Chemical Synthesis of Atactic Poly-3-hydroxybutyrate (a-P3HB) by Self-Polycondensation: Catalyst Screening and Characterization.

Poly-3-hydroxybutyrate (P3HB) is a biodegradable polyester produced mainly by bacterial fermentation in an isotactic configuration. Its high crystallinity (about 70%) and brittle behavior have limited the process window and the application of this polymer in different sectors. Atactic poly-3-hydroxybutyrate (a-P3HB) is an amorphous polymer that can be synthesized chemically and blended with the isotactic P3HB to reduce its crystallinity and improve its processability Ring-opening polymerization (ROP) is the most cited synthesis route for this polymer in the literature.

Water loss after stomatal closure: quantifying leaf minimum conductance and minimal water use in nine temperate European tree species during a severe drought.

Residual canopy transpiration (Emin_canop) is a key physiological trait that determines trees' survival time under drought after stomatal closure and after trees have limited access to soil water. Emin_canop mainly depends on leaf minimum conductance (gmin) and vapor pressure deficit. Here we determined the seasonal variation of gmin and how gmin is related to interspecies variation in leaf cuticular and stomatal traits for nine European tree species in a mature forest.

[Aerosols and SARS-CoV-2: Statement of the "Expert Group Aerosols" on the development, infectivity, spread and reduction of airborne, virus-containing particles in the air].

Aerosols are currently seen as one of the main transmission routes for SARS-CoV-2, but a comprehensive understanding of the processes and appropriate action/adaptation of protection concepts requires the exchange of information across interdisciplinary boundaries. Against this background, the Baden-Württemberg state government launched in October 2020 a multidisciplinary "Expert Group Aerosols" comprising engineers, natural scientists and medical professionals. In its statement, the group has compiled the current state of knowledge in all relevant disciplines in the context of airborne SARS-CoV-2 infection.

Shape Memory Polymer Foam with Programmable Apertures.

In this work, a novel type of polyester urethane urea (PEUU) foam is introduced. The foam was produced by reactive foaming using a mixture of poly(1,10-decamethylene adipate) diol and poly(1,4-butylene adipate) diol, 4,4'-diphenylmethane diisocyanate, 1,4-butanediol, diethanolamine and water as blowing agent. As determined by differential scanning calorimetry, the melting of the ester-based phases occurred at temperatures in between 25 °C and 61 °C, while the crystallization transition spread from 48 °C to 20 °C.

Peritoneal free autologous fat graft for the control of pulmonary air leaks in emphysematous rat lungs.

Background: Persistent pulmonary air leak is the most frequent complication after lung resection, resulting in an increase in postoperative morbidity and mortality. We evaluated the viability, integration, and efficacy of a free peritoneal fat graft as a method for controlling air leak in normal and emphysematous rat lungs.

Methods: Sixty Wistar rats were divided into two groups: elastase-produced lung emphysema (n=30) and control (normal) lungs (n=30).