2,068 research outputs found

    Direct reconstruction of dynamical dark energy from observational Hubble parameter data

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    Reconstructing the evolution history of the dark energy equation of state parameter w(z)w(z) directly from observational data is highly valuable in cosmology, since it contains substantial clues in understanding the nature of the accelerated expansion of the Universe. Many works have focused on reconstructing w(z)w(z) using Type Ia supernova data, however, only a few studies pay attention to Hubble parameter data. In the present work, we explore the merit of Hubble parameter data and make an attempt to reconstruct w(z)w(z) from them through the principle component analysis approach. We find that current Hubble parameter data perform well in reconstructing w(z)w(z); though, when compared to supernova data, the data are scant and their quality is worse. Both Λ\LambdaCDM and evolving w(z)w(z) models can be constrained within 10%10\% at redshifts z1.5z \lesssim 1.5 and even 5%5\% at redshifts 0.1 \lesssim z \lesssim 1 by using simulated H(z)H(z) data of observational quality.Comment: 25 pages, 11 figure

    Optical Interferometric Force Sensor based on a Buckled Beam

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    This paper reports a novel extrinsic Fabry-Perot interferometer (EFPI)-based fiber optic sensor for force measurement. The prototype force sensor consists of two EFPIs mounted on a stainless-steel rectangular frame. The primary sensing element, i.e., the first EFPI, is formed between the endface of a horizontally placed optical fiber and a stainless-steel buckled beam. The second EFPI, fashioned between a longitudinally placed optical fiber and a silver-coated glass beam, is arranged to demonstrate the amplification mechanism of the buckled beam structure. When the sensor is subjected to a tension force, the pre-buckled beam will deflect backward, resulting in a longitudinal/axial displacement of the pre-buckled beam. The axial displacement is further transferred and amplified to a horizontal/vertical deflection at the middle of the buckled beam, leading to a relatively significant change in the Fabry-Perot cavity length. A force sensitivity of 796 nm/ {N} (change in cavity length/Newton) is achieved with a low-temperature dependence of 0.005 {N} /°C. The stability of the sensor is also investigated with a standard deviation of ± 5 nm, corresponding to a measurement resolution of ±0.0064 N. A simulation is conducted to study the axial displacement and stress distribution of the sensor when it is subjected to a tension load of 250 N. It is demonstrated that the maximum stress of the sensor is tremendously reduced attributed to the buckled design, enabling a long service life cycle of the force sensor. The robust and simple-to-manufacture force sensor has great potential in structural health monitoring, robotics control, and oil/ gas refining systems

    血液透析患者的中医药治疗及中医护理现状

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    This paper aims to present situation of traditional Chinese medicine therapy and nursing of hemodialysis patients, to review relevant literature on hemodialysis and to analyze and understand the hemodialysis patients with traditional Chinese medicine therapy and nursing. It is put forward that the future research should focus on specification of hemodialysis lateral comparative evaluation development, etc., in order to standardize and form evidence-based prevention intervention in hemodialysis patients with complications, better improve the quality of survival in hemodialysis patients.综述血液透析患者的中医药治疗及护理现状,通过有关血液透析的相关文献整理研究,分析了目前血液透析患者的中医药治疗干预及护理现状,提出了今后血液透析的中西医结合研究应着眼于技术规范、横向比较评价、继承创新等,以建立规范、形成标准,做到有据可循地防治血液透析患者的并发症,更好地提高血液透析患者的生存率与生存质量,促进患者回归社会

    Embeddable Soil Moisture Content Sensor based on Open–end Microwave Coaxial Cable Resonator

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    In This Paper, We Propose and Demonstrate a Novel Corrosion-Resistant, Embeddable Open-End Coaxial Cable Soil Moisture Sensor. This Microwave Resonator is Constructed using Two Reflectors Along the Coaxial Line. the First Reflector is a Metal Post at the Signal Input End, Short-Circuiting the Inner Conductor to the Outer Conductor. the Second Reflector Comprises a Welded Metal Plate Parallel to the Open-End of the Coaxial Line, Maintaining a Fixed Gap. a Moisture-Sensitive Polyvinyl Alcohol (PVA) Film is Inserted into This Gap. the Resonance Frequency of the Open-End Coaxial Cable Resonator is Highly Dependent on the Fringe Capacitance, Which Varies with Soil Moisture Levels. as Such, Tracking Resonance Frequency Changes Allows for Correlation with Soil Moisture Fluctuations. We Provide a Detailed Discussion of the Embeddable Open-End Microwave Coaxial Cable Resonator (EOE-MCCR) Mathematical Model and a Proof of Concept for Soil Moisture Measurement. the Demonstration Experiments Investigate Soil Moisture Content Ranging from 4% to 24%. the Prototype Device Exhibits a Soil Moisture Measurement Sensitivity of 0.76MHz% for Soil Moisture between 4% and 10%, and 1.44MHz% for Soil Moisture between 10% and 24%. the Soil Moisture Sensor Presented Here is Robust, Easy to Manufacture, Chemically Resistant, Low-Cost, and Suitable for Long-Term Applications and Potential Industrial Uses. This Innovative Sensor is Ideal for Sensing Applications in Harsh Environments, Advancing the Field of Chemical Trace Sensing

    Overexpression of the Tomato Pollen Receptor Kinase LePRK1 Rewires Pollen Tube Growth to a Blebbing Mode

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    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP), a Rop guanine nucleotide exchange factor. Here, we show that pollen tubes overexpressing LePRK1 or a truncated LePRK1 lacking its extracellular domain (LePRK1ΔECD) have enlarged tips but also extend their leading edges by producing “blebs.” Coexpression of LePRK1 and tomato PLIM2a, an actin bundling protein that interacts with KPP in a Ca2+-responsive manner, suppressed these LePRK1 overexpression phenotypes, whereas pollen tubes coexpressing KPP, LePRK1, and PLIM2a resumed the blebbing growth mode. We conclude that overexpression of LePRK1 or LePRK1ΔECD rewires pollen tube growth to a blebbing mode, through KPP- and PLIM2a-mediated bundling of actin filaments from tip plasma membranes. Arabidopsis thaliana pollen tubes expressing LePRK1ΔECD also grew by blebbing. Our results exposed a hidden capability of the pollen tube cell: upon overexpression of a single membrane-localized molecule, LePRK1 or LePRK1ΔECD, it can switch to an alternative mechanism for extension of the leading edge that is analogous to the blebbing growth mode reported for Dictyostelium and for Drosophila melanogaster stem cells.Fil: Gui, Cai Ping. Chinese Academy of Sciences; República de ChinaFil: Dong, Xin. Chinese Academy of Sciences; República de ChinaFil: Liu, Hai Kuan. Chinese Academy of Sciences; República de ChinaFil: Huang, Wei Jie. Chinese Academy of Sciences; República de ChinaFil: Zhang, Dong. Chinese Academy of Sciences; República de ChinaFil: Wang, Shu Jie. Chinese Academy of Sciences; República de ChinaFil: Barberini, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Gao, Xiao Yan. Chinese Academy of Sciences; República de ChinaFil: Muschietti, Jorge Prometeo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: McCormick, Sheila. University of California at Berkeley; Estados UnidosFil: Tang, Wei Hua. Chinese Academy of Sciences; República de China. University of California at Berkeley; Estados Unido

    Thoughts on Intervention in HIV/AIDS with Traditional Chinese Medicine

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    AbstractsHIV/AIDS has become a worldwide pandemic and highly active antiretroviral therapy (HAART) is the only generally recognized effective therapy at present. However, various unresolvable problems appear with the widespread use of HAART. Traditional Chinese Medicine shows good efficacy for intervention in HIV/AIDS and could become an effective treatment option
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