Understanding the Behavior of Dicalcium Ferrite (Ca2Fe2O5) in Chemical Looping Syngas Production from CH4.

Previous work on calcium ferrites showed they were able to convert syngas to hydrogen via chemical looping. The mixture of iron and calcium and their oxides has different thermodynamic properties than iron oxide alone. Here, the use of methane, an abundant fuel, is investigated as the reductant in chemical looping syngas production. In contrast to syngas-fueled cycles, the looping materials became more active with cycling using methane as the fuel. When reduced by methane, the looping material often showed a significant induction period, indicating that products of reduction (in particular metallic Fe) acted as a catalyst for further reduction. The behavior in a thermogravimetric analyzer (TGA) and a fluidized bed was comparable, i.e., no degradation with cycling. The reduced C2F appeared to be easily reformed when oxidized with CO2, and there was little evidence of bulk phase segregation. The improved kinetics on cycling was likely due to the separation of metallic Fe onto the surface. Using hydrogen to partially reduce C2F promotes the catalytic pyrolysis of methane.

Results From an All Wales Trainee Led Collaborative Prospective Audit on Management of Ankle Fractures.

Aim The purpose of this all Wales national audit was to compare compliance against British Orthopedic Association Standards for Trauma (BOAST) guidelines on the management of ankle fractures. Methods A multi-center prospective audit of the management of adult ankle fractures was conducted between February 2, 2020, and February 17, 2020, via the Welsh Orthopedic Research Collaborative (WORC). Regional leads were recruited in nine NHS hospitals across six university health boards, and recruited collaborators in their respective hospitals. Questionnaires for the data collection on both surgical and conservative management were made available via a password-protected website (walesortho.co.uk). We defined early weight-bearing (EWB) as unrestricted weight-bearing on the affected leg within three weeks of injury or surgery and delayed weight-bearing (DWB) as unrestricted weight-bearing after three weeks of injury or surgery. Results A total of 28 collaborators contributed data for 238 ankle fractures. Poor documentation at the time of injury was noted. Less than 50% of patients with posterior malleolus fracture had a CT scan for further evaluation. Eighty-four percent of the non-operatively treated patients did not have a weight-bearing X-ray (WBXR). Patients who had a WBXR were more likely to be allowed EWB but this was not statistically significant. EWB was allowed in 59.43% and 10% of the non-operatively and operatively treated patients, respectively. DWB was higher in patients who had fixation of the posterior malleolus or syndesmosis. Conclusion There is poor compliance with BOAST guidelines on the management of ankle fractures across Wales. We need to improve documentation and also consider performing a CT scan when the posterior malleolus is fractured. A weight-bearing X-ray should be performed more often to ascertain the stability of an ankle fracture, and those that are deemed stable should be treated with early weight-bearing. The guidelines need to be clearer regarding weight-bearing after fixation especially when posterior malleolus and/or syndesmosis are fixed.

Epidemic of fractures during a period of snow and ice: has anything changed 33†years on?

OBJECTIVES: We reproduced a frequently cited study that was published in the British Medical Journal (BMJ) in 1981 assessing the extent of 'snow-and-ice' fractures during the winter period. SETTING: This study aims to provide an insight into how things have changed within the same emergency department (ED) by comparing the findings of the BMJ paper published 33 years ago with the present date. PARTICIPANTS: As per the original study, all patients presenting to the ED with a radiological evidence of fracture during three different 4-day periods were included. The three 4-day periods included 4 days of snow-and-ice conditions and two control 4-day periods when snow and ice was not present; the first was 4 days within the same year, with a similar amount of sunshine hours, and the second was 4 days 1 calendar year later. PRIMARY AND SECONDARY OUTCOME MEASURES: To identify the frequency, distribution and pattern of fractures sustained in snow-and-ice conditions compared to control conditions as well as comparisons with the index study 33 years ago. RESULTS: A total of 293 patients with fractures were identified. Overall, there was a 2.20 (CI 1.7 to 3.0, p <0.01) increase in risk of fracture during snow-and-ice periods compared to control conditions. There was an increase (p <0.01) of fractures of the arm, forearm and wrist (RR 3.2 (CI 1.4 to 7.6) and 2.9 (CI 1.5 to 5.4) respectively). CONCLUSIONS: While the relative risk was not of the magnitude 33 years ago, the overall number of patients presenting with a fracture during snow-and-ice conditions remains more than double compared to control conditions. This highlights the need for improved understanding of the impact of increased fracture burden on hospitals and more effective preventative measures.

Early versus late surgery for closed ankle fractures.

PURPOSE: To compare the outcome after early versus late surgery for closed ankle fractures in terms of the length of hospital stay and infection rate. METHODS: Records of 95 men and 119 women aged 14 to 92 (mean, 46) years who underwent open reduction and internal fixation for ankle fractures during three 6-month periods in 2004, 2007, and 2010 were reviewed. 82 and 132 patients underwent surgery <24 hours and >24 hours after presentation, respectively. The most common reason for delayed surgery was unavailability of the operation theatre, followed by delayed admission to the fracture clinic and excess soft tissue swelling. RESULTS: Patient and injury characteristics of the 3 study periods were comparable (p=0.399). The early and late surgery groups were comparable in proportions of various fracture patterns but not in patient age (40 vs. 49 years, p=0.002). The mean postoperative length of hospital stay was shorter in the early surgery group (2.9 vs. 5.5 days, p=0.009). The 2 groups did not differ significantly in the infection rate (7% vs. 11%, p=0.589) or the need for additional surgery (3.7% vs. 5.3%, p=0.63). CONCLUSION: Patients with delayed surgery for ankle fracture had a longer postoperative length of hospital stay. Surgery should be performed within 24 hours of injury to minimise the length of hospital stay.

Stress significantly increases mortality following a secondary bacterial respiratory infection.

A variety of mechanisms contribute to the viral-bacterial synergy which results in fatal secondary bacterial respiratory infections. Epidemiological investigations have implicated physical and psychological stressors as factors contributing to the incidence and severity of respiratory infections and psychological stress alters host responses to experimental viral respiratory infections. The effect of stress on secondary bacterial respiratory infections has not, however, been investigated. A natural model of secondary bacterial respiratory infection in naive calves was used to determine if weaning and maternal separation (WMS) significantly altered mortality when compared to calves pre-adapted (PA) to this psychological stressor. Following weaning, calves were challenged with Mannheimia haemolytica four days after a primary bovine herpesvirus-1 (BHV-1) respiratory infection. Mortality doubled in WMS calves when compared to calves pre-adapted to weaning for two weeks prior to the viral respiratory infection. Similar results were observed in two independent experiments and fatal viral-bacterial synergy did not extend beyond the time of viral shedding. Virus shedding did not differ significantly between treatment groups but innate immune responses during viral infection, including IFN-γ secretion, the acute-phase inflammatory response, CD14 expression, and LPS-induced TNFα production, were significantly greater in WMS versus PA calves. These observations demonstrate that weaning and maternal separation at the time of a primary BHV-1 respiratory infection increased innate immune responses that correlated significantly with mortality following a secondary bacterial respiratory infection.

Effect of knee position on gap size following acute Achilles rupture.

BACKGROUND: Acute traumatic rupture of the tendoachilles is a common problem. Following a recent Cochrane review, operative treatment has been shown to have a lower re-rupture rate compared with conservative treatment, but is associated with a slightly higher rate of other complications. Debate concerning the method and duration of conservative treatment remains. We aimed to assess the effect of knee position on the gap in acute tendoachilles ruptures. MATERIALS AND METHODS: Patients with a history and examination consistent with an acute rupture were collected prospectively. They were investigated by the same musculoskeletal consultant radiologist using ultrasonography. Tendon gap was measured with the foot in neutral and full tolerable equinus with the knee both flexed to 90 degrees and fully extended. A pilot study of 10 patients was used to provide data for a power calculation. Following this a total of 25 consecutive patients were recruited for inclusion. A paired Student t-test was used to compare mean differences between the knee flexed/ankle plantarflexed and knee extended/ankle plantarflexed positions on the gap at the rupture site. RESULTS: A diagnosis of acute tendoachilles rupture was confirmed in all patients and tendon gap was measured with the knee flexed and extended with the ankle either neutral or plantarflexed. This confirmed there was no significant difference in the tendon gap with the knee flexed or extended provided the foot was in full equinus (p>0.05). CONCLUSION: This study showed that knee position had no significant effect on the tendon gap at the rupture site. This study could have considerable implications on the rationale behind conservative treatment and splinting of acute tendoachilles ruptures with no apparent role for knee flexed immobilization.

Locked intramedullary fixation vs plating for displaced and shortened mid-shaft clavicle fractures: a randomized clinical trial.

BACKGROUND: Recent literature supports surgical intervention for shortened, displaced, mid-shaft clavicle fractures. We present the results of a randomized clinical trial comparing locked intramedullary fixation and plate fixation for short, displaced, mid-shaft clavicle fractures. MATERIALS AND METHODS: Local ethical approval was obtained and power analysis and sample size calculations were performed prior to commencement. Patients randomized to 2 groups to be treated with either locked intramedullary fixation or plating. Patients regularly followed up to clinical and radiographic union. The primary outcome measure was the Constant score, secondary outcome measures included the Oxford shoulder score, union rate, and complication rates. RESULTS: Seventeen patients were randomized to locked intramedullary fixation and 15 randomized to plating. Mean age was 29.3 years. Mean follow-up was 12.4 months. There was no significant difference in either Constant scores (P = .365) or Oxford scores (P = .773). There was 100% union in both groups. In the intramedullary group, 1 case of soft tissue irritation settled after the pin removal; 1 pin backed out and was revised. Three superficial wound infections resulted in plate removal and 8 plates (53%) were removed. DISCUSSION: Intramedullary fixation has the theoretical advantage of preserving the periosteal blood supply, but carries the morbidity of pin removal. Clavicle plates are not routinely removed but require greater exposure and may compromise periosteal blood supply. CONCLUSION: Both locked intramedullary fixation and plating produce good functional results; however, metalwork may need to be removed as a second procedure.

Urinary retention following lower limb arthroplasty: analysis of predictive factors and review of literature.

Acute urinary retention is a common complication after lower limb arthroplasty. The aim of our study was to assess whether the International Prostate Symptom Score (IPSS) and other patient related factors could predict the likelihood of patients developing urinary retention after lower limb arthroplasty. We have also reviewed the literature on this subject. This is a prospective study of 102 male patients undergoing hip or knee arthroplasty. Data collected included age, IPSS, type of operation, type of anaesthesia and development of acute urinary retention in the immediate postoperative period. Thirty-one patients (30.4%) developed acute urinary retention. Of all the parameters studied, age was the only factor that correlated significantly with development of urinary retention. The risk factors for progression of benign prostatic hyperplasia could all be considered as factors for the development of this complication. However, apart from age more than 70 years, it is not practical to use the other parameters.

Piscine UDP-glucuronosyltransferase 1B.

Glucuronidation is an important detoxification pathway for organic pollutants in fish. We report here the isolation and characterisation of UDP-glucuronosyltransferases (UGT) genes from the closely related marine flatfish, plaice (Pleuronectes platessa) and flounder (Platichthys flesus). The deduced amino acid sequences share greater similarity with mammalian UGT1 family genes than UGT2 genes (44-47% and 39-40% amino acid identity, respectively) and have been designated UGT1B. Both plaice and flounder UGT1B mRNAs are expressed in all tissues and are most highly expressed in liver, with high levels in intestine, gill, kidney and adipose tissue and much lower levels in muscle, heart and brain. Plaice UGT1B mRNA is undetectable in gametes or fertilised eggs and there is a large increase in expression between gastrulation and myotome formation after which levels decline some 5-10-fold. Flounder UGT1B mRNA was increased in liver after intraperitoneal injection of Arochlor 1254 or lindane (gamma-hexachlorocyclohexane), but not after perflourooctanoic acid or 3-methylcholanthrene treatment. In isolated flounder hepatocytes UGT1B mRNA was increased after exposure to benzo(a)pyrene but not by 17alpha-ethynylestradiol. Expression of a cDNA for plaice UGT1B in cos7 cells resulted in higher 1-naphthol conjugation in cell homogenates compared to steroid conjugation, whilst bilirubin and bile acid conjugation were undetectable. This indicates that the plaice gene codes for the phenol-conjugating UGT previously purified in our laboratory from this species and that it is likely to play a major role in the detoxification of polyaromatic hydrocarbons in flatfish. Its role in development is unknown. UGT1B genes are also present in pufferfish (Tetraodon nigroviridis) and zebrafish (Danio rerio) genomes, but they differ in their genic organisation. Pufferfish possess multiple (repeated) complete UGT1 genes and Southern blots indicate that the homologous plaice UGT1B gene may also be organised in this way. In contrast, zebrafish appear to have two UGT1 loci whose sequences and intron/exon structures are closely related to that of plaice, however, the organisation of these genes is similar to the mammalian UGT1 family since each has multiple repeated exon 1's which are alternatively spliced to a common set of exons encoding the aglycone binding domain. Taken together with evidence from phylogenetic comparison of fish sequences with UGT1 and UGT2 families in mammals, we suggest these homologous fish UGTs should all be included within the vertebrate UGT1 family and designated as UGT1B.

Molecular analyses of disease pathogenesis: application of bovine microarrays.

The molecular analysis of disease pathogenesis in cattle has been limited by the lack of availability of tools to analyze both host and pathogen responses. These limitations are disappearing with the advent of methodologies such as microarrays that facilitate rapid characterization of global gene expression at the level of individual cells and tissues. The present review focuses on the use of microarray technologies to investigate the functional pathogenomics of infectious disease in cattle. We discuss a number of unique issues that must be addressed when designing both in vitro and in vivo model systems to analyze host responses to a specific pathogen. Furthermore, comparative functional genomic strategies are discussed that can be used to address questions regarding host responses that are either common to a variety of pathogens or unique to individual pathogens. These strategies can also be applied to investigations of cell signaling pathways and the analyses of innate immune responses. Microarray analyses of both host and pathogen responses hold substantial promise for the generation of databases that can be used in the future to address a wide variety of questions. A critical component limiting these comparative analyses will be the quality of the databases and the complete functional annotation of the bovine genome. These limitations are discussed with an indication of future developments that will accelerate the validation of data generated when completing a molecular characterization of disease pathogenesis in cattle.

Scalar coupling between the 15N centres in methylated 1,8-diaminonaphthalenes and 1,6-diazacyclodecane: to what extent is 2HJNN a reliable indicator of N-N distance?

The scalar couplings between hydrogen bonded nitrogen centres ((2H)J(NN)) in the free-base and protonated forms of the complete series of [(15)N(2)]-N-methylated 1,8-diamino naphthalenes in [D(7)]DMF solution have been determined, either directly (15N[1H] NMR), or, indirectly (13C[1H] NMR and simulation of the X part of the ABX spectrum (X=13C, A,B=15N)). Additionally, the (2H)J(NN) value in the HBF(4) salt of [(15)N(2)]-1,6-dimethyl-1,6-diazacyclodecane was determined, indirectly by 13C[(1H] NMR spectroscopy. As confirmed by DFT calculations and by reference to CSD, the rigid nature of the naphthalene scaffold results in rather low deviations in N,N distance or H-N,N angle within each series, apart from the free base of the permethylated compound (proton sponge) where the naphthalene ring is severely distorted to relieve strain. Despite such restrictions, the (2H)J(NN) values increase smoothly from 1.5 to 8.5 Hz in the protonated series as the degree of methylation increases. The effect in the free-base forms is much less pronounced (2.9 to 3.7 Hz) with no scalar N,N coupling detected in the permethylated compound (proton sponge) due to the lack of hydrogen bond between the N,N centres. Neither the pK(a) nor the N-N distance in the protonated forms correlates with (2H)J(NN). However, the sum of the (13)C NMR shifts of the naphthalene ring C(1,8) carbons which are attached directly to the nitrogen centres correlates linearly with (2H)J(NN) and with the degree of methylation. The gas-phase computed (2H)J(NN) is almost constant throughout the homologous series, and close to the experimental value for the tetramethylated ion. However, the computed coupling constant is attenuated in structures involving microsolvation of each N-H unit, and the trend then matches experiment. These experimental and computational observations suggest that Fermi contact between the two N centres is decreased upon formation of strong charge-dispersing intermolecular hydrogen bonds of the free N-H groups with the solvent.