Analysis of the Light Transmission Ability of Reinforcing Glass Fibers Used in Polymer Composites

This goal of our research was to show that E-glass fiber bundles used for reinforcing composites can be enabled to transmit light in a common resin without any special preparation (without removing the sizing). The power of the transmitted light was measured and the attenuation coefficient, which characterizes the fiber bundle, was determined. Although the attenuation coefficient depends on temperature and the wavelength of the light, it is independent of the power of incident light, the quality of coupling, and the length of the specimen. The refractive index of commercially available transparent resins was measured and it was proved that a resin with a refractive index lower than that of the fiber can be used to make a composite whose fibers are capable of transmitting light. The effects of temperature, compression of the fibers, and the shape of fiber ends on the power of transmitted light were examined. The measurement of emitted light can provide information about the health of the fibers. This can be the basis of a simple health monitoring system in the case of general-purpose composite structures

Foszfor-hatások és -utóhatások vizsgálata erdőmaradványos csernozjom talajon beállított trágyázási tartamkísérletekben = Effects and after-effects of phosphorus in long-term fertilisation experiments on chernozem soil with forest residues

A kutatási program keretében erdőmaradványos csernozjom talajon beállított trágyázási tartamkísérletekben vizsgáltuk az N, P, és K-műtrágyák kombinációinak hatását, a foszfor utóhatását a kukoricára és az őszi búzára. A fenológiai felvételezések eredményei szerint az utóhatások vizsgálatára alkalmas parcellákon a gyenge foszfor-ellátottság három-öt nappal meghosszabbította a búza és 2-3 nappal a kukorica vegetatív periódusát. A későbbi kalászolás fokozza az őszi búza aszályérzékenységét, ugyanakkor az elhúzódó nővirágzás a kukoricában a szemtelítődési periódus időtartamára hathat negatívan. A P-trágyák hatásának és ?utóhatásának vizsgálatára alkalmas, N-nel is kezelt parcellákon a betakarított termés minősége nem különbözött szignifikánsan a csak N-nel trágyázott, igen gyenge-gyenge P-ellátottságú talajokon fejlődött növényekétől. A diagnosztikai célú növényanalízisek jól jellemezték a növények tápláltsági állapotát, ezáltal a P-utóhatások csökkenésének is megfelelő indikátorai voltak. Erősen meszes erdőmaradványos csernozjom talajon a kukorica termése dikultúrában a termesztés 14., az őszi búza mennyisége a termesztés 23. évét követően csökkent a P-trágyázatlan kontroll szintjére. Közepesen meszes erdőmaradványos csernozjom talajon a kukorica P-reakciója a vizsgálatok 22. évében mérséklődött a kontroll szintjére. Őszi búzában az utóhatás teljes megszűnése a relatív termésekhez illesztett logaritmusfüggvény paraméterei alapján a 36. évre prognosztizálható. | Within the framework of the project, the effect of various combinations of NPK fertilisers and the after-effect of P fertiliser were tested on maize and winter wheat grown in a long-term experiment set up on chernozem soil with forest residues. The results of phenological analysis showed that on plots suitable for the analysis of after-effects poor P supplies lengthened the vegetative period by 3?5 days in wheat and 2?3 days in maize. Later heading makes winter wheat more susceptible to drought, while protracted silking in maize may have a negative effect on the duration of the grain filling period. On plots treated with N and suitable for testing the effects and after-effects of P fertilisers the quality of the yield did not differ significantly from that of plants fertilised only with N on plots with poor or very poor P supply levels. Diagnostic plant analysis provided a clear picture of plant nutritional status and was thus a satisfactory indicator of the decline in P after-effects. On intensely calcareous chernozem soil with forest residues the maize yield in a maize?wheat diculture decreased to the level of the control plot given no P fertiliser after 14 years and that of wheat after 23 years. The P response of maize on moderately calcareous forms of this soil only decreased to the control level after 22 years. In winter wheat the after-effect could be expected to disappear completely after 36 years judging by the parameters of a log function fitted to the relative yield data

A novel mathematical model describing adaptive cellular drug metabolism and toxicity in the chemoimmune system

Cells cope with the threat of xenobiotic stress by activating a complex molecular network that recognizes and eliminates chemically diverse toxic compounds. This "chemoimmune system" consists of cellular Phase I and Phase II metabolic enzymes, Phase 0 and Phase III ATP Binding Cassette (ABC) membrane transporters, and nuclear receptors regulating these components. In order to provide a systems biology characterization of the chemoimmune network, we designed a reaction kinetic model based on differential equations describing Phase 0-III participants and regulatory elements, and characterized cellular fitness to evaluate toxicity. In spite of the simplifications, the model recapitulates changes associated with acquired drug resistance and allows toxicity predictions under variable protein expression and xenobiotic exposure conditions. Our simulations suggest that multidrug ABC transporters at Phase 0 significantly facilitate the defense function of successive network members by lowering intracellular drug concentrations. The model was extended with a novel toxicity framework which opened the possibility of performing in silico cytotoxicity assays. The alterations of the in silico cytotoxicity curves show good agreement with in vitro cell killing experiments. The behavior of the simplified kinetic model suggests that it can serve as a basis for more complex models to efficiently predict xenobiotic and drug metabolism for human medical applications

A spermium/petesejt együttműködés genetikai boncolása. = Genetic dissection of sperm and egg cell cooperation.

Munkánk célja az, hogy a Drosophila HimcaD, HorkaD valamint KompoltD domináns nőstény-steril mutációiból kiindulva molekuláris szinten ismerjük meg az ép Himca, Horka és Kompolt gének szerepét a megtermékenyülésben, az embriógenezis elkezdődésében. Megtudtuk, hogy (i) a Himca gén terméke az inozitol-1,4,5-trifoszfát (ITF) kináz enzim, amely a Ca2+ ionok belső raktárakból történő felszabadulásáért felelős. Úgy tűnik, hogy ITF hiányában a Ca2+ ion-hullámok elmaradása okozza a megtermékenyüléssel, a spermiumfarok elhelyezkedésével, illetve az embriógenezis elkezdődésével kapcsolatos problémákat. (ii) A Horka gén terméke a transzkripció-terminációs-faktor-2 (TTF2). A TTF2 úgy okoz abortív transzkripciót, hogy eltávolítja az RNS polimeráz-II-t a DNS-ről. A DNS-csip, valamint a Q-RT-PCR technika módszereivel arra derítettünk fény, hogy TTF2 hiányában - a HorkaD/+ és a horkanull/? hemizigóta nőstények petéiben - 54 olyan ép gén terméke bukkan fel, amelyek a vadtípusú petékben nincsenek jelen. A szokatlan géntermékek megmérgezik az embriókat. A HorkaD mutációból kiindulva a nőstény-sterilitás eddig ismeretlen típusára derítettünk fényt. (iii) Kompolt gén terméke egy olyan transzmembrán fehérje, amely többféle, több kópiában meglevő, és ismert domént tartalmaz. A doménoknak a spermium adhézióban, a sejt-sejt kölcsönhatásban, valamint a szingnáltranszdukcióban van szerepe. | We aimed to reveal molecular function of the Himca, Horka és Kompolt genes in fertilization and in the commencement of embryogenesis in Drosophila. The genes have been previously identified by the HimcaD, HorkaD and the KompoltD dominant female-sterile mutations. It has turned out that (i) product of the Himca gene is the inozitol-1,4,5-triphosphate (ITF) kinase enzyme. ITF is required for release of Ca2+ from the store sites. It appears that Ca2+ waves do not develop in absence of ITF that leads subsequently to abnormal sperm tail positioning in the egg cytoplasm, aberrant fertilization and the lack of commencement of embryogenesis. (ii) The Horka gene encodes the formation of transcription-termination-factor-2 (TTF2). TTF2 has been known to cause abortive transcription through the removal of RNA polymerase-II from the DNA. Making use of the DNA chip technology and the Q-RT-PCR technique we showed that in absence of TTF2 - in eggs of the HorkaD/+ and the horkanull/? hemizygous females - products of 54 genes appear in the egg cytoplasm that are missing in the wild type eggs. The unusual gene products poison the embryos. Starting from the HorkaD mutation we revealed a thus far unknown type of female sterility. (iii) Product of the Kompolt gene is a giant transmembrane protein that contains several copies of several known domains. The domains play role in sperm adhesion, cell-to-cell interaction and signal transduction

Jump into a new fold-A homology based model for the ABCG2/BCRP multidrug transporter

ABCG2/BCRP is a membrane protein, involved in xenobiotic and endobiotic transport in key pharmacological barriers and drug metabolizing organs, in the protection of stem cells, and in multidrug resistance of cancer. Pharmacogenetic studies implicated the role of ABCG2 in response to widely used medicines and anticancer agents, as well as in gout. Its Q141K variant exhibits decreased functional expression thus increased drug accumulation and decreased urate secretion. Still, there has been no reliable molecular model available for this protein, as the published structures of other ABC transporters could not be properly fitted to the ABCG2 topology and experimental data. The recently published high resolution structure of a close homologue, the ABCG5-ABCG8 heterodimer, revealed a new ABC transporter fold, unique for ABCG proteins. Here we present a structural model of the ABCG2 homodimer based on this fold and detail the experimental results supporting this model. In order to describe the effect of mutations on structure and dynamics, and characterize substrate recognition and cholesterol regulation we performed molecular dynamics simulations using full length ABCG2 protein embedded in a membrane bilayer and in silico docking simulations. Our results show that in the Q141K variant the introduced positive charge diminishes the interaction between the nucleotide binding and transmembrane domains and the R482G variation alters the orientation of transmembrane helices. Moreover, the R482 position, which plays a role the substrate specificity of the transporter, is located in one of the substrate binding pockets identified by the in silico docking calculations. In summary, the ABCG2 model and in silico simulations presented here may have significant impact on understanding drug distribution and toxicity, as well as drug development against cancer chemotherapy resistance or gout. © 2016 László et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Lipid Regulation of the ABCB1 and ABCG2 Multidrug Transporters

This chapter deals with the interactions of two medically important multidrug ABC transporters (MDR-ABC), ABCB1 and ABCG2, with lipid molecules. Both ABCB1 and ABCG2 are capable of transporting a wide range of hydrophobic drugs and xenobiotics and are involved in cancer chemotherapy resistance. Therefore, the exploration of their mechanism of action has major therapeutic consequences. As discussed here in detail, both ABCB1 and ABCG2 are significantly affected by various lipid compounds especially those residing in their close proximity in the plasma membrane. ABCB1 is capable of transporting lipids and lipid derivatives, and thus may alter the general membrane composition by "flopping" membrane lipid constituents, while there is no such information regarding ABCG2. Still, both ABCB1 and ABCG2 show complex interactions with a variety of lipid molecules, and the transporters are significantly modulated by cholesterol and cholesterol derivatives at the posttranslational level. In this chapter, we explore the molecular details of the direct transporter-lipid interactions, the potential role of lipid-sensor domains within the proteins, as well as the application of experimental site-directed mutagenesis, detailed structural studies, and in silico modeling for examining these interactions. We also discuss the regulation of ABCB1 and ABCG2 expression at the transcriptional level, occurring through nuclear receptors involved in lipid sensing. The better understanding of lipid interactions with these medically important MDR-ABC transporters may significantly improve further drug development and clinical treatment options