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Monte Carlo method for evaluation of surface emission rate measurement uncertainty

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Nuclear Science and Techniques 2024年第7期35卷 126-136页

作者： Yuan-Qiao Li Min Lin Li-Jun Xu Rui Luo Yu-He Zhang Qian-Xi Ni yun-tao liu China Institute of Atomic Energy Beijing102413China National Key Laboratory for Metrology and Calibration Techniques Beijing102413China Department of Radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)<0.070 for the comparison of each source,and the uncertainty results of the GUM were all lower than those of the ***,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

关键词： Surface emission rate Monte Carlo method Metrology Probability distribution function Dead time Low-energy loss correction Least-squares method

Theoretical framework and experimental solution for the air-water interface adsorption problem in cryoEM

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Biophysics Reports 2023年第4期9卷 215-229页

作者： Joon S.Kang Xueting Zhou yun-tao liu Kaituo Wang Z.Hong Zhou Department of Microbiology Immunology & Molecular Genetics University of California Los Angeles (UCLA) Molecular Biology Institute UCLA California Nano Systems Institute UCLA

As cryogenic electron microscopy(cryoEM) gains traction in the structural biology community as a method of choice for determining atomic structures of biological complexes, it has been increasingly recognized that many complexes that behave well under conventional negative-stain electron microscopy tend to have preferential orientation, aggregate or simply mysteriously “disappear” on cryoEM grids. However, the reasons for such misbehavior are not well understood, which limits systematic approaches to solving the problem. Here, we have developed a theoretical formulation that explains these observations. Our formulation predicts that all particles migrate to the air–water interface(AWI)to lower the total potential surface energy-rationalizing the use of surfactant, which is a direct solution to reduce the surface tension of the aqueous solution. By performing cryogenic electron tomography(cryo ET) on the widely-tested sample, Gro EL, we demonstrate that, in a standard buffer solution, nearly all particles migrate to the AWI. Gradually reducing the surface tension by introducing surfactants decreased the percentage of particles exposed to the surface. By conducting single-particle cryoEM, we confirm that suitable surfactants do not damage the biological complex, thus suggesting that they might provide a practical, simple, and general solution to the problem for high-resolution cryoEM. Applying this solution to a real-world AWI adsorption problem involving a more challenging membrane protein,namely, the Cl C-1 channel, has resulted in its near-atomic structure determination using cryoEM.

关键词： CryoEM CryoET Sample preparation Air-water interface adsorption Surfactant Surface energy

Analysis of Dimer Impurity in Polyamidoamine Dendrimer Solutions by Small-angle Neutron Scattering

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Chinese Journal of Polymer Science 2019年第8期37卷 827-833页

作者： Tian-Fu Li Yi-yun Cheng Yu Wang Hui Wang Dong-Feng Chen yun-tao liu Li Zhang Wen-Ze Han Rong-Deng liu Zi-Jun Wang Chun-Ming Yang Charl J. Jafta Daniel Clemens Uwe Keiderling China Institute of Atomic Energy Beijing 102413 China Key Laboratory of Regulatory Biology School of Life Sciences East China Normal University Shanghai 200062 China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201204 China Helmholtz-Zentrum Berlin fürMaterialien und Energie Lise-Meitner-Campus Berlin 14109 Germany

Dimer impurity in the solution of a generation five(G5) polyamidoamine(PAMAM) dendrimer has been investigated by small-angle neutron scattering(SANS). The existence of dimer impurity in dendrimer solution was evidenced by indirect Fourier transform(IFT) analysis of the SANS data, in which the maximum dimension of particles in solution was found to be about twice the diameter of G5 dendrimer. We then developed an analytical model which accounts for the scattering contribution from both dendrimer monomer and dimer. The experimental data were well fitted by using the established model. The results showed that the amount of dimer impurities is significant for the measured three batches of G5 PAMAM dendrimers.

关键词： PAMAM dendrimer Dimer impurity Small-angle neutron scattering Scattering model

The behavior of cesium adsorption on zirconyl pyrophosphate

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Nuclear Science and Techniques 2016年第3期27卷 74-79页

作者： feng-li song xiao-wei yang xiao-long li wei he dan lü ji que chun-long zhang shan-gui zhao shi-jun wang yun-tao liu Nuclear and Radiation Safety Center Ministry of Environmental ProtectionBeijing 100082China

Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was *** show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/*** exchange capacity of ZrP_2O_7 was0.35 mmol/*** dynamic tests,Cs can be separated from other fission products very well by ZrP_2O_*** ZrP_2O_7was stable both at high temperatures and in high concentration of nitric *** Cs adsorption by ZrP_2O_7 is a monolayer and chemical adsorption.

关键词：吸附行为磷酸锆铯动态测试分布系数交换能力裂变产物化学吸附

Research on protection system of resonant network in CSNS magnet power supplies

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Radiation Detection Technology and Methods 2020年第3期4卷 277-283页

作者： Xiao-Ling Guo Wen-qing Zhang Jun Li Yuan Huang Xin Qin yun-tao liu Zu-yue Hao Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Dongguan Neutron Science Center Dongguan 523803China

Purpose Chinese Spallation Neutron Source(CSNS)is one of the key projects of China,in which the main magnet power supplies adopt the structures of resonant networks(Wang et *** Sci China Phys Mech Astron 54(Suppl 2):239-244,2011).Since each network contains a lot of components,and the working state of all the components will affect the whole accelerator,it is necessary to monitor the operation of each part in the resonant *** In this protections system,a supervision to 314 switch signals and 118 analog signals is realized using a chip of field programmable gate array(FPGA).The details about the hardware and software designs are introduced in this *** This protection system has been used in CSNS project,and the result proves that the RCS has been well monitored by this *** This system is a self-developed protection system according to the engineering needs of *** can realize the real-time monitoring and protection of the working state of resonance network by processing a large number of data using FPGA.

关键词： CSNS Resonant network Protection system Magnet power supply

The research of laser-based rapid measurement system for scintillator neutron detectors arrays

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Radiation Detection Technology and Methods 2020年第4期4卷 400-406页

作者： Bin Tang Qian Yu Chan Huang Hai-yun Teng Yan-feng Wang Hong Xu yun-tao liu Lin Qiu Guang-you Wei Zhi-jia Sun Institute of High Energy Physics China Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523000China University of Chinese Academy of Sciences(UCAS) Beijing 100039China School of Nuclear Science and Technology University of LanzhouLanzhou 730000China Fundamental Science On Nuclear Waste and Environmental Security Laboratory Southwest University of Science and TechnologyMianyang 621010China Department of Nuclear Science and Technology School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Particle Detection and Electronics Beijing 100049China

Purpose Scintillator Neutron Detectors Arrays(SNDA)were successfully installed at General Purpose Powder Diffractome-ter(GPPD)at the China Spallation Neutron Source(CSNS).The inhomogeneity of the detection efficiency in each detector module,which caused by the gain nonuniformity of the multi-anode photo-multiplier tubes(MA-PMTs)and the inconsistency of the wave-length shifting fibers in collecting scintillation photons,need to be mitigated before the *** An automated rapid measurement system based on the blue laser and the two-dimensional mobile platform was developed to calibrate the light response of each channel in detector *** to the test results of this system,the electronics threshold of each channel of the SNDA is *** the installation of the all 40 SNDA modules in GPPD,the electronics thresholds of each channel are adjusted according to the measurement results of this rapid measurement *** and Conclusion Compared with the unadjusted detector module,the adjusted one obtained a better uniformity of the neutron detection *** inhomogeneity of the detection efficiency is improved from 27.4%to 10.9%.The test result of the diffraction peak of the standard sample Si showed that the adjusted SNDA works well in GPPD.

关键词： system shifting laser

An efficient protocol of cryo-correlative light and electron microscopy for the study of neuronal synapses

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Biophysics Reports 2019年第3期5卷 111-122页

作者： Rong Sun yun-tao liu Chang-Lu tao Lei Qi Pak-Ming Lau Z.Hong Zhou Guo-Qiang Bi Center for Integrative Imaging Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences University of Science and Technology of China Chinese Academy of Sciences Key Laboratory of Brain Function and Disease University of Science and Technology of China The California Nano Systems Institute and Department of Microbiology Immunology and Molecular GeneticsUniversity of California Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology University of Science and Technology of China

Cryo-electron tomography is an emerging electron microscopy technique for determining three-dimensional structures of cellular architectures near their native state at nanometer resolution, with a shortcoming of lack of specific labels. Fluorescence light microscopy, on the other hand, specifically visualizes target cellular and molecular components with fluorescent labels, but is limited to a resolution of tens to hundreds nanometers. Combining the advantages of the two techniques, we have developed a cryocorrelative light and electron microscopy system. Our system consists a custom-designed cryo-chamber that allows for fluorescence imaging of frozen-hydrated samples, and an algorithm to achieve accurate correlation. With this system and our optimized protocol, high-quality tomograms of neuronal synapses labelled by specific fluorescent tags in cultured hippocampal neurons are obtained at high efficiency.

关键词： Cryo-correlative light and electron microscopy Cryo-electron tomography Neuronal synapse

Cloning and evolutionary analysis of cyclin B gene introns in cyprinids with different ploidy levels

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Progress in Natural Science:Materials International 2009年第9期19卷 1103-1108页

作者： Liangguo liu 1, Cuiping You 1, Shaojun liu , Huan Zhong, Dong liu, Zhen liu, Min tao, yun liu Key Laboratory of Protein Chemistry and Fish Developmental Biology of National Education Ministry, College of Life Sciences, Hunan Normal University, Changsha 410081, China Key Laboratory of Protein Chemistry and Fish Developmental Biology of National Education Ministry College of Life Sciences Hunan Normal University Changsha 410081 China

Partial fragments of the cyclin B gene from triploid, tetraploid, and pentaploid hybrids of red crucian carp blunt snout bream, blunt snout bream, grass carp, silver carp, and bighead carp were amplified. One DNA fragment was amplified from the blunt snout bream, grass carp, silver carp, and bighead carp (750, 950, 720, and 720 bp, respectively). Two fragments (1200 and 900 bp) were amplified from the red crucian carp, common carp, and allotetraploids. The triploid and pentaploid hybrids yielded three DNA fragments (1200, 900, and 750 bp). The 1200 bp fragment of the allotetraploid crucian carp, triploid, tetraploid, pentaploid hybrids of red crucian carp blunt snout bream shared 99.5%, 98.9%, 99.5%, and 88.7% homology, respectively, with the maternal DNA. The 900 bp fragment shared 97.5%, 94.6%, 94.2%, and 89.9% homology, respectively. Our results suggest that inheritance is maternally dominated. Furthermore, we observed preferential elimination of the paternal sequences in the allotetraploid hybrids. Based on these sequence analyses we constructed a phylogenetic tree to explain the relationships among the different ploidy levels.

关键词： Cyprinids Allotetraploid Cyclin B gene Intron Phylogeny

CAF-derived exosome-miR-3124-5p promotes malignant biological processes in NSCLC via the TOLLIP/TLR4-MyD88-NF-κB pathway

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Oncology Research 2025年第1期33卷 133-148页

作者： tao SUN QINGHUA SONG HUA liu Department of Respiratory and Critical Care Medicine Affiliated Hospital of Nantong UniversityMedical School of Nantong UniversityNantong226001China Department of Emergency The People’s Hospital of RugaoNantong226500China Department of Haematology The People’s Hospital of RugaoNantong226500China

Background:Lung cancer is a life-threatening disease that occurs worldwide,but is especially common in *** crucial role of the tumour microenvironment(TME)in non-small cell lung cancer(NSCLC)has attracted recent ***-associated fibroblasts(CAFs)are the main factors that contribute to the TME function,and CAF exosomes are closely linked to ***:The expression levels of miR-3124-5p and Toll-interacting protein(TOLLIP)were analysed by bioinformatics prediction combined with RT-qPCR/Western Blot *** were isolated and identified from clinical NSCLC *** electron microscopy and Western Blot were used to identify exosomes from these *** in proliferation(CCK-8 and clone formation),migration(wound healing),and invasion(transwell)of NSCLC cells were *** Luciferase reporter test was applied to clarify the binding of miR-3124-5p to *** TOLLIP/TLR4/MyD88/NF-κB pathway proteins were determined using Western blot ***:MiR-3124-5p is overexpressed in clinical tissues and cells of ***-3124-5p was dramatically enriched in CAF-derived *** experiments revealed that CAFs delivered miR-3124-5p into NSCLC cells via exosomes,stimulating cancer cell ***-3124-5p acted as a sponge to negatively regulate TOLLIP expression,which activated the TLR4/MyD88/NF-κB axis to promote the occurrence and development of *** salvage tests were performed to determine whether CAF-exosome-derived miR-3124-5p plays a pro-cancer role in NSCLC by affecting the TOLLIP signalling ***:These results provide an interesting direction for the diagnosis and therapy of NSCLC.

关键词： Non-small cell lung cancer(NSCLC) Cancer-associated fibroblasts(CAFs) Exosomes miR-3124-5p Toll-interacting protein(TOLLIP)