C. Mapelli¹, A. Manes^1,2, M. Giglio¹, D. Mombelli¹

Structural Durability & Health Monitoring, Vol.9, No.2, pp. 181-199, 2013, DOI:10.32604/sdhm.2013.009.181

Abstract The definition of a complex operative scenario like ballistic damage, that introduces large strains and failure, is a current challenge in the design of critical mechanical components. Aerospace, automotive and manufacturing industries have recently increased their interest in numerical simulations with the long term aim to make these approaches not only reliable enough to reproduce the experimental results but also to provide a trustworthy and effective tool for design. To achieve this aim, the knowledge and calibration of material behaviour is required. Starting from a previous characterization of the constitutive law and ductile failure criterion of Al 6061-T6 aluminium alloy,… More >

F. De Angelis¹

Structural Durability & Health Monitoring, Vol.8, No.4, pp. 341-358, 2012, DOI:10.32604/sdhm.2012.008.341

Abstract The influence of different loading rates on the structural response of elasto/viscoplastic materials is illustrated with specific numerical examples. An associated formulation of the evolutive laws in elasto/viscoplasticity is presented within the framework of the generalized standard material model with internal variables. An appropriate solution scheme is applied which is capable to be adopted for different constitutive models. Different loading programs are analyzed by considering different values of the loading rate and of the intrinsic properties of the material. Computational applications and examples are illustrated which describe the rate-dependency of the elasto/viscoplastic material behavior. The significance of the loading program… More >

D.K. Anding¹

Structural Durability & Health Monitoring, Vol.1, No.2, pp. 95-106, 2005, DOI:10.3970/sdhm.2005.001.095

Abstract The paper deals with the implementation of constitutive equations for isotropic viscoplastic material behaviour into modern Finite Element codes like ABAQUS. ABAQUS provides an user interface called UMAT (USER MATERIAL) for the definition of quite general material behaviour. The user can take advantage of the complete Finite Element code from ABAQUS and has to focus only on the solution of the constitutive equations. Key problems are accuracy and stability of this local solution procedure, which comes from the numerical stiffness of the governing equations (mostly first order ordinary differential equations). The numerical stiffness does not allow to use explicit integration… More >

Orlando J. CASTEJÓN^*

BIOCELL, Vol.39, No.2-3, pp. 33-40, 2015, DOI:10.32604/biocell.2015.39.033

Abstract Twenty one days old Swiss albino mice that received diphenylhydantoin (25 mg/kg, i.p., daily for 15 days) progressively developed gait alterations, changes of behavior and cerebellar ataxia. Cerebellar slices were processed by conventional transmission electron microscopy. The body of Purkinje cells exhibited fragmented limiting plasma membranes, dilated nuclear envelopes, swelling and disassembly of nuclear pores, enlargement of rough and smooth endoplasmic reticulum and a notable detachment of membrane associated ribosomes, together with distorted vacuoles of smooth endoplasmic reticulum, bizarre shaped and swollen mitochondria with dilated cristae, as well as disrupted limiting lysosomal membranes. Degenerated axosomatic synapses apparently corresponding to basket… More >

GLADYS N. HERMIDA, ALEJANDRO FARÍAS, LUISA E. FIORITO

BIOCELL, Vol.26, No.3, pp. 347-355, 2002, DOI:10.32604/biocell.2002.26.347

Abstract The lung of the toad, Melanophryniscus stelzneri stelzneri was studied using scanning and transmission electron microscopy. In M.s.stelzneri the parenchyma forms a polygonal network arrangement, therefore the parenchyma is edicular. These spaces are delimited by the interconnection of third order septa which are covered by respiratory epithelium. Small patches of ciliated epithelium without goblet cells appear irregularly distributed on the septa. The respiratory epithelium consists of one type of pneumocyte, which shows characteristics of both type I and type II alveolar cells of higher vertebrates. The pneumocytes are irregular in shape and possess attenuated cytoplasmic processes, which spread around the… More >

DANIELA CARVALHO DOS SANTOS, ELISA APARECIDA GREGÓRIO

BIOCELL, Vol.26, No.2, pp. 229-235, 2002, DOI:10.32604/biocell.2002.26.229

Abstract The ultrastructure of the ovariole sheath along the Diatraea saccharalis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles of myofilaments that are… More >

JUAN J. LÓPEZ-COSTA, CAROLINA ACUIPIL, PATRICIA TAGLIAFERRO, SAMEER PATEL, JAVIER RAMOS, ALICIA BRUSCO, JORGE PECCI SAAVEDRA*

BIOCELL, Vol.26, No.2, pp. 247-252, 2002, DOI:10.32604/biocell.2002.26.247

Abstract NADPH-diaphorase is a useful technique to reveal NO producing neurons at light microscopic level (LM). A modification of the technique using the tetrazolium salt BSPT as susbtrate, is useful to study the ultrastructure of NO neurons. The aim of this work was to perform a detailed analysis of NADPH diaphorase reactive neurons in rat mesencephalon both at light and electron microscopic levels.
NADPH-diaphorase reactive neurons were observed in superior colliculus, in central gray matter, in dorsal and medial raphe and in the pedunculopontine tegmental nucleus using two histochemical techniques at LM. Electron microscopy showed deposits on membranes of the… More >

Ning Li^{1, 2, 3}, Xiao Zhang^{1, 2}, Peiwen Li^{1, 2}, Hao Yang^{1, 2}, Chunfang Tong^{1, 2}, Shouqin Lü^{1, 2}, Yan Zhang^{1, 2}, Zhiyi Ye³, Jun Pan^{3, *}, Mian Long^{1, 2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 263-279, 2018, DOI:10.31614/cmes.2018.04079

Abstract Neutrophil (PMN) accumulation on liver sinusoidal endothelial cells (LSECs) is crucial to pathogen clearance and tissue damage in the liver sinusoids and controlled by a series of adhesion molecules expressed on the surface of PMNs and LSECs. The role of lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1) in this process is still contentious. Here we compared the dynamic force spectra of the binding of β2 integrin to intercellular adhesion molecule-1 (ICAM-1) on LSECs using atomic force microscopy (AFM) and performed free and steered molecular dynamics (MD) simulations to analyze their structural bases of LFA-1- or Mac-1-I-domain and ICAM-1-D1 or… More >

Ibtissem Moussa^1,2, Ramzi Khiari^1,3,4,*, Ali Moussa², Gérard Mortha⁴, Mohamed Farouk Mhenni¹

Journal of Renewable Materials, Vol.7, No.4, pp. 345-354, 2019, DOI:10.32604/jrm.2019.04011

Abstract The most abundant phenolic biopolymer in the biosphere is the lignin. This phenolic biopolymer commonly exists in combination with polysaccharides and other cell wall components. In this study, the solvent system dioxane-water is used to extract lignin, which is considered as unaltered native lignin. The dioxane lignin extracted from fig stems was characterized regarding to its structural feature, quantification of its functional groups, molecular weight, and evaluation of its thermal properties. Purity and molecular weight distribution of the studied lignin indicated that isolated lignin contained a low amount of sugar (c.a. 19%) and had a high weight-average molecular weight (10… More >

R. C. Lee¹, F. Despa¹, X. Tang¹, I. Titushkin², M. Cho²

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 185-186, 2006, DOI:10.32604/mcb.2006.003.185

Abstract This article has no abstract. More >