High-temperature Treatment Research Articles

The role of zinc addition on the microstructural evolution and mechanical properties of wire-arc directed energy deposited Mg-Gd-Y-(Zn)-Zr alloys

Wire-arc directed energy deposition (WA-DED) demonstrates significant potential in the rapid and free forming of high-strength magnesium rare-earth (Mg-RE) alloys. This highlights a growing demand for tailored wire alloy compositions to promote engineering applications of this technology. In this work, the role of zinc addition on WA-DED processed Mg-Gd-Y based alloys has been thoroughly investigated by utilizing Mg-6Gd-3Y-0.5Zr (wt.%, GW63K) and Mg-6Gd-3Y-0.5Zn-0.5Zr (wt.%, GWZ631K) alloy wires as model materials. The microstructure evolution of these two alloys during deposition and heat treatment is revealed by multi-scale microstructure characterization techniques. The influences of Zn addition on mechanical properties of these deposited alloys are investigated comparatively. Obtained results indicate that addition of Zn element into Mg-Gd-Y based alloys promotes phase transformation between eutectic phases and long period stacking order (LPSO) phases during the WA-DED deposition process owing to the multiple thermal cycling. More importantly, the addition of Zn element increases the tendency of solidification shrinkage of the deposited metal. During high-temperature solid solution treatment, the presence of Zn is conducive to improving the thermal stability of the as-deposited grain boundaries and thus suppressing grain coarsening. After optimized T6 treatments, the strength of GW63K alloys increases to 374±7MPa, and is obviously higher than that (315±6MPa) of GWZ631K alloys. The addition of Zn element weakens the precipitation strengthening effect. This can be attributed to the formation of LPSO phases, which consumes a substantial amount of RE elements, and in turn decreases the density of aging precipitated nanoscale β´ phases. This work promotes the understanding of the non-equilibrium solidified microstructure evolution of multi-component Mg-RE alloys and guides the optimization of alloy composition of WA-DED specific wire materials.

Development of V2O3 Nanostructures for Alkali Metal Ion Batteries: A Novel Approach through Mild Metal Vapor Reduction and Interface Engineering.

V2O3 has been extensively researched as a battery electrode material due to its ample reserves and high theoretical capacity. However, the synthesis of valence-sensitive V2O3 presents technical challenges as it requires a strict combination of high-temperature treatment and a narrow range of oxygen partial pressures. This study proposes a gentle Li vapor-assisted thermal reduction method to synthesize pure-phase V2O3 at a relatively low temperature of 480 °C without any hazardous gases. It has been discovered that reducing the temperature also improves the specific surface area of the nanoto-mesoscale hierarchical structures and enhances the reactive sites between their secondary grains. These advantages enable the V2O3 micronano particles to store higher levels of Li+, Na+, and K+, increase ionic transport, and tolerate volume expansion. It demonstrates a significant capacity of 767 mA h g-1 in lithium-ion batteries, 393 mA h g-1 in sodium-ion batteries, and 209 mA h g-1 in potassium-ion batteries. It has also been discovered that the crystal structure of V2O3 is easily adjustable by varying the synthesis temperature, which significantly affects the electrochemical storage mechanism. The V2O3 synthesized at 480 °C with low crystallinity exhibits a notable intercalation reaction, facilitating the electrochemical kinetics of reversible insertion/extraction of Li+, Na+, and K+. In contrast, the highly crystalline sample synthesized at 580 °C displays pseudocapacitance behavior instead of an intercalation reaction. The highly crystalline sample synthesized at 680 °C exhibits a thorough pseudocapacitance reaction possessing the capacitive functionality for the electrochemical storage of Na+ or K+ with larger ion radii. This study describes a new synthesis strategy and rational modification of vanadium-based electrodes for alkali metal ion batteries, leading to the development of reasonably priced rechargeable battery systems with applications extending beyond lithium-ion batteries.

Carbon whiskers reinforced porous glassy carbon composites by synchronous growth

A crystalline and non-crystalline composite of pure carbon was proposed, which is a carbon whiskers reinforced porous glassy carbon composite, where crystalline carbon whiskers support the microscopic pores of non-crystalline glassy carbon matrix. Two allotropes of carbon were produced simultaneously and compounded together in a single high temperature treatment of thermosetting phenolic resin, with aluminum oxide (Al2O3) as a catalyst. A synchronous growth theory was proposed to explain the growth mechanism. In the pyrolysis process of phenolic resin to generate porous glassy carbon, hydrocarbon gas was produced and trapped in the generated pores. By the same time, the hydrocarbon gas in pores was decomposed and grew carbon whiskers by catalysis of Al2O3. With linear thermal expansion coefficient from 2.0∙10−6 to 3.8∙10−6 K−1, thermal conductivity from 1.763 to 2.518 W∙m−1 K−1, specific heat capacity from 0.396 to 0.752 J∙g−1 K−1, thermal diffusivity from 6.115 to 4.598 mm2 s−1, between room temperature (RT) and 500 °C, the Vickers hardness is at 65 MPa, and the fracture toughness is at 0.329 Mpa∙m1/2 in RT. The carbon whiskers reinforced porous glassy carbon composite keeps a balance between thermophysical and mechanical properties, showing its application value in thermal insulation materials and high temperature structure materials.

Molecular-level insight into the effects of low moisture and trehalose on the thermostability of β-glucosidase

The high temperature induces conformational changes in β-glucosidase, making it inactive and limiting its application field. In this paper, the effect of trehalose on the thermostability of β-glucosidase from low-moisture Hevea brasiliensis seeds was investigated. The results showed that the residual enzyme activities of β-glucosidase supplemented with trehalose after high-temperature treatment were significantly higher than that of the control group. The improvement of thermostability could be explained by low-field nuclear magnetic resonance (LF-NMR) and molecular dynamics (MD) simulations at the molecular level. Moreover, adding trehalose increased the water activity and water content of β-glucosidase, leading to a more stable conformation. Trehalose replaced some water and formed a stable network of hydrogen bonds with protein and surrounding water. The glass formed by trehalose also reduced molecular movement, thus providing good protection for enzymes.

Effect of carbonization methods on graphitization of soft and hard carbons

Pressurized carbonization is known to improve carbon content and create textural changes in resultant carbon compared to conventional (atmospheric) carbonization. However, further studies investigating the impact of these carbonization methods on the graphitic quality of the carbon precursors have not been explored extensively. This study investigates the influence of carbonization methods on the graphitization behavior of soft and hard carbons using a three-model system: phenolic resole (hard carbon), polyvinyl chloride (PVC) (soft carbon), and a 50:50 blend of resole and PVC. Carbonization was conducted under autogenic pressure (AGP) and atmospheric pressure (APP) at 500 °C for 5 h, followed by high-temperature treatment at varying temperatures. Various techniques, including X-ray diffraction and Raman spectroscopy showed hard carbon precursors exhibited improved properties under AGP carbonization such as larger crystallite size, sharp crystalline peaks, lower ID/IG ratio, and narrow G-full width half-maximum, an indication of improved crystallinity by lowering amorphous phase at high temperature. For soft carbon precursors, the method of carbonization did not impact the graphitization level. The most significant finding was the enhanced crystalline nature observed in hard carbon under AGP conditions, without the need for any catalyst. It shows the influence of pressure on improving the crystallinity of hard carbon precursors.

Comparative Transcriptomic Analysis Reveals the Involvement of Auxin Signaling in the Heat Tolerance of Pakchoi under High-Temperature Stress

Pakchoi is a kind of nonheading Chinese cabbage being widely cultivated not only in China but also all over Asia. High temperature is a major limiting factor influencing the yield and quality of pakchoi, while the mechanism of pakchoi dealing with high-temperature challenges remains largely elusive. In the present study, we conducted a comparative transcriptomic analysis, which was also validated by qPCR, of the heat-tolerant Xinxiaqing (XXQ) variant and Suzhouqing (SZQ) variant, which are heat-sensitive under high-temperature treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest that high-temperature-induced phytohormones signal transduction, especially auxin signal transduction, regulates the heat responses of pakchoi. Our further investigations imply that high-temperature-activated auxin signal plays a positive role in helping pakchoi deal with high-temperature challenge; IAA-pretreated pakchoi plants exhibited greater resistance to the high-temperature treatment, probably due to the induction of antioxidant activity. In addition, our study also identified six heat shock proteins/factors (HSPs/HSFs) whose up-regulation correlates with the elevated heat tolerance of pakchoi. Notably, among these high-temperature-induced heat-responsive factors, HSP20 and HSP26.5 are under the regulation of auxin signal, and this signal cascade contributes to enhancing the thermostability of pakchoi. In the present study, we identified crucial high-temperature-responsive factors and signaling pathways in pakchoi, which help in understanding the mechanism of pakchoi coping with high-temperature challenge.

THE INFLUENCE OF TEMPERATURE TREATMENT ON THE STRUCTURAL-PHASE COMPOSITION OF SUPPORTED Со-Мо/Al2О3 CATALYTIC SYSTEMS

Using the method of impregnation in an excess of impregnating solution and subsequent temperature treatment in the temperature range of 100-400 °C, the synthesis of γ-modified catalytic systems based on transition metals (Co, Mo) supported on active aluminum oxide was carried out and their physicochemical properties were studied. A distinctive feature of these systems was the use of polyoxometalate complexes (molybdenum blues) obtained by mechanical activation of commercial molybdenum disulfide as a source of molybdenum. The carrier was obtained by high-temperature treatment of industrial pseudoboehmite powder AlOOH (Ishimbay Specialized Chemical Plant of Catalysts LLC). This approach makes it possible to significantly simplify the synthesis of catalytic systems. At the same time, the reagents and technologies used are publicly available and are produced on the territory of the Russian Federation on an industrial scale. The resulting systems are expected to be used in hydrotreating processes (hydrodesulfurization and hydrodenitrogenation) of diesel fractions. The synthesis included the stage of obtaining an impregnating solution by adding a weighed portion of cobalt nitrate to an alcohol solution of molybdenum blue, and the stage of directly impregnating the carrier in an excess of the impregnating solution. After impregnation, the systems were calcined at various temperatures in order to study the genesis of the active components and the effect of temperature treatment on various physicochemical properties. The synthesized systems were studied using various physicochemical methods (XRD, IR spectroscopy). It was found that to completely eliminate the nitro group from the system, a temperature treatment of at least 400 °C is necessary. It was also shown that molybdenum blue can act as a source of Mo. For citation: Zhirov N.А., Akimov Al.S., Sudarev Е.А., Akimov A.S. The influence of temperature treatment on the structural-phase composition of supported Со-Мо/Al2О3 catalytic systems. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 8. P. 44-49. DOI: 10.6060/ivkkt.20246708.3t.

Defect-rich carbon nanosheets promoting power density of lithium-ion capacitors in redox electrolyte system

The introduction of redox additives, for example lithium iodide into the catholyte of lithium-ion capacitors can achieve capacity matching between the cathode and anode through the additional capacity provided by the redox reaction. However, the relatively slow redox reaction rate exacerbates the issue of kinetic imbalance between the cathode and anode during charging and discharging process, resulting in reduced coulombic efficiency and power density of lithium-ion capacitors. Herein, we doped carbon nanosheets with NH3 followed by high temperature treatment to obtain carbon nanosheets with rich defects. Theoretical calculations show that defect sites have a mild adsorption effect on iodide. Moreover, the electrochemical evaluation reveals that the defect structure can promote the redox reaction kinetics, thus increasing the electrochemical performance, especially power density of lithium-ion capacitors in the redox electrolyte system.

Semliki Forest Virus (SFV) Self-Amplifying RNA Delivered to J774A.1 Macrophage Lineage by Its Association with a Purified Recombinant SFV Capsid Protein.

The Semliki Forest virus capsid protein (C) is an RNA binding protein which exhibits both specific and unspecific affinities to single-strand nucleic acids. The putative use of the self-amplifying RNAs (saRNAs) of alphaviruses for biotechnological purpose is one of the main studied strategies concerning RNA-based therapies or immunization. In this work, a recombinant C protein from SFV was expressed and purified from bacteria and used to associate in vitro with a saRNA derived from SFV. Results showed that the purified form of C protein can associate with the saRNA even after high temperature treatment. The C protein was associated with a modified saRNA coding for the green fluorescent protein (GFP) and delivered to murine macrophage cells which expressed the GFP, showing that the saRNA was functional after being associated with the recombinant purified C protein.

Sustainable sonoprocess for synthesizing γ-Ga2O3/In3Sn core–shell submicron particles via acoustic emulsification and oxidation of molten EGaInSn at room temperature

This study investigated the sustainable room-temperature synthesis of In3Sn/γ-Ga2O3 core–shell particles via an acoustic route using molten eutectic Ga–In–Sn alloy (EGaInSn). Sonication was used for the emulsification and oxidation steps. During the emulsification step, the sonication of molten EGaInSn in ethanol (EtOH) at 45 kHz facilitated the formation of the smallest EGaInSn particles (average diameter, Dav = 782 nm). In terms of EGaInSn particle size, 45 kHz sonication was suitable for emulsification of molten EGaInSn and ethanol system than 24 kHz sonication.During the oxidation step, the preferential oxidation of Ga in the EGaInSn particles occurred via sonication in a solution of EtOH and hydrazine monohydrate (N2H4·H2O). This selective oxidation of Ga on the surface of the EGaInSn particles resulted in the formation of In3Sn/γ-Ga2O3 core–shell particles via sonication at 45 kHz and room temperature.The entire process eliminated the need for dispersants and high-temperature treatments. Additionally, the process did not generate waste fluid containing counter anions, such as chloride anions. This sustainable sonochemical method offers a carbon–neutral approach for synthesizing functional nanocomposites with improved safety, simplicity, and energy efficiency.

Heat stress reprograms herbivory-induced defense responses in potato plants

Climate change is predicted to increase the occurrence of extreme weather events such as heatwaves, which may thereby impact the outcome of plant-herbivore interactions. While elevated temperature is known to directly affect herbivore growth, it remains largely unclear if it indirectly influences herbivore performance by affecting the host plant they feed on. In this study, we investigated how transient exposure to high temperature influences plant herbivory-induced defenses at the transcript and metabolic level. To this end, we studied the interaction between potato (Solanum tuberosum) plants and the larvae of the potato tuber moth (Phthorimaea operculella) under different temperature regimes. We found that P. operculella larvae grew heavier on leaves co-stressed by high temperature and insect herbivory than on leaves pre-stressed by herbivory alone. We also observed that high temperature treatments altered phylotranscriptomic patterns upon herbivory, which changed from an evolutionary hourglass pattern, in which transcriptomic responses at early and late time points after elicitation are more variable than the ones in the middle, to a vase pattern. Specifically, transcripts of many herbivory-induced genes in the early and late defense stage were suppressed by HT treatment, whereas those in the intermediate stage peaked earlier. Additionally, we observed that high temperature impaired the induction of jasmonates and defense compounds upon herbivory. Moreover, using jasmonate-reduced (JA-reduced, irAOC) and -elevated (JA-Ile-elevated, irCYP94B3s) potato plants, we showed that high temperature suppresses JA signaling mediated plant-induced defense to herbivore attack. Thus, our study provides evidences on how temperature reprograms plant-induced defense to herbivores.

Tailoring microstructure and conductivity of porous hollow carbon spheres to enhance their performance as electrode materials for supercapacitors

Porous carbon materials are widely used in electrical double-layered capacitors for energy storage applications due to their abundant pores, high specific surface area and excellent electrochemical stability although their intrinsic electrical conductivity is generally low. Traditional high-temperature treatment was always adopted to boost the electrical conductivity of porous carbon materials by enhancing their graphitization degree, while this would always be accompanied by severe damage to pore structure and corresponding electrochemical performance. To solve the dilemma between boosting electrical conductivity and retaining pore structure, in this research, we proposed a low-temperature catalytic graphitization for hollow carbon spheres (HCSs) prepared by modified Stöber method accompanied with a special pore structure tailoring strategy. By altering the timing of adding carbon source, followed by secondary pore-forming and catalytic graphitization, HCSs with thin and porous shell walls along with enhanced conductivity were synthesized. Compared with the untreated HCSs or high-temperature graphitized HCSs, HCSs fabricated by the aforementioned combined strategies exhibited enhanced pore volume, specific surface area (2160.1 m2·g−1, 165.3 % of the untreated group) and conductivity (16.44±0.05 S·cm−2, 221.5 % of the untreated group), demonstrating much better electrochemical performance as the mass specific capacitance reached 256.7 F·g−1 and a volume specific capacitance reached 102.7 F·cm−3 at a current density of 1 A·g−1. Moreover, due to the largely promoted conductivity, the capacitance with the catalytic graphitized HCSs as the electrode material could be further boosted up to 273.4 F·g−1 at 1 A·g−1 by exempting the generally indispensable conductive agents and a high capacitance retention of 100.7 % was achieved after 5000 cycles at a relatively high current density of 10 A·g−1. This could be attributed to local graphitization brought by dispersed catalyst particles instead of entire atom rearrangement during high-temperature graphitization which would result in severe pore vanishing. The synergy of low-temperature catalytic graphitization and secondary pore-forming might be a novel strategy in electrode material fabrication for advanced supercapacitors or other energy storage devices.

LsFUL–LsSMU2 module positively controls bolting time in leaf lettuce (Lactuca sativa L.) under high temperature

High temperature (HT) is an environmental factor that considerably affects plant physiology, development, crop yield, and economic value. HT can cause diseases and early bolting of leaf lettuce, thereby reducing the yield and quality of leaf lettuce. Herein, we used two leaf lettuce (Lactuca sativa L.) cultivars (bolting-resistant ‘S24’ and bolting-sensitive ‘S39’) to investigate the key factors and molecular mechanism impacting bolting. We found that 14 MADS-box genes implicated in bolting and flowering, LsMADS54 (also referred to as L. sativa FRUITFULL, LsFUL), was significantly up-regulated 1000 times after 5-d HT treatment and that HT-induced up-regulation of LsFUL was higher in bolting-sensitive than in resistant cultivars. The overexpression lines of LsFUL exhibited an earlier bolting time than that in the non-transformed ‘S39’(CK). However, the RNA interference, and CRISPR-Cas9-mediated knockout lines of LsFUL exhibited a later bolting time than that in CK. In addition, we found that L. sativa SUPPRESSORS OF MEC-8 AND UNC-52 PROTEIN 2 (LsSMU2) and L. sativa CONSTANS-LIKE PROTEIN 5 (LsCOL5) interact with LsFUL, and these interactions could stimulate or prevent bolting. We observed that elevated temperature stimulated the abundance of LsSMU2 in the stem, which collaborated with LsFUL to accelerate bolting. Conversely, room temperature (RT) condition led to relatively more stable LsCOL5, which worked with LsFUL to postpone bolting. In summary, our findings demonstrate a molecular regulatory module of LsSMU2–LsFUL associated with HT-induced premature bolting, which serves as a reference for understanding HT-induced premature bolting phenomenon in leaf lettuce.

Genome-Wide Identification and Expression Pattern Analysis of GATA Gene Family in Orchidaceae.

The GATA transcription factors play crucial roles in plant growth, development, and responses to environmental stress. Despite extensive studies of GATA genes in many plants, their specific functions and mechanisms in orchids remain unexplored. In our study, a total of 149 GATA genes were identified in the genomes of seven sequenced orchid species (20 PeqGATAs, 23 CgGATAs, 24 CeGATAs, 23 DcaGATAs, 20 DchGATAs, 27 DnoGATAs, and 12 GelGATAs), classified into four subfamilies. Subfamily I typically contains genes with two exons, while subfamily II contains genes with two or three exons. Most members of subfamilies III and IV have seven or eight exons, with longer introns compared to subfamilies I and II. In total, 24 pairs (CgGATAs-DchGATAs), 27 pairs (DchGATAs-DnoGATAs), and 14 pairs (DnoGATAs-GelGATAs) of collinear relationships were identified. Cis-acting elements in GATA promoters were mainly enriched in abscisic acid (ABA) response elements and methyl jasmonate (MeJA) elements. Expression patterns and RT-qPCR analysis revealed that GATAs are involved in the regulation of floral development in orchids. Furthermore, under high-temperature treatment, GL17420 showed an initial increase followed by a decrease, GL18180 and GL17341 exhibited a downregulation followed by upregulation and then a decrease, while GL30286 and GL20810 displayed an initial increase followed by slight inhibition and then another increase, indicating diverse regulatory mechanisms of different GATA genes under heat stress. This study explores the function of GATA genes in orchids, providing a theoretical basis and potential genetic resources for orchid breeding and stress resistance improvement.

Revealing the deterioration mechanism in gelling properties of pork myofibrillar protein gel induced by high-temperature treatments: Perspective on the protein aggregation and conformation

The purpose of the present study was to investigate the mechanism of gel deterioration of myofibrillar proteins (MP) gels induced by high-temperature treatments based on the protein aggregation and conformation. The results showed that the gel strength and water holding capacity of MP obviously increased and then decreased as the temperature increased, reaching the maximum value at 80 °C (P < 0.05). The microstructure analysis revealed that appropriate temperature (80 °C) contributed to the formation of a more homogeneous, denser, and smoother three-dimensional mesh structure when compared other treatment temperatures, whereas excessive temperature (95 °C) resulted in the formation of heterogeneous and large protein aggregates of MP, decreasing the continuity of gel networks. This was verified by the rheological properties of MP gels. The particle size (D4,3 and D3,2) of MP obviously increased with larger clusters at excessive temperature, and the surface hydrophobicity of MP decreased (P < 0.05), which has been linked to the formation of soluble or insoluble protein aggregates. Tertiary structure and secondary structure results revealed that the proteins had a tendency to be more stretched under higher temperature treatments, which resulted in a decrease in covalent interactions and non-covalent interactions, fostering the over-aggregation of MP. Therefore, our present study indicated that the degradation of MP gels treated at high temperatures was explained by protein aggregation and conformational changes in MP.

Highly flexible and transparent colorless polyimide substrate sandwiched between plasma polymerized fluorocarbon and InGaTiO for high performance flexible perovskite solar cells

ABSTRACT We integrated transparent antireflective coatings and transparent electrodes onto flexible colorless polyimide (CPI) substrates to fabricate high-performance flexible perovskite solar cells. Multifunctional PPFC/CPI/IGTO substrates were fabricated by sputtering the optimal plasma-polymerized fluorocarbon (PPFC) antireflective coating and InGaTiO (IGTO) electrode films on both sides of the CPI substrate. By applying PPFC with a low refractive index (1.38) as an antireflective coating, the transparency of the PPFC/CPI/IGTO substrate increased by an additional 1.2%. In addition, owing to the amorphous characteristics of the PPFC and IGTO layers, the PPFC/CPI/IGTO substrate showed constant sheet resistance and transmittance change even after 10,000 cycles during the bending tests. The flexible perovskite solar cells, fabricated on the PPFC/CPI/IGTO substrate, exhibited an increase in current density of 1.48 mA/cm2 after the deposition of the PPFC antireflective coating. These results confirmed that the PPFC/CPI/IGTO substrate was durable against high-temperature treatment, flexible, and exhibited excellent electrical characteristics. This enhanced the efficiency and durability of the flexible perovskite solar cells. Moreover, the hydrophobic PPFC layer allowed the self-cleaning of inflexible perovskite solar cells. Given these attributes, the PPFC/CPI/IGTO structure has been recognized as a good choice for multifunctional substrates of flexible perovskite solar cells, presenting the potential for enhancing performance.

Phase transition of Fe-containing phase in naturally cooled and water-quenched copper slags during high-temperature treatment

Iron (Fe) accounts for the highest-content of valuable metal recoverable from copper slag, which is most effectively recycled using pyrometallurgical high-temperature treatment. It is believed that the roasting temperature significantly affects the physical structure of copper slag. Therefore, this paper used thermogravimetry-differential scanning calorimetry (TG-DTG-DSC), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM) to examine the Fe phase transformation in water-quenched copper slag (WQCS) and naturally cooled copper slag (NCCS) after high-temperature treatment (700–1100 °C). The main Fe-containing phases in the WQCS were represented by fayalite (Fe2SiO4) and magnetite (Fe3O4). As the temperature increased, the Fe2SiO4 underwent oxidative decomposition and re-formation, with a phase transition law of Fe2SiO4→Fe2O3+Fe3O4→FeSiO3+Fe2SiO4, while that of the Fe3O4 was Fe3O4→Fe2O3→Fe3O4. The phase transition processes were more complex in the NCCS, where the main Fe-containing phases were Fe2SiO4, Fe3O4 and chalcopyrite (CuFeS2). The oxidative decomposition temperatures of the Fe2SiO4 ranged from 700 °C to 850 °C. As the temperature increased, the phase transition law of Fe3O4 was Fe3O4→Fe2O3→Fe3O4→Fe2O3. Lastly, at 700 °C, the CuFeS2 began to oxidize and decompose, with a phase transition law of CuFeS2→FeS + Fe2O3→Fe3O4.

The involvement of CaMKKI in activating AMPKα in yesso scallop Patinopecten yessoensis under high temperature stress

Calcium/calmodulin dependent protein kinase kinase (CaMKK), a highly conserved protein kinase, is involved in the downstream processes of various biological activities by phosphorylating and activating 5′-AMP-activated protein kinase (AMPK) in response to the increase of cytosolic-free calcium (Ca2+). In the present study, a CaMKKI was identified from Yesso scallop Patinopecten yessoensis. Its mRNA was ubiquitously expressed in haemocytes and all tested tissues with the highest expression level in mantle. The expression level of PyCaMKKI mRNA in adductor muscle was significantly upregulated at 1, 3 and 6 h after high temperature treatment (25 °C), which was 3.43-fold (p < 0.05), 5.25-fold (p < 0.05), and 5.70-fold (p < 0.05) of that in blank group, respectively. At 3 h after high temperature treatment (25 °C), the protein level of PyAMPKα, as well as the phosphorylation level of PyAMPKα at Thr170 in adductor muscle, and the positive co-localized fluorescence signals of PyCaMKKI and PyAMPKα in haemocyte all increased significantly (p < 0.05) compared to blank group (18 °C). The pull-down assay showed that rPyCaMKKI and rPyAMPKα could bind each other in vitro. After PyCaMKKI was silenced by siRNA, the mRNA and protein levels of PyCaMKKI and PyAMPKα, and the phosphorylation level of PyAMPKα at Thr170 in adductor muscle were significantly down-regulated (p < 0.05) compared with the negative control group receiving an injection of siRNA-NC. These results collectively suggested that PyCaMKKI was involved in the activation of PyAMPKα in response to high temperature stress and would be helpful for understanding the function of PyCaMKKI-PyAMPKα pathway in maintaining energy homeostasis under high temperature stress in scallops.

Differential survival of Ilyanassa obsoleta to water temperature and association with the non-native red alga Gracilaria vermiculophylla

AbstractAlong the U.S. east coast, the widespread non-native red alga Gracilaria vermiculophylla provides habitat for an array of macroinvertebrates, including the eastern mudsnail Ilyanassa obsoleta. Though I. obsoleta tolerates a wide temperature range, increases in summer water temperatures may enhance mortality; furthermore, the presence of non-native algae in rising seawater temperatures could exacerbate harmful conditions. We tested how the presence or absence of G. vermiculophylla influenced snail mortality across a range of summer temperatures over a 3-week period. We found that I. obsoleta survived the longest in the lowest temperature (27 °C), followed by the medium (32 °C), and lastly the highest (36 °C) where all snails died within 2 days. Mortality was also higher and faster for snails in the presence versus absence of G. vermiculophylla. We suspected dissolved oxygen became very low at the higher temperatures with G. vermiculophylla; thus we conducted a laboratory-based dissolved oxygen experiment. We found that G. vermiculophylla degraded and oxygen declined faster at the highest temperature treatment, thereby creating anoxic conditions. Altogether, our results demonstrate that G. vermiculophylla could enhance anoxic conditions at high summer temperatures, potentially leading to enhanced faunal mortality.

Encapsulation of Imidazole into Ce-Modified Mesoporous KIT-6 for High Anhydrous Proton Conductivity.

Imidazole molecules entrapped in porous materials can exhibit high and stable proton conductivity suitable for elevated temperature (>373 K) fuel cell applications. In this study, new anhydrous proton conductors based on imidazole and mesoporous KIT-6 were prepared. To explore the impact of the acidic nature of the porous matrix on proton conduction, a series of KIT-6 materials with varying Si/Al ratios and pure silica materials were synthesized. These materials were additionally modified with cerium atoms to enhance their Brønsted acidity. TPD-NH3 and esterification model reaction confirmed that incorporating aluminum into the silica framework and subsequent modification with cerium atoms generated additional acidic sites. UV-Vis and XPS identified the presence of Ce3+ and Ce4+ in the KIT-6 materials, indicating that high-temperature treatment after cerium introduction may lead to partial cerium incorporation into the framework. EIS studies demonstrated that dispersing imidazole within the KIT-6 matrices resulted in composites showing high proton conductivity over a wide temperature range (300-393 K). The presence of weak acidic centers, particularly Brønsted sites, was found to be beneficial for achieving high conductivity. Cerium-modified composites exhibited conductivity surpassing that of molten imidazole, with the highest conductivity (1.13 × 10-3 S/cm at 393 K) recorded under anhydrous conditions for Ce-KIT-6. Furthermore, all tested composites maintained high stability over multiple heating and cooling cycles.