An alternative filament fabrication method as the basis for 3D-printing personalized implants from elastic ethylene vinyl acetate copolymer.

In this work, a novel tool for small-scale filament production is presented. Unlike traditional methods such as hot melt extrusion (HME), the device (i) allows filament manufacturing from small material amounts as low as three grams, (ii) ensures high diameter stability almost independent of the viscoelastic behavior of the polymer melt, and (iii) enables processing of materials with rheological profiles specifically tailored toward fused filament fabrication (FFF). Hence, novel materials, previously difficult to process due to HME limitations, become easily accessible for FFF for the first time.

Understanding the role of endothelial cells in brain tumor formation and metastasis: a proposition to be explored for better therapy.

Glioblastoma is one of the most devastating central nervous system disorders. Being a highly vascular brain tumor, it is distinguished by aberrant vessel architecture. This lends credence to the idea that endothelial cells (ECs) linked with glioblastoma vary fundamentally from ECs seen in the healthy human brain.

Challenges of Current Anticancer Treatment Approaches with Focus on Liposomal Drug Delivery Systems.

According to a 2020 World Health Organization report (Globocan 2020), cancer was a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020. The aim of anticancer therapy is to specifically inhibit the growth of cancer cells while sparing normal dividing cells. Conventional chemotherapy, radiotherapy and surgical treatments have often been plagued by the frequency and severity of side effects as well as severe patient discomfort.

Smart polymer nanoparticles designed for environmentally compliant coatings.

We describe the synthesis, characterization, and film-forming properties of two-component nanoparticles that undergo a reversible morphology transformation in water as a function of pH. The particles consist of a high molecular weight acrylate copolymer and an acid-rich oligomer designed to be miscible with the polymer when its -COOH groups are protonated. Attaching a fluorescence resonance energy transfer (FRET) pair to components inside the nanoparticles enabled us to assess morphology at the molecular level.

Determination of the Förster distance in polymer films by fluorescence decay for donor dyes with a nonexponential decay profile.

Fluorescence resonance energy transfer (FRET) experiments were carried out on three pairs of donor-acceptor dyes in polymer films in which the donor dyes had absorption maxima in the range of 350-450 nm. Two of the donors, a coumarin dye and a naphthalimide dye covalently bound to polystyrene, gave nonexponential decays in the absence of acceptors. The decay profiles could be fitted to a stretched exponential form with a beta value on the order of 0.

Tracking polymer diffusion in a wet latex film with fluorescence resonance energy transfer.

We describe an instrument to measure the polymer interdiffusion between donor-labeled and acceptor-labeled latex polymers in a partially wet latex film with fluorescence resonance energy transfer (FRET). It is possible to temporarily arrest the drying process of a wet latex film by sealing the film in an airtight chamber. In our approach, we measure donor fluorescence decays from 0.

Pain and pain-related interference associated with recurrent aphthous ulcers.

Aims: (1) To use psychometrically sound measures to characterize the pain levels and pain-related interference associated with recurrent aphthous ulcers (RAU); (2) to determine whether subjects with RAU report clinically significant psychologic symptoms; and (3) to examine the relationships between physical characteristics and self-reported psychologic symptoms, pain, and pain-related interference.

Methods: Forty-seven subjects with RAU and an active ulcer completed the Graded Chronic Pain Scale and the Symptom Checklist-90R (SCL-90R). Ulcers were photographed for measurement, and subjects rated pain levels on a 0-to-l0 scale before and after swabbing of the ulcer with a saturated solution of sodium chloride and distilled water.

Dynamics of a poly(ethylene oxide) tracer in a poly(methyl methacrylate) matrix: remarkable decoupling of local and global motions.

The tracer diffusion coefficient of unentangled poly(ethylene oxide) (PEO, M=1000 gmol) in a matrix of poly(methyl methacrylate) (PMMA, M=10 000 gmol) has been measured over a temperature range from 125 to 220 degrees C with forced Rayleigh scattering. The dynamic viscosities of blends of two different high molecular weight PEO tracers (M=440 000 and 900 000 gmol) in the same PMMA matrix were also measured at temperatures ranging from 160 to 220 degrees C; failure of time-temperature superposition was observed for these systems. The monomeric friction factors for the PEO tracers were extracted from the diffusion coefficients and the rheological relaxation times using the Rouse model.