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Geant4 simulation of multi-sphere spectrometer response function and the detection of 241Am–Be neutron spectrum

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Nuclear Science and Techniques 2017年第12期28卷 204-208页

作者： Xiao-Fei jiang Jing Cao chun-yu jiang Ze-Jie Yin College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

This paper is aimed at detecting the neutron spectrum of^(241)Am–Be, a widely used neutron source, with the SP9 ~3He proportional counter, which is a multi-sphere spectrometer system of eight thermal neutron detectors embedded in eight polyethylene(PE) spheres of varying diameters. The transport processes of a neutron in the multi-sphere spectrometer are simulated using the Geant4 code. Two sets of response functions of the PE spheres are obtained for calculating the^(241)Am–Be neutron *** Function 1 utilizes the thermal neutron scattering model G4 Neutron HPThermal Scattering for neutron energies of ≤4 eV, and Response Function 2 has no thermal treatment. Neutron spectra of an^(241)Am–Be neutron source are measured and compared to those calculated by using the response functions. The results show that response function with thermal treatment is more accurate and closer to the real spectrum.

关键词： Response function Neutron energy spectrum Multi-sphere Geant4 241Am–Be G4NeutronHPThermalScattering

A novel X-ray tube spectra reconstruction method based on transmission measurements

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Nuclear Science and Techniques 2016年第2期27卷 73-78页

作者： Jing Cao chun-yu jiang Yan-Feng Zhao Qing-Wei Yang Ze-Jie Yin State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China Southwestern Institute of Physics Chengdu 610041 China

A novel X-ray tube spectrum reconstruction method has been proposed based on transmission measurements. Aluminum bars of varying lengths attenuate the X-rays to different levels. The detectors are of lutetium yttrium oxyorthosilicate scintillator and silicon photomultiplier. With the detected X-ray intensities, the X-ray spectrum is unfolded using the least square method. The detectors, aluminum bars, and collimating apertures are integrated in a detection module made of lead. Its response to X-ray is calculated by Monte Carlo codes Geant4. Due to the high photon flux, the detectors work in current *** electronics system, consisting of 24-bit high-precision ADCs with 144 KSPS sampling rate and field programmable gate array, makes the data acquisition process effective and precise. Measurements on a 70-k Vp tungsten anode X-ray were taken to verify the method. The unfolded spectrum agrees well with the simulated spectrum,demonstrating that the method is reliable and practical.

关键词： X射线管重建方法传输测量光谱现场可编程门阵列透射 Geant4 蒙特卡罗程序

Glutamine:aprecursor of glutathione and its effect on liver

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World Journal of Gastroenterology 1999年第2期5卷 55-58页

作者： yu Jian chun, jiang Zhu Ming and LI De Min

AIM To investigate the relationship between alanyl-glutamine (ALA-GLN) and glutathione (GSH) biosynthesis in hepatic *** Twenty male Wistar rats were randomly divided into two groups: one receiving standard parenteral nutrition (STD) and the other supplemented with or without ALA-GLN for 7 days. The blood and liver tissue samples were examined after 5-fluorouracil (5-FU) was injected *** The concentration measurements were significantly higher in ALA-GLN group than in STD group in serum GLN (687 μmol/ L±50 μmol/ L vs 505 μmol/ L±39 μmol/ L, P＜0.05), serum GSH (14 μmol/ L±5 μmol/ L vs 7 μmol/ L±3 μmol/ L, P＜0.01) and in liver GSH content (6.9 μmol/ g±2.5 μmol/ g vs 4.4 μmol/ g±1.6 μmol/ g liver tissue, P＜0.05). Rats in ALA-GLN group had lesser elevations in hepatic enzymes after 5-FU *** The supplemented nutrition ALA-GLN can protect the liver function through increasing the glutathione biosynthesis and preserving the glutathione stores in hepatic tissue.

关键词： glutamine glutathione/biosynthesis liver/drug effects

β-Secretase inhibitor increases amyloid-β precursor protein level in rat brain cortical primary neurons induced by okadaic acid

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Chinese Medical Journal 2008年第15期121卷 1439-1444页

作者： yu chun-jiang WANG Wei-zhi LIU Wei Department of Neurology the Second Affiliated Hospital of Harbin Medical University Harbin Heilongjiang 150086 China Department of Neurology Hai-Dian Hospital Beijing100080 China

Background Senile plaques and neurofibrillary tangles （NFTs） represent two of the major histopathological hallmarks of Alzheimer＇s disease （AD）. The plaques are primarily composed of aggregated amyloid β （Aβ） peptides. The processing of amyloid-β precursor protein （AβPP） in okadaic acid （OA）-induced tau phosphorylation primary neurons was studied. Methods Primary cultures of rat brain cortical neurons were treated with OA and β-secretase inhibitor. Neurons＇ viability was measured. AβPP processing was examined by immunocytochemistry and Western blotting with specific antibodies against the AβPP-N-terminus （NT） and AβPP-C-terminus （CT）. Results Ten nmol/L OA had a time-dependent suppression effect on primary neurons＇ viability. The suppression effect was alleviated markedly by pretreatment with β-secretase inhibitor. After OA treatment, both AβPP and β-C-terminal fragment （βCTF） were significantly increased in neurons. AβPP level was increased further in neurons pretreated with β-secretase inhibitor. Conclusions In OA-induced tau phosphorylation cell model, inhibition of β-secretase may protect neurons from death induced by OA. Because of increased accumulation of AβPP in neurons after OA treatment, more AβPP turns to be cleaved by β-secretase, producing neurotoxic βCTF. As a potential effective therapeutic target, β-secretase is worth investigating further.

关键词： tau phosphorylation amyloid-β precursor protein β-C-terminal fragment β-secretase inhibitor

Optimization of transfection efficiency of small interfering RNA in purified human prolactinoma cells

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Chinese Medical Journal 2011年第12期124卷 1862-1869页

作者： SONG Yong-mei ZHAO jiang yu chun-jiang ZHAN Qi-min Department of Neurosurgery Beijing Sanbo Brain Hospital of theCapital Medical University Beijing 100093 China (Meng QH Department of Neurosurgery Beijing Sanbo Brain Hospital of theCapital Medical University Beijing 100093 China State Key Laboratory of Molecular Oncology Chinese Academy ofMedical Sciences and Peking Union Medical College CancerInstitute and Cancer Hospital Beijing 100021 China Department of Neurosurgery Daqing Oil-field General HospitalDaqing Heilongiiang 163001 China

Background Control of hypersecretion of certain hormones is one of the key targets in the treatment of pituitary adenomas. RNA interference has been shown to inhibit protein expression, and thus it may represent a promising method for the treatment of pituitary adenomas. In the present study, transfection efficiency of small interfering RNA （siRNA） was optimized in human prolactinoma cells. Methods First, a method was optimized to extract highly purified human prolactinoma cells in vitro. The extracted cells were verified to retain the physiological features of prolactin （PRL） secretion. Second, three conditions for siRNA transfection were tested by the evaluation of transfectfon efficiency and cell viability. The proper transfection condition was verified for human prolactinoma cells. Third, the siRNA for prolactin was transfected into the human prolactinoma cells, and the suppression of PRL mRNA was evaluated by quantitative real-time reverse transcription-PCR. Results The siRNA of 100 pmol with Lipofectamine 2000 of 5 μl for 1×10^6 cells was proved preferable, with transfection efficiency being 53.3% and cell viability being 69.7%. In the preliminary experiment the siRNA against PRL decreased the mRNA of PRL by 34.0%. Conclusion It is possible to inhibit hormone hypersecretion by RNA interference, that may eventually enable therapeutic siRNA drugs developed.

关键词： RNA interference prolactinoma prolactin cell culture techniques, transfection

Correction and verification of HL-2A Tokamak Bonner sphere spectrometer in monoenergetic neutron fields from 100 keV to 5 MeV

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Nuclear Science and Techniques 2019年第11期30卷 72-82页

作者： Bo-Wen Zheng chun-yu jiang Zi-Hao Liu Yin-Hai Pan Xian-Ying Song Shi-Biao Tang Ze-Jie Yin State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China Southwestern Institute of Physics Chengdu 610041China

A real-time Bonner sphere spectrometer(BSS)has been developed for spectral neutron measurements with the HL-2A *** correct and verify the accuracy of the neutron spectrum from the BSS,the BSS system was calibrated using monoenergetic neutron beams in the energy range of 100 keV–5 *** response function of the BSS was corrected based on the calibration results,and the corrected BSS system was verified by unfolding monoenergetic neutron *** neutron spectra on the HL-2A have been obtained from the calibrated BSS system for the first time.

关键词： Bonner sphere spectrometer Calibration Response function Neutron spectrometry

Verification of a fusion neutron diagnostic Bonner sphere spectrometer on measurement of a ^(241)Am–Be neutron source

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Nuclear Science and Techniques 2016年第6期27卷 125-129页

作者： Jing Cao chun-yu jiang Qing-Wei Yang Ze-Jie Yin State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science andTechnology of ChinaHefei 230026China Southwestern Institute of Physics Chengdu 610041China

A Bonner sphere spectrometer(BSS) was developed for neutron diagnostic on HL_2A *** contains eight polyethylene spheres embedded with SP9~3 He proportional *** setting up on the Tokamak experimental hall,a verification experiment was arranged on a^(241)Am–Be neutron source to test its spectrometry *** neutron response functions were calculated by Monte Carlo code Geant4 to simulate the real measurement *** least square method,the neutron spectrum was finally unfolded on log domain from0.1 e V to 11 Me *** has a remarkable consistency to the ISO 8529-1 standard^(241)Am–Be neutron *** shows that the BSS is effective and reliable for neutron spectrum determination.

关键词：中子诊断中子源光谱仪计量检定聚变托卡马克装置托卡马克实验 Geant4

Significance of Vestibular Testing on Distinguishing the Nerve of Origin for Vestibular Schwannoma and Predicting the Preservation of Hearing

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Chinese Medical Journal 2016年第7期129卷 799-803页

作者： yu-Bo He chun-jiang yu Hong-Ming Ji Yan-Ming Qu Ning Chen Department of Neurosurgery Sanbo Brain Hospital Capital Medical University Beijing 100093 China Department of Neurosurgery Shanxi Provincial People's Hospital Taiyuan Shanxi 030012 China

Background： Determining the nerve of origin for vestibular schwannoma （VS）, as a method for predicting hearing prognosis, has not been systematically considered. The vestibular test can be used to investigate the function of the superior vestibular nerve （SVN） and the inferior vestibular nerve （IVN）. This study aimed to preoperatively distinguish the nerve of origin for VS patients using the vestibular test, and determine if this correlated with hearing preservation. Methods： A total of 106 patients with unilateral VS were enrolled in this study prospectively. Each patient received a caloric test, vestibular-evoked myogenic potential （VEMP） test, and cochlear nerve function test （hearing） before the operation and 1 week, 3, and 6 months, postoperatively. All patients underwent surgical removal of the VS using the suboccipital approach. During the operation, the nerve of tumor origin （SVN or IVN） was identified by the surgeon. Tumor size was measured by preoperative magnetic resonance imaging. Results： The nerve of tumor origin could not be unequivocally identified in 38 patients （38/106, 35.80%）. These patients were not subsequently evaluated. In 26 patients （nine females, seventeen males）, tumors arose from the SVN and in 42 patients （18 females, 24 males）, tumors arose from the IVN. Comparing with tile nerve of origins （SVN and IVN） of tumors, the results of the caloric tests and VEMP tests were significantly different in tumors originating from the SVN and the IVN in our study. Hearing was preserved in 16 of 26 patients （61.54%） with SVN-originating tumors, whereas hearing was preserved in only seven of 42 patients （16.67%） with IVN-originating tumors. Conclusions： Our data suggest that caloric and VEMP tests might help to identify whether VS tumors originate from the SVN or IVN. These tests could also be used to evaluate the residual function of the nerves after surgery. Using this information, we might better predict the preservation of hearing for patients.

关键词： Caloric Test Hearing Preservation Inferior Vestibular Nerve Superior Vestibular Nerve Vestibular-evoked MyogenicPotential

Large and giant medial sphenoid wing meningiomas involving vascular structures： clinical features and management experience in 53 patients

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Chinese Medical Journal 2013年第23期126卷 4470-4476页

作者： YANG Jun MA Shun-chang LIU Yan-hong WEI Lin ZHANG chun-yang QI Jian-fa yu chun-jiang Department of Neurosurgery Fu Xing Hospital Capital Medical University Beijing 100038 China Beijing Neurosurgical Institute Capital Medical University Beijing 100050 China Department of Neurosurgery Qianfoshan Hospital affiliated to Shandong University Jinan Shandong 250014 China Department of Neurosurgery First Hospital affiliated to Inner Mongolia Scientific and Technical University Baotou Medical School Baotou Inner Mongolia 014010 China

Background Large and giant medial sphenoid wing meningiomas that are located deeply in the skull base where they are closely bounded by cavernous sinus,optic nerve,and internal carotid artery make the gross resection hard to ***,this kind of meningiomas is often accompanied by a series of severe ***,it was regarded as a formidable challenge to even the most experienced *** study aimed to investigate the clinical features and management experience of patients with large and giant medial sphenoid wing *** In this study,53 patients （33 female and 20 male,mean age of 47.5 years） with large and giant medial sphenoid wing meningiomas were treated surgically between April 2004 to March 2012,with their clinical features analyzed,management experience collected,and treatment results investigated *** In this study,gross total resection （Simpson Ⅰ and Ⅱ） was applied in 44 patients （83％）.Fifty-three patients had accepted the routine computed tomography scan and magnetic resonance imaging scan as postoperative neuroradiological *** performance showed surgical complications of vascular lesions and helped us evaluate patients＇ conditions,***,the drugs resisting cerebral angiospasm,such as Nimodipine,were infused in every postoperative patient through vein as *** a result,11 patients （21％） were found to have secondary injury of cranial nerves Ⅱ,Ⅲ,and Ⅳ,and nine patients got recovered during the long-term observing follow-up *** surgical complications of vascular lesions occurred after surgery,such as cerebral angiospasm,ischemia,and edema;24 patients （45％） appeared to have infarction and dyskinesia of ***,visual ability was improved in 41 patients （77％）.No patient died during the *** Microsurgical treatment may be the most effective method for the large and giant medial sphenoid wing *** surgical strategy should fo

关键词： meningioma sphenoid anterior clinoid process microsurgery approach operative complication skull base