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

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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

Degree Conditions on Copies of Forests in Graphs

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Journal of the Operations Research Society of China 2023年第3期11卷 667-672页

作者： xiao-Dong chen Shuai-jun chen Ming-Chu Li School of Mathematics Liaoning Normal UniversityDalian116029LiaoningChina College of Science Liaoning University of TechnologyJinzhou121001LiaoningChina School of Softsware Dalian University of TechnologyDalian116024LiaoningChina

For a graph G,letμ(G)=min{max{d(x),d(y)}:x≠y,xy∉E(G),x,y∈V(G)}if G is non-complete,otherwise,μ(G)=+∞.For a given positive number s,we call that a graph G satisfies Fan-type conditions ifμ(G)≥s.Supposeμ(G)≥s,then a vertex v is called a small vertex if the degree of v in G is less than s.In this paper,we prove that for a forest F with m edges,if G is a graph of order n≥|F|andμ(G)≥m with at most max{n−2m,0}small vertices,then G contains a copy of F.We also give examples to illustrate both the bounds in our result are best possible.

关键词： Fan-type conditions Forest Copy Small vertex

Multifractal estimation of NMR T_(2) cut-off value in low-permeability rocks considering spectrum kurtosis: SMOTE-based oversampling integrated with machine learning

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Petroleum Science 2023年第6期20卷 3411-3427页

作者： Xiao-Jun Chen Rui-Xue Zhang xiao-Bo Zhao jun-Wei Yang Zhang-Jian Lan cheng-Fei Luo Jian-Chao Cai MOE Key Laboratory of Tectonics and Petroleum Resources Wuhan430074HubeiChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchesterM139PLUK Jianghan Oilfied SINOPECQianjiang430063HubeiChina Hainan Branch of CNOOC Ltd Haikou570311HainanChina CNOOC EnerTech-Drilling&Production Co.CNOOC Central Laboratory(Zhanjiang) Zhanjiang524057GuangdongChina National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China

The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight 0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.

关键词： Nuclear magnetic resonance Low-permeability porous media T_(2)cut-off value Fractal and multifractal Data augmentation Machine learning

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Arthroscopic treatment of ankle impingement syndrome

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Chinese Journal of Traumatology 2023年第6期26卷 311-316页

作者： Xin chen He-Qin Huang xiao-jun Duan Center for Joint Surgery Southwest HospitalThird Military University(Amy Medical University)Chongqing400038China Department of Nuclear Medicine Southwest HospitalThird Military University(Amy Medical University)Chongqing400038China

Arthroscopic treatment of ankle impingement syndrome(AIS)is a minimally invasive surgical procedure used to address symptoms caused by impingement in the ankle joint.This syndrome occurs when there is abnormal contact between certain bones or soft tissues in the ankle,leading to pain,swelling,or limited range of motion.Traditionally,open surgery was the standard approach for treating AIS.However,with advancements in technology and surgical techniques,arthroscopic treatment has become a preferred method for many patients and surgeons.With improved visualization and precise treatment of the arthroscopy,patients can experience reduced pain and improved functionality,allowing them to return to their daily activities sooner.In this paper,we reviewed the application and clinical efficacy the of arthroscopic approach for treating AIS,hoping to provide a reference for its future promotion.

关键词： Ankle impingement syndrome Arthroscopy Joint Surgery Clinical treatment

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Learning from nature for healthcare,energy,and environment

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The Innovation 2021年第3期2卷 7-8页

作者： xiao xiao xiao xiao Yang Lan jun chen Department of Bioengineering University of CaliforniaLos AngelesLos AngelesCA 90095USA Centre for Nature-Inspired Engineering University College LondonLondon WC1E 7JEUK

Have you ever looked into the sky and wondered why birds could fly?Or perhaps why the leaves of cacti are needle-like?Throughout evolution,organisms have experimented with various forms and functions for over 3 billion years before the first human manipulations of stone,bone,and antler.From animal teeth to spears,fish fins to paddles,human beings have studied nature not only to satisfy curiosity but,more importantly,to learn from it for innovations and inventions.Along with the development of technology,our understanding of the creatures in nature goes beyond the pure observation of morphology to investigate exquisite composition and knowledge of fundamentals of their unique functions.Nowadays,people draw inspiration from nature to create shark skin swimsuits that increase swimming speeds,buzzard-inspired flaps that improve aircraft maneuver,and self-cleaning clothes that mimic the surface wettability of lotus leaves.These ideas are bio-inspired strategies,aiming to inspire biological methods and natural approaches to design modern technology or resolve engineering problems.

关键词： needle perhaps teeth

An automatic optimization method for minimizing supporting structures in additive manufacturing

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Advances in Manufacturing 2020年第1期8卷 49-58页

作者： Xiao-Jun Chen jun-Lei Hu Qing-Long Zhou Constantinus Politis Yi Sun Institute of Biomedical Manufacturing and Life Quality Engineering State Key Laboratory of Mechanical System and VibrationSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240P.R.China OMFS-IMPATH Research Group Department of Imaging and PathologyFaculty of MedicineKatholieke Universiteit LeuvenLeuvenBelgium Department of Oral and Maxillofacial Surgery University Hospitals LeuvenLeuvenBelgium

The amount of supporting structure usage has been a major research topic in layer-based additive manufacturing(AM)over the past years as it leads to increased fabrication time and decreased surface quality.Previous studies focused on deformation and topology optimization to eliminate the number of support structures.However,during the actual fabrication process,the properties of shape and topology are essential.Therefore,they should not be modified casually.In this study,we present an optimizer that reduces the number of supporting structures by identifying the prime printing direction.Without rotation,models are projected in each direction in space,and the basis units involved in the generation of support structures are separated.Furthermore,the area of the supporting structures is calculated.Eventually,the prime printing direction with minimal supporting area is obtained through pattern-searching method.The results of the experiment demonstrated that the printing area was reduced by up to 60%for some cases,and the surface quality was also improved correspondingly.Furthermore,both the material consumption and fabrication time were decreased in most cases.In future work,additional factors will be considered,such as the height of the supporting S Xiao-Jun Chen xiaojunchen@*** 1 Institute of Biomedical Manufacturing and Life Quality Engineering,State Key Laboratory of Mechanical System and Vibration,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,P.R.China 2 OMFS-IMPATH Research Group,Department of Imaging and Pathology,Faculty of Medicine,Katholieke Universiteit Leuven,Leuven,Belgium 3 Department of Oral and Maxillofacial Surgery,University Hospitals Leuven,Leuven,Belgium structures and the adhesion locations to improve the efficiency of this optimizer.

关键词： Printing direction Optimization Supporting structures

Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin Ji xiao-song Zhang chen-jun Yang xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise underwater.The blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance flow.In the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence model.The measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip geometry.The strong fluctuations of duct-surface pressures are caused by intensive tip separation vortices.The duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

Perspectives on early-stage lung cancer identification and challenges to thoracic surgery

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Chronic Diseases and Translational Medicine 2022年第2期8卷 79-82页

作者： xiao Li Kezhong chen Fan Yang jun Wang Department of Thoracic Surgery Peking University People's HospitalBeijing100044China

Lung cancer is one of the leading causes of cancer-related death worldwide with the long-term survival rate for stage I cancers treated with surgery reaching over 80%,but rapidly reducing as disease develops with stage III cancer patients presenting with a long-term survival rate of just 20%.Altliough surgery remains die most effective strategy for treating early stage lung cancers,screening and early diagnosis remain critical for improving prognosis in lung cancer.In addition to advancements in surgical techniques,die rapid development of artificial intelligence(AI),liquid biopsy,and other technologies in recent years has led to new breakthroughs in the diagnosis of this disease.Clinical application of neoadjuvant therapies using immune checkpoint inhibitors have also shown promise for improved efficacy in the treatment of early stage lung cancers.This editorial was designed to summarize the recent progress around the screening and diagnosis of early stage lung cancers and the challenges associated with various surgical strategies for treating these patients.

关键词： early-stage lung cancer progress thoracic surgery

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Probing recycled carbonate in the lower mantle

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National Science Review 2022年第6期9卷 10-11页

作者： Li-Hui chen xiao-jun Wang Sheng-Ao Liu Department of Geology State Key Laboratory of Continental Dynamics Northwest University State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences

Carbonates in marine sediments and altered oceanic crust are major carbon reservoirs on Earth’s surface, which can be transported into Earth’s interior by subduction. High-pressure experiments and thermodynamic mode... 详细信息

关键词： ISOTOPES