Predicting bioavailability of PAHs in field-contaminated soils by passive sampling with triolein embedded cellulose acetate membranes

Triolein embedded cellulose acetate membrane (TECAM) was used for passive sampling of the fraction of naphthalene, phenanthrene, pyrene and benzo[a]pyrene in 18 field -contaminated soils. The sampling process of PAHs by TECAM fitted well with a first-order kinetics model and PAHs reached 95% of equilibrium in TECAM within 20 h. Concentrations of PAHs in TECAM (C-TECAM) correlated well with the concentrations in soils (r(2) = 0.693-0.962, p < 0.001). Furthermore. concentrations of PAHs determined in the soil solution were very close to the values estimated by C-TECAM and the partition coefficient between TECAM and water (KTECAM-W). After lipid normalization nearly 1:1 relationships were observed between PAH concentrations in TECAMs and earthworms exposed to the soils (r(2) = 0.591-0.824, n = 18, p < 0.01). These results suggest that TECAM can be a useful tool to predict bioavailability of PAHs in field-contaminated soils. (C) 2008 Elsevier Ltd. All rights reserved

Uptake and acropetal translocation of polycyclic aromatic hydrocarbons by wheat (Triticum aestivum L.) grown in field-contaminated soil

Uptake and acropetal translocation of 14 priority polycyclic aromatic hydrocarbons (PAHs) by wheat (Triticum aestivum L.) grown in 15 field-contaminated soils were investigated in a growth chamber. PAN concentrations in roots correlated positively with the corresponding concentrations in soils and negatively with the contents of soil organic carbon (p < 0.01). No clear linear relationship was found between log RCF (root concentration factor, mu g g(-1)root/mu g g(-1)soil on dry weight basis) and log K(ow) of these PAHs. Four-ring PAHs had the highest tendency to be taken up by roots. PAH concentrations in shoots correlated well with their concentrations in soils and roots. Furthermore, distribution profiles of PAHs in shoots were fairly similar to those in soils. Acropetal translocation of 10 PAHs (with log K(ow) varying from 3.45 to 5.78) was also implicated by R(t) (ratio of PAH from root-to-shoot translocation to the total accumulation in shoots) ranging from 53.6 to 72.6%. A negative linear relationship was found between log R(t) and log K(ow) of these PAHs (p < 0.01), and acropetal translocation of PAHs depended on their chemical properties

DEM simulation of the mechanical properties of SiC ceramic under pre-stressing

In this paper, the method of discrete element model (DEM) simulation was used to investigate the mechanical properties of SiC ceramic materials under the action of pre-stress. Using the bonded particle model (BPM), several different numerical tests (such as UCT, TPB, SENB tests) of SiC ceramic were established. Different pre-stress values were applied on the lateral surface of the ceramic specimen during the numerical simulation process, all tests were carried out at least 5 times with different random number, and the average mechanical properties results were calculated. It was showed that the existence of pre-stress has a significant effect on the mechanical properties of materials. It can enhance the strength of materials, while the force action on material in machining process force or action force the crack’s initiation and propagation was limited

Identification of a candidate gene for Rc-D1, a locus controlling red coleoptile colour in wheat

Red coleoptile is an easily observed agronomic trait of wheat and has been extensively studied. However, the molecular mechanism of this trait has not yet been revealed. In this study, the MYB gene TaMYB-D1 was isolated from the wheat cultivar ‘Gy115’, which possesses red coleoptiles. This gene resided at the short arm of the homoelogous group 7 chromosomes. TaMYB-D1 was the only gene expressed in the coleoptiles of ‘Gy115’ and was not expressed in ‘Opata’ and ‘CS’, which have uncoloured coleoptiles. Phylogenetic analysis placed TaMYB-D1 very close to ZmC1 and other MYB proteins regulating anthocyanin biosynthesis. The encoded protein of TaMYB-D1 had an integrated DNA binding domain of 102 amino acids and a transcription domain with 42 amino acids, similar to the structure of ZmC1. Transient expression analysis in onion epidermal cells showed that TaMYB-D1 was located at the plant nucleus, which suggested its role as a transcription factor. The expression of TaMYB-D1 was accompanied with the expression of TaDFR and anthocyanin biosynthesis in the development of the coleoptile of ‘Gy115’. Transient expression analysis showed that only TaMYB-D1 induced a few ‘Opata’ coleoptile cells to synthesize anthocyanin in light, and the gene also induced a colour change to red in many cells with the help of ZmR. All of these results suggested TaMYB-D1 as the candidate gene for the red coleoptile trait of ‘Gy115’

Charge-order melting and magnetic phase separation in thin films of Pr0.7Ca0.3MnO3

Quantum Matter and Optic

First-order nature of a metamagnetic transition and mechanism of giant magnetoresistance in Mn2Sb0.95Sn0.05

Quantum Matter and Optic

Plasmid encoding matrix protein of vesicular stomatitis viruses as an antitumor agent inhibiting rat glioma growth in situ

Aim: Oncolytic effect of vesicular stomatitis virus (VSV) has been proved previously. Aim of the study is to investigate glioma inhibition effect of Matrix (M) protein of VSV in situ. Materials and Methods: A recombinant plasmid encoding VSV M protein (PM) was genetically engineered, and then transfected into cultured C6 gliomas cells in vitro. C6 transfected with Liposome-encapsulated PM (LEPM) was implanted intracranially for tumorigenicity study. In treatment experiment, rats were sequentially established intracranial gliomas with wild-typed C6 cells, and accepted LEPM injection intravenously. Possible mechanism of M protein was studied by using Hoechst staining, PI-stained flow cytometric analysis, TUNEL staining and CD31 staining. Results: M protein can induce generous gliomas lysis in vitro. None of the rats implanted with LEPM-treated cells developed any significant tumors, whereas all rats in control group developed tumors. In treatment experiment, smaller tumor volume and prolonged survival time was found in the LEPM-treated group. Histological studies revealed that possible mechanism were apoptosis and anti-angiogenesis. Conclusion: VSV-M protein can inhibit gliomas growth in vitro and in situ, which indicates such a potential novel biotherapeutic strategy for glioma treatment.Цель: изучить способность матриксного протеина (М протеина) вируса везикулярного стоматита (ВВС) угнетать рост глиомы in situ. Материалы и методы: сконструирована рекомбинантная плазмида, кодирующая М протеин ВВС, которая затем была трансфецирована в культивированные клетки глиомы С6 in. Клетки глиомы С6, трансфецированные инкапсулированным в липосомы М протеином (ЛИМП), имплантировали интракраниально для изучения туморогенности. В эксперименте крысам с трансплантированной интракраниально глиомой С6 (исходный штамм) внутривенно вводили ЛИМП. Апоптотическое действие М протеина на опухолевые клетки изучали с применением флуоресценцентной микроскопии (окрашивание по Хехсту), проточной цитометрии (окрашивание пропидиумом йодидом), TUNEL васкуляризацию опухоли оценивали гистологически и васкуляризацию опухоли оценивали гистологически и иммуногистохимически с применением анти-CD31 моноклональных антител. 31 моноклональных антител. 31 моноклональных антител. Результаты: М протеин может индуцировать лизис клеток глиомы in. Ни у одного животного с трансплантированными клетками глиомы, обработанными ЛИМП, не возникали опухоли значительного размера, тогда как у всех крыс из контрольной группы опухоли развивались. В группе животных, которым вводили ЛИМП, опухоли были меньшего объема и отмечали увеличение продолжительности жизни животных. Показано, что М протеин проявляет антиангиогенные свойства и обладает способностью индуцировать апоптоз. Выводы: М протеин ВВС ингибирует рост глиомы in и in. На этой основе может быть разработана потенциально новая биотерапевтическая стратегия для лечения пациентов с глиомами

Defect-induced charge-order melting in thin films of Pr0.5Ca0.5MnO3

Quantum Matter and Optic