As a biosorbent,algae are frequently used for the biotreatment or bioremediation of water contaminated by heavymetal or radionuclides.However,it is unclear that whether or not the biomineralization of these metal or r...As a biosorbent,algae are frequently used for the biotreatment or bioremediation of water contaminated by heavymetal or radionuclides.However,it is unclear that whether or not the biomineralization of these metal or radionuclides can be induced by algae in the process of bioremediation and what the mechanism is.In this work,Ankistrodsemus sp.has been used to treat the uranium-contaminated water,and more than 98%of uranium in the solution can be removed by the alga,when the initial uranium concentration ranges from 10 to 80 mg/L.Especially,an unusual phenomenon of algae-induced uranium biomineralization has been found in the process of uranium bioremediation and its mineralization mechanism has been explored bymultiple approaches.It is worth noticing that the biomineralization of uranium induced by Ankistrodsemus sp.is significantly affected by contact time and pH.Uranium is captured rapidly on the cell surface via complexation with the carboxylate radical,amino and amide groups of themicroalgae cells,which provides nucleation sites for the precipitation of insolubleminerals.Uranium stimulates Ankistrodsemus sp.to metabolize potassium ions(K+),which may endow algae with the ability to biomineralize uranium into the rose-like compreignacite(K_(2)[(UO_(2))6O_(4)(OH)_(6)]•8H_(2)O).As the time increased,the amorphous gradually converted into compreignacite crystals and a large number of crystals would expand over both inside and outside the cells.To the best of our knowledge,this is the first investigated microalgae with a time-dependent uranium biomineralization ability and superior tolerance to uranium.This work validates that Ankistrodsemus sp.is a promising alga for the treatment of uranium-contaminated wastewater.展开更多
For a broader understanding of uranium migration affected by microorganisms in natural anaerobic environment,the bioreduction of uranium(Ⅵ)(U(Ⅵ))was revealed in Bacillus thuringiensis,a dominant bacterium strain wit...For a broader understanding of uranium migration affected by microorganisms in natural anaerobic environment,the bioreduction of uranium(Ⅵ)(U(Ⅵ))was revealed in Bacillus thuringiensis,a dominant bacterium strain with potential of uranium-tolerant isolated from uranium contaminated soil.The reduction behavior was systematically investigated by the quantitative analysis of U(Ⅳ)in bacteria,and mechanism was inferred from the pathway of electron transmission.Under anaerobic conditions,appropriate biomass and sodium lactate as electron donor,reduction behavior of U(Ⅵ)induced by B.thuringiensis was restricted by the activity of lactate dehydrogenase,which was directly affected by the initial pH,temperature and initial U(Ⅵ)concentration of bioreduction system.Bioreduction of U(Ⅵ)was driven by the generation of nicotinamide adenine dinucleotide(NADH)from enzymatic reaction of sodium lactate with various dehydrogenase.The transmission of the electrons from bacteria to U(Ⅵ)was mainly supported by the intracellular NADH dehydrogenase-ubiquinone system,this process could maintain the biological activity of cells.展开更多
Astatine-211(^(211)At,t_(1/2)=7.21 h)emitting twoαparticles with energies of 5.87 and 7.45 MeV,can lead to a high linear energy transfer(LET=98.84 ke V/μm)and short tissue range(50~90μm).Since the 1950s,^(211)At ha...Astatine-211(^(211)At,t_(1/2)=7.21 h)emitting twoαparticles with energies of 5.87 and 7.45 MeV,can lead to a high linear energy transfer(LET=98.84 ke V/μm)and short tissue range(50~90μm).Since the 1950s,^(211)At had stepped into endoradiotherapy and has always been regarded as one of the most promisingα-emitters for targeted-alpha therapy(TAT)in various malignancies.In the past two decades,^(211)At related radiopharmaceuticals have achieved great progress in the studies of basic physicochemical properties of astatine,^(211)At labeling strategies,preclinical and clinical studies,producing profound effects in nuclear medicine.This work will give a panorama of^(211)At-related researches in the recent 20 years,which will cover both the fundamental insights of^(211)At radiochemistry and applied labeling compounds.It can provide some important hints for the studies of TAT and other radiopharmaceuticals applied in tumor radiotherapy.展开更多
基金supported by the National Natural Science Foundation of China (No. 21876123)the Fundamental Research Funds for the Central Universities and the key Research and Development Program of Sichuan Province, China (No. 2020YFN0127)
文摘As a biosorbent,algae are frequently used for the biotreatment or bioremediation of water contaminated by heavymetal or radionuclides.However,it is unclear that whether or not the biomineralization of these metal or radionuclides can be induced by algae in the process of bioremediation and what the mechanism is.In this work,Ankistrodsemus sp.has been used to treat the uranium-contaminated water,and more than 98%of uranium in the solution can be removed by the alga,when the initial uranium concentration ranges from 10 to 80 mg/L.Especially,an unusual phenomenon of algae-induced uranium biomineralization has been found in the process of uranium bioremediation and its mineralization mechanism has been explored bymultiple approaches.It is worth noticing that the biomineralization of uranium induced by Ankistrodsemus sp.is significantly affected by contact time and pH.Uranium is captured rapidly on the cell surface via complexation with the carboxylate radical,amino and amide groups of themicroalgae cells,which provides nucleation sites for the precipitation of insolubleminerals.Uranium stimulates Ankistrodsemus sp.to metabolize potassium ions(K+),which may endow algae with the ability to biomineralize uranium into the rose-like compreignacite(K_(2)[(UO_(2))6O_(4)(OH)_(6)]•8H_(2)O).As the time increased,the amorphous gradually converted into compreignacite crystals and a large number of crystals would expand over both inside and outside the cells.To the best of our knowledge,this is the first investigated microalgae with a time-dependent uranium biomineralization ability and superior tolerance to uranium.This work validates that Ankistrodsemus sp.is a promising alga for the treatment of uranium-contaminated wastewater.
基金supported by the National Natural Science Foundation of China (No.21876123)the Fundamental Research Funds for the Central Universities and the Key Research and Development Program of Sichuan Province,China (No.2020YFN0127)。
文摘For a broader understanding of uranium migration affected by microorganisms in natural anaerobic environment,the bioreduction of uranium(Ⅵ)(U(Ⅵ))was revealed in Bacillus thuringiensis,a dominant bacterium strain with potential of uranium-tolerant isolated from uranium contaminated soil.The reduction behavior was systematically investigated by the quantitative analysis of U(Ⅳ)in bacteria,and mechanism was inferred from the pathway of electron transmission.Under anaerobic conditions,appropriate biomass and sodium lactate as electron donor,reduction behavior of U(Ⅵ)induced by B.thuringiensis was restricted by the activity of lactate dehydrogenase,which was directly affected by the initial pH,temperature and initial U(Ⅵ)concentration of bioreduction system.Bioreduction of U(Ⅵ)was driven by the generation of nicotinamide adenine dinucleotide(NADH)from enzymatic reaction of sodium lactate with various dehydrogenase.The transmission of the electrons from bacteria to U(Ⅵ)was mainly supported by the intracellular NADH dehydrogenase-ubiquinone system,this process could maintain the biological activity of cells.
基金the financial supports from the National Natural Science Foundation of China(No.22006105)the China Postdoctoral Science Foundation(No.2020M683309)the Fundamental Research Funds for the Central Universities。
文摘Astatine-211(^(211)At,t_(1/2)=7.21 h)emitting twoαparticles with energies of 5.87 and 7.45 MeV,can lead to a high linear energy transfer(LET=98.84 ke V/μm)and short tissue range(50~90μm).Since the 1950s,^(211)At had stepped into endoradiotherapy and has always been regarded as one of the most promisingα-emitters for targeted-alpha therapy(TAT)in various malignancies.In the past two decades,^(211)At related radiopharmaceuticals have achieved great progress in the studies of basic physicochemical properties of astatine,^(211)At labeling strategies,preclinical and clinical studies,producing profound effects in nuclear medicine.This work will give a panorama of^(211)At-related researches in the recent 20 years,which will cover both the fundamental insights of^(211)At radiochemistry and applied labeling compounds.It can provide some important hints for the studies of TAT and other radiopharmaceuticals applied in tumor radiotherapy.
