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Assessing OBT formation and enrichment: ROS signaling is involved in the radiation hormesis induced by tritium exposure in algae

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JOURNAL OF HAZARDOUS MATERIALS 2023年第PT A期443卷 130159页

作者： Huang, Yan Qin, Min Lai, Jinlong Liang, Juncheng Luo, Xuegang Li, chen Southwest Univ Sci & Technol Sch Life Sci Mianyang 621010 Peoples R China Natl Inst Metrolggy Beijing 100013 Peoples R China Southwest Univ Sci & Technol Engn Res Ctr Biomass Mat Minist Educ Mianyang 621010 Peoples R China Shaanxi Univ Technol Coll Chem & Environm Sci Hanzhong 723000 Peoples R China

Tritium is the main component of radioactive wastewater from nuclear power plants and can be migrated into organisms to form organically bound tritium (OBT), which may pose a potential risk to aquatic ecosystem. Hence, it is essential to monitor OBT conversion in the presence of tritium exposure. In this study, the effects of pretreatment methods such as digestion on the recovery of tritium were discussed. It was found that microwave digestion pretreatment could improve the recovery of tritium by up to 90 % and allow OBT measurement with a small sample size equivalent to about 60 mg (dry weight). In addition, the efficiency of OBT transformation was different among biological samples, and the radiation hormesis phenomenon was induced by tritium exposure (3.7 x 106 Bq/L) in microalgae chlorella vulgaris(c. vulgaris). The tritium exposure may induce radiation hormesis through the reactive oxygen species (ROS) signaling pathway, thus improving the photosynthetic ca-pacity and metabolism level of c. vulgaris. Furthermore, enhancement of photorespiration metabolism and the antioxidation system may be important means for c. vulgaris to balance damage by tritium radiation. This study provides insights for further investigating OBT behavior, and will contribute to understanding the equilibrium damage mechanism of algae exposed to tritium.

关键词： Tritium OBT c vulgaris Microwave digestion Radiation hormesis

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Structural, mechanical, and in vitro characterization of freeze-cast scaffolds prepared using a sol-gel-derived bioactive glass from the SiO2-caO-Na2O-P2O5-K2O-MgO system

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cERAMIcS INTERNATIONAL 2023年第2期49卷 2183-2193页

作者： Fantecelle, Francisco B. dos Santos, Diogo M. M. Barrioni, Breno R. Pereira, Marivalda M. Alcamand, Himad A. Laper, Miguel L. Houmard, Manuel Nunes, Eduardo H. M. Univ Fed Minas Gerais Escola Engn Ave Presidente Antonio Carlos 6627 BR-31270901 Belo Horizonte MG Brazil Univ Fed Vales Jequitinhonha & Mucuri UFVJM Inst Engn Ciencia & Tecnol IECT Campus JanaubiAve Um 4-050 Cidade Univ BR-39447814 Janauba MG Brazil Ctr Tecnol Nanomat & Grafeno CTNano R Prof Jose Vieira de Mendonca 520 BR-31310260 Belo Horizonte MG Brazil

This work deals with the preparation of freeze-cast scaffolds using a bioactive glass from the SiO2-caO-Na2O-P2O5-K2O-MgO system. This material could be sintered at lower temperatures (650 degrees c) than other variations of bioactive glasses, which is an important advantage in terms of energy and cost savings. This behavior represents a great advantage in terms of energy and cost savings. The freeze-casting step was conducted using water as a solvent and liquid nitrogen as a coolant. The prepared samples were examined according to their pore structure, thermal behavior, mechanical stability, and bioactivity. The glass transition temperature (Tg), crystallization onset temperature (Tx), and maximum crystallization temperature (Tc) evaluated for this bioactive glass were about 660 degrees c, 690 degrees c, and 705 degrees c. consequently, the freeze-cast scaffolds could be sintered at 650 degrees c for 2-8 h, which favored viscous flow sintering without crystallization. Bioactivity assays were conducted by soaking the scaffolds in simulated body fluid for up to 21 days, showing that these materials present a bioactive behavior, inducing hydroxyapatite formation. These materials' mechanical properties and biocompatibility make them promising candidates for use in trabecular bone repair.

关键词： A Sintering B Porosity c Mechanical properties E Biomedical applications

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Determining the toxicity of organic compounds to the nematode caenorhabditis elegans based on aqueous concentrations

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第42期30卷 96290-96300页

作者： Hoess, Sebastian Sanders, David van Egmond, Roger Ecossa Giselastr 6 D-82319 Starnberg Germany Unilever Safety & Environm Assurance Ctr Colworth Sci Pk Bedford MK44 1LQ England

caenorhabditis elegans is used for assessing the toxicity of chemicals in aqueous medium. However, chemicals can absorb to the bacterial food, which reduces the freely dissolved concentrations of the tested compounds. Thus, based on total or nominal concentrations, toxicity is underestimated, resulting in misleading assumptions on toxicity mechanisms or comparisons to other test organisms. As the verification of freely dissolved exposure concentrations (c-free) is challenging in small test systems, simple partitioning models might by a good option for estimating c-free. Therefore, c. elegans was exposed to seven differently acting organic chemicals with varying hydrophobicities, thus also different affinities to bind to the food of c. elegans. Measured concentrations of the dissolved aqueous and the bacterial-bound fraction allowed the calculation of binding constants (K-b). Experimental K-b were comparable to literature data of hydrophobic chemicals and correlated well with their hydrophobicity, expressed as log K-OW. The chronic toxicity of the various compounds on c. elegans' reproduction, based on their aqueous concentration, was weakly related to their log K-OW. Toxicity expressed based on chemical activity and comparisons with a baseline toxicity model, nevertheless, suggested a narcotic mode of action for most hydrophobic compounds (except methylisothiazolinone and trichlorocarbanilide). Although revealing a similar toxicity ranking than Daphnia magna, c. elegans was less sensitive, probably due to its ability to reduce its internal concentrations by means of its very impermeable cuticle or by efficient detoxification mechanisms. It could be shown that measured aqueous concentrations in the nematode test system corresponded well with freely dissolved concentrations that were modeled using simple mass-balance models from nominal concentrations. This offers the possibility to estimate freely dissolved concentrations of chemicals from nominal concentrations, mak

关键词： c elegans Aquatic toxicity testing Organic chemicals Freely dissolved concentrations

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Prediction of gas product yield from packaging waste pyrolysis: support vector and Gaussian process regression models

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INTERNATIONAL JOURNAL OF ENVIRONMENTAL ScIENcE AND TEcHNOLOGY 2023年第1期20卷 461-476页

作者： Yapici, E. Akgun, H. Ozkan, K. Gunkaya, Z. Ozkan, A. Banar, M. Eskisehir Tech Univ Fac Engn Dept Environm Engn TR-26555 Eskisehir Turkey Eskisehir Osmangazi Univ Fac Engn & Architecture Dept Comp Engn Eskisehir Turkey

The pyrolysis process enables the transformation of plastic waste into products such as oil, solid residue, and gas at temperatures of around 300-900 degrees c by thermal decomposition. conversion of such waste into valuable products depends on various factors, such as raw material composition, temperature, heating rate, residence time, and catalyst. From this point of view, in this study, predictions of gas product yield based on different pyrolysis conditions including waste types (LDPE-c/LDPE), temperature (400-600-800 degrees c), heating rate (5-10-20 degrees c/min), type of catalyst (zeolite-clay-sludge) and amount of catalyst (5%, 10%, 15%, by weight) were carried out with support from the vector regression (SVR) and the Gaussian process (GPR) models using the results of experimental studies performed under various conditions. Different kernel functions were used for SVR (Linear, Quadratic, cubic, Gaussian) and GPR (Squared Exponential, Matern 5/2, Exponential, Rational Quadratic). The Gaussian Kernel Function presented a good prediction performance (89% R-2 and 0.0011 RMSE) for SVR while the Exponential Kernel Function was the most appropriate for GPR (93% R-2 and 0.0011 RMSE). On the other hand, the deviations in the SVR model with linear Kernel change over a wide range of 0.25-80.85%, and the GPR model with exponential kernel show deviations close to each other in the range of 0.06-3.91%. The present study provides new information for future studies by understanding the pyrolysis process of plastic waste and predicting product yield.

关键词： c LDPE Gaussian process regression LDPE Pyrolysis Support vector regression

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Photoluminescence of SiO2:Eu and SiON:Eu films: color selection through activating emissions from SiOx, Eu3+, and Eu2+

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cERAMIcS INTERNATIONAL 2023年第11期49卷 16673-16680页

作者： Akazawa, Housei Nishi, Hidetaka NTT Corp NTT Device Innovat Ctr 3-1 Morinosato Wakamiya Atsugi Kanagawa 2430198 Japan NTT Corp NTT Device Technol Labs 3-1 Morinosato Wakamiya Atsugi Kanagawa 2430198 Japan

Photoluminescence (PL) from Eu-doped SiO2 (SiON) thin films sputter-deposited in O2, H2O vapor, or a mixture of O2 and N2 gases was characterized by excitation at a wavelength of 325 nm. The SiO2 films deposited at 500 degrees c with O2 contained small amount of alpha-quartz nanocrystals. The primary condition for either or both of the Eu3+ and Eu2+ emissions to appear was Eu content between 1 and 3 at.%, and 2.5 at.% gave the maximum emission intensity of Eu3+. The PL spectra showed only the Eu3+ emission when the films were deposited at room tem-perature (RT) and subsequently post annealed in an O2 atmosphere. changing the annealing atmosphere from O2 to a vacuum and annealing at temperatures above 600 degrees c resulted in an intense broad violet emission signal peaking at 390 nm along with the Eu3+ emission signal. This violet emission originated from reduced SiOx species. When deposited at RT, similar temperature-dependent emission properties were obtained regardless of the reactive gas (H2O vapor or a mixture of O2 and N2). complete transformation of Eu3+ into Eu2+ occurred when deposition was carried out at temperatures between 400 and 500 degrees c;a blue emission at around 467 nm was predominant from the SiO2:Eu2+ films. Deposition in the O2 and N2 gas mixture at elevated temperatures pro-duced SiON:Eu2+ films, from which an intense white emission band peaking at 525 nm and ranging between 400 and 650 nm was observed.

关键词： A Films B Spectroscopy c Optical properties D SiO2

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PMMA composite bone cement containing bioactive and ferrimagnetic glass-ceramic particles: Effect of temperature and of the additional phase on some physical and mechanical properties

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cERAMIcS INTERNATIONAL 2023年第15期49卷 24885-24894页

作者： Miola, Marta Barberis, Fabrizio Lagazzo, Alberto Verne, Enrica Politecn Torino Dept Appl Sci & Technol Cso Duca Abruzzi 24 I-10129 Turin Italy Univ Genoa Dept Civil Chem & Environm Engn Via allOpera Pia 15 I-16145 Genoa Italy

In this work, PMMA-based composite bone cements, embedding bioactive and ferrimagnetic glass-ceramic particles, have been prepared and characterized. Bioactivity, wettability, density, curing parameters, viscoelastic behaviour, bending strengths and creep have been investigated at 37 degrees c. The growth of a layer of HA on the samples surface after immersion in SBF has been confirmed. The presence of glass-ceramic particles improved the wetting behaviour of the composite cements. Shorter curing times and lower maximum temperatures for the three composite cements, in comparison to the plain one, have been detected. Almost unaffected mechanical properties of the composite bone cements have been found in comparison to those of the plain commercial cement both at room and at 37 degrees c. A little increase of the viscous flow has been evidenced in the composite samples at 37 degrees c. Radiographic imaging confirmed the intrinsic radiopacity of the composite cements.

关键词： B composites c Mechanical properties D Glass ceramics E Biomedical applications Hyperthermia

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Special color change mechanism of Disperse Red 60 in alkaline dyeing system

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TEXTILE RESEARcH JOURNAL 2023年第3-4期93卷 807-816页

作者： Ai, Li Zhu, Yawei Wuhan Text Univ Hubei Key Lab Biomass Fibers & Ecodyeing & Finish Wuhan Peoples R China Soochow Univ Coll Text & Clothing Engn Suzhou Peoples R China

color Intex (c.I.) Disperse Red 60 is a bright red anthraquinone dye, but it is easy to produce dyeing defects (a kind of discoloration phenomenon, the partial color is random blue patches) in the polyester dyeing process, and the mechanism of blue patches is unknown, resulting in a low right-one-time of dyeing. To investigate the mechanism of this particular color change, the interaction between c.I. Disperse Red 60 and borax was investigated by absorbance, and samples with blue patches were prepared;the presence of B-N bonds was confirmed by testing the X-ray Photoelectron Spectroscopy (XPS) of the dyed samples. The functional additive LV200 (a polymer containing polyester and polyether) was selected to control the interaction between the Disperse Red 60 and LV200. The results showed the co-existence of the red component (1-amino-2-phenoxy-4-hydroxy-9,10-anthraquinone) and the blue component (1-amino-2-phenoxy-10-hydroxy-4,9-anthraquinone) of Disperse Red 60 was the main reason for the random blue patches (dye defects) during the dyeing process of c.I. Disperse Red 60. By using the functional auxiliary LV200 and the H-bonding of the polar group of the dye, the conversion of the red and blue components of the reciprocal isomers can be controlled, and both bright red polyester-dyed fabrics and purplish red polyester-dyed fabrics can be produced. This provides a theoretical guide to improving the dyeing authentic rate of c.I. Disperse Red 60.

关键词： Polyester fiber disperse dyes c I Disperse Red 60 1-amino anthraquinone isomers dyeing defects

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Effect of eco-friendly probiotics-supplemented rapeseed meal-based diet on the performance of catlacatla fingerlings

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第44期30卷 99219-99230页

作者： Shahzad, Muhammad Mudassar Hussain, Syed Makhdoom Hussain, Majid Ahmad, Naveed Tahir, Laraib Akhtar, Kalsoom Univ Educ Dept Zool Div Sci & Technol Lahore Pakistan Govt Coll Univ Dept Zool Lahore Pakistan Univ Okara Dept Zool Okara Pakistan Univ Educ Dept Zool Vehari Campus Vehari Pakistan

Ever-increasing human population compels the researchers to search for alternative food sources such as fish meat. For increase of fish growth and proper feed utilization, probiotics were added in rapeseed meal-based diet in current trial for proper digestion and absorption of nutrients in fish and ultimately higher growth with lower aquatic pollution. Fish gut microbiota is important for the feed utilization and absorption in body for higher growth. A 70-day study was conducted to investigate the effects of probiotics-supplemented rapeseed meal-based diet on growth performance, digestibility of nutrients, and absorption of minerals in catlacatla fingerlings with lowering water pollution level. Six test diets were prepared by using different levels of multi-strain probiotics i.e. 0, 1, 2, 3, 4 and 5 g/kg (0.0-0.5%) in rapeseed meal-based diet. At the rate of 4% of live wet weight, catla fingerlings were fed two times a day and faeces samples from each tank were collected. According to the results, it was observed that probiotics supplementation (@2 g/kg) in rapeseed meal-based diet resulted with improvement in nutrient digestibility (cP, 72%;fat, 75% and GE, 70%), mineral absorption (ca, 72%;Na, 76%;K, 70% and P, 70%), specific growth rate (SGR, 1.55), improved feed conversion ratio (FcR, 1.22) and weight gain percentage (WG%, 303%) of fingerlings. It was also noticed that probiotics supplementation decreased the discharge of minerals and nutrient through faeces, as compared to control diet;hence, it plays a significant role in reducing water pollution. On the basis of these results, it was concluded that probiotics inclusion at level of 2 g/kg was useful to formulate the cost effective and eco-friendly fish feed with the maximum improvement in growth and fish health by using rapeseed meal-based diet, as compared to control and other test diets.

关键词： Rapeseed meal Probiotics c catla Growth performance Nutrient digestibility Mineral absorption

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Investigation on the effect of carbon on clustering of defects in tungsten by first principles calculations

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MATERIALS TODAY cOMMUNIcATIONS 2023年 35卷

作者： Wen, Shulong Lv, YiNi Pan, Min Huang, Zheng Wang, Jiaming Han, Lei Zhao, Yong Deng, Huiqiu Southwest Jiaotong Univ Sch Elect Engn Chengdu 610031 Peoples R China Hunan Univ Sch Phys & Elect Changsha 410082 Peoples R China

carbon (c) impurity would be inevitably introduced in the process of industrial-scale tungsten production. In this work, by using the first-principles density functional theory, the c atom behaviors in tungsten lattice and the effect of c atom on defects clustering have been studied systematically. calculation results show that c atom prefers to occupy the octahedral interstitial site of the tungsten lattice, the migration barrier energy of c atom is 1.46 eV along the optimal pathway. Both vacancy cluster and c atom can form stable complex structure according to the attractive interaction, and c atom promotes the nucleation of the vacancy cluster. The growth mechanism shows that vacancy clusters are more likely to grow by combining a cluster rather than a single vacancy, where c atom plays a positive role of promoting vacancy clusters nucleation. In addition, c atom can cause tungsten lattice distortion and lead to the formation of the potential well, which prompts SIA rapidly diffuse toward it and forms a SIA-c complex structure. The calculation results of the nucleation rate indicate that c atom can enlarge the effective radius of the 2SIA cluster, and enhance the nucleation rate of 3SIA cluster. Therefore, we conjecture that the c atom can inhibit the recovery of the Frenkel pair and weaken the self-repair of the tungsten materials under irradiation. These results are meaningful for further understanding the mechanism of the effect of c impurity for the defects evolution of irradiation defects of W-based material.

关键词： Tungsten Defects evolution First-principles calculations c

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Multigenerational effects of co-exposure to dimethylarsinic acid and polystyrene microplastics on the nematode caenorhabditis elegans

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第36期30卷 85359-85372页

作者： Muller, Larissa Josende, Marcelo Estrella Soares, Gabriela correa Monserrat, Jose Maria Ventura-Lima, Juliane Univ Fed Rio Grande FURG Inst Ciencias Biol ICB Av ItaliaKm 08 BR-96201900 Rio Grande RS Brazil Programa Posgrad Ciencias Fisiol FURG Rio Grande RS Brazil

In the current study, we assessed the impact of DMA (dimethylarsinic acid) and MPs (microplastics) interactions in c. elegans over the course of five generations. We found that the redox state of the organisms changed over generations as a result of exposure to both pollutants. From the third generation onward, exposure to MPs reduced GST activity, indicating reduced detoxifying abilities of these organisms. Additionally, dimethylarsinic exposure decreased the growth of organisms in the second, fourth, and fifth generations. In comparison to isolated pollutants, the cumulative effects of co-exposure to DMA and MPs seem to have been more harmful to the organisms, as demonstrated by correlation analysis. These findings demonstrate that DMA, despite being considered less hazardous than its inorganic equivalents, can still have toxic effects on species at low concentrations and the presence of MPs, can worsen these effects.

关键词： c elegans Multigenerational Dimethylarsinic acid Microplastic co-exposure Ecotoxicology

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