11 research outputs found

    Correlation Analysis of Health Factors of Elderly People in Traditional Miao Dwellings in Western Hunan

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    Under the macro context of severe global aging, the typical villages and dwellings of the Miao ethnic group in western Hunan were selected, and the daily life and health status of the local elderly were evaluated through behavioral observation, interviews, and questionnaires (e.g., physiological, psychological, and residential environments). In addition, the health status and relevant evaluation factors of the respondents were correlated and then analyzed using SPSS software. As indicated by the results of this study, the local elderly used all the spaces and functions of the existing dwellings and were satisfied with the spaces except for the toilet. In addition, their physiological functions had declined, and their daily behaviors were affected by a wide variety of physical diseases. From a psychological perspective, more than 60% of the elderly had significant feelings of loneliness and frustration. As indicated by the correlation results, the health status of the elderly in traditional Miao dwellings in western Hunan was positively correlated with family, income, daily acts, dwellings, and infrastructure, and negatively correlated with age. They showed linear correlations with all impact factors: Health = 157.44 − 5.242 ∗ Gender − 1.611 ∗ Age − 0.606 ∗ Education level − 0.411 ∗ Family + 0.001 ∗ Income − 7.191 ∗ Daily acts + 13.621 ∗ Dwelling + 4.682 ∗ Infrastructure + 17.198 ∗ Natural. Based on the results of study, targeted improvement strategies were proposed for the elderly in traditional Miao dwellings in western Hunan from four aspects—infrastructure, traditional dwellings, mental health, and policy support—to improve the health status of the elderly in traditional Chinese villages and towns

    Complex Oscillations of Chua Corsage Memristor with Two Symmetrical Locally Active Domains

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    This paper proposes a modified Chua Corsage Memristor endowed with two symmetrical locally active domains. Under the DC bias voltage in the locally active domains, the memristor with an inductor can construct a second-order circuit to generate periodic oscillation. Based on the theories of the edge of chaos and local activity, the oscillation mechanism of the symmetrical periodic oscillations of the circuit is revealed. The third-order memristor circuit is constructed by adding a passive capacitor in parallel with the memristor in the second-order circuit, where symmetrical periodic oscillations and symmetrical chaos emerge either on or near the edge of chaos domains. The oscillation mechanisms of the memristor-based circuits are analyzed via Domains distribution maps, which include the division of locally passive domains, locally active domains, and the edge of chaos domains. Finally, the symmetrical dynamic characteristics are investigated via theory and simulations, including Lyapunov exponents, bifurcation diagrams, and dynamic maps

    Complex Oscillations of Chua Corsage Memristor with Two Symmetrical Locally Active Domains

    No full text
    This paper proposes a modified Chua Corsage Memristor endowed with two symmetrical locally active domains. Under the DC bias voltage in the locally active domains, the memristor with an inductor can construct a second-order circuit to generate periodic oscillation. Based on the theories of the edge of chaos and local activity, the oscillation mechanism of the symmetrical periodic oscillations of the circuit is revealed. The third-order memristor circuit is constructed by adding a passive capacitor in parallel with the memristor in the second-order circuit, where symmetrical periodic oscillations and symmetrical chaos emerge either on or near the edge of chaos domains. The oscillation mechanisms of the memristor-based circuits are analyzed via Domains distribution maps, which include the division of locally passive domains, locally active domains, and the edge of chaos domains. Finally, the symmetrical dynamic characteristics are investigated via theory and simulations, including Lyapunov exponents, bifurcation diagrams, and dynamic maps

    A cell sorting and trapping microfluidic device with an interdigital channel

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    The growing interest in cell sorting and trapping is driving the demand for high performance technologies. Using labeling techniques or external forces, cells can be identified by a series of methods. However, all of these methods require complicated systems with expensive devices. Based on inherent differences in cellular morphology, cells can be sorted by specific structures in microfluidic devices. The weir filter is a basic and efficient cell sorting and trapping structure. However, in some existing weir devices, because of cell deformability and high flow velocity in gaps, trapped cells may become stuck or even pass through the gaps. Here, we designed and fabricated a microfluidic device with interdigital channels for cell sorting and trapping. The chip consisted of a sheet of silicone elastomer polydimethylsiloxane and a sheet of glass. A square-wave-like weir was designed in the middle of the channel, comprising the interdigital channels. The square-wave pattern extended the weir length by three times with the channel width remaining constant. Compared with a straight weir, this structure exhibited a notably higher trapping capacity. Interdigital channels provided more space to slow down the rate of the pressure decrease, which prevented the cells from becoming stuck in the gaps. Sorting a mixture K562 and blood cells to trap cells demonstrated the efficiency of the chip with the interdigital channel to sort and trap large and less deformable cells. With stable and efficient cell sorting and trapping abilities, the chip with an interdigital channel may be widely applied in scientific research fields

    Recovery and separation of rare earths and boron from spent Nd-Fe-B magnets

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    The environmental and economic benefits of recycling spent Nd-Fe-B magnets are becoming increasingly important. Nevertheless, the reprocessing of this type of material by conventional processes remains a challenge due to the difficulties of rare earth elements (REEs) and Fe separation, low products purity and large-scale generation of boron wastewater. This research presents an effective approach for the comprehensive recovery of REEs, iron and boron from Nd-Fe-B magnet wastes. Investigations of the initial roasting pretreatment showed it to be an effective method that aids the subsequent selective separation of REEs, with the most suitable temperature determined to be 800 °C. During the following selective hydrochloric acid pressure leaching of the roasted magnet, the addition of 2 g/L NaNO3 was found to significantly improve the separation of REEs and B from Fe. The results indicated that almost 99% of REEs and 97% of B could be extracted, whilst in contrast, less than 0.1% of iron dissolved, to leave a hematite rich residue. The extracted REEs were then directly precipitated as oxalates with &gt;99% extraction and 99.95% purity at a value n(oxalic acid)/n(REEs) of 1, resulting in significant improvements to oxalic acid consumption and REEs product purity. In the final step, 99.5% of boron was recovered via a three-stage counter current extraction with 30% (v/v) (EHD) and 70% (v/v) sulfonated kerosene. These findings demonstrate that high recoveries of REEs, Fe and B are achievable with hydrochloric acid pressure leaching followed oxalate precipitation and boron recovery.</p

    Late quaternary slip rate and paleoseismic sequence of the Cuopuhu section of the Litang-Yidun fault, western Sichuan, China

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    Objective  The Litang-Yidun fault is a left-lateral strike-slip active fault zone extending approximately 130 km in the Sichuan-Yunnan rhombic block in the Holocene. As a significant seismogenic structure controlling seismic activity in the Litang area of western Sichuan, research on both paleoseismicity and surface ruptures primarily focuses on the Litang and Damaoyaba sections, with relatively limited study on the Cuopuhu section in the northern part. Detailed investigation of the Cuopuhu section can provide fundamental information on its activity characteristics, paleoseismic events, and slip rates.  Methods  The Cuopuhu section of the Litang-Yidun fault was investigated using field surveys, high-precision mapping, trenching, and 14C dating methods to explore its slip rate and paleoseismic events. Two trench sites were excavated at the foothills of Dongou Mountain to identify the relationships between faulting and strata, sedimentary characteristics, and fault motion.  Conclusion  Four paleoseismic events were identified: Event Ⅰ occurred before BC 3382±60 a; Event Ⅱ occurred between BC 3382±60 a and BC 1094±51 a; Events Ⅲ and Ⅳ occurred after AD 1330±44 a. The recurrence intervals of the four earthquakes are approximately 0.4±0.3 ka, 2.42±0.1 ka, and 2.40±0.1 ka, respectively. Based on the calculated intervals, Events Ⅰ and Ⅱ, and Events Ⅱ and Ⅲ, Ⅳ, have recurrence intervals of about 2.4 ka. Events Ⅲ and Ⅳ occurred after AD 1330±44 a, making it difficult to determine their sequence and exact timing. It can be inferred that the Cuopuhu section of the Litang-Yidun fault likely has a recurrence interval of about 2.4 ka for paleoseismic events, with a possibility of seismic events with recurrence intervals of 0.4±0.3 ka. By comparing the research data between the Cuopuhu section and the Litang and Damaoyaba segments, differences in paleoseismic events between the Cuopuhu section and the other sections are evident. However, the seismic activity of different fault sections has shown a sustained strengthening trend since the Holocene. Based on mapped fault scarps and moraine ridges from the last glacial period, the average slip rate of the Cuopuhu section since the Late Pleistocene is estimated to be 4.15±0.5 mm/a, similar to the slip rates of different branches of the Litang-Yidun fault in the late Quaternary period.  Significance  This study provides information on the tectonic features, paleoseismicity, and slip rates of the Litang-Yidun fault, aiding in a better understanding of the seismic history and structural deformation patterns in the area and giving more data for medium- and long-term earthquake prediction in the future. It also contributes to the seismic risk assessment of relevant projects along the Sichuan-Tibet Railway

    Characterization and modulation of the unimolecular conformation of integrins with nanopore sensors

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    Integrins are a large family of heterodimeric mammalian transmembrane receptors that connect extracellular matrix (ECM) and the cytoskeleton. Integrin-mediated adhesion governs the cellular adhesion, mobility, and cell mechanobiology. Investigations on different integrins in cellular and the conformation change regulated by divalent metal ions and oligopeptides have been documented, they mainly adopted the cellular assays or surface manipulation to achieve the information of ensemble integrins with proteins and small molecules. This work presents the nanopore approach for the characterization of unimolecular integrin via resistive pulse sensing. The orientation selection in distinct nanopore in size and pH condition discloses the tiny disparity of the conformation and the local surface charge distribution. The divalent metal ions could efficiently modulate the conformation alteration of integrin, in which Ca2+ and Mn2+ could activate integrin alpha L beta 2 to take larger physical dimension than Mg2+, and Ca2+ is superior to Mn2+ in the activation when integrin alpha L beta 2 is treated in the mixed metal ions. The oligopeptide cRGD (cyclic Arg-Gly-Asp) and its derivatives cRGDfk and cRGDyk show specific binding with integrin alpha V beta 3 and the complex of alpha V beta 3-cRGD exhibits largest geometry upon Ca2+-mediation with characteristic nanopore translocation feature. This work provides a platform for unimolecular integrin sensing and the modulation of the local conformation transition regulated by divalent metal ions and oligopeptides, which will be valuable for the representation of integrin-related cellular behavior and bio-function

    Wearable and flexible electrochemical sensors for sweat analysis: a review

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    Abstract Flexible wearable sweat sensors allow continuous, real-time, noninvasive detection of sweat analytes, provide insight into human physiology at the molecular level, and have received significant attention for their promising applications in personalized health monitoring. Electrochemical sensors are the best choice for wearable sweat sensors due to their high performance, low cost, miniaturization, and wide applicability. Recent developments in soft microfluidics, multiplexed biosensing, energy harvesting devices, and materials have advanced the compatibility of wearable electrochemical sweat-sensing platforms. In this review, we summarize the potential of sweat for medical detection and methods for sweat stimulation and collection. This paper provides an overview of the components of wearable sweat sensors and recent developments in materials and power supply technologies and highlights some typical sensing platforms for different types of analytes. Finally, the paper ends with a discussion of the challenges and a view of the prospective development of this exciting field

    &beta;-Delayed &gamma; Emissions of 26P and Its Mirror Asymmetry

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    The study of the origin of asymmetries in mirror &beta; decay is extremely important to understand the fundamental nuclear force and the nuclear structure. The experiment was performed at the National Laboratory of Heavy Ion Research Facility in Lanzhou (HIRFL) to measure the &beta;-delayed &gamma; rays of 26P by silicon array and Clover-type high-purity Germanium (HPGe) detectors. Combining with results from the &beta; decay of 26P and its mirror nucleus 26Na, the mirror asymmetry parameter &delta; ( &equiv;ft+/ft&minus;&minus; 1) was determined to be 46(13)% for the transition feeding the first excited state in the daughter nucleus. Our independent results support the conclusion that the large mirror asymmetry is close to the proton halo structure in 26P
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