Background:Swift and accurate detection of Vibrio parahaemolyticus,which is a prominent causative pathogen associated with seafood contamination,is required to effectively combat foodborne disease and wound infections...Background:Swift and accurate detection of Vibrio parahaemolyticus,which is a prominent causative pathogen associated with seafood contamination,is required to effectively combat foodborne disease and wound infections.The toxR gene is relatively conserved within V.parahaemolyticus and is primarily involved in the expression and regulation of virulence genes with a notable degree of specificity.The aim of this study was to develop a rapid,simple,and constant temperature detection method for V.parahaemolyticus in clinical and nonspecialized laboratory settings.Methods:In this study,specific primers and CRISPR RNA were used to target the toxR gene to construct a reaction system that combines recombinase polymerase amplification(RPA)with CRISPR‒Cas13a.The whole-genome DNA of the sample was extracted by self-prepared sodium dodecyl sulphate(SDS)nucleic acid rapid extraction reagent,and visual interpretation of the detection results was performed by lateral flow dipsticks(LFDs).Results:The specificity of the RPA-CRISPR/Cas13a-LFD method was validated using V.parahaemolyticus strain ATCC-17802 and six other non-parahaemolytic Vibrio species.The results demonstrated a specificity of 100%.Additionally,the genomic DNA of V.parahaemolyticus was serially diluted and analysed,with a minimum detectable limit of 1 copy/μL for this method,which was greater than that of the TaqMan-qPCR method(10^(2) copies/μL).The established methods were successfully applied to detect wild-type V.parahaemolyticus,yielding results consistent with those of TaqMan-qPCR and MALDI-TOF MS mass spectrometry identification.Finally,the established RPA-CRISPR/Cas13a-LFD method was applied to whole blood specimens from mice infected with V.parahaemolyticus,and the detection rate of V.parahaemolyticus by this method was consistent with that of the conventional PCR method.Conclusions:In this study,we describe an RPA-CRISPR/Cas13a detection method that specifically targets the toxR gene and offers advantages such as simplicity,rapidity,high specificity,and visual interpretation.This method serves as a valuable tool for the prompt detection of V.parahaemolyticus in nonspecialized laboratory settings.展开更多
Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and...Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and quality of the lily.This study attempted to evaluate the effect of gibberellic acid(GA3)on tiller-bulb development and plant growth of Lanzhou lily by applying GA3 at various concentrations(0 mg/L,10 mg/L,30 mg/L,60 mg/L,and 100 mg/L)before planting and in the seedling period.Results showed that the 60-mg/L GA3 application had an inhibiting effect on tiller-bulb formation and increased the ratios of single and double bulbs but decreased the ratios of bulbs with three or more tiller bulbs,as com pared to the control(CK)and other GA3 treatments.The difference in flower number did not reach significant levels among the treatments.The tillering-related endogenous hormones IAA(indole-3-acetic acid)and Z(zeatin)content de creased,while IAA/Z increased with the 60-mg/L GA3 treatment during tiller initiation.And also,the shoot-bulb number and total daughter-bulb number decreased significantly with the 60-mg/L GA3 treatment.Furthermore,the 10-mg/L GA3 application promoted growth of Lanzhou lily significantly and resulted in an increase in plant height;bulb diameter;bulb circumference;and biomass of shoots,bulbs,fibrous roots,and the whole plant.Therefore,GA3 application is promising as a new regulation method for inhibiting tiller-bulb development and promoting bulb growth in Lanzhou lily production.展开更多
The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experie...The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experienced severe desertification in recent decades due to its fragile ecology together with inappropriate human activities. Currently, the landscape of the Horqin Sandy Land is dominated by irrigated croplands and sand dunes with different degrees of vegetation cover, as the region has become the most important part of the semiarid agro-pastoral ecotone of northern China. In this study, we compared soil physical and chemical properties under different land-use and cover types （irrigated cropland, rainfed cropland, sandy grassland, fixed dunes, and mobile dunes）. We found that soil particle size distribution; organic C, total N, and total mineral element, microelement, and available microelement and nutrient contents; pH; CEC; and bulk density differed significantly among the land-use and cover types. In general, soil quality was highest in the cropland, intermediate in the sandy grassland, and lowest in the dunes. The most important soil quality attribute, soil organic carbon （SOC） storage, decreased in the fol-lowing order： irrigated cropland （5,699 g/m^2） 〉 sandy grassland （3,390 g/m^2） 〉 rainfed cropland （2,411 g/m^2） 〉 fixed dunes （821 g/m^2） 〉 mobile dunes （463 g/m^2）. SOC was significantly positively correlated with a large proportion of the other soil physico-chemical parameters. Our results suggest that the key issue in restoration of the degraded soils will be to increase SOC storage, which would also create a high potential for sequestering soil C in desertified areas of the Horqin Sandy Land.展开更多
This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moist...This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK （control） increased gradually at 0-50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling groundwater depth of 120 em was more advantageous for plant growth because of weak ecological characteristics. A height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots.展开更多
Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and...Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi （NM3-1, NM3-2, NM3-3, and NM3-4） were screened using a CMC （carboxymethyl cellulose） carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89% by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decom- position and available nutrient input in the Horqin Sandy Land.展开更多
The Pictet-Spengler/transamination cascade reaction enables modular synthesis of marinoquinoline analoguesthrough three-component indole ring-expansion/cyclization in the manner of novel N1–C2 cleavage of indoles.Thi...The Pictet-Spengler/transamination cascade reaction enables modular synthesis of marinoquinoline analoguesthrough three-component indole ring-expansion/cyclization in the manner of novel N1–C2 cleavage of indoles.This metal-free protocol exhibits very broad functional group tolerance with up to quantitative yields. Preliminarystudies on the antitumor activity of the resultant marinoquinoline analogues reveal that the indolyl-attachedpyrrolo[2,3-c]quinoline product (5d) shows great potential (IC50 of 0.32 μg/mL to HeLa cells) as a promisinganticancer agent in clinic.展开更多
Zinc oxide nanoparticles （ZnO NPs）, as a new type of pH-sensitive drug carrier, have received much attention. ZnO NPs are stable at physiological pH, but can dissolve quickly in the acidic tumor environment （pH 〈 ...Zinc oxide nanoparticles （ZnO NPs）, as a new type of pH-sensitive drug carrier, have received much attention. ZnO NPs are stable at physiological pH, but can dissolve quickly in the acidic tumor environment （pH 〈 6） to generate cytotoxic zinc ions and reactive oxygen species （ROS）. However, the protein corona usually causes the non-specific degradation of ZnO NPs, which has limited their application considerably. Herein, a new type of pH-sensitive nanoreactor （ZnO-DOX@F-mSiO2-FA）, aimed at reducing the non-specific degradation of ZnO NPs, is presented. In the acidic tumor environment （pH 〈 6）, it can release cytotoxic zinc ions, ROS, and anticancer drugs to kill cancer cells effectively. In addition, the fluorescence emitted from fluorescein isothiocyanate （FITC）-labeled mesoporous silica （F-mSiO2） and doxorubicin （DOX） can be used to monitor the release behavior of the anticancer drug. This report provides a new method to avoid the non-specific degradation of ZnO NPs, resulting in synergetic therapy by taking advantage of ZnO NPs-induced oxidative stress and targeted drug release.展开更多
A novel high resolution imaging technique-subpixel imaging with area-array CCD sensors-is presented. The imaging method is practical as demonstrated by the computer simulation and expetimental results. It is useful to...A novel high resolution imaging technique-subpixel imaging with area-array CCD sensors-is presented. The imaging method is practical as demonstrated by the computer simulation and expetimental results. It is useful to reduce the effective focal length and enhance the spatial resolution. As there are no moving elements, the subpixel imaging system will be suitable for space application.展开更多
文摘Background:Swift and accurate detection of Vibrio parahaemolyticus,which is a prominent causative pathogen associated with seafood contamination,is required to effectively combat foodborne disease and wound infections.The toxR gene is relatively conserved within V.parahaemolyticus and is primarily involved in the expression and regulation of virulence genes with a notable degree of specificity.The aim of this study was to develop a rapid,simple,and constant temperature detection method for V.parahaemolyticus in clinical and nonspecialized laboratory settings.Methods:In this study,specific primers and CRISPR RNA were used to target the toxR gene to construct a reaction system that combines recombinase polymerase amplification(RPA)with CRISPR‒Cas13a.The whole-genome DNA of the sample was extracted by self-prepared sodium dodecyl sulphate(SDS)nucleic acid rapid extraction reagent,and visual interpretation of the detection results was performed by lateral flow dipsticks(LFDs).Results:The specificity of the RPA-CRISPR/Cas13a-LFD method was validated using V.parahaemolyticus strain ATCC-17802 and six other non-parahaemolytic Vibrio species.The results demonstrated a specificity of 100%.Additionally,the genomic DNA of V.parahaemolyticus was serially diluted and analysed,with a minimum detectable limit of 1 copy/μL for this method,which was greater than that of the TaqMan-qPCR method(10^(2) copies/μL).The established methods were successfully applied to detect wild-type V.parahaemolyticus,yielding results consistent with those of TaqMan-qPCR and MALDI-TOF MS mass spectrometry identification.Finally,the established RPA-CRISPR/Cas13a-LFD method was applied to whole blood specimens from mice infected with V.parahaemolyticus,and the detection rate of V.parahaemolyticus by this method was consistent with that of the conventional PCR method.Conclusions:In this study,we describe an RPA-CRISPR/Cas13a detection method that specifically targets the toxR gene and offers advantages such as simplicity,rapidity,high specificity,and visual interpretation.This method serves as a valuable tool for the prompt detection of V.parahaemolyticus in nonspecialized laboratory settings.
基金supported by the Science and Technology Service Network Initiative of the Chinese Academy of Sciences (Grant No. KFJ-STS-QYZD-120)the Gansu Province Major Project of Science and Technology (Grant No. 18ZD2NA010)the National Natural Science Foundation of China (Grant No. 41801076)
文摘Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and quality of the lily.This study attempted to evaluate the effect of gibberellic acid(GA3)on tiller-bulb development and plant growth of Lanzhou lily by applying GA3 at various concentrations(0 mg/L,10 mg/L,30 mg/L,60 mg/L,and 100 mg/L)before planting and in the seedling period.Results showed that the 60-mg/L GA3 application had an inhibiting effect on tiller-bulb formation and increased the ratios of single and double bulbs but decreased the ratios of bulbs with three or more tiller bulbs,as com pared to the control(CK)and other GA3 treatments.The difference in flower number did not reach significant levels among the treatments.The tillering-related endogenous hormones IAA(indole-3-acetic acid)and Z(zeatin)content de creased,while IAA/Z increased with the 60-mg/L GA3 treatment during tiller initiation.And also,the shoot-bulb number and total daughter-bulb number decreased significantly with the 60-mg/L GA3 treatment.Furthermore,the 10-mg/L GA3 application promoted growth of Lanzhou lily significantly and resulted in an increase in plant height;bulb diameter;bulb circumference;and biomass of shoots,bulbs,fibrous roots,and the whole plant.Therefore,GA3 application is promising as a new regulation method for inhibiting tiller-bulb development and promoting bulb growth in Lanzhou lily production.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41271007, 31260089, and 31560161)the One Hundred Person Project of the Chinese Academy of Sciences (Y551821002)
文摘The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experienced severe desertification in recent decades due to its fragile ecology together with inappropriate human activities. Currently, the landscape of the Horqin Sandy Land is dominated by irrigated croplands and sand dunes with different degrees of vegetation cover, as the region has become the most important part of the semiarid agro-pastoral ecotone of northern China. In this study, we compared soil physical and chemical properties under different land-use and cover types （irrigated cropland, rainfed cropland, sandy grassland, fixed dunes, and mobile dunes）. We found that soil particle size distribution; organic C, total N, and total mineral element, microelement, and available microelement and nutrient contents; pH; CEC; and bulk density differed significantly among the land-use and cover types. In general, soil quality was highest in the cropland, intermediate in the sandy grassland, and lowest in the dunes. The most important soil quality attribute, soil organic carbon （SOC） storage, decreased in the fol-lowing order： irrigated cropland （5,699 g/m^2） 〉 sandy grassland （3,390 g/m^2） 〉 rainfed cropland （2,411 g/m^2） 〉 fixed dunes （821 g/m^2） 〉 mobile dunes （463 g/m^2）. SOC was significantly positively correlated with a large proportion of the other soil physico-chemical parameters. Our results suggest that the key issue in restoration of the degraded soils will be to increase SOC storage, which would also create a high potential for sequestering soil C in desertified areas of the Horqin Sandy Land.
基金funded by the Chinese National Key Projects for Basic Scientific Research (No.2009CB421303)the Chinese National Support Projects of Science and Technology (No.2011BAC07B02)+1 种基金the Strategic Leading Science and Technology Project of Chinese Academy of Sciences (No.XDA05050201-04-01)the Chinese National Science Foundation (No.41371053)
文摘This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK （control） increased gradually at 0-50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling groundwater depth of 120 em was more advantageous for plant growth because of weak ecological characteristics. A height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots.
基金financially supported by the National Science and Technology Support Program (2011BAC07B02)National Natural Science Foundation of China (41401620 and 41171414)the Key Laboratory of Desert and Desertification Foundation (KLDD-2014-010) from Cold and Arid Regions Environmental and Engineering Research Institute,CAS
文摘Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi （NM3-1, NM3-2, NM3-3, and NM3-4） were screened using a CMC （carboxymethyl cellulose） carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89% by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decom- position and available nutrient input in the Horqin Sandy Land.
基金Support by the National Natural Science Foundation of China(Nos.22271244 and 22071211)the Hunan Provincial Natural Science Foundation of China(Nos.2023JJ40561 and 2022JJ40359)+1 种基金the Hunan Provincial Health Commission Foundation(B202313020111)Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(No.2022C02)is gratefully acknowledged.
文摘The Pictet-Spengler/transamination cascade reaction enables modular synthesis of marinoquinoline analoguesthrough three-component indole ring-expansion/cyclization in the manner of novel N1–C2 cleavage of indoles.This metal-free protocol exhibits very broad functional group tolerance with up to quantitative yields. Preliminarystudies on the antitumor activity of the resultant marinoquinoline analogues reveal that the indolyl-attachedpyrrolo[2,3-c]quinoline product (5d) shows great potential (IC50 of 0.32 μg/mL to HeLa cells) as a promisinganticancer agent in clinic.
文摘Zinc oxide nanoparticles （ZnO NPs）, as a new type of pH-sensitive drug carrier, have received much attention. ZnO NPs are stable at physiological pH, but can dissolve quickly in the acidic tumor environment （pH 〈 6） to generate cytotoxic zinc ions and reactive oxygen species （ROS）. However, the protein corona usually causes the non-specific degradation of ZnO NPs, which has limited their application considerably. Herein, a new type of pH-sensitive nanoreactor （ZnO-DOX@F-mSiO2-FA）, aimed at reducing the non-specific degradation of ZnO NPs, is presented. In the acidic tumor environment （pH 〈 6）, it can release cytotoxic zinc ions, ROS, and anticancer drugs to kill cancer cells effectively. In addition, the fluorescence emitted from fluorescein isothiocyanate （FITC）-labeled mesoporous silica （F-mSiO2） and doxorubicin （DOX） can be used to monitor the release behavior of the anticancer drug. This report provides a new method to avoid the non-specific degradation of ZnO NPs, resulting in synergetic therapy by taking advantage of ZnO NPs-induced oxidative stress and targeted drug release.
文摘A novel high resolution imaging technique-subpixel imaging with area-array CCD sensors-is presented. The imaging method is practical as demonstrated by the computer simulation and expetimental results. It is useful to reduce the effective focal length and enhance the spatial resolution. As there are no moving elements, the subpixel imaging system will be suitable for space application.
