Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon

The carbon–carbon coupling via electrochemical reduction of carbon dioxide represents the biggest challenge for using this route as platform for chemicals synthesis. Here we show that nanostructured iron (III) oxyhydroxide on nitrogen-doped carbon enables high Faraday efficiency (97.4%) and selectivity to acetic acid (61%) at very-low potential (−0.5 V vs silver/silver chloride). Using a combination of electron microscopy, operando X-ray spectroscopy techniques and density functional theory simulations, we correlate the activity to acetic acid at this potential to the formation of nitrogen-coordinated iron (II) sites as single atoms or polyatomic species at the interface between iron oxyhydroxide and the nitrogen-doped carbon. The evolution of hydrogen is correlated to the formation of metallic iron and observed as dominant reaction path over iron oxyhydroxide on oxygen-doped carbon in the overall range of negative potential investigated, whereas over iron oxyhydroxide on nitrogen-doped carbon it becomes important only at more negative potentials

Respiratory viral pathogens among Singapore military servicemen 2009 - 2012: Epidemiology and clinical characteristics

10.1186/1471-2334-14-204BMC Infectious Diseases141-BIDM

Recurrent Recruitment Manoeuvres Improve Lung Mechanics and Minimize Lung Injury during Mechanical Ventilation of Healthy Mice

INTRODUCTION: Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. METHODS: Mice were ventilated at low tidal volume V(T) = 8 mL/kg or high tidal volume V(T) = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cm H(2)O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. RESULTS: MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. CONCLUSIONS: Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and reduce the development of pulmonary inflammation

Applying physical science techniques and CERN technology to an unsolved problem in radiation treatment for cancer: the multidisciplinary ‘VoxTox’ research programme

The VoxTox research programme has applied expertise from the physical sciences to the problem of radiotherapy toxicity, bringing together expertise from engineering, mathematics, high energy physics (including the Large Hadron Collider), medical physics and radiation oncology. In our initial cohort of 109 men treated with curative radiotherapy for prostate cancer, daily image guidance computed tomography (CT) scans have been used to calculate delivered dose to the rectum, as distinct from planned dose, using an automated approach. Clinical toxicity data have been collected, allowing us to address the hypothesis that delivered dose provides a better predictor of toxicity than planned dose.JES was supported by Cancer Research UK through the Cambridge Cancer Centre. NGB, ASP and MG are supported by the National Institute of Health Research Cambridge Biomedical Research Centre. KH, MR AMB, EW and SJB were supported by the VoxTox Research Programme, funded by Cancer Research UK. DJN is supported by Addenbrooke’s Charitable Trust and Cancer Research UK through the Cambridge Cancer Centre. FMB was supported by the Science and Technology Facilities Council. MPDS was part supported by the VoxTox Research Programme, funded by Cancer Research UK. RJ was part supported by the VoxTox Research Programme, funded by Cancer Research UK. LS is supported by the Armstrong Trust. XC was supported by the Isaac Newton Trust. CBS acknowledges support from the EPSRC Centre for Mathematical and Statistical Analysis of Multimodal Clinical Imaging, the Leverhulme Trust, the EU-RISE project CHiPS and the Cantab Capital Institute for the Mathematics of Information. NT was supported by a Gates-Cambridge Scholarship, funded by the Bill and Melinda Gates Foundation, PLY and SYKS by the Singapore Government

Approaches to analyzing insulators with Auger electron spectroscopy: Update and overview

This paper provides an updated overview, intended to be of practical value to analysts, of methods that can be applied to minimize or control the build-up of near-surface electrical charge during electron-induced Auger electron spectroscopy (AES). Although well-developed methods can be highly effective, dealing with insulating or ungrounded samples for which high spatial resolution is needed remains a challenge. Examples of the application of methods involving low-energy ion sources and sample thinning using a focused ion beam that can allow high-resolution measurements on a variety of samples are highlighted. The physical bases of newer and traditional methods are simply described along with strengths and limitations of the methods. Summary tables indicate methods that can be applied to most AES spectrometers, methods that require special instrumental capabilities and methods that require special sample preparation or mounting

Approaches to analyzing insulators with Auger electron spectroscopy: Update and overview

This paper provides an updated overview, intended to be of practical value to analysts, of methods that can be applied to minimize or control the build-up of near-surface electrical charge during electron-induced Auger electron spectroscopy (AES). Although well-developed methods can be highly effective, dealing with insulating or ungrounded samples for which high spatial resolution is needed remains a challenge. Examples of the application of methods involving low-energy ion sources and sample thinning using a focused ion beam that can allow high-resolution measurements on a variety of samples are highlighted. The physical bases of newer and traditional methods are simply described along with strengths and limitations of the methods. Summary tables indicate methods that can be applied to most AES spectrometers, methods that require special instrumental capabilities and methods that require special sample preparation or mounting

Macrocyclic Dual-Locked “Turn-On” Drug for Selective and Traceless Release in Cancer Cells

Drug safety and efficacy due to premature release into the bloodstream and poor biodistribution remains a problem despite seminal advances in this area. To circumvent these limitations, we report drug cyclization based on dynamic covalent linkages to devise a dual lock for the small molecule anticancer drug, camptothecin (CPT). Drug activity is "locked" within the cyclic structure by the redox responsive disulfide and pH-responsive boronic acid-salicylhydroxamate and turns on only in the presence of acidic pH, reactive oxygen species and glutathione through traceless release. Notably, the dual-responsive CPT is more active (100-fold) than the non-cleavable (permanently closed) analogue. We further include a bioorthogonal handle in the backbone for functionalization to generate cyclic-locked, cell-targeting peptide- and protein-CPTs, for targeted delivery of the drug and traceless release in triple negative metastatic breast cancer cells to inhibit cell growth at low nanomolar concentrations