Physiological and transcriptomic analyses reveal the regulatory mechanisms of Anoectochilus roxburghii in response to high-temperature stress.

BACKGROUND: High temperatures significantly affect the growth, development, and yield of plants. Anoectochilus roxburghii prefers a cool and humid environment, intolerant of high temperatures. It is necessary to enhance the heat tolerance of A. roxburghii and breed heat-tolerant varieties. Therefore, we studied the physiological indexes and transcriptome of A. roxburghii under different times of high-temperature stress treatments. RESULTS: Under high-temperature stress, proline (Pro), H2O2 content increased, then decreased, then increased again, catalase (CAT) activity increased continuously, peroxidase (POD) activity decreased rapidly, then increased, then decreased again, superoxide dismutase (SOD) activity, malondialdehyde (MDA), and soluble sugars (SS) content all decreased, then increased, and chlorophyll and soluble proteins (SP) content increased, then decreased. Transcriptomic investigation indicated that a total of 2740 DEGs were identified and numerous DEGs were notably enriched for "Plant-pathogen interaction" and "Plant hormone signal transduction". We identified a total of 32 genes in these two pathways that may be the key genes for resistance to high-temperature stress in A. roxburghii. CONCLUSIONS: To sum up, the results of this study provide a reference for the molecular regulation of A. roxburghii's tolerance to high temperatures, which is useful for further cultivation of high-temperature-tolerant A. roxburghii varieties.

Melatonin confers thermotolerance and antioxidant capacity in Chinese cabbage.

Due to the damaging effect of high temperatures on plant development, global warming is predicted to increase agricultural risks. Chinese cabbage holds considerable importance as a leafy vegetable that is extensively consumed and cultivated worldwide. Its year-round production also encounters severe challenges in the face of high temperatures. In this study, melatonin (MT), a pivotal multifunctional signaling molecule that coordinates responses to diverse environmental stressors was used to mitigate the harmful effects of high temperatures on Chinese cabbage. Through the utilization of growth indices, cytological morphology, physiological and biochemical responses, and RNA-Seq analysis, alongside an examination of the influence of crucial enzymes in the endogenous MT synthesis pathway on the thermotolerance of Chinese cabbage, we revealed that MT pretreatment enhanced photosynthetic activity, maintained signaling pathways associated with endoplasmic reticulum protein processing, and preserved circadian rhythm in Chinese cabbage under high temperatures. Furthermore, pretreatment with MT resulted in increased levels of soluble sugar, vitamin C, proteins, and antioxidant enzyme activity, along with decreased levels of malondialdehyde, nitrate, flavonoids, and bitter glucosinolates, ultimately enhancing the capacity of the organism to mitigate oxidative stress. The knockdown of the tryptophan decarboxylase gene, which encodes a key enzyme responsible for MT biosynthesis, resulted in a significant decline in the ability of transgenic Chinese cabbage to alleviate oxidative damage under high temperatures, further indicating an important role of MT in establishing the thermotolerance. Taken together, these results provide a mechanism for MT to improve the antioxidant capacity of Chinese cabbage under high temperatures and suggest beneficial implications for the management of other plants subjected to global warming.

Exploring the gene expression network involved in the heat stress response of a thermotolerant tomato genotype.

BACKGROUND: The increase in temperatures due to the current climate change dramatically affects crop cultivation, resulting in yield losses and altered fruit quality. Tomato is one of the most extensively grown and consumed horticultural products, and although it can withstand a wide range of climatic conditions, heat stress can affect plant growth and development specially on the reproductive stage, severely influencing the final yield. In the present work, the heat stress response mechanisms of one thermotolerant genotype (E42) were investigated by exploring its regulatory gene network. This was achieved through a promoter analysis based on the identification of the heat stress elements (HSEs) mapping in the promoters, combined with a gene co-expression network analysis aimed at identifying interactions among heat-related genes. RESULTS: Results highlighted 82 genes presenting HSEs in the promoter and belonging to one of the 52 gene networks obtained by the GCN analysis; 61 of these also interact with heat shock factors (Hsfs). Finally, a list of 13 candidate genes including two Hsfs, nine heat shock proteins (Hsps) and two GDSL esterase/lipase (GELPs) were retrieved by focusing on those E42 genes exhibiting HSEs in the promoters, interacting with Hsfs and showing variants, compared to Heinz reference genome, with HIGH and/or MODERATE impact on the translated protein. Among these, the Gene Ontology annotation analysis evidenced that only LeHsp100 (Solyc02g088610) belongs to a network specifically involved in the response to heat stress. CONCLUSIONS: As a whole, the combination of bioinformatic analyses carried out on genomic and trascriptomic data available for tomato, together with polymorphisms detected in HS-related genes of the thermotolerant E42 allowed to determine a subset of candidate genes involved in the HS response in tomato. This study provides a novel approach in the investigation of abiotic stress response mechanisms and further studies will be conducted to validate the role of the highlighted genes.

Metagenomic analysis of a thermophilic bacterial consortium and its use in the bioremediation of a petroleum-contaminated soil.

Biodegradation is difficult at high temperatures due to the limited capacity of microorganisms to survive and function outside their optimum temperature range. Here, a thermophilic petroleum-degrading consortium was enriched from compost at a temperature of 55 °C. 16S rDNA and metagenomic techniques were used to analyze the composition of the consortium and the mechanisms of degradation. The consortium degraded 17000 mg total petroleum hydrocarbons (TPHs) L-1 with a degradation efficiency of 81.5% in 14 days. The consortium utilized a range of substrates such as n-hexadecane, n-docosane, naphthalene and pyrene and grew well over a wide range of pH (4-10) and salinity (0-90 g L-1). The hydrocarbon-degrading extremophilic consortium contained, inter alia, (relative abundance >1%) Caldibacillus, Geobacillus, Mycolicibacterium, Bacillus, Chelatococcus, and Aeribacillus spp. Metagenomic analysis was conducted to discover the degradation and environmental tolerance functional genes of the consortium. Two alkane hydroxylase genes, alkB and ladA, were found. A microcosm study shows that the consortium promoted the bioremediation of soil TPHs. The results indicate that the consortium may be a good candidate for the high-temperature bioremediation of petroleum-contaminated soils.

Laue microdiffraction on polycrystalline samples above 1500†K achieved with the QMAX-µLaue furnace.

X-ray Laue microdiffraction aims to characterize microstructural and mechanical fields in polycrystalline specimens at the sub-micrometre scale with a strain resolution of ∼10-4. Here, a new and unique Laue microdiffraction setup and alignment procedure is presented, allowing measurements at temperatures as high as 1500 K, with the objective to extend the technique for the study of crystalline phase transitions and associated strain-field evolution that occur at high temperatures. A method is provided to measure the real temperature encountered by the specimen, which can be critical for precise phase-transition studies, as well as a strategy to calibrate the setup geometry to account for the sample and furnace dilation using a standard α-alumina single crystal. A first application to phase transitions in a polycrystalline specimen of pure zirconia is provided as an illustrative example.

High-Temperature Reactive Wetting of Natural Quartz by Liquid Magnesium.

High-temperature wetting of natural, high-purity quartz (SiO2) and liquid magnesium (Mg) was investigated at temperatures between 973 and 1273 K. Sessile drop experiments using the capillary purification (CP) procedure were carried out under an Ar gas atmosphere (N6.0), eliminating the native oxide layer on the surface of Mg melt. The results showed that the wetting behavior was strongly dependent on temperature. At 973 and 1073 K, the wetting system displayed relatively large contact angles of 90° and 65°, respectively, demonstrating modest wetting. The wetting increased to some extent by increasing the temperature to 1123 K with a wetting angle of 22°. However, the SiO2/Mg system demonstrated complete wetting at temperatures of 1173 K and above. Furthermore, interface microstructure examination showed different reaction product phases/microstructures, depending on the wetting experiment temperature.

The Effect of Adding CeO2 Nanoparticles to Cu-Ni-Al Alloy for High Temperatures Applications.

This work presents the effect of CeO2 nanoparticles (CeO2-NPs) on Cu-50Ni-5Al alloys on morphological, microstructural, degradation, and electrochemical behavior at high temperatures. The samples obtained by mechanical alloying and spark plasma sintering were exposed to a molten eutectic mixture of Li2CO3-K2CO3 for 504 h. The degradation of the materials was analyzed using gravimetry measurements and electrochemical impedance spectroscopy. Different characterization techniques, such as X-ray diffraction and scanning electron microscopy, were used to investigate the phase composition, parameter lattice, and microstructure of Cu-Ni-Al alloys reinforced with CeO2-NPs. The hardness of the composite was also examined using the Vickers hardness test. Gravimetry measurements revealed that the sample with 1 wt.% CeO2-NPs presented the best response to degradation with a less drastic mass variation. Impedance analysis also revealed that by adding 1 wt.% CeO2-NPs, the impedance modulus increased, which is related to a lower porosity of the oxide film or a thicker oxide layer. The microhardness also significantly increased, incorporating 1 wt.% CeO2-NPs, which reduced with higher CeO2-NPs content, which is possibly associated with a more uniform distribution using 1 wt.% CeO2-NPs in the Cu-Ni-Al matrix that avoided the aggregation phenomenon.

Thermal bleaching in the northern South China Sea: impact of abnormal environment and climate on high-latitude coral reefs.

Extensive coral bleaching events can result in catastrophic degradation of coral reefs and reorganization of coral communities. In the present study, we analyzed the spatial differences in coral bleaching and possible reasons of large-scale coral bleaching, based on the results of a survey carried out in the northern South China Sea in 2020. In addition, we have continuously monitored the sea surface temperature (SST) of the northernmost Weizhou Island for more than six years. The living coral cover at Weizhou Island (W), Xuwen Nature Reserve (X), and Haihua Island (H) was relatively high at 24.6% ± 4.8%, 12.1% ± 3.8%, and 8.1% ± 2.6%, respectively, whereas their bleaching rates were 9.7% ± 2.6%, 9.7% ± 3.3%, and 6.9% ± 2.1%, respectively. Among them, the living coral cover of W was significantly different from those of X and H, whereas the bleaching rate was not significantly different among the three areas. In all three areas, the massive and encrusting corals predominate and exhibit relatively high bleaching rates, with Porites lutea and Bernardpora stutchburyi being the dominant species. In addition, the temperature monitoring results of Weizhou Island for six consecutive years showed that the critical SST of coral bleaching was 31.5 ℃. The monitoring results also showed that the average SST of Weizhou Island was 32.1 ℃, exceeding 32 ℃ in July 2020 for up to 533 h. The longest continuous time when the SST exceeded 32 ℃ was 97 h. These findings indicated that the coral bleaching event that occurred in the Beibu Gulf during 2020 was a large-scale and high-temperature transient event that presented a relatively homogeneous threat to the coral communities. We inferred that this sudden heat stress event was caused by the enclosed tidal current in the Beibu Gulf, which prevented the southern upwelling from reaching the north, as well as by the inability of the SST to decrease without rainfall caused by typhoon cyclones. Our findings suggested that abnormal heat waves can result in coral bleaching at high latitudes and even coral reef degradation. Furthermore, our study provides a new perspective for investigating the self-recovery and reorganization of coral communities following accumulated coral bleaching.

Organic High-Temperature Synaptic Phototransistors for Energy-Efficient Neuromorphic Computing.

Organic optoelectronic synaptic devices that can reliably operate in high-temperature environments (i.e., beyond 121°C) or remain stable after high-temperature treatments have significant potential in biomedical electronics and bionic robotic engineering. However, it is challenging to acquire this type of organic devices considering the thermal instability of conventional organic materials and the degradation of photoresponse mechanisms at high temperatures. Here, high-temperature synaptic phototransistors (HTSPs) based on thermally stable semiconductor polymer blends as the photosensitive layer are developed, successfully simulating fundamental optical-modulated synaptic characteristics at a wide operating temperature range from room temperature to 220°C. Robust optoelectronic performance can be observed in HTSPs even after experiencing 750 h of the double 85 testing due to the enhanced operational reliability. Using HTSPs, Morse-code optical decoding scheme and the visual object recognition capability are also verified at elevated temperatures. Furthermore, flexible HTSPs are fabricated, demonstrating an ultralow power consumption of 12.3 aJ per synaptic event at a low operating voltage of -0.05 mV. Overall, the conundrum of achieving reliable optical-modulated neuromorphic applications while balancing low power consumption can be effectively addressed. This research opens up a simple but effective avenue for the development of high-temperature and energy-efficient wearable optoelectronic devices in neuromorphic computing applications.

[Spatio-temporal Characteristics and Influencing Factors of Ozone Suppression Events Under High Temperature in China].

Temperature is a key meteorological factor affecting ozone formation. In general, a positive correlation is observed between ozone and temperature, that is, ozone concentration increases with the increase in temperature. However, this relationship may change at extremely high temperatures. When the temperature exceeds a threshold value, the ozone concentration tends to decrease, which is referred to as an ozone suppression event. Ozone suppression events lead to greater uncertainties in the prediction of future air quality under climate change. Based on the national air quality monitoring data, reanalysis data, and meteorological observation data, this study used the Z test to systematically analyze the spatio-temporal characteristics of the critical temperature(Tx) and frequency of ozone suppression events in China during the warm season(April to September) from 2013 to 2020 and further analyzed the possible influencing factors for the occurrence of ozone suppression events. The results showed that approximately 18% of the sites in China experienced ozone suppression events in the warm season from 2013 to 2020. The sites with a high frequency of ozone suppression events were mainly distributed in the central and western regions of China, such as Sichuan, Xinjiang, and Shaanxi, with an average frequency of ten times per year. The critical temperature(Tx) ranged from 19.2 to 39.3℃, and the Tx of most sites showed an increasing trend from 2013 to 2020. The high values of Tx were mainly distributed in the central and western regions such as Sichuan, Chongqing, Hunan, and Hubei, whereas the low values of Tx were concentrated in the Qinghai-Tibet Plateau. Contrary to the interannual trend of Tx, the frequency of ozone suppression events decreased significantly in the Beijing-Tianjin-Hebei Region and exhibited a characteristic of "increase-decrease-increase" in the Fenwei Plain, the Yangtze River Delta, and the Chengdu-Chongqing regions. The most significant effect of extreme high temperature on ozone suppresion was found in the Pearl River Delta Region. In addition, ozone precursors(e.g., NO2) and meteorological conditions(wind speed and direction) were possible factors affecting the occurrence of ozone suppression events.

Possibilities of Using Geopolymers in Welding Processes and Protection against High Temperatures.

Geopolymer materials have long been known for their competitive properties against traditional construction materials. Their special features include high resistance to elevated temperatures and good fire resistance. They are typically used as insulating materials at temperatures not exceeding 100 °C (because they can achieve a thermal conductivity coefficient of 0.060 W/m × K or less under these conditions). Still, they can also be used as thermal insulation at temperatures exceeding 1000 °C. One technology that uses very high temperatures is metal welding technology, where temperatures often exceed as many as 3000 °C. Geopolymers, due to their properties, can also be an interesting new alternative in various welding applications. This paper presents the preliminary results of pot-proofing the resistance of geopolymers to temperatures exceeding 3000 °C. Test results of a foamed geopolymer insulating a steel substrate are presented, and a geopolymer mold for thermite rail welding was made and realistically tested. The results confirmed the feasibility of using cast geopolymer molds for thermite welding of railroad rails. The geopolymer material performed well during the test and no cracks or other damage occurred. The following article presents the potential of using geopolymer materials for welding applications.

A Functional Janus Ag Nanowires/Bacterial Cellulose Separator for High-Performance Dendrite-Free Zinc Anode Under Harsh Conditions.

Aqueous zinc-ion batteries (AZIBs) offer promising prospects for large-scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, a Janus separator with an exceptionally ultrathin thickness of 29 µm is developed. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. High zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn2+ transport in the electrolyte, resulting in greatly improved Zn2+ conductivity, deposition of homogeneous Zn nuclei, and dendrite-free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 h under 80 mA cm-2 and are sustained for over 600 h at 10 mA cm-2 under 50 °C. Further, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc-ion capacitors (AZICs), and scaled-up flexible soft-packaged batteries. This study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.

Changes in cortisol and cortisone in hair of pigs reared under heat stress conditions.

Heat stress accounts for millions of dollars in losses for swine producers worldwide. The aim of the present study was to determine and evaluate cortisol and cortisone in hair as indicators of thermal stress in growing pigs reared under high environmental temperatures. The study was carried out in two independent batches of commercial crosses of Lean Duroc and Pietrain in trials 1 and 2, respectively, during the growing period (from 40 to 100 kg; 81 days in trial 1 and 77 days in trial 2) in the same commercial farm in Spain during the summers of 2020 and 2021. In both cases, four rooms were used. In Trial 1, Room 1 had cooling and 11 pigs per pen; Room 2 had no cooling and 13 pigs per pen; Room 3 had no cooling and 11 pigs per pen, and Room 4 had cooling and 13 pigs per pen. In Trial 2, Rooms 2 and 3 had cooling and rooms 1 and 4 had no cooling, and all of them had 13 pigs per pen. Mean THI value was higher (p < 0.0001) in rooms without cooling systems (75.0 trial 1; 74.9 trial 2) than with them (71.3 trial 1; 71.7 trial 2). A total of four pens per room (16 in total) was selected for analysis of hair corticoids and all pigs inside were sampled at the end of the study. Fifty percent of the pigs were males (castrated and intact in trial 1 and 2, respectively) and 50% females. In total, 44, 52, 44, and 52 pigs, respectively, were sampled in four rooms from the first trial and 52 for each of four rooms in Trial 2. Cortisol concentrations in hair did not show any significant change in relation to cooling-non-cooling in any trial. However, hair cortisone concentration was 172.3 pg./mg and 105.8 pg./mg less (p < 0.001) in pigs housed with cooling systems compared to those without them in Trial 1 and 2, respectively. In addition, the cortisone/cortisol ratio, which is an estimator of the activity of 11ß-hydroxysteroid dehydrogenase (11ß-HSD) type 2, was also greater in rooms without cooling than in rooms with cooling in both trials (p < 0.0001 and p = 0.0105 for Trials 1 and 2, respectively). In relation to the sex effect, the results showed greater levels in females than in castrated males both in cortisone and the cortisol/cortisone ratio while cortisol hair levels were greater in intact males than in females. Therefore, the use of cortisone and the estimation of 11ß-HSD type 2 activity in hair is recommended to evaluate the chronic stress produced by high environmental conditions in pigs instead of using hair cortisol concentrations alone.

Structural and mineralogical variation upon reoxidation of reduced Fe-bearing clay minerals during thermal activation.

The hydroxyl radicals (OH) produced from Fe(II) oxidation upon reoxidation of reduced Fe-bearing clay minerals (RFC) have received increased attention and thermal activation was used to enhance Fe(II) oxidation to improve OH production. However, changes in mineral morphology and structure during thermally-activated RFC reoxidation are not yet clear. Herein, the Fe(II) oxidation extent was measured by chemical analysis during the reoxidation of model RFC (reduced nontronite (rNAu-2) at elevated temperatures. Mineralogical variation of rNAu-2 particles was observed by scanning electron microscopy (SEM), Mössbauer spectra, and X-ray photoelectron spectroscopy (XPS). The structural Fe(II) oxidation in rNAu-2 was accelerated with increasing temperature, accompanied by the transformation of structural entities and the dissolution of Fe and Si, while the overall structure of rNAu-2 minerals was relatively intact. The surface microstructure of particles showed the dissolved holes, net-shape flocs, and even large pore channels after Fe(II) oxidation by thermal activation. Moreover, the rearrangement of structural Fe(II) entities, the regeneration of edge Fe(II), and the electron transport from the interior to the edge were enhanced during rNAu-2 reoxidation by thermal activation. The increasing electron transfer at elevated temperatures could possibly be owing to the increasing number of reactive sites by increasing the internal disorder of rNAu-2. This work provides novel insights into the structural and mineralogical changes in promoting electron transfer upon RFC reoxidation.

Temporal and spatial characteristics of high temperatures, heat waves, and population distribution risk in China from 1951 to 2019.

Understanding the relationships between high temperatures (HT) and heat waves (HW) is vital for enhancing human health, especially in areas with dense population. This paper analyzes the temporal and spatial characteristics of different HT and HW intensities, their spatial influence, and the population distribution risk at different HW intensities for 844 meteorological stations between 1951 and 2019. The results indicate that (1) HT and extreme temperature (ET) days are symmetrically distributed along the Huhuanyong Line, from southeast to northwest China. The times, days, and accumulated temperatures of HW, the times, days, and accumulated temperature of strong heat waves (SHW), and the times, days, and accumulated temperature of extreme heat waves (EHW) were distributed similarly; (2) with the increase in high temperatures or heat waves from HT to ET or from HW to SHW, the proportion of stations with an upward trend was always greater in China, while stations with a downward trend were mainly located in the North China Plain and Huai River Basin. For HW, SHW, and EHW, the increasing range of times and days were less than the accumulated temperatures; (3) between 1990 and 2019, there was an expansion of the HW and SHW distribution area with an annual average of more than 10 days, and the EHW distribution area with an annual average of more than 3 days. Moreover, the number of people exposed to HW, SHW, and EHW also increased during this period; and (4) considering the population distribution characteristics and the regional HT and HW characteristics, society needs to form regional adaptation actions for different HT and HW intensities.

Research Progress of Liquid Electrolytes for Lithium Metal Batteries at High Temperatures.

Lithium metal batteries (LMBs) are the most promising high energy density energy storage technologies for electric vehicles, military, and aerospace applications. LMBs require further improvement to operate efficiently when chronically or routinely exposed to high temperatures. Electrolyte engineering with high temperature tolerance and electrode compatibility has been essential to the development of LMBs. In this review, the primary obstacles to achieving high-temperature LMBs are first explored. Subsequently, electrolyte tailoring options, such as lithium salt optimization, solvation structure modification, and the addition of additives are reviewed in detail. In addition, the feasibility of utilizing LMBs at high temperatures has been investigated. In conclusion, this study provides insights and perspectives for future research on electrolyte design at high temperatures.

Specific Adsorption-Oxidation Strategy in Cathode Inner Helmholtz Plane Enabling 4.6 V Practical Lithium-Ion Full Cells.

Increasing the cutoff voltage effectively maximizes the available capacity of the state-of-art layered-oxide cathodes (LiTMO2). However, the spontaneous dehydrogenation-oxidation of carbonates in the cathode inner Helmholtz plane (C-IHP) under high voltage/temperature leads to side effects, including weak cathode electrolyte interphase (CEI) and cathode structural collapse. Here, we report a specific adsorption-oxidation (Ad-O) mechanism that dominates the later CEI formation through molecular regulation in C-IHP. The two tailored additives with specific electron-rich groups will enter the C-IHP and mask the active sites of cathodes, thereby reducing the weak CEI generation from conventional carbonates. As-formed hierarchical CEI with inner LiF and outer B-F/-CN rich organic structure will further protect the aggressive cathode from harmful electrolyte corrosion under harsh conditions of high voltages (4.6 V) and elevated temperatures (60 °C). This synergistic strategy guided by the specific Ad-O mechanism enables 3.5 Ah LiNi0.8Co0.1Mn0.1O2/Graphite pouch cells, which remarkably achieve 270 Wh/kg with 450 cycles.

The CsHSFA-CsJAZ6 module-mediated high temperature regulates flavonoid metabolism in Camellia sinensis.

High temperatures (HTs) seriously affect the yield and quality of tea. Catechins, derived from the flavonoid pathway, are characteristic compounds that contribute to the flavour of tea leaves. In this study, we first showed that the flavonoid content of tea leaves was significantly reduced under HT conditions via metabolic profiles; and then demonstrated that two transcription factors, CsHSFA1b and CsHSFA2 were activated by HT and negatively regulate flavonoid biosynthesis during HT treatment. Jasmonate (JA), a defensive hormone, plays a key role in plant adaption to environmental stress. However, little has been reported on its involvement in HT response in tea. Herein, we demonstrated that CsHSFA1b and CsHSFA2 activate CsJAZ6 expression through directly binding to heat shock elements in its promoter, and thereby repress the JA pathway. Most secondary metabolites are regulated by JA, including catechin in tea. Our study reported that CsJAZ6 directly interacts with CsEGL3 and CsTTG1 and thereby reduces catechin accumulation. From this, we proposed a CsHSFA-CsJAZ6-mediated HT regulation model of catechin biosynthesis. We also determined that negative regulation of the JA pathway by CsHSFAs and its homologues is conserved in Arabidopsis. These findings broaden the applicability of the regulation of JAZ by HSF transcription factors and further suggest the JA pathway as a valuable candidate for HT-resistant breeding and cultivation.

Effect of Magnetite Concrete on Splitting Tensile Strength and Gamma Ray Shielding Performance Exposed to Repeated Heating at High Temperature.

Radiation shielding concrete is one of the most used materials in the construction of nuclear power plants and will be subjected to high temperatures for a long time during its service life. This study aims to investigate deterioration of radiation shielding concrete with multiple heating at different temperatures. A microwave oven was used as a heating apparatus to simulate irradiation, and 200, 300, and 400 °C were selected as experimental cycle temperatures. The apparent characteristics, mass loss, splitting tensile strength, and gamma ray shielding properties of the commonly used magnetite shielding concrete were investigated. The results showed that the splitting tensile strength and gamma shielding performance of concrete were dramatically reduced at first heating. Then, as the heating times increased, the splitting tensile strength and gamma shielding properties of the concrete continued to deteriorate, and the higher the increase in heating temperature, the more severe the deterioration of the concrete. During the service period of radiation shielded concrete, the magnitude of temperature under the service conditions will affect the deterioration degree of concrete, and the continuous change of temperature will continuously lead to the deterioration of concrete.

High Temperature Self-Regenerative Granular Hydrogels for Fracture Treatments During Subsurface Energy Recovery.

The uses of granular hydrogels to assemble macroscopic bulk hydrogels display numerous distinct advantages. However, prior assembly of bulk hydrogels is accomplished by interparticle linking strategy, which compromised mechanical property and thermal stability under hostile conditions. To expand their applications as engineering soft materials, self-regenerative granular hydrogels via a seamless integrating approach to regenerate bulk hydrogels is highly desirable. Herein, covalent regenerative granular hydrogels (CRHs) are prepared at low-temperature synthetic conditions and re-construct bulk seamless hydrogels at high-temperature aqueous environments. The re-formed bulk hydrogels display rubber-like viscoelastic behaviors over a wide range of temperatures from 90 to 150 °C, where the covalent re-crosslinking reactions homogeneously occurr along the periphery and in the matrix of granular hydrogels, accounting for the increased structural integrity at high temperatures. The bulk hydrogel shows increased elasticity and long-term thermal integrity at 150 °C for more than six months in the confined fractures. Moreover, regenerative granular CRH-based bulk hydrogels significantly improve mechanical robustness under destructive pressure. Thus, high temperature water induced regenerative granular hydrogels present the paradigm to treat engineering scenarios such as large fractures for hydraulic fracturing, drilling operation, and disproportionate permeability reduction under extremely hostile conditions during subsurface energy recovery.