Design of an Aircraft Rolling Bearings Platform and its Thermal Performance Evaluation

The thermal instability is one crucial factor leading to low bearing operation performance. This paper presents a novel experiment device for thermal performance investigation of an aircraft rolling bearings. A bidirectional fixing structure was designed to balance the spindle thermal deformation. The hydraulic loading was used and the oil injection manner was adopted in the new device. Experimental test was conducted using the new device and experimental results were compared with the calculation based on the temperature and thermal nodes theory. The comparison demonstrates that the temperature distribution trends between the theoretical and experimental results remained the same; specifically, the error between the theoretical and experimental results was 1.0 % under the condition of 200 kg load and 2250 rpm driving speed. Consequently, the analysis result shows that the new device is feasible and reliable to provide precise thermal characteristics for the aircraft rolling bearings

Development and trend of condition monitoring and fault diagnosis of multi-sensors information fusion for rolling bearings : a review

A rolling bearing is an essential component of a rotating mechanical transmission system. Its performance and quality directly affects the life and reliability of machinery. Bearings’ performance and reliability need high requirements because of a more complex and poor working conditions of bearings. A bearing with high reliability reduces equipment operation accidents and equipment maintenance costs and achieves condition-based maintenance. First in this paper, the development of technology of the main individual physical condition monitoring and fault diagnosis of rolling bearings are introduced, then the fault diagnosis technology of multi-sensors information fusion is introduced, and finally, the advantages, disadvantages, and trends developed in the future of the detection main individual physics technology and multi-sensors information fusion technology are summarized. This paper is expected to provide the necessary basis for the follow-up study of the fault diagnosis of rolling bearings and a foundational knowledge for researchers about rolling bearings.The Natural Science Foundation of China (NSFC) (grant numbers: 51675403, 51275381 and 51505475), National Research Foundation, South Africa (grant numbers: IFR160118156967 and RDYR160404161474), and UOW Vice-Chancellor’s Postdoctoral Research Fellowship.International Journal of Advanced Manufacturing Technology2019-04-01hj2018Electrical, Electronic and Computer Engineerin

Early-start antiplatelet therapy after operation in patients with spontaneous intracerebral hemorrhage and high risk of ischemic events (E-start):Protocol for a multi-centered, prospective, open-label, blinded endpoint randomized controlled trial

BACKGROUND: For severe spontaneous intracerebral hemorrhage (sSICH) patients with high risk of ischemic events, the incidence of postoperative major cardiovascular/cerebrovascular and peripheral vascular events (MACCPE) is notable. Although antiplatelet therapy is a potential way to benefit these patients, the severe hemorrhagic complications, e.g., intracranial re-hemorrhage, is a barrier for early starting antiplatelet therapy. OBJECTIVES: This randomized controlled trial aims to identify the benefit and safety of early starting antiplatelet therapy after operation for sSICH patients with high risk of ischemic events. METHODS: This study is a multicenter, prospective, randomized, open-label, blinded-endpoint trial. We will enroll 250 sSICH patients with a high risk of ischemic events (including cerebral infarcts, transient ischemic attack, myocardial infarction, pulmonary embolism, and deep venous thrombosis). The participants will be randomized in a 1:1 manner to early-start group (start antiplatelet therapy at 3 days after operation) and normal-start group (start antiplatelet therapy at 30 days after operation). The early-start group will receive aspirin 100 mg daily. The control group will not receive antithrombotic therapy until 30 days after operation. The efficacy endpoint is the incidence of MACCPE, and the safety endpoint is the incidence of intracranial re-hemorrhage. DISCUSSION: The Early-Start antiplatelet therapy after operation in patients with spontaneous intracerebral hemorrhage trial (E-start) is the first randomized trial about early start antiplatelet therapy for operated sSICH patients with a high risk of ischemic events. This study will provide a new strategy and evidence for postoperative management in the future. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT04820972; Available at: https://clinicaltrials.gov/ct2/show/NCT04820972?term=NCT04820972&draw=2&rank=1. Chinese Clinical Trial Registry, identifier ChiCTR2100044560; Available at: http://www.chictr.org.cn/showproj.aspx?proj=123277

Incorporating the Soil Gas Gradient Method and Functional Genes to Assess the Natural Source Zone Depletion at a Petroleum-Hydrocarbon-Contaminated Site of a Purification Plant in Northwest China

An increasing number of studies have demonstrated that natural source zone depletion (NSZD) in the vadose zone accounts for the majority (90%~99%) of the natural attenuation of light non-aqueous phase liquid (LNAPL). Until now, 0.05 to 12 kg/a.m2 NSZD rates at tens of petroleum LNAPL source zones have been determined in the middle or late evolution stage of LNAPL release, in which limited volatile organic compounds (VOCs) and methane (CH4) were detected. NSZD rates are normally estimated by the gradient method, yet the associated functional microbial activity remains poorly investigated. Herein, the NSZD at an LNAPL-releasing site was studied using both soil gas gradient methods quantifying the O2, CO2, CH4, and VOCs concentrations and molecular biology methods quantifying the abundance of the pmoA and mcrA genes. The results showed that the methanogenesis rates were around 4 to 40 kg/a.m2. The values were greater than the rates calculated by the sum of CH4 escaping (0.3~1.2 kg/a.m2) and O2 consuming (3~13 kg/a.m2) or CO2 generating rates (2~4 kg/a.m2), suggesting that the generated CH4 was oxidized but not thoroughly to CO2. The functional gene quantification also supported the indication of this process. Therefore, the NSZD rates at the site roughly equaled the methanogenesis rates (4~40 kg/a.m2), which were greater than most of the previously studied sites with a 90th percentile value of 4 kg/a.m2. The study extended the current knowledge of the NSZD and has significant implications for LNAPL remediation management

Development and trend of condition monitoring and fault diagnosis of multi-sensors information fusion for rolling bearings: a review

A rolling bearing is an essential component of a rotating mechanical transmission system. Its performance and quality directly affects the life and reliability of machinery. Bearings\u27 performance and reliability need high requirements because of a more complex and poor working conditions of bearings. A bearing with high reliability reduces equipment operation accidents and equipment maintenance costs and achieves condition-based maintenance. First in this paper, the development of technology of the main individual physical condition monitoring and fault diagnosis of rolling bearings are introduced, then the fault diagnosis technology of multi-sensors information fusion is introduced, and finally, the advantages, disadvantages, and trends developed in the future of the detection main individual physics technology and multi-sensors information fusion technology are summarized. This paper is expected to provide the necessary basis for the follow-up study of the fault diagnosis of rolling bearings and a foundational knowledge for researchers about rolling bearings

Model based on single-nucleotide polymorphism to discriminate aspirin resistance patients

Background Aspirin is widely used for preventing ischaemic events. About 20%–40% of patients have aspirin resistance (ASR), which prevents them from benefiting from aspirin medication. This study aimed to develop and validate a model based on single-nucleotide polymorphism (SNP) to distinguish ASR patients.Methods We included patients with spontaneous intracerebral haemorrhage and continuing antiplatelet therapy from a multicentre, prospective cohort study as the derivation cohort. Thromboelastography (inhibition of arachidonic acid channel<50%) was used to identify ASR. Genotyping was performed to identify the ASR-related SNP. Based on the result of the logistic analysis, the aspirin resistance in the Chinese population score (ASR-CN score) was established, and its accuracy was evaluated using the area under the curve (AUC). Patients receiving dual antiplatelet therapy for unruptured intracranial aneurysm embolism were prospectively included in the validation cohort. After embolism, 30-day ischaemic events, including ischaemic stroke, new or more frequent transient ischaemic attack, stent thrombosis and cerebrovascular death, were recorded.Results The derivation cohort included 212 patients (155 male patients and the median age as 59). 87 (41.0%) individuals were identified with ASR. The multivariate logistic analysis demonstrated six SNPs of GP1BA, TBXA2R, PTGS2 and NOS3 as risk factors related to ASR. The ASR-CN score integrating these SNPs performed well to discriminate ASR patients from non-ASR patients (AUC as 0.77). Based on the validation cohort of 372 patients receiving antiplatelet therapy after embolism (including 130 ASR patients), the ASR-CN score continued to distinguish ASR patients with good accuracy (AUC as 0.80). Patients with high a ASR-CN score were more likely to suffer from 30-day ischaemic events after embolism (OR, 1.28; 95% CI, 1.10 to 1.50; p=0.002).Conclusion GP1BA, TBXA2R, PTGS2 and NOS3 were SNPs related to ASR. The ASR-CN score is an effective tool to discriminate ASR patients, which may guide antiplatelet therapy.Clinical trial registration Surgical Treatments of Antiplatelet Intracerebral Hemorrhage cohort (unique identifier: ChiCTR1900024406, http://www.chictr.org.cn/edit.aspx?pid=40640&htm=4)

Ultraspecific One-Pot CRISPR-Based “Green-Yellow-Red” Multiplex Detection Strategy Integrated with Portable Cartridge for Point-of-Care Diagnosis

Versatile, informative, sensitive, and specific nucleic acid detection plays a crucial role in point-of-care pathogen testing, genotyping, and disease monitoring. In this study, we present a novel one-pot Cas12b-based method coupled with the “Green-Yellow-Red” strategy for multiplex detection. By integrating RT-LAMP amplification and Cas12b cleavage in a single tube, the entire detection process can be completed within 1 h. Our proposed method exhibits high specificity, enabling the discrimination of single-base mutations with detection sensitivity approaching single molecule levels. Additionally, the fluorescent results can be directly observed by the naked eye or automatically analyzed using our custom-designed software Result Analyzer. To realize point-of-care detection, we developed a portable cartridge capable of both heating and fluorescence excitation. In a clinical evaluation involving 20 potentially SARS-CoV-2-infected samples, our method achieved a 100% positive detection rate when compared to standard RT-PCR. Furthermore, the identification of SARS-CoV-2 variants using our method yielded results that were consistent with the sequencing results. Notably, our proposed method demonstrates excellent transferability, allowing for the simultaneous detection of various pathogens and the identification of mutations as low as 0.5% amidst a high background interference. These findings highlight the tremendous potential of our developed method for molecular diagnostics