82 research outputs found

    Palmitoylation Regulates Intracellular Trafficking of β\u3csub\u3e2\u3c/sub\u3e Adrenergic Receptor/Arrestin/Phosphodiesterase 4D Complexes in Cardiomyocytes

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    β2 adrenergic receptor (β2AR) is a prototypical G-protein coupled receptor that stimulates the classic cAMP-protein kinase A (PKA) signaling pathway. Recent studies indicate that the cAMP-PKA activities are spatiotemporally regulated in part due to dynamic association of β2AR with phosphodiesterase 4D (PDE4D), a group of cAMP degradation enzymes. Here, we demonstrate that in cardiomyocytes, palmitoylation of β2AR, the covalent acylation of cysteine residue 341, plays a critical role in shaping subcellular cAMP-PKA activities in cardiomyocytes via regulating β2AR association with arrestin/PDE4D. Replacing cysteine 341 on β2AR with alanine (C341A) leads to an impaired binding to β arrestin 2. Surprisingly, the C341A mutant is able to internalize via an arrestin-independent pathway at saturated concentration of agonist stimulation; the internalization becomes caveolae-dependent and requires dynamin GTPase. However, the impaired binding to β arrestin 2 also leads to an impaired recruitment of PDE4D to the C341A mutant. Thus, the mutant C341A β2AR is transported alone from the plasma membrane to the endosome without recruiting PDE4D. This alteration leads to an enhanced cytoplasmic cAMP signal for PKA activation under β2AR stimulation. Functionally, Mutation of the C341 residue or inhibition of palmitoylation modification of β2AR enhances the receptor-induced PKA activities in the cytoplasm and increases in myocyte contraction rate. Our data reveal a novel function of palmitoylation in shaping subcellular cAMP-PKA signaling in cardiomyocytes via modulating the recruitment of β arrestin 2-PDE4D complexes to the agonist-stimulated β2AR

    A Citizen Science approach for better knowledge of our Urban Trees

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    La ciencia ciudadana, tambien conocida como "participación pública en la investigación científica", se define como actividades científicas en las que científicos no profesionales participan como voluntarios en la recopilación, análisis y difusión de datos dentro de un proyecto científico. Con el advenimiento de la era de la informacion, los proyectos de ciencia ciudadana, especialmente en conservacion ecológica y monitoreo ambiental, están expandiendo rápidamente nuestro conocimiento del mundo que nos rodea y contribuyendo a la gestion y las decisiones políticas. Se puede utilizar un enfoque de ciencia ciudadana para un mejor conocimiento de nuestros árboles urbanosCitizen science, also known as "public participation in scientific research", is defined as scientific activities in which non-professional scientists participate as volunteers in data collection, analysis and dissemination within a scientific project. With the advent of the information age, citizen science projects, especially in ecological conservation and environmental monitoring, are rapidly expanding our knowledge of the world around us, and contributing to management and policy decisions. A Citizen Science approach can be used for better knowledge of our Urban Tree

    Advanced Geological Prediction

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    Due to the particularity of the tunnel project, it is difficult to find out the exact geological conditions of the tunnel body during the survey stage. Once it encounters unfavorable geological bodies such as faults, fracture zones, and karst, it will bring great challenges to the construction and will easily cause major problems, economic losses, and casualties. Therefore, it is necessary to carry out geological forecast work in the tunnel construction process, which is of great significance for tunnel safety construction and avoiding major disaster accident losses. This lecture mainly introduces the commonly used methods of geological forecast in tunnel construction, the design principles, and contents of geological forecast and combines typical cases to show the implementation process of comprehensive geological forecast. Finally, the development direction of geological forecast theory, method, and technology is carried out. Prospects provide a useful reference for promoting the development of geological forecast of tunnels

    In-Orbit Instrument Performance Study and Calibration for POLAR Polarization Measurements

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    POLAR is a compact space-borne detector designed to perform reliable measurements of the polarization for transient sources like Gamma-Ray Bursts in the energy range 50-500keV. The instrument works based on the Compton Scattering principle with the plastic scintillators as the main detection material along with the multi-anode photomultiplier tube. POLAR has been launched successfully onboard the Chinese space laboratory TG-2 on 15th September, 2016. In order to reliably reconstruct the polarization information a highly detailed understanding of the instrument is required for both data analysis and Monte Carlo studies. For this purpose a full study of the in-orbit performance was performed in order to obtain the instrument calibration parameters such as noise, pedestal, gain nonlinearity of the electronics, threshold, crosstalk and gain, as well as the effect of temperature on the above parameters. Furthermore the relationship between gain and high voltage of the multi-anode photomultiplier tube has been studied and the errors on all measurement values are presented. Finally the typical systematic error on polarization measurements of Gamma-Ray Bursts due to the measurement error of the calibration parameters are estimated using Monte Carlo simulations.Comment: 43 pages, 30 figures, 1 table; Preprint accepted by NIM

    Biological control of Fusarium crown rot of wheat with Chaetomium globosum 12XP1-2-3 and its effects on rhizosphere microorganisms

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    Chaetomium globosum is a common plant endophytic fungi that exhibits great biocontrol potential in plant disease. Fusarium crown rot (FCR) is an important disease in wheat that seriously threatens wheat production worldwide. The control effect of C. globosum against wheat FCR remains unclear. In this study, we introduced an identified C. globosum 12XP1-2-3 and tested its biological control potential against wheat FCR. The hypha and fermentation broth exhibited an antagonistic effect against Fusarium pseudograminearum. Results from indoor experiments showed that C. globosum 12XP1-2-3 might delay the onset of symptoms of brown stem base and significantly reduced the disease index (37.3%). Field trials showed that wheat seeds coated with a spore suspension of 12XP1-2-3 grew better than the control seeds, had control effects of 25.9–73.1% on FCR disease, and increased wheat yield by 3.2–11.9%. Analysis of rhizosphere microorganisms revealed that seeds coated with C. globosum (‘Cg’ treatment) had a greater effect on fungal rather than on bacterial alpha diversity and may improve the health state of rhizosphere microorganisms, as reflected by the significantly increased fungal Shannon index at Feekes 11 and the increased complexity of the bacterial co-occurrence network but decreased complexity of the fungal network. Moreover, the accumulation of beneficial bacteria such as Bacillus and Rhizobium at Feekes 3, and Sphingomonas at Feekes 7 in the ‘Cg’ treatment may be the important contributions to healthier wheat growth state, significantly reduced relative abundance of Fusarium at Feekes 11, and reduced occurrence of FCR disease. These results provide a basis for further research on the mechanism of action of C. globosum and its application in the biological control of FCR in the field

    Elastic loading enhanced NH3 sensing for surface acoustic wave sensor with highly porous nitrogen doped diamond like carbon film

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    We proposed a surface acoustic wave (SAW) NH3 gas sensor based on nitrogen doped diamond like carbon (N-DLC) film. The N-DLC film, prepared using a microwave electron cyclotron resonance plasma chemical vapor deposition (ECR-PECVD) method, is highly porous and physically and chemically stable, and have active polar groups on its surface, which can selectively absorb polar NH3 gas molecules. These features of the film lead to the high sensitivity, low noise and excellent stability of the sensor. The sensor can achieve capabilities of in-situ monitoring NH3 in a concentration range from 100 ppb to 100 ppm with fast response (∼5 s) and recovery (∼29 s) at room temperature. The NH3 sensing mechanism is attributed to the decreased porosity of the N-DLC film caused by adsorbed NH3 molecules on its polar groups, which leads an increase of the elastic modulus of the film

    H2S gas sensing performance and mechanisms using CuO-Al2O3 composite films based on both surface acoustic wave and chemiresistor techniques

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    Surface acoustic wave and chemiresistor based gas sensors integrated with a sensing layer of sol-gel CuO-Al2O3 composite film were fabricated and their performance and mechanisms for H2S sensing were characterized and compared. In the composite film, CuO nanoparticles provide active sites for adsorption and reaction of H2S molecules while Al2O3 nanoparticles help to form a uniform and mesoporous film structure, both of which enhance the sensitivity of the sensors by providing numerous active CuO surfaces. Through the comparative studies, the SAW based H2S sensor operated at room temperature showed a lower detection limit, higher sensitivity, better linearity and good selectivity to H2S gas with its concentration ranging from 5 ppb to 100 ppm, compared with those of the chemiresistor sensor, which are mainly attributed to the effective mass sensing properties of the SAW sensor, because a minor change in the mass of the film caused by adsorbed H2S molecules would lead to a significant and monotonous change of the resonant frequency of the SAW devices
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