Designing an efficient electrocatalyst for hydrogen evolution reaction(HER)is rather essential for the field of electrocatalytic hydrogen production.We here report a three-dimensional(3D)graphene nanowire grown on our...Designing an efficient electrocatalyst for hydrogen evolution reaction(HER)is rather essential for the field of electrocatalytic hydrogen production.We here report a three-dimensional(3D)graphene nanowire grown on our self-made porous nickel tube prepared by a microwave plasma enhanced chemical vapor deposition(MPCVD)method.Then,the MoS_(2) nanosheets are in situ grown on graphene in a vertically stacked manner through a simple hydrothermal synthesis method.It is found that these vertical graphene nanosheets can be used as an effective support to anchor MoS_(2) nanosheets stably and evenly on its surface.As a result,the prepared catalyst exhibits excellent HER electrocatalytic activity,which is attributed to plentiful edge active sites provided by the vertical MoS_(2) nanosheets and the efficient electron transport pathway provided by graphene on a matrix with good conductivity.In addition,the outwardly extending nanowire-like structure of the catalyst increases its surface area,as well as reduces the steric hindrance between active sites and the electrolyte.展开更多
Traditional Chinese medicine(TCM)has garnered significant global interest owing to its multi-component and multi-target theoretical framework and extensive therapeutic efficacy.However,the identification of quality ma...Traditional Chinese medicine(TCM)has garnered significant global interest owing to its multi-component and multi-target theoretical framework and extensive therapeutic efficacy.However,the identification of quality markers(Q-markers)remains a formidable challenge in TCM.Hence,this study aimed to integrate network pharmacology and chemometrics to identify Q-markers in Chinese patent medicine,with a focus on Huo-Luo-San(HLS)as a case study.HLS,a widely used powdered Chinese patent medicine in China,comprises a complex formula of 10 herbs,initially formulated during the Qing dynasty for treating fractures.Initially,13 components,chlorogenic acid,typhaneoside,isorhamnetin-3-O-neohesperidoside,cynaroside,notoginsenoside R_1,ginsenoside Rg_1,baicalin,berberine hydrochloride,ginsenoside Rb_1,dehydrocostus lactone,dioscin,imperatorin,and costunolide,were selected as phytochemical markers for each herb based on the Chinese Pharmacopoeia(2020 version),forming the“Herbs-Compounds-targets”network of HLS using network pharmacology.Subsequently,employing network pharmacology,the 13 HLS components were quantified using UPLC-QqQ-MS.Chromatographic conditions were optimized on a Waters Cortecs C_(18)column(2.1 mm×100 mm,1.6μm)with a gradient elution comprising 0.1%formic acid in water and acetonitrile.Analyte detection was performed in the multiple-reaction monitoring mode,and the method underwent validation for linearity,detection limit,precision,repeatability,stability,and accuracy.The validated method was then utilized to analyze the 13 components in 15 batches of HLS samples.Chemometric techniques,including hierarchical cluster analysis,principal component analysis,orthogonal partial least squares projection discriminant analysis,and box map analyses,were subsequently employed to identify the Q-markers.Ultimately,six components,baicalin,notoginsenoside R_1,berberine hydrochloride,dioscin,imperatorin,and chlorogenic acid,were selected as Q-markers for HLS.The integration of network pharmacology with chemometrics represented a novel approach for selecting Q-markers in Chinese patent medicine.展开更多
As of December 2022,2603 laboratory-identified Middle East respiratory syndrome coronavirus(MERS-CoV)infections and 935 associated deaths,with a mortality rate of 36%,had been reported to the World Health Organization...As of December 2022,2603 laboratory-identified Middle East respiratory syndrome coronavirus(MERS-CoV)infections and 935 associated deaths,with a mortality rate of 36%,had been reported to the World Health Organization(WHO).However,there are still no vaccines for MERS-CoV,which makes the prevention and control of MERS-CoV difficult.In this study,we generated two DNA vaccine candidates by integrating MERS-CoV Spike(S)gene into a replicating Vaccinia Tian Tan(VTT)vector.Compared to homologous immunization with either vaccine,mice immunized with DNA vaccine prime and VTT vaccine boost exhibited much stronger and durable humoral and cellular immune responses.The immunized mice produced robust binding antibodies and broad neutralizing antibodies against the EMC2012,England1 and KNIH strains of MERS-CoV.Prime-Boost immunization also induced strong MERS-S specific T cells responses,with high memory and poly-functional(CD107a-IFN-γ-TNF-α)effector CD8t T cells.In conclusion,the research demonstrated that DNA-Prime/VTT-Boost strategy could elicit robust and balanced humoral and cellular immune responses against MERS-CoV-S.This study not only provides a promising set of MERS-CoV vaccine candidates,but also proposes a heterologous sequential immunization strategy worthy of further development.展开更多
Functional tissue engineering strategies provide innovative approach for the repair and regeneration of damaged cartilage.Hydrogel is widely used because it could provide rapid defect filling and proper structure supp...Functional tissue engineering strategies provide innovative approach for the repair and regeneration of damaged cartilage.Hydrogel is widely used because it could provide rapid defect filling and proper structure support,and is biocompatible for cell aggregation and matrix deposition.Efforts have been made to seek suitable scaffolds for cartilage tissue engineering.Here Alg-DA/Ac-β-CD/gelatin hydrogel was designed with the features of physical and chemical multiple crosslinking and self-healing properties.Gelation time,swelling ratio,biodegradability and biocompatibility of the hydrogels were systematically characterized,and the injectable self-healing adhesive hydrogel were demonstrated to exhibit ideal properties for cartilage repair.Furthermore,the new hydrogel design introduces a pre-gel state before photo-crosslinking,where increased viscosity and decreased fluidity allow the gel to remain in a semi-solid condition.This granted multiple administration routes to the hydrogels,which brings hydrogels the ability to adapt to complex clinical situations.Pulsed electromagnetic fields(PEMF)have been recognized as a promising solution to various health problems owing to their noninvasive properties and therapeutic potentials.PEMF treatment offers a better clinical outcome with fewer,if any,side effects,and wildly used in musculoskeletal tissue repair.Thereby we propose PEMF as an effective biophysical stimulation to be 4th key element in cartilage tissue engineering.In this study,the as-prepared Alg-DA/Ac-β-CD/gelatin hydrogels were utilized in the rat osteochondral defect model,and the potential application of PEMF in cartilage tissue engineering were investigated.PEMF treatment were proven to enhance the quality of engineered chondrogenic constructs in vitro,and facilitate chondrogenesis and cartilage repair in vivo.All of the results suggested that with the injectable self-healing adhesive hydrogel and PEMF treatment,this newly proposed tissue engineering strategy revealed superior clinical potential for cartilage defect treatment.展开更多
Research works on the synergistic effect of surface modified bioactive molecules and bone metal implants have been highlighted.N-cadherin is regarded as a key factor in directing cell-cell interactions during the mese...Research works on the synergistic effect of surface modified bioactive molecules and bone metal implants have been highlighted.N-cadherin is regarded as a key factor in directing cell-cell interactions during the mesenchymal condensation preceding the osteogenesis in the musculoskeletal system.In this study,the N-cadherin mimetic peptide(Cad)was biofunctionalized on the titanium metal surface via the acryloyl bisphosphonate(Ac-BP).To learn the synergistic effect of N-cadherin mimetic peptide,when tethered with titanium substrates,on promoting osteogenic differentiation of the seeded human mesenchymal stem cells(hMSCs)and the osseointegration at the bone-implant interfaces.Results show that the conjugation of N-cadherin mimetic peptide with Ac-BP promoted the osteogenic gene markers expression in the hMSCs.The biofunctionalized biomaterial surfaces promote the expression of the Wnt/β-catenin downstream axis in the attached hMSCs,and then enhance the in-situ bone formation and osseointegration at the bone-implant interfaces.We conclude that this N-cadherin mimetic peptide tethered on Ti surface promote osteogenic differentiation of hMSCs and osseointegration of biomaterial implants in vitro and in vivo.These findings demonstrate the importance of the development-inspired surface bioactivation of metal implants and shed light on the possible cellular mechanisms of the enhanced osseointegration.展开更多
Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service lifetime.Here,we propose a breeze wake-up anemom...Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service lifetime.Here,we propose a breeze wake-up anemometer(B-WA)based on a rolling-bearing triboelectric nanogenerator(RB-TENG)with extremely low static power.The B-WA consists of two RB-TENGs,a self-waking-up module(SWM),a signal processing module(SPM),and a wireless transmission unit.The two RB-TENGs are employed for system activation and wind-speed sensing.Once the ambient wind-speed exceeds 2 m/s,the wake TENG(W-TENG)and the SWM can wake up the system within 0.96 s.At the same time,the SPM starts to calculate the signal frequency from the measured TENG(M-TENG)to monitor the wind speed with a sensitivity of 9.45 Hz/(m/s).After the wind stops,the SWM can switch off the B-WA within 0.52 s to decrease the system energy loss.In quiescent on-duty mode,the operating power of the B-WA is less than 30 nW,which can greatly extend the service lifetime of the B-WA.By integrating triboelectric devices and rolling bearings,this work has realized an ultralow quiescent power and self-waked-up wireless wind-speed monitoring system,which has foreseeable applications in remote weather monitoring,IoT nodes,and so on.展开更多
Purpose Compared to pixelated crystal detectors,monolithic crystal detectors present more advantages.Without reflective layer between crystal pixel,monolithic crystal detectors provide higher detection efficiency whil...Purpose Compared to pixelated crystal detectors,monolithic crystal detectors present more advantages.Without reflective layer between crystal pixel,monolithic crystal detectors provide higher detection efficiency while being cheaper.Another important feature is that monolithic crystal detectors can provide depth of interaction(DOI)information,which can improve image quality in nuclear imaging systems.In this article,we aim to study a new positioning scheme of this kind of detector in order to push its applications in nuclear imaging systems.Methods Fan-beam collimation and convolutional neural network are combined to reconstruct interaction points in crystal.Firstly,we built a monolithic detector model based on Geant4 and validated this positioning scheme with simulation data.Then,we constructed a monolithic GAGG(Ce)detector and evaluated its performance with experimental data.Results With proposed positioning scheme,in experiment,we obtained~1.7 mm FWHM resolution on average in x-/ydirection,while~2.5 mm FWHM resolution on average in DOI direction for a 33×33×10 mm3 monolithic GAGG(Ce)crystal coupled with 8×8 SiPM array.Conclusion Through simulations and experiments,we validated our positioning scheme,i.e.,fan-beam collimation and convolutional neural network.Convolutional neural network can reconstruct 3D positions of gamma-rays interaction points in a high resolution,and fan-beam collimation can provide high calibration efficiency;with combination of them,we established a high position resolution and high calibration efficiency positioning scheme for monolithic crystal detector.展开更多
In this paper, the consensus problem for heterogeneous multi-agent systems composed of first-order and second-order agents is investigated with directed network topologies. Based on a system transformation method, thi...In this paper, the consensus problem for heterogeneous multi-agent systems composed of first-order and second-order agents is investigated with directed network topologies. Based on a system transformation method, this consensus problem is turned into a consensus problem for homogeneous multi-agent systems. With certain assumption on the control parameters, firstly, necessary and sufficient condition for consensus is proposed with fixed topology. Secondly, sufficient condition is proposed for heterogeneous multi-agent systems to achieve consensus with switching topologies. Finally, simulation examples are presented to verify the effectiveness of the theoretical results.展开更多
基金sponsored by the National Natural Science Foundation of China(No.22522818 and 22308381)Science Foundation of China University of Petroleum-Beijing(No.2462023QNXZ002).
文摘Designing an efficient electrocatalyst for hydrogen evolution reaction(HER)is rather essential for the field of electrocatalytic hydrogen production.We here report a three-dimensional(3D)graphene nanowire grown on our self-made porous nickel tube prepared by a microwave plasma enhanced chemical vapor deposition(MPCVD)method.Then,the MoS_(2) nanosheets are in situ grown on graphene in a vertically stacked manner through a simple hydrothermal synthesis method.It is found that these vertical graphene nanosheets can be used as an effective support to anchor MoS_(2) nanosheets stably and evenly on its surface.As a result,the prepared catalyst exhibits excellent HER electrocatalytic activity,which is attributed to plentiful edge active sites provided by the vertical MoS_(2) nanosheets and the efficient electron transport pathway provided by graphene on a matrix with good conductivity.In addition,the outwardly extending nanowire-like structure of the catalyst increases its surface area,as well as reduces the steric hindrance between active sites and the electrolyte.
基金The Subject of Fujian Province Science and Technology Hall of China(Grant No.2022J01867)National Key R&D Program of China(Grant No.2019YFC1710505)School Management Project of Fujian University of Traditional Chinese Medicine University(Grant No.X2021001 and No.XJC202301)。
文摘Traditional Chinese medicine(TCM)has garnered significant global interest owing to its multi-component and multi-target theoretical framework and extensive therapeutic efficacy.However,the identification of quality markers(Q-markers)remains a formidable challenge in TCM.Hence,this study aimed to integrate network pharmacology and chemometrics to identify Q-markers in Chinese patent medicine,with a focus on Huo-Luo-San(HLS)as a case study.HLS,a widely used powdered Chinese patent medicine in China,comprises a complex formula of 10 herbs,initially formulated during the Qing dynasty for treating fractures.Initially,13 components,chlorogenic acid,typhaneoside,isorhamnetin-3-O-neohesperidoside,cynaroside,notoginsenoside R_1,ginsenoside Rg_1,baicalin,berberine hydrochloride,ginsenoside Rb_1,dehydrocostus lactone,dioscin,imperatorin,and costunolide,were selected as phytochemical markers for each herb based on the Chinese Pharmacopoeia(2020 version),forming the“Herbs-Compounds-targets”network of HLS using network pharmacology.Subsequently,employing network pharmacology,the 13 HLS components were quantified using UPLC-QqQ-MS.Chromatographic conditions were optimized on a Waters Cortecs C_(18)column(2.1 mm×100 mm,1.6μm)with a gradient elution comprising 0.1%formic acid in water and acetonitrile.Analyte detection was performed in the multiple-reaction monitoring mode,and the method underwent validation for linearity,detection limit,precision,repeatability,stability,and accuracy.The validated method was then utilized to analyze the 13 components in 15 batches of HLS samples.Chemometric techniques,including hierarchical cluster analysis,principal component analysis,orthogonal partial least squares projection discriminant analysis,and box map analyses,were subsequently employed to identify the Q-markers.Ultimately,six components,baicalin,notoginsenoside R_1,berberine hydrochloride,dioscin,imperatorin,and chlorogenic acid,were selected as Q-markers for HLS.The integration of network pharmacology with chemometrics represented a novel approach for selecting Q-markers in Chinese patent medicine.
基金financially supported by National Nature Science Foundation of China(U20A20362)the Subject of SKLID(2020SKLID102).
文摘As of December 2022,2603 laboratory-identified Middle East respiratory syndrome coronavirus(MERS-CoV)infections and 935 associated deaths,with a mortality rate of 36%,had been reported to the World Health Organization(WHO).However,there are still no vaccines for MERS-CoV,which makes the prevention and control of MERS-CoV difficult.In this study,we generated two DNA vaccine candidates by integrating MERS-CoV Spike(S)gene into a replicating Vaccinia Tian Tan(VTT)vector.Compared to homologous immunization with either vaccine,mice immunized with DNA vaccine prime and VTT vaccine boost exhibited much stronger and durable humoral and cellular immune responses.The immunized mice produced robust binding antibodies and broad neutralizing antibodies against the EMC2012,England1 and KNIH strains of MERS-CoV.Prime-Boost immunization also induced strong MERS-S specific T cells responses,with high memory and poly-functional(CD107a-IFN-γ-TNF-α)effector CD8t T cells.In conclusion,the research demonstrated that DNA-Prime/VTT-Boost strategy could elicit robust and balanced humoral and cellular immune responses against MERS-CoV-S.This study not only provides a promising set of MERS-CoV vaccine candidates,but also proposes a heterologous sequential immunization strategy worthy of further development.
基金This work was partially supported by grants from University Grants Committee,Research Grants Council of the Hong Kong Special Administrative Region,China(14108720,14121721,14202920,T13-402/17-N and AoE/M-402/20).
文摘Functional tissue engineering strategies provide innovative approach for the repair and regeneration of damaged cartilage.Hydrogel is widely used because it could provide rapid defect filling and proper structure support,and is biocompatible for cell aggregation and matrix deposition.Efforts have been made to seek suitable scaffolds for cartilage tissue engineering.Here Alg-DA/Ac-β-CD/gelatin hydrogel was designed with the features of physical and chemical multiple crosslinking and self-healing properties.Gelation time,swelling ratio,biodegradability and biocompatibility of the hydrogels were systematically characterized,and the injectable self-healing adhesive hydrogel were demonstrated to exhibit ideal properties for cartilage repair.Furthermore,the new hydrogel design introduces a pre-gel state before photo-crosslinking,where increased viscosity and decreased fluidity allow the gel to remain in a semi-solid condition.This granted multiple administration routes to the hydrogels,which brings hydrogels the ability to adapt to complex clinical situations.Pulsed electromagnetic fields(PEMF)have been recognized as a promising solution to various health problems owing to their noninvasive properties and therapeutic potentials.PEMF treatment offers a better clinical outcome with fewer,if any,side effects,and wildly used in musculoskeletal tissue repair.Thereby we propose PEMF as an effective biophysical stimulation to be 4th key element in cartilage tissue engineering.In this study,the as-prepared Alg-DA/Ac-β-CD/gelatin hydrogels were utilized in the rat osteochondral defect model,and the potential application of PEMF in cartilage tissue engineering were investigated.PEMF treatment were proven to enhance the quality of engineered chondrogenic constructs in vitro,and facilitate chondrogenesis and cartilage repair in vivo.All of the results suggested that with the injectable self-healing adhesive hydrogel and PEMF treatment,this newly proposed tissue engineering strategy revealed superior clinical potential for cartilage defect treatment.
基金supported by grants from Hong Kong Government Research Grant Council,General Research Fund(14120118,14160917,14120118,14108720 and T13-402/17-N)National Natural Science Foundation of China(81772322)+1 种基金Health and Medical Research Fund,Hong Kong(16170951 and 17180831)Hong Kong Innovation Technology Commission Funds(PRP/050/19FX).
文摘Research works on the synergistic effect of surface modified bioactive molecules and bone metal implants have been highlighted.N-cadherin is regarded as a key factor in directing cell-cell interactions during the mesenchymal condensation preceding the osteogenesis in the musculoskeletal system.In this study,the N-cadherin mimetic peptide(Cad)was biofunctionalized on the titanium metal surface via the acryloyl bisphosphonate(Ac-BP).To learn the synergistic effect of N-cadherin mimetic peptide,when tethered with titanium substrates,on promoting osteogenic differentiation of the seeded human mesenchymal stem cells(hMSCs)and the osseointegration at the bone-implant interfaces.Results show that the conjugation of N-cadherin mimetic peptide with Ac-BP promoted the osteogenic gene markers expression in the hMSCs.The biofunctionalized biomaterial surfaces promote the expression of the Wnt/β-catenin downstream axis in the attached hMSCs,and then enhance the in-situ bone formation and osseointegration at the bone-implant interfaces.We conclude that this N-cadherin mimetic peptide tethered on Ti surface promote osteogenic differentiation of hMSCs and osseointegration of biomaterial implants in vitro and in vivo.These findings demonstrate the importance of the development-inspired surface bioactivation of metal implants and shed light on the possible cellular mechanisms of the enhanced osseointegration.
基金supported by the National Natural Science Foundation of China(Nos.U23A20640,52250112,52203308)Beijing Natural Science Foundation(3242013).
文摘Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service lifetime.Here,we propose a breeze wake-up anemometer(B-WA)based on a rolling-bearing triboelectric nanogenerator(RB-TENG)with extremely low static power.The B-WA consists of two RB-TENGs,a self-waking-up module(SWM),a signal processing module(SPM),and a wireless transmission unit.The two RB-TENGs are employed for system activation and wind-speed sensing.Once the ambient wind-speed exceeds 2 m/s,the wake TENG(W-TENG)and the SWM can wake up the system within 0.96 s.At the same time,the SPM starts to calculate the signal frequency from the measured TENG(M-TENG)to monitor the wind speed with a sensitivity of 9.45 Hz/(m/s).After the wind stops,the SWM can switch off the B-WA within 0.52 s to decrease the system energy loss.In quiescent on-duty mode,the operating power of the B-WA is less than 30 nW,which can greatly extend the service lifetime of the B-WA.By integrating triboelectric devices and rolling bearings,this work has realized an ultralow quiescent power and self-waked-up wireless wind-speed monitoring system,which has foreseeable applications in remote weather monitoring,IoT nodes,and so on.
文摘Purpose Compared to pixelated crystal detectors,monolithic crystal detectors present more advantages.Without reflective layer between crystal pixel,monolithic crystal detectors provide higher detection efficiency while being cheaper.Another important feature is that monolithic crystal detectors can provide depth of interaction(DOI)information,which can improve image quality in nuclear imaging systems.In this article,we aim to study a new positioning scheme of this kind of detector in order to push its applications in nuclear imaging systems.Methods Fan-beam collimation and convolutional neural network are combined to reconstruct interaction points in crystal.Firstly,we built a monolithic detector model based on Geant4 and validated this positioning scheme with simulation data.Then,we constructed a monolithic GAGG(Ce)detector and evaluated its performance with experimental data.Results With proposed positioning scheme,in experiment,we obtained~1.7 mm FWHM resolution on average in x-/ydirection,while~2.5 mm FWHM resolution on average in DOI direction for a 33×33×10 mm3 monolithic GAGG(Ce)crystal coupled with 8×8 SiPM array.Conclusion Through simulations and experiments,we validated our positioning scheme,i.e.,fan-beam collimation and convolutional neural network.Convolutional neural network can reconstruct 3D positions of gamma-rays interaction points in a high resolution,and fan-beam collimation can provide high calibration efficiency;with combination of them,we established a high position resolution and high calibration efficiency positioning scheme for monolithic crystal detector.
基金Supported by Natural Science Foundation of Hebei Province(A2013202198)
文摘In this paper, the consensus problem for heterogeneous multi-agent systems composed of first-order and second-order agents is investigated with directed network topologies. Based on a system transformation method, this consensus problem is turned into a consensus problem for homogeneous multi-agent systems. With certain assumption on the control parameters, firstly, necessary and sufficient condition for consensus is proposed with fixed topology. Secondly, sufficient condition is proposed for heterogeneous multi-agent systems to achieve consensus with switching topologies. Finally, simulation examples are presented to verify the effectiveness of the theoretical results.
