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 | Acesso ao texto completo restrito à biblioteca da Embrapa Caprinos e Ovinos. Para informações adicionais entre em contato com cnpc.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
05/06/2023 |
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Autoria: |
RANDALL, J. T.; FRIEDLAENDER, M. H. G. |
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Título: |
The microstructure of ram spermatozoa. |
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Ano de publicação: |
1950 |
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Fonte/Imprenta: |
Experimental Cell Research, v. 1, n. 1, p. 1-32, 1950. |
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DOI: |
https://doi.org/10.1016/0014-4827(50)90046-2 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: The microstructure of the mature ram spermatozoon has been investigated by means of the electron microscope, and has been supplemented by preliminary optical studies. Various fixatives and stains were employed, and extensive use was made of ultrasonics as a means of partial disintegration. The results indicate a more complex structure than has yet been found for other mammalian spermatozoa. The investigation included an examination of the membrane system of the head, and various features such as the equatorial segment, the acrosome cap, the innermost membrane and structures underlying it. The evidence for a skeletal framework of the sperm-head was also discussed. The axial-fibre was found to consist of 12 fibrils, each of which is made up of two filaments surrounded by a doublet coil. The suggestion was put forward that a fibril bundle consisting of 3 pairs of fibrils runs down the whole length of the tail. The main-piece itself was shown to be surrounded by a doublet helix; the tail-end consisted of modified fibrils of the axialfibre, surrounded by a fine doublet-helix of its own. Considerable attention was given to the middle-piece structure where three systems of helices were identified. The complexity of the neck structure was investigated; the junction of the head and middle-piece was found to be partly fibrillar, and partly fibrous and membranous. The continuity of the fibrils from the middle-piece and the fibrils which disappear into the head was established. Provisional membrane systems were described for middle-piece, tail, and tail-end. MenosAbstract: The microstructure of the mature ram spermatozoon has been investigated by means of the electron microscope, and has been supplemented by preliminary optical studies. Various fixatives and stains were employed, and extensive use was made of ultrasonics as a means of partial disintegration. The results indicate a more complex structure than has yet been found for other mammalian spermatozoa. The investigation included an examination of the membrane system of the head, and various features such as the equatorial segment, the acrosome cap, the innermost membrane and structures underlying it. The evidence for a skeletal framework of the sperm-head was also discussed. The axial-fibre was found to consist of 12 fibrils, each of which is made up of two filaments surrounded by a doublet coil. The suggestion was put forward that a fibril bundle consisting of 3 pairs of fibrils runs down the whole length of the tail. The main-piece itself was shown to be surrounded by a doublet helix; the tail-end consisted of modified fibrils of the axialfibre, surrounded by a fine doublet-helix of its own. Considerable attention was given to the middle-piece structure where three systems of helices were identified. The complexity of the neck structure was investigated; the junction of the head and middle-piece was found to be partly fibrillar, and partly fibrous and membranous. The continuity of the fibrils from the middle-piece and the fibrils which disappear into the head was established... Mostrar Tudo |
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Palavras-Chave: |
Histofisiologia; Histophysiology. |
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Thesagro: |
Espermatozóide; Ovino; Reprodução. |
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Thesaurus Nal: |
Rams; Reproduction; Sheep; Spermatozoa. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02274naa a2200253 a 4500
001 1521943
005 2023-06-05
008 1950 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1016/0014-4827(50)90046-2$2DOI
100 1 $aRANDALL, J. T.
245 $aThe microstructure of ram spermatozoa.$h[electronic resource]
260 $c1950
520 $aAbstract: The microstructure of the mature ram spermatozoon has been investigated by means of the electron microscope, and has been supplemented by preliminary optical studies. Various fixatives and stains were employed, and extensive use was made of ultrasonics as a means of partial disintegration. The results indicate a more complex structure than has yet been found for other mammalian spermatozoa. The investigation included an examination of the membrane system of the head, and various features such as the equatorial segment, the acrosome cap, the innermost membrane and structures underlying it. The evidence for a skeletal framework of the sperm-head was also discussed. The axial-fibre was found to consist of 12 fibrils, each of which is made up of two filaments surrounded by a doublet coil. The suggestion was put forward that a fibril bundle consisting of 3 pairs of fibrils runs down the whole length of the tail. The main-piece itself was shown to be surrounded by a doublet helix; the tail-end consisted of modified fibrils of the axialfibre, surrounded by a fine doublet-helix of its own. Considerable attention was given to the middle-piece structure where three systems of helices were identified. The complexity of the neck structure was investigated; the junction of the head and middle-piece was found to be partly fibrillar, and partly fibrous and membranous. The continuity of the fibrils from the middle-piece and the fibrils which disappear into the head was established. Provisional membrane systems were described for middle-piece, tail, and tail-end.
650 $aRams
650 $aReproduction
650 $aSheep
650 $aSpermatozoa
650 $aEspermatozóide
650 $aOvino
650 $aReprodução
653 $aHistofisiologia
653 $aHistophysiology
700 1 $aFRIEDLAENDER, M. H. G.
773 $tExperimental Cell Research$gv. 1, n. 1, p. 1-32, 1950.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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Registro Completo
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Biblioteca(s): |
Embrapa Hortaliças. |
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Data corrente: |
25/01/2022 |
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Data da última atualização: |
26/01/2022 |
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Tipo da produção científica: |
Boletim de Pesquisa e Desenvolvimento |
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Autoria: |
ALMEIDA, J. M. de; HABER, L. L.; SILVA, H. R. da; RESENDE, F. V. |
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Afiliação: |
JOANDERSON MENDES DE ALMEIDA, SECRETARIA MUNICIPAL DE AGRICULTURA E ABASTECIMENTO, PICOS, PI.; LENITA LIMA HABER, CNPH; HENOQUE RIBEIRO DA SILVA, SPD; FRANCISCO VILELA RESENDE, CNPH. |
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Título: |
Avaliação agronômica, conservação e qualidade pós-colheita de variedades de alho precoces livres de vírus na região do semiárido piauiense. |
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Ano de publicação: |
2022 |
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Fonte/Imprenta: |
Brasília, DF: Embrapa Hortaliças, 2022. |
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Série: |
(Embrapa Hortaliças. Boletim de pesquisa e desenvolvimento, 249). |
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ISSN: |
1677-2229 |
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Idioma: |
Português |
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Conteúdo: |
Este trabalho teve por objetivo avaliar o desempenho agronômico, conservação e qualidade pós-colheita de bulbos de variedades de alho precoce livres de vírus na região de Picos (PI). |
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Thesagro: |
Alho; Allium Sativum; Armazenamento; Características Agronômicas; Conservação; Genótipo; Produtividade. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/230497/1/BPD-249-Final-2.pdf
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Marc: |
LEADER 01021nam a2200253 a 4500
001 2139306
005 2022-01-26
008 2022 bl uuuu u0uu1 u #d
022 $a1677-2229
100 1 $aALMEIDA, J. M. de
245 $aAvaliação agronômica, conservação e qualidade pós-colheita de variedades de alho precoces livres de vírus na região do semiárido piauiense.$h[electronic resource]
260 $aBrasília, DF: Embrapa Hortaliças$c2022
490 $a(Embrapa Hortaliças. Boletim de pesquisa e desenvolvimento, 249).
520 $aEste trabalho teve por objetivo avaliar o desempenho agronômico, conservação e qualidade pós-colheita de bulbos de variedades de alho precoce livres de vírus na região de Picos (PI).
650 $aAlho
650 $aAllium Sativum
650 $aArmazenamento
650 $aCaracterísticas Agronômicas
650 $aConservação
650 $aGenótipo
650 $aProdutividade
700 1 $aHABER, L. L.
700 1 $aSILVA, H. R. da
700 1 $aRESENDE, F. V.
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