Brachiaria brizantha Grass as a Feedstock for Ethanol Production

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.

Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications / Estructuras de tipo microbialito en Cladophora sp. (Ulvophyceae) de una cuenca andina subtropical: implicaciones ecológicas

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)

Dificuldades no diagnóstico diferencial entre mesotelioma pleural e adenocarcinoma metastático para pleura patológica / Difficulties in the differential diagnosis between pleural mesothelioma and metastatic adenocarcinoma for pathological pleura

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.

Simple homemade apparatus for harvesting uncultured magnetotactic microorganisms

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.

Evaluación in vitro de la eficacia del Neosono Ultima Ez como localizador electrónico del foramen apical / In vitro efficacy evaluation of Neosono Ultima Ez as an electronic locator of apical foramen

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

Estudo morfologico de Triatoma guazu Lent & Wygodzinsky, 1979 (Hemiptera, Reduviidae, Triatominae) / Morphologic study of Triatoma guazu Lent & Wygodzinsky, 1979 (Hemiptera, Reduviidae, Triatominae)

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.

ultrastructural study of epidermal-melanin unit in vitiligo

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

Electron microscopic study on the pancrease of albino rat after bilateral vagotomy

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

Light and electron microscopic studies of isospora chalchidis [Amoudi, 1989] infecting chalchidis ocellatus in Egypt

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

Effect of mebendazole and ivermectin in experimental hepatic capillariasis: parasitological, scanning electron microscopy and immunological studies

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

Electron microscopy in Jamaica: applications and techniques

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.

Pathologic and ultrastructure characterization of two different strains of schistosoma mansoni

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

Light and electron microscopy of skeletal muscle tissues of patients versus carriers of duchenne muscular dystrophy

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

Histopathological changes in cryptorchidism: light and electron microscopic study

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

Stages of development of renal glomeruli in the newborn rat kidney

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

Scanning electromicroscopy study for the enamel surface after debonding of metal orthodontic brackets bonded with glass ionomer cement

The glass ionomer cement was used, versus composite as a bonding agent for orthodontic brackets, to be studied for its effect on the enamel surface after debonding of the brackets and clean up procedures. The enamel surface was examined by SEM, which revealed less adverse effect for the glass ionomer cement on the microsurface of enamel as compared with that treated with composite material

Ultrastructural study of the body surface and the flame cell of oochoristica sp [cestoda: anoplocephalidae]

Ultrastructural studies on the body surface of the adult tapeworm Oochoristica sp. revealed that all the strobilar surface including the scolex and the adhesive surfaces of the suckers are covered with long filamentous microtriches. Using scanning and transmission electron microscopes, the basic morphology of the microtriches was studied and found to be similar to those described in other cestodes, but differs in having a relatively long basal regions. The flame cell was also described

Scanning electron microscopy of ascaridia galli [Shrank, 1788], freeborn, 1923 and A columbae [Linstow, 1903]

The morphology of the two ascaridoid nematodes Ascaridia galli and A. columbae was studied by scanning electron microscopy. The two nematodes were compared together and their specific characteristics were established, including lips, cephalic papillae, body cuticle, spicules and caudal papillae of the male

Endothelial tissue pathological alterations demonstrated in mice naturally infected with sarcocystis

Comparative electron microscopical study showed a spectrum of cytopathological changes ranging from exudative to obstructive inflammation of the vascular endothelium in mice naturally infected with sarcocystis. The endothelial cells changes were characteristic of necrotizing vasculitis and ischemic injury indicating loss of metabolic integrity and impaired perfusion. Signs of chronic inflammation and reflecting macrophage-lymphocyte interaction were also, evident. The fact that the endothelial affection was not a consistent feature in all infected mice, indicates that such cytopathological alterations may often be temporary and repairable or more likely genetically predisposed