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Changes in extreme high-temperature tolerance and activities of antioxidant enzymes of sacred lotus seeds 被引量:4
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作者 DING YanFen CHENG HongYan SONG SongQuan 《Science China(Life Sciences)》 SCIE CAS 2008年第9期842-853,共12页
Sacred lotus (Nelumbo nucifera Gaertn. ‘Tielian’) seed is long-lived and extremely tolerant of high temperature. Water content of lotus and maize seeds was 0.103 and 0.129 g H2O [g DW] ?1, respectively. Water conten... Sacred lotus (Nelumbo nucifera Gaertn. ‘Tielian’) seed is long-lived and extremely tolerant of high temperature. Water content of lotus and maize seeds was 0.103 and 0.129 g H2O [g DW] ?1, respectively. Water content, germination percentage and fresh weight of seedlings produced by surviving seeds gradually decreased with increasing treatment time at 100℃. Germination percentage of maize (Zea mays L. ‘Huangbaogu’) seeds was zero after they were treated at 100℃ for 15 min and that of lotus seeds was 13.5% following the treatment at 100℃ for 24 h. The time in which 50% of lotus and maize seeds were killed by 100℃ was about 14.5 h and 6 min, respectively. With increasing treatment time at 100℃, relative electrolyte leakage of lotus axes increased significantly, and total chlorophyll content of lotus axes markedly decreased. When treatment time at 100℃ was less than 12 h, subcellular structure of lotus hypocotyls remained fully intact. When treatment time at 100℃ was more than 12 h, plasmoly-sis gradually occurred, endoplasmic reticulum became unclear, nuclei and nucleoli broke down, most of mitochondria swelled, lipid granules accumulated at the cell periphery, and organelles and plas-molemma collapsed. Malondialdehyde (MDA) content of lotus axes and cotyledons decreased during 0-12 h of the treatment at 100℃ and then increased. By contrast, the MDA content of maize embryos and endosperms increased during 5-10 min of the treatment at 100℃ and then decreased slightly. For lotus seeds: (1) activities of superoxide dismutase (SOD) and glutathione reductase (GR) of axes and cotyledons and of catalase (CAT) of axes increased during the early phase of treatment at 100℃ and then decreased; and (2) activities of ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) of axes and cotyledons and of CAT of cotyledons gradually decreased with increasing treat-ment time at 100℃. For maize seeds: (1) activities of SOD and DHAR of embryos and endosperms and of GR of embryos increased during the early phase of the treatment at 100℃ and then decreased; and (2) activities of APX and CAT of embryos and endosperms and of GR of endosperms rapidly decreased with increasing treatment time at 100℃. With decrease in seed germination, activities of SOD, APX, CAT, GR and DHAR of axes and cotyledons of lotus seeds decreased slowly, and those of embryos and endosperms of maize seeds decreased rapidly. 展开更多
关键词 activities of antioxidant enzymes extreme high-temperature tolerance lipid peroxidation Nelumbo nucifera seeds subcellular structure Zea mays seeds
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Abiotic stress treatment reveals expansin like A gene OfEXLA1 improving salt and drought tolerance of Osmanthus fragrans by responding to abscisic acid 被引量:1
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作者 Bin Dong Qianqian Wang +7 位作者 Dan Zhou Yiguang Wang Yunfeng Miao Shiwei Zhong Qiu Fang Liyuan Yang Zhen Xiao Hongbo Zhao 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期573-585,共13页
Sweet osmanthus(Osmanthus fragrans) is a having general approval aromatic tree in China that is widely applied to landscaping and gardening. However, the evergreen tree adaptability is limited by many environmental st... Sweet osmanthus(Osmanthus fragrans) is a having general approval aromatic tree in China that is widely applied to landscaping and gardening. However, the evergreen tree adaptability is limited by many environmental stresses. Currently, limited information is available regarding the genetic analysis and functional identification of expansin genes in response to abiotic stress in sweet osmanthus. In this study, a total of 29 expansin genes were identified and divided into four groups by genome-wide analysis from the sweet osmanthus genome. Transcriptome and quantitative Real-time PCR analysis showed that the cell wall-localized protein expansin-like A(OfEXLA1) gene was significantly induced by salt and drought treatment. Histochemical GUS staining of transgenic Arabidopsis lines in which GUS activity was driven with the OfEXLA1 promoter, GUS activity was significantly induced by salt, drought, and exogenous abscisic acid(ABA). In yeast, we found OfEXLA1overexpression significantly improved the population of cells compared with wild-type strains after NaCl and polyethylene glycol(PEG)treatment. Additionally, OfEXLA1 overexpression not only promoted plant growth, but also improved the salt and drought tolerance in Arabidopsis. To gain insight into the role of ABA signaling in the regulation of OfEXLA1 improving abiotic tolerance in sweet osmanthus, four differentially expressed ABA Insensitive 5(ABI5)-like genes(OfABL4, OfABL5, OfABL7, and OfABL8) were identified from transcriptome, and dualluciferase(dual-LUC) and yeast one hybrid(Y1H) assay showed that OfABL4 and OfABL5 might bind to OfEXLA1 promoter to accumulate the OfEXLA1 expression by responding to ABA signaling to improve abiotic tolerance in sweet osmanthus. These results provide the information for understanding the molecular functions of expansin-like A gene and molecular breeding of sweet osmanthus in future. 展开更多
关键词 Osmanthus fragrans Abiotic tolerance EXPANSIN Abscisic acid
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Harness High-Temperature Thermal Energy via Elastic Thermoelectric Aerogels
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作者 Hongxiong Li Zhaofu Ding +5 位作者 Quan Zhou Jun Chen Zhuoxin Liu Chunyu Du Lirong Liang Guangming Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期196-210,共15页
Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature moni... Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge.Herein,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor enhancement.The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring.Subsequently,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 K.This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines.Moreover,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand gestures.The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability.Benefitting from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare. 展开更多
关键词 THERMOELECTRICS AEROGEL SELF-POWERED high-temperature monitoring high-temperature warning
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The UDP-glycosyltransferase OsUGT706D2 positively regulates cold and submergence stress tolerance in rice
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作者 Qing Liu Lanlan Zhang +12 位作者 Shuwei Lyu Hang Yu Wenjie Huang Liqun Jiang Jing Zhang Bingrui Sun Xingxue Mao Pingli Chen Junlian Xing Wenfeng Chen Zhilan Fan Shijuan Yan Chen Li 《The Crop Journal》 SCIE CSCD 2024年第3期732-742,共11页
In a genome-wide association study,we identified a rice UDP-glycosyltransferase gene,OsUGT706D2,whose transcription was activated in response to cold and submergence stress and to exogenous abscisic acid(ABA).OsUGT706... In a genome-wide association study,we identified a rice UDP-glycosyltransferase gene,OsUGT706D2,whose transcription was activated in response to cold and submergence stress and to exogenous abscisic acid(ABA).OsUGT706D2 positively regulated the biosynthesis of tricin-4’-O-(syringyl alcohol)ether-7-O-glucoside at both the transcriptional and metabolic levels.OsUGT706D2 mediated cold and submergence tolerance by modulating the expression of stress-responsive genes as well as the abscisic acid(ABA)signaling pathway.Gain of function of OsUGT706D2 increased cold and submergence tolerance and loss of function of OsUGT706D2 reduced cold tolerance.ABA positively regulated OsUGT706D2-mediated cold tolerance but reduced submergence tolerance.These findings suggest the potential use of OsUGT706D2 for improving abiotic stress tolerance in rice. 展开更多
关键词 UDP-glycosyltransferase RICE Cold tolerance Submergence tolerance ABA
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Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus
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作者 Jianjun Wang Yanan Shao +4 位作者 Xin Yang Chi Zhang Yuan Guo Zijin Liu Mingxun Chen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期1864-1878,共15页
Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid bi... Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.However,the function of SAD orthologs from L.usitatissimum has not been assessed.Here,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of L.usitatissimum cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.Interestingly,ectopic expression of LuSAD2 in A.thaliana caused altered plant architecture.Similarly,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.Furthermore,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane damage.These findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation. 展开更多
关键词 LuSAD oleic acid cold tolerance drought tolerance Linum usitatissimum Brassica napus
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Synergistic effect of Zr and Mo on precipitation and high-temperature properties of Al-Si-Cu-Mg alloys
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作者 Chao Gao Bing-rong Zhang +2 位作者 Yin-ming Li Zhi-ming Wang Xiang-bin Meng 《China Foundry》 SCIE EI CAS CSCD 2024年第1期71-81,共11页
This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,... This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg alloy.The synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were studied.Results show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the alloy.They can improve the strength of the alloy by hindering dislocation movement and crack propagation.In addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain refinement.The addition of Mo greatly improves the heat resistance of the alloy.The extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy. 展开更多
关键词 Al-Si-Cu-Mg alloy high-temperature properties Zr-Mo-rich intermetallics nano-strengthening phases
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HZSM-5 zeolites undergoing the high-temperature process for boosting the bimolecular reaction in n-heptane catalytic cracking
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作者 Chenggong Song Zhenzhou Ma +6 位作者 Xu Hou Hao Zhou Huimin Qiao Changchang Tian Li Yin Baitang Jin Enxian Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期136-144,共9页
High-temperature treatment is key to the preparation of zeolite catalysts.Herein,the effects of hightemperature treatment on the property and performance of HZSM-5 zeolites were studied in this work.X-Ray diffraction,... High-temperature treatment is key to the preparation of zeolite catalysts.Herein,the effects of hightemperature treatment on the property and performance of HZSM-5 zeolites were studied in this work.X-Ray diffraction,N2physisorption,27Al magic angle spinning nuclear magnetic resonance(MAS NMR),and temperature-programmed desorption of ammonia results indicated that the hightemperature treatment at 650℃ hardly affected the inherent crystal and texture of HZSM-5zeolites but facilitated the conversion of framework Al to extra-framework Al,reducing the acid site and enhancing the acid strength.Moreover,the high-temperature treatment improved the performance of HZSM-5 zeolites in n-heptane catalytic cracking,promoting the conversion and light olefins yield while inhibiting coke formation.Based on the kinetic and mechanism analysis,the improvement of HZSM-5 performance caused by high-temperature treatment has been attributed to the formation of extra-framework Al,which enhanced the acid strength,facilitated the bimolecular reaction,and promoted the entropy change to overcome a higher energy barrier in n-heptane catalytic cracking. 展开更多
关键词 HZSM-5 N-HEPTANE Catalytic cracking high-temperature treatment Extra-framework Al
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Rice Heat Tolerance Breeding: A Comprehensive Review and Forward Gaze
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作者 Ravindran Lalithambika VISAKH Sreekumar ANAND +4 位作者 Sukumaran Nair ARYA Behera SASMITA Uday Chand JHA Rameswar Prasad SAH Radha BEENA 《Rice science》 SCIE CSCD 2024年第4期375-400,I0022,共27页
The yield potential of rice is seriously affected by heat stress due to climate change. Since rice is a staple food globally, it is imperative to develop heat-resistant rice varieties. Thus, a thorough understanding o... The yield potential of rice is seriously affected by heat stress due to climate change. Since rice is a staple food globally, it is imperative to develop heat-resistant rice varieties. Thus, a thorough understanding of the complex molecular mechanisms underlying heat tolerance and the impact of high temperatures on various critical stages of the crop is needed. Adoption of both conventional and innovative breeding strategies offers a long-term advantage over other methods, such as agronomic practices, to counter heat stress. In this review, we summarize the effects of heat stress, regulatory pathways for heat tolerance, phenotyping strategies, and various breeding methods available for developing heat-tolerant rice. We offer perspectives and knowledge to guide future research endeavors aimed at enhancing the ability of rice to withstand heat stress and ultimately benefit humanity. 展开更多
关键词 genetic mechanism high-temperature stress molecular breeding genomics selection
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Cardiac Tolerance of Hydroalcoholic Extract of Bark of Terminalia mantaly H. Perrier (HAEBTM) in Wistar Rats
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作者 Irié Lou Bohila Emilie Kamo Kouakou Serge Kouassi +3 位作者 Virginie Atto Allico Joseph Djaman Jean David N’guessan Mireille Dosso 《American Journal of Molecular Biology》 CAS 2024年第3期126-137,共12页
Terminalia mantaly H. Perrier is a plant used in traditional medicine for the treatment of various pathologies. However, Terminalia mantaly H. Perrier could present potential health effects on patients. In order to de... Terminalia mantaly H. Perrier is a plant used in traditional medicine for the treatment of various pathologies. However, Terminalia mantaly H. Perrier could present potential health effects on patients. In order to determine the possible cardiotoxic effects of the hydro-alcoholic extract of the bark of Terminalia mantaly H. Perrier, (HAEBTM) forty (40) rats distributed randomly into 4 groups, including 10 animals per group (5 males and 5 females) were used. Animals in group 1 received distilled water and were used as a control group. On the other hand, groups 2, 3, 4 received oral administration a volume of the hydroalcoholic extract of Terminalia mantaly H. Perrier corresponding to 1 mL/100g of body weight at 150 mg/kg, 300 mg/kg, 600 mg/kg, respectively. The extract was administered daily at the same time for 28 days and serum was collected once a week to evaluate cardiac biochemical markers using spectrophotometric methods using a Cobas C311 HITACHI biochemistry system. After one month of study, all rats were euthanized by overdose of ether, and the hearts of the rats were removed for gross morphological and histopathological analysis. Results were analysed using variance analysis (ANOVA) to compare outcomes as a function of doses administered and treatment times. The biochemical parameters ALT, LDH, CPK, CPKMB showed no significant change (p Terminalia mantaly showed no lesions, edema and necrosis. These results suggest that the hydroalcoholic extract of Terminalia mantaly did not interfere with the functioning or alter the integrity of the heart. 展开更多
关键词 Terminalia mantaly Bio Cardiac tolerance Biochemical Markers HISTOPATHOLOGY
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Leaf Morphology Genes SRL1 and RENL1 Co-Regulate Cellulose Synthesis and Affect Rice Drought Tolerance
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作者 LIU Dan ZHAO Huibo +18 位作者 WANG Zi’an XU Jing LIU Yiting WANG Jiajia CHEN Minmin LIU Xiong ZHANG Zhihai CEN Jiangsu ZHU Li HU Jiang REN Deyong GAO Zhenyu DONG Guojun ZHANG Qiang SHEN Lan LI Qing QIAN Qian HU Songping ZHANG Guangheng 《Rice science》 SCIE CSCD 2024年第1期103-117,I0020-I0022,共18页
The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between... The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to drought environment.In this study,a drought-sensitive,roll-enhanced,and narrow-leaf mutant(renl1)was induced from a semi-rolled leaf mutant(srl1)by ethyl methane sulfonate(EMS),which was obtained from Nipponbare(NPB)through EMS.Map-based cloning and functional validation showed that RENL1 encodes a cellulose synthase,allelic to NRL1/OsCLSD4.The RENL1 mutation resulted in reduced vascular bundles,vesicular cells,cellulose,and hemicellulose contents in cell walls,diminishing the water-holding capacity of leaves.In addition,the root system of the renl1 mutant was poorly developed and its ability to scavenge reactive oxygen species(ROS)was decreased,leading to an increase in ROS after drought stress.Meanwhile,genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components.Our results revealed a theoretical basis for further elucidating the molecular regulation mechanism of cellulose on rice drought tolerance,and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance,thereby realizing simultaneous improvement of multiple traits in rice. 展开更多
关键词 CELLULOSE cell wall drought tolerance leaf morphology RICE
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MIR1868 negatively regulates rice cold tolerance at both the seedling and booting stages
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作者 Yang Shen Xiaoxi Cai +7 位作者 Yan Wang Wanhong Li Dongpeng Li Hao Wu Weifeng Dong Bowei Jia Mingzhe Sun Xiaoli Sun 《The Crop Journal》 SCIE CSCD 2024年第2期375-383,共9页
Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive s... Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive stages.This study revealed a rice-specific 24-nt miRNA,miR1868,whose accumulation was suppressed by cold stress.Knockdown of MIR1868 increased seedling survival,pollen fertility,seed setting,and grain yield under cold stress,whereas its overexpression conferred the opposite phenotype.Knockdown of MIR1868 increased reactive oxygen species(ROS)scavenging and soluble sugar content under cold stress by increasing the expression of peroxidase genes and sugar metabolism genes,and its overexpression produced the opposite effect.Thus,MIR1868 negatively regulated rice cold tolerance via ROS scavenging and sugar accumulation. 展开更多
关键词 RICE Cold tolerance MIRNA ROS scavenging Soluble sugar accumulation
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Overexpression of the peroxidase gene ZmPRX1 increases maize seedling drought tolerance by promoting root development and lignification
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作者 Xiuzhen Zhai Xiaocui Yan +6 位作者 Tinashe Zenda Nan Wang Anyi Dong Qian Yang Yuan Zhong Yue Xing Huijun Duan 《The Crop Journal》 SCIE CSCD 2024年第3期753-765,共13页
Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the m... Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars. 展开更多
关键词 Drought tolerance MAIZE ZmPRX1 Root development Lignin biosynthesis
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A Novel Fracturing Fluid with High-Temperature Resistance for Ultra-Deep Reservoirs
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作者 Lian Liu Liang Li +2 位作者 Kebo Jiao Junwei Fang Yun Luo 《Fluid Dynamics & Materials Processing》 EI 2024年第5期975-987,共13页
Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do ... Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are used.In response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking agents.The fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/L.Compared with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction wells.Moreover,the new fracturing fluid can significantly mitigate safety risks. 展开更多
关键词 Ultra-deep reservoir high-temperature resistance weighted fracturing fluid guanidine gum potassium formatted
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Humoral Response and Tolerance of Vaccination against SARS-CoV-2 in Adults Senegalese Patients Undergoing Hemodialysis: A Multicenter Prospective Study
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作者 Lot Nehemie Motoula Latou Moustapha Mbow +3 位作者 Modou Ndongo Gnagna Faye Gora Lo Sidy Mohamed Seck 《Open Journal of Nephrology》 2024年第1期70-80,共11页
Introduction: Following the COVID-19 pandemic, vaccination has been proposed in several countries as the main preventive measure despite very limited data, particularly in dialysis patients. We conducted this study to... Introduction: Following the COVID-19 pandemic, vaccination has been proposed in several countries as the main preventive measure despite very limited data, particularly in dialysis patients. We conducted this study to assess the immunological response to vaccination in Senegalese hemodialysis patients. Patients and Methods: We conducted a prospective study, in two dialysis centers in Dakar from March 30<sup>th</sup> to August 30<sup>th</sup>, 2021 including patients on hemodialysis for >6 months, vaccinated against SARS-CoV-2 according to the vaccination schedule recommended by WHO. A vaccine response was considered positive when seroconversion was observed after one dose of vaccine. The clinical efficacy of immunization was defined as the absence of new COVID-19 infection in patients who received a complete vaccination. Results: Among the 81 patients included in the study, 7.4% had anti-Spike IgM antibodies before their first vaccination. Seroprevalence of IgM antibodies was 38.3% one month after the first vaccine dose (at M1) and 8.6% one month after the second dose (at M4). Anti-Spike IgG antibodies were present in 40.3% of patients before vaccination, in 90.1% at M1, and in 59.7% at M4. Among patients previously infected with SARS-CoV-2, 10.2% had IgM antibodies at M0, 31.6% at M1, and 10.5% at M4 post-vaccination. Similarly, seroprevalences of IgG antibodies in this subgroup were 31.5%, 61.3%, and 50.0% respectively at M0, M1, and M4 post-vaccination. A comparison of seroconversion rates between M0 and M4 showed significant differences only for IgG in COVID-19 naive patients. Mean duration in dialysis and the existence of previous COVID-19 infection were associated with patients’ vaccinal response after the two doses. Age, gender and the use of immunosuppressive treatment did not influence post-vaccinal antibody production. Conclusion: Vaccination against COVID-19 in Senegalese hemodialysis patients induced a low seroconversion rate but it was well tolerated. Moreover, the induced protection was neither strong nor durable, particularly in patients with longer duration in dialysis. 展开更多
关键词 SARS-Cov2 Vaccination Humoral Response tolerance HEMODIALYSIS Senegal
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Alkali Tolerance of Concrete Internal Curing Agent Based on Sodium Carboxymethyl Starch
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作者 陈梅花 刘荣进 +3 位作者 CHEN Ping JING Daiyan WAN Dandan FU Siyuan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期82-90,共9页
Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete.An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using ... Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete.An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using sodium carboxymethyl starch (CMS) with high hydrophilicity,acrylic acid (AA) containing anionic carboxylic group and acrylamide (AM) containing non-ionic amide group as the main raw materials.The results show that the ratio of CAA-ICA alkali absorption solution is higher than that existing ICA,which solves the low water absorption ratio of the ICA in alkali environment.The water absorption ratio of CAA-ICA in saturated Ca(OH)_(2) solution is 95.8 g·g^(-1),and the alkali tolerance coefficient is 3.4.The application of CAA-ICA in cement-based materials can increase the internal relative humidity and miniaturize the pore structure.The compressive strength of mortar increases up to 12.95%at 28 d,which provids a solution to overcome the reduction of the early strength. 展开更多
关键词 alkali tolerance sodium carboxymethyl starch internal curing agent compressive strength
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Novel Method for Evaluating the Aging of Aviation Turbine Engine Oils via High-Temperature Bearing Deposit Tests
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作者 Hao Lichun Yang He +3 位作者 Song Haiqing Zhou Yunfan He Jingjian Liang Yuxiang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期67-77,共11页
Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidat... Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidative performance of aviation lubricant oils,and the relevant apparatus was improved in the present study.Two different commercial aviation turbine engine oils were tested,one with standard performance(known as the SL oil)and the other with high thermal stability,and their thermal-oxidative stability characteristics were evaluated.After 100 h of high-temperature bearing testing,the SL oil was analyzed by using various analytical techniques to investigate its thermal-oxidative process in the bearing test,with its thermal-oxidative degradation mechanism also being discussed.The results indicate that the developed high-temperature bearing apparatus easily meets the test requirements of method 3410.1 in standard FED-STD-791D.The viscosity and total acid number(TAN)of the SL oil increased with the bearing test time,and various deposits were produced in the bearing test,with the micro-particles of the carbon deposits being sphere-like,rod-like,and sheet-like in appearance.The antioxidant additives in the oil were consumed very rapidly in the first 30 h of the bearing test,with N-phenyl-1-naphthylamine being consumed faster than dioctyldiphenylamine.Overall,the oil thermal-oxidative process involves very complex physical and chemical mechanisms. 展开更多
关键词 aviation turbine engine oil high-temperature bearing deposit test thermal-oxidative degradation antioxidant additives
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Compositional and Hollow Engineering of Silicon Carbide/Carbon Microspheres as High-Performance Microwave Absorbing Materials with Good Environmental Tolerance
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作者 Lixue Gai Yahui Wang +5 位作者 Pan Wan Shuping Yu Yongzheng Chen Xijiang Han Ping Xu Yunchen Du 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期128-146,共19页
Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable M... Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications. 展开更多
关键词 SiC/C composites Compositional engineering Hollow engineering Microwave absorption Environmental tolerance
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High-performance and robust high-temperature polymer electrolyte membranes with moderate microphase separation by implementation of terphenyl-based polymers
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作者 Jinyuan Li Congrong Yang +3 位作者 Haojiang Lin Jicai Huang Suli Wang Gongquan Sun 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期572-578,共7页
Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(te... Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the membrane.Highly rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing effect.As a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer ratios.The designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging tests.As a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel cell.The results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs. 展开更多
关键词 Fuel cell high-temperature polymer electrolyte membranes Microphase separation Poly(terphenyl piperidinium)s Phosphoric acid
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A Data Intrusion Tolerance Model Based on an Improved Evolutionary Game Theory for the Energy Internet
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作者 Song Deng Yiming Yuan 《Computers, Materials & Continua》 SCIE EI 2024年第6期3679-3697,共19页
Malicious attacks against data are unavoidable in the interconnected,open and shared Energy Internet(EI),Intrusion tolerant techniques are critical to the data security of EI.Existing intrusion tolerant techniques suf... Malicious attacks against data are unavoidable in the interconnected,open and shared Energy Internet(EI),Intrusion tolerant techniques are critical to the data security of EI.Existing intrusion tolerant techniques suffered from problems such as low adaptability,policy lag,and difficulty in determining the degree of tolerance.To address these issues,we propose a novel adaptive intrusion tolerance model based on game theory that enjoys two-fold ideas:(1)it constructs an improved replica of the intrusion tolerance model of the dynamic equation evolution game to induce incentive weights;and (2)it combines a tournament competition model with incentive weights to obtain optimal strategies for each stage of the game process.Extensive experiments are conducted in the IEEE 39-bus system,whose results demonstrate the feasibility of the incentive weights,confirm the proposed strategy strengthens the system’s ability to tolerate aggression,and improves the dynamic adaptability and response efficiency of the aggression-tolerant system in the case of limited resources. 展开更多
关键词 Energy Internet Intrusion tolerance game theory racial competition adaptive intrusion response
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Cellular strategies to induce immune tolerance after liver transplantation:Clinical perspectives
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作者 Ai-Wei Zhou Jing Jin Yuan Liu 《World Journal of Gastroenterology》 SCIE CAS 2024年第13期1791-1800,共10页
Liver transplantation(LT)has become the most efficient treatment for pediatric and adult end-stage liver disease and the survival time after transplantation is becoming longer due to the development of surgical techni... Liver transplantation(LT)has become the most efficient treatment for pediatric and adult end-stage liver disease and the survival time after transplantation is becoming longer due to the development of surgical techniques and perioperative management.However,long-term side-effects of immunosuppressants,like infection,metabolic disorders and malignant tumor are gaining more attention.Immune tolerance is the status in which LT recipients no longer need to take any immunosuppressants,but the liver function and intrahepatic histology maintain normal.The approaches to achieve immune tolerance after transplantation include spontaneous,operational and induced tolerance.The first two means require no specific intervention but withdrawing immunosuppressant gradually during follow-up.No clinical factors or biomarkers so far could accurately predict who are suitable for immunosuppressant withdraw after transplantation.With the understanding to the underlying mechanisms of immune tolerance,many strategies have been developed to induce tolerance in LT recipients.Cellular strategy is one of the most promising methods for immune tolerance induction,including chimerism induced by hematopoietic stem cells and adoptive transfer of regulatory immune cells.The safety and efficacy of various cell products have been evaluated by prospective preclinical and clinical trials,while obstacles still exist before translating into clinical practice.Here,we will summarize the latest perspectives and concerns on the clinical application of cellular strategies in LT recipients. 展开更多
关键词 Cellular therapy Induced tolerance Liver transplantation Regulatory T cells Regulatory dendritic cells
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