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Mesenchymal stem cells (MSCs) regulate immune cell activity by expressing tumor necrosis factor-α (TNF-α)-stimulated gene 6 (TSG-6) in inflammatory environments; however, whether anti-inflammatory responses affect TSG-6 expression in MSCs is not well understood. Therefore, we investigated whether transforming growth factor-β (TGF-β) regulates TSG-6 expression in adipose tissue-derived stem cells (ASCs) and whether effective immunosuppression can be achieved using ASCs and TGF-β signaling inhibitor A83-01. TGF-β significantly decreased TSG-6 expression in ASCs, but A83-01 and the p38 inhibitor SB202190 significantly increased it. However, in septic C57BL/6 mice, A83-01 further reduced the survival rate of the lipopolysaccharide (LPS)-treated group and ASC transplantation did not improve the severity induced by LPS. ASC transplantation alleviated the severity of sepsis induced by LPS+A83-01. In co-culture of macrophages and ASCs, A83-01 decreased TSG-6 expression whereas A83-01 and SB202190 reduced Cox-2 and IDO-2 expression in ASCs. These results suggest that TSG-6 expression in ASCs can be regulated by high concentrations of pro-inflammatory cytokines in vitro and in vivo, and that A83-01 and SB202190 can reduce the expression of immunomodulators in ASCs. Therefore, our data suggest that co-treatment of ASCs with TGF-β or p38 inhibitors is not adequate to modulate inflammation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Critically ill surgical patients are susceptible to various postoperative complications, including acute kidney injury (AKI) and multiorgan distress syndrome (MODS). These complications intensify patient suffering and significantly increase morbidity and mortality rates. This study aimed to identify the biomarkers for predicting AKI and MODS in critically ill surgical patients. Materials and Methods: We prospectively enrolled critically ill surgical patients admitted to the intensive care unit via the emergency department between July 2022 and July 2023. A total of 83 patients were recruited, and their data were used to analyze MODS. Three patients who showed decreased creatinine clearance at the initial presentation were excluded from the analysis for AKI. Patient characteristics and laboratory parameters including white blood cell (WBC) count, neutrophil count, delta neutrophil index, urine and serum β2-microglobulin, and urine serum mitochondrial DNA copy number (mtDNAcn) were analyzed to determine the reliable biomarker to predict AKI and MODS. Results: The following parameters were independently correlated with MODS: systolic blood pressure (SBP), initial neutrophil count, and platelet count, according to a logistic regression model. The optimal cut-off values for SBP, initial neutrophil count, and platelet count were 113 mmHg (sensitivity 66.7%; specificity 73.9%), 8.65 (X3) (109/L) (sensitivity 72.2%; specificity 64.6%), and 195.0 (X3) (109/L) (sensitivity 66.7%; specificity 81.5%), respectively. According to the logistic regression model, diastolic blood pressure (DBP) and initial urine mtDNAcn were independently correlated with AKI. The optimal cut-off value for DBP and initial urine mtDNAcn were 68.5 mmHg (sensitivity 61.1%; specificity 79.5%) and 1225.6 copies/μL (sensitivity 55.6%; specificity 95.5%), respectively. Conclusions: SBP, initial neutrophil count, and platelet count were independent predictors of MODS in critically ill patients undergoing surgery. DBP and initial urine mtDNAcn levels were independent predictors of AKI in critically ill surgical patients. Large-scale multicenter prospective studies are needed to confirm our results. [ABSTRACT FROM AUTHOR]

Background: A simultaneous gene expression pattern of immune checkpoint molecules might exist in colorectal cancer. This hypothesis has rarely been tested in human in vivo samples. Objective: We investigated the gene expression patterns of immune checkpoint molecules in human colorectal cancer tissues using quantitative polymerase chain reaction (qPCR) with a focus on concurrent gene expression. Results: We included 14 females and 16 males with a mean age was 68.5 years. The mean number of all immune checkpoint molecules did not differ significantly between normal and tumor tissues. Histological grade 3 tumors were more common in the PDCD1-expressing group [3 (25.0%) vs. 0 (0%) (p = 0.042)]. All six and four immune checkpoint molecules were expressed in eight and three PDCD1-positive patients, respectively. Specifically, CD274 was expressed in 11 of 12 PDCD1-positive patients, while LAG3 and IDO1 were expressed simultaneously in all patients expressing CD274. Conclusion: Colorectal cancers more commonly express multiple immune checkpoint molecules simultaneously than single molecules. This suggests that blocking multiple immune checkpoint pathways may serve as a potential strategy for immunotherapy. [ABSTRACT FROM AUTHOR]

This study investigates the effects of organizational factors on firms' adoption and use of internal staffing strategies. In particular, we examine the different effects of firm- and branch-level factors on the adoption of internal development programs and the selection of entry-level employees. We find that firm-level factors, such as firm size and organizational prestige, are positively associated with the adoption of development programs. Branch-level factors, such as branch size and leverage ratio, are positively associated with entry-level hiring. This study offers new insight into the dynamics between different levels of organizational factors and their relationship with human resource management practices. [ABSTRACT FROM AUTHOR]

Multifocal intraocular lenses (MF-IOLs) are increasingly implanted as the need for good near- and intermediate-distance vision increases. Although retinal disease is known to be a relative contraindication for MF-IOL implantation, there are no detailed guidelines for MF-IOL implantation with respect to the type and severity of retinal diseases/statuses. In this study, because retinal diseases can affect the performance of MF-IOLs, we analyzed the opinions of 111 retinal specialists, who were members of the Korean Retina Society, on the implantation of diffractive MF-IOLs in eyes with 15 retinal diseases/statuses using a web-based survey. For each underlying condition, retinal specialists were asked to rate their approval regarding implantation of MF-IOLs on a scale from 1 (completely disapprove) to 7 (completely approve), under the assumption that there were no known contraindications except for a given retinal disease/status. As a result, retinal specialists disapproved MF-IOL implantation (median value of Likert score < 4) in the eyes with wet age-related macular degeneration, dry age-related macular degeneration with geographic atrophy, proliferative diabetic retinopathy, nonproliferative diabetic retinopathy with macular edema, previous macula-off retinal detachment, previous retinal vein occlusion, and epiretinal membrane, but the scores varied by disease/status. The factors that affected the specialists' opinions were the type of practice and the frequency of MF-IOL implantation (p = 0.013 and p = 0.021, respectively; one-way ANOVA). [ABSTRACT FROM AUTHOR]

Haeckel's recapitulation theory has been a controversial topic in evolutionary biology. However, we have seen some recent cases applying Haeckel's view to interpret the interspecific variation of prenatal ontogeny. To revisit the validity of Haeckel's recapitulation theory, we take bats that have undergone drastic morphological changes and possess a characteristic ecology as a case study. All members of Rhinolophoidea and Yangochiroptera can generate an ultrasonic pulse from the larynx to interpret surrounding objects (laryngeal echolocation) whereas Pteropodidae lacks such ability. It is known that the petrosal bone is particularly derived in shape and expanded in laryngeal echolocators. If Haeckel's recapitulation theory holds, the formation of this derived trait should occur later than those of other bones. Therefore, we compared the prenatal ossification timing of the petrosal in 15 bat species and five outgroup species. We found that the ossification of the petrosal is accelerated in laryngeal echolocators while it is the last bone to ossify in non‐laryngeal echolocating bats and non‐volant mammals, which runs counter to the prediction generated by Haeckel's recapitulation theory. We point out the evolutionarily labile nature of trait developmental timing and emphasize that Haeckel's recapitulation theory does not hold in many cases. We caution that generating predictions on ancestral conditions and evolutionary history leading from Haeckel's recapitulation theory is not well supported. Highlight: We found that the ossification of the petrosal is accelerated in laryngeal echolocators while it is the last bone to ossify in non‐laryngeal echolocating bats and non‐volant mammals, which runs counter to the prediction generated by Haeckel's recapitulation theory. [ABSTRACT FROM AUTHOR]

Skeletal muscle satellite cells (SkMSCs) play crucial roles in muscle fiber maintenance, repair, and remodeling; however, it remains unknown if these properties are preserved in cultured SkMSCs. In this study, we investigated the characteristics of cultured SkMSCs and their ability to regulate the activity of M1 macrophages. SkMSCs grew well with an average population doubling time of 26.26 ± 6.85 h during 10 passages (P). At P5, Pax7, MyoD, cluster of differentiation (CD)34, and CD56 were not expressed in SkMSCs, but the MSC markers CD73, CD105, and CD90 were expressed and the cells were differentiated into adipocytes and osteoblasts. When SkMSCs were cocultured with macrophages, interleukin (IL)‐1β secretion was decreased, prostaglandin (PG)E2 was produced in coculture, and cyclooxygenase‐2 protein was induced in an SkMSC‐dependent manner. Hepatocyte growth factor (HGF) was highly secreted by monocultured SkMSCs; interferon‐γ and lipopolysaccharide reduced its expression level. However, HGF expression recovered when SkMSCs and macrophages were cocultured. Although exogenous PGE2 upregulated macrophage pro‐IL‐1β expression, it suppressed the secretion of cleaved IL‐1β. In contrast, HGF decreased active IL‐1β secretion without affecting pro‐IL‐1β expression. Co‐treatment of macrophages with HGF and PGE2 reduced pro‐IL‐1β expression level and active IL‐1β secretion. Our results suggest that SkMSCs lose their satellite cell properties during serial passaging but acquire mesenchymal stem cell properties including the ability to exert an anti‐inflammatory response for macrophages through PGE2 and HGF. [ABSTRACT FROM AUTHOR]

Anatomy of bat genital organs has been conventionally studied by gross and microscopic observations to date. Here, we employ both histological observation and diceCT (diffusible iodine-based contrast-enhanced computed tomography) to study the detailed three-dimensional morphological structure of the male genital organs in bats, using the greater horseshoe bat, Rhinolophus ferrumequinum. This is the first study to three-dimensionally describe the whole reproductive organs of bats in detail. Our highly resolved three-dimensional reconstruction reveals that the male organs of R. ferrumequinum consist of paired testes, epididymides, deferent ducts, and five accessory genital glands. The boundary between the ampullary and vesicular glands has been difficult to identify in previous observations, but our diceCT imaging allowed us to clearly differentiate the two. We found that the ampullary gland is located at the terminal part of the deferent ducts, and the vesicular gland lies distal to the ampullary glands. This species possesses a single and carrot-shaped urethral gland, which is not found in most chiropteran families. The presence of the urethral gland in this species and its secretions suggest that after copulation this species is capable of forming a vaginal plug, which can seal the female's vaginal orifice to block the entrance of spermatozoa from other males. The presence of the urethral gland and elongated epididymal tail and the fact that some individuals can terminate their hibernation and reactivate imply forced copulation on hibernating females can occur in R. ferrumequinum. [ABSTRACT FROM AUTHOR]

Recent studies on neural network quantization have demonstrated a beneficial compromise between accuracy, computation rate, and architecture size. Implementing a 3D Vertical RRAM (VRRAM) array accompanied by device scaling may further improve such networks' density and energy consumption. Individual device design, optimized interconnects, and careful material selection are key factors determining the overall computation performance. In this work, the impact of replacing conventional devices with microfabricated, graphene-based VRRAM is investigated for circuit and algorithmic levels. By exploiting a sub-nm thin 2D material, the VRRAM array demonstrates an improved read/write margins and read inaccuracy level for the weighted-sum procedure. Moreover, energy consumption is significantly reduced in array programming operations. Finally, an XNOR logic-inspired architecture designed to integrate 1-bit ternary precision synaptic weights into graphene-based VRRAM is introduced. Simulations on VRRAM with metal and graphene word-planes demonstrate 83.5 and 94.1% recognition accuracy, respectively, denoting the importance of material innovation in neuromorphic computing. [ABSTRACT FROM AUTHOR]

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of dwarf rainbowfish (Melanotaenia praecox) belong to Melanotaeniidae using light and electron microscopes. The fertilized eggs were spherical with adhesive filament, transparent, demersal, and had a narrow perivitelline space and small oil droplets. The size of fertilized egg was 1.02 ± 0.18 mm (n = 30), and there were two kinds of adhesive filament on the fertilized eggs. The long and thick (diameter 12.22 ± 0.52 μm, n = 20) adhesive filaments were only at the area of animal pole, and short and thin (diameter 1.99 ± 0.23 μm, n = 20) adhesive filaments were around the long filaments. A micropyle was conical shaped with adhesive filament and located near the animal pole of egg. The outer surface of fertilized egg was rough side. Also, the total thickness of the fertilized egg envelope was about 7.46 ± 0.41 μm (n = 20), the fertilized egg envelope consisted of two layers, an inner lamellae layer and an outer layer with high electron-density. And the inner layer was 8 layers. Collectively, these morphological characteristics and adhesive property of fertilized egg with adhesive filaments, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity. [ABSTRACT FROM AUTHOR]

In this study, we examined the role of the eastern bent-winged bat (Miniopterus fuliginosus) in the dispersion of bat adenovirus and bat alphacoronavirus in east Asia, considering their gene flows and divergence times (based on deep-sequencing data), using bat fecal guano samples. Bats in China moved to Jeju Island and/or Taiwan in the last 20,000 years via the Korean Peninsula and/or Japan. The phylogenies of host mitochondrial D-loop DNA was not significantly congruent with those of bat adenovirus (m2XY = 0.07, p = 0.08), and bat alphacoronavirus (m2XY = 0.48, p = 0.20). We estimate that the first divergence time of bats carrying bat adenovirus in five caves studied (designated as K1, K2, JJ, N2, and F3) occurred approximately 3.17 million years ago. In contrast, the first divergence time of bat adenovirus among bats in the 5 caves was estimated to be approximately 224.32 years ago. The first divergence time of bats in caves CH, JJ, WY, N2, F1, F2, and F3 harboring bat alphacoronavirus was estimated to be 1.59 million years ago. The first divergence time of bat alphacoronavirus among the 7 caves was estimated to be approximately 2,596.92 years ago. The origin of bat adenovirus remains unclear, whereas our findings suggest that bat alphacoronavirus originated in Japan. Surprisingly, bat adenovirus and bat alphacoronavirus appeared to diverge substantially over the last 100 years, even though our gene-flow data indicate that the eastern bent-winged bat serves as an important natural reservoir of both viruses. [ABSTRACT FROM AUTHOR]

Background and Aim: There is no consensus regarding the safe resection margin in hepatocellular carcinoma (HCC). Several studies reported that different gross types require different resection margins. We investigated the changes in the tumor microenvironment (TME) in different gross types of HCC. Methods: We selected tumor tissue and normal tissue 1 and 2 cm away from the HCC. We analyzed the expression status of TME genes and the correlation between TME genes and the effective resection margin. We further divided the patients into two groups: group 1 included expanding and vaguely nodular types, whereas group 2 included nodular with perinodular extension, multinodular confluent, and infiltrative types. Results: Group 2 showed 27% and 45% 5‐year disease‐free survival (DFS) and overall survival (OS) rates, respectively. Group 2 was a significant prognostic factor for DFS and OS. In cases with a resection margin of less than 1 cm or more than 2 cm, there were no differences in recurrence and survival rate between the two groups. Group 1 patients who had a resection margin that ranged from 1 to 2 cm showed significantly better DFS and OS rates. β‐Catenin and matrix metalloproteinase 9 expression was significantly decreased and that of E‐cadherin was significantly increased according to the resection margin in group 1. Conclusions: Patients with expanding and vaguely nodular HCC may safely undergo surgical resection with a narrow resection margin, and patients with the other gross types must undergo surgical resection with more than a 2‐cm resection margin because of their TME conditions. [ABSTRACT FROM AUTHOR]

To better understand the genetic relatedness of the eastern bent-wing bat Miniopterus fuliginosus across East Asia, mitochondrial D-loop sequences were analyzed from 39 M. fuliginosus individuals living on Jeju Island, South Korea. Seven different haplotypes were identified. Neighbor-joining analysis was performed and divergence time was calculated in combination with available online data on D-loop and ND2 sequences of M. fuliginosus in East Asia, respectively. Results suggest that M. fuliginosus populations living on Jeju Island and in Japan originated from China in the past 20,000 years. [ABSTRACT FROM AUTHOR]

In teleost, the structural characteristics of fertilized egg and egg envelope are very important for classification of genus or species. The structures of fertilized egg and egg envelope from Corydoras adolfoi and Corydoras sterbai, Callichthyidae, Siluriformes in teleost were examined by scanning and transmission electron microscopes to confirm whether these morphological structures have specificities of species and family or not. The fertilized eggs of C. adolfoi and C. sterbai were non‐transparent, spherical, demersal, and strong adhesive. There were no structural differences between two species through the light microscope. The size of the fertilized eggs of C. adolfoi was 1.95 ± 0.03 mm (n = 20), and that of C. sterbai was 1.92 ± 0.03 mm (n = 20). The perivitelline space was almost not developed in both species. In both species, the adhesive protuberances structures were on the outer surface of egg envelope. And fibrous structures were specially located at attachment part of spawning bed. And the egg envelope consisted of two layers, an inner lamellae layer and an outer strong adhesive layer with high electron dense protuberances structures in cross section. Consequentially, the fertilized eggs, outer surface on the egg envelope and cross section of egg envelope have identical structure. So, these structural characteristics of fertilized eggs and egg envelope show genus Corydoras specificity. In teleost, the structural characteristics of fertilized egg and egg envelope are very important for classification of genus or species. The external shapes of fertilized egg, ultrastuctures of fertilized egg envelope have same structure including data on the one species of other research before. So we suggest that these morphological characteristics of fertilized egg and fertilized egg envelope show genus Corydoras specificity. [ABSTRACT FROM AUTHOR]

Objective: Malnutrition is very complex in patients with end-stage renal disease (ESRD) and is associated with poor prognosis. This is because hemodynamic changes, hormonal changes, persistent inflammatory reactions, and fluid overloads are more complicated as uremia is worsening. Bio-impedance spectroscopy (BIS) is a useful method to estimate fluid balance (Overhydration/ extracellular water, OH/ECW) and nutritional status (Phase angle, PhA). We aimed to evaluate the volume and nutritional status by BIS and to investigate the relationship between the appetite regulating hormones and the parameters of BIS in patients with stage 5 chronic kidney disease not undergoing dialysis (CKD5-ND). Methods: We enrolled a total of 91 CKD5-ND patients. We measured routine serum markers including albumin and NT-proBNP and the appetite regulating hormones, leptin and ghrelin. We defined poor nutritional status as a PhA < 4.5°, and proper nutritional status as a PhA ≥ 4.5°. We also evaluated each patient’s nutritional status by assessing their geriatric nutritional risk index (GNRI) and their volume status by measuring NT-proBNP. Results: Forty-one patients (45%) had poor nutritional status. Patients with a poor nutritional status had significantly higher OH/ECW (29.6 ± 12.7% vs. 6.2 ± 10.3%, p<0.001) and lower levels of leptin (3.8 ± 3.1 vs. 7.0 ± 6.2 ng/mL, p = 0.004) than those with proper nutritional status. PhA was associated with GNRI (r = 0.597, P<0.001) and NT-proBNP was associated with OH/ECW (r = 0.384, P<0.001). Leptin was negatively correlated with OH/ECW (r = -0.288, p = 0.006). In contrast, leptin was positively correlated with PhA (r = 0.263, p = 0.012). In multivariate logistic regression, high level of leptin (OR 7.00, 95% CI 1.74–28.10) was associated with proper nutrition, while an increased OH/ECW (OR 0.65, 95% CI 0.51–0.84) was associated with poor nutrition. Conclusions: Our study demonstrates that CKD5-ND patients with poor nutrition generally also suffer from excessive body fluid. Low leptin level suggests poor nutrition in CKD5-ND patients. PhA could be used as a nutritional index for ESRD patients. [ABSTRACT FROM AUTHOR]

In this study, crosslinked sulfonated poly(ether ether ketone) (SPEEK) membranes containing various amounts of zirconium phosphate (ZrP) particles were fabricated using an electron beam irradiation method. The water uptake and IEC value of the crosslinked SPEEK/ZrP hybrid membranes were higher than those of crosslinked SPEEK membranes and increased with an increase in ZrP content. Furthermore, under high temperature and low humidity conditions (120°C and RH 35%), the crosslinked SPEEK/ZrP hybrid membrane exhibited a higher proton conductivity (1.41 × 10−3 S/cm) compared with the crosslinked SPEEK membrane (1.13 × 10−4 S/cm). POLYM. COMPOS., 39:1905–1912, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Emerging non-volatile memory technologies are promising due to their anticipated capacity benefits, non-volatility, and zero idle energy. One of the most promising candidates is resistive random access memory (RRAM) based on resistive switching (RS). This paper reviews the development of RS device technology including the fundamental physics, material engineering, three-dimension (3D) integration, and bottom-up fabrication. The device operation, physical mechanisms for resistive switching, reliability metrics, and memory cell selector candidates are summarized from the recent advancement in both industry and academia. Options for 3D memory array architectures are presented for the mass storage application. Finally, the potential application of bottom-up fabrication approaches for effective manufacturing is introduced. [ABSTRACT FROM AUTHOR]

ABSTRACT Crosslinked sulfonated poly(ether ether ketone) (SPEEK) membranes were prepared through the electron beam (EB)-irradiation crosslinking of SPEEK/1,4-butanediol under various irradiation conditions and used as a proton exchange membrane (PEM) for fuel cell applications. The crosslinked membranes were characterized by gel fraction, a universal testing machine (UTM), dynamic mechanical analysis (DMA), and small-angle X-ray scattering (SAXS). The gel fraction of the crosslinked membranes was used to estimate the degree of crosslinking, and the gel fraction was found to be increased with an increase of the crosslinker content and EB-absorbed dose. The UTM results indicate that a brittle EB-crosslinked membrane becomes more flexible with an increase in the crosslinker content. The DMA results show that the EB-crosslinked membranes have well-developed ionic aggregation regions and the cluster Tg of membranes decrease with an increase in the 1,4-butanediol crosslinker content. The SAXS results show that the Bragg and persistence distance of crosslinked membranes increase with an increase in the crosslinker content. The proton conductivities of the EB-crosslinked membranes were more than 9 × 10−2 S/cm. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41760. [ABSTRACT FROM AUTHOR]

Highly cross-linked poly(styrene sulfonic acid)-grafted poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA-g-PSSA) membranes with various thicknesses have been successfully prepared through the simultaneous irradiation grafting of styrene/divinylbenzene (DVB) onto PFA films with thicknesses of 25, 50, and 100 μm followed by sulfonation to introduce sulfonic acid moiety. It was observed that a concentrated chlorosulfonic acid solution and a high reaction temperature are needed to provide sufficient sulfonic acid as the thickness of the PFA films and the content of DVB both increase. The physicochemical properties of the prepared membranes such as water uptake, proton conductivity, methanol permeability, and chemical stability, were also investigated in this study. [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of the degree of grafting (DOG) on the thermal behavior of poly(vinylbenzyl chloride)-grafted poly(ethylene- co-tetrafluoroethylene) (ETFE- g-PVBC) films was investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), dynamic mechanical analysis (DMA), FT-IR, and thermogravimetric analysis (TGA) instruments. Several ETFE- g-PVBC films with various degrees of grafting, including 10, 24, 41, 60, and 94%, were prepared using a radiation grafting technique. The DSC and XRD results of the ETFE- g-PVBC films revealed that the crystallinity of the films decreased as the DOG increased. The DMA and FT-IR results of the films indicated that a crosslinking reaction occurred at temperatures above 250 °C. In the thermal properties of the grafted films, an increase in the DOG led to an increase in the decomposition temperature. The activation energy ( Ea) of the thermal decomposition was calculated using Kissinger's equation from TGA results. The Ea value of the PVBC graft chain was found to increase as the DOG increased, indicating that the crosslinking reaction of ETFE- g-PVBC films increased with an increase in the DOG during the thermal degradation process. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 517-525 [ABSTRACT FROM AUTHOR]

We report the synthesis of a new fuel cell membrane, poly((vinyloxy)ethanesulfonic acid)-grafted poly(ethylene- co-tetrafluoroethylene) (ETFE) film by simultaneous radiation grafting of 2-chloroethyl vinyl ether onto ETFE film followed by sulfonation. The effects of various irradiation conditions such as the solvents, dose rate, and monomer concentration on the degree of grafting were investigated in detail. The sulfonation procedure of the grafted ETFE films used to replace the chlorine group with a sulfonic acid group includes the following steps. The first step is the formation of thiouronium salt with thiourea, the second step is the hydrolysis with NaOH to form thiol, and the final step is an oxidation of thiol using hydrogen peroxide to achieve the desired sulfonic acid group. Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) instruments were used to confirm the chemical reaction at every step of the process. In addition, the thermal degradation behaviors of the original ETFE film, grafted ETFE film, and sulfonated membrane were investigated by thermogravimetric analysis. To elucidate the possible applications of poly((vinyloxy)ethanesulfonic acid)-grafted ETFE membranes for direct methanol fuel cells, ion exchange capacity, water uptake, proton conductivity, and methanol permeability were investigated and compared with Nafion 212. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

To fabricate silane-crosslinked oraganic/inorganic hybrid proton exchange membranes (PEMs), poly(styrene sulfonic acid- co-(trimethoxysilyl)propyl methacrylate (TMSPM))-grafted ethylene- alt-tetrafluoroethylene (ETFE) membranes (ETFE- g-PSSA/PTMSPM) were prepared by a simultaneous irradiation grafting of various compositions of binary monomers (styrene and TMSPM) onto ETFE film and followed by hydrolysis-condensation and sulfonation to provide crosslinked structures and proton conducting ability, respectively. The effects of the individual degree of grafting of each graft polymer component on the chemical, physical, and morphological properties of the prepared PEMs, were also investigated. The results indicate that the silane-crosslinked PEM prepared with the monomers composition (Styrene (St)/TMSPM=5/5, v/v) has not only a lower water uptake but also a high proton conductivity, compared to those of ETFE- g-PSSA with similar ion exchange capacities (IEC). The silane-crosslinked PEM with 35% of the degree of grafting for PTMSPM were also found to have an improved chemical stability. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Commercial Victrex® poly(ether ether ketone) was dissolved and sulfonated using sulfonic acid at an elevated temperature of 55-70 °C. Various techniques such as thermogravimetric analysis, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and small-angle X-ray scattering (SAXS) were employed to investigate the mechanical properties and morphology of sulfonated poly(ether ether ketone) (SPEEK) film. Sulfonation temperatures were shown to have a direct effect on the degree of sulfonation. The DMA study showed that well-developed α-relaxation peaks related to chain relaxation in the ionic regions shifted to higher temperatures as sulfonation degree increased. However, the β- and γ-relaxation peaks showed that the peaks related to chain relaxation in the crystalline regions shifted to lower temperatures as sulfonation degree increased. These DMA results suggest that the sulfonic acid groups act as very effective plasticizers for the intercrystalline regions. DSC thermograms showed that the glass transition shifted systematically to higher temperatures as the sulfonation degree increased. In the SAXS study, an ionic domain peak was observed and the peak position shifted to a slightly higher angle as sulfonation degree increased, implying that the number of ionic aggregates increased. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

RNA interference (RNAi) is a powerful tool used to produce post-translational gene silencing in a sequence-dependent manner. However, sequence-independent activation of interferon systems induced by double-stranded RNA can interfere with the data interpretation of RNAi experiments. In this study, we observed cytokine activation and cytotoxicity caused by small interfering RNA (siRNA) in human umbilical vein endothelial cells (HUVECs). Transfection with different sequences of siRNAs (21-nucleotides) induced apoptosis in HUVECs within 24 hours, in a dose-dependent and sequence-independent manner. These effects could not be achieved by the application of transfection agents nor by siRNA only. In HUVECs, the expression of toll-like receptor 3 (TLR3), a receptor for double-stranded RNA, was significantly increased by the transfection with siRNAs regardless of their sequences. The expressions of interleukin 6, interleukin 8, and interferon-β were also up-regulated by siRNA transfection. The activation of RNA-dependent protein kinase (PKR) peaked within 30 min and slowly decreased 4 hours after transfection with siRNA, which was followed by the phosphorylation of eukaryotic initiation factor 2α(eIF2α). These studies suggest that transfection with double-stranded oligonucleotides in HUVECs shows sequence-independent apoptotic effects associated with the upregulation of TLR3 and cytokines, which should be considered when designing experiments using RNAi. [ABSTRACT FROM AUTHOR]

Microporous poly(vinylidenefluoride- co-hexafluoropropylene) (PVDF-HFP)/poly(methyl methacryate) (PMMA)-coated polyethylene (PE) separators were prepared by a simple dip-coating process with various compositions of PVDF-HFP/PMMA mixture under 40% relative humidity condition. The results indicate that the porosity, liquid electrolyte uptake, and ionic conductivity of the coated separators are largely affected by a ratio of PVDF-HFP/PMMA mixture and the highest porosity, electrolyte uptake, and ionic conductivity can be achieved at a composition of PVDF-HFP/PMMA (5/5). The results of the cell performance tests also reveal that the PE separator coated with PVDF-HFP/PMMA in a ratio of 5:5 provides better rate capability and cycle stability than other PE separators coated with different ratios. [ABSTRACT FROM AUTHOR]

Crosslinked sulfonated poly(ether ether ketone) (SPEEK) membranes were prepared by the radiation crosslinking of SPEEK with various crosslinker contents. The prepared membranes were subjected to a comparative study of proton exchange membranes (PEM) for fuel cell applications. The crosslinked SPEEK membranes were characterized by H nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), dynamic mechanical analysis (DMA), and Small angle X-ray scattering (SAXS). H NMR and FTIR-ATR confirmed the sulfonation and crosslinking of the membranes. DMA indicated that the ionic modulus and cluster T increased with decreasing crosslinker content. This suggests that the amount of clustering in the crosslinked membrane could be reduced by increasing the crosslinker content. SAXS data showed that the crosslinker did not affect the ionic domain morphology in the membranes. The proton conductivity of all the membranes was > 10 S/cm. The overall findings suggest that the crosslinked SPEEK membranes offer the possibility for improving the performance of proton exchange membrane fuel cell (PEMFC), provided membranes with thermal and hydration stability. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Growth of Escherichia coli in the presence of glyphosate, an inhibitor of aromatic amino acid biosynthesis, has permitted the production of proton-dislocating ATPase that is specifically labeled with 5-fluorotryptophan. Five sets of 19F resonances could be assigned to each tryptophan residue by lauryldimethylamine oxide and carboxypeptidase treatment. On labeling with 4-chloro-7-nitro-benzofurazan, the label attached to β155Lys, which is known to be in the catalytic site, which caused one of the residues, β108Trp, to become nonequivalent. 19F NMR spectroscopic investigation of internally fluorotryptophan-labeled F1-ATPase will provide valuable information about the asymmetric nature of F1-ATPase and the conformational changes induced by ligand binding. [ABSTRACT FROM AUTHOR]

This letter presents the novel CMOS-compatible all-metal-nitride resistive random access memory (RRAM) devices based on the TiN/AlN/TiN stack. The device has low operation current <100 \mu A, retention of > 3\times 10^{5} s at 150 °C, and ac endurance of up to 10^{5}$ Hz. The device switch characteristics are found to agree with the filamentary switch mechanism. In addition, the RRAM devices built with an additional hafnium nitride capping layer have showed less switch voltage variations and stable switch characteristics. [ABSTRACT FROM PUBLISHER]

In this letter, we examine the role of the Ti capping layer in HfOx-based resistive random access memory (RRAM) devices on the memory performance. It is found that with a thicker Ti capping layer, the fresh device initial leakage current increases and as a result, the forming voltage decreases. In addition, with a thin Ti layer of <3 nm (on top of 8-nm HfOx), there is no resistive switching, while by inserting a thicker Ti layer of 10 nm, the memory window enlarges to about two orders. Very good uniformity has also been observed in thick Ti capping devices, demonstrating the effectiveness in RRAM device engineering. It is believed that the Ti layer serves as an oxygen reservoir, by extracting oxygen during device formation and electrical forming process and facilitates resistive switching thereafter. [ABSTRACT FROM AUTHOR]