Pt Single Atoms Supported on Defect Ceria as an Active and Stable Dual-Site Catalyst for Alkaline Hydrogen Evolution.

This work evaluates the feasibility of alkaline hydrogen evolution reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria (Pt1/CeOx) as an active and stable dual-site catalyst. The catalyst displayed a low overpotential and a small Tafel slope in an alkaline medium. Moreover, Pt1/CeOx presented a high mass activity and excellent durability, competing with those of the commercial Pt/C (20 wt %). In this picture, the defective CeOx is active for water adsorption and dissociation to create H* intermediates, providing the first site where the reaction occurs. The H* intermediate species then migrate to adsorb and react on the Pt2+ isolated atoms, the site where H2 is formed and released. DFT calculations were also performed to obtain mechanistic insight on the Pt1/CeOx catalyst for the HER. The results indicate a new possibility to improve the state-of-the-art alkaline HER catalysts via a combined effect of the O vacancies on the ceria support and Pt2+ single atoms.

Designing a Novel C3-Fe-N Interface Local Coordination Microenvironment for Efficient Electrocatalytic Water Splitting.

Developing single-atomic electrocatalysts (SACs) with high activity and stability for electrocatalytic water-splitting has been challenging. Moreover, the practical utilization of SACs is still far from meeting the the theoretical prediction. Herein a facile and easy scale-up fabrication method is proposed for designing a novel carbon-iron-nitrogen (C-Fe-N) electrocatalyst with a single atom electron bridge (C-Fe-N SAEBs), which exhibits lower overpotential and impedance than previously reported electrocatalysts. 0.8-C-Fe-N SAEBs exhibits significant activity and excellent stability in the bi-functional decomposition of water. The excellent performance of the C-Fe-N SAEBs electrocatalyst can be attributed to the strong coupling effect at the interface owing to the formation of a single atom C3-Fe-N local coordination microenvironment at the interface, which enhance the exposure of active sites and charge transfer, and reduced the adsorption energy barrier of intermediates. Theoretical calculation and synchrotron radiation analysis are performed to understand the mechanistic insights behind the experimental results. The results reveal that the active C3-Fe-N local coordination microenvironment at the interface not only improves water-splitting behavior but also provides a deeper understanding of local-interface geometry/electronic structure for improving the electrocatalytic activity. Thus, the proposed electrocatalyst, as well as the mechanistic insights into its properties, presents a significant stride toward practical application.

Induction of Apoptosis in HeLa by Corn Small RNAs.

Insights in RNA biology have opened up a plethora of opportunities to explore the small regulatory RNAs from various natural and artificial sources. These small RNAs have been suggested to play a role too in tumor progression by either as oncogenic or tumor suppressor small RNAs. In this study, authors have attempted to evaluate the therapeutic potential of small RNAs fractionated from corn (Zea mays) upon growth and survival of HeLa. Here, authors have employed standard cellular-based approaches including microscopy, spectroscopy, and flow cytometry-based staining assays. Our data indicate that corn small RNAs fraction can appreciably decrease HeLa cell proliferation and survival, which is supported by a number of complementary assays such as Trypan blue dye exclusion, MTT, propidium iodide, and Annexin V/PI apoptotic cell death. Taken together, present finding suggests that corn small RNAs fraction may display up to 70% reduction in HeLa cell viability. Furthermore, these data indicate that around 40-50% of HeLa cells become apoptotic due to exogenous use of corn small. Overall, this finding proposes that possibility of cross-kingdom anticancer use of small RNAs from corn and present data need to be explored in depth.

Engineering core-shell hollow-sphere Fe3O4@FeP@nitrogen-doped-carbon as an advanced bi-functional electrocatalyst for highly-efficient water splitting.

Given the rapidly increasing energy demand and environmental pollution, to achieve energy conservation and emission reduction, hydrogen production has emerged as a promising alternative to traditional fossil fuels because of its high gravimetric energy density, and renewable and environmentally friendly characteristics. Herein, a core-shell hollow-sphere Fe3O4@FeP@nitrogen-doped-carbon (labeled as H-Fe3O4@FeP@NC) with a dual-interface, novel morphology, and superior conductivity is prepared as an advanced bi-functional electrocatalyst for electrochemical overall water splitting using a collaborative strategy comprising of facile self-assembly and phosphating. The prepared catalyst exhibits superior electrocatalytic activity compared to H-Fe3O4@NC and H-Fe3O4 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Additionally, the overpotential of H-Fe3O4@FeP@NC for OER/HER (258/165 mV at 10 mA/cm2) is significantly lower than those of H-Fe3O4@NC (274/209 mV) and H-Fe3O4 (287/213 mV) at 10 mA/cm2. Meanwhile, the as-synthesized H-Fe3O4@FeP@NC, as an electrode pair, displays a low cell voltage of 1.69 V at 10 mA/cm2 and excellent stability after 100 h, indicating its practical application for overall water splitting. This work presents a practical and economical strategy toward the fabrication of catalyst for efficient water splitting and fuel cell.

A Novel Synthesis of the Graphene Oxide-Silver (GO-Ag) Nanocomposite for Unique Physiochemical Applications.

Graphene oxide-silver nanocomposite (GO-Ag) was fabricated via the sonochemical method, which shows unique physiochemical properties. Graphene oxide (GO) and silver nanoparticles (AgNPs) were synthesized by modified Hummer's and Chemical reduction methods, respectively. The synthesized nanocomposite was characterized using powder X-ray diffraction, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The surface morphology of synthesized nanoparticles was studied using scanning electron microscopy and transmission electron microscopy. The thermoluminescence property of the nanocomposite was analyzed by irradiating the samples in gamma radiation at 1 kGy. Electrochemical reversibility of the GO-Ag nanocomposite was examined by cyclic voltammetry. The photocatalytic application of the nanocomposite was studied using degradation of methylene blue dye. Results reveal that doping of AgNPs on the GO surface not only improves its dye degradation property but also enhances its thermoluminescence property. This knowledge will be helpful in determining the antibacterial property of the GO-Ag nanocomposite in the future.

Zinc Oxide Nanoparticles Functionalized on Hydrogel Grafted Silk Fibroin Fabrics as Efficient Composite Dressing.

Recent advances in woundcare is targeted towards developing active-dressings, where multiple components are combined to provide a suitable environment for rapid healing. The aim of the present research is to study the preparation of biomimic composite wound dressings by the grafting of hydrogel on silk fibroin fabric. The swelling ability of hydrogel grafted silk fibroin fabric was optimized by changing the initiator concentration. In order to impart antimicrobial properties, these dressing are further coated sono-chemically with zinc oxide nanoparticles. The water vapor transmission rate of the prepared samples was measured. The conformation of silk fibroin proteins after grafting with hydrogel was also confirmed using Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the zinc oxide-coated silk fibroin fabric and hydrogel-coated silk fibroin was studied using Scanning Electron Microscope (SEM). The antimicrobial activity of the zinc oxide-coated samples was studied against E coli. The cytocompatibility of the prepared dressing materials were evaluated using L929 fibroblast cells. MTT assay and phase contrast microscopic studies showed that the adherence, growth, and proliferation of the L929 fibroblast cells that were seeded on zinc oxide nanoparticles on the functionalized hydrogel-coated silk fibroin dressing was significantly higher than that of pure silk fibroin due to the highly porous, bio-mimic structure that allowed ease of passage of nutrients, growth factors, metabolites, and the exchange of gases which is beneficial for successful regeneration of damaged tissues. The expression of TNF-α and IL-2 were not significantly higher than that of control. The proposed composite dressing would be a promising material for wound dressing and regenerative medicine but in order to prove the efficacy of these materials, more in vivo experiments and clinical tests are required to be conducted in future.

Erratum: Majumder, S. et al. Zinc Oxide Nanoparticles Functionalized on Hydrogel Grafted Silk Fibroin Fabrics as Efficient Composite Dressing. Biomolecules 2020, 10, 710.

The authors wish to make the following correction to this paper [...].

Induction of S-phase Cell Cycle Arrest and Apoptosis in HeLa Cells by Small RNAs Fraction of Solanum tuberosum L.

BACKGROUND: In cancer therapeutics, several new classes of small molecules based targeted drug options are reported including peptide mimetic and small RNAs therapeutics. OBJECTIVE: Small RNAs represent a class of short non-coding endogenous RNAs that play an important role in transcriptional and post transcriptional gene regulation among varied types of species including plants and animals. METHODS: To address the role of small RNAs from plant sources upon cancer cells, authors report on the effects of small RNAs fraction of potato in in-vitro model of human derived HeLa cancer cells. This paper reports the anti-proliferative and anti-survival effect of small RNAs fraction of S. tuberosum L. (potato) tuber tissue. Here, authors employed small RNAs fractionation protocol, cell viability, cell cytotoxicity MTT, PI stained cell cycle analysis and FITC-Annexin-V/PI stained apoptosis assays. RESULTS: In this paper, small RNAs fractions of potato clearly indicate 40-50% inhibition of HeLa cell proliferation and viability. Interestingly, flow cytometer data point out appreciable increase from 7% to 14% of S-phase in HeLa cells by displaying the presence of an S-phase cell cycle arrest. Further, arrest in S-phase of HeLa cells is also supported by an appreciable increase in total <2N plus >4N DNA containing HeLa cells over 2N containing HeLa cells. For apoptotic assay, data suggest a significant increase in apoptotic HeLa cells from (5%) control treated HeLa cells to (18%) small RNAs treated HeLa cells. CONCLUSION: Taken together, findings suggest that small RNAs fractions of potato can induce Sphase cell cycle arrest and these agents can act as an anti-proliferative agent in HeLa cells. This paper proposes a huge scope for novel finding to dissect out the small RNAs target within HeLa cells and other cancer cell types.

Natural and artificial small RNAs: a promising avenue of nucleic acid therapeutics for cancer.

Since the failure of traditional therapy, gene therapy using functional DNA sequence and small RNA/DNA molecules (oligonucleotide) has become a promising avenue for cancer treatment. The discovery of RNA molecules has impelled researchers to investigate small regulatory RNA from various natural and artificial sources and determine a cogent target for controlling tumor progression. Small regulatory RNAs are used for therapeutic silencing of oncogenes and aberrant DNA repair response genes. Despite their advantages, therapies based on small RNAs exhibit limitations in terms of stability of therapeutic drugs, precision-based delivery in tissues, precision-based intercellular and intracellular targeting, and tumor heterogeneity-based responses. In this study, we summarize the potential and drawbacks of small RNAs in nucleic acid therapeutics for cancer.

High alert! Alarming rise in the Prevalence of cardiovascular risk events among the students of medical profession in India.

Cardiovascular disease (CVD) risk events increase at an alarming rate among student of medical profession (SMP) in India. By estimating the prevalence, awareness could be created and further consequences could be prevented at early stage. The prevalence of CVD risk events was found to be 12.4% among SMP in India. Because evidence suggests that at early stage pathophysiological process for CVD begins.