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| Registros recuperados: 155 | |
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| Silva-Briano,Marcelo; Martínez-Hernández,Sandra Luz; Adabache-Ortíz,Araceli; Ventura-Juárez,Javier; Salinas,Eva; Quintanar,J. Luis. |
| Syntaxin-1 and 25-kDa Synaptosome-associated Protein (SNAP-25) are present in the plasma membrane of several different secretory cell types and are involved in the exocytosis process. In this work, the free-living amoeba Difflugia corona was studied in relation to ultrastructure, structural membrane proteins, and proteins such as Syntaxin-1 and SNAP-25. Our results obtained by scanning electron microscopy in the amoeba without its theca, showed many membrane projections and several pore-like structures. Using immunocytochemistry, we found structural proteins Syntaxin-1 and SNAP-25. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amoeba; Membrane proteins; Pore-like; Theca; Ultrastructure. |
| Ano: 2007 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452007000200004 |
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| Aquino Luque,Maria Carolina; Báo,Sônia Nair. |
| The ultrastructure of normal, ejaculated spermatozoa of Bos indicus was studied by means of electron microscopy, being evaluated in two principal parts, the head and the tail. The head is flat, oval or paddle-shaped with a square base, which provides a concave recess for the insertion of the tail. The acrosome tightly covers the anterior two thirds of the nucleus. A distinct unilateral acrosomal bulge was observed along the apical edge of the head. The equatorial region demarcates the acrosome from the post-equatorial region that covers the caudal one third of the nucleus. The classical 9+9+2 fiber pattern which composes the axoneme was observed along three segments of the tail, namely middle, principal and terminal pieces. The axoneme is anteriorly bound... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spermatozoon; Ultrastructure; Bos indicus. |
| Ano: 2006 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452006000100005 |
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| Mancini,Karina; Dolder,Heidi. |
| This study was undertaken to detect protein components in both sperm types of the butterfly Euptoieta hegesia. These spermatozoa possess complex extracellular structures for which the composition and functional significance are still unclear. In the apyrene sperm head, the proteic cap presented an external ring and an internal dense content; basic proteins were detected only in external portions. In the tail, the paracrystalline core of mitochondrial derivatives and the axoneme are rich in proteins. The extratesticular spermatozoa are covered by a proteic coat, which presented two distinct layers. In eupyrene spermatozoa, acrosome and nucleus were negatively stained, probably because of their high compaction. In the tail, there is no paracrystalline core... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ultrastructure; Protein; Apyrene; Eupyrene. |
| Ano: 2004 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452004000300006 |
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| Sousa,Liliana G.; Cuartas,Elena I.; Petriella,Ana María. |
| 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 tubules, a central area with the nucleus and RER, and a basal area containing a sER-like tubule system and mitochondria. B-cells were observed at different... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crustacea; Caridea; Hepatopancreas; Ultrastructure. |
| Ano: 2005 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452005000100004 |
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| LIU,ZHAO; YI-SONG,LI; JUN-GANG,LI; FU-KANG,GU. |
| In order to reveal the differentiation characteristics of organelles of ciliates under different physiological status, the cellular ultrastructure of Urostyla grandis was studied by transmission electron microscopy. In the resting cells most ciliary shafts, kinetosomes and sub-pellicle microtubules were resorbed, and the endoplasmic reticulum (ER) disappeared with the autophagocytosis taking place within the cytoplasm. As well, the nuclear matrix of the macronucleus was extruded into the cytoplasm, forming pseudopodia-like structures with large quantities of heterochromatin (CH) attached to the inner nuclear membrane. During excystment, membraneous structures developed and gradually increased in number to form the ER. Autophagic vacuoles (AVs) appeared... |
| Tipo: Journal article |
Palavras-chave: Urostyla grandis; Ultrastructure; Vegetative cell; Resting cell; Excysting cell. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602009000400001 |
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| Deniz Koç,Nazan; Yüce,Rikap. |
| In sexually reproducing organisms, primordial germ cells (PGCs) give rise to the cells of the germ line, the gametes. In many animals, PGCs are set apart from somatic cells early during embryogenesis. This study explores the origin of primordial germ cells (PGCs) of the zebra fish and examines their morphology during early development (1st day-15th day). PGCs were selectively stained by the alkaline phosphatase histochemical reaction and viewed by light and electron microscopy from the time they are first detectable in the yolk sac endoderm. PGCs occurred in the subendodermal space on the syncytial periblast; differing from the surrounding endodermal cells. Later the PGCs moved to between the blastoderm and yolk sac and transferred to the dorsal mesentery... |
| Tipo: Journal article |
Palavras-chave: Primordial germ cell; Zebra fish; Ultrastructure; Morphology. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602012000400001 |
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| Medeiros,Gabriela; Amaral,Mailor Wellinton Wedig; Ferreira,Paula Carolina; Ludwig,Thelma Veiga; Bueno,Norma Catarina. |
| Abstract: Gomphonema Ehrenberg is a genus well represented in periphytic algal flora of epicontinental environments. The substrate colonization is facilitated by the secretion of mucilage by the pore field, allowing cell adhesion. Samples were scraped off and analyzed from vegetative portions of the macrophyte Eichhornia azurea Kunth, collected in São Francisco Falso River, located in Santa Helena City, Paraná State. The sampling occurred in four different sites, in four different periods, totaling 16 samples. The quantitative material analysis resulted in 28 identified taxa, in which Gomphonema brasiliense ssp. pacificum, Gomphonema neoapiculatum Lange-Bertalot, Reichardt & Metzeltin Gomphonema pantropicum Reichardt and Gomphonema perapicatum... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lotic environment; Diatoms; Taxonomy; Ultrastructure. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032018000300205 |
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| Ramos Giacosa,Juan P; Morbelli,Marta A; Giudice,Gabriela E. |
| The spores of Schizaea fistulosa from Chile were studied using light microscopy (LM), scanning (SEM) and transmission electron microscopy (TEM). The spores are monolete and elliptic in polar view. The major equatorial diameter is 71-85 µm and the polar diameter is 54-61 µm. The laesurae are 50-60 µm long and, in some cases, bifurcated. The sporoderm ultrastructure is first mentioned and described here. The exospore is two-layered in section, verrucate-tuberculate with single or fused elements forming short ridges. The perispore is single-layered, 10-30 nm thick and it is only visible under transmission electron microscopy. On the spore surface, numerous, single or fused, spheroids and nanospheroids of different sizes were observed attached to the perispore... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Schizaeaceae; Schizaea fistulosa; Spores; Morphology; Ultrastructure. |
| Ano: 2015 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-23722015000100003 |
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| Sajo,Maria das Graças; Machado,Silvia Rodrigues. |
| The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Xyris; Ultrastructure; Leaf. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000400011 |
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| Ninhaus-Silveira,Alexandre; Foresti,Fausto; Veríssimo-Silveira,Rosicleire; Senhorini,José Augusto. |
| Aiming to improve fish reproduction techniques, the characterization and cryopreservation of semen of Brycon cephalus were performed. The seminal characteristics observed were: an almost transparent, milky semen with a mean volume of 4mL, and sperm concentration of 9.617±1.630 x 10(6) spermatozoa/mm³. Spermatozoa (length = 31.288 ±4.47µm) were of the aquasperm type and displayed a small, round head (length = 1.727 ±0.18 µm; width = 1.752 ±0.17µm) without acrosomal vesicle, nucleus with highly condensed chromatin forming coarse clots and centriolar complex located in the nuclear fossa; a midpiece (length = 2.561±0.44µm), narrowed rearward, with a cytoplasmic canal; and a flagellum (length = 29.521 ±4.37µm). Fertilization tests with thawed semen demonstrated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Semen characteristics; Cryopreservation; Brycon cephalus; Ultrastructure; Fish. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000500015 |
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| Registros recuperados: 155 | |
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