Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researchin...Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.展开更多
Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)i...Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)in dementias that account for less than 10%of dementia diagnoses.Published studies were identified through searches conducted in Medical Literature Analysis and Retrieval System Online(MEDLINE),Excerpta Medica Database(Embase),Excerpta Medica Care(Emcare),PsycINFO,and Cumulative Index in Nursing and Allied Health Literature(CINAHL).The search criteria included terms related to‘rarer dementias’,‘activities of daily living’and‘longitudinal or cross-sectional studies’following a predefined protocol registered.Studies were screened,and those that met the criteria were citation searched.Quality assessments were performed,and relevant data were extracted.20 articles were selected,of which 19 focused on dementias within the frontotemporal dementia/primary progressive aphasia spectrum,while one addressed posterior cortical atrophy.Four studies were cross-sectional and 16 studies were longitudinal,with a median duration of 2.2 years.The Disability Assessment for Dementia was used to measure decline in 8 of the 20 studies.The varied sequences of ADL decline reported in the literature reflect variation in diagnostic specificity between studies and within-syndrome heterogeneity.Most studies used Alzheimer’s disease staging scales to measure decline,which cannot capture variant-specific symptoms.To enhance care provision in dementia,ADL scales could be deployed postdiagnosis to aid treatment and planning.This necessitates staging scales that are variant-specific and span the disease course from diagnosis to end of life.展开更多
Microbial participation in biofortification can improve the availability of selenium(Se)in soil and contribute to the enrichment of Se in crops.In this study,a selenite(Se(IV))reducing strain was isolated from Se-rich...Microbial participation in biofortification can improve the availability of selenium(Se)in soil and contribute to the enrichment of Se in crops.In this study,a selenite(Se(IV))reducing strain was isolated from Se-rich soil,and its Se transformation and bio-enhancement ability were studied.The strain was identified as Bacillus pseudomycoides and could reduce more than 93.48%of 1.0 m M Se(IV)in 54 h.The results of scanning electron microscope(SEM)and energy dispersive Xray spectrometry(EDS)showed that Se(IV)was reduced to Se(0),and Se nanoparticles(Se NPs)were eventually formed.In pot experiments,B.pseudomycoides SA14 could promote the bioavailable Se in soils and the concentration of Se in Brassica chinensis L..The concentrations of watersoluble Se,ion exchange Se and carbonate-binding Se in soil were increased by 23.13%,22.05%and 30.89%,respectively.The Se concentration of Brassica chinensis L.in pot experiments was increased by 145.05%.The relative abundance of Bacillus in soil increased from 0.97%to 2.08%in the pot experiments.As far as we know,this is the first report of Se reduction by B.pseudomycoides.This study might provide a prospective strategy for microbial fortification of Se in crops.展开更多
Fine-grained aircraft target detection in remote sensing holds significant research valueand practical applications,particularly in military defense and precision strikes.Given the complex-ity of remote sensing images...Fine-grained aircraft target detection in remote sensing holds significant research valueand practical applications,particularly in military defense and precision strikes.Given the complex-ity of remote sensing images,where targets are often small and similar within categories,detectingthese fine-grained targets is challenging.To address this,we constructed a fine-grained dataset ofremotely sensed airplanes;for the problems of remote sensing fine-grained targets with obvious head-to-tail distributions and large variations in target sizes,we proposed the DWDet fine-grained tar-get detection and recognition algorithm.First,for the problem of unbalanced category distribution,we adopt an adaptive sampling strategy.In addition,we construct a deformable convolutional blockand improve the decoupling head structure to improve the detection effect of the model ondeformed targets.Then,we design a localization loss function,which is used to improve the model’slocalization ability for targets of different scales.The experimental results show that our algorithmimproves the overall accuracy of the model by 4.1%compared to the baseline model,and improvesthe detection accuracy of small targets by 12.2%.The ablation and comparison experiments alsoprove the effectiveness of our algorithm.展开更多
The utilization of coalbed methane(CBM)cannot only alleviate the energy crisis,but also reduce greenhouse gas emissions.Gas injection is an effective method to enhance CBM recovery.Compared to single-gas injection,the...The utilization of coalbed methane(CBM)cannot only alleviate the energy crisis,but also reduce greenhouse gas emissions.Gas injection is an effective method to enhance CBM recovery.Compared to single-gas injection,the injection of CO_(2)/N_(2) mixtures can balance the sharp decline in permeability caused by pure CO_(2) and the premature breakthrough by pure N_(2).In this study,a more comprehensive thermo-hydro-mechanical(THM)coupled mathematical model was developed,incorporating processes such as ternary gas non-isothermal adsorption,gas dissolution in water,gas-water two-phase flow,energy exchange,and coal deformation.After experimental validation,the model was applied to simulate the entire process of gas mixtures for enhanced CBM recovery(GM-ECBM).Results indicate that the permeability near the production well(Pw)initially decreases due to increased effective stress,then increases as a result of CH_(4) desorption.Near the injection well(Iw),the permeability first increases due to reduced effective stress and later stabilizes under the combined effects of effective stress and CO_(2)/N_(2) adsorption.The initial CH_(4) pressure and coal seam permeability have the most significant impact on CH_(4) production,while the coal seam permeability and temperature significantly affect CO_(2)/N_(2) injection.As the coal seam permeability increases,the optimal CO_(2)/N_(2) ratio also increases accordingly.These findings provide important theoretical guidance for improving GM-ECBM efficiency in coal seams with varying permeabilities.展开更多
Ferroptosis is a new regulated cell death process executed by lipid peroxidation(LPO)of polyunsaturated fatty acids.Lipid droplets(LDs),as an important organelle for lipid storage and metabolism,are probably a major s...Ferroptosis is a new regulated cell death process executed by lipid peroxidation(LPO)of polyunsaturated fatty acids.Lipid droplets(LDs),as an important organelle for lipid storage and metabolism,are probably a major site of LPO and play critical roles in the regulation of ferroptosis.However,the detailed study on LPO in LDs has not been carried out because of the lack of LD-targeting tools for the in situ monitoring of LPO.Herein,the first LD-targeting LPO fluorescence probe(LD-LPO)has been developed.LD-LPO exhibits a rapid and selective fluorescence enhancement at 518 nm,which is unaffected by highly destructive reactive oxygen species(e.g.,hydroxyl radical)and environmental factor changes(e.g.,polarity and viscosity).LD-LPO is capable of targeting LDs and visualizing LPO within LDs in situ during erastin-or(1S,3R)-RSL3(RSL3)-induced ferroptosis.Moreover,LD-LPO has also been used to image LPO in the ferroptosis-associated non-alcoholic fatty liver disease(NAFLD),and to evaluate the medicine treatment of NAFLD with saroglitazar,demonstrating its utility for monitoring LPO levels in biosystems.The favorable analytical and imaging performance of LD-LPO may allow its application in more ferroptosisassociated physiological and pathological processes.展开更多
With their high economic value and cultural significance,modern roses are one of the most important ornamental plants.Because of their complicated genetic background and tetraploid nature,the creation of high-density ...With their high economic value and cultural significance,modern roses are one of the most important ornamental plants.Because of their complicated genetic background and tetraploid nature,the creation of high-density genetic maps of roses has been a challenge that has slowed the pace of molecular breeding for modern roses.The current construction of tetraploid genetic maps based on existing diploid rose genomes could lead to inaccurate marker information and genotyping results.Therefore,we generated the first high-quality tetraploid genome of Rosa chinensis‘Yunzheng Xiawei.'Utilizing Illumina,PacBio,and Hi-C sequencing technologies,we assembled a genome of 858.59 Mb with 14pseudo-chromosomes.Mode of inheritance analysis using PolyOrigin indicated that modern roses show both quadrivalent and bivalent pairing.Based on this reference genome,high-density genetic maps were constructed using MSTmap with nearly saturated markers.Quantitative trait locus(QTL)analysis was conducted using WinQTLCart and R/qtl for flavonoids and carotenoids,and 11 QTL clusters were identified.By combining the genome annotation,phylogenetic analyses,and gene expression analyses,we were able to identify several key genes related to flavonoid and carotenoid biosynthesis.This study provides the basis for further genetic analyses of highly heterozygous tetraploid roses and could facilitate the progress of marker-assisted selection in modern roses.展开更多
Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure ind...Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (<40 mg/L) could promote the germination of wheat seed. Interactive effects of the dye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.展开更多
The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, sca...The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag- Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of A8 content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.展开更多
With approximately 3% of the world’s population (170 million people) infected with the hepatitis C virus (HCV), the WHO has declared HCV a global health problem. Upon acute infection about 50%-80% of subjects develop...With approximately 3% of the world’s population (170 million people) infected with the hepatitis C virus (HCV), the WHO has declared HCV a global health problem. Upon acute infection about 50%-80% of subjects develop chronic hepatitis with viral persistence being at risk to develop liver cirrhosis and hepatocellular carcinoma. One characteristic of HCV is its enormous sequence diversity, which represents a significant hurdle to the development of both effective vaccines as well as to novel therapeutic interventions. Due to a polymerase that lacks a proofreading function HCV presents with a high rate of evolution, which enables rapid adaptation to a new environment including an activated immune system upon acute infection. Similarly, novel drugs designed to specifically inhibit viral proteins will face the potential problem of rapid selection of drug resistance mutations. This review focuses on the sequence diversity of HCV, the driving forces of evolution and the impact on immune control and treatment response. An important feature of any therapeutic or prophylactic intervention will be an efficient attack of a structurally or functionally important region in the viral protein. The understanding of the driving forces, but also the limits of viral evolution, will be fundamental for the design of novel therapies.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U2244227,U2244226,42177172)the National Key R&D Program of China(No.2022YFC3004301)China Geological Survey Project(No.DD20230538)。
文摘Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.
基金supported by UKResearch and Innovation(MR/S03546X/1)National BrainAppeal,Economic and Social ResearchCouncil(ES/S010467/1)+4 种基金Wellcome Trust(221915/Z/20/Z),ESRC(ES/W006014/1)Royal National Institute for Deaf People-Dunhill Medical Trust Pauline Ashley(204841/Z/16/Z,PA23)London Hospitals Biomedical Research Centre(221915/Z/20/Z)Bloomsbury and East London Doctoral Training Partnership(ES/P000592/1)National Institute for Health Research.
文摘Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)in dementias that account for less than 10%of dementia diagnoses.Published studies were identified through searches conducted in Medical Literature Analysis and Retrieval System Online(MEDLINE),Excerpta Medica Database(Embase),Excerpta Medica Care(Emcare),PsycINFO,and Cumulative Index in Nursing and Allied Health Literature(CINAHL).The search criteria included terms related to‘rarer dementias’,‘activities of daily living’and‘longitudinal or cross-sectional studies’following a predefined protocol registered.Studies were screened,and those that met the criteria were citation searched.Quality assessments were performed,and relevant data were extracted.20 articles were selected,of which 19 focused on dementias within the frontotemporal dementia/primary progressive aphasia spectrum,while one addressed posterior cortical atrophy.Four studies were cross-sectional and 16 studies were longitudinal,with a median duration of 2.2 years.The Disability Assessment for Dementia was used to measure decline in 8 of the 20 studies.The varied sequences of ADL decline reported in the literature reflect variation in diagnostic specificity between studies and within-syndrome heterogeneity.Most studies used Alzheimer’s disease staging scales to measure decline,which cannot capture variant-specific symptoms.To enhance care provision in dementia,ADL scales could be deployed postdiagnosis to aid treatment and planning.This necessitates staging scales that are variant-specific and span the disease course from diagnosis to end of life.
基金supported by the Open Project of Technology Innovation Center for Ecological Evaluation and Remediation of Agricultural Land in Plain Area,MNR(No.ZJGCJ202001)Basic Public Welfare Research Program of Zhejiang Province(No.LGF22D030001)Jiande City(No.HX2022B-011)。
文摘Microbial participation in biofortification can improve the availability of selenium(Se)in soil and contribute to the enrichment of Se in crops.In this study,a selenite(Se(IV))reducing strain was isolated from Se-rich soil,and its Se transformation and bio-enhancement ability were studied.The strain was identified as Bacillus pseudomycoides and could reduce more than 93.48%of 1.0 m M Se(IV)in 54 h.The results of scanning electron microscope(SEM)and energy dispersive Xray spectrometry(EDS)showed that Se(IV)was reduced to Se(0),and Se nanoparticles(Se NPs)were eventually formed.In pot experiments,B.pseudomycoides SA14 could promote the bioavailable Se in soils and the concentration of Se in Brassica chinensis L..The concentrations of watersoluble Se,ion exchange Se and carbonate-binding Se in soil were increased by 23.13%,22.05%and 30.89%,respectively.The Se concentration of Brassica chinensis L.in pot experiments was increased by 145.05%.The relative abundance of Bacillus in soil increased from 0.97%to 2.08%in the pot experiments.As far as we know,this is the first report of Se reduction by B.pseudomycoides.This study might provide a prospective strategy for microbial fortification of Se in crops.
基金supported by National Natural Science Foundation of China(No.62471034)Hebei Natural Science Foundation(No.F2023105001).
文摘Fine-grained aircraft target detection in remote sensing holds significant research valueand practical applications,particularly in military defense and precision strikes.Given the complex-ity of remote sensing images,where targets are often small and similar within categories,detectingthese fine-grained targets is challenging.To address this,we constructed a fine-grained dataset ofremotely sensed airplanes;for the problems of remote sensing fine-grained targets with obvious head-to-tail distributions and large variations in target sizes,we proposed the DWDet fine-grained tar-get detection and recognition algorithm.First,for the problem of unbalanced category distribution,we adopt an adaptive sampling strategy.In addition,we construct a deformable convolutional blockand improve the decoupling head structure to improve the detection effect of the model ondeformed targets.Then,we design a localization loss function,which is used to improve the model’slocalization ability for targets of different scales.The experimental results show that our algorithmimproves the overall accuracy of the model by 4.1%compared to the baseline model,and improvesthe detection accuracy of small targets by 12.2%.The ablation and comparison experiments alsoprove the effectiveness of our algorithm.
基金supported by the National Natural Science Foundation of China(Grant No.52174117)the Universitylocal Government Scientific and Technical Cooperation Cultivation Project of Ordos Institute-LNTU(Grant No.YJY-XD-2024-A-009)+2 种基金the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTZD2023073)the Liaoning Revitalization Talents Program(XLYC2203139)the Liaoning Provincial Natural Science Foundation Program(Excellent Youth Fund)(Grant No.2024JH3/10200043).
文摘The utilization of coalbed methane(CBM)cannot only alleviate the energy crisis,but also reduce greenhouse gas emissions.Gas injection is an effective method to enhance CBM recovery.Compared to single-gas injection,the injection of CO_(2)/N_(2) mixtures can balance the sharp decline in permeability caused by pure CO_(2) and the premature breakthrough by pure N_(2).In this study,a more comprehensive thermo-hydro-mechanical(THM)coupled mathematical model was developed,incorporating processes such as ternary gas non-isothermal adsorption,gas dissolution in water,gas-water two-phase flow,energy exchange,and coal deformation.After experimental validation,the model was applied to simulate the entire process of gas mixtures for enhanced CBM recovery(GM-ECBM).Results indicate that the permeability near the production well(Pw)initially decreases due to increased effective stress,then increases as a result of CH_(4) desorption.Near the injection well(Iw),the permeability first increases due to reduced effective stress and later stabilizes under the combined effects of effective stress and CO_(2)/N_(2) adsorption.The initial CH_(4) pressure and coal seam permeability have the most significant impact on CH_(4) production,while the coal seam permeability and temperature significantly affect CO_(2)/N_(2) injection.As the coal seam permeability increases,the optimal CO_(2)/N_(2) ratio also increases accordingly.These findings provide important theoretical guidance for improving GM-ECBM efficiency in coal seams with varying permeabilities.
基金the financial support from the National Natural Science Foundation of China(Nos.82060626,22004137,22164022,22174147,22074151,22374153,22174148)Excellent Youth scientific and technological talents of Guizhou Province(No.Qiankehe platform talents[2021]5638)+3 种基金Talents of Guizhou Science and Technology Cooperation Platform(No.[2020]4104)Science and Technology Innovation Team of Higher Education of Guizhou Provincial Education Department(No.Qianjiaoji[2023]073)Future Science and Technology Elite Talent Cultivation Project of Zunyi Medical University(No.ZYSE-2021-01)Zunyi Science and Technology Plan Project(No.Zunshi Keren Platform[2023]2)。
文摘Ferroptosis is a new regulated cell death process executed by lipid peroxidation(LPO)of polyunsaturated fatty acids.Lipid droplets(LDs),as an important organelle for lipid storage and metabolism,are probably a major site of LPO and play critical roles in the regulation of ferroptosis.However,the detailed study on LPO in LDs has not been carried out because of the lack of LD-targeting tools for the in situ monitoring of LPO.Herein,the first LD-targeting LPO fluorescence probe(LD-LPO)has been developed.LD-LPO exhibits a rapid and selective fluorescence enhancement at 518 nm,which is unaffected by highly destructive reactive oxygen species(e.g.,hydroxyl radical)and environmental factor changes(e.g.,polarity and viscosity).LD-LPO is capable of targeting LDs and visualizing LPO within LDs in situ during erastin-or(1S,3R)-RSL3(RSL3)-induced ferroptosis.Moreover,LD-LPO has also been used to image LPO in the ferroptosis-associated non-alcoholic fatty liver disease(NAFLD),and to evaluate the medicine treatment of NAFLD with saroglitazar,demonstrating its utility for monitoring LPO levels in biosystems.The favorable analytical and imaging performance of LD-LPO may allow its application in more ferroptosisassociated physiological and pathological processes.
基金supported by National Natural Science Foundation of China(Grant No.32071818)。
文摘With their high economic value and cultural significance,modern roses are one of the most important ornamental plants.Because of their complicated genetic background and tetraploid nature,the creation of high-density genetic maps of roses has been a challenge that has slowed the pace of molecular breeding for modern roses.The current construction of tetraploid genetic maps based on existing diploid rose genomes could lead to inaccurate marker information and genotyping results.Therefore,we generated the first high-quality tetraploid genome of Rosa chinensis‘Yunzheng Xiawei.'Utilizing Illumina,PacBio,and Hi-C sequencing technologies,we assembled a genome of 858.59 Mb with 14pseudo-chromosomes.Mode of inheritance analysis using PolyOrigin indicated that modern roses show both quadrivalent and bivalent pairing.Based on this reference genome,high-density genetic maps were constructed using MSTmap with nearly saturated markers.Quantitative trait locus(QTL)analysis was conducted using WinQTLCart and R/qtl for flavonoids and carotenoids,and 11 QTL clusters were identified.By combining the genome annotation,phylogenetic analyses,and gene expression analyses,we were able to identify several key genes related to flavonoid and carotenoid biosynthesis.This study provides the basis for further genetic analyses of highly heterozygous tetraploid roses and could facilitate the progress of marker-assisted selection in modern roses.
基金国家自然科学基金项目资助(50579008)Support of the Foundation for Polish Science through TEAM Programme‘Smart&Safe’co-financed by the EUEuropean Regional Development Fund
文摘Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (<40 mg/L) could promote the germination of wheat seed. Interactive effects of the dye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.
基金supported by the National Natural Science Foundation of China (No. 50805038)Program for New Century Excellent Talents in University
文摘The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag- Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of A8 content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.
基金the German Hepatitis Network (BMBF)and the Deutsche Forschungsgemeinschaft
文摘With approximately 3% of the world’s population (170 million people) infected with the hepatitis C virus (HCV), the WHO has declared HCV a global health problem. Upon acute infection about 50%-80% of subjects develop chronic hepatitis with viral persistence being at risk to develop liver cirrhosis and hepatocellular carcinoma. One characteristic of HCV is its enormous sequence diversity, which represents a significant hurdle to the development of both effective vaccines as well as to novel therapeutic interventions. Due to a polymerase that lacks a proofreading function HCV presents with a high rate of evolution, which enables rapid adaptation to a new environment including an activated immune system upon acute infection. Similarly, novel drugs designed to specifically inhibit viral proteins will face the potential problem of rapid selection of drug resistance mutations. This review focuses on the sequence diversity of HCV, the driving forces of evolution and the impact on immune control and treatment response. An important feature of any therapeutic or prophylactic intervention will be an efficient attack of a structurally or functionally important region in the viral protein. The understanding of the driving forces, but also the limits of viral evolution, will be fundamental for the design of novel therapies.
