Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.     

Malformin-A1 (MA1) Sensitizes Chemoresistant Ovarian Cancer Cells to Cisplatin-Induced Apoptosis

High-grade epithelial ovarian cancer is a fatal disease in women frequently associated with drug resistance and poor outcomes. We previously demonstrated that a marine-derived compound MalforminA1 (MA1) was cytotoxic for the breast cancer cell line MCF-7. In this study, we aimed to examine the effect of MA1 on human ovarian cancer cells. The potential cytotoxicity of MA1was tested on cisplatin-sensitive (A2780S) and cisplatin-resistant (A2780CP) ovarian cancer cell lines using AlamarBlue assay, Hoechst dye, flow cytometry, Western blot, and RT-qPCR. MA1 had higher cytotoxic activity on A2780S (IC50 = 0.23 µM) and A2780CP (IC50 = 0.34 µM) cell lines when compared to cisplatin (IC50 = 31.4 µM and 76.9 µM, respectively). Flow cytometry analysis confirmed the cytotoxic effect of MA1. The synergistic effect of the two drugs was obvious, since only 13% of A2780S and 7% of A2780CP cells remained alive after 24 h of treatment with both MA1 and cisplatin. Moreover, we examined the expression of bcl2, p53, caspase3/9 genes at RNA and protein levels using RT-qPCR and Western blot, respectively, to figure out the cell death mechanism induced by MA1. A significant down-regulation in bcl2 and p53 genes was observed in treated cells compared to non-treated cells (p < 0.05), suggesting that MA1 may not follow the canonical pathway to induce apoptosis in ovarian cancer cell lines. MalforminA1 showed promising anticancer activity by inducing cytotoxicity in cisplatin-sensitive and cisplatin-resistant cancer cell lines. Interestingly, a synergistic effect was observed when MA1 was combined with cisplatin, leading to it overcoming its resistance to cisplatin.     

Exploring the Role of Surface States in Emissive Carbon Nanodots: Analysis at Single-Particle Level

Fluorescent carbon nanodots (CDs) have been highlighted as promising semiconducting materials due to their outstanding chemical and optical properties. However, the intrinsic heterogeneity of CDs has impeded a clear understanding of the mechanisms behind their photophysical properties. In this study, as-prepared CDs are fractionated via chromatography to reduce their structural and chemical heterogeneity and analyzed through ensemble and single-particle spectroscopies. Many single particles reveal fluorescence intensity fluctuations between two or more discrete levels with bi-exponential decays. While the intrinsic τ₁ components are uniform among single particles, the τ₂ components from molecule-like emissions spans a wider range of lifetimes, reflecting the inhomogeneity of the surface states. Furthermore, it is concluded that the relative population and chemical states of surface functional groups in CDs have a significant impact on emissive states, brightness, blinking, stability, and lifetime distribution of photoluminescence.     

Synthesis and antimicrobial evaluation of new 2-pyridinone and 2-iminochromene derivatives containing morpholine moiety

As trail to overcome on the antimicrobial drug-resistance problems, new functionalized 2-pyridinone and 2-iminochromene derivatives bearing morpholine moiety were designed and synthesized. The 2-pyridinone derivatives were obtained through the cyclization of cyanoacetohydrazone of 4-morpholinylacetophenone with 1,3-dicarbonyl compounds, α,β-unsaturated nitriles or 2-(arylidene)malononitriles. The 2-iminochromene derivatives were synthesized through the ring closure of cyanoacetohydrazonewith salicylaldehyde derivatives. The antibacterial and antifungal activities for the synthesized 2-pyridinone and 2-iminochromene derivatives were investigated. Most of the tested compounds showed moderate activity against P. vulgaris. Compounds 4a,b and 5a,b showed moderate activity against G −ve bacteria. All iminochromene derivatives showed moderate activity against C. albicans. Compound 8c was the most active compound.     

Identification of phytobioconstituents present in Simmondsia chinensis L. seeds extract by GC-MS analysis

Simmondsia chinensis L. commonly called as Jojoba and belongs to family Simmondsiaceae. It has shown positive pharmacological activities of these compounds which include antidiabetic, antirheumatic, anthelminthic, antipsoriatic, antioxidant, antiepileptic, antigonorrheal, analgesic, anti-inflammatory, and pesticidal activity of jojoba. The multifaceted action of numerous bioactives existing in the seed extract with therapeutic activity have attracted great research interest by pharmaceutical industries. n-hexane extract of Simmondsia chinensis L. (SC) Seeds was analysed by gas chromatography-mass spectroscopy for identification and characterization of phytobioconstituents and its therapeutic claim by traditional system. The major compounds discovered in SC seeds extract are cis-9-octadecen-1-ol (24.85%), 9-octadecen-1-ol, (Z)- (18.24%), Stigmast-5-en-3-ol (14.10%), Ergost-5-en-3-ol, (3-β)-ol (5.26%), (Z)-14-tricosenyl formate (5.24%), Thiositosteroldisulfide (3.64%), Silane, Dimethyl (dimethylpentyloxysilyloxy) tetradecyloxy- (3.41%), Ergost-5-ene, 3-methoxy-, (3β,24R)- (2.55%), Ergosta-5,22-dien-3-ol (2.22%), 1,19-eicosadiene (2.17%), Pentacosane (2.02%), Stigmasta-5,22-dien-3-ol (1.64%), 1,19-eicosadiene (1.57%), 9-octadecen-1-ol, (Z)- (1.46%), 9,19-cyclo-9β-lanostan-3β-ol, 24-methylene- (1.14%), (9Z)-9-octadecenyl palmitate (1.50%), Hexadecanoic acid, 9-octadecenyl ester, (Z) (1.37%), 9Z)-9-octadecenyl (9Z)-9-hexadecenoate (1.01%). The hexane extract of Simmondsia chinensis seeds comprises various polar and nonpolar phytobioconstituents. These compounds were established qualitatively via GC-MS evaluation. GC-MS reports will be promising in pharmaceutical sector in identification of variety of Phytobioconstituents in distinct plant extracts, polyherbal extract and the standardization of particular plant materials.     

Synthesis and application of silica and calcium carbonate nanoparticles in the reduction of organics from refinery wastewater

Oil refinery is one of the fast growing industries across the globe and it is expected to progress in the near future. The worldwide increase in the generation of refinery wastewater along with strict environmental regulations in the discharge of industrial effluent, persistent efforts have been devoted to recycle and reuse the treated water. The wastewater from the refining operation leads to serious environmental threat to the ecosystem. Therefore, this study aimed to synthesize silica (SiO₂) and calcium carbonate nanoparticles (CaCO₃) in the reduction of organics from refinery wastewater. The synthesized nanoparticles were employed in the reduction of chemical oxygen demand (COD) from refinery wastewater by studying the influence of solution pH, contact time, dosage of nanoparticles and stirring speed on adsorption performance. From the batch experimental studies, the optimized processing conditions for the reduction of COD using SiO₂ nanoparticles are pH 4.0, dosage 0.5 g, stirring speed 125 rpm and 90 min stirring time, and the corresponding values for CaCO₃ nanoparticles are pH 8.0, dosage 0.4 g, stirring speed 100 rpm and 90 min stirring time. The study demonstrates that SiO₂ and CaCO₃ nanoparticles have a promising future in the reduction organics from refinery wastewater in different pH regimes.     

Weighted Cebysev-Ostrowski type inequalities

In account of the famous Cebysev inequality, a rich theory has appeared in the literature. We establish some new weighted Cebysev type integral inequalities. Our proofs are of independent interest and provide new estimates on these types of inequalities.     

The effect of orientation of square perforations on the heat transfer enhancement from a fin subjected to natural convection

The heat transfer dissipation from a horizontal rectangular fin embedded with square perforations of two orientations under natural convection is numerically investigated. The parameters considered in this investigation are the geometrical dimensions and the orientations of the perforation. A comparison between heat dissipation of the fin with variable orientations of the perforations is presented. It is found that the heat dissipation enhancement from a fin with square perforation parallel to the fin base was more than that of fin with inclined square perforation. The problem of this study was numerically solved using the variational approach finite element technique.     

Convective heat transfer in the thermal entrance region of finned double-pipe

Numerical simulation of the steady and laminar convection in the thermal entry region of the finned annulus is carried out for the case of hydrodynamically fully developed flow when subjected to uniform heat flux thermal boundary condition. Finite difference based marching procedure is used to compute the numerical solution of the energy equation. The results to be presented include Nusselt number, as a function of dimensionless axial length and thermal entrance length for various configurations of the finned double-pipe. The numerical results show that Nusselt number has complex dependence on the geometric variables like ratio of radii, fin height, and number of fins. A comparison of the computed results for certain limiting cases with the results available in the literature validates the numerical procedure used in this work.     

THE DYNAMIC BUCKLING OF AN ORTHOTROPIC CYLINDRICAL THIN SHELL UNDER TORSION VARYING AS A POWER FUNCTION OF TIME

The subject of this investigation is to study the buckling of orthotropic cylindricalthin shells under torsion,which is a power function of time.The dynamic stability and compati-bility equations are obtained first.These equations are subsequently reduced to a time dependentdifferential equation with variable coefficient by using Galerkin's method.Finally,the critical dy-namic and static loading,the corresponding wave numbers,the dynamic factors,critical time andcritical impulse are found analytically by applying the Ritz type variational method.Using thoseresults,the effects of the variations of the power of time in the torsion load expression,of theloading parameter,the ratio of the Young's moduli and the ratio of the radius to thickness onthe critical parameters are studied numerically.It is observed that these factors have appreciableeffects on the critical parameters of the problem in the heading.