AIM:To assess the prognostic significance of nuclear factor-kB (NF-kB) and its target genes in gastric cancer. METHODS:The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using m...AIM:To assess the prognostic significance of nuclear factor-kB (NF-kB) and its target genes in gastric cancer. METHODS:The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-kB RelA. Preoperative serum levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) were assessed via enzyme-linked immuno-sorbent assay. C-reactive protein (CRP) and serum amyloid A (SAA) were measured via immunotrubidimetry. RESULTS:Positive rate of NF-kB RelA was 42.6%. NF-kB RelA expression in tumor tissues was also related to serum levels of IL-6 (P = 0.044) and CRP (P = 0.010). IL-6, SAA, CRP were related to depth of invasion, VEGF and SAA were correlated with lymph node metastasis. IL-6, VEGF, SAA and CRP were related to the stage. Univariate analysis demonstrated that immunostaining of NF-kB RelA, levels of IL-6, VEGF, SAA were significantly related with both disease free survival and over-all survival (OS). Multivariate analysis verified that NF-kB RelA [hazard ratio (HR): 3.40, P = 0.024] and SAA (HR: 3.39, P = 0.045) were independently associated with OS. CONCLUSION: Increased expression of NF-kB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients.展开更多
AIM In this study we investigated the relationship of the X protein of HBV and nuclear factor-κB(NF-κB)and the expression of NF-κB in human hepatocellular carcinoma tissues. METHODS Immunohistochemistry SP method w...AIM In this study we investigated the relationship of the X protein of HBV and nuclear factor-κB(NF-κB)and the expression of NF-κB in human hepatocellular carcinoma tissues. METHODS Immunohistochemistry SP method was used to detect the expression of NF-κB and the X protein of HBV in human hepatocellular carcinoma tissues of 52 cases.Gene transfection mediated by lipofectamine was used to transfect the eukaryotic expression vector pCDNA3.1-HBX of HBV x gene into human hepatocellular carcinoma cell line HCC-9204 and NF-κB was detected. RESULTS NF-κB was widely expressed in human hepatocellular carcinoma tissues in a total of 52 cases and its expression was related to the X protein of HBV.NF-κB was localized both in the cytoplasm and the nuclei of hepatocellular carcinoma cells in 11 cases which were positive for the X protein of HBV while in 41 cases negative for the X protein of HBV,NF-κB was only localized in the cytoplasm of hepatocellular carcinoma cells but translocated to the nuclei of hepatocellular carcinoma cells after the eukaryotic expression vector pCDNA3.1-HBX was transfected into HCC-9204 cells. CONCLUSION This study strongly suggests that the nuclear factor NF-κB is widely expressed in hepatocellular carcinoma tissues in different styles according to the expression of the X protein of HBV.NF-κB is abnormally activated in hepatocellular carcinoma,which is probably rélated to the X protein of HBV.The X protein of HBV can activate NF-κB to translocate into nuclei of hepatocellular carcinoma cells.展开更多
Protein arginine methyltransferase-6 participates in a range of biological functions,particularly RNA processing,transcription,chromatin remodeling,and endosomal trafficking.However,it remains unclear whether protein ...Protein arginine methyltransferase-6 participates in a range of biological functions,particularly RNA processing,transcription,chromatin remodeling,and endosomal trafficking.However,it remains unclear whether protein arginine methyl transferase-6 modifies neuropathic pain and,if so,what the mechanisms of this effect.In this study,protein arginine methyltransferase-6 expression levels and its effect on neuropathic pain were investigated in the spared nerve injury model,chronic constriction injury model and bone cancer pain model,using immunohistochemistry,western blotting,immunoprecipitation,and label-free proteomic analysis.The results showed that protein arginine methyltransferase-6 mostly co-localized withβ-tubulinⅢin the dorsal root ganglion,and that its expression decreased following spared nerve injury,chronic constriction injury and bone cancer pain.In addition,PRMT6 knockout(Prmt6~(-/-))mice exhibited pain hypersensitivity.Furthermore,the development of spared nerve injury-induced hypersensitivity to mechanical pain was attenuated by blocking the decrease in protein arginine methyltransferase-6 expression.Moreover,when protein arginine methyltransferase-6 expression was downregulated in the dorsal root ganglion in mice without spared nerve injury,increased levels of phosphorylated extracellular signal-regulated kinases were observed in the ipsilateral dorsal horn,and the response to mechanical stimuli was enhanced.Mechanistically,protein arginine methyltransferase-6 appeared to contribute to spared nerve injury-induced neuropathic pain by regulating the expression of heterogeneous nuclear ribonucleoprotein-F.Additionally,protein arginine methyltransfe rase-6-mediated modulation of hete rogeneous nuclear ribonucleoprotein-F expression required amino atids 319 to 388,but not classical H3R2 methylation.These findings indicated that protein arginine methyltransferase-6 is a potential therapeutic target fo r the treatment of peripheral neuro pathic pain.展开更多
Nuclear factor Y is a ubiquitous heterotrimeric transcription factor complex conserved across eukaryotes that binds to CCAAT boxes,one of the most common motifs found in gene promoters and enhancers.Over the last 30 y...Nuclear factor Y is a ubiquitous heterotrimeric transcription factor complex conserved across eukaryotes that binds to CCAAT boxes,one of the most common motifs found in gene promoters and enhancers.Over the last 30 years,research has revealed that the nuclear factor Y complex controls many aspects of brain development,including differentiation,axon guidance,homeostasis,disease,and most recently regeneration.However,a complete understanding of transcriptional regulatory networks,including how the nuclear factor Y complex binds to specific CCAAT boxes to perform its function remains elusive.In this review,we explore the nuclear factor Y complex’s role and mode of action during brain development,as well as how genomic technologies may expand understanding of this key regulator of gene expression.展开更多
Neuron-derived clone 77 (Nur77) is a member of the NR4A subfamily that plays critical roles in apoptosis, survival, proliferation, autophagy, angiogenesis, inflammatory responses, DNA repair, glycolipid metabolism and...Neuron-derived clone 77 (Nur77) is a member of the NR4A subfamily that plays critical roles in apoptosis, survival, proliferation, autophagy, angiogenesis, inflammatory responses, DNA repair, glycolipid metabolism and energy consumption. The deregulation of Nur77 signalling often relates to various serious diseases, including cancer and non-cancer diseases. A systematic review is necessary for the better understanding of Nur77 in clinical treatment. In this article, we comprehensively conclude the lipid regulation function and expression of Nur77, and its role in COPD. Finally, we prospect that development of drugs and clinical biochemical investigations targeting of Nur77 has considerable potential within healthcare.展开更多
1989 is the beginning of intensive research into the phenomena of cold nuclear fusion, renamed “The Low Energy Nuclear Synthesis Reactions” (LENR). Based on these results and the long-term research of earthquakes an...1989 is the beginning of intensive research into the phenomena of cold nuclear fusion, renamed “The Low Energy Nuclear Synthesis Reactions” (LENR). Based on these results and the long-term research of earthquakes and volcanic activity, the authors of this article put forward a hypothesis about the mainly chemical nature of the energy released at earthquakes and volcanic eruptions with the participation of primordial hydrogen and helium: high mobility of hydrogen and oxidizers provide focusing and accumulation of the latent chemical energy, which is realized suddenly and instantaneously as explosions and initiate the earthquake and/or eruptions. The volcanic eruption is viewed therein as a special type of earthquake whereby the hypocenter rises to the earth’s surface. The authors proposed a new hypothesis that LENRs significant energy to earthquakes and eruptions at the synthesis of elements lighter than iron, thus creating excess energy, which is partially used for the synthesis of heavier elements. The combination of the chemical and nuclear reactions transforms these centers of geophysical activity into giant reactors where the nuclear, chemical, and thermal transformation of mantle materials and the creation of primary deposits of heavy elements such as uranium, thorium, gold, etc. So, all chemical elements heavier than iron are not detected in the solar wind. These elements discovered on our planet could be (and probably were) created on planet Earth and not imported from explosive supernovae or far-off remote stars. To the best of our knowledge, this hypothesis has not been proposed until now.展开更多
A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to ...A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.展开更多
Background： Osteoporosis is a common complication of chronic obstructive pulmonary disease （COPD）. Recent clinical and biological researches have increasingly delineated the biomolecular pathways of bone metabolism...Background： Osteoporosis is a common complication of chronic obstructive pulmonary disease （COPD）. Recent clinical and biological researches have increasingly delineated the biomolecular pathways of bone metabolism regulation in COPD. We extended this work by examining the specific association and potential contribution of the osteoprotegerin （OPG）/receptor activator of nuclear factor-riB ligand （RANKL） axis to the pathogenesis of osteoporosis in advanced COPD. The aim of this study was to assess the relationships of serum OPG, RANKL, and tumor necrosis factor-alpha （TNF-a） with bone turnover in men with very severe COPD. Methods： Pulmonary function, T-score at the lumbar spine （LS） and femoral neck （FN）, serum OPG, RANKL, soluble receptor of tumor necrosis factor-alpha-1 and 11 （sTNFR-I, sTNFR-II）, osteocalcin （OC）, and β-CrossLaps （βCL） levels were measured in 45 men with very severe stage COPD and 36 male non-COPD volunteers. COPD patients and healthy controls were compared using all independent t-test and Mann-Whitney U-test. The Pearson coefficient was used to assess the relationships between variables. Results： OPG and OC were lower in male COPD patients than in control subjects whereas RANKL, serum ~CL, TN F-o~, and its receptors were higher. OPG directly correlated with forced expiratory volume in I s （FEVI） % predicted （r = 0.46, P 〈 0.005）, OC （r= 0.34, P 〈 0.05）, LS （I.= 0.56, P 〈 0.001 ）, and FN T-score （r= 0.47, P 〈 0.01 ）. In contrast, serum RANKL inversely associated with LS and FN T-score （r = -0.62, P 〈 0.001 and r = -0.48, P 〈 0.001 ） but directly correlated with [3CL （r = 0.48, P 〈 0.001 ）. In addition, OPG was inversely correlated with RANKL （r = -0.39, P 〈 0.01 ）, TNF-a （r = -0.56, P 〈 0.001 ）, and sTNFR-I （r = -0.40, P 〈 0.01 ）. Conelusion： Our results suggest that serum OPG and RANKL levels are inversely associated with bone loss in men with advanced stage COPD.展开更多
Background A20, also known as tumor necrosis factor α induced protein 3 （TNFaip3）, is a cytoplasmic zinc finger protein that inhibits nuclear factor kappa-B （NF-κB） activity and prevents tumor necrosis factor （...Background A20, also known as tumor necrosis factor α induced protein 3 （TNFaip3）, is a cytoplasmic zinc finger protein that inhibits nuclear factor kappa-B （NF-κB） activity and prevents tumor necrosis factor （TNF）-mediated programmed cell death. NF-κB is a transcription factor that regulates expression of genes involved in cell proliferation, cell survival and anti-apoptosis. Several studies have implicated that the NF-κB signal pathway is associated with angiogenesis and clinico-pathological process of adenoid cystic carcinoma （ACC） of the salivary glands.Methods The ability of overexpression of A2.0 to influence the biological behavior and invasion of ACC cells was examined. The cells were stably transfected with full-length A20 cDNA. Stable gene transfer was verified by realtime-polymerase chain reaction （PCR） and Western blot analysis. The change of cell biological behavior was examined by methyl thiazolyl tetrazolium （MTT） and NF-κB luciferase reporter assay and the invasion of the cells was examined by a Matrigel invasion chamber.Results pEGPFN3-A2.0 gene was stably transferred into ACC-2 cells and overexpressed. When cells were treated with TNFα, the NF-κB activity of ACC-2-A20 cells could be down-regulated about 46.32% in contrast to ACC-2-GFP cells （P〈0.05）. A20 potently inhibited growth of A20 transfectant ACC-2-A20 compared with control vector transfected groups and the ACC-2 empty control group （P〈0.05）. The ACC-2-A20 cells showed significantly reduced ability to invade through Matdgei-coated filters compared to ACC-2-GFP and ACC-2 cells. The inhibition rate was up to 71.05% （P〈0.05）. Conclusions A2.0 gene transfer is associated with decreased tumor invasion, in part via the down-regulation of NF-κB expression, providing evidence for a potential application of A20 in designing a treatment modality for salivary gland cancers such as ACC.展开更多
Background： In addition to neurons, all components of the neurovascular unit （NVU）, such as glial, endothelial, and basal membranes, are destroyed during traumatic brain injury （TBI）. Previous studies have shown ...Background： In addition to neurons, all components of the neurovascular unit （NVU）, such as glial, endothelial, and basal membranes, are destroyed during traumatic brain injury （TBI）. Previous studies have shown that excessive stimulation ofcalpain is crucial for cerebral injury after traumatic insult. The objective of this study was to investigate whether calpain activation participated in NVU disruption and edema formation in a mouse model of controlled cortical impact （CCI）. Methods： One hundred and eight mice were divided into three groups： the sham group, the control group, and the MDL28170 group. MDL28170 （20 mg/kg）, an efficient calpain inhibitor, was administered intraperitoneally at 5 rain, 3 h, and 6 h after experimental CCI. We then measured neurobehavioral deficits, calpain activity, inflammatory mediator levels, blood-brain barrier （BBB） disruption, and NVU deficits using electron microscopy and histopathological analysis at 6 h and 24 h after CCI. Results： The MDL28170 treatment significantly reduced the extent of both cerebral contusion （MDL28170 vs. vehicle group, 16.90 ± 1.01 mm3 and 17.20±1.17 mm3 vs. 9.30 ± 1.05 mm^3 and 9.90 ± 1.17 mm3, both P 〈 0.001 ） and edema （M DL28170 vs. vehicle group, 80.76 ± 1.25% and 82.00 ± 1.84% vs. 82.55 ± 1.32% and 83.64 ± 1.25%, both P 〈 0.05）, improved neurological scores （MDL28170 vs. vehicle group, 7.50 ±0.45 and 6.33 ±0.38 vs. 12.33 ± 0.48 and 11.67±0.48, both P 〈 0.001）, and attenuated NVU damage resulting （including tight junction （TJ）, basement membrane, BBB, and neuron） from CCI at 6 h and 24 h. Moreover, MDL28170 markedly downregulated nuclear factor-κB-related inflammation （tumor necrosis factor-α [TNF-α]： MDL28170 vs. vehicle group, 1.15 ± 0.07 and 1.62± 0.08 vs. 1.59±0.10 and 2.18± 0.10, both P 〈 0.001 ： inducible nitric oxide synthase： M DL28170 vs. vehicle group, 4.51± 0.23 vs. 6.23± 0.12, P 〈 0.001 at 24 h; intracellular adhesion molecule- I ： MDL28170 vs. vehicle group, 1.45± 0.13 vs. 1.70 ± 0.12, P 〈 0.01 at 24 h） and lessened both myeloperoxidase activity （MDL28170 vs. vehicle group, 0.016± 0.001 and 0.016± 0.001 vs. 0.024± 0.001 and 0.023 ± 0.001, P 〈 0.001 and 0.01, respectively） and matrix metalloproteinase-9 （MMP-9） levels （MDL28170 vs. vehicle group, 0.87±0.13 and 1.10 ± 0.10 vs. 1.17 ± 0.13 and 1.25 ± 0.12, P 〈 0.001 and 0±05, respectively） at 6 h and 24 h after CCI. Conclusions： These findings demonstrate that MDL28170 can protect the structure of the NVU by inhibiting the inflammatory cascade, reducing the expression of MMP-9, and supporting the integrity of TJ during acute TBI.展开更多
A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic Energy.The leakage neutron spectra within energy levels of 0.8-16 MeV at 60°an...A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic Energy.The leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight method.The samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 cm.The leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and JEFF-3.3.Based on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were analyzed.The results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.展开更多
The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayto...The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.展开更多
Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system util...Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system utilizes a DD neutron generator based on inertial electrostatic confinement(IEC)to interrogate suspicious objects.To detect secondary neutrons produced during fission reactions induced in SNMs,a tensioned metastable fluid detector(TMFD)is employed.The current status of the system's development is reported in this paper,accompanied by the results from experiments conducted to detect 10 g of highly enriched uranium(HEU).Notably,the experimental findings demonstrate a distinct difference in the count rates of measurements with and without HEU.This difference in count rates surpasses two times the standard deviation,indicating a confidence level of more than 96% for identifying the presence of HEU.The paper presents and extensively discusses the proof-of-principle experimental results,along with the system's planned trajectory.展开更多
A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in...A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new challenge.This paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole explosions.First,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was analyzed.The plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the site.According to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole blasting.The time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear explosion.This comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion.展开更多
Given the challenge of definitively discriminating between chemical and nuclear explosions using seismic methods alone,surface detection of signature noble gas radioisotopes is considered a positive identification of ...Given the challenge of definitively discriminating between chemical and nuclear explosions using seismic methods alone,surface detection of signature noble gas radioisotopes is considered a positive identification of underground nuclear explosions(UNEs).However,the migration of signature radionuclide gases between the nuclear cavity and surface is not well understood because complex processes are involved,including the generation of complex fracture networks,reactivation of natural fractures and faults,and thermo-hydro-mechanical-chemical(THMC)coupling of radionuclide gas transport in the subsurface.In this study,we provide an experimental investigation of hydro-mechanical(HM)coupling among gas flow,stress states,rock deformation,and rock damage using a unique multi-physics triaxial direct shear rock testing system.The testing system also features redundant gas pressure and flow rate measurements,well suited for parameter uncertainty quantification.Using porous tuff and tight granite samples that are relevant to historic UNE tests,we measured the Biot effective stress coefficient,rock matrix gas permeability,and fracture gas permeability at a range of pore pressure and stress conditions.The Biot effective stress coefficient varies from 0.69 to 1 for the tuff,whose porosity averages 35.3%±0.7%,while this coefficient varies from 0.51 to 0.78 for the tight granite(porosity<1%,perhaps an underestimate).Matrix gas permeability is strongly correlated to effective stress for the granite,but not for the porous tuff.Our experiments reveal the following key engineering implications on transport of radionuclide gases post a UNE event:(1)The porous tuff shows apparent fracture dilation or compression upon stress changes,which does not necessarily change the gas permeability;(2)The granite fracture permeability shows strong stress sensitivity and is positively related to shear displacement;and(3)Hydromechanical coupling among stress states,rock damage,and gas flow appears to be stronger in tight granite than in porous tuff.展开更多
The occurrence of blockages of trash intercepting net in nuclear power plant due to marine biofouling has become increasingly frequent,leading to significant changes in the mechanical state.This paper establishes a CF...The occurrence of blockages of trash intercepting net in nuclear power plant due to marine biofouling has become increasingly frequent,leading to significant changes in the mechanical state.This paper establishes a CFD(Computational Fluid Dynamics)model to simulate the hydrodynamic forces of trash intercepting net under the action of regular waves.The porous media model is used to calculate the hydrodynamic forces,and the maximum mooring load is also evaluated.The simplified calculation method considering the different curved shape based on the flat nets are proposed,and the influences of wave parameters,solidity,and curved shape are investigated.The results indicate that under the regular wave conditions,as the solidity increases,the phenomenon of secondary wave peaks becomes more pronounced.The horizontal wave force reduction coefficient follows a three-piecewise linear relationship with the non-dimensional deformation level of curved shape.The trash intercepting net exhibits more potent scattering effects on short-wave conditions,displaying significant non-linear characteristics.The deformation level of the trash intercepting net is a significant factor influencing the mooring load.展开更多
The newly developed software,Nucleus++,is an advanced tool for displaying basic nuclear physics properties from NubAsE and integrating comprehensive mass information for each nuclide from Atomic Mass Evaluation.Additi...The newly developed software,Nucleus++,is an advanced tool for displaying basic nuclear physics properties from NubAsE and integrating comprehensive mass information for each nuclide from Atomic Mass Evaluation.Additionally,it allows users to compare experimental nuclear masses with predictions from different mass models.Building on the success and learning experiences of its predecessor,Nucleus,this enhanced tool introduces improved functionality and compatibility.With its user-friendly interface,Nucleus++was designed as a valuable tool for scholars and practitioners in the field of nuclear science.This article offers an in-depth description of Nucleus++,highlighting its main features and anticipated impacts on nuclear science research.展开更多
Nuclear astrophysics is a rapidly developing interdisciplinary feld of research that has received extensive attention from the scientifc community since the midtwentieth century.Broadly,it uses the laws of extremely s...Nuclear astrophysics is a rapidly developing interdisciplinary feld of research that has received extensive attention from the scientifc community since the midtwentieth century.Broadly,it uses the laws of extremely small atomic nuclei to explain the evolution of the universe.Owing to the complexity of nucleosynthesis processes and our limited understanding of nuclear physics in astrophysical environments,several critical astrophysical problems remain unsolved.To achieve a better understanding of astrophysics,it is necessary to measure the cross sections of key nuclear reactions with the precision required by astrophysical models.Direct measurement of nuclear reaction cross sections is an important method of investigating how nuclear reactions infuence stellar evolution.Given the challenges involved in measuring the extremely low crosssections of nuclear reactions in the Gamow peak and preparing radioactive targets,indirect methods,such as the transfer reaction,coulomb dissociation,and surrogate ratio methods,have been developed over the past several decades.These are powerful tools in the investigation of,for example,neutron-capture(n,r)reactions with short-lived radioactive isotopes.However,direct measurement is still preferable,such as in the case of reactions involving light and stable nuclei.As an essential part of stellar evolution,these low-energy stable nuclear reactions have been of particular interest in recent years.To overcome the diffculties in measurements near or deeply within the Gamow window,the combination of an underground laboratory and high-exposure accelerator/detector complex is currently the optimal solution.Therefore,underground experiments have emerged as a new and promising direction of research.In addition,to better simulate the stellar environment in the laboratory,research on nuclear physics under laser-driven plasma conditions has gradually become a frontier hotspot.In recent years,the CIAE team conducted a series of distinctive nuclear astrophysics studies,relying on the Jinping Underground Nuclear Astrophysics platform and accelerators in Earth’s surface laboratories,including the Beijing Radioactive Ion beam Facility,as well as other scientifc platforms at home and abroad.This research covered nuclear theories,numerical models,direct measurements,indirect measurements,and other novel approaches,achieving great interdisciplinary research results,with high-level academic publications and signifcant international impacts.This article reviews the above research and predicts future developments.展开更多
A sustainability-oriented assessment of the nuclear energy system can provide informative and convincing decision-making support for nuclear development strategies in China.In our previous study,four authentic nuclear...A sustainability-oriented assessment of the nuclear energy system can provide informative and convincing decision-making support for nuclear development strategies in China.In our previous study,four authentic nuclear fuel cycle(NFC)transi-tion scenarios were proposed,featuring different development stages and exhibiting distinct environmental,economic,and technical characteristics.However,because of the multiple and often conflicting criteria embedded therein,determining the top-priority NFC alternative for a sustainability orientation remains challenging.To address this issue,this study proposed a novel hybrid multi-criteria decision-making framework comprising fuzzy AHP,PROMETHEE GAIA,and MOORA.Initially,an improved fuzzy AHP weighting model was developed to determine criteria weights under uncertainty and investigate the influence of various weight aggregation and defuzzification approaches.Subsequently,PROMETHEE GAIA was used to address conflicts among the criteria and prioritize alternatives on a visualized k-dimensional GAIA plane.As a result,the alternative for direct recycling PWR spent fuel in fast reactors is considered the most sustainable.Furthermore,a sensitivity analysis was conducted to examine the influence of criteria weight variation and validate the screening results.Finally,using MOORA,some significant optimization ideas and valuable insights were provided to support decision-makers in shaping nuclear development strategies.展开更多
Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins ...Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.展开更多
基金Supported by The Dong-A University Research Fund
文摘AIM:To assess the prognostic significance of nuclear factor-kB (NF-kB) and its target genes in gastric cancer. METHODS:The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-kB RelA. Preoperative serum levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) were assessed via enzyme-linked immuno-sorbent assay. C-reactive protein (CRP) and serum amyloid A (SAA) were measured via immunotrubidimetry. RESULTS:Positive rate of NF-kB RelA was 42.6%. NF-kB RelA expression in tumor tissues was also related to serum levels of IL-6 (P = 0.044) and CRP (P = 0.010). IL-6, SAA, CRP were related to depth of invasion, VEGF and SAA were correlated with lymph node metastasis. IL-6, VEGF, SAA and CRP were related to the stage. Univariate analysis demonstrated that immunostaining of NF-kB RelA, levels of IL-6, VEGF, SAA were significantly related with both disease free survival and over-all survival (OS). Multivariate analysis verified that NF-kB RelA [hazard ratio (HR): 3.40, P = 0.024] and SAA (HR: 3.39, P = 0.045) were independently associated with OS. CONCLUSION: Increased expression of NF-kB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients.
文摘AIM In this study we investigated the relationship of the X protein of HBV and nuclear factor-κB(NF-κB)and the expression of NF-κB in human hepatocellular carcinoma tissues. METHODS Immunohistochemistry SP method was used to detect the expression of NF-κB and the X protein of HBV in human hepatocellular carcinoma tissues of 52 cases.Gene transfection mediated by lipofectamine was used to transfect the eukaryotic expression vector pCDNA3.1-HBX of HBV x gene into human hepatocellular carcinoma cell line HCC-9204 and NF-κB was detected. RESULTS NF-κB was widely expressed in human hepatocellular carcinoma tissues in a total of 52 cases and its expression was related to the X protein of HBV.NF-κB was localized both in the cytoplasm and the nuclei of hepatocellular carcinoma cells in 11 cases which were positive for the X protein of HBV while in 41 cases negative for the X protein of HBV,NF-κB was only localized in the cytoplasm of hepatocellular carcinoma cells but translocated to the nuclei of hepatocellular carcinoma cells after the eukaryotic expression vector pCDNA3.1-HBX was transfected into HCC-9204 cells. CONCLUSION This study strongly suggests that the nuclear factor NF-κB is widely expressed in hepatocellular carcinoma tissues in different styles according to the expression of the X protein of HBV.NF-κB is abnormally activated in hepatocellular carcinoma,which is probably rélated to the X protein of HBV.The X protein of HBV can activate NF-κB to translocate into nuclei of hepatocellular carcinoma cells.
基金supported by the National Natural Science Foundation of China,Nos.82001178(to LW),81901129(to LH),82001175(to FX)Shanghai Sailing Program,No.20YF1439200(to LW)+1 种基金the Natural Science Foundation of Shanghai,China,No.23ZR1450800(to LH)and the Fundamental Research Funds for the Central Universities,No.YG2023LC15(to ZX)。
文摘Protein arginine methyltransferase-6 participates in a range of biological functions,particularly RNA processing,transcription,chromatin remodeling,and endosomal trafficking.However,it remains unclear whether protein arginine methyl transferase-6 modifies neuropathic pain and,if so,what the mechanisms of this effect.In this study,protein arginine methyltransferase-6 expression levels and its effect on neuropathic pain were investigated in the spared nerve injury model,chronic constriction injury model and bone cancer pain model,using immunohistochemistry,western blotting,immunoprecipitation,and label-free proteomic analysis.The results showed that protein arginine methyltransferase-6 mostly co-localized withβ-tubulinⅢin the dorsal root ganglion,and that its expression decreased following spared nerve injury,chronic constriction injury and bone cancer pain.In addition,PRMT6 knockout(Prmt6~(-/-))mice exhibited pain hypersensitivity.Furthermore,the development of spared nerve injury-induced hypersensitivity to mechanical pain was attenuated by blocking the decrease in protein arginine methyltransferase-6 expression.Moreover,when protein arginine methyltransferase-6 expression was downregulated in the dorsal root ganglion in mice without spared nerve injury,increased levels of phosphorylated extracellular signal-regulated kinases were observed in the ipsilateral dorsal horn,and the response to mechanical stimuli was enhanced.Mechanistically,protein arginine methyltransferase-6 appeared to contribute to spared nerve injury-induced neuropathic pain by regulating the expression of heterogeneous nuclear ribonucleoprotein-F.Additionally,protein arginine methyltransfe rase-6-mediated modulation of hete rogeneous nuclear ribonucleoprotein-F expression required amino atids 319 to 388,but not classical H3R2 methylation.These findings indicated that protein arginine methyltransferase-6 is a potential therapeutic target fo r the treatment of peripheral neuro pathic pain.
基金supported by National Health and Medical Research Council GNT1105374,GNT1137645,GNT2000766 and veski Innovation Fellowship(VIF23)to RP.
文摘Nuclear factor Y is a ubiquitous heterotrimeric transcription factor complex conserved across eukaryotes that binds to CCAAT boxes,one of the most common motifs found in gene promoters and enhancers.Over the last 30 years,research has revealed that the nuclear factor Y complex controls many aspects of brain development,including differentiation,axon guidance,homeostasis,disease,and most recently regeneration.However,a complete understanding of transcriptional regulatory networks,including how the nuclear factor Y complex binds to specific CCAAT boxes to perform its function remains elusive.In this review,we explore the nuclear factor Y complex’s role and mode of action during brain development,as well as how genomic technologies may expand understanding of this key regulator of gene expression.
文摘Neuron-derived clone 77 (Nur77) is a member of the NR4A subfamily that plays critical roles in apoptosis, survival, proliferation, autophagy, angiogenesis, inflammatory responses, DNA repair, glycolipid metabolism and energy consumption. The deregulation of Nur77 signalling often relates to various serious diseases, including cancer and non-cancer diseases. A systematic review is necessary for the better understanding of Nur77 in clinical treatment. In this article, we comprehensively conclude the lipid regulation function and expression of Nur77, and its role in COPD. Finally, we prospect that development of drugs and clinical biochemical investigations targeting of Nur77 has considerable potential within healthcare.
文摘1989 is the beginning of intensive research into the phenomena of cold nuclear fusion, renamed “The Low Energy Nuclear Synthesis Reactions” (LENR). Based on these results and the long-term research of earthquakes and volcanic activity, the authors of this article put forward a hypothesis about the mainly chemical nature of the energy released at earthquakes and volcanic eruptions with the participation of primordial hydrogen and helium: high mobility of hydrogen and oxidizers provide focusing and accumulation of the latent chemical energy, which is realized suddenly and instantaneously as explosions and initiate the earthquake and/or eruptions. The volcanic eruption is viewed therein as a special type of earthquake whereby the hypocenter rises to the earth’s surface. The authors proposed a new hypothesis that LENRs significant energy to earthquakes and eruptions at the synthesis of elements lighter than iron, thus creating excess energy, which is partially used for the synthesis of heavier elements. The combination of the chemical and nuclear reactions transforms these centers of geophysical activity into giant reactors where the nuclear, chemical, and thermal transformation of mantle materials and the creation of primary deposits of heavy elements such as uranium, thorium, gold, etc. So, all chemical elements heavier than iron are not detected in the solar wind. These elements discovered on our planet could be (and probably were) created on planet Earth and not imported from explosive supernovae or far-off remote stars. To the best of our knowledge, this hypothesis has not been proposed until now.
基金supported by the Army Laboratory Animal Foundation of China,No.SYDW[2020]22(to TC)the Shaanxi Provincial Key R&D Plan General Project of China,No.2022SF-236(to YM)the National Natural Science Foundation of China,No.82202070(to TC)。
文摘A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.
文摘Background： Osteoporosis is a common complication of chronic obstructive pulmonary disease （COPD）. Recent clinical and biological researches have increasingly delineated the biomolecular pathways of bone metabolism regulation in COPD. We extended this work by examining the specific association and potential contribution of the osteoprotegerin （OPG）/receptor activator of nuclear factor-riB ligand （RANKL） axis to the pathogenesis of osteoporosis in advanced COPD. The aim of this study was to assess the relationships of serum OPG, RANKL, and tumor necrosis factor-alpha （TNF-a） with bone turnover in men with very severe COPD. Methods： Pulmonary function, T-score at the lumbar spine （LS） and femoral neck （FN）, serum OPG, RANKL, soluble receptor of tumor necrosis factor-alpha-1 and 11 （sTNFR-I, sTNFR-II）, osteocalcin （OC）, and β-CrossLaps （βCL） levels were measured in 45 men with very severe stage COPD and 36 male non-COPD volunteers. COPD patients and healthy controls were compared using all independent t-test and Mann-Whitney U-test. The Pearson coefficient was used to assess the relationships between variables. Results： OPG and OC were lower in male COPD patients than in control subjects whereas RANKL, serum ~CL, TN F-o~, and its receptors were higher. OPG directly correlated with forced expiratory volume in I s （FEVI） % predicted （r = 0.46, P 〈 0.005）, OC （r= 0.34, P 〈 0.05）, LS （I.= 0.56, P 〈 0.001 ）, and FN T-score （r= 0.47, P 〈 0.01 ）. In contrast, serum RANKL inversely associated with LS and FN T-score （r = -0.62, P 〈 0.001 and r = -0.48, P 〈 0.001 ） but directly correlated with [3CL （r = 0.48, P 〈 0.001 ）. In addition, OPG was inversely correlated with RANKL （r = -0.39, P 〈 0.01 ）, TNF-a （r = -0.56, P 〈 0.001 ）, and sTNFR-I （r = -0.40, P 〈 0.01 ）. Conelusion： Our results suggest that serum OPG and RANKL levels are inversely associated with bone loss in men with advanced stage COPD.
基金Chinese National Natural and Scientific Committee(No.30330580)
文摘Background A20, also known as tumor necrosis factor α induced protein 3 （TNFaip3）, is a cytoplasmic zinc finger protein that inhibits nuclear factor kappa-B （NF-κB） activity and prevents tumor necrosis factor （TNF）-mediated programmed cell death. NF-κB is a transcription factor that regulates expression of genes involved in cell proliferation, cell survival and anti-apoptosis. Several studies have implicated that the NF-κB signal pathway is associated with angiogenesis and clinico-pathological process of adenoid cystic carcinoma （ACC） of the salivary glands.Methods The ability of overexpression of A2.0 to influence the biological behavior and invasion of ACC cells was examined. The cells were stably transfected with full-length A20 cDNA. Stable gene transfer was verified by realtime-polymerase chain reaction （PCR） and Western blot analysis. The change of cell biological behavior was examined by methyl thiazolyl tetrazolium （MTT） and NF-κB luciferase reporter assay and the invasion of the cells was examined by a Matrigel invasion chamber.Results pEGPFN3-A2.0 gene was stably transferred into ACC-2 cells and overexpressed. When cells were treated with TNFα, the NF-κB activity of ACC-2-A20 cells could be down-regulated about 46.32% in contrast to ACC-2-GFP cells （P〈0.05）. A20 potently inhibited growth of A20 transfectant ACC-2-A20 compared with control vector transfected groups and the ACC-2 empty control group （P〈0.05）. The ACC-2-A20 cells showed significantly reduced ability to invade through Matdgei-coated filters compared to ACC-2-GFP and ACC-2 cells. The inhibition rate was up to 71.05% （P〈0.05）. Conclusions A2.0 gene transfer is associated with decreased tumor invasion, in part via the down-regulation of NF-κB expression, providing evidence for a potential application of A20 in designing a treatment modality for salivary gland cancers such as ACC.
文摘Background： In addition to neurons, all components of the neurovascular unit （NVU）, such as glial, endothelial, and basal membranes, are destroyed during traumatic brain injury （TBI）. Previous studies have shown that excessive stimulation ofcalpain is crucial for cerebral injury after traumatic insult. The objective of this study was to investigate whether calpain activation participated in NVU disruption and edema formation in a mouse model of controlled cortical impact （CCI）. Methods： One hundred and eight mice were divided into three groups： the sham group, the control group, and the MDL28170 group. MDL28170 （20 mg/kg）, an efficient calpain inhibitor, was administered intraperitoneally at 5 rain, 3 h, and 6 h after experimental CCI. We then measured neurobehavioral deficits, calpain activity, inflammatory mediator levels, blood-brain barrier （BBB） disruption, and NVU deficits using electron microscopy and histopathological analysis at 6 h and 24 h after CCI. Results： The MDL28170 treatment significantly reduced the extent of both cerebral contusion （MDL28170 vs. vehicle group, 16.90 ± 1.01 mm3 and 17.20±1.17 mm3 vs. 9.30 ± 1.05 mm^3 and 9.90 ± 1.17 mm3, both P 〈 0.001 ） and edema （M DL28170 vs. vehicle group, 80.76 ± 1.25% and 82.00 ± 1.84% vs. 82.55 ± 1.32% and 83.64 ± 1.25%, both P 〈 0.05）, improved neurological scores （MDL28170 vs. vehicle group, 7.50 ±0.45 and 6.33 ±0.38 vs. 12.33 ± 0.48 and 11.67±0.48, both P 〈 0.001）, and attenuated NVU damage resulting （including tight junction （TJ）, basement membrane, BBB, and neuron） from CCI at 6 h and 24 h. Moreover, MDL28170 markedly downregulated nuclear factor-κB-related inflammation （tumor necrosis factor-α [TNF-α]： MDL28170 vs. vehicle group, 1.15 ± 0.07 and 1.62± 0.08 vs. 1.59±0.10 and 2.18± 0.10, both P 〈 0.001 ： inducible nitric oxide synthase： M DL28170 vs. vehicle group, 4.51± 0.23 vs. 6.23± 0.12, P 〈 0.001 at 24 h; intracellular adhesion molecule- I ： MDL28170 vs. vehicle group, 1.45± 0.13 vs. 1.70 ± 0.12, P 〈 0.01 at 24 h） and lessened both myeloperoxidase activity （MDL28170 vs. vehicle group, 0.016± 0.001 and 0.016± 0.001 vs. 0.024± 0.001 and 0.023 ± 0.001, P 〈 0.001 and 0.01, respectively） and matrix metalloproteinase-9 （MMP-9） levels （MDL28170 vs. vehicle group, 0.87±0.13 and 1.10 ± 0.10 vs. 1.17 ± 0.13 and 1.25 ± 0.12, P 〈 0.001 and 0±05, respectively） at 6 h and 24 h after CCI. Conclusions： These findings demonstrate that MDL28170 can protect the structure of the NVU by inhibiting the inflammatory cascade, reducing the expression of MMP-9, and supporting the integrity of TJ during acute TBI.
基金This work was supported by the general program(No.1177531)joint funding(No.U2067205)from the National Natural Science Foundation of China.
文摘A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic Energy.The leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight method.The samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 cm.The leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and JEFF-3.3.Based on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were analyzed.The results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.
基金This work was supported of National Natural Science Foundation of China Fund(No.52306033)State Key Laboratory of Engines Fund(No.SKLE-K2022-07)the Jiangxi Provincial Postgraduate Innovation Special Fund(No.YC2022-s513).
文摘The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.
基金supported by Special Coordination Funds for Promoting Science and Technology,sponsored by Japan’s Ministry of Education,Culture,Sports,Science and Technology(MEXT).
文摘Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system utilizes a DD neutron generator based on inertial electrostatic confinement(IEC)to interrogate suspicious objects.To detect secondary neutrons produced during fission reactions induced in SNMs,a tensioned metastable fluid detector(TMFD)is employed.The current status of the system's development is reported in this paper,accompanied by the results from experiments conducted to detect 10 g of highly enriched uranium(HEU).Notably,the experimental findings demonstrate a distinct difference in the count rates of measurements with and without HEU.This difference in count rates surpasses two times the standard deviation,indicating a confidence level of more than 96% for identifying the presence of HEU.The paper presents and extensively discusses the proof-of-principle experimental results,along with the system's planned trajectory.
基金supported by the General Program of the National Natural Science Foundation of China(Grant No.52074295)the Special Fund for Basic Scientific Research Business Expenses of Central Universities(Grant No.2022YJSSB06)supported by State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and technology,Beijing,China(Grant No.SKLGDUEK202217).
文摘A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new challenge.This paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole explosions.First,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was analyzed.The plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the site.According to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole blasting.The time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear explosion.This comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion.
基金supported by the Laboratory Directed Research&Development(LDRD)program at the Los Alamos National Laboratory(LANL)(Grant No.20220019DR).
文摘Given the challenge of definitively discriminating between chemical and nuclear explosions using seismic methods alone,surface detection of signature noble gas radioisotopes is considered a positive identification of underground nuclear explosions(UNEs).However,the migration of signature radionuclide gases between the nuclear cavity and surface is not well understood because complex processes are involved,including the generation of complex fracture networks,reactivation of natural fractures and faults,and thermo-hydro-mechanical-chemical(THMC)coupling of radionuclide gas transport in the subsurface.In this study,we provide an experimental investigation of hydro-mechanical(HM)coupling among gas flow,stress states,rock deformation,and rock damage using a unique multi-physics triaxial direct shear rock testing system.The testing system also features redundant gas pressure and flow rate measurements,well suited for parameter uncertainty quantification.Using porous tuff and tight granite samples that are relevant to historic UNE tests,we measured the Biot effective stress coefficient,rock matrix gas permeability,and fracture gas permeability at a range of pore pressure and stress conditions.The Biot effective stress coefficient varies from 0.69 to 1 for the tuff,whose porosity averages 35.3%±0.7%,while this coefficient varies from 0.51 to 0.78 for the tight granite(porosity<1%,perhaps an underestimate).Matrix gas permeability is strongly correlated to effective stress for the granite,but not for the porous tuff.Our experiments reveal the following key engineering implications on transport of radionuclide gases post a UNE event:(1)The porous tuff shows apparent fracture dilation or compression upon stress changes,which does not necessarily change the gas permeability;(2)The granite fracture permeability shows strong stress sensitivity and is positively related to shear displacement;and(3)Hydromechanical coupling among stress states,rock damage,and gas flow appears to be stronger in tight granite than in porous tuff.
基金financially supported by National Natural Science Foundation of China(Grant No.52201311)Fundamental Research Funds for the Central Universities.
文摘The occurrence of blockages of trash intercepting net in nuclear power plant due to marine biofouling has become increasingly frequent,leading to significant changes in the mechanical state.This paper establishes a CFD(Computational Fluid Dynamics)model to simulate the hydrodynamic forces of trash intercepting net under the action of regular waves.The porous media model is used to calculate the hydrodynamic forces,and the maximum mooring load is also evaluated.The simplified calculation method considering the different curved shape based on the flat nets are proposed,and the influences of wave parameters,solidity,and curved shape are investigated.The results indicate that under the regular wave conditions,as the solidity increases,the phenomenon of secondary wave peaks becomes more pronounced.The horizontal wave force reduction coefficient follows a three-piecewise linear relationship with the non-dimensional deformation level of curved shape.The trash intercepting net exhibits more potent scattering effects on short-wave conditions,displaying significant non-linear characteristics.The deformation level of the trash intercepting net is a significant factor influencing the mooring load.
基金supported in part by the National Key R&D Program of China(No.2021YFA1601500)CAS Project for Young Scientists in Basic Research(No.YSBR-002)+5 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB34000000)the Regional Development Youth Program of the Chinese Academy of Sciences(People’s Character[2023]No.15)Argonne National Laboratory was performed with the support of the US Department of EnergyOffice of Nuclear Physicsunder Contract No.DE-AC02-06CH11357support of France's IN2P3。
文摘The newly developed software,Nucleus++,is an advanced tool for displaying basic nuclear physics properties from NubAsE and integrating comprehensive mass information for each nuclide from Atomic Mass Evaluation.Additionally,it allows users to compare experimental nuclear masses with predictions from different mass models.Building on the success and learning experiences of its predecessor,Nucleus,this enhanced tool introduces improved functionality and compatibility.With its user-friendly interface,Nucleus++was designed as a valuable tool for scholars and practitioners in the field of nuclear science.This article offers an in-depth description of Nucleus++,highlighting its main features and anticipated impacts on nuclear science research.
基金National Natural Science Foundation of China(Nos.12435010)National Key R&D Program of China(No.2022YFA1602301)。
文摘Nuclear astrophysics is a rapidly developing interdisciplinary feld of research that has received extensive attention from the scientifc community since the midtwentieth century.Broadly,it uses the laws of extremely small atomic nuclei to explain the evolution of the universe.Owing to the complexity of nucleosynthesis processes and our limited understanding of nuclear physics in astrophysical environments,several critical astrophysical problems remain unsolved.To achieve a better understanding of astrophysics,it is necessary to measure the cross sections of key nuclear reactions with the precision required by astrophysical models.Direct measurement of nuclear reaction cross sections is an important method of investigating how nuclear reactions infuence stellar evolution.Given the challenges involved in measuring the extremely low crosssections of nuclear reactions in the Gamow peak and preparing radioactive targets,indirect methods,such as the transfer reaction,coulomb dissociation,and surrogate ratio methods,have been developed over the past several decades.These are powerful tools in the investigation of,for example,neutron-capture(n,r)reactions with short-lived radioactive isotopes.However,direct measurement is still preferable,such as in the case of reactions involving light and stable nuclei.As an essential part of stellar evolution,these low-energy stable nuclear reactions have been of particular interest in recent years.To overcome the diffculties in measurements near or deeply within the Gamow window,the combination of an underground laboratory and high-exposure accelerator/detector complex is currently the optimal solution.Therefore,underground experiments have emerged as a new and promising direction of research.In addition,to better simulate the stellar environment in the laboratory,research on nuclear physics under laser-driven plasma conditions has gradually become a frontier hotspot.In recent years,the CIAE team conducted a series of distinctive nuclear astrophysics studies,relying on the Jinping Underground Nuclear Astrophysics platform and accelerators in Earth’s surface laboratories,including the Beijing Radioactive Ion beam Facility,as well as other scientifc platforms at home and abroad.This research covered nuclear theories,numerical models,direct measurements,indirect measurements,and other novel approaches,achieving great interdisciplinary research results,with high-level academic publications and signifcant international impacts.This article reviews the above research and predicts future developments.
基金supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20200694,20KJB530002,and 21KJB480014)Jiangsu Specially-Appointed Professors ProgramMinistry of Science and ICT under the Nuclear R&D project(NRF-2017M2A8A5015072).
文摘A sustainability-oriented assessment of the nuclear energy system can provide informative and convincing decision-making support for nuclear development strategies in China.In our previous study,four authentic nuclear fuel cycle(NFC)transi-tion scenarios were proposed,featuring different development stages and exhibiting distinct environmental,economic,and technical characteristics.However,because of the multiple and often conflicting criteria embedded therein,determining the top-priority NFC alternative for a sustainability orientation remains challenging.To address this issue,this study proposed a novel hybrid multi-criteria decision-making framework comprising fuzzy AHP,PROMETHEE GAIA,and MOORA.Initially,an improved fuzzy AHP weighting model was developed to determine criteria weights under uncertainty and investigate the influence of various weight aggregation and defuzzification approaches.Subsequently,PROMETHEE GAIA was used to address conflicts among the criteria and prioritize alternatives on a visualized k-dimensional GAIA plane.As a result,the alternative for direct recycling PWR spent fuel in fast reactors is considered the most sustainable.Furthermore,a sensitivity analysis was conducted to examine the influence of criteria weight variation and validate the screening results.Finally,using MOORA,some significant optimization ideas and valuable insights were provided to support decision-makers in shaping nuclear development strategies.
基金Supported by the National Natural Science Foundation of China(No.31970429)the Shandong Provincial Natural Science Foundation(No.ZR 2022 MC 032)。
文摘Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.
