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Normalized glandular dose coefficients for digital breast tomosynthesis using detailed Chinese breast models

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Nuclear Science and Techniques 2024年第5期35卷 42-59页

作者： jia-Hao Wang Rui Qiu An-Kang Hu Ye-Qi Liu Zhen Wu Hui zha.g jun-Li Li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China Joint Institute of Tsinghua University Nuctech Company Limited BeijingBeijing 100084China

The rise in breast cancer diagnoses among Chinese women has necessitated the use of X-ray breast screening,which carries a radiation *** study aimed to provide a dosimetry protocol for the Chinese female population to replace the traditional standard that utilizes simplified breast models,for the accurate estimation of the mean glandular dose of a patient undergoing digital breast tomosynthesis(DBT).The first set of detailed Chinese female breast models and representative breast parameters was *** backscatter radiation and computational efficiency,we improved the combination of these models and the Chinese reference adult female whole-body voxel *** acquisition for four commercial DBT systems that are widely employed in China was simulated using the Monte Carlo method to obtain the normalized glandular dose coefficients of DBT(D_(gN)^(DBT))and the glandular depth dose(D_(g)^(dep)(z))for different breast characteristics and X-ray *** calculated a series of D_(gN)^(DBT) values for breasts with different percentage mass glandularities(5%,25%,50%,75%,and 100%)and compressed breast thicknesses(2,3,4,5,6,and 7 cm)at various tube potentials(25,28,30,32,35,and 49 kV)and target/filter combinations(W/Rh,W/Al,Mo/Mo,Rh/Rh,and Rh/Ag).The parameter dependence of the breast characteristics and beam conditions on D_(gN)^(DBT) in detailed breast models was *** D_(gN)^(DBT) results were 14.6-51.0%lower than those of the traditional dosimetry standard in *** difference in D_(gN)^(DBT) was mainly due to a decrease in the depth of the main energy deposition area caused by the glandular distribution along the depth *** results obtained in this study may be used to improve breast dosimetry in China and provide more detailed information on risk assessment during DBT.

关键词： Digital breast tomosynthesis Normalized glandular dose coefficients Detailed breast model Monte Carlo simulation

Novel C_(sf)/SiBCN composites prepared by densifying C_(sf)/MA-SiBCN with the PIP process:Oxidation behavior and damage mechanism

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Journal of Advanced Ceramics 2024年第5期13卷 666-678页

作者： Wenhao Dou Daxin Li Bingzhu Wang Zhihua Yang jun Chen Dechang jia Ralf Riedel Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China Chongqing Research Institute of HIT Chongqing 401135China Beijing Institute of Control Engineering Beijing 100094China Institut für Materialwissenschaft Technische Universität DarmstadtDarmstadt D-64287Germany School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

To improve the oxidation resistance of short carbon fiber(C_(sf))-reinforced mechanically alloyed SiBCN(MA-SiBCN)(C_(sf)/MA-SiBCN)composites,dense amorphous C_(sf)/SiBCN composites containing both MA-SiBCN and polymer-derived ceramics SiBCN(PDCs-SiBCN)were prepared by repeated polymer infiltration and pyrolysis(PIP)of layered C_(sf)/MA-SiBCN composites at 1100℃,and the oxidation behavior and damage mechanism of the as-prepared C_(sf)/SiBCN at 1300–1600℃ were compared and discussed with those of C_(sf)/*** C_(sf)/MA-SiBCN composites resist oxidation attack up to 1400℃ but fail at 1500℃ due to the collapse of the porous framework,while the PIP-densified C_(sf)/SiBCN composites are resistant to static air up to 1600℃.During oxidation,oxygen diffuses through preexisting pores and the pores left by oxidation of carbon fibers and pyrolytic carbon(PyC)to the interior of the *** to the oxidative coupling effect of the MA-SiBCN and PDCs-SiBCN matrices,a relatively continuous and dense oxide layer is formed on the sample surface,and the interfacial region between the oxide layer and the matrix of the as-prepared composite contains an amorphous glassy structure mainly consisting of Si and O and an incompletely oxidized but partially crystallized matrix,which is primarily responsible for improving the oxidation resistance.

关键词： mechanically alloyed SiBCN(MA-SiBCN) polymer-derived ceramics SiBCN(PDCs-SiBCN) short carbon fiber-reinforced SiBCN(C_(sf)/SiBCN)composites polymer infiltration and pyrolysis(PIP) oxidation damage mechanism

Understanding the cooperative effects in the catalysis of homodimeric fluoroacetate dehalogenase

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Science China Chemistry 2024年第7期67卷 2382-2391页

作者： Ke-Wei Chen jia-Nan Chen jun zha.g Chao Wang Tian-Yu Sun Yun-Dong Wu Key Laboratory of Computational Chemistry and Drug Design State Key Laboratory of Chemical OncogenomicSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of Chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Changping Laboratory Beijing 102200China

Fluoroacetate dehalogenases(FAcD),a homodimeric enzyme,catalyzes the conversion of fluoroacetic acid to glycolic acid(GoA).It has been proved that the enzyme has a half-of-the-site ***,its catalytic(C)subunit converts the first substrate to a covalent intermediate;then,the non-catalytic(NC)subunit binds a second substrate and promotes the conversion of the intermediate in the C subunit into the final *** the release of the product,the C subunit becomes the NC subunit,and the previous NC subunit becomes the C *** elucidate the detailed mechanism behind this cooperative catalysis,we have conducted microsecond-scale MD simulations along the reaction *** simulations indicate that the substrate in the NC subunit induces W185 and Y141 adopting an open conformation in the C *** opening of W185(C)facilitates the entry of catalytic water,enhancing the catalytic activity for product formation,while the opening of Y141(C)creates an unfavorable environment for product binding,promoting its *** interaction network analysis reveals that the substrate in the NC subunit can induce conformational changes through a conserved water chain at the interface.

关键词： enzyme catalysis molecular dynamics cooperative effect pre-reaction state

Au nanoclusters anchored on TiO_(2) nanosheets for high-efficiency electroreduction of nitrate to ammonia

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Nano Research 2024年第3期17卷 1209-1216页

作者： Miaosen Yang Tianran Wei jia He Qian Liu Ligang Feng Hongyi Li jun Luo Xijun Liu School of Chemical Engineering Northeast Electric Power UniversityJilin 132012China Nanchang Institute of Technology Nanchang 330044China State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830017China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China Institute for New Energy Materials and Low-Carbon Technologies School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Institute for Advanced Study Chengdu UniversityChengdu 610106China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Guangzhou Panyu Polytechnic Guangzhou 511483China ShenSi Lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaLonghua DistrictShenzhen 518110China

Electrocatalytic nitrate reduction reaction(NO_(3)RR)offers a unique rationale for green NH_(3) synthesis,yet the lack of high-efficiency NO_(3)RR catalysts remains a great *** this work,we show that Au nanoclusters anchored on TiO_(2) nanosheets can efficiently catalyze the conversion of NO_(3)RR-to-NH_(3) under ambient conditions,achieving a maximal Faradic efficiency of 91%,a peak yield rate of 1923μg·h^(-1)·mgcat.-1,and high durability over 10 consecutive cycles,all of which are comparable to the recently reported metrics(including transition metal and noble metal-based catalysts)and exceed those of pristine TiO_(2).Moreover,a galvanic Zn-nitrate battery using the catalyst as the cathode was proposed,which shows a power density of 3.62 mW·cm^(-2) and a yield rate of 452μg·h^(-1)·mgcat.-*** simulations further indicate that the atomically dispersed Au clusters can promote the adsorption and activation of NO_(3)-species,and reduce the NO_(3)RR-to-NH_(3) barrier,thus leading to an accelerated cathodic *** work highlights the importance of metal clusters for the NH_(3) electrosynthesis and nitrate removal.

关键词： NH3 electrosynthesis Zn-nitrate battery Au nanoclusters nitrate reduction reaction(NRR) TiO_(2)nanosheets

Grain boundary-induced drastic sensing performance enhancement of Fe2O3 gas sensors for acetone

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Rare Metals 2024年第9期43卷 4412-4424页

作者： Tian-jun Hu Yi-Fan Li Yu-Zhu Tian Ying Wang Ya-Ru Chen jun-Ming zha.g Er-Gui Luo jian-Feng jia Key Laboratory of Magnetic Molecules & Magnetic Information Materials Ministry of Education School of Chemical and Material ScienceShanxi Normal University

Exploring the structure-activity relationship between the performance of gas sensors and the structure of semiconductor metal oxide （SMO） nanomaterials is crucial for understanding and designing gas-sensing materials and overcoming the application limitations of SMO-based gas *** of a single SMO microstructure provides a promising solution to address this scientific problem due to its controllable *** this study,we control the grain boundary （GB） density of Fe2O3nanomaterials using a simple solvothermal *** have similar chemical compositions and crystal phases,providing an ideal platform for studying the influence of the GB density on the gas-sensing ***-sensing tests showed that the Fe2O3-1 sensor with medium GB density and the Fe2O3-2 sensor with high GB density had higher sensitivity and selectivity than the Fe2O3-0 sensors with low GB density before reaching the optimal operating ***,when the GB density increased,the response to acetone decreased slightly,whereas the optimal operating temperature *** work highlights the unique performance of the GB density in enhancing the gas sensitivity of a single SMO.

关键词： Charge transfer Gas sensors Grain boundary (GB) density Oxygen adsorption Semiconductor metal oxide (SMO)

Effects of Acupotomy on Immobilization-Induced Gastrocnemius Contracture and Fibrosis in Rats via Wnt/β-Catenin Signaling

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Chinese Journal of Integrative Medicine 2024年第7期30卷 633-642页

作者： HU Rui PAN jun-kang LI jia-hui zha.G Han LI Shao-rong zha.G Yi School of Acupuncture-Moxibustion and Tuina Beijing University of Chinese MedicineBeijing100029China Acupuncture Department Kunming Municipal Hospital of Traditional Chinese MedicineKunming650500China

Objective To determine whether acupotomy ameliorates immobilization-induced muscle contracture and fibrosis via Wnt/β-catenin signaling *** Thirty Wistar rats were randomly divided into 5 groups(n=6)by a random number table,including control,immobilization,passive stretching,acupotomy,and acupotomy 3 weeks(3-w)*** rat model of gastrocnemius contracture was established by immobilizing the right hind limb in plantar flexion for 4 *** in the passive stretching group received passive stretching at gastrocnemius,a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive *** in the acupotomy and acupotomy 3-w groups received acupotomy once and combined with passive stretching at gastrocnemius a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive ***,rats in the acupotomy 3-w group were allowed to walk freely for 3 weeks after 10-day *** treatment,range of motion(ROM),gait analysis[i.e.,paw area,stance/swing and maximum ratio of paw area to paw area duration(Max dA/dT)],gastrocnemius wet weight and the ratio of muscle wet weight to body weight(MWW/BW)were *** morphometric and muscle fiber cross-sectional area(CSA)were assessed by hematoxylin-eosin ***-related mRNA expressions(i.e.,Wnt 1,β-catenin,axin-2,α-smooth muscle actin,fibronectin,and types I and III collagen)were measured using real-time quantitative polymerase chain *** 1,β-catenin and fibronectin concentrations were measured by enzyme-linked immunosorbent *** I and III collagen in the perimysium and endomysium were analyzed using *** Compared with the control group,ROM,gait function,muscle weight,MWW/BW and CSA were significantly decreased in the immobilization group(all P<0.01),while protein levels of types I and III collagen,Wnt 1,β-catenin,fibronectin and mRNA levels of fibrosis-related genes were obviously increased(all P<0.01).Tr

关键词： acupotomy immobilization muscle contracture muscle fibrosis Wnt/β-catenin signaling

Differential bonding behaviors of sodium/potassium-ion storage in sawdust waste carbon derivatives

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Chinese Chemical Letters 2024年第4期35卷 496-501页

作者： jun-Ming Cao Kai-Yang zha.g jia-Lin Yang Zhen-Yi Gu Xing-Long Wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Department of Chemistry Northeast Normal UniversityChangchun 130024China

Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) are the most promising alternatives to lithium-ion batteries, and thus have drawn intensive research attention. Porous carbon materials from different precursors have been widely used as anode materials owing to their compatible storage effectiveness of both larger radii sodium and potassium ions. However, the differential bonding behaviors of Na and K ions with porous carbon-based anode are the significant one worth investigating, which could provide a clean picture of alkali ions storage mechanism. Therefore, in this work, we prepare a porous carbon network derived from sawdust(SDC) wastes, to further analyze the differences on sodium and potassium ions storage behaviors in terms of bond-forming process. It is found that, as-prepared SDC anodes could deliver stable sodium and potassium storage capacities, however, there are notable distinctions in terms of electrochemical behaviors and diffusion processes. By virtue of ex-situ XRD and Raman spectroscopy, the phase transition reaction of potassium ions could be well-observed, and the results shows that the multiple intercalated compounds was formed in SDC network during ions insertion, further resulting in slower diffusion kinetics and larger resistance compared to non-bonded process of sodium ions storage. This study provides more insights into the differences between sodium and potassium ions storage, as well as the energy storage mechanism of porous carbon as anodes for secondary batteries.

关键词： Porous carbon Sodium-ion storage Potassium-ion storage Bonding behaviors Batteries

Association between Gene Polymorphisms and SNP-SNP Interactions of the Matrix Metalloproteinase 2 Signaling Pathway and the Risk of Vascular Senescence

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Biomedical and Environmental Sciences 2024年第2期37卷 146-156页

作者： LIAO Zhen Yu YANG Shuo HU Song LIU jia MAO Yong jun SUN Shu Qin Department of Geriatrics the Affiliated Hospital of Qingdao UniversityQingdao 266000ShandongChina Department of Critical Care Medicine the Affiliated Hospital of Qingdao UniversityQingdao 266000ShandongChina

Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were *** SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic *** multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)*** Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs7201,and MMP2 *** of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased ***2 rs4586 and MMP-2 rs14070 exhibited the most significant *** CCL2 rs4586,MMP-2 rs14070,MMP-2 rs7201,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.

关键词： Vascular senescence Pulse wave velocity(PWV) Single nucleotide polymorphism(SNP) Matrix metalloproteinase 2(MMP-2) Extracellular matrix(ECM) Structural degradation Multifactor dimensionality reduction(MDR)

Evolution of Cenozoic sedimentary architecture in Central and Southern South China Sea basins

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Journal of Palaeogeography 2024年第1期13卷 35-53页

作者： Wu Tang Xiao-jun Xie Yi-Bo Wang Lian-Qiao Xiong jia Guo Xin Li China National Offshore Oil Corporation Research Institute Beijing 100028China

The Central and Southern South China Sea(CSSCS) has a complex tectonic dynamic background and abundant oil and gas resources, which has always been a hot topic of academic and industrial ***, systematic analyses are still lacking regarding its sediment filling structure and evolution, mostly due to limited borehole penetration and poor quality of seismic reflection data for deeply buried sequences. No consensus has been reached yet on the sedimentary infilling processes, which impeded the reconstruction of the palaeogeography of Southeast Asia and the oil-and-gas exploration undertakings. Here, we illustrate the Cenozoic sedimentary evolution of the CSSCS region by synthesizing relevant data from previous literature and our own observations and displaying the evolution of depositional systems in sequential reconstructions. Besides, the controlling factors of preferred sedimentary scenarios in the CSSCS incorporate the latest interpretations of the spreading of South China Sea(SCS) as well as the demise of the hypothetical Proto-South China Sea(PSCS). The results show that there are three types of sedimentary basins in the CSSCS(foreland,strike-slip, and rift basins) with different sedimentary filling structures. The foreland basins formed a depositional pattern of ‘transition from deep water to shallow water environments', dominated by deep-water depositional systems which were formed before the Early Oligocene with submarine fans developed. Later,the foreland basins were gradually dominated by shallow-water depositional systems with deltas and shallow marine facies. The strike-slip basins showed the depositional architecture of ‘transition from lake to marine environments', i.e. the basins were dominated by lacustrine deposits during the Eocene and evolved into the marine depositional environment since Oligocene with delta developed in the western part of the basin. The depositional evolution of rift basins illustrated the characteristics of 'transiti

关键词： Central and Southern South China Sea Sedimentary filling Main controlling factors Proto-South China Sea South China Sea