Further experimental evidences of the compatibility of poly(vinyl acetate) with poly(ethyl methacrylate) and its dependence on the ratio of the molecular weight of the two homopolymers

Using various fractions of poly(ethyl methacrylate) (PEMA) and poly(vinyl acetate) (PVAc) of very narrow molecular weight distribution, a very wide range of 2–120 of molecular weight ratio M¯_ν PEMA/M¯_ν PVAc, (M¯_ν)_r was obtained. Studies of some tensile mechanical properties of films of the blends produced from solution on mercury confirmed strong dependence of the improvements of PVAc properties for blend with 18% PEMA on (M¯_ν)_r, especially in the range 5 ≤ (M¯_ν)_r < 100. The density of the films of the blend was much higher than those of the individual polymers and increased monotonically with (M¯_ν)_r. Optical micrographs of the films of the blends showed interactions between the two polymers with 18% PEMA composition, which appears to be more intimate as (M¯_ν)_r increases, as further evidence of compatibility and miscibility of the two polymers.     

Homology Model Adjustment and Ligand Screening with a Pseudoreceptor of the Human Histamine H4 Receptor

A new pseudoreceptor modeling method (PRPS) was applied to the refinement of a homology model of the human histamine H₄ receptor (H₄R), the prediction of a ligand binding site, and virtual screening. Retrieval of two new H₄R ligands demonstrates the biological relevance of the pseudoreceptor model and provides a means for finding new hits and leads in the early phases of drug discovery.

     

Nickel Oxide Based Supported Catalysts for the In-situ Reactions of Methanation and Desulfurization in the Removal of Sour Gases from Simulated Natural Gas

Supported nickel oxide based catalysts were prepared by wetness impregnation method for the in-situ reactions of H₂S desulfurization and CO₂ methanation from ambient temperature up to 300 °C. Fe/Co/Ni (10:30:60)–Al₂O₃ and Pr/Co/Ni (5:35:60)–Al₂O₃ catalysts were revealed as the most potential catalysts, which yielded 2.9% and 6.1% of CH₄ at reaction temperature of 300 °C, respectively. From XPS, Ni₂O₃ and Fe₃O₄ were suggested as the surface active components on the Fe/Co/Ni (10:30:60)–Al₂O₃ catalyst, while Ni₂O₃ and Co₃O₄ on the Pr/Co/Ni (5:35:60)–Al₂O₃ catalyst.     

Dynamics of boring processes: Part III-time domain modeling

This article presents a mathematical model and a computational algorithm for the time domain solution of boring process dynamics. The model is developed in a modular form; it includes a workpiece geometry and surface topography module, a kinamatics and tool position module, a dynamic chip load module, a dynamic cutting force prediction module and a structural dynamics module. The time domain model takes cutting process parameters, tool and workpiece geometries and modal parameters of the structure as inputs. It predicts instantanous cutting forces and vibrations along the machining time, and machined workpiece topography as outputs. Some of the simulated and experimental results for various cutting conditions are presented and compared for validation purposes.     

Comparative study of a variety of ATRP systems with high oxidation state metal catalyst system

MMA (methyl methacrylate) was polymerized in different ATRP systems using the different ligands of HMTETA (1, 1, 4, 7, 10, 10, hexamethyltriethylenetetraamine), TMEDA (N,N,N′,N′-Tetramethylethylenediamine) with copper salts (CuBr/CuBr₂) and EBriB was used as an initiator in toluene at a reaction temperature of 80 °C. Both conventional and a low catalyst to initiator ratios ranging from 1/1 to 0.01/1 were compared in this study. All four of the ATRP methods, such as normal, reverse, AGET and ATRP using a high oxidation state metal complex without any additives, were evaluated at different conditions. The ATRP using a high oxidation state metal system in the absence of a conventional radical initiator like AIBN, which is used in reverse ATRP, or reducing agents such as Sn (EH)₂ in AGET ATRP was a better controlled system in terms of both the catalytic activity and controllability (PDI ∼ 1.2).     

Nanomaterials for Antiangiogenic Therapies for Cancer: A Promising Tool for Personalized Medicine

Angiogenesis is one of the hallmarks of cancer. Several studies have shown that vascular endothelium growth factor (VEGF) plays a leading role in angiogenesis progression. Antiangiogenic medication has gained substantial recognition and is commonly administered in many forms of human cancer, leading to a rising interest in cancer therapy. However, this treatment method can lead to a deteriorating outcome of resistance, invasion, distant metastasis, and overall survival relative to its cytotoxicity. Furthermore, there are significant obstacles in tracking the efficacy of antiangiogenic treatments by incorporating positive biomarkers into clinical settings. These shortcomings underline the essential need to identify additional angiogenic inhibitors that target numerous angiogenic factors or to develop a new method for drug delivery of current inhibitors. The great benefits of nanoparticles are their potential, based on their specific properties, to be effective mechanisms that concentrate on the biological system and control various important functions. Among various therapeutic approaches, nanotechnology has emerged as a new strategy for treating different cancer types. This article attempts to demonstrate the huge potential for targeted nanoparticles and their molecular imaging applications. Notably, several nanoparticles have been developed and engineered to demonstrate antiangiogenic features. This nanomedicine could effectively treat a number of cancers using antiangiogenic therapies as an alternative approach. We also discuss the latest antiangiogenic and nanotherapeutic strategies and highlight tumor vessels and their microenvironments.     

Poly(lactide)/cellulose nanocrystal nanocomposites by high-shear mixing

There is currently considerable interest in developing stiff, strong, tough, and heat resistant poly(lactide) (PLA) based materials with improved melt elasticity in response to the increasing demand for sustainable plastics. However, simultaneous optimization of stiffness, strength, and toughness is a challenge for any material, and commercial PLA is well-known to be inherently brittle and temperature-sensitive and to show poor melt elasticity. In this study, we report that high-shear mixing with cellulose nanocrystals (CNC) leads to significant improvements in the toughness, heat resistance, and melt elasticity of PLA while further enhancing its already outstanding room temperature stiffness and strength. This is evidenced by (i) one-fold increase in the elastic modulus (6.48 GPa), (ii) 43% increase in the tensile strength (87.1 MPa), (iii) one-fold increase in the strain at break (∼6%), (iv) two-fold increase in the impact strength (44.2 kJ/m²), (v) 113-fold increase in the storage modulus at 90°C (787.8 MPa), and (vi) 10³-fold increase in the melt elasticity at 190°C and 1 rad/s (∼10⁵ Pa) via the addition of 30 wt% CNC. It is hence possible to produce industrially viable, stiff, strong, tough, and heat resistant green materials with improved melt elasticity through high-shear mixing.     

Protein Kinase C as a Therapeutic Target in Non-Small Cell Lung Cancer

Driver-directed therapeutics have revolutionized cancer treatment, presenting similar or better efficacy compared to traditional chemotherapy and substantially improving quality of life. Despite significant advances, targeted therapy is greatly limited by resistance acquisition, which emerges in nearly all patients receiving treatment. As a result, identifying the molecular modulators of resistance is of great interest. Recent work has implicated protein kinase C (PKC) isozymes as mediators of drug resistance in non-small cell lung cancer (NSCLC). Importantly, previous findings on PKC have implicated this family of enzymes in both tumor-promotive and tumor-suppressive biology in various tissues. Here, we review the biological role of PKC isozymes in NSCLC through extensive analysis of cell-line-based studies to better understand the rationale for PKC inhibition. PKC isoforms α, ε, η, ι, ζ upregulation has been reported in lung cancer, and overexpression correlates with worse prognosis in NSCLC patients. Most importantly, PKC isozymes have been established as mediators of resistance to tyrosine kinase inhibitors in NSCLC. Unfortunately, however, PKC-directed therapeutics have yielded unsatisfactory results, likely due to a lack of specific evaluation for PKC. To achieve satisfactory results in clinical trials, predictive biomarkers of PKC activity must be established and screened for prior to patient enrollment. Furthermore, tandem inhibition of PKC and molecular drivers may be a potential therapeutic strategy to prevent the emergence of resistance in NSCLC.     

Correction to: Two New Co(II) Complexes of Picolinate: Synthesis,Crystal Structure,Spectral Characterization, α-Glucosidase İnhibition and TD/DFT Study

Journal of Inorganic and Organometallic Polymers and Materials -