Design and Lipase Catalyzed Synthesis of 4-Methylcoumarin-siloxane Hybrid Copolymers

Poly dimethylsiloxanes with amino end groups were copolymerized with diesters of 4-methylcoumarins enzymatically using a lipase (Candida antarctica lipase) as a biocatalyst. In a separate synthesis, 4-methylcoumarin was also incorporated into the poly siloxanes-isophthalate copolymers by functionalization of hydroxyl groups in the isophthalate moiety. The synthesis and characterization of two sets of novel copolymers are presented. The thermal and flammability properties of these polymers have also been studied using TGA and microcalorimetry, respectively.     

Doped SiO x emitter layer in amorphous/crystalline silicon heterojunction solar cell

In this work we propose to replace the emitter layer of the n-type doped a-Si:H/p-type doped crystalline silicon heterojunction solar cell, with an n-type doped SiO _x amorphous oxide layer. The n-type doped SiO _x :H shows a lower activation energy and higher carrier mobility value with respect to the n-type doped a-Si:H. Moreover, higher transmission, below 500 nm of wavelength, and higher conductivity are measured. The relevance of transparency of the (n) a-SiO _x :H has been studied using that film in solar cells. The electrical parameters revealed a solar cell efficiency of 15.8 %. Moreover, the effect of TCO as a front side cell electrode is considered and discussed on the base of its workfunction when applied on top of the n-type doped SiO _x emitter layer using also numerical simulations.     

Cord blood metabolomic profiling in intrauterine growth restriction

A number of metabolic abnormalities have been observed in pregnancies complicated by intrauterine growth restriction (IUGR). Metabolic fingerprinting and clinical metabolomics have recently been proposed as tools to investigate individual phenotypes beyond genomes and proteomes and to advance hypotheses on the genesis of diseases. Non-targeted metabolomic profiling was employed to study fetal and/or placental metabolism alterations in IUGR fetuses by liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis of cord blood collected soon after birth. Samples were collected from 22 IUGR and 21 appropriate for gestational age (AGA) fetuses. Birth weight differed significantly between IUGR and AGA fetuses (p < 0.001). Serum samples were immediately obtained and deproteinized by mixing with methanol at room temperature and centrifugation; supernatants were lyophilized and reconstituted in water for analysis. LC-HRMS analyses were performed on an Orbitrap mass spectrometer linked to a Surveyor Plus LC. Samples were injected into a 1.0 × 150-mm Luna C18 column. Spectra were collected in full-scan mode at a resolution of approximately 30,000. Data were acquired over the m/z range of 50–1,000, with measurements performed in duplicate. To observe metabolic variations between the two sets of samples, LC-HRMS data were analyzed by a principal component analysis model. Many features (e.g., ionic species with specific retention times) differed between the two classes of samples: among these, the essential amino acids phenylalanine, tryptophan, and methionine were identified by comparison with available databases. Logistic regression coupled to a receiver-operating characteristic curve identified a cut-off value for phenylalanine and tryptophan, which gave excellent discrimination between IUGR and AGA fetuses. Non-targeted LC-HRMS analysis of cord blood collected at birth allowed the identification of significant differences in relative abundances of essential amino acids between IUGR and AGA fetuses, emerging as a promising tool for studying metabolic alterations.     

Accidental exposure to UV radiation produced by germicidal lamp: case report and risk assessment

Ultraviolet radiation is known to cause both benefits and harmful effects on humans. The adverse effects mainly involve two target organs, skin and eye, and can be further divided into short- and long-term effects. The present case report describes an accidental exposure of two health-care workers to ultraviolet radiation produced by a germicidal lamp in a hospital pharmacy. The germicidal lamp presented a spectrum with an intense UV-C component as well as a modest UV-B contribution. Overexposure to UV-C radiation was over 100 times as large as the ICNIRP exposure limits. A few hours after the exposure, the two subjects reported symptoms of acute UV injury and both of them continued having significant clinical signs for over 2 years. In this study, we describe acute and potentially irreversible effects caused by high UV exposure. In addition, we present the results of risk assessment by occupational exposure to germicidal lamps.