Dopamine(DA)is a vital neurotransmitter,and accurate detection of its concentration is critical for both clinical diagnos-tics and neuroscience research.Due to its electrochemical activity,DA is commonly detected usin...Dopamine(DA)is a vital neurotransmitter,and accurate detection of its concentration is critical for both clinical diagnos-tics and neuroscience research.Due to its electrochemical activity,DA is commonly detected using electrochemical methods,which are favored for their simplicity,fast response time,and suitability for in vivo analysis.In this work,a highly sensitive DA electrochemical sensor was developed using an Au@MoS_(2)composite,created by modifying molybdenum disulfide(MoS_(2))nanosheets with gold nanoparticles through HAuCl_(4) reduction,and it was aimed at enhancing DA adsorption and improving detection performance.Scanning Electron Microscopy(SEM),transmission electron microscopy(TEM),Energy Dispersive Spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS)and X-ray Diffraction(XRD)confirmed the suc-cessful synthesis of Au@MoS_(2)and the uniform distribution of gold nanoparticles across the MoS_(2)nanosheets.Then,the electrochemical characterization demonstrated that the Au@MoS_(2)/GCE exhibited distinct oxidation peaks in a 10μmol·L^(-1)DA solution,with significantly enhanced electrochemical activity compared to both unmodified GCE and pristine MoS_(2).Furthermore,differential pulse voltammetry(DPV)further revealed a strong linear relationship between DA concentration and the current response in the range of 800 nmol·L^(-1)to 10μmol·L^(-1),with a low detection limit(LOD)of 78.9 nmol·L^(-1)(S/N=3).Additionally,the sensor showed excellent selectivity against other interfering substances.Moreover,the laser-induced Au@MoS_(2)(LIAu@MoS_(2)),with its abundance of negatively charged surface defects,enabled the ultra-sensitive detection of the ultra-low concentrations of DA.In conclusion,the successfully fabricated Au@MoS_(2)based sensor offers advantages such as low cost,ease of operation,and scalability,making it a promising candidate for biosensing applications due to its enhanced DA detection capabilities.展开更多
Asteroids,as the primitive building blocks for the formation of our solar system,could reveal its evolution mechanism,and have attracted more and more attention from the public and professional institutions in recent ...Asteroids,as the primitive building blocks for the formation of our solar system,could reveal its evolution mechanism,and have attracted more and more attention from the public and professional institutions in recent years.Their physical properties,such as rotational period,spin axis and overall shape,can be inverted from ground-and space-based photometric observations.Since the inversion process is very time-consuming,this paper combines the genetic algorithm with the Levenberg–Marquardt(LM) algorithm,and presents a hybrid optimization algorithm based on a Cellinoid shape model for the inversion of rotational periods,which greatly improves the inversion efficiency.The proposed hybrid algorithm is applied to the synthetic lightcurves generated for an assumed Cellinoid shape model and the inverted rotational period results are consistent with the preset ones with a reduced search time,compared with the LM algorithm.Finally,multiple numerical experiments on the periods are performed on lightcurves and sparse observations of real asteroids to confirm that the proposed method can perform well in improving computational efficiency.展开更多
Plants respond to diurnal and seasonal changes in temperature by reprogramming vital developmental pathways. Understanding the molecular mechanisms that define environmental modulation of plant growth and reproduction...Plants respond to diurnal and seasonal changes in temperature by reprogramming vital developmental pathways. Understanding the molecular mechanisms that define environmental modulation of plant growth and reproduction is critical in the context of climate change that threatens crop yield worldwide. Here, we report that elevated temperature accelerates fruit dehiscence in members of the Brassicaceae family including the model plant Arabidopsis thaliana and important crop species. Arabidopsis fruit development is controlled by a network of interacting regulatory genes. Among them, the INDEHISCENT （IND） gene is a key regulator of the valve-margin tissue that mediates fruit opening, hence facilitating fruit dehiscence. We demonstrated that the valve-margin development is accelerated at higher temperature and that IND is tar- geted for thermosensory control. Our results reveal that IND upregulation is facilitated via temperature- induced chromatin dynamics leading to accelerated valve-margin specification and dispersal of the seed. Specifically, we show that temperature-induced changes in IND expression are associated with ther- mosensory H2A.Z nucleosome dynamics. These findings establish a molecular framework connecting tis- sue identity with thermal sensing and set out directions for the production of temperature-resilient crops.展开更多
The phytohormone auxin is implied in steering various developmental decisions during plant morphogenesis in a concentration-dependent manner.Auxin maxima have been shown to maintain meristematic activity,for example,o...The phytohormone auxin is implied in steering various developmental decisions during plant morphogenesis in a concentration-dependent manner.Auxin maxima have been shown to maintain meristematic activity,for example,of the root apical meristem,and position new sites of outgrowth,such as during lateral root initiation and phyllotaxis.More recently,it has been demonstrated that sites of auxin minima also provide positional information.In the developingArabidopsis fruit,auxin minima are required for correct differentiation of the valve margin.It remains unclear,however,how this auxin minimum is generated and maintained.Here,we employ a systems biology approach to model auxin transport based on experimental observations.This allows us to determine the minimal requirements for its establishment.Our simulations reveal that two alternative processes-which we coin "flux-barrier" and "flux-passage"-are both able to generate an auxin minimum,but under different parameter settings.Both models are in principle able to yield similar auxin profiles but present qualitatively distinct patterns of auxin flux.The models were tested by tissue-specific inducible ablation,revealing that the auxin minimum in the fruit is most likely generated by a flux-passage process.Model predictions were further supported through 3D PIN localization imaging and implementing experimentally observed transporter localization.Through such an experimental-modeling cycle,we predict how the auxin minimum gradually matures during fruit development to ensure timely fruit opening and seed dispersal.展开更多
基金supported by the Young Talent Innovation Team Support Project from Zhengzhou University(No.32213280)the scientific research program of innovation platform in State Tobacco Monopoly Administrationthe State Key Program of National Natural Science Foundation of China(Grant No.32130083).
文摘Dopamine(DA)is a vital neurotransmitter,and accurate detection of its concentration is critical for both clinical diagnos-tics and neuroscience research.Due to its electrochemical activity,DA is commonly detected using electrochemical methods,which are favored for their simplicity,fast response time,and suitability for in vivo analysis.In this work,a highly sensitive DA electrochemical sensor was developed using an Au@MoS_(2)composite,created by modifying molybdenum disulfide(MoS_(2))nanosheets with gold nanoparticles through HAuCl_(4) reduction,and it was aimed at enhancing DA adsorption and improving detection performance.Scanning Electron Microscopy(SEM),transmission electron microscopy(TEM),Energy Dispersive Spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS)and X-ray Diffraction(XRD)confirmed the suc-cessful synthesis of Au@MoS_(2)and the uniform distribution of gold nanoparticles across the MoS_(2)nanosheets.Then,the electrochemical characterization demonstrated that the Au@MoS_(2)/GCE exhibited distinct oxidation peaks in a 10μmol·L^(-1)DA solution,with significantly enhanced electrochemical activity compared to both unmodified GCE and pristine MoS_(2).Furthermore,differential pulse voltammetry(DPV)further revealed a strong linear relationship between DA concentration and the current response in the range of 800 nmol·L^(-1)to 10μmol·L^(-1),with a low detection limit(LOD)of 78.9 nmol·L^(-1)(S/N=3).Additionally,the sensor showed excellent selectivity against other interfering substances.Moreover,the laser-induced Au@MoS_(2)(LIAu@MoS_(2)),with its abundance of negatively charged surface defects,enabled the ultra-sensitive detection of the ultra-low concentrations of DA.In conclusion,the successfully fabricated Au@MoS_(2)based sensor offers advantages such as low cost,ease of operation,and scalability,making it a promising candidate for biosensing applications due to its enhanced DA detection capabilities.
基金financially supported by the National Natural Science Foundation of China(Nos.52071347,51971205)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),China(No.311020012)。
基金funded by the grant from the Macao Young Scholars Program (Project code: AM201920)the National Natural Science Foundation of China (NSFC, grant No. E11903085)+5 种基金funded by the Science and Technology Development Fund, Macao SAR (File Nos. 0073/ 2019/A2 & 0096/2022/A)supported by the Science and Technology Development Fund, Macao SAR (File No. 0042/ 2018/A2)supported by the B-type Strategic Priority Program of CAS (Grant No. XDB41000000)the NSFC (Grant Nos. 62227901 & 11633009)Space debris and NEO research project (Nos. KJSP2020020204 & KJSP2020020102)Minor Planet Foundation。
文摘Asteroids,as the primitive building blocks for the formation of our solar system,could reveal its evolution mechanism,and have attracted more and more attention from the public and professional institutions in recent years.Their physical properties,such as rotational period,spin axis and overall shape,can be inverted from ground-and space-based photometric observations.Since the inversion process is very time-consuming,this paper combines the genetic algorithm with the Levenberg–Marquardt(LM) algorithm,and presents a hybrid optimization algorithm based on a Cellinoid shape model for the inversion of rotational periods,which greatly improves the inversion efficiency.The proposed hybrid algorithm is applied to the synthetic lightcurves generated for an assumed Cellinoid shape model and the inverted rotational period results are consistent with the preset ones with a reduced search time,compared with the LM algorithm.Finally,multiple numerical experiments on the periods are performed on lightcurves and sparse observations of real asteroids to confirm that the proposed method can perform well in improving computational efficiency.
文摘Plants respond to diurnal and seasonal changes in temperature by reprogramming vital developmental pathways. Understanding the molecular mechanisms that define environmental modulation of plant growth and reproduction is critical in the context of climate change that threatens crop yield worldwide. Here, we report that elevated temperature accelerates fruit dehiscence in members of the Brassicaceae family including the model plant Arabidopsis thaliana and important crop species. Arabidopsis fruit development is controlled by a network of interacting regulatory genes. Among them, the INDEHISCENT （IND） gene is a key regulator of the valve-margin tissue that mediates fruit opening, hence facilitating fruit dehiscence. We demonstrated that the valve-margin development is accelerated at higher temperature and that IND is tar- geted for thermosensory control. Our results reveal that IND upregulation is facilitated via temperature- induced chromatin dynamics leading to accelerated valve-margin specification and dispersal of the seed. Specifically, we show that temperature-induced changes in IND expression are associated with ther- mosensory H2A.Z nucleosome dynamics. These findings establish a molecular framework connecting tis- sue identity with thermal sensing and set out directions for the production of temperature-resilient crops.
文摘The phytohormone auxin is implied in steering various developmental decisions during plant morphogenesis in a concentration-dependent manner.Auxin maxima have been shown to maintain meristematic activity,for example,of the root apical meristem,and position new sites of outgrowth,such as during lateral root initiation and phyllotaxis.More recently,it has been demonstrated that sites of auxin minima also provide positional information.In the developingArabidopsis fruit,auxin minima are required for correct differentiation of the valve margin.It remains unclear,however,how this auxin minimum is generated and maintained.Here,we employ a systems biology approach to model auxin transport based on experimental observations.This allows us to determine the minimal requirements for its establishment.Our simulations reveal that two alternative processes-which we coin "flux-barrier" and "flux-passage"-are both able to generate an auxin minimum,but under different parameter settings.Both models are in principle able to yield similar auxin profiles but present qualitatively distinct patterns of auxin flux.The models were tested by tissue-specific inducible ablation,revealing that the auxin minimum in the fruit is most likely generated by a flux-passage process.Model predictions were further supported through 3D PIN localization imaging and implementing experimentally observed transporter localization.Through such an experimental-modeling cycle,we predict how the auxin minimum gradually matures during fruit development to ensure timely fruit opening and seed dispersal.
