Foot orientation and trajectory variability in locomotion: Effects of real-world terrain.

Capturing human locomotion in nearly any environment or context is becoming increasingly feasible with wearable sensors, giving access to commonly encountered walking conditions. While important in expanding our understanding of locomotor biomechanics, these more variable environments present challenges to identify changes in data due to person-level factors among the varying environment-level factors. Our study examined foot-specific biomechanics while walking on terrain commonly encountered with the goal of understanding the extent to which these variables change due to terrain. We recruited healthy adults to walk at self-selected speeds on stairs, flat ground, and both shallow and steep sloped terrain. A pair of inertial measurement units were embedded in both shoes to capture foot biomechanics while walking. Foot orientation was calculated using a strapdown procedure and foot trajectory was determined by double integrating the linear acceleration. Stance time, swing time, cadence, sagittal and frontal orientations, stride length and width were extracted as discrete variables. These data were compared within-participant and across terrain conditions. The physical constraints of the stairs resulted in shorter stride lengths, less time spent in swing, toe-first foot contact, and higher variability during stair ascent specifically (p<0.05). Stride lengths increased when ascending compared to descending slopes, and the sagittal foot angle at initial contact was greatest in the steep slope descent condition (p<0.05). No differences were found between conditions for horizontal foot angle in midstance (p≥0.067). Our results show that walking on slopes creates differential changes in foot biomechanics depending on whether one is descending or ascending, and stairs require different biomechanics and gait timing than slopes or flat ground. This may be an important factor to consider when making comparisons of real-world walking bouts, as greater proportions of one terrain feature in a data set could create bias in the outcomes. Classifying terrain in unsupervised walking datasets would be helpful to avoid comparing metrics from different walking terrain scenarios.

Curriculum content for Environmental Sustainability in Dentistry.

OBJECTIVES: (i) To identify suitable strategies and opportunities to embed Environmental Sustainability (ES) within an existing Oral Health Professional (OHP) curriculum through a series of focus groups with students and academic staff and (ii) To create high-level evidence-based and subject-specific ES content through an approach grounded in evidence and collaboration with key stakeholders in OHP education. METHODS: Focus groups were used to explore academic staff and student views on appropriate teaching and assessment methods for ES. Content statements were developed from an extensive literature search, mapped to curriculum subjects, and validated through consultation with students, discipline-experts and education-experts. RESULTS: Five themes were identified from the focus groups: ES transcends all disciplines of dentistry and oral healthcare; baseline knowledge transmission with relevant practical application; viewing and modifying existing teaching and assessment events through a different lens; normalising the topic of ES to support attitude and behaviour change and safeguarding against misinformation and disinformation. Forty-four content statements were developed and mapped to nineteen curriculum subjects. CONCLUSIONS: This study identifies for the first time a comprehensive strategy for the inclusion and delivery of ES (method and content) in the curriculum. A novel method to define and map curriculum content has been explored and validated using a range of complementary methodologies. A comprehensive and robust list of evidence-based and subject-specific educational content statements have been defined in the field of Environmental Sustainability in dentistry and oral healthcare. CLINICAL SIGNIFICANCE: Oral healthcare has a significant environmental impact, the key to all mitigation strategies is educating the profession at all levels.

The adsorption of nitrobenzene over an alumina-supported palladium catalyst: an infrared spectroscopic study.

As part of an on-going programme of development of an aniline synthesis catalyst suitable for operation at elevated temperatures, the geometry of the adsorption complex for nitrobenzene on a 5 wt% Pd/Al2O3 catalyst is investigated by infrared (IR) spectroscopy. Via an appreciation of the reduced site symmetry resulting from adsorption, application of the metal surface selection rule, and observation of in-plane modes only, the adsorption complex (Pd-nitrobenzene) at 28 °C is assigned as occurring vertically or tilted with respect to the metal surface, adopting Csσv(yz) symmetry. Moreover, adsorption occurs via a single Pd-O bond. Single molecule DFT calculations and simulated IR spectra assist vibrational assignments but indicate a parallel adsorption geometry to be energetically favourable. The contradiction between calculated and observed structures is attributed to the DFT calculations corresponding to an isolated molecule adsorption complex, while IR spectra relate to multi molecule adsorption that is encountered during sustained catalytic turnover. Residual hydrogen from the catalyst reduction stage leads to aniline formation on the Pd surface at low nitrobenzene coverages but, on increasing nitrobenzene exposure, the aniline is forced on to the alumina support. A reaction scheme is proposed whereby the nitrobenzene adsorption geometry is inherently linked to the high aniline selectivity observed for Pd/Al2O3 catalysts.

Urban biogeography of fungal endophytes across San Francisco.

In natural and agricultural systems, the plant microbiome-the microbial organisms associated with plant tissues and rhizosphere soils-has been shown to have important effects on host physiology and ecology, yet we know little about how these plant-microbe relationships play out in urban environments. Here we characterize the composition of fungal communities associated with living leaves of one of the most common sidewalk trees in the city of San Francisco, California. We focus our efforts on endophytic fungi (asymptomatic microfungi that live inside healthy leaves), which have been shown in other systems to have large ecological effects on the health of their plant hosts. Specifically, we characterized the foliar fungal microbiome of Metrosideros excelsa (Myrtaceae) trees growing in a variety of urban environmental conditions. We used high-throughput culturing, PCR, and Sanger sequencing of the internal transcribed spacer nuclear ribosomal DNA (ITS nrDNA) region to quantify the composition and structure of fungal communities growing within healthy leaves of 30 M. excelsa trees from six distinct sites, which were selected to capture the range of environmental conditions found within city limits. Sequencing resulted in 854 high-quality ITS sequences. These sequences clustered into 85 Operational Taxonomic Units (97% OTUs). We found that these communities encompass relatively high alpha (within) and beta (between-site) diversity. Because the communities are all from the same host tree species, and located in relatively close geographical proximity to one another, these analyses suggest that urban environmental factors such as heat islands or differences in vegetation or traffic density (and associated air quality) may potentially be influencing the composition of these fungal communities. These biogeographic patterns provide evidence that plant microbiomes in urban environments can be as dynamic and complex as their natural counterparts. As human populations continue to transition out of rural areas and into cities, understanding the factors that shape environmental microbial communities in urban ecosystems stands to become increasingly important.

Perceptions of Primary Care Providers on Public Health Services in Primary Care in Oman: A Qualitative Study.

Background The integration of public health functions in primary care is not well-defined in the literature. This paper examines the perceptions of healthcare workers on public health services in primary care, as well as the challenges and views on strengthening the integration of public health functions in a primary care setting in Oman. Methodology This qualitative study (employing a face-to-face interview) was conducted in a primary healthcare setting in Muscat from January 1, 2022, to May 31, 2022. This study is based on interpretative phenomenological analysis using purposeful sampling. Participants were interviewed to answer the study questions. The targeted participants included directors and other official personnel, physicians, nurses, pharmacists, nutritionists, health educators, and lab technicians. Verbal consent was obtained from the participants before the interview, and all responses were anonymously audio recorded, transcribed verbatim, and analyzed using thematic analysis. Results A total of 10 primary care providers were interviewed once for 30 minutes over a two-week period. All participants were females apart from one male participant. The study included three physicians, five nurses, one pharmacist, and one nutritionist. All participants had over 10 years of experience as primary care providers at the time of the interview. The main themes were a lack of awareness of public health services in a primary care setting, challenges to practicing public health in a primary care setting, and recommendations to strengthen the integration of public health services in primary care. In general, there were inconsistent views on public health services in a primary care setting, and the interactions between the functions were not clear. Participants reported an absence of clear guidelines, training, and competencies for public health in a primary care setting. Building public health capacities and reforming the health system were highly recommended to integrate public health into primary health care. Conclusions Understanding how public health and primary care interact is crucial to improve population health. Building competencies and supportive health systems are required for the effective integration of public health in primary care settings.

A Systematic Review of Behaviour Change Techniques within Interventions to Increase Vaccine Uptake among Ethnic Minority Populations.

COVID-19 caused significant morbidity and mortality amongst ethnic minority groups, but vaccine uptake remained lower than non-minoritised groups. Interventions to increase vaccine uptake among ethnic minority communities are crucial. This systematic review synthesises and evaluates behaviour change techniques (BCTs) in interventions to increase vaccination uptake in ethnic minority populations. We searched five databases and grey literature sources. From 7637 records identified, 23 studies were included in the review. Interventions were categorised using the Behaviour Change Wheel (BCW) and Behaviour Change Taxonomy v1. Vaccines included influenza, pertussis, tetanus, diphtheria, meningitis and hepatitis. Interventions were primarily delivered in health centres/clinics and community settings. Six BCW intervention functions and policy categories and 26 BCTs were identified. The main intervention functions used were education, persuasion and enablement. Overall, effective interventions had multi-components and were tailored to specific populations. No strong evidence was observed to recommend specific interventions, but raising awareness and involvement of community organisations was associated with positive effects. Several strategies are used to increase vaccine uptake among ethnic minority communities; however, these do not address all issues related to low vaccine acceptance. There is a strong need for an increased understanding of addressing vaccine hesitancy among ethnic minority groups.

Atomistic simulations on the carbidisation processes in Pd nanoparticles.

The formation of interstitial PdC x nanoparticles (NPs) is investigated through DFT calculations. Insights on the mechanisms of carbidisation are obtained whilst the material's behaviour under conditions of increasing C-concentration is examined. Incorporation of C atoms in the Pd octahedral interstitial sites is occurring through the [111] facet with an activation energy barrier of 19.3-35.7 kJ mol-1 whilst migration through the [100] facet corresponds to higher activation energy barriers of 124.5-127.4 kJ mol-1. Furthermore, interstitial-type diffusion shows that C will preferentially migrate and reside at the octahedral interstitial sites in the subsurface region with limited mobility towards the core of the NP. For low C-concentrations, migration from the surface into the interstitial sites of the NPs is thermodynamically favored, resulting in the formation of interstitial carbide. Carbidisation reaction energies are exothermic up to 11-14% of C-concentration and slightly vary depending on the shape of the structure. The reaction mechanisms turn to endothermic for higher concentration levels showing that C will preferentially reside on the surface making the interstitial carbide formation unfavorable. As experimentally observed, our simulations confirm that there is a maximum concentration of C in Pd carbide NPs opening the way for further computational investigations on the activity of Pd carbides in directed catalysis.

Analysis of sex steroids in human tears using LC-MS and GC-MS: Considerations and developments to improve method sensitivity and accuracy.

Sex steroids play a role in regulation of tear film function and may exert their action locally at the ocular surface. However, measurement of sex steroids in tears is difficult due to small-volume tear samples and very low concentrations of the hormones. This short communication highlights what has been achieved to date in the analysis of tear sex steroids using ultra-performance LC-MS (UPLC-MS) as previously published, and reports further and more recent investigations toward optimising mass spectrometry method sensitivity and accuracy. The published UPLC-MS method successfully measured progesterone, androsterone glucuronide and 5α-androstane-3α,17ß-diol in pooled basal tears of postmenopausal women, and fourteen sex steroid standards in methanol. Limitations included sub-optimal limits of detection (LOD) and lower limits of quantification (LLOQ) for some analytes (particularly oestrogens), exclusion of sample matrix effects and no use of internal standards. This update reports on further experiments carried out to improve sensitivity and accuracy. Sample matrix effects, internal standard spiking, and derivatisation with dansyl chloride and oximes were investigated. Dansylation significantly improved the LOD and LLOQ of oestrogens and their metabolites, by a factor of 10 for oestradiol and a factor of 5 for oestrone, but sensitivity of this updated method is not sufficient however for analysis of these oestrogens in human tears. Using gas chromatography-mass spectrometry (GC-MS) as an alternative technique to LC-MS, improved sensitivity for derivatised oestradiol is reported. This work demonstrates the need to develop higher sensitivity methods and points researchers towards specific MS ionisation techniques for future analysis of sex steroids in tears, in order to progress current understanding of the role of sex steroids in tear function and dry eye.

No new fast-food outlets allowed! Evaluating the effect of planning policy on the local food environment in the North East of England.

The environment in which we live impacts on our health. The food available to us in our environment is likely to influence what we eat and subsequently our weight. The use of planning policy can be one way for both local and national government to help shape a healthy environment. In England there are three main types of planning policy used to promote a healthy food environment: 1) restricting new fast-food outlets near schools; 2) restricting new fast-food outlets if the density of existing outlets has surpassed a certain threshold of all retail outlets, 3) restricting new fast-food outlets if childhood obesity rates are above a certain threshold. In 2015, Gateshead council, a local authority in the North East of England implemented all three types of guidance. We utilise a longitudinal administrative dataset, the Food Standards Agency Food Hygiene Rating Scheme Data, covering the period 2012-2019 on all premises selling or preparing food in Great Britain. To analyse the impact of employing all three types of planning guidance on the density, proportion, and number of fast-food outlets in Gateshead, we employ a propensity score matching difference-in-difference approach. We match small geographical areas in Gateshead (lower super output areas) to other local authorities in the North East with similar demographic characteristics that did not implement planning guidance. Results show a reduction in density of fast-food outlets by 12.45 per 100,000 of the population and a 13.88% decrease in the proportion of fast-food outlets in Gateshead compared to other similar local authorities in the North East. There was a marginally significant reduction in the number of restaurants which became insignificant after controlling for population density. These results suggest that a multi-pronged planning approach significantly changed the proportion and density of fast-food outlets in the food environment in the short term (4 years).

An Unstructured Supplementary Service Data System for Daily Tracking of Patient Samples and Diagnostic Results in a Diagnostic Network in Malawi: System Development and Field Trial.

BACKGROUND: Diagnostics in many low- and middle-income countries are conducted through centralized laboratory networks. Samples are collected from patients at remote point-of-care health facilities, and diagnostic tests are performed at centralized laboratories. Sample transportation systems that deliver diagnostic samples and test results are crucial for timely diagnosis and treatment in such diagnostic networks. However, they often lack the timely and accurate data (eg, the quantity and location of samples prepared for collection) required for efficient operation. OBJECTIVE: This study aims to demonstrate the feasibility, adoption, and accuracy of a distributed data collection system that leverages basic mobile phone technology to gather reports on the quantity and location of patient samples and test results prepared for delivery in the diagnostic network of Malawi. METHODS: We designed a system that leverages unstructured supplementary service data (USSD) technology to enable health workers to submit daily reports describing the quantity of transportation-ready diagnostic samples and test results at specific health care facilities, free of charge with any mobile phone, and aggregate these data for sample transportation administrators. We then conducted a year-long field trial of this system in 51 health facilities serving 3 districts in Malawi. Between July 2019 and July 2020, the participants submitted daily reports containing the number of patient samples or test results designated for viral load, early infant diagnosis, and tuberculosis testing at each facility. We monitored daily participation and compared the submitted USSD reports with program data to assess system feasibility, adoption, and accuracy. RESULTS: The participating facilities submitted 37,771 reports over the duration of the field trial. Daily facility participation increased from an average of 50% (26/51) in the first 2 weeks of the trial to approximately 80% (41/51) by the midpoint of the trial and remained at or above 80% (41/51) until the conclusion of the trial. On average, more than 80% of the reports submitted by a facility for a specific type of sample matched the actual number of patient samples collected from that facility by a courier. CONCLUSIONS: Our findings suggest that a USSD-based system is a feasible, adoptable, and accurate solution to the challenges of untimely, inaccurate, or incomplete data in diagnostic networks. Certain design characteristics of our system, such as the use of USSD, and implementation characteristics, such as the supportive role of the field team, were necessary to ensure high participation and accuracy rates without any explicit financial incentives.

Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in gasoline particulate filters and the effect of the manufacturing process on the catalytic activity.

Platinum group metals such as palladium and rhodium based catalysts are currently being implemented in gasoline particulate filter (GPF) autoexhaust after treatment systems. However, little is known about how the trapped particulate matter, such as the incombustible ash, interacts with the catalyst and so may affect its performance. Thisoperandostudy follows the evolution of the Pd found in two different model GPF systems: one containing ash components extracted from a GPF and another from a catalyst washcoat prior to adhesion onto the GPF. We show that the catalytic activity of the two systems vary when compared with a 0 g ash containing GPF. Compared to the 0 g ash sample the 20 g ash containing sample had a higher CO light off temperature, in addition, an oscillation profile for CO, CO2and O2was observed, which is speculated to be a combination of CO oxidation, C deposition via a Boudouard reaction and further partial oxidation of the deposited species to CO. During the ageing procedure the washcoat sample reduces NO at a lower temperature than the 0 g ash sample. However, post ageing the 0 g ash sample recovers and both samples reduce NO at 310 °C. In comparison, the 20 g ash GPF sample maintains a higher NO reduction temperature of 410 °C post ageing, implying that the combination of high temperature ageing and presence of ash has an irreversible negative effect on catalyst performance.

Spatial Profiling of a Pd/Al2O3 Catalyst during Selective Ammonia Oxidation.

The utilization of operando spectroscopy has allowed us to watch the dynamic nature of supported metal nanoparticles. However, the realization that subtle changes to environmental conditions affect the form of the catalyst necessitates that we assess the structure of the catalyst across the reactant/product gradient that exists across a fixed bed reactor. In this study, we have performed spatial profiling of a Pd/Al2O3 catalyst during NH3 oxidation, simultaneously collecting mass spectrometry and X-ray absorption spectroscopy data at discrete axial positions along the length of the catalyst bed. The spatial analysis has provided unique insights into the structure-activity relationships that govern selective NH3 oxidation-(i) our data is consistent with the presence of PdN x after the spectroscopic signatures for bulk PdN x disappear and that there is a direct correlation to the presence of this structure and the selectivity toward N2; (ii) at high temperatures, ≥400 °C, we propose that there are two simultaneous reaction pathways-the oxidation of NH3 to NO x by PdO and the subsequent catalytic reduction of NO x by NH3 to produce N2. The results in this study confirm the structural and catalytic diversity that exists during catalysis and the need for such an understanding if improvements to important emission control technologies, such as the selective catalytic oxidation of NH3, are to be made.

Design, Identification, and Evolution of a Surface Ruthenium(II/III) Single Site for CO Activation.

RuII compounds are widely used in catalysis, photocatalysis, and medical applications. They are usually obtained in a reductive environment as molecular O2 can oxidize RuII to RuIII and RuIV . Here we report the design, identification and evolution of an air-stable surface [bipy-RuII (CO)2 Cl2 ] site that is covalently mounted onto a polyphenylene framework. Such a RuII site was obtained by reduction of [bipy-RuIII Cl4 ]- with simultaneous ligand exchange from Cl- to CO. This structural evolution was witnessed by a combination of in situ X-ray and infrared spectroscopy studies. The [bipy-RuII (CO)2 Cl2 ] site enables oxidation of CO with a turnover frequency of 0.73×10-2  s-1 at 462 K, while the RuIII site is completely inert. This work contributes to the study of structure-activity relationship by demonstrating a practical control over both geometric and electronic structures of single-site catalysts at molecular level.

Ultrasensitive Serum Estradiol Measurement by Liquid Chromatography-Mass Spectrometry in Postmenopausal Women and Mice.

Accurate measurement of very low circulating estradiol (E2) (<5 pg/ml) in postmenopausal women and in mice is essential to investigating sex steroid action in target tissues. However, direct immunoassays are too inaccurate and conventional mass spectrometry-based measurement too insensitive at these serum E2 levels. We report application of an ultrasensitive method using a novel estrogen-selective derivatization in liquid chromatography-mass spectrometry to measure serum E2, with a detection limit of 0.25 pg/ml in small (0.2 ml) serum volumes that can quantify serum E2 in 98% and serum E1 in 100% of healthy postmenopausal women. Aromatase inhibitor (AI) treatment of postmenopausal women with breast cancer further reduces serum E2 by 85% and serum estrone (E1) by 80%. The wide scatter of circulating E2 in AI-treated women suggests that the degree of sustained E2 depletion, now quantifiable, may be an efficacy or safety biomarker of adjuvant AI treatment. This ultrasensitive method can also measure serum E2 in most (65%) female but not in any male mice. Further studies are warranted using this and comparable ultrasensitive liquid chromatography-mass spectrometry estrogen measurements to investigate the relationship of circulating E2 (and E1) in male, postmenopausal female, and childhood health where accurate quantification of serum estrogens was not previously feasible. This will focus on the direct impact of estrogens as well as the indirect effects of androgen aromatization on reproductive, bone, and brain tissues and, notably, the efficacy and safety of AIs in adjuvant breast cancer treatment.

The Experiences and Perceptions of Health-Care Workers During the COVID-19 Pandemic in Muscat, Oman: A Qualitative Study.

INTRODUCTION: Predominantly, studies on COVID-19 report quantitative data that often miss the social implications and other determinants of health. The objective of this study was to explore the experiences and perceptions of health care workers (HCWs) in primary health care in the management of COVID-19 with respect to medical response experiences, socio-cultural and religious reforms, psychological impressions, and lessons learned. METHODS: This was a qualitative study using an empirical phenomenological approach. Six focus group discussions were conducted across various stakeholders working frontline in the management of COVID-19 (managerial, public health/field/community and primary care health centers). They participated in semi-structured, in-depth group discussions from 11th to 20th May 2020. All discussions were audio-recorded, transcribed verbatim and analyzed using thematic analysis. RESULTS: Forty participants were involved in this study. Three themes emerged related to the medical response experiences, including the rapid re-structuring of the PHC services, use of technology and challenges of working on COVID-19. Perceptions on the socio-cultural and religious reforms included changes in social and religious norms, and anticipated gaps in accessing health care among the vulnerable groups (elderly, expatriates, and individuals with low economic status). Perceptions on psychological disturbances were themed as consequences of social distancing, management of dead bodies, exhaustion among the health care workers, and risk of exposure. Finally, lessons learned were centered around building on the existing epidemiological and public health capacities, improving access to health care and overcoming resistance to change. Most participants labelled their experience in COVID-19 as an "experience of wisdom" in which learning was a continuous process. CONCLUSION: This qualitative study amongst primary HCWs revealed certain aspects of response to COVID-19 in Muscat, Oman. Results has unfolded various aspects of COVID-19. The situation was perceived by primary HCWs as a new experience that challenged the primary health care; enforced the utilization of public health/epidemiological skills, and linked to unfavorable socio-religious and psychological events.

Adsorption and activation of molecular oxygen over atomic copper(I/II) site on ceria.

Supported atomic metal sites have discrete molecular orbitals. Precise control over the energies of these sites is key to achieving novel reaction pathways with superior selectivity. Here, we achieve selective oxygen (O2) activation by utilising a framework of cerium (Ce) cations to reduce the energy of 3d orbitals of isolated copper (Cu) sites. Operando X-ray absorption spectroscopy, electron paramagnetic resonance and density-functional theory simulations are used to demonstrate that a [Cu(I)O2]3- site selectively adsorbs molecular O2, forming a rarely reported electrophilic η2-O2 species at 298 K. Assisted by neighbouring Ce(III) cations, η2-O2 is finally reduced to two O2-, that create two Cu-O-Ce oxo-bridges at 453 K. The isolated Cu(I)/(II) sites are ten times more active in CO oxidation than CuO clusters, showing a turnover frequency of 0.028 ± 0.003 s-1 at 373 K and 0.01 bar PCO. The unique electronic structure of [Cu(I)O2]3- site suggests its potential in selective oxidation.

Redox-Active Hybrid Polyoxometalate-Stabilised Gold Nanoparticles.

We report the design and preparation of multifunctional hybrid nanomaterials through the stabilization of gold nanoparticles with thiol-functionalised hybrid organic-inorganic polyoxometalates (POMs). The covalent attachment of the hybrid POM forms new nanocomposites that are stable at temperatures and pH values which destroy analogous electrostatically functionalised nanocomposites. Photoelectrochemical analysis revealed the unique photochemical and redox properties of these systems.

Synergistic ultraviolet and visible light photo-activation enables intensified low-temperature methanol synthesis over copper/zinc oxide/alumina.

Although photoexcitation has been employed to unlock the low-temperature equilibrium regimes of thermal catalysis, mechanism underlining potential interplay between electron excitations and surface chemical processes remains elusive. Here, we report an associative zinc oxide band-gap excitation and copper plasmonic excitation that can cooperatively promote methanol-production at the copper-zinc oxide interfacial perimeter of copper/zinc oxide/alumina (CZA) catalyst. Conversely, selective excitation of individual components only leads to the promotion of carbon monoxide production. Accompanied by the variation in surface copper oxidation state and local electronic structure of zinc, electrons originating from the zinc oxide excitation and copper plasmonic excitation serve to activate surface adsorbates, catalysing key elementary processes (namely formate conversion and hydrogen molecule activation), thus providing one explanation for the observed photothermal activity. These observations give valuable insights into the key elementary processes occurring on the surface of the CZA catalyst under light-heat dual activation.

In situ K-edge X-ray absorption spectroscopy of the ligand environment of single-site Au/C catalysts during acetylene hydrochlorination.

The replacement of HgCl2/C with Au/C as a catalyst for acetylene hydrochlorination represents a significant reduction in the environmental impact of this industrial process. Under reaction conditions atomically dispersed cationic Au species are the catalytic active site, representing a large-scale application of heterogeneous single-site catalysts. While the metal nuclearity and oxidation state under operating conditions has been investigated in catalysts prepared from aqua regia and thiosulphate, limited studies have focused on the ligand environment surrounding the metal centre. We now report K-edge soft X-ray absorption spectroscopy of the Cl and S ligand species used to stabilise these isolated cationic Au centres in the harsh reaction conditions. We demonstrate the presence of three distinct Cl species in the materials; inorganic Cl-, Au-Cl, and C-Cl and how these species evolve during reaction. Direct evidence of Au-S interactions is confirmed in catalysts prepared using thiosulfate precursors which show high stability towards reduction to inactive metal nanoparticles. This stability was clear during gas switching experiments, where exposure to C2H2 alone did not dramatically alter the Au electronic structure and consequently did not deactivate the thiosulfate catalyst.

Retroileal anastomosis in hand-assisted laparoscopic left colectomy: experience at a single institution.

BACKGROUND: Left hemicolectomy and complicated sigmoid colectomy require an anastomosis between the transverse colon and rectum. Generous mobilization will typically allow the colon to reach to the rectum. However, despite full mobilization of the splenic flexure and extensive work on the mesentery, there are cases in which reach to the pelvis is still an issue. Retroileal routing of the colon is one technique for overcoming such a reach problem and achieving a tension-free anastomosis. Performing retroileal routing using laparoscopic techniques has been reported rarely, and to date, there are no data on this technique when performed in a hand-assisted laparoscopic fashion. This study aimed to describe the feasibility of doing a retroileal routing using a hand-assisted laparoscopic technique. METHODS: This was a retrospective chart review of patients who underwent a colon or rectal resection, either open or laparoscopic, with a pelvic anastomosis, by a single colorectal surgeon at an academic institution between 2008 and 2015 with a focus on the immediate and long-term postoperative complications, estimated blood loss, and operating room time for patients having an operation that included retroileal routing for construction of a colorectal anastomosis. RESULTS: A total of 340 patients fit inclusion criteria and of these, 13 underwent hand-assisted laparoscopic procedures with retroileal routing of the proximal colon to the colorectal anastomosis. Postoperative morbidity included intubation for CO2 retention in one patient and a RLL effusion in another patient; there were no anastomotic leaks. Long-term morbidities included two ventral hernias at 2 years postoperatively. Mean operating room time was 208 min. There were no 30- or 90-day mortalities. CONCLUSIONS: Hand-assisted laparoscopic retroileal routing is a feasible and safe technique in accomplishing a tension-free colorectal anastomosis when proximal colon length makes standard routing of the colon to the rectum an issue.