Moellerella wisconsensis is proposed for a member of the family Enterobacteriaceae previously designated as Enteric Group 46.In 1984,the majority of the bacterial isolates(6/8,75%)had been identified in Wisconsin,USA(...Moellerella wisconsensis is proposed for a member of the family Enterobacteriaceae previously designated as Enteric Group 46.In 1984,the majority of the bacterial isolates(6/8,75%)had been identified in Wisconsin,USA(Hickman-Brenner et al.2021).Thus,this bacterial was named M.wisconsensis.Despite the passage of nearly four decades since its discovery,limited research has been conducted on this bacterium.This may be attributed to the misidentification of M.wisconsensis as Escherichia coli(Stock et al.2003).Currently,the presence of these microorganisms has been identified in both humans and animals,leading to the development of various clinical symptoms such as diarrhea,urinary tract infections,and bacteremia(Aller et al.2009;Leroy et al.2016).展开更多
Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were so...Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction.Here,we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling.The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value.Among them,[C_(16)H_(33)N(CH_(3))_(3)]_(3)PW_(12)O_(40)(abbreviated as[CTA]_(3)PW)exhibits the highest activity and the most suitable pH responsive values.Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET,but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid.Additionally,the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive[CTA]_(3)PW.展开更多
Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) wi...Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) without any further heating as a post-treatment. The surfactant acts as a self-assembling supermolecular template, which stimulated the crystallization of LiFePOand directed the nanoparticles growing into nanorods between bilayers of surfactant(BOS). LiFePOnanorods with the reducing crystal size along the b axis shorten the diffusion distance of Liextraction/insertion, and thus improve the electrochemical properties of LiFePOnanorods. Such prepared LiFePOnanorods exhibited excellent specific capacity and high rate capability with discharge capacity of 151 mAh/g, 122 mAh/g and 95 mAh/g at 0.1C, 1 C and 5 C, respectively. Such excellent performance of LiFePOnanorods is supposed to be ascribed to the fast Lidiffusion velocity from reduced crystal size along the b axis and the well electrochemical conductivity. The structure, morphology and electrochemical performance of the samples were characterized by XRD, FE-SEM, HRTEM, charge/discharge tests, and EIS(electrochemical impedance spectra).展开更多
Quantum cascade(QC)superluminescent light emitters(SLEs)have emerged as desirable broadband mid-infrared(MIR)light sources for growing number of applications in areas like medical imaging,gas sensing and national defe...Quantum cascade(QC)superluminescent light emitters(SLEs)have emerged as desirable broadband mid-infrared(MIR)light sources for growing number of applications in areas like medical imaging,gas sensing and national defense.However,it is challenging to obtain a practical high-power device due to the very low efficiency of spontaneous emission in the intersubband transitions in QC structures.Herein a design of^5μm SLEs is demonstrated with a two-phonon resonancebased QC active structure coupled with a compact combinatorial waveguide structure which comprises a short straight part adjacent to a tilted stripe and to a J-shaped waveguide.The as-fabricated SLEs achieve a high output power of 1.8 mW,exhibiting the potential to be integrated into array devices without taking up too much chip space.These results may facilitate the realization of SLE arrays to attain larger output power and pave the pathway towards the practical applications of broadband MIR light sources.展开更多
Background: This study was conducted to measure the concentration of branched chain amino acid(BCAA) in different species and detect the expression pattern of the liver Bckdha gene in Goto-Kakizaki(GK) rats during typ...Background: This study was conducted to measure the concentration of branched chain amino acid(BCAA) in different species and detect the expression pattern of the liver Bckdha gene in Goto-Kakizaki(GK) rats during type 2 diabetes(T2D)progression.Methods: We measured the concentration of BCAA in GK rats, induced T2D cynomolgus monkeys and T2D humans by liquid chromatography tandem mass spectrometry, and used real-time quantitative PCR to analyze the gene expression of Bckdha and Bckdk, which encode the rate-limiting enzymes in catabolism of,respectively, branched chain amino acids and branched chain α-keto acid dehydrogenase kinase.Results: In this study, we showed that GK rat BCAA concentrations were significantly reduced at 4 and 8 weeks(P < 0.05 and P < 0.01, respectively), while the expression of Bckdha in GK rat liver was increased at 4 and 8 weeks(1.62-fold and1.93-fold, respectively). The BCAA concentrations were significantly reduced in diet-induced T2D cynomolgus monkeys(P < 0.01), but significantly increased in T2D humans(P < 0.001).Conclusions: Our results showed that BCAA concentrations changed at different times and by different amounts in different species and during different periods of T2D progress, and the significant changes of BCAA concentration in the three species indicated that BCAA might participate in the progress of T2D. The results suggested that the increased expression of Bckdha in GK rat liver might partially explain the reduced plasma BCAA concentration at 4 and 8 weeks. Further studies are required to investigate the exact mechanism of BCAA changes in non-obese T2D.展开更多
Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their struc...Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their structure and function in ecosystems,we investigated the spatial patterns and nitrogen(N)transfer of EM networks usingN labelling technique in a Mongolian scotch pine(Pinus sylvestris var.mongolica Litv.)plantation in Northeastern China.In August 2011,four plots(20 × 20 m)were set up in the plantation.125 ml 5 at.%0.15 mol/LNHNOsolution was injected into soil at the center of each plot.Before and 2,6,30 and 215 days after theN application,needles(current year)of each pine were sampled along four 12 m sampling lines.Needle total N andN concentrations were analyzed.We observed needle N andN concentrations increased significantly over time afterN application,up to 31 and0.42%,respectively.There was no correlation between needle N concentration andN/N ratio(R2=0.40,n=5,P=0.156),while excess needle N concentration and excess needleN/N ratio were positively correlated across different time intervals(R~2=0.89,n=4,P\0.05),but deceased with time interval lengthening.NeedleN/N ratio increased with time,but it was not correlated with distance.NeedleN/N ratio was negative with distance before and 6th day and 30th day,positive with distance at 2nd day,but the trend was considerably weaker,their slop were close to zero.These results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random network.We found N transfer efficiency was very high,absorbed N by EM network was transferred as wide as possible,we observed N uptake of plant had strong bias forN andN,namely N fractionation.Understanding the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution,and thus provide new theoretical approaches to improve conservation practices for the management of the Earth’s ecosystems.展开更多
Since the idea of“Curriculum-Based Ideological and Political Education”was formally proposed in 2016,it has rapidly become a research hotspot in education reform.Although a large number of relevant studies have focu...Since the idea of“Curriculum-Based Ideological and Political Education”was formally proposed in 2016,it has rapidly become a research hotspot in education reform.Although a large number of relevant studies have focused on the effective paths to curriculum-based ideological and political education in specific courses,there are few studies on how to integrate ideological and political education contents into particular courses under specific educational concepts and by particular teaching methods.Thus,this paper will explore how to improve the teaching effectiveness of curriculumbased ideological and political education in College English course with the OBE concept as the driving force and the case teaching method as the means.Finally,a few thoughts on the application of case teaching method in College English course are offered.展开更多
Objective:To investigate the guiding role of pharmaceutical care in the treatment of bronchial asthma.Methods:Eighty patients with bronchial disease admitted to our hospital from November 2008 to December 1818 were en...Objective:To investigate the guiding role of pharmaceutical care in the treatment of bronchial asthma.Methods:Eighty patients with bronchial disease admitted to our hospital from November 2008 to December 1818 were enrolled in this research.The computer program was used to generate random numbers.The method was divided into two groups:control group and observation group,40 cases respectively.40 patients in the control group were treated with normal medication according to the doctor’s advice;40 patients in the observation group were enrolled in the pharmacological care on the basis of the control group,and the rational drug use was compared between the two groups.Results:The incidence of adverse reactions in the observation group and the control group were 5.00%and 17.50%,respectively,and the difference was statistically significant(P<0.05);the incidence of medication error events in the observation group was 7.50%,which was significantly lower than that of the control group,which was 25.00%,and the difference was statistically significant(P<0.05).The medication errors mainly include improper administration,incorrect dosage,and unscientific administration.Conclusion:The guiding role of pharmaceutical care in bronchial asthma rational drug use can reduce medication error events and ensure rational drug use,which is worthy of popularization in clinical practice.展开更多
Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Her...Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE(BDE-47)and deca-BDE(BDE-209) were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that:(1) The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS(Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations.(2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.(3) Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females(OF/NOF), the ratio of mictic females/amictic females(MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.展开更多
A co-location pattern is a set of spatial features whose instances frequently appear in a spatial neighborhood. This paper efficiently mines the top-k probabilistic prevalent co-locations over spatially uncertain data...A co-location pattern is a set of spatial features whose instances frequently appear in a spatial neighborhood. This paper efficiently mines the top-k probabilistic prevalent co-locations over spatially uncertain data sets and makes the following contributions: 1) the concept of the top-k prob- abilistic prevalent co-locations based on a possible world model is defined; 2) a framework for discovering the top- k probabilistic prevalent co-locations is set up; 3) a matrix method is proposed to improve the computation of the preva- lence probability of a top-k candidate, and two pruning rules of the matrix block are given to accelerate the search for ex- act solutions; 4) a polynomial matrix is developed to further speed up the top-k candidate refinement process; 5) an ap- proximate algorithm with compensation factor is introduced so that relatively large quantity of data can be processed quickly. The efficiency of our proposed algorithms as well as the accuracy of the approximation algorithms is evaluated with an extensive set of experiments using both synthetic and real uncertain data sets.展开更多
Decabromodiphenyl ether(BDE-209) is a prevalent polybrominated diphenyl ether(PBDE)congener known to have neurotoxicity. Effects of BDE-209 on Neuro-2a cells were performed in the present study and the possible ap...Decabromodiphenyl ether(BDE-209) is a prevalent polybrominated diphenyl ether(PBDE)congener known to have neurotoxicity. Effects of BDE-209 on Neuro-2a cells were performed in the present study and the possible apoptotic pathway was discussed. Results indicated that BDE-209 induced Neuro-2a cell apoptosis, increased the protein expression of Fas and Fas-associated death domain-containing protein(FADD) and activated the caspase-8 and-3activities in a concentration-dependent manner, inferring the death-receptor pathway was involved in the apoptotic process. Meanwhile, BDE-209 exposure increased the Bax/Bcl-2 ratio and decreased the cellular mitochondrial membrane potential(MMP) which led to cytochrome C released to the cytoplasm. The intracellular caspase-9 was elevated simultaneously,which caused downstream caspase cascade and triggered cell apoptosis. Moreover, BDE-209 exposure increased cellular reactive oxygen species(ROS) level in a concentration-dependent manner and the addition of N-acetyl-L-cysteine(NAC), known as ROS scavengers, obviously reduced the apoptotic rate and a positive relationship was observed between the degree of apoptosis blocking and the loss of MMP and ROS production. We thus concluded that BDE-209 induced Neuro-2a cell apoptosis via the combination of the death-receptor signaling pathway and the mitochondrial signaling pathway. The elevated ROS production was considered to magnify the intracellular apoptosis signal and played a crucial role in apoptosis of Neuro-2a cells induced by BDE-209.展开更多
基金funded by the National Natural Science Foundation of China(32141002)the Postdoctoral Fellowship Program of CPSF under Grant,China(GZC20241939)the China Agriculture Research System of MOF and MARA(CARS-39-14).
文摘Moellerella wisconsensis is proposed for a member of the family Enterobacteriaceae previously designated as Enteric Group 46.In 1984,the majority of the bacterial isolates(6/8,75%)had been identified in Wisconsin,USA(Hickman-Brenner et al.2021).Thus,this bacterial was named M.wisconsensis.Despite the passage of nearly four decades since its discovery,limited research has been conducted on this bacterium.This may be attributed to the misidentification of M.wisconsensis as Escherichia coli(Stock et al.2003).Currently,the presence of these microorganisms has been identified in both humans and animals,leading to the development of various clinical symptoms such as diarrhea,urinary tract infections,and bacteremia(Aller et al.2009;Leroy et al.2016).
基金the support of the National Natural Science Foundation of China(22005276)。
文摘Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction.Here,we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling.The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value.Among them,[C_(16)H_(33)N(CH_(3))_(3)]_(3)PW_(12)O_(40)(abbreviated as[CTA]_(3)PW)exhibits the highest activity and the most suitable pH responsive values.Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET,but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid.Additionally,the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive[CTA]_(3)PW.
基金financially sponsored by the National Natural Science Foundation of China(Grant No:91534205)
文摘Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) without any further heating as a post-treatment. The surfactant acts as a self-assembling supermolecular template, which stimulated the crystallization of LiFePOand directed the nanoparticles growing into nanorods between bilayers of surfactant(BOS). LiFePOnanorods with the reducing crystal size along the b axis shorten the diffusion distance of Liextraction/insertion, and thus improve the electrochemical properties of LiFePOnanorods. Such prepared LiFePOnanorods exhibited excellent specific capacity and high rate capability with discharge capacity of 151 mAh/g, 122 mAh/g and 95 mAh/g at 0.1C, 1 C and 5 C, respectively. Such excellent performance of LiFePOnanorods is supposed to be ascribed to the fast Lidiffusion velocity from reduced crystal size along the b axis and the well electrochemical conductivity. The structure, morphology and electrochemical performance of the samples were characterized by XRD, FE-SEM, HRTEM, charge/discharge tests, and EIS(electrochemical impedance spectra).
基金supported by the Key Research and Development Plan of Ministry of Science and Technology(No.2016YFB0402303)the National Natural Science Foundation of China(No.61575222)+1 种基金the open project of the State Key Laboratory of Luminescence and ApplicationsChina Postdoctoral Science Foundation(No.2017M621858)
文摘Quantum cascade(QC)superluminescent light emitters(SLEs)have emerged as desirable broadband mid-infrared(MIR)light sources for growing number of applications in areas like medical imaging,gas sensing and national defense.However,it is challenging to obtain a practical high-power device due to the very low efficiency of spontaneous emission in the intersubband transitions in QC structures.Herein a design of^5μm SLEs is demonstrated with a two-phonon resonancebased QC active structure coupled with a compact combinatorial waveguide structure which comprises a short straight part adjacent to a tilted stripe and to a J-shaped waveguide.The as-fabricated SLEs achieve a high output power of 1.8 mW,exhibiting the potential to be integrated into array devices without taking up too much chip space.These results may facilitate the realization of SLE arrays to attain larger output power and pave the pathway towards the practical applications of broadband MIR light sources.
基金Science and Technology Program of Guangzhou,China,Grant/Award Number:201508020040,201707010330National Science and Technology Support Program,Grant/Award Number:2014BAI03B00,2015BAI07B0+1 种基金Science and Technology Program of Guangdong province,Grant/Award Number:2014B070706020S&T Development Project of Guangdong Academy of Science,Grant/Award Number2017A070702014
文摘Background: This study was conducted to measure the concentration of branched chain amino acid(BCAA) in different species and detect the expression pattern of the liver Bckdha gene in Goto-Kakizaki(GK) rats during type 2 diabetes(T2D)progression.Methods: We measured the concentration of BCAA in GK rats, induced T2D cynomolgus monkeys and T2D humans by liquid chromatography tandem mass spectrometry, and used real-time quantitative PCR to analyze the gene expression of Bckdha and Bckdk, which encode the rate-limiting enzymes in catabolism of,respectively, branched chain amino acids and branched chain α-keto acid dehydrogenase kinase.Results: In this study, we showed that GK rat BCAA concentrations were significantly reduced at 4 and 8 weeks(P < 0.05 and P < 0.01, respectively), while the expression of Bckdha in GK rat liver was increased at 4 and 8 weeks(1.62-fold and1.93-fold, respectively). The BCAA concentrations were significantly reduced in diet-induced T2D cynomolgus monkeys(P < 0.01), but significantly increased in T2D humans(P < 0.001).Conclusions: Our results showed that BCAA concentrations changed at different times and by different amounts in different species and during different periods of T2D progress, and the significant changes of BCAA concentration in the three species indicated that BCAA might participate in the progress of T2D. The results suggested that the increased expression of Bckdha in GK rat liver might partially explain the reduced plasma BCAA concentration at 4 and 8 weeks. Further studies are required to investigate the exact mechanism of BCAA changes in non-obese T2D.
基金supported by National Natural Science Foundation of China(30830024)
文摘Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so on.To deeply their structure and function in ecosystems,we investigated the spatial patterns and nitrogen(N)transfer of EM networks usingN labelling technique in a Mongolian scotch pine(Pinus sylvestris var.mongolica Litv.)plantation in Northeastern China.In August 2011,four plots(20 × 20 m)were set up in the plantation.125 ml 5 at.%0.15 mol/LNHNOsolution was injected into soil at the center of each plot.Before and 2,6,30 and 215 days after theN application,needles(current year)of each pine were sampled along four 12 m sampling lines.Needle total N andN concentrations were analyzed.We observed needle N andN concentrations increased significantly over time afterN application,up to 31 and0.42%,respectively.There was no correlation between needle N concentration andN/N ratio(R2=0.40,n=5,P=0.156),while excess needle N concentration and excess needleN/N ratio were positively correlated across different time intervals(R~2=0.89,n=4,P\0.05),but deceased with time interval lengthening.NeedleN/N ratio increased with time,but it was not correlated with distance.NeedleN/N ratio was negative with distance before and 6th day and 30th day,positive with distance at 2nd day,but the trend was considerably weaker,their slop were close to zero.These results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random network.We found N transfer efficiency was very high,absorbed N by EM network was transferred as wide as possible,we observed N uptake of plant had strong bias forN andN,namely N fractionation.Understanding the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution,and thus provide new theoretical approaches to improve conservation practices for the management of the Earth’s ecosystems.
基金A general project granted by NingBo Education Science Planning in 2020——A Research on the Application of Case Teaching Method in“curriculum-based Ideological and political education”in College English Course under the Idea of OBE(No.:2020ygh033).
文摘Since the idea of“Curriculum-Based Ideological and Political Education”was formally proposed in 2016,it has rapidly become a research hotspot in education reform.Although a large number of relevant studies have focused on the effective paths to curriculum-based ideological and political education in specific courses,there are few studies on how to integrate ideological and political education contents into particular courses under specific educational concepts and by particular teaching methods.Thus,this paper will explore how to improve the teaching effectiveness of curriculumbased ideological and political education in College English course with the OBE concept as the driving force and the case teaching method as the means.Finally,a few thoughts on the application of case teaching method in College English course are offered.
文摘Objective:To investigate the guiding role of pharmaceutical care in the treatment of bronchial asthma.Methods:Eighty patients with bronchial disease admitted to our hospital from November 2008 to December 1818 were enrolled in this research.The computer program was used to generate random numbers.The method was divided into two groups:control group and observation group,40 cases respectively.40 patients in the control group were treated with normal medication according to the doctor’s advice;40 patients in the observation group were enrolled in the pharmacological care on the basis of the control group,and the rational drug use was compared between the two groups.Results:The incidence of adverse reactions in the observation group and the control group were 5.00%and 17.50%,respectively,and the difference was statistically significant(P<0.05);the incidence of medication error events in the observation group was 7.50%,which was significantly lower than that of the control group,which was 25.00%,and the difference was statistically significant(P<0.05).The medication errors mainly include improper administration,incorrect dosage,and unscientific administration.Conclusion:The guiding role of pharmaceutical care in bronchial asthma rational drug use can reduce medication error events and ensure rational drug use,which is worthy of popularization in clinical practice.
基金supported by the Natural Science Foundation of China (No. 41276140)
文摘Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE(BDE-47)and deca-BDE(BDE-209) were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that:(1) The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS(Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations.(2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.(3) Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females(OF/NOF), the ratio of mictic females/amictic females(MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.
文摘A co-location pattern is a set of spatial features whose instances frequently appear in a spatial neighborhood. This paper efficiently mines the top-k probabilistic prevalent co-locations over spatially uncertain data sets and makes the following contributions: 1) the concept of the top-k prob- abilistic prevalent co-locations based on a possible world model is defined; 2) a framework for discovering the top- k probabilistic prevalent co-locations is set up; 3) a matrix method is proposed to improve the computation of the preva- lence probability of a top-k candidate, and two pruning rules of the matrix block are given to accelerate the search for ex- act solutions; 4) a polynomial matrix is developed to further speed up the top-k candidate refinement process; 5) an ap- proximate algorithm with compensation factor is introduced so that relatively large quantity of data can be processed quickly. The efficiency of our proposed algorithms as well as the accuracy of the approximation algorithms is evaluated with an extensive set of experiments using both synthetic and real uncertain data sets.
基金supported by the National Natural Science Foundation of China(Nos.41476109 and 41276140)the Joint Fund of the National Natural Science Foundation of China and Shandong Province(No.NSFC-U 1406403)
文摘Decabromodiphenyl ether(BDE-209) is a prevalent polybrominated diphenyl ether(PBDE)congener known to have neurotoxicity. Effects of BDE-209 on Neuro-2a cells were performed in the present study and the possible apoptotic pathway was discussed. Results indicated that BDE-209 induced Neuro-2a cell apoptosis, increased the protein expression of Fas and Fas-associated death domain-containing protein(FADD) and activated the caspase-8 and-3activities in a concentration-dependent manner, inferring the death-receptor pathway was involved in the apoptotic process. Meanwhile, BDE-209 exposure increased the Bax/Bcl-2 ratio and decreased the cellular mitochondrial membrane potential(MMP) which led to cytochrome C released to the cytoplasm. The intracellular caspase-9 was elevated simultaneously,which caused downstream caspase cascade and triggered cell apoptosis. Moreover, BDE-209 exposure increased cellular reactive oxygen species(ROS) level in a concentration-dependent manner and the addition of N-acetyl-L-cysteine(NAC), known as ROS scavengers, obviously reduced the apoptotic rate and a positive relationship was observed between the degree of apoptosis blocking and the loss of MMP and ROS production. We thus concluded that BDE-209 induced Neuro-2a cell apoptosis via the combination of the death-receptor signaling pathway and the mitochondrial signaling pathway. The elevated ROS production was considered to magnify the intracellular apoptosis signal and played a crucial role in apoptosis of Neuro-2a cells induced by BDE-209.