Search results for "PLASTICS"

Running thermoregulation effects using bioceramics versus polyester fibres socks

2020

The feet, covered by socks and shoes during running, undergo an increase of temperature. The aim of this study was to reduce heat generation in the feet of athletes during running by wearing novel thermoregulatory socks impregnated with bioceramic materials. Thirty male athletes ran a half-marathon (21.0975 km) wearing polyester based with bioceramic fibres (zirconium silicate and titanium oxide) and control socks (polyester). The average temperatures were measured with a thermographic camera (FLIR e60bx) before and after the run. Nine regions of interests were evaluated in the plantar surface and eight in the dorsum. Before running, the plantar region with the highest temperature was the …

Effects of a fatiguing run in popliteal vein flow using sports compression socks

2018

Introduction Although the use of sports compression socks is becoming more popular, there is still a lack of knowledge regarding the helpfulness of these garments for physical movement or sports use. One of the main effects attributed to the use of compression sock is the facilitation of venous blood flow return which is thought to improve performance and recovery. Methodology In this study, 10 trained runners performed 2 treadmill running tests for 30 min to 75% of their maximum aerobic speed, without sports socks (control) and with different sports compression socks. We measured popliteal vein flow volume before and after each test using magnetic resonance imaging. Results and discussion …

Translational development and pre-clinical evaluation of prototype gastrointestinal mock-up devices: only robotic placement of plastic?

2020

Background: The aim of this study was to address the vision of wireless theranostic devices distributed along the gastrointestinal (GI) tract by defining design requirements, developing prototype mock-ups, and establishing a minimally invasive surgical approach for the implantation process. Methods: Questionnaires for contextual analysis and use case scenarios addressing the technical issues of an implantable GI device, a possible scenario for implantation, preparation and calibration of a device, and therapeutic usage by professionals and patients were completed and discussed by an interdisciplinary team of surgeons, engineers, and product designers. Two acute porcine experiments were cond…

Two-Stage operation for cleft palate

1963

Occurrence of Microplastics in Waste Sludge of Wastewater Treatment Plants: Comparison between Membrane Bioreactor (MBR) and Conventional Activated S…

2022

In this study, the presence of microplastics in the sludge of three wastewater treatment plants (WWTPs) was examined. The investigated WWTPs operated based on a conventional activated sludge (CAS) process, with (W1) or without (W2) primary clarification, and a membrane bioreactor process (MBR) (W3). The microplastics (MPs) concentration in the samples of W3 was approximately 81.1 ± 4.2 × 103 particles/kg dry sludge, whereas MPs concentrations in W1 and W2 were 46.0 ± 14.8 × 103 particles/kg dry sludge and 36.0 ± 5.2 × 103 particles/kg dry sludge, respectively. Moreover, MPs mainly consisted of fragments (66–68%) in the CAS plants, whereas the fra…

Hybrid nanocomposites with ultra-low filling content by nano-coating fragmentation

2021

In the current study, a new technique for the manufacturing of polymer nanocomposites (PNCs) with ultra-low filling content (<0.05 wt%) is presented. Specifically, this method has been validated through the production of polypropylene (PP) nanocomposites with Ag nanoparticles. The presented method first consisted in a metal nano-film deposition on PP pellet substrates by a physical vapor deposition (PVD) sputtering equipment. Subsequently, a percentage of the coated pellet was mixed to uncoated ones via an injection molding machine to produce the PNC in a single step. Different mixing percentages of coated PP pellet to the uncoated ones were studied. As a result, the fragmentation of the…

Mercury and Amino Acid Content Relations in Northern Pike (Esox Lucius) in Subarctic Lakes Along a Climate-Productivity Gradient

2023

Mercury is a highly toxic element for consumers, but its relation to amino acids and physiology of wild fish is not well known. The main aim of this study was to evaluate how total mercury content (THg) of northern pike (Esox lucius) is related to amino acids and potentially important environmental and biological factors along a climate-productivity gradient of ten subarctic lakes. Linear regression between THg and sixteen amino acids content [nmol mg−1 dry weight] from white dorsal muscle of pike from these lakes were tested. Lastly, a general linear model (GLM) for age-corrected THg was used to test which factors are significantly related to mercury content of pike. There was a positive r…

Comparisons of processing and strength properties of two adhesive systems for composite joints

2007

Abstract In the present study rheological, static and impact tests are carried out on two adhesive resins usually employed in marine applications; then single lap joint tests are conducted on composites joints evidencing the effect of the curing time of both resins on the mechanical properties of the joint. The applicability and workability conditions of the adhesive resins are determined evaluating the curing evolution by a preliminary rheological analysis; then the relation of curing properties with the mechanical performances of the resins themselves and with ones of the composite joints is estimated. Static flexural and Izod impact tests are performed on the resins at increasing time af…

Hyaluronan‐coated poly(propylene imine) dendrimers as biomimetic nanocarriers of doxorubicin

2022

A coating technology based on low molecular weight hyaluronic acid (HA) and ferulic acid (FA) was applied to the coating of low generation poly(propylene imine) dendrimers through a biocompatible hexa(ethylene glycol) spacer. The ensuing HA-FA-HEG-PPID dendrimeric materials showed interesting loading capability (between 7.65% and 9.08%) regarding anticancer agent doxorubicin, and their interactions with the drug appeared to hamper the drug release in the physiological environment. Thus, the stable nanostructured loaded delivery systems were able to internalize into cells expressing the HA receptor CD44 and to demonstrate high cytotoxicity comparable to that shown by equivalent amounts of fr…

Blends of Semiflexible Polymers: Interplay of Nematic Order and Phase Separation

2021

Mixtures of semiflexible polymers with a mismatch in either their persistence lengths or their contour lengths are studied by Density Functional Theory and Molecular Dynamics simulation. Considering lyotropic solutions under good solvent conditions, the mole fraction and pressure is systematically varied for several cases of bending stiffness κ (the normalized persistence length) and chain length N. For binary mixtures with different chain length (i.e., NA=16, NB=32 or 64) but the same stiffness, isotropic-nematic phase coexistence is studied. For mixtures with the same chain length (N=32) and large stiffness disparity (κB/κA=4.9 to 8), both isotropic-nematic and nematic-nematic unmixing oc…