Proton conducting composite membranes from crosslinked poly(vinyl alcohol) and poly(styrene sulfonic acid)-functionalized silica nanoparticles

Proton conducting membranes based on crosslinked poly(vinyl alcohol) (PVA) and poly (styrene sulfonic acid)-functionalized silica particles (PSSA-Si) were reported. Two-step crosslinking process involving sulfosuccinic acid (SSA) and glutaraldehyde as crosslinking agents was conducted to provide additional proton source and to enhance hydrolytic and mechanical stabilities. PSSA-Si was synthesized from vinyltrimethoxysilane via Stöber method, followed by radical polymerization of sodium 4-vinylbenzenesulfonate on the silica particle. The obtained PSSA-Si was characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The effects of PSSA-Si loading (0, 2.5, 5, and 10%) and PSSA content in PSSA-Si (2, 5, 8, and 12%) on membrane properties including surface morphology, water vapor absorption, water uptake, ion exchange capacity, mechanical and oxidative stabilities, and proton conductivity were investigated and discussed. Proton conductivities of these composite membranes were found to increase with PSSA-Si loading and PSSA content. Promising proton conductivities of ～0.072 S/cm were obtained from PVA-8%PSSA-Si-10 and PVA-12%PSSA-Si-10 membranes, having PSSA-Si loading of 10%, and PSSA contents of 8%, and 12%, respectively. In addition, these membranes showed good hydrolytic and oxidative stabilities with high storage moduli.     

Role of PI3K-AKT-mTOR Pathway as a Pro-Survival Signaling and Resistance-Mediating Mechanism to Therapy of Prostate Cancer

Androgen deprivation therapy (ADT) and androgen receptor (AR)-targeted therapy are the gold standard options for treating prostate cancer (PCa). These are initially effective, as localized and the early stage of metastatic disease are androgen- and castration-sensitive. The tumor strongly relies on systemic/circulating androgens for activating AR signaling to stimulate growth and progression. However, after a certain point, the tumor will eventually develop a resistant stage, where ADT and AR antagonists are no longer effective. Mechanistically, it seems that the tumor becomes more aggressive through adaptive responses, relies more on alternative activated pathways, and is less dependent on AR signaling. This includes hyperactivation of PI3K-AKT-mTOR pathway, which is a central signal that regulates cell pro-survival/anti-apoptotic pathways, thus, compensating the blockade of AR signaling. The PI3K-AKT-mTOR pathway is well-documented for its crosstalk between genomic and non-genomic AR signaling, as well as other signaling cascades. Such a reciprocal feedback loop makes it more complicated to target individual factor/signaling for treating PCa. Here, we highlight the role of PI3K-AKT-mTOR signaling as a resistance mechanism for PCa therapy and illustrate the transition of prostate tumor from AR signaling-dependent to PI3K-AKT-mTOR pathway-dependent. Moreover, therapeutic strategies with inhibitors targeting the PI3K-AKT-mTOR signal used in clinic and ongoing clinical trials are discussed.     

Establishment of Human-Induced Pluripotent Stem Cell-Derived Neurons—A Promising In Vitro Model for a Molecular Study of Rabies Virus and Host Interaction

Rabies is a deadly viral disease caused by the rabies virus (RABV), transmitted through a bite of an infected host, resulting in irreversible neurological symptoms and a 100% fatality rate in humans. Despite many aspects describing rabies neuropathogenesis, numerous hypotheses remain unanswered and concealed. Observations obtained from infected primary neurons or mouse brain samples are more relevant to human clinical rabies than permissive cell lines; however, limitations regarding the ethical issue and sample accessibility become a hurdle for discovering new insights into virus–host interplays. To better understand RABV pathogenesis in humans, we generated human-induced pluripotent stem cell (hiPSC)-derived neurons to offer the opportunity for an inimitable study of RABV infection at a molecular level in a pathologically relevant cell type. This study describes the characteristics and detailed proteomic changes of hiPSC-derived neurons in response to RABV infection using LC-MS/MS quantitative analysis. Gene ontology (GO) enrichment of differentially expressed proteins (DEPs) reveals temporal changes of proteins related to metabolic process, immune response, neurotransmitter transport/synaptic vesicle cycle, cytoskeleton organization, and cell stress response, demonstrating fundamental underlying mechanisms of neuropathogenesis in a time-course dependence. Lastly, we highlighted plausible functions of heat shock cognate protein 70 (HSC70 or HSPA8) that might play a pivotal role in regulating RABV replication and pathogenesis. Our findings acquired from this hiPSC-derived neuron platform help to define novel cellular mechanisms during RABV infection, which could be applicable to further studies to widen views of RABV-host interaction.     

Effect of CaO–ZrO2 addition to Ni supported on γ-Al2O3 by sequential impregnation in steam methane reforming

Ni catalysts supported on (CaO–ZrO₂)-modified γ-Al₂O₃ were prepared by sequential impregnation. The effects of varied CaO to ZrO₂ mole ratios at 0, 0.20, 0.35, 0.45, and 0.55 on the activity and stability of the modified Ni catalysts were studied. As a result of using CaO–ZrO₂ as a promoter, each catalyst contained CaO–ZrO₂ at only 5%. γ-Al₂O₃ used as support was modified by CaO–ZrO₂ before the deposition of nickel oxide. The addition of CaO–ZrO₂ at an optimum ratio was expected to improve the stability of Ni catalysts due to the decrease of carbon formation resulting from carbon gasification. All the fresh catalysts were characterized by ICP, XRD, BET surface area, TGA in H₂, and TPR before catalytic testing in steam methane reforming at 600 °C. The spent catalysts were examined by TEM and TGA to observe the catalysts deactivation. The identification of CaO–ZrO₂ phases indicated that CaO and ZrO₂ reacted with each other to be monoclinic solid solution ZrO₂, CaZr₄O₉, CaZrO₃, and CaO corresponding to the phase diagram of CaO–ZrO₂. The existence of CaZrO₃ for 0.55 mol ratio of CaO/ZrO₂ enhanced activity in steam methane reforming because oxygen vacancies in CaZrO₃ greatly preferred the water adsorption creating the favorable conditions for carbon gasification and, then, water gas shift. The prominence and continued existence of these two reactions on the Ni catalysts leads to the particular increase of H₂ yield. Moreover, the increasing amount of CaZrO₃ in the Ni catalysts significantly improved carbon gasification. However, the Ni catalysts with CaZrO₃ showed whisker carbon after catalytic testing; this carbon specie has not been tolerated in steam methane reforming. Therefore, these results significantly differed from the hypothesis.     

Comparison of Odor and Taste of Commercial Brand Fish Sauces from East and South East Asian Countries

This study focused on the odor and taste components of 14 commercial brands of fish sauces from various Asian countries. Odor components were extracted by headspace monolithic material sorptive extraction techniques and analyzed by gas chromatography-mass spectrometry/olfactometry. The taste compounds were identified from the concentration of sodium chloride, free amino acids, minerals, and 5´-nucleotides. The sensory evaluation was carried out by 11 trained tasters. Seventy-nine different types of volatile compounds were identified, described, and quantified by concentration and odor active value. Acid groups were the dominant volatile compounds. Trimethylamine, butanoic acid, and 2-methyl butanoic acid produced odors described as rotten fish, ammonia, rancid butter, cheesy, sweet, and rancid. The concentration of salt contents was estimated at 21.30% (w/v). Aspartic and glutamic acids gave high taste values and nutrients produced the umami taste. Analysis showed that the various flavors obtained from the fish sauces resulted from differences in ingredients and production techniques.     

Prediction of later-age compressive strength of normal concrete based on the accelerated strength of concrete cured with microwave energy

Microwave energy can accelerate the hydration of cement, resulting in rapid strength development of concrete in an early period. In this paper, prediction of later-age compressive strength of normal concrete, made with rapid-hardening and ordinary Portland cement, based on the accelerated strength of concrete cured with microwave energy was investigated. To accelerate curing properly, the optimal microwave curing process for concrete was first determined and then was applied to concrete. The possible early ages for the strength prediction were found to be at 3.5 and 5.5 h for concrete made with rapid-hardening and ordinary Portland cement, respectively. For each cement type, a formula for the strength prediction was derived from the relationship between accelerated early-age strength of concrete cured with microwave energy and later-age strength of normally cured concrete. Predictions of strength at 7 days for concrete made with rapid-hardening Portland cement and 28 days of concrete made with ordinary Portland cement were within 15% agreement with actual test results.     

Nonlinear Reservoir Analysis with Risk-Benefit Objectives

ABSTRACT

The surrogate worth trade-off method has been extended to a quadratic programming optimization model and risk has been incorporated into the vector of objective functions which explicitly shows the decision maker the trade-offs between net benefits and increased reliability of the system or the trade-offs between competing reliabilities such as flood control and water supply. The approach is called the Nonlinear Risk-Benefit (NRB) Algorithm. The NRB Algorithm is applied to the Broken Bow Reservoir to illustrate the increased information made available by this approach.     

Thermostable and alkaline-tolerant cellulase-free xylanase produced by thermotolerant Streptomyces sp. Ab106

Cellulase-free xylanase was produced by Streptomyces sp. Ab106 using cane bagasse as the substrate at 55 degrees C. Its maximum activity was 13 IU without cellulase and mannanase activities. Its profiles were investigated. Its optimum temperature and pH were 60 degrees C and 6.0, respectively. More than 70% of its activity was remained at 60 degrees C at pH 9. This enzyme was quite stable and exhibited an active of more than 70% for 144 h at 60 degrees C, and of more than 80% for 144 h at 40 degrees C, pH 9. This thermo-tolerant and alkaline-tolerant xylanase can be used in the pulp bleaching process.     

Simple hydrothermal preparation of nanofibers from a natural ilmenite mineral

Titanate nanofibers were synthesized by a simple hydrothermal method using a natural ilmenite mineral as the starting material. The chemical composition, crystalline structure, shape, size, and specific surface area of the prepared samples were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and the Brunauer–Emmett–Teller analysis (BET). The crystalline structure of the as-synthesized nanofibers demonstrated a layered titanate form, H₂Ti_xO_2x+1. The length of the prepared nanofibers ranged from 2 to 7 μm with diameters ranging from 20 to 90 nm. The as-synthesized nanofibers were solids with BET surface areas of approximately 50 m²/g. This synthetic method provides a simple route for the fabrication of one-dimensional (1-D) nanostructured materials from a low-cost natural mineral.