Investigation Of Synergistic Effects Research Articles

The roles of the biochemical and molecular changes in resistance of Tetranychus urticae populations selected with spiromesifen+abamectin mixture </p >

The physiological changes in Tetranychus urticae selected with spiromesifen+abamectin (S+A) mixture formulation were demonstrated by biochemical and molecular methods. The susceptible (GSS) population of T. urticae, was selected with S+A and made resistant with increasing doses of the mixture formulation. The resistant population was divided into two, and selection pressure was terminated in one population which is named IR (Interrupt resistant). In the other population, the selection with S+A was continued and the population named IR2. Activities of some detoxification enzymes (esterase, glutathione-S-transferase (GST) and cytochrome P450) were investigated in the GSS and IR populations. The activity of esterase, GST and P450 enzymes were increased by 1.77, 2.57 and 2.58-fold, respectively, in the IR population compared to the GSS population. Also, investigation of synergistic effects with esterase inhibitor (TTP), GST inhibitor (DEM) and P450 inhibitor (PBO) in this population revealed that all three synergists showed significant synergistic effects in IR population. In molecular studies, when the population was screened for the presence of two previously identified glutamate channel mutations (G314D and G326E) by qPCR with TaqMan probes no mutations could be detected in glutamate channels. and the CTD domain of acetyl coenzyme-A carboxylase (ACCase). Furthermore, possible genetic mutations in the biotin carboxylase domain (BCD) and carboxyl transferase domain (CTD) of the ACCase target sites were determined by sequencing. Although a single amino acid mutation G37D in the BCD of the ACCase gene of the IR and IR2 populations was detected, its association with spiromesifen resistance was not confirmed. The results indicated that increased detoxification and possible target site mutation may be responsible for the S+A resistance in the IR and IR2 populations.

Human Milk Oligosaccharides, Important Milk Bioactives for Child Health: A Perspective.

Human milk contains all nutritive and bioactive compounds to give infants the best possible start in life. Human milk bioactives cover a broad range of components, including immune cells, antimicrobial proteins, microbes, and human milk oligosaccharides (HMOs). Over the last decade, HMOs have gained special attention as their industrial production has allowed the study of their structure-function relation in reductionist experimental setups. This has shed light on how HMOs steer microbiome and immune system development in early life but also how HMOs affect infant health (e.g., antibiotic use, respiratory tract infections). We are on the verge of a new era where we can examine human milk as a complex biological system. This allows not only study of the mode of action and causality of individual human milk components but also investigation of synergistic effects that might exist between different bioactives. This new wave in human milk research is largely fueled by significant advances in analytical tools in the field of systems biology and network analysis. It will be exciting to explore how human milk composition is affected by different factors, how different human milk compounds work together, and how this influences healthy infant development.

Anaerobic co-digestion of sewage sludge and Cladophora green algae: Investigation of synergistic effects and Optimization of substrate composition ratio

Anaerobic co-digestion of primary and secondary sewage sludge and <i>Cladophora</i> green algae was investigated under mesophilic temperature conditions. The design of experiment method and the optimal mixture design were used to systematically optimize the substrate composition ratios and elucidate the possible synergistic effects for an anaerobic digestion system. A reduced cubic model was created by Design-Expert software as a function of substrate composition ratios. The model was validated by ANOVA experimentally. Also, the substrate composition ratio's effects on variations in biogas production were studied. All linear impacts on changes in biogas production were significantly observed, and interactions between substrates in combined digestion had synergistic impacts on biogas production rate. The highest amount of biogas (235.17-296.03 ml/g VS) was obtained with ratios of equal to 70-60%, B equal to 0-17%, and C equal to 18-30%. Eventually, the model optimization was performed to predict the optimal conditions to achieve the maximum biogas production rate. It was seen that the predicted and actual values of produced biogas in favorable conditions with an error of about 1.3% are well consistent. The authors conclude that the optimal mixture design can be utilized to assess the optimal composition of substrates in an anaerobic digestion system.

Investigation of Synergistic Effects and Kinetics on Co-Pyrolysis of Alternanthera philoxeroides and Waste Tires.

A thermogravimetric analysis is used to analyze the thermal kinetics and investigate the synergistic effects between Alternanthera philoxeroides (AP) and waste tires (WTS) in a temperature range of 50–900 °C under three heating rates (15, 25, and 35 °C/min). Two model-free methods (FWO and KAS) and a model-fitting method (CR) were applied to calculate the activation energy. Results revealed that heating rates had no significant effect on the pyrolysis operation. The addition of WTS improved the thermal degradation of the samples as the samples had more than one stage during the main reaction period. A promoting synergistic effect was found in the blend 75A25WT and obtained the lowest activation energy among all the blends without a catalyst, while the blend 50A50WT exhibited an inhibiting effect. On the other hand, the addition of HZSM-5 accelerated the reaction time and obtained the lowest activation energy among all the blends without a catalyst. Furthermore, ΔW of 75A25WT+C was the lowest, indicating that the blend with a catalyst exhibited the strongest synergistic effect. This research confirmed that the addition of WTS improved the thermal parameters of the samples and clarified the capacity of HZSM-5 to reduce the activation energy.

TiO2@UiO‐66 Composites with Efficient Adsorption and Photocatalytic Oxidation of VOCs: Investigation of Synergistic Effects and Reaction Mechanism

AbstractTiO2@UiO‐66 composite with intimate contact interfaces is fabricated by in situ solvothermal methods. Compared with other UiO‐based composites, TiO2@UiO‐66 exhibits superior photocatalytic activity for oxidation of toluene into CO2 during long‐time reaction under flowing conditions. This is because (1) the intimate contact interface and well‐matched band structure between TiO2 and UiO‐66 can effectively separate and transfer photogenerated electrons; (2) the synergistic effect between UiO‐66 and TiO2 promotes the adsorption of toluene and desorption of CO2 and provides sufficient active sites for photocatalytic reaction. The toluene conversion and CO2 production on 4TiO2@U are 3.27 and 4.10 times higher than that on UiO‐66, respectively. 4TiO2@U also shows the highest activity for formaldehyde and rhodamine B degradations. The in situ FTIR results exhibit that toluene can be oxidized by .O2− and h+ to benzaldehyde and benzoic acid, then further oxidized to oxalic acid, and finally mineralized into CO2 and H2O.

Investigation of Synergistic Effects between Co and Fe in Co3-xFexO4 Spinel Catalysts for the Liquid-Phase Oxidation of Aromatic Alcohols and Styrene

Transition metal oxides are attractive catalyst alternatives in liquid-phase oxidation reactions due to their lower cost and higher abundance compared with conventional noble metal catalysts. We investigated the catalytic properties of a systematic series of Co3-xFexO4 spinel catalysts synthesized by a hard-templating method, which were applied in the liquid-phase oxidation of styrene, benzyl alcohol and cinnamyl alcohol. O2 and tert-butyl hydroperoxide (TBHP) were used as the oxidants in a comparative manner. For alcohol oxidation, TBHP leads to similar or slightly higher selectivity to the corresponding aldehydes compared with O2. For the activation of C=C bonds, TBHP favors the oxidative cleavage pathway, while O2 favors the epoxidation pathway. The comparison of the catalytic performance revealed that the activity of Co3O4 does not benefit from Fe doping using O2 as the oxidant, while the substitution of Fe ≤ 10 % in the spinel structure is beneficial when TBHP is used. This is attributed to the different activation mechanisms of the oxidizing agents, being spin transfer in case of O2 and partial decomposition in case of TBHP. Heterogeneity tests and reusability studies demonstrated the stability of the spinel catalysts.

Investigation of synergistic effects and high performance of La-Co composite oxides for toluene catalytic oxidation at low temperature.

Cobalt oxides have been considered as a kind of highly efficient catalyst for the oxidation of volatile organic compounds (VOCs). In this work, lanthanum-cobalt composite oxides were prepared by using the co-precipitation method, and toluene was used as the model compound. Diversified techniques including XRD, SEM, Raman spectra, XPS, H2-TPR, and N2 adsorption-desorption were applied to investigate the physicochemical properties of as-prepared materials. The composite catalysts showed different morphology including larger specific surface area and higher pore volume which would accelerate the adsorption of toluene and improve the amount of active sites on surface. Moreover, the addition of lanthanum could enhance the low-temperature reducibility, and it could be also beneficial to expose more Co3+ and adsorbed oxygen species on the surface of catalysts which could accelerate the oxidation of toluene and lower onset oxidation temperature. 0.05La-Co (with a molar ratio of lanthanum against cobalt is 0.05) showed the best catalytic performance. The complete conversion of toluene was achieved at 225°C under the condition of toluene concentration = 1000ppm and SV = 20,000ml·g-1·h-1. Stability test over 0.05La-Co was conducted at 225°C and it could maintain the 100% conversion of toluene for 720min, indicating the excellent stability of as-prepared catalysts. Undoubtedly, lanthanum-cobalt composite oxide is a kind of promising material for the catalytic oxidation of VOCs.

Investigation of synergistic effects between silica nanoparticles, biosurfactant and salinity in simultaneous flooding for enhanced oil recovery.

The purpose of this study was to investigate the effect of process parameters including silica nanoparticle (NP) concentration, biosurfactant (BS) concentration, and salinity as well as their synergistic effects on oil recovery in simultaneous flooding. Additionally, the effect of NP morphology (in the BS-NP solution) on oil recovery was investigated in this research. Micromodel flooding tests were designed with a central composite design (CCD) and carried out using BS and spherical silica NPs. The results showed that there is a positive synergistic effect between BS and silica NPs to shift the wettability to the water-wet condition and decrease interfacial tension (IFT), resulting in improved oil recovery. Indeed, the maximum oil recovery was obtained at an optimum salt concentration. Several micromodel tests were then carried out with BS and different-shaped NPs at the optimum point predicted by a mathematical model to study the effect of NP morphology on oil recovery. The results showed that minimum IFT of 1.85 mN m−1 and the most reduction in the glass contact angle of 92.8% could be achieved by the BS-spherical NP solution as compared to those of the BS-non spherical NP solutions, which led to the highest oil recovery of 53.4%. The better performance of spherical NPs was attributed to the higher uniformity, which resulted in better distribution and more effective interactions with crude oil components. The results of core flooding tests showed that the BS-spherical NP solution yielded 26.1% final oil recovery after brine flooding. In addition, the BS-NP solution was more effective in wettability alteration of an oil-wet carbonate rock compared with the BS solution. It was deduced that the main mechanisms involved in oil recovery improvement were wettability alteration to the water-wet state, IFT reduction, and mobility ratio improvement.

Synergistic effects of interstitial impurities and radiation defects on mechanical characteristics of ferritic steels

Ferritic steels are generally used in pressure vessels and various reactor support structures in light water reactors. They are known to exhibit radiation embrittlement in terms of decreased toughness and increased ductile–brittle transition temperature as a result of exposure to neutron radiation. The superimposed effects of strain aging due to interstitial impurity atoms on radiation embrittlement were considered first by Wechsler, Hall and others. Here we summarize some of our efforts on the investigation of synergistic effects between interstitial impurity atoms (IIAs) and radiation-induced point defects, which result in interesting effects at appropriate temperature and strain rate conditions. Two materials, a mild steel and a pressure vessel steel (A516 Gr.70), are evaluated using tensile and three-point bend tests.

Electrochemical and spectroscopic investigation of synergistic effects in corrosion inhibition of aluminium bronze Part 2 – In acidified 4 wt-%NaCl solution

Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy have been used to investigate changes of surface composition when 4-phenyl semicarbazide hydrochloride (PSC) is used as an inhibitor, with and without additions of KI, to suppress the corrosion of aluminium bronze in acidified 4 wt-%NaCl solution of pH 1.8 – 2 at 60 ° C. Anodic polarisation studies in the presence of the PSC inhibitor alone have shown oscillations of the corrosion current at elevated potentials owing to localised attack. The results of AES have shown that in the case of inhibition by PSC some depressions had formed on the surface, within which chloride species were present due either to localised attack by Cl- at weak points in the inhibitor film or to the adsorption of Cl- at the depressions, preventing the formation of a Cu – PSC protective film. In contrast, a synergistic effect between PSC and KI suppressed the occurrence of current oscillations and the development of surface depressions during anodic polarisation owing to the formation of a continuous CuI – PSC film, which can retard or stifle localised attack.

Genetic, carcinogenic and teratogenic effects of radiofrequency fields.

This paper reviews the literature data on the genetic toxicology of radiofrequency (RF) radiation. Whereas in the past most studies were devoted to microwave ovens and radar equipment, it is now mobile telecommunication that attracts most attention. Therefore we focus on mobile telephone frequencies where possible. According to a great majority of the papers, radiofrequency fields, and mobile telephone frequencies in particular, are not genotoxic: they do not induce genetic effects in vitro and in vivo, at least under non-thermal exposure conditions, and do not seem to be teratogenic or to induce cancer. Yet, some investigations gave rather alarming results that should be confirmed and completed by further experiments. Among them the investigation of synergistic effects and of possible mechanisms of action should be emphasised.