Effect of DLC Coating on Tribological Behavior of Cylinder Liner-piston Ring Material Combination When Lubricated with Jatropha Oil

AbstractThe expansion of modern engines would have been unfeasible without advanced lubricant chemistry and proper lubricant formulation. Introduction of diamond like carbon (DLC) coatings opens further possibilities in improving performance of engine and transmission components, which cannot longer be achieved only by lubricant design.DLC coatings show extremely good promise for a number of applications in automotive components as they exhibit excellent tribological properties. In this paper, the tribological performance of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil was evaluated using a four ball Tribometer also with commercial synthetic lubrication oil (SAE 40) used as base lubricant. Experimental results demonstrated that the hydrogenated amorphous carbon (a-C: H)DLC coating exhibited better performance with Jatropha oil in terms of wear and friction under similar operating conditions compared to the uncoated stainless. Thus, usage of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil in the long run may have a positive impact on engine life

Antimicrobial activities of eugenol and cinnamaldehyde against the human gastric pathogen <i>Helicobacter pylori</i>

Background: Eradication of Helicobacter pylori is an important objective in overcoming gastric diseases. Many regimens are currently available but none of them could achieve 100% success in eradication. Eugenol and cinnamaldehyde that are commonly used in various food preparations are known to possess antimicrobial activity against a wide spectrum of bacteria. Aim: The present study was performed to assess the in vitro effects of eugenol and cinnamaldehyde against indigenous and standard H. pylori strains, their minimum inhibitory concentrations (MICs) and time course lethal effects at various pH. Methods: A total of 31 strains (29 indigenous and one standard strain of H. pylori ATCC 26695, one strain of E. coli NCIM 2089) were screened. Agar dilution method was used for the determination of drug sensitivity patterns of isolates to the commonly used antibiotics and broth dilution method for the test compounds. Results: Eugenol and cinnamaldehyde inhibited the growth of all the 30 H. pylori strains tested, at a concentration of 2 μg/ml, in the 9th and 12th hours of incubation respectively. At acidic pH, increased activity was observed for both the compounds. Furthermore, the organism did not develop any resistance towards these compounds even after 10 passages grown at sub-inhibitory concentrations. Conclusion: These results indicate that the two bioactive compounds we tested may prevent H. pylori growth in vitro, without acquiring any resistance

Cyano-and ketone-containing selenoesters as multi-target compounds against resistant cancers

Fifteen selenocompounds, comprising of eight ketone-containing selenoesters (K1–K8, also known as oxoselenoesters) and seven cyano-containing selenoesters (N1–N7, known also as cyanoselenoesters), have been designed, synthesized, and evaluated as novel anticancer agents. These compounds are derivatives of previously reported active selenoesters and were prepared following a three-step one-pot synthetic route. The following evaluations were performed in their biological assessment: cytotoxicity determination, selectivity towards cancer cells in respect to non-cancer cells, checkerboard combination assay, ABCB1 inhibition and inhibition of ABCB1 ATPase activity, apoptosis induction, and wound healing assay. As key results, all the compounds showed cytotoxicity against cancer cells at low micromolar concentrations, with cyanoselenoesters being strongly selective. All of the oxoselenoesters, except K4, were potent ABCB1 inhibitors, and two of them, namely K5 and K6, enhanced the activity of doxorubicin in a synergistic manner. The majority of these ketone derivatives modulated the ATPase activity, showed wound healing activity, and induced apoptosis, with K3 being the most potent, with a potency close to that of the reference compound. To summarize, these novel derivatives have promising multi-target activity, and are worthy to be studied more in-depth in future works to gain a greater understanding of their potential applications against cancer.The study was supported by the projects SZTE ÁOK-KKA 2018/270-62-2 of the University of Szeged, Faculty of Medicine and GINOP-2.3.2-15-2016-00038 (Hungary); and Consejo Superior de Investigaciones Científicas (CSIC, Spain, project LINKA20285). This research was funded by VISEGRAD FUND, grant number 22010090; and by the mobility project from the Czech Ministry of Education, Youth and Sports INTER-COST, grant number LTC19007. This article is based upon work from COST Action 17104 , supported by COST (European Cooperation in Science and Technology), (http://www.cost.eu, accessed on 17 September 2021). The study was supported also by two cultural associations: “Trevinca” and “Iniciativas Ropelanas”

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Phylogenetic analysis, based on EPIYA repeats in the cagA gene of Indian Helicobacter pylori, and the implications of sequence variation in tyrosine phosphorylation motifs on determining the clinical outcome

The population of India harbors one of the world’s most highly diverse gene pools, owing to the influx of successive waves of immigrants over regular periods in time. Several phylogenetic studies involving mitochondrial DNA and Y chromosomal variation have demonstrated Europeans to have been the first settlers in India. Nevertheless, certain controversy exists, due to the support given to the thesis that colonization was by the Austro-Asiatic group, prior to the Europeans. Thus, the aim was to investigate pre-historic colonization of India by anatomically modern humans, using conserved stretches of five amino acid (EPIYA) sequences in the cagA gene of Helicobacter pylori. Simultaneously, the existence of a pathogenic relationship of tyrosine phosphorylation motifs (TPMs), in 32 H. pylori strains isolated from subjects with several forms of gastric diseases, was also explored. High resolution sequence analysis of the above described genes was performed. The nucleotide sequences obtained were translated into amino acids using MEGA (version 4.0) software for EPIYA. An MJ-Network was constructed for obtaining TPM haplotypes by using NETWORK (version 4.5) software. The findings of the study suggest that Indian H. pylori strains share a common ancestry with Europeans. No specific association of haplotypes with the outcome of disease was revealed through additional network analysis of TPMs

Impact of the Monetary Policy Instruments on Islamic Stock Market Index Return

Previous studies found that Islamic stock market index in Malaysia (KLSI), does not react, or react negatively to interest rate, although one of the main criteria of Islamic finance is to avoid business and activities that yield interest because of its prohibition in Islamic laws. On the other hand, studies of Islamic stock market index in the US (DJIMI) found that there is no impact of interest rate on DJIMI. These two stock market indices have different screening criteria and different composite of securities. This study aims at investigating the monetary policy variables impact, the effect of interest rate, and the use of stock market indices as a hedge against inflation. It also examines the volatilities of monetary variables, interest rates, and inflation rate on two Islamic stock market indices. Using time series analysis such as GARCH the results are as follows. It is found that in the variance univariate models of the conventional indices that M1, M3, inflation rate, and real growth in GDP are significant in influencing KLCI volatility, while M2, M3, inflation rate and interest rate affected DJINA volatility. On the other hand, in the Islamic indices, KLSI and DJIMI variance is influenced by M2, M3, and inflation rate. In addition, in the multivariate model, DJIMI is influenced by the interest rate and the inflation rate in the mean and variance equations. In contrast, KLSI is influenced commonly in the mean and variance equations by M3, and the inflation rate