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Design of a compact C-band high brightness photoinjector for an ultra-fast electron diffraction

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Chinese Science Bulletin 2013年第36期58卷 4577-4581页

作者： LIU XiaoHan TANG ChuanXiang QIAN HouJun CHEN HuaiBi HUANG WenHui Key Laboratory of Particle & Radiation imaging Ministry of Education Department of Engineering Physics Tsinghua University

A compact C-band high brightness photoinjector for ultra-fast electron diffraction(UED)is under development at Tsinghua *** C-band photoinjector,operating at 5.172 GHz,uses a 1.45-cell C-band RF gun as the electron *** design of the RF gun has addressed the physics,beam dynamics and mechanical aspects,and based on these design studies,a prototype has been *** order to obtain optimized performance for the UED,beam dynamics simulation has been carried out using the particle tracking code Astra for the photoinjector consisting of an alternative multi-cell RF gun design and a C-band compressor *** beam dynamics parameters that are optimized include the bunch length,peak current,horizontal emittance,and position of the minimum bunch length.

关键词：电子衍射 C波段高亮度紧凑型设计微波电子枪束流动力学束团长度

Variability in Fluoroscopic Time during Interventional Non-Cardiac Procedures Performed Outside of the Radiology Department

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International Journal of medical physics, Clinical Engineering and Radiation Oncology 2018年第4期7卷 464-471页

作者： Murdhi A. Al Harbi Abdullah H. Al Malki Saeed A. Al Ahmari Khaled Soliman Diagnostic Radiology and medical imaging Department Prince Sultan Military Medical City Riyadh KSA medical physics Department Prince Sultan Military Medical City Riyadh KSA

Purpose: Increasing physician awareness of patient exposure to radiation is an important step towards the reduction of potentially harmful effects of radiation. Published studies demonstrated that providing physicians with feedback regarding their fluoroscopy time leads to a reduction in average fluoroscopy times. The aim of this work was to analyze and publish our medical center data observed during the past year;fluoroscopy time (FT), Dose Area Product (DAP) and cumulative dose (CD) were monitored for radiation protection purposes. Methods: Fluoroscopy time is one of multiple radiation dose indices used in radiation safety auditing. Such auditing is nowadays turning into requirement of patient care safety and quality improvement;as indicated by accreditation bodies both nationally and internationally. All non-cardiac procedures performed outside radiology department by surgeons and interventionists are viewed. FT, DAP and CD are extracted for analysis. Results: a total of 846 cases were studied (643 orthopedic, 99 others, 73 urology, 17 chest, 7 vascular and 4 ERCP cases). Mean FT was 1.3 minutes, mean CD to the patient was 12.98 mGy and the mean DAP was 4.53 Gy/cm2. The longest FT noted was 55 min. The maximum CD was 904 mGy and the maximum DAP was 689 Gy/cm2. Using spearman’s correlation test we found out that there is a significant correlation between FT and DAP (correlation coefficient = 0.615, p. value 0.001). There is a significant correlation between FT and CD (correlation coefficient = 0.628, p. value 0.001). Conclusion: Information about FT that used in each procedure can be used as a tool for patient dose optimization. As we found a significant correlation between DAP as well as CD. Reducing fluoroscopic time (FT) is a radiation protection goal, since it serves the purpose of protection for both the patient and the workers.

关键词： Fluoroscopy Time Interventional Radiology Cumulative Dose Dose Area Product

A new horizon for neuroscience:terahertz biotechnology in brain research

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Neural Regeneration Research 2025年第2期20卷 309-325页

作者： Zhengping Pu Yu Wu Zhongjie Zhu Hongwei Zhao Donghong Cui Shanghai Key Laboratory of Psychotic Disorders Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina Department of Psychiatry Kangci Hospital of JiaxingTongxiangZhejiang ProvinceChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina Key Laboratory of Interfacial physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of ScienceShanghaiChina National Facility for Protein Science in Shanghai Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina

Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain *** this article,we review the development of terahertz biotechnology and its applications in the field of *** evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin *** vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric *** the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic ***,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical *** review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.

关键词： biological effect brain neuron neuropsychiatry neuroscience non-thermal effect terahertz imaging terahertz radiation terahertz spectroscopy terahertz technology

Limits on light WIMPs with a 1 kg-scale germanium detector at 160 eVee physics threshold at the China Jinping Underground Laboratory

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Chinese physics C 2018年第2期42卷 12-21页

作者：杨丽桃李浩斌岳骞康克军程建平李元景王子敬 M.Agartioglu 安海鹏常建平陈景瀚陈云华邓智杜强宫辉何力胡津纬胡庆东黄瀚雄贾历平江灏李红李荐民李金李霞李学潜李玉兰林枫凯林兴德刘书魁刘仲智马豪马菁露潘辉任杰阮锡超 B.Sevda Vivek Sharma 申满斌 Lakhwinder Singh Manoj Kumar Singh 唐昌建唐维优田阳王继敏王力王青王轶吴世勇吴玉成幸浩洋徐音薛涛杨松伟易难喻纯旭于海军岳剑峰曾雄辉曾鸣曾志张云华赵明刚赵伟周济芳周祖英朱敬军朱忠华 Key Laboratory of Particle and Radiation imaging (Ministry of Education) and Department of Engineering physics Tsinghua University Department of physics Tsinghua University Institute of physics Academia Sinica Key Laboratory of Particle and Radiation imaging vand Department of Engineering physics Tsinghua University NUCTECH Company YaLong River Hydropower Development Company College of Physical Science and Technology Sichuan University Department of Nuclear physics China Institute of Atomic Energy School of physics Nankai University Department of physics Banaras Hindu University Key Laboratory of Particle and Radiation imaging and Department of Engineering physics Tsinghua University

We report results of a search for light weakly interacting massive particle（WIMP） dark matter from the CDEX-1 experiment at the China Jinping Underground Laboratory（CJPL）. Constraints on WIMP-nucleon spin-independent（SI） and spin-dependent（SD） couplings are derived with a physics threshold of 160 eVee, from an exposure of 737.1 kg-days. The SI and SD limits extend the lower reach of light WIMPs to 2 GeV and improve over our earlier bounds at WIMP mass less than 6 GeV.

关键词： dark matter WIMPs CDEX pPCGe

Radiation Dose Survey of Pediatric Chest Computed Tomography Examinations: A Local Diagnostic Reference Levels Approach to Patient Safety

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Journal of Applied Mathematics and physics 2023年第7期11卷 2137-2143页

作者： Turki Alruwaili Bani Alsubaie Salman Altimyat Khaled Soliman medical physics Department Prince Sultan Military Medical City Riyadh Saudi Arabia Radiodiagnostic and medical imaging Department Prince Sultan Military Medical City Riyadh Saudi Arabia

Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .

关键词： Computed Tomography Chest CT Diagnostic Reference Levels Monitoring Optimization

Analysis of Local Diagnostic Reference Levels for Pediatric Patients Undergoing 18F-FDG PET/CT imaging for Oncology

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Journal of Applied Mathematics and physics 2023年第7期11卷 2144-2155页

作者： Saad Alqahtani Khaled Soliman Saad Alotaibi Khaled Alnofaie Abdullah Alahmari Fahad Alyahya Abdullah Albdullah Rashed Alharbi Radiodiagnostic and medical imaging Department Prince Sultan Military Medical City Riyadh Saudi Arabia medical physics Department Prince Sultan Military Medical City Riyadh Saudi Arabia

Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDIvol values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .

关键词： Diagnostic Reference Levels PET/CT 18-F-FDG Pediatric Radiation Dose CTDIvol Oncology

Life Time Attributable Cancer Risk Estimated Using Scanner Reported Dose Length Product during Chest Computed Tomography imaging in Young Children

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Open Journal of Radiology 2024年第2期14卷 74-82页

作者： Mousa Bakkari Khaled Soliman Abdullah Alrushoud Marwan Fahad Alosaimi Hanaa Alsheikh Abdelwahed Alhejaili medical physics Department Prince Sultan Military Medical City Riyadh Saudi Arabia Radiogiadnostic and medical imaging Department Prince Sultan Military Medical City Riyadh Saudi Arabia

This study aims to estimate the lifetime attributable cancer risk (LAR) for pediatric chest computed tomography (CT) examinations in five age groups using recently published age and region-specific conversion coefficients multiplying the widely available scanner registered dose length products (DLP) displayed on the CT console and hence calculating the Effective Dose (ED). The ED is then multiplied by the International Commission on Radiological Protection (ICRP) published risk factor for LAR. The obtained LAR values are compared with the international literature. Factors that may affect the LAR value are reported and discussed. The study included one hundred twenty five chest CT examinations for both males and females aged from less than one year to fifteen years. The patients reported data are from one single medical institution and using two CT scanners from June 2022 to December 2023. The results of this study may serve as benchmark for institutional radiation dose reference levels and risk estimation.

关键词： Cancer Risk LAR Chest CT Pediatric Radiology Radiation Dose DLP

Relationship between Whole Body Iodine-131 Effective Half-Life and Estimated Glomerular Filtration Rate for Papillary Thyroid Cancer Patients Undergoing Radioactive Iodine Therapy

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Journal of Applied Mathematics and physics 2023年第8期11卷 2472-2479页

作者： Asim Abualnaja Hanaa Alsheikh Khaled Soliman Meshal Alnefaie Abdulraheem Alsheri medical physics Department Prince Sultan Military Medical City Riyadh Saudi Arabia Radiodiagnostics and medical imaging Department Prince Sultan Military Medical City Riyadh Saudi Arabia

Background: The aim of this work was to examine the relationship between the estimated glomerular filtration rate (eGFR) as indicator of renal efficiency potentially related to the ability to release radioactive iodine from the patients bodies and the radioactive iodine whole body effective half-life (WBEHL) defined as the time taken for the administered activity to decay to half of its value for papillary thyroid cancer (PTC) patients undergoing radioactive iodine therapy (RAIT) in a tertiary care medical Centre. Methods: This retrospective observational study included seventy nine patients, sixty females and nineteen males. The patients were divided in two subgroups, those who have WBEHL of less than 11 hours (n = 51) and those with more than 11 (n = 28) hrs based on k-means clustering technique. Results: Analysis of variance (ANOVA) was used to find out if there is a statistically significant difference between the two subgroups Conclusion: There was not a statistically significant difference between the short and the longer WBEHL patients’ groups analyzed in this study. .

关键词： GFR Thyroid Cancer Radioactive Iodine Therapy Renal Function

Rational design of novel ultra-small amorphous Fe_(2)O_(3)nanodots/graphene heterostructures for all-solid-state asymmetric supercapacitors

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Nano Research 2021年第4期14卷 953-960页

作者： Chenxiao Wu Zhifang Zhang Zhonghui Chen Zuimin Jiang Huiyu Li Haijing Cao Yongsheng Liu Yanyan Zhu Zebo Fang Xiangrong Yu College of Mathematics and physics Shanghai University of Electric PowerShanghai 200090China Key Lab for Special Functional Materials of Ministry of Education School of Materials Science and EngineeringHenan UniversityKaifeng 475004China Department of physics Fudan UniversityShanghai 200433China Department of physics Shaoxing UniversityShaoxing 312000China Department of medical imaging Zhuhai Peoples HospitalZhuhai Hospital affiliated with Jinan UniversityZhuhai 519000China

Constructing graphene-based heterostructures with large interfacial area is an efficient approach to enhance the electrochemical performance of supercapacitors but remains great challenges in their ***,a novel ultra-small amorphous Fe_(2)O_(3)nanodots/graphene heterostructure(a-Fe_(2)O_(3)NDs/RGO)aerogel was facilely synthesized via excessive metal-ion-induced self-assembly and subsequent calcination route using Prussian blue/graphene oxide(PB/GO)composite aerogel as *** deliberately designed a-Fe_(2)O_(3)NDs/RGO heterostructure offers a highly interconnected porous conductive network,large heterostructure interfacial area,and plenty of accessible active sites,greatly facilitating the electron transfer,electrolyte diffusion,and pseudocapacitive *** obtained a-Fe_(2)O_(3)NDs/RGO aerogel could be used as flexible free-standing electrodes after mechanical compression,which exhibited a significantly enhanced specific capacitance of 347.4 F·g^(-1)at 1 A·g^(-1),extraordinary rate capability of 184 F·g^(-1)at 10 A·g^(-1),and decent cycling *** the as-prepared a-Fe_(2)O_(3)NDs/RGO as negative electrodes and the Co_(3)O_(4)NDs/RGO as positive electrodes,an all-solid-state asymmetric supercapacitor(a-Fe_(2)O_(3)NDs/RGO//Co_(3)O_(4)NDs/RGO asymmetric supercapacitor(ASC))was assembled,which delivered a high specific capacitance of 69.1 F·g^(-1)at 1 A·g^(-1)and an impressive energy density of 21.6 W·h·k·g^(-1)at 750 W·k·g^(-1),as well as good cycling stability with a capacity retention of 94.3%after 5,000 *** work provides a promising avenue to design high-performance graphene-based composite electrodes and profound inspiration for developing advanced flexible energy-storage devices.

关键词： graphene heterostructures amorphous Fe_(2)O_(3) Co_(3)O_(4) all-solid-state asymmetric supercapacitors