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71.
Xi Chen Pei Niu Xiaolong Niu Wenzeng Shen Fei Duan Liang Ding Xiliang Wei Yanjun Gong Yong Huo Ghassan S. Kassab Wenchang Tan Yunlong Huo 《Journal of the Royal Society Interface》2015,12(113)
Despite the well-known design principles of vascular systems, it is unclear whether the vascular arterial tree obeys some scaling constraints during normal growth and ageing in a given species. Based on the micro-computed tomography measurements of coronary arterial trees in mice at different ages (one week to more than eight months), we show a constant exponent of 3/4, but age-dependent scaling coefficients in a length–volume scaling law (
Lc is the crown length, Vc is the crown volume, Klength–volume is the age-dependent scaling coefficient) during normal growth and ageing. The constant 3/4 exponent represents the self-similar fractal-like branching pattern (i.e. basic mechanism to regulate the development of vascular trees within a species), whereas the age-dependent scaling coefficients characterize the structural growth or resorption of vascular trees during normal growth or ageing, respectively. This study enhances the understanding of age-associated changes in vascular structure and function. 相似文献
72.
Early detection of hepatocellular carcinoma (HCC) while in its early stages is critical for reducing HCC mortality in high-risk patients. However, highly sensitive and specific surveillance biomarkers for early-stage HCC detection are still lacking. In recent years, great efforts have been made to research tumor-derived molecular features that are detectable in circulation, such as circulating tumor deoxyribonucleic acid and circulating tumor ribonucleic acid, in order to explore their potential as non-invasive biomarker candidates in many tumor types. In this review, we summarize current studies on these new approaches and their application in early HCC detection. 相似文献
73.
In this paper we propose a new approach that addresses both the problems of design validation and hardware testing since the early stages of the design flow. The approach consists in adapting the mutation testing, a software method, to circuits described in VHDL. At the functional level, the approach behaves as a design validation method and at the hardware level as a classical ATPG. Standard software test metrics are used for assessing the quality of the design validation process, and the hardware fault coverage for assessing the test quality at the hardware level. An enhancement process that allows design validation to be efficiently reused for hardware testing is detailed. The approach is shown to be efficient upon a set of representative circuits. 相似文献
74.
The physiochemical composition of durum wheat cultivars was studied in order to investigate the influence of vitreousness on the chemical composition of starch and its thermal and pasting properties. Six durum wheat lines were chosen and grown in northern Syria. Grains of each cultivar were visually sorted according to the degree of vitreousness into fully vitreous and fully starchy fractions. Amylose/amylopectin ratio and total starch was determined using Megazyme methods, while thermal and pasting properties were determined using DSC and RVA. Starchy kernels were higher in total starch than vitreous kernels but showed a decreased amylose content. Negative linear relations were found between amylose content, and both peak viscosity and breakdown. Trends in variation of gelatinisation characteristics were observed between vitreous and starchy kernels from the same cultivar, with higher total enthalpy being associated with starchy grains compared with vitreous grains of the same line. 相似文献
75.
76.
An approach to local area network interconnection is presented Which combines the advances in static interconnection topologies, demand assignment multiple access protocols, and the availability of high-bandwidth fiber optic channels to create a cost-effective structure capable of interconnecting a large number of LAN's with heavy traffic. This approach is independent of the protocol implemented at each LAN. The structure is based on a hypercube topology where each vertex of the graph represents a LAN. Multiple access channels spanning all dimensional axes are used in this scheme. This approach is compared to a topology with direct point-to-point connections between all nodes sharing a common axis. Through the development of the degree, diameter, average distance, cost, and average packet delay, we show that using fewer high-capacity channels, a LAN interconnection network with excellent performance characteristics can be constructed, able to support a large number of LAN's with heavy traffic at a significant reduction in cost over the point-to-point case. The resulting structure has many of the desirable characteristics for static interconnection networks such as high fault tolerance, totally distributed packet routing in the interconnection network, low average distance for good performance, and low degree, resulting in low cost. For the total number of required LAN nodes and the expected amount of internode traffic, the structure is optimized for minimum cost. 相似文献
77.
78.
Noise confounds present serious complications to functional magnetic resonance imaging (fMRI) analysis. The amount of discernible signals within a single dataset of a subject is often inadequate to obtain satisfactory intra-subject activation detection. To remedy this limitation, we propose a novel group Markov random field (GMRF) that extends each subject's neighborhood system to other subjects to enable information coalescing. A distinct advantage of GMRF over standard fMRI group analysis is that no stringent one-to-one voxel correspondence is required. Instead, intra- and inter-subject neighboring voxels are jointly regularized to encourage spatially proximal voxels to be assigned similar labels across subjects. Our proposed group-extended graph structure thus provides an effective means for handling inter-subject variability. Also, adopting a group-wise approach by integrating group information into intra-subject activation, as opposed to estimating a single average group map, permits inter-subject differences to be characterized and studied. GMRF can be elegantly implemented as a single MRF, thus enabling all subjects' activation maps to be simultaneously and collaboratively segmented with global optimality guaranteed in the case of binary labeling. We validate our technique on synthetic and real fMRI data and demonstrate GMRF's superior performance over standard fMRI analysis. 相似文献
79.
Kyu‐Sung Lee Inho Kim Chang Bong Yeon Jung Wook Lim Sun Jin Yun Ghassan E. Jabbour 《ETRI Journal》2013,35(4):587-593
We demonstrate semitransparent organic photovoltaics (OPVs) based on thin metal electrodes and polymer photoactive layers consisting of poly(3‐hexylthiophene) and [6,6]‐phenyl C61 butyric acid methyl ester. The power conversion efficiency of a semitransparent OPV device comprising a 15‐nm silver (Ag) rear electrode is 1.98% under AM 1.5‐G illumination through the indium‐tin‐oxide side of the front anode at 100 mW/cm2 with 15.6% average transmittance of the entire cell in the visible wavelength range. As its thickness increases, a thin Ag electrode mainly influences the enhancement of the short circuit current density and fill factor. Its relatively low absorption intensity makes a Ag thin film a viable option for semitransparent electrodes compatible with organic layers. 相似文献
80.
Flavonoid‐Rich Apple Improves Endothelial Function in Individuals at Risk for Cardiovascular Disease: A Randomized Controlled Clinical Trial 下载免费PDF全文