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Hydrogel-supported poly(L-lactic acid) and polystyrene microsphere-based three-dimensional culture systems for in vitro cell expansion

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Frontiers of Materials Science 2024年第2期18卷 129-137页

作者： Huaying Hao Lihong Sun jiaxuan chen Jun Liang State Key Laboratory of Food Nutrition and Safety Tianjin University of Science&TechnologyTianjin 300457China College of Light Industry Science and Engineering Tianjin University of Science&TechnologyTianjin 300457China College of Food Science and Engineering Tianjin University of Science&TechnologyTianjin 300457China

The in vitro expansion of stem cells is important for their application in different life science fields such as cellular tissue and organ *** objective of this paper was to achieve static cell culture in vitro through peptide hydrogel-supported microspheres(MSs).The peptides,with their gel-forming properties,microstructures,and mechanical strengths characterized,were found to have good support for the MSs and to be *** internal structures of poly(L-lactic acid)microspheres(PLLA-MSs)and polystyrene microspheres(PS-MSs)made in thelaboratory were observed and statistically analyzed in terms of particle size and pore size,following which the co-cultured MSs with cells were found to have good cell *** addition,three-dimensional(3D)culturing of cells was performed on the peptide and microcarrier composite scaffolds to measure cell viability and cell *** results showed that the peptides could be stimulated by the culture medium to self-assembly form a 3D fiber network *** the peptide-Ms composite scaffold-based cell culture system,further enhancement of the cell culture effect was *** peptide-Ms composite scaffolds have great potential for the application in 3D cell culture and in vitro cellexpansion.

关键词： microcarrier microsphere peptide hydrogel cell scaffold three-dimensional culture cell expansion

Effects of UV/Ag-TiO_2/O_3 advanced oxidation on unicellular green alga Dunaliella salina:Implications for removal of invasive species from ballast water

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Journal of Environmental Sciences 2011年第3期23卷 513-519页

作者： Donghai Wu Hong You jiaxuan Du Chuan chen Darui Jin State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China

The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of effluent was determined. Compared with individual unit processes using ozone or UV/Ag-TiO2, the inactivation efficiency ofD. salina by the combined UV/Ag-TiO2/O3 process was enhanced. The presence of ozone caused an immediate decrease in chlorophyll a （chl-a） concentration. Inactivation efficiency and chl-a removal efficiency were positively correlated with ozone dose and ultraviolet intensity. The initial total residual oxidant （TRO） concentration of effluent increased with increasing ozone dose, and persistence of TRO resulted in an extended period of toxicity. The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment.

关键词： ballast water UV/Ag-TiO2/O3 process Dunaliella salina inactivation total residual oxidant

Research on the influence of machining introduced sub-surface defects and residue stress upon the mechanical properties of single crystal copper

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Science China(Technological Sciences) 2010年第12期53卷 3161-3167页

作者： chen MingJun, XIAO GaoBo, chen jiaxuan & WU ChunYa Harbin Institute of Technology, Harbin 150001, China 1. Harbin Institute of Technology Harbin 150001 China

Large scale molecular dynamics simulations of nanomachining and stretching of single crystal copper are performed to analyze the machining process’ influence on the material’s mechanical properties. The simulation results show that the machining process will introduce interfacial defects inside the specimen and enhance the compressive stress beneath the surface. Gener- ally speaking, interfacial defects lead to the decrease of the strength limit, while residue compressive stress can enhance the elastic limit and even the strength limit. Various machining parameters are adopted to investigate their influence on the me- chanical behavior of machined specimen. Lower cutting speed and smaller cutting depth lead to less defects and greater residue compressive stress, which brings about better mechanical properties. The elastic limit increases by 36.8% under the cutting depth of 0.73 nm and decreases by 21.1% under the cutting depth of 1.46 nm. The strength limit increases by 7.7% under the cutting speed of 100 m/s and decreases by 28.2% under the cutting speed of 300 m/s.

关键词： nanomachining deformation residue stress molecular dynamics dislocations

Encapsulation of polyethylene glycol in cellulose-based porous capsules for latent heat storage and light-to-thermal conversion

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1038-1050页

作者： Jiangwei Li Lina Meng jiaxuan chen Xu chen Yonggui Wang Zefang Xiao Haigang Wang Daxin Liang Yanjun Xie Key Laboratory of Bio-based Material Science and Technology(Ministry of Education) College of Material Science and EngineeringNortheast Forestry UniversityHarbin 150040China

Phase change materials are potential candidates for the application of latent heat ***,we fabricated porous capsules as shape-stable materials from cellulose-based polyelectrolyte complex,which were first prepared using cellulose 6-(N-pyridinium)hexanoyl ester as the cationic polyelectrolyte and carboxymethyl cellulose as the anionic polyelectrolyte to encapsulate polyethylene glycol by the vacuum impregnation ***,the multi-walled carbon nanotube or graphene oxide,which were separately composited into the polyelectrolytes complex capsules to enhance thermal conductivity and light-to-thermal conversion *** capsules owned a typical core–shell structure,with an extremely high polyethylene glycol loading up to 34.33 g∙g^(‒1).After loading of polyethylene glycol,the resulted cellulose-based composite phase change materials exhibited high thermal energy storage ability with the latent heat up to 142.2 J∙g^(‒1),which was 98.5%of pure polyethylene *** results showed that the composite phase change materials demonstrated good form-stable property and thermal ***,studies involving light-to-thermal conversion determined that composite phase change materials exhibited outstanding light-to-thermal conversion *** their exceptional comprehensive features,innovative composite phase change materials generated from cellulose presented a highly interesting choice for thermal management and renewable thermal energy storage.

关键词： cellulose polyelectrolytes phase change materials thermal energy storage light-to-thermal conversion

CD55 Variant Associated with Pegylated-interferonαTherapy Response in HBeAg-positive Chronic Hepatitis B Patients

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Journal of Clinical and Translational Hepatology 2023年第2期11卷 295-303页

作者： jiaxuan chen Shuang Lou Haitao chen Bin Zhou Jian Sun Jinlin Hou De-Ke Jiang State Key Laboratory of Organ Failure Research Guangdong Key Laboratory of Viral Hepatitis ResearchGuangdong Institute of Liver DiseasesDepartment of Infectious Diseases and Hepatology UnitNanfang HospitalSouthern Medical UniversityGuangzhouGuangdongChina The Key Laboratory of Molecular Pathology(Hepatic Diseases)of Guangxi Department of Pathologythe Affiliated Hospital of Youjiang Medical University for NationalitiesBaiseGuangxiChina School of Public Health(Shenzhen) Sun Yat-sen UniversityShenzhenGuangdongChina

Background and Aims:Only a small percentage of chronic hepatitis B(CHB)patients effectively respond to treatment with pegylated-interferon alpha(PegIFNα)or nucleos(t)ide analogues(NUCs).We aimed to detect the correlations of complement regulators-associated single-nucleotide polymorphisms(SNPs)with treatment response of hepatitis B e antigen(HBeAg)-positive CHB ***:A total of 1,763 HBeAg-positive CHB patients were enrolled,894 received PegIFNαfor at least 48 weeks and were followed up for 24 weeks,and 869 received NUCs for 104 *** each patient,nine SNPs in genes encoding for complement regulators were determined and *** assess the cumulative effect of numerous SNPs,a polygenic score(PGS)was *** correlations of SNPs and PGS with the levels of combined response(CR)and hepatitis B s antigen(HBsAg)loss were also ***:In PegIFNα-treated patients,an intronic SNP of CD55,rs28371597,was strongly related to CR,and the CR rate in rs28371597_GG genotype carriers was only approximately half that of rs28371597_GT/TT genotype carriers(20.29%vs.37.10%,p=2.00×10^(−3)).A PGS incorporating CD55_rs28371597 and two additional SNPs,CFB_rs12614 and STAT4_rs7574865,which had been considered as predictors for PegIFNαtreatment response before,was strongly correlated with the levels of CR(ptrend=7.94×10^(−6))and HBsAg loss(p-trend=9.40×10^(−3))in PegIFNα-treated *** NUCs-treated individuals,however,none of the nine SNPs were shown to be significantly linked to CHB treatment ***:CD55_rs28371597 is a promising biomarker for predicting CHB patients’responsiveness to PegIFNα*** updated PGS may be used for optimizing CHB treatment.

关键词： Complement regulator Chronic hepatitis B patients Polygenic score Single-nucleotide polymorphism Treatment response

Amphiphilic Dendrimer Vectors for RNA Delivery:State-of-the-Art and Future

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Accounts of Materials Research 2022年第5期3卷 484-497页

作者： jiaxuan chen Dandan Zhu Xiaoxuan Liu Ling Peng Aix Marseille Université CNRSCenter Interdisciplinaire de Nanoscience de MarseilleCINaM UMR 7325“Equipe Labellisée Ligue Contre le Cancer”13288 MarseilleFrance State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Drug DiscoveryCenter of Advanced Pharmaceuticals and BiomaterialsChina Pharmaceutical University210009 NanjingP.R.China

Dendrimers,a special family of polymers,are particularly promising materials for various biomedical applications by virtue of their well-defined dendritic structure and cooperative ***,in this Account,we present state-of-the-art amphiphilic dendrimers for nucleic acid *** acid(RNA)molecules are fast becoming an important drug modality,particularly since the recent success of mRNA vaccines against ***,RNA therapeutics offer the unique opportunity to treat diseases at the gene level and address“undruggable”***,RNA therapeutics are not stable and have poor bioavailability,imposing the need for their protection and safe delivery by vectors to the sites-of-action to allow the desired therapeutic ***,the two most advanced nonviral vectors are based on lipids and polymers,with lipid vectors primarily exploiting the membrane-fusion mechanism and polymer vectors mainly endocytosis-mediated ***,only lipid vectors have been advanced through to their clinical use in the delivery of,for example,the first siRNA drug and the first mRNA *** success of lipid vectors for RNA delivery has motivated research for further innovative materials as delivery ***,we have pioneered lipid/dendrimer conjugates,referred to as amphiphilic dendrimers,for siRNA delivery with the view to harnessing the delivery advantages of both lipid and polymer vectors while enjoying the unique structural features of *** amphiphilic dendrimer vectors are lipid/dendrimer hybrids and are thus able to mimic lipid vectors and exploit membranefusion-mediated delivery,while simultaneously retaining the multivalent properties of polymer vectors that allow endocytosis-based *** addition,they have precisely controllable and stable nanosized chemical structures and offer nanotechnology-based *** amphiphilic dendrimer vectors share two important elements:chemical hydrophilic

关键词： breakthrough retaining desired

Three-dimensional domain swapping as a mechanism to lock the active conformation in a super-active octamer of SARS-CoV main protease

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Protein & Cell 2010年第4期1卷 371-383页

作者： Shengnan Zhang Nan Zhong Fei Xue Xue Kang Xiaobai Ren jiaxuan chen Changwen Jin Zhiyong Lou Bin Xia Beijing Nuclear Magnetic Resonance Center Peking UniversityBeijing 100871China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Structural Biology Laboratory Tsinghua UniversityBeijing 100084China College of Life Sciences Peking UniversityBeijing 100871China

Proteolytic processing of viral polyproteins is indispensible for the lifecycle of *** main protease(M^(pro))of SARS-CoV is an attractive target for anti-SARS drug development as it is essential for the polyprotein processing.M^(pro) is initially produced as part of viral polyproteins and it is matured by ***,we report that,with the addition of an N-terminal extension peptide,M^(pro) can form a domain-swapped *** complete removal of the extension peptide from the dimer,the mature M^(pro) self-assembles into a novel super-active octamer(AO-M^(pro)).The crystal structure of AO-M^(pro) adopts a novel fold with four domainswapped dimers packing into four active units with nearly identical conformation to that of the previously reported M^(pro) active dimer,and 3D domain swapping serves as a mechanism to lock the active conformation due to entanglement of polypeptide *** with the previously well characterized form of M^(pro),in equilibrium between inactive monomer and active dimer,the stable AO-M^(pro) exhibits much higher proteolytic activity at low *** all eight active sites are bound with inhibitors,the polyvalent nature of the interaction between AO-M^(pro) and its polyprotein substrates with multiple cleavage sites,would make AO-M^(pro) functionally much more superior than the M^(pro) active dimer for polyprotein ***,during the initial period of SARS-CoV infection,this novel active form AOM^(pro) should play a major role in cleaving polyproteins as the protein level is extremely *** discovery of AOM^(pro) provides new insights about the functional mechanism of M^(pro) and its maturation process.

关键词： SARS-CoV main protease crystal structure 3D domain swapping polyprotein processing

松散承压含水层的载荷传递作用对关键层复合破断的影响

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岩石力学与工程学报 2007年第4期26卷 699-704页

作者：许家林陈稼轩蒋坤中国矿业大学能源与安全工程学院江苏徐州221008

采用专门设计的物理模拟试验装置及数值模拟试验方法,就松散承压含水层的载荷传递机制及对覆岩关键层复合破断的影响进行深入研究。研究结果表明:松散承压含水层条件下,由于承压水的流动性和补给作用,上覆表土层的载荷通过松散承压含水... 详细信息

采用专门设计的物理模拟试验装置及数值模拟试验方法,就松散承压含水层的载荷传递机制及对覆岩关键层复合破断的影响进行深入研究。研究结果表明:松散承压含水层条件下,由于承压水的流动性和补给作用,上覆表土层的载荷通过松散承压含水层均匀地作用于下部基岩上,开挖过程中基岩顶界面上的载荷基本保持恒定,松散承压含水层起到均匀传递载荷的作用;无松散承压含水层时,作用在基岩顶界面上的表土层载荷随煤层开挖而显著降低。在松散承压含水层的载荷传递作用下,作用在基岩顶界面的载荷较大,当基岩厚度较薄时,采场覆岩关键层易产生复合破断。基于松散承压含水层对薄基岩采场关键层复合破断影响机制,很好地解释华东矿区部分矿井在松散承压含水层与薄基岩的特殊条件下采场发生压架事故的原因。

关键词：采矿工程松散承压含水层薄基岩关键层复合破断压架事故

Enhanced asymmetrically clipped DC biased optical OFDM for intensity-modulated direct-detection systems

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Journal of Communications and Information Networks 2017年第4期2卷 36-46页

作者： Ruowen Bai jiaxuan chen Tianqi Mao Zhaocheng Wang Tsinghua National Laboratory for Information Science and Technology(TNList) Department of Electronic EngineeringTsinghua UniversityBeijing 100084China

In this paper,we propose an EADO-OFDM(Enhanced Asymmetrically Clipped DC Biased Optical Orthogonal Frequency Division Multiplexing)method for IM/DD(Intensity-Modulated DirectDetection)optical systems,in which the AV-DCO-OFDM(Absolute Valued DC Biased Optical OFDM)symbols on the even subcarriers and ACO-OFDM(Asymmetrically Clipped Optical OFDM)symbols on the odd subcarriers are combined for simultaneous ***,we discuss the PDF(Probability Density Function)and electrical SNR(Signal to Noise Ratio)of the symbols,which are utilized to estimate the BER(Bit Error Ratio)performance and overall performance of *** Monte Carlo simulation results have validated the theoretical analysis and have also confirmed the EADO-OFDM is attractive considering the following ***,EADO-OFDM is more energy efficient compared to the power-efficient DCO-OFDM(DC Biased Optical OFDM),since the required DC bias is smaller when appropriate constellation size combinations are *** addition,EADO-OFDM performs better than the conventional ADO-OFDM(Asymmetrically Clipped DC Biased Optical OFDM),because the absolute value operation causes no clipping distortion.

关键词： orthogonal frequency division multiplexing intensity modulation with direct detection optical wireless communications visible light communications absolute value operation