Fabrication of a High-Performance and Reusable Planar Face Mask in Response to the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has caused a surge in demand for face masks, with the massive consumption of masks leading to an increase in resource-related and environmental concerns. In this work, we fabricated meltblown polypropylene (mb-PP)-based high-performance planar face masks and investigated the effects of six commonly used disinfection methods and various mask-wearing periods on the reusability of these masks. The results show that, after three cycles of treatment using hot water at 70 °C for 30 min, which is one of the most scalable, user-friendly methods for viral disinfection, the particle filtration efficiency (PFE) of the mask remained almost unchanged.

Coupling effect of molecular weight and crosslinking kinetics on the formation of rubber nanoparticles and their agglomerates in EPDM/PP TPVs during dynamic vulcanization.

It is well-known that a fine dispersed rubber phase in thermoplastic vulcanizates (TPVs) is a key to obtain good mechanical properties and high elasticity of TPV products. Previous studies reported that the rubber nanodroplets formed during shearing blending can transform into rubber nanoparticles by in situ rapid crosslinking and these rubber nanoparticles spontaneously form agglomerates dispersed in a plastic matrix during dynamic vulcanization (DV). However, important influencing factors on the formation of rubber nanoparticles and their agglomeration during DV have not been reported yet.

Effect of Rubber Nanoparticle Agglomeration on Properties of Thermoplastic Vulcanizates during Dynamic Vulcanization.

We previously reported that the dispersed rubber microparticles in ethylene-propylene-diene monomer (EPDM)/polypropylene (PP) thermoplastic vulcanizates (TPVs) are actually agglomerates of rubber nanoparticles. In this study, based on this new understanding of the microstructure of TPV, we further revealed the microstructure-properties relationship of EPDM/PP TPV during dynamic vulcanization, especially the effect of the size of rubber nanoparticle agglomerates (), the thicknesses of PP ligaments () and the rubber network on the properties of EPDM/PP TPV. We were able to simultaneously obtain a high tensile strength, elongation at break, elastic modulus, and elasticity for the EPDM/PP TPV by the achievement of a smaller , a thinner and a denser rubber network.

New understanding of microstructure formation of the rubber phase in thermoplastic vulcanizates (TPV).

The breakup of the rubber phase in an ethylene-propylene-diene monomer (EPDM)/polypropylene (PP) blend at the early stage of dynamic vulcanization is similar to that in an unvulcanized EPDM/PP blend because of the low crosslink density of the EPDM phase. In this work, the minimum size of the rubber phase in the unvulcanized EPDM/PP blend was first calculated by using the critical breakup law of viscoelastic droplets in a matrix. The calculated results showed that the minimum size of the rubber phase in the unvulcanized blend was in the nanometer scale (25-46 nm), not the micrometer scale as reported in many works.

Dynamic lipidomic insights into the adaptive responses of Saccharomyces cerevisiae to the repeated vacuum fermentation.

Vacuum fermentation is utilized in a wide range of life science industries and biomedical R&D. Little is known, however, on the effects of the vacuum on the yeast, and in particular, on the yeast lipidome that plays a central role in maintaining cell membrane and other vital (yeast) cell functions. The present study evaluated the adaptive responses of Saccharomyces cerevisiae to repeated vacuum fermentation by lipidomic analysis.

Lipidome profiling of Saccharomyces cerevisiae reveals pitching rate-dependent fermentative performance.

A high cell density strategy has been used in bioethanol production to shorten the fermentation period. To reveal the molecular basis of fermentative behavior in high cell density, the profiling of the phospholipids and sterols of Saccharomyces cerevisiae during fermentation at five different pitching rates (1, 5, 10, 20, and 40 g/L) was investigated. Using LC/ESI/MS(n) technology, 148 phospholipid species were detected, of which 91 species were quantified, and using the gas chromatography-time-of-flight mass spectrometry procedure, a total of 11 sterols were quantified.

Inoculum size-dependent interactive regulation of metabolism and stress response of Saccharomyces cerevisiae revealed by comparative metabolomics.

To investigate the metabolic regulation against inoculum density and stress response to high cell density, comparative metabolomic analysis was employed on Saccharomyces cerevisiae under fermentations with five different inoculum sizes by gas chromatography time-of-flight mass spectrometry. Samples from these fermentations were clearly distinguished by principal components analysis, indicating that inoculum size had a profound effect on the metabolism of S. cerevisiae.

Inoculation-density-dependent responses and pathway shifts in Saccharomyces cerevisiae.

The cell-density-dependent responses of Saccharomyces cerevisiae to inoculation sizes were explored by a proteomic approach. According to their gene ontology, 100 protein spots with differential expression, corresponding to 67 proteins, were identified and classed into 17 different functional groups. Upregulation of eight heat shock, oxidative response and amino acid biosynthesis-related proteins (e.