Arbuscular mycorrhizal(AM)fungi distribute widely in natural habits and play a variety of ecological functions.In order to test the physiological response to salt stress mediated by different AM fungi,Viola prionantha...Arbuscular mycorrhizal(AM)fungi distribute widely in natural habits and play a variety of ecological functions.In order to test the physiological response to salt stress mediated by different AM fungi,Viola prionantha was selected as the host,the dominant AM fungus in the rhizosphere of V.philippica growing in Songnen saline-alkali grassland,Rhizophagus irregularis,and their mixtures were used as inoculants,and NaCl stress was applied after the roots were colonized.The results showed that V.philippica could be colonized by AM fungi in the field and the colonization rate ranged from 73.33%to 96.67%,and Claroideoglomus etunicatum was identified as the dominant AM fungi species in the rhizosphere of V.philippica by morphology combined with sequencing for AM fungal AML1/AML2 target.Inoculation with both the species resulted in the formation of mycorrhizal symbiosis(the colonization rate was more than 70%)and AM fungi significantly enhanced plants’tolerance to salt stress of varying magnitude.Higher activity of antioxidant enzymes and augmented levels of proline and other osmoregulators were observed in AM plants.The content of MDA in CK was higher than that in the inoculations with the stress of 100,200,and 250 mM.All indices except soluble protein content and MDA content were significantly correlated with AM fungal colonization indices.The analysis for different AM fungal effects showed that the mixtures and R.irregularis worked even better than C.etunicatum.These results will provide theoretical support for the exploration and screening of salt-tolerant AM fungi species and also for the application of AM-ornamental plants in saline-alkali urban greening.展开更多
Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and sc...Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and screen AM fungi species with great functions,roots and soil samples were collected from the three succession stages of Songnen saline-alkali grassland.The soil properties and AM fungal colonization were measured,and the fungus distributed extensively in three stages was annotated by sequencing for AML1/AML2 target,subsequently,maize was selected as the host to verify its colonization.The results showed that the soil properties improved with the succession of saline-alkali grassland.The plants’communities of the three stages could be colonized by AM fungi,and the colonization rate of Leymus chinensis(the third stage)ranged from 66.67%to 100%,Puccinellia tenuiflora(the second stage)ranged from 50%to 80%,while the Suaeda glauca(the first stage)was only 35%–60%.Glomeraceae sp1 was identified as the dominant AM fungi species which occurred frequently in the succession of saline-alkali land with the isolation frequency,relative abundance,and importance value of 100%,18.1%,and 59.1%,respectively.The colonization rate of Glomeraceae sp1 in maize ranged from 80%to 87%and similar mycorrhizal characteristics were detected in the roots of P.tenuiflora,S.glauca,and L.chinensis,indicating that Glomeraceae sp1 colonized the samples in the field.The correlation matrix indicated that colonization rate,colonization intensity,and vesicle abundance were closely related to soil conditions most,and they were related significantly to all the soil properties except cellulase activity.Besides,redundancy analysis(RDA)showed that soil properties drove the changes of AM fungal colonization and sporulation.These results will provide theoretical support for realizing the relationship between AM fungal colonization and soil conditions,and also for the exploration of AM fungi species with great functions.展开更多
To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C...To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.展开更多
Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple...Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8 B pencil.Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries(KIBs), significantly better than in lithium-ion batteries(LIBs), with capacity retention of 66% for the KIB vs. 28% for the LIB from 0.1 to 0.5 A g^(-1). It also shows a high reversible capacity of ～230 mAh g^(-1) at 0.2 A g^(-1), 75% capacity retention over350 cycles at 0.4 A g^(-1)and the highest rate performance(based on the total electrode weight) among graphite electrodes for K+ storage reported so far.展开更多
To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high o...To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high ornamental value,was selected as the experimental material,and the colonization characteristics of its roots and the AM fungal diversity in its rhizosphere were explored.The results of the observations and calculations of mycorrhizae from ten different samples showed that AM fungi colonized the roots of I.lactea and formed Arum-type mycorrhizal structures.There was a significant correlation between soil spore density and pH value,while the colonization rate showed a fluctuating trend with increasing pH values.The observed colonization intensities were of Levels II(1%–10%)or III(11%–50%),and the vesicle abundances were of grades A2 or A3 among different sites.AM fungi produced a large number of mycelia and vesicles in the roots of I.lactea after colonization.Thirty-seven species belonging to 15 genera of AM fungi were isolated from the rhizosphere of I.lactea and identified by morphological identification.Funneliformis and Glomus were the dominant genera,accounting for 21.79%and 20.85%of the total number,respectively.F.mosseae and Rhizophagus intraradices were isolated in all samples with importance values of 58.62 and 51.19,respectively.These results are expected to provide a theoretical basis for the analysis of the salt tolerance mechanism of I.lactea and for the discovery,exploration and further screening of AM fungal resources with salinity tolerances in saline-alkaline soils.展开更多
Numerical simulation technology is nowadays an important means for groundwater issues because of its efficiency and economical advantages. But in case of natural hydrogeological boundaries are not within the interest ...Numerical simulation technology is nowadays an important means for groundwater issues because of its efficiency and economical advantages. But in case of natural hydrogeological boundaries are not within the interest area, it may be a big trouble to set boundary conditions of the model artificially without enough field investigation information. This paper introduced a method for solving such problem applying field pumping test and recovery test. The method was applied to build an in-situ leaching of uranium model. Results showed that the model boundary conditions can be set satisfactorily, and also the calculated heads matched the observed data well in both two models.展开更多
The goal of this research is to develop an emergency disaster relief mobilization tool that determines the mobilization levels of commodities, medical service and helicopters (which will be utilized as the primary mea...The goal of this research is to develop an emergency disaster relief mobilization tool that determines the mobilization levels of commodities, medical service and helicopters (which will be utilized as the primary means of transport in a mountain region struck by a devastating earthquake) at pointed temporary facilities, including helicopter-based delivery plans for commodities and evacuation plans for critical population, in which relief demands are considered as uncertain. The proposed mobilization model is a two-stage stochastic mixed integer program with two objectives: maximizing the expected fill rate and minimizing the total expenditure of the mobilization campaign. Scenario decomposition based heuristic algorithms are also developed according to the structure of the proposed model. The computational results of a numerical example, which is constructed from the scenarios of the Great Wenchuan Earthquake, indicate that the model can provide valuable decision support for the mobilization of post-earthquake relief, and the proposed algorithms also have high efficiency in computation.展开更多
Salinization has led to the deterioration of the ecological environment,affected the growth of plants,and hindered the development of agriculture and forestry.Arbuscular mycorrhizal(AM)fungi,as important soil microorg...Salinization has led to the deterioration of the ecological environment,affected the growth of plants,and hindered the development of agriculture and forestry.Arbuscular mycorrhizal(AM)fungi,as important soil microorganisms,play significant physiological and ecological roles in promoting plant nutrient absorption and improving soil structure.Puccinellia tenuiflora(Turcz.)Scribn.et Merr.in Songnen saline-alkaline grassland was selected as the research object to observe AM fungal colonization of the roots and explore the species and diversity of AM fungi in symbiotic association with P.tenuiflora.This study showed that AM fungi colonized in P.tenuiflora roots and formed a typical Arum-type mycorrhizal structure.A significant correlation was observed between vesicular abundance and the colonization intensity of mycorrhiza.Isolation and identification revealed 40 species of AM fungi in the rhizosphere of P.tenuiflora,belonging to 14 genera,of which two species could not be identified.The richness of the genus Glomus was the highest,accounting for 30%of the total species.Funneliformis mosseae and Rhizophagus intraradices were isolated from all the samples and were the species with the widest distribution in the rhizosphere of P.tenuiflora.Correlation analysis showed that pH only had a significant impact on the distribution of a few species,such as Glomus pustulatum,Diversispora spurca,Glomus aggregatum,Rhizophagus clarum,and Acaulospora foveata.The present study provides a theoretical basis for further exploring the resources of AM fungi in saline-alkaline soil.展开更多
A research on the stable fatigue crack propagation of 16MnR steel is investigated systematically in this paper.First,control experiments of 16MnR with compact tension specimen is conducted to study the effect of R-rat...A research on the stable fatigue crack propagation of 16MnR steel is investigated systematically in this paper.First,control experiments of 16MnR with compact tension specimen is conducted to study the effect of R-ratios,specimen thickness and notch sizes.The experiments show that the fatigue crack growth(FCG)rate in stable propagation was insensitive to these factors.Then,the stress intensity factor(SIF)is computed and compared by displacement interpolation method,J integral and interaction integral method respectively.The simulation shows that optimization on the mesh density and the angle of singular element improved the computational efficiency and accuracy of SIF and the interaction integral method has an obvious advantage on stability.Finally,the FCG rate is modeled by the Jiang fatigue damage criterion and the extended finite element method(XFEM)respectively.The simulation results of FCG rate are in line with experiments data and indicate that XFEM method is more accurate than Jiang fatigue damage method.展开更多
Arbuscular mycorrhizal(AM)fungi are widely distributed in various habitats,and the community composition varies in response to the changing environmental conditions.To explore the response of community composition to ...Arbuscular mycorrhizal(AM)fungi are widely distributed in various habitats,and the community composition varies in response to the changing environmental conditions.To explore the response of community composition to the succession of saline-alkali land,soil samples were collected from three succession stages of Songnen saline-alkali grassland.Subsequently,the soil characteristics were determined and the AM fungi in soil samples were analyzed by high-throughput sequencing.Then,the response relationship between community composition and soil characteristics was studied by Canonical correlation and Pearson analyses.The soil properties improved with the succession of saline-alkali grassland.There was no significant difference in alpha diversity between the first and second succession stage(Suaeda glauca and Puccinellia tenuiflora,respectively),and the microbial community had a dense association network at the third stage(Leymus chinensis);in addition,each succession stage had significantly enriched amplicon sequence variants(ASVs)and functional pathways.All the soil properties except cellulase activity had significant effects on community composition.Furthermore,the pH,organic carbon,organic matter,and sucrase activity significantly correlated with alpha diversity indices.These results provide a theoretical basis for realizing the significant changes in AM fungal community and soil properties during the saline-alkali grassland vegetation succession.展开更多
Background:Acute decompensated heart failure(ADHF)is a life-threatening and costly disease.Controversy re-mains regarding the effi cacy and renal tolerability of ultrafi ltration for treating ADHF.We therefore perform...Background:Acute decompensated heart failure(ADHF)is a life-threatening and costly disease.Controversy re-mains regarding the effi cacy and renal tolerability of ultrafi ltration for treating ADHF.We therefore performed this meta-analysis to evaluate this clinical issue.Methods:A search of PubMed,EMBASE,and the Cochrane database of controlled trials was performed from in-ception to March 2021 for relevant randomized controlled trials.The quality of the included trials and outcomes was evaluated with the use of the risk of bias assessment tool and the Grading of Recommendations,Assessment,Develop-ment and Evaluation(GRADE)approach,respectively.The risk ratio and the standardized mean difference(SMD)or weighted mean difference(WMD)were computed and pooled with fi xed-effects or random-effects models.Results:This meta-analysis included 19 studies involving 1281 patients.Ultrafi ltration was superior to the control treatments for weight loss(WMD 1.24 kg,95%confi dence interval[CI]0.38-2.09 kg,P=0.004)and fl uid removal(WMD 1.55 L,95%CI 0.51-2.59 l,P=0.003)and was associated with a signifi cant increase in serum creatinine level compared with the control treatments(SMD 0.15 mg/dL,95%CI 0.00-0.30 mg/dL,P=0.04).However,no signifi cant effects were found for serum N-terminal prohormone of brain natriuretic peptide level,length of hospital stay,all-cause mortality,or all-cause rehospitalization in the ultrafi ltration group.Conclusions:The use of ultrafi ltration in patients with ADHF is superior to the use of the control treatments for weight loss and fl uid removal,but has adverse renal effects and lacks signifi cant effects on long-term prognosis,in-dicating that this approach to decongestion in ADHF patients is effi cient for fl uid management but less safe renally.展开更多
[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method a...[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method and Fourier transform infrared spectroscopy on the different growth years and different parts of Radix Chuanmingshinis Violacei for infrared spectrum and second derivative spectrum. [Results]With the increasing growth time,Radix Chuanmingshinis Violacei accumulated in the secondary metabolism substances gradually increased,the characteristic absorption peak appeared in the position such as 3 366,2 927,1 634,1 416,1 516,1 080,1 020,and 928 cm^(-1),the main chemicals as polysaccharide,coumarin,saponins and steroids. The difference of chemical position between root tuber and cauline leaf is obvious. [Conclusions]Infrared spectroscopy was applied in studying different growing periods and different parts of Radix Chuanmingshinis Violacei,of obvious characteristics,identification and quality evaluation method,is simple and suitable for Radix Chuanmingshinis Violacei.展开更多
The expansion of protein topological diversity requires new and efficient synthetic tools.Herein,we report the second and third generations of the SpyStapler-mediated SpyTag/BDTag ligation system for the efficient syn...The expansion of protein topological diversity requires new and efficient synthetic tools.Herein,we report the second and third generations of the SpyStapler-mediated SpyTag/BDTag ligation system for the efficient synthesis of 4-arm star proteins and the repurposing of the third generation as an active template to enable the synthesis of higher-order protein[n]catenanes(n=3,4,and 5).SpyStapler003 has a higher affinity to its cognate SpyTag and BDTag reactive pairs relative to the original SpyStapler.Hence,it can overcome much more profound steric hindrance in protein ligation and improve the efficiency of the resulting active template tool to facilitate the construction of radial protein[n]catenanes.Various proteins of interest,such as dihydrofolate reductase and the nanobody KN035,can be modularly incorporated into the[n]catenanes with intact activity.Combination of passive and active template strategies gives rise to linear protein[4]catenanes,which further expands the current topological diversity.Moreover,higher-order protein catenation not only leads to enhanced thermal stability and proteolytic resistance but also higher affinity of the nanobody via multivalent effects.Our study provides tools useful for bioconjugation and new topological protein scaffolds for the multivalent display of enzymes and antibodies.展开更多
Chemical topology refers to the three-dimensional arrangement(i.e.,connectivity and spatial relationship)of a molecule's constituent atoms and bonds.The molecular mechanism for translation defines the linear confi...Chemical topology refers to the three-dimensional arrangement(i.e.,connectivity and spatial relationship)of a molecule's constituent atoms and bonds.The molecular mechanism for translation defines the linear configuration of all nascent proteins.Nontrivial protein topology arises only upon post-translational processing events and often imparts functional benefits such as enhanced stability,making topology a unique dimension for protein engineering.Utilizing the assembly-reaction synergy,our group has developed several methods for the effective and convenient cellular synthesis of a variety of topological proteins,such as lasso proteins,protein rotaxanes,and protein catenanes.The work opens the access to new protein classes and paves the road toward illustrating the topological effects on structure-function relationship of proteins,which lays solid foundation for exploring topological proteins’practical application.展开更多
Ferroptosis is a type of cell death accompanied by iron-dependent lipid peroxidation,thus stimulating ferroptosis may be a potential strategy for treating gastric cancer,therapeutic agents against which are urgently r...Ferroptosis is a type of cell death accompanied by iron-dependent lipid peroxidation,thus stimulating ferroptosis may be a potential strategy for treating gastric cancer,therapeutic agents against which are urgently required.Jiyuan oridonin A(JDA) is a natural compound isolated from Jiyuan Rabdosia rubescens with anti-tumor activity,unclear anti-tumor mechanisms and limited water solubility hamper its clinical application.Here,we showed a2,a new JDA derivative,inhibited the growth of gastric cancer cells.Subsequently,we discovered for the first time that a2 induced ferroptosis.Importantly,compound a2 decreased GPX4 expression and overexpressing GPX4 antagonized the anti-proliferative activity of a2.Furthermore,we demonstrated that a2 caused ferrous iron accumulation through the autophagy pathway,prevention of which rescued a2 induced ferrous iron elevation and cell growth inhibition.Moreover,a2 exhibited more potent anti-cancer activity than 5-fluorouracil in gastric canc er cell line-derived xenograft mice models.Patient-derived tumor xenograft models from different patients displayed varied sensitivity to a2,and GPX4 downregulation indicated the sensitivity of tumors to a2.Finally,a2 exhibited well pharmacokinetic characteristic s.Overall,our data suggest that inducing ferroptosis is the major mechanism mediating anti-tumor activity of a2,and a2 will hopefully serve as a promising compound for gastric cancer treatment.展开更多
background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showe...background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showed that the short-term safety and efficacy of stenting was acceptable.However,it remained uncertain whether the low event rate could be of a long term.We reported the 1-year outcome of this registry study to evaluate the long-term efficacy of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Methods Patients with symptomatic ICAS caused by 70%-99% stenosis located at the intracranial internal carotid,middle cerebral,intracranial vertebral or basilar arteries combined with poor collaterals were enrolled.Balloon-mounted stent or balloon plus self-expanding stent were selected based on the ease of vascular access and lesion morphology determined by the operators.The primary outcome was the rate of 30-day stroke,transient ischaemic attack and death,and 12-month ischaemic stroke within the same vascular territory,haemorrhagic stroke and vascular death after stenting.results From September 2013 to January 2015,300 patients(ages 58.3±9.78 years)were recruited.Among them,159 patients were treated with balloon-mounted stent and 141 with balloon plus self-expanding stent.During the 1-year follow-up,25 patients had a primary end point event.The probability of primary outcome at 1 year was 8.1%(95% CI 5.3% to 11.7%).In 76 patients with digital subtraction angiography follow-up,27.6%(21/76)had re-stenosis≥50% and 18.4%(14/76)had re-stenosis≥70%.No baseline characteristic was associated with the primary outcome.Conclusion The event rate remains low over 1 year of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Further randomised trial of comparing individually tailored stenting with best medical therapy is needed.展开更多
基金Research was funded by National Natural Science Foundation of China with the Grant No.31601986 and Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘Arbuscular mycorrhizal(AM)fungi distribute widely in natural habits and play a variety of ecological functions.In order to test the physiological response to salt stress mediated by different AM fungi,Viola prionantha was selected as the host,the dominant AM fungus in the rhizosphere of V.philippica growing in Songnen saline-alkali grassland,Rhizophagus irregularis,and their mixtures were used as inoculants,and NaCl stress was applied after the roots were colonized.The results showed that V.philippica could be colonized by AM fungi in the field and the colonization rate ranged from 73.33%to 96.67%,and Claroideoglomus etunicatum was identified as the dominant AM fungi species in the rhizosphere of V.philippica by morphology combined with sequencing for AM fungal AML1/AML2 target.Inoculation with both the species resulted in the formation of mycorrhizal symbiosis(the colonization rate was more than 70%)and AM fungi significantly enhanced plants’tolerance to salt stress of varying magnitude.Higher activity of antioxidant enzymes and augmented levels of proline and other osmoregulators were observed in AM plants.The content of MDA in CK was higher than that in the inoculations with the stress of 100,200,and 250 mM.All indices except soluble protein content and MDA content were significantly correlated with AM fungal colonization indices.The analysis for different AM fungal effects showed that the mixtures and R.irregularis worked even better than C.etunicatum.These results will provide theoretical support for the exploration and screening of salt-tolerant AM fungi species and also for the application of AM-ornamental plants in saline-alkali urban greening.
基金funded by National Natural Science Foundation of China with the Grant No.31601986Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and screen AM fungi species with great functions,roots and soil samples were collected from the three succession stages of Songnen saline-alkali grassland.The soil properties and AM fungal colonization were measured,and the fungus distributed extensively in three stages was annotated by sequencing for AML1/AML2 target,subsequently,maize was selected as the host to verify its colonization.The results showed that the soil properties improved with the succession of saline-alkali grassland.The plants’communities of the three stages could be colonized by AM fungi,and the colonization rate of Leymus chinensis(the third stage)ranged from 66.67%to 100%,Puccinellia tenuiflora(the second stage)ranged from 50%to 80%,while the Suaeda glauca(the first stage)was only 35%–60%.Glomeraceae sp1 was identified as the dominant AM fungi species which occurred frequently in the succession of saline-alkali land with the isolation frequency,relative abundance,and importance value of 100%,18.1%,and 59.1%,respectively.The colonization rate of Glomeraceae sp1 in maize ranged from 80%to 87%and similar mycorrhizal characteristics were detected in the roots of P.tenuiflora,S.glauca,and L.chinensis,indicating that Glomeraceae sp1 colonized the samples in the field.The correlation matrix indicated that colonization rate,colonization intensity,and vesicle abundance were closely related to soil conditions most,and they were related significantly to all the soil properties except cellulase activity.Besides,redundancy analysis(RDA)showed that soil properties drove the changes of AM fungal colonization and sporulation.These results will provide theoretical support for realizing the relationship between AM fungal colonization and soil conditions,and also for the exploration of AM fungi species with great functions.
基金This work was supported by the National Natural Science Foundation of China(31601986)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH–Q16005).
文摘To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.
基金Support from the Australian Research Council through a Discovery project (DP170102406)Future Fellowship project (FT150100109)+1 种基金Auto CRC 2020 (Project 1-117)funded by an Australian Research Council grant (LE0237478)
文摘Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8 B pencil.Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries(KIBs), significantly better than in lithium-ion batteries(LIBs), with capacity retention of 66% for the KIB vs. 28% for the LIB from 0.1 to 0.5 A g^(-1). It also shows a high reversible capacity of ～230 mAh g^(-1) at 0.2 A g^(-1), 75% capacity retention over350 cycles at 0.4 A g^(-1)and the highest rate performance(based on the total electrode weight) among graphite electrodes for K+ storage reported so far.
基金This work was supported by the National Natural Science Foundation of China(31601986)the Fundamental Research Funds for the Central Universities(2572018BK02)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high ornamental value,was selected as the experimental material,and the colonization characteristics of its roots and the AM fungal diversity in its rhizosphere were explored.The results of the observations and calculations of mycorrhizae from ten different samples showed that AM fungi colonized the roots of I.lactea and formed Arum-type mycorrhizal structures.There was a significant correlation between soil spore density and pH value,while the colonization rate showed a fluctuating trend with increasing pH values.The observed colonization intensities were of Levels II(1%–10%)or III(11%–50%),and the vesicle abundances were of grades A2 or A3 among different sites.AM fungi produced a large number of mycelia and vesicles in the roots of I.lactea after colonization.Thirty-seven species belonging to 15 genera of AM fungi were isolated from the rhizosphere of I.lactea and identified by morphological identification.Funneliformis and Glomus were the dominant genera,accounting for 21.79%and 20.85%of the total number,respectively.F.mosseae and Rhizophagus intraradices were isolated in all samples with importance values of 58.62 and 51.19,respectively.These results are expected to provide a theoretical basis for the analysis of the salt tolerance mechanism of I.lactea and for the discovery,exploration and further screening of AM fungal resources with salinity tolerances in saline-alkaline soils.
文摘Numerical simulation technology is nowadays an important means for groundwater issues because of its efficiency and economical advantages. But in case of natural hydrogeological boundaries are not within the interest area, it may be a big trouble to set boundary conditions of the model artificially without enough field investigation information. This paper introduced a method for solving such problem applying field pumping test and recovery test. The method was applied to build an in-situ leaching of uranium model. Results showed that the model boundary conditions can be set satisfactorily, and also the calculated heads matched the observed data well in both two models.
基金supported by the National Natural Science Foundation of China 71371181 91024006China Postdoctoral Science Foundation (2012M521918)
文摘The goal of this research is to develop an emergency disaster relief mobilization tool that determines the mobilization levels of commodities, medical service and helicopters (which will be utilized as the primary means of transport in a mountain region struck by a devastating earthquake) at pointed temporary facilities, including helicopter-based delivery plans for commodities and evacuation plans for critical population, in which relief demands are considered as uncertain. The proposed mobilization model is a two-stage stochastic mixed integer program with two objectives: maximizing the expected fill rate and minimizing the total expenditure of the mobilization campaign. Scenario decomposition based heuristic algorithms are also developed according to the structure of the proposed model. The computational results of a numerical example, which is constructed from the scenarios of the Great Wenchuan Earthquake, indicate that the model can provide valuable decision support for the mobilization of post-earthquake relief, and the proposed algorithms also have high efficiency in computation.
基金This work was supported by the National Natural Science Foundation of China(31601986)the Fundamental Research Funds for the Central Universities(2572018BK02)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘Salinization has led to the deterioration of the ecological environment,affected the growth of plants,and hindered the development of agriculture and forestry.Arbuscular mycorrhizal(AM)fungi,as important soil microorganisms,play significant physiological and ecological roles in promoting plant nutrient absorption and improving soil structure.Puccinellia tenuiflora(Turcz.)Scribn.et Merr.in Songnen saline-alkaline grassland was selected as the research object to observe AM fungal colonization of the roots and explore the species and diversity of AM fungi in symbiotic association with P.tenuiflora.This study showed that AM fungi colonized in P.tenuiflora roots and formed a typical Arum-type mycorrhizal structure.A significant correlation was observed between vesicular abundance and the colonization intensity of mycorrhiza.Isolation and identification revealed 40 species of AM fungi in the rhizosphere of P.tenuiflora,belonging to 14 genera,of which two species could not be identified.The richness of the genus Glomus was the highest,accounting for 30%of the total species.Funneliformis mosseae and Rhizophagus intraradices were isolated from all the samples and were the species with the widest distribution in the rhizosphere of P.tenuiflora.Correlation analysis showed that pH only had a significant impact on the distribution of a few species,such as Glomus pustulatum,Diversispora spurca,Glomus aggregatum,Rhizophagus clarum,and Acaulospora foveata.The present study provides a theoretical basis for further exploring the resources of AM fungi in saline-alkaline soil.
文摘A research on the stable fatigue crack propagation of 16MnR steel is investigated systematically in this paper.First,control experiments of 16MnR with compact tension specimen is conducted to study the effect of R-ratios,specimen thickness and notch sizes.The experiments show that the fatigue crack growth(FCG)rate in stable propagation was insensitive to these factors.Then,the stress intensity factor(SIF)is computed and compared by displacement interpolation method,J integral and interaction integral method respectively.The simulation shows that optimization on the mesh density and the angle of singular element improved the computational efficiency and accuracy of SIF and the interaction integral method has an obvious advantage on stability.Finally,the FCG rate is modeled by the Jiang fatigue damage criterion and the extended finite element method(XFEM)respectively.The simulation results of FCG rate are in line with experiments data and indicate that XFEM method is more accurate than Jiang fatigue damage method.
基金This work was supported by the National Natural Science Foundation of China(31601986)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘Arbuscular mycorrhizal(AM)fungi are widely distributed in various habitats,and the community composition varies in response to the changing environmental conditions.To explore the response of community composition to the succession of saline-alkali land,soil samples were collected from three succession stages of Songnen saline-alkali grassland.Subsequently,the soil characteristics were determined and the AM fungi in soil samples were analyzed by high-throughput sequencing.Then,the response relationship between community composition and soil characteristics was studied by Canonical correlation and Pearson analyses.The soil properties improved with the succession of saline-alkali grassland.There was no significant difference in alpha diversity between the first and second succession stage(Suaeda glauca and Puccinellia tenuiflora,respectively),and the microbial community had a dense association network at the third stage(Leymus chinensis);in addition,each succession stage had significantly enriched amplicon sequence variants(ASVs)and functional pathways.All the soil properties except cellulase activity had significant effects on community composition.Furthermore,the pH,organic carbon,organic matter,and sucrase activity significantly correlated with alpha diversity indices.These results provide a theoretical basis for realizing the significant changes in AM fungal community and soil properties during the saline-alkali grassland vegetation succession.
基金funded by grants from the National Natural Science Foundation of China(no 81900631)the China Postdoctoral Science Foundation(2019M653354)+1 种基金the Natural Science Foundation Postdoctoral Program of Chongqing Science and Technology Bureau(cstc2019jcyj-bsh0012)the Kuanren Talents Program of the Second Affi liated Hospital of Chongqing Medical University.
文摘Background:Acute decompensated heart failure(ADHF)is a life-threatening and costly disease.Controversy re-mains regarding the effi cacy and renal tolerability of ultrafi ltration for treating ADHF.We therefore performed this meta-analysis to evaluate this clinical issue.Methods:A search of PubMed,EMBASE,and the Cochrane database of controlled trials was performed from in-ception to March 2021 for relevant randomized controlled trials.The quality of the included trials and outcomes was evaluated with the use of the risk of bias assessment tool and the Grading of Recommendations,Assessment,Develop-ment and Evaluation(GRADE)approach,respectively.The risk ratio and the standardized mean difference(SMD)or weighted mean difference(WMD)were computed and pooled with fi xed-effects or random-effects models.Results:This meta-analysis included 19 studies involving 1281 patients.Ultrafi ltration was superior to the control treatments for weight loss(WMD 1.24 kg,95%confi dence interval[CI]0.38-2.09 kg,P=0.004)and fl uid removal(WMD 1.55 L,95%CI 0.51-2.59 l,P=0.003)and was associated with a signifi cant increase in serum creatinine level compared with the control treatments(SMD 0.15 mg/dL,95%CI 0.00-0.30 mg/dL,P=0.04).However,no signifi cant effects were found for serum N-terminal prohormone of brain natriuretic peptide level,length of hospital stay,all-cause mortality,or all-cause rehospitalization in the ultrafi ltration group.Conclusions:The use of ultrafi ltration in patients with ADHF is superior to the use of the control treatments for weight loss and fl uid removal,but has adverse renal effects and lacks signifi cant effects on long-term prognosis,in-dicating that this approach to decongestion in ADHF patients is effi cient for fl uid management but less safe renally.
基金Supported by Sichuan Science and Technology Support Program Funding(No.2014SZ0132)
文摘[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method and Fourier transform infrared spectroscopy on the different growth years and different parts of Radix Chuanmingshinis Violacei for infrared spectrum and second derivative spectrum. [Results]With the increasing growth time,Radix Chuanmingshinis Violacei accumulated in the secondary metabolism substances gradually increased,the characteristic absorption peak appeared in the position such as 3 366,2 927,1 634,1 416,1 516,1 080,1 020,and 928 cm^(-1),the main chemicals as polysaccharide,coumarin,saponins and steroids. The difference of chemical position between root tuber and cauline leaf is obvious. [Conclusions]Infrared spectroscopy was applied in studying different growing periods and different parts of Radix Chuanmingshinis Violacei,of obvious characteristics,identification and quality evaluation method,is simple and suitable for Radix Chuanmingshinis Violacei.
基金support from the National Natural Science Foundation of China(grant nos.21991132,21925102,92056118,22101010,22201016,and 22201017)the National Key R&D Program of China(grant no.2020YFA0908100)the Beijing National Laboratory for Molecular Sciences(grant no.BNLMSCXXM-202006)。
文摘The expansion of protein topological diversity requires new and efficient synthetic tools.Herein,we report the second and third generations of the SpyStapler-mediated SpyTag/BDTag ligation system for the efficient synthesis of 4-arm star proteins and the repurposing of the third generation as an active template to enable the synthesis of higher-order protein[n]catenanes(n=3,4,and 5).SpyStapler003 has a higher affinity to its cognate SpyTag and BDTag reactive pairs relative to the original SpyStapler.Hence,it can overcome much more profound steric hindrance in protein ligation and improve the efficiency of the resulting active template tool to facilitate the construction of radial protein[n]catenanes.Various proteins of interest,such as dihydrofolate reductase and the nanobody KN035,can be modularly incorporated into the[n]catenanes with intact activity.Combination of passive and active template strategies gives rise to linear protein[4]catenanes,which further expands the current topological diversity.Moreover,higher-order protein catenation not only leads to enhanced thermal stability and proteolytic resistance but also higher affinity of the nanobody via multivalent effects.Our study provides tools useful for bioconjugation and new topological protein scaffolds for the multivalent display of enzymes and antibodies.
基金We are grateful for the financial support from the National Key R&D Program of China(No.2020YFA0908100)the National Natural Science Foundation of China(Nos.21991132,21925102,92056118,22101010,22201016,22201017)Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202006)。
文摘Chemical topology refers to the three-dimensional arrangement(i.e.,connectivity and spatial relationship)of a molecule's constituent atoms and bonds.The molecular mechanism for translation defines the linear configuration of all nascent proteins.Nontrivial protein topology arises only upon post-translational processing events and often imparts functional benefits such as enhanced stability,making topology a unique dimension for protein engineering.Utilizing the assembly-reaction synergy,our group has developed several methods for the effective and convenient cellular synthesis of a variety of topological proteins,such as lasso proteins,protein rotaxanes,and protein catenanes.The work opens the access to new protein classes and paves the road toward illustrating the topological effects on structure-function relationship of proteins,which lays solid foundation for exploring topological proteins’practical application.
基金supported by grants from the National Natural Science Foundation of China (Nos. 81773562, 82020108030, and U1904163)National Key Research and Development Project (No. 2018YFE0195100, China)the Science and Technology Program of Henan Province (No. 202102310152, China)。
文摘Ferroptosis is a type of cell death accompanied by iron-dependent lipid peroxidation,thus stimulating ferroptosis may be a potential strategy for treating gastric cancer,therapeutic agents against which are urgently required.Jiyuan oridonin A(JDA) is a natural compound isolated from Jiyuan Rabdosia rubescens with anti-tumor activity,unclear anti-tumor mechanisms and limited water solubility hamper its clinical application.Here,we showed a2,a new JDA derivative,inhibited the growth of gastric cancer cells.Subsequently,we discovered for the first time that a2 induced ferroptosis.Importantly,compound a2 decreased GPX4 expression and overexpressing GPX4 antagonized the anti-proliferative activity of a2.Furthermore,we demonstrated that a2 caused ferrous iron accumulation through the autophagy pathway,prevention of which rescued a2 induced ferrous iron elevation and cell growth inhibition.Moreover,a2 exhibited more potent anti-cancer activity than 5-fluorouracil in gastric canc er cell line-derived xenograft mice models.Patient-derived tumor xenograft models from different patients displayed varied sensitivity to a2,and GPX4 downregulation indicated the sensitivity of tumors to a2.Finally,a2 exhibited well pharmacokinetic characteristic s.Overall,our data suggest that inducing ferroptosis is the major mechanism mediating anti-tumor activity of a2,and a2 will hopefully serve as a promising compound for gastric cancer treatment.
基金This work is supported by National Natural Science Foundation of China(81371290),Beijing High-level Personnel Funds(2013-2-019)This study is also funded by the National Science and Technology Support Program of‘The 12th Five-Year Plan’of the Ministry of Science and Technology(2011BAI08B02).
文摘background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showed that the short-term safety and efficacy of stenting was acceptable.However,it remained uncertain whether the low event rate could be of a long term.We reported the 1-year outcome of this registry study to evaluate the long-term efficacy of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Methods Patients with symptomatic ICAS caused by 70%-99% stenosis located at the intracranial internal carotid,middle cerebral,intracranial vertebral or basilar arteries combined with poor collaterals were enrolled.Balloon-mounted stent or balloon plus self-expanding stent were selected based on the ease of vascular access and lesion morphology determined by the operators.The primary outcome was the rate of 30-day stroke,transient ischaemic attack and death,and 12-month ischaemic stroke within the same vascular territory,haemorrhagic stroke and vascular death after stenting.results From September 2013 to January 2015,300 patients(ages 58.3±9.78 years)were recruited.Among them,159 patients were treated with balloon-mounted stent and 141 with balloon plus self-expanding stent.During the 1-year follow-up,25 patients had a primary end point event.The probability of primary outcome at 1 year was 8.1%(95% CI 5.3% to 11.7%).In 76 patients with digital subtraction angiography follow-up,27.6%(21/76)had re-stenosis≥50% and 18.4%(14/76)had re-stenosis≥70%.No baseline characteristic was associated with the primary outcome.Conclusion The event rate remains low over 1 year of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Further randomised trial of comparing individually tailored stenting with best medical therapy is needed.
