Controllable electromechanical stability of a torsional micromirror actuator with piezoelectric composite structure under capillary force

Various types of micro/nano functional devices are being widely designed as optical switches, micro scanners, micromirrors and other core optical devices. The continuing miniaturization of the functional devices makes the size dependence of electromechanical property significant in micro/nano scale due to the sharp increase of surface interactions such as capillary force from liquid bridge, van der Waals and Casimir forces from quantum fluctuations. The surface interactions can cause the pull-in instability, adhesion between parts, and even failure of device. This work provides an active control method to avoid the pull-in instability of an electrostatically driven circular micromirror by applying voltage on a torsional piezoelectric composite structure. The influences of the three types are compared of dispersion forces on the electromechanical stability of the micromirror actuator. A comprehensive electromechanical model of a torsional piezoelectric beam was established to numerically investigate the electromechanical coupling of the micromirror. The results show that the influence of capillary force on the stability of the micromirror is as significant as van der Waals force and Casimir force. By introducing piezoelectric nanoplates into the laminated torsional structure, the micromirror stability can be controlled based on the piezoelectric effect of the torsional piezoelectric composite structure. This work can contribute to the structural optimization design and manufacture of micromirror systems.Cited as: Liu, M., Chen, Y., Cheng, W., Chen, S., Yu, T., Yang, W. Controllable electromechanical stability of a torsional micromirror actuator with piezoelectric composite structure under capillary force. Capillarity, 2022, 5(3): 51-64. https://doi.org/10.46690/capi.2022.03.0

Liquiritin alleviates spinal cord injury through suppression of inflammation, oxidative stress, and cell apoptosis in a rat model

Purpose: Liquiritin is an extract from Glycyrrhiza Radix, one of the oldest traditional Chinese herbal medicines, which is commonly used to treat various injuries and swellings. This study is aimed to determine whether liquiritin can protect spinal cord injuries (SCIs) from secondary injuries. Methods: A rat SCI model was established. After liquiritin treatment, the neural-function of Rats was determined by Basso, Beattie and Bresnahan (BBB) scores, paw withdrawal threshold (PWT), and thermal withdrawal latency (PWL). The effects of anti-inflammation, anti-oxidation, and anti-apoptosis of liquiritin were also examined in the rats with SCI. Moreover, the activities of several signaling elements, such as, inflammation-associated nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), toll-like receptor 4 (TLR4), proliferative-related p38 mitogen-activated protein kinases (MAPK) and myeloid differentiation primary response 88 (MyD88) which was involved in the TLR4 signaling, were used for further investigation of the underlying molecular mechanisms. Results: Liquiritin improved locomotor function recovery, alleviated allodynia and hyperalgesia, and decreased water content of spinal cord in SCI rats. Also, liquiritin reduced SCI–induced inflammatory responses by decreasing the levels of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and IL-6. Liquiritin inhibited SCI–induced oxidative stress by decreasing malondialdehyde (MDA) level and increasing the levels of uperoxide dismutase (SOD) (p < 0.05), glutathione (GSH) (p < 0.01), and GSH-PX (p < 0.001). In addition, liquiritin alleviated spinal cord injury (SCI) –induced apoptosis of neural cells by decreasing the expression of cleaved caspase-9, -3 and cleaved poly ADP-ribose polymerase (PARP). Finally, liquiritin decreased spinal cord injury (SCI) -induced up-regulation of TLR4/MyD88/NF-κB and p38 MAPK signaling cascades. Conclusion: Liquiritin exerts protective role in SCI by reducing excessive inflammation, suppressing oxidative stress, and inhibiting neural cell apoptosis in a rat model of SCI. Thus, the agent can potentially be used for the management of SC

Multi-feature fusion learning for Alzheimer's disease prediction using EEG signals in resting state

IntroductionDiagnosing Alzheimer's disease (AD) lesions via visual examination of Electroencephalography (EEG) signals poses a considerable challenge. This has prompted the exploration of deep learning techniques, such as Convolutional Neural Networks (CNNs) and Visual Transformers (ViTs), for AD prediction. However, the classification performance of CNN-based methods has often been deemed inadequate. This is primarily attributed to CNNs struggling with extracting meaningful lesion signals from the complex and noisy EEG data.MethodsIn contrast, ViTs have demonstrated proficiency in capturing global signal patterns. In light of these observations, we propose a novel approach to enhance AD risk assessment. Our proposition involves a hybrid architecture, merging the strengths of CNNs and ViTs to compensate for their respective feature extraction limitations. Our proposed Dual-Branch Feature Fusion Network (DBN) leverages both CNN and ViT components to acquire texture features and global semantic information from EEG signals. These elements are pivotal in capturing dynamic electrical signal changes in the cerebral cortex. Additionally, we introduce Spatial Attention (SA) and Channel Attention (CA) blocks within the network architecture. These attention mechanisms bolster the model's capacity to discern abnormal EEG signal patterns from the amalgamated features. To make well-informed predictions, we employ a two-factor decision-making mechanism. Specifically, we conduct correlation analysis on predicted EEG signals from the same subject to establish consistency.ResultsThis is then combined with results from the Clinical Neuropsychological Scale (MMSE) assessment to comprehensively evaluate the subject's susceptibility to AD. Our experimental validation on the publicly available OpenNeuro database underscores the efficacy of our approach. Notably, our proposed method attains an impressive 80.23% classification accuracy in distinguishing between AD, Frontotemporal dementia (FTD), and Normal Control (NC) subjects.DiscussionThis outcome outperforms prevailing state-of-the-art methodologies in EEG-based AD prediction. Furthermore, our methodology enables the visualization of salient regions within pathological images, providing invaluable insights for interpreting and analyzing AD predictions

中美贸易冲突、全球价值链重构与国际产能合作

Abstract: At present, China-US economic and trade relations have entered a period of frequent frictions and economic and trade relations have changed from "ballast stone" (stable) Sino-US relations to "fire" (unstable). The US government frequently launches trade disputes with China, uses various trade relief tools to protect domestic sensitive industries and adopts unilateral trade measures to increase the price of Sino-US trade negotiations. Faced with the trend of US unilateralism in trade and the sustained slowdown of the global economy, the key questions are; how to improve China's right to speak and rule in the field of international trade and investment? How to enhance the ability of China and the vast number of developing countries to participate in the global value chain division of labor? Based on the perspective of global value chain reconstruction, this paper analyzes the industrial policy choices and micro-foundation of China's ability to participate in global economic governance based on the experience and evidence of China-Lithuania economic and trade investment cooperation. The study found that developed countries led by the United States have attracted domestic and foreign industrial capital and production factors to return to their own countries, raising the threshold for foreign investment and technical cooperation in developed countries. On the contrary, the space for seeking international capacity cooperation among developing countries has greatly increased. If the integration of the “Belt and Road” value chain is substantially promoted, China and the countries along the route will gradually transfer from the low-end state of the global value chain, which is embedded in Europe and America, to the regional value chain form of high value-added links of mutual benefit and win-win scenarios. Keywords: Sino-US trade conflict; Regional value chain; International capacity cooperation; Global economic governance.当前中美经贸关系步入摩擦多发期，经贸关系已从中美关系的“压舱石”蜕变为“导火索”。美国政府频繁发起对华贸易争端，使用各种贸易救济工具为国内敏感产业提供保护，采取单边贸易措施提高在中美贸易谈判中的要价。面临美国的贸易单边主义政策和全球经济持续性放缓的趋势，如何提升中国在国际贸易投资领域的话语权和规则制定权？如何增强中国和广大发展中国家参与全球价值链分工的能力？本文从全球价值链重构视角，基于中国与立陶宛经贸投资合作的经验与证据，探析我国提升参与全球经济治理能力的产业政策选择与微观基础。研究发现美国为首的发达国家吸引国内外产业资本和生产要素向本国回流，提高了发达国家对外投资与技术合作的门槛，反而导致发展中国家之间寻求国际产能合作空间大为增加。若“一带一路”价值链整合得到实质性推进，中国与沿线国家将可能从嵌入欧美主导的全球价值链低端锁定状态，逐渐转换为互利共赢的高附加值环节的区域价值链形态。 【关键词】中美贸易冲突；区域价值链；国际产能合作；全球经济治

Involvement of a Response Regulator VdSsk1 in Stress Response, Melanin Biosynthesis and Full Virulence in Verticillium dahliae

Verticillium dahliae causes vascular wilt disease on over 200 plant species worldwide. This fungus forms melanized microsclerotia which help it to survive under adverse conditions and these structures are vital to the disease spread. Here, we identified and characterized a V. dahliae homolog to of the Saccharomyces cerevisiae Ssk1, a response regulator of the two-component system. Herein, we demonstrated that the VdSsk1 deletion strains were more sensitive to various stresses, including oxidative stress conferred by H2O2 and sodium nitroprusside dihydrate, while the mutants confered higher resistance to fungicides such as fludioxonil and iprodione. Furthermore, disruption of VdSsk1 resulted in significant downregulation of melanin biosynthesis-related genes but did not affect microsclerotial development. Phosphorylation of VdHog1 was not detected in the VdSsk1 deletion strains under the treatment of sorbitol, indicating that phosphorylation of VdHog1 is dependent on VdSsk1. Finally, we demonstrated that VdSsk1 is required for full virulence. Taken together, this study suggests that VdSsk1 modulates stress response, melanin biosynthesis and virulence of V. dahliae

TLR3 Regulated Poly I:C-Induced Neutrophil Extracellular Traps and Acute Lung Injury Partly Through p38 MAP Kinase

Acute lung injury (ALI) is the leading cause of morbidity and mortality in critically ill patients. Neutrophil extracellular traps (NETs) have been well documented in the ALI model of bacterial infection. In the present study, we demonstrated that poly I:C could induce pulmonary NETs. Upon poly I:C intratracheal inoculation, neutrophil infiltration in the bronchoalveolar lavage fluid (BALF) was significantly increased. Furthermore, the inflammatory cytokines IL-1β, IL-6, and TNF-α in the lung were also significantly elevated. Neutrophil depletion abolished NETs and decreased both neutrophil infiltration and IL-1β in the lung. As expected, DNase I, an inhibitor of MPO and NADPH, decreased pulmonary inflammation and NETs. Blocking of the poly I:C receptor TLR3 reduced lung inflammation and NETs. The MAPK kinase inhibitor p38 diminished the formation of NETs and restored the expression of the tight junction protein claudin-5 in the mouse lung when challenged with poly I:C. In summary, poly I:C induced the formation of pulmonary NETs and ALI, which may be associated with the activation of p38 MAPK and the decreased expression of claudin-5

Modification and validation of the COVID-19 stigma instrument in nurses: A cross-sectional survey

BackgroundNurses taking care of patients with infectious diseases have suffered from noticeable societal stigma, however currently, there is no validated scale to measure such stigma. This study aimed to revise and validate the COVID-19 Stigma Instrument-Nurse-Version 3 (CSI-N-3) by using item response theory (IRT) as well as classical test theory analysis.MethodsIn phase I, the Chinese CSI-N-3 was modified from the English version of HIV/AIDS Stigma Instrument-Nurse based on standard cross-cultural procedures, including modifications, translation/back translations, pilot testing, and psychometric testing with classical test theory and Rasch analysis. In phase II, a cross-sectional study using cluster sampling was conducted among 249 eligible nurses who worked in a COVID-19-designed hospital in Shanghai, China. The influencing factors of COVID-19-associated stigma were analyzed through regression analysis.ResultsIn phase I, the two-factor structure was verified by confirmatory factor analysis, which indicated a good model fit. The 15-item CSI-N-3 achieved Cronbach’s α of 0.71–0.84, and composite reliability of 0.83–0.91. The concurrent validity was established by significant association with self-reported physical, psychological, and social support levels (r = −0.18, −0.20, and −0.21, p < 0.01). In IRT analysis, the CSI-N-3 has ordered response thresholds, with the Item Reliability and Separation Index of 0.95 and 4.15, respectively, and the Person Reliability and Separation Index of 0.20 and 0.50, respectively. The infit and outfit mean squares for each item ranged from 0.39 to 1.57. In phase II, the mean score for the CSI-N-3 in Chinese nurses was 2.80 ± 3.73. Regression analysis showed that social support was the only factor affecting nurses’ COVID-19-associated stigma (standardized coefficients β = −0.21, 95% confidence interval: −0.73 ~ −0.19).ConclusionThe instrument CSI-N-3 is equipped with rigorous psychometric properties that can be used to measure COVID-19-associated stigma during and after the COVID-19 pandemic among nurses. The use of this instrument may facilitate the evaluation of tailored stigma-reduction interventions

Herb-Drug Interaction: Effects of Relinqing® Granule on the Pharmacokinetics of Ciprofloxacin, Sulfamethoxazole, and Trimethoprim in Rats

Relinqing granule (RLQ) is the best-selling Chinese patent drug for treatment of urinary system diseases. In this study, the effects of RLQ on the pharmacokinetics of ciprofloxacin, sulfamethoxazole, and trimethoprim in SD rats were investigated. Rats were randomly divided into control group 1, control group 2, RLQ group 1, and RLQ group 2. RLQ group 1 and RLQ group 2 were treated orally with RLQ for 7 days, and rats were treated with the same volume of water in control group 1 and control group 2. Then, RLQ group 1 and control group 1 were given intragastrically ciprofloxacin on day 8, while RLQ group 2 and control group 2 were given intragastrically sulfamethoxazole and trimethoprim on day 8. Blood samples were collected and determined. There was no significant influence of pharmacokinetic parameters of trimethoprim on two groups. But some pharmacokinetic parameters of ciprofloxacin and sulfamethoxazole in RLQ pretreated rats were evidently altered (P < 0.05), which indicated that absorption of ciprofloxacin and sulfamethoxazole in RLQ pretreated rats was significantly affected. It indicated the coadministration of RLQ would have an influence on the efficacy of ciprofloxacin and sulfamethoxazole, and the doses of ciprofloxacin tablet and compound sulfamethoxazole tablet need adjustment

Susceptibility assessment of geological hazard based on XGBoost and cloud model

In the conventional process of geological hazard assessment, issues such as subjectivity in selecting susceptibility factor weights, randomness, and fuzziness in factor grading are prevalent. The application of a single assessment model can only provide qualitative evaluation of geological hazard susceptibility, lacking quantitative analysis. To overcome these challenges, this study employs an enhanced integrated algorithm (XGBoost) and cloud model. Among 189 disaster potential points in Chaoyang City, twelve susceptibility factors including slope, meteorological conditions, vegetation coverage and elevation were selected. The XGBoost classification algorithm was used to determine susceptibility factor weights. The results showed that the algorithm classification achieved high performance with fitting accuracy of 96.5%. On this basis, the cloud model was employed to transform the fuzzy factor grading into a quantitative problem, establishing a susceptibility evaluation index system for geological hazards in Chaoyang City, thereby assessing their susceptibility. To validate the evaluation index system, the Dadongshan landslide in Chaoyang City was selected as the assessment unit. Results indicate a high susceptibility level for this evaluation unit, consistent with actual conditions. The methodology proposed in this study is promising and can offers reference for evaluating geological hazard susceptibility

Two-element interferometer for millimeter-wave solar flare observations

In this paper, we present the design and implementation of a two-element interferometer working in the millimeter wave band (39.5 GHz - 40 GHz) for observing solar radio emissions through nulling interference. The system is composed of two 50 cm aperture Cassegrain antennas mounted on a common equatorial mount, with a separation of 230 wavelengths. The cross-correlation of the received signals effectively cancels the quiet solar component of the large flux density (~3000 sfu) that reduces the detection limit due to atmospheric fluctuations. The system performance is obtained as follows: the noise factor of the AFE in the observation band is less than 2.1 dB, system sensitivity is approximately 12.4 K (~34 sfu) with an integration time constant of 0.1 ms (default), the frequency resolution is 153 kHz, and the dynamic range is larger than 30 dB. Through actual testing, the nulling interferometer observes a quiet sun with a low level of output fluctuations (of up to 50 sfu) and has a significantly lower radiation flux variability (of up to 190 sfu) than an equivalent single-antenna system, even under thick cloud cover. As a result, this new design can effectively improve observation sensitivity by reducing the impact of atmospheric and system fluctuations during observation