Polyaryl ethers and related polysiloxane copolymer molecular coatings preparation and radiation degrdation

Poly(arylene ether sulfones) comprise a class of materials known as engineering thermoplastics which have a variety of important applications. These polymers are tough, rigid materials with good mechanical properties over a wide temperature range, and they are processed by conventional methods into products typically having excellent hydrolytic, thermal, oxidative and dimensional stability. Wholly aromatic random copolymers of hydroquinone and biphenol with 4.4 prime dichlorodiphenyl sulfone were synthesized via mechanical nucleophilic displacement. Their structures were characterized and mechanical behavior studied. These tough, ductile copolymers show excellent radiation resistance to electron beam treatment and retain much of the mechanical properties up to at least 700 Mrads under argon

Effect of 300 year water-logging on chemical properties and natural decay and termite resistance of wood Abies bornmulleriana M.

Special conditions such as water-logging may allow wood to survive thousands of years however some biological, chemical or physical modifications may occur. In this study, 300 year-waterlogged fir (Abies bornmulleriana M.) was tested for its chemical properties and natural decay and termite resistance in comparison with a recent fir. It was found that water-logging for 300 years caused few changes in chemical properties of waterlogged wood. Lignin was the most resistant component in the waterlogged wood specimens however polyoses and extractives were more affected during water-logging. Laboratory decay tests were performed using according to ASTM D 2017-81 standard method using two brown-rot fungi, Gloeophyllum trabeum and Serpula lacrymans and two white-rot fungi, Coriolus versicolor and Irpex lacteus. Wood specimens were also bioassayed against subterranean termite Coptotermes formosanus. Tests showed that 300 year water-logging had no any effect on natural durability however weight losses in the waterlogged specimens were slightly higher

Effects of the fusionless instrumentation on the disks and facet joints of the unfused segments: A pig model

PubMedID: 23812137Background: Growing rod (GR) is a state-of-the-art procedure favored when curvatures of the spine cannot be managed non-operatively in early-onset scoliosis. Although some postulate that multiple distractions and/or relative immobilization of the unfused segments affect the health of disk and facet joint (FJ) and cause degeneration and/or spontaneous fusion, this has not thoroughly been investigated. In this study, changes in the un-fused segment after a spine-based fusionless instrumentation (SBFI) are investigated and compared with the control (CG) and instrumented fusion (IF) groups. Methods: A total of 13 piglets, 10 to 14 weeks of age, were used. SBFI and IF were performed on 7 and 3 piglets, respectively, and 3 formed the CG. In SBFI, lengthening procedures of 5mm were applied once monthly for 3 months, and, after 4 months, all piglets were euthanized. Histologic sections of the unfused disks and FJ were analyzed, and morphometric histologic analysis was performed. Results: On the basis of the Gries criteria, unfused disk median grades were 1, 2, and 4 for control, SBFI, and IF, respectively, that revealed a statistical difference (P < 0.001). Unfused FJ median grades were 1 and 2 for control and SBFI, respectively, that revealed a statistical difference (P < 0.001). The mean hyper-trophic zone (HZ) heights were 69.78, 84.20, and 66.14 mm; HZ chondrocyte cell widths were 19.03, 18.76, and 17.36 mm; and HZ chondrocyte cell heights were 15.01, 15.04, and 12.42 mm in the CG, SBFI, and IF groups, respectively. Statistically, for HZ heights, SBFI was different compared with CG and IF (P < 0.001), and, for HZ chondrocyte cell widths and heights, IF was different compared with CG and SBFI (P < 0.001). Conclusions: Morphometric analysis in this study supports the findings that SBFI preserves the growth potential of the spine. Furthermore, changes in the HZ heights show that distractive forces stimulate the apophyseal growth of the axial skeleton describing how the growth rate of the spine in GR might surpass the normal growth rate. Overall, although some degenerative changes are observed, SBFI and repeated distractions alone are not solely responsible for FJ arthrosis and disk degeneration, given that they are structurally preserved. Clinical Relevance: GR and regular lengthening procedures do not impair disk health and preserve the growth potential of the spine if it is applied with a meticulous technique. Copyright © 2013 by Lippincott Williams & Wilkins

Severe infantile hypotonia with ethylmalonic aciduria: Case report

An 8-month-old girl was admitted to an outpatient clinic with significant hypotonia and weakness. Organic acid analysis in urine revealed a significant increase in ethylmalonic acid. A deoxyribonucleic analysis revealed the presence of a 625G>A (G-to-A substitution at nucleotide 625) variant short-chain acyl-coenzyme A dehydrogenase gene polymorphism. With the clinical, biochemical and molecular findings, short-chain acyl-coenzyme A dehydrogenase deficiency was suspected. Because 625G>A and 511C>T (C-to-T substitution at nucleotide 511) genetic variations are also present in 14% of the general population, these are considered to be genetic sensitivity variations rather than causing a disease themselves and to result in possible short-chain acyl-coenzyme A dehydrogenase deficiency in the presence of environmental factors such as fever and hunger as well as cellular, biochemical, and other genetic factors. It was stressed that severe infantile hypotonia could also be the only manifestation of ethylmalonic aciduria spectrum disorders. \ua9 2008 Sage Publication