M. I. ROSATTI, M. T. BECONI, M. CÓRDOBA

BIOCELL, Vol.28, No.3, pp. 311-316, 2004, DOI:10.32604/biocell.2004.28.311

Abstract Acrosin activity is associated with normal fertility in human and bovine spermatozoa. The aim of the study was to determine the variation of the enzyme activity in the proacrosin-acrosin system in capacitated and acrosome reacted cryopreserved bovine sperm. Enzyme activity was assessed spectrophotometrically using N-α-benzoyl-DL-arginine p-nitroanilide (BAPNA) as specific substrate for acrosin at pH 8. Capacitation with heparin and quercitin failed to induce conversion of proacrosin to acrosin. An increase in acrosin activity produced by the presence of progesterone, in a dose-dependent manner, was related with the induction of true acrosome reaction. The total level of acrosin activity registered showed… More >

ROMINA J. BEVACQUA, RAFAEL FERNANDEZ-MARTIN, DANIEL F. SALAMONE

BIOCELL, Vol.35, No.1, pp. 1-7, 2011, DOI:10.32604/biocell.2011.35.001

Abstract Parthenogenetic embryos are an ethically acceptable alternative for the derivation of human embryonic stem cells. In this work, we propose a new strategy to produce bovine parthenogenetic embryos inhibiting the emission of the first polar body during in vitro maturation, and allowing the extrusion of the second polar body during oocyte activation. Cytochalasin B, an inhibitor of actin microfilaments, was employed during in vitro maturation to inhibit first polar body emission or during parthenogenetic activation to block second polar body emission. Only one polar body was inhibited in each strategy in order to keep the diploid chromosome set. In experiment… More >

Longjia Li^1,2, Tianbao Qian^2,3, Fei Hang^{1, 2, *}

Molecular & Cellular Biomechanics, Vol.14, No.4, pp. 221-234, 2017, DOI:10.3970/mcb.2017.014.221

Abstract Bone is an important natural hierarchical biomaterial which supports human body and protect organs. Its mechanical property has been researched extensively. In this experimental work, 3D microscope and scanning electron microscope (SEM) were used to research crack expansion on bovine femur cortical bone transverse section. Softwares such as image J and Photoshop were used in image and data analyses. Our results suggested that the interface energy of extending through osteons is smaller than the interface energy of extending along cement lines. Cracks are more likely to extend through osteons. Further investigations are needed to reduce errors and validate our findings. More >