Heartburn is a common symptom shared by both gastroesophageal reflux disease(GERD)and functional heartburn(FHB),which can make it challenging to differentiate between the two conditions.However,examining oral manifest...Heartburn is a common symptom shared by both gastroesophageal reflux disease(GERD)and functional heartburn(FHB),which can make it challenging to differentiate between the two conditions.However,examining oral manifestations of GERD can be a cost-effective and readily available method to aid in this differentiation process.It may serve as a valuable tool in distinguishing GERD from FHB.展开更多
The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energ...The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.展开更多
The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by ...The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.展开更多
In this study,we theoretically investigate the feasibility of using laser-wakefield accelerated(LWFA)electrons for the photonuclear measurement of nuclear isomers according to the characteristics of the electrons obta...In this study,we theoretically investigate the feasibility of using laser-wakefield accelerated(LWFA)electrons for the photonuclear measurement of nuclear isomers according to the characteristics of the electrons obtained from LWFA experiments conducted at the Compact Laser-Plasma Accelerator(CLAPA)laboratory.The experiments at the CLAPA show that a stable electron beam with an energy of 78-135 MeV and a charge of 300-600 pC can be obtained.The bremsstrahlung spectra were simulated using Geant4,which suggests that a bremsstrahlung source with a peak intensity of 10^(19) photons/s can be generated.Theoretical calculations of isomer production cross sections from the photonuclear reactions on six target nuclei,^(197)Au,^(180)Hf,^(159)Tb,^(115)In,^(103)Rh,and ^(90)Zr,were performed and compared with the available experimental data in EXFOR,which suggest that further experiments are required for a series of photonuclear reaction channels.Flux-averaged cross sections and isomer ratios(IR)resulting from such bremsstrahlung sources are theoretically deduced.The results suggest that IR measurements can be used to constrain nuclear components,such asγstrength function and optical model potential.In addition,the detection of the decay characteristics was evaluated with Geant4 simulations.The use of the LWFA electron beam and its bremsstrahlung for photonuclear studies involving nuclear isomers is anticipated.展开更多
To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross s...To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross section spectrometer(NTOX), a dedicated lithium-containing scintillation detector has been developed on the Back-n beam line at the China Spallation Neutron Source. The Fast Scintillator-based Neutron Total Cross Section(FAST) spectrometer has been designed based on a Cs2Li La Br6(CLLB) scintillator considering the γ-ray flash and neutron environment on the Back-n beam line. The response of the CLLB scintillator to neutrons and γ-rays was evaluated with different 6Li/7 Li abundance ratios using Geant4. The neutron-γdiscrimination performance of the CLLB has been simulated considering different scintillation parameters, physical designs,and light readout modes. A cubic 6Li-enriched( > 90%) CLLB scintillator, which has a thickness of 4-9 mm and side length of no less than 50 mm to cover the Φ 50 mm neutron beam at the spectrometer position, has been proposed coupling to a side readout SiPM array to construct the FAST spectrometer. The developed simulation techniques for neutron-γ discrimination performance could provide technical support for other neutron-induced reaction measurements on the Back-n beam line.展开更多
The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture ...The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture events were detected using four C_(6)D_(6) detectors.The pulse-height weighting technique and double-bunch unfolding method based on Bayesian theory were used in the data analysis.Background deductions,normalization,and corrections were carefully considered to obtain reliable measurement results.The multilevel R-matrix Bayesian code SAMMY was used to extract the resonance parameters in the resolved resonance region(RRR).The average cross sections in the unresolved resonance region(URR)were obtained from 10 to 400 keV.The experimental results were compared with data from several evaluated libraries and previous experi-ments in the RRR and URR.The TALYS code was used to describe the average cross sections in the URR.The astrophysical Maxwell average cross sections(MACSs)of ^(79,81)Br from kT=5 to 100 keV were calculated over a sufficiently wide range of neutron energies.At a thermal energy of kT=30 keV,the MACS value for ^(79)Br 682±68 mb was in good agreement with the KADoNiS v1.0 recommended value.By contrast,the value of 293±29 mb for ^(81)Br was substantially higher than that of the evaluated database and the KADoNiS v1.0 recommended value.展开更多
Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation pote...Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.展开更多
Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this st...Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this study,we propose the extraction of PNCS distributions using a combination of gamma activation and reaction yield ratio methods.To verify the validity of the proposed extraction method,experiments for generating^(62,64)Cu and^(85m,87m)Sr isotopes via laser-induced pho-toneutron reactions were performed,and the reaction yields of these isotopes were obtained.Using the proposed extraction method,the PNCS distributions of^(63)Cu and^(86)Sr isotopes(leading to^(85m)Sr isotope production)were successfully extracted.These extracted PNCS distributions were benchmarked against available PNCS data or TALYS calculations,demonstrating the validity of the proposed extraction method.Potential applications for predicting the PNCS distributions of the 30 iso-topes are further introduced.We conclude that the proposed extraction method is an effective complement to the available sophisticated methods for measuring and evaluating PNCS data.展开更多
The flow and heat transfer characteristics of n-decane in the sub-millimeter spiral tube(SMST) at supercritical pressure(p = 3 MPa) are studied by the RNG k-ε numerical model in this paper. The effects of various Rey...The flow and heat transfer characteristics of n-decane in the sub-millimeter spiral tube(SMST) at supercritical pressure(p = 3 MPa) are studied by the RNG k-ε numerical model in this paper. The effects of various Reynolds numbers(Re) and structural parameters pitch(s) and spiral diameter(D) are analyzed.Results indicate that the average Nusselt numberNu and friction factorNu increase with an increase in Re, and decrease with an increase in D/d(tube diameter). In terms of the structural parameter s/d, it is found that as s/d increases, the Nu first increase, and then decrease. and the critical structural parameter is s/d = 4. Compared with the straight tube, the SMST can improve Nu by 34.8% at best, while it can improve Nu by 102.1% at most. In addition, a comprehensive heat transfer coefficient is applied to analyze the thermodynamic properties of SMST. With the optimal structural parameters of D/d = 6 and s/d = 4, the comprehensive heat transfer factor of supercritical pressure hydrocarbon fuel in the SMST can reach 1.074. At last, correlations of the average Nusselt number and friction factor are developed to predict the flow and heat transfer of n-decane at supercritical pressure.展开更多
BACKGROUND Lung invasive mucinous adenocarcinoma(LIMA),formerly referred to as mucinous bronchioloalveolar carcinoma,is a rare disease that usually presents as bilateral lung infiltration,is unsuitable for surgery and...BACKGROUND Lung invasive mucinous adenocarcinoma(LIMA),formerly referred to as mucinous bronchioloalveolar carcinoma,is a rare disease that usually presents as bilateral lung infiltration,is unsuitable for surgery and radiotherapy,and shows poor response to conventional chemotherapy.CASE SUMMARY We report a 56-year-old Chinese man with a history of smoking and epidermal growth factor receptor mutation-positivity who was initially misdiagnosed as severe pneumonia,but was ultimately diagnosed as a case of invasive mucinous adenocarcinoma of the lung by computed tomography-guided percutaneous lung biopsy.Bronchorrhea and dyspnea were improved within 24 h after initiation of gefitinib therapy and the radiographic signs of bilateral lung consolidation showed visible improvement within 30 d.After more than 11 months of treatment,there is no evidence of recurrence or severe adverse events.CONCLUSION Although the precise mechanism of the antitumor effects of gefitinib are not clear,our experience indicates an important role of the drug in LIMA and provides a reference for the diagnosis and treatment of this disease.展开更多
Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung canc...Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung cancer(NSCLC)cells.Methods NSCLC tissues and adjacent normal tissues from 60 patients with NSCLC adenocarcinoma were obtained via pathological biopsy or intraoperative resection.Several cell lines were cultured in vitro,including the human normal lung epithelial cell line BEAS-2B and human NSCLC cell lines A549,SPCA-1,PC-9,and 95-D.miR-183-5p and FOXO1 mRNA expression in tissues and cells were detected by qRT-PCR;the corresponding correlations in NSCLC tissues were analyzed using the Pearson test,and the relationship between miR-183-5p expression and clinicopathological parameters was analyzed.The miR-183-5p-mediated regulation of FOXO1 was verified by bioinformatics prediction alongside double luciferase,RNA-binding protein immunoprecipitation(RIP)assay,and pull-down experiments.A549 cells were divided into control,anti-miR-NC,anti-miR-183-5p,miR-NC,miR-183-5p,miR-183-5p+pcDNA3.1,and miR-183-5p+pcDNA3.1-FOXO1 groups.Cell proliferation,invasion,migration,apoptosis,and cell cycle distribution were detected using an MTT assay,clone formation assay,Transwell assay,scratch test,and flow cytometry,respectively.The expression of EMT-related proteins in the cells was analyzed by western blotting.The effect of miR-185-3p silencing on the development of transplanted tumors was detected by analyzing tumor formation in nude mice.Results miR-183-5p expression was significantly higher in NSCLC tissues and cells than in adjacent normal tissues,whereas FOXO1 mRNA expression was significantly down-regulated.There was a significant negative correlation between miR-183-5p and FOXO1 mRNA in NSCLC tissues(P<0.05).Additionally,the expression of miR-183-5p was significantly correlated with tumor size,tumor differentiation,and tumor-node-metastasis stage in patients with NSCLC(P<0.05).miR-183-5p targeted and inhibited FOXO1 expression.Compared to the anti-miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the anti-miR-183-5p group,whereas the protein expression of E-cadherin andα-catenin and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion were significantly lower in the anti-miR-183-5p group(P<0.05).Compared to the miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells in the miR-183-5p group were significantly higher,whereas the E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly lower;furthermore,the frequency of colony formation and invasion were significantly higher in the miR-183-5p group(P<0.05).Compared with the miR-183-5p+pcDNA3.1 group,the OD value,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group,whereas E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion was significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group(P<0.05).Overall,silencing miR-185-3p inhibited the growth of transplanted tumors and promoted FOXO1 expression.Conclusion Overexpression of miR-183-5p can inhibit apoptosis and promote the proliferation,migration,invasion,and EMT,of NSCLC cells by down-regulating FOXO1 expression.展开更多
AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was estab...AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10 -4) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10-4), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10-4). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10-6). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10-7). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.展开更多
The effects of photogenerated-hole scavengers(ascorbic acid,oxalic acid,humic acid and citric acid)on chalcopyrite bioleaching in the presence of visible light were studied using Acidithiobacillus ferrooxidans(A.ferro...The effects of photogenerated-hole scavengers(ascorbic acid,oxalic acid,humic acid and citric acid)on chalcopyrite bioleaching in the presence of visible light were studied using Acidithiobacillus ferrooxidans(A.ferrooxidans).Four sets of bioleaching experiments were performed:(1)visible light+0 g/L scavenger,(2)visible light+0.1 g/L of different scavenger(ascorbic acid,oxalic acid,humic acid and citric acid),(3)dark+0.1 g/L of different scavenger(ascorbic acid,oxalic acid,humic acid and citric acid),and(4)dark+0 g/L scavenger(control group).The results showed that ascorbic acid and oxalic acid could act as photogenerated-hole scavengers and significantly enhance chalcopyrite bioleaching under visible light.The dissolved copper in the light group without scavenger was only 18.7%higher than that of the control group.The copper extraction rates of the light groups with oxalic acid and ascorbic acid were respectively 30.1%and 32.5%higher than those of the control group.Scanning electron microscopy(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FT-IR)analyses indicated that ascorbic acid and oxalic acid as photogenerated-hole scavenger could capture photo-generated holes and inhibit jarosite formation on the chalcopyrite surface,thereby enhancing bioleaching of chalcopyrite under visible light.展开更多
Background: The feed conversion ratio(FCR) and residual feed intake(RFI) are common indexes in measuring feed efficiency for livestock. RFI is a feed intake adjusted for requirements for maintenance and production so ...Background: The feed conversion ratio(FCR) and residual feed intake(RFI) are common indexes in measuring feed efficiency for livestock. RFI is a feed intake adjusted for requirements for maintenance and production so these two traits are related. Similarly, FCR is related to feed intake and weight gain because it is their ratio. Cholecystokinin type A receptor(CCKAR) plays an important role in animal digestive process. We examined the interplay of these three parameters in a local Chinese chicken population.Results: The feed intake(FI) and body weights(BW) of 1,841 individuals were monitored on a daily basis from 56 to 105 d of age. There was a strong correlation between RFI and average daily feed intake(ADFI) and a negative correlation between the FCR and daily gain(r=-0.710). Furthermore, we identified 51 single nucleotide polymorphisms(SNPs) in the CCKAR and 4 of these resulted in amino acid mutations. The C334A mutation was specifically associated with FI and the expected feed intake(EFI)(P < 0.01) and significantly associated with the average daily gain(ADG)(P < 0.05). G1290A was significantly associated with FI and EFI(P < 0.05).Conclusion: FCR is apply to weight selecting, and RFI is more appropriate if the breeding focus is feed intake. And C334A and G1290A of the CCKAR gene can be deemed as candidate markers for feed intake and weight gain.展开更多
In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostru...In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostructures including antimony selenide(Sb_2Se_3) nanowires and selenium(Se) microrods can be achieved by merely varying the volume ratio of ethylene glycol(EG) and H_2O free from expensive chemical and additional surfactant. The achieved uniform Sb_2Se_3 nanowire is single crystalline along [001]growth direction with a diameter of 100 nm and a length up to tens of micrometers. When evaluated as an anode of lithium-ion battery, Sb_2Se_3 nanowire can deliver a high reversible capacity of 650.2 m Ah g^(-1) at 100 mA g^(-1) and a capacity retention of 63.8% after long-term 1000 cycles at 1000 mA g^(-1), as well as superior rate capability(389.5 m Ah g^(-1) at 2000 mA g^(-1)). This easy solvent-mediated microwave synthesis approach exhibits its great universe and importance towards the fabrication of high-performance metal chalcogenide electrode materials for future low-cost, large-scale energy storage systems.展开更多
For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or...For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or experimental database are chosen as input data.For checking the validity of the use of the data-based photonuclear algorithm,benchmarking simulations are presented in detail.We calculate photonuclear cross sections or reaction yield for ~9Be,^(48)Ti,^(133)Cs,and ^(197)Au and compare them with experimental data in the region of incident photon energy below ~30 MeV.While Geant4 can hardly reproduce photonuclear experimental data,results obtained from the data-based photonuclear algorithm are found in good agreement with experimental measurements.Potential application in estimation of specific activity of radioisotopes is further discussed.We conclude that the developed data-based photonuclear algorithm is suitable for an accurate prediction of photoninduced neutron or proton productions.展开更多
Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu iso...Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu isotope through a^(65)Cu(γ,n) reaction using high-intensity γ-beams produced at the Extreme Light InfrastructureNuclear Physics facility(ELI-NP). The specific activity for^(64)Cu was obtained as a function of target geometry, irradiation time, and electron beam energy, which translates into γ-beam energy. Optimized conditions for the generation of^(64)Cu isotopes at the ELI-NP were discussed. We estimated that an achievable saturation specific activity is of the order of 1–2 m Ci/g for thin targets(radius 1–2 mm,thickness 1 cm) and for a γ-beam flux of 10^(11) s ~1. Based on these results, the ELI-NP could provide great potential for the production of some innovative radioisotopes of medical interest in sufficient quantities suitable for nuclear medicine research.展开更多
Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.The...Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.Therefore,a novel method of using hematite to inhibit chalcopyrite biodissolution was proposed and verified.The results indicated that chalcopyrite biodissolution could be significantly inhibited by hematite,which consequently decreased the formation of AMD.In the presence of hematite,the final biodissolution rate of chalcopyrite decreased from 57.9%to 44.4%at 20 day.This in turn suggested that the formation of AMD was effectively suppressed under such condition.According to the biodissolution results,mineral composition and morphology analyses,and electrochemical analysis,it was shown that hematite promoted the formation and accumulation of passivation substances(jarosite and Cu2-xS)on chalcopyrite surface,thus inhibiting the biodissolution of chalcopyrite and limiting the formation of AMD.展开更多
文摘Heartburn is a common symptom shared by both gastroesophageal reflux disease(GERD)and functional heartburn(FHB),which can make it challenging to differentiate between the two conditions.However,examining oral manifestations of GERD can be a cost-effective and readily available method to aid in this differentiation process.It may serve as a valuable tool in distinguishing GERD from FHB.
基金This work is supported by the National Natural Science Foundation of China(No.12375296)the Key Laboratory of Nuclear Data Foundation(No.JCKY2022201C153)+2 种基金the Natural Science Foundation of Hunan Province of China(Nos.2021JJ40444,2020RC3054)the Youth Innovation Promotion Association CAS(No.2023014)the National Key Research and Development Plan(No.2022YFA1603303).
文摘The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.
基金supported by the National Natural Science Foundation of China(No.11675075)Youth Talent Project of Hunan Province,China(No.2018RS3096)+1 种基金Independent Research Project of Key Laboratory of Plasma Physics,CAEP(No.JCKYS2020212006)Innovation and Entrepreneurship Training Program for College Students of University of South China(No.X2019083)。
文摘The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.
基金supported by the National Natural Science Foundation of China (Nos.11921006,U2230133)Beijing Outstanding Young Scientists Program+2 种基金National Grand Instrument Project (No.2019YFF01014400)National Key R&D Program of China (No.2022YFA1603303)Open Foundation of Key Laboratory of High Power Laser and Physics,Chinese Academy of Sciences (No.SGKF202104)。
文摘In this study,we theoretically investigate the feasibility of using laser-wakefield accelerated(LWFA)electrons for the photonuclear measurement of nuclear isomers according to the characteristics of the electrons obtained from LWFA experiments conducted at the Compact Laser-Plasma Accelerator(CLAPA)laboratory.The experiments at the CLAPA show that a stable electron beam with an energy of 78-135 MeV and a charge of 300-600 pC can be obtained.The bremsstrahlung spectra were simulated using Geant4,which suggests that a bremsstrahlung source with a peak intensity of 10^(19) photons/s can be generated.Theoretical calculations of isomer production cross sections from the photonuclear reactions on six target nuclei,^(197)Au,^(180)Hf,^(159)Tb,^(115)In,^(103)Rh,and ^(90)Zr,were performed and compared with the available experimental data in EXFOR,which suggest that further experiments are required for a series of photonuclear reaction channels.Flux-averaged cross sections and isomer ratios(IR)resulting from such bremsstrahlung sources are theoretically deduced.The results suggest that IR measurements can be used to constrain nuclear components,such asγstrength function and optical model potential.In addition,the detection of the decay characteristics was evaluated with Geant4 simulations.The use of the LWFA electron beam and its bremsstrahlung for photonuclear studies involving nuclear isomers is anticipated.
基金supported by the Key Laboratory of Nuclear Data Foundation(No.JCKY2022201C153)National Natural Science Foundation of China(No.11505216),Educational Commission of Hunan Province of China(No.19B488)Natural Science Foundation of Hunan Province of China(Nos.2021JJ40444 and 2020RC3054).
文摘To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross section spectrometer(NTOX), a dedicated lithium-containing scintillation detector has been developed on the Back-n beam line at the China Spallation Neutron Source. The Fast Scintillator-based Neutron Total Cross Section(FAST) spectrometer has been designed based on a Cs2Li La Br6(CLLB) scintillator considering the γ-ray flash and neutron environment on the Back-n beam line. The response of the CLLB scintillator to neutrons and γ-rays was evaluated with different 6Li/7 Li abundance ratios using Geant4. The neutron-γdiscrimination performance of the CLLB has been simulated considering different scintillation parameters, physical designs,and light readout modes. A cubic 6Li-enriched( > 90%) CLLB scintillator, which has a thickness of 4-9 mm and side length of no less than 50 mm to cover the Φ 50 mm neutron beam at the spectrometer position, has been proposed coupling to a side readout SiPM array to construct the FAST spectrometer. The developed simulation techniques for neutron-γ discrimination performance could provide technical support for other neutron-induced reaction measurements on the Back-n beam line.
基金This work was supported by the National Natural Science Foundation of China(Nos.U1832182,11875328,11761161001,and U2032137)the Natural Science Foundation of Guangdong Province,China(Nos.18zxxt65 and 2022A1515011184)+3 种基金the Science and Technology Development Fund,Macao SAR(Grant No.008/2017/AFJ)the Macao Young Scholars Program of China(No.AM201907)the China Postdoctoral Science Foundation(Nos.2016LH0045 and 2017M621573)the Fundamental Research Funds for the Central Universities(Nos.22qntd3101 and 2021qntd28).
文摘The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture events were detected using four C_(6)D_(6) detectors.The pulse-height weighting technique and double-bunch unfolding method based on Bayesian theory were used in the data analysis.Background deductions,normalization,and corrections were carefully considered to obtain reliable measurement results.The multilevel R-matrix Bayesian code SAMMY was used to extract the resonance parameters in the resolved resonance region(RRR).The average cross sections in the unresolved resonance region(URR)were obtained from 10 to 400 keV.The experimental results were compared with data from several evaluated libraries and previous experi-ments in the RRR and URR.The TALYS code was used to describe the average cross sections in the URR.The astrophysical Maxwell average cross sections(MACSs)of ^(79,81)Br from kT=5 to 100 keV were calculated over a sufficiently wide range of neutron energies.At a thermal energy of kT=30 keV,the MACS value for ^(79)Br 682±68 mb was in good agreement with the KADoNiS v1.0 recommended value.By contrast,the value of 293±29 mb for ^(81)Br was substantially higher than that of the evaluated database and the KADoNiS v1.0 recommended value.
基金Supported by the Hainan Provincial Natural Science Foundation of China,No.822RC828.
文摘Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.
基金This work was supported by the National Key R&D Program of China(No.2022YFA1603300)the National Natural Science Foundation of China(Nos.U2230133)+2 种基金the Independent Research Project of the Key Laboratory of Plasma Physics,CAEP(No.JCKYS2021212009)the Open Fund of the Key Laboratory of Nuclear Data,CIAE(No.JCKY2022201C152)Hengyang Municipal Science and Technology Project(No.202150054076).
文摘Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this study,we propose the extraction of PNCS distributions using a combination of gamma activation and reaction yield ratio methods.To verify the validity of the proposed extraction method,experiments for generating^(62,64)Cu and^(85m,87m)Sr isotopes via laser-induced pho-toneutron reactions were performed,and the reaction yields of these isotopes were obtained.Using the proposed extraction method,the PNCS distributions of^(63)Cu and^(86)Sr isotopes(leading to^(85m)Sr isotope production)were successfully extracted.These extracted PNCS distributions were benchmarked against available PNCS data or TALYS calculations,demonstrating the validity of the proposed extraction method.Potential applications for predicting the PNCS distributions of the 30 iso-topes are further introduced.We conclude that the proposed extraction method is an effective complement to the available sophisticated methods for measuring and evaluating PNCS data.
基金support by the Scientific Research Start-up Funds for introducing Talent in the Sichuan University (20822041C4014)National Science and Technology Major Project of China (2017-I-0004-0004)。
文摘The flow and heat transfer characteristics of n-decane in the sub-millimeter spiral tube(SMST) at supercritical pressure(p = 3 MPa) are studied by the RNG k-ε numerical model in this paper. The effects of various Reynolds numbers(Re) and structural parameters pitch(s) and spiral diameter(D) are analyzed.Results indicate that the average Nusselt numberNu and friction factorNu increase with an increase in Re, and decrease with an increase in D/d(tube diameter). In terms of the structural parameter s/d, it is found that as s/d increases, the Nu first increase, and then decrease. and the critical structural parameter is s/d = 4. Compared with the straight tube, the SMST can improve Nu by 34.8% at best, while it can improve Nu by 102.1% at most. In addition, a comprehensive heat transfer coefficient is applied to analyze the thermodynamic properties of SMST. With the optimal structural parameters of D/d = 6 and s/d = 4, the comprehensive heat transfer factor of supercritical pressure hydrocarbon fuel in the SMST can reach 1.074. At last, correlations of the average Nusselt number and friction factor are developed to predict the flow and heat transfer of n-decane at supercritical pressure.
基金Supported by the Science and Technology Research Project of Sichuan Provincial Administration of Traditional Chinese Medicine,No.2021MS164Scientific research project of Sichuan Medical Association,No.S21012。
文摘BACKGROUND Lung invasive mucinous adenocarcinoma(LIMA),formerly referred to as mucinous bronchioloalveolar carcinoma,is a rare disease that usually presents as bilateral lung infiltration,is unsuitable for surgery and radiotherapy,and shows poor response to conventional chemotherapy.CASE SUMMARY We report a 56-year-old Chinese man with a history of smoking and epidermal growth factor receptor mutation-positivity who was initially misdiagnosed as severe pneumonia,but was ultimately diagnosed as a case of invasive mucinous adenocarcinoma of the lung by computed tomography-guided percutaneous lung biopsy.Bronchorrhea and dyspnea were improved within 24 h after initiation of gefitinib therapy and the radiographic signs of bilateral lung consolidation showed visible improvement within 30 d.After more than 11 months of treatment,there is no evidence of recurrence or severe adverse events.CONCLUSION Although the precise mechanism of the antitumor effects of gefitinib are not clear,our experience indicates an important role of the drug in LIMA and provides a reference for the diagnosis and treatment of this disease.
文摘Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung cancer(NSCLC)cells.Methods NSCLC tissues and adjacent normal tissues from 60 patients with NSCLC adenocarcinoma were obtained via pathological biopsy or intraoperative resection.Several cell lines were cultured in vitro,including the human normal lung epithelial cell line BEAS-2B and human NSCLC cell lines A549,SPCA-1,PC-9,and 95-D.miR-183-5p and FOXO1 mRNA expression in tissues and cells were detected by qRT-PCR;the corresponding correlations in NSCLC tissues were analyzed using the Pearson test,and the relationship between miR-183-5p expression and clinicopathological parameters was analyzed.The miR-183-5p-mediated regulation of FOXO1 was verified by bioinformatics prediction alongside double luciferase,RNA-binding protein immunoprecipitation(RIP)assay,and pull-down experiments.A549 cells were divided into control,anti-miR-NC,anti-miR-183-5p,miR-NC,miR-183-5p,miR-183-5p+pcDNA3.1,and miR-183-5p+pcDNA3.1-FOXO1 groups.Cell proliferation,invasion,migration,apoptosis,and cell cycle distribution were detected using an MTT assay,clone formation assay,Transwell assay,scratch test,and flow cytometry,respectively.The expression of EMT-related proteins in the cells was analyzed by western blotting.The effect of miR-185-3p silencing on the development of transplanted tumors was detected by analyzing tumor formation in nude mice.Results miR-183-5p expression was significantly higher in NSCLC tissues and cells than in adjacent normal tissues,whereas FOXO1 mRNA expression was significantly down-regulated.There was a significant negative correlation between miR-183-5p and FOXO1 mRNA in NSCLC tissues(P<0.05).Additionally,the expression of miR-183-5p was significantly correlated with tumor size,tumor differentiation,and tumor-node-metastasis stage in patients with NSCLC(P<0.05).miR-183-5p targeted and inhibited FOXO1 expression.Compared to the anti-miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the anti-miR-183-5p group,whereas the protein expression of E-cadherin andα-catenin and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion were significantly lower in the anti-miR-183-5p group(P<0.05).Compared to the miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells in the miR-183-5p group were significantly higher,whereas the E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly lower;furthermore,the frequency of colony formation and invasion were significantly higher in the miR-183-5p group(P<0.05).Compared with the miR-183-5p+pcDNA3.1 group,the OD value,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group,whereas E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion was significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group(P<0.05).Overall,silencing miR-185-3p inhibited the growth of transplanted tumors and promoted FOXO1 expression.Conclusion Overexpression of miR-183-5p can inhibit apoptosis and promote the proliferation,migration,invasion,and EMT,of NSCLC cells by down-regulating FOXO1 expression.
基金Supported by Grants from the Natural Science Foundation of China, No. 81060201Natural Science Foundation of Guangxi,No. 2011GXNSFA018273 and No. 2013GXNSFAA019163the Key Health Science Foundation of Guangxi, No. 1298003-2-6
文摘AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10 -4) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10-4), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10-4). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10-6). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10-7). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.
基金Project(41773089)supported by the National Natural Science Foundation of ChinaProject(2017SK2255)supported by the Key R&D Program of Hunan Province,China+2 种基金Project(2015CNERC-CTHMP-05)supported by the Opening Foundation of the Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,ChinaProject(CX20190136)supported by the Hunan Provincial Innovation Foundation for Postgraduates,ChinaProject(CSUZC201808)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China.
文摘The effects of photogenerated-hole scavengers(ascorbic acid,oxalic acid,humic acid and citric acid)on chalcopyrite bioleaching in the presence of visible light were studied using Acidithiobacillus ferrooxidans(A.ferrooxidans).Four sets of bioleaching experiments were performed:(1)visible light+0 g/L scavenger,(2)visible light+0.1 g/L of different scavenger(ascorbic acid,oxalic acid,humic acid and citric acid),(3)dark+0.1 g/L of different scavenger(ascorbic acid,oxalic acid,humic acid and citric acid),and(4)dark+0 g/L scavenger(control group).The results showed that ascorbic acid and oxalic acid could act as photogenerated-hole scavengers and significantly enhance chalcopyrite bioleaching under visible light.The dissolved copper in the light group without scavenger was only 18.7%higher than that of the control group.The copper extraction rates of the light groups with oxalic acid and ascorbic acid were respectively 30.1%and 32.5%higher than those of the control group.Scanning electron microscopy(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FT-IR)analyses indicated that ascorbic acid and oxalic acid as photogenerated-hole scavenger could capture photo-generated holes and inhibit jarosite formation on the chalcopyrite surface,thereby enhancing bioleaching of chalcopyrite under visible light.
基金financial support from the High Technology Research and Development Program of China (2013AA102501)the National Key Technology Research and Development Program (2014BAD08B08)the China Agriculture Research System (CARS-41-G03,CARS-41-Z17)
文摘Background: The feed conversion ratio(FCR) and residual feed intake(RFI) are common indexes in measuring feed efficiency for livestock. RFI is a feed intake adjusted for requirements for maintenance and production so these two traits are related. Similarly, FCR is related to feed intake and weight gain because it is their ratio. Cholecystokinin type A receptor(CCKAR) plays an important role in animal digestive process. We examined the interplay of these three parameters in a local Chinese chicken population.Results: The feed intake(FI) and body weights(BW) of 1,841 individuals were monitored on a daily basis from 56 to 105 d of age. There was a strong correlation between RFI and average daily feed intake(ADFI) and a negative correlation between the FCR and daily gain(r=-0.710). Furthermore, we identified 51 single nucleotide polymorphisms(SNPs) in the CCKAR and 4 of these resulted in amino acid mutations. The C334A mutation was specifically associated with FI and the expected feed intake(EFI)(P < 0.01) and significantly associated with the average daily gain(ADG)(P < 0.05). G1290A was significantly associated with FI and EFI(P < 0.05).Conclusion: FCR is apply to weight selecting, and RFI is more appropriate if the breeding focus is feed intake. And C334A and G1290A of the CCKAR gene can be deemed as candidate markers for feed intake and weight gain.
基金supported by the National Key Research and Development Program of China(2016YFA0202603)the National Basic Research Program of China(2013CB934103)+5 种基金the National Natural Science Foundation of China(51521001,51602239)the National Natural Science Fund for Distinguished Young Scholars(51425204)Yellow Crane Talent(Science&Technology)Program of Wuhan Citythe Fundamental Research Funds for the Central Universities(WUT:2016III001,2016III003,2016IVA090)the Programme of Introducing Talents of Discipline to Universities(B17034)support from the Lorraine Region(nowpart of Grand Est Region)Cooperation Research Lorraine/Hubei Program 2015/2017
文摘In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostructures including antimony selenide(Sb_2Se_3) nanowires and selenium(Se) microrods can be achieved by merely varying the volume ratio of ethylene glycol(EG) and H_2O free from expensive chemical and additional surfactant. The achieved uniform Sb_2Se_3 nanowire is single crystalline along [001]growth direction with a diameter of 100 nm and a length up to tens of micrometers. When evaluated as an anode of lithium-ion battery, Sb_2Se_3 nanowire can deliver a high reversible capacity of 650.2 m Ah g^(-1) at 100 mA g^(-1) and a capacity retention of 63.8% after long-term 1000 cycles at 1000 mA g^(-1), as well as superior rate capability(389.5 m Ah g^(-1) at 2000 mA g^(-1)). This easy solvent-mediated microwave synthesis approach exhibits its great universe and importance towards the fabrication of high-performance metal chalcogenide electrode materials for future low-cost, large-scale energy storage systems.
基金supported by the National Natural Science Foundation of China(Nos.11405083 and 11675075)the Young Talent Project of the University of South Chinathe Extreme Light Infrastructure-Nuclear Physics(ELI-NP)-Phase I,a project co-financed by the European Union through the European Regional Development Fund
文摘For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or experimental database are chosen as input data.For checking the validity of the use of the data-based photonuclear algorithm,benchmarking simulations are presented in detail.We calculate photonuclear cross sections or reaction yield for ~9Be,^(48)Ti,^(133)Cs,and ^(197)Au and compare them with experimental data in the region of incident photon energy below ~30 MeV.While Geant4 can hardly reproduce photonuclear experimental data,results obtained from the data-based photonuclear algorithm are found in good agreement with experimental measurements.Potential application in estimation of specific activity of radioisotopes is further discussed.We conclude that the developed data-based photonuclear algorithm is suitable for an accurate prediction of photoninduced neutron or proton productions.
基金supported by Extreme Light Infrastructure-Nuclear Physics(ELI-NP)-Phase Ia project co-financed by the European Union through the European Regional Development Fund+1 种基金the National Natural Science Foundation of China(No.11405083)the Young Talent Project of the University of South China
文摘Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu isotope through a^(65)Cu(γ,n) reaction using high-intensity γ-beams produced at the Extreme Light InfrastructureNuclear Physics facility(ELI-NP). The specific activity for^(64)Cu was obtained as a function of target geometry, irradiation time, and electron beam energy, which translates into γ-beam energy. Optimized conditions for the generation of^(64)Cu isotopes at the ELI-NP were discussed. We estimated that an achievable saturation specific activity is of the order of 1–2 m Ci/g for thin targets(radius 1–2 mm,thickness 1 cm) and for a γ-beam flux of 10^(11) s ~1. Based on these results, the ELI-NP could provide great potential for the production of some innovative radioisotopes of medical interest in sufficient quantities suitable for nuclear medicine research.
基金supported by the Natural Science Foundation of Hunan Province(No.2018JJ1041)National Natural Science Foundation of China(Nos.51774332,U1932129,51804350 and51934009)。
文摘Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.Therefore,a novel method of using hematite to inhibit chalcopyrite biodissolution was proposed and verified.The results indicated that chalcopyrite biodissolution could be significantly inhibited by hematite,which consequently decreased the formation of AMD.In the presence of hematite,the final biodissolution rate of chalcopyrite decreased from 57.9%to 44.4%at 20 day.This in turn suggested that the formation of AMD was effectively suppressed under such condition.According to the biodissolution results,mineral composition and morphology analyses,and electrochemical analysis,it was shown that hematite promoted the formation and accumulation of passivation substances(jarosite and Cu2-xS)on chalcopyrite surface,thus inhibiting the biodissolution of chalcopyrite and limiting the formation of AMD.
