Orientation Distribution of Crystalline β-Sheet Domains in Silk Fiber Studied with Vibrational Sum Frequency Generation Spectroscopy.

Silk fibers have good biocompatibility and mechanical properties, which make them attractive in biomaterial applications as well as textile industries. It is believed that the superior mechanical property is associated with the crystalline β-sheet structure in the fiber; but a deeper understanding of the structure-property relationship is still needed for full exploitation of its physical properties. Especially, accurate information on hydrogen-bonding interactions within β-sheet domains at the nanoscale and their spatial distributions at the mesoscale are critically needed.

Tissue-specific directionality of cellulose synthase complex movement inferred from cellulose microfibril polarity in secondary cell walls of Arabidopsis.

In plant cells, cellulose synthase complexes (CSCs) are nanoscale machines that synthesize and extrude crystalline cellulose microfibrils (CMFs) into the apoplast where CMFs are assembled with other matrix polymers into specific structures. We report the tissue-specific directionality of CSC movements of the xylem and interfascicular fiber walls of Arabidopsis stems, inferred from the polarity of CMFs determined using vibrational sum frequency generation spectroscopy. CMFs in xylems are deposited in an unidirectionally biased pattern with their alignment axes tilted about 25° off the stem axis, while interfascicular fibers are bidirectional and highly aligned along the longitudinal axis of the stem.

Regiospecific Cellulose Orientation and Anisotropic Mechanical Property in Plant Cell Walls.

Cellulose microfibrils (CMFs) are a major load-bearing component in plant cell walls. Thus, their structures have been studied extensively with spectroscopic and microscopic characterization methods, but the findings from these two approaches were inconsistent, which hampers the mechanistic understanding of cell wall mechanics. Here, we report the regiospecific assembly of CMFs in the periclinal wall of plant epidermal cells.

Trifluoromethyl-Substituted Conjugated Random Terpolymers Enable High-Performance Small and Large-Area Organic Solar Cells Using Halogen-Free Solvent.

The advancement of non-fullerene acceptors with crescent-shaped geometry has led to the need for polymer donor improvements. Additionally, there is potential to enhance the photovoltaic parameters in high-efficiency organic solar cells (OSCs). The random copolymerization method is a straightforward and effective strategy to further optimize photoactive morphology and enhance device performance.

Morphology and Performance Enhancement through the Strong Passivation Effect of Amphoteric Ions in Tin-based Perovskite Solar Cells.

Despite the optoelectronic similarities between tin and lead halide perovskites, the performance of tin-based perovskite solar cells remains far behind, with the highest reported efficiency to date being ≈14%. This is highly correlated to the instability of tin halide perovskite, as well as the rapid crystallization behavior in perovskite film formation. In this work, l-Asparagine as a zwitterion plays a dual role in controlling the nucleation/crystallization process and improving the morphology of perovskite film.

Overexpression of a gibberellin 20-oxidase gene in poplar xylem led to an increase in the size of nanocellulose fibrils and improved paper properties.

Cellulose, the major component of secondary cell walls, is the most abundant renewable long-chain polymer on earth. Nanocellulose has become a prominent nano-reinforcement agent for polymer matrices in various industries. We report the generation of transgenic hybrid poplar overexpressing the Arabidopsis gibberellin 20-oxidase1 gene driven by a xylem-specific promoter to increase gibberellin (GA) biosynthesis in wood.

Numerical Simulation of Vibrational Sum Frequency Generation Intensity for Non-Centrosymmetric Domains Interspersed in an Amorphous Matrix: A Case Study for Cellulose in Plant Cell Wall.

Vibrational sum frequency generation (SFG) spectroscopy can specifically probe molecular species non-centrosymmetrically arranged in a centrosymmetric or isotropic medium. This capability has been extensively utilized to detect and study molecular species present at the two-dimensional (2D) interface at which the centrosymmetry or isotropy of bulk phases is naturally broken. The same principle has been demonstrated to be very effective for the selective detection of non-centrosymmetric crystalline nanodomains interspersed in three-dimensional (3D) amorphous phases.

A Prospective Study on the Association between Oxidative Stress and Duration of Symptoms in Allergic Rhinitis.

Oxidative stress has been known to play an important role in inflammatory responses of allergic rhinitis. We investigated the association between degree of oxidative stress and severity of allergic rhinitis. A total 226 allergic rhinitis students were classified by a history of allergic rhinitis into groups according to number and duration of symptoms within the previous year.

Phenotypic effects of changes in the FTVTxK region of an secondary wall cellulose synthase compared with results from analogous mutations in other isoforms.

Understanding protein structure and function relationships in cellulose synthase (CesA), including divergent isomers, is an important goal. Here, we report results from mutant complementation assays that tested the ability of sequence variants of AtCesA7, a secondary wall CesA of , to rescue the collapsed vessels, short stems, and low cellulose content of the AtCesA7 null mutant. We tested a catalytic null mutation and seven missense or small domain changes in and near the AtCesA7 FTVTSK motif, which lies near the catalytic domain and may, analogously to bacterial CesA, exist within a substrate "gating loop.

Performance data of CHNHPbI inverted planar perovskite solar cells via ammonium halide additives.

The data provided in this data set is the study of organic-inorganic hybrid perovskite solar cells fabricated through incorporating the small amounts of ammonium halide NHX (X = F, Cl, Br, I) additives into a CHNHPbI (MAPbI) perovskite solution and is published as "High-Performance CHNHPbI Inverted Planar Perovskite Solar Cells via Ammonium Halide Additives", available in Journal of Industrial and Engineering Chemistry [1]. A compact and uniform perovskite absorber layer with large perovskite crystalline grains, is realized by simply incorporating small amounts of additives into precursor solutions, and utilizing the anti-solvent engineering technique to control the nucleation and growth of perovskite crystal, turning out the enhanced device efficiency (NHF: 14.88 ± 0.

Simple and Versatile Non-Fullerene Acceptor Based on Benzothiadiazole and Rhodanine for Organic Solar Cells.

Most non-fullerene acceptors (NFAs) are designed in a complex planar molecular conformation containing fused aromatic rings in high-efficiency organic solar cells (OSCs). To obtain the final molecules, however, numerous synthetic steps are necessary. In this work, a novel simple-structured NFA containing alkoxy-substituted benzothiadiazole and a rhodanine end group (BTDT2R) is designed and synthesized.

Stable P3HT: amorphous non-fullerene solar cells with a high open-circuit voltage of 1 V and efficiency of 4.

A non-fullerene small molecule acceptor, SF-HR composed of 3D-shaped spirobifluorene and hexyl rhodanine, was synthesized for use in bulk heterojunction organic solar cells (OSCs). It possesses harmonious molecular aggregation between the donor and acceptor, due to the interesting diagonal molecular shape of SF-HR. Furthermore, the energy level of SF-HR matches well with that of the donor polymer, poly(3-hexyl thiophene) (P3HT) in this system which can affect efficient charge transfer and transport properties.

Amine-Based Interfacial Engineering in Solution-Processed Organic and Perovskite Solar Cells.

Solution-processed organic solar cells (OSCs) and hybrid perovskite solar cells (PvSCs) generally require appropriate transparent electrode with a low work function, which improves the electron extraction, increases the built-in potential, and suppresses charge recombinations. Hence, interfacial modifiers between the cathode and the photoactive layer play a significant role in OSCs and PvSCs, as they provide suitable energy-level alignment, leading to desirable charge carrier selectivity and suppressing charge carrier recombinations at the interfaces. Here, we present a comprehensive study of the energy-level mapping between a transparent electrode and photoactive layers to enhance the electron-transport ability by introducing amine-based interfacial modifiers (ABIMs).

High-Efficiency Nonfullerene Polymer Solar Cells with Band gap and Absorption Tunable Donor/Acceptor Random Copolymers.

Energy level alignment between a donor and an acceptor has a critical role in determining the open-circuit voltage ( V) in polymer solar cells (PSCs). Also, broad absorption of the photoactive layer is required to generate a high photocurrent. Herein, non-fullerene PSCs with D/A random copolymers and 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3- d:2',3'- d']- s-indaceno[1,2- b:5,6- b']dithiophene (ITIC) has been demonstrated.

Effective Molecular Engineering Approach for Employing a Halogen-Free Solvent for the Fabrication of Solution-Processed Small-Molecule Solar Cells.

To utilize the potential of small-molecule-based organic solar cells, proper designs of the photoactive materials which result in reasonable performance in a halogen-free solvent system and thickness tolerance over a range are required. One of the best approaches to achieve these requirements is via the molecular engineering of small-molecule electron donors. Here, we have modified a previously reported dithienobenzodithiophene (DTBDT)-based small molecule (SM1) via the dimerization approach, that is, the insertion of an additional DTBDT into the main backbone of the small molecule (SM2).

High-Performance CHNHPbI-Inverted Planar Perovskite Solar Cells with Fill Factor Over 83% via Excess Organic/Inorganic Halide.

The reduction of charge carrier recombination and intrinsic defect density in organic-inorganic halide perovskite absorber materials is a prerequisite to achieving high-performance perovskite solar cells with good efficiency and stability. Here, we fabricated inverted planar perovskite solar cells by incorporation of a small amount of excess organic/inorganic halide (methylammonium iodide (CHNHI; MAI), formamidinium iodide (CH(NH)I; FAI), and cesium iodide (CsI)) in CHNHPbI perovskite film. Larger crystalline grains and enhanced crystallinity in CHNHPbI perovskite films with excess organic/inorganic halide reduce the charge carrier recombination and defect density, leading to enhanced device efficiency (MAI+: 14.

The Use of Korean Medicine to Treat Patients with Spinobulbar Muscular Atrophy, Kennedy's Disease - A Case Study.

Objectives: Studies involving patients with spinobulbar muscular atrophy (SBMA), which is often referred to as Kennedy's disease, similar to those involving patients with progressive muscular disease (PMD), are rare. This paper reports a case study involving the use of Korean medicine to treat a patient with SBMA.

Methods: We treated a patient with SBMA with unique symptoms by using various kinds of pharmacopuncture and herbal medicines for about two and a half years.

Effects on Photovoltaic Performance of Dialkyloxy-benzothiadiazole Copolymers by Varying the Thienoacene Donor.

A series of four donor-acceptor alternating copolymers based on dialkyloxy-benzothiadiazole (ROBT) as an acceptor and thienoacenes as donor units were synthesized and tested for polymer solar cells (PSCs). These new polymers had different donor units with varied electron-donating ability (thieno[3,2-b]thiophene (TT), dithieno[3,2-b:2',3'-d]thiophene (DTT), benzo[1,2-b:4,5-b']dithiophene (BDT), and naphtha[1,2-b:5,6-b']dithiophene (NDT)) in the polymer backbone. To understand the effect of these thienoacenes on the optoelectronic and photovoltaic properties of the copolymers, we systematically analyzed and compared the energy levels, crystallinity, morphology, charge recombination, and charge carrier mobility in the resulting polymers.

Study on the Single Dose Toxicity of ShinEumHur Pharmacopuncture Injected into the Muscles of Rats.

Objectives: This study was carried out to analyze the single dose toxicity of ShinEumHur (SEH) pharmacopuncture injected into the muscles of Sprague-Dawley rats.

Methods: The SEH pharmacopuncture was made in a clean room at the Korean Pharmacopuncture Institute (K-GMP). After the mixing process with sterile distilled water had been completed, the pH was controlled to between 7.

Impact of the Crystalline Packing Structures on Charge Transport and Recombination via Alkyl Chain Tunability of DPP-Based Small Molecules in Bulk Heterojunction Solar Cells.

A series of small compound materials based on benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) with three different alkyl side chains were synthesized and used for organic photovoltaics. These small compounds had different alkyl branches (i.e.

Erratum: A Study on the Single-dose Oral Toxicity of Super Key in Sprague-Dawley Rats.

[This corrects the article DOI: 10.3831/KPI.2015.

A Study on the Single-dose Oral Toxicity of Super Key in Sprague-Dawley Rats.

Objectives: This study was performed to analyze the single-dose oral toxicity of the super key (processed sulfur).

Methods: All experiments were conducted at Medvill, an institution authorized to perform non-clinical studies, under the Good Laboratory Practice (GLP) regulations. In order to investigate the oral toxicity of super key We administered it orally to Sprague-Dawley (SD) rats.

Single-dose Toxicity of ShinYangHur Herbal Acupuncture.

Objectives: This study was carried out to analyze the single-dose toxicity of ShinYangHur (SYH) herbal acupuncture injected into the muscles of Sprague-Dawley (SD) rats.

Methods: The SYH herbal acupuncture was made in a clean room at the Korean Pharmacopuncture Institute (KPI, Korea-Good Manufacturing Practice, K-GMP). After the mixing process with sterile distilled water, the pH was controlled to between 7.

Effects of hole and electron transporting interlayers for inverted polymer solar cells.

An efficient inverted polymer solar cell (PSC) with a transparent amorphous titanium oxide (TiOx) as an electron transporting layer (ETL) between bottom electrode and photo-active layer, and a tungsten oxide (WO3) inserted as a hole transporting layer (HTL) was fabricated. Introducing of ETL and HTL results in increases in the open circuit voltage (VOC), short circuit current (JSC) and the fill factor (FF). The inverted PSC device with TiOx and WO3 layer showed the higher power conversion efficiency (PCE) than that of conventional PSC.

Synthesis and characterization of new silafluorene-based copolymers for polymer solar cells.

A series of silafluorene-based copolymers, poly[9-(2-ethylhexyl)-9-dodecyl-silafluorene-2,7-diyl-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (P1), poly[9-(2-ethylhexyl)-9-dodecyl-silafluorene-2,7-diyl-alt-2,5-bis-(thiophene-2-yl)thiazolo [5,4-d]thiazole] (P2), and poly[9-(2-ethylhexyl)-9-dodecyl-silafluorene-2,7-diyl-alt-5,5-(5',8'-di-2-thienyl-2,3-bis(4-octyloxyl)phenyl)quinoxaline] (P3), were synthesized and used as donor materials in polymer solar cells (PSCs). The optical, electrochemical, and photovoltaic properties of the copolymers were investigated. The results indicate that the acceptor units in the copolymers influenced the band gap, electronic energy levels, and photovoltaic properties of the copolymers significantly.