To study the resistant mechanisms of cisplatin in human lung adenocarcinoma cell line A 549 DDP. A 549 DDP cells was established by stepwise increasing concentration of cisplatin (CDDP) in medium. Interstran...To study the resistant mechanisms of cisplatin in human lung adenocarcinoma cell line A 549 DDP. A 549 DDP cells was established by stepwise increasing concentration of cisplatin (CDDP) in medium. Interstrand cross linked DNA (ICL) was measured by ethidium bromide fluorescence assay. The intracellular and intranuclear accumulation of cisplatin was measured by atomic absorption spectrometry. The removal of GS X was determined by FCM and fluorescence microscopy. Results: The A 549 DDP cell line was 8.9 fold resistance relative to the parental A 549 cell line. The formation of ICL in A 549 was 6.28 times higher than that in A 549 DDP cells. The intracellular and intranuclear accumulation of cisplatin in A 549 cells was 5.9 times and 4.1 times higher than that in A 549 DDP cells, respectively. The ability of GS X pump pumped GS X complex (GS Pt) in A 549 DDP cells was higher than that in A 549 . The repair rate in A 549 DDP cells was 2 times higher than that in A 549 . Conclusions: Decreased accumulation and increased export of cisplatin might be the main mechanism of cisplatin resistant A 549 DDP cells while the enhanced repair capacity of DNA may play a role in CDDP resistance.展开更多
The microporous corundum material was prepared using alumina micro-powder as the main raw material, alumina sol and starch as binders by a wet process, achieving the bulk density of 3.05 g · cm^-3, the apparent p...The microporous corundum material was prepared using alumina micro-powder as the main raw material, alumina sol and starch as binders by a wet process, achieving the bulk density of 3.05 g · cm^-3, the apparent porosity of 9. 1%, the closed porosity of 12.3%, the median pore diameter of 0. 43 μm, and the thermal conductivity of 6. 5 W· m^-1· K^-1 at 800 ℃ which is 41.6% lower than that of common corundum. The slag resistance of the microporous corundum material was studied by immersion and compared with that of the common corundum aggregate, and the slag resistant mechanism of microporous corundum material was revealed. The results show that the slag resistance of the microporous corundum material is superior to that of the common corundum aggregate, the SEM and EDX show that on the reaction interface between microporous corundum and molten, slag, a continuous isolation layer with a large quantity of CA2 and CA6 columnar crystals is formed; while the common corundum aggregate reacts with the molten slag interface to form a discontinuous isolation layer of columnar crystals, through which a lot of molten slag corrodes or permeates into the aggregate. The mechanism is mainly that the microporous structure is more advantageous to nucleation and growth of CA2 and CA6 columnar crystals; in the reaction with the aggregate, the molten slag gets saturated and the critical solution thickness of the microporous corundum and the common corundum is 0. 16 μm and 0. 34 μm, respectively, this is caused by the smaller microporous corundum aggregate pores; and the smaller pores also increase the second phase ripening rate of microporous corundum, which is 9. 7 times of that of the common corundum.展开更多
Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylost...Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylostella.In the present study,we aimed to confirm the resistance risk,cross-resistance,and mechanisms of resistance to thiotraniliprole in P.xylostella.After 40 consecutive generations of thiotraniliprole selection,we obtained a thiotraniliprole-resistance P.xylostella strain with a 5141.58-fold resistance ratio(RR)to thiotraniliprole.The overall realized heritability(h^(2))value of resistance was estimated as 0.9 using threshold trait analysis,indicating that the risk of developing resistance to thiotraniliprole is high in P.xylostella.The thiotraniliprole-resistant(TR)strain showed noticeable cross-resistance to chlorantraniliprole(RR=44670.05),cyantraniliprole(RR=7038.58),and tetrachlorantraniliprole(RR=1506.01),but no cross-resistance to tolfenpyrad,indoxacarb,diafenthiuron,or abamectin compared with the susceptible(S)strain.The enzyme assay data showed that the activities of glutathione-S transferase(GST),carboxylesterase(CarE),and the content of cytochrome P450 monooxygenase(P450s)were significantly higher in the TR strain than in the S strain.Sequencing of the full-length PxRyR cDNA revealed the gene site I4790K in the TR strain with a 100%frequency.This mutation in PxRyR likely underlies the high-level cross-resistance between thiotraniliprole and three other diamide insecticides.These findings provide valuable information for optimizing resistance management strategies to delay thiotraniliprole resistance development and ensure sustainable control of P.xylostella.展开更多
Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed qual...Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed quality of soybean.The current resistant varieties are difficult to meet the production demand.The breeders have identified 50 different physiological small species and discussed the physiological and biochemical characteristics of soybean resistance to FLS.In soybean disease resistance breeding,resistance resources are screened for the main physiological races in different countries,resistance materials are created,more than 100 genome regions associated with resistance are located,and 12 resistance-related genes are identified.In order to promote the research of soybean disease resistance breeding,this paper expounded and analyzed the pathogenesis characteristics of soybean FLS,the division of races,the physiological and biochemical mechanism of soybean resistance to FLS disease,quantitative trait locus(QTL),quantitative trait nucleotides(QTN),genes of resistance sites,the screening of resistant germplasm resources,and the breeding of new varieties,so as to gain an in-depth understanding of the pathogenesis principle of soybean FLS disease.In order to provide a theoretical basis and technical support for the breeding of soybean FLS disease,the resistance mechanism of soybean FLS disease was analyzed from the molecular level.展开更多
Verticillium wilt,caused by the infamous pathogen Verticillium dahliae,presents a primary constraint on cotton cul-tivation worldwide.The complexity of disease resistance in cotton and the largely unexplored interacti...Verticillium wilt,caused by the infamous pathogen Verticillium dahliae,presents a primary constraint on cotton cul-tivation worldwide.The complexity of disease resistance in cotton and the largely unexplored interaction dynamics between the cotton plant host and V.dahliae pathogen pose a crucial predicament for effectively managing cotton Verticillium wilt.Nevertheless,the most cost-effective approach to controlling this disease involves breeding and cul-tivating resistant cotton varieties,demanding a meticulous analysis of the mechanisms underlying cotton’s resistance to Verticillium wilt and the identification of pivotal genes.These aspects constitute focal points in disease-resistance breeding programs.In this review,we comprehensively discuss genetic inheritance associated with Verticillium wilt resistance in cotton,the advancements in molecular markers for disease resistance,the functional investiga-tion of resistance genes in cotton,the analysis of pathogenicity genes in V.dahliae,as well as the intricate interplay between cotton and this fungus.Moreover,we delve into the future prospects of cutting-edge research on cotton Verticillium wilt,aiming to proffer valuable insights for the effective management of this devastating fungus.展开更多
Rockburst is a common disaster in deep underground engineering,which seriously impacts project construction safety.Understanding its causes and burst resistance mechanism is of significance for rockburst prevention an...Rockburst is a common disaster in deep underground engineering,which seriously impacts project construction safety.Understanding its causes and burst resistance mechanism is of significance for rockburst prevention and mitigation.We developed a new type of high strength,large elongation,and strong energy-absorbing material,and conducted comparative tests on both basic and anchored rock specimens with such material.We analyzed the rockburst process,energy release and peak stress of the rock,and force and deformation withstood by the energy-absorbing bolts.The experimental results show that the energy reduction rate of the rocks reinforced by energy-absorbing bolts is more than 80%,compared with that of the basic rock.The force exerted on the energy-absorbing bolts increases suddenly when the rockburst occurs,and the strength utilization rates of the energy-absorbing bolts under strain rockburst and impact rockburst conditions are 73.3%and 61.2%,respectively.Rockburst also causes non-uniform shear deformation of the anchor bolt.Based on the rockburst energy criterion,the peak stress of the anchored rock is 2.2 times and 2.5 times the uniaxial compressive strength of the rock,respectively,under strain rockburst and impact rockburst conditions.The energy required for rockburst is 396.0 and 478.4 kJ/m^(3),respectively.The energy-anchoring bolts can effectively reduce the likelihood of rockburst.The results can provide a reference for support design for burst-prone rock in underground engineering.展开更多
Neuromorphic computing has the potential to overcome limitations of traditional silicon technology in machine learning tasks.Recent advancements in large crossbar arrays and silicon-based asynchronous spiking neural n...Neuromorphic computing has the potential to overcome limitations of traditional silicon technology in machine learning tasks.Recent advancements in large crossbar arrays and silicon-based asynchronous spiking neural networks have led to promising neuromorphic systems.However,developing compact parallel computing technology for integrating artificial neural networks into traditional hardware remains a challenge.Organic computational materials offer affordable,biocompatible neuromorphic devices with exceptional adjustability and energy-efficient switching.Here,the review investigates the advancements made in the development of organic neuromorphic devices.This review explores resistive switching mechanisms such as interface-regulated filament growth,molecular-electronic dynamics,nanowire-confined filament growth,and vacancy-assisted ion migration,while proposing methodologies to enhance state retention and conductance adjustment.The survey examines the challenges faced in implementing low-power neuromorphic computing,e.g.,reducing device size and improving switching time.The review analyses the potential of these materials in adjustable,flexible,and low-power consumption applications,viz.biohybrid spiking circuits interacting with biological systems,systems that respond to specific events,robotics,intelligent agents,neuromorphic computing,neuromorphic bioelectronics,neuroscience,and other applications,and prospects of this technology.展开更多
Rice bakanae disease(RBD)is a devastating plant disease caused by Fusarium fujikuroi.This study aimed to evaluate the potential of cyclobutrifuram,a novel succinate dehydrogenase inhibitor(SDHI),to control RBD,and det...Rice bakanae disease(RBD)is a devastating plant disease caused by Fusarium fujikuroi.This study aimed to evaluate the potential of cyclobutrifuram,a novel succinate dehydrogenase inhibitor(SDHI),to control RBD,and determine the risk and mechanism of resistance to cyclobutrifuram in F.fujikuroi.In vitro experiments showed that cyclobutrifuram significantly inhibited mycelial growth and spore germination,and altered the morphology of mycelia and conidia.Treatment with cyclobutrifuram signifcantly decreased mycotoxin production and increased cell membrane permeability in F.fujikuroi.The baseline sensitivity of 72 F.fujikuroi isolates to cyclobutrifuram was determined using mycelial growth and spore germination inhibition assays,which revealed EC50values of 0.0114-0.1304 and 0.0012-0.016μg mL^(-1),with mean EC50values of(0.0410±0.0470)and(0.0038±0.0015)μg mL^(-1),respectively.Pot experiments demonstrated that the protective effect of cyclobutrifluram against F.fujikuroi was more significant than that of phenamacril and azoxystrobin,indicating that cyclobutrifuram is a promising antifungal agent for the control of RBD.Six cyclobutrifuramresistant mutants of F.fujikuroi were obtained via fungicide adaptation.Moreover,these mutants exhibited weaker ftness than their parental isolate and positive cross-resistance with other SDHI fungicides,including pydifumetofen and penfufen;however,no cross-resistance was detected with other classes of fungicides,including phenamacril,fudioxonil,prochloraz,or azoxystrobin.These results indicated that the resistance risk of F.fujikuroi to cyclobutrifuram might be moderate.Sequencing analysis revealed that mutations,including H248D in Ff Sdh B,A83V in Ff Sdh C2,and S106F and E166K in Ff Sdh D,contributed to resistance,which was confrmed by molecular docking and homologous replacement experiments.The results suggest a high potential for cyclobutrifuram to control RBD and a moderate resistance risk of F.fujikuroi to cyclobutrifuram,which are meaningful fndings for the scientifc application of cyclobutrifuram.展开更多
Chlamydia Trachomatis (C.T.) is one of the most common pathogens of human sexually transmitted diseases. Treatment of C.T. infection primarily depends on Tetracyclines, Macrolides and Quinolones, but with the wide use...Chlamydia Trachomatis (C.T.) is one of the most common pathogens of human sexually transmitted diseases. Treatment of C.T. infection primarily depends on Tetracyclines, Macrolides and Quinolones, but with the wide use of antibiotics an increasing number of drug-resistant Chlamydia trachomatis cases have been reported. This review summarizes the resistant conditions and the possible resistance mechanisms of C.T..展开更多
One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper （SBPH） （Laodelphax striatellus Fallen） by the modified seedbox screening test. Twenty-five rice accessions w...One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper （SBPH） （Laodelphax striatellus Fallen） by the modified seedbox screening test. Twenty-five rice accessions with different levels of resistance to SBPH were detected, accounting for 18.1% of the total accessions, which included 2 highly resistant, 9 resistant and 14 moderately resistant varieties. Compared with indica rice, japonica rice was more susceptible to SBPH. Antixenosis test, antibiosis test and correlation analysis were performed to elucidate the resistance mechanism. The resistant check Rathu Heenati （RHT）, highly resistant varieties Mudgo and Kasalath, and resistant variety IR36 expressed strong antixenosis and antibiosis against SBPH, indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties. Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis. Dular, ASD7 and Milyang 23 had relatively strong antixenosis and antibiosis, indicating the two resistance mechanisms were significant in these three varieties. The resistant DV85 expressed relatively high level of antixenosis but low antibiosis, whereas Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH, suggesting tolerance in these three varieties. Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311. Antixenosis was the main resistance type in V20A. Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance. The above accessions with strong antibiosis or antixenosis were the ideal materials for the resistance breeding.展开更多
Carbapenem resistance presents a major challenge for the global public health network, as clinical infections caused by carbapenem-resistant organisms(CRO) are frequently associated with significant morbidity and mort...Carbapenem resistance presents a major challenge for the global public health network, as clinical infections caused by carbapenem-resistant organisms(CRO) are frequently associated with significant morbidity and mortality. Ceftazidime–avibactam(CAZ–AVI) is a novel cephalosporin/β-lactamase inhibitor combination offering an important advance in the treatment of CRO infections. CAZ–AVI has been reported to inhibit the activities of Ambler classes A, C, and some class D enzymes. However, bacterial resistance has been emerging shortly after the introduction of this combination in clinical use, with an increasing trend. Understanding these resistance mechanisms is crucial for guiding the development of novel treatments and aiding in the prediction of underlying resistance mechanisms. This review aims to systematically summarize the epidemiology of CAZ–AVI-resistant strains and recently identified resistance mechanisms of CAZ–AVI, with a focus on the production of β-lactamase variants, the hyperexpression of β-lactamases, reduced permeability, and overexpressed efflux pumps. The various mechanisms of CAZ–AVI resistance that have emerged within a short timescale emphasize the need to optimize the use of current agents, as well as the necessity for the surveillance of CAZ–AVI-resistant pathogens.展开更多
The Ti fire found in high performance engines promotes the development of burn resistant Ti alloys. The burn resistant mechanism of Ti40 alloy is investigated. Ti40 alloy reveals good burn resistance. Its interfacial ...The Ti fire found in high performance engines promotes the development of burn resistant Ti alloys. The burn resistant mechanism of Ti40 alloy is investigated. Ti40 alloy reveals good burn resistance. Its interfacial products between burning products and the matrix are tenacious, which retard the diffusion of oxygen into the matrix. Two burn resistant mechanisms, that is, fast scatter dispersion of heat and suppression of oxygen diffusion, are proposed.展开更多
Drought and shortage of water resources, which restrict the economy, society development and environmental protection, are key factors in arid zones of China. In the arid zones of Western China, researching plant drou...Drought and shortage of water resources, which restrict the economy, society development and environmental protection, are key factors in arid zones of China. In the arid zones of Western China, researching plant drought resistance mechanism, selecting plant species with higher drought resistance, and developing water-saving techniques, are important for environmental improvement and economic development. This paper reviews research advances on drought resistance mechanism of plant species, based on research of morphological, physiological, and ecological adaptation mechanism of plant species under drought stress, such as anatomical structure of root systems and leaves, photosynthesis, antioxidant enzyme system, malondialdehyde （MDA）, osmotic adjustment, endogenous hormone, drought-induced proteins and δ^13C. Finally, this paper points out the key field of future research.展开更多
Objective: To investigate the antimicrobial susceptibility of 97 clinical Staphylococcus aureus(S. aureus) strains against 14 antimicrobials and corresponding resistance mechanisms.Methods: The antimicrobial susceptib...Objective: To investigate the antimicrobial susceptibility of 97 clinical Staphylococcus aureus(S. aureus) strains against 14 antimicrobials and corresponding resistance mechanisms.Methods: The antimicrobial susceptibility of the isolates was determined using a disk diffusion method and antimicrobial resistance genes were screened by polymerase chain reaction. Mutations responsible for ciprofloxacin and rifampicin resistance were investigated by polymerase chain reaction and DNA sequencing.Results: All isolates were found to be susceptible to vancomycin. Various rates of resistance to penicillin(83.5%), ampicillin(77.3%), erythromycin(63.9%), tetracycline(16.5%), amoxicillin/clavulanic acid(16.5%), ciprofloxacin(15.5%), trimethoprim/sulfamethoxazole(15.5%), oxacillin(13.4%), fusidic acid(12.4%), rifampin(6.2%), clindamycin(6.2%), gentamicin(6.2%) and mupirocin(5.2%) were determined. In addition,different combinations of resistance genes were identified among resistant isolates.Ciprofloxacin resistant isolates had mutations in codon 84(Ser84 Leu) and 106(Gly106 Asp) in the gyr A gene. Mutations in grl A were mostly related to Ser80 Phe substitution. Leu466 Ser mutation in the rpo B gene was detected in all rifampin resistant isolates. All methicillin resistant S. aureus isolates were SCCmec type V.Conclusions: In conclusion, it was determined that the isolates were resistant to different classes of antimicrobials at varying rates and resistance was mediated by different genetic mechanisms. Therefore, continuous monitoring of resistance in S. aureus strains is necessary to control their resistance for clinically important antimicrobials.展开更多
The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area betw...The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine chain is fatigue wear, and its failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. In addition, the material, hot-treatment method and shaping technique for roller have a great influence upon the resistance to multi-impact. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technique are the effective method to increase its resistance to multi-impact.展开更多
Ovarian cancer is among the most lethal gynecological cancers,primarily due to the lack of specific symptoms leading to an advanced-stage diagnosis and resistance to chemotherapy.Drug resistance(DR)poses the most sign...Ovarian cancer is among the most lethal gynecological cancers,primarily due to the lack of specific symptoms leading to an advanced-stage diagnosis and resistance to chemotherapy.Drug resistance(DR)poses the most significant challenge in treating patients with existing drugs.The Food and Drug Administration(FDA)has recently approved three new therapeutic drugs,including two poly(ADP-ribose)polymerase(PARP)inhibitors(olaparib and niraparib)and one vascular endothelial growth factor(VEGF)inhibitor(bevacizumab)for maintenance therapy.However,resistance to these new drugs has emerged.Therefore,understanding the mechanisms of DR and exploring new approaches to overcome them is crucial for effective management.In this review,we summarize the major molecular mechanisms of DR and discuss novel strategies to combat DR.展开更多
In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation,the...In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation,theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified.展开更多
Cucumber is an important vegetable worldwide,and powdery mildew(PM)is a common and serious disease of cucumbers.Breeding disease-resistant cucumber varieties is the most advantageous strategy to control this disease.I...Cucumber is an important vegetable worldwide,and powdery mildew(PM)is a common and serious disease of cucumbers.Breeding disease-resistant cucumber varieties is the most advantageous strategy to control this disease.In recent years,exploration and identification of cucumber PM resistance genes have achieved great advancement,and many genes have been cloned and verified using different methods.However,the resistance mechanism of cucumber PM is still unclear,and many ambiguities need to be elucidated urgently.In this review,we summarized the research advances in PM resistance in cucumbers,including genetic analysis,quantitative trait locus mapping,map-based cloning,transcriptomics,mlo-mediated PM resistance,and mining of noncoding RNAs involved in resistance.Finally,the research directions and the problems that need to be solved in the future were discussed.展开更多
The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet saf...The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadwavs in Tertiary deed soft rock.展开更多
The measured data and simulation test phenomenon of surrounding rock deformation and failure at the project site indicate that shear failure which firstly occurs in surrounding rock, block slip and second shear failur...The measured data and simulation test phenomenon of surrounding rock deformation and failure at the project site indicate that shear failure which firstly occurs in surrounding rock, block slip and second shear failure are the root cause of deformation and damage of supporting structure of the surrounding rock at a large scale. We derived limit load of surrounding rock shear slip failure and reasonable support resistance of given load by means of shear slip line field theory, discussed the main factors which influence the limit load of surrounding rock. Shear slip line field and limit load of circular tunnel surrounding rock were obtained by means of physical simulation test, which agreed well with the theoretical analysis results. Based on the theoretical analysis and physical simulation test, the cause deformation and failure at large scale of Xinshanghai No. 1 coal mine big section ingate was analyzed, and the shear failure resistance and block slip in surrounding rock were proposed as the core technical supporting ideas. Proper range of supporting resistance which came from calculation was suggested. The support scheme which is mainly composed of large grouting anchor, sprayed anchor net support technique and full-face grille concrete finally ended the dilemma of repeated failure and mending of ingate and created critical conditions for smooth production in the coal mine.展开更多
文摘To study the resistant mechanisms of cisplatin in human lung adenocarcinoma cell line A 549 DDP. A 549 DDP cells was established by stepwise increasing concentration of cisplatin (CDDP) in medium. Interstrand cross linked DNA (ICL) was measured by ethidium bromide fluorescence assay. The intracellular and intranuclear accumulation of cisplatin was measured by atomic absorption spectrometry. The removal of GS X was determined by FCM and fluorescence microscopy. Results: The A 549 DDP cell line was 8.9 fold resistance relative to the parental A 549 cell line. The formation of ICL in A 549 was 6.28 times higher than that in A 549 DDP cells. The intracellular and intranuclear accumulation of cisplatin in A 549 cells was 5.9 times and 4.1 times higher than that in A 549 DDP cells, respectively. The ability of GS X pump pumped GS X complex (GS Pt) in A 549 DDP cells was higher than that in A 549 . The repair rate in A 549 DDP cells was 2 times higher than that in A 549 . Conclusions: Decreased accumulation and increased export of cisplatin might be the main mechanism of cisplatin resistant A 549 DDP cells while the enhanced repair capacity of DNA may play a role in CDDP resistance.
基金Financial supports from the National Natural Science Foundation of China(Nos.51474165 and 51204126)
文摘The microporous corundum material was prepared using alumina micro-powder as the main raw material, alumina sol and starch as binders by a wet process, achieving the bulk density of 3.05 g · cm^-3, the apparent porosity of 9. 1%, the closed porosity of 12.3%, the median pore diameter of 0. 43 μm, and the thermal conductivity of 6. 5 W· m^-1· K^-1 at 800 ℃ which is 41.6% lower than that of common corundum. The slag resistance of the microporous corundum material was studied by immersion and compared with that of the common corundum aggregate, and the slag resistant mechanism of microporous corundum material was revealed. The results show that the slag resistance of the microporous corundum material is superior to that of the common corundum aggregate, the SEM and EDX show that on the reaction interface between microporous corundum and molten, slag, a continuous isolation layer with a large quantity of CA2 and CA6 columnar crystals is formed; while the common corundum aggregate reacts with the molten slag interface to form a discontinuous isolation layer of columnar crystals, through which a lot of molten slag corrodes or permeates into the aggregate. The mechanism is mainly that the microporous structure is more advantageous to nucleation and growth of CA2 and CA6 columnar crystals; in the reaction with the aggregate, the molten slag gets saturated and the critical solution thickness of the microporous corundum and the common corundum is 0. 16 μm and 0. 34 μm, respectively, this is caused by the smaller microporous corundum aggregate pores; and the smaller pores also increase the second phase ripening rate of microporous corundum, which is 9. 7 times of that of the common corundum.
基金Supported by the Zhejiang Provincial Public Welfare Technology Application Research Program(No:LGN21C140001).
文摘Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylostella.In the present study,we aimed to confirm the resistance risk,cross-resistance,and mechanisms of resistance to thiotraniliprole in P.xylostella.After 40 consecutive generations of thiotraniliprole selection,we obtained a thiotraniliprole-resistance P.xylostella strain with a 5141.58-fold resistance ratio(RR)to thiotraniliprole.The overall realized heritability(h^(2))value of resistance was estimated as 0.9 using threshold trait analysis,indicating that the risk of developing resistance to thiotraniliprole is high in P.xylostella.The thiotraniliprole-resistant(TR)strain showed noticeable cross-resistance to chlorantraniliprole(RR=44670.05),cyantraniliprole(RR=7038.58),and tetrachlorantraniliprole(RR=1506.01),but no cross-resistance to tolfenpyrad,indoxacarb,diafenthiuron,or abamectin compared with the susceptible(S)strain.The enzyme assay data showed that the activities of glutathione-S transferase(GST),carboxylesterase(CarE),and the content of cytochrome P450 monooxygenase(P450s)were significantly higher in the TR strain than in the S strain.Sequencing of the full-length PxRyR cDNA revealed the gene site I4790K in the TR strain with a 100%frequency.This mutation in PxRyR likely underlies the high-level cross-resistance between thiotraniliprole and three other diamide insecticides.These findings provide valuable information for optimizing resistance management strategies to delay thiotraniliprole resistance development and ensure sustainable control of P.xylostella.
基金Supported by the 14th Five-Year National Key Research and Development Program(2021YFD1201103–01–05)the National Natural Science Foundation of China(32301819)the Cooperation Project of Research and Development Center between Wudalianchi Government and Northeast Agricultural University.
文摘Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed quality of soybean.The current resistant varieties are difficult to meet the production demand.The breeders have identified 50 different physiological small species and discussed the physiological and biochemical characteristics of soybean resistance to FLS.In soybean disease resistance breeding,resistance resources are screened for the main physiological races in different countries,resistance materials are created,more than 100 genome regions associated with resistance are located,and 12 resistance-related genes are identified.In order to promote the research of soybean disease resistance breeding,this paper expounded and analyzed the pathogenesis characteristics of soybean FLS,the division of races,the physiological and biochemical mechanism of soybean resistance to FLS disease,quantitative trait locus(QTL),quantitative trait nucleotides(QTN),genes of resistance sites,the screening of resistant germplasm resources,and the breeding of new varieties,so as to gain an in-depth understanding of the pathogenesis principle of soybean FLS disease.In order to provide a theoretical basis and technical support for the breeding of soybean FLS disease,the resistance mechanism of soybean FLS disease was analyzed from the molecular level.
基金supported by National Natural Science Foundation of China(32201752)Xinjiang Tianchi Talents Program (TCYC2023TP02)Key Project of the Natural Science Foundation of Xinjiang Production and Construction Corps (2024DA001)
文摘Verticillium wilt,caused by the infamous pathogen Verticillium dahliae,presents a primary constraint on cotton cul-tivation worldwide.The complexity of disease resistance in cotton and the largely unexplored interaction dynamics between the cotton plant host and V.dahliae pathogen pose a crucial predicament for effectively managing cotton Verticillium wilt.Nevertheless,the most cost-effective approach to controlling this disease involves breeding and cul-tivating resistant cotton varieties,demanding a meticulous analysis of the mechanisms underlying cotton’s resistance to Verticillium wilt and the identification of pivotal genes.These aspects constitute focal points in disease-resistance breeding programs.In this review,we comprehensively discuss genetic inheritance associated with Verticillium wilt resistance in cotton,the advancements in molecular markers for disease resistance,the functional investiga-tion of resistance genes in cotton,the analysis of pathogenicity genes in V.dahliae,as well as the intricate interplay between cotton and this fungus.Moreover,we delve into the future prospects of cutting-edge research on cotton Verticillium wilt,aiming to proffer valuable insights for the effective management of this devastating fungus.
基金Projects(51927807,52074164,42477166,42077267,42277174)supported by the National Natural Science Foundation of ChinaProject(2024JCCXSB01)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(KFJJ24-01M)supported by the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,China。
文摘Rockburst is a common disaster in deep underground engineering,which seriously impacts project construction safety.Understanding its causes and burst resistance mechanism is of significance for rockburst prevention and mitigation.We developed a new type of high strength,large elongation,and strong energy-absorbing material,and conducted comparative tests on both basic and anchored rock specimens with such material.We analyzed the rockburst process,energy release and peak stress of the rock,and force and deformation withstood by the energy-absorbing bolts.The experimental results show that the energy reduction rate of the rocks reinforced by energy-absorbing bolts is more than 80%,compared with that of the basic rock.The force exerted on the energy-absorbing bolts increases suddenly when the rockburst occurs,and the strength utilization rates of the energy-absorbing bolts under strain rockburst and impact rockburst conditions are 73.3%and 61.2%,respectively.Rockburst also causes non-uniform shear deformation of the anchor bolt.Based on the rockburst energy criterion,the peak stress of the anchored rock is 2.2 times and 2.5 times the uniaxial compressive strength of the rock,respectively,under strain rockburst and impact rockburst conditions.The energy required for rockburst is 396.0 and 478.4 kJ/m^(3),respectively.The energy-anchoring bolts can effectively reduce the likelihood of rockburst.The results can provide a reference for support design for burst-prone rock in underground engineering.
基金financially supported by the Ministry of Education(Singapore)(MOE-T2EP50220-0022)SUTD-MIT International Design Center(Singapore)+3 种基金SUTD-ZJU IDEA Grant Program(SUTD-ZJU(VP)201903)SUTD Kickstarter Initiative(SKI 2021_02_03,SKI 2021_02_17,SKI 2021_01_04)Agency of Science,Technology and Research(Singapore)(A20G9b0135)National Supercomputing Centre(Singapore)(15001618)。
文摘Neuromorphic computing has the potential to overcome limitations of traditional silicon technology in machine learning tasks.Recent advancements in large crossbar arrays and silicon-based asynchronous spiking neural networks have led to promising neuromorphic systems.However,developing compact parallel computing technology for integrating artificial neural networks into traditional hardware remains a challenge.Organic computational materials offer affordable,biocompatible neuromorphic devices with exceptional adjustability and energy-efficient switching.Here,the review investigates the advancements made in the development of organic neuromorphic devices.This review explores resistive switching mechanisms such as interface-regulated filament growth,molecular-electronic dynamics,nanowire-confined filament growth,and vacancy-assisted ion migration,while proposing methodologies to enhance state retention and conductance adjustment.The survey examines the challenges faced in implementing low-power neuromorphic computing,e.g.,reducing device size and improving switching time.The review analyses the potential of these materials in adjustable,flexible,and low-power consumption applications,viz.biohybrid spiking circuits interacting with biological systems,systems that respond to specific events,robotics,intelligent agents,neuromorphic computing,neuromorphic bioelectronics,neuroscience,and other applications,and prospects of this technology.
基金the National Natural Science Fundation of China(32302392)the Key Project of the Natural Science Foundation of Anhui Provincial Department of Education,China(2022AH050877 and 2023AH040129)+4 种基金the Programs for the Scientific Research Activities of Academic and Technical Leaders of Anhui Province,China(2020D251)the Development Fund for Talent Personnel of Anhui Agricultural University,China(rc342006 and rc342008)the University Synergy Innovation Program of Anhui Province,China(GXXT-2021-059)the Grants from Anhui Agricultural University,China(2020zd27)the Anhui Province Agricultural Eco-Environmental Protection and Quality Safety Industry Technology System,China。
文摘Rice bakanae disease(RBD)is a devastating plant disease caused by Fusarium fujikuroi.This study aimed to evaluate the potential of cyclobutrifuram,a novel succinate dehydrogenase inhibitor(SDHI),to control RBD,and determine the risk and mechanism of resistance to cyclobutrifuram in F.fujikuroi.In vitro experiments showed that cyclobutrifuram significantly inhibited mycelial growth and spore germination,and altered the morphology of mycelia and conidia.Treatment with cyclobutrifuram signifcantly decreased mycotoxin production and increased cell membrane permeability in F.fujikuroi.The baseline sensitivity of 72 F.fujikuroi isolates to cyclobutrifuram was determined using mycelial growth and spore germination inhibition assays,which revealed EC50values of 0.0114-0.1304 and 0.0012-0.016μg mL^(-1),with mean EC50values of(0.0410±0.0470)and(0.0038±0.0015)μg mL^(-1),respectively.Pot experiments demonstrated that the protective effect of cyclobutrifluram against F.fujikuroi was more significant than that of phenamacril and azoxystrobin,indicating that cyclobutrifuram is a promising antifungal agent for the control of RBD.Six cyclobutrifuramresistant mutants of F.fujikuroi were obtained via fungicide adaptation.Moreover,these mutants exhibited weaker ftness than their parental isolate and positive cross-resistance with other SDHI fungicides,including pydifumetofen and penfufen;however,no cross-resistance was detected with other classes of fungicides,including phenamacril,fudioxonil,prochloraz,or azoxystrobin.These results indicated that the resistance risk of F.fujikuroi to cyclobutrifuram might be moderate.Sequencing analysis revealed that mutations,including H248D in Ff Sdh B,A83V in Ff Sdh C2,and S106F and E166K in Ff Sdh D,contributed to resistance,which was confrmed by molecular docking and homologous replacement experiments.The results suggest a high potential for cyclobutrifuram to control RBD and a moderate resistance risk of F.fujikuroi to cyclobutrifuram,which are meaningful fndings for the scientifc application of cyclobutrifuram.
文摘Chlamydia Trachomatis (C.T.) is one of the most common pathogens of human sexually transmitted diseases. Treatment of C.T. infection primarily depends on Tetracyclines, Macrolides and Quinolones, but with the wide use of antibiotics an increasing number of drug-resistant Chlamydia trachomatis cases have been reported. This review summarizes the resistant conditions and the possible resistance mechanisms of C.T..
文摘One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper （SBPH） （Laodelphax striatellus Fallen） by the modified seedbox screening test. Twenty-five rice accessions with different levels of resistance to SBPH were detected, accounting for 18.1% of the total accessions, which included 2 highly resistant, 9 resistant and 14 moderately resistant varieties. Compared with indica rice, japonica rice was more susceptible to SBPH. Antixenosis test, antibiosis test and correlation analysis were performed to elucidate the resistance mechanism. The resistant check Rathu Heenati （RHT）, highly resistant varieties Mudgo and Kasalath, and resistant variety IR36 expressed strong antixenosis and antibiosis against SBPH, indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties. Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis. Dular, ASD7 and Milyang 23 had relatively strong antixenosis and antibiosis, indicating the two resistance mechanisms were significant in these three varieties. The resistant DV85 expressed relatively high level of antixenosis but low antibiosis, whereas Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH, suggesting tolerance in these three varieties. Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311. Antixenosis was the main resistance type in V20A. Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance. The above accessions with strong antibiosis or antixenosis were the ideal materials for the resistance breeding.
基金supported by the National Key Research and Development Program of China (2017YFC1200200)Major Infectious Diseases such as AIDS and Viral Hepatitis Prevention and Control Technology Major Projects (2018ZX10712-001)+1 种基金National Natural Science Foundation of China (81702045 and 81902030)Shenzhen Basic Research projects (JCYJ20190807144409307)
文摘Carbapenem resistance presents a major challenge for the global public health network, as clinical infections caused by carbapenem-resistant organisms(CRO) are frequently associated with significant morbidity and mortality. Ceftazidime–avibactam(CAZ–AVI) is a novel cephalosporin/β-lactamase inhibitor combination offering an important advance in the treatment of CRO infections. CAZ–AVI has been reported to inhibit the activities of Ambler classes A, C, and some class D enzymes. However, bacterial resistance has been emerging shortly after the introduction of this combination in clinical use, with an increasing trend. Understanding these resistance mechanisms is crucial for guiding the development of novel treatments and aiding in the prediction of underlying resistance mechanisms. This review aims to systematically summarize the epidemiology of CAZ–AVI-resistant strains and recently identified resistance mechanisms of CAZ–AVI, with a focus on the production of β-lactamase variants, the hyperexpression of β-lactamases, reduced permeability, and overexpressed efflux pumps. The various mechanisms of CAZ–AVI resistance that have emerged within a short timescale emphasize the need to optimize the use of current agents, as well as the necessity for the surveillance of CAZ–AVI-resistant pathogens.
文摘The Ti fire found in high performance engines promotes the development of burn resistant Ti alloys. The burn resistant mechanism of Ti40 alloy is investigated. Ti40 alloy reveals good burn resistance. Its interfacial products between burning products and the matrix are tenacious, which retard the diffusion of oxygen into the matrix. Two burn resistant mechanisms, that is, fast scatter dispersion of heat and suppression of oxygen diffusion, are proposed.
基金supported by the Key Project of Research Institute of Forestry,Chinese Academy of Forestry(ZD200908)the National Eleventh "Five-year Plan" Science and Technology Funded Project of the State Forestry Administration,P.R.of China (2006BAD26B0101)
文摘Drought and shortage of water resources, which restrict the economy, society development and environmental protection, are key factors in arid zones of China. In the arid zones of Western China, researching plant drought resistance mechanism, selecting plant species with higher drought resistance, and developing water-saving techniques, are important for environmental improvement and economic development. This paper reviews research advances on drought resistance mechanism of plant species, based on research of morphological, physiological, and ecological adaptation mechanism of plant species under drought stress, such as anatomical structure of root systems and leaves, photosynthesis, antioxidant enzyme system, malondialdehyde （MDA）, osmotic adjustment, endogenous hormone, drought-induced proteins and δ^13C. Finally, this paper points out the key field of future research.
基金supported by the Scientific Research Projects Unit of Mustafa Kemal University,Hatay,Turkey(Project no:47)
文摘Objective: To investigate the antimicrobial susceptibility of 97 clinical Staphylococcus aureus(S. aureus) strains against 14 antimicrobials and corresponding resistance mechanisms.Methods: The antimicrobial susceptibility of the isolates was determined using a disk diffusion method and antimicrobial resistance genes were screened by polymerase chain reaction. Mutations responsible for ciprofloxacin and rifampicin resistance were investigated by polymerase chain reaction and DNA sequencing.Results: All isolates were found to be susceptible to vancomycin. Various rates of resistance to penicillin(83.5%), ampicillin(77.3%), erythromycin(63.9%), tetracycline(16.5%), amoxicillin/clavulanic acid(16.5%), ciprofloxacin(15.5%), trimethoprim/sulfamethoxazole(15.5%), oxacillin(13.4%), fusidic acid(12.4%), rifampin(6.2%), clindamycin(6.2%), gentamicin(6.2%) and mupirocin(5.2%) were determined. In addition,different combinations of resistance genes were identified among resistant isolates.Ciprofloxacin resistant isolates had mutations in codon 84(Ser84 Leu) and 106(Gly106 Asp) in the gyr A gene. Mutations in grl A were mostly related to Ser80 Phe substitution. Leu466 Ser mutation in the rpo B gene was detected in all rifampin resistant isolates. All methicillin resistant S. aureus isolates were SCCmec type V.Conclusions: In conclusion, it was determined that the isolates were resistant to different classes of antimicrobials at varying rates and resistance was mediated by different genetic mechanisms. Therefore, continuous monitoring of resistance in S. aureus strains is necessary to control their resistance for clinically important antimicrobials.
基金This project is supported by National Innovation Foundation for TechnologyBased Firms, China (No.01C26213300872).
文摘The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine chain is fatigue wear, and its failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. In addition, the material, hot-treatment method and shaping technique for roller have a great influence upon the resistance to multi-impact. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technique are the effective method to increase its resistance to multi-impact.
基金This study received support for Open Access Publikationskosten from the DFG.
文摘Ovarian cancer is among the most lethal gynecological cancers,primarily due to the lack of specific symptoms leading to an advanced-stage diagnosis and resistance to chemotherapy.Drug resistance(DR)poses the most significant challenge in treating patients with existing drugs.The Food and Drug Administration(FDA)has recently approved three new therapeutic drugs,including two poly(ADP-ribose)polymerase(PARP)inhibitors(olaparib and niraparib)and one vascular endothelial growth factor(VEGF)inhibitor(bevacizumab)for maintenance therapy.However,resistance to these new drugs has emerged.Therefore,understanding the mechanisms of DR and exploring new approaches to overcome them is crucial for effective management.In this review,we summarize the major molecular mechanisms of DR and discuss novel strategies to combat DR.
基金support by the National Natural Science Foundation of China (Nos. 51374106 and 51434006)
文摘In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation,theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified.
基金supported by the National Natural Science Foundation of China(Grant No.31701915)Zhejiang Province Public Welfare Technology Application Research Project(Grant No.LGN19C150007).
文摘Cucumber is an important vegetable worldwide,and powdery mildew(PM)is a common and serious disease of cucumbers.Breeding disease-resistant cucumber varieties is the most advantageous strategy to control this disease.In recent years,exploration and identification of cucumber PM resistance genes have achieved great advancement,and many genes have been cloned and verified using different methods.However,the resistance mechanism of cucumber PM is still unclear,and many ambiguities need to be elucidated urgently.In this review,we summarized the research advances in PM resistance in cucumbers,including genetic analysis,quantitative trait locus mapping,map-based cloning,transcriptomics,mlo-mediated PM resistance,and mining of noncoding RNAs involved in resistance.Finally,the research directions and the problems that need to be solved in the future were discussed.
基金supported by the Program of the National Natural Science Foundation of China (No. 51374214)National Science Foundation of China (No. 41040027)Fundamental Research Funds for the Central Universities (No. 2009QL06)
文摘The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadwavs in Tertiary deed soft rock.
基金Financial support towards this work was provided by the Jiangsu Province Ordinary College Graduate Student Research Innovative Projects (No. CXZZ12_0938)the National Natural Science Foundation of China (Nos. 51074162, 51179189 and 51174197)the Eleventh Five-Year Technology Support Program (No.2008BAB36B07)
文摘The measured data and simulation test phenomenon of surrounding rock deformation and failure at the project site indicate that shear failure which firstly occurs in surrounding rock, block slip and second shear failure are the root cause of deformation and damage of supporting structure of the surrounding rock at a large scale. We derived limit load of surrounding rock shear slip failure and reasonable support resistance of given load by means of shear slip line field theory, discussed the main factors which influence the limit load of surrounding rock. Shear slip line field and limit load of circular tunnel surrounding rock were obtained by means of physical simulation test, which agreed well with the theoretical analysis results. Based on the theoretical analysis and physical simulation test, the cause deformation and failure at large scale of Xinshanghai No. 1 coal mine big section ingate was analyzed, and the shear failure resistance and block slip in surrounding rock were proposed as the core technical supporting ideas. Proper range of supporting resistance which came from calculation was suggested. The support scheme which is mainly composed of large grouting anchor, sprayed anchor net support technique and full-face grille concrete finally ended the dilemma of repeated failure and mending of ingate and created critical conditions for smooth production in the coal mine.
