The membrane depolarization and increase intracellular calcium level produced by silver nanoclusters are responsible for bacterial death

This work highlights how our silver ultra nanoclusters (ARGIRIUM-SUNc) hand-made synthesized, are very useful as a bactericide and anti-biofilm agent. The Argirium-SUNc effective antibacterial concentrations are very low (< 1 ppm) as compared to the corresponding values reported in the literature. Different bacterial defense mechanisms are observed dependent on ARGIRIUM-SUNc concentrations. Biochemical investigations (volatilome) have been performed to understand the pathways involved in cell death. By using fluorescence techniques and cell viability measurements we show, for the first time, that membrane depolarization and calcium intracellular level are both primary events in bacteria death. The ARGIRIUM-SUNc determined eradication of different biofilm at a concentration as low as 0.6 ppm. This suggests that the effect of the nanoparticles follows a common mechanism in different bacteria. It is highly probable that the chemical constitution of the crosslinks could be a key target in the disrupting mechanism of our nanoparticles. Since the biofilms and their constituents are essential for bacterial survival in contact with humans, the silver nanoparticles represent a logical target for new antibacterial treatments.

Evaluation of radiation interaction parameters of some shape memory alloys

In this study, effective atomic number (Zeff), atomic (σta) and electronic cross section (σte) values of some shape memory alloys (SMA) were calculated at energies 5.9, 6.1, 8, 11.2, 25, 59.543, 75, 112, 149 keV. It has been observed that the obtained values of the calculated parameters vary depending on the photon intensity, chemical constitution and density of the alloys. Calculations were made using the WinXCom program and the graph of the change according to the energy of the obtained results was drawn. The results of this study are thought to be beneficial in the application of various fields.

Study on the Tribological Mechanism of Ultrafine SiO2/MoS2 Powders in Complex Calcium Sulfonate Grease

The purpose of this work was to study and further clarify the anti-wear and anti-friction mechanism of ultrafine SiO2/MoS2 powders in the complex calcium sulfonate grease. In this paper, 15nm nanoSiO2, 1μm MoS2 and commercial NLGI Grade No.2 complex calcium sulfonate grease were used as the research objects, SEM, EDS and XPS were used to study the morphology, composition and film chemical constitution of the long friction wear spots of grease containing single nanoSiO2 powder, ultrafine MoS2 powder and the two compound powders, which formed in the process of four ball long friction. The results show that nanoSiO the grease plays a role in filling the undercut, ball bearings and polishing and forming high hardness Ca3Fe2(SiO4)3 and part of Fe2O3 anti-wear films in the process of long friction. The ultrafine MoS2 powder has a self-repairing effect to fill the grooves,forming the MoS2, MoO3 anti-friction films and Fe2(SO4)3 anti-wear film. The two powders in the composite grease have a synergistic effect, acting on the friction pair together, and simultaneously forming self-repairing anti-friction and anti-wear films, thereby further improving the tribological performance of the base grease.

Microplastics and Their Effect in Horticultural Crops: Food Safety and Plant Stress

The presence of micro and nanoplastics in the food chain constitutes an emergent multifactorial food safety and physiological stress problem, which must be approached with a strategic perspective since it affects public health when consuming products that have this pollutant, such as fish and crustaceans, fruits, and vegetables. In this review, the authors present the results by scientists from different disciplines who are dedicated to discovering their chemical constitution and origin, the contents of these microparticles in edible plants, the contamination of water-irrigated soils, the mechanisms that concentrate microplastics in these soils, methods to determine them, contamination of freshwater sources of cities, and the negative effect of nano and microplastics on various food products and their detrimental impact on the environment. Recent findings of plant uptake mechanisms complement this, but more research is needed.

QUALITATIVE ANALYSIS OF CARICA PAPAYA LEAVES TABLET FORMULATION AND STUDY OF FRAGMENTATION PATTERN OF RUTIN

The chemical constitution of Carica papaya leaves tablets and the fragmentation pattern of rutin is poorly investigated. Rutin was found to a constituent of tablet formulation. This work reports a study on the fragmentation pattern of rutin by electrospray ionization with multistage mass spectrometry in positive mode. Potential dissociation pathway for rutin is proposed. The fragmentation pattern provides important information for its determination by liquid chromatography coupled to mass spectrometry.

Animal venoms

Venoms are poisons or toxins of animal origin in which the animal that produce the toxins are capable of introducing the toxins into the body of the victims. Animals that produce toxins but lack the ability to introduce the toxins into their victims are said to be poisonous animals. Venoms are classified based on their site of action in the bodies of their victims. Thus, they classified into local, auto pharmacological, antihaemostic, neurological mascular cardiac and renal types; and based on the type of animal producing the venom, it is difficult to classify venom based on chemical constitution because of the fact that a particular venom is highly complex chemically with many reactive sites. The role venoms play on organisms in the environment is highlighted.

QSPR analysis of some novel neighbourhood degree-based topological descriptors

Topological index is a numerical value associated with a chemical constitution for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. In this work, some new indices based on neighborhood degree sum of nodes are proposed. To make the computation of the novel indices convenient, an algorithm is designed. Quantitative structure property relationship (QSPR) study is a good statistical method for investigating drug activity or binding mode for different receptors. QSPR analysis of the newly introduced indices is studied here which reveals their predicting power. A comparative study of the novel indices with some well-known and mostly used indices in structure-property modelling and isomer discrimination is performed. Some mathematical properties of these indices are also discussed here.