Consulta: subjectFacets:"TEM"
Registros recuperados: 17
Data/hora: 07/06/2024 00:31:41

Les virus de l'estuaire de la Charente el du bassin de Marennes-Oleron. Dynamiques spatio-temporelles et  interactions avec les communautés bactériennes
Provedor de dados: 5
Autores: Auguet, Jean-christophe.
This study is divided in two parts; one aim is to evaluate the in situ spalio-temporal dynamics of viral communities  in the Charante estuary in order to define the appropriate seasons to conduct in vitro viral enrichment experiments. These experiments, that constitute the second part of this study, were performed to assess the impact of freshwater viruses carried by the Charante River on the dynamics and composition of coastal bacterial communities. With abundance ranging from 1.4 x 107 to 208 x I07 VLPml-1. viruses are the most abundant component among plankton microorganisms in surface waters of the Charente estuary. Thre temporal dynamics of this component reflects the indirect influence of temperature through the control of bacterial abundance,...
Tipo: Text
Palavras-chave: Richesse spécifique; Composition clonale; Enrichissement vital; Infection lyrique; Structure des communautés; MET; PPGE; Dynamique temporelle; Gradient de salinité; Estuaire; Bactérioplancton; Virioplancton; Species richness; Clonal composition; Viral enrichment; Lytic infection; Community structure; Diversity; TEM; PEGE; Temporal dynamic; Gradient; Salinity; Estuary; Bacterioplankton; Virioplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-3071.pdf

Elemental composition of individual pico- and nano-sized marine detrital particles in the northwestern Mediterranean Sea
Provedor de dados: 5
Autores: Mostajir, B; Fagerbakke, Km; Heldal, M; Thingstad, Tf; Rassoulzadegan, F.
The elemental composition of individual &lt; 10 mu m detrital particles from Mediterranean surface waters was analysed using a Transmission Electron Microscope (TEM) equipped with an energy dispersive X-Ray microanalyser. Results show that carbon and phosphorus content per detritus volume are much higher in pico-detrital particles &lt; 2 mu m (42 kg C m(-3) and 1 kg P m(-3)) than in 5-10 mu m detrital particles (20 kg C m-3 and 0.1 kg P m(-3)). The C:N:P atomic ratios for different sized fractions of the detrital particles were found to be 82:10:1 for &lt; 2 mu m particles, 120:29:1 for 2-5 mu m particles and 308:37:1 for 5-10 mu m particles. The average ratio for all size classes of detrital particles (&lt; 10 mu m) was 132:23:1. The differences in...
Tipo: Text
Palavras-chave: Détritus; Composition élémentaire; Microscope électronique à transmission; Rayons X; Méditerranée; Detritus; Elemental composition; TEM; X-ray; Mediterranean.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43661/43208.pdf

Ultrastructure of the Myelinated and Unmyelinated Nerve Fibers of the Tongue Mucosa of Albinus Rat (Wistar) with Aging
Provedor de dados: 77
Autores: Grisolia,D. F.; Ogawa,K; Motoyama,A.A.; Kronka,M. C.; Carneiro Jr.,J. T.; Duro,C. C.; Watanabe,I.
The purpose of this paper was to study the sensory myelinated and unmyelinated nerve fibers found in the subepithelial lamina propria of tongue mucosa of aging rats. It was used the silver impregnation, transmission electron microscopy methods and morphometric measurements. The results revealed that subepithelial nerve fiber bundles of the anterior, medium and posterior regions of tongue were arise from deep muscular layer of tongue. The nerve fiber bundles were verified inside of the connective tissue of lamina propria. These nerve fibers branched several times and into the connective tissue papillae they form a single or ramified sensory nerve endings. The fungiform and vallate papillae contain numerous nerve terminals. The fine structure demonstrated...
Tipo: Journal article
Palavras-chave: Nerve fiber; Myelinated fiber; Unmyelinated fiber; Tongue mucosa; Aging rat; TEM.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000400018

Morphometric and High Resolution Scanning Electron Microscopy Study of Calomys callosus Major Palatine Nerve
Provedor de dados: 77
Autores: Tanisaki,Maurício; Ogawa,Koichi; Lapa,Rita de Cássia Ribeiro da Silva; da Silva,Marcelo Cavenaghi Pereira; Watanabe,Ii-sei.
The characteristics of Calomys callosus major palatine nerve were studied employing light, transmission and high resolution scanning electron microscopy methods. For light microscopy, the specimens were fixed in Bouin's fixative solution, processed routinely and the sections were stained with hematoxylin­eosin and Azo-Carmin to identify nerve fibers. For high resolution scanning electron microscopy the O-D-O method reported by &lt;a href="#13"&gt;Tanaka (1989)&lt;/a&gt; was used to examine nerve fiber components and to measure the myelin sheath. Thin sections were examined by transmission electron microscopy to show axoplasmic elements and adjacent structures. The results revealed nerve fiber bundles in the lamina propria of Calomys callosus palatine...
Tipo: Journal article
Palavras-chave: Major palatine nerve; HRSEM; TEM; Calomys callosus; Myelin sheath; Morphometric.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022005000100003

Metformin Induces Ultrastructural Alterations in Hepatocytes of Spontaneously Hypertensive Rats
Provedor de dados: 77
Autores: Gharbaran,Rajendra.
Metformin, an oral biguanide approved for the treatment of type II diabetes is widely prescribed for other clinical conditions. Currently, metformin is being investigated as potential anti-tumor agent. However, there have been recent concerns about hepatotoxicity associated with the use of metformin. This study, by means of high resolution transmission electron microscopy (TEM) and morphometry, investigated potential ultrastructural changes induced by metformin treatment on the hepatocytes of spontaneously hypertensive rats (SHR). Morphometric analysis was carried out on images of randomly selected cells from sectioned gluteraldehyde-osmium-fixed, Epon embedded liver tissue. One-way analysis of variance (ANOVA) on morphometric data showed statistically...
Tipo: Journal article
Palavras-chave: Metformin; Rats; TEM; Cancer; Diabetes.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022014000300016

The Morphological Effects of Asthma, As Well As Conventional and Alternative Asthma Therapies on Parietal and Chief Cells in the Stomach of BALB/c Mice
Provedor de dados: 77
Autores: Vieira,Warren Antonio; Oberholzer,Hester Magdalena; Pretorius,Etheresia.
Scientific literature, although limited in this area, supports the hypothesis that asthma, by means of selective leukocyte trafficking between the various mucosal and glandular sites of the body, can have the same pathophysiological effects on the stomach as the airways. This study aimed to determine if asthma, in the absence and presence of various asthma therapies (Hydrocortisone and Modul8TM), imparted any morphological alteration on the stomach parietal and chief cells. The BALB/c murine asthmatic mouse model was the model of choice in this study. The asthma induction protocol as well as the asthma therapies were proved to be effective with the aid of bronchial lavage fluid leukocyte quantification. Fundic and pyloric biopsies were extracted at...
Tipo: Journal article
Palavras-chave: Fundus; Pylorus; Hypertrophy; Hypersecretion; TEM.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000400046

Palynotaxonomy of the genus Gladiopappus (Dicomeae, Asteraceae) with special emphasis on the exine ultrastructure and mesoapertures
Provedor de dados: 16
Autores: Pereira Coutinho, A.; Sá da Bandeira, D.; Currais, L.; Soukiazes, E.; Ortiz, S.
The pollen morphology of Gladiopappus vernonioides was studied with transmission (TEM) and scanning (SEM) electron microscopy and with light microscopy (LM). An Anthemoid pattern of exine ultrastructure was found. The pollen morphology of Gladiopappus supports the inclusion of this genus in the tribe Dicomeae and subtribe Dicominae but not in the Mutisieae s.str. The apertural system of G. vernonioides includes a mesoaperture that intersects the foot layer and the upper layer of the endexine, a condition already pointed out for several tribes of Asteroideae (Helenieae, Gnaphaliinae, Heliantheae, Inuleae, Senecioneae) and Carduoideae (Cardueae, Dicomeae). It is suggested that the existence of an intermediate aperture could characterize the apertural system...
Tipo: Article / Letter to the editor
Palavras-chave: Dicomeae; Exine; LM; Mutisieae; Pollen; SEM; TEM.
Ano: 2018
URL: http://www.repository.naturalis.nl/record/655821

Palynological Variation in Balsaminoid Ericales. I. Marcgraviaceae
Provedor de dados: 16
Autores: Lens, F.; Dressler, S.; Vinckier, S.; Janssens, S.; Dessein, S.; Van Evelghem, L.; Smets, E.
Background and Aims Marcgraviaceae are a rather small family of seven genera and approx. 130 neotropical species. This study aims to present a detailed palynological survey of the family in order to comment on the intrafamily relationships and possible correlations with pollinators. Methods In total, 119 specimens representing 67 species and all genera are observed using light microscopy and scanning electron microscopy. Furthermore, eight species from five genera are studied with transmission electron microscopy.  Key Results Our results show that pollen grains of Marcgraviaceae are small (20–35 mm), have three equatorial apertures, granules on the colpus membrane, oblate spheroidal to prolate spheroidal shapes, mainly psilate to perforate ornamentations,...
Tipo: Article / Letter to the editor
Palavras-chave: Balsaminoids; Ericales; Marcgraviaceae; Neotropics; Orbicules; Palynology; SEM; TEM.
Ano: 2005
URL: http://www.repository.naturalis.nl/record/407283

Palynological Variation in Balsaminoid Ericales. II. Balsaminaceae, Tetrameristaceae, Pellicieraceae and General Conclusions
Provedor de dados: 16
Autores: Janssens, S.; Lens, F.; Dressler, S.; Geuten, K.; Smets, E.; Vinckier, S.
Background and Aims The objective of this study is to examine the palynological diversity of Balsaminaceae (two genera/61000 species), Tetrameristaceae (two genera/two species) and Pellicieraceae (one genus/one species). The diversity found will be used to infer the systematic value of pollen features within the balsaminoid clade.  Methods Pollen morphology and ultrastructure of 29 species, representing all families of the balsaminoid clade except Marcgraviaceae, are investigated by means of light microscopy, scanning electron microscopy and transmission electron microscopy.  Key Results Balsaminaceae pollen is small to medium sized with three to four apertures, which can be either colpate or porate, and a sexine sculpturing varying from coarsely...
Tipo: Article / Letter to the editor
Palavras-chave: Balsaminaceae; Ericales; Orbicules; Pellicieraceae; Pollen; SEM; TEM; Tetrameristaceae.
Ano: 2005
URL: http://www.repository.naturalis.nl/record/407278

Caracterización óptica y estructural de nanopartículas de Allium sativum L. impregnadas en lomo de bovino
Provedor de dados: 109
Autores: Figueroa-López,Kelly Johana; Torres Vargas,Olga Lucía; Prías-Barragán,John Jairo; Ariza-Calderón,Hernando.
En el trabajo se determinaron las características ópticas y estructurales de nanopartículas de polvo de ajo (Allium sativum L.), obtenidas por reducción y selección de tamaño, para comparación con muestras de polvo de ajo comercial. El tamaño de partícula se determinó empleando microscopía electrónica de transmisión (TEM) y las caracterizaciones óptica y estructural se realizaron, respectivamente, por espectroscopia infrarroja transformada de Fourier (FTIR) y difracción de rayos X (DRX). Para determinar el efecto de las nanopartículas de polvo de ajo cuando fueron aplicadas sobre trozos de lomo (Longissimus dorsi) de bovino se utilizó la técnica de fluorescencia. Los tamaños de las partículas del polvo sometido a reducción y selección de tamaño presentaron...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ajo; Especia; Nanopartículas; TEM; DRX; FTIR; Fluorescencia; Lomo bovino.
Ano: 2015
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122015000100007

Spores of Plagiochila (Dumort.) Dumort.: the taxonomic relevance of morphology and ultrastructure
Provedor de dados: 39
Autores: Silva-e-Costa,Juliana da Costa; Luizi-Ponzo,Andrea Pereira.
ABSTRACT Plagiochilaceae is a family of leafy liverworts that are distributed worldwide. It is of great importance due to its taxonomic and ecological implications among bryophytes. Most species of the family belong to the genus Plagiochila, but there is no consensus regarding its infrageneric circumscription. There have been few palynological studies involving Plagiochilaceae and Plagiochila. Here, we describe the spore morphology of seventeen species of Plagiochila and discuss the taxonomic value of palynological characters for these taxa. The spores were processed by standard palynological techniques and analyzed using light and electron microscopy. The spores were found to be apolar, spheroidal, released monads that vary in size from 13µm to 58µm...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bryophytes; Liverworts; Morphology; Palynology; SEM; Taxonomy; TEM; Ultrastructure.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062019000300391

Morphological characterization of pollen grains of Brazilian species of Bombacoideae (Malvaceae s.l.)
Provedor de dados: 39
Autores: Saba,Marileide Dias; Esteves,Gerleni Lopes; Santos,Valdira de Jesus; Santos,Francisco de Assis Ribeiro dos.
ABSTRACT The pollen grains of 15 species belonging to five genera (Ceiba Mill., Eriotheca Schott &amp; Endl., Pachira Aubl., Pseudobombax Dugand, and Rhodognaphalopsis A. Robyns) of the subfamily Bombacoideae (Malvaceae s.l.) were acetolysed, measured, described and photomicrographed under light microscopy and scanning and transmission electron microscopy, in order to characterize the pollen morphology of species of the subfamily occurring in Brazil. The pollen characters studied were size, shape, exine constitution, and apertural type. Pollen grains were medium to large-sized and isopolar with a (sub)circular and (sub)triangular amb with flat, convex or concave sides; oblate to suboblate; 3(-4)-colp(or)ate or 4-5(-6)-colporate, planaperturate,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ceiba; Pachira; Palynology; Pseudobombax; SEM; TEM.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000100094

Green Synthesis of AgNPs Stabilized with biowaste and their antimicrobial activities
Provedor de dados: 58
Autores: Jasuja,Nakuleshwar Dut; Gupta,Deepak Kumar; Reza,Mohtashim; Joshi,Suresh C.
In the present study, rapid reduction and stabilization of Ag+ ions with different NaOH molar concentration (0.5 mM, 1.0 mM and 1.5 mM) has been carried out in the aqueous solution of silver nitrate by the bio waste peel extract of P.granatum. Generally, chemical methods used for the synthesis of AgNPs are quite toxic, flammable and have adverse effect in medical application but green synthesis is a better option due to eco-friendliness, non-toxicity and safe for human. Stable AgNPs were synthesized by treating 90 mL aqueous solution of 2 mM AgNO3 with the 5 mL plant peels extract (0.4% w/v) at different NaOH concentration (5 mL). The synthesized AgNPs were characterized by UV-Vis spectroscopy, TEM and SEM. Further, antimicrobial activities of AgNPs were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Silver nanoparticles; Biowaste; Antibacterial activity; MIC; SEM; TEM.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400024

Differences in the cell wall architecture of melanin lacking and melanin producing Cryptococcus neoformans clinical isolates from India: an electron microscopic study
Provedor de dados: 58
Autores: Mandal,Piyali; Roy,Tara S.; Das,Taposh K.; Banerjee,Uma; Xess,Immaculata; Nosanchuk,Joshua D.
Cryptococcus neoformans is an important opportunistic fungal pathogen that causes life-threatening infection of the central nervous system. A major virulence factor for C. neoformans is the production of melanin in the cell wall. Using transmission electron microscopy, we studied the cell walls of three pairs of isolates obtained from patients with dual cryptococcal infections, where a melanotic and an albino strain were isolated from the CSF of each patient. Transmission Electron Microscopy revealed that the albino strains lacked a melanin layer whereas a melanin layer was associated with the cell wall of the melanotic strains, comprising approximately 75% of the cell wall area. The cell wall size of the melanin producing cells was approximately double...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cryptococcus neoformans; Melanin; TEM; Cell wall.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000400015

Impact of environmental stress on biochemical parameters of bacteria reducing chromium
Provedor de dados: 58
Autores: Batool,Rida; Yrjälä,Kim; Hasnain,Shahida.
Chromium pollution is produced in connection with industrial processes like in tanneries. It has been suggested that bioremediation could be a good option for clean up. The stress effect of variable chromate levels, pHs and growth temperatures on biochemical parameters of two Cr(VI) reducing bacterial strains Pseudomonas aeruginosa Rb-1 and Ochrobactrum intermedium Rb-2 was investigated. Transmission electrone microscopy (TEM) was performed to study the intracellular distribution of Cr(VI). It was observed that initial stress of 1000 µgmL-1 caused significant enhancement of all studied biochemical parameters at pH 7.0 and growth temperature of 37 °C showing great bioremediation potential of the strains. Transmission electron microscopy revealed that the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cr(VI); PH; Temperature; Biochemical parameters; TEM; FTIR spectroscopy.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000200028

Antibacterial activity of α-terpineol may induce morphostructural alterations in Escherichia coli
Provedor de dados: 58
Autores: Li,Li; Shi,Chaofeng; Yin,Zhongqiong; Jia,Renyong; Peng,Lianci; Kang,Shuai; Li,Zhengwen.
The antibacterial effect of α-terpineol from Cinnamomum longepaniculatum (Gamble) N. Chao leaf essential oils were studied with special reference to the mechanism of inhibiting the standard strain of Escherichia coli (CMCC (B) 44102) growth at ultrastructural level. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) and time-kill curves of α-terpineol were determined; Escherichia coli was treated with α-terpineol and observed under a transmission electron microscope. The MIC and MBC values of α-terpineol were all 0.78 µL/mL, and time-kill curves showed the concentration-dependent. Under the transmission electron microscopy (TEM), Escherichia coli exposed to MIC levels of α-terpineol exhibited decreased cell size and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Α-terpineol; Escherichia coli; Antibacterial activity; TEM.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400035

Extended-spectrum beta-lactamase-producing bacteria isolated from hematologic patients in Manaus, State of Amazonas, Brazil
Provedor de dados: 58
Autores: Ferreira,Cristina Motta; Ferreira,William Antunes; Almeida,Nayanne Cristina Oliveira da Silva; Naveca,Felipe Gomes; Barbosa,Maria das Graças Vale.
Antibiotic therapy in hematologic patients, often weak and susceptible to a wide range of infections, particularly nosocomial infections derived from long hospitalization periods, is a challenging issue. This paper presents ESBL-producing strains isolated from such hematologic patients treated at the Amazon Hematology and Hemotherapy Foundation (HEMOAM) in the Brazilian Amazon Region to identify the ESBL genes carried by them as well as the susceptibility to 11 antimicrobial agents using the E-test method. A total of 146 clinical samples were obtained from July 2007 to August 2008, when 17 gram-negative strains were isolated in our institution. The most frequent isolates confirmed by biochemical tests and 16S rRNA sequencing were E. coli (8/17), Serratia...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ESBL; Beta-lactams; Nosocomial infection; TEM; SHV; OXA; CTX-M.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000300028