Tissue Invasion by Entamoeba histolytica: Evidence of Genetic Selection and/or DNA Reorganization Events in Organ Tropism

Entamoeba histolytica infection may have various clinical manifestations. Nine out of ten E. histolytica infections remain asymptomatic, while the remainder become invasive and cause disease. The most common form of invasive infection is amebic diarrhea and colitis, whereas the most common extra-intestinal disease is amebic liver abscess. The underlying reasons for the different outcomes are unclear, but a recent study has shown that the parasite genotype is a contributor. To investigate this link further we have examined the genotypes of E. histolytica in stool- and liver abscess-derived samples from the same patients. Analysis of all 18 paired samples (16 from Bangladesh, one from the United States of America, and one from Italy) revealed that the intestinal and liver abscess amebae are genetically distinct. The results suggest either that E. histolytica subpopulations in the same infection show varying organ tropism, or that a DNA reorganization event takes place prior to or during metastasis from intestine to liver

Interleukin 21 collaborates with interferon-γ for the optimal expression of interferon-stimulated genes and enhances protection against enteric microbial infection.

The mucosal surface of the intestinal tract represents a major entry route for many microbes. Despite recent progress in the understanding of the IL-21/IL-21R signaling axis in the generation of germinal center B cells, the roles played by this signaling pathway in the context of enteric microbial infections is not well-understood. Here, we demonstrate that Il21r-/- mice are more susceptible to colonic microbial infection, and in the process discovered that the IL-21/IL-21R signaling axis surprisingly collaborates with the IFN-γ/IFN-γR signaling pathway to enhance the expression of interferon-stimulated genes (ISGs) required for protection, via amplifying activation of STAT1 in mucosal CD4+ T cells in a murine model of Citrobacter rodentium colitis. As expected, conditional deletion of STAT3 in CD4+ T cells indicated that STAT3 also contributed importantly to host defense against C. rodentium infection in the colon. However, the collaboration between IL-21 and IFN-γ to enhance the phosphorylation of STAT1 and upregulate ISGs was independent of STAT3. Unveiling this previously unreported crosstalk between these two cytokine networks and their downstream genes induced will provide insight into the development of novel therapeutic targets for colonic infections, inflammatory bowel disease, and promotion of mucosal vaccine efficacy

Synthesis of multiwalled carbon nanotubes on Cu-Fe nano-catalyst substrate

Considering the importance of metal nano catalysts, this research tries to apply sputtered nanoparticles as catalyst for growing carbon nanotubes and studies the effect of metals in modifying the catalytic property. One and bilayer Cu and Fe thin films were placed inside a quartz tube reactor to synthesis carbon nanotubes using acetylene gas as carbon source and argon gas for cooling down the reactor from 850 °C to room temperature. By scanning electron microscope images distribution of diameter of multi walled carbon nanotubes has recorded. The amounts of ID/IG obtained from Raman spectroscopy analysis showed the best quality of carbon nanotubes for Cu-Fe bilayer. Both analyses indicate the improve of catalytic effect of one transition metal by another one. On the other hand, multi walled carbon nanotubes are confirmed by both Raman spectroscopy and transmission electron microscopy images. Keywords: Transition metal nano catalyst, TCVD, MWCNT, Raman spectroscop

CNTs-Supercapacitors: A Review of Electrode Nanocomposites Based on CNTs, Graphene, Metals, and Polymers

Carbon nanotubes (CNTs), due to mechanical, electrical, and surface area properties and their ability to adapt to different nanocomposite structures, are very substantial in supercapacitor electrodes. In this review, we have summarized high-performance, flexible, and symmetry CNT supercapacitors based on the CNTs/graphene, CNTs/metal, and CNTs/polymer electrodes. To present recent developments in CNT supercapacitors, we discuss the performance of supercapacitors based on electrical properties such as specific capacitance (SC), power and energy densities, and capacitance retention (CR). The comparison of supercapacitor nanocomposite electrodes and their results are reported for future researchers

Electrochemical Stability Enhancement in Reactive Magnetron Sputtered VN Films upon Annealing Treatment

Vanadium nitride (VN) thin films were produced via direct-current reactive magnetron sputtering technique followed by vacuum annealing. The treatment was carried out at different temperatures for any effect on their electrochemical (EC) stability, up to 10,000 charge⁻discharge cycles in 0.5 M K2SO4 solution. The film surface chemistry was investigated by using X-ray photoelectron spectroscope (XPS) and cyclic voltammetry (CV) techniques. For the as-deposited film, the oxide layer formed on the VN surface was unstable upon K2SO4 immersion treatment, along with ~23% reduction in the EC capacitance. Vacuum annealing under optimized conditions, however, made the oxide layer stable with almost no capacitance loss upon cycling for up to 10,000 cycles. Annealing treatment of the VN films makes them a potential candidate for long-term use in electrochemical capacitors

Diamond nanocrystal thin films : case study on surface texture and power spectral density properties

Analyzing diamond nanocrystal (DNC) thin film morphology produced by the HFCVD technique is the main objective of the present work. Stereometric analysis of three-dimensional surface microtextures was carried out based on data obtained through atomic force microscopy (AFM), while the ISO 25178-2:2012 standard was applied to characterize surface topography. The Abbott–Firestone curve, peak count histograms, and Cartesian graphs, which were extracted through AFM images, gave valuable statistical information. As can be seen, the most isotropic sample was the Au catalyst (etched) deposited by the hot filament chemical vapor deposition method. Moreover, by increasing the time of DNC growth from 15 min to 60 min, the surface roughness was increased. In addition, the average power spectral density was calculated and furrows were determined for all samples.https://aip.scitation.org/journal/advhj2020Physic

A meta-analysis of the effectiveness of albendazole compared with metronidazole as treatments for infections with Giardia duodenalis.

BackgroundMetronidazole is the most commonly used drug for the treatment of giardiasis in humans. In spite of its therapeutic efficacy for giardiasis, low patient compliance, especially in children, side effects, and the emergence of metronidazole-resistant strains may restrict its use. Albendazole has been used to treat Giardia duodenalis infections in recent years. However, efficacy studies in vivo and in vitro have produced diverse results as to its effectiveness. A moderately benign side effect profile, combined with established efficacy against many helminths, renders it promising for treatment of giardiasis in humans.Methodology and principal findingsWe performed a search in the PubMed, Scopus, EMBASE, the ISI Web of Science, LILIACS, and Cochrane Controlled Trials Register for trials published before February 2010 as well as in references of relevant research and review articles. Eight randomized clinical trials (including 900 patients) comparing the effectiveness of albendazole with that of metronidazole were included in meta-analysis. After extracting and validating the data, the pooled risk ratio (RR) was calculated using an inverse-variance random-effects model. Albendazole was found to be equally as effective as metronidazole in the treatment of giardiasis in humans (RR 0.97; 95% CI, 0.93, 1.01). In addition, safety analysis suggested that patients treated with albendazole had a lower risk of adverse effects compared with those who received metronidazole (RR 0.36; 95% CI, 0.10, 1.34), but limitations of the sample size precluded a definite conclusion.Conclusions/significanceThe effectiveness of albendazole, when given as a single dose of 400 mg/day for 5 days, was comparable to that of metronidazole. Patients treated with albendazole tended to have fewer side effects compared with those who took metronidazole. Given the safety, effectiveness, and low costs of albendazole, this drug could be potentially used as an alternative and/or a replacement for the existing metronidazole therapy protocols in the treatment of giardiasis in humans

Reactive sputtering of vanadium nitride thin films as pseudo-capacitor electrodes for high areal capacitance and cyclic stability

International audienc

Characterization of microroughness parameters in Cu-C nanocomposite prepared by co-deposition of RF-sputtering and RF-PECVD

The morphological parameter of a thin film surface can be characterized by power spectral density (PSD) function which provides a better description on topography rather than the root mean square (RMS) and super structure contributions. Through the present study, nanoparticle copper-carbon composite films were prepared by co-deposition of RF-sputtering and RF-PECVD method using acetylene gas and copper target. These films’ surface roughnesses were determined by using an atomic force microscope (AFM). The carbon content of the films was obtained by Rutherford back scattering (RBS) which was varied from 5% to 73%. The power values of PSD for the AFM data were determined by the fast Fourier transform (FFT) algorithms. The effect of carbon on the surface roughness of thin films was investigated. Changes in the relationship between the resistivity and fractal dimension were observed for investigating films