Label-free PSA electrochemical determination by seed-mediated electrochemically-deposited gold nanoparticles on an FTO electrode

Journal of Solid State Electrochemistry - A facile and sensitive approach is introduced to precisely determine trace amounts of prostate specific antigen (PSA) by gold nanostructures deposited on...     

Selenium Alleviates the Adverse Effect of Drought in Oilseed Crops Camelina (Camelina sativa L.) and Canola (Brassica napus L.)

Drought poses a serious threat to oilseed crops by lowering yield and crop failures under prolonged spells. A multi-year field investigation was conducted to enhance the drought tolerance in four genotypes of Camelina and canola by selenium (Se) application. The principal aim of the research was to optimize the crop yield by eliciting the physio-biochemical attributes by alleviating the adverse effects of drought stress. Both crops were cultivated under control (normal irrigation) and drought stress (skipping irrigation at stages i.e., vegetative and reproductive) conditions. Four different treatments of Se viz., seed priming with Se (75 μM), foliar application of Se (7.06 μM), foliar application of Se + Seed priming with Se (7.06 μM and 75 μM, respectively) and control (without Se), were implemented at the vegetative and reproductive stages of both crops. Sodium selenite (Na₂SeO₃), an inorganic compound was used as Se sources for both seed priming and foliar application. Data regarding physiochemical, antioxidants, and yield components were recorded as response variables at crop maturity. Results indicated that WP, OP, TP, proline, TSS, TFAA, TPr, TS, total chlorophyll contents, osmoprotectant (GB, anthocyanin, TPC, and flavonoids), antioxidants (APX, SOD, POD, and CAT), and yield components (number of branches per plant, thousand seed weight, seed, and biological yields were significantly improved by foliar Se + priming Se in both crops under drought stress. Moreover, this treatment was also helpful in boosting yield attributes under irrigated (non-stress) conditions. Camelina genotypes responded better to Se application as seed priming and foliar spray than canola for both years. It has concluded that Se application (either foliar or priming) can potentially alleviate adverse effects of drought stress in camelina and canola by eliciting various physio-biochemicals attributes under drought stress. Furthermore, Se application was also helpful for crop health under irrigated condition.     

Is PF-00835231 a Pan-SARS-CoV-2 Mpro Inhibitor? A Comparative Study

The COVID-19 outbreak continues to spread worldwide at a rapid rate. Currently, the absence of any effective antiviral treatment is the major concern for the global population. The reports of the occurrence of various point mutations within the important therapeutic target protein of SARS-CoV-2 has elevated the problem. The SARS-CoV-2 main protease (Mpro) is a major therapeutic target for new antiviral designs. In this study, the efficacy of PF-00835231 was investigated (a Mpro inhibitor under clinical trials) against the Mpro and their reported mutants. Various in silico approaches were used to investigate and compare the efficacy of PF-00835231 and five drugs previously documented to inhibit the Mpro. Our study shows that PF-00835231 is not only effective against the wild type but demonstrates a high affinity against the studied mutants as well.     

Heavy Metals in Acrylic Color Paints Intended for the School Children Use: A Potential Threat to the Children of Early Age

Heavy metals are the harmful elements, regarded as carcinogens. Nevertheless, owing to their physical and chemical properties, they are still used in the production of several commercial products. Utilization of such products increases the chance for the exposure of heavy metals, some of them are categorized as probable human carcinogens (Group 1) by the International Agency for Research on Cancer. Exposure of heavy metals to school children at early age can result severe life time health issues and high chance of emerging cancer. Thus, we have performed study relating to the presence of heavy metals in acrylic color paints commonly used by the school children. Acrylic paints of different colors were assayed for seven potential heavy metals manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) using microwave digestion and iCAPQ inductively coupled plasma mass spectrometry (ICP-MS) system. The optimized method including paints digestion reagents nitric acid (HNO₃, 65%, 5 mL) and hydrofluoric acid (HF, 40%, 2 mL) have offered excellent method performance with recovery values ranged between 99.33% and 105.67%. The elements were identified in all of the analyzed samples with concentrations ranged from 0.05 to 372.59 µg/g. Cd constitutes the lower percentage (0.05%), whereas Zn constitutes high ratio contribution which was tremendously high (68.33%). Besides, the paints contamination was also color specific, with considerably total heavy metal concentrations found in brunt umber (526.57 µg/g) while scarlet color (12.62 µg/g) contained lower amounts. The outcomes of our investigation highlight the necessity for guidelines addressing the heavy metals in acrylic color paints intended for the school children usage.     

Production of Terretonin N and Butyrolactone I by Thermophilic Aspergillus terreus TM8 Promoted Apoptosis and Cell Death in Human Prostate and Ovarian Cancer Cells

The anticancer activity of terretonin N (1) and butyrolactone I (2), obtained from the thermophilic fungus Aspergillus terreus TM8, was intensively studied against prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines. According to this study, both compounds showed potent cytotoxicity towards ovarian adenocarcinoma cells (SKOV3) with IC₅₀ 1.2 and 0.6 μg/mL, respectively. With respect to metastatic prostate cells (PC-3), the two compounds 1 and 2 showed a significantly promising cytotoxicity effect with IC₅₀ of 7.4 and 4.5 μg/mL, respectively. The tested fungal metabolites showed higher rates of early and late apoptosis with little or no necrotic apoptotic pathway in all treated prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines, respectively. The results reported in this study confirmed the promising biological properties of terretonin N (1) and butyrolactone I (2) as anticancer agents via the induction of cellular apoptosis. However, further studies are needed to elucidate the molecular mechanism by which cellular apoptosis is induced in cancer cells.     

Quasi Monte Carlo-based isotropic distribution of gradient directions for improved reconstruction quality of 3D EPR imaging

In continuous wave (CW) electron paramagnetic resonance imaging (EPRI), high quality of reconstructed image along with fast and reliable data acquisition is highly desirable for many biological applications. An accurate representation of uniform distribution of projection data is necessary to ensure high reconstruction quality. The current techniques for data acquisition suffer from nonuniformities or local anisotropies in the distribution of projection data and present a poor approximation of a true uniform and isotropic distribution. In this work, we have implemented a technique based on Quasi-Monte Carlo method to acquire projections with more uniform and isotropic distribution of data over a 3D acquisition space. The proposed technique exhibits improvements in the reconstruction quality in terms of both mean-square-error and visual judgment. The effectiveness of the suggested technique is demonstrated using computer simulations and 3D EPRI experiments. The technique is robust and exhibits consistent performance for different object configurations and orientations.     

<Emphasis Type="Italic">Q</Emphasis>-Switched Yb-Doped Fiber Ring Laser with a Saturable Absorber Based on a Graphene Polyvinyl Alcohol Film

We propose, design, and demonstrate a Q-switched ytterbium-doped fiber laser (YDFL) employing a thin graphene polyvinyl alcohol (PVA) film as a passive saturable absorber (SA). The graphene is synthesized by electrochemical exfoliation of graphite at room temperature in 1% sodium dodecyl sulfate (SDS) aqueous solution. Graphene flakes obtained from the process are mixed with PVA solution as the host polymer to produce a thin film, which acts as a passive Q-switcher in the YDFL ring cavity. The laser generates a stable pulse operating at a wavelength of 1,076.4 nm with a threshold pump power of 73.7 mW. At a maximum 980 nm pump power of 113.6 mW, the YDFL generates an optical pulse train with a repetition rate of 25.53 kHz and a pulse width of 10 μs. The maximum pulse energy of 50.9 nJ is obtained at a pump power of 109.9 mW. A higher-performance Q-switched YDFL is expected to be achieved with optimization of the graphene saturable absorber and the laser cavity.     

Gradual Growth of Gold Nanoseeds on Silica for Silica@Gold Core–Shell Nano Applications by Two Different Methods: A Comparison on Structural Properties

This paper describes the homogeneous growth of gold shells on the surfaces of spherical dielectric silica nanoparticle cores by two different approaches: common two-step method (the name) and deposition–precipitation process. The methods basically are different in forming the precursor gold seed particles on silica. The structural and optical properties and morphology of the nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV–Vis spectrophotometery, and photo luminescence spectroscopy (PL). The results showed that, although in both the methods the core–shell nanoparticles can be reliably prepared in a controlled fashion with a favorable uniformity, but deposition–precipitation method indicated a better mechanical stability while it was more cost and time effective too. A regular red shift, from 488 to 662 nm, and peak broadening was also risen for the striking plasmon absorption peak as gold nanoseeds created by each of the two methods grew in size on silica cores.