Highly Efficient Solar‐Driven Carbon Dioxide Reduction on Molybdenum Disulfide Catalyst Using Choline Chloride‐Based Electrolyte

Conversion of CO₂ to energy‐rich chemicals using renewable energy is of much interest to close the anthropogenic carbon cycle. However, the current photoelectrochemical systems are still far from being practically feasible. Here the successful demonstration of a continuous, energy efficient, and scalable solar‐driven CO₂ reduction process based on earth‐abundant molybdenum disulfide (MoS₂) catalyst, which works in synergy with an inexpensive hybrid electrolyte of choline chloride (a common food additive for livestock) and potassium hydroxide (KOH) is reported. The CO₂ saturated hybrid electrolyte utilized in this study also acts as a buffer solution (pH ≈ 7.6) to adjust pH during the reactions. This study reveals that this system can efficiently convert CO₂ to CO with solar‐to‐fuel and catalytic conversion efficiencies of 23% and 83%, respectively. Using density functional theory calculations, a new reaction mechanism in which the water molecules near the MoS₂ cathode act as proton donors to facilitate the CO₂ reduction process by MoS₂ catalyst is proposed. This demonstration of a continuous, cost‐effective, and energy efficient solar driven CO₂ conversion process is a key step toward the industrialization of this technology.     

Effects of Silver Nanoparticles and Silver Nitrate on Antioxidant Responses in Echium amoenum

Russian Journal of Plant Physiology - Nanoparticles have entered agriculture and biology fields because of their special effects and unique features. One of the most important properties of silver...     

Modifying bio-catalytic properties of enzymes for efficient biocatalysis: a review from immobilization strategies viewpoint

Enzyme-based catalysis has become one of the most important disciplines in organic synthesis and plays a noteworthy role in the establishment of many chemical industries, e.g. fine chemicals, food or energy, textiles, agricultural, cosmeceutical, medicinal and pharmaceutical industries. However, pristine enzymes fail to demonstrate requisite functionalities for an industrial setting where extremely specific and stable catalysts are required. Immobilization enhances the catalytic stability and activity of enzymes and trims the overall cost burden of the enzyme. Therefore, it widely endeavours for proficient, sustainable, and environmentally responsive catalytic processes. Amongst several immobilization strategies, e.g. (1) supports-assisted, i.e. physical or covalent coupling and (2) supports-free techniques, i.e. cross-linked enzyme crystals (CLECs) or aggregates are the most promising ones and widely pursued for enzyme immobilization purposes. This perspective review focuses on up-to-date developments in the area of enzyme immobilization and presents their potentialities to upgrade and/or modify enzyme properties. Both types of immobilization strategies, i.e. supports-assisted and supports-free techniques are discussed with particular reference to CLECs or aggregates and protein-coated microcrystals. Also, several useful traits achieved after immobilization are also discussed in the second half of the review.     

Community structure,spatial distribution,diversity and functional characterization of culturable endophytic fungi associated with Glycyrrhiza glabra L.

A total of 266 endophytic fungal isolates were recovered from 1019 tissue segments of Glycyrrhiza glabra collected from four different locations in the North-Western Himalayas. The endophytes grouped into 21 genera and 38 different taxa. The host had strong affinity for the genus Phoma, followed by Fusarium. The species richness was highest at the sub-tropical location, followed by the sub-temperate location and the temperate locations, respectively. The tissue specificity of endophytes was also evident. Some endophytes showed potential antimicrobial activity against phyto-pathogens indicating that they may be helpful to the host in evading pathogens. All the endophytic taxa produced the plant growth promoting hormone, indole acetic acid (IAA), though in varying concentrations. None of these endophytes caused any symptoms of disease in co-cultivation with the tissue cultured plants. Further, all the endophytes had a positive influence on the phenolic and flavonoid content of the host. Three endophytes, Stagonosporopsis cucurbitacearum, Bionectria sp. and Aspergillus terreus also increased the host root (rhizome) and shoot growth visibly. Such endophytes are potential candidates for developing endophyte-based technologies for sustainable cultivation and enhanced productivity of G. glabra. This is the first report of community structure and biological properties of fungal endophytes associated with G. glabra.     

Hexose monophosphate shunt,the role of its metabolites and associated disorders: A review

The hexose monophosphate (HMP) shunt acts as an essential component of cellular metabolism in maintaining carbon homeostasis. The HMP shunt comprises two phases viz. oxidative and nonoxidative, which provide different intermediates for the synthesis of biomolecules like nucleotides, DNA, RNA, amino acids, and so forth; reducing molecules for anabolism and detoxifying the reactive oxygen species during oxidative stress. The HMP shunt is significantly important in the liver, adipose tissue, erythrocytes, adrenal glands, lactating mammary glands and testes. We have researched the articles related to the HMP pathway, its metabolites and disorders related to its metabolic abnormalities. The literature for this paper was taken typically from a personal database, the Cochrane database of systemic reviews, PubMed publications, biochemistry textbooks, and electronic journals uptil date on the hexose monophosphate shunt. The HMP shunt is a tightly controlled metabolic pathway, which is also interconnected with other metabolic pathways in the body like glycolysis, gluconeogenesis, and glucuronic acid depending upon the metabolic needs of the body and depending upon the biochemical demand. The HMP shunt plays a significant role in NADPH₂ formation and in pentose sugars that are biosynthetic precursors of nucleic acids and amino acids. Cells can be protected from highly reactive oxygen species by NADPH ₂. Deficiency in the hexose monophosphate pathway is linked to numerous disorders. Furthermore, it was also reported that this metabolic pathway could act as a therapeutic target to treat different types of cancers, so treatments at the molecular level could be planned by limiting the synthesis of biomolecules required for proliferating cells provided by the HMP shunt, hence, more experiments still could be carried out to find additional discoveries.     

Preparation of superparamagnetic iron oxide/doxorubicin loaded chitosan nanoparticles as a promising glioblastoma theranostic tool

Theranostic nanoparticles (NPs) are promising for opening new windows toward personalized disease management. Using a single particle capable of both diagnosis and drug delivery, is the major benefit of such particles. In the present study, chitosan NPs were used as a dual action carrier for doxorubicin (DOX; chemotherapeutic agent) and superparamagnetic iron oxide nanoparticles (SPIONs; imaging agent). SPIONs and DOX were loaded at different concentrations within poly-l -arginine-chitosan-triphosphate matrix (ACSD) using the ionic gelation method. NPs’ size were in the range of 184.33 ± 4.4 nm. Drug release analysis of DOX loaded NPs (NP-DOX) showed burst release at pH 5.5 (as in tumor environment) and slow release at pH 7.4 (physiological condition), demonstrating pH-sensitive drug release profile. NP-DOX internalization was confirmed by flowcytometry and fluorescent microscopy. Uptake process results were corroborated by accumulation of drug in the intracellular space. Iron content was evaluated by inductively coupled plasma and prussian blue staining. In vitro magnetic resonance imaging (MRI) showed a decline in T ₂ relaxation times by increasing iron concentration. MRI analysis also confirmed uptake of NPs at the optimum concentration in C6 glioma cells. In conclusion, ACSD NPs could be utilized as a promising theranostic formulation for both diagnosis and treatment of glioblastoma.     

The role of nitric oxide signaling in renoprotective effects of hydrogen sulfide against chronic kidney disease in rats: Involvement of oxidative stress,autophagy and apoptosis

The interplay between H₂S and nitric oxide (NO) is thought to contribute to renal functions. The current study was designed to assess the role of NO in mediating the renoprotective effects of hydrogen sulfide in the 5/6 nephrectomy (5/6 Nx) animal model. Forty rats were randomly assigned to 5 experimental groups: (a) Sham; (b) 5/6 Nx; (c) 5/6Nx+sodium hydrosulfide-a donor of H ₂S, (5/6Nx+sodium hydrosulfide [NaHS]); (d) 5/6Nx+NaHS+ L -NAME (a nonspecific nitric oxide synthase [NOS] inhibitor); (e) 5/6Nx+NaHS+aminoguanidine (a selective inhibitor of inducible NOS [iNOS]). Twelve weeks after 5/6 Nx, we assessed the expressions of iNOS and endothelial NOS (eNOS), oxidative/antioxidant status, renal fibrosis, urine N-acetyl-b-glucosaminidase (NAG) activity as the markers of kidney injury and various markers of apoptosis, inflammation, remodeling, and autophagy. NaHS treatment protected the animals against chronic kidney injury as depicted by improved oxidative/antioxidant status, reduced apoptosis, and autophagy and attenuated messenger RNA (mRNA) expression of genes associated with inflammation, remodeling, and NAG activity. Eight weeks Nω-nitro-l-arginine methyl ester ( L -NAME) administration reduced the protective effects of hydrogen sulfide. In contrast, aminoguanidine augmented the beneficial effects of hydrogen sulfide. Our finding revealed some fascinating interactions between NO and H ₂S in the kidney. Moreover, the study suggests that NO, in an isoform-dependent manner, can exert renoprotective effects in 5/6 Nx model of CKD.     

Analysis of VEGF gene polymorphisms and serum VEGF protein levels contribution in polycystic ovary syndrome of patients

Vascular endothelial growth factor (VEGF) is a well-known factor in reproductive function and contributes to the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in VEGFA gene were suggested to contribute alterations in VEGF secretion and PCOS. This study evaluated the association of VEGFA SNPs with altered VEGF secretion level and PCOS among ethnically-matched control women. This prospective case–control study was conducted from 2016 to 2018 and comprised of 55 women with PCOS and 52 control subjects. ELISA was used to measure VEGF levels; and various other related bio chemicals whereas the genotyping of VEGFA variants was performed through the analysis of nine SNPs of VEGF. PRL, E2, PRGE testosterone and glucose level were found to be insignificantly different. The levels of FSH, LH, LH/FSH, TT, insulin, SHBG and HOMA-IR were significantly higher in the study group. Among the nine tested variants of VEGF SNPs, two SNPs rs3025020 and rs833061, consisted of TT (Recessive and Dominant homozygous, respectively) which were marginally higher in test. The SNP rs1570360 had significantly higher GG allele (32.73%) which was recessive homozygous. There was no significant difference observed in genotype frequencies related to higher value of VEGF. The genotype frequencies for the studied SNPs were in alignment with Hardy–Weinberg equilibrium (HWE). The mean serum VEGF levels got significantly increased in PCOS group. No significant association was found between VEGF genotypes and its serum levels. VEGF levels in rs699947 (AA-major homozygous), rs3025039 (CC-major homozygous) and rs833061 (TT & CC-major & minor homozygous) genotypes were significantly higher in PCOS. The study results evidently proved that the allelic variants in genes may be a factor for PCOS and VEGF serum levels with respect to few SNP variants only. These findings indicated that VEGF may be involved in PCOS status and confirmed the previous association between genetic variants in VEGF, serum level of VEGF protein and PCOS.