To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produce...To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.展开更多
This paper presents new estimations for all parameters(amplitude,frequency,quality factor,and initial phase)of the_(0)S_(0)Earth fundamental mode,which was triggered by the 2004 Sumatra-Andaman earthquake with a magni...This paper presents new estimations for all parameters(amplitude,frequency,quality factor,and initial phase)of the_(0)S_(0)Earth fundamental mode,which was triggered by the 2004 Sumatra-Andaman earthquake with a magnitude of Mw9.1.Sixteen records from the IGETS superconducting gravimeters have been analyzed.Using the maximum likelihood method algorithm,frequency,initial phase,and amplitude estimates have been acquired with remarkable accuracy.The values of frequency(814.6568±0.0002μHz)and quality factor(5455±17)obtained in this study differ slightly from those of the PREM model,and the amplitude variations qualitatively correspond to those of the SKS12WM13model.The estimated time delay between the onset of the earthquake and the excitation of the mode(290 s)is consistent with the moment tensor analysis from the USGS National Earthquake Information Center.展开更多
In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,...In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,allowing them to target deep brain lesions.Recent studies have demonstrated that exosomes derived from different cell types may exert therapeutic effects by regulating the expression of various inflammatory cytokines,mRNAs,and disease-related proteins,thereby halting the progression of neurodegenerative diseases and exhibiting beneficial effects.However,exosomes are composed of lipid bilayer membranes and lack the ability to recognize specific target cells.This limitation can lead to side effects and toxicity when they interact with non-specific cells.Growing evidence suggests that surface-modified exosomes have enhanced targeting capabilities and can be used as targeted drug-delivery vehicles that show promising results in the treatment of neurodegenerative diseases.In this review,we provide an up-to-date overview of existing research aimed at devising approaches to modify exosomes and elucidating their therapeutic potential in neurodegenerative diseases.Our findings indicate that exosomes can efficiently cross the blood-brain barrier to facilitate drug delivery and can also serve as early diagnostic markers for neurodegenerative diseases.We introduce the strategies being used to enhance exosome targeting,including genetic engineering,chemical modifications(both covalent,such as click chemistry and metabolic engineering,and non-covalent,such as polyvalent electrostatic and hydrophobic interactions,ligand-receptor binding,aptamer-based modifications,and the incorporation of CP05-anchored peptides),and nanomaterial modifications.Research into these strategies has confirmed that exosomes have significant therapeutic potential for neurodegenerative diseases.However,several challenges remain in the clinical application of exosomes.Improvements are needed in preparation,characterization,and optimization methods,as well as in reducing the adverse reactions associated with their use.Additionally,the range of applications and the safety of exosomes require further research and evaluation.展开更多
This study establishes and validates a method for the precise quantification of aquatic microbial loads using microbial diversity absolute quantitative sequencing.By adding synthetic spike-in DNA to water samples from...This study establishes and validates a method for the precise quantification of aquatic microbial loads using microbial diversity absolute quantitative sequencing.By adding synthetic spike-in DNA to water samples from the Dahei River prior to DNA extraction and 16S rRNA gene sequencing,it generates standard curves to convert sequencing data into absolute microbial copy numbers.The method,which is proved highly accurate(R^(2)>0.99),reveals a clear contrast between the river sites:the upstream community has not only a significantly higher total microbial load but also a completely different makeup of species compared to the downstream site.This approach effectively overcomes the limitations of relative abundance analysis,providing a powerful tool for environmental monitoring,and proposes key steps for future standardization to ensure data comparability and integration.展开更多
Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad ...Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad in Arabidopsis thaliana cryp-tochrome,focusing on how vibrational envi-ronments affect the ultrafast electron trans-fer.Using the numerically exact low temper-ature quantum Fokker-Planck equation(LT-QFPE)within the hierarchical equations of motion(HEOM)framework,we resolve the contributions of individual Brownian oscillator modes:low frequency modes with large reorganization energies markedly reduce the ET rate,whereas weakly damped high frequency modes generate oscillations linked to electronic-vibra-tional coherence.The LT-QFPE results are also used to benchmark three second order pertur-bative methods:the non-equilibrium Fermi’s golden rule(NE-FGR),non-interacting blip ap-proximation(NIBA),and the time local generalized quantum master equation.Although all approximate methods reproduce correct long-time ET rates,they fail to capture short time non-equilibrium dynamics.These findings clarify how spectral width and bath correlation time,in addition to total reorganization energy,govern the validity of perturbative treat-ments and highlight the need for numerically exact methods such as HEOM in modeling non-equilibrium cryptochrome ET dynamics.s.展开更多
食源性蛋白淀粉样纤维化聚集具有独特的结构特性,蚕豆11S蛋白(fava bean 11S protein,FP)作为一种可持续蛋白资源,表现出巨大的潜力。该研究探究了蚕豆11S蛋白淀粉样纤维化聚集(fibrotic aggregation of 11S protein in fava bean,FPF)...食源性蛋白淀粉样纤维化聚集具有独特的结构特性,蚕豆11S蛋白(fava bean 11S protein,FP)作为一种可持续蛋白资源,表现出巨大的潜力。该研究探究了蚕豆11S蛋白淀粉样纤维化聚集(fibrotic aggregation of 11S protein in fava bean,FPF)在形成过程中的动态演变,包括其结构表征和功能特性。6 g/100 mL的FP通过酸热处理(pH 2,85℃)不同时间(0~24 h)后得到FPF。处理后的样品通过硫黄素T、荧光、二酪氨酸、透射电子显微镜、傅里叶红外光谱等进行结构表征,结果表明FP先在酸热过程中水解成多肽,再自组装成富含β-折叠结构的FPF(由0 h的34.44%增加到24 h的45.89%)。通过起泡性、乳化性和凝胶特性等对FPF功能特性进行表征,与FP相比,反应24 h后的FPF具有更好的起泡性、乳化性和凝胶特性。此外,FPF在体外细胞实验中没有表现出细胞毒性。研究结果为FPF的形成规律提供了理论支撑。展开更多
基金National Natural Science Foundation of China(12125509,11961141003,12275361,U2267205,12175152,12175121)National Key Research and Development Project(2022YFA1602301)Continuous-support Basic Scientific Research Project。
文摘To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.
基金conducted under the state assignment of Lomonosov Moscow State University。
文摘This paper presents new estimations for all parameters(amplitude,frequency,quality factor,and initial phase)of the_(0)S_(0)Earth fundamental mode,which was triggered by the 2004 Sumatra-Andaman earthquake with a magnitude of Mw9.1.Sixteen records from the IGETS superconducting gravimeters have been analyzed.Using the maximum likelihood method algorithm,frequency,initial phase,and amplitude estimates have been acquired with remarkable accuracy.The values of frequency(814.6568±0.0002μHz)and quality factor(5455±17)obtained in this study differ slightly from those of the PREM model,and the amplitude variations qualitatively correspond to those of the SKS12WM13model.The estimated time delay between the onset of the earthquake and the excitation of the mode(290 s)is consistent with the moment tensor analysis from the USGS National Earthquake Information Center.
基金supported by the National Natural Science Foundation of China,No.22103055(to JG)the Natural Science Foundation of Hebei Province,No.F2024110001(to HC)Open Project of Tianjin Key Laboratory of Optoelectronic Detection Technology and System,Nos.2024LODTS215(to NL),2024LODTS216(to XS).
文摘In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,allowing them to target deep brain lesions.Recent studies have demonstrated that exosomes derived from different cell types may exert therapeutic effects by regulating the expression of various inflammatory cytokines,mRNAs,and disease-related proteins,thereby halting the progression of neurodegenerative diseases and exhibiting beneficial effects.However,exosomes are composed of lipid bilayer membranes and lack the ability to recognize specific target cells.This limitation can lead to side effects and toxicity when they interact with non-specific cells.Growing evidence suggests that surface-modified exosomes have enhanced targeting capabilities and can be used as targeted drug-delivery vehicles that show promising results in the treatment of neurodegenerative diseases.In this review,we provide an up-to-date overview of existing research aimed at devising approaches to modify exosomes and elucidating their therapeutic potential in neurodegenerative diseases.Our findings indicate that exosomes can efficiently cross the blood-brain barrier to facilitate drug delivery and can also serve as early diagnostic markers for neurodegenerative diseases.We introduce the strategies being used to enhance exosome targeting,including genetic engineering,chemical modifications(both covalent,such as click chemistry and metabolic engineering,and non-covalent,such as polyvalent electrostatic and hydrophobic interactions,ligand-receptor binding,aptamer-based modifications,and the incorporation of CP05-anchored peptides),and nanomaterial modifications.Research into these strategies has confirmed that exosomes have significant therapeutic potential for neurodegenerative diseases.However,several challenges remain in the clinical application of exosomes.Improvements are needed in preparation,characterization,and optimization methods,as well as in reducing the adverse reactions associated with their use.Additionally,the range of applications and the safety of exosomes require further research and evaluation.
基金supported by the National Natural Science Foundation of China(Grant No.32160172)the Key Science-Technology Project of Inner Mongolia(2023KYPT0010)+1 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region of China(Grant No.2025QN03006)the 2023 Inner Mongolia Public Institution High-level Talent Introduction Scientific Research Support Project.
文摘This study establishes and validates a method for the precise quantification of aquatic microbial loads using microbial diversity absolute quantitative sequencing.By adding synthetic spike-in DNA to water samples from the Dahei River prior to DNA extraction and 16S rRNA gene sequencing,it generates standard curves to convert sequencing data into absolute microbial copy numbers.The method,which is proved highly accurate(R^(2)>0.99),reveals a clear contrast between the river sites:the upstream community has not only a significantly higher total microbial load but also a completely different makeup of species compared to the downstream site.This approach effectively overcomes the limitations of relative abundance analysis,providing a powerful tool for environmental monitoring,and proposes key steps for future standardization to ensure data comparability and integration.
基金supported by the National Natural Science Foundation of China(No.22433006).
文摘Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad in Arabidopsis thaliana cryp-tochrome,focusing on how vibrational envi-ronments affect the ultrafast electron trans-fer.Using the numerically exact low temper-ature quantum Fokker-Planck equation(LT-QFPE)within the hierarchical equations of motion(HEOM)framework,we resolve the contributions of individual Brownian oscillator modes:low frequency modes with large reorganization energies markedly reduce the ET rate,whereas weakly damped high frequency modes generate oscillations linked to electronic-vibra-tional coherence.The LT-QFPE results are also used to benchmark three second order pertur-bative methods:the non-equilibrium Fermi’s golden rule(NE-FGR),non-interacting blip ap-proximation(NIBA),and the time local generalized quantum master equation.Although all approximate methods reproduce correct long-time ET rates,they fail to capture short time non-equilibrium dynamics.These findings clarify how spectral width and bath correlation time,in addition to total reorganization energy,govern the validity of perturbative treat-ments and highlight the need for numerically exact methods such as HEOM in modeling non-equilibrium cryptochrome ET dynamics.s.
