基于拟合法和谱减法的牙釉质电子顺磁共振波谱处理方法对比研究

目的:建立拟合法和谱减法的牙釉质电子顺磁共振(EPR)波谱处理方法,分析对比两种方法处理羊牙釉质EPR波谱的结果.方法:收集自由放养的2～5岁山羊牙齿,根据年龄分为2岁组、3岁组和5岁组,采用物理化学结合的方法获取3组年龄不同的山羊牙釉质样品,测量牙釉质样品的EPR波谱.利用基于矩阵模型的拟合法和谱减法处理EPR波谱,...     

电子顺磁共振技术在辐射事故剂量估算中应用研究进展

核与辐射在造福于人类的同时其潜在危险也在增加。核与辐射事故的评估及事故中受照者的临床救治关键在于快速、准确的剂量重建[1]。电子顺磁共振(Electron paramagnetic resonance,EPR)技术可直接测量物质中的顺磁分子,可以在最短的时间内(≤10min)提供吸收剂量的评估结果。与剂量计相关的顺磁分子是辐射诱导的自由基。辐射诱导的自由基在牙齿、骨、指甲和头发等非水介质中是稳定的,且稳定     

牙齿样品的选取和制备对牙釉质电子顺磁共振剂量测量的影响

牙齿的牙冠表面覆盖的一层的坚硬的物质是牙釉质,它被认为是一种可靠的生物剂量计,可用于回顾性估算个人辐射剂量[1,2].     

磁共振设备安全运行的探讨与研究

目的:研究和讨论磁共振成像设备在日常工作中影响人员安全和设备安全运行的因素以及应对策略和方法.方法:通过对磁共振成像设备在日常工作中影响安全运行的各种因素如人员、场地、设备的管理以及设置进行逐一的分析和讨论,建立了相应的预防措施和管理规章制度 结果:通过实施相应的制度和措施,降低了磁共振设备使用的风险.结论:建立明确有效的管理制度是确保磁共振设备安全、稳定运行的重要方法.     

功能磁共振成像联合头颈部3D-TOF-MRA在急性脑卒中患者临床诊断中的价值研究

目的:探讨功能磁共振成像(fMRI)联合头颈部三维时间飞跃法磁共振血管成像(3D-TOF-MRA)在急性脑卒中患者临床诊断中的应用价值。方法:选取医院放射科接诊的92例疑似急诊脑卒中患者,将采用快速自旋回波T₁加权成像(FSE-T₁WI)、快速自旋回波-流动衰减反转恢复(FSE-T₂flair)序列扫描的患者纳入常规扫描组(46例),采用fMRI的弥散加权成像(DWI)、灌注加权成像(PWI)和3D-TOF-MRA序列扫描的患者纳入联合扫描组(46例)。以数字减影血管造影(DSA)检查结果为金标准,对比两组影像诊断的准确性。结果:联合扫描组影像诊断的真阳性率、真阴性率、阳性预测值、阴性预测值及准确率好于常规扫描组,其差异有统计学意义(x²=15.482,x²=7.985,x²=4.522,x²=13.179,x²=16.209;P<0.05);联合扫描组对血管狭窄诊断准确率高于常规扫描组,其差异有统计学意义...     

人工智能电子病历质量控制技术应用效果研究

目的:评价人工智能技术应用于电子病历(EMR)质量控制系统的效果,为推进人工智能EMR质量控制技术提供理论依据。方法:选取2022年5-10月医院EMR的运营数据,其中5月份为测试数据,从医院层面、医生层面、科室层面和核心医疗制度层面采用人工智能监控系统对6-10月份EMR质量控制的数据进行对比研究,检验人工智能EMR质量控制技术的应用效果。结果:医院EMR书写违规情况由6月份的48%降至10月份的37%,甲级病历比率由3.4%增长到5.6%;违规数量最高的前10个科室6-10月份的EMR书写违规数量均显著下降,差异有统计学意义(F=16.15,P<0.05);违规数量最高的前10名医生6-10月份的EMR书写违规数量均显著下降,差异有统计学意义(F=5.77,P<0.05);违规数量最高的前10名核心医疗制度6-10月份的违规数量均显著下降,差异有统计学意义(F=10.46,P<0.05)。结论:人工智能EMR质量控制技术能够降低病历缺陷率,提高病历质量。     

常规磁共振成像及磁共振弥散张量成像对肌骨肿瘤的鉴别诊断价值研究

目的：分析磁共振成像(MRI)及磁共振弥散张量成像(DTI)对肌骨肿瘤良、恶性病变的鉴别诊断价值。方法：选取医院收治的43例肌骨肿瘤患者,均行MRI与DTI扫描,观察两种检测方法的影像结果,以病理组织学结果为“金标准”,比较两种检测方法对肌骨肿瘤良恶性检出率、诊断准确率、漏诊率、误诊率、灵敏度以及特异度。结果：43例肌骨肿瘤患者中19例良性肌骨瘤,24例恶性肌骨瘤。良性肿瘤实质区表观弥散系数(ADC)值大于恶性肿瘤实质区,差异有统计学意义(t=2.140,P<0.05),良性肿瘤实质区各项异性分数(FA)值、相对各向异性(RA)值显著小于恶性肿瘤实质区,差异有统计学意义(t=8.776,t=5.049;P<0.05);良性肿瘤边缘区ADC值、FA及RA值显著小于恶性肿瘤边缘区,差异有统计学意义(t=2.239,t=3.307,t=4.327;P<0.05);DTI恶性检出率、诊断灵敏度和特异度,以及良恶性诊断准确率高于MRI检测,差异有统计学意义(x²=3.414,x2=6.454,x²=4.892,x²     

7.0T磁共振成像设备安全管理研究

目的:梳理7.0T磁共振成像(MRI)设备在科研临床双模应用中的经验,研究7.0T MRI科研临床双模态运行的安全风险,提出安全管理方案.方法:基于医用MRI设备的成像原理,分析7.0T超高场MR科研临床双模态操作中可能会存在的风险,制定7.0T MRI临床应用的安全管理流程.结果:研究制定的7.0T MRI临床安全管...     

磁共振脂肪抑制技术评估强直性脊柱炎骶髂关节成像效果研究

目的:分析磁共振成像(MRI)脂肪抑制技术评估强直性脊柱炎(AS)骶髂关节成像效果.方法:选取医院收治的98例AS患者,所有患者均行MRI检查,采用频率选择饱和(FS)序列、短时间反转恢复(STIR)序列和频率衰减反转恢复(SPAIR)序列,比较三种脂肪抑制序列骶髂关节左右两侧影像均匀性、臀部脂肪肌肉及骨髓水肿的相对信...     

磁共振成像和彩色多普勒超声在卵泡膜细胞瘤诊断应用中的差异性研究

目的:探讨磁共振成像(MRI)技术和彩色多普勒超声在卵泡膜细胞瘤(OTs)诊断应用中的差异性.方法:选取医院妇科收治且经病理学确诊为卵泡膜细胞瘤的50例患者,根据检查方法将采用MRI检查的患者纳入MRI检查组(20例),将采用彩色多普勒超声检查的患者纳入超声检查组(30例),收集两组的诊断结果数据并进行比较,评估MRI...     

Behavior of the electron spin resonance signals in X-ray irradiated human fingernails for the establishment of a dose reconstruction procedure

The retrospective dosimetry that follows accidental X-ray exposure is becoming more significant for improving radiation diagnosis and treatment. We investigated the dosimetric properties of electron spin resonance (ESR) signals in X-ray irradiated fingernails under conditions that resemble realistic situations. We collected fingernails from 12 Japanese donors between the ages of 30 to 70. The sampled fingernails were utilized for X-ray irradiation, mechanical stimulation and background measurements. We also collected 10 toenails from one of the donors to evaluate their differences from fingernails. Additionally, we prepared 15 samples from two donors to compare the signals generated by γ-rays to those by X-rays. After observing the linear dose–response for both X- and γ-ray irradiated samples, we found that the sensitivity of the air-absorbed dose of γ-ray irradiated samples was identical to that of X-ray irradiated samples. The effect from secondary electrons seemed to be small in fingernails. The inter-individual variation in the sensitivity was no greater than the intra-individual variation. The signal intensities in each measurement fluctuated about the linear response curve, and the size of the fluctuation was dependent on the sample. The average fluctuation corresponded to 1.7 Gy, and the standard deviation was 1.3 Gy. The signal induced by X-rays could be erased by soaking the samples in water and subsequently drying them for four days, which allowed us to estimate the signal intensity prior to the exposure. These characteristics of the ESR signal induced by X-rays facilitate the development of a feasible protocol for fingernail dose reconstruction.     

血液净化装置电导率测量结果不确定度的评定与表示

依据JJF1059-1999《测量不确定度评定与表示》的方法,对血液净化装置的电导率测量结果的不确定度进行评定与表示。     

Detection limit of electron spin resonance for Japanese deciduous tooth enamel and density separation method for enamel–dentine separation

Electron spin resonance (ESR) dosimetry is one of the most powerful tools for radiation dose reconstruction. The detection limit of this technique using human teeth is reported to be 56 mGy or 67 mGy; however, the absorbed dose of Fukushima residents after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident was estimated to be lower than this detection limit. Our aim is to assess the absorbed radiation dose of children in Fukushima Prefecture after the accident; therefore, it is important to estimate the detection limit for their teeth. The detection limit for enamel of deciduous teeth of Japanese children separated by the mechanical method is estimated to be 115.0 mGy. The density separation method can effectively separate enamel from third molars of Japanese people. As we have collected thousands of teeth from children in Fukushima, the present technique may be useful to examine their external absorbed dose after the FNPP accident.     

Analysis of the antioxidative function of the radioprotective Japanese traditional (Kampo) medicine,hangeshashinto, in an aqueous phase

Oral mucositis (OM) is a common and painful complication of radiotherapy for head and neck cancer. Hangeshashinto (HST), a Japanese traditional medicine, is known to alleviate radiotherapy- and/or chemotherapy-induced OM; however, the detailed mechanism has not yet been clarified. The aim of the present study was to clarify the details of the antioxidative functions of HST against reactive oxygen species (ROS) produced by radiation. The hydroxyl radical (•OH)–scavenging ability and the reduction ability was simultaneously measured using a modified electron paramagnetic resonance (EPR) spin-trapping method. The superoxide (O₂^•−)–scavenging ability was estimated by an EPR redox probing method. Water suspensions of powdered HST and of its seven constitutive crude drugs were tested. In addition, some of the main water-soluble ingredients of the crude drugs were also tested. HST was found to scavenge both •OH and O₂^•−. Furthermore, HST was observed to reduce relatively stable nitroxyl radicals. Glycyrrhizae Radix (kanzo), Ginseng Radix (ninjin), Zizyphi Fructus (taiso) and glycyrrhizin (an ingredient of kanzo) were all found to be relatively good •OH scavengers. Scutellariae Radix (ogon) and Coptidis Rhizoma (oren) demonstrated reducing ability. In addition, acteoside and berberine chloride, which are water-soluble ingredients of ogon and oren, respectively, also demonstrated reducing ability. Oren exhibited oxidative ability at higher concentrations, which may have a function in maintaining catalytic redox action. The antioxidative function of HST probably worked via a balance of scavenging ROS, reducing stable free radicals, and some minor oxidizing activities.     

食品菌落总数检验中不确定度的评定

目的:为减小实验误差,提高检测结果精确度,评定菌落总数的不确定度。方法:分析样品中菌落总数不确定度的来源,采用合并样本标准差的方法来评定菌落总数的不确定度。结果:测量结果表明扩展不确定度为0.046%,适合于每一个样本的检测结果。结论:方法简便,适合于每一个样本的检验结果,随着检验结果的不断增加,可随时加入到合并样本中,重新计算合并样本标准差,更新其不确定度的取值范围。     

活塞压力计活塞有效面积的测量与不确定度评定方法研究

目的与实际工作结合,研究获得较小重复性的活塞压力计活塞有效面积的测量和不确定度评定方法。方法对各量程的活塞进行实验,和对结果进行评定,并用该结果与溯源结果进行对比,分析其得到的不确定度的可靠程度。结果通过分组测量的方法,得到了较小的重复性,且结果具有较高可信度。结论利用分组测量方法在保证结果科学可靠的同时,减小了测量重复性。     

Recombinant Newcastle disease viral vector expressing hemagglutinin or fusion of canine distemper virus is safe and immunogenic in minks

Canine Distemper Virus (CDV) infects many carnivores and cause several high-mortality disease outbreaks. The current CDV live vaccine cannot be safely used in some exotic species, such as mink and ferret. Here, we generated recombinant lentogenic Newcastle disease virus (NDV) LaSota expressing either envelope glycoproyein, heamagglutinine (H) or fusion protein (F), named as rLa-CDVH and rLa-CDVF, respectively. The feasibility of these recombinant NDVs to serve as live virus-vectored CD vaccine was evaluated in minks. rLa-CDVH induced significant neutralization antibodies (NA) to CDV and provided solid protection against virulent CDV challenge. On the contrast, rLa-CDVF induced much lower NA to CDV and fail to protected mink from virulent CDV challenge. Results suggest that recombinant NDV expressing CDV H is safe and efficient candidate vaccine against CDV in mink, and maybe other host species.     

永磁型MRI技术探讨

介绍开放式永磁型磁共振的技术特点。对磁体结构、梯度场、发射和接收线圈等进行分析,指出实际调试工作的关键点,使设备处于最佳运行状态,图像品质最佳。