Silver and Copper Nitride Cooperate for CO Electroreduction to Propanol.

The need of carbon sources for the chemical industry, alternative to fossil sources, has pointed to CO2 as a possible feedstock. While CO2 electroreduction (CO2 R) allows production of interesting organic compounds, it suffers from large carbon losses, mainly due to carbonate formation. This is why, quite recently, tandem CO2 R, a two-step process, with first CO2 R to CO using a solid oxide electrolysis cell followed by CO electroreduction (COR), has been considered, since no carbon is lost as carbonate in either step. Here we report a novel copper-based catalyst, silver-doped copper nitride, with record selectivity for formation of propanol (Faradaic efficiency: 45 %), an industrially relevant compound, from CO electroreduction in gas-fed flow cells. Selective propanol formation occurs at metallic copper atoms derived from copper nitride and is promoted by silver doping as shown experimentally and computationally. In addition, the selectivity for C2+ liquid products (Faradaic efficiency: 80 %) is among the highest reported so far. These findings open new perspectives regarding the design of catalysts for production of C3 compounds from CO2 .

Do animal models of brain tumors replicate human peritumoral edema? a systematic literature search.

INTRODUCTION: Brain tumors cause morbidity and mortality in part through peritumoral brain edema. The current main treatment for peritumoral brain edema are corticosteroids. Due to the increased recognition of their side-effect profile, there is growing interest in finding alternatives to steroids but there is little formal study of animal models of peritumoral brain edema. This study aims to summarize the available literature. METHODS: A systematic search was undertaken of 5 literature databases (Medline, Embase, CINAHL, PubMed and the Cochrane Library). The generic strategy was to search for various terms associated with "brain tumors", "brain edema" and "animal models". RESULTS: We identified 603 reports, of which 112 were identified as relevant for full text analysis that studied 114 peritumoral brain edema animal models. We found significant heterogeneity in the species and strain of tumor-bearing animals, tumor implantation method and edema assessment. Most models did not produce appreciable brain edema and did not test for observable manifestations thereof. CONCLUSION: No animal model currently exists that enable the investigation of novel candidates for the treatment of peritumoral brain edema. With current interest in alternative treatments for peritumoral brain edema, there is an unmet need for clinically relevant animal models.

Selective Ethylene Production from CO2 and CO Reduction via Engineering Membrane Electrode Assembly with Porous Dendritic Copper Oxide.

Gas-fed zero-gap electrolyzers have recently emerged as attractive systems for limiting ohmic losses and costs associated with electrolytes and for optimizing energy efficiencies. Here, we report that using a dendritic Cu oxide (D-CuO) material deposited on a gas diffusion layer as the cathode of a gas-fed zero-gap membrane electrode assembly (MEA) system results in a very selective conversion of CO to ethylene. More specifically, CO reduction yielded ethylene with an FE up to 68% at 100-125 mA·cm-2 with H2 as the only other gaseous product and the electrolysis could be carried out for several hours with good stability. Ethylene was also the major product during CO2 electrolysis (FE = 41%) at 125-150 mA·cm-2, reflecting the high selectivity of D-CuO for ethylene production. Such systems are relevant for tandem CO2 electroreduction processes, allowing energy efficiencies above 30%.

Acupuncture and osteopathic medicine for atopic dermatitis: a three-armed, randomized controlled explorative clinical trial.

BACKGROUND: Patients with atopic dermatitis (AD) frequently use acupuncture (ACU) and osteopathic medicine (OM), although their therapeutic benefits are unclear. AIM: To investigate the effectiveness of ACU and OM in patients with AD. METHODS: In a three-armed, single-centre, randomized controlled open explorative clinical trial, adult patients with AD received ACU, OM or no study intervention (control group; CG) plus routine care. Outcomes included disease severity (SCORing Atopic Dermatitis; SCORAD), itching intensity (visual analogue scale; VAS), frequency of topical corticosteroid (TCS) use over 7 days and cost-effectiveness. Endpoints were analysed by analysis of covariance adjusted for the respective baseline value and TCS use. RESULTS: Overall, 121 patients (92 women, 29 men) with a mean ± SD age of 31.4 ± 10.5 years were randomized. After 12 weeks, the adjusted means (95% CI) for ACU, OM and control were, respectively, 22.3 (18.3-26.3), 26.4 (22.6-30.2) and 23.7 (19.9-27.5) for SCORAD (P = 0.32); 27.9 (19.5-36.4), 35.0 (26.9-43.0) and 42.3 (34.7-50.0) for VAS itching (P < 0.05); and 2.3 (0.8-3.9), 1.9 (0.4-3.5) and 4.3 (2.6-6.0), for TCS use (P = 0.10). ACU and OM were not cost-effective compared with the CG. CONCLUSION: Although no differences in disease severity were found, our findings indicate that ACU might reduce itching in patients with AD. Furthermore, ACU and OM showed a trend towards reducing TCS use.

Molecular Inhibition for Selective CO2 Conversion.

Electrochemical CO2 reduction presents a sustainable route to the production of chemicals and fuels. Achieving a narrow product distribution with heterogeneous Cu catalysts is challenging and conventional material modifications offer limited control over selectivity. Here, we show that surface-immobilised molecular species can act as inhibitors for specific carbon products to provide rational control over product distributions. Combined experimental and computational results showed that anchoring of a thiol-functionalised pyridine on Cu destabilises a surface-bound reaction intermediate to energetically block a CO-producing pathway, thereby favouring formate production. The nitrogen atom was shown to be essential to the inhibition mechanism. The ability of molecules to control selectivity through inhibition of specific reaction pathways offers a unique approach to rationally modify heterogeneous catalysts.

Surgically generated aerosol and mitigation strategies: combined use of irrigation, respirators and suction massively reduces particulate matter aerosol.

BACKGROUND: Aerosol is a health risk to theatre staff. This laboratory study quantifies the reduction in particulate matter aerosol concentrations produced by electrocautery and drilling when using mitigation strategies such as irrigation, respirator filtration and suction in a lab environment to prepare for future work under live OR conditions. METHODS: We combined one aerosol-generating procedure (monopolar cutting or coagulating diathermy or high-speed diamond- or steel-tipped drilling of cadaveric porcine tissue) with one or multiple mitigation strategies (instrument irrigation, plume suction and filtration using an FFP3 respirator filter) and using an optical particle counter to measure particulate matter aerosol size and concentrations. RESULTS: Significant aerosol concentrations were observed during all aerosol-generating procedures with concentrations exceeding 3 × 106 particles per 100 ml. Considerable reductions in concentrations were observed with mitigation. In drilling, suction, FFP3 filtration and wash alone respectively reduced aerosol by 19.3-31.6%, 65.1-70.8% and 97.2 to > 99.9%. The greatest reduction (97.38 to > 99.9%) was observed when combining irrigation and filtration. Coagulating diathermy reduced concentrations by 88.0-96.6% relative to cutting, but produced larger particles. Suction alone, and suction with filtration reduced aerosol concentration by 41.0-49.6% and 88.9-97.4% respectively. No tested mitigation strategies returned aerosol concentrations to baseline. CONCLUSION: Aerosol concentrations are significantly reduced through the combined use of filtration, suction and irrigation. Further research is required to characterise aerosol concentrations in the live OR and to find acceptable exposure limits, and in their absence, to find methods to further reduce exposure to theatre staff.

Fronto-orbital advancement and reconstruction using reverse frontal bone graft without the use of orbital bar: a technical note.

INTRODUCTION: We describe our technique of using reverse frontal bone graft for FOAR for patients with metopic or coronal synostosis and present our complications using the Leeds classification system for complications in craniosynostosis surgery. METHODS: Since April 2015, seventeen patients have been operated using this technique. We perform a frontal bone graft that is then reversed, and supraorbital margins are drilled out. The orbital bar is then removed and drilled down to make bone dust and on-lay bone grafts which are then used to fill gaps on exposed dura and fill in around the temporal region. RESULTS: All 17 patients who underwent this technique have good cosmetic results. We report 5 (29%) complications and 8 (47%) blood transfusions (7 exposures, 1 cell salvage).

Exploring the origins of crystallisation kinetics in hierarchical materials using in situ X-ray diffraction and pair distribution function analysis.

The discovery of novel catalytic materials is predicated on understanding contemporary synthetic processes. With this fundamental knowledge in place it becomes possible to modify the final material with subtle changes to the synthesis process. In this vein, hierarchical materials, formed by the addition of a mesoporogen within the hydrothermal synthesis, have attracted a significant amount of attention due to their catalytic benefits over analogous microporous species. In this work we monitor the hydrothermal synthesis in situ of a hierarchical and a microporous aluminophosphate, for the first time, combining total scattering and pairwise distribution function data. In doing so we observe the local formation of the species, and the longer range crystallisation processes concurrently.

Evaluation of nationwide referral pathways, investigation and treatment of suspected cauda equina syndrome in the United Kingdom.

Purpose: Cauda equina syndrome (CES) is a spinal emergency with clinical symptoms and signs that have low diagnostic accuracy. National guidelines in the United Kingdom (UK) state that all patients should undergo an MRI prior to referral to specialist spinal units and surgery should be performed at the earliest opportunity. We aimed to evaluate the current practice of investigating and treating suspected CES in the UK. Materials and Methods: A retrospective, multicentre observational study of the investigation and management of patients with suspected CES was conducted across the UK, including all patients referred to a spinal unit over 6 months between 1st October 2016 and 31st March 2017. Results: A total of 28 UK spinal units submitted data on 4441 referrals. Over half of referrals were made without any previous imaging (n = 2572, 57.9%). Of all referrals, 695 underwent surgical decompression (15.6%). The majority of referrals were made out-of-hours (n = 2229/3517, 63.4%). Patient location and pre-referral imaging were not associated with time intervals from symptom onset or presentation to decompression. Patients investigated outside of the spinal unit experienced longer time intervals from referral to undergoing the MRI scan. Conclusions: This is the largest known study of the investigation and management of suspected CES. We found that the majority of referrals were made without adequate investigations. Most patients were referred out-of-hours and many were transferred for an MRI without subsequently requiring surgery. Adherence to guidelines would reduce the number of referrals to spinal services by 72% and reduce the number of patient transfers by 79%.

Lewis-Brønsted Acid Pairs in Ga/H-ZSM-5 To Catalyze Dehydrogenation of Light Alkanes.

The active sites for propane dehydrogenation in Ga/H-ZSM-5 with moderate concentrations of tetrahedral aluminum in the lattice were identified to be Lewis-Brønsted acid pairs. With increasing availability, Ga+ and Brønsted acid site concentrations changed inversely, as protons of Brønsted acid sites were exchanged with Ga+. At a Ga/Al ratio of 1/2, the rate of propane dehydrogenation was 2 orders of magnitude higher than with the parent H-ZSM-5, highlighting the extraordinary activity of the Lewis-Brønsted acid pairs. Density functional theory calculations relate the high activity to a bifunctional mechanism that proceeds via heterolytic activation of the propane C-H bond followed by a monomolecular elimination of H2 and desorption of propene.

Improved physiological properties of gravity-enforced reassembled rat and human pancreatic pseudo-islets.

Previously we demonstrated the superiority of small islets vs large islets in terms of function and survival after transplantation, and we generated reaggregated rat islets (pseudo-islets) of standardized small dimensions by the hanging-drop culture method (HDCM). The aim of this study was to generate human pseudo-islets by HDCM and to evaluate and compare the physiological properties of rat and human pseudo-islets. Isolated rat and human islets were dissociated into single cells and incubated for 6-14 days by HDCM. Newly formed pseudo-islets were analysed for dimensions, morphology, glucose-stimulated insulin secretion (GSIS) and total insulin content. The morphology of reaggregated human islets was similar to that of native islets, while rat pseudo-islets had a reduced content of α and δ cells. GSIS of small rat and human pseudo-islets (250 cells) was increased up to 4.0-fold (p < 0.01) and 2.5-fold (p < 0.001), respectively, when compared to their native counterparts. Human pseudo-islets showed a more pronounced first-phase insulin secretion as compared to intact islets. GSIS was inversely correlated to islet size, and small islets (250 cells) contained up to six-fold more insulin/cell than large islets (1500 cells). Tissue loss with this new technology could be reduced to 49.2 ± 1.5% in rat islets, as compared to the starting amount. With HDCM, pseudo-islets of standardized size with similar cellular composition and improved biological function can be generated, which compensates for tissue loss during production. Transplantation of small pseudo-islets may represent an attractive strategy to improve graft survival and function, due to better oxygen and nutrient supply during the phase of revascularization. Copyright © 2014 John Wiley & Sons, Ltd.

Surface relaxation of Cu(5 1 1).

The multilayer relaxation of the stepped Cu(5 1 1) surface has been studied by quantitative low-energy electron diffraction and analyzed using the CLEED program package. Relaxations with respect to the bulk interlayer spacing of 0.6934 Å are -9.5%, -10.4%, +8.2% and -1.8% for the first four interlayer spacings, respectively (negative sign corresponds to contraction). The relaxation sequence (- - + -…) is thus in agreement with the theoretical prediction. The deeper relaxations are damped in a non-uniform manner and the lateral relaxations are smaller than 2% of the lateral spacing. This result agrees well with theoretical studies of the same surface. The Pendry R-factor for the favored structure is 0.21.

Novel genetic algorithm search procedure for LEED surface structure determination.

Low Energy Electron Diffraction (LEED) is one of the most powerful experimental techniques for surface structure analysis but until now only a trial-and-error approach has been successful. So far, fitting procedures developed to optimize structural and nonstructural parameters-by minimization of the R-factor-have had a fairly small convergence radius, suitable only for local optimization. However, the identification of the global minimum among the several local minima is essential for complex surface structures. Global optimization methods have been applied to LEED structure determination, but they still require starting from structures that are relatively close to the correct one, in order to find the final structure. For complex systems, the number of trial structures and the resulting computation time increase so rapidly that the task of finding the correct model becomes impractical using the present methodologies. In this work we propose a new search method, based on Genetic Algorithms, which is able to determine the correct structural model starting from completely random structures. This method-called here NGA-LEED for Novel Genetic Algorithm for LEED-utilizes bond lengths and symmetry criteria to select reasonable trial structures before performing LEED calculations. This allows a reduction of the parameter space and, consequently of the calculation time, by several orders of magnitude. A refinement of the parameters by least squares fit of simulated annealing is performed only at some intermediate stages and in the final step. The method was successfully tested for two systems, Ag(1 1 1)(4 × 4)-O and Au(1 1 0)-(1 × 2), both in theory versus theory and in theory versus experiment comparisons. Details of the implementation as well as the results for these two systems are presented.

Multi-cell type human liver microtissues for hepatotoxicity testing.

Current 2-dimensional hepatic model systems often fail to predict chemically induced hepatotoxicity due to the loss of a hepatocyte-specific phenotype in culture. For more predictive in vitro models, hepatocytes have to be maintained in a 3-dimensional environment that allows for polarization and cell-cell contacts. Preferably, the model will reflect an in vivo-like multi-cell type environment necessary for liver-like responses. Here, we report the characterization of a multi-cell type microtissue model, generated from primary human hepatocytes and liver-derived non-parenchymal cells. Liver microtissues were stable and functional for 5 weeks in culture enabling, for example, long-term toxicity testing of acetaminophen and diclofenac. In addition, Kupffer cells were responsive to inflammatory stimuli such as LPS demonstrating the possibility to detect inflammation-mediated toxicity as exemplified by the drug trovafloxacin. Herewith, we present a novel 3D liver model for routine testing in 96-well format capable of reducing the risk of unwanted toxic effects in the clinic.

An array of field-effect nanoplate SOI capacitors for (bio-)chemical sensing.

An array of individually addressable nanoplate field-effect capacitive (bio-)chemical sensors based on an SOI (silicon-on-insulator) structure has been developed. The isolation of the individual capacitors was achieved by forming a trench in the top Si layer with a thickness of 350 nm. The realized sensor array allows addressable biasing and electrical readout of multiple nanoplate EISOI (electrolyte-insulator-silicon-on-insulator) capacitive biosensors on the same SOI chip as well as differential-mode measurements. The feasibility of the proposed approach has been demonstrated by realizing sensors for the pH and penicillin concentration detection as well as for the label-free electrical monitoring of polyelectrolyte multilayers formation and DNA (deoxyribonucleic acid)-hybridization event. A potential change of ∼ 120 mV has been registered after the DNA hybridization for the sensor immobilized with perfectly matched single-strand DNA, while practically no signal changes have been observed for a sensor with fully mismatched DNA. The realized examples demonstrate the potential of the nanoplate SOI capacitors as a new basic structural element for the development of different types of field-effect biosensors.

Structure determination of the coincidence phase of graphene on Ru(0001).

The structure of the commensurate (23x23) phase of graphene on Ru(0001) has been analyzed by quantitative low-energy electron diffraction (LEED)-I(V) analysis and density-functional theory calculations. The I(V) analysis uses Fourier components as fitting parameters to determine the vertical corrugation and the lateral relaxation of graphene and the top Ru layers. Graphene is shown to be strongly corrugated by 1.5 A with a minimum C-Ru distance of 2.1 A. Additionally, lateral displacements of C atoms and a significant buckling in the underlying Ru layers are observed, indicative for strong local C-Ru interactions.

Surface geometry of C(60) on Ag(111).

The geometry of adsorbed C(60) influences its collective properties. We report the first dynamical low-energy electron diffraction study to determine the geometry of a C(60) monolayer, Ag(111)-(2 square root of 3 x 2 square root of 3) 30 degrees -C(60), and related density functional theory calculations. The stable monolayer has C(60) molecules in vacancies that result from the displacement of surface atoms. C(60) bonds with hexagons down, with their mirror planes parallel to that of the substrate. The results indicate that vacancy structures are the rule rather than the exception for C(60) monolayers on close-packed metal surfaces.

Graphene on Ru(0001): a 25 x 25 supercell.

The structure of a single layer of graphene on Ru(0001) has been studied using surface x-ray diffraction. A surprising superstructure containing 1250 carbon atoms has been determined, whereby 25 x 25 graphene unit cells lie on 23 x 23 unit cells of Ru. Each supercell contains 2 x 2 crystallographically inequivalent subcells caused by corrugation. Strong intensity oscillations in the superstructure rods demonstrate that the Ru substrate is also significantly corrugated down to several monolayers and that the bonding between graphene and Ru is strong and cannot be caused by van der Waals bonds. Charge transfer from the Ru substrate to the graphene expands and weakens the C-C bonds, which helps accommodate the in-plane tensile stress. The elucidation of this superstructure provides important information in the potential application of graphene as a template for nanocluster arrays.

Has time come for new goals in human islet transplantation?

The enthusiasm regarding clinical islet transplantation has been dampened by the long-term results. Concerns about the associated risks of life-long immunosuppression and the striking imbalance between potential recipients and available donor pancreata warrant changes in some of the current goals. Islet transplantation will never be a cure of type 1 diabetes in the majority of patients with no secondary complications, but is a valid option for a limited number of patients with brittle diabetes waiting for an organ or after organ transplantation. Furthermore, insulin independence should not be the main goal of islet transplantation, but avoidance of severe hypoglycemia and good glycemic control, which can be achieved with a relatively small functional beta-cell mass. Therefore, initially one islet infusion is sufficient. Retransplantation at a later time point remains an option, if glucose control deteriorates. Efforts to improve islet transplantation should no longer focus on islet isolation and immunosuppression, but rather on the low posttransplant survival rate of islets caused by activation of the coagulation pathway and the limited oxygen delivery to the islets. Transplantation of smaller islets be it naturally small or size tailored reaggregated islets has the potential to facilitate these processes.

Preconditioning with death ligands FasL and TNF-alpha protects the cirrhotic mouse liver against ischaemic injury.

BACKGROUND: Ischaemic preconditioning is the preemptive proven strategy to reduce ischaemic injury in the liver, but it can be harmful in the elderly or in patients with liver diseases. Ischaemic preconditioning induces a protective effect via activation of oxidative stress. We hypothesised that Fas ligand and tumour necrosis factor alpha can induce a similar response. Therefore, we tested if death ligands could mimic ischaemic preconditioning. METHODS: Ischaemia was maintained for 60 min in cirrhotic mice. Death ligands were given 40 min before ischaemia. Ischaemic injury was assessed by histology and biochemical assays. To elucidate the mechanism, we used zinc protophorphyrin, an inhibitor of haem oxygenase-1 (HO-1), and gadolinium chloride, an inhibitor of Kupffer cells. RESULTS: Compared with the control group, death ligand preconditioning strongly reduced all markers of injury: serum transaminase levels, necrosis and apoptosis. Preconditioning caused an upregulation of HO-1, predominantly in macrophages. When zinc protophorphyrin or gadolinium chloride was applied prior to preconditioning, the beneficial effect of preconditioning was lost. CONCLUSION: These results demonstrate that ischaemic preconditioning can be replaced by death ligand preconditioning in the cirrhotic liver to prevent ischaemic injury. The protective mechanism depends on HO-1 induction in macrophages. These results open doors for novel hepato-protective strategies in liver surgery and transplantation.