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Nanosized Hf6Ta2O17 particles reinforced Hfc ceramic coating for high temperature applications

JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2023年第8期43卷 3043-3052页

作者： Feng, Guanghui Yu, Yulan Yao, Xiyuan Wu, Xiaopeng Zhang, Hao Jia, Yujun Li, Hejun Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite M Xian 710072 Peoples R China

There is an urgent need for the thermal protection of carbon/carbon composites to increase their service span in aerospace field. As members of ultra-high temperature ceramics, Hfc and Zrc are thought to be alternative materials, but their poor oxidation behavior and fracture toughness at temperature over 2000 degrees c prevent them from taking full advantages. Herein, we synthesized nanosized Hf6Ta2O17 powders and introduced them into Hfc ceramic to tackle the above problems. Plasma-sprayed Hfc coatings with Hf6Ta2O17 varied from 0 to 15 mol.% (0, 1.25, 2.5, 5, 15) were exposed to an oxyacetylene torch with a heat flux of 2.38 MW/m2. The one with 2.5 mol.% Hf6Ta2O17 showed the best ablation resistance. Smaller doping was unable to effectively hinder oxygen diffusion given the inadequate compactness of the formed scale, conversely substantial humps and ruptures formed on the samples with higher amounts, acting as straightforward paths for oxygen.

关键词： Sol-gel Plasma spraying c c composites Ablation resistance

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Kinetic and thermodynamic studies of novel acid phosphatase isolated and purified from carthamus oxyacantha seedlings

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INTERNATIONAL JOURNAL OF BIOLOGIcAL MAcROMOLEcULES 2023年第1期224卷 20-31页

作者： Zaman, Umber Khan, Shahid Ullah Hendi, Awatif A. Rehman, Khalil Ur Badshah, Syed Refat, Moamen S. Alsuhaibani, Amnah Mohammed Ullah, Kalim Wahab, Abdul Gomal Univ Inst Chem Sci Dera Ismail Khan Pakistan Khyber Med Univ KPK Women Med & Dent Coll Dept Biochem Peshawar Pakistan Natl Key Lab Crops Genet & Improvement Wuhan Peoples R China Princess Nourah bint Abdulrahman Univ Coll Sci Dept Phys POB 84428 Riyadh 11671 Saudi Arabia Taif Univ Coll Sci Dept Chem POB 11099 Taif 21944 Saudi Arabia Princess Nourah bint Abdulrahman Univ Coll Educ Dept Phys Sport Sci POB 84428 Riyadh 11671 Saudi Arabia Kohat Univ Sci & Technol Dept Zool Kohat Khyber Pakhtunk Pakistan Kohat Univ Sci & Technol Dept Pharm Kohat Khyber Pakhtunk Pakistan

Acid phosphatase (AcP) is a key enzyme in the regulation of phosphate feeding in plants. In this study, a new AcP from c. oxyacantha was isolated to homogeneity and biochemically described for the first time. Specific activity (283 nkat/mg) was found after 2573 times purification fold and (17 %) yield. Using SDS-PAGE under denaturing and nondenaturing conditions, AcP was isolated as a monomer with a molecular weight of 36 kDa. Lc-MS/MS confirmed the presence of this band, suggesting that c. oxycantha AcP is a monomer. The enzyme could also hydrolyze orthophosphate monoester with an optimal pH of 5.0 and a temperature of 50 degrees c. Ther-modynamic parameters were also determined (Ea, Delta H degrees, Delta G degrees, and Delta S degrees). AcP activity was further studied in the presence of cysteine, DTT, SDS, EDTA, beta-ME, Triton-X-100 H2O2, and PMSF. The enzyme had a Km of 0.167 mM and an Ea of 9 kcal/mol for p-nitrophenyl phosphate. The biochemical properties of the c. oxyacantha enzyme distinguish it from other plant acid phosphatases and give a basic understanding of AcP in c. oxyacantha. The results of this investigation also advance our knowledge about the biochemical significance of AcP in c. oxyacantha. Thermal stability over a wide pH and temperature range make it more suitable for use in harsh industrial environments. However, further structural and physiological studies are anticipated to completely comprehend its important aspects in oxyacantha species.

关键词： Isolation Purification Acid phosphatase c oxyacantha Seeds

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See the Unseen: Red-Emissive carbon Dots for Visualizing the Nucleolar Structures in Two Model Animals and In Vivo Drug Toxicity

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SMALL 2023年第31期19卷 2205890-2205890页

作者： Xu, Ke-Fei Jia, Hao-Ran Wang, Zihao Feng, Hui-Heng Li, Ling-Yi Zhang, Rufeng Durrani, Samran Lin, Fengming Wu, Fu-Gen Southeast Univ Sch Biol Sci & Med Engn State Key Lab Bioelect 2 Sipailou Rd Nanjing 210096 Peoples R China

Nucleolus, which participates in many crucial cellular activities, is an ideal target for evaluating the state of a cell or an organism. Here, bright red-emissive carbon dots (termed cPcDs) with excitation-independent/polarity-dependent fluorescence emission are synthesized by a one-step hydrothermal reaction between congo red and p-phenylenediamine. The cPcDs can achieve wash-free, real-time, long-term, and high-quality nucleolus imaging in live cells, as well as in vivo imaging of two common model animals-zebrafish and caenorhabditis elegans (c. elegans). Strikingly, cPcDs realize the nucleolus imaging of organs/flowing blood cells in zebrafish at a cellular level for the first time, and the superb nucleolus imaging of c. elegans suggests that the germ cells in the spermatheca probably have no intact nuclei. These previously unachieved imaging results of the cells/tissues/organs may guide the zebrafish-related studies and benefit the research of c. elegans development. More importantly, a novel strategy based on cPcDs for in vivo toxicity evaluation of materials/drugs (e.g., Ag+), which can visualize the otherwise unseen injuries in zebrafish, is developed. In conclusion, the cPcDs represent a robust tool for visualizing the structures and dynamic behaviors of live zebrafish and c. elegans, and may find important applications in cell biology and toxicology.

关键词： c elegans carbon nanodots in vivo toxicity nucleolar imaging zebrafish

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Probing the randomness of the local current distributions of 316 L stainless steel corrosion in Nacl solution

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cORROSION ScIENcE 2023年 217卷

作者： coelho, Leonardo Bertolucci Torres, Daniel Bernal, Miguel Paldino, Gian Marco Bontempi, Gianluca Ustarroz, Jon Univ Libre Bruxelles ULB ChemSIN Chem Surfaces Interfaces & Nanomat Brussels Belgium Vrije Univ Brussel Res Grp Electrochem & Surface Engn SURF Brussels Belgium Univ Libre Bruxelles ULB Machine Learning Grp MLG Brussels Belgium

This investigation proposes using Scanning Electrochemical cell Microscopy (SEccM) as a high throughput tool to collect corrosion activity from randomly probed locations on 316 L SS. In the presence of chloride, poten-tiodynamic polarisation tests triggered the development of pitting corrosion. Data science methods were deployed to handle and explore 955 j Vs E curves. Normality tests and fitting with theoretical functions were used to understand the conditional log(j) distributions at different potentials. Unimodal and uniform distributions were assigned to the passive and pitting regions. Our "big-data" local strategy revealed a potential-dependent distribution of log(j), with the randomness increasing with testing aggressiveness. Data availability: All data generated or analysed during this study are included in this published article (and its supplementary information files) and are available in the Mendeley Data repository, [https://***. com/datasets/78rz8vw46x/2]. code availability: The code required to reproduce these findings is included in this published article (and its supplementary information files) and is available to download from GitHub: https://***/bcoelho-leona rdo/Data-driven-analysis-of-the-local-current-distributions-of-316L-corrosion-in-Nacl-solution/blob/4efff485b 115468840b25ea56ad81b31711c0f51/local%20current%20distributions%20of%20316L%***.

关键词： A Stainless steel B polarization c pitting corrosion

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Effect of sulfate reducing bacteria on the galvanic corrosion behavior of X52 carbon steel and 2205 stainless steel bimetallic couple

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cORROSION ScIENcE 2023年第1期212卷

作者： Wan, Huihai Zhang, Tiansui Xu, Zixuan Rao, Zhuang Zhang, Guoan Li, Guangfang Liu, Hongfang Huazhong Univ Sci & Technol Hubei Engn Res Ctr Biomat & Med Protect Mat Hubei Key Lab Mat Chem & Serv Failure Key Lab Mat Chem Energy Convers & StorageSch Chem Wuhan 430074 Peoples R China

Effect of sulfate reducing bacteria (SRB) on the galvanic corrosion between 2205 SS (stainless steel) and X52 carbon steel in enriched artificial seawater (EASW) was comprehensively investigated, which was significant for understanding the microbiologically influenced corrosion of bimetallic composite pipelines. Electrochemical tests indicate that the galvanic effect in the SRB-containing medium was higher than that in the sterile medium. The coupling also promoted the corrosion of 2205 SS in biotic medium with a 13-fold increase in weight loss. The galvanic effect could increase the sessile cell density and accelerate the deterioration of the passive film of 2205 SS.

关键词： A Stainless steel Sulfate reducing bacteria B Weight loss c Microbiologically influenced corrosion Galvanic corrosion

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combinational exposure to hydroxyatrazine increases neurotoxicity of polystyrene nanoparticles on caenorhabditis elegans

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ScIENcE OF THE TOTAL ENVIRONMENT 2023年第1期880卷 163283页

作者： Wang, Yuxing Yuan, Xiaoan Zhou, Rong Bu, Yuanqing Wang, Dayong Southeast Univ Med Sch Key Lab Environm Med Engn Minist Educ Nanjing Peoples R China Nanjing Inst Environm Sci Minist Ecol & Environm Nanjing Peoples R China Shenzhen Ruipuxun Acad Stem Cell & Regenerat Med Shenzhen Peoples R China

Using caenorhabditis elegans as an animal model, we investigated combinational effect between 2-hydroxyatrazine (HA) and polystyrene nanoparticle (PS-NP) on function and development of D-type motor neurons. Exposure to HA (10 and 100 mu g/L) alone caused decreases in body bend, head thrash, and forward turn and increase in backward turn. Exposure to 100 mu g/L HA also caused neurodegeneration of D-type motor neurons. Moreover, combinational exposure to HA (0.1 and 1 mu g/L) induced enhancement in PS-NP (10 mu g/L) toxicity in inhibiting body bend, head thrash, and forward turn, and in increasing backward turn. In addition, combinational exposure to HA (1 mu g/L) could result in neurodegeneration of D-type motor neurons in PS-NP (10 mu g/L) exposed nematodes. combinational exposure to HA (1 mu g/L) and PS-NP (10 mu g/L) increased expressions of crt-1, itr-1, mec-4, asp-3, and asp-4, which govern the induction of neurodegeneration. Moreover, combinational exposure to HA (0.1 and 1 mu g/L) strengthened PS-NP (10 mu g/L)-induced decreases in glb-10, mpk-1, jnk-1, and daf-7 expressions, which encode neuronal signals regulating response to PS-NP. Therefore, our results demonstrated the effect of combinational exposure to HA and nanoplastics at environmentally relevant concentrations in causing toxic effect on nervous system in organisms.

关键词： c elegans combinational exposure Nanoplastic Hydroxyatrazine

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Design of enhanced mechanical properties by interpenetrating network of 3D printing dual-curing resins

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POLYMER 2023年第1期282卷

作者： Wang, Haohuan Huang, Zhengyong Zhang, Yingfan Li, Licheng Li, Jian Chongqing Univ Sch Elect Engn State Key Lab Power Transmiss Equipment & Syst Sec Chongqing 401331 Peoples R China

Photopolymer resins with low viscosity are used in 3D printing for accuracy and process performance, although the major of their mechanical strength does not meet engineering requirements. In this work, we develop a photothermal dual-curing 3D printing resin with high mechanical strength and great toughness through the construction of interpenetrating network (IPN) structures composed of epoxy resin and bio-based methacrylate. The nonbonded energy and the number of hydrogen bonds per unit volume of the IPN structures are found to increase for a certain ratio of epoxy resin and bio-based methacrylate based on the molecular dynamic simulation, which are the key factors in the mechanism for improving the mechanical properties of dual-curing resins. The resulting dual-curing resin exhibits satisfactory mechanical properties at the viscosity of 803 mPa s: A tensile strength of 60 MPa and a flexural strength of 119 MPa are comparable to the epoxy resin, and an impact toughness of 12.9 kJ cm-2 and an elongation at break of 7.9% are founded to increase by 126% and 316%, respectively, as compared to the epoxy resin. The dual-curing resin also shows high 3D printing precision, relatively low water absorption and volume shrinkage, excellent thermostability, and great dielectric properties. The results presented in this paper provide a promising route to develop high-performance 3D printing materials.

关键词： A Resins B Mechanical properties c computational modelling E 3-D printing

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Activation of FGF signal in germline mediates transgenerational toxicity of polystyrene nanoparticles at predicted environmental concentrations in caenorhabditis elegans

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JOURNAL OF HAZARDOUS MATERIALS 2023年第1期451卷 131174页

作者： Hua, Xin cao, chang Zhang, Le Wang, Dayong Southeast Univ Med Sch Key Lab Environm Med Engn Minist Educ Nanjing 210009 Peoples R China Shenzhen Ruipuxun Acad Stem Cell & Regenerat Med Shenzhen 518122 Peoples R China

Nanoplastics in the environment could cause the ecological and health risks. Recently, the transgenerational toxicity of nanoplastic has been observed in different animal models. In this study, using caenorhabditis elegans as an animal model, we aimed to examine the role of alteration in germline fibroblast growth factor (FGF) signal in mediating the transgenerational toxicity of polystyrene nanoparticle (PS-NP). Exposure to 1-100 mu g/L PS-NP (20 nm) induced transgenerational increase in expressions of germline FGF ligand/EGL-17 and LRP-1 governing FGF secretion. Germline RNAi of egl-17 and lrp-1 resulted in resistance to transgenerational PS-NP toxicity, indicating the requirement of FGF ligand activation and secretion in formation of transgenerational PS-NP toxicity. Germline overexpression of EGL-17 increased expression of FGF receptor/EGL-15 in the offspring, and RNAi of egl-15 at F1 generation (F1-G) inhibited transgenerational toxicity of PS-NP exposed animals overexpressing germline EGL-17. EGL-15 functions in both the intestine and the neurons to control transgenerational PS-NP toxicity. Intestinal EGL-15 acted upstream of DAF-16 and BAR-1, and neuronal EGL-15 functioned upstream of MPK-1 to control PS-NP toxicity. Our results suggested the important role of activation in germline FGF signal in mediating the induction of transgenerational toxicity in organisms exposed to nanoplastics in the range of mu g/L.

关键词： Transgenerational toxicity Nanoplastic FGF c elegans

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Dissecting Physical and Biochemical Effects in Nanotopographical Regulation of cell Behavior

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AcS NANO 2023年第3期17卷 2124-2133页

作者： Wang, Kai Man, Kun Liu, Jiafeng Meckes, Brian Yang, Yong Univ North Texas Dept Biomed Engn Denton TX 76207 USA Schoen Adams Res Inst Spaulding Discovery Ctr Musculoskeletal Recovery Charlestown MA 02129 USA Harvard Med Sch Dept Phys Med & Rehabil Boston MA 02115 USA

Regulating cell behavior using nanotopography has been widely implemented. To facilitate cell adhesion, physical nanotopography is usually coated with adhesive proteins such as fibronectin (FN). However, the confounding effects of physical and biochemical cues of nanotopography hinder the understanding of nanotopography in regulating cell behavior, which ultimately limits the biomedical applications of nanotopography. To delineate the roles of the physical and biochemical cues in cell regulation, we fabricate substrates that have either the same physical nanotopography but different biochemical (FN) nanopatterns or identical FN nanopatterns but different physical nanotopographies. We then examine the influences of physical and biochemical cues of nanotopography on spreading, nuclear deformation, mechanotransduction, and function of human mesenchymal stem cells (hMScs). Our results reveal that physical topographies, especially nanogratings, dominantly control cell spreading, YAP localization, proliferation, and differentiation of hMScs. However, biochemical FN nanopatterns affect hMSc elongation, YAP intracellular localization, and lamin a/c (LAMAc) expression. Furthermore, we find that physical nanogratings induce nanoscale curvature of nuclei at the basal side, which attenuates the osteogenic differentiation of hMScs. collectively, our study highlights the dominant effect of physical nanotopography in regulating stem cell functions, while suggesting that fine-tuning of cell behavior can be achieved through altering the presentation of biochemical cues on substrate surfaces.

关键词： nanotopography adhesive proteins contact printing stem cells nuclear curvature lamin A c

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Patterns of carbon, nitrogen, and phosphorus stoichiometry of three life-form desert plants and responses to soil and microbial biomass factors in a hyper-arid desert ecosystem

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第15期30卷 43962-43974页

作者： Gao, Yanju Zeng, Fanjiang Chinese Acad Sci Xinjiang Inst Ecol & Geog Xinjiang Key Lab Desert Plant Roots Ecol & Vegetat Urumqi 830011 Peoples R China Chinese Acad Sci Xinjiang Inst Ecol & Geog State Key Lab Desert & Oasis Ecol Urumqi 830011 Peoples R China Cele Natl Stn Observat & Res Desert Grassland Ecos Cele 848300 Hotan Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Plant, soil, and microbial biomass ratios of carbon (c), nitrogen (N), and phosphorus (P) are crucial in maintaining stability of desert ecosystems. Nevertheless, variation in relations of elemental ratios between different life forms of plants and soil and microbial biomass in desert ecosystems remains unclear. In a hyper-arid desert ecosystem, c, N, and P concentrations and ratios were analyzed in the plant-soil-microbial biomass system of three perennial desert species (Alhagi sparsifolia Shap. [Herb, Fabaceae], Karelinia caspica Pall. [Herb, non-Fabaceae], and Tamarix ramosissima Ledeb. [Shrub]). concentrations of N and P in Alhagi sparsifolia leaf, stem, and root were significantly greater than those in Karelinia caspica and Tamarix ramosissima, whereas plant c and soil organic c (SOc) were highest with Tamarix ramosissima. Alhagi sparsifolia and Tamarix ramosissima were P-limited, whereas Karelinia caspica was N-limited. According to correlation analysis, SOc rather than soil total P (STP) regulated plant N:P ratios, and microbial biomass c, N, and P rather than SOc, soil total N, and STP regulated plant c:N:P ratios. Soil water content also affected plant nutrient balance. Thus, in a hyper-arid desert ecosystem, the plant-soil-microbial biomass system and the balance of c, N, and P are closely related, and the role of soil microbial biomass in affecting plant nutrient balance should receive increased attention.

关键词： Desert ecosystem Desert plant life forms Ecological stoichiometry Microbial biomass Nutrient limitation Soil nutrients Plant-soil-microbial biomass system c N P ratio

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