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Friction and wear behavior of bioinspired composites with nacre-like lamellar and brick-and-mortar architectures against human enamel

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Journal of Materials Science & Technology 2022年第33期128卷 133-141页

作者： Kefeng Gao Jianjun Guan Hui Sun Chengwei Han Guoqi Tan Zengqian Liu Qiang Wang Zhefeng Zhang School of Mechanical Engineering Liaoning Petrochemical UniversityFushun 113001China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Liaoning Provincial Key Laboratory of Oral Diseases School and Hospital of StomatologyChina Medical UniversityShenyang 110001China Liaoning Upcera Co. Ltd.Benxi 117004China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Friction and wear performance is critical for dental materials which are inevitably subject to reciprocating friction against opposing teeth in applications.Here in-vitro friction and wear behavior of bioinspired ceramic-polymer composites,which possess nacre-like lamellar and brick-and-mortar architectures and resemble human teeth in their stiffness and hardness,against human tooth enamel were quantitatively investigated to imitate actual service conditions in line with standardized testing configuration.The composites were revealed to exhibit different wear mechanisms and lead to differing extents of wear to the opposing tooth enamel depending on their specific architectural types and orientations.In particular,the brick-and-mortar architecture displayed much less wear than the lamellar one,without obviously roughening the contact surfaces with enamel owing to its high ceramic content,and as such did not accelerate the wear of enamel as compared to smooth ceramics.Such characteristics,combined with its unique stiffness and hardness matching those of human enamel as well as the good fracture toughness and machinability,endow the composite with a promising potential for dental applications.This work may provide an experimental basis to this end and may also give insights towards designing new bioinspired wear-resistant materials for reducing friction and wear.

关键词： Bioinspired materials Nacre-like structures Friction Wear mechanisms Orientation

Sustained delivery of rhMG53 promotes diabetic wound healing and hair follicle development

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Bioactive Materials 2022年第12期7卷 104-115页

作者： Hong Niu Haichang Li Ya guan Xin Zhou Zhongguang Li Serana Li Zhao Peng Chen Tao Tan Hua Zhu Valerie Bergdall Xuehong Xu Jianjie Ma Jianjun Guan Department of Mechanical Engineering and Materials Science Washington University in St.LouisSt.LouisMO63130USA Institute of Materials Science and Engineering Washington University in St.LouisSt.LouisMO63130USA Department of Surgery Davis Heart and Lung Research InstituteThe Ohio State UniversityColumbusOH43210USA Laboratory of Cell Genetics and Developmental Biology Shaanxi Normal University College of Life SciencesXi’an710062China Department of Veterinary Preventive Medicine University Laboratory Animals ResourcesThe Ohio State UniversityColumbusOH43210USA

MG53 is an essential component of the cell membrane repair machinery,participating in the healing of dermal wounds.Here we develop a novel delivery system using recombinant human MG53(rhMG53)protein and a reactive oxygen species(ROS)-scavenging gel to treat diabetic wounds.Mice with ablation of MG53 display defective hair follicle structure,and topical application of rhMG53 can promote hair growth in the mg53􀀀/􀀀mice.Cell lineage tracing studies reveal a physiological function of MG53 in modulating the proliferation of hair follicle stem cells(HFSCs).We find that rhMG53 protects HFSCs from oxidative stress-induced apoptosis and stimulates differentiation of HSFCs into keratinocytes.The cytoprotective function of MG53 is mediated by STATs and MAPK signaling in HFSCs.The thermosensitive ROS-scavenging gel encapsulated with rhMG53 allows for sustained release of rhMG53 and promotes healing of chronic cutaneous wounds and hair follicle development in the db/db mice.These findings support the potential therapeutic value of using rhMG53 in combination with ROS-scavenging gel to treat diabetic wounds.

关键词： Diabetic wound healing hair follicle stem cell MG53 ROS-Scavenging hydrogel Controlled drug delivery

Stability analysis on tunnels with karst caves using the distinct lattice spring model

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Underground Space 2021年第4期6卷 469-481页

作者： jianjun Ma Junwei guan Junfeng Duan Linchong Huang Yu Liang School of Civil Engineering Sun Yat-sen UniversityGuangzhou 510275China Southern Marine Science and Engineering guangdong Laboratory(Zhuahai) Guangdong Key Laboratory of Oceanic Civil EngineeringGuangdong Research Center for Underground Space Exploitation TechnologyZhuhai 519082China MOE Key Laboratory of Engineering Structures of Heavy Haul Railway(Central South University) Changsha 410075China China Railway Wuhan Survey and Design&Institute Co.Ltd Wuhan 430074China School of Aeronautics and Astronautics Sun Yat-Sen UniversityGuangzhou 510006China

The effects of karst caves on tunnel stability were numerically investigated using the distinct lattice spring model(DLSM).The DLSM was validated by investigating the mechanical behavior of Brazilian discs with various sizes of central circular holes.Then,the effects of karst cave on U-shaped tunnel were investigated under various karst caves positions(top,bottom,and right side of the tunnel),tunnelcave distances(0.5-4 times the radius of the tunnel arc),and cave shapes(circular,rectangular flat,and rectangular vertical caves).The failure processes of the tunnel under those various conditions were analyzed and both the failure process and the final failure patterns of the tunnel were discussed.Numerical simulation demonstrated that karst caves around the tunnel could weaken the stability of the tunnel,indicating tunnel-cave distance effects.The closer the cave to the tunnel,the weaker the tunnel under loading.This effect was not significant when the tunnel-cave distance(d)was larger than three times the tunnel arc radius(R).In addition,the final failure pattern of the tunnel and its surrounding rock mass were dependent on both the position and the size of the cave.The larger the cave,the weaker the tunnel and its surrounding rock mass.Furthermore,compared with those cases with top and bottom caves,the tunnel with a right side cave had more impacts on tunnel stability.The main research finding could help engineers carry out stability analysis on tunnels in karst areas and take effective measures to enhance tunnel stability.

关键词： Stability analysis Tunnel Karst cave Distinct lattice spring model

A Practical Design of X-Band Receiver Front-End in 65-nm CMOS

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Chinese Journal of Electronics 2016年第3期25卷 413-417页

作者： LU Zhijian guan Rui LI Xiaoyong ZHOU jianjun Center for Analog/RF IC School of MicroelectronicsShanghai Jiao Tong University

A low-cost low-power area-efficient receiver front-end prototype for X-band applications is presented.The front-end primarily consists of 3 blocks: a singleended input differential-output Low noise amplifier（LNA）,a double balanced down-converter, and Inter-frequency（IF） buffers providing single-ended output. Including are also Low dropout regulators（LDO） and Electrostatic discharge（ESD） protection circuits coinciding with the forgoing blocks. Local oscillator（LO） frequency is chosen such that output signal locates in L/S-band for extending subsequent applications. Experimentally exhibiting a conversion gain of around 44 dB with 7.5-dB Single-sideband（SSB）Noise figure（NF）, the front-end totally draws 24 m A from an external 3.3-V supply. Fabricated in a 65-nm CMOS technology, this compact receiver occupies an area of only0.22mm;.

关键词： Area-efficient Low cost CMOS Receiver front-end X-band

Magnetic storms in Mercury's magnetosphere

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Science China(Technological Sciences) 2022年第6期65卷 1427-1432页

作者： ZONG QiuGang ZHAO JiuTong LIU jianjun FU SuiYan SUN WeiJie ZHANG Hui LE guan RANKIN Robert WEI Yong Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871 China Polar Research Institute of China Shanghai 2000136China Department of Climate and Space Sciences and Engineering University of MichiganAnn Arbor 48109USA Geophysical Institute University of Alaska FairbanksFairbanks 99775USA ITM Laboratory Heliophysics Science DivisionNASA Goddard Space Flight CenterGreenbelt 20771USA Department of Physics University of AlbertaEdmonton T6G2R3Canada Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the planet.Our findings answer the question of whether geomagnetic storms can occur in other planetary magnetospheres.The interaction of the solar wind with Mercury’s magnetosphere is known to involve flux transfer events in the dayside magnetosphere,plasmoids and flux ropes in the magnetotail,and substorm-like processes,all of which occur morphologically similar to Earth but with significant differences.The significantly weaker magnetic field,smaller magnetosphere,and much faster timescale of processes around Mercury,when compared with Earth,enable charged particles to escape its magnetosphere more efficiently through magnetopause shadowing and direct bombard of the surface.Our analysis of MESSENGER’s data during a coronal mass ejection(CME)proves that,despite these substantial differences,a bifurcated ring current can form in Mercury’s magnetosphere that initiates magnetic storms under strong solar wind driving.

关键词： magnetic storm Mercury magnetosphere ring current

Utilization of 3D printing technology in hepatopancreatobiliary surgery

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第2期25卷 123-134页

作者： Wujiang SHI Jiangang WANG jianjun GAO Xinlei ZOU Qingfu DONG Ziyue HUANG Jialin SHENG Canghai guan Yi XU Yunfu CUI Xiangyu ZHONG Department of Hepatopancreatobiliary Surgery the Second Affiliated Hospital of Harbin Medical UniversityHarbin150086China Department of General Surgery Tangdu HospitalAir Force Medical UniversityXi’an710032China Key Laboratory of Basic Pharmacology of Ministry of Education Zunyi Medical UniversityZunyi563006China Key Laboratory of Functional and Clinical Translational Medicine Fujian Province UniversityXiamen Medical CollegeXiamen361000China Department of Pathology Li Ka Shing Faculty of MedicineThe University of Hong KongHong KongChina Jiangsu Province Engineering Research Center of Tumor Targeted Nano Diagnostic and Therapeutic Materials Yancheng Teachers UniversityYancheng224007China Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province Hangzhou310053China Key Laboratory of Gastrointestinal Cancer(Fujian Medical University) Ministry of EducationSchool of Basic Medical SciencesFujian Medical UniversityFuzhou350122China Key Laboratory of Myocardial Ischemia Harbin Medical UniversityMinistry of EducationHarbin150086China

The technology of three-dimensional(3D)printing emerged in the late 1970s and has since undergone considerable development to find numerous applications in mechanical engineering,industrial design,and biomedicine.In biomedical science,several studies have initially found that 3D printing technology can play an important role in the treatment of diseases in hepatopancreatobiliary surgery.For example,3D printing technology has been applied to create detailed anatomical models of disease organs for preoperative personalized surgical strategies,surgical simulation,intraoperative navigation,medical training,and patient education.Moreover,cancer models have been created using 3D printing technology for the research and selection of chemotherapy drugs.With the aim to clarify the development and application of 3D printing technology in hepatopancreatobiliary surgery,we introduce seven common types of 3D printing technology and review the status of research and application of 3D printing technology in the field of hepatopancreatobiliary surgery.

关键词： 3D printing Hepatopancreatobiliary surgery Organ model Cancer model

Anchoring Ni single atoms on sulfur-vacancy-enriched ZnIn_(2)S_(4) nanosheets for boosting photocatalytic hydrogen evolution

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Journal of Energy Chemistry 2021年第7期30卷 408-414页

作者： Jingwen Pan Gongxin Zhang Zhongjie guan Qianyu Zhao Guoqiang Li jianjun Yang Qiuye Li Zhigang Zou National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Engineering Research Center for nanomaterials Co.LtdHenan UniversityKaifeng 475004HenanChina School of Pharmacy Henan UniversityKaifeng 475004HenanChina School of Physics&Electronics Henan UniversityKaifeng 475004HenanChina Jiangsu Key Laboratory for Nano Technology National Laboratory of Solid State Microstructures and Department of PhysicsNanjing UniversityNanjing 210093JiangsuChina

Structure manipulation of photocatalysts at an atomic scale is a promising way to improve its photocatalytic performance.Herein,we realize the anchoring of single Ni atoms on the ZnIn_(2)S_(4) nanosheets with rich sulfur vacancies.Experimental results demonstrate that single Ni atoms induce the formation of NiO-M(Zn/In) atomic interface,which can efficiently promote the carriers separation and prolong the carrier life time.In addition,in situ electron spin resonance spectroscopy(ESR) confirms that the single Ni atoms act as an electron trapping center for protons reduction.As a result,the single Ni atoms decorated ZnIn_(2)S_(4) nanosheets with rich sulfur vacancies(Ni/ZnIn_(2)S_(4)-RVs) shows a hydrogen evolution rate up to 89.4 μmol h^(-1), almost 5.7 and 2.3 times higher compared to that of ZnIn_(2)S_(4) nanosheets with poor sulfur vacancies and rich sulfur vacancies(denoted as ZnIn_(2)S_(4)-PVs and ZnIn_(2)S_(4)-RVs).This work opens up a new perspective manipulating the single-atom cocatalyst and sulfur vacancy on sulfide supports for improving photocatalytic hydrogen evolution.

关键词： ZnIn_(2)S_(4)nanosheets Sulfur vacancies Single-atom Ni Charge carriers separation Photocatalytic hydrogen evolution

Urban land-use classification by combining high-resolution optical and long-wave infrared images

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Geo-Spatial Information Science 2017年第4期20卷 299-308页

作者： Xuehua guan Shuai Liao Jie Bai Fei Wang Zhixin Li Qiang Wen jianjun He Ting Chen Twenty First Century Aerospace Technology Co.Ltd Beijing China Beijing Remote Sensing Information Institute Beijing China China TOPRS Technology Co.Ltd Beijing China Chinese Academy of Surveying and Mapping Beijing China Lyles School of Civil Engineering Purdue University West Lafayette IN USA

Multi-sensor and multi-resolution source images consisting of optical and long-wave infrared (LWlR) images are analyzed separately and then combined for urban mapping in this study.The framework of its methodology is based on a two-level classification approach.In the first level,contributions of these two data sources in urban mapping are examined extensively by four types of classifications,i.***.spectral-based,spectral-spatial-based,joint classification,and multiple feature classification.In the second level,an objected-based approach is applied to decline the boundaries.The specificity of our proposed framework not only lies in the combination of two different images,but also the exploration of the LWlR image as one complementary spectral information for urban mapping.To verify the effectiveness of the presented classification framework and to confirm the LWlR's complementary role in the urban mapping task,experiment results are evaluated by the grss_dfc_2014 data-set.

关键词： Very high-resolution image long-wave infrared image combined imagery multisource data fusion urban mapping classification

Targeting angiogenesis for fracture nonunion treatment in inflammatory disease

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Bone Research 2021年第3期9卷 336-348页

作者： Cuicui Wang Jun Ying Xiaolei Nie Tianhong Zhou Ding Xiao Gaurav Swarnkar Yousef Abu-Amer Jianjun Guan Jie Shen Department of Orthopaedic Surgery School of MedicineWashington UniversitySt.LouisMOUSA Department of Orthopaedic Surgery the First Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhouChina Institute of Orthopaedics and Traumatology the First Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhouChina Department of Mechanical Engineering&Materials Science School of EngineeringWashington UniversitySt.LouisMOUSA Shriners Hospital for Children St.LouisMOUSA

Atrophic fracture nonunion poses a significant clinical problem with limited therapeutic interventions.In this study,we developed a unique nonunion model with high clinical relevance using serum transfer-induced rheumatoid arthritis(RA).Arthritic mice displayed fracture nonunion with the absence of fracture callus,diminished angiogenesis and fibrotic scar tissue formation leading to the failure of biomechanical properties,representing the major manifestations of atrophic nonunion in the clinic.Mechanistically,we demonstrated that the angiogenesis defect observed in RA mice was due to the downregulation of SPP1 and CXCL12 in chondrocytes,as evidenced by the restoration of angiogenesis upon SPP1 and CXCL12 treatment in vitro.In this regard,we developed a biodegradable scaffold loaded with SPP1 and CXCL12,which displayed a beneficial effect on angiogenesis and fracture repair in mice despite the presence of inflammation.Hence,these findings strongly suggest that the sustained release of SPP1 and CXCL12 represents an effective therapeutic approach to treat impaired angiogenesis and fracture nonunion under inflammatory conditions.

关键词： CXCL12 angiogenesis impaired