Dopamine modulates the optomotor response to unreliable visual stimuli in Drosophila melanogaster

State‐dependent modulation of sensory systems has been studied in many organisms and is possibly mediated through neuromodulators such as monoamine neurotransmitters. Among these, dopamine is involved in many aspects of animal behaviour, including movement control, attention, motivation and cognition. However, the precise neural mechanism underlying dopaminergic modulation of behaviour induced by sensory stimuli remains poorly understood. Here, we used Drosophila melanogaster to show that dopamine can modulate the optomotor response to moving visual stimuli including noise. The optomotor response is the head‐turning response to moving objects, which is observed in most sight‐reliant animals including mammals and insects. First, the effects of the dopamine system on the optomotor response were investigated in mutant flies deficient in dopamine receptors D1R1 or D1R2, which are involved in the modulation of sleep‐arousal in flies. We examined the optomotor response in D1R1 knockout (D1R1 KO) and D1R2 knockout (D1R2 KO) flies and found that it was not affected in D1R1 KO flies; however, it was significantly reduced in D1R2 KO flies compared with the wild type. Using cell‐type‐specific expression of an RNA interference construct of D1R2, we identified the fan‐shaped body, a part of the central complex, responsible for dopamine‐mediated modulation of the optomotor response. In particular, pontine cells in the fan‐shaped body seemed important in the modulation of the optomotor response, and their neural activity was required for the optomotor response. These results suggest a novel role of the central complex in the modulation of a behaviour based on the processing of sensory stimulations.     

对旋轴流通风机流场预测及两级电机功率匹配研究

对旋风机是矿井通风系统的重要组成部分，其安全稳定的运行是煤矿工人生命安全的保障。针对在长距离送风状态下，对旋风机风量显著减小、前后两级电机功率匹配难度加大的问题，依据流体动力学原理(Computational Fluid Dynamics，CFD)，采用对旋风机全域流体场数值模拟方法，对两级对旋叶轮性能与两级电动机性能的“线(点对点)”匹配进行研究。仿真结果揭示了对旋轴流通风机流场内部气流的真实流动规律以及两级电机轴功率匹配情况。将数值模拟结果和实验数据进行对比，验证该数值模拟方法的准确性，同时验证通过改变叶片安装角提高风机运行效率的可行性，为高性能对旋风机调速控制和节能控制提供理论依据。     

Conversion factors for determining organ doses received by paediatric patients in high-resolution single slice computed tomography with narrow collimation

Estimations of organ doses D_T received during computed tomographic examinations are usually performed by applying conversion factors to basic dose indicators like the computed tomography dose index (CTDI) or the dose-length-product (DLP). In addition to the existing conversion factors for beam apertures of 5 mm or 10 mm, we present new DLP-D_T conversion factors adapted to high-resolution CT (HRCT) examinations of infants and young children with beam apertures of the order of 1 mm and under consideration of bow tie filtration. Calculations are performed on mathematical MIRD phantoms for an age range from 0, 1, 5, 10, 15 up to (for comparison) 30 years by adapting PCXMC, a Monte Carlo algorithm originally developed by STUK (Helsinki, Finland) for dose reconstructions in projection radiography. For this purpose, each single slice CT examination is approximated by a series of corresponding virtual planar radiographies comprising all focus positions. The transformation of CT exposure parameters into exposure parameters of the series of corresponding planar radiographies is performed by a specially developed algorithm called XCT. The DLP values are evaluated using the EGSRay code. The new method is verified at a beam aperture of 10 mm by comparison with formerly published conversion factors. We show that the higher spatial resolution leads to an enhanced DLP-D_T conversion factor if a small organ (e. g. thyroid gland, mammae, uterus, ovaries, testes) is exactly met by the chosen CT slice, while the conversion factor is drastically reduced if the chosen CT slice is positioned above or below the organ. This effect is utilized for dose-saving examinations with only a few single slices instead a full scan, which technique is applied in about 10% of all paediatric chest CT examinations.     

An intelligent FFR with a self-adjustable ventilation fan

This article presents an intelligent Filtering Facepiece Respirator (FFR) with a self-adjustable ventilation fan for improved comfort. The ventilation fan with an intelligent control aims to reduce temperature, relative humidity, and CO₂ concentrations inside the facepiece. Compared with a previous version of the FFR, the advantage of this new FFR is the intelligent control of the fan's rotation speed based on the change in temperature and relative humidity in the FFR dead space. The design of the control system utilizes an 8-bit, ultra-low power STC15W404AS microcontroller (HongJin technology, Shenzhen, China), and adopts a high-precision AM2320 device (AoSong electronic, Guangzhou, China) as temperature and relative humidity sensor so that control of temperature and relative humidity is realized in real time within the FFR dead space. The ventilation fan is intelligently driven and runs on a rechargeable lithium battery with a power-save mode that provides a correspondingly longer operational time. Meanwhile, the design is simplistic. Two experiments were performed to determine the best location to place the fan.     

投影旋转间隔对CT重建图像的影响

目的探讨CT扇形束扫描的投影旋转间隔对成像时间、成像质量以及图像重建计算齄的影响。方法采用Matlab软件编程,实现对仿真模型的投影数据取得、图像反投影重建,外将此方法用于实际颅脑的CT图像进行投影和反投影重建验证。结果本文通过对模型图像重建研究,得到了投影及重建过程中投影旋转间隔对成像时间、成像质量以及图像重建计算量的影响因素。结论在扇形束投影CT的成像过程中,投影旋转间隔在〈2°的范围内会对成像时间、成像质苗以及计算量产生较小影响。     

新型冠状病毒肺炎CT征象再讨论

目的寻找新型冠状病毒肺炎（NCP）的特征性CT征象,并从影像病理学角度探讨其临床意义。方法收集整理2020年1月26日至2月12日河北省确诊为NCP的40例病人的CT图像,对其72侧肺部,234个肺段,共459个病灶进行分析;同时与随机抽取的20例本院诊治的其他性质肺炎（非NCP）病人的28侧肺部,79个肺段,共258个病灶的CT图像进行比较研究。结果NCP组病灶多位于两肺下叶（分别为30个,23.44%）,多累及双侧（32例,80.00%）,且累及5个肺叶的比例较大,其在左、右侧肺分布上差异不大,伴有胸腔积液的仅为1例（2.50%）。NCP组与非NCP组在病灶累及肺叶数量、扇形分布、肺血增多或肺水肿、伴有血管增粗和支气管壁增厚上差异有统计学意义。18例有复查资料的患者中有进展的为13例（占72.22%）,其中8例有肺血增多或肺水肿（占62%）,11例累及双侧（约占85%）。结论NCP的CT表现有其特征性,而且其可能更容易侵犯血管引起血管炎,进而会导致肺水肿和心肺循环紊乱的发生,这对于预测患者病情发展可能具有提示作用。     

Cambridge Breathlessness Intervention Service (CBIS)

Abstract

Breathlessness is a common disabling symptom of advanced cardiorespiratory disease both malignant and non-malignant in nature. It is profoundly distressing for both patient and those who care for them, and often leads to disability, social isolation, and depression. It is extremely difficult to palliate successfully and interventions that help breathlessness are still poorly understood. Breathlessness occurs in 90% of patients with advanced chronic obstructive pulmonary disease and lung cancer and is also common in heart failure. The Cambridge Breathlessness Intervention Service was set up to deliver an evidence-based complex intervention for breathlessness and to carry out research to improve its management. The team consists of a palliative care consultant, specialist physiotherapists, a lead occupational therapist: it is part of a palliative care department at an acute hospital but sees patients in the community and carries out ward consultations. The evaluation and modelling of the service (using the Medical Research Council (MRC) methodology for research in complex interventions) has taken 10 years and has shown the value of the fan, using pacing techniques, an individualized exercise programme, breathing exercises, learning anxiety reduction techniques, and support for carers delivered with a rehabilitative approach. Recently, the Phase III evaluation of the service has demonstrated its effectiveness in reducing distress due to breathlessness in patients with lung cancer. The qualitative data also demonstrated the importance not only of the interventions themselves but also the manner in which they were delivered, i.e. that empathy; kindness and active listening were central to effective management.     

微型轴流风扇间隙流动分析

以某微型轴流风扇为研究对象,测量了其在5 600 r/min转速下的气动特性曲线,同时采用商用软件NUMECA模拟了在4种流量下该风扇叶轮内的三维流场,详细研究了泄漏涡和分离涡的结构、泄漏流速度的分布、叶片两侧的压差分布以及泄漏流对叶顶载荷的影响。研究结果显示：由于叶顶间隙的存在,气流在叶顶形成了分离涡;而泄漏流进入相邻通道后卷起形成泄漏涡。叶顶分离涡和泄漏涡的起始位置都随着流量的增加而向下游移动。从叶顶到外端壁方向,泄漏流速度的大小及其与叶片型线的夹角(θ)均呈现先增大后减小的趋势。间隙区域叶片两侧的压差(Δp)随着流量的增加而变小,泄漏流速度、泄漏流量也随之变小。叶顶卸载是顶端间隙流动的主要特征,随着流量系数的增加,叶顶卸载变大。     

E-GB110型风机机组支撑结构的振动分析

为了解决E-GB110风机机组出现强烈振动的问题,利用振动测试和有限元分析对风机机组和支撑系统进行分析,诊断出振动主要是机器和支撑结构发生了共振。通过支撑结构计算机模型优化,确定了支撑结构的改造方案,并实施改造。在改造的同时,对风机机组进行检修。改造后振动明显减小,符合国家标准。保证了机组的高效、安全运行。     

扇形额肌筋膜瓣悬吊治疗上睑下垂

目的：探计上睑下垂的较好治疗方法，以改进治疗效果方法：设计井应用扇形额肌筋膜瓣悬吊治疗上睑下垂，结果应用本方击治疗上睑下垂83倒，126只眼，致采满意。其中43例经3个月-10年随访，除3例(4只眼)下垂复发外，其余均取得了良好效果，未见其他并发症发生。结论：本方法的主要特点是扇形筋膜瓣有丰富的血供，并且能均衡覆盖在睑板上以充分上提上睑，符合生理和解音4的要求。