Histological aspects of skeletal muscle fibers splitting of C57BL/6NCrl mice

The objective of the current study is to present data on the splitting of skeletal muscle fibers in C57BL/6NCrl mice. Skeletal muscles (m. rectus femoris (m. quadriceps femoris)) from 500 (250 ♀ and 250 ♂) C57BL/6NCrl mice in the 16th week of life were sampled during autopsy and afterwards standardly histologically processed. Results show spontaneous skeletal muscle fiber splitting which is followed by skeletal muscle fiber regeneration. One solitary skeletal muscle fiber is split, or is in contact with few localized splitting skeletal muscle fibers. Part of the split skeletal muscular fiber is phagocytosed, but the remaining skeletal muscular fiber splits are merged into one regenerating skeletal muscle fiber. Nuclei move from the periphery to the regenerating skeletal muscle fiber center during this process. No differences were observed between female and male mice and the morphometry results document <1 % skeletal muscle fiber splitting. If skeletal muscular fibers splitting occurs 5 %> of all skeletal muscular fibers, it is suggested to describe and calculate this in the final histopathological report.

Tremolite–actinolite fiber coatings of sub-nanometer silica-rich particles in lungs from deceased Quebec miners

Tremolite–actinolite (TA) fibers from the lungs of deceased former Quebec mine workers were found to be coated with sub-nanometer particles. Qualitative chemical analyses were performed on the particles indicating that they were composed of silicon and oxygen. The crystal lattice structure of all amphibole minerals, including the TA series, is arranged as pairs of linear chains of SiO4 tetrahedra that are linked together to form double chains. Our observations of the TA fibers from miner’s lungs, made using a high-resolution transmission electron microscope, indicated that the tetrahedral silica chains were progressively split, forming dispersed sub-nanometer particles. The non-tetrahedral sites were removed at the surface of the TA fibers, presumably by the oxidation process involved in attempted phagocytosis, which also resulted in fragmentation of the tetrahedral chains. It was found that the silicon-rich particles (SRPs) were variable in diameter, consistent with fragments formed from the splitting of the tetrahedral chains. The TA fibers from lungs displayed coatings and linear interior zones of SRP parallel to the planes of longitudinal fiber splitting. The literature on very small nanoparticles is consistent with deep penetration of SRP into cell DNA interiors, oxidative stress, and carcinogenesis.

Melt-Electrospun Polyethylene Nanofiber Obtained from Polyethylene/Polyvinyl Butyral Blend Film

We prepared low-density polyethylene (LDPE) nanofiber, a few hundred nanometers in diameter, using polyvinyl butyral (PVB) and a laser melt-electrospinning (M-ESP) device. We blended PVB with LDPE via an internal melt mixer, removed the PVB after M-ESP by ethanol treatment, and studied the influence of PVB on fiber diameter. A substantial diameter reduction with improved crystallinity of LDPE fiber was observed with increased PVB content in the blend. PVB inclusion also increased the polarity of the LDPE/PVB blend, resulting in better spinnability. The removal of PVB from LDPE/PVB blend fiber caused a massive drop in the LDPE fiber diameter, due to fiber splitting, particularly in PVB-rich samples. Fourier transform infrared (FTIR) spectroscopy of fibers confirmed that the prepared nanofiber was the same as pure LDPE fiber.

Inexpensive α-amylase production and application for fiber splitting in leather processing

Recently, the production of superior quality enzymes using waste sources has promoted greater research interest due to their enhanced enzyme activity, selectivity and stability.

Impact Strength of Carbon Reinforced Epoxy Composite at Different Temperatures

Charpy impact tests were conducted on carbon reinforced epoxy composites fabricated by hand lay-up method using 0.47, 0.56 and 0.66 carbon fiber volume fractions; tests were conducted at temperatures between -60oC to 60oC. The impact strength was found, in general, to increase when the samples were fractured at temperatures above 0oC and the impact strength decreased with the increase of fiber content. The impact energy absorption was highest of 270 KJm-2 with 47 vol% fiber when fractured at +60oC and it reduced to 130 KJm-2 at -60oC. With decreasing the fracture temperature and increasing the fiber content the impact strength reduced significantly. The reduction of impact energy was from 235 KJm-2 to 107 KJm-2 for 56 vol% fiber and from 196 KJm-2 to 90 KJm-2 for 66 vol% fiber when fractured at +60oC and -60oC, respectively. Failure occurred mostly by fiber delamination; fiber splitting and matrix cracking were also present. Delamination was more in specimens tested at -60oC while fiber splitting and matrix cracking were more when fractured at +60oC.