58 research outputs found
Nano-structured interpenetrating composites with enhanced Young's modulus and desired Poisson's ratio
This paper has demonstrated that interpenetrating composites could be designed to not only have an significantly enhanced
Young�s modulus, but also have a Poisson�s ratio at a desired value (e.g. positive, or negative, or zero). It is
found that when the effect of the Poisson�s ratio is absent, the Young�s modulus of interpenetrating composites is closer
to the Hashin and Shtrikman�s upper limit than to their lower limit, and much larger than the simulation and experimentally
measured results of the conventional isotropic particle or fibre composites. It is also illustrated that at the nanoscale,
the interphase can either strengthen or weaken the stiffness, and the elastic properties of interpenetrating composites are
size-dependent
Effect of Fuzheng Huayu formula and its actions against liver fibrosis
Liver fibrosis is a common histological process to develop into cirrhosis in various chronic liver diseases including chronic hepatitis and fatty liver. Therefore anti-liver fibrosis is very important strategy to treat chronic liver diseases. Fuzheng Huayu (FZHY), a preparation containing herbs such as Radix Salvia Miltiorrhizae, Cordyceps, Semen Persicae, was formulated on the basis of Chinese medicine theory in treating liver fibrosis and was approved. Pharmacological studies and clinical trials demonstrate that FZHY has a significant effect against liver fibrosis and that many of the pharmacological actions are attributable to the effect. This article reviews the effects and actions of FZHY, in particular the effects observed from clinical trials in treating liver fibrosis caused by chronic hepatitis B and the actions on inhibition of hepatic stellate cell activation, protection of hepatocytes and inhibition of hepatic sinusoidal capillarization. This article also reviews the coordinated effects of the constituent herbs of FZHY and the actions of their active compounds such as salvianonic acid B (SA-B) on liver fibrosis
Application of CCG Sensors to a High-Temperature Structure Subjected to Thermo-Mechanical Load
This paper presents a simple methodology to perform a high temperature coupled thermo-mechanical test using ultra-high temperature ceramic material specimens (UHTCs), which are equipped with chemical composition gratings sensors (CCGs). The methodology also considers the presence of coupled loading within the response provided by the CCG sensors. The theoretical strain of the UHTCs specimens calculated with this technique shows a maximum relative error of 2.15% between the analytical and experimental data. To further verify the validity of the results from the tests, a Finite Element (FE) model has been developed to simulate the temperature, stress and strain fields within the UHTC structure equipped with the CCG. The results show that the compressive stress exceeds the material strength at the bonding area, and this originates a failure by fracture of the supporting structure in the hot environment. The results related to the strain fields show that the relative error with the experimental data decrease with an increase of temperature. The relative error is less than 15% when the temperature is higher than 200 °C, and only 6.71% at 695 °C
3D Model-Based Simulation Analysis of Energy Consumption in Hot Air Drying of Corn Kernels
To determine the mechanism of energy consumption in hot air drying, we simulate the interior heat and mass transfer processes that occur during the hot air drying for a single corn grain. The simulations are based on a 3D solid model. The 3D real body model is obtained by scanning the corn kernels with a high-precision medical CT machine. The CT images are then edited by MIMICS and ANSYS software to reconstruct the three-dimensional real body model of a corn kernel. The Fourier heat conduction equation, the Fick diffusion equation, the heat transfer coefficient, and the mass diffusion coefficient are chosen as the governing equations of the theoretical dry model. The calculation software, COMSOL Multiphysics, is used to complete the simulation calculation. The influence of air temperature and velocity on the heat and mass transfer processes is discussed. Results show that mass transfer dominates during the hot air drying of corn grains. Air temperature and velocity are chosen primarily in consideration of mass transfer effects. A low velocity leads to less energy consumption
Using Two-stage Network to Segment Kidneys and Kidney Tumors
There are many new cases of kidney cancer each year, and surgery is the most common treatment. To assist doctors in surgical planning, an accurate and automatic kidney and tumor segmentation method is helpful in the clinical practice. In this paper, we propose a deep learning framework for the segmentation of kidneys and tumors in abdominal CT images. The key idea is using a two-stage strategy. First, for each case, we use a 3d U-shape convolution network to get the localization of each kidney. Then using next 3d U-shape convolution network we obtain the precise segmentation results of each kidney. Finally, merge the results to obtain the complete segmentation. Also, we try some tricks to improve the performance
Probabilistic Reliability Analysis of Carbon/Carbon Composite Nozzle Cones with Uncertain Parameters
A methodology to perform the probabilistic and reliability-based design of a novel carbon/carbon rocket nozzle subjected to operational thermal and mechanical loads is described in this paper. In this methodology, the nozzle is represented by a multiphysics finite element model capable of predicting the temperature and stress fields of the exit cone. The analysis shows that the most likely failure modes of the exit cone are related to compressive stress along the axial and hoop directions, as well as interlaminar shear. The probabilistic models used in this methodology account for the uncertainty of the material properties by using uniform and normal distributions and different variances. The reliability analysis is performed by using surface response methods. A global sensitivity analysis is also carried out using polynomial expansion chaos surface response models. A particular novelty of the analysis is the use of Sobol indices to rank the importance of the single uncertain parameters in the models. The methodology provides a high level of confidence and robustness in determining that the axial thermal conductivity of the carbon/carbon material is the most critical material property to affect the three main failure modes, whereas the coefficient of the thermal expansion and the heat capacity play a very marginal role
Measurement of high-temperature strains in superalloy and carbon/carbon composites using chemical composition gratings
Measurement of high-temperature strains in superalloy and carbon/carbon composites using chemical composition gratings
This is a text file associated with Ref. [11] from R. Siew, "Practical automated glass selection and the design of apochromats with large field of view,"Â App. Opt. 55, pp. 9232 - 9236Â (2016). It lists the lens prescription for the Zemax lens file of Ref. [10] in the above manuscript. Â This lens represents a re-optimized state of the prior lens "AUTO GLASS FINISHED.zmx". Â The design form is based on the design by A. Yang, X. Gao, and M. Li, "Design of apochromatic lens with large field and high definition for machine vision," App. Opt. 55, 5977 - 5985 (2016)
Clinicopathological characteristics and treatment outcome of resectable gastric cancer patients with small para-aortic lymph node
BackgroundResectable gastric cancer (GC) patients with small para-aortic lymph node (smaller than 10mm in diameter, sPAN) were seldom reported, and existing guidelines did not provide definite treatment recommendation for them.MethodsA total of 667 consecutive resectable GC patients were enrolled. 98 patients were in the sPAN group, and 569 patients without enlarged para-aortic lymph node were in the nPAN group. Standard D2 lymphadenectomy was performed. Neoadjuvant and adjuvant chemotherapy were administrated according to the cTNM and pTNM stage, respectively. Clinicopathological features and prognosis were compared between these two groups.ResultsThe median size of sPAN was 6 (range, 2−9) mm and the distribution was prevalent in No. 16b1. cN stage (p=0.001) was significantly related to the presence of sPAN. sPAN was both independent risk factor for OS (p=0.031) and RFS (p=0.046) of all patients. The prognosis of patients with sPAN was significantly worse than that of patients with nPAN (OS: p=0.008; RFS: p=0.007). Preoperative CEA and CA19-9 were independent risk factors for prognosis of patients with sPAN. Furthermore, patients in the sPAN group with normal CEA and CA19-9 exhibited acceptable prognosis (5-year OS: 67%; RFS: 64%), while those with elevated CEA or CA19-9 suffered significantly poorer prognosis (5-year OS: 17%; RFS: 17%) than patients in the nPAN group (5-year OS: 64%; RFS 62%) (both p < 0.05).ConclusionsStandard D2 lymphadenectomy should be considered a valid approach for GC patients with sPAN associate to normal preoperative CEA and CA19-9 levels. Patients with sPAN associated to elevated CEA or CA19-9 levels could benefit from a multimodal approach: neoadjuvant chemotherapy; radical surgery with D2 plus lymph nodal dissection extended to No. 16 station
Crystal structure of rhodopsin bound to arrestin by femtosecond X-ray laser.
G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a ∼20° rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology
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