Comparison of Gamma Pass Rate between the Dose-to-Water and Dose-to-Medium Reporting Modes for Patient-Specific QA Using a Helical Diode Array Dosimeter with a Fixed Phantom Density

Introduction: To compare the measured dose distributions to calculated ones in dose-to-water (Dw) and dose-to-medium (Dm) reporting modes for simple plans and patient-specific intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans using ArcCHECK with a fixed phantom density. Methods: The recommended density value of 1.18 g/cm3 for Acuros XB and X-ray voxel Monte Carlo was assigned to ArcCHECK on CT images. A total of 45 simple plans, including a 1-field plan, a 3-field plan, a 4-field plan, a half-arc plan from 270° to 90°, and a full-arc plan, were assessed. Subsequently, the patient-specific 96 IMRT and VMAT plans were evaluated. Gamma analysis with a 3% normalized global dose error and a 3 mm distance-to-agreement criteria (γ3%G/3mm) was performed in the Dw and Dm. The change in γ3%G/3mm between Dw and Dm were statistically analyzed using JMPPro11 software. Results: The median values of γ3%G/3mm for all simple plans for Dw and Dm were 98.1% (range, 75.2% - 100%) and 95.5% (range, 23.7% - 100%), respectively (p 0.01). In the patient-specific IMRT and VMAT plans, the median values of γ3%G/3mm for Dw and Dm were 98.6% (range, 90.1% - 100%) and 90.5% (range, 38.5% - 97.2%), respectively (p 0.01). Conclusion: Our results showed that the calculated and measured dose distributions were in good agreement for Dw, but were not for Dm. From the viewpoint of the rationale of dosimetry, Dw shows better agreement with measured dose distribution when using the fixedphantom density recommended by the vendor.

Assessment of Monitor Units and Gamma Pass Rate for 6 MV and Flattening Filter Free (FFF) Beams in Volumetric Modulated Arc Therapy (VMAT)

Background: In linear accelerators, the treatment field’s uniform intensity is achieved by including a flattening filter in the beam. However, to produce more conformal dose distributions, contemporary radiotherapy practice now frequently uses fluence and aperture modifying techniques, such as volumetric modulated arc therapy. In these circumstances, the flattening filter in the beam manufacturing process is no longer required. It is therefore necessary to compare the monitor units of 6 MV and flattening filter free plans and how it influences the gamma pass rates to determine which is best for treating cervical cancer with pelvic lymph node metastasis. Methods: VMAT plans for fifteen patients with cervical cancer with pathological pelvic lymph node metastasis were included in this study. Each patient had two VMAT plans using conventional 6 MV beam with flattening filter and one with flattening filter free beam (FFF). The VMAT plans were made using two arcs, and then recalculated to give the planned dose distribution to the detectors in a Delta4 phantom. The VMAT plans were irradiated on the Delta4 phantom using an Elekta linear accelerator (6 MV). Results: The mean monitor unit for the 6 MV plans was 506.3 MU and a standard deviation of 48.6 while that of the FFF plans had a mean MU of 701.5 with a standard deviation of 87.6. The total monitor units (MUs) for the FFF plans were significantly greater than the 6 MV plans (p = 6.1 × 10-5). Conclusion: Flattening filter free (FFF) plans require more numbers of monitor units in comparison to conventional 6 MV filtered beams for external radiation of cervical cancer with pelvic lymph nodes involvement.

CPA Pass Rates in Texas： A 12-Year Analysis

This research examines the CPA exam pass rates for higher education institutions in Texas. An investigation related to the top schools and AACSB accreditation is conducted as well as analyses related to public vs. private schools, area of the state where the institution is located, and University Systems. The results reflect impressive pass rates by University of Texas at Austin and Texas A＆M University at College Station in terms of both number of students taking the exam and the percentage passing it. There was a significant CPA rate lead with private universities only when the two outstanding public universities were omitted from the analysis. The research also found significant differences in terms of areas of the state as well as university systems. The analysis and the findings are very important to students with CPA exam success as their academic primary goal with their university education, the educational institutions preparing the students, and society as a whole. The fmdings may help guide both the universities and the students to better success with the exam as well as perhaps help taxpayers and legislators know how well tax money is being spent in this area.

Evaluation of the Impact of Refined Quality Control Management Model on the Qualified Rate of Disinfection and Sterilization of Surgical Instruments in the Sterilization Supply Center

Objective:To evaluate the application value of a refined quality control management model for a sterilization supply center.Methods:A retrospective analysis was conducted on the work situation of the sterilization supply center from January 2021 to January 2023.The work situation before January 31,2022,was classified as the control group;a routine quality control management model was implemented,and the work situation after January 31,2022,was classified as the observation group.The quality of medical device management and department satisfaction between the two groups were compared.Results:The timely recovery and supply rate,classification and cleaning pass rate,disinfection pass rate,packaging pass rate,sterilization pass rate,and department satisfaction score in the observation group were all higher than those of the control group(P<0.05).Conclusion:Implementing a refined quality control management model in the sterilization supply center can improve the quality management level of medical devices and department satisfaction and is worthy of promotion.

CBCT引导下头颈肩联合腹膜固定方式在乳腺癌IMRT中的临床适用性研究

目的基于锥形束CT(Cone Beam CT,CBCT)影像比较头颈肩联合腹膜体位固定方式和乳腺托架体位固定方式的摆位误差,研究头颈肩联合腹膜在乳腺癌患者调强放射治疗(Intensity Modulated Radiotherapy,IMRT)中体位固定方法的可行性。方法选取需要进行IMRT的40例乳腺癌患者为研究对象,并将其随机分成头颈肩联合腹膜固定组(20例)、乳腺托架固定组(20例)。每例患者在放射治疗(以下简称“放疗”)前行CBCT扫描,每周1次,分析2组患者在X(左右)、Y(进出)、Z(前后)方向的摆位误差、分次间位移和摆位效率。结果头颈肩联合腹膜和托架摆位2组患者在X、Y、Z方向上的摆位误差分别为(1.97±0.94)和(2.11±1.55)mm、(2.54±0.57)和(2.82±1.46)mm、(1.27±0.62)和(2.28±0.96)mm(P=0.801、0.604、0.013);分次间位移分别为(0.76±0.50)和(1.24±0.52)mm、(1.34±0.15)和(2.52±1.18)mm、(0.73±0.33)和(0.88±0.53)mm(P=0.453、0.296、0.773);摆位时间分别为(6.5±1.7)和(8.7±3.1)min(P=0.485);2组X、Y、Z方向上的首次摆位通过率分别为90%和85%、80%和70%、100%和95%(P=0.632、0.464、0.235);分次间摆位通过率为92%和82%、88%和79%、94%和88%(P=0.036、0.086、0.138)。结论头颈肩联合腹膜体位固定方式简单易行,可在一定程度上控制乳腺癌患者IMRT的摆位误差和分次间位移,尤其是Z方向上的摆位误差,提高摆位效率。

COMPASS验证系统在放射治疗中的应用研究

目的:测试COMPASS三维验证系统在临床应用中的可行性。方法:以三维水箱为基准,比较分析COMPASS系统在百分深度剂量(Percentage depth dose,PDD)、输出因子(Output factor,OUF)、离轴曲线(Profile)和绝对剂量等方面的测量数据与三维水箱所测量数据的相关性和一致性;在均匀模体和非均匀模体中验证7例患者的放疗计划,检测COMPASS系统软件的剂量计算精度和剂量重建精度;通过BallBearming模体测试COMPASS系统硬件对加速器等中心的影响。结果:COMPASS系统测量和重新计算的PDD、OUF、Profile与三维水箱测量的数据具有较好的一致性,其绝对剂量偏差均小于2.5%;COMPASS系统软件在均匀模体和非均匀模体中验证7例患者放疗计划的绝对剂量偏差均小于3%,γ通过率不低于93%,重建精度和剂量计算精度接近于计划系统(Teatmentplanning system,TPS);COMPASS系统的硬件不影响等中心的精度,在三个方向上的偏差都小于1mm。结论:COMPASS系统的独立计算功能和剂量重建功能具有类似TPS的精度,可以提供三维的剂量分布信息,为临床治疗提供安全、可靠的技术保障。

基于DEFORM-3D的哈氏合金基带多道次轧制仿真研究

使用DEFORM-3D三维模拟软件对哈氏合金基带的粗轧过程进行多道次仿真,依托流变应力的计算,建立了材料物性模型和仿真模型,并利用前几道次的粗轧实验验证了模型的准确性。通过仿真实验探索了压下率、轧辊形状和摩擦因数对轧制流程的影响。结果表明,随着道次压下率的升高,平均轧制力升高,30%道次压下率的轧制流程带来基带应变不均匀性是表面裂纹产生的重要原因,成功预测了后续轧制实验中带材表面产生的裂纹,实际生产应尽量选用20%及以下的压下率;在该应用条件中,新设计的凹面轧辊流程能有效减小轧制力,降低设备要求,提高轧制安全性,实验中部分流程采用凹面轧辊有效地将侧面裂纹的出现延迟到了第8道次;好的润滑条件能减小摩擦,模拟结果表明摩擦因数越小,基带轧制的均匀性越好,但会增加工序的时间,也会提高材料进给的难度。研究结果优化了实际轧制流程,降低了基带轧制过程中的表面及边部裂纹等缺陷。

大面积混凝土张拉工序验收合格率提升策略研究

大面积混凝土张拉工序是混凝土施工中一种常见且关键的技术,通过预应力钢筋的张拉达到增强混凝土结构性能的目的。该工序的验收合格率直接影响到工程质量和安全性。在大面积混凝土工程中,由于施工复杂性和环境变量的多样性,因此保证张拉工序的合格率非常重要。文章首先明确了张拉工序验收的基本要求与标准规范;其次系统地分析了影响验收合格率的主要因素,包括材料质量和施工环境;再次提出了一系列实用的提升方法,如加强施工前的准备、改进施工过程中的质量控制,以及施工后的详细验收;最后通过具体案例的内容与数据分析,展示了这些方法的实际效果和应用价值。

班多水电站鱼道内鱼类通过性研究

为了解班多水电站鱼道设计的合理性,选用7种土著鱼类进行鱼类通过性试验。试验结果表明,在通过率与折返率方面,鱼类通过率范围为14.3%~72.7%,折返率范围为2.0%~28.6%,整体通过率为45.8%,整体折返率为15.5%。在上溯时间方面,整体表现为鮈亚科>条鳅亚科>裂腹鱼亚科。在上溯速度方面,整体表现为裂腹鱼亚科>条鳅亚科>鮈亚科。在过鱼规格方面,表现为随着鱼类体长的增加,鱼类通过的比例呈递增趋势。在鱼类活动昼夜分布方面,表现为白天下午活动频率显著高于夜间活动频率。

Efficient Rate Control for Motion JPEG2000 under Constraint Memory

Fine scalability can provide not only precise rate control for constant bitrate (CBR) traffic, but also accurate quality control for variable bitrate (VBR) traffic. Motion JPEG2000 is a codec that can provide fine scalability with bitstreams. An efficient rate control approach utilizing a single buffer and two kinds of threshold for Motion JPEG2000 under resource constraint was proposed, which can offer good result in the constant quality video.

The Effectiveness of a Structured Remediation Program to Pass the NCLEX-RN Examination

The National Council Licensure Examination for Registered Nurses (NCLEX-RN) has been the standard by which all undergraduate nursing programs are judged for program effectiveness. Consistent patterns of low pass rates can have serious implications for the academic institution, the nursing program, the nursing faculty, the program graduates, and the community at large. Preparing undergraduate nursing students for licensure is a major concern for undergraduate nursing faculty. Present pass rates for the graduate nursing baccalaureate students at a state university are currently below the national average. To address this problem, these researchers have identified interventions that predict success on the NCLEX-RN examination. The implementation of a five week online NCLEX-RN review course in conjunction with three workshops taught and designed by these researchers is used to increase the pass rate on the NCLEX-RN exam. The goal of the implementation of this assessment project is to provide the nursing student with the necessary tools to be successful on the NCLEX-RN. Furthermore, findings from this project have the potential to identify areas for the improvement in the nursing curriculum as well as the increase of the nursing program’s NCLEX-RN pass rate.

Multiple Phase Change Materials for Performance Enhancement of a Solar Dryer with Double Pass Collector

The fluctuation in drying temperature influences the food products’quality and drying time significantly during the drying process using an indirect solar dryer.One of the effective methods to reduce these variations in the temperature is based on thermal storage materials to control the drying temperature.An experimental investigation is presented in this study to evaluate the performance of an indirect solar dryer with air double pass using multiple phase change materials(PCM)as thermal storage materials.Two PCMs with different melting points are used to store the available heat energy during peak sunshine periods and reduce the drying temperature fluctuations.Drying tests on a food product sample are conducted in three cases,the first was without PCMs using natural convection.The second and third cases are based on forced convection with and without using multiple PCMs under Baghdad city conditions.The results showed that;approximately a steady temperature of hot drying air was obtained during relatively low ambient temperatures when the dryer was incorporated with multiple PCMs.The drying time of the product sample for the natural,forced convection without PCMs and forced with PCMs was 87,72 and 47 h,respectively.The higher performance of the dryer was for the forced convection with PCMs.The reduction percentage in drying time was about 17.2%and 46%for the forced convection without and with PCMs respectively compared with natural convection.The average drying rate for the natural,forced without PCMs and forced convection with PCMs was 0.0093,0.0135 and 0.0172 kg/h,respectively.The enhancement in thermal efficiency of the solar collector and drying chamber with multiple PCMs was 43%and 25.5%,respectively,compared with a typical solar dryer.

露天爆破中炸药单耗对岩石破碎块度的数值模拟研究

露天爆破中岩石破碎块度是钻爆、铲装、运输及后续工艺等综合成本的主要衡量标准,炸药单耗是其主要影响因素,而炸药单耗对破碎块度的研究一般采用爆破模型试验,但其存在成本高、试验结果误差大等缺点.为了优化炸药单耗来降低爆堆的大块率、平均块度,并预测实际工程块度,在爆炸破岩理论基础上,运用基础力学测试设备对模型材料进行了单轴抗压、弹性模量、断裂韧度等测试,标定RHT本构模型参数,通过LS-DYNA数值仿真软件和粒子流算法(SPH)构建了三维露天台阶爆破数值仿真模型,首次对爆破破岩数值模拟结果实现块度精准统计,并对爆破破岩块度随炸药单耗的变化规律开展了系统研究.研究结果表明:炸药单耗在0.23~0.79 kg·m^(-3)范围内,岩块最大尺寸均小于240 mm,其变化区域分为240、220、140 mm三个最大块度相近区和240~220 mm、220~140 mm两个明显下降区;随单耗增加,均匀性指数n呈波浪式减小,分形维数D与n的变化趋势相反,平均块度尺寸呈现先快速下降后缓慢变化的趋势;炸药单耗的块度分布拟合曲线采用G–G–S函数拟合,相关系数均在0.91~0.97间,其变化规律验证了通过SPH法来模拟岩石爆破和岩石破碎块度统计方法的可行性和准确性.研究结果对爆破破碎块度分布规律的完善及块度控制工程具有一定的意义.

“国考”成绩与学业成绩相关性分析及教学建议——以物理学科知识与教学能力科目成绩为例

目前,国家教师资格证考试中物理学科知识与教学能力科目的合格率较低。其原因,可能与学生之前学过的各科成绩有关。所以,该文把部分公共课和专业核心课的期末总评成绩,分别与“国考”物理学科知识与教学能力科目成绩进行相关性分析。分析得到,相关性最强的三个科目分别是教师职业道德、物理课程与教学论和物理学科知识与教学能力课程。根据这个研究结果,结合考生考试后的问卷调查情况总结,分别从提高学生的教师职业认知、注重专业课和中学物理课程结合、加强中学物理教学实践训练三方面,给出对物理学科课程与教学论和物理学科知识与教学能力等课程的教学建议,以供同行参考。

基于AIS大数据耦合分析的沿海港口泊位利用率研究

针对我国沿海港口能力供给水平数据跟踪方面长期存在的时效性差、人为统计过程中易出现错漏等诸多问题,分析传统泊位通过能力统计失真的具体原因,提出将泊位利用率作为评价港口服务水平的表征指标,依托地理信息系统(GIS)平台和基于船舶自动识别系统(AIS)等数据耦合的空间拓扑分析,综合考虑空间关系、航速特征、经留时间等影响因素,研发基于AIS大数据的泊位利用率算法模型,并以上海港2019年集装箱泊位利用率为例进行算法验证。结果表明,所提出的泊位利用率算法模型是可信的;提供了一种能够反映客观实际、定量分析判断港口服务水平的技术手段,可为政府部门长期动态监测港口能力与运输需求互动平衡关系,支撑政府部门决策港口发展重点和建设时序,避免空间资源浪费、重复建设、能力过剩等问题提供技术支撑。

宫颈癌调强计划Portal Dosimetry剂量验证中拼接野的应用分析

目的提出一种生成Portal Dosimetry(以下简称PD)分野的拼接野(以下简称PD拼接野)方法,并对宫颈癌计划的PD拼接野进行分析研究。方法选取20例宫颈癌患者的七野调强治疗计划进行研究,治疗计划中每个大野分成1对分野。首先制作仅含分野的PD剂量验证计划,然后使用直线加速器出束执行。通过矩阵拼接和矩阵叠加,分别得到每对PD分野对应的PD拼接野和PD大野。使用PD软件模块,得到PD拼接野和PD大野的伽玛通过率,分别记为Gp和Gd。使用Gm表示每对PD分野的平均伽玛通过率值。对Gp、Gd和Gm进行统计分析和比较研究。结果所有140个射野的Gp、Gd和Gm的值分别为98.78%±0.70%、97.34%±1.25%和98.87%±0.51%。两两比较结果显示,Gp和Gd差异具有统计学意义(P<0.05);Gp和Gm的数据差异较小。对每个PD验证计划,计算所有同一类射野对应的计划验证通过率(Gplan)。对Gplan数据进行统计分析显示,PD拼接野和PD大野差异具有统计学意义(P<0.05),PD拼接野和PD分野的数据差异较小。结论本文提出的PD拼接野概念为评价PD剂量验证结果提供了有益的参考信息。

辊模在高碳钢丝连续拉拔中的应用

采用2种拉拔应变对高碳钢丝进行辊模拉拔,并与传统拉拔对比。结果表明:在拉拔应变1.12时,辊模拉拔钢丝的抗拉强度、扭转性能、弯曲性能、金相组织、捻制断丝率与传统拉拔相近;在拉拔应变2.21时,辊模拉拔和传统拉拔相比,钢丝抗拉强度更高,扭转性能、弯曲性能较差,金相组织不均匀程度更大,捻制断丝率明显升高。在钢丝材质、机床功率、拉拔速度、道次压缩率等因素相同的情况下,辊模拉拔的能耗和传统拉拔相近。

针刺合谷、内关、足三里联合药物治疗急性胆囊炎的临床研究

目的分析针刺合谷、内关、足三里联合药物治疗急性胆囊炎(AC)的效果。方法选择2021年3月至2022年3月郏县中医院收治的AC患者62例,按照随机数字表法分为A组(常规药物治疗)和B组(常规药物治疗+针刺合谷、内关、足三里),对比两组治疗有效率、并发症发生率、临床症状评分、胆囊指标、炎性因子指标、疼痛程度、生活质量评分。结果B组治疗有效率高于A组,并发症发生率低于A组,差异具有统计学意义(P<0.05);治疗后B组临床症状评分(厌食、黄疸、口苦、发热、便秘、恶心、腹痛)、胆囊指标(胆囊横径、胆囊壁厚度)、炎性因子指标[白细胞计数(WBC)、高敏C反应蛋白(hs-CRP)、降钙素原(PCT)、白介素-6(IL-6)]、VAS、PPI、PRI评分低于A组,差异具有统计学意义(P<0.05);B组生活质量评分(躯体疼痛、社会功能、情感职能、活力、生理职能、生理机能、精神健康)高于A组,差异具有统计学意义(P<0.05)。结论AC患者在常规服用药物治疗的基础上联合针刺合谷、内关、足三里,能更好地改善患者临床症状、疼痛感,降低炎症指标、胆囊指标,在一定程度上降低并发症风险,提高患者生活质量。

MLC运动误差对不同射野面积的鼻咽癌容积调强计划的影响

目的 研究多叶准直器运动误差(Multi-Leaf Collimator Error,MLC_(error))对不同射野平均面积(Mean Aperture Area,MAA)的鼻咽癌容积调强的影响。方法 选取30例鼻咽癌患者为研究对象,每例患者的原始计划导出后使用Python编译,依据不同的MLC_(error)制作6组模拟计划(±0.2 mm、±0.5 mm和±1.0 mm)。对比原始计划与模拟计划的剂量学参数和验证通过率,分析MLC_(error)和MAA对计划验证的影响。其中,将鼻咽肿瘤计划靶区(Planning Target Volume,PTV)与颈部转移淋巴结肿瘤靶区通过布尔运算整合为PTV69。结果 随着MLC_(error)的变化(-1~1 mm),PTV69、原发灶高危亚临床靶区和中危亚临床靶区的剂量梯度分别为6.1、6.0、6.3%/mm(P<0.05);危及器官(Organ At Risk,OAR)的剂量梯度均高于靶区剂量梯度。脊髓、脑干、左侧腮腺、右侧腮腺、口腔和喉的剂量梯度分别为10.6、10.5、12.3、12.0、8.1、11.2%/mm(P<0.05)。在对射野面积、MLC_(error)及验证通过率关系的研究中发现,不同MAA计划的验证通过率差异随MLC_(error)的增加而增大;当MLC_(error)误差达到±1.0 mm时,不同MAA计划的验证通过率差异最大(51.7%~90.2%)。结论 相较于靶区,控制MLC_(error)更有利于OAR的保护。对于鼻咽癌等复杂的放疗计划,建议将MLC_(error)精度控制在0.5 mm以内并降低小子野使用,以保护危及器官,保证计划执行的精确度。

中国碳市场下发电企业碳成本传导率及动态特征

深化中国碳市场建设、促进发电企业碳排放成本向下游需求侧科学传导是加快经济社会全面绿色低碳转型的重要政策着力点。合理的碳成本传导率不仅能激发企业减排动力,还可以将碳排放成本通过提高电力价格的方式向消费端转嫁,引导其节约用电,从而推动碳市场在更大范围内形成减排效应。该研究基于发电企业经营行为的微观视角,将碳排放成本纳入企业的投资决策范畴,在充分考虑排放强度、风险偏好和采纳低碳技术意愿等异质性因素的基础上,构建了基于Agent的碳成本传导评估模型。通过模拟发电企业在面对有限信息时的策略选择,探讨了2021—2030年中国碳市场下发电企业碳成本传导率的变化趋势,并分析了不同的市场机制设计和低碳技术对碳成本传导率的作用影响。研究发现:①发电企业碳成本传导率呈现“缓慢增长—快速上升—保持高位”的动态特征。②初始碳价、市场规制系数和拍卖比例等市场机制设计均对发电企业碳成本传导率产生正向作用。具体地,初始碳价的增长会在短期内推高碳成传导率,作用效果在中长期将逐渐减弱;市场规制系数对碳成本传导率的推动作用存在门槛效应;随着拍卖比例的提高,企业的排放成本将会增加,进而引起碳成本传导率升高。③低碳技术能够缓解碳排放约束下发电企业的经营成本压力,避免碳成本传导率过度上升。该研究不仅为发电企业碳成本传导问题的探究提供了理论支撑,还为健全中国碳市场的机制设计提供了实践指引。