151 research outputs found

    Uptake, sequestration and tolerance of cadmium at cellular levels in the hyperaccumulator plant species Sedum alfredii.

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    Sedum alfredii is one of a few plant species known to hyperaccumulate cadmium (Cd). Uptake, localization, and tolerance of Cd at cellular levels in shoots were compared in hyperaccumulating (HE) and non-hyperaccumulating (NHE) ecotypes of Sedum alfredii. X-ray fluorescence images of Cd in stems and leaves showed only a slight Cd signal restricted within vascular bundles in the NHEs, while enhanced localization of Cd, with significant tissue- and age-dependent variations, was detected in HEs. In contrast to the vascular-enriched Cd in young stems, parenchyma cells in leaf mesophyll, stem pith and cortex tissues served as terminal storage sites for Cd sequestration in HEs. Kinetics of Cd transport into individual leaf protoplasts of the two ecotypes showed little difference in Cd accumulation. However, far more efficient storage of Cd in vacuoles was apparent in HEs. Subsequent analysis of cell viability and hydrogen peroxide levels suggested that HE protoplasts exhibited higher resistance to Cd than those of NHE protoplasts. These results suggest that efficient sequestration into vacuoles, as opposed to rapid transport into parenchyma cells, is a pivotal process in Cd accumulation and homeostasis in shoots of HE S. alfredii. This is in addition to its efficient root-to-shoot translocation of Cd

    Single-cell photoacoustic thermometry

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    A novel photoacoustic thermometric method is presented for simultaneously imaging cells and sensing their temperature. With three-seconds-per-frame imaging speed, a temperature resolution of 0.2°C was achieved in a photo-thermal cell heating experiment. Compared to other approaches, the photoacoustic thermometric method has the advantage of not requiring custom-developed temperature-sensitive biosensors. This feature should facilitate the conversion of single-cell thermometry into a routine lab tool and make it accessible to a much broader biological research community

    Atlas of Mineral Deposits Distribution in China (2020)

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    This open access book includes instruction of national mineral database 2020 and atlas of national mineral deposits distribution derived from national mineral database 2020. National mineral database 2020 is based on data from National Geological Archives China(NGAC). Moreover, it introduces the construction method and updates maintenance mechanism of the mineral deposits database and proposes the concept of updating data based on collected archives. The construction guideline on national mineral deposits database provides guiding framework for the future development on geological database

    Preparation and Characterization of Emamectin Benzoate Solid Nanodispersion

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    The solid nanodispersion of 15% emamectin benzoate was prepared by the method of solidifying nanoemulsion. The mean particle size and polydispersity index of the solid nanodispersions were 96.6±1.7 nm and 0.352±0.041, respectively. The high zeta potential value of 31.3±0.5 mV and stable crystalline state of the nanoparticles suggested the excellent physical and chemical stabilities. The contact angle and retention compared with microemulsions and water dispersible granules on rice, cabbage, and cucumber leaves indicated its improved wettability and adhesion properties. The bioassay compared with microemulsions and water dispersible granules against diamondback moths and green peach aphids provided an evidence of its enhanced biological activity. This formulation composition could avoid organic solvents and obviously reduce surfactants. It is perspective in raising bioavailability and reducing residual pollution of pesticides and further improving agricultural production and environmental safety

    Large room-temperature magnetoresistance in van der Waals ferromagnet/semiconductor junctions

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    The magnetic tunnel junction (MTJ) is the core component in memory technologies, such as the magnetic random-access memory, magnetic sensors and programmable logic devices. In particular, MTJs based on two-dimensional (2D) van der Waals (vdW) heterostructures offer unprecedented opportunities for low power consumption and miniaturization of spintronic devices. However, their operation at room temperature remains a challenge. Here, we report a large tunnel magnetoresistance (TMR) of up to 85% at room temperature (T = 300 K) in vdW MTJs based on a thin (< 10 nm) semiconductor spacer WSe2 layer embedded between two Fe3GaTe2 electrodes with intrinsic above-room-temperature ferromagnetism. The TMR in the MTJ increases with decreasing temperature up to 164% at T = 10 K. The demonstration of TMR in ultra-thin MTJs at room-temperature opens a realistic and promising route for next-generation spintronic applications beyond the current state of the art

    Electric dipole moments and the search for new physics

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    Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss the current status and prospects in the near future for a compelling suite of such experiments, along with developments needed in the encompassing theoretical framework.Comment: Contribution to Snowmass 2021; updated with community edits and endorsement

    Signal Frequency Estimation Based on Kalman Filtering Method

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    In order to further improve the frequency estimation precision under high dynamic, the frequency estimation method based on Kalman filter is studied. Two methods of Kalman filter directly using for frequency estimation are studied, taking the phase of echo signal and the echo signal for measurements, which adopt nonlinear and linear Kalman filtering algorithm to estimate the Doppler frequency. Based on the study of performance of these two methods, the Doppler adaptability of the two methods is studied. The simulation results show that the speed precision is improved. But, the two methods of this research are limited by the fixed frequency conversion, and when Doppler changed a large range, the filtering is easy to diverge

    Signal Frequency Estimation Based on Kalman Filtering Method

    No full text
    In order to further improve the frequency estimation precision under high dynamic, the frequency estimation method based on Kalman filter is studied. Two methods of Kalman filter directly using for frequency estimation are studied, taking the phase of echo signal and the echo signal for measurements, which adopt nonlinear and linear Kalman filtering algorithm to estimate the Doppler frequency. Based on the study of performance of these two methods, the Doppler adaptability of the two methods is studied. The simulation results show that the speed precision is improved. But, the two methods of this research are limited by the fixed frequency conversion, and when Doppler changed a large range, the filtering is easy to diverge
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