A particle detector array designed for light-charged particles, known as the CsI-bowl, was built for exit channel selection for in-beam γ-ray spectroscopy experiments. This device is composed of 64 CsI(Tl) detectors,...A particle detector array designed for light-charged particles, known as the CsI-bowl, was built for exit channel selection for in-beam γ-ray spectroscopy experiments. This device is composed of 64 CsI(Tl) detectors, organized in a structure reminiscent of a tea-bowl. High quantum efficiency photodiodes, characterized by their minimal mass, were employed to collect scintillation light. Its design, construction, particle identification resolution, and its effectiveness in relation to exit channel selection are described in this paper. In source tests, the optimal figure of merit for the identification of α-particles and γ-rays using the charge comparison method was found to be 3.3 and 12.1 for CsI detectors coupled to photodiodes and avalanche photodiodes, respectively. The CsI-bowl demonstrated effectiveness in identifying particles, specifically the emission of protons and α-particles in the58Ni(19F, xpyn) fusion–evaporation reaction, thereby enabling the selection of the desired exit channels.展开更多
BACKGROUND:Post-infarct left ventricular free wall rupture(LVFWR)is not always an immediately catastrophic complication.The rupture can be subacute,allowing time for diagnosis and intervention.Accordingly,early recogn...BACKGROUND:Post-infarct left ventricular free wall rupture(LVFWR)is not always an immediately catastrophic complication.The rupture can be subacute,allowing time for diagnosis and intervention.Accordingly,early recognition of the entity may be lifesaving.METHODS:We present an electrocardiogram(ECG)change pattern in two cases,which was erroneously attributed to ischemia.Two women in their 80s were admitted to our institute after experiencing the sudden onset of chest pain.They were managed as anterior ST-segment elevation myocardial infarction without reperfusion treatment.Unfortunately,they experienced a recurrence of severe chest pain with cardiogenic shock during hospitalisation.The ECG recorded at that time showed a ST-segment re-elevation in infract-related leads.RESULTS:The two cases were regrettably received a misjudgement of reinfarction at first,and one of the patients even was administrated with tirofi ban.Afterwards the diagnosis of subacute LVFWR was made through antemortem echocardiography.CONCLUSION:New ST-segment elevation(STE)in infarct-associated leads,coupled with recurrence of chest pain and new-onset hypotension,may constitute the premonitory signs of a subacute LVFWR.展开更多
A gas detector 140×140×140 mm^(3)in size,termed the compact active target time projection chamber(CAT-TPC),was developed in this study to measure resonant scattering associated with cluster structures in uns...A gas detector 140×140×140 mm^(3)in size,termed the compact active target time projection chamber(CAT-TPC),was developed in this study to measure resonant scattering associated with cluster structures in unstable nuclei.The CAT-TPC consists of an electronic field cage,double-thick gas-electron-multiplier foils,a general-purpose digital data acquisition system,and a newly developed two-dimensional strip-readout structure.The CAT-TPC was operated using a^(4)He(96%)+CO_(2)(4%)gas mixture at 400 mbar.The working gas also serves as an active target for tracking charged particles.The overall performance of the CAT-TPC was evaluated using a collimated a-particle source.A time resolution of less than 20 ns and a position resolution of less than 0.2 mm were observed along the electron drift direction.Threedimensional images of incident trajectories and scattering events can be clearly reconstructed under an angular resolution of approximately 0.45 degree.展开更多
BACKGROUND:The predictive scoring systems for early stent thrombosis(EST)remains blank in China.The study aims to evaluate the risk factors and conduct a prediction model of EST in the Chinese population.METHODS:EST w...BACKGROUND:The predictive scoring systems for early stent thrombosis(EST)remains blank in China.The study aims to evaluate the risk factors and conduct a prediction model of EST in the Chinese population.METHODS:EST was defined as thrombosis that occurs within the first 30 days after primary percutaneous coronary intervention(PCI).Patients from ten Chinese hospitals diagnosed as stent thrombosis(ST)from January 2010 to December 2016 were retrospectively included as the study group.A control group(1 case:2 controls)was created by including patients without ST,major adverse cardiovascular events,or cerebrovascular events during follow-up.The present study evaluated 426 patients with single-vessel lesions and ultimately included 40 patients with EST and 80 control patients,who were included to identify factors that predicted EST and to develop a prediction scoring system.The other 171 patients without integrated 1:2 pair were used for external validation.RESULTS:EST was independently associated with a low hemoglobin concentration(adjusted odds ratio[OR]0.946,95%confi dence interval[95%CI]0.901-0.993,P=0.026),a high pre-PCI Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score(OR 1.166,95%CI 1.049-1.297,P=0.004),and a DAPT(DAPT)duration of<30 days(OR 28.033,95%CI 5.302-272.834,P<0.001).The simple EST prediction score provided an area under the curve(AUC)of 0.854(95%CI 0.777-0.932,P<0.001)with 70.0%sensitivity and 90.0%specifi city,and 0.742(95%CI 0.649-0.835,P<0.001)with 54.5%sensitivity and 81.0%specifi city for external validation dataset.CONCLUSIONS:EST may be independently associated with DAPT discontinuation within 30 days,a low hemoglobin concentration,and a high SYNTAX score.The scoring system also has a good ability to predict the risk of EST and may be useful in the clinical setting.展开更多
A newly developed digital data acquisition system,which is based on the digital pulse processor Pixie-16 modules by XIA LLC,was tested with the c-ray detector array of the China Institute of Atomic Energy using the cr...A newly developed digital data acquisition system,which is based on the digital pulse processor Pixie-16 modules by XIA LLC,was tested with the c-ray detector array of the China Institute of Atomic Energy using the cray source and in-beam c-rays.A comparison between this digital data acquisition system and the conventional analog data acquisition system was made.At a low count rate,both systems exhibit good and comparable energy resolutions.At a high count rate above 8.8 k/s,while the energy resolution obtained by the analog system deteriorates significantly,the energy resolution obtained by the digital system is nearly unchanged.Meanwhile,experimental data with higher statistics can be collected by the digital system.The advantage of this digital system over the conventional analog system can be ascribed to its excellent capability of handling pile-up pulses at higher count rates,and the fact that it has nearly no dead time in data transmission and conversion.展开更多
An experiment for m p（14C},14C＊→10Be＋α）p inelastic excitation and decay was performed in inverse kinematics at a beam energy of 25.3 MeV/u. A series of 14C excited states, including a new one at 18.3（1） MeV, w...An experiment for m p（14C},14C＊→10Be＋α）p inelastic excitation and decay was performed in inverse kinematics at a beam energy of 25.3 MeV/u. A series of 14C excited states, including a new one at 18.3（1） MeV, were observed which decay to various states of the final nucleus of 10Be. A specially designed telescope system, installed around zero degrees, played an essential role in detecting the resonant states near the α-separation threshold. A state at 14.1（1） MeV is clearly identified, being consistent with the predicted band-head of the molecular rotational band characterized by the π-bond linear chain configuration. Further clarification of the properties of this exotic state is suggested by using appropriate reaction tools.展开更多
基金supported by the Major program of Natural Science Foundation of Shandong Province(No.ZR2020ZD30)the National Natural Science Foundation of China(Nos.11775133,U2167202,U1432119).
文摘A particle detector array designed for light-charged particles, known as the CsI-bowl, was built for exit channel selection for in-beam γ-ray spectroscopy experiments. This device is composed of 64 CsI(Tl) detectors, organized in a structure reminiscent of a tea-bowl. High quantum efficiency photodiodes, characterized by their minimal mass, were employed to collect scintillation light. Its design, construction, particle identification resolution, and its effectiveness in relation to exit channel selection are described in this paper. In source tests, the optimal figure of merit for the identification of α-particles and γ-rays using the charge comparison method was found to be 3.3 and 12.1 for CsI detectors coupled to photodiodes and avalanche photodiodes, respectively. The CsI-bowl demonstrated effectiveness in identifying particles, specifically the emission of protons and α-particles in the58Ni(19F, xpyn) fusion–evaporation reaction, thereby enabling the selection of the desired exit channels.
基金supported by National Natural Science Foundation of China General Program(81970298)the National Key R&D Project(2016YFC1301300,2016YFC1301303)
文摘BACKGROUND:Post-infarct left ventricular free wall rupture(LVFWR)is not always an immediately catastrophic complication.The rupture can be subacute,allowing time for diagnosis and intervention.Accordingly,early recognition of the entity may be lifesaving.METHODS:We present an electrocardiogram(ECG)change pattern in two cases,which was erroneously attributed to ischemia.Two women in their 80s were admitted to our institute after experiencing the sudden onset of chest pain.They were managed as anterior ST-segment elevation myocardial infarction without reperfusion treatment.Unfortunately,they experienced a recurrence of severe chest pain with cardiogenic shock during hospitalisation.The ECG recorded at that time showed a ST-segment re-elevation in infract-related leads.RESULTS:The two cases were regrettably received a misjudgement of reinfarction at first,and one of the patients even was administrated with tirofi ban.Afterwards the diagnosis of subacute LVFWR was made through antemortem echocardiography.CONCLUSION:New ST-segment elevation(STE)in infarct-associated leads,coupled with recurrence of chest pain and new-onset hypotension,may constitute the premonitory signs of a subacute LVFWR.
基金supported by the National Key R&D Program of China(No.2018YFA0404403)the National Natural Science Foundation of China(Nos.U1967201,11875074,11875073,and 11961141003)the State Key Laboratory of Nuclear Physics and Technology,PKU(No.NPT2020KFY06)。
文摘A gas detector 140×140×140 mm^(3)in size,termed the compact active target time projection chamber(CAT-TPC),was developed in this study to measure resonant scattering associated with cluster structures in unstable nuclei.The CAT-TPC consists of an electronic field cage,double-thick gas-electron-multiplier foils,a general-purpose digital data acquisition system,and a newly developed two-dimensional strip-readout structure.The CAT-TPC was operated using a^(4)He(96%)+CO_(2)(4%)gas mixture at 400 mbar.The working gas also serves as an active target for tracking charged particles.The overall performance of the CAT-TPC was evaluated using a collimated a-particle source.A time resolution of less than 20 ns and a position resolution of less than 0.2 mm were observed along the electron drift direction.Threedimensional images of incident trajectories and scattering events can be clearly reconstructed under an angular resolution of approximately 0.45 degree.
基金from National Key R&D Program of China(2016YFC1301300,2016YFC1301302)。
文摘BACKGROUND:The predictive scoring systems for early stent thrombosis(EST)remains blank in China.The study aims to evaluate the risk factors and conduct a prediction model of EST in the Chinese population.METHODS:EST was defined as thrombosis that occurs within the first 30 days after primary percutaneous coronary intervention(PCI).Patients from ten Chinese hospitals diagnosed as stent thrombosis(ST)from January 2010 to December 2016 were retrospectively included as the study group.A control group(1 case:2 controls)was created by including patients without ST,major adverse cardiovascular events,or cerebrovascular events during follow-up.The present study evaluated 426 patients with single-vessel lesions and ultimately included 40 patients with EST and 80 control patients,who were included to identify factors that predicted EST and to develop a prediction scoring system.The other 171 patients without integrated 1:2 pair were used for external validation.RESULTS:EST was independently associated with a low hemoglobin concentration(adjusted odds ratio[OR]0.946,95%confi dence interval[95%CI]0.901-0.993,P=0.026),a high pre-PCI Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score(OR 1.166,95%CI 1.049-1.297,P=0.004),and a DAPT(DAPT)duration of<30 days(OR 28.033,95%CI 5.302-272.834,P<0.001).The simple EST prediction score provided an area under the curve(AUC)of 0.854(95%CI 0.777-0.932,P<0.001)with 70.0%sensitivity and 90.0%specifi city,and 0.742(95%CI 0.649-0.835,P<0.001)with 54.5%sensitivity and 81.0%specifi city for external validation dataset.CONCLUSIONS:EST may be independently associated with DAPT discontinuation within 30 days,a low hemoglobin concentration,and a high SYNTAX score.The scoring system also has a good ability to predict the risk of EST and may be useful in the clinical setting.
基金supported by the National Key R&D Program of China(No.2018YFA0404403)the National Natural Science Foundation of China(Nos.12035001,12075006,11675003)the State Key Laboratory of Nuclear Physics and Technology,PKU(No.NPT2020KFY18)。
文摘A newly developed digital data acquisition system,which is based on the digital pulse processor Pixie-16 modules by XIA LLC,was tested with the c-ray detector array of the China Institute of Atomic Energy using the cray source and in-beam c-rays.A comparison between this digital data acquisition system and the conventional analog data acquisition system was made.At a low count rate,both systems exhibit good and comparable energy resolutions.At a high count rate above 8.8 k/s,while the energy resolution obtained by the analog system deteriorates significantly,the energy resolution obtained by the digital system is nearly unchanged.Meanwhile,experimental data with higher statistics can be collected by the digital system.The advantage of this digital system over the conventional analog system can be ascribed to its excellent capability of handling pile-up pulses at higher count rates,and the fact that it has nearly no dead time in data transmission and conversion.
基金Supported by National Key R&D Program of China(2018YFA0404403)the National Natural Science Foundation of China(11535004,11775004,11405005,11375017)
文摘An experiment for m p（14C},14C＊→10Be＋α）p inelastic excitation and decay was performed in inverse kinematics at a beam energy of 25.3 MeV/u. A series of 14C excited states, including a new one at 18.3（1） MeV, were observed which decay to various states of the final nucleus of 10Be. A specially designed telescope system, installed around zero degrees, played an essential role in detecting the resonant states near the α-separation threshold. A state at 14.1（1） MeV is clearly identified, being consistent with the predicted band-head of the molecular rotational band characterized by the π-bond linear chain configuration. Further clarification of the properties of this exotic state is suggested by using appropriate reaction tools.
