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.

Application and Efficacy of Vitamin E-Bonded Polysulfone Membrane in Acute Blood Purification Therapy.

INTRODUCTION: Acute blood purification therapy (BPT) has been evaluated in the context of intensive care for serious conditions related to systemic inflammation, but its mechanism and efficacy are not fully understood. OBJECTIVE: This study examined the feasibility of using vitamin E-bonded polysulfone membranes (VEPS) for BPT in a LPS-induced rat model of systemic inflammation. METHODS: To evaluate the efficacy of BPT with a VEPS membrane, polysulfone (PS) membranes conventionally used in intensive care were bonded with the antioxidant vitamin E and used in a rat model of lipopolysaccharide (LPS)-induced systemic inflammation. BPT using a PS membrane (PS group) or a VEPS membrane (VEPS group) was performed 6 h after administration of LPS. Extracorporeal circulation was established in normal rats as a control (sham group). Survival rates, histology of lung specimens, and levels of myeloperoxidase (MPO) and high mobility group box-1 (HMGB-1) were examined in each group. RESULTS: Survival rates at 24 h after LPS administration were 100% in the VEPS group and 50% in the PS group. Pulmonary architecture was largely maintained and the level of infiltration of inflammatory cells remained moderate in the VEPS group. Levels of active MPO before and after BPT were significantly higher in the PS and VEPS groups than in the sham group, with no significant differences between the PS and VEPS groups. HMGB-1 levels were significantly elevated after BPT in the PS group. CONCLUSIONS: This study demonstrated that use of the VEPS membrane for BPT increased survival rate and reduced lung injury in a rat model of systemic inflammatory response syndrome (SIRS), suggesting the possible use of VEPS membranes in the treatment of serious conditions related to systemic inflammation.

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.

Evaluation of Proteins and Cells that Adsorb to Dialysis Membranes Used in Continuous Hemodiafiltration: Comparison of AN69ST, Polymethylmethacrylate, and Polysulfone Membranes.

OBJECTIVE: In intensive care medicine, continuous renal replacement therapy (CRRT) is important for critically ill patients. Various types of dialysis membranes are currently used in clinical settings, each having unique structures and characteristics. This study aimed to perform a detailed analysis of the characteristics of polysulfone (PS), polymethylmethacrylate (PMMA), and polyacrylonitrile (AN69ST) membranes, and to determine differences in the adsorption of proteins and blood cells by membrane material. METHODS: Subjects were patients undergoing CRRT in the ICU of the Kokura Memorial Hospital. After use, membranes were collected and analyzed. Semi-quantitative analysis of the membrane surface was performed by scanning electron microscopy. We determined the identity of proteins adsorbed to the surface of membranes by TOF/MS analysis, and measured the amount of adsorbed chemical mediators. RESULTS: Electron microscopy revealed that, compared to PS and PMMA membranes, AN69ST membranes had a greater amount of adsorbed activated white blood cells (WBCs). A large amount of platelets was adsorbed to PMMA membranes. In terms of the amount of adsorbed protein, significantly more proteins adsorbed to AN69ST membranes compared to PS and PMMA membranes. Moreover, TOF/MS analysis revealed a difference in the types of adsorbed proteins by membrane. Chemokines were particularly prevalent among adsorbed proteins for all 3 membranes. CONCLUSION: Compared to PS and PMMA membranes, AN69ST membranes had a higher capacity to remove activated WBCs. Moreover, apparent differences were noted in the types of proteins that adsorbed to each type of membrane. These differences in membrane properties may impact clinical outcomes.

Closed Fracture Diagnosed by Bedside Ultrasonography During Hemodialysis: A Report of Seven Cases and Relevant Clinical Characteristics.

BACKGROUND: Patients undergoing dialysis have a high incidence of fracture, and early diagnosis is important. We report seven cases of closed rib or upper-limb fractures diagnosed by bedside ultrasonography during maintenance hemodialysis sessions and describe relevant clinical characteristics. CASE PRESENTATION: We identified seven patients who were injured by falls in their homes. No injuries occurred on the day of dialysis. Five of the 7 patients did not visit the emergency room. All patients complained of persistent unexplained pain during a regular hemodialysis session. Ultrasonography (US) was performed during dialysis sessions, without any reports of pain. Before US evaluation, the sensitivity of radiography for diagnosis of fracture was 25%, while the sensitivity of US was 100%. Compared with other patients in our clinic, these patients were significantly older and had lower serum albumin concentrations and lower hemodialysis efficiency as determined by Kt/V. They also had a higher incidence of diabetes and a greater need for vasopressors during dialysis. These findings were consistent with the results of previous studies of the characteristics of fractures in dialysis patients. However, blood levels of creatinine, corrected calcium, phosphate, intact parathyroid hormone, and hemoglobin, as well as bone density and blood pressure, after the previous dialysis session were not different. CONCLUSIONS: To our knowledge, this is the first report of closed fracture of superficial bone diagnosed by bedside ultrasonography during a hemodialysis session. Ultrasonography is especially useful for diagnosis in these cases because it is noninvasive and highly accurate. Doctors should determine the differential diagnosis for closed fracture in patients undergoing dialysis, especially in those who are older, have diabetes, and are malnourished, and in those with recent contusions and persistent pain.

Observation of Granulocyte Adsorption in Adacolumn Cellulose Acetate Beads after Granulocytapheresis.

Adacolumn is a therapeutic mode for ulcerative colitis that achieves therapeutic efficacy through the adhesion of leukocytes to cellulose acetate beads. We used scanning electron microscopy and observed leukocyte adsorption on Adacolumn beads after granulocytapheresis/granulocyte and monocyte adsorption apheresis. We then compared results between two patients with a low and high C-reactive protein (CRP) levels to determine whether adhesion is affected by a difference in leukocyte activity depending on the level of inflammation. We found that the surface layers of the beads from both patients were covered by a clay-like layer, and spherical granulocytes were adsorbed here and there on top of it. In cross-section the adsorbed granulocytes were visible in the clay-like layer and the surface layer alike. The clay-like layer had a maximum thickness of approximately 12 µm in the low CRP patient and approximately 50 µm in the high CRP patient, so in the high CRP patient the clay-like adsorption layer was thicker. Taken together, adsorption onto beads is considered to involve an immunological mechanism. Our findings suggest that granulocytes contact and adhere to each other at the surface layer after adsorption, and that granulocyte-granulocyte adhesion is enhanced by a higher inflammatory response.

Time-Dependent Multicomponent Density Functional Theory for Coupled Electron-Positron Dynamics.

Electron-positron interactions have been utilized in various fields of science. Here we develop time-dependent multicomponent density functional theory to study the coupled electron-positron dynamics from first principles. We prove that there are coupled time-dependent single-particle equations that can provide the electron and positron density dynamics, and derive the formally exact expression for their effective potentials. Introducing the adiabatic local density approximation to time-dependent electron-positron correlation, we apply the theory to the dynamics of a positronic lithium hydride molecule under a laser field. We demonstrate the significance of the coupling between electronic and positronic motion by revealing the complex positron detachment mechanism and the suppression of electronic resonant excitation by the screening effect of the positron.

Hepatic Angiosarcoma with Dyskeratosis Congenita.

Nail dystrophy, oral leukoplakia and abnormal skin pigmentation are the defining features of dyskeratosis congenita. Dyskeratosis congenita is a disorder of poor telomere maintenance and is known to increase the risk of developing multiple types of malignancy. However, there are few reports of liver tumors arising in dyskeratosis congenita patients. We herein report the second case of hepatic angiosarcoma arising from dyskeratosis congenita: a 23-year-old man was introduced to our hospital due to the detection of multiple tumors in the liver. A histological analysis showed angiosarcoma that stained positive for antibodies to both CD31 and blood coagulation factor VIII.

Clinical and histological features of different types of Budd-Chiari syndrome: a comparison of 4 cases.

Budd-Chiari syndrome (BCS) is a rare condition characterized by hepatic venous outflow obstruction. In this report, we present 4 cases of BCS with complete and incomplete obstruction of the inferior vena cava (IVC) and hepatic vein (HV). Each case showed different and unique features of liver damage, which were attributed to the site and degree of obstruction. Interestingly, improved liver functions such as increased serum albumin levels, decreased hyaluronic acid levels and a normal indocyanine green clearance test were evident within 1 month of the balloon angioplasty. Pericellular fibrosis and hypervascular regenerative nodules were also reversible after obstruction removal. Therefore, it is very important to manage this rare disease before it progresses to liver cirrhosis.

[Relationships between damage-associated molecular patterns and organ injury].

Recently studies have demonstrated that cell components called damage-associated molecular patterns (DAMPs) are secreted from cells in response to inflammation and organ injury. While DAMPs are maintained within the cell under normal conditions, they are secreted in response to systemic or chronic inflammation. DAMPs are recognized by pattern recognition receptors (PRRs) such as Toll-like receptor (TLR) and receptor for advanced glycation end products (RAGE). DAMPs also induce the phosphorylation of various intracellular proteins and activate NF-kappaB signaling. This induces an inflammatory response via cytokine production and activation of macrophages and dendritic cells. In essence, DAMPs alert the immune system to danger. Some DAMPs are considered therapeutic targets for acute systemic inflammation (e.g., sepsis). Indeed, anti-HMGB1 and anti-histone antibodies attenuated the inflammatory response and organ injury in a systemic inflammation model. Anti-RAGE antibodies were also shown to have beneficial effects in an animal inflammation model. These findings suggest that DAMPs may serve as novel therapeutic targets against severe systemic inflammation as well. We anticipate that in the near future, anti-DAMP therapy may become more widespread in the clinical setting.

Can endoscopic submucosal dissection be safely performed in a smaller specialized clinic?

AIM: To investigate whether endoscopic submucosal dissection (ESD) can be safely performed at small clinics, such as the Shirakawa Clinic. METHODS: One thousand forty-seven ESDs to treat gastrointestinal tumors were performed at the Shirakawa Clinic from April 2006 to March 2011. The efficacy, technical feasibility and associated complications of the procedures were assessed. The ESD procedures were performed by five endoscopists. Sedation was induced with propofol for esophagogastorduodenal ESD. RESULTS: One thousand forty-seven ESDs were performed to treat 64 patients with esophageal cancer (E), 850 patients with gastric tumors (G: 764 patients with cancer, 82 patients with adenomas and four others), four patients with duodenal cancer (D) and 129 patients with colorectal tumors (C: 94 patients with cancer, 21 patients with adenomas and 14 others). The en bloc resection rate was 94.3% (E: 96.9%, G: 95.8%, D: 100%, C: 79.8%). The median operation time was 46 min (range: 4-360 min) and the mean size of the resected specimens was 18 mm (range: 2-150 mm). No mortal complications were observed in association with the ESD procedures. Perforation occurred in 12 cases (1.1%, E: 1 case, G: 9 cases, D: 1 case, C: 1 case) and postoperative bleeding occurred in 53 cases (5.1%, G: 51 cases, D: 1 case, C: 1 case); however, no case required either emergency surgery or blood transfusion. All of the perforations and postperative bleedings were resolved by endoscopic clipping or hemostasis. The other problematic complication observed was pneumonia, which was treated with conservative therapy. CONCLUSION: ESD can be safely performed in a clinic with established therapeutic methods and medical services to address potential complications.

[Pathological complete remission using low-dose cisplatin plus S-1 for gastric cancer patient with liver metastases].

A 70-year-old female presented with epigastralgia. Gastrointestinal endoscopic examination showed advanced gastric cancer type 2. Computed tomography(CT)showed a liver tumor of 37mm in segment 6. She was treated with oral S-1, 80 mg/body for 14 days, followed by a 7-day rest, and CDDP 20mg/m2(day 1 and 8). After ten courses of treatment, CT showed reduction of the primary cancer, the liver tumor, and the affected lymph nodes. Then, distal gastrectomy, lymph node dissection, and partial liver resection were performed. The histological diagnosis was no viable cancer cells found in stomach, liver or lymph nodes. One year and 1 month postoperatively, the patient is alive without recurrence.

Bolus injection of newly synthesized vitamin E derivative ETS-GS for the treatment of acute severe ulcerative colitis in a mouse model. New vitamin E derivative for acute severe UC.

PURPOSE: Vitamin E with its antioxidant action has therapeutic effects on ulcerative colitis (UC), but use of vitamin E is limited because of its insolubility in water. We developed ETS-GS (γ-L-glutamyl-S-[2-[[[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltri-decyl)-2 H-1-benzopyran-6-yl]oxy]carbonyl]-3-oxo-3-[(2-sulfoethyl)amino]propyl]-L-cysteinylglycine sodium salt), a newly synthesized soluble vitamin E derivative with strong antioxidant action. We evaluated the therapeutic effects of bolus injection of ETS-GS on acute severe UC in a mouse model. METHODS: An animal model of acute severe UC was induced by feeding mice 5 % dextran sulfate sodium (DSS) for 5 days, followed by 1 % DSS on days 5-8, the experimental period. ETS-GS or saline was administered by subcutaneous bolus injection during the experimental period. We examined disease activity index (DAI) score, histological score, colon length, colon weight, and serum cytokines in the mice. RESULTS: The following results at day 8 in the DSS + ETS-GS group were significantly lower than those in the DSS + Saline group: DAI score, 2.6 ± 0.6 vs. 3.1 ± 0.5; histological score, 2.1 ± 1.0 vs. 3.1 ± 0.8; serum interleukin (IL)-6, 15 ± 9.4 vs. 39 ± 23 pg/ml; and keratinocyte-derived chemokine (KC), 122 ± 61 vs. 228 ± 66 pg/ml (P < 0.05). Colon length, colon weight, and serum IL-10 in the DSS + ETS-GS group were significantly higher than those in the DSS + Saline group (88 ± 12 vs. 75 ± 5.7 mm, 0.48 ± 0.09 vs. 0.38 ± 0.05 g, and 55 ± 18 vs. 31 ± 10 pg/ml, respectively; P < 0.05). CONCLUSIONS: Bolus injection of ETS-GS may be one therapeutic modality for acute severe UC. Its effects are associated with suppression of serum IL-6 and serum KC and promotion of serum IL-10.

Use of perioperative ureteral stent in abdominal aortic aneurysm with retroperitoneal fibrosis - A report of two cases -.

Retroperitoneal fibrosis is associated with fibroblast proliferation due to inflammatory changes in adipose/fibrous tissue. Given that aortic dilation in abdominal aortic aneurysm can cause compression of the ureter, abdominal aortic aneurysm complicated by retroperitoneal fibrosis is likely to result in urinary tract obstruction. Accordingly, close attention to changes in perioperative urine volume is warranted when operating on patients with abdominal aortic aneurysm complicated by retroperitoneal fibrosis. We have recently performed laparotomies on two cases of abdominal aortic aneurysm complicated by retroperitoneal fibrosis. In the first case, surgery was performed without the placement of a ureteral stent. The patient developed postrenal acute renal failure caused by postoperative urinary retention. In the second case, ureteral stent placement in advance enabled perioperative management without complications. The clinical course of these cases suggests that, in laparotomy with concomitant retroperitoneal fibrosis, preoperative ureteral stent placement can prevent postoperative complications in the renal and urinary systems.

Establishment of a model of atrial fibrillation associated with chronic kidney disease in rats and the role of oxidative stress.

BACKGROUND: An animal model of atrial fibrillation (AF) associated with chronic kidney disease (CKD) has not been available. OBJECTIVE: The purpose of this study was to test the validity of 5/6 nephrectomy (5.6Nx) as an appropriate model of AF associated with CKD and to investigate the role of oxidative stress. METHODS: Male Sprague-Dawley rats were subjected to 5.6Nx. A novel derivative of lipoic acid, sodium zinc dihydrolipoylhistidinate (DHLHZn), was subcutaneously infused. Four weeks later, hearts were isolated. RESULTS: We observed 5 main findings. (1) 5.6Nx induced renal dysfunction with elevation of systolic blood pressure and impaired glucose tolerance. (2) In the left atrium (LA), expressions of α-smooth muscle action and collagen type I, the compositional proteins of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and malondialdehyde were increased by 5.6Nx, which was reversed by DHLHZn treatment. (3) In the LA, the tissue content of angiotensin II was elevated by 5.6Nx, which was also reversed by DHLHZn. (4) Masson trichrome staining revealed that heterogeneous LA interstitial fibrosis was induced by 5.6Nx, which was attenuated by DHLHZn. (5) In isolated perfused heart experiments, 5.6Nx caused slowing of interatrial conduction. In the hearts of rats of the 5.6Nxgroup, right atrial extrastimuli invariably induced AF (8/8 [100%]), which were suppressed by DHLHZn (3/8 [38%], P <.05). CONCLUSION: We successfully established an appropriate model of AF associated with CKD in rats. Because the amount of NADPH oxidase was increased and the potent antioxidant agent DHLHZn was effective, oxidative stress may be involved in the pathogenesis of LA fibrosis and enhanced AF vulnerability in our model.

The vitamin E derivative, EPC-K1, suppresses inflammation during hepatic ischemia-reperfusion injury and exerts hepatoprotective effects in rats.

BACKGROUND: An important component of postoperative management includes alleviation of hepatic ischemia-reperfusion (I/R) injury, which commonly results from liver surgery. EPC-K1 is a hydroxyl radical scavenger reported to have mitigating effects on I/R injury in many organs. This study evaluates the effects of EPC-K1 on hepatic I/R injury. MATERIALS AND METHODS: Rats were injected subcutaneously with either EPC-K1 (100 mg/kg) or saline. The hepatic artery and left branch of the portal vein were clamped for 45 min under general anesthesia. Indicators of liver function, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), and of liver tissue damage were evaluated after 6h and 24h of reperfusion. Serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and high-mobility group box 1 (HMGB1) protein were measured, and apoptosis was quantified via caspase 3/7 activity and TUNEL assay. RESULTS: AST, ALT, and LDH levels increased significantly as a result of hepatic I/R injury, but were attenuated by EPC-K1 administration. Histologic findings revealed that normal structure of the hepatic parenchyma was maintained in rats pretreated with EPC-K1. TNF-α, IL-6, and HMGB1 levels rose significantly after reperfusion, together with activation of the inflammatory response. However, EPC-K1 administration suppressed levels of inflammatory markers and attenuated the inflammatory response. Moreover, EPC-K1 administration prevented apoptosis as determined by inhibition of caspase 3/7 activity and a decrease in apoptotic cells. CONCLUSIONS: Results demonstrate that EPC-K1 inhibits the inflammatory response and suppresses apoptosis during hepatic I/R injury. This suggests that EPC-K1 has hepatoprotective effects, and may be a valuable and novel therapeutic agent in the clinical setting.