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3.
Chaos ; 28(9): 093110, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30278622

ABSTRACT

The lacunarity index (monolacunarity) averages the behavior of variable size structures in a binary image. The generalized lacunarity concept (multilacunarity) on the basis of generalized distribution moments is an appealing model that can account for differences in the mass content at different scales. The model was tested previously on natural images [J. Vernon-Carter et al., Physica A 388, 4305 (2009)]. Here, the computational aspects of multilacunarity are validated using synthetic binary images that consist of random maps, spatial stochastic patterns, patterns with circular or polygonal elements, and a plane fractal. Furthermore, monolacunarity and detrended fluctuation analysis were employed to quantify the mesostructural changes in the intercellular air spaces of frozen-thawed parenchymatous tissue of pome fruit [N. A. Valous et al., J. Appl. Phys. 115, 064901 (2014)]. Here, the aim is to further examine the coherence of the multilacunarity model for quantifying the mesostructural changes in the intercellular air spaces of parenchymatous tissue of pome and stone fruit, acquired with X-ray microcomputed tomography, after storage and ripening, respectively. The multilacunarity morphometric is a multiscale multi-mass fingerprint of spatial pattern composition, assisting the exploration of the effects of metabolic and physiological activity on the pore space of plant parenchyma tissue.


Subject(s)
Malus , Mangifera , Models, Biological , Fruit/cytology , Fruit/physiology , Malus/cytology , Malus/physiology , Mangifera/cytology , Mangifera/physiology
4.
Br J Surg ; 95(6): 785-92, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18412296

ABSTRACT

BACKGROUND: Reduced-size livers suffer from portal hyperperfusion, diminished arterial blood flow and the risk of postoperative liver injury. The aim of this experimental study was to unravel the role of nitric oxide in this setting. METHODS: Rats underwent 85 per cent partial hepatectomy and either substitution of nitric oxide with molsidomine or inhibition of nitric oxide synthase (NOS) with N(G)-nitro-L-arginine methyl ester. Untreated hepatectomized animals served as controls and unresected animals as the sham group. RESULTS: Ultrasonic flowmetry following partial hepatectomy revealed a marked increase in portal venous inflow with a concomitant decrease in hepatic arterial inflow. Nitric oxide substitution counteracted the decline in hepatic arterial inflow and caused a significantly greater increase in cell proliferation after partial hepatectomy compared with control or NOS-inhibited animals. Hepatectomized animals further profited from nitric oxide substitution, as indicated by reduced aminotransferase release and improved liver function. CONCLUSION: Nitric oxide improves the postoperative course of rats with reduced-size livers by modulating hepatic macrohaemodynamics and mediating regeneration and cytoprotection, but not by reducing hepatic hyperperfusion and the accompanying sinusoidal shear stress.


Subject(s)
Endothelium-Dependent Relaxing Factors/pharmacology , Hepatic Artery/drug effects , Liver Circulation/drug effects , Liver Regeneration/drug effects , Nitric Oxide/pharmacology , Animals , Aspartate Aminotransferases/metabolism , Cell Proliferation/drug effects , Enzyme Inhibitors/pharmacology , Hepatectomy , Hepatocytes/cytology , Hepatocytes/drug effects , Immunohistochemistry , Male , Microcirculation/drug effects , Molsidomine/pharmacology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Donors/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Postoperative Period , Rats , Rats, Wistar
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