Synthesis of Room Temperature Curable Polymer Binder Mixed with Polymethyl Methacrylate and Urethane Acrylate for High-Strength and Improved Transparency.

Urethane acrylate (UA) was synthesized from various di-polyols, such as poly(tetrahydrofuran) (PTMG, Mn = 1000), poly(ethylene glycol) (PEG, Mn = 1000), and poly(propylene glycol) (PPG, Mn = 1000), for use as a polymer binder for paint. Polymethyl methacrylate (PMMA) and UA were blended to form an acrylic resin with high transmittance and stress-strain curve. When PMMA was blended with UA, a network structure was formed due to physical entanglement between the two polymers, increasing the mechanical properties. UA was synthesized by forming a prepolymer using di-polyol and hexamethylene diisocyanate, which were chain structure monomers, and capping them with 2-hydroxyethyl methacrylate to provide an acryl group. Fourier transform infrared spectroscopy was used to observe the changes in functional groups, and gel permeation chromatography was used to confirm that the three series showed similar molecular weight and PDI values. The yellowing phenomenon that appears mainly in the curing reaction of the polymer binder was solved, and the mechanical properties according to the effects of the polyol used in the main chain were compared. The content of the blended UA was quantified using ultravioletvisible spectroscopy at a wavelength of 370 nm based on 5, 10, 15, and 20 wt%, and the shear strength and tensile strength were evaluated using specimens in a suitable mode. The ratio for producing the polymer binder was optimized. The mechanical properties of the polymer binder with 5-10 wt% UA were improved in all series.

Polytypic Two-Dimensional FeAs with High Anisotropy.

In the realm of two-dimensional (2D) crystal growth, the chemical composition often determines the thermodynamically favored crystallographic structures. This relationship poses a challenge in synthesizing novel 2D crystals without altering their chemical elements, resulting in the rarity of achieving specific crystallographic symmetries or lattice parameters. We present 2D polymorphic FeAs crystals that completely differ from bulk orthorhombic FeAs (Pnma), differing in the stacking sequence, i.e., polytypes. Preparing polytypic FeAs outlines a strategy for independently controlling each symmetry operator, which includes the mirror plane for 2Q-FeAs (I4/mmm) and the glide plane for 1Q-FeAs (P4/nmm). As such, compared to bulk FeAs, polytypic 2D FeAs shows highly anisotropic properties such as electrical conductivity, Young's modulus, and friction coefficient. This work represents a concept of expanding 2D crystal libraries with a given chemical composition but various crystal symmetries.

Nontypical Wulff-Shape Silicon Nanosheets with High Catalytic Activity.

Nanostructured silicon with an equilibrium shape has exhibited hydrogen evolution reaction activity mainly owing to its high surface area, which is distinct from that of bulk silicon. Such a Wulff shape of silicon favors low-surface-energy planes, resulting in silicon being an anisotropic and predictably faceted solid in which certain planes are favored, but this limits further improvement of the catalytic activity. Here, we introduce nanoporous silicon nanosheets that possess high-surface-energy crystal planes, leading to an unconventional Wulff shape that bolsters the catalytic activity. The high-index plane, uncommonly seen in the Wulff shape of bulk Si, has a band structure optimally aligned with the redox potential necessary for hydrogen generation, resulting in an apparent quantum yield (AQY) of 12.1% at a 400 nm wavelength. The enhanced light absorption in nanoporous silicon nanosheets also contributes to the high photocatalytic activity. Collectively, the strategy of making crystals with nontypical Wulff shapes can provide a route toward various classes of photocatalysts for hydrogen production.

Synthesis of a Room-Temperature Curable Acrylic-Urethane Polymer Binder for Road Markings with High Transmittance.

Triol acrylic-urethane (t-AU) was synthesized from an addition reaction using trimethylolpropane, hexamethylene diisocyanate, and 2-hydroxyethyl methacrylate. The novel acrylic-urethane polymer was applied to a high-performance binder to prepare a reliable road marking paint. Acrylic-urethane polymer binder formulations were designed to optimize the effect of t-AU on the physical properties. The t-AU content in the formulation affected the adhesion and optical properties. The improvement in the adhesive performance and transparency ability for road markings was attributed to the optimal chemical structure or design of the acrylic-urethane polymer. The synthesis of t-AU was confirmed by Fourier transform infrared spectroscopy, and molecular weight and polydispersity index (PDI; PDI = Mw/Mn) measurements. The tensile and shear strength, hardness, gel fraction, crosslink density, contact angle, and transmittance of the acrylic-urethane polymer binder (AUP) were evaluated by curing at room temperature using a redox initiator system. An optimized AUP by adding 5 wt.% t-AU provides a viable alternative to high-performance binders in road marking paints.

Commensal Microbiota and Cancer Immunotherapy: Harnessing Commensal Bacteria for Cancer Therapy.

Cancer is one of the leading causes of death worldwide and the number of cancer patients is expected to continuously increase in the future. Traditional cancer therapies focus on inhibiting cancer growth while largely ignoring the contribution of the immune system in eliminating cancer cells. Recently, better understanding of immunological mechanisms pertaining to cancer progress has led to development of several immunotherapies, which revolutionized cancer treatment. Nonetheless, only a small proportion of cancer patients respond to immunotherapy and maintain a durable response. Among multiple factors contributing to the variability of immunotherapy response rates, commensal microbiota inhabiting patients have been identified as one of the most critical factors determining the success of immunotherapy. The functional diversity of microbiota differentially affects the host immune system and controls the efficacy of immunotherapy in individual cancer patients. Moreover, clinical studies have demonstrated that changing the gut microbiota composition by fecal microbiota transplantation in patients who failed a previous immunotherapy converts them to responders of the same therapy. Consequently, both academic and industrial researchers are putting extensive efforts to identify and develop specific bacteria or bacteria mixtures for cancer immunotherapy. In this review, we will summarize the immunological roles of commensal microbiota in cancer treatment and give specific examples of bacteria that show anticancer effect when administered as a monotherapy or as an adjuvant agent for immunotherapy. We will also list ongoing clinical trials testing the anticancer effect of commensal bacteria.

Transparency- and Repellency-Enhanced Acrylic-Based Binder for Stimuli-Responsive Road Paint Safety Improvement Technology.

In the current study, an acrylic polymer binder applicable to road signs was successfully developed by mixing various acrylic, acrylate-type, and photoinitiator-based monomer species at different acrylate series/silicone acrylate ratios. An amorphous acrylic monomer was used, and the distance between the polymers was increased to improve transparency. The binder was designed with the purpose of reducing the yellowing phenomenon due to resonance by excluding the aromatic ring structure, which is the main cause of yellowing. The optical properties of the binder were determined according to the content of n-butyl methacrylate/methyl methacrylate and the composition of the crosslinking agent in the formulation. Allyl glycidyl ether and dilauroyl peroxide were used to improve the yellowing problem of benzoyl peroxide, an aromatic photoinitiator. Adding a silicone-based trivalent acrylic monomer, 3-(trimethoxysilyl)propyl methacrylate (TMSPMA), was also found to have a significant effect on the transparency, shear properties, and water resistance of the binder. When 15 wt% TMSPMA was added, the best water repellency and mechanical properties were exhibited. The surface morphology of the improved binder and the peeling part were confirmed using field emission scanning electron microscopy. The acrylic polymer developed in this study can be applied in the coating and adhesive industries.

Kinetic 2D Crystals via Topochemical Approach.

The designing of novel materials is a fascinating and innovative pathway in materials science. Particularly, novel layered compounds have tremendous influence in various research fields. Advanced fundamental studies covering various aspects, including reactants and synthetic methods, are required to obtain novel layered materials with unique physical and chemical properties. Among the promising synthetic techniques, topochemical approaches have afforded the platform for widening the extent of novel 2D materials. Notably, the synthesis of binary layered materials is considered as a major scientific breakthrough after the synthesis of graphene as they exhibit a wide spectrum of material properties with varied potential applicability. In this review, a comprehensive overview of the progress in the development of metastable layered compounds is presented. The various metastable layered compounds synthesized from layered ternary bulk materials through topochemical approaches are listed, followed by the descriptions of their mechanisms, structural analyses, characterizations, and potential applications. Finally, an essential research direction concerning the synthesis of new materials is indicated, wherein the possible application of topochemical approaches in unprecedented areas is explored.

Highly Flexible and Photo-Activating Acryl-Polyurethane for 3D Steric Architectures.

An acryl-functionalized polyurethane (PU) series was successfully synthesized using poly(tetramethylene ether) glycol-methylene diphenyl diisocyanate (PTMG-MDI) oligomer based on urethane methacrylates to control the flexibility of photo-cured 3D printing architectures. The mass ratio of acryl-urethane prepolymer: 1,4-butanediol (BD) chain-extender: diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) photoinitiator was 10:0.25:1. To produce suitably hard and precisely curved 3D architectures, the optimal UV absorbance and exposure energy of the acryl-PTMG-MDI resin were controlled precisely. Owing to the optimized viscosity of the acryl-PTMG-MDI resins, they could be printed readily by digital light processing (DLP) to form precisely curved 3D architectures after mixing with 1,6-hexanediol diacrylate (HDDA). The acryl-PTMG-MDI formulations showed much better flexural resolution than the neat resins. The printed 3D structure exhibited high surface hardness, good mechanical strength, and high elasticity for flexible applications in consumer/industrial and biomedical fields.

Tacky-Free Polyurethanes Pressure-Sensitive Adhesives by Molecular-Weight and HDI Trimer Design.

Polyurethane pressure-sensitive adhesives (PU-PSAs) with satisfactory tack, cohesion, and removability were newly developed through the synthetic process by reacting methylene diisocyanate, poly(ethylene glycol) (PEG), and a 1,4-butanediol chain extender based on the different HDI/HDI trimer ratios. The sticking properties of PU-PSAs depended on both the HDI/HDI trimer ratio and crosslinking-agent composition in the formulation. The molecular weight (MW) dependence of adhesion in PU-PSA was observed in the range of 1000 < Mn < 3000, suggesting that the increase in MW limits the pressure-sensitive adhesion of these samples. The differences in the crosslinking-density significantly affected the cohesion, adhesion, and tack in PU-PSA. The formulation of 50 wt.% 600PEG and 50 wt.% crosslinking-agent and an HDI/HDI trimer ratio of 1.0 led to the optimal balance between the adhesion and cohesion properties owing to the sufficient tack, high 180-peel strength, and good cohesion.

Synthesis and Characteristics of Eco-Friendly 3D Printing Material Based on Waterborne Polyurethane.

Photo-cured 3D architectures are successfully printed using the designed waterborne polyurethane-acrylate (WPUA) formulation. A WPUA series is synthesized in the presence of polycaprolactone diol (PCL) and 4,4'-methylene dicyclohexyl diisocyanate (H12MDI) as the soft segment part, dimethylolbutanoic acid (DMBA) as the emulsifier, and triethylamine (TEA) as the neutralizer, as a function of prepolymer molecular weight. The compatibility of WPUA and the photo-activating acryl monomer is as a key factor to guarantee the high resolution of 3D digital light processing (DLP) printing. The optimized blending formulations are tuned by using triacrylate monomers instead of diacrylate derivatives. For the high-accuracy and fine features of 3D DLP printing, WPUA are designed to be a suitable molecular structure for a 385 nm wavelength source, and the target viscosity is achieved in the range from 150 to 250 Cp. Photo-cured 3D architectures based on WPUA exhibit good flexural strength and high resolution.

A facile template-free strategy for synthesizing hydroxymethyl-poly(3,4-ethylenedioxythiophene) nanospheres.

Hydroxymethyl-poly(3,4-ethylenedioxythiophene)(PEDOT-OH) nanospheres self-assembled using physical blowing method, which continually used a syringe, were successfully formed through aqueous solution polymerization under the oxidative initiators. The effect of blowing on the morphological properties of PEDOT-OH was precisely evaluated based on the different amount of initiator. The concentration of ammonium persulfate might be a driving force in the self-assembly process to create the PEDOT-OH nanospheres. The electrical and electrochemical properties of the resulting nanospheres were also characterized using four-point probe and cyclic voltammetry.

Novel Mutation in PTHLH Related to Brachydactyly Type E2 Initially Confused with Unclassical Pseudopseudohypoparathyroidism.

BACKGROUND: Autosomal-dominant brachydactyly type E is a congenital abnormality characterized by small hands and feet, which is a consequence of shortened metacarpals and metatarsals. We recently encountered a young gentleman exhibiting shortening of 4th and 5th fingers and toes. Initially, we suspected him having pseudopseudohypoparathyroidism (PPHP) because of normal biochemical parameters, including electrolyte, Ca, P, and parathyroid hormone (PTH) levels; however, his mother and maternal grandmother had the same conditions in their hands and feet. Furthermore, his mother showed normal biochemical parameters. To the best of our knowledge, PPHP is inherited via a mutated paternal allele, owing to the paternal imprinting of GNAS (guanine nucleotide binding protein, alpha stimulating) in the renal proximal tubule. Therefore, we decided to further analyze the genetic background in this family. METHODS: Whole exome sequencing was performed using genomic DNA from the affected mother, son, and the unaffected father as a negative control. RESULTS: We selected the intersection between 45,490 variants from the mother and 45,646 variants from the son and excluded 27,512 overlapping variants identified from the father. By excluding homogenous and compound heterozygous variants and removing all previously reported variants, 147 variants were identified to be shared by the mother and son. Variants that had least proximities among species were excluded and finally 23 variants remained. CONCLUSION: Among them, we identified a defect in parathyroid hormone like hormone (PTHLH), encoding the PTH-related protein, to be disease-causative. Herein, we report a family affected with brachydactyly type E2 caused by a novel PTHLH mutation, which was confused with PPHP with unclassical genetic penetrance.