280 research outputs found
Measurement and Prediction of Coupling Coordination Level of Economic Development, Social Stability and Ecological Environment in QinghaiâThoughts on Sustainable Societal Safety
Societal safety is the result of the coordinated development of several subsystems; the couplingâcoordination relationship among economic development (ED), social stability (SS), and ecological environment (EE) is the premise of realizing sustainable societal safety (SSS). Taking Qinghai Province as an example, this paper quantitatively evaluates the development index of each subsystem by constructing ED-SS-EE evaluation index system, then analyzes the spatio-temporal evolution of ED, SS, and EE coupling coordination levels based on the coupling coordination model, and finally predicts the coupling coordination level of ED, SS, and EE by using the GM(1.1) model. The findings are as follows: (1) The economy is developing rapidly, but the regional development is extremely uneven; ED is driving SS, and SS lags behind ED and slowly improves; EE is improving continuously, and the spatial pattern is relatively stable. (2) The ED, SS, and EE systems have a high degree of coupling, showing a fluctuating upward trend. Coordination level is low, showing a slow upward trend, and the regional differences are obvious. (3) In the future, the coordination level of ED, SS, and EE systems in different regions will be upgraded from the level of near imbalance and barely coordination to the level of intermediate coordination, good coordination, and even high-quality coordination. The spatio-temporal description of ED, SS, and EE coupling coordination level not only reveals the development trend and problems of SSS in Qinghai, it also proves the feasibility of evaluating societal safety level based on the coupling coordination level of sustainable social structure system.publishedVersionPeer reviewe
MeV Astrophysical Spectroscopic Surveyor (MASS): A Compton Telescope Mission Concept
We propose a future mission concept, the MeV Astrophysical Spectroscopic
Surveyor (MASS), which is a large area Compton telescope using 3D position
sensitive cadmium zinc telluride (CZT) detectors optimized for emission line
detection. The payload consists of two layers of CZT detectors in a misaligned
chessboard layout, with a total geometric area of 4096 cm for on-axis
observations. The detectors can be operated at room-temperature with an energy
resolution of 0.6\% at 0.662 MeV. The in-orbit background is estimated with a
mass model. At energies around 1 MeV, a line sensitivity of about
photons cm s can be obtained with a 1 Ms observation. The main
science objectives of MASS include nucleosynthesis in astrophysics and high
energy astrophysics related to compact objects and transient sources. The
payload CZT detectors weigh roughly 40 kg, suggesting that it can be integrated
into a micro- or mini-satellite. We have constructed a pathfinder, named as
MASS-Cube, to have a direct test of the technique with 4 detector units in
space in the near future.Comment: accepted for publication in Experimental Astronom
Hypo-high density lipoproteinemia is a predictor for recurrent stroke during the long-term follow-up after revascularization in adult moyamoya disease
ObjectivePrevious studies have reported that hypo-high-density lipoproteinemia (HHDL) was an independent risk factor for the cerebrovascular event. However, the risk of HHDL for stroke recurrence in moyamoya disease (MMD) during long-term follow-up after revascularization remains poorly understood. We aim to investigate the association between HHDL and stroke recurrence in adult patients with MMD.MethodsA total of 138 adult patients with MMD were prospectively recruited from 1 July to 31 December 2019. After excluding 15 patients who did not meet the inclusion criteria, all the 123 patients were enrolled. Participants were grouped according to the stroke recurrence and HHDL presentation, respectively. Clinical data and laboratory examinations were compared by the statistical analysis. The KaplanâMeier survival analysis was conducted to compare the stroke-free survival rates between participants with HHDL and those without. Univariate and multivariate logistic regression analyses were performed to identify independent factors of the neurological status. Univariate and multivariate Cox regression analyses were conducted to identify the predictors for the recurrent stroke.ResultsParticipants with recurrent stroke group showed a lower level of high-density lipoprotein (HDL) (p = 0.030). More participants in the recurrent stroke group had HHDL (p = 0.045). What is more, there was statistical significance in the KaplanâMeier curve of stroke incidence between the normal HDL group and the HHDL group (log-rank test, p = 0.034). Univariate logistic analysis results showed that HHDL (OR 0.916, 95% CI 0.237â3.543; p = 0.899) and HDL (OR 0.729, 95% CI 0.094â5.648; p = 0.763) were not predictive factors for the neurological status. In the multivariate Cox regression analysis, diabetes (HR 4.195, 95% CI 1.041â16.899; p = 0.044), HDL (HR 0.061, 95% CI 0.006â0.626; p = 0.019), and HHDL (HR 3.341, 95% CI 1.110â10.051; p = 0.032) were independent risk factors for the recurrent stroke.ConclusionsHypo-high-density lipoproteinemia might be a predictor or the potential therapeutic target for recurrent stroke during the long-term follow-up after revascularization in adult patients with MMD
Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
The recently discovered neutron star transient Swift J0243.6+6124 has been
monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT).
Based on the obtained data, we investigate the broadband spectrum of the source
throughout the outburst. We estimate the broadband flux of the source and
search for possible cyclotron line in the broadband spectrum. No evidence of
line-like features is, however, found up to . In the absence of
any cyclotron line in its energy spectrum, we estimate the magnetic field of
the source based on the observed spin evolution of the neutron star by applying
two accretion torque models. In both cases, we get consistent results with
, and peak luminosity of which makes the source the first Galactic ultraluminous
X-ray source hosting a neutron star.Comment: publishe
Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite
As China's first X-ray astronomical satellite, the Hard X-ray Modulation
Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15,
2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy
satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was
designed to perform pointing, scanning and gamma-ray burst (GRB) observations
and, based on the Direct Demodulation Method (DDM), the image of the scanned
sky region can be reconstructed. Here we give an overview of the mission and
its progresses, including payload, core sciences, ground calibration/facility,
ground segment, data archive, software, in-orbit performance, calibration,
background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech.
Astron. arXiv admin note: text overlap with arXiv:1910.0443
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Advanced construction strategies to obtain nanocomposite hydrogels for bone repair and regeneration
Abstract Bone tissue engineering is pivotal in facilitating bone reconstruction by promoting persistent angiogenesis and osteogenesis. Initially, the hot gel composite hydrogel scaffold technique was employed. However, to address various limitations, numerous gel structures have since been developed, including osteogenic gellan gels, semi-interpenetrating network hydrogels, photoinduced crosslinking methacrylate gels, and supramolecular hydrogels. This review examines the mechanisms, formation principles, and medical benefits of these gel structures. In addition, novel bioengineering techniques to regulate human bone growth are expected to emerge in the future. This work is expected to significantly expedite the advancement of hydrogel membranes in the field of bone repair
New Results on Synchronization of Fractional-Order MemristorâBased Neural Networks via State Feedback Control
This paper addresses the synchronization issue for the drive-response fractional-order memristorâbased neural networks (FOMNNs) via state feedback control. To achieve the synchronization for considered drive-response FOMNNs, two feedback controllers are introduced. Then, by adopting nonsmooth analysis, fractional Lyapunovâs direct method, Young inequality, and fractional-order differential inclusions, several algebraic sufficient criteria are obtained for guaranteeing the synchronization of the drive-response FOMNNs. Lastly, for illustrating the effectiveness of the obtained theoretical results, an example is given
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