At high count rates,pile-up events involving neutron and gamma signals result in inaccurate neutron counting and distortions in the energy spectrum.Additionally,a bipolar cusp-like pulse shaping algorithm based on an ...At high count rates,pile-up events involving neutron and gamma signals result in inaccurate neutron counting and distortions in the energy spectrum.Additionally,a bipolar cusp-like pulse shaping algorithm based on an unfolding synthesis technique was proposed.This algorithm exhibits a narrow pulse shape,and the parallel design of the dual algorithms enables the recovery of pile-up signal amplitudes while preserving the distinct characteristics of neutron and gamma signals.The simplicity of the algorithm facilitates real-time neutron/gamma discrimination on an FPGA,allowing the energy spectra to be updated with each incoming signal.Furthermore,the algorithm can be readily tailored to various experimental conditions by adjusting the decay time constants.Multi-objective optimization reduces the need for manual parameter tuning by rapidly identifying the optimal parameters.Testing with a^(241)Am-Be neutron source and a NaIL scintillator yielded a figure of merit(FoM)value of 2.11 and produced a clear energy spectrum even at high count rates.展开更多
The early developmental period is a critical window during which brain cells mature and contribute to both brain development and later life functions.Gamma-aminobutyric acid(GABA),recognized as a major neurotransmitte...The early developmental period is a critical window during which brain cells mature and contribute to both brain development and later life functions.Gamma-aminobutyric acid(GABA),recognized as a major neurotransmitter,plays a crucial role in coordinating synapse formation,neuronal proliferation,and migration during this time.展开更多
Gamma delta(γδ)T cells and invariant natural killer T(iNKT)cells are unconventional T cells with limited T cell receptor(TCR)diversity.Both can recognize lipid or non-peptide antigens,often through cluster of differ...Gamma delta(γδ)T cells and invariant natural killer T(iNKT)cells are unconventional T cells with limited T cell receptor(TCR)diversity.Both can recognize lipid or non-peptide antigens,often through cluster of differentiation 1d(CD1d),rapidly produce cytokines,express natural killer(NK)cell markers,and are mainly found in mucosal and barrier tissues.Acting as a bridge between innate and adaptive immunity,they show great promise for cancer immunotherapy.DevelopingγδT and iNKT cells for treatment involves shared features like thymic origin,MHC-independent recognition,rapid cytotoxicity,low graft-vs.-host disease(GvHD)risk,ex vivo expansion,and genetic modification,making them suitable for adoptive cell therapies.While their mechanisms are similar,iNKT cells rely on CD1d-mediated antigen presentation,provided by CD1d-expressing antigen-presenting cells(APCs)or engineered cell lines,to activate their invariant TCR and expand effectively.Chimeric antigen receptors(CAR)-induced functional activations make these cell types viable alternatives to conventional cell-based or CAR-T therapies with additional safety benefits.Early clinical trials have shown encouraging results,and their completion will confirm their potential for future treatments.This review explores the biology and mechanisms ofγδT and iNKT cells,focusing on how APCs,cytokines,feeder cells,and CARs contribute to boosting their cytotoxic function,cytokine production,and expansion,enhancing their promise as cancer immunotherapies.It also explores the advancements and challenges in developingγδT and iNKT cell-based immunotherapies,with preclinical and early clinical outcomes offering promising insights.展开更多
The multiple nuclides identification algorithm with low consumption and strong robustness is crucial for rapid radioactive source searching.This study investigates the design of a low-consumption multiple nuclides ide...The multiple nuclides identification algorithm with low consumption and strong robustness is crucial for rapid radioactive source searching.This study investigates the design of a low-consumption multiple nuclides identification algorithm for portable gamma spectrometers.First,the gamma spectra of 12 target nuclides(including the background case)were measured to create training datasets.The characteristic energies,obtained through energy calibration and full-energy peak addresses,are utilized as input features for a neural network.A large number of single-and multiple-nuclide training datasets are generated using random combinations and small-range drifting.Subsequently,a multi-label classification neural network based on a binary cross-entropy loss function is applied to export the existence probability of certain nuclides.The designed algorithm effectively reduces the computation time and storage space required by the neural network and has been successfully implemented in a portable gamma spectrometer with a running time of t_(r)<2 s.Results show that,in both validation and actual tests,the identification accuracy of the designed algorithm reaches 94.8%,for gamma spectra with a dose rate of d≈0.5μSv∕h and a measurement time t_(m)=60 s.This improves the ability to perform rapid on-site nuclide identification at important sites.展开更多
Energy-variable gamma-rays are produced in Laser Compton Slant-scattering mode at the Shanghai Laser Electron Gamma Source(SLEGS),a beamline of the Shanghai Synchrotron Radiation Facility(also called Shanghai Light So...Energy-variable gamma-rays are produced in Laser Compton Slant-scattering mode at the Shanghai Laser Electron Gamma Source(SLEGS),a beamline of the Shanghai Synchrotron Radiation Facility(also called Shanghai Light Source).Based on the SLEGS energy-variable gamma-ray beam,a positron generation system composed of a gamma-ray-driven section,positron-generated target,magnet separation section and positron experimental section was designed for SLEGS.Geant4 simulation results show that the energy tunable positron beam in the energy range of 1–12.9 MeV with a flux of 3.7×10^(4)–6.9×10^(5)e^(+)∕s can be produced in this positron generation system.The positron beam generation and separation provide favorable experimental conditions for conducting nondestructive positron testing on SLEGS in the future.The positron generation system is currently under construction and will be completed in 2025.展开更多
Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Cu...Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.展开更多
We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chi...We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chiral anomaly of QCD and the spontaneously broken symmetry are invoked to explain the non-conservation of the axion current. From the coupling form factors, the axion emissivities ϵacan be derived, from which fluxes can be determined. We predict a photon flux, which may be detectable by Fermi LAT, and limits on the QCD mass ma. In this model, axions decay to gamma rays in a 2-photon vertex. We may determine the expected fluxes from the theoretical emissivity. The sensitivity curve from the Fermi Large Area Telescope (Fermi LAT) would allow axion mass constraints for neutron stars as low as ma≤10−14eV 95% C.L. Axions could thus be detectable in gamma rays for neutron stars as distant as 100 kpc. A signal from LIGO GWS 170817 could be placed from the NS-NS merger, which gives an upper limit of ma≤10−10eV.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(No.12075308)。
文摘At high count rates,pile-up events involving neutron and gamma signals result in inaccurate neutron counting and distortions in the energy spectrum.Additionally,a bipolar cusp-like pulse shaping algorithm based on an unfolding synthesis technique was proposed.This algorithm exhibits a narrow pulse shape,and the parallel design of the dual algorithms enables the recovery of pile-up signal amplitudes while preserving the distinct characteristics of neutron and gamma signals.The simplicity of the algorithm facilitates real-time neutron/gamma discrimination on an FPGA,allowing the energy spectra to be updated with each incoming signal.Furthermore,the algorithm can be readily tailored to various experimental conditions by adjusting the decay time constants.Multi-objective optimization reduces the need for manual parameter tuning by rapidly identifying the optimal parameters.Testing with a^(241)Am-Be neutron source and a NaIL scintillator yielded a figure of merit(FoM)value of 2.11 and produced a clear energy spectrum even at high count rates.
基金supported by the Center for Cognition and Sociality,Institute for Basic Science(IBS)(IBS-R001-D2)(to WK).
文摘The early developmental period is a critical window during which brain cells mature and contribute to both brain development and later life functions.Gamma-aminobutyric acid(GABA),recognized as a major neurotransmitter,plays a crucial role in coordinating synapse formation,neuronal proliferation,and migration during this time.
文摘Gamma delta(γδ)T cells and invariant natural killer T(iNKT)cells are unconventional T cells with limited T cell receptor(TCR)diversity.Both can recognize lipid or non-peptide antigens,often through cluster of differentiation 1d(CD1d),rapidly produce cytokines,express natural killer(NK)cell markers,and are mainly found in mucosal and barrier tissues.Acting as a bridge between innate and adaptive immunity,they show great promise for cancer immunotherapy.DevelopingγδT and iNKT cells for treatment involves shared features like thymic origin,MHC-independent recognition,rapid cytotoxicity,low graft-vs.-host disease(GvHD)risk,ex vivo expansion,and genetic modification,making them suitable for adoptive cell therapies.While their mechanisms are similar,iNKT cells rely on CD1d-mediated antigen presentation,provided by CD1d-expressing antigen-presenting cells(APCs)or engineered cell lines,to activate their invariant TCR and expand effectively.Chimeric antigen receptors(CAR)-induced functional activations make these cell types viable alternatives to conventional cell-based or CAR-T therapies with additional safety benefits.Early clinical trials have shown encouraging results,and their completion will confirm their potential for future treatments.This review explores the biology and mechanisms ofγδT and iNKT cells,focusing on how APCs,cytokines,feeder cells,and CARs contribute to boosting their cytotoxic function,cytokine production,and expansion,enhancing their promise as cancer immunotherapies.It also explores the advancements and challenges in developingγδT and iNKT cell-based immunotherapies,with preclinical and early clinical outcomes offering promising insights.
文摘The multiple nuclides identification algorithm with low consumption and strong robustness is crucial for rapid radioactive source searching.This study investigates the design of a low-consumption multiple nuclides identification algorithm for portable gamma spectrometers.First,the gamma spectra of 12 target nuclides(including the background case)were measured to create training datasets.The characteristic energies,obtained through energy calibration and full-energy peak addresses,are utilized as input features for a neural network.A large number of single-and multiple-nuclide training datasets are generated using random combinations and small-range drifting.Subsequently,a multi-label classification neural network based on a binary cross-entropy loss function is applied to export the existence probability of certain nuclides.The designed algorithm effectively reduces the computation time and storage space required by the neural network and has been successfully implemented in a portable gamma spectrometer with a running time of t_(r)<2 s.Results show that,in both validation and actual tests,the identification accuracy of the designed algorithm reaches 94.8%,for gamma spectra with a dose rate of d≈0.5μSv∕h and a measurement time t_(m)=60 s.This improves the ability to perform rapid on-site nuclide identification at important sites.
基金supported by the National Key Research and Development program(Nos.2022YFA1602404,2023YFA1606901)the National Natural Science Foundation of China(Nos.12275338,12388102,and U2441221)the Key Laboratory of Nuclear Data foundation(JCKY2022201C152)xm。
文摘Energy-variable gamma-rays are produced in Laser Compton Slant-scattering mode at the Shanghai Laser Electron Gamma Source(SLEGS),a beamline of the Shanghai Synchrotron Radiation Facility(also called Shanghai Light Source).Based on the SLEGS energy-variable gamma-ray beam,a positron generation system composed of a gamma-ray-driven section,positron-generated target,magnet separation section and positron experimental section was designed for SLEGS.Geant4 simulation results show that the energy tunable positron beam in the energy range of 1–12.9 MeV with a flux of 3.7×10^(4)–6.9×10^(5)e^(+)∕s can be produced in this positron generation system.The positron beam generation and separation provide favorable experimental conditions for conducting nondestructive positron testing on SLEGS in the future.The positron generation system is currently under construction and will be completed in 2025.
基金supported by the National Natural Science Foundation of China,No.82071254(to WZ).
文摘Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.
文摘We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chiral anomaly of QCD and the spontaneously broken symmetry are invoked to explain the non-conservation of the axion current. From the coupling form factors, the axion emissivities ϵacan be derived, from which fluxes can be determined. We predict a photon flux, which may be detectable by Fermi LAT, and limits on the QCD mass ma. In this model, axions decay to gamma rays in a 2-photon vertex. We may determine the expected fluxes from the theoretical emissivity. The sensitivity curve from the Fermi Large Area Telescope (Fermi LAT) would allow axion mass constraints for neutron stars as low as ma≤10−14eV 95% C.L. Axions could thus be detectable in gamma rays for neutron stars as distant as 100 kpc. A signal from LIGO GWS 170817 could be placed from the NS-NS merger, which gives an upper limit of ma≤10−10eV.
