Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native ...Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.展开更多
Sesame Fusarium wilt(SFW),caused by Fusarium oxysporum f.sp.sesami(Fos),is one of the most devastating diseases affecting sesame cultivation.Deciphering the genetic control of SFW resistance is pivotal for effective d...Sesame Fusarium wilt(SFW),caused by Fusarium oxysporum f.sp.sesami(Fos),is one of the most devastating diseases affecting sesame cultivation.Deciphering the genetic control of SFW resistance is pivotal for effective disease management in sesame.An inheritance study on a cross between the highly resistant variety Yuzhi 11 and the highly susceptible accession Sp1 using a Fos pathogenicity group 1 isolate indicated that resistance was conferred by a single dominant allele.The target locus was located in a 1.24 Mb interval on chromosome 3 using a combination of cross-population association mapping and bulked segregant analysis.Fine genetic mapping further narrowed the interval between 21,350 and 21,401 kb.The locus Sindi_0812400 was identified as the SFW resistance gene and officially designated SiRLK1.This gene encodes a specific malectin/receptor-like protein kinase with three putative tandem kinase domains and is considered a kinase fusion protein.Sequence analysis revealed that a high proportion(49.44%)of variants within the locus was located within the kinase domainⅢ,and several of which were evidently associated with the diversity in SFW response,indicating the critical role of kinase domainⅢin expression of disease resistance.These findings provide valuable information for further functional analysis of SFW resistance genes and marker-assisted resistance breeding in sesame.展开更多
Diferent from necrosis,apoptosis,autophagy and other forms of cell death,ferroptosis is a mechanism that catalyzes lipid peroxidation of polyunsaturated ftty acids under the action of iron divalent or lipoxygenase,lea...Diferent from necrosis,apoptosis,autophagy and other forms of cell death,ferroptosis is a mechanism that catalyzes lipid peroxidation of polyunsaturated ftty acids under the action of iron divalent or lipoxygenase,leading to cell death.Apatinib is currently used in the third line standard treatment of advanced gastric cancer,targeting the anti-angiogenesis pathway.However,Apatinib mediated ferroptosis in vascular endothelial cells has not been reported yet.Tumor.secreted exosomes can be taken up into target cells to regulate tumor development,but the mechanism related to vascular endothelial cell ferroptosis has not yet been discovered.Here,we show that exosomes secreted by gastric cancer cells carry miR-214.3p into vascular endothelial cells and directdy target zinc finger protein A20 to negatively regulate ACSL4,a key enzyme of lipid peroxidation during frroptosis thereby inhibiting ferroptosis in vascular endothelial cells and reducing the eficiency of Apatinib.In conclusion,inhibition of miR-214-3p can increase the sensitivity of vascular endothelial cells to Apatinib,thereby promoting the antiangiogenic efect of Apatinib,suggesting a potential combination therapy for advanced gastric cancer.展开更多
Sesame is a labor intensive crop with limited mechanized harvesting mainly due to the seed shattering(SS)trait.In this study,we performed a genetic analysis of the seed-shattering resistance(SR)trait with a SR sesame ...Sesame is a labor intensive crop with limited mechanized harvesting mainly due to the seed shattering(SS)trait.In this study,we performed a genetic analysis of the seed-shattering resistance(SR)trait with a SR sesame mutant 12M07.Unlike the SS type,the parenchyma cells in the abscission zone of the 12M07 mutant are arranged loosely but adhere to the seed coat.Inheritance analysis of six generations derived from 12M07(SR)×Xiangcheng Dazibai(SS)showed that the SR trait is recessive and controlled by a single gene pair.Association mapping of the F2population with 888,619 variants(single-nucleotide polymorphisms(SNPs)and insertion-deletion(InDels))and 31,884 structural variations(SVs)determined that only SV12002 in the 5′upstream region of gene Sindi0765000(named SiHEC3)in Chr.3 was significantly associated with the SR trait.SiHEC3 encodes the bHLH transcription factor.A 1,049 bp deletion occurred in the 5′UTR of Sihec3 in 12M07.SiHEC3 is mainly expressed in developing placental tissues,with the expression peaking in capsules at 45 days after pollination.A dual-luciferase reporter assay in tobacco confirmed that the promoter activity of Sihec3 was reduced because of the deletion of the 1,049 bp promoter sequence.Protein–protein interaction network analysis showed that HEC3 is co-expressed with nine key proteins,such as SHATTERPROOF1(SHP1)and SEEDSTICK(STK)which participate in the secondary wall biosynthesis of the abscission layer in plants.The findings of this study show the important function of Sihec3corresponding with the SR trait and supply the genetic information for breeding new varieties that are amenable to mechanized harvesting in sesame and other crops.展开更多
Sensitive monitoring of the target products during the biosynthesis process is crucial,and facile analytical approaches are urgently needed.Herein,phosphatidylserine(PS)was chosen as the model target,a colorimetric ap...Sensitive monitoring of the target products during the biosynthesis process is crucial,and facile analytical approaches are urgently needed.Herein,phosphatidylserine(PS)was chosen as the model target,a colorimetric aptasensor was developed for the rapid quantitation in biosynthesis samples.A chimeric aptamer was constructed with two homogeneous original PS aptamers.Specific recognition between the chimeric aptamer and PS results in the desorption of aptamer from the surface of the AuNPs nanozyme,and the peroxidase-like enzymatic activity of the AuNPs nanozyme was weakened in a relationship with the different concentrations.The developed aptasensor performed well when applied for analyzing PS in biosynthesis samples.The aptasensor offers good sensitivity and selectivity,under optimal conditions,achieving monitoring and quantitation of PS in the range of 2.5-80.0μmol/L,with a limit of detection at 536.2 nmol/L.Moreover,the aptasensor provides good accuracy,with comparison rates of 98.17%-106.40%,when compared with the HPLC-ELSD.This study provides a good reference for monitoring other biosynthesized products and promoting the development of aptamers and aptasensors in real-world applications.展开更多
Meibomian gland dysfunction(MGD)is a common ocular surface disease,and the pathogenesis of MGD is closely related to the alteration of meibomian gland morphology and(or)function.At present,the treatment strategy for M...Meibomian gland dysfunction(MGD)is a common ocular surface disease,and the pathogenesis of MGD is closely related to the alteration of meibomian gland morphology and(or)function.At present,the treatment strategy for MGD consists of physical therapy,artificial lubricants,topical and systemic antibiotics and antiinflammatory agents,topical steroids andΩ-3 dietary supplementation.Recently,the thermal pulsation system(LipiFlow)has been used clinically,which allows heat to be applied to the palpebral surfaces of the upper and lower eyelids directly over the meibomian glands,while simultaneously applying pulsatile pressure to the outer eyelid surfaces.Due to its specific design,the cornea and eyeball can successfully avoid the potential damage from overheating and improper expression,which will greatly improve the safety during the clinical application and patients'compliance.Studies have showed that the effectiveness of LipiFlow when treating MGD is at least as well as twice-daily lid warming and massage for 3 months,which displays a broad application prospect.At present,the application of LipiFlow in China has not been fully developed,and only some hospitals have experimental applications.This paper summarizes the research progress of LipiFlow treatment in MGD.展开更多
Environmental stresses caused by climate change have severely affected agriculture in the present century;Salinity and drought have challenged most forecasts for increased agricultural production in the past few decad...Environmental stresses caused by climate change have severely affected agriculture in the present century;Salinity and drought have challenged most forecasts for increased agricultural production in the past few decades,there-fore,different methods that reduce the effect of these stresses on plants have attracted scientists’attention.The effect of beneficial soil microorganisms on soil health and increasing plants’resistance to stresses is one of the solutions that researchers have paid attention to.This study investigated how Trichoderma species can be affected by the molecular and morphophysiological mechanisms of plants and improve their salt and drought resistance.This study also studied the different Trichoderma species’functions to get a better understanding of how they reduce salt and drought stresses.Furthermore,thefindings of this study provide a clear path for future research to focus on the unknown aspects of Trichoderma species andfind effective ways to boost crop production under environmental stresses.展开更多
Rice is an essential part of the human diet in most parts of the world;On the other hand,the industrialization of societies has led to pollution of the environment,including heavy metal contamination of soil and water...Rice is an essential part of the human diet in most parts of the world;On the other hand,the industrialization of societies has led to pollution of the environment,including heavy metal contamination of soil and water,which negatively affects rice production and quality.Therefore,finding ways to increase the yield and quality of this strategic crop seems essential.Several studies have been conducted in recent decades to find effective and inexpensive solutions to reduce the adverse effects of heavy metals in rice fields.Due to the negative effect of cadmium pollution on rice quality and yield,the current study aimed to investigate cadmium absorption and transfer mechanisms in rice(from absorption by roots to loading in grains),and its effects on rice morphology,physiology,and biochemistry(such as biomass,nutrient absorption,antioxidant defenses).Also,rice’s natural mechanisms for detoxifying cadmium were discussed.This study also intended to identify the absorption and transfer pathways of silicon and selenium in rice,their roles in improving rice structures,and their antagonistic effects on reducing cadmium stress(absorption,transport,and toxicity of cadmium).展开更多
Fusarium wilt is a common fungal disease in sesame caused by Fusarium oxysporum f.sp.sesami(FOS).To determine the toxin production profiles of the FOS isolates with different pathogenicity levels under various culture...Fusarium wilt is a common fungal disease in sesame caused by Fusarium oxysporum f.sp.sesami(FOS).To determine the toxin production profiles of the FOS isolates with different pathogenicity levels under various culture conditions,we assessed the content variation of fusaric acid(FA)and 9,10-dehydrofusaric acid(9,10-DFA)produced by the four representative FOS isolates.Results indicated that the concentration of FA reached to a maximum of 2848.66μg/mL in Czapek medium,while 9,10-DFA was mainly produced in Richard and Lowcarbon Richard medium.The concentration of 9,10-DFA on Richard culture medium varied from 0μg/mL to 716.89μg/mL.Of the five culture media used in this study,Czapek culture medium was the most conductive to produce FA.FA production was significantly affected by culture medium,culture time,and their interactions.Results suggest that there is no correlation between toxin production and pathogenicity level of FOS isolates.These findings provide key information for the mechanism analysis of FOS-sesame interaction and pathogen control.展开更多
The first step for engineering students to understand the practical system is to describe the system,which means to establish the mathematic model for the considered system.However,traditional mathematical modeling te...The first step for engineering students to understand the practical system is to describe the system,which means to establish the mathematic model for the considered system.However,traditional mathematical modeling techniques are not readily assimilated by students,because the traditional modeling needs to obey the complicated physical laws for different engineering areas and requires a highly iterative process.In this paper,the simulation-based graphic modeling method is introduced to help students model the system and improve their performance in engineering education.The results from the questionnaire indicate that the simulation-based graphic method can help students to do the modeling of the system and improve their performance compared to the traditional ways.展开更多
To gain insight into the molecular and genetic basis of fruit size and shape in cucumber,we conducted Quantitative Trait Locus(QTL)mapping with F2 and BC1F1 populations derived froma cross between the Northern-China t...To gain insight into the molecular and genetic basis of fruit size and shape in cucumber,we conducted Quantitative Trait Locus(QTL)mapping with F2 and BC1F1 populations derived froma cross between the Northern-China type inbred line CNS21 and the Southern-China type inbred line RNS7.Populations were evaluated during two developmental stages,ovary at anthesis and commercial fruit(immature fruit).A total of 13 major-effect QTLs(R2>10%)were detected for six traits,and one of them,fruit shape index 2.1,explained more than 50%of phenotypic variation.All QTLs distributed on chromosome(chr)1 and 2.We constructed a physical map containing almost all of the QTLs with their physical location from previous studies.For fruit size and shape,the highest number of QTLs were mapped on chr1 and chr6,and the fewest number were mapped on chr2 and chr7.At least one consensus region was presented on each chromosome.In addition,three candidate genes were predicted between the long-fruited and round-fruited inbred lines by comparing the sequences of the consensus region of chr3,where many QTLs for marketable fruit length had been detected.Our results provide a base for additional QTLs and molecular markers for fruit size and shape in cucumber breeding.展开更多
Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embry...Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells （ESCs） or adult stem cells （ASCs）. It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction （ED） in both animal models and human research. We performed a search on PubMed for articles related to definition, iocalisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.展开更多
The pathophysiology of LaPeyronie＇s disease （PD） is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been valida...The pathophysiology of LaPeyronie＇s disease （PD） is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been validated using animal models. In this study, we have presented a new model obtained by tunica albuginea allograft. A total of 40, 16-week-old male rats were used. Of these, 8 rats served as controls and underwent a 10 × 2-mm-wide tunical excisionwith subsequent autografting, whereas the remaining 32 underwent the same excision with grafting of the defect with another rat＇s tunica. Morphological and functional testing was performed at 1, 3, 7 and 12 weeks after grafting. Intracavernous pressure, the degree of penile curvature and elastic fiber length were evaluated for comparison between the allograft and control groups. The tissues were obtained for histological examination. The penile curvature was significantly greater in the allografted rats as compared with the control rats. The erectile function was maintained in all rats, except in those assessed at 12 weeks. The elastin fiber length was decreased in the allografted tunica as compared to control. SMAD2 expression was detected in the inner part of the allograff, and both collagen-Ⅱ- and osteocalcin-positive cells were also noted. Tunica albuginea （TA） allograft in rats is an excellent model of PD. The persistence of curvature beyond 12 weeks and the presence of ossification in the inner layer of the TA were similar to those observed in men with PD. Validation studies using this animal model would aid understanding of the PD pathophysiology for effective therapeutic interventions.展开更多
Objective:The aim of this research was to identify whether exosomes were involved in impairing adipogenesis in cancer-associated cachexia(CAC)by detecting the adipodifferentiation capacity and the expressions of adipo...Objective:The aim of this research was to identify whether exosomes were involved in impairing adipogenesis in cancer-associated cachexia(CAC)by detecting the adipodifferentiation capacity and the expressions of adipogenic proteins in gastric cancer(GC)-associated adipocytes.Methods:Western blotting and RT-PCR were used to investigate the expressions of C/EPBβ,C/EPBα,PPARγ,and UCP1 in adipose mesenchymal stem cells(A-MSCs)to evaluate the function of exosomal miR-155.BALB/c nude mice were intravenously injected in vivo with GC exosomes with different levels of miR-155 to determine changes in adipodifferentiation of A-MSCs.Results:Exosomes derived from GC cells suppressed adipogenesis in A-MSCs as characterized by decreased lipid droplets.Similarly,A-MSCs co-cultured with GC exosomes exhibited increased ATP production through brown adipose differentiation characterized by highly dense mitochondria and enhanced UCP1 expression(P<0.05).Mechanistically,exosomal miR-155 secreted from GC cells suppressed adipogenesis and promoted brown adipose differentiation by targeting C/EPBβ,accompanied by downregulated C/EPBαand PPARγand upregulated UCP1(P<0.05).Moreover,overexpression of miR-155 in GC exosomes improved CAC in vivo,which was characterized by fat loss,suppressed expressions of C/EPBβ,C/EPBα,and PPARγin A-MSCs,and high expression of UCP1(P<0.05).Decreasing the level of miR-155 in injected GC exosomes abrogated the improved CAC effects.Conclusions:GC exosomal miR-155 suppressed adipogenesis and enhanced brown adipose differentiation in A-MSCs by targeting C/EPBβof A-MSCs,which played a crucial role in CAC.展开更多
Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,ex...Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.展开更多
Ru-based catalysts modified in different atmospheres by plasma technology were prepared to catalyze the acetylene hydrochlorination reaction.The(Ru/AC)-N2(AC = activated carbon)catalyst yielded by the plasma modificat...Ru-based catalysts modified in different atmospheres by plasma technology were prepared to catalyze the acetylene hydrochlorination reaction.The(Ru/AC)-N2(AC = activated carbon)catalyst yielded by the plasma modification of Ru/AC catalyst in N2 atmosphere exhibits the best catalytic performance with a stable C2H2 conversion of 87.2%;a relative increase of 27.1%in C2H2 conversion was achieved compared with that of the untreated Ru/AC catalyst.The results of the analysis revealed that the modification produced a mutual effect between the generated function groups on carrier AC and the active components, which can disperse and yield more active species in the fresh catalysts.These are benefits of enhancing the activity of the catalysts.Moreover, the modification can restrain coke formation and inhibit the loss of active species in the reaction, as well as strengthen the adsorption ability of reactants on the catalysts.These are benefits of improving the catalysts’ performance.展开更多
This study analyzes and predicts the vibration characteristics of fiberreinforced composite sandwich(FRCS)cylindrical-spherical(CS)combined shells with hexagon honeycomb core(HHC)for the first time based on an analyti...This study analyzes and predicts the vibration characteristics of fiberreinforced composite sandwich(FRCS)cylindrical-spherical(CS)combined shells with hexagon honeycomb core(HHC)for the first time based on an analytical model developed,which makes good use of the advantage of the first-order shear deformation theory(FSDT),the multi-segment decomposition technique,the virtual spring technology,the Jacobi-Ritz approach,and the transfer function method.The equivalent material properties of HHC are firstly determined by the modified Gibson’s formula,and the related energy equations are derived for the HHC-FRCS-CS combined shells,from which the fundamental frequencies,the mode shapes,and the forced vibration responses are solved.The current model is verified through the discussion of convergence and comparative analysis with the associated published literature and finite element(FE)results.The effects of geometric parameters of HHC on the dynamic property of the structure are further investigated with the verified model.It reveals that the vibration suppression capability can be greatly enhanced by reducing the ratio of HHC thickness to total thickness and the ratio of wall thickness of honeycomb cell to overall radius,and by increasing the ratio of length of honeycomb cell to overall radius and honeycomb characteristic angle of HHC.展开更多
The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are ...The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are widely planted and used in the furniture industry,interior decoration,and wood structure construction in China.The aim of this work was to investigate the bonding performance of moso bamboo dowel rotation welded joints with different dowel/receiving hole diameter ratios.The results indicated that the ratio of dowel/receiving hole diameter was an important parameter that influenced the welding performance.The bonding strength of the bamboo-to-poplar welded joints at the optimal ratio of 10/7 was as high as 7.50 MPa,which was higher than that of the beech(Fagus sylvatica,L.),schima(Schima superba)dowels and PVAc glued joints.The temperature measurement results showed a peak temperature of bamboo dowel welding as high as 350–360°C.Some differences in the temperature curves between each dowel/hole diameter ratio group were observed at the three different hole depths,such as the friction time,peak temperatures,and stabilization time at the maximum temperature,which could explain the differences in welding strengths between different ratios.The SEM results showed the temperature-induced softening,melting and flowing of cell-interconnected polymer material in the wood and bamboo structure.In addition,the bamboo fibers(mainly vascular bundles)were wrapped to form a dense continuous bonding layer,similar to the reinforced concrete,thus producing a good bonding effect.The Fourier transform-infrared spectroscopy(FT-IR)analyses showed that the high temperature resulted in the increase of the lignin relative content due to the degradation reaction of cellulose in the welding zone,which improved the bonding properties.展开更多
基金funded by the National Natural Science Foundation of China (32171746,31870522,42077450,32371786)the leading talents of basic research in Henan Province+3 种基金Funding for Characteristic and Backbone Forestry Discipline Group of Henan Provincethe Scientific Research Foundation of Henan Agricultural University (30500854)Research Funds for overseas returnee in Henan Province,Chinasupported by National Key Research and Development Program of China (2019YFE0117000)。
文摘Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.
基金This work was supported by China Agriculture Research System(CARS-14)the Key Research and Development Project of Henan Province(221111520400)+3 种基金the Henan Provincial Science and Technology Research Project(222102110081)the Zhongyuan Science and Technology Innovation Leading Talent Plan(214200510020)the Key Research Project of the Shennong Laboratory(SN012022-04)the Fund for Distinguished Young Scholars from Henan Academy of Agricultural Sciences(2022JQ01).
文摘Sesame Fusarium wilt(SFW),caused by Fusarium oxysporum f.sp.sesami(Fos),is one of the most devastating diseases affecting sesame cultivation.Deciphering the genetic control of SFW resistance is pivotal for effective disease management in sesame.An inheritance study on a cross between the highly resistant variety Yuzhi 11 and the highly susceptible accession Sp1 using a Fos pathogenicity group 1 isolate indicated that resistance was conferred by a single dominant allele.The target locus was located in a 1.24 Mb interval on chromosome 3 using a combination of cross-population association mapping and bulked segregant analysis.Fine genetic mapping further narrowed the interval between 21,350 and 21,401 kb.The locus Sindi_0812400 was identified as the SFW resistance gene and officially designated SiRLK1.This gene encodes a specific malectin/receptor-like protein kinase with three putative tandem kinase domains and is considered a kinase fusion protein.Sequence analysis revealed that a high proportion(49.44%)of variants within the locus was located within the kinase domainⅢ,and several of which were evidently associated with the diversity in SFW response,indicating the critical role of kinase domainⅢin expression of disease resistance.These findings provide valuable information for further functional analysis of SFW resistance genes and marker-assisted resistance breeding in sesame.
基金grants from the National Science Foundation of China(Nos.82173125,81974374,82072664,82103677)Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-009A)The Science&Technology Development Fund of Tianjin Education Commission for Higher Education(2020KJ127).
文摘Diferent from necrosis,apoptosis,autophagy and other forms of cell death,ferroptosis is a mechanism that catalyzes lipid peroxidation of polyunsaturated ftty acids under the action of iron divalent or lipoxygenase,leading to cell death.Apatinib is currently used in the third line standard treatment of advanced gastric cancer,targeting the anti-angiogenesis pathway.However,Apatinib mediated ferroptosis in vascular endothelial cells has not been reported yet.Tumor.secreted exosomes can be taken up into target cells to regulate tumor development,but the mechanism related to vascular endothelial cell ferroptosis has not yet been discovered.Here,we show that exosomes secreted by gastric cancer cells carry miR-214.3p into vascular endothelial cells and directdy target zinc finger protein A20 to negatively regulate ACSL4,a key enzyme of lipid peroxidation during frroptosis thereby inhibiting ferroptosis in vascular endothelial cells and reducing the eficiency of Apatinib.In conclusion,inhibition of miR-214-3p can increase the sensitivity of vascular endothelial cells to Apatinib,thereby promoting the antiangiogenic efect of Apatinib,suggesting a potential combination therapy for advanced gastric cancer.
基金financially supported by the earmarked funding for the China Agriculture Research System of MOF and MARA(CARS-14)the Key Project of Science and Technology of Henan Province,China(201300110600)+6 种基金the Henan Province Specific Professor Position Program,China(SPPP2022)the Zhongyuan Scientist Workshop Construction,China(ZSWC2019 and 214400510026)the Innovation Scientist and Technician Troop Construction Project of Henan Province,China(ISTTCPHP2016)the Shennong Laboratory First Class Program,China(SN01-2022-04)the Key Research and Development Project of Henan Province,China(221111520400)the Innovation Scientists and Technicians Troop Construction Project of Henan Academy of Agricultural Sciences,China(2023TD04)the Henan Province Science and Technology Research and Development Plan Joint Fund,China(232301420108)。
文摘Sesame is a labor intensive crop with limited mechanized harvesting mainly due to the seed shattering(SS)trait.In this study,we performed a genetic analysis of the seed-shattering resistance(SR)trait with a SR sesame mutant 12M07.Unlike the SS type,the parenchyma cells in the abscission zone of the 12M07 mutant are arranged loosely but adhere to the seed coat.Inheritance analysis of six generations derived from 12M07(SR)×Xiangcheng Dazibai(SS)showed that the SR trait is recessive and controlled by a single gene pair.Association mapping of the F2population with 888,619 variants(single-nucleotide polymorphisms(SNPs)and insertion-deletion(InDels))and 31,884 structural variations(SVs)determined that only SV12002 in the 5′upstream region of gene Sindi0765000(named SiHEC3)in Chr.3 was significantly associated with the SR trait.SiHEC3 encodes the bHLH transcription factor.A 1,049 bp deletion occurred in the 5′UTR of Sihec3 in 12M07.SiHEC3 is mainly expressed in developing placental tissues,with the expression peaking in capsules at 45 days after pollination.A dual-luciferase reporter assay in tobacco confirmed that the promoter activity of Sihec3 was reduced because of the deletion of the 1,049 bp promoter sequence.Protein–protein interaction network analysis showed that HEC3 is co-expressed with nine key proteins,such as SHATTERPROOF1(SHP1)and SEEDSTICK(STK)which participate in the secondary wall biosynthesis of the abscission layer in plants.The findings of this study show the important function of Sihec3corresponding with the SR trait and supply the genetic information for breeding new varieties that are amenable to mechanized harvesting in sesame and other crops.
基金supported by the National Natural Science Foundation of China(31922072)the Natural Science Foundation of Shandong Province(ZR2020JQ15)the Taishan Scholar Project of Shandong Province(tsqn201812020)。
文摘Sensitive monitoring of the target products during the biosynthesis process is crucial,and facile analytical approaches are urgently needed.Herein,phosphatidylserine(PS)was chosen as the model target,a colorimetric aptasensor was developed for the rapid quantitation in biosynthesis samples.A chimeric aptamer was constructed with two homogeneous original PS aptamers.Specific recognition between the chimeric aptamer and PS results in the desorption of aptamer from the surface of the AuNPs nanozyme,and the peroxidase-like enzymatic activity of the AuNPs nanozyme was weakened in a relationship with the different concentrations.The developed aptasensor performed well when applied for analyzing PS in biosynthesis samples.The aptasensor offers good sensitivity and selectivity,under optimal conditions,achieving monitoring and quantitation of PS in the range of 2.5-80.0μmol/L,with a limit of detection at 536.2 nmol/L.Moreover,the aptasensor provides good accuracy,with comparison rates of 98.17%-106.40%,when compared with the HPLC-ELSD.This study provides a good reference for monitoring other biosynthesized products and promoting the development of aptamers and aptasensors in real-world applications.
文摘Meibomian gland dysfunction(MGD)is a common ocular surface disease,and the pathogenesis of MGD is closely related to the alteration of meibomian gland morphology and(or)function.At present,the treatment strategy for MGD consists of physical therapy,artificial lubricants,topical and systemic antibiotics and antiinflammatory agents,topical steroids andΩ-3 dietary supplementation.Recently,the thermal pulsation system(LipiFlow)has been used clinically,which allows heat to be applied to the palpebral surfaces of the upper and lower eyelids directly over the meibomian glands,while simultaneously applying pulsatile pressure to the outer eyelid surfaces.Due to its specific design,the cornea and eyeball can successfully avoid the potential damage from overheating and improper expression,which will greatly improve the safety during the clinical application and patients'compliance.Studies have showed that the effectiveness of LipiFlow when treating MGD is at least as well as twice-daily lid warming and massage for 3 months,which displays a broad application prospect.At present,the application of LipiFlow in China has not been fully developed,and only some hospitals have experimental applications.This paper summarizes the research progress of LipiFlow treatment in MGD.
基金supported by the Anhui Province Large-Scale Online Open Course(MOOC)Demonstration Project(2018mooc428)the Quality Engineering Project of Suzhou University:College of Geographic Information and Energy Agriculture Modern Industry(szxy2021cyxy06)+1 种基金the Key Project of Quality Engineering in Anhui Province(2021jyxm1499)the Scientific Research Platform Project of Suzhou University:Research Center of Non-Point Source Pollution Control and Ecological Remediation(2021XJPT11).
文摘Environmental stresses caused by climate change have severely affected agriculture in the present century;Salinity and drought have challenged most forecasts for increased agricultural production in the past few decades,there-fore,different methods that reduce the effect of these stresses on plants have attracted scientists’attention.The effect of beneficial soil microorganisms on soil health and increasing plants’resistance to stresses is one of the solutions that researchers have paid attention to.This study investigated how Trichoderma species can be affected by the molecular and morphophysiological mechanisms of plants and improve their salt and drought resistance.This study also studied the different Trichoderma species’functions to get a better understanding of how they reduce salt and drought stresses.Furthermore,thefindings of this study provide a clear path for future research to focus on the unknown aspects of Trichoderma species andfind effective ways to boost crop production under environmental stresses.
基金This work was supported by the Anhui Province Large-Scale Online Open Course(MOOC)Demonstration Project(2018mooc428)the Quality Engineering Project of Suzhou University:College of Geographic Information and Energy Agriculture Modern Industry(szxy2021cyxy06)+1 种基金the Key Project of Quality Engineering in Anhui Province(2021jyxm1499)the Scientific Research Platform Project of Suzhou University:Research Center of Non-Point Source Pollution Control and Ecological Remediation(2021XJPT11).
文摘Rice is an essential part of the human diet in most parts of the world;On the other hand,the industrialization of societies has led to pollution of the environment,including heavy metal contamination of soil and water,which negatively affects rice production and quality.Therefore,finding ways to increase the yield and quality of this strategic crop seems essential.Several studies have been conducted in recent decades to find effective and inexpensive solutions to reduce the adverse effects of heavy metals in rice fields.Due to the negative effect of cadmium pollution on rice quality and yield,the current study aimed to investigate cadmium absorption and transfer mechanisms in rice(from absorption by roots to loading in grains),and its effects on rice morphology,physiology,and biochemistry(such as biomass,nutrient absorption,antioxidant defenses).Also,rice’s natural mechanisms for detoxifying cadmium were discussed.This study also intended to identify the absorption and transfer pathways of silicon and selenium in rice,their roles in improving rice structures,and their antagonistic effects on reducing cadmium stress(absorption,transport,and toxicity of cadmium).
基金financially supported by China Agriculture Research System of MOF and MARA(CARS-14)the Key Project of Science and Technology of Henan province(201300110600)+4 种基金Zhongyuan Science and Technology Innovation Leading Talent Plan(214200510020)the Zhongyuan Scientist Workshop Construction(214400510026)the Science and Technology Research Project of Henan Province(222102110081)Key Research and Development Project of Henan Province(22111520400)Distinguished Young Scholars from Henan Academy of Agricultural Sciences(2022JQ01).
文摘Fusarium wilt is a common fungal disease in sesame caused by Fusarium oxysporum f.sp.sesami(FOS).To determine the toxin production profiles of the FOS isolates with different pathogenicity levels under various culture conditions,we assessed the content variation of fusaric acid(FA)and 9,10-dehydrofusaric acid(9,10-DFA)produced by the four representative FOS isolates.Results indicated that the concentration of FA reached to a maximum of 2848.66μg/mL in Czapek medium,while 9,10-DFA was mainly produced in Richard and Lowcarbon Richard medium.The concentration of 9,10-DFA on Richard culture medium varied from 0μg/mL to 716.89μg/mL.Of the five culture media used in this study,Czapek culture medium was the most conductive to produce FA.FA production was significantly affected by culture medium,culture time,and their interactions.Results suggest that there is no correlation between toxin production and pathogenicity level of FOS isolates.These findings provide key information for the mechanism analysis of FOS-sesame interaction and pathogen control.
基金supported by the Jiangsu Science and Technology Programme(Grant No.BK20230229)the Research Development Fund of Xi’an JiaotongLiverpool University under Grant RDF-21-01-022+1 种基金the XJTLU AI University Research Centre,Jiangsu Province Engineering Research Centre of Data ScienceCognitive Computation at XJTLU and SIP AI innovation platform(YZCXPT2022103)。
文摘The first step for engineering students to understand the practical system is to describe the system,which means to establish the mathematic model for the considered system.However,traditional mathematical modeling techniques are not readily assimilated by students,because the traditional modeling needs to obey the complicated physical laws for different engineering areas and requires a highly iterative process.In this paper,the simulation-based graphic modeling method is introduced to help students model the system and improve their performance in engineering education.The results from the questionnaire indicate that the simulation-based graphic method can help students to do the modeling of the system and improve their performance compared to the traditional ways.
基金supported by the National Natural Science Foundation of China(21625304,21733012,and 21772190)the Ministry of Science and Technology of China(2016YFB0100102)。
基金supported by the National Natural Science Foundation of China(Grant Nos.31672170,31872950 and 31222048)the Natural Science Foundation of Shandong Province(Grant No.JQ201309),the Shandong“Double Tops”Program(Grant No.SYL2017YSTD06)the‘Taishan Scholar’Foundation of the People’s Government of Shandong Province(Grant No.ts20130932).
文摘To gain insight into the molecular and genetic basis of fruit size and shape in cucumber,we conducted Quantitative Trait Locus(QTL)mapping with F2 and BC1F1 populations derived froma cross between the Northern-China type inbred line CNS21 and the Southern-China type inbred line RNS7.Populations were evaluated during two developmental stages,ovary at anthesis and commercial fruit(immature fruit).A total of 13 major-effect QTLs(R2>10%)were detected for six traits,and one of them,fruit shape index 2.1,explained more than 50%of phenotypic variation.All QTLs distributed on chromosome(chr)1 and 2.We constructed a physical map containing almost all of the QTLs with their physical location from previous studies.For fruit size and shape,the highest number of QTLs were mapped on chr1 and chr6,and the fewest number were mapped on chr2 and chr7.At least one consensus region was presented on each chromosome.In addition,three candidate genes were predicted between the long-fruited and round-fruited inbred lines by comparing the sequences of the consensus region of chr3,where many QTLs for marketable fruit length had been detected.Our results provide a base for additional QTLs and molecular markers for fruit size and shape in cucumber breeding.
文摘Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells （ESCs） or adult stem cells （ASCs）. It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction （ED） in both animal models and human research. We performed a search on PubMed for articles related to definition, iocalisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.
文摘The pathophysiology of LaPeyronie＇s disease （PD） is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been validated using animal models. In this study, we have presented a new model obtained by tunica albuginea allograft. A total of 40, 16-week-old male rats were used. Of these, 8 rats served as controls and underwent a 10 × 2-mm-wide tunical excisionwith subsequent autografting, whereas the remaining 32 underwent the same excision with grafting of the defect with another rat＇s tunica. Morphological and functional testing was performed at 1, 3, 7 and 12 weeks after grafting. Intracavernous pressure, the degree of penile curvature and elastic fiber length were evaluated for comparison between the allograft and control groups. The tissues were obtained for histological examination. The penile curvature was significantly greater in the allografted rats as compared with the control rats. The erectile function was maintained in all rats, except in those assessed at 12 weeks. The elastin fiber length was decreased in the allografted tunica as compared to control. SMAD2 expression was detected in the inner part of the allograff, and both collagen-Ⅱ- and osteocalcin-positive cells were also noted. Tunica albuginea （TA） allograft in rats is an excellent model of PD. The persistence of curvature beyond 12 weeks and the presence of ossification in the inner layer of the TA were similar to those observed in men with PD. Validation studies using this animal model would aid understanding of the PD pathophysiology for effective therapeutic interventions.
基金supported by a grant from National Natural Science Foundation of China(Grant Nos.82072664,81772629,81802363,81702431,81702437,81772843,81974374).
文摘Objective:The aim of this research was to identify whether exosomes were involved in impairing adipogenesis in cancer-associated cachexia(CAC)by detecting the adipodifferentiation capacity and the expressions of adipogenic proteins in gastric cancer(GC)-associated adipocytes.Methods:Western blotting and RT-PCR were used to investigate the expressions of C/EPBβ,C/EPBα,PPARγ,and UCP1 in adipose mesenchymal stem cells(A-MSCs)to evaluate the function of exosomal miR-155.BALB/c nude mice were intravenously injected in vivo with GC exosomes with different levels of miR-155 to determine changes in adipodifferentiation of A-MSCs.Results:Exosomes derived from GC cells suppressed adipogenesis in A-MSCs as characterized by decreased lipid droplets.Similarly,A-MSCs co-cultured with GC exosomes exhibited increased ATP production through brown adipose differentiation characterized by highly dense mitochondria and enhanced UCP1 expression(P<0.05).Mechanistically,exosomal miR-155 secreted from GC cells suppressed adipogenesis and promoted brown adipose differentiation by targeting C/EPBβ,accompanied by downregulated C/EPBαand PPARγand upregulated UCP1(P<0.05).Moreover,overexpression of miR-155 in GC exosomes improved CAC in vivo,which was characterized by fat loss,suppressed expressions of C/EPBβ,C/EPBα,and PPARγin A-MSCs,and high expression of UCP1(P<0.05).Decreasing the level of miR-155 in injected GC exosomes abrogated the improved CAC effects.Conclusions:GC exosomal miR-155 suppressed adipogenesis and enhanced brown adipose differentiation in A-MSCs by targeting C/EPBβof A-MSCs,which played a crucial role in CAC.
基金financially supported by the National Natural Science Foundation of China[grant numbers:21503265,51603135,21473241]Ministry of Science and Technology[grant number:2016YFB0100102]Nantong Science and Technology Bureau[grant number:JC2018038]。
文摘Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.
基金supported by National Natural Science Foundation of China (Nos.21706167 and 21776179)Fok Ying Tung Education Foundation (161108)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT_15R46)Yangtze River Scholar Research Project of Shihezi University (No.CJXZ201601)the Start-Up Foundation for Young Scientists of Shihezi University (RCZX201507)
文摘Ru-based catalysts modified in different atmospheres by plasma technology were prepared to catalyze the acetylene hydrochlorination reaction.The(Ru/AC)-N2(AC = activated carbon)catalyst yielded by the plasma modification of Ru/AC catalyst in N2 atmosphere exhibits the best catalytic performance with a stable C2H2 conversion of 87.2%;a relative increase of 27.1%in C2H2 conversion was achieved compared with that of the untreated Ru/AC catalyst.The results of the analysis revealed that the modification produced a mutual effect between the generated function groups on carrier AC and the active components, which can disperse and yield more active species in the fresh catalysts.These are benefits of enhancing the activity of the catalysts.Moreover, the modification can restrain coke formation and inhibit the loss of active species in the reaction, as well as strengthen the adsorption ability of reactants on the catalysts.These are benefits of improving the catalysts’ performance.
基金supported by the National Natural Science Foundation of China(Nos.52175079 and 12072091)the Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments of China(No.6142905192512)+2 种基金the Fundamental Research Funds for the Central Universities of China(No.N2103026)the Major Projects of AeroEngines and Gas Turbines of China(No.J2019-I-0008-0008)the China Postdoctoral Science Foundation(No.2020M680990)。
文摘This study analyzes and predicts the vibration characteristics of fiberreinforced composite sandwich(FRCS)cylindrical-spherical(CS)combined shells with hexagon honeycomb core(HHC)for the first time based on an analytical model developed,which makes good use of the advantage of the first-order shear deformation theory(FSDT),the multi-segment decomposition technique,the virtual spring technology,the Jacobi-Ritz approach,and the transfer function method.The equivalent material properties of HHC are firstly determined by the modified Gibson’s formula,and the related energy equations are derived for the HHC-FRCS-CS combined shells,from which the fundamental frequencies,the mode shapes,and the forced vibration responses are solved.The current model is verified through the discussion of convergence and comparative analysis with the associated published literature and finite element(FE)results.The effects of geometric parameters of HHC on the dynamic property of the structure are further investigated with the verified model.It reveals that the vibration suppression capability can be greatly enhanced by reducing the ratio of HHC thickness to total thickness and the ratio of wall thickness of honeycomb cell to overall radius,and by increasing the ratio of length of honeycomb cell to overall radius and honeycomb characteristic angle of HHC.
基金the National Natural Science Foundation of China(31870543)the Youth Science and Technology Innovation Fund of Nanjing Forestry University(cx2016017)+4 种基金the National Key R&D Program of China(2017YFC0703501)the National Natural Science Foundation of China(51878590)Jiangsu Province High-level Talent Selection Training(JNHB-127)Jiangsu Provincial Department of Housing and construction(2018ZD117 and 2019ZD092)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170926 and BK20150878)for their funding。
文摘The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are widely planted and used in the furniture industry,interior decoration,and wood structure construction in China.The aim of this work was to investigate the bonding performance of moso bamboo dowel rotation welded joints with different dowel/receiving hole diameter ratios.The results indicated that the ratio of dowel/receiving hole diameter was an important parameter that influenced the welding performance.The bonding strength of the bamboo-to-poplar welded joints at the optimal ratio of 10/7 was as high as 7.50 MPa,which was higher than that of the beech(Fagus sylvatica,L.),schima(Schima superba)dowels and PVAc glued joints.The temperature measurement results showed a peak temperature of bamboo dowel welding as high as 350–360°C.Some differences in the temperature curves between each dowel/hole diameter ratio group were observed at the three different hole depths,such as the friction time,peak temperatures,and stabilization time at the maximum temperature,which could explain the differences in welding strengths between different ratios.The SEM results showed the temperature-induced softening,melting and flowing of cell-interconnected polymer material in the wood and bamboo structure.In addition,the bamboo fibers(mainly vascular bundles)were wrapped to form a dense continuous bonding layer,similar to the reinforced concrete,thus producing a good bonding effect.The Fourier transform-infrared spectroscopy(FT-IR)analyses showed that the high temperature resulted in the increase of the lignin relative content due to the degradation reaction of cellulose in the welding zone,which improved the bonding properties.
