Symmetric Catalyst Design Employing Ir Nanoparticles on Black WO3- x Nanofiber Support for Boosting Water Electrolysis

The efficient evolution of gaseous hydrogen and oxygen from water is required to realize sustainable energy conversion systems. To address the sluggish kinetics of the multielectron transfer reaction, bifunctional catalyst materials for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) should be developed. Herein, a tailored combination of atomically minimized iridium catalysts and highly conductive black WO3- x nanofiber supports are developed for the bifunctional electrolyzer system. Atomic Ir catalysts, particularly those that activate the OER, minimize the utilization of precious metals. The oxygen-deficient black WO3- x NF support, which boosts the HER, offers increased electronic conductivity and favorable nucleation sites for Ir loading. The Ir-black WO3- x NFs exhibit increased double-layer capacitance, a significantly reduced onset potential, lower Tafel slope, and stable cyclability for both the OER and HER, compared to large-sized Ir catalysts loaded on white WO3 nanofibers. This study offers a strategy for developing an optimal catalyst material with suitable supports for high-performance and economical water electrolysis systems for achieving carbon-negative targets.

Addressing health inequalities in times of austerity: implementation of a place-based approach in multitiered local government

AIMS

This article focuses on how local authorities in England are tackling wider determinants of health and inequalities in their population's outcomes while budgets for public services are diminishing.

METHODS

It reports the experience from one case study engaged in rolling out a devolved, place- and asset-based strategy over multiple tiers of local government. Relating these findings to relevant social theory, we draw out aspects of context and mechanisms of change. We offer plausible hypotheses for the experiences observed, which supports transferability and implementation of place-based strategies in other local authority areas struggling with similar challenges.

RESULTS

Findings highlight the importance of high-level and political buy-in, as well as the role of the COVID-19 pandemic as a potential catalyst to rollout. Creating the foundations for a new, place-based working was important for achieving coherence among partners around what local government was trying to achieve. These included investment in infrastructure, both relational and tangible inputs such as organisational and human resources, to establish the conditions for systemic change towards early intervention and prevention.

CONCLUSION

This study identified clear foundations for place-based action, plus enablers and barriers to significant transformation of practice towards asset-based approaches between local authorities, partners and the public.

Review: Environmental enrichment builds functional capacity and improves resilience as an aspect of positive welfare in production animals

The success of the animal in coping with challenges, and in harnessing opportunities to thrive, is central to its welfare. Functional capacity describes the capacity of molecules, cells, organs, body systems, the whole animal, and its community to buffer against the impacts of environmental perturbations. This buffering capacity determines the ability of the animal to maintain or regain functions in the face of environmental perturbations, which is recognised as resilience. The accuracy of physiological regulation and the maintenance of homeostatic balance underwrite the dynamic stability of outcomes such as biorhythms, feed intake, growth, milk yield, and egg production justifying their assessment as indicators of resilience. This narrative review examines the influence of environmental enrichments, especially during developmental stages in young animals, in building functional capacity and in its subsequent expression as resilience. Experience of enriched environments can build skills and competencies across multiple functional domains including but not limited to behaviour, immunity, and metabolism thereby increasing functional capacity and facilitating resilience within the context of challenges such as husbandry practices, social change, and infection. A quantitative method for measuring the distributed property of functional capacity may improve its assessment. Methods for analysing embedded energy (emergy) in ecosystems may have utility for this goal. We suggest functional capacity provides the common thread that links environmental enrichments with an ability to express resilience and may provide a novel and useful framework for measuring and reporting resilience. We conclude that the development of functional capacity and its subsequent expression as resilience is an aspect of positive animal welfare. The emergence of resilience from system dynamics highlights a need to shift from the study of physical and mental states to the study of physical and mental dynamics to describe the positive dimension of animal welfare.

Exploring the cause of reduced production responses to feeding corn dried distillers' grains in lactating dairy cows

An experiment was conducted to identify the factors that cause reduced production of cows fed a diet with high corn distiller's grains with solubles (DDGS). We hypothesized that the factors could be high S content in DDGS which may directly (S toxicity) or indirectly [dietary cation-anion difference (DCAD)] cause reduced production. We also hypothesized that high polyunsaturated fatty acids (PUFA) in DDGS could be another major factor. In a randomized complete block design, 60 lactating cows (15 primiparous and 45 multiparious; average ± SD at the beginning of the trial: milk yield, 44.0 ± 6.9 kg/d; DIM, 123 ± 50; BW, 672 ± 82 kg) were blocked and cows in each block were randomly assigned to one of the following treatments: SBM [4.7% fatty acids (FA), 0.22% S, and 178 mEq/kg DM of DCAD], a diet containing soybean meal as the main protein source; DG, SBM replacing mainly soybean byproducts and supplemental fat with DG at 30% dietary DM (4.7% FA, 0.44% S, and 42 mEq/kg DM of DCAD); SBM+S, SBM with sodium bisulfate for additional dietary S (4.8% FA, 0.37% S, and 198 mEq/kg DM of DCAD); SBM+CO, SBM with corn oil (4.7% FA, 0.23%, and 165 mEq/kg DM of DCAD); and DG+DCAD, DG with increased DCAD (4.7% FA, 0.40% S, and 330 mEq/kg DM of DCAD). Due to the limited tie stalls, the blocks of 1 to 6 started the experiment first as phase 1 and the rest of the blocks as phase 2 started the experiment after phase 1. All cows were fed the SBM diet for 10 d as a covariate period followed by the experimental period for 35 d. Data were analyzed using the PROC MIXED of SAS, block and phase were random effects and treatments, repeated wk, and interaction were fixed effects. There was an interaction of wk by treatment for DMI. While milk yield did not change, milk fat concentration tended to decrease (2.78 vs. 3.34%) for DG compared with SBM. Dry matter, OM, NDF, and CP digestibilities were lower when cows were fed the DG diet compared with SBM. Additionally, cows fed DG had lower blood concentrations of HCO3-, base excess, and tCO2 compared with SBM. The SBM+S diet did not affect production, nutrient digestibility, or blood parameters when compared with SBM. The SBM+CO diet decreased milk fat concentration and yield compared with SBM. The DG+DCAD diet tended to increase milk fat yield and concentration (1.24 vs. 1.47 kg/d; 2.78 vs. 3.37%) and increased ECM (40.9 vs. 45.1 kg/d) compared with DG but did not improve nutrient digestibility. However, blood HCO3-, base excess, and tCO2 were greater for DG+DCAD compared with DG. In conclusion, the indirect role of S-, altering DCAD, along with the high PUFA content in DDGS appears to be the factors causing reduced production responses to a high DDGS diet. Increasing DCAD to 300 mEq/kg DM in a high DDGS diet can be a feeding strategy to alleviate the reduced production responses.

Measuring bioavailability, utilization, and excretion of rumen-protected lysine in lactating cows using an isotope technique

Supplementing a diet with rumen-protected amino acids (AAs) is a common feeding strategy for efficient production. For a cost-effective use of rumen-protected AA, the accurate bioavailability of rumen-protected amino acids should be known and their metabolism after absorption needs to be well understood. The current study determined the bioavailability, absorption, utilization, and excretion of rumen-protected Lys (RP-Lys). Four ruminally cannulated cows in a 4 × 4 Latin square design (12 d for diet adaptation; 5 or 6 d for total collections) received the following treatments: L0, a basal diet; L25, the basal diet and L-Lys infused into the abomasum to provide 25.9 g/d L-Lys; L50, the basal diet and L-Lys infused into the abomasum to provide 51.8 g/d L-Lys; and RPL, the basal diet supplemented with 105 g/d (as-is) of RP-Lys to provide 26.7 g of digestible Lys. During the last 5 or 6 d in each period, 15N-Lys (0.38 g/d) was infused into the abomasum for all cows to label the pool of AA, and the total collection of milk, urine, and feces were conducted. 15N enrichment of samples on d 4 and 5 were used to calculate the bioavailability and Lys metabolism. We used a model containing a fast AA turnover (≤ 5 d) and slow AA turnover pool (> 5 d) to calculate fluxes of Lys. The Lys flux to the fast AA turnover pool (absorbed Lys + Lys from the slow AA turnover pool to fast AA turnover pool) was calculated using 15N enrichment of milk Lys. The flux of Lys from the fast AA turnover pool to milk and urine was calculated using 15N transfer into milk and urine. Then, absorbed Lys was estimated by the sum of Lys flux to milk and urine assuming no net utilization of Lys by body tissues. Duodenal Lys flow was estimated by 15N enrichment of fecal Lys. The bioavailability of RP-Lys was calculated from duodenal Lys flows and Lys absorption for RPL. Increasing Lys supply from L25 to L50 increased Lys utilization for milk by 9 g/d but also increased urinary excretion by 10 g/d. For RPL, absorbed Lys was estimated to be 136 g/d where 28 g of absorbed Lys originated from RP-Lys. In conclusion, 68% of bioavailability was obtained for RP-Lys. The Lys provided from RP-Lys was not only utilized for milk protein (48%) but also excreted in urine (20%) after oxidation.

Enhanced methane production with co-feeding spent coffee grounds using spare capacity of existing anaerobic food waste digesters

With increasing coffee consumption worldwide, the efficient and sustainable management of spent coffee grounds (SCG) has become increasingly challenging. This study investigated the anaerobic co-digestion of small amounts of SCG with food waste (FW) at increasing co-feeding ratios of 1:100-1:10 (volatile solids basis) to assess the possibility of SCG treatment using the spare capacity of existing anaerobic digesters. Co-feeding SCG increased methane production compared to FW mono-digestion in the tested range of co-feeding ratios without compromising process stability. Methane yield did not further increase when the SCG/FW ratio increased above 4%, and process failure occurred at a 1:10 co-feeding ratio without trace element supplementation. The enhanced methanogenic performance was attributed to increased protein removal efficiency, which was potentially related to the promotion of peptide hydrolysis. The overall results suggest that co-feeding appropriate small amounts of SCG to FW digesters can be a realistic sustainable option for SCG management.

Effects of saturated fatty acids with lysophospholipids on production and nutrient digestibility in lactating cows

The objective of the experiment was to determine the effects of supplemental saturated fatty acid (SFA) sources, lysophospholipids (LPL), and their interaction on production and nutrient digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (total 12 blocks) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (palmitic acid, PA)- or C18:0 (stearic acid, SA)-enriched fat, with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake and milk yield and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze for milk fatty acid (FA) profile. All data were analyzed using the mixed procedure of SAS where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, PA increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between PA and SA, but PA increased (41.4 vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7 vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1 vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, PA was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.

Comparative study of exoelectrogenic utilization preferences and hydrogen conversion among major fermentation products in microbial electrolysis cells

This study comparatively investigated the exoelectrogenic utilization and hydrogen conversion of major dark fermentation products (acetate, propionate, butyrate, lactate, and ethanol) from organic wastes in dual-chamber microbial electrolysis cells (MECs) alongside their mixture as a simulated dark fermentation effluent (DFE). Acetate-fed MECs showed the highest hydrogen yield (1,465 mL/g chemical oxygen demand), near the theoretical maximum yield, with the highest coulombic efficiency (105%) and maximum current density (7.9 A/m2), followed by lactate-fed, propionate-fed, butyrate-fed, mixture-fed, and ethanol-fed MECs. Meanwhile, the highest hydrogen production rate (514 mL/L anolyte∙d) was observed in ethanol-fed MECs despite their lower coulombic efficiency. Butyrate was the least favored substrate, followed by propionate, leading to significantly delayed startup and reaction. The active anodic microbial community structure varied considerably among the MECs utilizing different substrates, particularly between Geobacter and Acetobacterium dominance. The results highlight the substantial effect of the DFE composition on its utilization and current-producing bioanode development.

Electrochemical recovery of nutrients from human urine coupled with biogas upgrading

This study explored the coupling of electrochemical nutrient recovery from human urine with biogas upgrading. Ammonia nitrogen-rich (≥300 mM) and alkaline (≥pH 9) hydrolyzed urine (HU) is a promising alternative CO2 solvent. Spent urine after biogas upgrading (SU), with neutralized pH and increased conductivity resulting from CO2 absorption, is advantageous over HU for recovering total ammonia nitrogen (TAN) through electro-concentration. Experiments using synthetic urine at varying applied current densities (13-77 A/m2) demonstrated effective TAN recovery from both HU and SU, with greater enrichment factors at higher currents (2.1-3.3-fold, 1.2-1.8 M TAN concentrate). Validation experiments using real urine at the optimized current density of 52 A/m2, considering energy consumption, exhibited superior TAN recovery and energy efficiency when using SU (3.7-fold enrichment, 1.6 M TAN concentrate; suitable for liquid fertilizer) compared to HU. These findings offer an advanced strategy for maximizing urine valorization, contributing to a circular economy.

Diffusion MRI correlation with p16 status and prediction for tumor progression in locally advanced head and neck cancer

Purpose

To investigate p16 effects on diffusion image metrics and associations with tumor progression in patients with locally advanced head and neck cancers.

Methods

Diffusion images pretreatment and after 20 Gy (2wk) of RT were analyzed in patients with cT4/N3 p16+ oropharynx cancer (OPSCC) (N=51) and locoregionally advanced head and neck squamous cell carcinoma (LAHNSCC) (N=28), enrolled onto a prospective adaptive RT trial. Mean ADC values, subvolumes with ADC <1.2 um2/ms (TVLADC), and peak values of low (µL) and high (µH) components of ADC histograms in primary and total nodal gross tumor volumes were analyzed for prediction of freedom from local, distant, or any progression (FFLP, FFDP or FFLRDP) using multivariate Cox proportional-hazards model with clinical factors. P value with false discovery control <0.05 was considered as significant.

Results

With a mean follow up of 36 months, 18 of LAHNSCC patients and 16 of p16+ OPSCC patients had progression. After adjusting for p16, small µL and ADC values, and large TVLADC of primary tumors pre-RT were significantly associated with superior FFLRDP, FFLP and FFDP in the LAHNSCC (p<0.05), but no diffusion metrics were significant in p16+ oropharynx cancers. Post ad hoc analysis of the p16+ OPSCC only showed that large TVLADC of the total nodal burden pre-RT was significantly associated with inferior FFDP (p=0.05).

Conclusion

ADC metrics were associated with different progression patterns in the LAHNSCC and p16+ OPSCC, possibly explained by differences in cancer biology and morphology. A deep understanding of ADC metrics is warranted to establish imaging biomarkers for adaptive RT in HNSCC.

A study of electron source preference and its impact on hydrogen production in microbial electrolysis cells fed with synthetic fermentation effluent

Fermentation effluents from organic wastes contain simple organic acids and ethanol, which are good electron sources for exoelectrogenic bacteria, and hence are considered a promising substrate for hydrogen production in microbial electrolysis cells (MECs). These fermentation products have different mechanisms and thermodynamics for their anaerobic oxidation, and therefore the composition of fermentation effluent significantly influences MEC performance. This study examined the microbial electrolysis of a synthetic fermentation effluent (containing acetate, propionate, butyrate, lactate, and ethanol) in two-chamber MECs fitted with either a proton exchange membrane (PEM) or an anion exchange membrane (AEM), with a focus on the utilization preference between the electron sources present in the effluent. Throughout the eight cycles of repeated batch operation with an applied voltage of 0.8 V, the AEM-MECs consistently outperformed the PEM-MECs in terms of organic removal, current generation, and hydrogen production. The highest hydrogen yield achieved for AEM-MECs was 1.26 L/g chemical oxygen demand (COD) fed (approximately 90% of the theoretical maximum), which was nearly double the yield for PEM-MECs (0.68 L/g COD fed). The superior performance of AEM-MECs was attributed to the greater pH imbalance and more acidic anodic pH in PEM-MECs (5.5-6.0), disrupting anodic respiration. Although butyrate is more thermodynamically favorable than propionate for anaerobic oxidation, butyrate was the least favored electron source, followed by propionate, in both AEM- and PEM-MECs, while ethanol and lactate were completely consumed. Further research is needed to better comprehend the preferences for different electron sources in fermentation effluents and enhance their microbial electrolysis.

Boosting oxygen evolution reaction activity with Mo incorporated NiFe-LDH electrocatalyst for efficient water electrolysis

This work demonstrates a simple and scalable methodology for the binder-free direct growth of Mo-doped NiFe-layered double hydroxides on a nickel substrate via an electrodeposition route at room temperature. A three-dimensional (3D) nanosheet array morphology of the electrocatalyst provides immense electrochemical surface area as well as abundant catalytically active sites. Mo incorporation in the NiFe-LDH plays a crucial role in regulating the catalytic activity of oxygen evolution reaction (OER). The prepared electrocatalyst exhibited low overpotential (i.e., 230 mV) at 30 mA cm-2 for OER in an alkaline electrolyte (i.e., 1 M KOH). Furthermore, the optimized Mo-doped NiFe-LDH electrode was used as an anode in a laboratory-scale in situ single cell test system for alkaline water electrolysis at 80 °C with a continuous flow of 30 wt% KOH, and it shows the efficient electrochemical performance with a lower cell voltage of 1.80 V at a current density of 400 mA cm-2. In addition, an admirable long-term cell durability is also demonstrated by the cell for 24 h. This work encourages new designs and further development of electrode material for alkaline water electrolysis on a commercial scale.

Continuous cultivation of mixed-culture microalgae using anaerobic digestion effluent in photobioreactors with different strategies for adjusting nitrogen loading rate

This study examined continuous mixed-culture microalgae cultivation for nutrient removal from anaerobic digestion (AD) effluents in photobioreactors, while altering the NH4+-N loading rate (NLR) by adjusting either the hydraulic retention time (HRT) (reactor set RH) or the influent NH4+-N concentration (reactor set RS). Both RH and RS demonstrated efficient nutrient removal and microalgae cultivation at NLRs of 4-10 mg NH4+-N/L∙d, reaching peak performance at 10 mg NH4+-N/L∙d. Within this range, RH obtained greater biomass yield and productivity, while RS maintained higher microalgal concentrations. The cultivated biomasses obtained from RH and RS had good settleability and suitable fatty acid compositions as a biodiesel feedstock, although their organic composition varied considerably with NLR and HRT. Parachlorella overwhelmingly dominated the reactors' microalgal communities throughout the experiment, co-existing with various microalgae-associated bacteria. Changes in NLR significantly influenced the bacterial community structures, underscoring its critical role in determining reactor performance and microalgal-bacterial community behavior.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. II: Biohydrogenation and incorporation into bacterial lipids

To maintain membrane homeostasis, ruminal bacteria synthesize branched-chain fatty acids (BCFA) or their derivatives (vinyl ethers) that are recovered during methylation procedures as branched-chain aldehydes (BCALD). Many strains of cellulolytic bacteria require 1 or more branched-chain volatile fatty acid (BCVFA). Therefore, the objective of this study was to investigate BCVFA incorporation into bacterial lipids under different dietary conditions. The study was an incomplete block design with 8 continuous culture fermenters used in 4 periods with treatments (n = 4) arranged as a 2 × 2 × 2 factorial. The factors were high (HF) or low forage (LF, 67 or 33% forage, 33:67 alfalfa:orchardgrass), without or with supplemental corn oil (CO; 3% dry matter, 1.5% linoleic fatty acid), and without or with 2.15 mmol/d (5 mg/d 13C each of isovalerate, isobutyrate, and 2-methylbutyrate). After methylation of bacterial pellets collected from each fermenter's effluent, fatty acids and fatty aldehydes were separated before analysis by gas chromatography and isotope ratio mass spectrometry. Supplementation of BCVFA did not influence biohydrogenation extent. Label was only recovered in branched-chain lipids. Lower forage inclusion decreased BCFA in bacterial fatty acid profile from 9.45% with HF to 7.06% with LF and decreased BCALD in bacterial aldehyde profile from 55.4% with HF to 51.4% with LF. Supplemental CO tended to decrease iso even-chain BCFA and decreased iso even-chain BCALD in their bacterial lipid profiles. The main 18:1 isomer was cis-9 18:1, which increased (P < 0.01) by 25% from CO (data not shown). Dose recovery in bacterial lipids was 43.3% lower with LF than HF. Supplemental CO decreased recovery in the HF diet but increased recovery with LF (diet × CO interaction). Recovery from anteiso odd-chain BCFA and BCALD was the greatest; therefore, 2-methylbutyrate was the BCVFA primer most used for branched-chain lipid synthesis. Recovery in iso odd-chain fatty acids (isovalerate as primer) was greater than label recovery in iso even-chain fatty acids (isobutyrate as primer). Fatty aldehydes were less than 6% of total bacterial lipids, but 26.0% of 13C recovered in lipids were recovered in BCALD because greater than 50% of aldehydes were branched-chain. Because BCFA and BCALD are important in the function and growth of bacteria, especially cellulolytics, BCVFA supplementation can support the rumen microbial consortium, increasing fiber degradation and efficiency of microbial protein synthesis.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. III: Protein metabolism and incorporation into bacterial protein

Some cellulolytic bacteria cannot transport branched-chain AA (BCAA) and do not express complete synthesis pathways, thus depending on cross-feeding for branched-chain volatile fatty acid (BCVFA) precursors for membrane lipids or for reductive carboxylation to BCAA. Our objective was to assess BCVFA uptake for BCAA synthesis in continuous cultures administered high forage (HF) and low forage (LF) diets without or with corn oil (CO). We hypothesized that BCVFA would be used for BCAA synthesis more in the HF than in LF diets. To help overcome bacterial inhibition by polyunsaturated fatty acids in CO, BCVFA usage for bacterial BCAA synthesis was hypothesized to decrease when CO was added to HF diets. The study was an incomplete block design with 8 dual-flow fermenters used in 4 periods with 8 treatments (n = 4) arranged as a 2 × 2 × 2 factorial. The factors were: HF or LF (67 or 33% forage, 33:67 alfalfa:orchardgrass pellets), without or with supplemental CO (3% of dry matter), and without or with 2.15 mmol/d (5 mg/d 13C) each of isovalerate, isobutyrate, and 2-methylbutyrate for one combined BCVFA treatment. The flow of bacterial BCAA increased by 10.7% by supplementing BCVFA and 9.14% with LF versus HF; similarly, dosing BCVFA versus without BCVFA increased BCAA by 1.98% in total bacterial AA, whereas LF increased BCAA by 1.92% versus HF. Additionally, BCVFA supplementation increased bacterial AA flow by 16.6% when supplemented in HF - CO and 12.4% in LF + CO diets, but not in the HF + CO (-1.5%) or LF - CO (+6.7%) diets (Diet × CO × BCVFA interaction). The recovery of 13C in bacterial AA flow was 31% lower with LF than with HF. Of the total 13C recovered in bacteria, 13.8, 17.3, and 30.2% were recovered in Val, Ile, and Leu, respectively; negligible 13C was recovered in other AA. When fermenters were dosed with BCVFA, nonbacterial and total effluent flows of AA, particularly of alanine and proline, suggest decreased peptidolysis. Increased ruminal outflow of bacterial AA, especially BCAA, but also nonbacterial AA could potentially support postabsorptive responses from BCVFA supplementation to dairy cattle.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. I: Digestibility, microbial protein, and prokaryotic community structure

Branched-chain amino acids are deaminated by amylolytic bacteria to branched-chain volatile fatty acids (BCVFA), which are growth factors for cellulolytic bacteria. Our objective was to determine the dietary conditions that would increase the uptake of BCVFA by rumen bacteria. We hypothesized that increased forage would increase cellulolytic bacterial abundance and incorporation of BCVFA into their structure. Supplemental polyunsaturated fatty acids, supplied via corn oil (CO), should inhibit cellulolytic bacteria growth, but we hypothesized that additional BCVFA would alleviate that inhibition. Further, supplemental BCVFA should increase neutral detergent fiber degradation and efficiency of bacterial protein synthesis more with the high forage and low polyunsaturated fatty acid dietary combination. The study was an incomplete block design with 8 dual-flow continuous cultures used in 4 periods with 8 treatments (n = 4 per treatment) arranged as a 2 × 2 × 2 factorial. The factors were: high forage (HF) or low forage (LF; 67 or 33%), without or with supplemental CO (3% dry matter), and without or with 2.15 mmol/d (which included 5 mg/d of 13C each of BCVFA isovalerate, isobutyrate, and 2-methylbutyrate). The isonitrogenous diets consisted of 33:67 alfalfa:orchardgrass pellet, and was replaced with a concentrate pellet that mainly consisted of ground corn, soybean meal, and soybean hulls for the LF diet. The main effect of supplementing BCVFA increased neutral detergent fiber (NDF) degradability by 7.6%, and CO increased NDF degradability only in LF diets. Supplemental BCVFA increased bacterial N by 1.5 g/kg organic matter truly degraded (6.6%) and 0.05 g/g truly degraded N (6.5%). The relative sequence abundance decreased with LF for Fibrobacter succinogenes, Ruminococcus flavefaciens, and genus Butyrivibrio compared with HF. Recovery of the total 13C dose in bacterial pellets decreased from 144 µg/ mg with HF to 98.9 µg/ mg with LF. Although isotope recovery in bacteria was greater with HF, BCVFA supplementation increased NDF degradability and efficiency of microbial protein synthesis under all dietary conditions. Therefore, supplemental BCVFA has potential to improve feed efficiency in dairy cows even with dietary conditions that might otherwise inhibit cellulolytic bacteria.

Association of body mass index with 30-day outcomes following groin hernia repair

PURPOSE

Although groin hernia repairs are relatively safe, efforts to identify factors associated with greater morbidity and resource utilization following these operations are warranted. An emphasis on obesity has limited studies from a comprehensive evaluation of the association between body mass index (BMI) and outcomes following groin hernia repair. Thus, we aimed to ascertain the association between BMI class with 30-day outcomes following these operations.

METHODS

The 2014-2020 National Surgical Quality Improvement Program database was queried to identify adults undergoing non-recurrent groin hernia repair. Patient BMI was used to stratify patients into six groups: underweight, normal, overweight, and obesity classes I-III. Association of BMI with major adverse events (MAE), wound complication, and prolonged length of stay (pLOS) as well as 30-day readmission and reoperation were evaluated using multivariable regressions.

RESULTS

Of the 163,373 adults who underwent groin hernia repair, the majority of patients were considered overweight (44.4%). Underweight patients more commonly underwent emergent operations and femoral hernia repair compared to others. After adjustment of intergoup differences, obesity class III was associated with greater odds of an MAE (AOR 1.50), wound complication (AOR 4.30), pLOS (AOR 1.40), and 30-day readmission (AOR 1.50) and reoperation (AOR 1.75, all p < 0.05). Underweight BMI portended greater odds of pLOS and unplanned readmission.

CONCLUSION

Consideration of BMI in patients requiring groin hernia repair could help inform perioperative expectations. Preoperative optimization and deployment of a minimally invasive approach when feasible may further reduce morbidity in patients at the extremes of the BMI spectrum.

Superiority of BNCT Treatment Planning Metrics Achieved Using Novel vs. Reference (BPA-F) Pharmaceuticals in Head and Neck Locations

PURPOSE/OBJECTIVE(S)

Several novel boron delivery compounds currently under investigation by our group have demonstrated formulation, biodistribution, and dose response benefits in small animal models [1]. In this study we analyze the potential clinical impact of these compounds for boron neutron capture therapy (BNCT) in human patients.

MATERIALS/METHODS

Pharmacokinetic models were used to estimate the tumor and normal tissue boron concentrations after continuous infusion of the novel compounds and BPA-F. Patient model segmentation, material assignment, and alignment of one or more treatment beams were exported from a commercial treatment planning system (TPS) to a novel dose calculation tool. This information was used to generate a voxelized model that incorporated the source, beam shaping assembly, collimator, and patient materials so that the full albedo effect was included in each dose calculation. Physical dose from 10B(n,α), 14N(n,p), 1H(n,n') interactions plus gamma rays from 1H(n,γ) and other reactions within the patient and treatment equipment were calculated by Monte Carlo transport of particles originating in a pre-generated phase space at the cover surface. RBE and CBE weighting factors are applied to combine these four physical dose volumes into an equivalent dose volume, and these five dose volumes were passed back to the TPS for evaluation.

RESULTS

Tumor dose was increased by up to 2.6x for the novel compounds while normal tissue doses were constant or slightly reduced in comparison to BPA-F plans. Alternatively, for identical tumor dose the normal tissue doses and treatment time were reduced by up to 2.6x. In addition, in some cases it was possible to generate a single beam treatment plan using the new compounds that delivered higher tumor dose and lower normal tissues doses than a multiple beam plan using BPA-F.

CONCLUSION

This study demonstrates both dosimetric and practical benefits of the new compounds in comparison to BPA-F, including the potential to deliver treatment using fewer beam directions and correspondingly easier treatment setups and higher patient throughput. The potential of these compounds to extend the range of clinical indications for BNCT is also discussed. These results motivate upcoming experimental testing of the key assumptions involved in their calculation.

Increasing prevalence of gonorrhoea and chlamydia among female sex workers in northern Sydney, 2005-2019

BACKGROUND

Recent reports indicate increasing gonorrhoea and chlamydia among female sex workers (FSWs) in Australia, with decreasing condom use for oral sex.

METHODS

We determined trends in prevalence and positivity of gonorrhoea and chlamydia among FSWs attending our clinic from 2005 to 2019, by analysing data from medical and pathology records. We conducted a sensitivity analysis by using an alternative prevalence definition of first test result only per calendar year.

RESULTS

Prevalence of gonorrhoea (all sites: pharynx, genital, rectal) increased from 1/130 (0.8%) in 2005 to 14/166 (8.4%) in 2012, to 31/257 (12.1%) in 2019; rate ratio (RR) 1.19, 95%CI 1.14-1.24, ptrend < 0.001. There were rising trends for pharyngeal (RR 1.11, 95% CI 1.05-1.17, ptrend = 0.001) and genital gonorrhoea (RR 1.17, 95% CI 1.08-1.26, ptrend < 0.001). Prevalence of chlamydia (all sites) increased from 4/130 (3.1%) in 2005 to 8/166 (4.8%) in 2012, to 20/257 (7.8%) in 2019; RR 1.05, 95%CI 1.01-1.09, ptrend = 0.006. This rise reflected predominately pharyngeal chlamydia (RR 1.16, 95%CI 1.04-1.29, ptrend = 0.004). Qualitatively similar trends with similar significant results, were seen for gonococcal and chlamydial infections in the sensitivity analyses, indicating robustness of results to potential changes in testing frequency. Gonorrhoea and chlamydia were significantly associated with FSWs born in China. Chlamydia was significantly associated with age group 18-25. In the 2015-2019 period, of 89 women with gonococcal infections, 56 (62.9%) were pharyngeal-only; of 93 with chlamydial infections, 32 (34.4%) were pharyngeal-only infections.

CONCLUSIONS

FSWs require screening for pharyngeal as well as genital infections. Enhanced and sustainable health promotion is required.

Direct interspecies electron transfer enables anaerobic oxidation of sulfide to elemental sulfur coupled with CO2-reducing methanogenesis

Electric syntrophy between fatty acid oxidizers and methanogens through direct interspecies electron transfer (DIET) is essential for balancing acidogenesis and methanogenesis in anaerobic digestion. Promoting DIET using electrically conductive additives proved effective in enhancing methanogenesis; however, its possibility to affect other microbial redox reactions in methanogenic systems has been little studied. This study provides the first confirmation of the electro-syntrophic coupling of sulfide oxidation to S0 with CO2-reducing methanogenesis in sulfur-rich methanogenic cultures supplemented with conductive magnetite (100-700-nm particle size). The H2S content in biogas, initially exceeding 5000 ppmv, decreased to below 1 ppmv along with an accumulation of extracellular S0 (60-70 mg/L; initially <1 mg/L) at a magnetite dose of 20 mM Fe, while there were no significant changes in methane yield. A comprehensive polyphasic approach demonstrated that the S0 formation occurs through electro-syntrophic oxidation of sulfide coupled with CO2-reducing methanogenesis, involving Methanothrix as the dominant methanogen.

Thin Film Composite Membranes as a New Category of Alkaline Water Electrolysis Membranes

Alkaline water electrolysis (AWE) is considered a promising technology for green hydrogen (H2 ) production. Conventional diaphragm-type porous membranes have a high risk of explosion owing to their high gas crossover, while nonporous anion exchange membranes lack mechanical and thermochemical stability, limiting their practical application. Herein, a thin film composite (TFC) membrane is proposed as a new category of AWE membranes. The TFC membrane consists of an ultrathin quaternary ammonium (QA) selective layer formed via Menshutkin reaction-based interfacial polymerization on a porous polyethylene (PE) support. The dense, alkaline-stable, and highly anion-conductive QA layer prevents gas crossover while promoting anion transport. The PE support reinforces the mechanical and thermochemical properties, while its highly porous and thin structure reduces mass transport resistance across the TFC membrane. Consequently, the TFC membrane exhibits unprecedentedly high AWE performance (1.16 A cm-2 at 1.8 V) using nonprecious group metal electrodes with a potassium hydroxide (25 wt%) aqueous solution at 80 °C, significantly outperforming commercial and other lab-made AWE membranes. Moreover, the TFC membrane demonstrates remarkably low gas crossover, long-term stability, and stack cell operability, thereby ensuring its commercial viability for green H2 production. This strategy provides an advanced material platform for energy and environmental applications.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Corporate social and community-oriented support by UK food retailers: a documentary review and typology of actions towards community wellbeing

AIM

This article provides a comprehensive exploration of the varied Corporate Social Responsibility (CSR) actions in relation to supporting communities reported by the UK's leading food retailers. Findings are discussed against a backdrop of enduring inequalities, exacerbated by the on-going global Coronavirus pandemic, with actions considered for their potential contribution to community-based approaches to addressing local wellbeing and inequalities.

METHOD

This article presents the structure and key characteristics of community-oriented CSR in food retailing in the UK. A thematic analysis of comprehensive documentary evidence from the 11 principle UK food retailers was conducted, drawing on asset-based frameworks of community-centred actions towards wellbeing.

FINDINGS

The findings suggest an increasing acknowledgement in food retail that local community is of key importance. Initiatives were categorised according to a typology, comprising national partnerships, local store-based funding and support actions, targeted programmes on healthy lifestyles or employability, and changes to store operations, in the favour of priority groups, prompted by the pandemic.

CONCLUSION

The article combines an up to date overview of community-focused CSR agendas and support by food retailers at a time of significant economic and social challenge for the UK. It highlights the potential of the sector to contribute more strategically to reducing inequalities and supporting community wellbeing, alongside statutory and voluntary sector partners.

Effects of corn silage and grain expressing α-amylase on ruminal nutrient digestibility, microbial protein synthesis, and enteric methane emissions in lactating cows

Increasing ruminal starch digestibility has the potential to improve microbial protein synthesis (MPS), milk production, and feed efficiency. Enogen corn (Syngenta Seeds LLC) expresses high α-amylase activity, and we evaluated effects of Enogen corn silage (CS) and grain (CG) on ruminal starch digestibility, MPS, and milk production in lactating dairy cows. Fifteen Holstein cows (6 ruminally cannulated and 9 noncannulated; average ± standard deviation at the beginning of the trial: 170 ± 40 d in milk; milk yield, 37.2 ± 7.73 kg/d; body weight, 714 ± 37 kg) were used in a replicated 3 × 3 Latin square design (28 d per period) with 3 treatments: a diet containing isoline CS and CG (control, CON); a diet with Enogen CS and isoline CG (ECS); and a diet with Enogen CS and CG (ECSCG). Dry matter (DM; 30%), starch (35% of DM), and particle size distribution of the isoline and Enogen CS were similar. However, the mean particle size of Enogen CG was larger (1.05 vs. 0.65 mm) than that of the isoline CG. Cannulated cows were used for digestibility and nutrient flow measurements, noncannulated cows were used for enteric CH₄ measurements, and all cows were used for production evaluation. Dry matter intake (DMI) and milk yield were greater for ECS and ECSCG compared with CON (26.7 and 26.6 vs. 25.1 kg/d and 36.5 and 34.1 vs. 33.1 kg/d, respectively) without a difference between ECS and ECSCG. Milk protein yield was greater (1.27 vs. 1.14 and 1.17 kg/d) for ECS compared with CON and ECSCG. Milk fat content was greater (3.79 vs. 3.32%) for ECSCG compared with ECS. Milk fat yield and energy-corrected milk did not differ among treatments. Ruminal digestibilities of DM, organic matter, starch, and neutral detergent fiber were not different among treatments. However, ruminal digestibility of nonammonia, nonmicrobial N was greater (85 vs. 75%) for ECS compared with ECSCG. Total-tract apparent starch digestibility was lower (97.6 and 97.1 vs. 98.3%) for ECS and ECSCG compared with CON, respectively, and tended to be lower (97.1 vs. 98.3%) for ECSCG compared with ECS. Ruminal outflows of bacterial OM and nonammonia N tended to be greater for ECS than for ECSCG. Efficiency of MPS tended to be greater (34.1 vs. 30.6 g of N/kg of organic matter truly digested) for ECS versus ECSCG. Ruminal pH and total and individual short-chain fatty acid concentrations did not differ among treatments. Concentration of ruminal NH₃ for ECS and ECSCG was lower (10.4 and 12.4 vs. 13.4 mmol/L, respectively) compared with CON. Methane per unit of DMI decreased for ECS and ECSCG compared with CON (11.4 and 12.2 vs. 13.5 g/kg of DMI, respectively) without a difference between ECS and ECSCG. In conclusion, ECS and ECSCG did not increase ruminal or total-tract starch digestibility. However, the positive effects of ECS and ECSCG on milk protein yield, milk yield, and CH₄ per unit of DMI may show potential benefits of feeding Enogen corn. Effects of ECSCG were not apparent when compared with ECS, partly due to larger particle size of Enogen CG compared with its isoline counterpart.

A quinary WTaCrVHf nanocrystalline refractory high-entropy alloy withholding extreme irradiation environments

In the quest of new materials that can withstand severe irradiation and mechanical extremes for advanced applications (e.g. fission & fusion reactors, space applications, etc.), design, prediction and control of advanced materials beyond current material designs become paramount. Here, through a combined experimental and simulation methodology, we design a nanocrystalline refractory high entropy alloy (RHEA) system. Compositions assessed under extreme environments and in situ electron-microscopy reveal both high thermal stability and radiation resistance. We observe grain refinement under heavy ion irradiation and resistance to dual-beam irradiation and helium implantation in the form of low defect generation and evolution, as well as no detectable grain growth. The experimental and modeling results-showing a good agreement-can be applied to design and rapidly assess other alloys subjected to extreme environmental conditions.

A253 PRIMARY PROPHYLAXIS FOR SPONTANEOUS BACTERIAL PERITONITIS IN HOSPITALIZED CIRRHOTIC PATIENTS WITH LOW PROTEIN ASCITES AND RENAL DYSFUNCTION OR LIVER FAILURE: A RETROSPECTIVE REVIEW FROM A TERTIARY CENTRE IN BRITISH COLUMBIA

Background

Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection that can occur in patients with cirrhosis and ascites. The benefits of primary prophylaxis with antibiotics for SBP have been demonstrated in patients with cirrhosis presenting with gastrointestinal (GI) bleeding; patients hospitalized for other reasons with an ascitic protein less than 10 g/L; and patients with ascitic protein less than 15 g/L with either impaired renal function (serum creatinine greater than 106 µmol/L, BUN greater than 8.9 mmol/L, or serum sodium less than or equal to 130 mEq/L) or liver failure (Child-Pugh score greater than or equal to 9 or bilirubin greater than 50 umol/L).

Purpose

To evaluate the rate of primary prophylaxis in patients discharged from a tertiary care hospital with low protein ascites and impaired renal function or liver failure, and subsequent episodes of SBP, hospitalizations, or deaths.

Method

A retrospective chart review at St. Paul’s Hospital in Vancouver, British Columbia, from November 2019 to August 2021 was conducted. Hospitalized patients with cirrhosis who had an ascitic protein less than 15 g/L and met criteria for either renal dysfunction or liver failure were included in the study. The rate of primary prophylaxis prescribed in eligible patients as well as the subsequent incidence of SBP, hospitalizations, or all-cause mortality were evaluated. Patients were followed up to 12 months after the index paracentesis.

Result(s)

A total of 279 patients with cirrhosis were hospitalized during the study period. 69 patients underwent a diagnostic paracentesis and 41 patients met the inclusion criteria for primary SBP prophylaxis. 28 patients were excluded with most common reasons being ascitic protein above 15 g/L (n=12), no documented ascitic protein concentration (n=9), or index paracentesis met the criteria for the diagnosis of SBP (n=5). Of the patients included, 37 (90.2%) did not receive primary prophylaxis. 8 of these patients (21.6%) developed subsequent SBP. 30 patients (81.1%) were hospitalized at least once in the following 12 months. 18 (48.6%) died during the follow-up period with 1 death attributed to SBP. 4 patients (9.76%) received primary prophylaxis and were prescribed either ciprofloxacin or trimethoprim/sulfamethoxazole. None of these patients developed SBP, however, 3 (75%) were hospitalized and died from other causes.

Conclusion(s)

The rate of primary prophylaxis for SBP in hospitalized patients with low protein ascites and impaired renal function or liver failure at our institution is low. The guarded prognosis in this subset of patients is also demonstrated. Further studies are needed to assess the root causes for the lack of primary prophylaxis given.

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Disclosure of Interest

None Declared

A9 INTESTINAL ORGANOID TRANSPLANTATION REVERSED THE INTESTINAL EPITHELIUM DAMAGE IN EXPERIMENTAL NECROTIZING ENTEROCOLITIS

NOT PUBLISHED AT AUTHOR’S REQUEST

GalaxyDock2-HEME: Protein-ligand docking for heme proteins

Prediction of protein-ligand binding poses is an essential component for understanding protein-ligand interactions and computer-aided drug design. Various proteins involve prosthetic groups such as heme for their functions, and adequate consideration of the prosthetic groups is vital for protein-ligand docking. Here, we extend the GalaxyDock2 protein-ligand docking algorithm to handle ligand docking to heme proteins. Docking to heme proteins involves increased complexity because the interaction of heme iron and ligand has covalent nature. GalaxyDock2-HEME, a new protein-ligand docking program for heme proteins, has been developed based on GalaxyDock2 by adding an orientation-dependent scoring term to describe heme iron-ligand coordination interaction. This new docking program performs better than other noncommercial docking programs such as EADock with MMBP, AutoDock Vina, PLANTS, LeDock, and GalaxyDock2 on a heme protein-ligand docking benchmark set in which ligands are known to bind iron. In addition, docking results on two other sets of heme protein-ligand complexes in which ligands do not bind iron show that GalaxyDock2-HEME does not have a high bias toward iron binding compared to other docking programs. This implies that the new docking program can distinguish iron binders from noniron binders for heme proteins.

Effects of different vitamin A supplies on performance and the risk of ketosis in transition cows

This experiment investigated the effects of feeding low and high supplies of vitamin A (VA) during the transition period on plasma metabolites, prevalence of ketosis, and early milk production. In a randomized complete block design, 42 prefresh Holstein cows and 21 heifers were blocked by parity and calving date and assigned to 1 of 3 dietary treatments (n = 21 per treatment unless noted): CON, a transition diet with supplemental VA (75,000 IU/d) to meet the requirement; LVA, a transition diet with no supplemental VA; or HVA, a transition diet receiving supplemental VA (187,500 IU/d) 2.5 times greater than the requirement. Experimental periods were prepartum (-14 d prepartum), postpartum (1 to 30 d in milk), and carryover period (31 to 58 d in milk; common lactating diet with adequate VA was fed). Differences in dry matter intake in the pre- and postpartum periods and milk yield were not detected among treatment. Milk fat, protein, and lactose yields were similar among treatments and not affected by VA. Somatic cell count increased linearly with increasing VA. Body weight and body condition score decreased postpartum, but no VA effect was observed. Plasma retinol concentrations (n = 10 per treatment) decreased at d 2 postpartum and increased as lactation progressed, but the concentrations were unaffected by treatment. Plasma β-carotene (n = 10 per treatment) had a treatment by time interaction and its concentration decreased after parturition and remained low for 2 wk. Plasma fatty acids and β-hydroxybutyrate did not differ among treatments. Milk retinol concentration and yield (n = 10 per treatment) increased as VA supply increased. Segmented neutrophils (%) decreased, and lymphocytes (%) increased in blood with increasing VA supply. In conclusion, providing different supplies of VA did not affect production, mobilization of body fat, and risk of ketosis; however, excessive VA supply may have negatively affected the immune response, in part contributing to increased milk somatic cell counts during early lactation.

Association between anaemia and hospital readmissions in patients undergoing major surgery requiring postoperative intensive care

Anaemia is a common sequela of surgery, although its relationship with patient recovery is unclear. The goal of this investigation was to assess the associations between haemoglobin concentrations at the time of hospital discharge following major surgery and early post-hospitalisation outcomes, with a primary outcome of 30 day unanticipated hospital readmissions. This investigation includes data from two independent population-based observational cohorts of adult surgical patients (aged ≥ 18 years) requiring postoperative intensive care unit admission between 1 January 2010 and 31 December 2019 in hospitals in Olmsted County, Minnesota, and between 1 July 2010 and 30 June 2017 in the Kaiser Permanente Northern California integrated healthcare system, California. Cox proportional hazards models assessed the associations between discharge haemoglobin concentrations (per 10 g.l-1 ) and outcomes, with prespecified multivariable adjustment. A total of 3260 patients were included from Olmsted County hospitals and 29,452 from Kaiser Permanente Northern California. In adjusted analyses, each 10 g.l-1 decrease in haemoglobin at hospital discharge was associated with a 9% (hazard ratio 1.09, 95%CI 1.02-1.18; p = 0.014) and 8% increase (hazard ratio 1.08, 95%CI 1.06-1.11; p < 0.001) in the hazard for readmission within 30 days in Olmsted County and Kaiser Permanente Northern California, respectively. In a sensitivity analysis exploring relationships across varying levels of pre-operative anaemia severity, these associations remained consistent, with lower discharge haemoglobin concentrations associated with higher readmissions irrespective of pre-operative anaemia severity. Anaemia at hospital discharge in surgical patients requiring postoperative intensive care is associated with increased rates of hospital readmission in two large independent cohorts. Future studies are necessary to evaluate strategies to prevent and/or treat anaemia in these patients for the improvement of post-hospitalisation outcomes.

Effects of submicron magnetite particles on granulation of flocculent sludge and process stability in upflow anaerobic sludge blanket reactor

Promoting direct interspecies electron transfer (DIET) with conductive additives is considered a promising approach to enhance methanogenesis. This study investigated the effects of adding submicron magnetite particles on sludge granulation and methanogenic performance in upflow anaerobic sludge blanket reactors inoculated with flocculent sludge. The reactor supplemented with magnetite was more stable and resilient than the no-magnetite control, with higher degree of granulation (up to 26.6-fold) and biomass retention. Magnetite addition to unstable reactors improved the methane yield in both reactors (1.2-1.3-fold). Electroactive Deltaproteobacteria bacteria, including Geobacter and Syntrophobacter, were enriched in the presence of magnetite. Methanogenic functional genes involved in DIET-based syntrophy were more abundant under magnetite-supplemented conditions. However, the improvement of methanogenic performance and granulation was limited, and inducing the self-embedment of magnetite into mature sludge granules rather than granulating flocculent sludge with magnetite appears to be a better strategy for engineering DIET in anaerobic granular sludge systems.

Proteomics profiling reveals signaling pathways associated with major adverse cardiovascular events in patients with hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy affecting 1 in 200–500 people in the US. It is characterized by a diverse clinical course, and only a subset of patients with HCM experience major adverse cardiovascular events (MACE) such as arrhythmias (e.g., ventricular tachycardia/fibrillation [VT/VF], atrial fibrillation [AF]), stroke, and heart failure. However, the molecular mechanisms underlying the presence of MACE in HCM are still not well understood.

Purpose

Our aim was to reveal signaling pathways associated with prior MACE in patients with HCM by applying plasma proteomics profiling.

Methods

We conducted a multicenter case-control study of patients with HCM comparing those with and without a prior history of MACE. We performed plasma proteomics profiling of 5032 proteins. We defined prior MACE as a composite outcome of sustained VT/VF, AF, stroke/transient ischemic attack, left ventricular ejection fraction ≤50%, New York Heart Association functional class ≥2 symptoms, resuscitated cardiac arrest, or appropriate implantable cardioverter defibrillator therapy. We applied the random forest method to derive a proteomics-based discrimination model developed in patients enrolled at one institution (training set) and externally validated the model on patients enrolled at another institution (test set). We then performed pathway analysis of proteins differentially regulated in patients with prior MACE. Pathways with a false discovery rate (FDR) &lt;0.05 with at least 5 associated proteins were declared positive.

Results

A total of 396 patients were included, with 278 in the training set and 118 in the test set. In this cohort, 251 (63%) patients had prior MACE (171 in the training set and 80 in the test set). Using the proteomics-based model derived from the training set, the area under the receiver operating characteristic curve was 0.81 (95% CI 0.73–0.88) in the test set (Figure 1). There were 632 differentially expressed proteins (univariable p&lt;0.05). Pathway analysis identified significantly dysregulated pathways in patients with prior MACE (Figure 2). This included both pathways known to be associated with MACE (e.g., TGF-β [FDR=0.03]) and novel pathways (e.g., Ras-MAPK [FDR=0.01] and its upstream PI3K-Akt [FDR=7.7x10–7] pathways). Pathways involved in cellular metabolism/proliferation (e.g., HIF 1 [FDR=0.01] and Wnt [FDR=0.04] pathways) and inflammation (e.g., complement and coagulation cascades [FDR=2.7x10–21], cytokine-cytokine receptor interaction [FDR=8.1x10–16]) were also significantly dysregulated.

Conclusions

Our study in patients with HCM reveals that those with a prior history of MACE have a distinctive plasma proteomics profile. We further identified both previously known and novel pathways dysregulated in this subset with a more severe form of HCM. Our findings may aid in development of targeted therapies for the prevention of MACE in HCM.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): R01 HL157216

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Atypical clinical presentations are common in TIA and minor stroke patients with DWI-MRI confirmed ischaemia

Background and Aims

Current diagnostic criteria for TIA/minor stroke disqualify several atypical clinical presentations, but pre-date DWI-MRI use. We investigated the proportion of DWI-positive patients with atypical presentations, identifying clinical factors predicting DWI positivity.

Methods

We retrospectively reviewed consecutive patients with suspected TIA/minor stroke (NIHSS<5) undergoing MRI at our comprehensive stroke centre from March 2020-February 2021. We identified pre- dictors of DWI positivity using logistic regression.

Results

Of 1615 patients, 442 DWI-positive, 39% had atypical presentations including 20% with progres- sive symptom onset. Atypical symptoms common in DWI-positive patients included headache(17%), unsteadiness(15%), positive sensory symptoms(11%), presyncope(10%), confusion(9%) and vertigo(8%). Symptoms independently associated with DWI-positivity included weakness(OR 1.30, 95% CI 1.01-1.67), dysarthria(OR 2.06, CI 1.56-2.70), and ataxia (OR 3.75, CI 2.27-6.20). Fluctuating symptoms(22%) predicted DWI positivity(OR 1.37, CI 1.00-1.81), but sudden onset(80%) did not (OR 1.05, CI 0.80-1.38). Risk factors associated with DWI positivity included increasing age(OR 1.01/year, CI 1.01-1.02), hypertension (OR 1.70, CI 1.30-2.22), diabetes(OR 1.44, CI 1.07-1.93), and smoking(OR 1.68, CI 1.19-2.39). DWI-positive patients had significantly more risk factors (mean 2.65 vs 1.95 p=<0.001).

Conclusions

Over one-third with DWI-confirmed TIA/minor stroke present atypically. The value of atypical symptoms in excluding ischaemia, particularly in patients with vascular risk factors, appears limited.