检索结果-南通市图书馆

Itch perception is reflected by neuronal ignition in the primary somatosensory cortex

在线全文

学校读者我要写书评

暂无评论

National Science Review 2022年第6期9卷 90-99页

作者： xiao-Jun chen yan-He Liu Ning-Long Xu yan-Gang Sun Institute of Neuroscience State Key Laboratory of Neuroscience Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences University of Chinese Academy of Sciences Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology

Multiple cortical areas including the primary somatosensory cortex(S1) are activated during itch signal processing, yet cortical representation of itch perception remains unknown. Using novel miniature two-photon microscopic imaging in free-moving mice, we investigated the coding of itch perception in S1.We found that pharmacological inactivation of S1 abolished itch-induced scratching behavior, and the itch-induced scratching behavior could be well predicted by the activity of a fraction of layer 2/3 pyramidal neurons, suggesting that a subpopulation of S1 pyramidal neurons encoded itch perception, as indicated by immediate subsequent scratching behaviors. With a newly established optogenetics-based paradigm that allows precisely controlled pruritic stimulation, we found that a small fraction of S1 neurons exhibited an ignition-like pattern at the detection threshold of itch perception. Our study revealed the neural mechanism underlying itch perceptual coding in S1, thus paving the way for the study of cortical representation of itch perception at the single-neuron level in freely moving animals.

关键词： itch perception primary somatosensory cortex miniature two-photon microscopic imaging

Repairing whole facial nerve defects with xenogeneic acellular nerve grafts in rhesus monkeys

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第5期17卷 1131-1137页

作者： Guo-chen Zhu Da-Jiang xiao Bi-Wen Zhu yan xiao Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi Clinical College of Nantong UniversityWuxiJiangsu ProvinceChina College of Animal Science&Technology Zhongkai University of Agriculture and EngineeringGuangzhouGuangdong ProvinceChina Department of Pathology Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina

Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically,both in terms of branching a single trunk and in connecting multiple branches of an extratemporal segment.However,in the clinical treatment of facial nerve defects,allogeneic donors are limited.In this experiment,we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve defect.Six monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft group.In the autograft group,the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve,and in the xenogeneic acellular nerve graft group,this was done using a xenogeneic acellular nerve graft with trunk-branches.Examinations of facial symmetry,nerve-muscle electrophysiology,retrograde transport of labeled neuronal tracers,and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement,and that they could actively close their eyelids completely.The degree of recovery from facial paralysis reached House-Brackmann grade II in both groups.Compound muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each monkey.Fluoro Gold-labeled neurons could be detected in the facial nuclei on the injured side.Immunohistochemical staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves.A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron microscope.Taken together,our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effective for repairing whole facial nerve defects in

关键词： acellular nerve compound muscle action potentials facial nerve defect facial symmetry monkey nerve graft nerve regeneration retrograde labeling test synaptophysin xenogeneic

Regional volume changes of the brain in migraine chronification

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第9期15卷 1701-1708页

作者： Xiao-Yan Chen Zhi-Ye chen Zhao Dong Meng-Qi Liu Sheng-Yuan Yu Department of Neurology First Medical Center of Chinese PLA General HospitalBeijingChina Department of Radiology First Medical Center of Chinese PLA General HospitalBeijingChina Department of Radiology Hainan Hospital of First Medical Center of Chinese PLA General HospitalSanyaHainan ProvinceChina

The pathophysiology of migraine is complex.Neuroimaging studies reveal functional and structural changes in the brains of migraine patients.We sought to explore regional volume differences in intracranial structures in patients with episodic and chronic migraine.Sixteen episodic migraine patients,16 chronic migraine patients,and 24 normal controls were recruited and underwent 3.0 T MRI scanning.The volumes of 142 brain regions were calculated by an automatic volumetric algorithm and compared with clinical variables.Results demonstrated that the volumes of specific regions in the frontal and occipital lobes,and the right putamen,were increased and the volume of the fourth ventricle was decreased in the episodic migraine patients compared with controls.The volumes of the left basal forebrain,optic chiasm,and,the fourth ventricle were decreased in the chronic migraine patients,while the occipital cortex and the right putamen were larger.Compared to episodic migraine patiants,chronic migraine patients displayed larger left thalamus and smaller frontal regions.Correlation analysis showed that headache frequency was negatively correlated with the volume of the right frontal pole,right lateral orbital gyrus,and medial frontal lobes and positively correlated with the volume of the left thalamus.The sleep disturbance score was negatively correlated with the volume of the left basal forebrain.This suggests that migraine patients have structural changes in regions associated with pain processing and modulation,affective and cognitive processing,and visual perception.The remodeling of selective intracranial structures may be involved in migraine attacks.This study was approved by the Ethics Committee of Chinese PLA General Hospital(approval No.S2018-027-02)on May 31,2018.

关键词： brain volume chronic migraine frontal lobe magnetic resonance imaging migraine remodeling thalamus visual processing system

Microstructures and mechanical properties of Cu/Al compound materials during thermal cycle

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第11期41卷 3911-3918页

作者： Bing Wang Ping Liu Xin-Kuan Liu Zi-yan Wang yan-yan Wang xiao-Hong chen xiao-Zhi Liu School of Materials Science and Engineering University of Shanghai for Science and TechnologyShanghai200093China Automobiles Science and Technology(Shanghai)Co. LtdShanghai200433China

Cu/Al compound materials,named as copperclad aluminum bus bars,are widely used in heat dissipation of modern engineering.The thermal cycle tests were conducted at 200,250 and 300℃for different cycle times,respectively.Effects of thermal cycle temperatures and thermal cycle times on micro structures and mechanical properties of the interface were studied.The results show that the width of bonding layer and bond strength are significantly affected by thermal cycle temperatures and times.Nonetheless,the variety or the quantity of intermediate compounds is scarcely influenced.Al_(2)Cu,Cu_(9) Al_(4)and CuAl were identified on the interface.With the increase in cycle times,grains of the material grew up.However,grains of the interface grew up more apparently than those of Cu and Al.The knowledge may be applied in the establishment of service condition and quality evaluation of material.

关键词： Copper-clad aluminum bus bars Thermal cycle Interface Bonding Microstructure Intermetallic

Volume Gain of Brainstem on Medication-Overuse Headache Using Voxel-Based Morphometry

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2018年第18期131卷 2158-2163页

作者： Zhioye chen Xiao-Yan Chen Meng-Qi Liu Lin Ma Sheng-Yuan Yu Department of Radiology Chinese People's Liberation Army General Hospital Beijing 100853 China Department of Radiology Hainan Branch of Chinese People's Liberation Army General Hospital Sanya Hainan 572013 China Department of Neurology Chinese People's Liberation Army General Hospital Beijing 100853 China

Background： Histopathology identified the anatomical and molecular abnormalities ofbrainstem nuclei in migraine patients. However, the exact whole brainstem structural changes in vivo have not yet been identified in medication-overuse headache （MOH） transformed from migraine. The aim of this study was to investigate the regional volume changes over the whole brainstem in the MOH patients using voxel-based morphometry （VBM） in vivo.Methods： High-resolution three-dimensional structural images were obtained using a 3.0-Tesla magnetic resonance system from 36 MOH patients and 32 normal controls （NCs） who were consecutively recruited from the International Headache Center, Chinese People＇s Liberation Army General Hospital, from March 2013 to June 2016. VBM was used to assess the brainstem structural alteration in the MOH patients, and voxel-wise correlation was performed to evaluate the relationship with the clinical characteristics.Results： The brainstem region with increased volume located in the left ventrolateral periaqueductal gray （MNI coordinate： -1, -33, -8）, ventral tegmental area （MNI coordinate： 0, -22, - 12）, bilateral substantia nigra （MNI coordinate： -8, - 16, - 12, 9, - 16, - 12）, and trigeminal root entry zone （MNI coordinate： -19, -29, -31; 19, -32, -29） in MOH patients compared with NCs. The headache visual analog scale score was positively related with the left rostral ventromedial medulla （RVM）（MNI coordinate： -1, -37, -56; cluster size： 20; r = 0.602） in the MOH patients.Conclusions： The regional volume gain ofbrainstem could underlie the neuromechanism of impaired ascending and descending pathway in the MOH patients, and the left RVM volume alteration could imply the impaired tolerance ofnociceptive pain input and could be used to assess the headache disability in the MOH patients.

关键词： Medication-Overuse Headache Substantia Nigra Trigeminal Root Entry Zone Ventral Tegmental Area Voxel-Based Morphometry

Altered cerebral activities and functional connectivity in depression:a systematic review of fMRI studies

在线全文

学校读者我要写书评

暂无评论

Quantitative Biology 2022年第4期10卷 366-380页

作者： Xue-Ying Li xiao chen Chao-Gan yan CAS Key Laboratory of Behavioral Science Institute of PsychologyBeijing 100101China Sino-Danish College University of Chinese Academy of SciencesBeijing 101400China Sino-Danish Center for Education and Research Beijing 101400China CFIN and PET Center Aarhus UniversityNørrebrogade 448000 AarhusDenmark Magnetic Resonance Imaging Research Center Institute of PsychologyChinese Academy of SciencesBeijing 100101China International Big-Data Center for Depression Research Chinese Academy of SciencesBeijing 100101China Department of Psychology University of Chinese Academy of SciencesBeijing 100049China

Background:As one of the leading causes of global disability,major depressive disorder(MDD)places a noticeable burden on individuals and society.Despite the great expectation on finding accurate biomarkers and effective treatment targets of MDD,studies in applying functional magnetic resonance imaging(fMRI)are still faced with challenges,including the representational ambiguity,small sample size,low statistical power,relatively high false positive rates,etc.Thus,reviewing studies with solid methodology may help achieve a consensus on the pathology of MDD.Methods:In this systematic review,we screened fMRI studies on MDD through strict criteria to focus on reliable studies with sufficient sample size,adequate control of head motion,and a proper multiple comparison control strategy.Results:We found consistent evidence regarding the dysfunction within and among the default mode network(DMN),the frontoparietal network(FPN),and other brain regions.However,controversy remains,probably due to the heterogeneity of participants and data processing strategies.Conclusion:Future studies are recommended to apply a comprehensive set of neuro-behavioral measurements,consider the heterogeneity of MDD patients and other potentially confounding factors,apply surface-based neuroscientific network fMRI approaches,and advance research transparency and open science by applying state-ofthe-art pipelines along with open data sharing.

关键词： depression resting-state fMRI task-based fMRI default mode network frontoparietal network

Mallows Model Averaging Estimation for Linear Regression Model with Right Censored Data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2022年第1期38卷 5-23页

作者： Zhong-qi LIANG xiao-lin chen yan-qiu ZHOU School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018China School of Statistics Qufu Normal UniversityQufu 273165China School of Science Guangxi University of Science and TechnologyLiuzhou 545006China

This paper is concerned with an optimal model averaging estimation for linear regression model with right censored data. The weights for model averaging are picked up via minimizing the Mallows criterion. Under some mild conditions, it is shown that the identified weights possess the property of asymptotic optimality, that is,the model averaging estimator corresponding to these weights achieves the lowest squared error asymptotically.Some numerical studies are conducted to evaluate the finite-sample performance of our method and make comparisons with its intuitive competitors, while an application to the PBC dataset is provided to serve as an illustration.

关键词： model averaging right censoring asymptotic optimality synthetic data

Invasion by exogenous RNA:cellular defense strategies and implications for RNA inference

在线全文

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2023年第4期5卷 573-584页

作者： Danxu Tang yan Liu Chundi Wang Lifang Li Saleh AAl‑Farraj xiao chen Ying yan Laboratory of Marine Protozoan Biodiversity and Evolution Marine CollegeShandong UniversityWeihai 264209China Key Laboratory of Evolution and Marine Biodiversity(Ministry of Education)and Institute of Evolution and Marine Biodiversity Ocean University of ChinaQingdao 266003China Zoology Department College of ScienceKing Saud University11451 RiyadhSaudi Arabia Suzhou Research Institute Shandong UniversitySuzhou 215123China

Exogenous RNA poses a continuous threat to genome stability and integrity across various organisms.Accumulating evidence reveals complex mechanisms underlying the cellular response to exogenous RNA,including endo-lysosomal degradation,RNA-dependent repression and innate immune clearance.Across a variety of mechanisms,the natural anti-sense RNAdependent defensive strategy has been utilized both as a powerful gene manipulation tool and gene therapy strategy named RNA-interference(RNAi).To optimize the efficiency of RNAi silencing,a comprehensive understanding of the whole life cycle of exogenous RNA,from cellular entry to its decay,is vital.In this paper,we review recent progress in comprehending the recognition and elimination of foreign RNA by cells,focusing on cellular entrance,intracellular transportation,and immune-inflammatory responses.By leveraging these insights,we highlight the potential implications of these insights for advancing RNA interference efficiency,underscore the need for future studies to elucidate the pathways and fates of various exogenous RNA forms,and provide foundational information for more efficient RNA delivery methods in both genetic manipulation and therapy in different organisms.

关键词： Endocytosis Exogenous RNA Innate immune response RNA inference

Multiple-antenna techniques in nonorthogonal multiple access:a review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2019年第12期20卷 1665-1697页

作者： Fei-yan TIAN xiao-ming chen chen College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China

As a promising physical layer technique, nonorthogonal multiple access(NOMA) can admit multiple users over the same space-time resource block, and thus improve the spectral efficiency and increase the number of access users. Specifically, NOMA provides a feasible solution to massive Internet of Things(IoT) in 5G and beyond-5G wireless networks over a limited radio spectrum. However, severe co-channel interference and high implementation complexity hinder its application in practical systems. To solve these problems, multiple-antenna techniques have been widely used in NOMA systems by exploiting the benefits of spatial degrees of freedom. This study provides a comprehensive review of various multiple-antenna techniques in NOMA systems, with an emphasis on spatial interference cancellation and complexity reduction. In particular, we provide a detailed investigation on multiple-antenna techniques in two-user, multiuser, massive connectivity, and heterogeneous NOMA systems.Finally, future research directions and challenges are identified.

关键词： Nonorthogonal multiple access Multiple-antenna technique B5G Internet of Things