Feasibility of transanal minimally invasive surgery for total pelvic exenteration for advanced primary and recurrent pelvic malignancies

BACKGROUND

The purpose of this study was to clarify the efficacy and safety of transanal minimally invasive surgery (TAMIS) for total pelvic exenteration (TPE) in advanced primary and recurrent pelvic malignancies.

METHODS

Using a prospectively collected database, we retrospectively analyzed the clinical, surgical, and pathological outcomes of TAMIS for TPE. Surgery was performed between September 2019 and April 2023. The median follow-up period was 22 months (2-45 months).

RESULTS

Fifteen consecutive patients were included in this analysis M:F = 14:1 and median (range) age was 63 (36-74). Their diagnoses were as follows: primary rectal cancer (n = 5; 33%), recurrent rectal cancer (n = 4; 27%), primary anorectal cancer (n = 5; 33%), and gastrointestinal stromal tumor (n = 1; 7%). Bladder-sparing TPE was selected for two patients (13%). In nine of 15 patients (60%) the anal sphincter could be successfully preserved, five patients (33%) required combined resection of the internal iliac vessels, and two (13%) required rectus muscle flap reconstruction. The median operative time was 723 min (561-1082), and the median intraoperative blood loss was 195 ml (30-1520). The Clavien-Dindo classifications of the postoperative complications were as follows: grade 0-2 (n = 11; 73%); 3a (n = 3; 20%); 3b (n = 1; 7%); and ≥ 4 (n = 0; 0%). No cases of conversion to laparotomy or mortality were observed. The pathological results demonstrated that R0 was achieved in 14 patients (93%).

CONCLUSIONS

The short-term outcomes of this initial experience proved that this novel approach is feasible for TPE, with low blood loss, acceptable postoperative complications, and a satisfactory R0 resection rate.

Electrocatalytic Mechanisms for an Oxygen Evolution Reaction at a Rhombohedral Boron Monosulfide Electrode/Alkaline Medium Interface

Rhombohedral boron monosulfide (r-BS) with a layer stacking structure is a promising electrocatalyst for an oxygen evolution reaction (OER) within an alkaline solution. We investigated the catalytic mechanisms at the r-BS electrode/alkaline medium interface for an OER using hybrid solvation theory based on the first-principles method combined with classical solution theory. In this study, we elucidate the activities of the OER at the outermost r-BS sheet with and without various surface defects. The Gibbs free energies along the OER path indicate that the boron vacancies at the first and second layers of the r-BS surface (VB1 and VB2) can promote the OER. However, we found that the VB1 is easily occupied by the oxygen atom during the OER, degrading its electrocatalytic performance. In contrast, VB2 is suitable for the active site of the OER due to its structure stability. Next, we applied a bias voltage with the OER potential to the r-BS electrode. The bias voltage incorporates the positive excess surface charge into pristine r-BS and VB2, which can be understood by the relationship between the OER potential and potentials of zero charge at the r-BS electrode. Because the OH- ions are the starting point of the OER, the positively charged surface is kinetically favorable for the electrocatalyst owing to the attractive interaction with the OH- ions. Finally, we qualitatively discuss the flat-band potential at a semiconductor/alkaline solution interface. It suggests that p-type carrier doping could promote the catalytic performance of r-BS. These results explain the previous measurement of the OER performance with the r-BS-based electrode and provide valuable insights into developing a semiconductor electrode/water interface.

A Combined Reaction Path Search and Hybrid Solvation Method for the Systematic Exploration of Elementary Reactions at the Solid-Liquid Interface

We present a combined simulation method of single-component artificial force induced reaction (SC-AFIR) and effective screening medium combined with the reference interaction site model (ESM-RISM), termed SC-AFIR+ESM-RISM. SC-AFIR automatically and systematically explores the chemical reaction pathway, and ESM-RISM directly simulates the precise electronic structure at the solid-liquid interface. Hence, SC-AFIR+ESM-RISM enables us to explore reliable reaction pathways at the solid-liquid interface. We applied it to explore the dissociation pathway of an H2O molecule at the Cu(111)/water interface. The reaction path networks of the whole reaction and the minimum energy paths from H2O to H2 + O depend on the interfacial environment. The qualitative difference in the energy diagrams and the resulting change in the kinematically favored dissociation pathway upon changing the solvation environments are discussed. We believe that SC-AFIR+ESM-RISM will be a powerful tool to reveal the details of chemical reactions in surface catalysis and electrochemistry.

First-Principles Investigation of Charged Germagraphene as a Cathode Material for Dual-Carbon Batteries

As part of the concerted effort for development of energy storage technologies, dual-ion batteries (DIBs) or dual-carbon batteries (DCBs) are attracting interest, owing primarily to their eco-friendly active materials. The use of carbon as the active materials of DCBs brings about several challenges involving capacity and stability. This contribution aims to provide an in-depth understanding of the structural and electronic properties of Ge-doped graphene (Germagraphene) as a novel cathode material for DCBs. Density functional theory (DFT) calculations are combined with the effective screening medium (ESM) method for analyzing the electronic and band structure of PF₆ ^- anion-adsorbed Germagraphene under a potential bias. These theoretical investigations indicate that the use of Ge as a dopant for graphene has a positive impact on the adsorption of the anion on the cathode under both neutral and electrically biased conditions.

Theoretical Analysis on the Stability of 1-Pyrenebutanoic Acid Succinimidyl Ester Adsorbed on Graphene

The adsorbed structure of 1-pyrenebutanoic acid succinimidyl ester (PASE) on graphene was investigated based on density functional theory. We found two locally stable structures: a straight structure with the chainlike part of butanoic acid succinimidyl ester (BSE) lying down and a bent structure with the BSE part directed away from graphene, keeping the pyrene (Py) part adsorbed on graphene. Then, to elucidate the adsorption mechanism, we separately estimated the contributions of the Py and BSE parts to the entire PASE adsorption, and the adsorption effect of the BSE part was found to be secondary in comparison to the contribution of the Py. Next, the mobility of the BSE part at room temperature was confirmed by the activation energy barrier between straight and bent structures. To take account of the external environment, we considered the presence of amino acids and the hydration effect by a three-dimensional reference interaction site model. The contributions of glycine molecules and the solvent environment to stabilizing the bent PASE structure relative to the straight PASE structure were found. Therefore, the effect of the external environment around PASE is of importance when the standing-up process of the BSE part from graphene is considered.

Quantifying Uncertainties in Solvation Procedures for Modeling Aqueous Phase Reaction Mechanisms

Computational quantum chemistry provides fundamental chemical and physical insights into solvated reaction mechanisms across many areas of chemistry, especially in homogeneous and heterogeneous renewable energy catalysis. Such reactions may depend on explicit interactions with ions and solvent molecules that are nontrivial to characterize. Rigorously modeling explicit solvent effects with molecular dynamics usually brings steep computational costs while the performance of continuum solvent models such as polarizable continuum model (PCM), charge-asymmetric nonlocally determined local-electric (CANDLE), conductor-like screening model for real solvents (COSMO-RS), and effective screening medium method with the reference interaction site model (ESM-RISM) are less well understood for reaction mechanisms. Here, we revisit a fundamental aqueous hydride transfer reaction-carbon dioxide (CO₂) reduction by sodium borohydride (NaBH₄)-as a test case to evaluate how different solvent models perform in aqueous phase charge migrations that would be relevant to renewable energy catalysis mechanisms. For this system, quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulations almost exactly reproduced energy profiles from QM simulations, and the Na⁺ counterion in the QM/MM simulations plays an insignificant role over ensemble averaged trajectories that describe the reaction pathway. However, solvent models used on static calculations gave much more variability in data depending on whether the system was modeled using explicit solvent shells and/or the counterion. We pinpoint this variability due to unphysical descriptions of charge-separated states in the gas phase (i.e., self-interaction errors), and we show that using more accurate hybrid functionals and/or explicit solvent shells lessens these errors. This work closes with recommended procedures for treating solvation in future computational efforts in studying renewable energy catalysis mechanisms.

Impact of coronary plaque characteristics on periprocedural myocardial injury after elective percutaneous coronary intervention -MDCT and CMR analysis-

Background

Percutaneous coronary intervention (PCI) is often complicated by periprocedural myocardial injury (PMI) manifested by elevated cardiac biomarkers. The occurrence of PMI has been shown to be associated with worse clinical outcome over short- and long-term.

Purpose

We performed multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (CMR) to evaluate the relationship between culprit plaque characteristics and PMI.

Methods

A total of 90 patients who underwent elective PCI were underwent CMR and multidetector coronary tomography before PCI. The high intensity plaque (HIP) on CMR was defined as a coronary plaque to myocardium signal intensity ratio (PMR) of >1.4. The plaque characteristics and the presence of napkin-ring sign (NRS) were analyzed on MDCT. PMI was defined as an increase in cardiac Troponin T levels to more than 5 times the upper limit of normal at 24 h after PCI. Patients were divided into 2 groups according to the presence (Group I, n=26) or absence (Group II, n=64) of PMI.

Results

Spotty calcification, positive remodeling, low attenuation plaque and NRS on MDCT were significantly more observed in Group I than in Group II. HIP on CMR was significantly more observed in Group I than in Group II. In the multivariable logistic regression analysis, the presence of NRS and HIP were significantly independent predictors of PMI (odds ratio (OR) 4.82, 95% confidence interval 1.13–20.60, P=0.034 and OR 3.66, 95% CI 1.09–12.30, P=0.036, respectively). Moreover, for prediction of PMI, NRS and HIP showed a high positive predictive value of 81%, and their absence showed a high negative predictive value of 91%.

Conclusions

MDCT and CMR may play an important role in detecting which lesions are high risks for myocardial necrosis after PCI in elective coronary stenting.

Funding Acknowledgement

Type of funding source: None

Toward Engineering of Solution Microenvironments for the CO2 Reduction Reaction: Unraveling pH and Voltage Effects from a Combined Density-Functional-Continuum Theory

Engineering the electrolyte microenvironment represents an attractive route to tuning the selectivity of electrocatalytic reactions beyond catalyst composition and morphology. However, harnessing the full potential of this approach requires understanding the interplay between voltage, electrolyte composition, and adsorbate binding within the electrical double layer, which is absent from the usual theoretical approaches. In this work, we apply a recently developed density functional theory (DFT)-continuum approach based on the effective screening medium method and reference interaction site model (ESM-RISM) to explore electrolyte effects with an enhanced description of the electrochemical interface. Applying this method to the binding of CO adsorbates in potassium-containing electrolytes on copper, a problem of direct relevance to CO₂ electroreduction to value-added products, we show that the interdependence of voltage and pH leads to an unexpected change in adsorption site preference on Cu(001) terraces. Our findings highlight the often-overlooked importance of the electrical double-layer structure for predicting catalyst operation.

Two-Phase Reaction Mechanism for Fluorination and Defluorination in Fluoride-Shuttle Batteries: A First-Principles Study

Fluoride-shuttle batteries (FSBs), which are based on fluoride-ion transfer, have attracted attention because of their high theoretical energy densities. The fluorination and defluorination reactions at the electrodes are the possible rate-determining steps in FSBs, and understanding the mechanism is important to achieve smooth charge/discharge. In this study, we discuss the thermodynamically favored pathways for the fluorination and defluorination reactions and compare the reactions through the solid-solution and two-phase-coexistent states by density functional theory (DFT) calculations. The free energies of the solid-solution and two-phase states approximate the energies calculated by DFT, and their accuracy was validated by comparison with experimental formation enthalpies and free energies. The relative formation enthalpies of typical, transition, and relativistic metal (Tl, Pb, and Bi) fluorides are well reproduced by DFT calculations within 0.1, 0.2, and 0.4 eV, respectively. We also show that the reaction pathway can be determined by comparing the formation enthalpies of the metal fluoride H, a fluorine vacancy H_V, and an interstitial fluorine defect H_I from the simple selection rule. The enthalpy relation of H_I > H > -H_V observed in all the calculations strongly suggests that fluorination and defluorination in FSB electrodes occur by a two-phase reaction. This fluorination and defluorination mechanism will be useful to clarify the rate-determining step in FSBs.

Specific ion effects at graphitic interfaces

Improved understanding of aqueous solutions at graphitic interfaces is critical for energy storage and water desalination. However, many mechanistic details remain unclear, including how interfacial structure and response are dictated by intrinsic properties of solvated ions under applied voltage. In this work, we combine hybrid first-principles/continuum simulations with electrochemical measurements to investigate adsorption of several alkali-metal cations at the interface with graphene and within graphene slit-pores. We confirm that adsorption energy increases with ionic radius, while being highly dependent on the pore size. In addition, in contrast with conventional electrochemical models, we find that interfacial charge transfer contributes non-negligibly to this interaction and can be further enhanced by confinement. We conclude that the measured interfacial capacitance trends result from a complex interplay between voltage, confinement, and specific ion effects-including ion hydration and charge transfer.

Understanding aqueous solutions at graphitic interfaces is critical in a wide variety of emerging technologies. Here, the authors unravel specific ion effects at the interface with graphene and within graphene slit-pores by coupling first-principles simulations and electrochemical measurements.

Origins and Implications of Interfacial Capacitance Enhancements in C60-Modified Graphene Supercapacitors

Understanding and controlling the electrical response at a complex electrode-electrolyte interface is key to the development of next-generation supercapacitors and other electrochemical devices. In this work, we apply a theoretical framework based on the effective screening medium and reference interaction site model to explore the role of electrical double-layer (EDL) formation and its interplay with quantum capacitance in graphene-based supercapacitors. In addition to pristine graphene, we investigate a novel C₆₀-modified graphene supercapacitor material, which promises higher charge-storage capacity. Beyond the expected enhancement in the quantum capacitance, we find that the introduction of C₆₀ molecules significantly alters the EDL response. These changes in EDL are traced to the interplay between surface morphology and charge localization character and ultimately dominate the overall capacitive improvement in the hybrid system. Our study highlights a complex interplay among surface morphology, electronic structure, and interfacial capacitance, suggesting general improvement strategies for optimizing carbon-based supercapacitor materials.

Ex Vivo Reperfusion Model to Evaluate Utility of Machine Preservation for Porcine Liver Donated After Cardiac Death

BACKGROUND

Machine perfusion (MP) techniques are expected to prove useful for preserving the organ viability and recovering organ function for organ transplantation. Furthermore, an accurate assessment of organ viability using MP is important for expanding the donor criteria. In this study, an ex vivo reperfusion model (ERM) simulating transplantation using diluted autologous blood under normothermic conditions was evaluated for its utility of MP under subnormothermic conditions for livers donated after cardiac death (DCD).

METHODS

The liver preservation methods for DCD porcine livers were evaluated using the ERM. This investigation was performed using a novel perfusion system developed by our research group. Porcine livers were procured with a warm ischemia time (WIT) of 60 minutes. The organs were then preserved using subnormothemic machine perfusion (SNMP) or static cold storage (CS) for 4 hours. We also compared these tissues with SNMP livers procured under a WIT of 0 minutes. After the preservation, the livers were reperfused for 2 hours using the ERM with diluted autologous blood oxygenated by a membrane oxygenator under NMP conditions. Reperfusion was evaluated based on perfusion flow dynamics and outflow of deviating enzymes.

RESULTS

In the early stages of reperfusion, pressure in the blood vessels increased sharply in the CS group. Furthermore, the amount of aspartate aminotransferase accumulation was lower in the SNMP group than in the other groups. These results suggest ischemia-reperfusion injury is suppressed in SNMP conditions.

CONCLUSION

An ERM has use in evaluating the utility of MP for the DCD liver.

Optimum Perfusate Volume of Purified Subnormothermic Machine Perfusion for Porcine Liver Donated After Cardiac Death

INTRODUCTION

Subnormothermic machine perfusion (SNMP) shows some advantages for the preservation of grafts donated after cardiac death (DCD) and improvements in machine perfusion (MP) technology are important to enhance organ preservation outcomes for liver transplantation. In this study, we focused on purified subnormothermic machine perfusion (PSNMP) and volumes of perfusate removed to substitute for purification and replaced by modified University of Wisconsin-gluconate after the start of perfusion and investigated, in particular, the optimum perfusate purification volume. Several purification volumes under SNMP were compared. In addition, the perfusate purification during MP was indicated as a potential technique to enhance the organ quality of DCD grafts and extended-criteria donors.

METHODS

The PSNMP at several volumes (0.5 L, 1.5 L, and 3 L) were compared with regular SNMP without any purification treatment (untreated control). In the PSNMP group, all perfusate was removed to substitute for purification of the perfusate by modified University of Wisconsin-gluconate solution after the start of perfusion. After removing the perfusate, new perfusate with the same components was perfused to preserve the porcine livers obtained under warm ischemia for 60 minutes using SNMP at 22°C porcine liver for 4 hours.

RESULTS

The concentrations of aspartate aminotransferase and lactate dehydrogenase in the untreated group were significantly higher during perfusion compared to those of the intervention group. There are no significant differences among the volume conditions of the purification groups.

CONCLUSIONS

The optimal volume of perfusate purification was confirmed with a simple experimental comparison between untreated and PSNMP conditions.

Li deposition and desolvation with electron transfer at a silicon/propylene-carbonate interface: transition-state and free-energy profiles by large-scale first-principles molecular dynamics

We report the result of a large-scale first-principles molecular dynamics simulation under different electric biases performed to understand the charge transfer process coupling with lithium deposition and desolvation processes.

Toward full simulation of the electrochemical oxygen reduction reaction on Pt using first-principles and kinetic calculations

First-principles molecular dynamics gave the kinetic and redox parameters of the oxygen reduction reaction in a fuel cell using a bias control scheme, and gave the current–voltage relationship.

The Necessity of Chest Physical Therapy for Thoracoscopic Oesophagectomy

Radical surgery for thoracic oesophageal cancer is highly invasive and often leads to respiratory complications; thoracoscopic surgery is a less-invasive alternative. We examined the need for chest physical therapy (CPT) after thoracoscopic oesophagectomy. Thirty-six consecutive patients, randomly selected for either thoracotomy or thoracoscopic surgery, were included in a randomized clinical trial and received CPT under the same protocol. During short-term post-operative follow-up, both groups showed a marked reduction in respiratory function and responded to CPT to the same extent, although 2 weeks after surgery some parameters of respiratory function were significantly higher in the thoracoscopy group. Thoracoscopic surgery has been reported to be less invasive than standard thoracotomy, but our results suggest that the procedure is also invasive with respect to respiratory function and that CPT should be performed before and after thoracoscopic surgery.

Poly(benzoquinonyl sulfide) as a High-Energy Organic Cathode for Rechargeable Li and Na Batteries

In concern of resource sustainability and environmental friendliness, organic electrode materials for rechargeable batteries have attracted increasing attentions in recent years. However, for many researchers, the primary impression on organic cathode materials is the poor cycling stability and low energy density, mainly due to the unfavorable dissolution and low redox potential, respectively. Herein, a novel polymer cathode material, namely poly(benzoquinonyl sulfide) (PBQS) is reported, for either rechargeable Li or Na battery. Remarkably, PBQS shows a high energy density of 734 W h kg^-1 (2.67 V × 275 mA h g^-1) in Li battery, or 557 W h kg^-1 (2.08 V × 268 mA h g^-1) in Na battery, which exceeds those of most inorganic Li or Na intercalation cathodes. Moreover, PBQS also demonstrates excellent long-term cycling stability (1000 cycles, 86%) and superior rate capability (5000 mA g^-1, 72%) in Li battery. Besides the exciting battery performance, investigations on the structure-property relationship between benzoquinone (BQ) and PBQS, and electrochemical behavior difference between Li-PBQS battery and Na-PBQS battery, also provide significant insights into developing better Li-organic and Na-organic batteries beyond conventional Li-ion batteries.

Potential-induced electronic structure changes in supercapacitor electrodes observed by in operando soft X-ray spectroscopy

The dynamic physiochemical response of a functioning graphene-based aerogel supercapacitor is monitored in operando by soft X-ray spectroscopy and interpreted through ab initio atomistic simulations. Unanticipated changes in the electronic structure of the electrode as a function of applied voltage bias indicate structural modifications across multiple length scales via independent pseudocapacitive and electric double layer charge storage channels.

Flexible metallic nanowires with self-adaptive contacts to semiconducting transition-metal dichalcogenide monolayers

In the pursuit of ultrasmall electronic components, monolayer electronic devices have recently been fabricated using transition-metal dichalcogenides. Monolayers of these materials are semiconducting, but nanowires with stoichiometry MX (M = Mo or W, X = S or Se) have been predicted to be metallic. Such nanowires have been chemically synthesized. However, the controlled connection of individual nanowires to monolayers, an important step in creating a two-dimensional integrated circuit, has so far remained elusive. In this work, by steering a focused electron beam, we directly fabricate MX nanowires that are less than a nanometre in width and Y junctions that connect designated points within a transition-metal dichalcogenide monolayer. In situ electrical measurements demonstrate that these nanowires are metallic, so they may serve as interconnects in future flexible nanocircuits fabricated entirely from the same monolayer. Sequential atom-resolved Z-contrast images reveal that the nanowires rotate and flex continuously under momentum transfer from the electron beam, while maintaining their structural integrity. They therefore exhibit self-adaptive connections to the monolayer from which they are sculpted. We find that the nanowires remain conductive while undergoing severe mechanical deformations, thus showing promise for mechanically robust flexible electronics. Density functional theory calculations further confirm the metallicity of the nanowires and account for their beam-induced mechanical behaviour. These results show that direct patterning of one-dimensional conducting nanowires in two-dimensional semiconducting materials with nanometre precision is possible using electron-beam-based techniques.

Gate-induced electron-state tuning of MoS2: first-principles calculations

The electronic structure of electrostatically doped MoS2 thin films is investigated on the basis of first-principles total-energy calculations. We find that electron injection leads to a rapid downward shift in the energy of the unoccupied nearly free electron (NFE) state relative to other conduction bands. The NFE state finally crosses the Fermi level at an electron density of 0.81 × 10(14) cm(-2) that is attributable to the strong local electric field induced by charge accumulation near the surface. Electrons accommodated in the NFE state play an important role in determining the conducting properties of MoS2 thin films.

Effect of thermal motion on catalytic activity of nanoparticles in polar solvent

In this study, we propose that electrode potential fluctuations due to the thermal motion of the solvent may serve to enhance the catalytic activity of nanostructures. The proposed model uses a simple, Marcus-type treatment of the statistical behavior of the solvent and the Butler-Volmer law for the instantaneous catalytic rate as a function of the electrode potential. The rapid development of probing techniques with high spatial and temporal resolution will help to further confirm and characterize the dynamical properties of nanostructures.

Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(θ23)=0.514±0.082 and mass splitting |Δm(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.

Highly ordered cobalt-phthalocyanine chains on fractional atomic steps: one-dimensionality and electron hybridization

Precisely controlled fabrication of low-dimensional molecular structures with tailored morphologies and electronic properties is at the heart of the nanotechnology research. Especially, the formation of one-dimensional (1D) structures has been strongly desired due to their expected high performance for information processing in electronic/magnetic devices. So far, however, they have been obtained by tough and slow methods such as manipulation of individual molecules, which are totally unsuited for mass production. Here we show that highly ordered cobalt-phthalocyanine chains can be self-assembled on a metal surface using fractional atomic steps as a template. We also demonstrate that the substrate surface electrons, which can be confined by cobalt-phthalocyanine molecules, can propagate along the step arrays and can hybridize with the molecular orbitals. These findings provide a significant step toward readily realization of 1D charge/spin transport, which can be mediated either directly by the molecules or by the surface electrons.

Charge manipulation in molecules encapsulated inside single-wall carbon nanotubes

We report clear experimental evidence for the charge manipulation of molecules encapsulated inside single-wall carbon nanotubes (SWCNTs) using electrochemical doping techniques. We encapsulated β-carotene (Car) inside SWCNTs and clarified electrochemical doping characteristics of their Raman spectra. C=C streching modes of encapsulated Car and a G band of SWCNTs showed clearly different doping behaviors as the electrochemical potentials were shifted. Electron extraction from encapsulated Car was clearly achieved. However, electrochemical characteristics of Car inside SWCNTs and doping mechanisms elucidated by calculations based on density-functional theory indicate the difficulty of charge manipulation of molecules inside SWCNTs due to the presence of strong on-site Coulomb repulsion energy at the molecules.

Limit on neutrinoless ββ decay of 136Xe from the first phase of KamLAND-Zen and comparison with the positive claim in 76Ge

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <m(ββ)> <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

First-principles molecular dynamics at a constant electrode potential

A simulation scheme for performing first-principles molecular dynamics at a constant electrode potential is presented, opening the way for a more realistic modeling of voltage-driven devices. The system is allowed to exchange electrons with a reservoir at fixed potential, and dynamical equations for the total electronic charge are derived by using the potential energy of the extended system. In combination with a thermostat, this potentiostat scheme reproduces thermal fluctuations of the charge with the correct statistics, implying a realistic treatment of the potential as a control variable. Practically, the dynamics of the charge are decoupled from the electronic structure calculations, making the scheme easily implementable in existing first-principles molecular dynamics codes. Our approach is demonstrated on a test system by considering various test cases.

Comparative risk of common peroneal nerve injury in far anteromedial portal drilling and transtibial drilling in anatomical double-bundle ACL reconstruction

PURPOSE

The purpose of this study was to investigate the risk of common peroneal nerve injury in FM drilling as compared to transtibial drilling in anatomical double-bundle ACL reconstruction.

METHODS

Ten cadaveric knees without ligament injury or significant arthritis were used for this study. Knees were secured at 90° and 120° of flexion. In transtibial drilling groups, a guide pin was drilled through either the anteromedial bundle (AMB) or posterolateral bundle (PLB) tibial insertion site to either the AMB or PLB femoral insertion site (tibial insertion site-femoral insertion site: AM-AM, PL-PL, PL-AM and AM-PL). In FM drilling groups (FM-AM and FM-PL),the pin was drilled at the AMB or PLB femoral insertion site through the FM. We measured the shortest distance between the point at which the pin ran through the lateral cortex of the femur and the ipsilateral common peroneal nerve at a knee flexion of 90° and 120°.

RESULTS

At a knee flexion of 90°, the shortest mean distance to the common peroneal nerve was 15.3 mm in the FM-PL group, 13.4 mm in the FM-AM group, 27.9 mm in the PL-PL group, 30.8 mm in the AM-AM group, 37.8 mm in the PL-AM group and 29.5 mm in the AM-PL group. At a knee of flexion 120°, the mean distance was 17.3 mm in the FM-PL group, 18.1 mm in the FM-AM group, 32.2 mm in the PL-PL group, 36.6 mm in the AM-AM group, 38.0 mm in the PL-AM group and 35.2 mm in the AM-PL group. Significant differences were observed between 90° and 120° of knee flexion in the FM-AM, PL-PL, AM-AM and AM-PL groups (P < 0.05). Significant differences were observed at flex 90° between the FM-AM group and AM-AM group, and between the FM-AM group and PL-AM group. Significant differences were observed at flex 120° between the FM-AM group and AM-AM group, between the FM-AM group and PL-AM group and between the FM-PL group and AM-PL group.

CONCLUSION

The distance to the peroneal nerve in FM drilling was significantly longer at 120° than at 90° of knee flexion. Therefore, the risk of peroneal injury using FM drilling should decrease at a higher angle of knee flexion.

Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam

The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3)  eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.

Semiconducting electronic property of graphene adsorbed on (0001) surfaces of SiO2

First-principles total energy calculations are performed to investigate the energetics and electronic structures of graphene adsorbed on both an oxygen-terminated SiO2 (0001) surface and a fully hydroxylated SiO2 (0001) surface. We find that there are several stable adsorption sites for graphene on both O-terminated and hydroxylated SiO2 surfaces. The binding energy in the most stable geometry is found to be 15 meV per C atom, indicating a weak interaction between graphene and SiO2 (0001) surfaces. We also find that the graphene adsorbed on SiO2 is a semiconductor irrespective of the adsorption arrangement due to the variation of on-site energy induced by the SiO2 substrate.

Influence of disorder on conductance in bilayer graphene under perpendicular electric field

Electron transport in bilayer graphene placed under a perpendicular electric field is revealed experimentally. Steep increase of the resistance is observed under high electric field; however, the resistance does not diverge even at low temperatures. The observed temperature dependence of the conductance consists of two contributions: the thermally activated (TA) conduction and the variable range hopping (VRH) conduction. We find that for the measured electric field range (0-1.3 V/nm) the mobility gap extracted from the TA behavior agrees well with the theoretical prediction for the band gap opening in bilayer graphene, although the VRH conduction deteriorates the insulating state more seriously in bilayer graphene with smaller mobility. These results show that the improvement of the mobility is crucial for the successful operation of the bilayer graphene field effect transistor.

Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice

AIMS

The purpose of this study is to assess the in vitro enzyme inhibition profile of DSP-7238, a novel non-cyanopyrrolidine dipeptidyl peptidase (DPP) IV inhibitor and to evaluate the acute and chronic effects of this compound on glucose metabolism in two different mouse models of type 2 diabetes.

METHODS

The in vitro enzyme inhibition profile of DSP-7238 was assessed using plasma and recombinant enzymes including DPP IV, DPP II, DPP8, DPP9 and fibroblast activation protein alpha (FAPalpha) with fluorogenic substrates. The inhibition type was evaluated based on the Lineweaver-Burk plot. Substrate selectivity of DSP-7238 and comparator DPP IV inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin) was evaluated by mass spectrometry based on the changes in molecular weight of peptide substrates caused by release of N-terminal dipeptides. In the in vivo experiments, high-fat diet-induced obese (DIO) mice were subjected to oral glucose tolerance test (OGTT) following a single oral administration of DSP-7238. To assess the chronic effects of DSP-7238 on glycaemic control and pancreatic beta-cell damage, DSP-7238 was administered for 11 weeks to mice made diabetic by a combination of high-fat diet (HFD) and a low-dose of streptozotocin (STZ). After the dosing period, HbA1c was measured and pancreatic damage was evaluated by biological and histological analyses.

RESULTS

DSP-7238 and sitagliptin both competitively inhibited recombinant human DPP IV (rhDPP IV) with K(i) values of 0.60 and 2.1 nM respectively. Neither vildagliptin nor saxagliptin exhibited competitive inhibition of rhDPP IV. DSP-7238 did not inhibit DPP IV-related enzymes including DPP8, DPP9, DPP II and FAPalpha, whereas vildagliptin and saxagliptin showed inhibition of DPP8 and DPP9. Inhibition of glucagon-like peptide-1 (GLP-1) degradation by DSP-7238 was apparently more potent than its inhibition of chemokine (C-X-C motif) ligand 10 (IP-10) or chemokine (C-X-C motif) ligand 12 (SDF-1alpha) degradation. In contrast, vildagliptin and saxagliptin showed similar degree of inhibition of degradation for all the substrates tested. Compared to treatment with the vehicle, single oral administration of DSP-7238 dose-dependently decreased plasma DPP IV activity and improved glucose tolerance in DIO mice. In addition, DSP-7238 significantly decreased HbA1c and ameliorated pancreatic damage following 11 weeks of chronic treatment in HFD/STZ mice.

CONCLUSIONS

We have shown in this study that DSP-7238 is a potent DPP IV inhibitor that has high specificity for DPP IV and substrate selectivity against GLP-1. We have also found that chronic treatment with DSP-7238 improves glycaemic control and ameliorates beta-cell damage in a mouse model with impaired insulin sensitivity and secretion. These findings indicate that DSP-7238 may be a new therapeutic agent for the treatment of type 2 diabetes.

Usefulness of spinal drainage for post-traumatic external hydrocephalus: report of two cases

An 8-year-old girl presented with symptoms of increased intracranial pressure on the 18th day after removal of an occipital epidural haematoma. A 69-year-old woman exhibited the same symptoms on the 6th day after the removal of a left frontal subdural haematoma. Computed tomography (CT) revealed that both patients were suffering from external hydrocephalus. Spinal drainage, maintained for 18 days in the former case and for 7 days in the latter, not only relieved those symptoms but also cured the external hydrocephalus. Recurrence of external hydrocephalus has not been observed in either case for several years since discontinuation of spinal drainage. Usefulness of spinal drainage for post-traumatic external hydrocephalus is discussed.