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Harnessing structural instability for cell durotaxis

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Acta Mechanica Sinica 2019年第2期35卷 355-364页

作者： Jie Wei xiaofeng chen Bin chen Department of Engineering Mechanics Zhejiang University Hangzhou 310012 China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Hangzhou 310012 China

Cells were suggested to sense matrix rigidity by applying fluctuating forces, but the underlying mechanism remains elusive. Here with a generic filament-crosslinker modeling system for stress fibers, we demonstrate that high mechanical forces can be induced by specific protein-protein interactions with biased kinetics. Strikingly, we further find that there exist two patterns of force generation, a stable pattern and a fluctuated pattern, in agreement with previous experimental observations. Our analysis indicates that the fluctuated force profile is essentially due to force-induced structural instability during structural assembly. We suggest that how cells utilize or circumvent such stable forces or fluctuated forces may be important in other biological processes as well, though whether such forces should be regarded as passive or active is still tentative.

关键词： Protein-protein interaction Biased kinetics Force generation Stable pattern Fluctuated pattern

Blockchain-based multiple groups data sharing with anonymity and traceability

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Science China(Information Sciences) 2020年第3期63卷 7-19页

作者： Hui HUANG xiaofeng chen Jianfeng WANG State Key Laboratory of Integrated Service Networks (ISN) Xidian University College of Computer Minnan Normal University

Group data sharing enables information sharing between multiple parties for cooperative purposes. However, the existing schemes only consider scenarios in which all parties in the same organization want to share data. Achieving secure data sharing between users of different groups is also a relevant research issue. In this paper, we propose a blockchain-based data sharing scheme for multiple groups with anonymity and traceability. Owing to the consortium blockchain technique, any user in the system can easily verify the validity of the shared data without interacting with a third-party auditor. Additionally, the proposed scheme can not only enable data sharing between different groups with enhanced security anonymously but also achieve traceability and non-frameability.

关键词： multiple groups data sharing blockchain anonymity traceability

Ordovician chitinozoan diversification events in China

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Science China Earth Sciences 2004年第10期47卷 874-879页

作者： WANG xiaofeng chen Xiaohong Center for Stratigraphy and Palaeontology CGS Yichang 443003 China Center for Stratigraphy and Palaeontology CGS Yichang 443003 China

Correlative study of the Ordovician chitinozoan biostratigraphy in China with grap- tolite and conodont biozones, and comprehensive analysis of the sequence- and event-strati- graphic indicated that 17 chitinozoan zones and 5 main chitinozoan diversification events subsequently occurring could be recognized in the Ordovician System of China. The 5 events comprise: event 1 — appearance of the earliest Ordovician chitinozoans, event 2 —appearance of C. symmetrica, event 3 —juvenile radiation of chitinozoans, event 4 —appearance of chitinozoans with high diversity, and event 5 —development of chitinozoans of deep-water facies. The age and feature of each event and its relation with the sea-level change and other geological event are discussed.

关键词： chitinozoan, Ordovician, diversification event.

Molecular phylogeography and population genetic structure of the planktonic copepod Calanus sinicus Brodsky in the coastal waters of China

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Acta Oceanologica Sinica 2014年第10期33卷 74-84页

作者： HUANG Yousong LIU Guangxing chen xiaofeng College of Environmental Science and Engineering Ocean University of China Key Laboratory of Marine Environment and Ecology of Ministry of Education Ocean University of China

Planktonic copepod Calanus sinicus is the dominant meso-zooplankton in the Northwest Pacific Ocean. To better understand its population dynamics and phylogeographic patterns, 243 C. sinicus individuals were collected from seven locations across the shelf waters of China and its population genetics was studied by mitochondrial DNA cytochrome oxidase I（mtCOI） sequences analyses. Thirty-nine different sequences, or haplotypes, were detected with moderate haplotype diversity（h=0.749） and low nucleotide diversity（π=0.003） for all populations. The evolutionary divergence between geographic populations varied from 0.24% to 0.37%, indicative of very limited genetic differentiation. Visualized minimum spanning network（MSN） and phylogenetic analysis of all the detected haplotypes did not reveal any clear phylogeographic pattern. Furthermore, AMOVA data showed no significant spatial population differentiation existed among the individuals collected across China shelf waters. Pairwise FST values showed that population collected from northwest of the East China Sea（ECS） displayed a low difference to other populations. Mismatch distribution analyses and neutrality tests indicated that C. sinicus might undergo a demographic/population expansion. No significant population genetic structuring was detected, indicating an extensive gene flow among the C. sinicus populations. Our results provide molecular evidence for the hypothesis that C. sinicus in the northwestern South China Sea in winter is transported from the East China Sea and the Yellow Sea by the China Coastal Current during the northeast monsoon period.

关键词： copepod Calanus sinicus mtCOI population genetic differentiation China Coastal Current

Lattice-based group encryptions with only one trapdoor

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Science China(Information Sciences) 2022年第5期65卷 205-222页

作者： Jing PAN Jiang ZHANG Fangguo ZHANG xiaofeng chen Willy SUSILO State Key Laboratory of Integrated Service Networks(ISN) Xidian University State Key Laboratory of Cryptology School of Computer Science and Engineering Sun Yat-sen University Guangdong Key Laboratory of Information Security Institute of Cybersecurity and Cryptology School of Computing and Information TechnologyUniversity of Wollongong

Group encryption(GE), the encryption analog of group signatures, is a fundamental primitive that offers a privacy-preserving service for a specific receiver concealed within a group of certified *** other cryptographic primitives, GE constructions are always considered relative to the potential danger of quantum computations. The only existing lattice-based variant appeared in the work of Libert et al.(Asiacrypt’16). Despite its non-trivial achievement, the construction suffers in terms of efficiency due to the extensive use of lattice trapdoors. In this paper, we develop an integrated zero-knowledge argument system that is friendly to both accumulated values and hidden matrices and supports efficient designs from *** on this system, we propose efficiency enhancing GE where only group users are required to possess the lattice trapdoors and the other parties are not. In particular, we utilize lattice-based cryptographic accumulators to confirm prospective group members and use the dual Regev encryption scheme to provide privacy for ciphertext recipients. These modifications significantly increase GE efficiency. In addition, under the intractability assumptions of the standard lattice problems, we prove the security of the proposed scheme in the standard model(assuming interaction during the proof phase), which retains the strongest level of security as the only currently available candidate.

关键词： Lattice cryptography lattice cryptography group encryptions lattice trapdoors accumulators zero-knowledge

Highly efficient nickel/phosphine catalyzed cross-couplings of diarylborinic acids with aryl tosylates and sulfamates

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Science China Chemistry 2014年第8期57卷 1126-1131页

作者： KE HaiHua chen xiaofeng FENG YuanYuan ZOU Gang Department of Fine Chemicals East China University of Science and Technology

Highly efficient cross-couplings of diarylborinic acids with aryl tosylates and sulfamates are reported for construction of biaryls using a tri(4-methoxyphenyl)phosphine-supported nickel catalyst system: Ni[P(4-MeOC6H4)3]2Cl2/2P(4-MeOC6H4)3 in the presence of K3PO4·3H2O in toluene. A variety of unsymmetrical biaryls could be obtained in good to excellent yields with1.5–3 mol% or 3–5 mol% catalyst loadings for aryl sulfamates and tosylates, respectively. In sharp contrast to the conventional nickel-catalyzed Suzuki coupling with arylboronic acids, arylsulfamates unexpectedly displayed a higher reactivity than the corresponding tosylates in coupling with diarylborinic acids catalyzed by the nickel/phosphine catalyst system.

关键词： nickel phosphine cross-coupling diarylborinic acid aryl tosylate aryl sulfamate

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BET protein inhibitor apabetalone represses Porphyromonas gingivalis LPS-induced macrophage M1 polarization via regulating miR-130a/STAT3 axis

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BIOCELL 2022年第10期46卷 2281-2289页

作者： MEIHUA chen HUIHUI WANG xiaofeng chen YAN chen TIANYING BIAN Department of Periodontics Shanghai Stomatological Hospital&School of StomatologyFudan UniversityShanghai200001China Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases Fudan UniversityShanghai200001China Department of Stomatology Shanghai Fifth People’s HospitalFudan UniversityShanghai200240China

Periodontitis is a frequent chronic inflammatory disorder destroying *** studies have revealed the role of bromodomain and extraterminal domain inhibitor(BETi)and microRNA(miR)-130a in regulating macrophage polarization and pro-inflammatory ***,little is known about whether apabetalone(a novel BETi)and miR-130a are correlated with chronic inflammatory state in periodontitis by regulating macrophage *** murine RAW264.7 macrophages were applied as an in vitro inflammatory *** treatment with Porphyromonas gingivalis-derived lipopolysaccharide(Pg LPS)and apabetalone,the expression of macrophage M1 polarization markers and inflammatory cytokines was assessed using real-time PCR,western blot,and enzyme-linked immuno sorbent assay(ELISA).MiR-130a level was assessed using real-time PCR,and the target gene was identified using dual luciferase reporter *** demonstrated that apabetalone repressed Pg LPS-induced macrophage M1 polarization in a dose-dependent manner,as evidenced by decreased expression of inducible nitric oxide synthase(iNOS),CD86,and pro-inflammatory cytokines,and increased expression of Arg-1 and ***,Pg LPS increased miR-130a expression in macrophages,whereas apabetalone treatment repressed the ***,forced expression of miR-130a promoted macrophage M1 polarization,and signal transducer and activator of transcription(STAT)-3 was the direct target gene of miR-130a in the *** together,apabetalone decreases Pg LPS-induced macrophage M1 polarization via regulating miR-130a-3p/STAT3 axis,and may be a promising target for the clinical management of periodontitis.

关键词： Periodontitis Macrophage polarization Porphyromonas gingivalis BET inhibitor miRNA

Mineralization regulation and biological influence of bioactive glass-collagen-phosphatidylserine composite scaffolds

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Science China(Life Sciences) 2012年第3期55卷 236-240页

作者： YANG ChunRong WANG YingJun chen xiaofeng Department of Materials Science and Engineering Fujian University of TechnologyFuzhou 350108China Key Laboratory of Specialty Functional Materials of Ministry of Education South China University of TechnologyGuangzhou 510640China

Biomimetic scaffolds are appealing products for the repair of bone defects using tissue engineering *** the present study,novel biomimetic composite scaffolds,with similar properties to natural bone,were prepared,blended and cross-linked with bioactive glass,type I collagen and *** exposed to cell culture solution in the absence of a cellular source,the composite scaffolds form crystals with octahedral *** crystals are similar to the products derived from MC3T3-E1 cell mineralization within the composite scaffolds,with respect to both composition and ***,crystals with octahedral structure were observed to develop into plate-like *** bio-mineralization behavior of the composite scaffolds is likely influenced by inorganic ***,a rabbit tibia defect model shows that the highly bioactive properties of the investigated composites result in excellent bone repair.

关键词： composite scaffold cell bio-mineralization regulation

Preparation and characterization of bioactive glass tablets and evaluation of bioactivity and cytotoxicity in vitro

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Bioactive Materials 2018年第3期3卷 315-321页

作者： Jianhui chen Lei Zeng xiaofeng chen Tianshun Liao Jiafu Zheng Department of Biomedical Engineering School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China National Engineering Research Center for Tissue Restoration and Reconstruction Guangzhou 510006China Key Laboratory of Biomedical Materials and Engineering Ministry of EducationSouth China University of TechnologyGuangzhou 510006China

In this study, the SiO2eCaOeP2O5 ternary component of bioactive glass particles were successfullysynthesized by sol-gel method, then the bioactive glass particles were pressed into tablets with drypressing molding technology. The physicochemical structure, in-vitro bioactivity and biocompatibility ofBG tablets were characterized by various methods, such as XRD、SEM、FTIR, etc. The results showedthat the sol-gel bioactive glass particle was distinguished with its amorphous structure and *** being soaked in Tris-Hcl solution for 15 d, the bioactive glass tablets didn't collapse. Also, themineralization assay in vitro showed that the bioactive glass tablets had good capability of inducing theformation of hydroxycarbonate apatite (HCA) after being immersed in simulated body fluid (SBF). Inaddition, the cytotoxicity assay indicated that the osteoblast (MC3T3) grew well on the surface ofbioactive glass tablets. According to the above results, the bioactive glass tablets presented good mechanicalstrength, excellent apatite-forming activity and high biocompatibility, which demonstratedtheir potential applications in the field of bone defect repairing.

关键词： Sol-gel bioactive glass Dry pressing molding BG tablets Bioactivity Cytotoxicity