Investigating the Production of Antimicrobial Nanoparticles by Chlorella vulgaris and the Link to Its Loss of Viability

Chlorella vulgaris from Al-Ahsa, KSA was proved to be an active silver and gold nanoparticle producer. Nanogold and nanosilver particles were characterized using UV-visible spectroscopy, Fourier-transform infrared spectroscopy, and scanning electronmicroscopy. Both nanoparticles were used in the antimicrobial bioassay. The two nanoparticles showed antibacterial activities, with the silver nanoparticles being the most effective. To investigate the argumentative nature of their biosynthesis (i.e., whether it is a biotic or abiotic process), we isolated total ribonucleic acid RNA as an indicator of vitality. RNA was completely absent in samples taken after one week of incubation with silver nitrate and even after one or two days. However, successful extraction was only achievable in samples taken after incubation for one and four hours with silver nitrate. Most importantly, the gel image showed recognizable shearing of the nucleic acid after 4 h as compared to the control. An assumption can be drawn that the synthesis of nanoparticles may start biotically by the action of enzyme(s) and abiotically by action of reducing entities. Nonetheless, with prolonged incubation, excessive nanoparticle accumulation can be deadly. Hence, their synthesis continues abiotically. From the RNA banding profile, we suggest that nanosilver production starts both biotically and abiotically in the first few hours of incubation and then continues abiotically. Nanosilver particles proved to have more of an antimicrobial impact than nanogold and hence are recommended for different applications as antibacterial agents.

Deposition of SiO2/SiC Coating on Carbon Fiber to Enhance the Oxidation Resistance

The objective of the present investigation is to study the oxidation resistance of SiO2/SiC coating on carbon fiber by electrolytic plasma spraying. The SiO2/SiC coating can be easily prepared within several tens seconds through this approach. The effect of spraying parameters (fixed point 5s and spray 5 times at the speed of 20mm/s) on the microstructure and oxidation resistance properties of coatings was discussed in this paper. Scanning electronmicroscopy (SEM), energy dispersive spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and DTG have been used to characterize the SiO2/SiC coatings. It was demonstrated that fixed-point spray 5s has better density and oxidation resistance coating, and the oxidation resistance increased by 12% compared with spray 5 times at the speed of 20mm/s. The fixed-point spray 5s coating was mainly composed of SiO2 and SiC. The SiO2 relative content was 72.6% and the SiC relative content was 27.4%.

Self-Healing Epoxy Coating Modified by Double-Walled Microcapsules Based Polyurea for Metallic Protection

The effectiveness of preploymer and 1,6-Hexamethylene diamine encapsulated by double-walled microcapsules based polyurea (PUA) was explored for healing the cracks generated in epoxy coatings. Double-walled microcapsules were systhesized by interfacial polymerization at the interface between the prepolymer droplets and the 1,6-Hexamethylene diamine droplets to form the polyurea shell. The effect of synthetic stirring speed on the morphology of the microcapsules was observed by scanning electronmicroscopy (SEM) and optical microscopy (OM). The chemical structure as well as the thermal properties and the core content were characterized by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analyzer (TGA) respectively. Electrochemical impedance spectroscopy (EIS) studies of the artificial scratched area showed that the coating containing 2wt% and 5wt% microcapsules could effectively prevent further corrosion of the coating with high corrosion resistance efficiencies of 61.61% and 45.99% after immersing for 144h in seawater.

PEMBUATAN MEMBRAN FOTOKATALITIK DARI SELULOSA DIASETAT SERBUK GERGAJI KAYU JATI (TECTONA GRANDIS L.F.) DAN TIO2 UNTUK PENGOLAHAN LIMBAH BAKU AIR PDAM

Membrane technology is growing rapidlybecause of its superiority and has beenwidely applied in various industries. Thewaste of teak sawdust is increasing as thefurniture industry develops, but its utilizationis not optimal. The purpose of this study wasto determine the effect of the addition of TiO2on the mechanical properties andperformance of photocalytic membranesfrom cellulose diacetate teak sawdust forprocessing PDAM water raw materials.Cellulose isolation from teak sawdust wascarried out by adding NaOH 17.5% (b / v)and continued with cellulose bleachingprocess. Cellulose teak sawdust wassynthesized into cellulose diacetate byacetylation method. Membrane production isdone by phase inversion method withvariations in the composition of TiO2 0.25%,0.5%, 0.75% and 1% and also variations inevaporation time 20 seconds, 25 seconds,30 seconds and 35 seconds. The photocyticmembrane of cellulose diacetate from teaksawdust and TiO2 produced wascharacterized by thickness test, mechanicalproperties and performance. Photocalyticmembranes with optimum conditions arecharacterized by SEM (Scanning ElectronMicroscopy), FT-IR (Fourier TransformInfraRed) and antibacterial effectiveness.The optimum composition of thephotocatalytic membrane is 16% cellulosediacetate, 4% formamide, acetone 79% and1% TiO2 with 30 seconds evaporation time.The mechanical properties obtained werestress 1562,50000 kN / m2, strains 0.01 m /m and Young Modulus 141593,4835 kN /m2. The membrane has an averagethickness of 0.04 mm, a flux value of 683.10L.m2.hari-1, a rejection value of 97.74% andan antibacterial effectiveness of 99.57%.

Use of Microwaves to Activate Bentonite in the Processes of Sorption of Nickel Ions from Concentrated Aqueous Solutions

The physicochemical parameters of the process of sorption water purification from compounds of Nickelwith clay sorbent in static conditions are studied. The absorption isotherm of ions of this metal from concentratedaqueous solutions on samples of bentonite using ultrahigh-frequency irradiation (microwave) is analyzed. Mostcorrectly, it is described by the linear equation of Langmuir. It is shown that irradiation of this sorbent bymicrowaves in the process of nickel ion sorting almost 2 times increases the value of the marginal sorptioncapacity for this metal (in comparison with the method of "stimulation" - preliminary washing of bentonite withpure water under the action of microwaves). The results of the study of spent bentonite by scanning electronmicroscopy, energy dispersion and X-ray diffraction analysis indicate that the metal under action of themicrowave is deposited on the surface of the bentonite not only in the form of an adsorbed monolayer of ions, butalso in the form of a separate crystalline phase, nickel silicate. Changes in the acidity of the medium duringsorption purification under the action of microwave are observed: from pH ≈ 5.7 ... 6.5 (before exposure) to pH ≈6.7 ... 7.1 (after irradiation). Confirmed assumption about that under the action of microwaves in the aqueousmedium there is a partial destruction of the silicate framework of clay sorbents with the release of silicon ionsSiO32-. These ions undergo hydrolysis, as a result of which the pH of the solution increases. Also, the directdiscontinuity of the Si-O bonds in the near-surface groups ≡Si-OH is not excluded, which leads to an increase inthe number of "free" hydroxyl groups.

Design of novel Surfactant Modified Carbon Nanotube PasteElectrochemical Sensor for the Sensitive Investigation of Tyrosineas a Pharmaceutical Drug

Purpose: The novel sodium dodecyl sulfate modified carbon nanotube paste electrode (SDS/CNTPE) was used as a sensitive sensor for the electrochemical investigation of L-tyrosine (TY).Methods: The electrochemical analysis of TY was displayed through cyclic voltammetry (CV)and differential pulse voltammetry (DPV). The surface morphology of SDS/CNTPE and barecarbon nanotube past electrode (BCNTPE) was reviewed trough field emission scanning electronmicroscopy (FESEM).Results: The functioning SDS/CNTPE shows a voltammetric response with superior sensitivitytowards TY. This study was conducted using a phosphate buffer solution having neutral pH(pH=7.0). The correlation between the oxidation peak current of TY and concentration of TYwas achieved linearly in CV method, in the range 2.0×10-6 to 5 ×10-5 M with the detection limit729 nM and limit of quantification 2.43 μM. The investigated voltammetric study at SDS/CNTPEwas also adopted in the examination of TY concentration in a pharmaceutical medicine as a realsample with the recovery of 97% to 98%.Conclusion: The modified electrode demonstrates optimum sensitivity, constancy, reproducibility,and repeatability during the electrocatalytic activity of TY.

Effect of black sesame (Sesamum indicum) and flaxseed flour (Linum usitatissimum) on bread quality using surface response methodology

The study aimed to evaluate the effect of black sesame andflaxseed flour addition in different proportions on bread quality.The bread formulations were developed through the RotationalCentral Composite Design (RCCD). The independent variableswere: black sesame and flaxseed flour which incorporated inamounts from 25.85% to 54.15%. The effect of the ingredients onbread quality was evaluated through physical parameters (specificvolume, expansion index and volume produced). Statisticalanalysis was performed using response surface methodology andthe two formulations with better technical performance weresubmitted to proximate composition (moisture, protein, fat, ash,carbohydrates and calcium), crumb structure, scanning electronmicroscopy (SEM) and sensorial analysis. It has been found thatblack sesame promotes greater reductions in the mass expansioncapacity than flax meal. There was an improvement in thenutritional value of the loaves by increasing the protein content,ashes, fat and calcium, in addition to the reduction ofcarbohydrates. The breads developed had good acceptability in allevaluated attributes. In this way, the inclusion of black sesameand flaxseed flour as ingredients in bread formulations promotesproducts with technological and sensorial quality.

Application of Spectroscopic Techniques for Antioxidant Property Analysis of Various Food Supplements and Ganoderma lucidum Coffee

In the present study, different methods were used to investigate the magnetic and structuralproperties of some food supplements and a kind of Ganoderma lucidum coffee. In order to understand theantioxidant capability of the samples and to detect paramagnetic centres, EPR (Electron ParamagneticResonance) experiment was carried out at room temperature. To examine the structural features andcrystalline property of the samples, XRD (X-ray diffraction) method was used. SEM (Scanning ElectronMicroscopy) technique was preferred to analyse the surface morphology. Also, EDS (Energy DispersiveSpectroscopy) was performed to get information about the elemental composition of the samples. Antioxidantpotential of these samples were examined in detail which is important to support our body functions.

EFFECT OF PROPRANOLOL;

Tuberculosis is the disease required long term treatment. Rifampicin is the majorelement of antiTB therapy if resistance is not documented. Potential of antitubercular dugsto produced hepatoxicity is very high and among all antiTB agents rifampicin (RIF) inducedhepatoxicity stands on top. Rifampicin is the major element of antiTB therapy if resistance is notdocumented. But its hepatotoxic effects are the main hurdle to continue with this therapy. In thisstudy RIF were administered to the rabbit alone or in combination of propranolol to evaluate thehepatotoxic effects of RIF and reduction of hepatotoxicity by propranolol. Histological evaluationof liver tissue on higher magnification, its micrometric analysis and SEM (scanning electronmicroscopy) of liver were used to estimate the effects of this combination. Micrometry revealedthat number of viable hepatocytes, their diameter and nuclear diameter were altered. SEMmicrograph showed distorted and swollen hepatic cords. All of these changes successfullyturned to normal by combined administration of propranolol. Propranolol successfully improvesthe hepatic architecture proved by both qualitative and quantitative microscopy.

Alimentary canal of fifth instar larvae of Lymantria dispar (Lepidoptera: Erebidae, Lymatriinae)

Here, the alimentary canal of fifth instar larvae of the gypsy moth (Lymantria dispar) was re-investigated with light microscopy (LM), and for the first time with laser scanning confocalmicroscopy (LSCM) and scanning electronmicroscopy (SEM). We describe morphological characteristics and provide morphometric data. Well-developed dilator muscles and Malpighian bladders suggest a high capacity for food propulsion, excretion, absorption, and detoxification. The epithelium of the alimentary canal of L. dispar is histologically simple and that of the midgut is composed of columnar, goblet, and regenerative cells. Particular arrangement of the intima of crop with a central ventral region recalling a ladder and numerous folds was detected, indicating the capability for a large increase in volume to store food. Numerous spinules were observed on the cuticular intima of pylorus and spinules of a different type were observed on the pyloric valve, and these might assist in propelling the feces.