The Influence of Material and Roughness on the Settlement and the Adhesive Strength of the Barnacle Balanus Improvisus in the Baltic Sea

Under natural conditions, barnacles, one of the most prominent marine hardfouling organisms, encounter a vast variety of heterogeneous surfaces including artificial ones, such as ship hulls on which they adhere efficiently. Despite intensive research in the last decades, it is still not clear, how material related factors influence the fouling development under natural conditions, and whether roughness at the micro scale affects the release dynamics of barnacles. In order to shed light on the relationship between these substrate factors and their effect on biofouling, both settlement and fouling development of Balanus (= Amphibalanus) improvisus was evaluated on epoxy resin and polyvinylsiloxane (PVS) substrates differing in their roughness (flat, asperity sizes: 0.3, 1, 3, 9, 12 μm) in a static field trial in the Baltic Sea for 17 weeks performed in 2014. All barnacles on these tested surfaces were individually tracked on a weekly basis, in order to calculate the release-to-settlement ratios (r/s), to evaluate the fouling- release performance and to monitor the actual attachment duration. It was demonstrated that both stiffness and surface free energy had no strong effect on initial settlement. The total fouling accumulation was nearly identical for epoxy resin and PVS, if fallen-off barnacles were included in the analysis. Roughness influenced initial settlement and fouling development. On PVS the r/s ranged between 0.5 and 0.7 and the attachment duration was around 4 weeks. However, samples with a roughness of 9 μm displayed a lower r/s ratio (0.35) and barnacles showed longer attachment durations (8 weeks). In a second field trial performed in 2017, attachment forces of barnacles were measured after the samples had been immersed for 10 weeks in the Baltic Sea. The shear stresses obtained were similar for substrates with different roughness with around 0.12 MPa and were independent of the barnacle’s size. These findings show that roughness even at the micro scale can impact the fouling release ability of a surface

Role of Nutrition in Alcoholic Liver Disease: Summary of the Symposium at the ESBRA 2017 Congress.

The symposium, "Role of Nutrition in Alcoholic Liver Disease", was held at the European Society for Biomedical Research on Alcoholism Congress on 9 October 2017 in Crete, Greece. The goal of the symposium was to highlight recent advances and developments in the field of alcohol and nutrition. The symposium was focused on experimental and clinical aspects in relation to the role of different types of dietary nutrients and malnutrition in the pathogenesis of alcoholic liver disease (ALD). The following is a summary of key research presented at this session. The speakers discussed the role of dietary fats and carbohydrates in the development and progression of alcohol-induced multi-organ pathology in animal models of ALD, analyzed novel nutrition-related therapeutics (specifically, betaine and zinc) in the treatment of ALD, and addressed clinical relevance of malnutrition and nutrition support in ALD. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows

Density Functional Theory Investigation of CH Coupling and CH Hydrogenation Reactions on Different Cobalt Surface Facets and Fischer-Tropsch Temperature Swing Reactor Optimization

Fischer-Tropsh Synthesis is a chemical process that converts CO and H₂ (syngas) into long stable hydrocarbon chains to use as fuel. This process suffers from large product distribution that requires expensive post processing. In this study, the reaction mechanism of hydrocarbon chain growth on Co is investigated on different surface facets of Co in order to study their effects on the rate-limiting reaction steps. Fischer-Tropsch is a complex multi-step process so a microkinetic model for the carbide chain growth mechanism, available literature data, and the degree of rate control analysis was used to determine the rate-limiting steps for hydrocarbon chain production, CO utilization, and minimization of CH₄ production. The CH-CH carbon coupling and CH hydrogenation were determined to be the critical steps in chain growth, CH₄ formation, and CO utilization based on the degree of rate control analysis of the microkinetic model. Density Functional Theory (DFT) was used to investigate these reaction steps on cobalt catalyst to understand how different surface facets affect these reaction steps. The calculated energy landscape, reaction and activation energies for the two reaction paths are initially compared on two different Co facets ((001) and (110)) and used to determine the most effective surface structure for CH-CH carbon coupling, which leads to chain growth, and the least effective surface structure for CH hydrogenation, which leads to CH₄ formation. Other surface facets under investigation include (111) and (101). The forward activation barrier for the CH coupling reaction showed little sensitivity to cobalt surface structure (ΔE₀₀₁,[subscript F] = 1.01 eV, ΔE₀₁₁,[subscript F] = 1.08 eV) as opposed to the CH hydrogenation reaction where forward activation barriers ranged between 0.29 eV and 0.96 eV on the (001) and (101) facets respectively. This study is a part of a larger initiative to design and optimize a FTS micro-reactor for commercial use which combines atomistic DFT calculations, multiphysics modeling (mass, heat and fluid transport), experimental catalyst design, and micro-reactor design

The association between sleep quality, preoperative risk factors for chronic postoperative pain and postoperative pain intensity 12 months after knee and hip arthroplasty

BACKGROUND: Chronic postoperative pain following total joint replacement (TJA) is a substantial clinical problem, and poor sleep may affect predictive factors for postoperative pain, such as pain catastrophizing. However, the magnitude of these associations is currently unknown. This exploratory study investigated (1) the relationship between preoperative sleep quality, clinical pain intensity, pain catastrophizing, anxiety, and depression and (2) their associations with chronic postoperative pain following TJA. METHODS: This secondary analysis from a larger randomized controlled trial included rest pain intensity (preoperative and 12 months postoperative; visual analogue scale, VAS), preoperative Pittsburgh Sleep Quality Index (PSQI), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS) data from 74 knee and 89 hip osteoarthritis (OA) patients scheduled for TJA. Poor sleepers were identified based on preoperative PSQI scores higher than 5. RESULTS: Poor sleepers demonstrated higher preoperative VAS, pain catastrophizing, anxiety, and depression compared with good sleepers (all p < 0.003). Preoperative PSQI (β = 0.23, p = 0.006), PCS (β = 0.44, p < 0.005), and anxiety (β = 0.18, p = 0.036) were independent factors for preoperative VAS. Preoperative VAS (β = 0.32, p < 0.005), but not preoperative sleep quality (β = −0.06, p = 0.5), was an independent factor for postoperative VAS. CONCLUSION: The OA patients reporting poor preoperative sleep quality show higher preoperative pain, pain catastrophizing, anxiety, and depression. High preoperative pain intensity, but not poor sleep quality, was associated with higher chronic postoperative pain intensity. Future studies are encouraged to explore associations between sleep and chronic postoperative pain