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  • Open Access

    ARTICLE

    Organogenesis and plant regeneration of Arachis villosa Benth. (Leguminosae) through leaf culture

    MARÍA LAURA FONTANA, LUIS AMADO MROGINSKI, HEBE YOLANDA REY*

    BIOCELL, Vol.33, No.3, pp. 179-186, 2009, DOI:10.32604/biocell.2009.33.179

    Abstract With the aim of developing an efficient plant regeneration protocol, leaflet explants of three accessions of Arachis villosa Benth. (S2866, S2867 and L97) were cultured on basic Murashige and Skoog medium supplemented with different combinations of plant growth regulators: α-naphthalenacetic acid, indole-3-butyric acid, 6-benzylaminopurine, kinetin and thidiazuron. The accession L97 was the only one able to differentiate buds through indirect organogenesis. The most suitable combination for bud regeneration was the basic medium added with 13.62 μM thidiazuron and 4.44 μM 6-benzylaminopurine. These results show the important role of the genotype in morphogenetic responses and the organogenetic effect of More >

  • Open Access

    ARTICLE

    Leaf blade anatomy and ultrastructure of six Simira species (Rubiaceae) from the Atlantic Rain Forest, Brazil

    TARSILA MARIA DA SILVA MORAES1, CLAUDIA FRANCA BARROS2, SEBASTIÃO JOSÉ DA SILVA NETO3, VALDIRENE MOREIRA GOMES4, MAURA DA CUNHA1*

    BIOCELL, Vol.33, No.3, pp. 155-165, 2009, DOI:10.32604/biocell.2009.33.155

    Abstract Simira is a predominantly woody Neotropical genus comprising 41 taxa, 16 of which occur in Brazil and eight of them in the southeastern region of Brazil. Leaf blades of Simira eliezeriana Peixoto, S. glaziovii (K. Schum.) Steyerm., S. grazielae Peixoto, S. pikia (K. Schum.) Steyerm., S. rubra (Mart.) Steyerm., S. sampaioana (Standl.) Steyerm. were collected in the southeastern region of Brazil and fixed according to usual methods for light and electron microscopy. The leaf blades show typical characteristics of the Rubiaceae family as dorsiventral mesophyll and paracytic stomata. The presence of two bundle sheaths that extend to the upper epidermal layer, More >

  • Open Access

    ABSTRACT

    The structure of BaZrO$_3$: a comparative first-principles study

    AnteBilić1

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.1, pp. 13-14, 2009, DOI:10.3970/icces.2009.013.013

    Abstract Using several popular first-principles packages for materials modeling the nature of the cubic lattice of barium zirconate has been investigated. The evaluated vibrational spectra typically exhibit an extended and prominent dynamical instability. The instability manifests through imaginary frequency optical modes along the whole R-M edge of the Brillouin zone. The experimentally observed simple cubic structure is found to be dynamically unstable against an antiferro-distortive transformation. The computations predict an orthorhombic crystal structure of the material, only slightly distorted from the cubic lattice, with an eight times larger unit cell and alternate ZrO6 octahedra slightly rotated in More >

  • Open Access

    ARTICLE

    DNA mismatch repair gene methylation in gastric cancer in individuals from northern Brazil

    ELEONIDAS MOURA LIMA1,2, MARIANA FERREIRA LEAL3, MARÍLIA DE ARRUDA CARDOSO SMITH3, ROMMEL RODRÍGUEZ BURBANO4, PAULO PIMENTEL DE ASSUMPÇÃO5, MARIA JOSE BELLO6, JUAN ANTONIO REY6, FRANCINALDO FERREIRA DE LIMA7, CACILDA CASARTELLI2

    BIOCELL, Vol.32, No.3, pp. 237-243, 2008, DOI:10.32604/biocell.2008.32.237

    Abstract Gastric cancer is one of the most common malignancies. DNA methylation is implicated in DNA mismatch repair genes deficiency. In the present study, we evaluated the methylation status of MLH1, MSH2, MSH6 and PMS2 in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosal of gastric cancer patients from Northern Brazil. We found that none of the nonneoplastic samples showed methylation of any gene promoter and 50% of gastric cancer samples showed at least one methylated gene promoter. Methylation frequencies of MLH1, MSH2, MSH6 and PMS2 promoter were 21.74%, 17.39%, 0% and 28.26% respectively… More >

  • Open Access

    ARTICLE

    Morphologic and morphometric analysis of testis of Pseudis limellum (Cope, 1862) (Anura, Hylidae) during the reproductive cycle in the Pantanal, Brazil

    ADELINA FERREIRA1, MAHMOUD MEHANNA1,2, CYNTHIA P. A. PRADO3

    BIOCELL, Vol.32, No.2, pp. 185-194, 2008, DOI:10.32604/biocell.2008.32.185

    Abstract The spermatogenesis of Pseudis limellum, from the Southern Pantanal, Brazil, was studied from July 1995 to May 1996, through histological sections of the testis. The cells could be differentiated as: primary spermatogonia, large cells, generally with bilobed nucleus; secondary spermatogonia, smaller cells, with darker cytoplasm, chromatin of radial form; primary and secondary spermatocytes, differentiated according to the different stages of the nucleus during the successive cells divisions. Furthermore, we observed cells in process of morphologic differentiation: rounded spermatids much smaller, with nucleus containing chromatin in compacting process and cytoplasm reduction; elongated spermatids, generally parallel organized in… More >

  • Open Access

    ARTICLE

    Evaluation of Seismic Design Values in the Taiwan Building Code by Using Artificial Neural Network

    Tienfuan Kerh1,2, J.S. Lai1, D. Gunaratnam2, R. Saunders2

    CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 1-12, 2008, DOI:10.3970/cmes.2008.026.001

    Abstract Taiwan frequently suffers from strong ground motion, and the current building code is essentially based on two seismic zones, A and B. The design value of horizontal acceleration for zone A is 0.33g, and the value for zone B is 0.23g. To check the suitability of these values, a series of actual earthquake records are considered for evaluating peak ground acceleration (PGA) for each of the zones by using neural network models. The input parameters are magnitude, epicenter distance, and focal depth for each of the checking stations, and the peak ground acceleration is calculated… More >

  • Open Access

    ARTICLE

    Decrease of intestinal tumors induced by 1,2-dimethylhydrazine in rats fed with cow milk and buffalo milk

    M. Sánchez Negrette, M.A. Montenegro, M.S. Catuogno, W.J. Lértora, M.C. Guanziroli

    BIOCELL, Vol.31, No.3, pp. 391-396, 2007, DOI:10.32604/biocell.2007.31.391

    Abstract Epidemiological studies in human beings and experimental studies in laboratory animals suggest that milk and dairy products can inhibit effects on the development of some kinds of tumors. Cow milk contains sphingomyelin, butyric acid, conjugated linoleic acid, calcium, vitamin A, carotene and vitamin D. All of these components are known to inhibit the process of carcinogenesis. Our objective was to determine the effect of cow milk and water buffalo milk on the development of colon neoplasias in an experimental model of carcinogenesis in rats induced with 1,2-dimethylhydrazine (DMH). Three-month-old Wistar male rats with an average… More >

  • Open Access

    ARTICLE

    Cased Hole Flexural Modes in Anisotropic Formations

    Ping’en Li1, Xianyue Su1,2, Youquan Yin1

    CMC-Computers, Materials & Continua, Vol.6, No.2, pp. 93-102, 2007, DOI:10.3970/cmc.2007.006.093

    Abstract Based on the perturbation method, for flexural wave in cased hole in anisotropic formation, the alteration in the phase velocity caused by the differences in elastic constants between anisotropic formation of interest and a reference, or unperturbed isotropic formation is obtained. Assuming the cased hole is well bonded, the Thomson-Haskell transfer matrix method is applied to calculate the dispersion relation of flexural wave in cased hole in unperturbed isotropic formation. Both the cases of a fast and slow formation are considered where the symmetry axis of a transversely isotropic (TI) formation makes an angle with… More >

  • Open Access

    ABSTRACT

  • Open Access

    ARTICLE

    In vitro multiplication of the Piñón Azul Pinus maximartinezii (Rzedowski)

    Ojeda-Zacarías1 Ma del Carmen, Hugo A Luna-Olvera2, Lilia H Morales-Ramos2, María J Verde-Star2, Teresa E Torres-Cepeda2, Benito Pereyra-Alférez2, Leobardo Iracheta-Donjuan3, Emilio Olivares-Sáenz4, Raúl Salazar-Sáenz4, Elizabeth Cárdenas-Cerda4

    Phyton-International Journal of Experimental Botany, Vol.75, pp. 109-113, 2006, DOI:10.32604/phyton.2006.75.109

    Abstract Pinus maximartinezii (Rzedowski) is an endemic endangered species, confined to a single population of approximately 2000 to 2500 mature trees. It covers about 400 ha in southern Zacatecas, Mexico. The success of tissue culture techniques for germplasm preservation depends on regeneration of cultures. The objective of this study was to achieve an in vitro proliferation protocol using organogenesis technique for Pinus maximartinezii. Mature seeds were surface sterilized in 6% H2O2 v/v. Isolated cotyledons and zygotic embryos were cultured on shoot induction media. DCR and GD media were supplemented with 0.3 and 0.5 mgl-1 BAP; 0.01 mgl-1 ANA and More >

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