72 research outputs found

    Effect of Grapevine Age on the Aroma Compounds in ‘Beihong’ Wine

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    The main aim of this study was to determine the influence of grapevine age (3, 6 and 12 years) on the aromacompounds in ‘Beihong’ wine. Aroma compounds in wine were analyzed by solid-phase microextractiongas chromatography-mass spectrometry (SPME-GC/MS). Thirty-three (33) volatile compounds wereidentified and quantified. The majority of aroma compounds were esters (20) and the concentrationof these totaled 90.63-92.82% (w/w) of the total aroma compounds; particularly, ethyl octanoate andethyl decanoate. Through the descriptive analysis aroma profile for ‘Beihong’ wine, the highest aromacontribution was from the fruity and floral series. As the age of the grapevine increased, the concentrationsof total volatiles and total odor activity values (OAVs) of the wines significantly increased (p < 0.001). Thissuggests that grapevine age could affect berry composition, enhance the content of wine aroma compoundsand improve wine quality

    The transmembrane channel-like 6 (TMC6) in primary sensory neurons involving thermal sensation via modulating M channels

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    Introduction: The transmembrane channel-like (TMC) protein family contains eight members, TMC1–TMC8. Among these members, only TMC1 and TMC2 have been intensively studied. They are expressed in cochlear hair cells and are crucial for auditory sensations. TMC6 and TMC8 contribute to epidermodysplasia verruciformis, and predispose individuals to human papilloma virus. However, the impact of TMC on peripheral sensation pain has not been previously investigated.Methods: RNAscope was employed to detect the distribution of TMC6 mRNA in DRG neurons. Electrophysiological recordings were conducted to investigate the effects of TMC6 on neuronal characteristics and M channel activity. Zn2+ indicators were utilized to detect the zinc concentration in DRG tissues and dissociated neurons. A series of behavioural tests were performed to assess thermal and mechanical sensation in mice under both physiological and pathological conditions.Results and Discussion: We demonstrated that TMC6 is mainly expressed in small and medium dorsal root ganglion (DRG) neurons and is involved in peripheral heat nociception. Deletion of TMC6 in DRG neurons hyperpolarizes the resting membrane potential and inhibits neuronal excitability. Additionally, the function of the M channel is enhanced in TMC6 deletion DRG neurons owing to the increased quantity of free zinc in neurons. Indeed, heat and mechanical hyperalgesia in chronic pain are alleviated in TMC6 knockout mice, particularly in the case of heat hyperalgesia. This suggests that TMC6 in the small and medium DRG neurons may be a potential target for chronic pain treatment

    DT-driven memory cutting control method using VR instruction of boom-type roadheader

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    Aiming at the problems of low intelligence of current tunneling equipment, difficulty in describing over-excavation, under-excavation and abnormal collision in tunneling process, and difficulty in adapting traditional automatic cutting and memory cutting technology to complex geological conditions, a digital twin-driven virtual teaching memory cutting control method for cantilever roadheader is proposed. By analyzing the research situation of digital twin technology in the field of intelligent coal mining, the overall scheme of memory cutting control system of cantilever roadheader driven by digital twin is designed, and the key technology of memory cutting of cantilever roadheader under complex working conditions is studied. Firstly, the characteristics of digital twin and virtual reality technology are fully utilized to study the virtual teaching strategy under complex working conditions. Based on the Unity3D platform, the virtual twin model of the working face and equipment with the same size of the corresponding entity, the kinematics model of the cutting unit and the virtual collision detection model are established. The virtual model movement is controlled through the intelligent interactive interface at the virtual end, and the teaching trajectory is designed and optimized according to the worker’s experience, so that it can be used as the target expected trajectory of trajectory tracking to make up for the excessive dependence on the worker’s experience caused by the traditional underground manual teaching due to the harsh working conditions. Secondly, in order to improve the quality of section forming, the control method of teaching trajectory tracking and reproduction in memory automatic cutting stage is studied. The dynamic model of cutting part is established by Lagrange method, and the tracking control accuracy of end effector to teaching trajectory is improved by combining iterative learning with sliding mode control. Finally, the simulation control platform of the memory cutting of the cantilever roadheader is built. Through the real-time data transmission and interaction between the virtual space and the physical space and between the modules, the three-dimensional visual simulation of the memory cutting virtual teaching and trajectory tracking control process is completed in the virtual space, and then the memory automatic cutting trajectory tracking control command is generated and sent to the end effector of the physical entity of the cantilever roadheader to drive it to carry out the section forming cutting according to the teaching trajectory. At the same time, the physical sensor collects the pose data of the cantilever roadheader fuselage and the cutting arm, and reversely drives the virtual model to move synchronously. The closed-loop control of robot virtual model and physical entity is realized. On this basis, the virtual and real synchronization of the system, the motion consistency between the virtual prototype and the physical prototype, and the trajectory tracking and reproduction control accuracy are verified. The experimental results show that the system data transmission delay is low, which can ensure the virtual and real consistency and synchronization, and the trajectory tracking control accuracy meets the actual use requirements. This method provides a new idea for memory cutting and intelligent control of tunneling equipment

    A novel RUNX2 missense mutation predicted to disrupt DNA binding causes cleidocranial dysplasia in a large Chinese family with hyperplastic nails

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    Background: Cleidocranial dysplasia (CCD) is a dominantly inherited disease characterized by hypoplastic or absent clavicles, large fontanels, dental dysplasia, and delayed skeletal development. The purpose of this study is to investigate the genetic basis of Chinese family with CCD. Methods: Here, a large Chinese family with CCD and hyperplastic nails was recruited. The clinical features displayed a significant intrafamilial variation. We sequenced the coding region of the RUNX2 gene for the mutation and phenotype analysis. Results: The family carries a c. T407C (p.L136P) mutation in the DNA- and CBF beta-binding Runt domain of RUNX2. Based on the crystal structure, we predict this novel missense mutation is likely to disrupt DNA binding by RUNX2, and at least locally affect the Runt domain structure. Conclusion: A novel missense mutation was identified in a large Chinese family with CCD with hyperplastic nails. This report further extends the mutation spectrum and clinical features of CCD. The identification of this mutation will facilitate prenatal diagnosis and preimplantation genetic diagnosis

    Associations of Educational Attainment, Occupation, Social Class and Major Depressive Disorder among Han Chinese Women

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    Background The prevalence of major depressive disorder (MDD) is higher in those with low levels of educational attainment, the unemployed and those with low social status. However the extent to which these factors cause MDD is unclear. Most of the available data comes from studies in developed countries, and these findings may not extrapolate to developing countries. Examining the relationship between MDD and socio economic status in China is likely to add to the debate because of the radical economic and social changes occurring in China over the last 30 years. Principal findings We report results from 3,639 Chinese women with recurrent MDD and 3,800 controls. Highly significant odds ratios (ORs) were observed between MDD and full time employment (OR = 0.36, 95% CI = 0.25–0.46, logP = 78), social status (OR = 0.83, 95% CI = 0.77–0.87, logP = 13.3) and education attainment (OR = 0.90, 95% CI = 0.86–0.90, logP = 6.8). We found a monotonic relationship between increasing age and increasing levels of educational attainment. Those with only primary school education have significantly more episodes of MDD (mean 6.5, P-value = 0.009) and have a clinically more severe disorder, while those with higher educational attainment are likely to manifest more comorbid anxiety disorders. Conclusions In China lower socioeconomic position is associated with increased rates of MDD, as it is elsewhere in the world. Significantly more episodes of MDD occur among those with lower educational attainment (rather than longer episodes of disease), consistent with the hypothesis that the lower socioeconomic position increases the likelihood of developing MDD. The phenomenology of MDD varies according to the degree of educational attainment: higher educational attainment not only appears to protect against MDD but alters its presentation, to a more anxious phenotype

    Experimental Study on Stress Monitoring of Sand-Filled Steel Tube during Impact Using Piezoceramic Smart Aggregates

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    The filling of thin-walled steel tubes with quartz sand can help to prevent the premature buckling of the steel tube at a low cost. During an impact, the internal stress of the quartz sand-filled steel tube column is subjected to not only axial force but also lateral confining force, resulting in complicated internal stress. A suitable sensor for monitoring the internal stress of such a structure under an impact is important for structural health monitoring. In this paper, piezoceramic Smart Aggregates (SAs) are embedded into a quartz Sand-Filled Steel Tube Column (SFSTC) to monitor the internal structural stress during impacts. The piezoceramic smart aggregates are first calibrated by an impact hammer. Tests are conducted to study the feasibility of monitoring the internal stress of a structure. The results reflect that the calibration value of the piezoceramic smart aggregate sensitivity test is in good agreement with the theoretical value, and the output voltage value of the piezoceramic smart aggregate has a good linear relationship with external forces. Impact tests are conducted on the sand-filled steel tube with embedded piezoceramic smart aggregates. By analyzing the output signal of the piezoceramic smart aggregates, the internal stress state of the structure can be obtained. Experimental results demonstrated that, under the action of impact loads, the piezoceramic smart aggregates monitor the compressive stress at different locations in the steel tube, which verifies the feasibility of using piezoceramic smart aggregate to monitor the internal stress of a structure

    Fabrication of high power density paper-based microfluidic fuel cell using a stepped catalyst layer

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    Paper-based microfluidic fuel cells (PMFCs) gradually become alternative energy sources due to their advanced features, including simple structure, low cost, without requiring auxiliary equipment. However, the applications of PMFCs are limited by the poor power density and expensive cost. Therefore, a novel design of catalyst layer with stepped Pd distribution is proposed to improve the PMFC performance and reduce the cost. An experimental investigation is performed to understand the underlying influence mechanism of the catalyst layer properties, including Nafion solution content catalyst layer area, catalyst loading and catalyst distribution. We found that the proportioin choice of 4.76% Nafion solution in preparing catalyst layer achieves a shortest reaction time and a highest output performance. In addition, choosing a small catalyst layer area and high catalyst loading is beneficial to improve the current density. With the hybrid arrangement of stepped catalyst layers, the PMFC reduces the cost and presents highest current density of 44.10 mA cm−2 and peak power density of 12.87 mWcm−2. Finally, our designed PMFC stack is employed to power a thermohygrograph and a blood glucose meter for at least 5 h. These practical applications are in favor of supporting the developments of integrated device with energy generation and electrochemical detection

    Experimental Investigation on Web Crippling Property of High-Strength Cold-Formed (HSCF) Rectangular Steel Tube

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    To research the web crippling performance (i.e., the ultimate web crippling bearing capacity and ductility) of high-strength cold-formed (HSCF) rectangular steel tubes under concentrated load, thirty-six specimens with different bearing plate width, width-to-height ratio, boundaries, and loading conditions are fabricated and tested in this paper. Particularly, four kinds of boundaries and loading conditions are utilized, including end-two-flange (ETF), end-one-flange (EOF), interior-two-flange (ITF), and interior-one-flange (IOF). Research revealed the failure modes of HSCF rectangular steel tubes under concentrated loads applied at the end or interior. Moreover, the load-displacement curves and load-strain curves are obtained. The results show that the ultimate crippling capacity of webs increases significantly with larger bearing plate width and width-to-height ratio. Specimens subjected to interior bearing load have higher ultimate strength and deformation capacity than counterparts that are subjected to bearing load at the end. Additionally, in the middle of the compression web, all strain measuring points enter the plasticity stage and finally appear in the plastic hinge area. Subsequently, the failure modes and ultimate bearing capacity are simulated by the finite element method (FEM), which is implemented via ABAQUS. By comparing the test results with the numerical values, demonstrate the effectiveness of the proposed numerical simulation on investigating the failure modes and the ultimate bearing capacity of HSCF rectangular steel tubes. Finally, regarding the conservative and dangerous calculation of web crippling ultimate bearing capacity in current codes, we can provide a good guidance for future work, particularly the proposed calculation equations for ultimate bearing capacity of HSCF rectangular steel tubes

    Extraction and Characterization of Lysozyme from Salted Duck Egg White

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    Salted duck egg white (SDEW), as the main by-product in the production process of salted egg yolk, has not been effectively used as a food resource because of its high salt concentration. This study creatively used isoelectric point precipitation, ultrafiltration, and cation exchange to separate and purify lysozyme from SDEW and preliminarily explored the enzymatic properties of lysozyme. The results showed that the relative molecular weight of lysozyme was about 14 KDa, and the specific activity of lysozyme reached 18,300 U/mg. Lysozyme had good stability in the temperature range of 30 °C to 60 °C and pH of 4 to 7. Metal ions, Fe2+, Cu2+, and Zn2+, strongly inhibited lysozyme activity. Different surfactants showed certain inhibition effects on lysozyme from SDEW, among which glycerin had the strongest inhibitory effect. This study aimed to provide a theoretical reference for industrial purification and production of lysozyme from SDEW
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