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SiC particulate-reinforced SiC ceramic matrix composites (SiCp/SiC) were fabricated by a modified polymer infiltration and pyrolysis (PIP) process using spark plasma sintering (SPS). The effects of pyrolysis conditions, green density, and polymer infiltration method on the densification and properties of the SiCp/SiC were investigated. SiCp/SiC with high relative density up to 88.06 % was fabricated after 4 PIP cycles by adopting high green density of SiC pellet (76.5 %) provided from drying the high solid loaded (70 vol. %) SiC slurry and fast SPS pyrolysis. The highest hardness of 21.05 ± 2.4 GPa was achieved for the as-fabricated SiCp/SiC, and the hardness value increased up to 23.99 ± 1.8 GPa after heat treatment at 2000℃. The improvement was attributed to the thermally stable SiC fillers, and partial sintering between the fillers and precursor derived ceramics (PDC) matrix. The excellent mechanical property, thermal stability, and short processing time render the SiCp/SiC composite a challenging candidate for high-temperature application.

The effects of heating method on the pyrolysis behavior, crystallinity and ceramic yield of a SiC-based precursor-derived ceramic (PDC) were investigated using commercial allylhydrido-polycarbosilane (AHPCS) precursors, spark plasma sintering (SPS) apparatus and tube furnace. The heating rate of SPS was ten times faster than that of tube furnace. Consequently, the total time of precursor impregnation and pyrolysis (PIP) process decreased distinctly after several PIP cycles. PDCs fabricated by SPS had higher crystallinity than those prepared by tube furnace. The crystallinity of PDCs was 70.4 and 65.1 %, respectively, after the pyrolysis using SPS and tube furnace at 1400℃ for 1h. The highest crystallinity of 82.92 % was achieved after the pyrolysis at 1500℃ for 2h using SPS. The ceramic yield of the precursor was not strongly affected by the heating method. This study provides a promising method for the pyrolysis of ceramic precursors with short processing time and improved thermal stability.

Urea-based selective catalytic reduction (SCR) is a promising method for removing NOx emissions. In the urea-based SCR method, zeolite-based catalysts are popularly used owing to their applicability over a wide range of temperatures compared to other catalysts. However, they still have several drawbacks such as inferior performance at low temperatures and thermal instability. This has subsequently led to numerous studies and experiments on the development of superior catalysts. While substantial experimental data exist on zeolite-based catalysts, extracting useful information from the data with a simple literature search is difficult owing to not only the amount of data but also complex correlations between feature, including preparation variables such as doped-metal loading and operational variables such as reaction temperature. Recently, extracting insights from a large database has become possible by utilizing machine learning tools. Among them, the decision tree can extract insights on the synthesis of the catalysts as the results derived from the models are intuitive and easy to interpret, unlike those from conventional discriminant machine learning models. In this study, classification models are obtained by training decision tree models with literature data on zeolite-based urea SCR catalysts, particularly the Beta and ZSM-5 types, and several experimental heuristics are extracted from the derived models.

The residual carbon content of ultra-fine hafnium carbide (HfC) powder was controlled by the optimization of the synthesis process, and the effect of residual carbon on the densification of HfC powder was analyzed. The amount of residual carbon in the HfC powder could be reduced by the de-agglomeration of HfO2 powder before the carbo-thermal reduction (CTR) process. The average particle size of HfO2 powder decreased from 230 to 130 nm after the de-agglomeration treatment. Ultra-fine (d50: 110 nm) and highly pure (metal basis purity: >99.9 % except for Zr) HfC powder was obtained after the CTR at 1600 °C for 1 h using the C/Hf mixing ratio of 3.3. In contrast, the C/Hf ratio increased to 3.6 without the de-agglomeration treatment, indicating that a large amount of excess carbon was required for the complete reduction of the agglomerated HfO2 particles. HfC ceramics with high relative density (>98 %) were obtained after spark plasma sintering at 2000 °C under 80 MPa pressure when using the HfC powder with low excess carbon content. In contrast, the densification did not complete at a higher temperature (2300 °C) and pressure (100 MPa) when the HfC powder contained a large amount of residual carbon. The results clearly indicated that residual carbon suppressed the densification of HfC powder in case the carbide powder had low oxygen content, and the residual carbon content could be controlled by the optimization of the synthesis process. The average grain size and Vickers hardness of the sintered specimen were 6.7(±0.7) μm and 19.6 GPa, respectively.

Effects of polyethylene glycol (PEG) dispersant and pH on the dispersion behavior of aqueous SiC slurry were investigated. High solid loading up to 62 vol% with low viscosity (202 mPa s) was achieved using fine SiC powders prepared by mechanical alloying process with the average diameter of 152 nm. The property analysis of the slurry in terms of zeta potential, particle size, sedimentation, TG-DTA analysis, and rheological measurements indicated that the optimum pH value and dispersant content of the highly concentrated slurry were pH 9 and 0.4 wt%, respectively. A SiC green body with the relative density of 62.9% was made by drying 62 vol% SiC slurry in an drying oven at 80 °C. Crack formation did not occur during drying because of the high solid loading and consequent low shrinkage rate (0.097%). In contrast, those prepared by cold isostatic press (CIP) under 200 MPa had a lower relative density of 58.8%.

Pancreatic islet transplantation is an ultimate solution for treating patients with type 1 diabetes (T1D). The pig is an ideal donor of islets for replacing scarce human islets. Besides immunological hurdles, non-immunological hurdles including fragmentation and delayed engraftment of porcine islets need solutions to succeed in porcine islet xenotransplantation. In this study, we suggest a simple but effective modality, a cell/islet co-localizing composite, to overcome these challenges. Endothelial-like mesenchymal stem cells (EMSCs), differentiated from bone-marrow derived mouse mesenchymal stem cells (MSCs), and MSCs evenly coated the surface of porcine islets (>85%) through optimized culture conditions. Both MSCs and EMSCs significantly reduced the fragmentation of porcine islets and increased the islet masses, designated as islet equivalents (IEQs). In fibrin in vitro and in vivo angiogenesis analysis, constructed EMSC-islet composites showed higher angiogenic potentials than naked islets, MSC-islet composites, or human endothelial cell-islet composites. This novel delivery method of porcine islets may have beneficial effects on the engraftment of transplanted islets by prevention of fragmentation and enhancement of revascularization.

SUMOylation is a critical regulator of a broad range of cellular processes, and is thought to do so in part by modulation of protein interaction. To comprehensively identify human proteins whose interaction is modulated by SUMOylation, we developed an in vitro binding assay using human proteome microarrays to identify targets of SUMO1 and SUMO2. We then integrated these results with protein SUMOylation and protein-protein interaction data to perform network motif analysis. We focused on a single network motif we termed a SUMOmodPPI (SUMO-modulated Protein-Protein Interaction) that included the INO80 chromatin remodeling complex subunits TFPT and INO80E. We validated the SUMO-binding activity of INO80E, and showed that TFPT is a SUMO substrate both in vitro and in vivo. We then demonstrated a key role for SUMOylation in mediating the interaction between these two proteins, both in vitro and in vivo. By demonstrating a key role for SUMOylation in regulating the INO80 chromatin remodeling complex, this work illustrates the power of bioinformatics analysis of large data sets in predicting novel biological phenomena.

Despite the higher energy density than the conventional Li-ion cells at a lower cost, commercialization of LiS batteries is hindered by the insulating nature of sulfur and the dissolution of intermediate polysulfides (Li2SX, 4

Islet transplantation is one of the most beneficial treatment modality to treat type 1 diabetic patients with frequent hypoglycemic unawareness. In clinical setting, human islets are infused via portal vein and are settled in the end-portal venules in the liver. However, mouse islets are transplanted into kidney subcapsule or liver through direct portal vein. These conventional transplantation methods have several drawbacks such as different physiological environments around the transplanted islets in kidney subcapsule from the liver and high mortality rate in direct portal vein approach. In this study, we introduced murine intrahepatic islet transplantation method via cecal vein to have the same surgical operation route in humans as well as guaranteeing low mortality rate after islet transplantation. With this protocol, consistent normoglycemia can be obtained in diabetic mice, while keeping operation-related mortality extremely low. This approach with easier accessibility and low mortality will make murine intrahepatic islet transplantation a useful model for studying immunological mechanisms such as strong innate and adaptive immune responses that occur in human islet transplantation.

Pig islets are an alternative source for islet transplantation to treat type 1 diabetes (T1D), but reproducible curative potential in the pig-to-nonhuman primate (NHP) model has not been demonstrated. Here, we report that pig islet grafts survived and maintained normoglycemia for >6 months in four of five consecutive immunosuppressed NHPs. Pig islets were isolated from designated pathogen-free (DPF) miniature pigs and infused intraportally into streptozotocin-induced diabetic rhesus monkeys under pretreatment with cobra venom factor (CVF), anti-thymocyte globulin (ATG) induction and maintenance with anti-CD154 monoclonal antibody and low-dose sirolimus. Ex vivo expanded autologous regulatory T cells were adoptively transferred in three recipients. Blood glucose levels were promptly normalized in all five monkeys and normoglycemia (90-110 mg/dL) was maintained for >6 months in four cases, the longest currently up to 603 days. Intravenous glucose tolerance tests during the follow-up period showed excellent glucose disposal capacity and porcine C-peptide responses. Adoptive transfer of autologous regulatory T cells was likely to be associated with more stable and durable normoglycemia. Importantly, the recipients showed no serious adverse effects. Taken together, our results confirm the clinical feasibility of pig islet transplantation to treat T1D patients without the need for excessive immunosuppressive therapy.

Background Successful outcomes following high tibial osteotomy (HTO) require precise realignment of the mechanical axis of the lower extremity. The present study investigated whether the weight-bearing limb scanogram (WBS) technique provided a more accurate mechanical axis realignment than the navigation technique in open high tibial osteotomy (OHTO). Methods This prospective study involved 80 knees (78 patients) undergoing OHTO. The WBS technique was used in 40 knees and the navigation technique in 40 knees. Each technique was performed by a different surgeon in a different hospital. Postoperative coronal limb alignment was assessed using the weight-bearing line (WBL) ratio on full-length standing hip-to-ankle radiographs. Results We found that the mean postoperative WBL ratio was greater in the WBS compared to the navigation group ( p =0.001), and hence the ratio for the WBS group was closer to the ratio target of 62%. There was a greater proportion of WBL ratio outliers in the navigation group than the WBS group (25% vs. 10%, p =0.034). Conclusion We conclude that the WBS technique was more accurate than the navigation technique for restoration of coronal leg alignment in OHTO. Level of Evidence Level II.

Photocatalyst represents alternative solutions for renewable energy generation and environmental remediation. For photocatalytic applications, semiconductor nanomaterials emerge as important materials due to their unique structures, chemical and physical properties. Herein, we illustrate a brief overview of the recent progress in the development of hetero-structure nanomaterial based photocatalysts. Particularly, we focus our discussions on various dimensional (0D, 1D, 2D, and 3D) hetero-nanostructure of semiconductors to solve essential problems that are visible light absorption, fast charge separation, effective cocatalyst for charge utilization, and photoelectrochemical stability.

Nitric oxide (NO) mediates a substantial part of its physiologic functions via S-nitrosylation, however the cellular substrates for NO-mediated S-nitrosylation are largely unknown. Here we describe the S-nitrosoproteome using a high-density protein microarray chip containing 16,368 unique human proteins. We identified 834 potentially S-nitrosylated human proteins. Using a unique and highly specific labeling and affinity capture of S-nitrosylated proteins, 138 cysteine residues on 131 peptides in 95 proteins were determined, defining critical sites of NO's actions. Of these cysteine residues 113 are novel sites of S-nitrosylation. A consensus sequence motif from these 834 proteins for S-nitrosylation was identified, suggesting that the residues flanking the S-nitrosylated cysteine are likely to be the critical determinant of whether the cysteine is S-nitrosylated. We identify eight ubiquitin E3 ligases, RNF10, RNF11, RNF41, RNF141, RNF181, RNF208, WWP2, and UBE3A, whose activities are modulated by S-nitrosylation, providing a unique regulatory mechanism of the ubiquitin proteasome system. These results define a new and extensive set of proteins that are susceptible to NO regulation via S-nitrosylation. Similar approaches could be used to identify other post-translational modification proteomes.

Homogeneous Ru catalysts, [RuCl2(p-cymene)]2 (Ru-p-cymene) and (η5-C5Ph4O)2HRu2H(CO)4 (Shvo’s catalyst), were immobilized on phosphotungstic acid (PTA)-modified γ-alumina (Augustine’s method) and applied to the dynamic kinetic resolution (DKR) of 1-phenylethanol (1-PE) with an enzyme (Novozym 435®). The immobilized catalysts showed rates similar to those of homogeneous catalysts in conventional reaction conditions and the immobilized Shvo’s catalyst showed no leaching during reaction. The yield to the ester of the immobilized catalysts was found to be dependent on the solvent and alkali additive. When the DKR of 1-PE was performed in n-octane, the reaction proceeded well without an alkali additive over Ru-p-cymene, which is a new observation. Furthermore, the reaction yields with the immobilized catalysts were greater than those with the corresponding homogeneous catalysts at that condition. The main factors influencing the process carried out in the DKR mode over the Ru complexes are the solvent, the support, the alkali additive and the catalyst type. The effects of the reaction temperature, type of acyl donor and catalyst/enzyme amount were further investigated in order to find the optimum process condition of the DKR using immobilized catalysts without alkali additive in n-octane.

Ru-BINAP was immobilized on alumina using the well-known Augustine method with heteropoly acid (HPA) as the anchoring agent (“Augustine catalyst”). The supported catalyst was tested in a high-pressure reaction such as asymmetric hydrogenation of methyl acetoacetate (MAA). Since the activity of the supported catalyst was significantly lower than that of the homogeneous catalyst, the solvent used in preparing PTA/Al2O3 was changed from ethanol to a solution of HCl. The modified supported catalyst (“modified Augustine catalyst”) exhibited higher conversion, better selectivity, and improved enantioselectivity compared with the catalyst prepared by the Augustine method. The modified Augustine catalyst also produced β-hydroxyesters with good yield and enantioselectivity in asymmetric hydrogenation of various β-ketoester derivatives. The modified Augustine catalyst was examined by FT-IR, XRD, NH3-TPD, and ICP-AES, which revealed the existence of strong acid sites formed by HPA with a Keggin structure. These results were attributed to the effect of enhanced acidity on the modified Augustine catalyst.

In an effort to make use of high acid value oils for biodiesel production, various solid acid catalysts such as cesium-doped heteropoly tungstate (CsHPW), 20%TPW/ZrO2, 20%WO3/ZrO2, 20%TPW/γ-Al2O3, and 20%TPW/SiO2 were prepared and evaluated. Leaching of the active species from the catalyst during actual reaction conditions was also investigated to estimate the contribution of homogeneous catalysis. CsHPW was found to be highly active and most stable among other acid catalysts and a maximum conversion of 90% was obtained at the optimum reaction conditions. Further, the recycled use of the selected catalyst was also examined.

Very long and highly dispersible multi-walled carbon nanotube (MWCNT) bundles were synthesized in large quantity by catalytic chemical vapor deposition, and their structural and electrical properties were characterized. It was found that the MWCNTs could be synthesized with either bundled (long-aligned) or short-entangled structure depending on the catalyst system. The aligned MWCNTs were found to be more conductive and more dispersible than the entangled ones. The MWCNT/poly (methyl methacrylate) composites were prepared using both entangled and aligned MWCNTs. The aligned MWCNTs were found to give the composite higher electrical conductivity, which might be attributed to long length and high dispersibility. It was further found that the longer the MWCNT bundle, the higher electrical conductivity of the composite.

So-cheong-ryong-tang (SCRT) and Yeon-gyo-pae-dok-san (YPS) extracts are widely used in treatment of the common cold. The purpose of this study is to evaluate the efficacy of SCRT and YPS on the common cold.Four hundred eighty participants with symptoms of the common cold within 48 h were recruited for this randomized, double-blind, placebo-controlled trial. SCRT extract and YPS extract were put in gelatin capsules and orally administered 3 times a day. The pattern of participants was determined according to the Questionnaire for Common Cold Pattern Identification (QCCPI), and the severity of illness was assessed by Wisconsin Upper Respiratory Symptom Survey-21 Korean version (WURSS-21-K) every 7 days.The test and control groups were not significantly different in gender, age, smoking history, and baseline score of WURSS-21-K at the time of enrollment. SCRT treatment significantly decreased the total WURSS-21-K score on the 6th and 7th day (p0.05) of the enrollment compared with the placebo group. YPS treatment decreased the total WURSS-21-K score on the 5th and 6th day (p0.05 vs. the placebo group) of the enrollment. In the patients with Wind-cold pattern cold, SCRT significantly decreased the total WURSS-21-K score from 4th to 8th day (p0.05), and YPS significantly decreased the total WURSS-21-K score from 4th to 6th day (p0.05). For the Wind-heat pattern cold, neither SCRT nor YPS group showed significant difference from the placebo group. SCRT and YPS did not significantly decrease the time to complete resolution of the cold symptoms.SCRT and YPS have beneficial, albeit limited, effects on common cold patients, especially those with the Wind-cold pattern cold.

Reactive oxygen species (ROS) have recently emerged as critical second messengers in many signaling pathways, including those regulating cell proliferation, migration, differentiation, and gene expression. While much progress has been made in understanding the mechanisms by which ROS levels are modulated inside cells, less is known about the molecular signaling events that occur downstream of ROS generation. A growing body of evidence suggests that protein kinases are directly regulated by oxidation. Indeed, the reversible oxidation of specific Cys residues in redox-sensitive kinases has been shown to influence their activity (either positively or negatively), subcellular localization, and protein-protein interactions. Interestingly, in many cases, the redox-sensitive Cys is located in a region involved in substrate recognition, suggesting that oxidation may alter the substrate preference of a given kinase. To investigate this notion further, we used functional protein microarrays to examine the global substrate selection of several kinase family members under oxidized and reduced states. These studies, together with further biochemical analyses using model peptide substrates, suggest that oxidation leads to differential phosphorylation of many substrates such that distinct sets of substrates are targeted by the oxidized and reduced forms of the kinase. Importantly, in many cases, the redox sensitive Cys in the affected kinases is conserved among other members in the same kinase family. This raises the possibility that reversible oxidation may be a general means of regulating kinase function inside cells.

ZrO2 nanoparticles were prepared under high temperature and high pressure conditions by precipitation from metal nitrates with aqueous potassium hydroxide. The effects of synthesis parameters, such as the concentration of starting solution, pH of starting solution, reaction temperature and time, were discussed. The results show that the ZrO2 nanoparticles are obtained at 230−270 ℃. The average size and size distribution of the synthesized particles are below 10 nm and narrow, respectively. The XRD pattern shows that the synthesized particles are composed of crystalline. The synthesis of ZrO2 nanosized crystalline particles is possible under glycothermal conditions in ethylene glycol solution.