92 research outputs found

    Design and analysis of magnetic circuit of permanent magnet eddy current brake

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    The eddy current brake has the advantages of no frictional contact or hydraulic fluid, high structural reliability, etc. The existing linear eddy current brakes are mostly flat type. A cylindrical permanent magnet eddy current brake is proposed in this paper, whose air gap magnetic field is generated by a series of ring-shaped permanent magnets and guided by iron pole to conductor layers, and can achieve higher air gap magnetic flux density. This paper introduces its basic structure and working principle. In order to obtain the analytical model of magnetic circuit design, the equivalent magnetic circuit method is used to analyze and derive the magnetic circuit, and it is verified by the axisymmetric finite element model. To derive the braking force generated by the eddy current brake, the layer theory approach is applied. The influence of electromagnetic parameters on the force characteristic is obtained by finite element numerical calculation, which provides a theoretical basis for the optimal design of the eddy current brake

    Efficient perpendicular magnetization switching by a magnetic spin Hall effect in a noncollinear antiferromagnet

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    Current induced spin-orbit torques driven by the conventional spin Hall effect are widely used to manipulate the magnetization. This approach, however, is nondeterministic and inefficient for the switching of magnets with perpendicular magnetic anisotropy that are demanded by the high-density magnetic storage and memory devices. Here, we demonstrate that this limitation can be overcome by exploiting a magnetic spin Hall effect in noncollinear antiferromagnets, such as Mn3Sn. The magnetic group symmetry of Mn3Sn allows generation of the out-of-plane spin current carrying spin polarization collinear to its direction induced by an in-plane charge current. This spin current drives an out-of-plane anti-damping torque providing the deterministic switching of the perpendicular magnetization of an adjacent Ni/Co multilayer. Due to being odd with respect to time reversal symmetry, the observed magnetic spin Hall effect and the resulting spin-orbit torque can be reversed with reversal of the antiferromagnetic order. Contrary to the conventional spin-orbit torque devices, the demonstrated magnetization switching does not need an external magnetic field and requires much lower current density which is useful for low power spintronics

    Ultrasound characteristics of the cervical vagus nerve in patients with type 2 diabetes and diabetic peripheral neuropathy

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    Introduction: Diabetic peripheral neuropathy (DPN) and autonomic neuropathy are commonly coexistent in patients with type 2 diabetes mellitus (T2DM). Current assessment tools for diabetic neuropathy remain complicated and limited. We aimed to investigate the sonographic changes of the cervical vagus nerve in DPN patients with T2DM. Material and methods: Patients with T2DM were divided into a DPN group (DPN, n = 44) and non-DPN controls (NDPN, n = 43) based on electromyogram results. Another 43 healthy controls (CON) were included. High-frequency ultrasound (HFU) of the vagus nerve was performed in all participants. Results: Compared with controls, the honeycomb structure of the vagus nerve in patients with T2DM decreased, p < 0.001. The DPN group had higher cross-sectional area (CSA) of the right vagus nerve than the NDPN group (1.60 ± 0.52 vs. 2.00 ± 0.57 mm2, p =0.001). Logistic regression showed that right vagus nerve CSA was a risk factor of DPN (odds ratio [OR] = 3.924, p = 0.002). Right vagus nerve CSA was positively correlated with diabetes duration (p = 0.003), and negatively correlated with the motor conduction velocity (MCV) of the ulnar, median, and common peroneal nerves (p < 0.001 for all), as well as the sensor conduction velocity (SCV) of the ulnar and median nerve (both p < 0.005). Conclusion: HFU shows thickening of the cervical vagus nerve in patients with DPN, which is a potential diagnostic feature of diabetic neuropathy

    Associations of COVID-19 lockdown with birth weight in China

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    BackgroundDuring the special period of the global spread of COVID-19, pregnant women are sensitive groups to the impacts of COVID-19 epidemic. However, the effects of lockdown measures implemented in response to the COVID-19 on fetal birthweight remain unclear.ObjectivesThis study investigated the associations of COVID-19 lockdown with birth weight in Chinese population.MethodsWe collected 730,153 data of participants from hospitals of five cities in the south of China, we defined the time period of level I response (1/23-2/24/2020) as level I lockdown, and women who were pregnant during level I lockdown as the exposure group. Women who were pregnant during the same calendar month from 2015 to 2019 were defined as the unexposed group. We quantitatively estimate the individual cumulative exposure dose by giving different weights to days with different emergency response levels. Generalized linear regression models were used to estimate the association between COVID-19 lockdown exposure with birth weight and risk of low birth weight (<2,500 g) and macrosomia (>4,000 g).ResultsThe birth weight of the exposed group is heavier than the unexposed group (3,238.52 vs. 3,224.11 g: adjusted β = 24.39 g [95% CI: 21.88, 26.91 g]). The exposed group had a higher risk of macrosomia (2.8% vs. 2.6%; adjusted OR = 1.17 [95% CI: 1.12, 1.22]). More obvious associations were found between COVID-19 lockdown and macrosomia in women who experienced the lockdown in their early pregnancy. Women who experienced the lockdown at their 4–7 weeks of pregnancy showed statistically significant heavier birth weight than unexposed group (after adjustment): β = 1.28 (95% CI: 1.11, 1.46) g. We also observed a positive association between cumulative exposure dose of COVID-19 lockdown in all pregnant women and birth weight, after divided into four groups, Q1: β = 32.95 (95% CI: 28.16, 37.75) g; Q2: β = 18.88 (95% CI: 14.12, 23.64) g; Q3: β = 19.50 (95% CI: 14.73, 24.28) g; Q4: β = 21.82 (95% CI: 17.08, 26.56) g. However, there was no statistically significant difference in the risk of low birth weight between exposed and unexposed groups.ConclusionsThe COVID-19 lockdown measures were associated with a heavier birth weight and a higher risk of macrosomia. Early pregnancy periods may be a more susceptible exposure window for a heavier birth weight and a higher risk of macrosomia. We also observed a positive association between cumulative exposure dose of COVID-19 lockdown and birth weight. The government and health institutions should pay attention to the long-term health of the infants born during the COVID-19 lockdown period, and follow up these mothers and infants is necessary

    Effects of exogenous retinoic acid on ocular parameters in Guinea pigs with form deprivation myopia

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    Aim: Myopia is a common chronic eye disease, this study is to investigate the effects of exogenous retinoic acid (RA) on intraocular parameters, especially choroidal thickness (CT) and retinal thickness (RT), in guinea pigs with form deprivation myopia (FDM).Methods: A total of 80 male guinea pigs were divided randomly into 4 groups: Control, FDM, FDM + RA, and FDM + Citral groups. The FDM + RA group was given 24 mg/kg RA dissolved in 0.4 mL peanut oil; the FDM + Citral group was given citral 445 mg/kg dissolved in 0.4 mL peanut oil; The other two groups were given 0.4 mL peanut oil. After 4 weeks, the refractive error (RE), axial length (AL), and intraocular pressure (IOP) of all guinea pigs were measured, and the parameters of RT and CT were obtained using enhanced depth imaging optical coherence tomography (EDI-OCT).Results: After 4 weeks, both the RE and AL in the FDM and FDM + RA groups were increased, and the RT and CT in both groups were smaller than those in the Control group (p < 0.05). Only the IOP of the right eye in the FDM + RA group increased significantly (p < 0.05). The RT of the right eye of the 4 groups was compared: Control group > FDM + Citral group > FDM group > FDM + RA group. Compared with the RT of the left eye and the right eye among the 4 groups, the RT of the right eye in the FDM and FDM + RA groups was significantly less than that in the left eye (p < 0.05). Moreover, the CT of the right eye in the Control group was greater than that in the other three groups (p < 0.0001). There was no significant difference in the CT among the FDM, FDM + RA, and FDM + Citral groups (p > 0.05). In contrast to the RT results, the CT results of the left and right eyes in the FDM + Citral group showed statistically significant differences (p < 0.05).Conclusion: RA participates in the progression of FDM as a regulatory factor. Exogenous RA can increase the RE, AL, and IOP of FDM guinea pigs, and might aggravate the retinal thinning of FDM guinea pigs. Citral can inhibit these changes, but RA might not affect the thickness of the choroid

    The role of N6-methyladenosine (m6A) in kidney diseases

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    Chemical modifications are a specific and efficient way to regulate the function of biological macromolecules. Among them, RNA molecules exhibit a variety of modifications that play important regulatory roles in various biological processes. More than 170 modifications have been identified in RNA molecules, among which the most common internal modifications include N6-methyladenine (m6A), n1-methyladenosine (m1A), 5-methylcytosine (m5C), and 7-methylguanine nucleotide (m7G). The most widely affected RNA modification is m6A, whose writers, readers, and erasers all have regulatory effects on RNA localization, splicing, translation, and degradation. These functions, in turn, affect RNA functionality and disease development. RNA modifications, especially m6A, play a unique role in renal cell carcinoma disease. In this manuscript, we will focus on the biological roles of m6A in renal diseases such as acute kidney injury, chronic kidney disease, lupus nephritis, diabetic kidney disease, and renal cancer

    Influenza vaccine uptake among children and older adults in China: a secondary analysis of a quasi-experimental study.

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    BACKGROUND: Influenza vaccination is the key to prevent influenza-related disease, especially among high-risk populations. However, influenza vaccine uptake in China is low. This secondary analysis of a quasi-experimental trial aimed to understand factors associated with influenza vaccine uptake among children and older people stratified by funding context. METHODS: A total of 225 children (aged 0.5-8 years) and 225 older people (aged 60 years or above) were recruited from three clinics (rural, suburban and urban) in Guangdong Province. Participants were allocated into two groups based on funding contexts: a self-paid group (N = 150, 75 children and 75 older adults) in which participants paid full price for their vaccination; and a subsidized group (N = 300, 150 children and 150 older adults) in which varying levels of financial support was provided. Univariate and multivariable logistic regressions were conducted stratified by funding contexts. RESULTS: Overall, 75.0% (225/300) of participants in the subsidized group and 36.7% (55/150) in the self-paid group got vaccinated. Older adults had lower vaccination rates than children in both funding groups, while both age groups showed much higher uptake in the subsidized group than in the self-paid group (aOR = 5.96, 95% CI: 3.77-9.42, p = 0.001). In the self-paid group, having prior influenza vaccination history of children (aOR:2.61, 95%CI: 1.06-6.42) or older people (aOR:4.76, 95%CI: 1.08-20.90) was associated with increased influenza vaccine uptake compared to those who had no prior vaccination experiences in the family. While in the subsidized group, participants who got married or lived with partners (aOR = 0.32, 0.10-0.98) had lower vaccination uptake than single ones. Trust in providers' advice (aOR = 4.95, 95%CI:1.99, 12.43), perceived effectiveness of the vaccine (aOR: 12.18, 95%CI: 5.21-28.50), and experienced influenza-like illnesses in the family in the past year (aOR = 46.52, 4.10, 533.78) were associated with higher vaccine uptake. CONCLUSIONS: Older people had suboptimal vaccine uptake compared to children in both contexts and need more attention to enhance influenza vaccination. Tailoring interventions to different vaccine funding contexts may help improve influenza vaccination: In self-paid context, motivating people to accept their first ever influenza vaccination may be a promising strategy. In subsidized context, improving public confidence in vaccine effectiveness and providers' advice would be useful

    Big-five personality and BIS/BAS traits as predictors of career exploration: The mediation role of career adaptability

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    Based on career construction theory, the current research examined whether career adaptability mediates the relations of the personality traits (Five-Factor Model personality traits and behavioral inhibition and activation systems (BIS/BAS)) to career exploration behavior. Results from a survey in Chinese university students (N = 264) showed that career exploration correlated negatively with neuroticism, and positively with openness to experience, extroversion, agreeableness, conscientiousness and BAS. Results of regression analyses further showed that openness to experience, agreeableness, conscientiousness and BAS served as the strongest predictors for career exploration. In addition, career adaptability was shown to be a key mediator for the relationships between personality traits and career exploration behavior. Career concern and career curiosity were the more important dimensions in the mediation model. These findings advance current understandings on how different personality traits predict career exploration behavio

    Integrated Genomic Analysis of the Ubiquitin Pathway across Cancer Types

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    Protein ubiquitination is a dynamic and reversibleprocess of adding single ubiquitin molecules orvarious ubiquitin chains to target proteins. Here,using multidimensional omic data of 9,125 tumorsamples across 33 cancer types from The CancerGenome Atlas, we perform comprehensive molecu-lar characterization of 929 ubiquitin-related genesand 95 deubiquitinase genes. Among them, we sys-tematically identify top somatic driver candidates,including mutatedFBXW7with cancer-type-specificpatterns and amplifiedMDM2showing a mutuallyexclusive pattern withBRAFmutations. Ubiquitinpathway genes tend to be upregulated in cancermediated by diverse mechanisms. By integratingpan-cancer multiomic data, we identify a group oftumor samples that exhibit worse prognosis. Thesesamples are consistently associated with the upre-gulation of cell-cycle and DNA repair pathways, char-acterized by mutatedTP53,MYC/TERTamplifica-tion, andAPC/PTENdeletion. Our analysishighlights the importance of the ubiquitin pathwayin cancer development and lays a foundation fordeveloping relevant therapeutic strategies
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