Aircraft

飞机
  • 文章类型: Journal Article
    从飞机聚合物涂层表面分离出Papiliotremalaurentii5307AH。基因组大小为19,510,785bp,G+C含量为56%。基因组包含编码加氧酶的基因,角质,脂肪酶,和降解苯乙烯的酶,所有这些都可能在异种生物表面的生存中起关键作用。
    Papiliotrema laurentii 5307AH was isolated from an aircraft polymer-coated surface. The genome size is 19,510,785 bp with a G + C content of 56%. The genome harbors genes encoding oxygenases, cutinases, lipases, and enzymes for styrene degradation, all of which could play a critical role in survival on xenobiotic surfaces.
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    文章类型: Journal Article
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  • 文章类型: Journal Article
    飞机获得的SARS-CoV-2的传播构成了公共卫生风险。按照PRISMA准则,我们对文章进行了系统的回顾和分析,在疫苗可用之前出版,从2020年1月24日至2021年4月20日,确定对传播重要的因素。如果文章提到索引案例和可识别的飞行持续时间,如果他们讨论非商业飞机,气流或传输模型,没有飞行数据的情况下,或者无法确定飞行中的传输。从精选的15篇文章中进行深入审查,50次总飞行按飞行持续时间进行了分析,两者都是分类变量-短(<3小时),中等(3-6小时),或长途飞行(>6小时)-并作为一个连续变量,案例计数由负二项回归建模。与没有遮罩的短途飞行相比,没有掩蔽的中长途飞行与4.66倍的增加(95%CI:[1.01,21.52];p<0.0001)和25.93倍的发病率增加(95%CI:[4.1,164];p<0.0001)相关,分别;强制屏蔽的长途飞行没有传播报告。飞行时间增加1小时与病例发生率比(IRR)增加1.53倍(95%CI:[1.19,1.66];p<0.001)相关。长途飞行应该考虑遮罩。
    The aircraft-acquired transmission of SARS-CoV-2 poses a public health risk. Following PRISMA guidelines, we conducted a systematic review and analysis of articles, published prior to vaccines being available, from 24 January 2020 to 20 April 2021 to identify factors important for transmission. Articles were included if they mentioned index cases and identifiable flight duration, and excluded if they discussed non-commercial aircraft, airflow or transmission models, cases without flight data, or that were unable to determine in-flight transmission. From the 15 articles selected for in-depth review, 50 total flights were analyzed by flight duration both as a categorical variable-short (<3 h), medium (3-6 h), or long flights (>6 h)-and as a continuous variable with case counts modeled by negative binomial regression. Compared to short flights without masking, medium and long flights without masking were associated with 4.66-fold increase (95% CI: [1.01, 21.52]; p < 0.0001) and 25.93-fold increase in incidence rates (95% CI: [4.1, 164]; p < 0.0001), respectively; long flights with enforced masking had no transmission reported. A 1 h increase in flight duration was associated with 1.53-fold (95% CI: [1.19, 1.66]; p < 0.001) increase in the incidence rate ratio (IRR) of cases. Masking should be considered for long flights.
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  • 文章类型: Journal Article
    背景:直升机飞行员在飞行过程中可能由于振动暴露和不对称姿势而出现慢性腰痛。
    目的:分析基于普拉提的锻炼计划对巴西空军直升机飞行员腰痛的影响。
    方法:这是一项由巴西空军15名直升机飞行员参与的随机对照试验,他们被评估疼痛强度(数字疼痛评定量表),与腰痛相关的残疾,和脊柱肌肉耐力在三个位置:躯干延伸(Ito测试)和左右侧桥。个体随机分配到常规锻炼组(REG)(n=7),以保持他们的日常锻炼为导向,普拉提组(PG)(n=8),进行了基于普拉提方法的锻炼计划,每周两次,持续12周。重新评估发生在6周和12周后。在SPSS20.0软件上使用5%的显著性水平分析数据。
    结果:PG与REG相比,训练12周后下腰痛明显减轻(平均差3.5分,p<0.0001)。与REG相比,我们还观察到PG中躯干伸肌(p=0.002),右(p=0.001)和左外侧肌(p=0.001)的耐力增加。然而,残疾指数在组间没有变化.
    结论:干预后,与REG相比,PG的疼痛强度显着降低,而脊柱肌肉耐力增加;因此,在直升机飞行员的身体调节计划中应考虑基于普拉提的练习。
    BACKGROUND: Helicopter pilots may present chronic low back pain due to vibration exposure and asymmetric posture during flight.
    OBJECTIVE: To analyze the effects of a Pilates-based exercise program on low back pain of helicopter pilots of the Brazilian Air Force.
    METHODS: This is a randomized controlled trial with fifteen helicopter pilots of the Brazilian Air Force, who were assessed for pain intensity (Numerical Pain Rating Scale), disability associated with low back pain, and spine muscle endurance in three positions: trunk extension (Ito test) and left and right lateral bridge. Individuals were randomly distributed into the regular exercises group (REG) (n = 7), oriented to maintain their exercise routine, and Pilates group (PG) (n = 8), which performed an exercise program based on Pilates method twice a week for 12 weeks. Reassessments occurred after 6 and 12 weeks. Data were analyzed on SPSS 20.0 software using a significance level of 5%.
    RESULTS: PG showed a significant reduction in low back pain after 12 weeks of training compared with REG (mean difference of 3.5 points, p < 0.0001). We also observed increased endurance of trunk extensors (p = 0.002) and right (p = 0.001) and left lateral muscles (p = 0.001) in the PG compared with REG. However, the indexes of disability did not change between groups.
    CONCLUSIONS: Pain intensity was significantly reduced while spine muscle endurance increased in PG compared with REG after intervention; thus, Pilates-based exercises should be considered in physical conditioning programs for helicopter pilots.
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  • 文章类型: Journal Article
    野生动物的人为干扰正在全球增加。一般化干扰对新情况的影响是具有挑战性的,因为动物对人类活动的耐受性随干扰频率而变化(例如由于习惯)。很少有研究量化了频率依赖的容忍度,更不用说确定它如何影响扰动影响的预测时,这些推断在大面积。在空中交通强度梯度的比较研究中,我们表明,如果飞机很少见,鸟类几乎总是逃跑(80%),而如果交通频繁,鸟类很少回应(7%)。当将特定地点的反应推断到整个区域时,考虑到频率相关的容忍度会极大地改变预测的干扰成本:干扰图以较少的热点均匀化。量化频率相关的容差已被证明具有挑战性,但是我们建议(i)忽略它会导致单个站点干扰影响的推断不可靠,(ii)它可以调和已发表的特殊物种或源特异性干扰反应。
    Anthropogenic disturbance of wildlife is increasing globally. Generalizing impacts of disturbance to novel situations is challenging, as the tolerance of animals to human activities varies with disturbance frequency (e.g. due to habituation). Few studies have quantified frequency-dependent tolerance, let alone determined how it affects predictions of disturbance impacts when these are extrapolated over large areas. In a comparative study across a gradient of air traffic intensities, we show that birds nearly always fled (80%) if aircraft were rare, while birds rarely responded (7%) if traffic was frequent. When extrapolating site-specific responses to an entire region, accounting for frequency-dependent tolerance dramatically alters the predicted costs of disturbance: the disturbance map homogenizes with fewer hotspots. Quantifying frequency-dependent tolerance has proven challenging, but we propose that (i) ignoring it causes extrapolations of disturbance impacts from single sites to be unreliable, and (ii) it can reconcile published idiosyncratic species- or source-specific disturbance responses.
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  • 文章类型: Journal Article
    对民航空气质量和环境影响的担忧导致了最近对非挥发性颗粒物(nvPM)质量和数量排放的规定。尽管这些法规并不要求测量粒度分布(PSD),了解PSD对于评估航空nvPM的环境影响至关重要。本研究引入了一个全面的数据集,详细介绍了19种涡轮风扇类型的42种发动机的PSD特性,从不受管制的小型公务机到受管制的大型商用飞机。通过使用具有并行PSD测量的欧洲和瑞士参考nvPM采样和测量系统独立进行排放测试。发动机出口处的几何平均直径(GMD)与nvPM数量质量比(N/M)和推力密切相关,变化从7到52nm。发动机出口几何标准偏差范围为1.7至2.5(平均值为2.05)。该研究提出了经验相关性,以根据排放认证发动机的N/M数据预测GMD。预期这些预测对于常规富燃发动机是有效的,并且如果可获得额外的数据,则可能扩展到新的燃烧器技术。研究结果支持改进排放模型,并有助于评估航空非CO2气候和空气质量影响。
    Concerns about civil aviation\'s air quality and environmental impacts have led to recent regulations on nonvolatile particulate matter (nvPM) mass and number emissions. Although these regulations do not mandate measuring particle size distribution (PSD), understanding PSDs is vital for assessing the environmental impacts of aviation nvPM. This study introduces a comprehensive data set detailing PSD characteristics of 42 engines across 19 turbofan types, ranging from unregulated small business jets to regulated large commercial aircraft. Emission tests were independently performed by using the European and Swiss reference nvPM sampling and measurement systems with parallel PSD measurements. The geometric mean diameter (GMD) at the engine exit strongly correlated with the nvPM number-to-mass ratio (N/M) and thrust, varying from 7 to 52 nm. The engine-exit geometric standard deviation ranged from 1.7 to 2.5 (mean of 2.05). The study proposes empirical correlations to predict GMD from N/M data of emissions-certified engines. These predictions are expected to be effective for conventional rich-burn engines and might be extended to novel combustor technologies if additional data become available. The findings support the refinement of emission models and help in assessing the aviation non-CO2 climate and air quality impacts.
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  • 文章类型: Journal Article
    随着城市化和人口增长的升级,噪声污染的挑战加剧,特别是在航空业。这篇综述探讨了当前对航空中噪声引起的听力损失(NIHL)的见解,强调飞行员的风险,乘务员,飞机维修工程师,和地面工作人员连续暴露在高水平的噪音中。它评估现有的噪声管理和听力保护策略,确定关键障碍并探索新的技术解决方案。虽然在开发保护装置和噪声控制技术方面取得了明显进展,其广泛实施的差距仍然存在。该研究强调需要一个结合监管合规的综合战略,技术进步,有针对性的教育工作。它倡导全球合作和政策制定,以保护航空工人的听觉健康,并提出了一个战略框架,以在航空部门的独特挑战中加强听力保护实践。
    As urbanization and population growth escalate, the challenge of noise pollution intensifies, particularly within the aviation industry. This review examines current insights into noise-induced hearing loss (NIHL) in aviation, highlighting the risks to pilots, cabin crew, aircraft maintenance engineers, and ground staff from continuous exposure to high-level noise. It evaluates existing noise management and hearing conservation strategies, identifying key obstacles and exploring new technological solutions. While progress in developing protective devices and noise control technologies is evident, gaps in their widespread implementation persist. The study underscores the need for an integrated strategy combining regulatory compliance, technological advances, and targeted educational efforts. It advocates for global collaboration and policy development to safeguard the auditory health of aviation workers and proposes a strategic framework to enhance hearing conservation practices within the unique challenges of the aviation sector.
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  • 文章类型: Journal Article
    飞机发动机排放的烟尘颗粒构成了机场附近和巡航高度的主要人为污染源。这种排放对人类健康构成重大威胁,并可能改变全球气候。了解煤烟颗粒的特性,特别是由双环形预混合旋流器(TAPS)燃烧器产生的那些,民用航空发动机的主流燃烧器,对航空环境保护至关重要。在这项研究中,使用扫描电子显微镜(SEM)对TAPS燃烧器排放的烟尘颗粒进行了全面表征,高分辨率透射电子显微镜(HRTEM),和拉曼光谱。在三个不同的燃料级比(FSR)中检查了烟灰颗粒的形态和纳米结构,10%,15%,和20%。对烟灰颗粒形态的SEM分析表明,包覆颗粒占总颗粒样品的90%以上,涂层含量与燃料级比成比例增加。从HRTEM获得的结果表明,平均初级粒径随燃料级比的增加而增加。HRTEM和拉曼光谱的结果表明,随着燃料级比的增加,烟灰颗粒的纳米结构变得更加有序和石墨化。导致较低的氧化活性。具体来说,烟灰条纹长度随燃料级比而增加,烟灰边缘弯曲度和分离距离减小。此外,在烟灰颗粒的石墨晶格结构中普遍存在缺陷,表明元素碳的高度无序。
    Soot particles emitted from aircraft engines constitute a major anthropogenic source of pollution in the vicinity of airports and at cruising altitudes. This emission poses a significant threat to human health and may alter the global climate. Understanding the characteristics of soot particles, particularly those generated from Twin Annular Premixing Swirler (TAPS) combustors, a mainstream combustor in civil aviation engines, is crucial for aviation environmental protection. In this study, a comprehensive characterization of soot particles emitted from TAPS combustors was conducted using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The morphology and nanostructure of soot particles were examined across three distinct fuel stage ratios (FSR), at 10%, 15%, and 20%. The SEM analysis of soot particle morphology revealed that coated particles constitute over 90% of the total particle sample, with coating content increasing proportionally to the fuel stage ratio. The results obtained from HRTEM indicated that average primary particle sizes increase with the fuel stage ratio. The results of HRTEM and Raman spectroscopy suggest that the nanostructure of soot particles becomes more ordered and graphitized with an increasing fuel stage ratio, resulting in lower oxidation activity. Specifically, soot fringe length increased with the fuel stage ratio, while soot fringe tortuosity and separation distance decreased. In addition, there is a prevalent occurrence of defects in the graphitic lattice structure of soot particles, suggesting a high degree of elemental carbon disorder.
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  • 文章类型: Journal Article
    这项研究评估了十种核酸提取方案(EP1至EP10),用于测量四个飞机废水样品(AWW1至AWW4)中的五个内源性抗生素抗性基因(ARG)。目标ARGs,包括BlaCTX-M,blaNDM-1,ermB,qnrS,还有tetA,包含高度和最低限度的ARGs。使用DNeasy血液和组织试剂盒和AllPrepPowerViralDNA/RNA试剂盒,在四个飞机废水样品中始终检测到TetA和ermB。QnrS在特定的提取方案和等分体积下显示出高检测率。ARGs的浓度因飞机废水样本而异,不同的提取方案影响定量结果。tetA的浓度,ermB,和AWW1中的qnrS是不同的,而AWW2到AWW4表现出更广泛的tetA范围,ermB,qnrS,BlaCTX-M,和blaNDM-1.EP1始终产生几种ARG的最高浓度。集体数据分析显示,在十种提取方案中,ARG浓度各不相同,这表明在飞机废水样品的ARG监测中仔细选择提取方案的重要性。根据结果,我们建议,小样品体积(低至0.2mL)可能足以用于飞机废水样品中的ARG表征。该发现还强调需要考虑在不损害核酸提取效率的情况下去除卫生纸。该研究强调了ARGs飞机废水监测的前景,呼吁进一步调查独特ARG通过交通枢纽的进口和传播。
    This study evaluated ten nucleic acid extraction protocols (EP1 to EP10) for measuring five endogenous antibiotic resistance genes (ARGs) in four aircraft wastewater samples (AWW1 to AWW4). The targeted ARGs, including blaCTX-M, blaNDM-1, ermB, qnrS, and tetA, encompassed highly and minimally abundant ARGs. TetA and ermB were consistently detected across four aircraft wastewater samples using the DNeasy Blood and Tissue Kit and the AllPrep PowerViral DNA/RNA kit. QnrS displayed high detection rates with specific extraction protocols and aliquot volumes. Concentrations of ARGs varied across aircraft wastewater samples, with differing extraction protocols influencing quantitative results. The concentrations of tetA, ermB, and qnrS in AWW1 were distinct, while AWW2 to AWW4 exhibited a broader range for tetA, ermB, qnrS, blaCTX-M, and blaNDM-1. EP1 consistently produced the highest concentrations for several ARGs. Collective data analysis revealed varying ARG concentrations across the ten extraction protocols, suggesting the importance of careful extraction protocol selection in ARG monitoring in aircraft wastewater samples. Based on the results, we suggest that a small sample volume (as low as 0.2 mL) may be sufficient for ARG characterization in aircraft wastewater samples. The findings also emphasize the need for considering toilet paper removal without compromising nucleic acid extraction efficiency. The study highlights promising prospects for aircraft wastewater monitoring of ARGs, calling for further investigation into the import and spread of unique ARGs through transport hubs.
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