Hepatic ischemia-reperfusion injury(HIRI)is characterized by mitochondrial dysfunction and oxidative stress.Monitoring mitochondrial hydrogen peroxide(mtH_(2)O_(2))levels in real-time through super-resolution imaging ...Hepatic ischemia-reperfusion injury(HIRI)is characterized by mitochondrial dysfunction and oxidative stress.Monitoring mitochondrial hydrogen peroxide(mtH_(2)O_(2))levels in real-time through super-resolution imaging is crucial for elucidating its distribution in live cells and its mechanism of action during HIRI.However,low-background fluorogenic probes have been overlooked in the context of super-resolution imaging.In this study,we developed a low-background fluorogenic probe(MitoWG)with the potential for super-resolution morphology-correlated mitochondrial identification to track the fluctuates of mtH_(2)O_(2)in HIRI.Activation of the desirable fluorescence properties of the probe by mtH_(2)O_(2)was confirmed using structural illumination microscopy(SIM),enabling high-quality mitochondrial imaging with exceptional specificity and sensitivity.Fluctuations in mtH_(2)O_(2)levels were successfully observed in both cellular and rat models of HIRI.Furthermore,we associated the decline in mitochondrial redox homeostasis with accelerated mtH_(2)O_(2)production during HIRI,which triggered mitophagy deficiency and led to cell death.In conclusion,Mito-WG possesses excellent photophysical and low-background properties for SIM imaging,making it a promising tool for mtH_(2)O_(2)tracking in HIRI research and clinical diagnosis.展开更多
Founded in 2009,the China Dark Matter Experiment(CDEX)collaboration was dedicated to the detection of dark matter(DM)and neutrinoless double beta decay using high-purity germanium(HPGe)detectors in the China Jinping U...Founded in 2009,the China Dark Matter Experiment(CDEX)collaboration was dedicated to the detection of dark matter(DM)and neutrinoless double beta decay using high-purity germanium(HPGe)detectors in the China Jinping Underground Laboratory.HPGe detectors are characterized by a high energy resolution,low analysis threshold,and low radioactive background,making them an ideal platform for the direct detection of DM.Over the years,CDEX has accumulated a massive amount of experimental data,based on which various results on DM detection and neutrinoless double beta decay have been presented.Because the dataset was collected in a low-background environment,apart from the analysis of DM-related physical channels,it has great potential as an indicator in other rare physical events searches.Furthermore,by providing raw pulse shapes,the dataset can serve as a tool for effectively understanding the internal mechanisms of HPGe detectors.展开更多
A low-background γ spectrometer named the Gamma spectrometer for Nuclear Activation Studies(GNAS)was developed to detect scarce γ radioactivity,with a special focus on conducting activation experiments in nuclear as...A low-background γ spectrometer named the Gamma spectrometer for Nuclear Activation Studies(GNAS)was developed to detect scarce γ radioactivity,with a special focus on conducting activation experiments in nuclear astrophysics.It consisted of a well-type HPGe detector surrounded by optimized multi-layer shielding,which reduced the laboratory background counting rate by 99.5%and enabled a sensitivity edge as low as 0.044 Bq for the 477.6 KeV γ line of ^(7)Be.The near 4π geometry of the HPGe detector introduces a severe true coincidence summing(TCS)effect along with its high detection efficiency.To determine the intrinsic detection efficiency and correct for the TCS effect,a Monte Carlo simulation method was developed with the Geant4 toolkit.The detector model was optimized by matching the simulated full energy peak(FEP)statistics with those of a ^(137)Cs monoenergetic source and calibrated ^(55,57,58)Co sources produced by low-energy proton beam bombardment of natural iron.The intrinsic detection efficiency curve was obtained,and an algorithm for the correction of the TCS effect was programmed using decay data from the ENSDF library and Nuclear Wallet Cards.The GNAS fulfills the requirements of the ongoing activation measurement of proton-and alpha-induced reactions in nuclear astrophysics on the ground and at the Jinping Underground Nuclear Astrophysics(JUNA)facility.展开更多
光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boos...光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boost电路中的占空比、输出负载、电感和电容参数,引入蚁群算法对Boost电路参数进行优化,增强搜索过程的多样性和探索性。采用随机化步长,通过模糊控制器,实现对最大功率点跟踪控制。仿真结果表明,当直流母线电压存在扰动时,所提方法可以迅速作出反应,并将电压恢复到正常水平;当光照强度骤减后,仅需要0.9 s左右的时间就可以稳定在最大功率点附近。展开更多
根据掺杂稀土离子固体材料激光冷却四能级理论模型,冷却样品的背景吸收系数是影响样品激光冷却性能的关键参数.为了探究冷却样品(以Yb^(3+):LuLiF_(4)(LLF)为例)中背景吸收系数与温度的函数关系,设计了在低温条件下获取冷却晶体背景吸...根据掺杂稀土离子固体材料激光冷却四能级理论模型,冷却样品的背景吸收系数是影响样品激光冷却性能的关键参数.为了探究冷却样品(以Yb^(3+):LuLiF_(4)(LLF)为例)中背景吸收系数与温度的函数关系,设计了在低温条件下获取冷却晶体背景吸收系数的低温-激光诱导温度调制光谱(laser-induced temperature modulation spectrum,LITMoS)实验方案.依据热负载理论推导了低温条件下冷却效率的实验计算公式,并对热负载来源进行理论分析.分析结果表明,接触传导热负载是低温-LITMoS实验样品热负载的主要来源.实验方案中采用液氮低温恒温器和特殊设计的冷指结构去控制晶体的温度,利用时间阀门-差分荧光光谱测温法对晶体进行非接触式测温获得晶体的温降,并对实验设计方案进行了可行性分析,计算了对应波长下的样品冷却效率.结果表明,在低温条件下实验设计方案可以测量样品背景吸收系数与温度之间的函数关系,制冷效率的测试结果符合光学制冷理论模型的预测.展开更多
基金supported by the National Natural Science Foundation of China(62288102,22077101,62475216)the Natural Science Foundation of Shaanxi Province(2022JM-130)+7 种基金the Key Research and Development Program of Shaanxi(2024GH-ZDXM-37)the Innovation Capability Support Program of Shaanxi(2023-CX-PT-23)the Natural Science Basic Research Program of Shaanxi(2024JC-YBQN-0919)the Open Project Program of the Analytical&Testing Center of Northwestern Polytechnical University(2020T018)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZC20240889)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2022034,CX2023098)the Startup Program of XMU(L.L.)Fundamental Research Funds for the Central Universities。
文摘Hepatic ischemia-reperfusion injury(HIRI)is characterized by mitochondrial dysfunction and oxidative stress.Monitoring mitochondrial hydrogen peroxide(mtH_(2)O_(2))levels in real-time through super-resolution imaging is crucial for elucidating its distribution in live cells and its mechanism of action during HIRI.However,low-background fluorogenic probes have been overlooked in the context of super-resolution imaging.In this study,we developed a low-background fluorogenic probe(MitoWG)with the potential for super-resolution morphology-correlated mitochondrial identification to track the fluctuates of mtH_(2)O_(2)in HIRI.Activation of the desirable fluorescence properties of the probe by mtH_(2)O_(2)was confirmed using structural illumination microscopy(SIM),enabling high-quality mitochondrial imaging with exceptional specificity and sensitivity.Fluctuations in mtH_(2)O_(2)levels were successfully observed in both cellular and rat models of HIRI.Furthermore,we associated the decline in mitochondrial redox homeostasis with accelerated mtH_(2)O_(2)production during HIRI,which triggered mitophagy deficiency and led to cell death.In conclusion,Mito-WG possesses excellent photophysical and low-background properties for SIM imaging,making it a promising tool for mtH_(2)O_(2)tracking in HIRI research and clinical diagnosis.
基金supported by the National Key Research and Development Program of China(Nos.2023YFA1607100 and 2022YFA1605000)the National Natural Science Foundation of China(No.12322511)。
文摘Founded in 2009,the China Dark Matter Experiment(CDEX)collaboration was dedicated to the detection of dark matter(DM)and neutrinoless double beta decay using high-purity germanium(HPGe)detectors in the China Jinping Underground Laboratory.HPGe detectors are characterized by a high energy resolution,low analysis threshold,and low radioactive background,making them an ideal platform for the direct detection of DM.Over the years,CDEX has accumulated a massive amount of experimental data,based on which various results on DM detection and neutrinoless double beta decay have been presented.Because the dataset was collected in a low-background environment,apart from the analysis of DM-related physical channels,it has great potential as an indicator in other rare physical events searches.Furthermore,by providing raw pulse shapes,the dataset can serve as a tool for effectively understanding the internal mechanisms of HPGe detectors.
基金supported by the National Key Research and Development Project(No.2022YFA1602301)the National Natural Science Foundation of China(Nos.U2267205 and 12275361)the Continuous-Support Basic Scientific Research Project.
文摘A low-background γ spectrometer named the Gamma spectrometer for Nuclear Activation Studies(GNAS)was developed to detect scarce γ radioactivity,with a special focus on conducting activation experiments in nuclear astrophysics.It consisted of a well-type HPGe detector surrounded by optimized multi-layer shielding,which reduced the laboratory background counting rate by 99.5%and enabled a sensitivity edge as low as 0.044 Bq for the 477.6 KeV γ line of ^(7)Be.The near 4π geometry of the HPGe detector introduces a severe true coincidence summing(TCS)effect along with its high detection efficiency.To determine the intrinsic detection efficiency and correct for the TCS effect,a Monte Carlo simulation method was developed with the Geant4 toolkit.The detector model was optimized by matching the simulated full energy peak(FEP)statistics with those of a ^(137)Cs monoenergetic source and calibrated ^(55,57,58)Co sources produced by low-energy proton beam bombardment of natural iron.The intrinsic detection efficiency curve was obtained,and an algorithm for the correction of the TCS effect was programmed using decay data from the ENSDF library and Nuclear Wallet Cards.The GNAS fulfills the requirements of the ongoing activation measurement of proton-and alpha-induced reactions in nuclear astrophysics on the ground and at the Jinping Underground Nuclear Astrophysics(JUNA)facility.
文摘光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boost电路中的占空比、输出负载、电感和电容参数,引入蚁群算法对Boost电路参数进行优化,增强搜索过程的多样性和探索性。采用随机化步长,通过模糊控制器,实现对最大功率点跟踪控制。仿真结果表明,当直流母线电压存在扰动时,所提方法可以迅速作出反应,并将电压恢复到正常水平;当光照强度骤减后,仅需要0.9 s左右的时间就可以稳定在最大功率点附近。
文摘根据掺杂稀土离子固体材料激光冷却四能级理论模型,冷却样品的背景吸收系数是影响样品激光冷却性能的关键参数.为了探究冷却样品(以Yb^(3+):LuLiF_(4)(LLF)为例)中背景吸收系数与温度的函数关系,设计了在低温条件下获取冷却晶体背景吸收系数的低温-激光诱导温度调制光谱(laser-induced temperature modulation spectrum,LITMoS)实验方案.依据热负载理论推导了低温条件下冷却效率的实验计算公式,并对热负载来源进行理论分析.分析结果表明,接触传导热负载是低温-LITMoS实验样品热负载的主要来源.实验方案中采用液氮低温恒温器和特殊设计的冷指结构去控制晶体的温度,利用时间阀门-差分荧光光谱测温法对晶体进行非接触式测温获得晶体的温降,并对实验设计方案进行了可行性分析,计算了对应波长下的样品冷却效率.结果表明,在低温条件下实验设计方案可以测量样品背景吸收系数与温度之间的函数关系,制冷效率的测试结果符合光学制冷理论模型的预测.
