A. DEL CAMPO*, M. BRACHO, L. MARCANO, J. GUÍÑEZ, C. DE LA TORRE**

BIOCELL, Vol.29, No.2, pp. 169-176, 2005, DOI:10.32604/biocell.2005.29.169

Abstract This work evaluated the qualitative and quantitative cellular changes induced by treatment with 5-aminouracil (5-AU) and a combination of 5-AU and caffeine in plant cells in relation to DNA damage, repaired damage, and residual damage. As biological material, Allium cepa L. root tips were used, grown in filtered water, in darkness, with aeration at constant temperature of 25 °C ± 0.5. Cell populations were synchronized using 5 mM caffeine in order to study the effects of 5-AU and caffeine/5-AU combined treatment on the DNA content and their incidence in the entrance to mitosis. The results showed More >

CARLOS A. MARTÍN, JOSÉ MIGUEL SURUR, MARCELA N. GARCÍA, FÉLIX CORRONS, AMADO F. BADRÁN

BIOCELL, Vol.29, No.1, pp. 33-38, 2005, DOI:10.32604/biocell.2005.29.033

Abstract Variations in DNA synthesis (DNAs) and Nucleolar Organizer Regions (NORs) were studied in the littoral cell population from regenerating liver of C3HS inbred mice standardized for periodicity analysis. Immunohistochemical detection of Bromodeoxyuridine (BrdU) with a monoclonal antibody and silver staining of NORs (AgNORs) were assessed by means of a digital image analysis system in histological sections. Tissue samples were obtained every four hours from the 30th to the 54th hours after a partial hepatectomy. The results showed, in both parameters, a gradual increment of the values during the period studied, with highest values (DNAs 107.1 More >

LILIANA G. SOUSA¹, ELENA I. CUARTAS², ANA MARÍA PETRIELLA^{1, 3}

BIOCELL, Vol.29, No.1, pp. 25-31, 2005, DOI:10.32604/biocell.2005.29.025

Abstract The aim of this study is to describe the ultrastructure of the hepatopancreas of P. argentinus in intermoult. P. argentinus hepatopancreas was studied using standard TEM techniques. Each tubule consists of four cellular types: E (embryonic), F (fibrillar), R (resorptive) and B (blister like). E-cells have embryonic features and some of them were found in mitosis. F, R and B cells possess an apical brush border. F-cells have a central or basal nucleus, a conspicuous RER, and dilated Golgi cisternae. R cells show a polar organization of organelles in three areas: apical, with numerous mitochondria and sER… More >

LILIAN BARRIOS, OSCAR HÉCTOR POLETTI

BIOCELL, Vol.29, No.1, pp. 7-14, 2005, DOI:10.32604/biocell.2005.29.007

Abstract We have evaluated the effect of filgrastim on proliferation and differentiation activity of granulopoietic cells in mice pretreated with methotrexate. Filgrastim was injected daily, from day 8 to 28 after cytotoxic agent administration. The granulopoiesis changes were measured by assessment of GM-CFU cells content, marrow and spleen granuloid cells pool as well as circulating neutrophils. In MTX pretreated mice, bone marrow GM-CFU oscillating values were higher than normal values, but these changes were not followed by high proliferative activity in granuloid precursor cell compartment. After MTX treatment, filgrastim administration was unable to stimulate marrow granulopoiesis… More >

S. Baragetti¹, A. Terranova²

Structural Durability & Health Monitoring, Vol.1, No.4, pp. 267-276, 2005, DOI:10.3970/sdhm.2005.001.267

Abstract Aim of this work is to investigate into the possibility of enhancing the fatigue resistance of CrN PVD coated components. In particular PVD coated spur gears were tested and numerical simulation of crack propagation was carried out. The coating layer micro-hardness and the residual stresses characterising the surface film were measured and the obtained results were introduced in a numerical modelling predicting fatigue life procedure of coated gears used in gearboxes for automotive applications. The number of cycles necessary to reach specified crack depths of coated and uncoated samples was numerically determined and represents a More >

A. Rama Ch,ra Murthy¹, G.S. Palani¹, Nagesh R. Iyer¹

Structural Durability & Health Monitoring, Vol.1, No.3, pp. 203-214, 2005, DOI:10.3970/sdhm.2005.001.203

Abstract This paper presents an improved Wheeler residual stress model for remaining life prediction of the cracked structural components under variable amplitude loading. The improvement to the Wheeler residual stress model is in two folds. One is expressions for the shaping exponent, which are generally obtained through experiments. Another is calculation of effective plastic zone size to incorporate the sequent effects under tensile-compressive overloading. The remaining life prediction has been carried out by employing the linear elastic fracture mechanics (LEFM) principles. Studies on remaining life prediction of cracked plate panels subjected to tensile-compressive overloading have been More >

D.Taylor¹

Structural Durability & Health Monitoring, Vol.1, No.2, pp. 145-154, 2005, DOI:10.3970/sdhm.2005.001.145

Abstract The Theory of Critical Distances (TCD) is a general term for any of those methods of analysis which use continuum mechanics in conjunction with a characteristic material length constant, L. This paper discusses the use of two simple versions of the TCD: a point-stress approach which we call the Point Method (PM) and a line-average approach: the Line Method (LM). It is shown that they are able to predict the onset of unstable, brittle fracture in specimens of metallic materials containing notches of varying root radii. The approach was successful whatever the micromechanism of crack… More >

J. Sladek¹, V. Sladek, Ch.Zhang²

Structural Durability & Health Monitoring, Vol.1, No.2, pp. 131-144, 2005, DOI:10.3970/sdhm.2005.001.131

Abstract A meshless method based on the local Petrov-Galerkin approach is proposed for crack analysis in two-dimensional (2-d), anisotropic and linear elastic solids with continuously varying material properties. Both quasi-static and transient elastodynamic problems are considered. For time-dependent problems, the Laplace-transform technique is utilized. A unit step function is used as the test function in the local weak-form. It is leading to local boundary integral equations (LBIEs) involving only a domain-integral in the case of transient dynamic problems. The analyzed domain is divided into small subdomains with a circular shape. The moving least-squares (MLS) method is More >

D. Gross¹, T. Rangelov², P. Dineva³

Structural Durability & Health Monitoring, Vol.1, No.1, pp. 35-48, 2005, DOI:10.3970/sdhm.2005.001.035

Abstract Scattering of time harmonic waves by a finite crack in a homogeneous piezoelectric plane under plane strain conditions is studied. Using generalized displacements and tractions, the problem is described by a non-hypersingular traction based boundary integral equation method (BIEM). The fundamental solution is derived in closed form by Radon transforms. As a typical example, the procedure is applied to a straight crack under incident longitudinal waves and under vertically polarized shear waves. The K-factor results are compared with those from the literature for a special case. Furthermore, their dependence on parameters like frequency, angle of More >

Dimitrije Stamenovic´ ¹

Molecular & Cellular Biomechanics, Vol.2, No.2, pp. 69-76, 2005, DOI:10.3970/mcb.2005.002.069

Abstract It is well established that adherent cells change their orientation in response to non-uniform substrate stretching. Most observations indicate that cells orient away from the direction of the maximal substrate strain, whereas in some cases cells also align with the direction of the maximal strain. Previous studies suggest that orientation and steering of the cell may be closely tied to cytoskeletal contractile stress but they could not explain the mechanisms that direct cell reorientation. This led us to develop a simple, mechanistic theoretical model that could predict a direction of cell orientation in response to More >