Super photo-base initiated organic-inorganic hybrid coatings by plural-cure mechanisms

Free-radical polymerization forms the core chemistry of a majority of commercial UV-curable coating system today. Rapid curing at ambient temperature using stable, single component coating systems form the key value proposition that such coating systems offer. However, owing to their limitations such as oxygen inhibition, volume shrinkage, toxicity profiles of reactive diluents (RD), and the limited chemistry available, efforts are being made to counter these challenges by innovating and exploring new systems that have the potential to replace the existing chemistries. Anionic polymerization is one such promising area that has the potential to introduce a wide variety of chemistries in the field of UV-curable coatings. A significant stride in this field has been the innovation of photo-labile bases in the UV industry and the diverse chemistries that these bases have brought to fore. The primary focus of the present study is use of a super photo-base generator (PBG) in catalyzing concomitant but independent reactions to develop organic-inorganic hybrid (OIH) coating networks by leveraging plural-cure chemistry. The super PBG has been used to initiate both Michael-addition (MA) reaction and sol-gel reaction concurrently, upon exposure to the UV source. Coatings have been formulated using uniquely designed acrylate functional oligomers (MA-acceptor), acetoacetate functional reactive diluents (MA-donors) and organo-silanes (sol-gel precursors), besides super PBG. The study highlights many technical and environmental benefits of these OIH coatings with potential for applications in advanced coatings and additive manufacturing

A novel approach for preferential recovery of Sr from (Sr, Th)O<SUB>2</SUB>

Quantitative leaching of Sr from homogeneous and calcined (Th,Sr) O2 in dilute perchloric acid medium suggests the possibility of reducing the hazardousness of discharged nuclear fuel by separation of 90Sr, a prominent fission product at dissolution stage itself rather than the conventional approach of its recovery from high level nuclear waste. Apart from mitigating the radiotoxicity of the nuclear waste, recovered 90Sr can be employed as a compact heat source and as parent radionuclide for 90Y (used in therapy radiopharmaceuticals), provided it can be made available at desired high purity. Leaching behavior of few other fission products was also investigated to quantify their contamination in leached Sr. Feasibility of employing extraction chromatography using Sr selective resin was explored in perchloric acid medium. In this context, the distribution coefficients of 85Sr(II), Th (IV), Zr(IV), Y(III), Pd(II) as well as 152Eu(III) and 137Cs (I) were determined under varying nitric acid/perchloric acid concentration and under varying loading conditions of metal ions. Perchloric acid medium appears better than nitric acid medium for preferential leaching of Sr from (Th,Sr)O2 as well as for uptake of Sr by Sr selective chromatographic resin

Bioactivity and In Silico Studies of Isoquinoline and Related Alkaloids as Promising Antiviral Agents: An Insight

Viruses are widely recognized as the primary cause of infectious diseases around the world. The ongoing global pandemic due to the emergence of SARS-CoV-2 further added fuel to the fire. The development of therapeutics becomes very difficult as viruses can mutate their genome to become more complex and resistant. Medicinal plants and phytocompounds could be alternative options. Isoquinoline and their related alkaloids are naturally occurring compounds that interfere with multiple pathways including nuclear factor-κB, mitogen-activated protein kinase/extracellular-signal-regulated kinase, and inhibition of Ca2+-mediated fusion. These pathways play a crucial role in viral replication. Thus, the major goal of this study is to comprehend the function of various isoquinoline and related alkaloids in viral infections by examining their potential mechanisms of action, structure-activity relationships (SAR), in silico (particularly for SARS-CoV-2), in vitro and in vivo studies. The current advancements in isoquinoline and related alkaloids as discussed in the present review could facilitate an in-depth understanding of their role in the drug discovery process

Wound Healing Activity of a Novel Formulation SKRIN via Induction of Cell Cycle Progression and Inhibition of PCNA–p21 Complex Interaction Leading to Cell Survival and Proliferation

The process of wound healing is a dynamic event that starts with inflammation, proliferation, and cell migration of various types of fibroblast cells. Therefore, identification of potential molecules which may increase the wound healing capacity of fibroblast cells is crucial. A novel hydroalcoholic formulation of belladonna (SKRIN), was developed and characterized by GC-MS/MS, DLS, TEM, and AFM and was found to contain atropine and scopolamine exhibit in aggregated nanosized particles. SKRIN-mediated fibroblast cell survival was elucidated in the presence of H2O2 by MTT and flow cytometry based assays. With an EC50 of 4.41 μg/mL, SKRIN treatment showed significant increase in cell survival that was evident from a 1.11-fold increase (p < 0.0122) in the live cell population and 4.21-fold (p < 0.0001) and 2.59-fold (p < 0.0001) reductions in the early and late apoptotic cell populations, respectively. SKRIN-mediated wound healing was measured by cell scratch assay and cell cycle analysis. During the wound closure phenomenon, SKRIN increases repairing fibroblast cell proliferation by 1.24-fold (p = 0.0481) and increases the count of G2/M phase cells by 1.76-fold (p = 0.0002) which was confirmed by increased PCNA and reduced p21 protein expressions probably mediated by molecular interactions of PCNA–p21 complex with alkaloids present in SKRIN. Relative gene expression analysis further showed that SKRIN increases the PI3K, Akt, and NF-κB expression. Our data suggests that SKRIN exhibits wound healing property by increasing cell survival and repairing fibroblast proliferation via activation of the PI3K–Akt–NF-κB pathway probably mediated by inhibition of PCNA–p21 complex interaction

A 2D DNA Lattice as an Ultrasensitive Detector for Beta Radiations

There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, ⁹⁰Sr-⁹⁰Y. We studied the Raman spectra and reflected intensities of DNA lattices at various distances from the source with different exposure times. Although beta particles have very low linear energy transfer values, the significant physical and chemical changes observed throughout the extremely thin, ∼0.6 nm, DNA lattices suggested the feasibility of using them to develop ultrasensitive detectors of beta radiations

Mass-yield distribution of fission products from photo-fission of

The mass-yield distribution of fission products in the 2.5GeV bremsstrahlung-induced fission of natPb has been measured by using a recoil catcher and an off-line $\gamma$ -ray spectrometric technique in the 2.5GeV electron linac at the Pohang Accelerator Laboratory. The determination of mass-yield distribution involves measurement of cumulative yields of 27 fission products and independent yields of 15 fission products in the photo-fission of natPb . It was found that the mass-yield distribution of fission products in natPb is symmetric with an average mass of 94±0.5 and a full-width at half-maximum of 55±2.0 mass units. The present data along with the literature data in the 50-85MeV bremsstrahlung-induced fission of natPb and 209Bi as well as the data at 2.5GeV for 209Bi show that the average mass of the mass-yield distributions in the bremsstrahlung-induced fission of natPb and 209Bi decreases from 102.63±0.51 at 50-85MeV to 94.5±0.5 at 2.5GeV. The full-width at half-maximum of the mass-yield distribution increases from about 21.5±1.44 mass units at 50-85MeV to 53±2 mass units at 2.5GeV. These observations in the 50MeV to 2.5GeV bremsstrahlung-induced fission of natPb and 209Bi have been explained from the point of view of increase in multi-chance fission probability with increasing excitation energy. The role of the fissility parameter (Z F 2/A F) on the full-width at half-maximum is also discussed

Mass-yield distributions of fission products from photo-fission of Pb-nat induced by 50-70 MeV bremsstrahlung

The mass-yield distributions of various fission products have been determined in the 50-, 60- and 70-MeV end point bremsstrahlung induced fission of Pb-nat using off-line gamma-ray spectrometric technique in the electron linac at Pohang Accelerator Laboratory, Korea. The mass-yield distributions are symmetric with average mass of 102.34, 102.25 and 102.03 and FWHM of 21, 22 and 23 mass unit, respectively. From the present data and literature data in the 50-85 MeV bremsstrahlung induced fission of Bi-209 the following observations were obtained: (i) The average masses of the yield distributions in the 50-85 MeV bremsstrahlung induced fission of Pb-nat and Bi-209 are around 102.25 +/- A 0.25 and 103 +/- A 0.5, respectively. (ii) The FWHM of the mass-yield distributions increases from about 21 mass units at 50 MeV to 23 mass units at 70-85 MeV, which is explained from the point of increase in multi-chance fission probability with increasing excitation energy. (iii) Within the bremsstrahlung energy range of 50-85 MeV, the role of nuclear structure effect in the mass-yield distribution was observed in the photo-fission of Bi-209, whereas it was not seen in case of Pb-nat. This may be due to the presence of so many isotopes in Pb-nat unlike mono-isotopic Bi-209.X1145sciescopu