In situ real-time neutron imaging of gaseous H2 adsorption and D2 exchange on carbon-supported Pd catalysts.

We use in situ neutron imaging to observe the adsorption/absorption of hydrogen within a packed catalyst bed of a Pd/C catalyst at a spatial and temporal resolution of ∼430 µm and a ∼9 s respectively. Additionally, the H2/D2 exchange process across the catalyst bed is followed in real time.

Surgical management strategies for colorectal malignancies of the splenic flexure - A systematic review and network meta-analysis.

BACKGROUND: Extended right hemicolectomy (ERHC) or left hemicolectomy (LHC) are accepted as the standard-of-care for colonic tumours of the splenic flexure. Lymphatic drainage at this site is poorly defined and subject to significant heterogeneity. Nevertheless, emerging evidence demonstrates the potential oncological safety of segmental splenic flexure colectomy (SFC). AIM: To perform a systematic review and network meta-analysis (NMA) to compare outcomes following ERHC, LHC and SFC for splenic flexure tumours (SFTs). METHODS: A systematic review was performed as per PRISMA guidelines. NMA was performed using R Shiny and Netmeta packages. RESULTS: A total of 13 studies, involving 6176 patients (ERHC n = 785; LHC n = 1527; SFC n = 3864) were included in the NMA. There was no difference in overall survival (OS) (SFC vs LHC Hazard Ratio [HR] 1.0, 95% Credible Interval [CrI] 0.76,1.34; SFC vs ERHC HR 1.18, 95% CrI 0.85,1.58) between the groups. SFC had a shorter operation time (Mean 176.37 min; Mean Difference [MD] SFC vs LHC 20.34 min 95% CrI 10.9, 29.97; SFC vs ERHC MD 22.19 95% CrI 11.09, 33.29) but also had a lower average lymph node yield (LNY) compared with ERHC (MD 7.15, 95% CrI 5.71, 8.60). ERHC had a significantly higher incidence of post-operative ileus (Odds Ratio [OR] 3.47, 95% CrI 1.11, 10.84). There was also no difference observed for minimally invasive approaches, anastomotic leak rate, perioperative mortality, reoperation rates or length of stay. CONCLUSIONS: While SFC may allow for reduced operative duration and improved bowel function postoperatively. SFC, LHC, ERHC are all acceptable approaches for curative resection of cancers of the splenic flexure, with no difference in OS observed. Thus, surgeon preference and candidate-specific factors will likely determine the management of SFTs.

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.

Risk scoring models for patients with proximal femur fractures: Qualitative systematic review assessing 30-day mortality and ease of use.

BACKGROUND: Hip fractures are a common orthopaedic injury affecting a particularly frail and vulnerable patient cohort. They are at risk of many complications, including prolonged length of stay and mortality. Efforts to identify those at high risk may be beneficial. Over 25 risk prediction models are published for patients with hip fractures. AIM: The primary aim of this study was to assess the performance of predictor scores in predicting 30-day mortality. The secondary aim was to assess the ease of use of these systems. METHODS: A qualitative systematic review was performed. A search was conducted on online databases, including PubMed, CINAHL, Clinical Trials.gov, Cochrane, DARE, EMBASE, SCOPUS, and Web of Science.. The terms fragility hip fractures and risk prediction models were utilised while performing the search. These were then expanded using Boolean operators and similar terms. Search results were imported to Covidence. Primary observational studies using one or more hip fracture mortality prediction models and 30-day mortality as an outcome were included. Systematic reviews and studies on specific patient groups defined other medical conditions (e.g. COVID positive or dialysis patients) were excluded. RESULTS: 3,101 studies were screened following duplicate removal. 34 papers were included in the review, in which 23 scoring systems were reported. Six of these were pre-operative and reported in multiple studies. Most demonstrated appropriate fit and fair discrimination. Five of the six pre-operative scoring systems examined, displayed appropriate ease of use, allowing risk calculation at the time of admission. CONCLUSION: Nottingham Hip Fracture Score remains the most extensive reported scoring system and performs fair overall with AUROCs of 0.64-0.80 and good fit in calibration across all studies. However, new systems utilise many similar predictors. There is a need for the standardisation of publications on scoring systems to allow further systematic review and meta-analyses.

Neutron Scattering Studies of Heterogeneous Catalysis.

Understanding the structural dynamics/evolution of catalysts and the related surface chemistry is essential for establishing structure-catalysis relationships, where spectroscopic and scattering tools play a crucial role. Among many such tools, neutron scattering, though less-known, has a unique power for investigating catalytic phenomena. Since neutrons interact with the nuclei of matter, the neutron-nucleon interaction provides unique information on light elements (mainly hydrogen), neighboring elements, and isotopes, which are complementary to X-ray and photon-based techniques. Neutron vibrational spectroscopy has been the most utilized neutron scattering approach for heterogeneous catalysis research by providing chemical information on surface/bulk species (mostly H-containing) and reaction chemistry. Neutron diffraction and quasielastic neutron scattering can also supply important information on catalyst structures and dynamics of surface species. Other neutron approaches, such as small angle neutron scattering and neutron imaging, have been much less used but still give distinctive catalytic information. This review provides a comprehensive overview of recent advances in neutron scattering investigations of heterogeneous catalysis, focusing on surface adsorbates, reaction mechanisms, and catalyst structural changes revealed by neutron spectroscopy, diffraction, quasielastic neutron scattering, and other neutron techniques. Perspectives are also provided on the challenges and future opportunities in neutron scattering studies of heterogeneous catalysis.

The association between weather warnings and hip fractures in the Republic of Ireland.

This study examined the relationship between hip fractures and weather warnings with the hypothesis higher rates of fractures occur during warnings. National hip fracture database and weather warning records were utilised. Higher rates of hip fractures were found with severe warnings. This has implications for planning in future severe warnings. BACKGROUND: Hip fractures represent a significant burden on the Irish Health system with 3666 in 2020. The Irish National Meteorological Service operates a colour coded warning system. Yellow being least severe, while orange represents weather with capacity to impact individuals in affected areas and red represents advice to protect themselves and property. Previous studies investigated the seasonality of hip fractures, which remains but none have investigated the relationship between weather warnings and rates of hip fractures. The hypothesis was that increasing weather warnings would be associated with increased hip fractures. The aim was to investigate the relationship between weather warnings and hip fractures in the Republic of Ireland. METHODS: Comparison of national weather warning archives from 2013 to 2019 to Fracture Database records. Reviews assessed whether fractures occurred on days a weather warning was in place in the individual's local county. A statistical analysis of warning features and their relationship to hip fractures was then performed. Fractures and weather warnings were stratified by county with both a panel and case crossover analysis performed. RESULTS: There was a tendency towards increased incidence of hip fractures with weather warnings in adjusted analysis (IRR 1.02; 95%CI 0.99-1.06; p-value 0.123). Orange warnings were associated with a statistically higher incidence of fractures (IRR 1.06; 1.01-1.12; p-value 0.026). In both panel and case crossover analysis, both orange and yellow warnings were associated with fractures. Red warnings were associated with a lower incidence of fracture on day of warning (adjusted incidence rate ratio 0.92; 0.70-1.22; p-value 0.569) but a higher incidence on the following day (adjusted incidence rate ratio 1.14; 0.88-1.46; p-value 0.313). CONCLUSION: An increased incidence of hip fractures appears to occur during weather warnings. Consideration should be given when preparing for periods of extreme weather, ensuring sufficiently resources.

Counting the Acid Sites in a Commercial ZSM-5 Zeolite Catalyst.

This work investigates the acid sites in a commercial ZSM-5 zeolite catalyst by a combination of spectroscopic and physical methods. The Brønsted acid sites in such catalysts are associated with the aluminum substituted into the zeolite lattice, which may not be identical to the total aluminum content of the zeolite. Inelastic neutron scattering spectroscopy (INS) directly quantifies the concentrations of Brønsted acid protons, silanol groups, and hydroxyl groups associated with extra-framework aluminum species. The INS measurements show that ∼50% of the total aluminum content of this particular zeolite is extra framework, a conclusion supported by solid-state NMR and ammonia temperature-programmed desorption (TPD) measurements. Evidence for the presence of extra-framework aluminum oxide species is also seen in neutron powder diffraction data from proton- and deuterium-exchanged samples. The differences between results from the different analytical methods are discussed, and the novelty of direct proton counting by INS in this typical commercial catalyst is emphasized.

Increasing hip fracture volume following repeated lockdowns: an Irish multicentre study of periods pre-Covid, during Covid lockdown and following vaccination.

BACKGROUND: Older age groups were identified as a high-risk cohort for Covid-19 and thus were a focus of lockdown measures enacted internationally. Resultant decreased social mobility and physical activity levels are associated with sarcopenia, which may lead to increased risk of hip fracture upon resuming social integration and physical activities after easing of lockdown restrictions. AIMS: Our aim was to compare the incidence of hip fractures during the period following vaccination with subsequent relaxation of restrictions, to those prior to and during the Covid pandemic. METHODS: A multicentre retrospective cohort study was performed consisting of all patients presenting with a "hip" fracture to 3 regional trauma units over the relevant time periods in 2019, 2020 and 2021. Tallaght, Galway and Waterford University Hospitals are large academic teaching hospitals with a combined mixed urban and rural catchment of over 1 million people. FINDINGS: Four-hundred-fourteen patients in total were included in the final analysis, with 133 eligible hip fractures observed proceeding to operative treatment across the study period in 2019, 132 in 2020 and 149 in 2021, representing a 12.88% increase. Demographic data revealed similar patient cohorts with respect to age and gender, fracture pattern and treatment. CONCLUSIONS: An increase in hip fracture volume was observed during the period post vaccination with subsequent relaxation of restrictions and increased social mobility, compared to those prior to and during the Covid pandemic. These findings have implications for hospital planning and orthopaedic resourcing as we navigate our way forward past the Covid-19 Pandemic.

Combining quasielastic neutron scattering and molecular dynamics to study methane motions in ZSM-5.

Quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations are applied in combination to investigate the dynamics of methane in H-ZSM-5 zeolite catalysts used for methanol-to-hydrocarbons reactions. Methane is employed as an inert model for the methanol reaction feedstock, and studies are made of the fresh catalyst and used catalysts with varying levels of coke buildup to investigate the effect of coking on reactant mobility. Measurements are made in the temperature range from 5 to 373 K. Methane mobility under these conditions is found to be extremely high in fresh ZSM-5, with the majority of movements occurring too fast to be resolved by the QENS instrument used. A small fraction of molecules undergoing jump diffusion on QENS time scales is identified and found to correspond with short-range jump diffusion within single zeolite pores as identified in MD simulations. Agreement between QENS and MD mobility measurements is found to be within 50%, validating the simulation approach employed. Methane diffusion is found to be minimally affected by moderate levels of coke buildup, while highly coked samples result in the confinement of methane to single pores within the zeolite with minimal long-range diffusion.

Mechanistic Insight Into the Application of Alumina-Supported Pd Catalysts for the Hydrogenation of Nitrobenzene to Aniline.

Two Pd/γ-Al2O3 catalysts are examined for the vapor phase hydrogenation of nitrobenzene over the temperature range of 60-200 °C. A 1 wt % catalyst is selected as a reference material that is diluted with γ-alumina to produce a 0.3 wt % sample, which is representative of a metal loading linked to a candidate industrial specification aniline synthesis catalyst. Cyclohexanone oxime is identified as a by-product that is associated with reagent transformation. Temperature-programed infrared spectroscopy and temperature-programed desorption measurements of chemisorbed CO provide information on the morphology of the crystallites of the higher Pd loading catalyst. The lower Pd loading sample exhibits a higher aniline selectivity by virtue of minimization of product overhydrogenation. Reaction testing measurements that were undertaken employing elevated hydrogen flow rates lead to the proposition of separate reagent and product-derived by-product formation pathways, each of which occurs in a consecutive manner. A global reaction scheme is proposed that defines the by-product distribution accessible by the grades of catalyst examined. This information is helpful in defining product purification procedures that would be required in certain heat recovery scenarios connected with large-scale aniline production.

Interaction of Methanol over CsCl- and KCl-Doped η-Alumina and the Attenuation of Dimethyl Ether Formation.

As part of a program to investigate aspects of surface chemistry relevant to methyl chloride synthesis catalysis, the interaction of methanol with η-alumina doped with either CsCl or KCl in the range 0.01-1.0 mmol g(cat) -1 is investigated by a combination of diffuse reflectance infrared Fourier transform spectroscopy and temperature-programed desorption (TPD). Infrared spectra (IR) recorded at 293 K show that increasing the concentration of the group 1 metal chloride progressively decreases the surface concentration of associatively chemisorbed methanol and changes the environment in which the adsorbed methanol resides. For CsCl concentrations of ≥0.6 mmol g(cat) -1, chemisorbed methoxy species dominate the IR spectrum, while TPD studies show that the amount of methanol adsorbed onto the surface, and subsequently desorbed unchanged, changes relatively little. In the TPD experiments, some of the adsorbed methanol reacts to give dimethyl ether (DME) which then desorbs; for dopant concentrations of 1.0 mmol g(cat) -1, DME formation is suppressed to below the limit of detection. Unexpectedly, the presence of formate species generated at 293 K is also observed spectroscopically, characterized by a νasym(COO) mode which exhibits a hypsochromic shift relative to potassium formate; surface concentrations of formate are higher at higher loadings of group 1 metal chloride. Temperature-programed IR spectroscopy shows that the room-temperature formate species desorbs, decomposes, or migrates on warming to 653 K. Thermal ramping of the methanol-saturated surface also results in formate production but one that exhibits an IR profile in agreement with earlier observations and literature values. Increasing the concentrations of the group 1 metal chloride progressively decreases the presence of the thermally induced formate moiety. The study not only reinforces the concept of group 1 metal chloride additives progressively rendering ineffective those Lewis acid sites present at the η-alumina surface which convey discrete reaction characteristics [e.g., (i) dimerization of methanol to form DME and (ii) an activated methoxy → formate transition] but also suggests the generation of reactive sites not present in the undoped alumina.

Athletes with primary glenohumeral instability demonstrate lower rates of bone loss than those with recurrent instability and failed prior stabilization.

BACKGROUND: The purpose of this study was to compare the preoperative magnetic resonance arthrography findings in patients who underwent glenohumeral stabilization with a history of primary instability, recurrent instability, or failed stabilization. METHODS: All patients who presented with glenohumeral instability and underwent stabilization performed by a single surgeon in our institution between 2008 and 2020 were considered for inclusion in this study. The magnetic resonance arthrography findings of all patients were recorded. Imaging findings were compared between patients with primary instability, those with recurrent instability, and those with failed prior stabilization. P < .05 was considered statistically significant. RESULTS: Overall, 871 patients were included, of whom 814 (93.5%) were male patients; the mean age was 23.1 years (range, 13-57 years). There were 200 patients with primary instability, 571 with recurrent instability, and 100 who required revision stabilization surgery, with no significant differences in demographic characteristics between the groups. A significantly higher amount of glenoid bone loss was noted in patients with recurrent instability (43.4%) and failed prior stabilization (56%) than in those with primary instability (26.5%) (P < .0001). Additionally, a significantly higher number of Hill-Sachs lesions were observed in patients with recurrent instability (70.1%) and failed prior stabilization (89%) than in those with primary instability (67.5%) (P < .0001). We found no significant differences between the groups regarding articular cartilage damage, glenolabral articular disruption, anterior labral periosteal sleeve avulsion, humeral avulsion of the glenohumeral ligaments, or superior labral anterior-posterior tears (P > .05). CONCLUSION: Patients presenting for stabilization with recurrent instability or following a failed stabilization procedure have higher rates of glenohumeral bone loss than those with primary instability. Therefore, stabilization of primary instability, particularly in high-functioning athletes with a view to preventing recurrence, may reduce the overall progression of glenohumeral bone loss and potential subsequent inferior clinical outcomes.

Phosgene Synthesis Catalysis: The Influence of Small Quantities of Bromine in the Chlorine Feedstream.

The effect of relatively low concentrations of Br2(g) in the Cl2(g) feedstock for phosgene synthesis catalysis via the reaction of CO(g) and Cl2(g) over activated carbon (Donau Supersorbon K40) is explored. Under the stated reaction conditions and in the absence of a catalyst, BrCl(g) forms from the reaction of Cl2(g) and Br2(g). Phosgene synthesis over the catalyst at 323 K is investigated for Br2(g):Cl2(g) molar flow ratios in the range 0-1.52% (0-15,190 ppm) and shows enhanced rates of phosgene production. Maximum phosgene production is observed at a Br2(g):Cl2(g) molar flow ratio of 1.52% (15,190 ppm), which corresponds to an enhancement in the rate of phosgene production of ∼227% with respect to the phosgene flow rate observed in the absence of an incident bromine co-feed. A reaction model is proposed to account for the experimental observables, where BrCl(g) is highlighted as a significant intermediate. Specifically, enhanced rates of phosgene production are associated with the dissociative adsorption of BrCl(g) that indirectly increases the pool of Cl(ad) available for reaction.

The interaction of CO with a copper(ii) chloride oxy-chlorination catalyst.

The interaction of CO with an attapulgite-supported, KCl modified CuCl2 catalyst has previously been examined using a combination of XANES, EXAFS and DFT calculations. Exposing the catalyst to CO at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment stage, where the supported CuCl2 sample is exposed to a diluted stream of dichlorine; subsequent CO exposure at ∼643 K then leads to phosgene production. This communication describes a series of FTIR based micro-reactor measurements, coupled with characterisation measurements utilising TEM, XRD and XPS to define the nature of the catalyst at different stages of the reaction coordinate. The CuCl2 catalyst is able to support Deacon activity , establishing this work with the possibility of utilising the oxy-chlorination of CO to produce phosgene. Continuous dosing of CO at elevated temperatures over the chlorine pre-dosed CuCl2 catalyst shows diminishing phosgene production as a function of time-on-stream, indicating surface chlorine supply to be rate-limiting under the reaction conditions studied. A pictorial reaction scheme is proposed to account for the surface chemistry observed.

Ankle conFUSION: The quality and readability of information on the internet relating to ankle arthrodesis.

BACKGROUND: The internet is an important source of information for patients undergoing surgery. Multiple studies have identified inappropriately high reading levels of patient information online. The average reading level in the United States is 7-8th grade. Multiple organisations have recommended that patient information not exceed 6th grade level. This study aims to evaluate the reading levels and quality of information regarding ankle fusion surgery online. METHODS: Google, Bing and Yahoo were searched (MeSH "ankle fusion", "ankle arthrodesis") and the top 30 URLs analysed. Readability was assessed using an online readability calculator to produce 3 scores (Gunning FOG, Flesch Kincaid Grade and Flesch Reading Ease). Quality was assessed using a HONcode detection web-extension and the JAMA benchmark criteria. RESULTS: Ninety-eight webpages were identified. The mean Flesch Kincaid Grade level was 9.24 ± 2.33 (95% CI 8.78-9.71). The mean Gunning FOG grade was 10.88 ± 3.1 (95% CI 10.26-11.5). The mean Flesch Reading Ease score was 49.88 ± 14.46 (95% CI 46.98-52.78). 7 webpages were at or below the 6th grade reading level. The mean JAMA score was 1.34 ± 1.32 out of 4 (95% CI 1.07-1.6). 14 websites were HONcode accredited. CONCLUSION: The overall readability of medical information online is too high for the average patient. Given the important role that health literacy provides in patient reported outcomes, improving the readability and quality of these materials is imperative. Awareness by the general public is essential for them to critically appraise the information they receive online.

Toward High Selectivity Aniline Synthesis Catalysis at Elevated Temperatures.

In connection with an initiative to enhance heat recovery from the large-scale operation of a heterogeneously catalyzed nitrobenzene hydrogenation process to produce aniline, it is necessary to operate the process at elevated temperatures (>100 °C), a condition that can compromise aniline selectivity. Alumina-supported palladium catalysts are selected as candidate materials that can provide sustained aniline yields at elevated temperatures. Two Pd/Al2O3 catalysts are examined that possess comparable mean Pd particle sizes (∼5 nm) for different Pd loading: 5 wt % Pd/Al2O3 and 0.3 wt % Pd/Al2O3. The higher Pd loading sample represents a reference catalyst for which the Pd crystallite morphology has previously been established. The lower Pd loading technical catalyst more closely corresponds to industrial specifications. The morphology of the Pd crystallites of the 0.3 wt % Pd/Al2O3 sample is explored by means of temperature-programmed infrared spectroscopy of chemisorbed CO. Reaction testing over the range of 60-180 °C shows effectively complete nitrobenzene conversion for both catalysts but with distinction in their selectivity profiles. The low loading catalyst is favored as it maximizes aniline selectivity and avoids the formation of overhydrogenated products. A plot of aniline yield as a function of WHSV for the 0.3 wt % Pd/Al2O3 catalyst at 100 °C yields a "volcano" like curve, indicating aniline selectivity to be sensitive to residence time. These observations are brought together to provide an indication of an aniline synthesis catalyst specification suited to a unit operation equipped for enhanced heat transfer.

Hydrogenation on Palladium Nanoparticles Supported by Graphene Nanoplatelets.

Pd nanoparticles (1 wt %; mean size ∼4 nm) were supported on ∼2 µm sized, but few nanometers thick, graphene nanoplatelets (GNPs) and compared to 1 wt % Pd on activated carbon or γ-alumina. Catalyst morphology, specific surface area, and Pd particle size were characterized by SEM, BET, and TEM, respectively. H2-TPD indicated that GNPs intercalated hydrogen, which may provide additional H2 supply to the Pd nanoparticles during C2H4 hydrogenation. Whereas the two types of Pd/GNPs (NaOH vs calcinated) catalysts were less active than Pd/C and Pd/Al2O3 below 40 °C, at 55 °C they were about 3-4 times more active. As for example Pd/GNPs (NaOH) and Pd/Al2O3 exhibited not too different mean Pd particle size (3.7 vs 2.5 nm, respectively), the higher activity is attributed to the additional hydrogen supply likely by the metal/support interface, as suggested by the varying C2H4 and H2 orders on the different supports. Operando XANES measurements during C2H4 hydrogenation revealed the presence of Pd hydride. The Pd hydride was more stable for Pd/GNPs (NaOH) than for Pd/C, once more pointing to a better hydrogen supply by graphene nanoplatelets.