Pervasiveness of UVC254-resistant Geobacillus strains in extreme environments

Applied Microbiology and Biotechnology - We have characterized a broad collection of extremophilic bacterial isolates from a deep subsurface mine, compost dumping sites, and several hot spring...     

Stable Formamidinium‐Based Perovskite Solar Cells via In Situ Grain Encapsulation

Formamidinium (FA)‐based lead iodide perovskites have emerged as the most promising light‐absorber materials in the prevailing perovskite solar cells (PSCs). However, they suffer from the phase‐instability issue in the ambient atmosphere, which is holding back the realization of the full potential of FA‐based PSCs in the context of high efficiency and stability. Herein, the tetraethylorthosilicate hydrolysis process is integrated with the solution crystallization of FA‐based perovskites, forming a new film structure with individual perovskite grains encapsulated by amorphous silica layers that are in situ formed at the nanoscale. The silica not only protects perovskite grains from the degradation but also enhances the charge‐carrier dynamics of perovskite films. The underlying mechanism is discussed using a joint experiment‐theory approach. Through this in situ grain encapsulation method, PSCs show an efficiency close to 20% with an impressive 97% retention after 1000‐h storage under ambient conditions.     

Lewis‐Adduct Mediated Grain‐Boundary Functionalization for Efficient Ideal‐Bandgap Perovskite Solar Cells with Superior Stability

State‐of‐the‐art perovskite solar cells (PSCs) have bandgaps that are invariably larger than 1.45 eV, which limits their theoretically attainable power conversion efficiency. The emergent mixed‐(Pb, Sn) perovskites with bandgaps of 1.2–1.3 eV are ideal for single‐junction solar cells according to the Shockley–Queisser limit, and they have the potential to deliver higher efficiency. Nevertheless, the high chemical activity of Sn(II) in these perovskites makes it extremely challenging to control their physical properties and chemical stability, thereby leading to PSCs with relatively low PCE and stability. In this work, the authors employ the Lewis‐adduct SnF₂·3FACl additive in the solution‐processing of ideal‐bandgap halide perovskites (IBHPs), and prepare uniform large‐grain perovskite thin films containing continuously functionalized grain boundaries with the stable SnF₂ phase. Such Sn(II)‐rich grain‐boundary networks significantly enhance the physical properties and chemical stability of the IBHP thin films. Based on this approach, PSCs with an ideal bandgap of 1.3 eV are fabricated with a promising efficiency of 15.8%, as well as enhanced stability. The concept of Lewis‐adduct‐mediated grain‐boundary functionalization in IBHPs presented here points to a new chemical route for approaching the Shockley–Queisser limit in future stable PSCs.     

Biotic and Abiotic Drivers of Peatland Growth and Microtopography: A Model Demonstration

Peatlands are important carbon reserves in terrestrial ecosystems. The microtopography of a peatland area has a strong influence on its carbon balance, determining carbon fluxes at a range of spatial scales. These patterned surfaces are very sensitive to changing climatic conditions. There are open research questions concerning the stability, behaviour and transformation of these microstructures, and the implications of these changes for the long-term accumulation of organic matter in peatlands. A simple two-dimensional peat microtopographical model was developed, which accounts for the effects of microtopographical variations and a dynamic water table on competitive interactions between peat-forming plants. In a case study of a subarctic mire in northern Sweden, we examined the consequences of such interactions on peat accumulation patterns and the transformation of microtopographical structure. The simulations demonstrate plausible interactions between peatland growth, water table position and microtopography, consistent with many observational studies, including an observed peat age profile from the study area. Our model also suggests that peatlands could exhibit alternative compositional and structural dynamics depending on the initial topographical and climatic conditions, and plant characteristics. Our model approach represents a step towards improved representation of peatland vegetation dynamics and net carbon balance in Earth system models, allowing their potentially important implications for regional and global carbon balances and biogeochemical and biophysical feedbacks to the atmosphere to be explored and quantified.     

Lead‐induced DNA damage and cell apoptosis in human renal proximal tubular epithelial cell: Attenuation via N‐acetyl cysteine and tannic acid

This study investigates the exposure of lead‐induced reactive oxygen species (ROS) generation, DNA damage, and apoptosis and also evaluates the therapeutic intervention using antioxidants in human renal proximal tubular cells (HK‐2 cells). Following treatment of HK‐2 cells with an increasing concentration of lead nitrate (0–50 μM) for 24 h, the intracellular ROS level increased whereas the GSH level decreased significantly in a dose‐dependent manner. Comet assay results revealed that lead nitrate showed the ability to increase the levels of DNA strand breaks in HK‐2 cells. Lead exposure also induced apoptosis through caspase‐3 activation at 30 μg/mL. Pretreatment with N‐acetylcysteine (NAC) and tannic acid showed a significant ameliorating effect on lead‐induced ROS, DNA damage, and apoptosis. In conclusion, lead induces ROS, which may exacerbate the DNA damage and apoptosis via caspase‐3 activation. Additionally, supplementation of antioxidants such as NAC and tannic acid may be used as salvage therapy for lead‐induced DNA damage and apoptosis in an exposed person.     

Evaluation of potential flavonoid inhibitors of glyoxalase-I based on virtual screening and in vitro studies

Glyoxalase-I (GLO-I) is a component of the ubiquitous detoxification system involved in the conversion of methylglyoxal (MG) to d-lactate in the glycolytic pathway. MG toxicity arises from its ability to form advanced glycation end products. GLO-I has been reported to be frequently overexpressed in various types of cancer cells. In this study, we performed structure-based virtual screening of focused flavonoids commercial library to identify potential and specific inhibitors of GLO-I. The compounds were ranked based on Glide extra precision docking score and five hits (curcumin, quercetin, morin, naringin and silibinin) were selected on the basis of their interaction with active site amino acid residues of GLO-I. Mixed mode QM/MM calculation was performed on the top-scoring hit to ascertain the role of zinc ion in ligand binding. In addition, the identified hits were subjected to MM/GBSA binding energy prediction, ADME prediction and similarity studies. The hits were tested in vitro for cell viability, and GLO-I inhibition. Naringin (ST072162) was found to be most potent inhibitor of GLO-I among the identified hits with highest glide XP dock score of ?14.906. These findings suggest that naringin could be a new scaffold for designing inhibitors against GLO-I with potential application as anticancer agents.     

Green synthesis of isoamyl acetate via silica immobilized novel thermophilic lipase from <Emphasis Type="Italic">Bacillus aerius</Emphasis>

Isoamyl acetate, a pear or banana flavor, is widely used in food, beverage, cosmetic, and pharmaceutical industries. In the present work, lipase from Bacillus aerius was immobilized on silica gel matrix in the presence of a cross-linking agent, glutaraldehyde, and its efficiency in synthesizing isoamyl acetate using esterification reaction was studied. The esterification of acetic acid and isoamyl alcohol by silica-bound lipase was studied as a function of time and temperatures. The incubation time of 10 h, temperature of 55°C, substrate molar ratio 1: 1, and the amount of lipase as 1% were found to be optimal for the esterification reaction. The bound lipase catalyzed the esterification of acetic acid by isoamyl alcohol with the yield of about 68% under the optimized reaction conditions. The product was identified as isoamyl acetate using gas-liquid chromatography, nuclear magnetic resonance, and Fourier transform IR spectroscopy analysis by the presence of an ester group at the wavenumber of 1720.5 cm^–1.     

Identification of a 55-kDa ezrin-related protein that induces cytoskeletal changes and localizes to the nucleolus.

Normal and transformed human cells when stained for ezrin, an F-actin-binding ERM (ezrin/radixin/moesin) family protein, revealed a faint and intense immunofluorescence, respectively. Surprisingly, nuclear staining that was assigned to the nucleolus by confocal laser and immunoelectron microscopy was detected in both cell types and was more prominent in normal cells due to the absence of glistering cytoplasmic fluorescence. By Western analysis the nuclear fraction was seen to have a 55-kDa ezrin-reactive protein that did not react to the antibodies raised against the C-terminus of the protein, suggesting that it may correspond to an endogenously cleaved N-terminus of the protein. Transfections of cells with a cDNA encoding full-length ezrin tagged with green fluorescent protein (GFP) at its N-terminus indeed resulted in two GFP-tagged products corresponding to full-length and 55-kDa endogenously cleaved forms. Transfection with a cDNA encoding approximately 55 kDa of the ezrin N-terminus (N-ezrin) showed that it can translocate to the nucleus. N-ezrin transfected cells exhibited irregular cell edges and collapse of actin fibers. Similar changes were seen following microinjection of anti-p81/ezrin antibody, suggesting that N-ezrin may function as a dominant negative competitor of ezrin. These data demonstrate the existence of an N-terminal cleavage form of ezrin that localizes to the nucleolus and that its overexpression induces cytoskeletal changes.     

The futuristic applications of transition metal dichalcogenides for cancer therapy

The second-most common cause of death resulting from genetic mutations in DNA sequences is cancer. The difficulty in the field of anticancer research is the application of the traditional methods, which also affects normal cells. Mutations, genetic replication alterations, and chromosomal abnormalities have a direct impact on the effectiveness of anticancer drugs at different stages. Presently, therapeutic techniques utilize nanotechnology, transition metal dichalcogenides (TMDCs), and robotics. TMDCs are being increasingly employed in tumor therapy and biosensing applications due to their biocompatibility, adjustable bandgap, versatile functionality, exceptional photoelectric properties, and wide range of applications. This study reports the advancement of nanoplatforms based on TMDCs that are specifically engineered for responsive and intelligent cancer therapy. This article offers a thorough examination of the current challenges, future possibilities for theranostic applications using TMDCs, and recent progress in employing TMDCs for cancer therapy. Currently, there is significant interest in two-dimensional (2D) TMDCs nanomaterials as ultrathin unique physicochemical properties. These materials have attracted attention in various fields, including biomedicine. Due to their inherent ability to absorb near-infrared light and their exceptionally large surface area, significant efforts are being made to prepare multifunctional nanoplatforms based on 2D TMDCs.