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The unprecedented impact of human activity on Earth’s climate and the ongoing increase in global energy demand have made the development of carbon-neutral energy sources ever more important. Hydrogen is an attractive and versatile energy carrier (and important and widely used chemical) obtainable from water through photocatalysis using sunlight, and through electrolysis driven by solar or wind energy1,2. The most efficient solar hydrogen production schemes, which couple solar cells to electrolysis systems, reach solar-to-hydrogen (STH) energy conversion efficiencies of 30% at a laboratory scale3. Photocatalytic water splitting reaches notably lower conversion efficiencies of only around 1%, but the system design is much simpler and cheaper and more amenable to scale-up1,2—provided the moist, stoichiometric hydrogen and oxygen product mixture can be handled safely in a field environment and the hydrogen recovered. Extending our earlier demonstration of a 1-m2 panel reactor system based on a modified, aluminium-doped strontium titanate particulate photocatalyst4, we here report safe operation of a 100-m2 array of panel reactors over several months with autonomous recovery of hydrogen from the moist gas product mixture using a commercial polyimide membrane5. The system, optimized for safety and durability, and remaining undamaged on intentional ignition of recovered hydrogen, reaches a maximum STH of 0.76%. While the hydrogen production is inefficient and energy negative overall, our findings demonstrate that safe, large-scale photocatalytic water splitting, and gas collection and separation are possible. To make the technology economically viable and practically useful, essential next steps are reactor and process optimization to substantially reduce costs and improve STH efficiency, photocatalyst stability and gas separation efficiency. Carbon-neutral hydrogen can be produced through photocatalytic water splitting, as demonstrated here with a 100-m2 array of panel reactors that reaches a maximum conversion efficiency of 0.76%.

Tantalum nitride (Ta3N5) is a visible-light-responsive semiconductor that may be capable of achieving the 10% solar-to-hydrogen (STH) efficiency required to allow the commercialization of water splitting systems. However, despite immense research efforts, the highest STH efficiency yet reported for photoanodes based on Ta3N5-nanorods (NRs) is only 2.7%. Therefore, it is imperative to build a theoretical foundation that explains the various loss mechanisms and their correlations with structural and material properties, so as to optimize the performance of this material. The present work devised a detailed numerical model based on an in-depth analysis of the performance characteristics of photoanodes made from either Ba-doped or undoped Ta3N5-NRs. This experimentally calibrated optoelectrical modelling enabled predictions of various factors related to performance loss, including optical effects, charge carrier recombination and resistive loss. Certain physical parameters, such as charge carrier lifetime, diffusion length, hole extraction rate from the NR surfaces to the electrolyte and the series resistance of the photoanode, could also be calculated. The results show that the enhanced performance obtained with Ba doping can be primarily attributed to increases in the carrier lifetime and diffusion length. The present model was recalibrated using experimental data from the literature to examine hidden effects of the NRs’ dimensions on optical and recombination losses. On this basis, various design principles are presented herein that should allow the fabrication of efficient Ta3N5-NRs photoanodes for commercial STH production.

Efficient, robust and environmentally friendly cocatalysts for photocatalysts are important for large-scale solar hydrogen production. Herein, we demonstrate that a Rh–Zr mixed oxide is an efficient cocatalyst for hydrogen evolution. Impregnation of Zr and Rh precursors (Zr/Rh = 5 wt/wt%) formed RhZrOx cocatalyst particles on Al-doped SrTiO3, which exhibited 31× higher photocatalytic water-splitting activity than a RhOx cocatalyst. X-ray photoelectron spectroscopy proved that the dissociation of Cl− ions from preformed Rh–Cl–Zr–O solid led to formation of the active phase of RhZrOx, in which the Zr/Rh ratio was critical to high catalytic activity. Additional CoOx loading as an oxygen evolution cocatalyst further improved the activity by 120%, resulting in an apparent quantum yield of 33 (±4)% at 365 nm and a long durability of 60 h. Our discovery could help scale up photocatalytic hydrogen production., An efficient, robust and environmentally friendly Rh–Zr mixed oxide formed though the activation of Rh–Cl–Zr–O solid efficiently functions as a HER cocatalyst on Al-doped SrTiO3.

Recent advances in neutron crystallographic studies have provided structural bases for quantum behaviors of protons observed in enzymatic reactions. Thus, we resolved the neutron crystal structure of a bacterial copper (Cu) amine oxidase (CAO), which contains a prosthetic Cu ion and a protein-derived redox cofactor, topa quinone (TPQ). We solved hitherto unknown structures of the active site, including a keto/enolate equilibrium of the cofactor with a nonplanar quinone ring, unusual proton sharing between the cofactor and the catalytic base, and metal-induced deprotonation of a histidine residue that coordinates to the Cu. Our findings show a refined active-site structure that gives detailed information on the protonation state of dissociable groups, such as the quinone cofactor, which are critical for catalytic reactions.

It is important to improve the apparent quantum yields (AQYs) of narrow bandgap photocatalysts to achieve efficient H2 production. The present work demonstrates a particulate solid solution of zinc selenide and copper gallium selenide (denoted as ZnSe:CGSe) that evolves H2 efficiently and is responsive to visible light up to 725 nm. This material was synthesized using a flux-assisted method and was found to comprise single-crystalline tetrahedral particles. The coloading of Ni and Rh, Pt, Pd or Ru as cocatalysts further improved the photocatalytic H2 evolution rate over this photocatalyst. With the optimal coloading of a Ni–Ru composite cocatalyst, an AQY of 13.7% was obtained at 420 nm during a sacrificial H2 evolution reaction, representing the highest value yet reported for a photocatalyst with an absorption edge longer than 700 nm. The present study demonstrates that the preparation of single-crystalline particles and the rational assembly of composite cocatalysts are effective strategies that allow the efficient utilization of long wavelengths by metal selenide photocatalysts for solar fuel production., Coloading of a Ni–Ru composite cocatalyst on a 700 nm-class single-crystalline particulate selenide photocatalyst improves its hydrogen evolution activity.

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel Ni3Se4 NCs (sp-Ni3Se4) and phase segregated berzelianite Cu2−xSe (ber-Cu2−xSe)/sp-Ni3Se4 heterostructured NCs as active oxygen evolution reaction (OER) catalysts. A rare sp-Ni3Se4 phase was formed by cation exchange of ber-Cu2−xSe NCs with Ni2+ ions, because both phases have the face-centered cubic (fcc) Se anion sublattice. Tuning the Ni : Cu molar ratio leads to the formation of Janus-type ber-Cu2−xSe/sp-Ni3Se4 heterostructured NCs. The NCs of sp-Ni3Se4 and ber-Cu2−xSe/sp-Ni3Se4 heterostructures exhibited high catalytic activities in the OER with small overpotentials of 250 and 230 mV at 10 mA cm−2 in 0.1 M KOH, respectively. They were electrochemically oxidized during the OER to give hydroxides as the real active species. We anticipate that the cation exchange reaction could have enormous potential for the creation of novel heterostructured NCs showing superior catalytic performance.

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel Ni3Se4 NCs (sp-Ni3Se4) and phase segregated berzelianite Cu2−xSe (ber-Cu2−xSe)/sp-Ni3Se4 heterostructured NCs as active oxygen evolution reaction (OER) catalysts. A rare sp-Ni3Se4 phase was formed by cation exchange of ber-Cu2−xSe NCs with Ni2+ ions, because both phases have the face-centered cubic (fcc) Se anion sublattice. Tuning the Ni : Cu molar ratio leads to the formation of Janus-type ber-Cu2−xSe/sp-Ni3Se4 heterostructured NCs. The NCs of sp-Ni3Se4 and ber-Cu2−xSe/sp-Ni3Se4 heterostructures exhibited high catalytic activities in the OER with small overpotentials of 250 and 230 mV at 10 mA cm−2 in 0.1 M KOH, respectively. They were electrochemically oxidized during the OER to give hydroxides as the real active species. We anticipate that the cation exchange reaction could have enormous potential for the creation of novel heterostructured NCs showing superior catalytic performance., Bimetallic selenide nanocrystals formed by cation exchange reaction work as a precursor of efficient water oxidation electrocatalyst.

The unprecedented impact of human activity on Earth's climate and the ongoing increase in global energy demand have made the development of carbon-neutral energy sources ever more important. Hydrogen is an attractive and versatile energy carrier (and important and widely used chemical) obtainable from water through photocatalysis using sunlight, and through electrolysis driven by solar or wind energy

Photocatalytic water splitting is a viable approach to the large-scale production of renewable solar hydrogen. The apparent quantum yield for this reaction has been improved, but the lifespan of photocatalysts functioning under sunlight at ambient pressure have rarely been examined, despite the critical importance of this factor in practical applications. Herein, we show that Al-doped SrTiO3 (SrTiO3:Al) loaded with a RhCrOx (rhodium chromium oxide) cocatalyst splits water with an apparent quantum yield greater than 50% at 365 nm. Moreover, following the photodeposition of CoOOH and TiO2, this material maintains 80% of its initial activity and a solar-to-hydrogen energy conversion efficiency greater than or equal to 0.3% over a span of 1300 h under constant illumination by simulated sunlight at ambient pressure. This result is attributed to reduced dissolution of Cr in the cocatalyst following the oxidative photodeposition of CoOOH. The photodeposition of TiO2 further improves the durability of this photocatalyst. This work demonstrates a concept that could allow the design of long-term, large-scale photocatalyst systems for practical sunlight-driven water splitting.

Summary Efficient and scalable sunlight-driven water-splitting systems are essential for practical renewable hydrogen production. Particulate photocatalyst sheets for Z-scheme water splitting can be printed at low cost using inks containing a hydrogen evolution photocatalyst (HEP), an oxygen evolution photocatalyst (OEP), and conductive metal nanoparticles, and can be applied to large areas. However, the metal nanoparticles lead to backward reactions and light absorption. Herein, we demonstrate printable photocatalyst sheets composed of SrTiO3:La,Rh as the HEP, BiVO4:Mo as the OEP, and nanoparticulate indium tin oxide as a transparent and electrochemically inert conductor, for efficient pure-water splitting. The photocatalyst sheets decompose water with a solar-to-hydrogen energy conversion efficiency of 0.4%, which is one of the highest values among Z-scheme overall water-splitting systems prepared without the requirement for a vacuum process. Printable and efficient photocatalyst sheets obtained using cost-effective and readily extensible procedures spread opportunities toward practical solar hydrogen production via the water-splitting reaction.

In this article, the status of the STARGazer data-processing software and its data-processing algorithms are described in detail. The STARGazer data-processing software is used for neutron time-of-flight single-crystal diffraction data collected using the IBARAKI Biological Crystal Diffractometer., The STARGazer data-processing software is used for neutron time-of-flight (TOF) single-crystal diffraction data collected using the IBARAKI Biological Crystal Diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC). This software creates hkl intensity data from three-dimensional (x, y, TOF) diffraction data. STARGazer is composed of a data-processing component and a data-visualization component. The former is used to calculate the hkl intensity data. The latter displays the three-dimensional diffraction data with searched or predicted peak positions and is used to determine and confirm integration regions. STARGazer has been developed to make it easier to use and to obtain more accurate intensity data. For example, a profile-fitting method for peak integration was developed and the data statistics were improved. STARGazer and its manual, containing installation and data-processing components, have been prepared and provided to iBIX users. This article describes the status of the STARGazer data-processing software and its data-processing algorithms.

Summary Sunlight-driven photocatalytic water splitting has been investigated as a potentially scalable and economically feasible means of producing renewable hydrogen. However, reactors suitable for efficient water splitting and prompt collection of gaseous products on a large scale have yet to be demonstrated. Here, we demonstrate a sunlight-powered water-splitting reactor using a fixed Al-doped SrTiO 3 photocatalyst and address the key issues in the reactor design associated with the scale-up. A panel reactor filled with only a 1-mm-deep layer of water was capable of rapid release of product gas bubbles without forced convection. A flat panel reactor with 1 m 2 of light-accepting area retained the intrinsic activity of the photocatalyst and achieved a solar-to-hydrogen energy conversion efficiency of 0.4% by water splitting under natural sunlight irradiation. The concept of a readily extensible water-splitting panel is a viable means for large-scale production of low-cost renewable solar hydrogen.

The high overpotential of the oxygen evolution reaction is a critical issue to be overcome to realize efficient overall water splitting and enable hydrogen generation powered by sunlight. Homogeneous and stable nanoparticles (NPs) dispersed in solvents are useful as both electrocatalysts and cocatalysts of photocatalysts for the electro- and photo-catalytic oxygen evolution reaction, respectively, through their adsorption on various electrode substrates. Here, phase-segregated NiPx@FePyOz core@shell NPs are selectively synthesized by the reaction of Fe(CO)5 with amorphous NiPx seed-NPs. The NiPx@FePyOz NPs on conductive substrates exhibit higher electrocatalytic activity in the oxygen evolution reaction than those of other metal phosphide-based catalysts. The NiPx@FePyOz NPs can also be used as a cocatalyst of an anodic BiVO4 photocatalyst to boost the photocatalytic water oxidation reaction. The excellent catalytic activity and high stability of the NiPx@FePyOz NPs without any post-treatments are derived from in situ activation through both the structural transformation of NiPx@FePyOz into mixed hydroxide species, (Ni, Fe)OxHy, and the spontaneous removal of the insulating organic ligands from NPs to form a smooth and robust (Ni, Fe)OxHy/substrate heterointerface during the oxygen evolution reaction.

Summary Photoelectrochemical (PEC) water oxidation by semiconductor photoanodes plays a fundamental role for sustainable solar fuel and chemical production. Advanced surface and interface engineering has been demonstrated to be of critical importance for the development of highly efficient and stable water oxidation photoanodes. In this review, we briefly introduce the fundamentals and some general considerations in the development and evaluation of water oxidation photoanodes and the assembly of PEC cells. We summarize several most important roles of surface and interface engineering identified in improving the PEC performance of photoanodes and highlight the most prominent research advancements in these fields. Finally, the outlook for the future development of surface and interface engineering for practical photoelectrochemical water oxidation is concisely discussed.

Graphene is expected to be used in separation applications such as desalination. However, it is difficult to predict the flow phenomena at the nanoscale using the conventional continuum law. Particularly at a Knudsen number (Kn) of >0.1, which is applied in filtration, it has been reported that not even slip boundary conditions can be applied. In this study, to identify the parameters that affect the applicability of the continuum law, we conducted a fluid permeation simulation using graphene. The deviation of the permeability from that of the continuum model was calculated by changing the channel width, fluid temperature, and fluid type. The result showed that the channel width has the largest influence among the three factors, and that the magnitude of the divergence is sorted out based on the Knudsen number. Therefore, the permeability can be predicted even at the nanoscale where the continuum law cannot be applied.

Reverse osmosis membranes based on aromatic polyamide (ar-PA) are widely used in desalination of seawater, yet the microscopic mechanism of water diffusion through a polyamide layer remains elusive. Here, we study the structure and dynamics of polymer chains and water molecules in ar-PA in comparison to nylon 6 (one of aliphatic polyamides) under various water contents (0.0–15.9 wt%). The infrared (IR) difference spectrum between dry and moist ar-PA shows little change in amide A bands, in contrast to that of nylon 6 which yields a prominent dip. Theoretical analyses using molecular dynamics simulations and quantum electronic and vibrational calculations reveal that the dip in nylon 6 is caused by breaking of hydrogen bonds (HBs) among amide groups. The incoming water molecules that break amide-amide HBs are bound to polyamide chains nearby and diffuse slowly. On the other hand, the amide-amide HBs of ar-PA are kept upon hydration. Such polymer structure facilitates growth of large water clusters with more than 100 water molecules and rapid diffusion of water molecules. The amide A band serves as a fingerprint to characterize the water permeability of polyamide materials.

We report a new fabrication method of flat, uniform BiVO4 films on an electrically conductive transparent indium tin oxide (ITO) film based on a solution process for depositing bismuth precursor films and a high-temperature calcination process with an organic vanadium precursor. The synthesised BiVO4 films, composed as a monolayer of crystallites (diameter ≤ 1 μm) fixed on the ITO, realised half-cell solar-to-hydrogen energy conversion efficiencies of over 1.5% by the aid of impregnated CoOx and atomic-layer-deposited NiO when tested as oxygen-evolving photoanodes for water splitting under solar simulator AM 1.5G illumination. Stoichiometric oxygen and hydrogen were generated with Faraday efficiencies of unity over 12 h at 0.6–0.9 VRHE. This morphology of our bulky semi-transparent BiVO4 films exhibited state-of-the-art solar water splitting performances.

The high overpotential of the oxygen evolution reaction is a critical issue to be overcome to realize efficient overall water splitting and enable hydrogen generation powered by sunlight. Homogeneous and stable nanoparticles (NPs) dispersed in solvents are useful as both electrocatalysts and cocatalysts of photocatalysts for the electro- and photo-catalytic oxygen evolution reaction, respectively, through their adsorption on various electrode substrates. Here, phase-segregated NiP

The particulate semiconductor La5Ti2CuS5O7 (LTC) with a band gap energy of 1.9 eV functioned as either a photocathode or a photoanode when embedded onto Au or Ti metal layers, respectively. By applying an LTC/Au photocathode and LTC/Ti photoanode to, respectively, photoelectrochemical (PEC) water reduction and oxidation concurrently, zero-bias overall water splitting was accomplished under visible light irradiation. The band structures of LTC/Au and LTC/Ti calculated using a semiconductor device simulator (AFORS-HET) confirmed the critical role of the solid/solid junction of the metal back contact in the charge separation and PEC properties of LTC photoelectrodes. The prominently long lifetime of photoexcited charge carriers in LTC, confirmed by transient absorption spectroscopy, allowed the utilization of both photoexcited electrons and holes depending on the band structure at the solid/solid junction.

The effects of a phosphate buffer electrolyte and surface modification with thin conductor layers on the photoelectrochemical properties of CdS and Pt-modified polycrystalline Cu(In,Ga)Se2 (CIGS) photocathodes were investigated. The photocurrent obtained from Pt/CdS/CIGS electrodes, in which the CIGS layer was fabricated by co-evaporation using a three stage method, clearly increased in a phosphate buffer electrolyte solution as a result of promotion of the hydrogen evolution reaction. The half-cell solar-to-hydrogen efficiency (HC-STH) of this device reached a maximum of 5.4% at 0.30 VRHE even under neutral conditions. Furthermore, significant enhancement of the hydrogen evolution reaction on a CIGS photocathode by surface modification with thin conductor layers was observed. The enhancement was due to the promoted charge transfer between the underlying photocathode and water through the Pt catalyst. The HC-STH of a CIGS photocathode modified with a conductive Mo/Ti layer (Pt/Mo/Ti/CdS/CIGS) was as high as 8.5% at 0.38 VRHE, a value that exceeds those previously reported for photocathodes based on polycrystalline thin films.

In situ dynamic observation of model biological cell membranes, formed on a water/gold substrate interface, has been performed by the combination of electrochemical scanning tunneling microscopy and reflection infrared absorption vibrational spectroscopy. Monolayers of 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) were formed on alkanethiol-modified gold surfaces in a buffer solution, and the microscopic phase transitions driven by electrochemical potential control were observed more in detail than our previous study on the same system [Electrochem. Commun. 2007, 9, 645-650]. This time the transitions were associated with the chemistry of DHPC by the aid of vibrational spectroscopy and the utilization of deuterium-labeled DHPC molecules. A negative potential shift solidifies the fluidic lipid layers into static striped or grainy features without notable chemical reactions. The first positive potential shift over the virginal DHPC monolayer breaks DHPC into choline and the corresponding phosphatidic acid (DHPA). This is the first case of a phospholipid electrochemical reaction microscopically detected at the solid surface.

BACKGROUND Primary volvulus of the small intestine associated with chylous ascites is very rare, with only four reported cases. In this paper, we report a new case of primary volvulus associated with chylous ascites. CASE PRESENTATION The patient was a 70-year-old man. After experiencing bloating and abdominal pain for several hours, he called an ambulance and underwent an emergency examination at our hospital. Abdominal distension, pressure pain, and rebound tenderness were observed throughout his entire abdomen. The patient had a history of hypertension for which he was receiving oral treatment. Abdominal contrast-enhanced computed tomography (CT) revealed an edematous change in the intestinal membrane and volvulus of the small intestine. As findings suggestive of ischemia were observed in part of the intestines, emergency surgery was performed on the day of admission. Open surgery revealed approximately 500 mL of chylous ascites in the abdominal cavity. The small intestine had twisted 180° in a counter-clockwise direction at the root of the superior mesenteric artery, and the mesentery appeared milky white with edematous changes extending 75 to 240 cm from the ligament of Treitz. There was no evidence of intestinal necrosis; therefore intestinal resection was not performed. The volvulus of the small intestine was corrected. Moreover, because there was no other underlying disease observed, surgery was completed. The ascites collected during surgery revealed high levels of triglycerides at 332 mg/dL, and chylous ascites was diagnosed. An abdominal CT performed on the third day after surgery showed an improvement in intestinal edema, and primary volvulus of the small intestine associated with chylous ascites was diagnosed. Postoperative progress was good, and the patient was discharged on hospital day 10.

Graphene membranes can be used for nanoscale filtration to remove atoms and are expected to be used for separation. To realize high-permeability and high-filtration performance, we must understand the flow configuration in the nanochannels. In this study, we investigated the applicability of continuum-dynamics laws to water flow through a graphene slit. We calculated the permeability of the flow through a slit using classical molecular dynamics (MD) and compared the MD simulation results for different Knudsen numbers (Kn) to predictions based on the no-slip model and slip model. Consequently, the flow through the graphene nanoslit was treated as slip flow only in the range of Kn

We plan to design a high-resolution biomacromolecule neutron time-of-flight diffractometer, which allows us to collect data from crystals with unit cells above 250 Å, in the materials and life science experimental facility at the Japan Proton Accelerator Research Complex. This new diffractometer can be used for a detailed analysis of large proteins such as membrane proteins and supermolecular complex. A quantitative comparison of the intensity and pulse width of a decoupled moderator (DM) against a coupled moderator (CM) considering the pulse width time resolution indicated that the DM satisfies the criteria for our diffractometer rather than the CM. The results suggested that a characteristic feature of the DM, i.e., narrow pulse width with a short tail, is crucial for the separation of Bragg reflections from crystals with large unit cells. On the other hand, it should be noted that the weak signals from the DM are buried under the high-level background caused by the incoherent scattering of hydrogen atoms, especially, in the case of large unit cells. We propose a profile-fitting integration method combined with the energy loss functions and a background subtraction method achieved by employing the statistics-sensitive nonlinear iterative peak-clipping algorithm.

The time-of-flight neutron single-crystal diffractometer iBIX at the next-generation neutron source J-PARC has been upgraded and is available for user experiments on protein samples in particular. Neutron structure analysis of a standard protein sample was carried out in order to evaluate the performance of iBIX., The IBARAKI biological crystal diffractometer, iBIX, is a high-performance time-of-flight neutron single-crystal diffractometer for elucidating mainly the hydrogen, protonation and hydration structures of biological macromolecules in various life processes. Since the end of 2008, iBIX has been available to users’ experiments supported by Ibaraki University. Since August 2012, an upgrade of the 14 existing detectors has begun and 16 new detectors have been installed for iBIX. The total measurement efficiency of the present diffractometer has been improved by one order of magnitude from the previous one with the increasing of accelerator power. In December 2012, commissioning of the new detectors was successful, and collection of the diffraction dataset of ribonucrease A as a standard protein was attempted in order to estimate the performance of the upgraded iBIX in comparison with previous results. The resolution of diffraction data, equivalence among intensities of symmetry-related reflections and reliability of the refined structure have been improved dramatically. iBIX is expected to be one of the highest-performance neutron single-crystal diffractometers for biological macromolecules in the world.

The neutron crystal structure of human transthyretin is presented., Transthyretin (TTR) is a tetrameric protein. TTR misfolding and aggregation are associated with human amyloid diseases. Dissociation of the TTR tetramer is believed to be the rate-limiting step in the amyloid fibril formation cascade. Low pH is known to promote dissociation into monomer and the formation of amyloid fibrils. In order to reveal the molecular mechanisms underlying pH sensitivity and structural stabilities of TTR, neutron diffraction studies were conducted using the IBARAKI Biological Crystal Diffractometer with the time-of-flight method. Crystals for the neutron diffraction experiments were grown up to 2.5 mm3 for four months. The neutron crystal structure solved at 2.0 Å revealed the protonation states of His88 and the detailed hydrogen-bond network depending on the protonation states of His88. This hydrogen-bond network is involved in monomer–monomer and dimer–dimer interactions, suggesting that the double protonation of His88 by acidification breaks the hydrogen-bond network and causes the destabilization of the TTR tetramer. Structural comparison with the X-ray crystal structure at acidic pH identified the three amino acid residues responsible for the pH sensitivity of TTR. Our neutron model provides insights into the molecular stability related to amyloidosis.

Pore-forming toxins (PFTs) are soluble proteins that can oligomerize on the cell membrane and induce cell death by membrane insertion. PFT oligomers sometimes form hexagonal close-packed (hcp) structures on the membrane. Here, we show the assembling of the sphingomyelin (SM)-binding PFT, lysenin, into an hcp structure after oligomerization on SM/cholesterol membrane. This process was monitored by high-speed atomic force microscopy. Hcp assembly was driven by reorganization of lysenin oligomers such as association/dissociation and rapid diffusion along the membrane. Besides rapid association/dissociation of oligomers, the height change for some oligomers, possibly resulting from conformational changes in lysenin, could also be visualized. After the entire membrane surface was covered with a well-ordered oligomer lattice, the lysenin molecules were firmly bound on the membrane and the oligomers neither dissociated nor diffused. Our results reveal the dynamic nature of the oligomers of a lipid-binding toxin during the formation of an hcp structure. Visualization of this dynamic process is essential for the elucidation of the assembling mechanism of some PFTs that can form ordered structures on the membrane.

We developed and employed a profile fitting method for the peak integration of neutron time-of-flight diffraction data collected by the IBARAKI Biological Crystal Diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC) for protein ribonuclease A and α-thrombin single crystals. In order to determine proper fitting functions, four asymmetric functions were evaluated using strong intensity peaks. A Gaussian convolved with two back-to-back exponentials was selected as the most suitable fitting function, and a profile fitting algorithm for the integration method was developed. The intensity and structure refinement data statistics of the profile fitting method were compared to those of the summation integration method. It was clearly demonstrated that the profile fitting method provides more accurate integrated intensities and model structures than the summation integration method at higher resolution shells. The integration component with the profile fitting method has already been implemented in the iBIX data processing software STARGazer and its user manual has been prepared.

UTokyo Research掲載「太陽光を用いて水を分解できる粉末光触媒シート」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/solar-water-splitting-using-particulate-photocatalyst-sheets.html, UTokyo Research "Solar water splitting using particulate photocatalyst sheets" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/solar-water-splitting-using-particulate-photocatalyst-sheets.html

蛋白質結晶構造解析用の新型中性子回折装置である茨城県生命物質構造解析装置(iBIX)が大強度陽子加速器施設(J-PARC)の次世代中性子源に建設され，2008年12月から本格運転を開始した。2009年度には，14台の検出器，データ処理ソフトウェアの基本的な部分，20Kまでの低温吹付装置が利用可能となり，有機物標準結晶の測定及び構造解析に成功した。2009年12月からの120kW加速器運転より，産業界ユーザーの試料を含む複数の無機，有機化合物そして蛋白質結晶の構造解析用中性子測定がなされ，そのうちいくつかは水素や水和水の位置がわかる程度まで構造解析が進んでいる。

To achieve coordination programming at an electrode surface, the first functional layer is highly important. In this study, high-resolution electron energy-loss spectroscopy (HREELS) was used to in...

症例は69歳の男性で，主訴は右下腹部腫瘤．約2年前に，Kugel法による右鼠径ヘルニア手術を他院で受けていた．小児期の鼠径ヘルニア手術，急性虫垂炎手術の既往があった．CT，注腸検査で右側結腸憩室炎による膿瘍形成を疑い，手術を行った．回盲部が腹壁に強固に癒着しており，剥離するとメッシュが盲腸に癒着，穿通し一塊となり腫瘤を形成していた．メッシュを取り除き，回盲部切除術を行った．病理組織では膿瘍内に放線菌の菌塊を認めた．術後は麻痺性イレウス，surgical site infectionを起こしたが保存的に軽快した．過去に報告のない，Kugel法による鼠径ヘルニア手術後にメッシュが盲腸に穿通した症例を経験した．

症例は98歳，女性．腹痛と嘔吐を認め，イレウスの診断で当院紹介となる．腹部全体に圧痛を認めたが，筋性防御はなかった．血液検査ではWBCが10,500/ul，CRPが26mg/dlと高値であった．腹部CTは腸管の拡張とニボー，肝腎嚢胞を認めた．CT，腹部所見から絞扼性イレウスの所見はなく，98歳という超高齢者でもあり経過観察とした．翌日ショック状態となったが，昇圧剤とアルブミン投与により状態が改善し絞扼性イレウスの疑いで開腹手術を行った．手術所見では，腸管の拡張は軽度であったが，胆嚢は捻転し右腎臓外側に陥入し壊死になっていた．壊死胆嚢を摘出し手術を終了した．術前CTで胆嚢と思われた部位は肝嚢胞であり，拡張した腸管と思われたものは捻転した胆嚢であった．胆嚢捻転症は比較的稀な疾患であるが，肝嚢胞と麻痺性イレウスを認める症例は胆嚢との鑑別に注意が必要である．98歳の胆嚢捻転症の報告は，本邦最高齢であり，若干の文献的考察を加え報告する．

We review a wet chemical process to prepare the high quality hydrogen-terminated Si(111)-(1×1) surface and show that the two key issues for the high reproducibility are the etching time and the oxygen in the etching solution. We add ammonium sulfite to remove the oxygen according to the previous report [Appl. Surf. Sci. 130, 146 (1998)]. To elucidate the optimal etching time, the vibrational properties and the surface morphology are investigated by high-resolution electron-energy-loss spectroscopy (HREELS), atomic force microscopy (AFM) and scanning tunneling microscopy (STM). The HREELS spectra and images of AFM and STM reveal the precise aqueous NH4F etching process of Si(111) and indicate the high controllability of steps and terraces with atomic scale. The surface cleanliness and morphology strongly depend on the etching time. At the etching time of 10 min, we obtain an ultra-clean and atomically ordered surface with wide terraces of 36 ± 7 nm step distance. It is confirmed by AFM and STM that the 1.0% ammonium sulfite is useful to remove dissolved oxygen in the 40% NH4F etching solution and to prepare a high quality H:Si(111)-(1×1) surface with low density of etch pits. The measurement of scanning tunneling spectroscopy(STS) shows the Schottky diode character of the surface. This surface is well applied to the initial stages of the nano-particle and film growth of Ag atoms and Pentacene molecules. [DOI: 10.1380/ejssnt.2009.557]

It was revealed that electrostatic forces between electrodes under the applied bias are almost completely suppressed by an electrochemical potential control. The force operating between n-decanethiol self-assembled monolayers (SAMs) on gold was examined by atomic force microscopy in liquid n-dodecane and in an aqueous solution of HClO4. In inert n-dodecane, the bias voltage was simply applied between the tip and the sample, and the force curve exhibited a long-range attractive force in accordance with the simple capacitance model. Meanwhile under the independent control of the tip and sample potentials in HClO4, the force curve did not depend on the applied potentials due to the small double-layer capacitance. [DOI: 10.1380/ejssnt.2009.731]

鼠径ヘルニア嚢に大腸癌腹膜転移をきたした症例を経験したので報告する．症例は75歳，男性．イレウスの疑いで入院となり，脾彎曲部に近い横行結腸に狭窄を伴う腫瘍を認め，結腸左半切除術を施行した．腹水，腹膜播種，肝転移等は認めず，病理診断は高分化腺癌，se，n0，ly1，v1であった．術後約1カ月後に右鼠径部膨隆を主訴に来院し，外鼠径ヘルニアの診断で初回手術から38日目にtension freeにて鼠径ヘルニア根治術を行った．ヘルニア嚢の病理学的診断にて横行結腸癌と同様の腺癌を認め，横行結腸癌の右鼠径ヘルニア嚢播種転移と診断された．他に転移を認めず，術後約3年経過した現在も再発徴候を認めていない．

Hydrolysis of carbohydrates is a major bioreaction in nature, catalyzed by glycoside hydrolases (GHs). We used neutron diffraction and high-resolution x-ray diffraction analyses to investigate the hydrogen bond network in inverting cellulase PcCel45A, which is an endoglucanase belonging to subfamily C of GH family 45, isolated from the basidiomycete Phanerochaete chrysosporium. Examination of the enzyme and enzyme-ligand structures indicates a key role of multiple tautomerizations of asparagine residues and peptide bonds, which are finally connected to the other catalytic residue via typical side-chain hydrogen bonds, in forming the Newton’s cradle - like proton relay pathway of the catalytic cycle. Amide-imidic acid tautomerization of asparagine has not been taken into account in recent molecular dynamics simulations of not only cellulases but also general enzyme catalysis, and it may be necessary to reconsider our interpretation of many enzymatic reactions., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: PA1610030000

La5Ti2CuS5O7 embedded into the surface of Au and Ti substrates shows a photocurrent attributable to HER and OER., The particulate semiconductor La5Ti2CuS5O7 (LTC) with a band gap energy of 1.9 eV functioned as either a photocathode or a photoanode when embedded onto Au or Ti metal layers, respectively. By applying an LTC/Au photocathode and LTC/Ti photoanode to, respectively, photoelectrochemical (PEC) water reduction and oxidation concurrently, zero-bias overall water splitting was accomplished under visible light irradiation. The band structures of LTC/Au and LTC/Ti calculated using a semiconductor device simulator (AFORS-HET) confirmed the critical role of the solid/solid junction of the metal back contact in the charge separation and PEC properties of LTC photoelectrodes. The prominently long lifetime of photoexcited charge carriers in LTC, confirmed by transient absorption spectroscopy, allowed the utilization of both photoexcited electrons and holes depending on the band structure at the solid/solid junction.