is difficult to control in the dairy industry. The use of lactic acid bacteria (LAB) and their antimicrobial substances against Listeria is promising in food applications. Here, we report the isolation from raw camel milk of LAB displaying antilisterial activity. Two isolates were selected for their secretion of bacteriocin(s) and identified by 16S rRNA sequencing as Enterococcus faecium S6 and R9. The produced bacteriocins were partially purified by ammonium sulfate precipitation and then biochemically characterized. Antimicrobial activity was estimated to be 6,400 and 400 AU (arbitrary units)/mL for E. faecium S6 and R9, respectively. The proteinaceous nature of the bacteriocins was confirmed via enzymatic reactions. Moreover, lipolytic and glycolytic enzymes completely inactivated the antimicrobial effect of the bacteriocins. These bacteriocins were heat-resistant and stable over a wide range of pH (2.0 to 10.0). To confirm its inactivation by lipolytic and glycolytic enzymes, the bacteriocin of E. faecium S6 was further purified by gel filtration, which suggested the existence of carbohydrate and lipid moieties. In addition, enterocin-coding genes were identified by PCR, showing DNA fragments corresponding in size to enterocins A, B, and P for E. faecium S6 and to enterocins B and P for E. faecium R9. In conclusion, these results indicate that partially purified bacteriocins from E. faecium S6 and R9 may be beneficial in controlling Listeria in the dairy industry.     

Synthesis and application of biocompatible nontoxic nanoparticles for reclamation of Ce3+ from synthetic wastewater: Toxicity assessment,kinetic, isotherm and thermodynamic study

The aim of present study is to synthesize forsterite nanoparticles(FRST) for the reclamation of cerium ions(Ce~(3+)) from synthetic wastewater.The aim to synthesize FRST nanoparticles is due to its biocompatible and nontoxic nature.The formation of nanoparticles with average diameter of 58 nm was confirmed by TEM analysis.SEM images of bare FRST nanoparticles show a heterogeneous surface with porous nature.BET surface area of FRST nanoparticles is calculated to be 33.69 m~2/g.The significant uptake of Ce~(3+) ions can be obtained for all the selected concentrations(25-150 mg/L) within 2 h of adsorbent—adsorbate interaction.The pH study shows that by increasing pH from acidic to alkaline range,higher removal can be achieved.Temperature study demonstrates the endothermic nature of Ce~(3+)adsorption.The value of sticking probability suggests very high sticking probability of Ce~(3+) ion for FRST nanoparticles.Ce~(3+) uptake is favored by higher temperature and with the increase in temperature from298 to 328 K,Langmuir adsorption capacity increases from 36.45 to 42.99 m~2/g.Applicability of FRST nanoparticles was also investigated for other light and heavy rare earth elements in single solute and multisolute systems,FRST nanoparticles show the significant removal of divalent metallic pollutants as well.The assessment of chemical toxicity of treated wastewater was carried out with the bioluminescent photobacterium(Vibrio fischeri) and decreased toxicity was observed in treated water samples.The outcome of present study suggests that the FRST nanoparticles can be efficiently utilized for the removal of Ce~(3+) ions and a wide range of other pollutant species as well.     

Finite capacity priority queues with potential health applications

The queuing processes of interest in this paper are that of waiting lines with two priorities and multiple service channels. The arrival process is assumed Poison and the service time distribution is negative exponential. Arriving units enter service if there is at least one idle channel, otherwise they join a finite queue and are served according to a non-preemptive priority discipline. If a low priority arriving unit finds the queue full, it is not allowed to enter the system and is considered “blocked” or lost. In the first model a high priority arrival may displace a low priority unit from the full queue and may be “blocked” if the queue consists of high priority units only. In the second model the high priority unit may still displace a low priority unit from the full queue but it will never be “blocked” and may wait “outside” the system if the system is full. Thus far there has been no discussion of such models in queuing theory literature. In this paper analytical expressions for average waiting times have been obtained for the two models. Two potential applications of the models are described and the usefulness of the models is illustrated by numerical examples.     

Iterative algorithm for a system of nonlinear variational-like inclusions

In this paper, we consider a system of nonlinear variational-like inclusions (SNVLI) in Hilbert spaces. In particular, SNVLI reduces to a variational inclusion, an extension of variational inclusion studied by ^{Hassouni and Moudafi [1]}. Using fixed-point method, we suggest an iterative algorithm for finding an approximate solution to SNVLI. Further, we prove the existence of solution and discuss convergence criteria for the approximate solution of SNVLI. The theorems presented in this paper improve and unify many known results of variational inclusions and variational inequalities, see for example ^{1., 2. and 3.}.     

Medicament Release from Ointment Bases: I. Indomethacin. In Vitro and in Vivo Release Studies

The in vitro release of indomethacin from 1%, 3%, and 5% indomethacin ointments and its in vivo absorption through the skin of rabbits was investigated. The in vitro release of indomethacin followed zero-order kinetics and was better from an absorption base ointment. No significant differences (F=3.047 and P=0.079 for the absorption base) and (F=2.15 and P=0.14 for the hydrophilic base) in the release rate of indomethacin in 1%, 3%, and 5% indomethacin ointments were observed. Indomethacin was most effectively absorbed from absorption ointment bases. A correlation between the in vitro release and the in vivo absorption was found; also, a correlation between the in vivo release pattern of the bases used and the in vivo data reported in the literature was observed.