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Two Monte Carlo-based simulators for imaging-system modeling and projection simulation of flat-panel X-ray source

Nuclear Science and Techniques 2024年第7期35卷 31-46页

作者： Meng-Ke Qi Ting He Yi-Wen Zhou jing Kang Zeng-Xiang Pan Song Kang Wang-Jiang Wu jun Chen Ling-Hong Zhou Yuan Xu School of Biomedical Engineering Southern Medical UniversityGuangzhou510515China State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou510275China Department of Radiotherapy Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhou510515China

The advantages of a flat-panel X-ray source(FPXS)make it a promising candidate for imaging *** imaging-system modeling and projection simulation are critical for analyzing imaging performance and resolving overlapping projection issues in *** conventional analytical ray-tracing approach is limited by the number of patterns and is not applicable to FPXS-projection ***,the computation time of Monte Carlo(MC)simulation is independent of the size of the patterned arrays in *** study proposes two high-efficiency MC projection simulators for FPXS:a graphics processing unit(GPU)-based phase-space sampling MC(gPSMC)simulator and GPU-based fluence sampling MC(gFSMC)*** two simulators comprise three components:imaging-system modeling,photon initialization,and physical-interaction simulations in the ***-system modeling was performed by modeling the FPXS,imaging geometry,and *** gPSMC simulator samples the initial photons from the phase space,whereas the gFSMC simulator performs photon initialization from the calculated energy spectrum and fluence *** entire process of photon interaction with the geometry and arrival at the detector was simulated in parallel using multiple GPU kernels,and projections based on the two simulators were *** accuracies of the two simulators were evaluated by comparing them with the conventional analytical ray-tracing approach and acquired projections,and the efficiencies were evaluated by comparing the computation *** results of simulated and realistic experiments illustrate the accuracy and efficiency of the proposed gPSMC and gFSMC simulators in the projection calculation of various phantoms.

关键词： Flat-panel X-ray source(FPXS) Imaging-system modeling Projection simulation Monte Carlo-based simulators

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Elimination of cracks in stainless steel casings via 3D printed sand molds with an internal topology structure

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China Foundry 2024年第4期21卷 319-326页

作者： jun-hang Xu Bao-zhi Li Zhao-wei Song Yun-bao Gao jing-ming Li Yu Wang Qiu-lin Wen Heng Cao Zeng-rui Wang National Key Laboratory of Advanced Casting Technologies Shenyang 110022China Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China

The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin *** the context of existing 3DP sand casting processes,casting crack defects are prone to *** leads to an increase in the scrap rate of casings,causing significant resource ***,the presence of cracks poses a significant safety hazard after the casings are put into *** generation of different types of crack defects in stainless steel casings is closely related to casting stress and the high-temperature concession of the sand ***,the types and causes of cracks in stainless steel casing products,based on their structural characteristics,were systematically *** sand molds with different internal topology designs were printed using the 3DP technology to investigate the impact of sand mold structures on high-temperature *** optimal sand mold structure was used to cast casings,and the crack suppression effect was verified by analyzing its eddy current testing *** experimental results indicate that the skeleton structure has an excellent effect on suppressing cracks in the *** research holds important theoretical and engineering significance in improving the quality of casing castings and reducing production costs.

关键词： gas turbine casing crack defects 3D printed sand mold topological structure high-temperature concession

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Cyclic Dinucleotide Self-Assembled Nanoparticles as a Carrier-Free Delivery Platform for STING-Mediated Cancer Immunotherapy

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CCS Chemistry 2024年第1期6卷 177-195页

作者： Lang Zhao Shao-Hua Zhuo Tian-Yang Wang jun-jun Wu jing-Yun Su Wen-Hao Li Bo-Dou Zhang Yan-Mei Li Key Lab of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084 Beijing Institute for Brain Disorders Beijing 100069 Center for Synthetic and Systems Biology Tsinghua UniversityBeijing 100084

Cyclic dinucleotides(CDNs)are natural agonists of the stimulator of interferon genes(STING),which is an attractive immunotherapy ***,CDNs and their derivatives are being investigated ***,the poor bioavailability of exogenous CDNs has limited their application in *** nanocarriers are widely used for cytosolic delivery of CDNs,their loading capacity is insufficient,and their complicated composition and purification process raises bio-compatibility ***,we report a super-simplified CDN self-assembly strategy for carrier-free delivery of *** the presence of excess K^(+),CDNs form oligomers which further self-assemble with divalent metal ions(such as Mn^(2+))to form nanoparticles(NPs)in aqueous *** demonstrate that the self-assembled CDN NPs promote cellular uptake of CDNs and enhance tumor immunogenicity by remodeling the tumor microenvironment,inducing immunogenic tumor cell death and increasing tumorinfiltrating lymphocytes,which is conducive to the generation of tumor neoantigen-specific T-cell *** also demonstrate that the use of CDN NPs alone or in combination with immune checkpoint blockades inhibits tumor growth,highlighting the fact that CDN NPs are a potent platform for cancer immunotherapy.

关键词： cyclic dinucleotide STING carrierfree delivery tumor immunogenicity cancer immunotherapy

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How to manage the malposition of deep vein catheterization into the artery?

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Journal of Geriatric Cardiology 2024年第6期21卷 682-685页

作者： jun-Na SUN Hai DONG Peng CHEN Zi-Qi LI Li-You SUI Bin QI Quan-Min jing Department of Cardiovascular Diseases the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhouChina Department of Cardiology General Hospital of Northern Theater CommandShenyangChina

Central venous catheterization establishes temporary,efficient,and rapid use of deep venous access in patients,which provides high flow rate fluid perfusion,enables measurement of central venous pressure,and acts as an important reference for clinical ***,various complications such as pneumothorax,hemothorax,hematoma,and puncture failure can easily occur during the puncture and catheterization process.

关键词： process enable catheter

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Self-assembly of differentiated dental pulp stem cells facilitates spheroid human dental organoid formation and prevascularization

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World Journal of Stem Cells 2024年第3期16卷 287-304页

作者： Fei Liu jing Xiao Lei-Hui Chen Yu-Yue Pan jun-Zhang Tian Zhi-Ren Zhang Xiao-Chun Bai School of Basic Medical Sciences Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of Health Management Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment Zhuhai People’s Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Centre of Reproduction Development and AgingFaculty of Health SciencesUniversity of MacaoMacao 999078China Department of Stomatology Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Zhuhai Institute of Translational Medicine Zhuhai Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Department of Cell Biology School of Basic Medical SciencesSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative *** cells can self-organise into microsized organ units,partially modelling tissue function and *** pulp organoids have been used to recapitulate the processes of tooth development and related ***,the lack of vasculature limits the utility of dental pulp *** To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and *** hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp *** biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were *** The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and ***-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with *** biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of *** In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.

关键词： Human dental pulp stem cells Prevascularized organoids Integrated analyses Angiogenesis Forkhead box protein O1

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Universal paradigm of ternary metacomposites with tunable epsilon-negative and epsilon-near-zero response for perfect electromagnetic shielding

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Rare Metals 2024年第2期43卷 796-809页

作者： Yun-Peng Qu Yun-Lei Zhou Yang Luo Yao Liu jun-Fei Ding Yan-Li Chen Xiu Gong jing-Liang Yang Qiong Peng Xiao-Si Qi College of Physics Guizhou UniversityGuiyang550025China Hangzhou Institute of Technology Xidian UniversityHangzhou311231China Department of Materials ETH Zurich8093ZurichSwitzerland Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan250061China

CaCu_(3)Ti_(4)O_(12)(CCTO)ceramic nanocomposites incorporating graphene–carbon black(GRCB)fillers were fabricated by spark plasma sintering *** percolative effects of conductive GRCB fillers on dielectric response of GRCB/CCTO ternary metacomposites were systematically *** weakly real permittivity(ε′)-negative response(ε′~−1×10^(2))was achieved which originated from weakly low-frequency plasmonic state of free carriers within constructed GRCB *** enhancing three-dimensional GRCB network,the plasma frequency of metacomposites increased while the damping factor ***,theε′-negative values of metacomposites were tuned from−10^(2) to−10^(4) orders of magnitude andε′-near-zero(ENZ)frequencies from~142 to~340 MHz which substantially benefited from the moderate carrier concentration of GRCB dual *** Drude model and equivalent circuit models were adopted to demonstrate dielectric and electrical *** obtained metacomposites show strong EM shielding effect along with enhanced plasmonic oscillation and even better achieving perfect EM shielding effect in ENZ *** work achieves the tunableε′-negative andε′-near-zero response and more importantly clarifies its regulation mechanism in ceramic-based ternary metacomposites,which opens up the possibility of designing high-performance EM shielding materials based on metacomposites.

关键词： Metacomposites Ceramic matrix composites Negative permittivity Epsilon-near-zero Electromagnetic shielding

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Ten-year observation of corneal densitometry and associated factors following small incision lenticule extraction

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International Journal of Ophthalmology(English edition) 2024年第3期17卷 485-490页

作者： Xiao-Song Han Fei Xia Zhuo-Yi Chen Pei-jun Yao Dong-Mei Yang jing Zhao Xing-Tao Zhou Eye Institute and Department of Ophthalmology Eye&ENT HospitalFudan UniversityShanghai 200031China NHC Key Laboratory of Myopia(Fudan University) Key Laboratory of MyopiaChinese Academy of Medical SciencesShanghai 200031China Shanghai Research Center of Ophthalmology and Optometry Shanghai 200031China Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care(20DZ2255000) Shanghai 200031China

●AIM:To investigate the long-term changes of corneal densitometry(CD)and its contributing elements after small incision lenticule extraction(SMILE).●METHODS:Totally 31 eyes of 31 patients with mean spherical equivalent of-6.46±1.50 D and mean age 28.23±7.38y were ***-scale examinations were conducted on all patients preoperatively and during *** acuity,manifest refraction,axial length,corneal thickness,corneal higher-order aberrations,and CD were evaluated.●RESULTS:All surgeries were completed successfully without complications or adverse ***-year safety index was 1.17±0.20 and efficacy 1.04±*** value of 0–6 mm zones in central layer was statistically significantly lower 10y postoperatively,compared with preoperative values(0–2 mmΔ=-1.62,2–6 mmΔ=-1.24,P<0.01).There were no correlations between CD values and factors evaluated.●CONCLUSION:SMILE is a safe and efficient procedure for myopia on a long-term *** values get lower 10y postoperatively,whose mechanism is to be further discussed.

关键词： myopia small incision lenticule extraction corneal densitometry

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Theoretical Exploration of Alloying Effects on Stabilities and Mechanical Properties ofγʹPhase in Novel Co–Al–Nb-Base Superalloys

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1238-1248页

作者： Guan-Cheng Gu Zhao-jing Han Ze-Yu Chen Zhao-Xuan Li Sheng-Bao Xia Zheng-Ning Li Hua Jin Wei-Wei Xu Xing-jun Liu Shenzhen Research Institute of Xiamen University School of Aerospace EngineeringXiamen UniversityXiamen361005China Institute of Materials Genome and Big Data Harbin Institute of TechnologyShenzhen518055China

The new developedγ/γʹCo–Al–Nb-base alloys show great potentials as high-temperature ***,finding appropriate compositions to improve performance of alloys still poses a great challenge to the development of Co–Al–Nb-base *** by the lack of alloying effects on fundamental properties of criticalγʹphase,we systematically performed a theoretical investigation on the effect of alloying elements TM(TM:Ti,V,Cr,Zr,Mo,Ta,W,Re,and Ru)on phase stabilities and mechanical properties of L1_(2)-typeγʹ(Co,Ni)_(3)(Al,Nb).By analyzing the stability ofγʹphase with respect to its competitive B2 and D0_(19) phases,the results shown that Ti,V,and Cr enhance the L1_(2) stability and widen the L1_(2)–D0_(19) energy barrier,in which V yields the maximum *** analysis of electronic structure indicated that the alternation of valence electrons at fermi level would be the atomic origin for doping TM inγʹ*** calculated results of mechanical properties shown that V and Cr are expected to be optimal dopant for enhancing the strength and the ductility ofγʹ*** addition of Ta is also beneficial for enhancing the strength at the slight expense of ductility ofγʹ*** drawing the mechanical maps,the preferred composition range for the phases with desired properties is roughly demarcated in theory for the multi-addition of V/Cr and V/Ta inγʹ*** findings would be useful for optimizing the performance of novelγ/γʹCo–Al–Nb-base superalloys.

关键词： Co-Al-Nb-base superalloys γ/γʹdual-phase Phase stability Mechanical properties First-principle methods

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FibroScan-aspartate transaminase:A superior non-invasive model for diagnosing high-risk metabolic dysfunction-associated steatohepatitis

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World Journal of Gastroenterology 2024年第18期30卷 2440-2453页

作者： jing-Ya Yin Tian-Yuan Yang Bing-Qing Yang Chen-Xue Hou jun-Nan Li Yue Li Qi Wang Center of Liver Diseases Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Department of Pathology Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Beijing institute of infectious disease Beijing 100015China Beijing Key Laboratory of Emerging Infectious Diseases Institute of Infectious DiseasesBeijing Ditan HospitalCapital Medical UniversityBeijing 100015China

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)with hepatic histological NAFLD activity score≥4 and fibrosis stage F≥2 is regarded as“at risk”non-alcoholic steatohepatitis(NASH).Based on an international consensus,NAFLD and NASH were renamed as metabolic dysfunction-associated steatotic liver disease(MASLD)and metabolic dysfunction-associated steatohepatitis(MASH),respectively;hence,we introduced the term“high-risk MASH”.Diagnostic values of seven non-invasive models,including FibroScan-aspartate transaminase(FAST),fibrosis-4(FIB-4),aspartate transaminase to platelet ratio index(APRI),*** high-risk MASH have rarely been studied and compared in *** To assess the clinical value of seven non-invasive models as alternatives to liver biopsy for diagnosing high-risk *** A retrospective analysis was conducted on 309 patients diagnosed with NAFLD via liver biopsy at Beijing Ditan Hospital,between January 2012 and December *** screening for MASLD and the exclusion criteria,279 patients wereincluded and categorized into high-risk and non-high-risk MASH *** threshold values of each model,sensitivity,specificity,positive predictive value(PPV),and negative predictive values(NPV),were *** operating characteristic curves were constructed to evaluate their diagnostic efficacy based on the area under the curve(AUROC).RESULTS MASLD diagnostic criteria were met by 99.4%patients with *** MASLD population was analyzed in two cohorts:Overall population(279 patients)and the subgroup(117 patients)who underwent liver transient elastography(FibroScan).In the overall population,FIB-4 showed better diagnostic efficacy and higher PPV,with sensitivity,specificity,PPV,NPV,and AUROC of 26.9%,95.2%,73.5%,72.2%,and ***,Forns index,and aspartate transaminase to alanine transaminase ratio(ARR)showed moderate diagnostic efficacy,whereas S index and gamma-glutamyl transpeptidase to platelet ratio(GPR)were relatively *** the sub

关键词： Metabolic dysfunction-associated steatotic liver disease High-risk metabolic dysfunction-associated steatohepatitis Non-invasive models Liver biopsy Diagnostic value

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Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest China

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan Er-Teng Wang Fu-Bo Yang jing-Yu Zhang School of Earth Sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of Geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline *** are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

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