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| 1 | mTOR signaling promotes stem cell activation via counterbalancing BMP-mediated suppression during hair regeneration显示文摘Hair follicles(HFs)undergo cycles of degeneration(catagen),rest(telogen),and regeneration(anagen)phases.Anagen begins when the hair follicle stem cells(HFSCs)obtain sufficient activation cues to overcome suppressive signals,mainly the BMP pathway,from their niche cells.Here,we unveil that mTOR complex 1(mTORC1)signaling is activated in HFSCs,which coincides with the HFSC activation at the telogen-to-anagen transition.By using both an inducible conditional gene targeting strategy and a pharmacological inhibition method to ablate or inhibit mTOR signaling in adult skin epithelium before anagen initiation,we demonstrate that HFs that cannot respond to mTOR signaling display significantly delayed HFSC activation and extended telogen.Unexpectedly,BMP signaling activity is dramatically prolonged in mTOR signaling-deficient HFs.Through both gain-and loss-of-function studies in vitro,we show that mTORC1 signaling negatively affects BMP signaling,which serves as a main mechanism whereby mTORC1 signaling facilitates HFSC activation.Indeed,in vivo suppression of BMP by its antagonist Noggin rescues the HFSC activation defect in mTORC1-null skin.Our findings reveal a critical role for mTOR signaling in regulating stem cell activation through counterbalancing BMP-mediated repression during hair regeneration. | Zhili Deng Xiaohua Lei Xudong Zhang Huishan Zhang Shuang Liu Qi Chen Huimin Hu Xinyue Wang Lina Ning Yujing Cao Tongbiao Zhao Jiaxi Zhou Ting Chen Enkui Duan | 2015 | Journal of Molecular Cell Biology2015，7，1： | 3 |
| 2 | Selective esterification of glycerol with acetic acid to diacetin using antimony pentoxide as reusable catalyst显示文摘Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, Sn O2, Ti O2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb2O5 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%,and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Br?nsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Br?nsted acid sites of Sb2O5. Reusability tests showed that with Sb2O5 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed. | Wenfei Hu Yan Zhang Yizheng Huang Jiaxi Wang Jin Gao Jie Xu | 2015 | Journal of Energy Chemistry2015，24，5： | 2 |
| 3 | New Small Shelly Fossils(Acanthocassis and Xinlispina Gen.Nov.) from the Fortunian Stage(Early Cambrian) in Southern China显示文摘We describe new material of three-dimensionally phosphatized small shelly fossils Acanthocassis and Xinlispina gen.nov.from the Fortunian Stage(early Cambrian) of southern Shaanxi and northern Sichuan Provinces.The new materials allow description of the delicate morphology of these skeletons, and also their skeletogenesis.Acanthocassis and Xinlispina have comparable morphological features: a main branch and radially arranged sub-branches.They differ from each other in many details, e.g., the presence of a single central branch only in Xinlispina, and the presence of small nodes only in Acanthocassis.Acanthocassis cannot be a naked anthopolyp or hydropolyp because of the more-or-less stiffened cuticle and the absence of a mouth.Acanthocassisand Xinlispina differ from coeval sponge spicules and chancelloriid sclerites and rosettes of crossed pedicellariae of echinoderms, and might be cuticular ornaments of animals of unclear affinities.They occur in the first small shelly fossil assemblage zone, and could be adopted as auxiliary fossils for biostratigraphic correlation in southern China. | SHAO Tiequan LIU Yunhuan WANG Qi ZHANG Huaqiao TANG Hanhua CAO Xi HE Huahua ZHANG Yanan LI Yuan ZHENG Panlin ZHU Chengyu HU Jiaxi | 2015 | Acta Geologica Sinica(English Edition)2015，89，5： | 2 |
| 4 | Salient spectral geometric features for shape matching and?retrieval显示文摘 | Jiaxi Hu Jing Hua | 2009 | The Visual Computer (-)2009，，5： | 1 |
| 5 | Engineering multifunctional bioadhesive powders through dynamic metal-ligand coordination显示文摘Bioadhesive gels with robust adhesion on wet and irregular tissue surfaces are desirable for clinical applications.Assembly of bioadhesive powders is an effective strategy for obtaining gels that adhere to wet and irregular tissue surfaces by absorbing interfacial water.However,current bioadhesive powders lack positive biological functions and are prone to postoperative adhesion.Here,we present a powder strategy based on metal-ligand coordination to create a series of bioadhesive polyacrylic acid(PAA)gels.In the gel network,metal ions(M^(n+))are used to coordinate with the carboxy ligands of PAA to form dynamic noncovalent crosslinks.The powders can absorb interfacial water and assemble into gels on wet and irregular tissue surfaces within a few seconds,forming an initial adhesion layer by electrostatic interactions.Furthermore,the polymers can diffuse into the tissue matrix,and metal-ligand coordination is reconstructed to enhance the adhesion.Moreover,with a cationic shield layer,the bioadhesive powders can effectively avoid postoperative adhesion.Importantly,M^(n+) ions endow the gel with customized biological functions.We demonstrate that the hemostatic,antibacterial,peroxidase-like catalytic,and photodetachment abilities of the gels by incorporating different M^(n+) ions.These advantages make the bioadhesive powder a promising platform for diverse tissue repair applications. | Junchang Guo Yue Hou Liansong Ye Junnan Chen Hong Wang Li Yang Jinbo Jiang Qiangqiang Sun Chaoming Xie Bing Hu Jiaxi Cui Xu Deng | 2022 | Science China Chemistry2022，65，11： | 0 |
| 6 | Fractional nonlinear energy sinks显示文摘The cubic or third-power(TP)nonlinear energy sink(NES)has been proven to be an effective method for vibration suppression,owing to the occurrence of targeted energy transfer(TET).However,TET is unable to be triggered by the low initial energy input,and thus the TP NES would get failed under low-amplitude vibration.To resolve this issue,a new type of NES with fractional nonlinearity,e.g.,one-third-power(OTP)nonlinearity,is proposed.The dynamic behaviors of a linear oscillator(LO)with an OTP NES are investigated numerically,and then both the TET feature and the vibration attenuation performance are evaluated.Moreover,an analogy circuit is established,and the circuit simulations are carried out to verify the design concept of the OTP NES.It is found that the threshold for TET of the OTP NES is two orders of magnitude smaller than that of the TP NES.The parametric analysis shows that a heavier mass or a lower stiffness coefficient of the NES is beneficial to the occurrence of TET in the OTP NES system.Additionally,significant energy transfer is usually accompanied with efficient energy dissipation.Consequently,the OTP NES can realize TET under low initial input energy,which should be a promising approach for micro-vibration suppression. | Shengtao ZHANG Jiaxi ZHOU Hu DING Kai WANG Daolin XU | 2023 | Applied Mathematics and Mechanics(English Edition)2023，44，5： | 0 |
| 7 | NUMERICAL MODELING OF BIOMASS GASIFICATION USING COW DUNG AS FEEDSTOCK显示文摘In this study,a biomass gasification model was developed and simulated based on Gibbs free energy minimization by using software Aspen Plus.Two reactors,RYIELD and RGIBBS,were moslty used.The biomass feedstock used was cow dung.The model was validated.The composition,H_(2)/CO ratio and low heating value(LHV)of the resulting synthetic gas(also known as syngas)was estimated by changing the operating parameters of gasification temperatures,steam and biomass ratios and pressures.Simulation results showed that increased gasification temperature helped to elevate H_(2) and CO content and H_(2) peaked at 900℃.When steam increased as the gasification agent,H_(2) production increased.However,the steam/biomass(S/B)ratio negatively affected CO and CH4,resulting in lower LHV.The optimal S/B ratio was 1.5.An increase in pressure lead to a decrease in H_(2) and CO content,so the optimal pressure for gasification was 0.1 MPa. | Yajun ZHANG Sen YAO Jianjun HU Jiaxi XIA Tao XIE Zhibin ZHANG Hai LI | 2023 | Frontiers of Agricultural Science and Engineering2023，10，3： | 0 |
| 8 | Aerosol Microphysical and Radiative Effects on Continental Cloud Ensembles显示文摘Aerosol–cloud–radiation interactions represent one of the largest uncertainties in the current climate assessment. Much of the complexity arises from the non-monotonic responses of clouds, precipitation and radiative fluxes to aerosol perturbations under various meteorological conditions. In this study, an aerosol-aware WRF model is used to investigate the microphysical and radiative effects of aerosols in three weather systems during the March 2000 Cloud Intensive Observational Period campaign at the US Southern Great Plains. Three simulated cloud ensembles include a low-pressure deep convective cloud system, a collection of less-precipitating stratus and shallow cumulus, and a cold frontal passage. The WRF simulations are evaluated by several ground-based measurements. The microphysical properties of cloud hydrometeors, such as their mass and number concentrations, generally show monotonic trends as a function of cloud condensation nuclei concentrations.Aerosol radiative effects do not influence the trends of cloud microphysics, except for the stratus and shallow cumulus cases where aerosol semi-direct effects are identified. The precipitation changes by aerosols vary with the cloud types and their evolving stages, with a prominent aerosol invigoration effect and associated enhanced precipitation from the convective sources. The simulated aerosol direct effect suppresses precipitation in all three cases but does not overturn the aerosol indirect effect. Cloud fraction exhibits much smaller sensitivity(typically less than 2%) to aerosol perturbations, and the responses vary with aerosol concentrations and cloud regimes. The surface shortwave radiation shows a monotonic decrease by increasing aerosols, while the magnitude of the decrease depends on the cloud type. | Yuan WANG Jonathan M. VOGEL Yun LIN Bowen PAN Jiaxi HU Yangang LIU Xiquan DONG Jonathan H. JIANG Yuk L. YUNG Renyi ZHANG | 2018 | Advances in Atmospheric Sciences2018，35，2： | 0 |
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