Improving the Process Ability of Poly (3-Hydroxybutyrate) by a Polyphenolic Natural Additive

The severe environmental issues generated by the non-biodegradability of most polymeric materials has fostered the search for more eco-friendly solutions. Polyhydroxybutyrate (PHB), produced by bacterial cells and easily hydrolyzed is one of appealing choice but its properties are still not competitive with those of standard polymers. Among others, one reason is related to the fact that the high processing temperature (due to the high crystallization point) is responsible for severe thermal degradation. In this paper, the effect of Tannic Acid (TA) as a thermal stabilizing processing agent for HPB is investigated by rheological as well as calorimetric techniques under conditions similar to those used in real processing applications. The results show that TA is effective in improving the thermal stability and processability of PHB, while keeping its biodegradable attitude. Compared to neat PHB, TA containing samples show a lower and delayed thermal degradation. FTIR measurements support the hypothesis that stabilization is determined by TA/PHB crosslinking

J Occup Environ Med

ObjectiveWe examined the association between job demand and occupational injury among older workers.MethodsParticipants were workers aged 50+ enrolled in the Health and Retirement Study, 2010\u20132014. Participants reported physical ability within three domains: physical effort, stooping/kneeling/crouching, and lifting. To measure subjective job demand, participants rated their job's demands within domains. We generated objective job demand measures through the Occupational Information Network (O*NET). Using Poisson regression, we modeled the association between physical ability, job demand, and self-reported occupational injury. A second model explored interaction between job demand and physical ability.ResultsThe injury rate was 22 /1,000 worker-years. Higher job demand was associated with increased injury risk. Within high job demands, lower physical ability was associated with increased injury risk.ConclusionsOlder workers whose physical abilities do not meet job demands face increased injury risk.T42 OH008433/OH/NIOSH CDC HHS/United StatesTL1 TR000422/TR/NCATS NIH HHS/United States2018-02-01T00:00:00Z28166127PMC5302493vault:2129

Colloidal fibers as structurant for worm-like micellar solutions

We investigate the rheological properties of a simplified version of a liquid detergent composed of an aqueous solution of the linear alkylbenzene sulphonate (LAS) surfactant, in which a small amount of fibers made of hydrogenated castor oil (HCO) is dispersed. At the concentration typically used in detergents, LAS is in a worm-like micellar phase exhibiting a Maxwellian behavior. The presence of HCO fibers provides elastic properties, such that the system behaves as a simple Zener body, mechanically characterized by a parallel connection of a spring and a Maxwell element. Despite this apparent independence of the contributions of the fibers and the surfactant medium to the mechanical characteristics of the system, we find that the low frequency modulus increases with increasing LAS concentration. This indicates that LAS induces attractive interactions among the HCO fibers, resulting in the formation of a stress-bearing structure that withstands shear at HCO concentrations, where the HCO fibers in the absence of attractive interactions would not sufficiently overlap to provide stress-bearing properties to the system

Investigar en Trabajo Social: diferentes experiencias como pasantes de investigación

El presente trabajo se propone compartir tres experiencias de investigación llevadas a cabo por estudiantes (ahora licenciadas) en la Facultad de Trabajo Social de la Universidad Nacional de La Plata, en diferentes proyectos de investigación. Dos de las experiencias de pasantías se enmarcaron en el proyecto de investigación “Seguridad, Violencia y Derechos Humanos. Un estudio de las representaciones sociales en jóvenes y policías”1. La otra pasantía se inserta en el proyecto “Disputas en el espacio público: cultura, política y desigualdades socio-urbanas”2. A su vez, dos de nosotras continuamos nuestro proceso de aprendizaje del oficio de investigar a través de dos becas CIN en el marco de los proyectos de investigación acreditados, mencionados anteriormente. Haremos una breve mención respecto a esto. Por último, analizaremos las experiencias como pasantes de investigación a la luz de los aportes de distintos autores/as, haciendo hincapié principalmente en la comprensión de las competencias, habilidades y destrezas necesarias para desarrollar la práctica investigativa.Eje Teórico-metodológico en Trabajo Social-GT 27: Metodología y Trabajo Social.Facultad de Trabajo Socia

The Changing Landscape of Neonatal Diabetes Mellitus in Italy Between 2003 and 2022

Context In the last decade the Sanger method of DNA sequencing has been replaced by next-generation sequencing (NGS). NGS is valuable in conditions characterized by high genetic heterogeneity such as neonatal diabetes mellitus (NDM).Objective To compare results of genetic analysis of patients with NDM and congenital severe insulin resistance (c.SIR) identified in Italy in 2003-2012 (Sanger) vs 2013-2022 (NGS).Methods We reviewed clinical and genetic records of 104 cases with diabetes onset before 6 months of age (NDM + c.SIR) of the Italian dataset.Results Fifty-five patients (50 NDM + 5 c.SIR) were identified during 2003-2012 and 49 (46 NDM + 3 c.SIR) in 2013-2022. Twenty-year incidence was 1:103 340 (NDM) and 1:1 240 082 (c.SIR) live births. Frequent NDM/c.SIR genetic defects (KCNJ11, INS, ABCC8, 6q24, INSR) were detected in 41 and 34 probands during 2003-2012 and 2013-2022, respectively. We identified a pathogenic variant in rare genes in a single proband (GATA4) (1/42 or 2.4%) during 2003-2012 and in 8 infants (RFX6, PDX1, GATA6, HNF1B, FOXP3, IL2RA, LRBA, BSCL2) during 2013-2022 (8/42 or 19%, P = .034 vs 2003-2012). Notably, among rare genes 5 were recessive. Swift and accurate genetic diagnosis led to appropriate treatment: patients with autoimmune NDM (FOXP3, IL2RA, LRBA) were subjected to bone marrow transplant; patients with pancreas agenesis/hypoplasia (RFX6, PDX1) were supplemented with pancreatic enzymes, and the individual with lipodystrophy caused by BSCL2 was started on metreleptin.Conclusion NGS substantially improved diagnosis and precision therapy of monogenic forms of neonatal diabetes and c.SIR in Italy

Rheology of viscoelastic suspensions

The rheology of suspensions of solid particles in viscoelastic fluids is important in many technological applications as exemplified by the processing of filled polymers e.g. injection molding, coating processes, application in food and health care products,... Consequently, considerable attention in the literature is given to the rheology of suspensions of particles. Most studies are focused on highly filled systems (typically, volume fractions greater than 10%), with polydisperse particles of irregular shapes due to their technological importance. In contrast, realtively few studies are conducted on the rheology of dilute or semi-dilute suspensions of monodisperse spheres. In the first part we elucidate the effect of viscoelasticity on the bulk rheological properties. The behavior of model suspensions composed of non Brownian, inertialess, rigid spheres immersed in Newtonian and viscoelastic matrices is investigated in the concentration range from 0 up to 10%, thus encompassing both the dilute and semidilute regimes. The data are fitted with quadratic polynomial functions of the particle volume fraction in order to compare with theoretical, empirical and experimental models. As second part, new simulation technique for suspensions in Newtonian fluids under oscillatory shear flow is presented. The cases of a single sphere and two particles are studied and discussed. Finally, the flow induced microstructure of suspensions in viscoelastic fluids is studied by rheo-optical techniques. More specifically, the flow-induced alignment of non-colloidal particles in viscoelastic fluids is investigated systematically in an attempt to quantify the alignment of the particles and correlate it with the shear rate, size of the particles and interactions with the wall