Dynamic measurements on polymer chain dimensions below the θ-temperature

To observe the contraction of a flexible chain, quasi-elastic light scattering and viscosity experiments were performed below the θ-temperature. The systems used were monodisperse polystyrene (Mw = 1.71 x 10 5, Mw =4.11 × 105, Mw = 1.26 ×106) dissolved in cyclohexane. It is observed that : — Hydrodynamic and viscosity expansion factors, αH and α3 η, scale with the reduced variable (θ-T T)√M. — αH and α3η have a linear behaviour in a «θ domain» (0≤ |θ - T / T| √M ≤ 10) which is symmetric with respect to the θ-temperature. — There is no evidence of an asymptotic collapsed regime for (θ-T T)√M≤ 35.Des expériences de diffusion de lumière quasi-élastique et de viscosité sont réalisées en dessous de la température θ pour observer la contraction d'une chaine flexible. Les échantillons utilisés sont du polystyrène monodisperse dissous dans du cyclohexane (Mw = 1,71 x 105; Mw =4,11 × 105; Mw = 1,26 × 106 ). On observe que : — Les facteurs d'expansion hydrodynamique (αH et de viscosité (α3 η) s'échellent selon la variable reduite (θ - T / T)√ M. — αH et α3η ont un comportement linéaire dans un « domaine θ » (0 ≤|θ - T / T| √M ≤ 10) qui est symétrique. par rapport à θ. — Le « régime asymptotique collapsé» n'est pas observé pour (θ-T T)√M≤ 35

Bringing community oriented primary care into an academic training setting: A qualitative study

Objectives: Identify patient-informed strategies through which an urban resident continuity clinic can implement the principles of community oriented primary care (COPC). Methods: As part of a larger sequential mixed methods study supporting implementation evaluation of a new urban academic medical center in Cleveland, Ohio, semi-structured telephone interviews using a descriptive phenomenological approach were conducted spring 2021 with patients to explore perspectives regarding community involvement by healthcare providers and what they want clinicians to know about their community. A constant comparative analysis of emerging themes was used to analyze the thematic contents of interviews. Results: Twenty-one participants completed interviews. Almost all thought clinicians’ community involvement is important. Thematic guidance from participants highlighted that clinicians should be: (1) knowledgeable about the Black experience, (2) seen in the community outside the clinic, and (3) aware that “knowing my community is knowing me.” Conclusions: Design with a target community in mind is a necessary but not sufficient step to implement COPC in practice. The visibility of clinicians in community settings is essential for COPC

Experimental study of polymer interactions in a bad solvent

The interactions between polymer chains in a bad solvent (polystyrene-cyclohexane at temperatures lower than 35 °C) was studied using light scattering intensity measurements. The results obtained in dilute solutions show that the demixing concentration CD is related to the second virial coefficient A 2 of the osmotic pressure. Using the reduced variables predicted by mean-field or scaling theories the demixion curves are dependent on M w, the molecular weight. Empirically, it is found that CD/C c and A2/Ac2 are only functions of Tc - T/Tc × M0.31w . Cc and Ac2 are the critical concentration and the second virial coefficient at the critical temperature Tc.Les interactions entre chaînes polymériques dans un mauvais solvant (polystyrène-cyclohexane à des températures plus petites que 35 °C) ont été étudiées en utilisant des mesures d'intensité de lumière diffusée. Les résultats obtenus, dans des solutions diluées, montrent que la concentration de demixtion, C D, est reliée au second coefficient du viriel, A2, de la pression osmotique. Les variables réduites à utiliser pour avoir une courbe universelle ne sont pas celles prédites par les théories de champ moyen ou de loi d'échelle. Il est trouvé empiriquement que CD/Cc et A2/Ac2 sont fonction de T c - T/Tc × M0,31w. Mw est la masse moléculaire, Cc et Ac 2 sont respectivement la concentration critique et Ie second coefficient du viriel à la température critique Tc

Intrinsic viscosity of flexible macromolecules : transition from theta to collapsed state

Intrinsic viscosity measurements have been performed on polystyrene-cyclohexane system as a function of temperature T (T ≲ θ and as a function of molecular weight (8.2 x 10 4 ≤ Mw ≤ 2.06 x 107) .The expansion factor α3 η = [η]/[ηθ] of the intrinsic viscosity [η] scales with the reduced variable (T — θ/T) · ∫M w. For (T—θ/T) º √Mw ≲ — 40, the intrinsic viscosity of a collapsed macromolecule is found to be independent of molecular weight A value ν = 1/3 is therefore given to the index relating size to molecular weight.Des mesures de viscosité intrinsèque [η] sont effectuées sur des solutions diluées de polystyrène dans le cyclohexane en fonction de la température (T ≲ 0) et de la masse moléculaire (8,2 x 104 ≤ M w ≤ 2,06 x 107). Le facteur d'expansion (α 3η = [η]/[ ηθ]) de la viscosité intrinsèque obéit à une loi d'échelle dont la variable réduite est (T — θ/T) · √Mw Lorsque (T — θ/T) · √Mw ≲ — 40, la viscosité intrinsèque d'une chaîne effondrée est indépendante de la masse moléculaire. L'indice ν reliant la taille à la masse moléculaire est trouvé égal à 1/3

Treating Severe Mental Illnesses and Comorbid Medical Conditions in the Primary Care Setting: An Idea Whose Time has Come

Abstract. The mortality of patients with comorbid serious mental illness (SMI) and diabetes (DM) is high. In this pilot study in patients with SMI and DM, the effect of group work using the strategy of "targeted training in illness management" with nurse educators and peer educators was examined. The results indicated that improvements in the outcome of both the serious mental illness and the diabetes might be achieved with this approach

Primary Care Practice Workplace Social Capital: A Potential Secret Sauce for Improved Staff Well-Being and Patient Experience

Patient experiences with the health-care system are increasingly seen as a vital measure of health-care quality. This study examined whether workplace social capital and employee outcomes are associated with patients’ perceptions of care quality across multiple clinic sites in a diverse, urban safety net care setting. Data from clinic staff were collected using paper and pencil surveys and data from patients were collected via a telephone survey. A total of 8392 adult primary care patients and 265 staff (physicians, nurses, allied health, and support staff) were surveyed at 10 community health clinics. The staff survey included brief measures of workplace social capital, burnout, and job satisfaction. The patient-level outcome was patients’ overall rating of the quality of care. Factor analysis and reliability analysis were conducted to examine measurement properties of the employee data. Data were aggregated and measures were examined at the clinic site level. Workplace social capital had moderate to strong associations with burnout ( r = −0.40, P < .01) and job satisfaction ( r = 0.59, P < .01). Mean patient quality of care rating was 8.90 (95% confidence interval: 8.86-8.94) ranging from 8.57 to 9.18 across clinic sites. Pearson correlations with patient-rated care quality were high for workplace social capital ( r = 0.88, P = .001), employee burnout ( r = −0.74, P < .05), and satisfaction ( r = 0.69, P < .05). Patient-perceived clinic quality differences were largely explained by differences in workplace social capital, staff burnout, and satisfaction. Investments in workplace social capital to improve employee satisfaction and reduce burnout may be key to better patient experiences in primary care

Food Insecurity Trajectories in the US During the First Year of the COVID-19 Pandemic.

INTRODUCTION: The objective of this study was to characterize population-level trajectories in the probability of food insecurity in the US during the first year of the COVID-19 pandemic and to examine sociodemographic correlates associated with identified trajectories. METHODS: We analyzed data from the Understanding America Study survey, a nationally representative panel (N = 7,944) that assessed food insecurity every 2 weeks from April 1, 2020, through March 16, 2021. We used latent class growth analysis to determine patterns (or classes) of pandemic-related food insecurity during a 1-year period. RESULTS: We found 10 classes of trajectories of food insecurity, including 1 class of consistent food security (64.7%), 1 class of consistent food insecurity (3.4%), 5 classes of decreasing food insecurity (15.8%), 2 classes of increasing food insecurity (4.6%), and 1 class of stable but elevated food insecurity (11.6%). Relative to the class that remained food secure, other classes were younger, had a greater proportion of women, and tended to identify with a racial or ethnic minority group. CONCLUSION: We found heterogeneous longitudinal patterns in the development, resolution, or persistence of food insecurity during the first year of the COVID-19 pandemic. Experiences of food insecurity were highly variable across the US population, with one-third experiencing some form of food insecurity risk. Findings have implications for identifying population groups who are at increased risk of food insecurity and related health disparities beyond the first year of the pandemic