正常成年人寰枢椎直立主动旋转运动特征的研究

目的观察正常成年人头部直立主动旋转过程中C_1相对于C-2的运动特征。方法纳入健康成年志愿者20名,志愿者坐于(标准坐姿)双平面X线投射系统内,并指导其持续主动旋转头颈部以进行动态测试。收集9个动态测试的反射标记数据和双平面X线片,其中屈曲伸展、横向弯曲、轴向旋转各3个。将志愿者的CT影像重建造模,采用跟踪技术记录C_1、C_2椎体的运动。结果 C-(1、2)旋转与头部旋转呈线性相关,旋转中间线在头部旋转大约30°处变为非线性。在头部轴向旋转过程中,C_1相对于C_2的最大轴向旋转角度为22.4°~47.5°(36.8±6.7)°;同时也观察到C1相对于C2的耦合旋转运动,屈伸3.6°~28.4°(7.8±4.8)°,横向弯曲3.0°~17.7°(9.8±3.8)°。C-1相对于C_2也发生平移,在椎体内侧从左往右平移3.8~12.0(7.8±1.5)mm,上下平移0.6~4.6(2.2±1.2)mm,前后平移1.4~5.5(3.3±1.0)mm。结论寰枢椎失稳在静态影像学成像中容易被忽视,应用跟踪技术在头部直立主动旋转过程中可以明确寰枢椎三维运动学特征,有利于诊断寰枕关节动态不稳。     

四川省《预包装食品标签通则》（GB 7718-2011） 应用情况跟踪评价调查

摘要:目的　了解四川省监督管理机构、生产经营企业对GB 7718-2011的应用情况,并分析影响知晓率的因素,提出相关意见和建议供卫生行政部门参考。方法　通过分层整群随机抽样抽取调查对象,进行问卷调查,收集其基本情况,并对标准的知晓及使用频次、合理性及可操作性进行评价。结果　评价结果显示预包装食品标签总体应用较好。93.8%的调查对象表示知晓GB 7718-2011,82.7%的调查对象认为其基本合理,81.1%的调查对象认为其可操作性较好。影响知晓率的因素有企业职工人数、所在部门。不同学历、人员类别、企业职工人数、所在部门对标准的使用频次差异有统计学意义。结论　整体来看标准实施情况较好,但通过跟踪评价,仍发现在具体应用中存在问题。应进一步加强对GB 7718-2011的宣传与人员培训,加强对食品安全国家标准使用情况的监管以提高其使用率,优化完善标准的内容,增强其合理性和可操作性。     

Geometric accuracy of a novel gimbals based radiation therapy tumor tracking system

Purpose

VERO is a novel platform for image guided stereotactic body radiotherapy. Orthogonal gimbals hold the linac-MLC assembly allowing real-time moving tumor tracking. This study determines the geometric accuracy of the tracking.

Materials and methods

To determine the tracking error, an 1D moving phantom produced sinusoidal motion with frequencies up to 30 breaths per minute (bpm). Tumor trajectories of patients were reproduced using a 2D robot and pursued with the gimbals tracking system prototype. Using the moving beam light field and a digital-camera-based detection unit tracking errors, system lag and equivalence of pan/tilt performance were measured.

Results

The system lag was 47.7 ms for panning and 47.6 ms for tilting. Applying system lag compensation, sinusoidal motion tracking was accurate, with a tracking error 90% percentile E_90% < 0.82 mm and similar performance for pan/tilt. Systematic tracking errors were below 0.14 mm. The 2D tumor trajectories were tracked with an average E_90% of 0.54 mm, and tracking error standard deviations of 0.20 mm for pan and 0.22 mm for tilt.

Conclusions

In terms of dynamic behavior, the gimbaled linac of the VERO system showed to be an excellent approach for providing accurate real-time tumor tracking in radiation therapy.     

2型糖尿病颈动脉血管回声跟踪技术检测指标与糖尿病合并症及并发症的相关性

目的探讨糖尿病颈动脉血管回声跟踪技术(ET)指标与其合并症及并发症间的关系,为防治糖尿病动脉粥样硬化性病变提供依据。方法纳入287例2型糖尿病患者,接受基线资料、病史的采集和颈动脉ET检测。观察ET参数(Ep、β、AC、PWVβ、AI)与糖尿病合并症及并发症的相关性。结果糖尿病合并高血压病与Ep呈正相关,有高血压病者明显高于无高血压病者。糖尿病合并冠心病与Ep、β、PWVβ呈正相关,有冠心病者明显高于无冠心病者。糖尿病合并卒中与Ep、β、PWVβ、AI呈正相关,有卒中者明显高于无卒中者。糖尿病并发下肢动脉病变与Ep、β呈正相关,有下肢动脉病变者明显高于无下肢动脉病变者。结论血管回声跟踪技术可获知颈动脉弹性的减退。糖尿病颈动脉ET参数与高血压病、冠心病、卒中、下肢动脉病变等大血管病变关系密切。     

Impact of noise structure and network topology on tracking speed of neural networks

Understanding why neural systems can process information extremely fast is a fundamental question in theoretical neuroscience. The present study investigates the effect of noise on accelerating neural computation. To evaluate the speed of network response, we consider a computational task in which the network tracks time-varying stimuli. Two noise structures are compared, namely, the stimulus-dependent and stimulus-independent noises. Based on a simple linear integrate-and-fire model, we theoretically analyze the network dynamics, and find that the stimulus-dependent noise, whose variance is proportional to the mean of external inputs, has better effect on speeding up network computation. This is due to two good properties in the transient network dynamics: (1) the instant firing rate of the network is proportional to the mean of external inputs, and (2) the stationary state of the network is robust to stimulus changes. We investigate two network models with varying recurrent interactions, and find that recurrent interactions tend to slow down the tracking speed of the network. When the biologically plausible Hodgkin–Huxley model is considered, we also observe that the stimulus-dependent noise accelerates neural computation, although the improvement is smaller than that in the case of linear integrate-and-fire model.     

2型糖尿病颈动脉血管回声跟踪技术检测指标与血瘀的相关性及其影响因素分析

目的:探讨糖尿病颈动脉血管回声跟踪技术(eTRACKING,ET)检测指标与血瘀之间的关系及ET的影响因素,为临床早期防治糖尿病患者动脉弹性减退提供依据。方法:纳入138例2型糖尿病患者,均接受基线资料和中医临床信息的采集以及颈总动脉ET检测。所有病例都进行中医辨证分型,分为兼血瘀组和无血瘀组。观察血瘀与颈总动脉压力-应变弹性系数(Pressure-strain Elastic modulus,Ep)、硬化参数β(Stiffness Parameter,β)、动脉顺应性(Arterial Compliance,AC)、脉搏波传导速度β(Pulse Wave Velocityβ,PWVβ)、管径增大指数(Augmentation Index,AI)的相关性。并分析糖尿病患者颈动脉ET参数的影响因素。结果:兼血瘀证患者的Ep、硬化参数β、PWVβ明显大于无血瘀证者(P0.001),AC明显小于无血瘀证者(P0.001)。在年龄、糖尿病病程、空腹血糖、餐后2h血糖、甘油三酯、总胆固醇等因素中,EP、硬化参数β、PWVβ均与年龄、糖尿病病程呈正相关(P0.001),AC与年龄、糖尿病病程呈负相关(P0.001),与总胆固醇呈正相关(P0.05),AI与年龄呈正相关(P0.001)。结论:血管回声跟踪技术检测可获知颈动脉弹性的减退。本研究显示兼血瘀证的糖尿病患者颈动脉硬化较严重。颈动脉血管回声跟踪技术检测指标受患者年龄和糖尿病病程影响较大。     

非结防机构网络直报肺结核病人核查追踪情况分析

目的分析淮北市非结防机构网络直报肺结核病人核查追踪情况,为提高病人发现率提供依据。方法收集淮北市2008年结核病控制工作月报表,统计分析非结防机构肺结核网络直报肺结核病人的转诊、核查追踪到位情况。结果2008年淮北市非结防机构网络直报应转诊肺结核病人或疑似病人783例,转诊主动到位345例,转诊主动到位率44.06%;经结防机构追踪后共到结防机构就诊病人数743例,总体到位率94.89%,明显高于转诊主动到位率（P〈0.01）。结论非结防机构网络直报是提高肺结核病人发现的重要方式,结防机构应加强肺结核病人核查追踪能力建设。