Objective: To investigate the characteristics of electromyography (EMG) signals and the starting threshold voltages of the orbicularis oris muscles (OOM) in healthy rhesus monkeys under different muscle movement conditions. Methods: The EMG signals and the starting threshold voltages at different time points in 4 healthy rhesus monkeys were acquired and recorded with EMG device and evoked potentiometer. The voltage amplitude variation of EMG signals was analyzed, and the voltage amplitude range of EMG signals at the beginning of OOM contraction was established. The data were statistically analyzed by one-way ANOVA. Results: The EMG of OOM in healthy monkeys in the quiet, natural and continuous mouth-closed state was linear and relatively stable, and the absolute value fluctuated between 15 and 50 μV. The EMG waveform increased rapidly during the natural lip contraction movement, and its amplitude fluctuated greatly, with the highest absolute value of the peak value reaching hundreds of microvolts. The amplitude of EMG induced by continuous mouth closure was more than thousands of microvolts. There was no significant difference in EMG amplitudes of OOM in the healthy rhesus monkey under quiet and continuous lip closure at different time points (P>0.05). There was no significant difference in threshold voltages in the state of natural lip contraction of bilateral OOM at different time points (average range: 57.17-57.47 μV) in the healthy rhesus monkeys (P>0.05). There was no significant difference in threshold voltages of OOM induced by bilateral OOM at different time points(average range: 55.38-55.99 μV) in the healthy rhesus monkeys(P>0.05). There were significant differences in the absolute values of EMG amplitudes of OOM between the three lip movement modes: (30.67±8.72) μV in quiet and natural continuous lip closure (475.12±54.72) μV in natural lip contraction, and (921.22±312.79) μV in the induced persistent lip closure, with t values of -8.48, -9.35 and -5.01 respectively, all P<0.001. Conclusions: The EMG signals of OOM show different characteristics under different muscle movement conditions, which can be used as a basis for computer to judge and recognize the movement conditions of OOM. The upper limits of the EMG threshold voltage values of OOM under different motion states are 55-60 μV.

In order to improve the operation difficulties in the narrow space of the nasal maxillary sinus, the nasal continuum minimally invasive surgical robot system is designed. The ball-and-socket joints and NiTiNol tubes are used as the main body of the continuum structure to improve the degree of freedom. The hardware systems and software systems are designed. The security control policies are planned. Finally, the robot confirmed prototype experiments are conducted and the feasibility of continuum robot confirmed through master-slave control experiment and animal experiment.

PURPOSE:Currently, self-retaining laryngoscopic surgery is not suitable for some patients, and there are dead zones relating to surgical field exposure and operation. The quality of the surgery can also be affected by the long periods of time required to complete it. Teleoperated continuum robots with flexible joints are expected to solve these issues. However, at the current stage of developing transoral robotic surgery systems, their large size affects the precision of surgical operative actions and there are high development and treatment costs.METHODS:We fabricated a flexible joint based on selective laser melting technology and designed a shallow neural network-based kinematic modeling approach for a continuum surgical robot. Then, human model and animal experiments were completed by master-slave teleoperation to verify the force capability and dexterity of the robot, respectively.RESULTS:As verified by human model and animal experiments, the designed continuum robot was demonstrated to achieve transoral laryngeal surgical field exposure without laryngoscope assistance, with sufficient load capability to finish the biopsy of vocal fold tissue in living animals.CONCLUSION:The designed continuum robotic system allows the biopsy of vocal fold tissue without laryngoscope assistance. Its stiffness and dexterity indicate the system's potential for applications in the diagnosis and treatment of vocal fold nodules and polyps. The limitations of this robotic system as shown in the experiments were also analyzed.

电离辐射是一种广泛存在于环境中的危害因素,不仅存在于自然环境中,随着工业和医学上的应用,人们接触电离辐射的机会也越来越多.电离辐射不仅直接导致细胞损伤,也具有遗传毒性,可引起多种远后效应,包括基因不稳定性、辐射致癌等.表观遗传可以调节基因活性和表达,而DNA甲基化是研究较多的表观遗传修饰方式,DNA甲基化在电离辐射所致损伤中也发挥着作用.从电离辐射与基因组甲基化、与重复序列DNA甲基化、与特定基因甲基化,以及电离辐射致甲基化改变的可能机制等方面,综述了电离辐射对DNA甲基化的影响及可能的作用机制.

目的 探讨咽鼓管功能声测法声源频率的选择.方法 以31例健康成人为研究对象,年龄20～43岁,平均26.2±2.8岁,男20例,女11例;用1～8 kHz线性扫频信号作为测试声源,统计静态情况下不同频带声源从单侧鼻腔至外耳道的声传递参数变化,初步寻找适合的声源信号频率区间;再分别用时长10秒、频率为7～9 kHz的窄带白噪声、2～20 kHz及1～8 kHz的宽带白噪声作为测试声源,分析白噪声通过单侧鼻腔至外耳道传导的声级衰减统计特性.结果 伴随95％以上的有效吞咽动作,外耳道所测得的声信号时频图中同步出现一种短时宽频冲击声信号,贯穿1～10 kHz.用1～8 kHz线性周期扫频信号进行测试可见,3 kHz以下的频段相对易受噪声干扰,6.3～8 kHz频带区间传导稳定性差;用三组白噪声作为声源信号测试发现,90％以上吞咽产生的短时冲击噪声在对应声源频带上的声功率级至少超过了测试信号基线值5 dB以上.结论 咽鼓管功能声测法采用7～8 kHz作为声源信号传导稳定性较差,宽频和相对窄带白噪声信号易受吞咽噪声干扰;咽鼓管功能声测法声源信号较为合适的测试声源频段为3～6 kHz.

BACKGROUND:Existing rigid instruments have difficulties in backward inspection and operation. Moreover, the pathway to the maxillary sinus is curved and narrow, resulting in complex and repetitive manual operations. There is a necessity to develop a retro-flexing robot and achieve path-following motion.METHODS:A continuum robotic system is developed for maxillary sinus surgery (MSS). And the system adopts an anatomical constraint-based optimization of the follow-the-leader strategy to generate a safe control scheme along a given path.RESULTS:The accuracy of the system is evaluated, and the task of reaching deep-seated targets is performed in a constrained anatomical space. The simulations and experiments of the path-following motion have validated the feasibility of the proposed method. Furthermore, a preliminary porcine study is performed to assess the capability of instruments.CONCLUSIONS:The developed continuum robotic system can meet the requirements of MSS.

目的 探索低浓度苯接触工人线粒体DNA拷贝数的变化及其影响因素.方法 选择上海某化工厂150名低浓度苯接触工人作为2018、2019年连续两年的追踪研究对象,采用问卷调查收集研究对象一般情况,采用实时荧光定量PCR法检测外周血相对线粒体DNA拷贝数并作为氧化应激的检测指标,利用重复测量分析以及广义估计模型分析两年间苯接触工人线粒体DNA拷贝数情况的变化,并探讨其与作业环境中苯接触的关系.结果 研究对象在追踪期间的苯接触浓度中位数为0.46 mg/m3,第25百分位数为0.14 mg/m3,第75百分位数为0.49 mg/m3.2018年苯接触工人相对线粒体DNA拷贝数为5.79±0.84,2019年工人相对线粒体DNA拷贝数显著降低,为(4.66±0.58),差异有统计学意义(P＜0.01).重复测量方差分析结果显示:不同接触浓度工人相对线粒体DNA拷贝数差异有统计学意义(P＜0.05);不同时间观察的线粒体DNA拷贝数不全相同,差异有统计学意义(P＜ 0.05).广义估计模型分析结果显示:与高接触浓度组相比,中接触浓度组工人相对线粒体DNA拷贝数降低了0.25(P＜ 0.05).未发现工龄、年龄、吸烟和饮酒对相对线粒体DNA拷贝数的影响.结论 在低于我国现行职业卫生标准的情况下,接触低浓度苯的作业工人仍可出现相对线粒体DNA拷贝数的改变,提示职业性苯接触可能导致线粒体损伤以及氧化应激的产生.

To provide a more comprehensive understanding of genotoxic effects from benzene exposure, its effects on induction of mitochondrial DNA copy number (MtDNAcn) and of micronucleus (MN) were investigated using peripheral blood from workers in China. Changes in mtDNAcn and MN were determined using quantitative real-time polymerase chain reaction (PCR) and cytokinesis-block micronucleus assays (CBMN), respectively, in 58 control and 174 benzene-exposed workers in Shanghai, China. Among the exposed workers, relative mtDNAcn increased and then decreased with increasing doses of benzene exposure. Significant and dose-dependent increase in MN frequencies were observed among the different exposure groups. In addition, the relative mtDNAcn were significantly associated with the MN frequencies in the low-level exposure group (P = 0.046), but not in the high dose groups. Therefore, the mechanisms for induction of MtDNAcn and MN by benzene may be similar from exposure to low doses but different from high doses. Similar increase of MN frequencies and MtDNAcn may be due to oxidative stress induced by benzene at low concentrations, while higher concentrations may start to initiate the cell death pathway. The pathway may be associated with excessive MtDNAcn which can initiate apoptosis while MN can continue to be induced. However, the differential mechanisms need to be investigated because they may represent different levels of risk for different health consequences. On the other hand, our data indicate that induction of MtDNAcn may be a sensitive genotoxic biomarker for workers with exposure to low dose of benzene. Environ. Mol. Mutagen. 2020. (c) 2020 Wiley Periodicals, Inc.

Objective:To explore the optimal matching of the current parameters about artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis.Methods:According to the combinations of different stimulus parameters, at different time points, we used AFN to induce contraction of the affected side OOM of the paralyzed rabbit in waking state. We recorded the current amplitudes of the threshold stimulation and peak stimulation under each combination, then compared the total charge of the stimulus consumption under different combinations.Results:Compared the total stimulus charge consumption of the AFN threshold stimulation and that in the peak stimulation respectively under different stimulus frequency and pulse width matching combinations, we found that the frequency, the pulse width and the interaction of the frequency and pulse width among different groups could affect the total charge, the differences were statistically significant ( P<0.05). Conclusions:When AFN stimulus frequency is 60 Hz and the stimulus pulse width is 100 μs, the output current intensity is relatively lowest and the total consumed charge is the lowest under the premise of effectively inducing the paralytic side OOM contraction. Thus we recommend this stimulus parametric combination as the optimal combination for meeting the low power consumption of AFN.

To provide a more comprehensive understanding of genotoxic effects from benzene exposure, its effects on induction of mitochondrial DNA copy number (MtDNAcn) and of micronucleus (MN) were investigated using peripheral blood from workers in China. Changes in mtDNAcn and MN were determined using quantitative real-time polymerase chain reaction (PCR) and cytokinesis-block micronucleus assays (CBMN), respectively, in 58 control and 174 benzene-exposed workers in Shanghai, China. Among the exposed workers, relative mtDNAcn increased and then decreased with increasing doses of benzene exposure. Significant and dose-dependent increase in MN frequencies were observed among the different exposure groups. In addition, the relative mtDNAcn were significantly associated with the MN frequencies in the low-level exposure group ( P = 0.046), but not in the high dose groups. Therefore, the mechanisms for induction of MtDNAcn and MN by benzene may be similar from exposure to low doses but different from high doses. Similar increase of MN frequencies and MtDNAcn may be due to oxidative stress induced by benzene at low concentrations, while higher concentrations may start to initiate the cell death pathway. The pathway may be associated with excessive MtDNAcn which can initiate apoptosis while MN can continue to be induced. However, the differential mechanisms need to be investigated because they may represent different levels of risk for different health consequences. On the other hand, our data indicate that induction of MtDNAcn may be a sensitive genotoxic biomarker for workers with exposure to low dose of benzene. Environ. Mol. Mutagen. 61:355–360, 2020. © 2020 Wiley Periodicals, Inc.

GBZ 2.1—2019《工作场所有害因素职业接触限值第1部分:化学有害因素》的发布,引起了业内的广泛关注和讨论。从国外系统性职业接触评估方法的角度,以美国工业卫生协会（American Industrial Hygiene Association,AHIA）职业接触评估与管理策略和日本《化学物质个人接触监测指南》为例,探讨新的职业接触限值标准给我国职业卫生工作带来的新思路、新变化,认为需要有配套的指导规范文件尽快出台,以促进用人单位职业病危害防控工作。

Objective: To explore the optimal method of microelectrode implantation that can produce efficient mouth closure with microelectrode for orbicularis oris muscle (OOM) in rhesus monkeys with unilateral peripheral facial paralysis (UPFP) in order to provide basis for the research and development of artificial facial nerve prosthesis (AFNP). Methods: Right lateral peripheral facial paralysis model on four healthy rhesus monkeys (two males and two femles, aged 5-6 years, weighed 2.0-3.0 kg) were prepared. AFNP electric stimulation was used to induce closed-mouth reaction of the affected OOM with a one-way rectangular pulse, 50 Hz frequency and 0.2 ms pulse width in vitro. Around the affected lateral OOM, four stimulus electrodes implantation positions were selected at the upper lip (position A), the lower lip (position B), the connection with the corner of the mouth to the ipsilateral tragus (position C), and the horizontal line of the mouth angle (position D). According to the different implantation positions of three stimulation electrodes on the stimulation side of AFNP and the results of our previous study, six groups of microelectrode implantation methods were designed. In Group A, two microelectrodes were implanted at position A and one microelectrode was implanted at position B; in Group B, one microelectrode was implanted at position A, B and C respectively; in Group C, one microelectrode was implanted at position A and two microelectrodes were implanted at position B; in Group D, one microelectrode was implanted at position A, B and D respectively; in Group E, one microelectrode was implanted at position A, C and D respectively; in Group F, one microelectrode was implanted at position B, C and D respectively. The minimum stimulating current (threshold current) required for effective mouth closure were recorded. The threshold and peak current values were compared using one-way ANOVA and LSD-t multiple comparisons. Results: The microelectrodes of the AFNP stimulating side in Group E and F failed to induce a smooth mouth closure. The microelectrodes in A, B, C and D group induced smooth mouth closure. The threshold current value of OOM contraction on affected side in the Group A, B, C, and D were (1.35±0.05), (1.02±0.04), (1.40±0.04) and (1.10±0.02) mA, respectively (F=295.302, P<0.001), with the lowest value in Group B and there was significant difference between the current value in Group B and those in the other groups (all P<0.05). The peak current value of OOM contraction on affected side in the four groups were (3.95±0.02), (2.95±0.03), (3.99±0.05) and (3.51±0.01) mA, respectively (F=1 014.985, P<0.001). Group B showed the best lip-closure morphology observed with naked eyes. Conclusions: When three output microelectrode of the AFNP stimulated side are separately imbedded into the upper lip, the lower lip and the connection with the corner of the mouth to the ipsilateral tragus, AFNP can sufficiently induce closed-mouth reaction. These positions are suitable as priority options microelectrodes implantation positions for the microelectrodes of the AFNP stimulated side.

伴随着经济发展,“过劳死”现象已成为一个全球性的职业健康问题.“过劳死”直接导致劳动人口的减少,增加疾病负担,对劳动者本人及其家庭均造成极大的不良影响.然而,目前亚洲仅日本、韩国及中国台湾地区制定有专门的认定基准.因此,本文拟通过对过劳死概念及中国、日本和韩国“过劳死”认定基准的发展进行综述,为今后我国制定相应的认定基准(标准)提供工作基础.

职业健康工作旨在保护广大劳动者的生命健康权益, 始终是我国的一项基本国策.新中国成立近70年, 我国职业健康工作从无到有、不断完善, 其发展凝聚了各届政府领导者、医疗卫生工作者、基层从业者的心血.回顾了我国职业健康法律法规、标准体系、职业健康监管体制以及职业健康技术服务的发展历程;从七个方面对当前职业健康重点工作提出建议, 并对今后职业健康事业做出展望.

PURPOSE:The aim of this study was to provide basis for future design and selection of cleft palate surgery through establishing finite element model of pharyngeal cavity which was suitable for biomechanical analysis.METHODS:One patient with isolated cleft palate and 1 normal child underwent multilayer head CT examination. The scanned data of pharyngeal cavity were imported into Mimics software for a 3-D geometric model reconstruction. The model was divided into a grid, so it can be further processed for subsequent finite element analysis.RESULTS:After applying 5cm water column pressure load of 0.0005 MPa at the back edge of the soft palate in the two models respectively, the results showed that the maximum stress of the abnormal nasopharyngeal cavity model was 0.025 MPa, greater than the normal model (0.017 MPa). The same pressure loading was applied to different parts of the two models, the stress change area in the posterior margin of the soft palate and the middle of the palate was the same, and the stress in the front of the hard palate was smaller.CONCLUSIONS:Finite element model has good biomechanical characteristics and geometric similarity. It can be used in isolated cleft palate with preoperative biomechanical analysis, for repairing and functional reconstructive surgery to provide ideal biomechanical model predicts.

[目的]分析上海市嘉定区汽车零部件制造行业化学性职业病危害因素接触的风险程度,为监管部门和企业职业病防治提供对策依据.[方法]采用模糊数学综合风险评价法,对上海市嘉定区60家汽车零部件制造企业2017年生产场所化学性职业病危害因素的检测结果进行分析,评价不同岗位职业病危害风险.[结果]焊接、机加工、清洗整理、涂胶、涂装、橡塑、质控测试、铸造、组装岗位的化学性职业病危害评价总评分值分别为6.852、6.209、6.780、6.500、6.853、6.653、7.000、7.000、7.000,评价等级均为Ⅰ级(优),整个行业化学性职业病危害总评分值为6.758,等级也为Ⅰ级(优).[结论]嘉定区汽车零部件制造行业化学性职业病危害总体处于较低水平.模糊数学综合风险评价法可综合考虑多种因素,成为职业病危害接触风险评价的有效手段.

通过调查发生在某公司司机休息室的一起一氧化碳(CO)中毒事故,发现中毒原因是废气管道布局设计不合理,直燃型空调锅炉节气阀垫片损坏没有及时更换垫片,单靠调节流量泵调节燃气流量,造成燃气、空气比例失调,导致大量CO产生,沿废气管道裂缝进入休息室引起CO中毒.有毒气体管道布局设计时要严格遵守相关规定,维修作业时应严格管理.

Objective: To investigate the diagnostic value of distortion product otoacoustic emission (DPOAE) together with tympanometry in assessing otitis media with effusion in children. Methods: Three hundred and thirty-nine patients, who were diagnosed with obstructive sleep apnea- hypopnea syndrome (OSAHS) and prepared to undergo adenotonsillectomy and had a unilateral or bilateral type 'B' or 'C' tympanogram were enrolled in this study. Patients were divided into the following four groups: Group 1, type 'B' tympanogram with positive DPOAE; Group 2, type 'B' tympanogram with negative DPOAE; Group 3, type 'C' tympanogram with positive DPOAE and Group 4, type 'C' tympanogram with negative DPOAE. Results: Tympanometry showed a type 'B' pattern in 467 ears and type 'C' pattern in 163 ears. Among 163 ears with type 'C' tympanogram, negative DPOAE results were seen in 96 ears. Group 4 (56/96) had a significant high rate of middle ear effusion than Group 3 (14/67) (p < .05). In patients with a type 'C' tympanogram, those with a low compliance value (similar to 0.25 ml), concurrent chronic tonsillitis and large tonsils are likely to have middle ear effusion. Conclusions: DPOAE could be a great help in screening for middle ear effusion in patients with a type 'C' tympanogram.

二甲基甲酰胺(N,N-Dimethylformamide,DMF)是重要的化工原料和性能优良的溶剂,广泛应用于工业企业.DMF可经呼吸道和皮肤进入机体,造成以肝脏最为突出的,以及肾脏、心脏等多器官的损害,发生DMF急性中毒或慢性损伤.就DMF中毒的接触方式、潜伏期、各器官(系统)损害的临床表现以及中毒治疗的研究进展作一综述,以期提高临床对于二甲基甲酰胺中毒的认识.

[目的]掌握上海市金山工业区生产企业的职业病危害、职业病防治和职业卫生管理现状,探索金山工业区职业卫生技术服务和监管的新模式,维护劳动者的职业健康权益.[方法]确定存在职业病危害企业后,通过单纯随机抽样的方式,选择87家企业,调查企业的基本情况、管理机构和人员、职业病危害因素分布、职业病防护设施、个人防护用品、职业健康监护、培训等情况.[结果]被调查企业以小型企业为主(69家,占79.31％),经济类型以私营企业为主(56家,占64.37％),职业病危害风险较重企业64家,占73.56％;粉尘、噪声、重金属、烃类、酯类、酮类、酸碱等职业病危害因素广泛存在;职业病危害因素榆测合格率为92.14％,但65.00％的企业检测布点不合理或有遗漏;接害人员总体榆率为76.99％,未发现职业病患者;职业卫生管理人员配置符合要求的企业60家,符合率68.97％.[结论]金山工业区被调查生产企业存在着职业病危害因素识别缺失错漏、部分职业病危害因素检测工作不规范、职业卫生人员配置不足、职业健康体检率不高等问题.工业园区应改进职业卫生服务监管模式,将技术服务支撑和职业卫生监管有效结合.