ABSTRACT
HIGHLIGHTS Brachiaria brizantha proved to be a promising biomass for ethanol production. Fermentation was not impaired by the inhibitors furfural and hydroxymethylfurfural.
Abstract Different lignocellulosic biomasses are found worldwide and each country has its own important industrial crop that can be converted into high-value products, such as ethanol. Therefore, evaluation of new biomasses to be used in biorefineries is important to decrease the dependence on non-renewable resources and to guarantee sustainable development. This work evaluated Brachiaria brizantha, a grass commonly used as animal forage, and the standard biomass for 2G-ethanol, sugarcane bagasse. The chemical compositions of both biomasses were determined and different times and temperature of acid pretreatment were tested. Morphological analysis via scanning electron microscopy showed more deconstructed fibers after harsher biomass pretreatments. Simultaneous saccharification and fermentation of pretreated Brachiaria brizantha presented higher efficiency than when using sugarcane bagasse as the carbon source. A biomass conversion of 46 % was achieved when Brachiaria brizantha grass was pretreated with 2% sulfuric acid for 60 minutes. Moreover, fermentation was not impaired by the inhibitors furfural and hydroxymethylfurfural. It was concluded that Brachiaria brizantha is a promising biomass for ethanol production.
Subject(s)
Biomass , Brachiaria/chemistry , Saccharum/chemistry , Ethanol , Microscopy, Electron/instrumentationABSTRACT
Abstract The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.(AU)
Resumen La fase sólida de las sales de los cuerpos de agua juega un papel importante en la concentración de los elementos mayoritarios. El equilibrio de solubilidad de la calcita está influenciado por factores fisicoquímicos, climáticos y biológicos. Los ciclos anuales de sequía excepcionalmente prolongada, junto con la contaminación orgánica difusa de origen natural, generan condiciones únicas para la precipitación de estructuras de carbonato litificado (microbialitos). El objetivo de este artículo es analizar las posibles implicaciones de la precipitación de calcita producida en Cladophora sp. en una cuenca subtropical andina, considerando que es la primera vez que se describe este fenómeno para la región. Recolectamos muestras en sitios seleccionados en la Cuenca del Río Lules, en cuatro fechas de muestreo entre 2003 y 2004, en el marco de un trabajo de monitoreo de quince años. Usamos red Surber para realizar los muestreos. Las muestras de algas, una vez libres de macroinvertebrados, se secaron y pesaron. Analizamos utilizando microscopía electrónica y difracción de rayos X. Encontramos que Gomphonema sp. unido a Cladophora contribuye a la precipitación de calcita y la formación de estructuras similares a microbialitos, en el área estudiada. Este trabajo presenta una discusión inicial sobre el descubrimiento de estructuras similares a microbialitos unidas a filamentos de Cladophora sp. en una cuenca andina subtropical y las condiciones ambientales que conducen a su producción, así como las posibles implicaciones ecológicas de lo mencionado anteriormente.(AU)
Subject(s)
Lithium Carbonate/analysis , Diatoms/chemistry , Environmental Pollution , Droughts , Argentina , X-Ray Diffraction/instrumentation , Microscopy, Electron/instrumentation , Sampling StudiesABSTRACT
As dificuldades diagnósticas entre mesotelioma pleural e adenocarcinoma metastático na pleura exigem estudo amplo. Os autores ilustram um caso clínico cujo diagnóstico só foi estabelecido após realização de toracotomia, com retirada de material para análise imuno-histoquímica. A diferenciação diagnóstica é de fundamental importância, uma vez que envolvem conduta terapêutica e prognóstico distintos. O estudo adequado deve utilizar material obtido através de toracoscopia ou toracotomia e empregar coloração imuno-histoquímica, estudos com anticorpos monoclonais, microscopia eletrônica e pesquisa de marcadores tumorais.
The diagnosis difficulties distinguishing mesothelioma from pleural metastatic adenocarcinoma request wide study. The authors illustrate a clinical case whose diagnosis was only established after thoracotomy removing material for immune-histochemical analysis. The diagnosis differentiating is very important, because involves distinct treatment and prognosis. The appropriate study should use material obtained through thoracoscopy or thoracotomy and submitted to immune-histochemical coloration, studies with monoclonal antibodies, electronic microscopy and research of tumor makers.
Subject(s)
Humans , Pleural Neoplasms/diagnosis , Mesothelioma/diagnosis , Immunohistochemistry , Thoracotomy/instrumentation , Microscopy, Electron/instrumentation , Antibodies, Monoclonal/immunologyABSTRACT
A simple apparatus for harvesting uncultured magnetotactic microorganisms is described. This apparatus consists of a glass container with two openings. A large opening on the topside is used to introduce the sediment and water. The sediment and water are previously stored in loosely capped bottles previously tested for the presence of magnetotactic bacteria. The apparatus is exposed to a properly aligned magnetic field of a homemade coil and the bacteria are removed through the capillary end of the second opening of the container. Harvested bacteria can then be used to ultrastrucutral studies using electron spectroscopic imaging. Large numbers of magnetotactic bacteria consisting of cocci and rod-shaped cells were efficiently collected from different environments. This apparatus is useful for microbiological studies on uncultured magnetotactic bacteria, especially in molecular approaches for phylogenetic investigations that give information on the natural diversity of microbial communities.
Subject(s)
Bacteria/ultrastructure , Models, Molecular , Methods , Microscopy, Electron/instrumentationABSTRACT
Los localizadores Apicales Electrónicos son dispositivos que permiten determinar, bajo diferentes principios eléctricos, la longitud de trabajo del conducto radicular. Sin embargo, su eficacia y exactitud han sido frecuentemente cuestionadas. El presente estudio fue diseñado para probar la hipótesis de que el Neosono Ultima EZ es un localizador apical electrónico eficiente para determinar el foramen aplical en piezas dentarias humanas. Treinta y cinco premolares sanos, extraídos por indicación ortodóncica, fueron utilizados para el presente estudio. Mediante procedimiento endodóntico convencional, y basados en el experiemento de Donnelly, se procedió a realizar conductometría electrónica para posteriormente observar y microfotografiar las muestras en un Microscopio de Epifluorescencia. Las imágenes así obtenidas fueron digitalizadas y procesadas para su evaluación morfométrica. Los resultados mostraron que en un 64,5 por ciento de los casos los instrumentos se encontraban a 0,26 mm cortos con respecto al foramen apical y en un 35,5 por ciento a 1,13 mm más allá de éste, con un promedio +- 0,2 mm. Por lo tanto, concluimos que el Neosono Ultima EZ es eficiente en la localización del foramen aplical, con un grado de exactitud técnicamente posible en la práctica clínica; registrando mediciones más exacta en relación a sus modelos de generación anterior
Subject(s)
Tooth Apex/anatomy & histology , In Vitro Techniques , Root Canal Therapy/instrumentation , Bicuspid , Microscopy, Electron/instrumentation , Root Canal TherapyABSTRACT
A female of triatoma of Triatoma guazu & Wygodzinsky, 1979, a rare species from which the allotype was recently described, was studied by scanning electronic microscopy and videomicroscope. Some structures of the head and the thorax are shown. Some of them could have taxonomic importance, as the oculto-ocellar region, the buccula, the anterolateral angle of the collar, the scutellum, wings and the stridulatory sulcus, which has as unusual lateral high rim.
Subject(s)
Animals , Triatoma/anatomy & histology , Microscopy, Video/instrumentation , Microscopy, Electron/instrumentationABSTRACT
Thirty adult male albino rats were included in this study and divided into six equal groups. Bilateral vagotomy was done in four groups, while the other two groups were used as control animals. Generalized swelling of mitochondria of acinar, insular and ductular cells as well as of the nerve terminals appeared by the third day after operation. These changes were more apparent by the 7th, 15th and 30th days with vascular congestion, hemorrhage and cellular infiltration. The early changes were first within the limits of the physiological parameters and destructive process soon occurred
Subject(s)
Animals, Laboratory , Microscopy, Electron/instrumentation , Vagotomy , Rats , Pancreas/physiopathology , PancreatinABSTRACT
The use of electron microscopy to define the cellular changes in vitiligo might prove to be a useful investigative procedure to clarify the pathogenic mechanism of this disease. Examination of vitiligenous skin taken from the margin and center of the depigmented lesions revealed ultrastructural changes in the form of cytoplasmic vacuoles in basal and suprabasal keratinocytes and deposits of extra-cellular granular material in between the keratinocytes in lower epidermis. Melanocytes and melanosomes were completely absent, while Langerhans' cells showed highly vacuolated cytoplasm. There was marked increased in degenerated Langerhans' cells in the center of the vitiligenous lesions. It seems logical to propose that degenerative changes in vitiligo do not only involve the melanocytes, but also keratinocytes and Langerhans' cells i.e. the whole epidermal- melanin unit
Subject(s)
Humans , Male , Female , Epidermis/ultrastructure , Melanins , Melanocytes/ultrastructure , Microscopy, Electron/instrumentation , Keratinocytes/ultrastructure , Immunity, Cellular , Langerhans Cells/ultrastructureABSTRACT
Oocysts of Isospora chalchidis [Amoudi, 1989] were described from the feces of the skink Chalcides ocellatus in Egypt. Non- sporulated oocysts were spheroidal, measuring 20 [l8.5-21] mum in diameter and contained granulated zygotes. Sporulated oocysts had the same dimensions of the non-sporulated ones and each contained two sporocysts. Sporocysts were ovoid with stieda and sporocyst residual bodies. Sporulation time was 50 hours at room temperature. Merogony and gamogony occurred in the intestinal mucosa. Electron microscopic investigations showed that meronts, merozoites, gamonts and gametes developed in a narrow parasitophorous vacuole within the host- cell nucleus. Nuclei of meronts were surrounded by rough endoplasmic reticulum. Merozoites showed the main characteristics of motile stages of apicomplexa. Macrogametes contained a large nucleus, two types of wall-forming bodies and a large amount of lipid inclusions. Nuclei of microgamonts were peripherally arranged and lacked nucleoli. Microgametes were flagellated
Subject(s)
Microscopy, Electron/instrumentation , Microscopy , Infections/diagnosisABSTRACT
In this study, mebendazole and ivermectin were tried during three different phases of C. hepatica infection. At an early phase when immature forms were present, both drugs were effective in causing destruction and degeneration of the larvae, thus, preventing subsequent growth and maturation and consequently, the complete absence of eggs. During the second phase which is found to be the most critical period, the two drugs used led to degeneration and resorption of most of adult worms. In the third phase, both mebendazole and ivermectin were effective in decreasing the mean number of eggs. After treatment, the topographic changes were in the form of disorganized cuticle of the worms and the absence of surface uniformity. Such a disorganized cuticle is vulnerable to be attacked. C. hepatica eggs showed irregularities and longitudinal grooves indicated shrinkage of the shell. The effect of the two drugs indicated that both of them were effective in the treatment of hepatic capillariasis
Subject(s)
Ivermectin/pharmacology , Microscopy, Electron/instrumentation , Immunologic Tests/methodsABSTRACT
Although the electron microscope was developed about 60 years ago in Germany, its arrival and subsequent use in Jamaica are of considerably more recent date. In this paper, the principles of scanning and transmission electron microscopy (SEM & TEM) are briefly explained, and examples are given of the research done with the electron microscopes at the University of the West Indies (UWI), Mona Campus, Jamaica, especially over the last three years. Detailed descriptions of specimen preparation are provided for both SEM and TEM and particular emphasis is placed on the methodology used in our laboratory, as it sometimes differs from the routine followed in electron microscopy units of temperate countries.
Subject(s)
Specimen Handling/methods , Microscopy, Electron/instrumentation , Microscopy, Electron, Scanning/instrumentation , ResearchABSTRACT
This study was performed on albino mice infected with both Egyptian and Saudi Schistosoma mansoni strains to investigate the characteristic differences between them. It was found that at the 8th week post-infection, the highest amount of egg deposition and granuloma formation was present in the liver of infected mice with the Egyptian strain, while it was highest in the small intestine of those infected with the Saudi strain, followed by the liver and the large intestine. Although no prominent histopathologic differences were detected in the cellular and tissue reactions in the resulting granulomata surrounding eggs, yet marked differences were observed in the surface topography of the tegument and distribution of papillae, pattern of ridges, microvilli and spines of both strains. These differences were more pronounced in males
Subject(s)
Schistosoma mansoni/pathogenicity , Schistosoma mansoni/ultrastructure , Microscopy, Electron/instrumentationABSTRACT
The study included 8 male patients [5 - 10 years old]. With Duchenne muscular dystrophy [DMD], their female carriers [20 - 50 years old] and 3 healthy volunteers [2 males and 1 female, 20 - 40 years old]. Carriers were classified into obligate symptomatic [4 carriers], obligate asymptomatic [2 carriers] and possible carriers [2 carriers]. Muscle biopsy was taken from the quadriceps muscle of all the studied persons and prepared for both light and electron microscopy processes. Light and electron microscopy of muscle biopsies revealed marked dystrophic changes in all patients and mild dystrophic changes in 2 obligate symptomatic carriers, while some ultrastructural changes were detected by electron microscopy only in the other 2 obligate symptomatic carriers and one of the 2 obligate asymptomatic carriers. The other obligate asymptomatic carrier and the possible carriers showed no changes by both light and electron microscopy. So, we can conclude that carriers of DMD might show dystrophic changes by both light and electron microscopy. These changes were more frequent in obligate symptomatic carriers. Although, electron microscopy was more accurate than light microscopy in their detection, it could not detect all the carrier state
Subject(s)
Muscles/diagnostic imaging , Microscopy, Electron/instrumentation , Microscopy/instrumentationABSTRACT
25 cases [26 testes] of cryptorchidism, were studied clinically, and histopathologically [light and electron microscopy]. Cases were divided into 3 age groups: Preschool [1-5 years] 8 testes, prepubertal [6-15 years] 9 testes and postpubertal [16-35 years] 9 testes. Position of the testes included intraabdominal [7 tests], intracanalicular [14 tests], at external ring [3 tests], and inguinal ectopic [2 tests]. Wedge testicular biobsies during one stage orchiopexy [25 testes], and orchiectomy [one testes], were subjected for light and electron microscopic studies in relation to different age groups, and site of testicular arrest. It is concluded that the pathological changes in seminiferous tubules start to appear by the age of 2 years in light microscopic study. On the other hand, mitochondria changes start to appear by the age of one year in electron microscopic study. In addition, these changes are a continuous process. There is also a significant relation between histopathological changes and site of arrest, where maximal changes appear in intraabdominal ones. Orchiopexy was recommended to be done at earlier age by one to two years of age to retain maximal testicular function
Subject(s)
Humans , Male , Histological Techniques/methods , Microscopy, Electron/instrumentation , Testis/anatomy & histologyABSTRACT
Glomerular development of the kidney was studied in newborn rats by electron microscopy. Four different stages of glomerular development were defined: vesicle formation, S-shaped body stage, capillary loop formation, and glomerular maturation. In the first stage, the mesenchymal cells form a spheroid mass. This is followed by the S-shaped body stage in which clefts appear in the mass. Afterwards, capillary loop formation, junctional migration, podocyte differentiation, and interdigitation of epithelial processes occur. Finally, the cytoplasm of endothelial cells becomes thinner. The urinary space is visible in this stage. The fusion of epithelial and endothelial basement membranes results in formation of the layers of the GBM. The increase in the number of podocyte processes and endothelial cell fenestrations are important events in the maturation phase
Subject(s)
Animals, Laboratory , Microscopy, Electron/instrumentationABSTRACT
To reveal the effect of tiaprofenic acid [surgam] administration on the renal tissue, thirty healthy adult male albino rats divided into 3 groups were utilized. Control group [10 rats] received only distilled water [1 mg/kg body weight] I.M. daily for 6 weeks, treated group [10 rats] received [15 mg/kg body weight] I.M. daily for 6 weeks and examined immediately after stopping treatment and recovery group [10 rats] received the same course of tiaprofenic acid as the treated group but they were examined 3 weeks after stopping treatment. The animals were anaesthetized with ether. Kidney specimens were processed for preparation of paraffin sections which were stained with Hx and E, P.A.S. and Masson trichrome stain for histological study. Other minute specimens from the kidneys were processed for transmission electron microscope study. Areas of necrosis were detected with increased interstitial fibrosis, thickening of glomerular capillaries basement membranes and hypertrophied glomeruli. Ultrastructural changes were also found in the form of fusion of podocytes foot processes, localized thickening of glomerular capillaries basement membranes, degenerated tubular cells with affected nuclei and mitochondria. These changes did not disappear in animals examined 3 weeks after stopping of treatment. Patches of necrosis, hyaline tubular casts and interstitial hemorrhage were also found. The ultrastructural examination revealed focal fusion of podocytes foot processes and thickened glomerular capillaries basement membranes as well as distorted mitochondria and vacuolated cytoplasm of proximal convoluted renal tubules cells
Subject(s)
Male , Kidney/drug effects , Microscopy, Electron/instrumentationABSTRACT
Few studies were carried out to characterize the tissue reaction induced by Trichinella spiralis in its muscle phase. In the present work mice, infected by T. spiralis, were sacrificed after 4 weeks to obtain larvae in the muscle phase. Both light and electron microscopic [E/M] studies were carried out to define the muscle reaction and specify its cause. A detailed E/M description of the encysted larvae was done. Encapsulation, in the form of a clear halo around the larvae, was noted both in light and E/M sections. Electron microscopy, however, def?ned this capsule to be formed as a result of compressed, degenerated muscle fibers surrounding the larvae. A mild inflammatory cell infiltrate and discrete foci of haemorrhages appeared within the surrounding degenerating muscle fibers. Electron microscopy described areas of definite loss of muscle striations and various degrees of degeneration ending in cystic degeneration. This study confirms definite destructive effects of T. spiralis on the affected muscles thereby calling for continuous advanced research in this field
Subject(s)
Animals , Animals, Laboratory , Trichinellosis/etiology , Microscopy, Electron/instrumentationABSTRACT
Fasting blood glucose estimation, histopathological and electron microscopic studies were carried out on mice experimentally infected with schistosoma mansoni, blood glucose level showed highly significant increase in the infected group as compared to the control group. The histopathological changes of pancreatic tissues included deposition of bilharzial eggs and formation of granuloma with reduction in size of islets of Langerhans and cloudy swelling of pancreatic cells. While ultrastructure changes included blunting of microvilli of acinar cells and swelling and disruption of mitochondrial membrane. These changes could be responsible for hyperglycaemia noticed in bilharzial cases
Subject(s)
Animals , Pancreas/physiopathology , Microscopy, Electron/instrumentation , Blood Glucose/analysisABSTRACT
This study was carried out on the cortex of the thymus gland of 5 adult rabbits. The thymic specimens were processed for light and electron microscopic examinations. Three epithelial cell types were recognized in the thymic cortex of adult rabbit and they showed evidences of secretory activity. These findings prove the heterogeneity of epithelial cells in the cortex of rabbit thymus and concluded that these cells continue to prepare T-lymphocytes in adult rabbits