Rare earth elements are indispensable raw materials for advanced aero-engines, special optical materials, and high-performance electronic products. With the development of the social economy, the global demand for rar...Rare earth elements are indispensable raw materials for advanced aero-engines, special optical materials, and high-performance electronic products. With the development of the social economy, the global demand for rare earth resources is increasing, and rare earths have become a key metal for the development of new industries and frontier technologies that are highly valued both at home and abroad. Ion-adsorbed rare earth ores are an important source of rare earths, so the efficient green leaching of ion-adsorbed rare earths is important. Researchers found that the selection of an efficient green leaching agent for ion-adsorbed rare earths is based on the zeta potential of tailing clay minerals in addition to leaching efficiency, and both zeta potential and leaching ion concentration are related to mineral acidity and alkalinity, and the pH of tailing water suspension is a direct indicator of environmental water quality requirements. Therefore, the efficiency of the leaching process is closely integrated with the environmental evaluation, and the characteristics and correlation of the changes in zeta potential, pH, conductivity and pollutant concentration of the pulp of clay mineral content during the leaching process of ore leaching and tailings aqueous electrolyte solution leaching are studied by evaluating the leaching system, and a set of correlation leaching efficiency and environmental impact evaluation method is established based on the results of the above analysis, which is of scientific development of ion adsorption rare earth resources. It has important theoretical significance and practical application value.展开更多
The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry.Benefiting from the unique luminescent and magnetic properties of lanthanide ions,the potential...The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry.Benefiting from the unique luminescent and magnetic properties of lanthanide ions,the potential applications of lanthanide-organic cages in biological imaging applications are promising,but only a few corresponding explorations have been reported.He rein,we introduced a series of lanthanide tetrahedral cages,(Eu_(n)Gd_(4-n)L_(4))(sol)_8(n=0,1,2,3 and 4,where L=(4,4',4"-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine,and sol=dimethyl sulfoxide and methanol),with potential applications in biological imaging.Given the good luminescent and magnetic properties of Eu^(3+) and Gd^(3+) ions,Eu_(4)L_(4) and Gd_(4)L_(4) complexes show a high luminescence quantum yield of 29% in DMSO and large longitudinal relaxivity(r_(1)) of 11.4(mmol/L)^(-1)/s at 0.5 T in water containing 1 vol% DMSO,respectively.The heterobimetallic Eu-Gd complexes achieve a dual imaging mode by combining luminescent and magnetic centers in one cage.When the Gd:Eu ratio increases from 1:3 to 3:1,the r_(1) values increases from 5.33 to 8.64(mmoI/L)^(-1)/s,higher than that of commercial contrast agent Gd-DOTA(3.23(mmol/L)^(-1)/s).Owing to their low toxicity and good cell imaging ability toward ECA 109 cells,the selfassembled Eu-Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.展开更多
The present study aimed to verify the practicability of performing screen-based surgical operations under the guidance of a real-time viewing and recording system (RTVRS) using a portable medium-soft electronic endosc...The present study aimed to verify the practicability of performing screen-based surgical operations under the guidance of a real-time viewing and recording system (RTVRS) using a portable medium-soft electronic endoscope (pmsEE).The middle cerebral artery in rats was occluded under screen-imaging guidance using a pmsEE RTVRS to reproduce an animal model of human cerebral infarction.The screen imaging of the pmsEE RTVRS was clear,life-like,stereoscopic and synchronous with the actual operation.Screen-imaging guidance led to an accurate,smooth,minimally invasive and comparatively easy surgical procedure.The surgical success rate,time of model establishment,neurological function scores,and infarct volume were similar to those using an operating microscope.These results indicate that the self-designed pmsEE RTVRS could be utilized for portable endoscopic screen-based surgical operations.展开更多
Dear Editor, Plants have evolved elaborate mechanisms by which cell elongation regulation is coupled to the environmental signals.The plasma membrane receptor kinase FERONIA (FER) has emerged as an important regulator...Dear Editor, Plants have evolved elaborate mechanisms by which cell elongation regulation is coupled to the environmental signals.The plasma membrane receptor kinase FERONIA (FER) has emerged as an important regulatory node in controlling cell elongation and hormone crosstalk (Guo et al.,2009;Deslauriers and Larsen,2010;Duan et al.,2010;Yu et al.,2012).Initially reported to inhibit pollen tube elongation during fertilization (Escobar-Restrepo et al.,2007),FER has been since found to promote cell elongation in leaves and root hairs (Guo et al.,2009;Duan et al.,2010).展开更多
文摘Rare earth elements are indispensable raw materials for advanced aero-engines, special optical materials, and high-performance electronic products. With the development of the social economy, the global demand for rare earth resources is increasing, and rare earths have become a key metal for the development of new industries and frontier technologies that are highly valued both at home and abroad. Ion-adsorbed rare earth ores are an important source of rare earths, so the efficient green leaching of ion-adsorbed rare earths is important. Researchers found that the selection of an efficient green leaching agent for ion-adsorbed rare earths is based on the zeta potential of tailing clay minerals in addition to leaching efficiency, and both zeta potential and leaching ion concentration are related to mineral acidity and alkalinity, and the pH of tailing water suspension is a direct indicator of environmental water quality requirements. Therefore, the efficiency of the leaching process is closely integrated with the environmental evaluation, and the characteristics and correlation of the changes in zeta potential, pH, conductivity and pollutant concentration of the pulp of clay mineral content during the leaching process of ore leaching and tailings aqueous electrolyte solution leaching are studied by evaluating the leaching system, and a set of correlation leaching efficiency and environmental impact evaluation method is established based on the results of the above analysis, which is of scientific development of ion adsorption rare earth resources. It has important theoretical significance and practical application value.
基金Project supported by the National Natural Science Foundation of China(52062034)the National Key Research and Development Program of China(2019YFC0605002)。
文摘The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry.Benefiting from the unique luminescent and magnetic properties of lanthanide ions,the potential applications of lanthanide-organic cages in biological imaging applications are promising,but only a few corresponding explorations have been reported.He rein,we introduced a series of lanthanide tetrahedral cages,(Eu_(n)Gd_(4-n)L_(4))(sol)_8(n=0,1,2,3 and 4,where L=(4,4',4"-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine,and sol=dimethyl sulfoxide and methanol),with potential applications in biological imaging.Given the good luminescent and magnetic properties of Eu^(3+) and Gd^(3+) ions,Eu_(4)L_(4) and Gd_(4)L_(4) complexes show a high luminescence quantum yield of 29% in DMSO and large longitudinal relaxivity(r_(1)) of 11.4(mmol/L)^(-1)/s at 0.5 T in water containing 1 vol% DMSO,respectively.The heterobimetallic Eu-Gd complexes achieve a dual imaging mode by combining luminescent and magnetic centers in one cage.When the Gd:Eu ratio increases from 1:3 to 3:1,the r_(1) values increases from 5.33 to 8.64(mmoI/L)^(-1)/s,higher than that of commercial contrast agent Gd-DOTA(3.23(mmol/L)^(-1)/s).Owing to their low toxicity and good cell imaging ability toward ECA 109 cells,the selfassembled Eu-Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.
文摘The present study aimed to verify the practicability of performing screen-based surgical operations under the guidance of a real-time viewing and recording system (RTVRS) using a portable medium-soft electronic endoscope (pmsEE).The middle cerebral artery in rats was occluded under screen-imaging guidance using a pmsEE RTVRS to reproduce an animal model of human cerebral infarction.The screen imaging of the pmsEE RTVRS was clear,life-like,stereoscopic and synchronous with the actual operation.Screen-imaging guidance led to an accurate,smooth,minimally invasive and comparatively easy surgical procedure.The surgical success rate,time of model establishment,neurological function scores,and infarct volume were similar to those using an operating microscope.These results indicate that the self-designed pmsEE RTVRS could be utilized for portable endoscopic screen-based surgical operations.
文摘Dear Editor, Plants have evolved elaborate mechanisms by which cell elongation regulation is coupled to the environmental signals.The plasma membrane receptor kinase FERONIA (FER) has emerged as an important regulatory node in controlling cell elongation and hormone crosstalk (Guo et al.,2009;Deslauriers and Larsen,2010;Duan et al.,2010;Yu et al.,2012).Initially reported to inhibit pollen tube elongation during fertilization (Escobar-Restrepo et al.,2007),FER has been since found to promote cell elongation in leaves and root hairs (Guo et al.,2009;Duan et al.,2010).
