Aptitude of Graphene Oxide–Silver in Advance Polymer Nanocomposite: A Review

This is a state-of-the art overview on polymer/graphene oxide–silver nanoparticle nanocomposite. Different polymer/graphene oxide–silver nanoparticle categories have been elucidated using polyethersulfone, polyimides, polyindole, poly(vinylidene fluoride), polyaniline, polyvinyl pyrrolidone, and poly(3,4-ethylenedioxythiophene). In situ reduction of silver salt and particle decoration on graphene oxide surface were effective to develop interaction between nanoparticles. Essential features of polymer/graphene oxide–silver nanoparticle revealed several advance technical applications. Conducting polymer/graphene oxide–silver nanoparticle is promising material for sensor, supercapacitor, and electrodes. Polymer/graphene oxide–silver nanoparticle possesses relevance in cancer treatment, gene transfection, cellular probing, imaging, antibacterial action, etc. Polyimide/graphene oxide–silver nanoparticle can also effectively prevent membrane bifouling. Catalytic activity of composites was also detected toward oxygen reduction in energy devices.     

Using LaModel to analyze coal bumps

Coal bumps have long been a safety hazard in coal mines, and even after decades of research, the exact mechanics that cause coal bumps are still not well understood. Therefore, coal bumps are still difficult to predict and control. The LaModel program has a long history of being used to effectively analyze displacements and stresses in coal mines, and with the recent addition of energy release and local mine stiffness calculations, the LaModel program now has greatly increased capabilities for evaluating coal bump potential. This paper presents three recent case histories where coal stress, pillar safety factor, energy release rate and local mine stiffness calculations in LaModel were used to evaluate the pillar plan and cut sequencing that were associated with a number of bumps. The first case history is a longwall mine where a simple stress analysis was used to help determine the limiting depth for safely mining in bump-prone ground. The second case history is a room-and-pillar retreat mine where the LaModel analysis is used to help optimize the pillar extraction sequencing in order to minimize the frequent pillar line bumps. The third case history is the Crandall Canyon mine where an initial bump and then a massive pillar collapse/bump which killed 6 miners is extensively back-analyzed. In these case histories, the calculation tools in LaModel are ultimately shown to be very effective for analyzing various aspects of the bump problem, and in the conclusions, a number of critical insights into the practical calculation of mine failure and stability developed as a result of this research are presented.     

A Review Featuring Fabrication,Properties, and Application of Polymeric Mixed Matrix Membrane Reinforced with Different Fillers

Mixed matrix membrane is composed of polymer matrix reinforced with organic or inorganic particles to improve its performance. This review presents comprehensive study on fabrication, properties, and application of polymeric composite-based mixed matrix membrane. Inorganic fillers (silica, alumina, and zeolite) are extensively used in mixed matrix membrane due to low cost, abundance, and simplistic surface treatment. Organic fillers (graphene and carbon nanotube) are also preferred due to low specific gravity, and high thermal, flame, and chemical resistance. Reinforcement of these nanofiller during membrane provides flux enhancement and low fouling. Various applications of mixed matrix membrane such as in tissue engineering, catalysis, and electrochemistry have also been discussed.     

Progression from Polyimide to Polyimide Composite in Proton-Exchange Membrane Fuel Cell: A Review

This review is designed as a comprehensive source of research on polyimide and polyimide composite-based fuel cell membranes. Polyimide and modified polyimide-based nanocomposite fuel cell membranes have gained research attention due to high operation temperature of ～150°C. To increase the lifetime of polyimide-based fuel cell, water stability and dimensional stability of hydrated membrane have been studied. Nanofillers such as silica, titania, graphene, carbon nanotube, and polyhedral oligomeric silsesquioxane have been reinforced in polyimide to improve proton conductivity (at low humidity/high temperature) and water stability. Design of new polyimide composite membranes must be focused in future for high water, chemical, and mechanical stability.     

State-of-the-Art Overview on Polymer/POSS Nanocomposite

Research into polymer containing polyhedral oligomeric silsesquioxane has been expanded during the past years, enlightening new categories of polymer/polyhedral oligomeric silsesquioxane nanocomposite and unanticipated applications. These hybrids own superior structural and functional properties (strength, thermal stability, optical features, low toxicity, biocompatibility) due to nanometer size of polyhedral oligomeric silsesquioxane. The state of polyhedral oligomeric silsesquioxane-reinforced polymeric [poly(methyl methacrylate, poly(vinyl chloride), polyurethane, polyamide, epoxy, and poly(ethylene glycol)] systems are reviewed in this article. Physical blending, covalent bonding, and chemical cross-linking have been used to provide excellent reinforcement. A comprehensive coverage of various appliances of polymer/polyhedral oligomeric silsesquioxane nanocomposite has been given particularly aerospace, semiconducting material, biomedical, and textile industry.     

Emerging Research Trends in Polyurethane/Graphene Nanocomposite: A Review

Polyurethane is a versatile engineering material, which is usually synthesized by polyaddition of polyol, isocyanate, and chain extender. Graphene is a monolayer of carbon atoms packed into honeycomb structure with fascinating thermal, electrical, and mechanical properties. Among the rapidly expanding families of nanocomposite, polyurethane/graphene materials have attracted considerable attention in academia and industry. This article reviews essential aspects of graphene-reinforced polyurethane nanocomposite. Various strategies for fabricating polyurethane/graphene nanocomposite have been conversed. Recent developments in the field of polyurethane/graphene nanocomposite (as shape memory, adsorbent, electromagnetic interference shielding, and gas barrier materials), associated challenges, and future potential have been reviewed.     

Anticarcinogenecity of microbiota and probiotics in breast cancer

Breast cancer is one of the most important causes of cancer related morbidity and mortality in the world. Along with genetic, environmental factors also play a multifaceted role in the development of disease. Breast contains several bacterial species performing specialized functions. Probiotics, as functional food, play pivotal role against breast cancer development in vivo and in vitro. Current review summarized all the available data related to diet, probiotics, and their association with breast cancer risk along with underlying mechanisms. Presently, it was believed that many of the commercially available probiotic products were safe to use and had some beneficial health effects for the host. Probiotics had a potential to act against breast cancer progression evidenced by many animal model and cell-based experiments. Some probiotics strains may be useful as an adjuvant therapy for breast cancer prevention or treatment, by modulating immune response or breast microbial community. However, large-scale clinical trials and intense research are mandatory to explore probiotics-related metabolic and molecular mechanisms in breast cancer.     

Der f 38 Is a Novel TLR4-Binding Allergen Related to Allergy Pathogenesis from Dermatophagoides farinae

It is difficult to treat allergic diseases including asthma completely because its pathogenesis remains unclear. House dust mite (HDM) is a critical allergen and Toll-like receptor (TLR) 4 is a member of the toll-like receptor family, which plays an important role in allergic diseases. The purpose of this study was to characterize a novel allergen, Der f 38 binding to TLR4, and unveil its role as an inducer of allergy. Der f 38 expression was detected in the body and feces of Dermatophagoides farinae (DF). Electron microscopy revealed that it was located in the granule layer, the epithelium layer, and microvilli of the posterior midgut. The skin prick test showed that 60% of allergic subjects were Der f 38-positive. Der f 38 enhanced surface 203c expression in basophils of Der f 38-positive allergic subjects. By analysis of the model structure of Der p 38, the expected epitope sites are exposed on the exterior side. In animal experiments, Der f 38 triggered an infiltration of inflammatory cells. Intranasal (IN) administration of Der f 38 increased neutrophils in the lung. Intraperitoneal (IP) and IN injections of Der f 38 induced both eosinophils and neutrophils. Increased total IgE level and histopathological features were found in BALB/c mice treated with Der f 38 by IP and IN injections. TLR4 knockout (KO) BALB/c mice exhibited less inflammation and IgE level in the sera compared to wild type (WT) mice. Der f 38 directly binds to TLR4 using biolayer interferometry. Der f 38 suppressed the apoptosis of neutrophils and eosinophils by downregulating proteins in the proapoptotic pathway including caspase 9, caspase 3, and BAX and upregulating proteins in the anti-apoptotic pathway including BCL-2 and MCL-1. These findings might shed light on the pathogenic mechanisms of allergy to HDM.