1,168 research outputs found

    Axial plane optical microscopy.

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    We present axial plane optical microscopy (APOM) that can, in contrast to conventional microscopy, directly image a sample's cross-section parallel to the optical axis of an objective lens without scanning. APOM combined with conventional microscopy simultaneously provides two orthogonal images of a 3D sample. More importantly, APOM uses only a single lens near the sample to achieve selective-plane illumination microscopy, as we demonstrated by three-dimensional (3D) imaging of fluorescent pollens and brain slices. This technique allows fast, high-contrast, and convenient 3D imaging of structures that are hundreds of microns beneath the surfaces of large biological tissues

    Associations of plasma very-long-chain SFA and the metabolic syndrome in adults

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    Plasma levels of very-long-chain SFA (VLCSFA) are associated with the metabolic syndrome (MetS). However, the associations may vary by different biological activities of individual VLCSFA or population characteristics. We aimed to examine the associations of VLCSFA and MetS risk in Chinese adults. Totally, 2008 Chinese population aged 35–59 years were recruited and followed up from 2010 to 2012. Baseline MetS status and plasma fatty acids data were available for 1729 individuals without serious diseases. Among 899 initially metabolically healthy individuals, we identified 212 incident MetS during the follow-up. Logistic regression analysis was used to estimate OR and 95 % CI. Cross-sectionally, each VLCSFA was inversely associated with MetS risk; comparing with the lowest quartile, the multivariate-adjusted OR for the highest quartile were 0·18 (95 % CI 0·13, 0·25) for C20 : 0, 0·26 (95 % CI 0·18, 0·35) for C22 : 0, 0·19 (95 % CI 0·13, 0·26) for C24 : 0 and 0·16 (0·11, 0·22) for total VLCSFA (all Pfor trend<0·001). The associations remained significant after further adjusting for C16 : 0, C18 : 0, C18 : 3n-3, C22 : 6n-3, n-6 PUFA and MUFA, respectively. Based on follow-up data, C20 : 0 or C22 : 0 was also inversely associated with incident MetS risk. Among the five individual MetS components, higher levels of VLCSFA were most strongly inversely associated with elevated TAG (≥1·7 mmol/l). Plasma levels of VLCSFA were significantly and inversely associated with MetS risk and individual MetS components, especially TAG. Further studies are warranted to confirm the findings and explore underlying mechanisms

    A Decentralized Fault Section Location Method Using Autoencoder and Feature Fusion in Resonant Grounding Distribution Systems

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    In industrial applications, the existing fault location methods of resonant grounding distribution systems suffer from low accuracy due to excessive dependence on communication, lack of field data, difficulty in artificial feature extraction and threshold setting, etc. To address these problems, this study proposes a decentralized fault section location method, which is implemented by the primary and secondary fusion intelligent switch (PSFIS) with two preloaded algorithms: autoencoder (AE) and backpropagation neural network. The relation between the transient zero-sequence current and the derivative of the transient zero-sequence voltage in each section is analyzed, and its features are extracted adaptively by using AE, without acquiring network parameters or setting thresholds. The current and voltage data are processed locally at PSFISs throughout the whole procedure, making it is insusceptible to communication failure or delay. The feasibility and effectiveness of the approach are investigated in PSCAD/EMTDC and real-time digital simulation system, which is then validated by field data. Compared with other methods, the experiment results indicate that the proposed method performs well in various scenarios with strong robustness to harsh on-site environment and roughness of data

    Understanding Transport of an Elastic, Spherical Particle through a Confining Channel

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    The transport of soft particles through narrow channels or pores is ubiquitous in biological systems and industrial processes. On many occasions, the particles deform and temporarily block the channel, inducing a built-up pressure. This pressure buildup often has a profound effect on the behavior of the respective system; yet, it is difficult to be characterized. In this work, we establish a quantitative correlation between the built-up pressure and the material and geometry properties through experiments and mechanics analysis. We fabricate microgels with a controlled diameter and elastic modulus by microfluidics. We then force them to individually pass through a constrictive or straight confining channel and monitor the pressure variation across the channel. To interpret the pressure measurement, we develop an analytical model based on the Neo-Hookean material law to quantify the dependence of the maximum built-up pressure on the radius ratio of the elastic sphere to the channel, the elastic modulus of the sphere, and two constant parameters in the friction constitutive law between the sphere and the channel wall. This model not only agrees very well with the experimental measurement conducted at large microgel deformation but also recovers the classical theory of contact at small deformation. Featuring a balance between accuracy and simplicity, our result could shed light on understanding various biological and engineering processes involving the passage of elastic particles through narrow channels or pores

    The X(3960)X(3960), X0(4140)X_0(4140), and other cscˉsˉcs\bar{c}\bar{s} compact states

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    We study the spectrum and rearrangement decays of S-wave cscˉsˉcs\bar{c}\bar{s} tetraquark states in a simplified quark model. The masses and widths are estimated by assuming that the X(4140)X(4140) is the lower 1++1^{++} cscˉsˉcs\bar{c}\bar{s} tetraquark. Comparing our results with experimental measurements, we find that the recently observed X(3960)X(3960) by LHCb can be assigned as the lowest 0++0^{++} cscˉsˉcs\bar{c}\bar{s} tetraquark state and the X0(4140)X_0(4140) could be the second lowest 0++0^{++} cscˉsˉcs\bar{c}\bar{s} tetraquark. Predictions of ratios between partial widths for the involved tetraquarks are given. We call for searches for more cscˉsˉcs\bar{c}\bar{s} tetraquarks with JPC=1+−J^{PC}=1^{+-}, 0++0^{++}, and 2++2^{++}

    Bar-driven Gas Dynamics of M31

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    The large-scale gaseous shocks in the bulge of M31 can be naturally explained by a rotating stellar bar. We use gas dynamical models to provide an independent measurement of the bar pattern speed in M31. The gravitational potentials of our simulations are from a set of made-to-measure models constrained by stellar photometry and kinematics. If the inclination of the gas disk is fixed at i=77∘i = 77^{\circ}, we find that a low pattern speed of 16−20  km  s−1  kpc−116-20\;\rm km\;s^{-1}\;kpc^{-1} is needed to match the observed position and amplitude of the shock features, as shock positions are too close to the bar major axis in high Ωb\Omega_{b} models. The pattern speed can increase to 20−30  km  s−1  kpc−120-30\;\rm km\;s^{-1}\;kpc^{-1} if the inner gas disk has a slightly smaller inclination angle compared with the outer one. Including sub-grid physics such as star formation and stellar feedback has minor effects on the shock amplitude, and does not change the shock position significantly. If the inner gas disk is allowed to follow a varying inclination similar to the HI and ionized gas observations, the gas models with a pattern speed of 38  km  s−1  kpc−138\;\rm km\;s^{-1}\;kpc^{-1}, which is consistent with stellar-dynamical models, can match both the shock features and the central gas features.Comment: 26 pages, 16 figures. To appear on Ap

    Effect of β-nerve growth factor on differentiation of endothelial progenitor cells in rats

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    Purpose: To investigate the effect of recombinant adenovirus-mediated human β-nerve growth factor (Ad-EGFP-hβ-NGF) on the differentiation of endothelial progenitor cells (EPCs) in rats.Methods: The successfully constructed Ad-EGFP-hβ-NGF and its negative control Ad-EGFP were infected into the isolated and purified rat EPCs to observe their morphological changes. Enzyme-linked immunosorbent assay (ELISA) was conducted to detect the levels of vascular endothelial growth factor (VEGF), von Willebrand factor (vWF) and basic fibroblast growth factor (bFGF) in different rat EPC culture solutions. Western blot was performed to determine the expression of tyrosine kinase receptor A (TrKA) protein in different groups of EPCs.Results: Primary fibrous EPCs were converted into epithelium-like cells. After infection with Ad-EGFPhβ- NGF for 1 week, some EPCs became round and exhibited neural stem cell-like changes. The expression levels of VEGF, vWF and bFGF in the Ad-EGFP-hβ-NGF infection group were significantly higher than those in the control group (p &lt; 0.01). TrKA protein in Ad-EGFP-hβ-NGF infection was also significantly up-regulated compared with that in the negative control and blank control groups (p &lt;0.01).Conclusion: β-NGF up-regulates the expression of TrKA receptor protein and secretion of angiogenic growth factors (i.e., VEGF, vWF and bFGF), thereby promoting the differentiation of rat EPCs, which may contribute to angiopoiesis or vascular repair.Keywords: β-Nerve growth factor, Endothelial progenitor cells, Angiogenic growth factors, Tyrosine kinase receptor A, Cell differentiatio
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