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BACKGROUND: Mechanical softening of the glial scar region regulates axonal regeneration to impede neurological recovery in central nervous system (CNS) injury. Microglia, a crucial cellular component of the glial scar, facilitate neuronal survival and neurological recovery after spinal cord injury (SCI). However, the critical mechanical characterization of injured spinal cord that harmonizes neuroprotective function of microglia remains poorly understood. METHODS: Spinal cord tissue stiffness was assessed using atomic force microscopy (AFM) in a mouse model of crush injury. Pharmacological depletion of microglia using PLX5622 was used to explore the effect of microglia on mechanical characterization. Conditional knockout of Fascin-1 in microglia (Fascin-1 CKO) alone or in combination with inhibition of myosin activity was performed to delve into relevant mechanisms of microglia regulating mechanical signal. Immunofluorescence staining was performed to evaluate the related protein levels, inflammatory cells, and neuron survival after SCI. The Basso mouse scale score was calculated to assess functional recovery. RESULTS: Spinal cord tissue significantly softens after SCI. Microglia depletion or Fascin-1 knockout in microglia limits tissue softening and alters mechanical characterization, which leads to increased tissue pathology and impaired functional recovery. Mechanistically, Fascin-1 inhibits myosin activation to promote microglial migration and control mechanical characterization after SCI. CONCLUSIONS: We reveal that Fascin-1 limits myosin activity to regulate mechanical characterization after SCI, and this mechanical signal should be considered in future approaches for the treatment of CNS diseases.
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Proteínas dos Microfilamentos , Microglia , Traumatismos da Medula Espinal , Animais , Camundongos , Proteínas de Transporte , Gliose/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microglia/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/patologiaRESUMO
Lactate-derived histone lactylation is involved in multiple pathological processes through transcriptional regulation. The role of lactate-derived histone lactylation in the repair of spinal cord injury (SCI) remains unclear. Here we report that overall lactate levels and lactylation are upregulated in the spinal cord after SCI. Notably, H4K12la was significantly elevated in the microglia of the injured spinal cord, whereas exogenous lactate treatment further elevated H4K12la in microglia after SCI. Functionally, lactate treatment promoted microglial proliferation, scar formation, axon regeneration, and locomotor function recovery after SCI. Mechanically, lactate-mediated H4K12la elevation promoted PD-1 transcription in microglia, thereby facilitating SCI repair. Furthermore, a series of rescue experiments confirmed that a PD-1 inhibitor or microglia-specific AAV-sh-PD-1 significantly reversed the therapeutic effects of lactate following SCI. This study illustrates the function and mechanism of lactate/H4K12la/PD-1 signaling in microglia-mediated tissue repair and provides a novel target for SCI therapy.
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Histonas , Ácido Láctico , Microglia , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Animais , Microglia/metabolismo , Microglia/efeitos dos fármacos , Histonas/metabolismo , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/fisiologia , Ácido Láctico/metabolismo , Ratos , Lisina/metabolismo , Lisina/análogos & derivados , Lisina/farmacologia , Camundongos , Cicatriz/metabolismo , Cicatriz/patologia , Feminino , Ratos Sprague-Dawley , Camundongos Endogâmicos C57BL , Masculino , Locomoção/efeitos dos fármacos , Locomoção/fisiologiaRESUMO
The rising concentration of carbon in the atmosphere leads to increasing climate change, and it has become a worldwide consensus to reduce emissions. Considering the degree of economic development and industrial structure of different regions and the vast differences in the spatial distribution of clean energy reserves, it is essential to develop localized emission reduction programs. This study investigates the changes in city GDP after implementing carbon pricing policies. The results show that the carbon pricing policy could effectively reduce inequalities between "rich" and "poor" regions. The Moran index before and after the implementation of the policy decreases from 0.416 to 0.401. We also found spatial clustering patterns of carbon emissions, with the main drivers of carbon emissions differing significantly between developed and developing cities, resource-based and industrial cities, and southern and northern cities in China. The most crucial driver of carbon emissions is still the demand for economic development, which can explain more than 30% of carbon emissions. This study focuses on the impact of carbon market & carbon pricing on poverty alleviation and carbon reduction, makes up for the lack of "spatial justice" in the existing studies and provides a feasible carbon reduction plan for different cities.
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Carbono , Desenvolvimento Econômico , Cidades , Carbono/análise , Análise Espacial , China , Dióxido de Carbono/análiseRESUMO
We report the design and synthesis of a tetraphenylethene substituted with naphthalimide at the 4, 6 positions, named NI-2TPE. NI-2TPE exhibits strong solvent-dependent emission properties with combined ICT and AIE characteristics in THF-H2O systems. This probe was used directly on test papers to distinguish normal organic solvents using their emission colours under UV light based on its AIE and ICT nature. Thanks to the vinyl group in NI-2TPE, we synthesized a copolymer of NIPAM and NI-2TPE, termed P(NIPAM-co-NI-2TPE). The resulting polymer is highly soluble and fluorescent in water (ΦF = 15.4%). Due to the well-known thermo-responsive character of NIPAM, P(NIPAM-co-NI-2TPE) exhibits an interesting fluorescence change in response to various temperatures. Due to the thermo-induced shrinking of the PNIPAM chain, the fluorescence intensity gradually increased from 20 to 34 °C. As the temperature further increased from 34 to 90 °C, the fluorescence intensity decreased sharply, which was caused by the well-known thermal effects. Furthermore, we synthesized a P(HEA-co-NI-2TPE-TPP acrylate) copolymer, in which HEA is a hydrophilic unit, TPP is a mitochondria label and NI-2TPE a fluorescent probe. The corresponding polymer probe is highly soluble in water with FLQY = 7% and we have further applied this probe as a mitochondria targeted imaging tracker in HeLa cells successfully.
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Células/química , Fluorescência , Corantes Fluorescentes/química , Naftalimidas/química , Imagem Óptica , Estilbenos/química , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Imagem Molecular , Estrutura Molecular , Polimerização , Raios UltravioletaRESUMO
The efficient data access of streaming vehicle data is the foundation of analyzing, using and mining vehicle data in smart cities, which is an approach to understand traffic environments. However, the number of vehicles in urban cities has grown rapidly, reaching hundreds of thousands in number. Accessing the mass streaming data of vehicles is hard and takes a long time due to limited computation capability and backward modes. We propose an efficient streaming spatio-temporal data access based on Apache Storm (ESDAS) to achieve real-time streaming data access and data cleaning. As a popular streaming data processing tool, Apache Storm can be applied to streaming mass data access and real time data cleaning. By designing the Spout/bolt workflow of topology in ESDAS and by developing the speeding bolt and other bolts, Apache Storm can achieve the prospective aim. In our experiments, Taiyuan BeiDou bus location data is selected as the mass spatio-temporal data source. In the experiments, the data access results with different bolts are shown in map form, and the filtered buses' aggregation forms are different. In terms of performance evaluation, the consumption time in ESDAS for ten thousand records per second for a speeding bolt is approximately 300 milliseconds, and that for MongoDB is approximately 1300 milliseconds. The efficiency of ESDAS is approximately three times higher than that of MongoDB.
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Monodisperse AIE (aggregation-induced emission)-active conjugated polymer nanoparticles are synthesized by dispersion polymerization using geminal Suzuki cross-coupling of 1,1-dibromoolefins. The size of the nanoparticles can be adjusted by varying the concentration of the initial monomer.
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The efficient sharing of spatio-temporal trajectory data is important to understand traffic congestion in mass data. However, the data volumes of bus networks in urban cities are growing rapidly, reaching daily volumes of one hundred million datapoints. Accessing and retrieving mass spatio-temporal trajectory data in any field is hard and inefficient due to limited computational capabilities and incomplete data organization mechanisms. Therefore, we propose an optimized and efficient spatio-temporal trajectory data retrieval method based on the Cloudera Impala query engine, called ESTRI, to enhance the efficiency of mass data sharing. As an excellent query tool for mass data, Impala can be applied for mass spatio-temporal trajectory data sharing. In ESTRI we extend the spatio-temporal trajectory data retrieval function of Impala and design a suitable data partitioning method. In our experiments, the Taiyuan BeiDou (BD) bus network is selected, containing 2300 buses with BD positioning sensors, producing 20 million records every day, resulting in two difficulties as described in the Introduction section. In addition, ESTRI and MongoDB are applied in experiments. The experiments show that ESTRI achieves the most efficient data retrieval compared to retrieval using MongoDB for data volumes of fifty million, one hundred million, one hundred and fifty million, and two hundred million. The performance of ESTRI is approximately seven times higher than that of MongoDB. The experiments show that ESTRI is an effective method for retrieving mass spatio-temporal trajectory data. Finally, bus distribution mapping in Taiyuan city is achieved, describing the buses density in different regions at different times throughout the day, which can be applied in future studies of transport, such as traffic scheduling, traffic planning and traffic behavior management in intelligent public transportation systems.
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One approach toward optical nanoimaging involves sequential molecular localization of photoswitchable fluorophores to achieve high resolution beyond optical limit of diffraction. Block copolymer micelles assembled from polystryrene-block-poly(ethylene oxide) block copolymers (PSt-b-PEO) are visualized in optical nanoimaging by staining the polystyrene blocks with spiropyrans (SPs). SPs localized in hydrophobic phase of block copolymer micelles exhibit reversible fluorescence on-off switching at alternating irradiation of UV and visible light. Phase-selective distribution of SPs in block copolymer micelles enables optical nanoimaging of microphase structures of block copolymer self-assembly at 50-nm resolution. To date, this is the sturdiest realization of optical nanoimaging with subdiffraction resolution for solution self-assembly of block copolymers.
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Nanotecnologia/métodos , Imagem Óptica/métodos , Polímeros/química , MicelasRESUMO
BACKGROUND: Effective environmental data management is meaningful for human health. In the past, environmental data management involved developing a specific environmental data management system, but this method often lacks real-time data retrieving and sharing/interoperating capability. With the development of information technology, a Geospatial Service Web method is proposed that can be employed for environmental data management. The purpose of this study is to determine a method to realize environmental data management under the Geospatial Service Web framework. METHODS: A real-time GIS (Geographic Information System) data model and a Sensor Web service platform to realize environmental data management under the Geospatial Service Web framework are proposed in this study. The real-time GIS data model manages real-time data. The Sensor Web service platform is applied to support the realization of the real-time GIS data model based on the Sensor Web technologies. RESULTS: To support the realization of the proposed real-time GIS data model, a Sensor Web service platform is implemented. Real-time environmental data, such as meteorological data, air quality data, soil moisture data, soil temperature data, and landslide data, are managed in the Sensor Web service platform. In addition, two use cases of real-time air quality monitoring and real-time soil moisture monitoring based on the real-time GIS data model in the Sensor Web service platform are realized and demonstrated. The total time efficiency of the two experiments is 3.7 s and 9.2 s. CONCLUSIONS: The experimental results show that the method integrating real-time GIS data model and Sensor Web Service Platform is an effective way to manage environmental data under the Geospatial Service Web framework.
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Sistemas Computacionais , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Gestão da Informação/métodos , Internet , Sistemas Computacionais/estatística & dados numéricos , Monitoramento Ambiental/estatística & dados numéricos , Sistemas de Informação Geográfica/estatística & dados numéricos , Humanos , Gestão da Informação/estatística & dados numéricos , Internet/estatística & dados numéricosRESUMO
Sharing and integrating Remote Sensing (RS) and Geographic Information System/Science (GIS) models are critical for developing practical application systems. Facilitating model sharing and model integration is a problem for model publishers and model users, respectively. To address this problem, a framework based on a Web service for sharing and integrating RS and GIS models is proposed in this paper. The fundamental idea of the framework is to publish heterogeneous RS and GIS models into standard Web services for sharing and interoperation and then to integrate the RS and GIS models using Web services. For the former, a "black box" and a visual method are employed to facilitate the publishing of the models as Web services. For the latter, model integration based on the geospatial workflow and semantic supported marching method is introduced. Under this framework, model sharing and integration is applied for developing the Pearl River Delta water environment monitoring system. The results show that the framework can facilitate model sharing and model integration for model publishers and model users.
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Sistemas de Informação Geográfica , Internet , Modelos TeóricosRESUMO
Hen egg white lysozyme (HEWL) is frequently applied as a model protein for research on protein folding, unfolding, and fibrillization identified by featured fluorescent probes. Here, a series of hydrophilic, pH-sensitive tetraarylethene (TAE)-type AIEgens are synthesized via a geminal cross-coupling (GCC) reaction and evaluated for their capabilities of fluorescence sensing and super-resolution localization imaging of HEWL fibrils. With superior optical and sensing properties, the selected TAE-type AIEgen probe is weakly emissive in aqueous media, without dependence on the pH value and buffer concentration, but exhibits "turn-on" fluorescence upon interaction with HEWL amyloid fibrils in a spontaneous and reversible way that just meets the requirement of fluorescence random switching for super-resolution imaging. The selected probe has the strongest fluorescence response to HEWL amyloid fibrils exhibiting a limit of detection of 0.59 nmol/L and enables super-resolution fluorescence imaging of amyloid aggregates with a high resolution of 40 nm.
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Amiloide/química , Microscopia de Fluorescência/métodos , Muramidase/química , Soluções Tampão , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e HidrofílicasRESUMO
The combination of critical coupling and coupled mode theory in this study elevated the absorption performance of a graphene-based absorber in the near-infrared band, achieving perfect absorption in the double bands (98.96% and 98.22%), owing to the guided mode resonance (the coupling of the leak mode and guided mode under the condition of phase matching, which revealed 100% transmission or reflection efficiency in the wavelet band), and a third high-efficiency absorption (91.34%) emerged. During the evaluation of the single-structure, cross-circle-shaped absorber via simulation and theoretical analysis, the cross-circle shaped absorber assumed a conspicuous preponderance through exploring the correlation between absorption and tunable parameters (period, geometric measure, and incident angle of the cross-circle absorber), and by briefly analyzing the quality factors and universal applicability. Hence, the cross-circle resonance structure provides novel potential for the design of a dual-band unpatterned graphene perfect absorber in the near-infrared band, and possesses practical application significance in photoelectric detectors, modulators, optical switching, and numerous other photoelectric devices.
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By means of critical coupling and impedance matching theory, we have numerically simulated the perfect absorption of monolayer graphene. Through the critical coupling effect and impedance matching, we studied a perfect single-band absorption of the monolayer graphene and obtained high quality factor (Q-factor = 664.2) absorption spectrum which has an absorbance close to 100% in the near infrared region. The position of the absorption spectrum can be adjusted by changing the ratio between the radii of the elliptic cylinder air hole and the structural period. The sensitivity of the absorber can be achieved S = 342.7 nm/RIU (RIU is the per refractive index unit) and FOM = 199.2 (FOM is the figure of merit), which has great potential for development on biosensors. We believe that our research will have good application prospects in graphene photonic devices and optoelectronic devices.
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In order to significantly enhance the absorption capability of solar energy absorbers in the visible wavelength region, a novel monolayer molybdenum disulfide (MoS2)-based nanostructure was proposed. Local surface plasmon resonances (LSPRs) supported by Au nanocubes (NCs) can improve the absorption of monolayer MoS2. A theoretical simulation by a finite-difference time-domain method (FDTD) shows that the absorptions of proposed MoS2-based absorbers are above 94.0% and 99.7% at the resonant wavelengths of 422 and 545 nm, respectively. In addition, the optical properties of the proposed nanostructure can be tuned by the geometric parameters of the periodic Au nanocubes array, distributed Bragg mirror (DBR) and polarization angle of the incident light, which are of great pragmatic significance for improving the absorption efficiency and selectivity of monolayer MoS2. The absorber is also able to withstand a wide range of incident angles, showing polarization-independence. Similar design ideas can also be implemented to other transition-metal dichalcogenides (TMDCs) to strengthen the interaction between light and MoS2. This nanostructure is relatively simple to implement and has a potentially important application value in the development of high-efficiency solar energy absorbers and other optoelectronic devices.
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In this article, we present a design for a triple-band tunable metamaterial absorber with an Au nano-cuboids array, and undertake numerical research about its optical properties and local electromagnetic field enhancement. The proposed structure is investigated by the finite-difference time domain (FDTD) method, and we find that it has triple-band tunable perfect absorption peaks in the near infrared band (1000-2500 nm). We investigate some of structure parameters that influence the fields of surface plasmons (SP) resonances of the nano array structure. By adjusting the relevant structural parameters, we can accomplish the regulation of the surface plasmons resonance (SPR) peaks. In addition, the triple-band resonant wavelength of the absorber has good operational angle-polarization-tolerance. We believe that the excellent properties of our designed absorber have promising applications in plasma-enhanced photovoltaic, optical absorption switching and infrared modulator optical communication.
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In this paper, ZnO@MoS2 core-shell heterojunction arrays were successfully prepared by the two-step hydrothermal method, and the growth mechanism was systematically studied. We found that the growth process of molybdenum disulfide (MoS2) was sensitively dependent on the reaction temperature and time. Through an X-ray diffractometry (XRD) component test, we determined that we prepared a 2H phase MoS2 with a direct bandgap semiconductor of 1.2 eV. Then, the photoelectric properties of the samples were studied on the electrochemical workstation. The results show that the ZnO@MoS2 heterojunction acts as a photoanode, and the photocurrent reaches 2.566 mA under the conditions of 1000 W/m2 sunshine and 0.6 V bias. The i-t curve also illustrates the perfect cycle stability. Under the condition of illumination and external bias, the electrons flow to the conduction band of MoS2 and flow out through the external electrode of MoS2. The holes migrate from the MoS2 to the zinc oxide (ZnO) valence band. It is transferred to the external circuit through the glass with fluorine-doped tin oxide (FTO) together with the holes on the ZnO valence band. The ZnO@MoS2 nanocomposite heterostructure provides a reference for the development of ultra-high-speed photoelectric switching devices, photodetector(PD) devices, and photoelectrocatalytic technologies.
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Neutral conjugated tetraarylethenes OFn (n = 1-3) and the corresponding cationic conjugated oligoelectrolytes OFn+ (n = 1-3) with aggregation-induced emission activity have been designed and synthesized using geminal cross-coupling. OFn+ (n = 1-3) feature ion-induced emission in aqueous solution. They are used for lysosomal fluorescence imaging and tracing of lysosome events.
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Corantes Fluorescentes/química , Lisossomos/metabolismo , Polieletrólitos/química , Compostos de Amônio Quaternário/química , Permeabilidade da Membrana Celular/efeitos dos fármacos , Fluorenos/síntese química , Fluorenos/química , Fluorescência , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Polieletrólitos/síntese química , Compostos de Amônio Quaternário/síntese química , Xantenos/síntese química , Xantenos/químicaRESUMO
All-optical modulation of a spiropyran-based device, integrating the transmittance switching (absorption) and wavelength modulation (emission) of visible light frequency induced by alternating UV/visible light irradiation is demonstrated. As an alternative to conventional organic transistors, all-optical devices based on SP-PCL have potential utility as single molecular transistors for optical switching and visible wavelength modulation.
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We demonstrate a novel synthetic approach to ortho-methyl substituted tetraphenylethene materials, which can be utilised for directly validating the restriction of intramolecular rotation hypothesis as the basic mechanism of aggregation-induced emission phenomenon and cell imaging.