Predicted Fracture Tendency of Naturally Occurring Aluminum Surface Coatings under Tensile Loading.

Naturally occurring coatings on aluminum metal, such as its oxide or hydroxide, serve to protect the material from corrosion. Understanding the conditions under which these coatings mechanically fail is therefore expected to be an important aspect of predictive models for aluminum component lifetimes. To this end, we develop and apply a molecular dynamics (MD) modeling framework for conducting tension tests that is capable of isolating factors governing the mechanical strength as a function of coating chemistry, defect morphology, and variables associated with the loading path. We consider two representative materials, including γ-Al2O3 and γ-Al(OH)3 (i.e., oxide and hydroxide), both of which form readily as aluminum surface coatings. Our results indicate that defects have a significant bearing on the strength of aluminum oxide, with grain boundaries serving to reduce the strain at failure from εzz = 0.300 to 0.219, relative to perfect single crystal. Our simulations also predict that porosity lowers the elastic stiffness and yield strength of the oxide. Relative to perfect crystal, we find porosity factors of 5%, 10% and 20% decrease the yield stress by 26%, 36% and 53%, respectively. MD predicts that perfect hydroxide and oxide single crystal have respective strains at failure of 0.08 and 0.31 under tensile uniaxial strain loading, and that the corresponding yield stresses are respectively 1.6 and 11.1 GPa. These data indicate that the hydroxide is substantially more susceptible to mechanical failure than the oxide. Our results, coupled with literature findings that indicate hot and humid conditions favor formation of hydroxide and defective oxide coatings, indicate the potential for a complicated dependence of aluminum corrosion susceptibility and stress corrosion cracking on aging history.

Clarifying mechanisms and kinetics of programmable catalysis.

Programmable catalysis-the purposeful oscillation of catalytic potential energy surfaces (PES)-has emerged as a promising method for the acceleration of catalyzed reaction rates. However, theoretical study of programmable catalysis has been limited by onerous computational demands of integrating the stiff differential equations that describe periodic cycling between PESs. This work details methods that reduce the computational cost of finding the limit cycle by ≳108×. These methods produce closed-form analytical solutions for didactic case studies, examination of which provides physical insights of programmable catalysis mechanisms. Generalization of these analyses to more complex reaction networks, including CO oxidation on Pt (111) surfaces, exposes the key catalyst properties required to achieve enhanced rates and conversions via one of two programmable catalysis mechanisms: quasi-static (high frequency) and stepwise (intermediate frequency). Analytical description of each mechanism is critical in understanding the consequences of the Sabatier principle on achievable rate enhancement through programmed catalysis.

A chemo-mechanical model for describing sorption hysteresis in a glassy polyurethane.

Hysteretic sorption and desorption of water is observed from 0 to 95% relative humidity and 298-333 K on a glassy polyurethane foam. It is postulated that sorption-induced swelling of the glassy polyurethane increases the concentration of accessible hydrogen-bonding adsorption sites for water. The accessibility of sites is kinetically controlled due to the restricted thermal motions of chains in the glassy polymer, causing a difference in accessible site concentrations during sorption and desorption. This discrepancy leads to hysteresis in the sorbed concentrations of water. A coupled chemo-mechanical model relating volumetric strain, adsorption site concentration, and sorbed water concentration is employed to describe water sorption hysteresis in the glassy polyurethane. This model not only describes the final mass uptake for each relative humidity step, but also captures the dynamics of water uptake, which exhibit diffusion and relaxation rate-controlled regimes.

Polyphenols as a partial replacement for vitamin E in nursery pig diets.

A total of 300 pigs (241 × 600; DNA, Columbus, NE; initially 6.0 ±â€…0.01 kg) were used in a 42-d trial to determine the effects of vitamin E levels and partially replacing vitamin E with a polyphenol (Cabanin CSD, R2 Argo, Denmark) on growth performance, complete blood count, serum thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), and cytokine panel. Sixty pens of pigs were weighed and allotted to one of the five dietary treatments in a completely randomized design with 12 pens per treatment. A control treatment was formulated to provide 15 IU/kg of vitamin E equivalence from vitamin E. This control treatment was then used as a base for three replacement strategy diets to determine the effects of replacing an additional 60 IU/kg of vitamin E with polyphenol in diets containing a basal level of vitamin E requirement estimate (15 IU/kg). First, an additional 60 IU/kg of vitamin E was added for a total of 75 IU/kg of vitamin E equivalence. Second, 50% of the additional vitamin E (30 IU/kg) was replaced with the equivalency of polyphenol. Third, all 60 IU/kg of the additional vitamin E was replaced with the equivalency of polyphenol. To evaluate whether there are negative effects of feeding nursery pigs a high level of polyphenol, a fifth treatment was formulated to provide 575 IU/kg of vitamin E equivalence with 75 IU/kg from vitamin E and 500 IU/kg from polyphenol. Whole blood and serum samples were collected on days 10 and 42, and pig weights and feed disappearance were measured on days 10, 21, 31, 38, and 42. For growth performance, increasing vitamin E equivalence tended to improve (quadratic, P < 0.10) gain-to-feed ratio (G:F) from days 10 to 21, and tended to improve (linear, P < 0.10) G:F from days 21 to 42 and 0 to 42. There was a vitamin E equivalence × day interaction (P = 0.050) for serum SOD activity. Increasing vitamin E equivalence increased (linear, P < 0.05) serum SOD activity on day 42 but not on days 10 (P > 0.10). For serum cytokines, there was no evidence of differences (P > 0.10) between treatments and vitamin E equivalence. Moreover, there was no evidence of differences (P > 0.10) in all response variables between the three replacement strategies throughout the entire periods. In summary, increasing vitamin E equivalence tended to improve G:F, which may be related to the improved SOD activity. Furthermore, polyphenol can effectively replace vitamin E provided above the vitamin E requirement to provide similar benefits from increasing vitamin E equivalence.

Readability of Online Materials in Spanish and English for Breast Reduction Insurance Coverage.

INTRODUCTION: Breast reduction surgery aims to alleviate physical discomfort and improve the quality of life for individuals with macromastia. Insurance coverage plays a crucial role in making this surgery accessible, but navigating the complex approval process can be challenging. Online resources have become a primary information source, but limited research exists on the adequacy of online materials, particularly for Spanish-speaking patients. This study evaluates the readability, actionability, and understandability of online educational materials on breast reduction insurance coverage for Spanish- and English-speaking patients. METHODS: We conducted an online search using the phrase "breast reduction insurance" and selected the first eight institutional or organizational websites that provided information on breast reduction insurance in both English and Spanish. We evaluated online materials using the Patient Education and Materials Assessment Tool (PEMAT), Cultural Sensitivity Assessment Tool (CSAT), and Simplified Measure of Gobbledygook, Spanish (SOL). These tools were used to assess factors such as understandability and actionability, cultural sensitivity, and readability of the materials. RESULTS: Both English and Spanish materials scored high in understandability and actionability, with similar average scores between the languages. Cultural sensitivity scores indicated acceptable materials. However, Spanish materials had a higher reading grade level and more hard words compared to English materials. CONCLUSION: There is a need for accessible and understandable online resources on breast reduction insurance coverage, particularly for Spanish-speaking patients. While the assessed websites generally provided comprehensible information, improvements can be made to enhance visual aids and simplify language. These improvements can better educate patients, improve outcomes, and reduce healthcare costs. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Patient Understanding of Provider Credentials and Selection of Plastic Surgery Providers.

BACKGROUND: Many physicians who are not board-certified plastic surgeons have started performing aesthetic procedures, leading to unsafe practices that jeopardize patients' health. METHODS: Patients of a cosmetic and reconstructive private plastic surgery practice were asked to complete a survey that assessed their understanding of plastic surgeon credentials and advertising practices, and what influences their choice of a plastic surgeon. RESULTS: Eighty-five patients completed the survey, with 37.2% reporting prior aesthetic surgery; 84.9% were unaware of the lack of legal regulations governing the advertising practices of physicians. When asked if a doctor can perform surgery to improve their appearance without being a board-certified plastic surgeon, 22.1% responded "yes," 50% responded "no," and 27.9% responded "I don't know;" 98.8% reported a sense of comfort knowing their provider is board-certified in plastic surgery. When asked what factors help them decide if a surgeon is knowledgeable and trustworthy, the overwhelming majority reported referral from patients and providers as the most important factor, followed by online ratings and reviews. When deciding whether to recommend a plastic surgeon, personal experience was the most important factor. When deciding who should perform their cosmetic procedure, the most important factor was experience, followed by plastic surgery board certification. DISCUSSION: Current physician advertising practices lack strict guidelines and are often misleading. Patients would benefit from more thorough education on these practices. Of the various plastic surgeon assessment factors, most patients rely heavily on feedback obtained from patients and providers.

A patient-centredness improvement study for efficacy of behaviour change for healthy lifestyle and weight loss in a student-run free clinic.

BACKGROUND: Primary care is the ideal place to implement behaviour change interventions for weight management. However, most primary care physicians are not managing patient weight as a standard of care due to lack of knowledge, skills and reimbursement. Generating more physicians who are familiar and comfortable with providing weight management is essential in leveraging a global change. In our university free clinic, medical students provide healthy lifestyle counselling using shared decision making to each patient at every clinic visit. OBJECTIVE: Improve the efficacy of behaviour change interventions via increased patient responsiveness and adherence. METHODS: The needs assessment demonstrated a subpar patient response rate to check-ins regarding behavioural change goals. In the first and second interventions, check-in message structure and contact schedule were varied to maximize patient responsiveness and goal achievement. RESULTS: In the needs assessment, 58% of patients responded to follow-ups and 58% of patients accomplished their goal. The first intervention cycle resulted in an improvement of responsiveness to 70% and accomplishment of goals to 59%. The second intervention cycle resulted in an improvement of responsiveness to 78% and accomplishment of goals to 74%. CONCLUSIONS: Messages that were frequent, unique, succinct and delivered within 4 weeks after the clinic visit resulted in the highest response rate and goal attainment. Other primary care clinics can use these interventions to increase patient completion of implemented behaviour changes for a healthier lifestyle.

Characterization of a Vivid Homolog in Botrytis cinerea.

Blue light-signaling pathways regulated by members of the light-oxygen-voltage (LOV) domain family integrate stress responses, circadian rhythms and pathogenesis in fungi. The canonical signaling mechanism involves two LOV-containing proteins that maintain homology to Neurospora crassa Vivid (NcVVD) and White Collar 1 (NcWC1). These proteins engage in homo- and heterodimerization events that modulate gene transcription in response to light. Here, we clone and characterize the VVD homolog in Botrytis cinerea (BcVVD). BcVVD retains divergent photocycle kinetics and is incapable of LOV mediated homodimerization, indicating modification of the classical hetero/homodimerization mechanism of photoadaptation in fungi.