Radiation Protection of a Patient Undergoing an Orthopedic Procedure by Using a Mobile C-Arm X-Ray System

Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures that meet the increased requirements are a priority in our time. X-ray examinations are of particular importance for the orthopedic and traumatological clinics, where they provide information about presence of a fracture in the patient’s body, about the concrete operation performed or about the effect of a suitable treatment. Along with their benefits X-rays have also a harmful effect. This requires special care to protect from this radiation. In this direction, research is constantly being done to improve the quality of radiation protection. Park MR, Lee KM and co-authors, compare the dose load obtained using C-arm and O-arm X-ray systems (which have the capability of combined 2D fluoroscopy and 3D computed tomography imaging). In their study, an orthopedic surgical procedure using C-arm and O-arm systems in 2D fluoroscopy modes was simulated. The radiation doses to susceptible organs of the operators were investigated. He results obtained show that the O-arm system delivered higher doses to the sensitive organs of the operator in all configurations [1]. The article of Stephen Balte briefly reviews the available technologies for measuring or estimation of patient skin dose in the interventional fluoroscopic environment, created by various X-ray equipment including C-arm systems. Given that many patients require multiple procedures, this documentation also aids in the planning of follow up visits [2]. Chong Hing Wong, Yoshihisa Kotani and co-authors evaluate the radiation exposures (RE) to the patient and surgeon during minimally invasive lumbar spine surgery with instrumentation using C-arm image intensifier or O-arm intraoperative CT. The results they get are in favor of the O-arm system [3]. The article “Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction” discusses positioning of an intraoperative C-arm system to achieve clear visualization of a particular anatomical feature by a system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time and received dose during the procedures. FluoroSim was found to reduce the radiation exposure required for C-arm positioning without reducing positioning time or accuracy, providing a potentially valuable tool to assist surgeons [4]. In our study, we performed practical measurements to show how the patient can be treated by applying most effective radiation protection when using a mobile C-arm X-ray system. For the study, we used exposure upon a phantom placed on the patient’s table. For an X-ray shielding, we used a protective apron with a lead equivalent of 1 mm, placed in two layers on the phantom. In each subsequent series of exposures, the protective apron was placed on the phantom, in a different position relative to the X-ray beam. The general conclusion of our study is that in order to obtain maximum protection from scattered radiation when using C-arm X-ray systems, the patient must be protected by a shielding with a suitable lead equivalent for the procedure performed which must be placed between patient’s body and X-ray tube, perpendicular to the X-ray beam pointed toward the region of interest.

Experimental Study for the Determination of the Material Diameter of the Riprap Bed Protection

Bed protection in apron downstream was installed to use riprap or gabion mattress. In the case of bed protection using riprap, the decision on the riprap diameter is very important because riprap diameter means the capacity to withstand the flow. Initial formulas for the decision on the riprap diameter applied velocity and weight as main factors. Since the main factors gradually expanded to depth, bed slope, and turbulence intensity, decision formulas for the riprap diameter were detailed. Because turbulence intensity was considered to be a main factor of the formula, the decision formulas for the riprap diameter could be expanded to apply to bed protection around hydraulic structures. Escarameia and May conducted a study on the riprap diameter of a strong turbulence area around the downstream of hydraulic structures. For the formula of Escarameia and May, the basis of the formula was the Izbash type, and the main factor was turbulence intensity. This study was an experimental study for deciding the riprap diameter installed around apron downstream and was based on the study results of Escarameia and May. The experiment measured the velocity upon change of discharge and riprap diameter to the installed weir model and analyzed the correlation of threshold velocity by diameter. The experimental formula in this study expanded the turbulence intensity limits of the Escarameia and May formula and increased application to turbulence intensity in weir downstream.

Study on Compliance with Radiation Protection Rules in the Medical Imaging Department of Pr Bocar Sidy Sall Hospital of Kati (Mali)

Objective: Evaluate the level of compliance with radiation protection rules in the medical imaging department of the University Hospital Center (CHU) of Kati. Methodology: This was a cross-sectional and descriptive study carried out in the medical imaging department of Pr Bocar Sidy Sall (BSS) Hospital of Kati. A questionnaire was developed and sent to the staff of the medical imaging department. The assessment focused on the radiation protection of personnel, radiation protection measures for patients, the delimitation and signage of zoning as well as the application of radiation protection principles. Results: Twenty-one people participated in the study, 90% of whom were men. The 30 - 39 age group was predominant with 61.90%. 33.33% of the staff knew the principles of radiation protection;86% of our sample knew the basic rules of radiation protection. The majority of the staff in the imaging department (61.90%) had a perfect knowledge of protective equipment. For 76% of our workforce, the limits of the radiation doses received are regulated in Mali. 76% of those surveyed have not taken any additional training in radiation protection. The doors are closed during the X-ray examination for 76.19% of the respondents and 95% of the staff put themselves behind the sealed screen during the examination. For 81% of the respondents, the design of the premises met radiation protection standards. 62% of practitioners have a dosimeter and 80% of them wear it during their shift. For 62% of our sample, the change of the dosimeter is quarterly. The systematic request for DDR (date of last menstrual period) in women and the adaptation of the delivered dose to the patient’s morphology was only carried out by 65% of practitioners. The majority of staff (81%) did not benefit from medical surveillance, while for 55% of respondents the level of radiation protection in the establishment was average. Conclusion: This study enabled us to highlight the shortcomings in terms of radiation protection within the imaging department of the CHU Kati.

PLA/EC共混制备自降解暂堵剂及性能评价

以聚乳酸为主剂,将其与乙基纤维素、腰果酚NSF3、纳米碳酸钙进行熔融共混改性,制备了新型自降解暂堵剂。通过扫描电镜分析和热重分析测试,对暂堵剂的结构进行表征,考察了自降解暂堵剂体系的降解性能、配伍性能、砂床封堵性能、储层保护性能等指标。结果表明,当聚乳酸和乙基纤维素的比例为4∶6时,暂堵剂具有较好的降解性能和热稳定性。90℃、pH=9的条件下,5d的降解率小于30%,15d的降解率大于90%,满足水平钻井作业要求。温度达到223℃时,质量损失仅为0.35%。在钻井液中加入质量分数为3%的暂堵剂后,在0.69MPa压力下,30min侵入石英砂床的深度小于5cm,能起到良好的封堵作用。此外,该暂堵剂与钻井液的配伍性良好,具有降滤失作用,且解堵后不同岩心的渗透率恢复值均在85%以上,具有较好的储层保护性能。

35t/h流化床燃煤锅炉烟气治理升级改造的实践研究与应用

针对太钢尖山铁矿选区35 t/h流化床燃煤锅炉烟气治理升级改造,从除尘系统、脱硫系统和脱硝系统分别进行了多种改造方案对比,选用电袋除尘工艺、石灰石-石膏湿法脱硫工艺和活性氨干法脱硝工艺对原有系统升级改造,并结合实际改造运行中存在的问题进行了实践研究。长期运行表明,尾气中的粉尘、二氧化硫和二氧化硫质量浓度分别达到了0.5~2,2~35,30~50 mg/m^(3),符合最新的排放标准要求。

Attenuation coefficients of gamma and X-rays passing through six materials

The aim of this study was to determine the attenuation of gamma and X-rays with different energies caused by passage through different materials.To this end,different materials with a range of atomic numbers were chosen to measure gamma and X-ray attenuation coefficients and to explore the mechanisms of interaction of gamma and X-rays with matter of various kinds.It is shown that the attenuation coefficients first decrease and then increase with increase in the radiation(photon)energy.The attenuation of gamma and X-rays passing through materials with high atomic number is greater than that in materials with low atomic number.The attenuation minimum is related to the atomic number of the irradiated materials.The larger the atomic number is,the lower the energy corresponding to attenuation minimum is.Photoelectric and Compton effects are the main processes when gamma rays pass through individual materials with high and low atomic numbers,respectively.Therefore,for radiotherapy and radiation protection,different methods should be considered and selected for the use of gamma and X-rays of different energies for use in different materials.

坦桑尼亚某晶质石墨大鳞片保护工艺研究

坦桑尼亚某晶质石墨矿固定碳含量为3.74%,鳞片粒径+147μm占比97.18%。对比了高压辊磨机和球磨机两种磨矿方式下浮选粗精矿的分质产品差异,并开展了各分质产品再磨再选试验。试验结果表明,采用层压粉碎(高压辊磨机)—分质分选新工艺效果较好,粗粒低碳分质产品单独再磨避免了脉石对粗精矿中高解离度大鳞片石墨的破坏,且碳品位提升较快,其再选精矿与中粒中碳产品合并成一个产品,与细粒高碳产品分别经两段再磨再选后,精矿碳品位均大于96%,最终获得了碳品位96.24%、回收率95.30%的精矿。层压粉碎—分质分选工艺相比常规粗精矿混目再磨再选工艺减少了五次再磨六次精选,最终精矿碳品位高1.04百分点,+0.30 mm粒级精矿产率高3.25百分点。

深井阳极地床杂散电流干扰特征分析及数值模拟研究

为研究深井阳极地床杂散电流干扰的影响范围及其严重程度,采用COMSOL软件建立典型深井阳极地床地电场数值模型,结合现场测试数据验证数值模型的可靠性,分析土壤电阻率、输出电流、阳极埋深和阳极体总长度等因素对深井阳极地床地电位梯度分布、地电位梯度峰值和杂散电流强干扰半径的影响。研究结果表明:地电位梯度峰值与土壤电阻率和输出电流之间呈线性增长关系,与阳极埋深和阳极体总长度呈二次函数负相关;杂散电流强干扰半径与土壤电阻率和输出电流呈二次函数正相关,与阳极埋深和阳极体总长度呈二次函数负相关;土壤电阻率和输出电流对深井阳极地床杂散电流干扰影响较大,针对输出电流大的深井阳极地床和多石、旱地等高土壤电阻率区域,应对其邻近金属构筑物做好监测及排流保护。研究结果可为深井阳极地床优化选址、设计及其邻近金属构筑物腐蚀防护提供指导。

松软煤层顺层定向钻进技术在杨柳矿的应用试验研究

针对松软煤层顺煤层定向瓦斯治理钻孔打不深、打不准、成孔率低的难题,详细分析了现有顺层定向钻进的技术瓶颈,创新尝试使用了底板定向梳状条带消突钻孔,突破了主孔快速开分支、分支孔水力下筛管护孔等技术难题,并选取杨柳煤矿1077中段机巷进行现场试验,在煤层坚固性系数为0.46的松软层中,共完成总进尺8 494 m,实验效果达到设计要求。现场试验表明,底板定向梳状条带消突钻孔有效缓解了采掘接替紧张局面,提高了矿井钻孔施工及瓦斯治理技术水平,为松软煤层定向瓦斯治理钻孔施工提供了新的技术思路。

甲状腺癌^(131)Ⅰ治疗患者被服清洁解控方案的构建

目的构建^(131)Ⅰ治疗甲状腺癌患者被服清洁解控方案,为临床被服清洁解控的开展提供借鉴。方法通过临床调研、文献研究、影响因素分析、半结构访谈和课题组讨论,构建^(131)Ⅰ治疗甲状腺癌患者被服清洁解控方案初稿。采用德尔菲专家咨询法,选取30名专家进行2轮专家咨询,结合研究小组讨论构建^(131)Ⅰ治疗患者被服清洁解控方案。结果2轮专家咨询问卷回收率均为100%,第2轮咨询中,各条目的变异系数为0.00~0.24,重要性得分为4.13~5.00分,专家权威系数为0.867,一级、二级、三级指标的肯德尔和谐系数分别为0.475、0.420、0.292(均P<0.05),形成的^(131)Ⅰ治疗甲状腺癌患者被服清洁解控方案包括5个一级指标、20个二级指标、59个三级指标。结论^(131)Ⅰ治疗甲状腺癌患者被服清洁解控方案构建过程规范严谨,可为临床^(131)Ⅰ治疗甲状腺癌患者被服的清洁解控提供指引。

煤层气井管柱阴极保护试验研究

针对煤层气井管柱腐蚀问题,采用外加电流阴极保护技术,建立煤层气井井下管柱外加电流阴极保护模型。以山西保德煤层气井为例,研究了N80管柱在井下25~45℃环境温度下的腐蚀行为,以及外加电流阴极保护技术对N80管柱的耐蚀性能影响,并通过失重法、电化学测试、电位检测等方法表征了管柱阴极保护成效。结果表明,随着井下环境温度升高,材料腐蚀速率上升,外加电流阴极保护技术对材料耐蚀性能提升更为显著,因此,采用外加电流阴极保护技术对N80管柱腐蚀防护是一种高效、可行的方法。

Knowledge of radiation exposure associated with common trauma imaging modalities among orthopaedic surgeons,emergency medicine physicians,and general surgeons in the United States

BACKGROUND:Few contemporary studies have assessed physicians’knowledge of radiation exposure associated with common imaging studies,especially in trauma care.The purpose of this study was to assess the knowledge of physicians involved in caring for trauma patients regarding the effective radiation doses of musculoskeletal(MSK)imaging studies routinely utilized in the trauma setting.METHODS:An electronic survey was distributed to United States orthopaedic surgery,general surgery,and emergency medicine(EM)residency programs.Participants were asked to estimate the radiation dose for common imaging modalities of the pelvis,lumbar spine,and lower extremity,in terms of chest X-ray(CXR)equivalents.Physician estimates were compared to the true effective radiation doses.Additionally,participants were asked to report the frequency of discussing radiation risk with patients.RESULTS:A total of 218 physicians completed the survey;102(46.8%)were EM physicians,88(40.4%)wereorthopaedicsurgeons,and28(12.8%)weregeneralsurgeons.Physicians underestimated the effective radiation doses of nearly all imaging modalities,most notably for pelvic computed tomaography(CT)(median 50 CXR estimation vs.162 CXR actual)and lumbar CT(median 50 CXR estimation vs.638 CXR actual).There was no difference between physician specialties regarding estimation accuracy(P=0.133).Physicians who regularly discussed radiation risks with patients more accurately estimated radiation exposure(P=0.007).CONCLUSION:The knowledge among orthopaedic and general surgeons and EM physicians regarding the radiation exposure associated with common MSK trauma imaging is lacking.Further investigation with larger scale studies is warranted,and additional education in this area may improve care.

Physicians’knowledge about radiation protection of patients during prescription of CT scan procedures in Morocco

Objective:To evaluate the knowledge and practices of Moroccan physicians in terms of radioprotection of patients when prescribing computed tomography(CT)procedures.Methods:This is a cross-sectional study in which a questionnaire with 23 multiple-choice questions was sent to prescribers of CT examinations such as radiotherapists(RMs),other medical specialists(OMSs),general practitioners(GPs)and residents/interns(R/Is).The first eight questions asked about the demographics of the participants,while the remaining questions asked about knowledge of ionizing radiation examinations,doses received,relative risks,and patient radiation safety training.Results:A total of 223 physicians participated in this survey.Radiation therapists,considered as the reference group,had a better knowledge of irradiating and non-irradiating imaging compared to the other groups(P=0.003).Thus,67%of the reference group declared to take into account the number of scans performed by the patient during the last year,unlike the other groups(P=0.002).Furthermore,the knowledge of the different groups about the risks related to exposure to ionizing radiation was globally low(2%)(P=0.73).Regardless of their specialties and seniority,only 12%of the participants informed the patient at the time of prescription about the risks of X-rays.Finally,only 21%of the participants declared having had training in radiation protection,with no significant differences between the subgroups(P=0.832).Conclusions:The results obtained are similar to those reported in previous studies.They show that Moroccan prescribers have a low level of knowledge of the risks associated with CT examinations.Training on patient radiation protection should be included in the initial curriculum of interns and the continuing professional development of physicians should be reinforced.

流化床气流超微粉碎协同超高压法提取赶黄草黄酮工艺优化及其保肝作用研究

目的优化流化床气流超微粉碎协同超高压法提取赶黄草黄酮的工艺,并对其保肝作用进行研究。方法采用流化床气流超微粉碎协同超高压法提取赶黄草黄酮,通过单因素和响应面实验优化提取工艺参数。同时采用随机法把小鼠分为正常对照组、CCl4模型组、联苯双酯组和赶黄草黄酮低、中、高剂量组。除正常对照组外,其余5组注射0.1%的CCl4构建肝损伤小鼠模型。采用全自动生化仪测定小鼠血清中谷草转氨酶(aspartate aminotransferase,AST)、谷丙转氨酶(alanine aminotransferase,ALT)、乳酸脱氢酶(lactate dehydrogenase,LDH)值和丙二醛(malondialdehyde,MDA)含量,肝组织中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和超氧化物歧化酶(superoxide dismutase,SOD)活性。结果最佳提取工艺条件为:溶剂倍数25、压力400 MPa、保压时间13 min,在此条件下,赶黄草黄酮得率为3.98%,此法的提取效果优于其他3种单一的提取方式。体外保肝实验结果表明:赶黄草黄酮能显著降低CCl4所致肝损伤小鼠血清中AST、ALT、LDH的值和MDA含量,提高小鼠肝组织中GSH-Px和SOD活性,表明赶黄草黄酮对CCl4所致肝损伤具有较好的保护作用。结论优化后的提取条件能够有效提取赶黄草黄酮,且得到的赶黄草黄酮具有明显的保肝作用。

循环流化床锅炉脱硫技术改造实践

我公司循环流化床锅炉烟气处理设施采用双碱法脱硫,在运行过程中脱硫设施经常出现故障,且随着新环保标准的出台,现有的环保设施已满足不了使用要求。本文介绍了循环流化床锅炉在由双碱法脱硫技改为石灰-石膏法脱硫过程中,对部分利旧设备、设施的技术改造,以及石灰-石膏法脱硫法关键技术的创新,改造完成后,不仅大大节约了投资,而且达到了预期的环保效益。

长庆气田储气库井大井眼钻井液技术

储气库是储备天然气战略资源和天然气生产调配的重要手段,具有良好的社会和经济效益。储气库钻井施工中,由于井眼尺寸大,会出现井眼清洁、井壁失稳、井下漏失等问题。针对上述问题,优化现有钻井液技术,有效减少井下复杂情况发生,形成了一套使储气库井大井眼井眼清洁、井壁稳定的超分子堵漏技术。现场应用表明,使用该技术钻井液动切力≥0.3 Pa,满足井眼清洁需求;完钻密度≤1.20 g/cm3,滤失量≤6 mL,保证了井壁稳定;使用超分子凝胶堵漏剂,地层承压能力可提至1.36 g/cm3以上当量密度;处理复杂情况损失时间占比由原先的10%下降至5.26%,满足储气库建设需求。

露天煤矿非工作帮顺层边坡致滑机理及稳定性分析

对新疆某露天煤矿地质特征进行分析,采用控制变量法,改变平盘宽度及边坡角,分析非工作帮顺层边坡的稳定性,得出该矿顺倾边坡的安全稳定系数,根据计算结果,提出合理的开采顺序,通过加强维护检查、加固抗滑工程等措施,做好边坡防护。

含页岩软弱层顺层边坡稳定性分析及优化设计研究

为解决含软弱层顺层高边坡临滑失稳问题,文中以德上高速某段页岩软弱顺层高边坡为例,基于现场调绘和地质资料,采用不平衡推力法和反算参数法确定边坡的安全系数;针对施工过程中出现的临滑险情,提出临时支护和永久加固相结合的设计思路。加固完成后,边坡处于稳定状态,研究成果可为此类山区高速公路夹页岩软弱顺层的高边坡治理提供实践经验。

EFFECTS OF UNDERSCOUR DEPTH AND HORIZONTAL SPACING BETWEEN TWO BED PROTECTION BLOCKS ON STABILITY OF FRONTAL BLOCK

The stability of a river-bed protection block in a flood event is affected by underscouring of the block. The effects of block spacing on block stability were investigated in different underscour conditions. Three blocks were placed at the bottom in a flume, and the underscour depth of the frontal block and distance between the first and second blocks were changed. Drag and lift forces were measured directly in each experimental condition. Particle Image Velocimetry （PIV） was used to visualize the flow and eva- luate the streamline pattern. Pressure measurements around the block to understand the pressure distribution show that the pressure distribution on the rear and bottom surfaces of the block is significantly affected by changes in block spacing and underscour depth. The experimental results show that for the same underscour gap, lift, and drag coefficients decreased with increasing space between the two blocks. In addition, if the underscour gap is increased with the same horizontal spacing, the lift coefficient increases and drag coefficient decreases. These results demonstrate that wider spacing enhance stability of the frontal block in the underscour condition. Moreover, analysis of block stability with changing underscouring and horizontal spacing shows that bed protection blocks seem to have more stability when the gap between two bed protection blocks was equal to height of the blocks.

长输石油管道阴极保护技术分析

介绍了阴极保护技术的分类与应用原理,详细阐述阴极保护装置形成的故障危害与发生故障的原因,随后将阴极保护技术应用到长输石油管道建设中,运用过程包括安装恒电位仪、设计参比电极、设置阳极地床、控制锌接地电池及安装测试箱等。完成阴极保护装置设计后,要定期进行装置设备维护,增强阴极保护技术在长输石油管道中的适应性。