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The role of Rho GTPase family in cochlear hair cells and hearing

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Neural Regeneration Research 2023年第10期18卷 2167-2172页

作者： Yu-Bei Dai Xiang Gao Dong Liu Jie Gong School of Life Science Nantong Laboratory of Development and DiseasesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of EducationCo-innovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina

Rho GTPases are essential regulators of the actin cytoskeleton.They are involved in various physiological and biochemical processes such as the regulation of cytoskeleton dynamics,development,proliferation,survival,and regeneration.During the development of cochlear hair cells,Rho GTPases are activated by various extracellular signals through membrane receptors to further stimulate multiple downstream effectors.Specifically,RhoA,Cdc42,and Rac1,members of the classical subfamily of the Rho GTPase family,regulate the development and maintenance of cilia by inducing the polymerization of actin monomers and stabilizing actin filaments.In addition,they also regulate the normal morphology orientation of ciliary bundles in auditory hair cells,which is an important element of cell polarity regulation.Moreover,the actin-related pathways mediated by RhoA,Cdc42,and Rac1 also play a role in the motility of outer hair cells,indicating that the function of Rho GTPases is crucial in the highly polar auditory sensory system.In this review,we focus on the expression of RhoA,Cdc42,and Rac1 in cochlear hair cells and how these small molecules participate in ciliary bundle morphogenesis and cochlear hair cell movement.We also discuss the progress of current research investigating the use of these small molecules as drug targets for deafness treatment.

关键词： actin assembly auditory sensory neurons cell polarity cell proliferation electromotility hair cell hearing loss morphogenesis Rho GTPases stereocilia

Improved Fractional-order Damping Method for Voltage-controlled DFIG System Under Weak Grid

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1531-1541页

作者： Zhen Xie Xiang Gao Shuying Yang Xing Zhang School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina

When a doubly-fed induction generator(DFIG)is connected to a weak grid,the coupling between the grid and the DFIG itself will increase,which will cause stability problems.It is difficult to maintain the tracking accuracy and robustness of the phase-locked loop(PLL)in the weak grid,and the risk of instability of the current-controlled DFIG(CC-DFIG)system will increase.In this paper,a new type of voltage-controlled DFIG(VC-DFIG)mode is adopted,which is a grid-forming structure that can independently support the voltage and frequency with a certain adaptability in the weak grid.A small-signal impedance model of the VC-DFIG system is also established.The impedance of DFIG inevitably generates coupling with the grid impedance in the weak grid,especially in parallel compensation grids,and results in resonance.On the basis of the VC-DFIG,impedance stability analysis is performed to study the influences of the control structure and short-circuit ratio.Then,a feedforward damping method is proposed to modify the impedance of the VC-DFIG system at resonance frequencies.The proposed fractional order damping is utilized,which can enhance the robustness and rapidity of resonance suppression under parameter fluctuations.Finally,the experimental results are presented to validate the effectiveness of the proposed control strategy.

关键词： Weak grid voltage-controlled doubly-fed induction generator(DFIG) resonance feedforward damping fractional-order damping

Comprehensive optimization design of aerodynamic and electromagnetic scattering characteristics of serpentine nozzle

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Chinese Journal of Aeronautics 2021年第3期34卷 118-128页

作者： Yubo HE Qingzhen YANG Xiang Gao School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China

Comprehensive optimization design of serpentine nozzle with trapezoidal outlet was studied to improve its aerodynamic and electromagnetic scattering performance.Serpentine nozzles with different center offsets and different ratios of the bases of the trapezoidal outlet were generated based on curvature control regulation.Computational Fluid Dynamics(CFD)simulations have been conducted to obtain the flow field in the nozzle,and Forward-Backward Iterative Physical Optics(FBIPO)method was applied to study the electromagnetic scattering characteristics of the nozzle.Guarantee Convergence Particle Swarm Optimization(GCPSO)algorithm based on Radial Basis Function(RBF)neural network was used to optimize the geometry of the nozzle in consideration of its aerodynamic and electromagnetic scattering characteristics.The results show that the GCPSO method based on RBF can be used to optimize the aerodynamic characteristics of the internal flow and the scattering characteristics of the cavity of the serpentine nozzle with irregular outlet.The optimized model has a higher center offset and a lower ratio of the bases of the trapezoidal outlet after optimization compared to the original model.The optimized model leads to a slight change in aerodynamic performance,with a total pressure recovery coefficient increase of 0.31%and a discharge coefficient increase of 0.41%.In addition,the Radar Cross Section(RCS)decreases also by around 83.33%and the overall performance is significantly improved,with a decrease of the optimized objective function by around 38.74%.

关键词： Forward-Backward Iterative Physical Optics(FBIPO) Guarantee Convergence Particle Swarm Optimization(GCPSO) Nozzle design Optimization design Radar Cross Section(RCS) Serpentine nozzle

Origin, evolution, and molecular function of DELLA proteins in plants

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The Crop Journal 2022年第2期10卷 287-299页

作者： Huidan Xue Xiang Gao Peng He Guanghui Xiao College of Life Sciences Shaanxi Normal UniversityXi’an 710119ShaanxiChina School of Food and Biological Engineering Shaanxi University of Science and TechnologyXi’an 710021ShaanxiChina School of Ecology and Environment Northwestern Polytechnical UniversityXi’an 710012ShaanxiChina

Gibberellic acid(GA), a ubiquitous phytohormone, has various effects on regulators of plant growth and development. GAs promote growth by overcoming growth restraint mediated by DELLA proteins(DELLAs). DELLAs, in the GRAS family of plant-specific nuclear proteins, are nuclear transcriptional regulators harboring a unique N-terminal GA perception region for binding the GA receptor GIBBERELLIN INSENSITIVE DWARF1(GID1) and a C-terminal GRAS domain necessary for GA repression activity via interaction with multiple regulatory proteins. The N-terminal conserved region of DELLAs evolved to form a mode of GID1/DELLA-mediated GA signaling originating in bryophytes and ferns. Binding of GA to GID1 increases the affinity between DELLAs and a SCF E3 ubiquitin–ligase complex, thus promoting the eventual destruction of DELLAs by the 26 S proteasome. DELLAs negatively regulate GA response by releasing transcription factors to directly activate downstream genes and indirectly regulate GA biosynthesis genes increasing GA responsiveness and feedback control by promoting GID1 transcription. GA communicates extensively with other plant hormones and uses crosstalk to regulate plant growth and development. In this review, we summarize current understanding of evolutionary DELLA-mediated gibberellin signaling and functional diversification of DELLA, focusing primarily on interactions of DELLAs with diverse phytohormones.

关键词： DELLA proteins GA signaling pathway Cross-talk Plant hormone Growth and development

The 2 ℃ Global Temperature Target and the Evolution of the Long-TermGoal of Addressing Climate Change-From the United Nations FrameworkConvention on Climate Change to the Paris Agreement

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Engineering 2017年第2期3卷 272-278页

作者： Yun gao Xiang Gao Xiaohua Zhang Department of Sdence & Technology and Climate Change China Meteorological Administration Beijing 100081 China Energy Research Institute National Development and Reform Commission Beijing 100038 China National Center for Climate Change Strategy and International Cooperation (NCSC) Beijing 100038 China

The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevels. It was thus the first international treaty to endow the 2 ℃ global temperature target with legal effect.The qualitative expression of the ultimate objective in Article 2 of the United Nations Framework Conventionon Climate Change （UNFCCC） has now evolved into the numerical temperature rise target in Article 2 of theParis Agreement. Starting with the Second Assessment Report （SAR） of the Intergovernmental Panel on Cli-mate Change （IPCC）, an important task for subsequent assessments has been to provide scientific informa-tion to help determine the quantified long-term goal for UNFCCC negotiation. However, due to involvementin the value judgment within the scope of non-scientific assessment, the IPCC has never scientifically af-firmed the unacceptable extent of global temperature rise. The setting of the long-term goal for addressingclimate change has been a long process, and the 2 ℃ global temperature target is the political consensuson the basis of scientific assessment. This article analyzes the evolution of the long-term global goal foraddressing climate change and its impact on scientific assessment, negotiation processes, and global low-carbon development, from aspects of the origin of the target, the series of assessments carried out by the 1PCCfocusing on Article 2 of the UNFCCC, and the promotion of the global temperature goal at the political level.

关键词： Climate change International negotiationln tergovernmental Panel on Climate Change United Nations Framework Convention on Climate ChangeLong-term goal Critical vulnerability Intuitive building

Acoustic Nonlinearity Parameters Due to Microstructural Defects

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Acta Mechanica Solida Sinica 2018年第5期31卷 525-534页

作者： Xiang Gao Jianmin Qu Department of Mechanical Engineering Tufts University Medford MA 02155 USA

This study presents a general approach to derive the acoustic nonlinearity parameters induced by various types of dislocation configurations including dislocation strings （monopoles）, dislocation dipoles, dislocation pileups and extended dislocations. It is found that expressions of the acoustic nonlinearity parameter induced by such a variety of dislocation con- figurations share a common mathematical form. They are all scaled with （Lch/b）n, where Lch is a characteristic length of the dislocation configuration, b is the magnitude of the Burgers vector, and n is either 3 or 4. Semiquantitative analysis is presented to compare the magnitudes of the acoustic nonlinearity parameters among different types of dislocation configurations.

关键词： Nonlinear ultrasound Nondestructive evaluation Acoustic nonlinearity parameter Microstructural defects Dislocations

Flexible Scanning Method by Integrating Laser Line Sensors with Articulated Arm Coordinate Measuring Machines

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 131-140页

作者： Zexiao Xie Ping Yu Hanlei Gong Shukai Chi Xiang Gao College of Engineering Ocean University of ChinaQingdao 266100China

Measuring and reconstructing the shape of workpieces have been considered as a fundamental step in both reverse engineering and product quality control.Owing to increasing structural complexity of recent products,measurements from multiple directions are typically required in current scanning techniques.Specifically,the plane structured light can be applied to measure one area of a part at a time,with an additional algorithm required to merge the collected data of each area.Alternatively,the line structured light sensor integrated on CNC machines or CMMs could also realize multi-view measurement.However,the system needs to be repeatedly calibrated at each new direction.This paper presents a flexible scanning method by integrating laser line sensors with articulated arm coordinate measuring machines(AACMM).Since the output of the laser line sensor is 2D raw data in the laser plane,our system model introduces an explicit transformation from the 2D sensor coordinate frame to the 3D base coordinate frame of the AACMM(i.e.,the translation and rotation the of the 2D sensor coordinate in the sixth coordinate system of AACMM).To solve the model,the“conjugate pairs”are proposed and identified by measuring a fixed point(e.g.,a sphere center).Moreover,a search algorithm is adopted to find the optimal solution,which noticeably boosts the model accuracy.The experimental results show that the error of the system is about 0.2 mm,which is caused by the error of the AACMM,the sensor error and the calibration error.By measuring a complicated part,the proposed system is proved to be flexible and facilitate,with the ability to measure a part expediently from any necessary direction.Furthermore,the proposed calibration method can also be used for robot hand-eye relationship calibration.

关键词： Reverse engineering Laser line sensors Articulated arm coordinate measuring machines Conjugate pairs

Efficient practical codebook-precoding MIMO scheme based on signal space diversity

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Journal of Systems Engineering and Electronics 2016年第1期27卷 1-9页

作者： Zhanji Wu Xiang Gao School of Information and Communication Engineering Beijing University of Posts and Telecommunications

A novel practical codebook-precoding multiple-input multiple-output（MIMO） system based on signal space diversity（SSD） with the minimum mean squared error（MMSE）receiver is proposed.This scheme utilizes rotation modulation and space-time-frequency component interleaving.A novel precoding matrix selection criterion to maximize the average signal to interference plus noise ratio（SINR） is also put forward for the proposed scheme,which has a larger average mutual information（AMI）.Based on the AMI- maximization criterion,the optimal rotation angles for the proposed system are also investigated.The new scheme can make full use of space-time-frequency diversity and signal space diversity,and exhibit high spectral efficiency and high reliability in fading channels.Simulation results show that the proposed scheme greatly outperforms the conventional bit- interleaved coded modulation（BICM） MIMO-orthogonal frequency division multiplexing（OFDM） scheme without SSD,which is up to4.5 dB signal-to-noise ratio（SNR） gain.

关键词： signal space diversity（SSD） average mutual information（AMI） Turbo code multiple-input multiple-output（MIMO） minimum mean squared error（MMSE）.

Mechanism Study on Chinese Medicine in Treatment of Nodular Goiter

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Chinese Journal of Integrative Medicine 2023年第6期29卷 566-576页

作者： WANG Chang-lin gao Ming-zhou gao xiang-ju MU xiang-yu WANG Jie-qiong gao Dong-mei QIAO Ming-qi School of Chinese Medicine Shandong University of Traditional Chinese MedicineJinan(250355)China Research and Innovation Team of Emotional Diseases and Syndromes of Shandong University of Traditional Chinese Medicine Jinan(250355)China Key Laboratory of Traditional Chinese Medicine for Classical Theory Ministry of EducationJinan(250355)China School of Pharmacy Shandong University of Traditional Chinese MedicineJinan(250355)China Youth Research and Innovation Team of Pharmacology of Liver Viscera in Emotional Disease and Syndromes Jinan(250355)China

Nodular goiter has become increasingly prevalent in recent years.Clinically,there has been a burgeoning interest in nodular goiter due to the risk of progression to thyroid cancer.This review aims to provide a comprehensive summary of the mechanisms underlying the therapeutic effect of Chinese medicine(CM)in nodular goiter.Articles were systematically retrieved from databases,including PubMed,Web of Science and China National Knowledge Infrastructure.New evidence showed that CM exhibited multi-pathway and multi-target characteristics in the treatment of nodular goiter,involving hypothalamus-pituitary-thyroid axis,oxidative stress,blood rheology,cell proliferation,apoptosis,and autophagy,especially inhibition of cell proliferation and promotion of cell apoptosis,involving multiple signal pathways and a variety of cytokines.This review provides a scientific basis for the therapeutic use of CM against nodular goiter.Nonetheless,future studies are warranted to identify more regulatory genes and pathways to provide new approaches for the treatment of nodulargoiter.

关键词： noduiar goiter Chinese medicine mechanism pharmacology review