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Polyvinyl alcohol (PVA) is a widely used polymer that is biocompatible, nontoxic, and water-soluble due to the presence of hydroxyl groups in its domain. This study aims to investigate the effects of fumaric acid (FA) cross-linking and thermal cross-linking (TC) on the PVA's mechanical and thermal properties. When the FA is mixed with PVA, it was found in the chemical reaction that the OH groups of PVA are condensing with the carboxylic acid units of FA to yield new ester linkages and water as a by-product, which further results in the reduction of the water absorption capacity. Quantitatively, the addition of 8 (wt. /wt. %) FA resulted in a minimum of 65% water absorption rate, as compared with 117% for pure PVA. The mechanical and thermal properties of PVA also enhanced with the addition of 2% to 8% FA by weight. For the TC case, the % increase in ultimate tensile strength was 30.9% and 42.5% with and without TC, respectively. As the wt. % of FA increased from 2 to 10%, the % elongation value decreased for both with and without TC films relative to pure PVA. The thermogravimetric analysis revealed the change in degradation temperature of FA-PVA blended film in comparison with pure PVA. Dynamic mechanical analysis was utilized to analyze the viscoelastic nature and temperature variation at the glass transition temperature. The current fabricated film is a potential candidate for the food packaging films application; moreover, the results reported in this investigation will accelerate the industrial applications of biodegradable PVA. Highlights * Increasing the weight percentage of fumaric acid leads to an enhancement in mechanical and thermal properties of the film. * Esterification is the usual reaction between fumaric acid and polyvinyl alcohol (PVA), in which ester linkages are formed when the carboxyl groups (-COOH) of fumaric acid and the hydroxyl groups (-OH) of PVA combine. * Water absorption characteristics of the film reduces as the wt. % of fumaric acid increases. * Thermal cross-linking of the film leads to further improvements in mechanical and thermal properties. * The overall effect of increasing the wt. % of fumaric acid is negative on the glass transition temperature of the film. * The developed film is a potential candidate for the food packaging films application. KEYWORDS biodegradable polymers, cross-linking, fumaric acid, mechanical and thermal properties, polyvinyl alcohol, 1 | INTRODUCTION Polyvinyl alcohol (PVA) owing to its biocompatibility, biodegradability, and moderate mechanical properties has gained worldwide attention as one of the most important synthetic biodegradable polymers for the [...]

An efficient catalytic system employing TMS•OTf for the regioselective thiolation of electron‐rich arenes with sulfonyl hydrazides has been developed. The reaction occurs in a solvent mixture of dichloroethane and trifluoroethanol under mild conditions, with the addition of water. This method furnishes a range of para‐thio‐substituted arenes and 3‐sulfenyl‐indoles in good to excellent yields, marking a significant advancement in organic synthesis. [ABSTRACT FROM AUTHOR]

The renin‐angiotensin system (RAS) is crucial for regulating and understanding the pathophysiology of hypertension. However, there has been little focus on the breakdown of the active peptide, angiotensin II (AngII). Given that animals lacking aminopeptidase A (APA) exhibit hypertension, it may be concluded that APA is a crucial enzyme in regulating blood pressure by breaking down AngII. It has been also seen that the elevated blood pressure in the spontaneously hypertensive rat (SHR) is caused by the activation of the RAS and a concurrent reduction in renal angiotensin‐converting enzyme (ACE) activity. The activity of APA is elevated at the beginning of pre‐eclampsia and decreases below the levels seen during a normal pregnancy as pre‐eclampsia progresses (particularly, in severe cases). The activity of Serum APA is also heightened after hormone replacement treatment (HRT), perhaps as a response to increasing levels of AngII. Therefore, it is crucial to examine the connection between the activation of the RAS, the levels of AngII in the bloodstream, and the presence of APA in hypertension conditions. Summary: Aminopeptidase A (APA) plays a critical role in the regulation of blood pressure by modulating the renin‐angiotensin system. Inhibiting APA offers a novel therapeutic approach to reducing hypertension, particularly, in cases resistant to conventional treatments. This systematic review highlights the growing evidence supporting APA as a promising target for effective hypertension management. [ABSTRACT FROM AUTHOR]

There is accumulating evidence of the presence of Cancer Stem Cells (CSCs) within meningiomas (MGs). In the present study, we assessed the Immunohistochemistry (IHC) expression of stem cell markers SOX2, OCT4, CD133 in different grades of MGs and their correlation with Ki 67 index. A cross-sectional analytical study where 140 MGs cases were graded and classified according to WHO-2021 classification. IHC for SOX2, OCT4, CD133 and Ki-67 was carried out. Out of 140 cases, 59 cases (42.1%) showed OCT4 positivity, 38 cases (27.1%) showed CD133 positivity and only 21 cases (15%) showed SOX2 positivity. Ki 67 index ranged from 1-30%. Statistically significant difference (Chi Square p-value <0.001) was found between SOX 2, OCT4 and CD133 expressions (positive/negative) and the grades of MG cases. As the grades of MG cases increased, the positive expression of SOX2, OCT 4 and CD 133 also increased. The Mean Ki 67 index value was significantly raised when SOX2, OCT 4 and CD 133 IHC expressions were positive (Student t Test p-value <0.001). Our results strongly support the hypothesis of presence of CSCs, in MGs regardless of their grade. We recommend that CSCs IHC markers (SOX2, OCT4 and CD133) to be used on initial diagnosis in all cases of MGs along with Ki-67 index. It can help quantitate CSCs and in turn, recommend closer follow up in patients with high percentage of CSCs to predict early recurrence. [ABSTRACT FROM AUTHOR]

Cricula trifenestrata Helfer (commonly known as Amphutukoni muga/Cricula silkworm), a wild sericigenous insect produces golden yellow silk similar to Antheraea assamensis (muga silkworm), with significant potential as a natural fiber and biomaterial. Cricula is considered as a pest as it competes for food with muga, which produces the prized golden silk. This study focuses on decoding the mitochondrial genome of C. trifenestrata using next-generation sequencing technology and includes comparative analysis with Bombycoids and other lepidopteran insects. We found that the Cricula mitogenome spans 15 425 bp and exhibits typical gene content and arrangement consistent with other Saturniids and lepidopterans. All protein-coding genes were found to undergo purifying selection, with the highest and lowest conservation observed in the cox1 and atp8 gene, respectively, indicating their potential role in future evolutionary events. We identified two types of mismatches: 23 "G–U" and 6 "U–U" pairs, similar to those found in Actias selene among the Saturniids. Additionally, our study uncovered the presence of two 33 bp repeat units and a "TTAGA" motif in the control region, in contrast to the typical "ATAGA" motif, suggesting functional similarity with evolving sequences. Furthermore, phylogenetic analysis supports the close relationship of Cricula with other species within the Saturniidae family. [ABSTRACT FROM AUTHOR]