bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological characterization of Frangula azorica bark as a potential herbal drug
Authors: Curica C. , Serrano R. , Gomes E. T. , Silva O. 
Published: August 2009

AbstractFrangula azorica V. Grubow (Rhamnaceae), locally known as “sanguinho”, is an Azorean endemism inscribed on the IUCN Red List of Threatened Species. Morphological, chemical and biological studies on F. azorica are scarce, but preliminary studies on the bark of this species enable the identification of anthraquinone derivatives as major compounds of this plant part. This kind of compounds are present and responsible for the laxative activity of Frangulae cortex and Rhamni purshianae cortex, two well known herbal drugs of the Western Pharmacopoeias belonging to the same botanical familly (Rhamnaceae).
Immunofluorescent study of the expression of Ang1, Ang2 and Tie2 in the corpus cavernosum of the Rat during aging
Authors: Figueiredo António , Cordeiro Ana Lúcia , Almeida Henrique , Neves Delminda 
Published: August 2009

AbstractAging is a recognized risk factor for erectile dysfunction (ED) contributing to vascular damage of penile tissue. Vascular system seems to be particularly prone to develop dysfunction along chronological aging, as supported by studies that associate aging with reduced endothelium-dependent dilation, atherosclerosis progression and angiogenic deficit in specific tissues. Cavernous tissue is particularly sensitive to atherosclerotic disease and to structural changes of the small vessels of the penis which conduces to functional impairment.
Iron-citrate can induce cell senescent phenotype in human fibroblasts in vitro
Authors: Matos L. , Almeida H. 
Published: August 2009

AbstractAfter a number of replications, human diploid fibroblasts (HDFs) in culture lose the ability to divide, become insensitive to further proliferation and enter a state of replicative senescence (RS). Subcytotoxic doses of several stressful agents such as hydrogen peroxide, tertbutylhydroperoxide or ethanol, are able to cause stress-induced premature senescence (SIPS) in HDFs in vitro. Such senescent cells display many features of RS as growth arrest, senescence associated beta-galactosidase (SA beta-gal), cell enlargement and overexpression of several genes (e.g., p21, TGF beta-1,IGFBP3). During ageing, iron accumulates in several tissues in vivo, and also in senescent HDFs in vitro. Due to its redox-active properties, it promotes hydroxyl radical production (Fenton reaction) and eventually leads to cell injury. Free radical reactions are known to cause the accumulation of intracellular damage resulting in ageing. Iron may thus be able to cause SIPS. The main objective of the present study was to investigate whether the exposure of HDFs to a subcytotoxic concentration of iron is able to cause SIPS.
Inflammatory response of young rabbits to calicivirus infection
Authors: Marques R. M. , Águas A. P. , Costa-e-Silva A. , Ferreira P. G. 
Published: August 2009

AbstractCaliciviruses cause rabbit haemorrhagic disease (RHD) that kills more than 90% of the infected adult animals within 1 a 3 days of infection. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to RHD. A mystery of the calicivirus infection is that young rabbits (less than 8-weeks old) are resistant to the infection, in spite of undergoing viral replication in the liver and of expressing transient hepatitis. Heterophils were the predominant inflammatory cells seen in hepatic tissue of infected adult rabbits, whereas mononuclear cells dominated the inflammatory infiltrates of the infected young rabbits (4-weeks-old). In order to define the role of inflammation in the pathogenesis of the calicivirus infection, we have studied the cellular inflammatory response in young rabbits experimentally infected by calicivirus. For this, we have used transmission electron microscopy (TEM) and flow cytometry to identify the inflammatory cells that infiltrate the hepatic tissue of young rabbits at 48 hours of calicivirus infection. In same infected rabbits, lymphoid organs (spleen and thymus) were used to quantify by flow cytometry the total number of leukocytes seen inside these organs.
Exposition of cork oak roots to cryptogein reduced the infection by Phytophtora cinnamomi
Authors: Maia I. , Medeira C. , Diniz I. , Candeias I. , Melo E. , Cravador A. 
Published: August 2009

AbstractThe oomycete P. cinnamomi has been described as strong contributing factor to the decline of cork oak and holm oak stands occurring in the Iberian Peninsula. There are no eradication methods available against this pathogen. Molecular mechanisms of oomycete — host interaction are not well understood, but it is known that oomycete species can induce biochemical and physiological processes in their host plants through a diverse array of virulence or avirulence molecules, known as effectors. Several Phytophtora effector molecules, the elicitins, are able to induce cellular defence responses in plants. Among these elicitors the 10- KDa (elicitins) are able to enhance plant defences in a systemic acquired resistance manner, against infection of different pathogens.
Ultrastructure and molecular cytogenetics of human metaphase II oocytes with granular vacuoles
Authors: Soares Célia , Azevedo Ana Raquel , Almeida Carolina , Oliveira Elsa , Alves Ângela , Silva Joaquina , Sá Rosália , Barros Alberto , Sousa Mário 
Published: August 2009

AbstractStudies demonstrated poor fertilization rates and compromised early embryo development in cases of oocytes with dark and granular ooplasm, or with central granular ooplasm and presence of a refractile body. Many other structural abnormalities of human mature oocytes do exist, but remain to be evaluated. In the present study we characterized granular vacuoles (GVa) of mature metaphase II human oocytes. Surplus abnormal MII oocytes (n=6) with GVa were used under informed consent, after controlled superovulation during IVF treatment cycles. In all cases, patients had normal karyotypes. For electron microscopy oocytes were fixed with karnovsky fixative for 2h at 4°C, post-fixed in 1-2% OsO4 in buffer containing 0,8% K3Fe3+(CN)6, dehydrated in ethanol series, equilibrated with propylene oxide and embedded in Epon. Semithin sections were stained with aqueous azur II and methylene blue (1:1). Ultrathin sections were stained with 3% aquous uranyl acetate (20 min) and Reynols lead citrate (10 min). Sections were observed with a transmission electron microscope JEOL 100CXII operated at 60kV.
Palynology of the genus Pulicaria Gaertn. (Asteraceae, Inuleae, Inulinae) in the Iberian Peninsula
Authors: Coutinho A. Pereira , Dinis A. M. 
Published: August 2009

AbstractPulicaria is the third largest genus of the tribe Inuleae. It comprises ca. 80 species of shrubs, shrublets and herbs with a European, North African and Asian distribution. All of the 5 European species are represented in the Iberian Peninsula. The genus has taxonomic problems, as recent cladistic analysis showed that, like the other two great genera of Inuleae (Inula and Blumea), Pulicaria is a paraphyletic taxon. In fact, the species investigated so far were placed in two distinct clades. Moreover, the species status of Pulicaria microcephala, a Portuguese endemism of Berlengas Islands, is still controversial. As already demonstrated by several authors, the palynological data are of great importance to understand the evolution, taxonomy and ecology of the Asteraceae. However, in spite of a few relevant contributions, the palynology of Pulicaria is still insufficiently known. In the present work we investigated the palynology of the Iberian species of Pulicaria using light (LM) and scanning electron microscopy (SEM). The exine structure of Pulicaria paludosa was also investigated using transmission electron microscopy (TEM).
A light, scanning electron and transmission electron microscopic study of a Fetal mouse Skin Dendritic Cell line (FSDC)
Authors: Dinis A. M. , Cruz M. T. , Lopes M. C. , Batista M. T. 
Published: August 2009

AbstractDendritic cells (DC) are major players in initiating immune responses by activating T-lymphocytes. They act as sentinels in peripheral tissues, continuously scavenging for antigens in their immediate surroundings. Their involvement in T-cell responses consists of a linear progression of events starting with capture of antigens in peripheral tissues, such as the skin, followed by migration to draining lymphoid organs and presentation of antigen-derived peptides to induce T-cell priming. In the last years, a number of DC lines have been generated and the electron microscopy has been used to define their characteristics, thus contributing to their formal validation. A cell line with features of early DC precursors was previously established from fetal mouse skin (FSDC), but its ultrastructural organization was not fully investigated. Here we report such investigation using light (LM), scanning electron (SEM) and transmission electron microscopy (TEM). The goal is to use FSDC as a model system to evaluate the safety and effectiveness of selected plant extracts, fractions and isolated polyphenols against inflammatory processes. Our preliminary results with these cells showed anti-inflammatory activity for some of the extracts we are currently investigating.
Microscopical characterization of the salivary glands of the carnivorous cephalaspidean Philinopsis depicta (Mollusca, Opisthobranchia)
Authors: Lobo-da-Cunha A. , Ferreira I. , Calado G. 
Published: August 2009

AbstractCephalaspideans are a group of opisthobranch gastropods comprising carnivorous and herbivorous species, allowing an investigation of the relationship between these diets and the morphofunctional features of the salivary glands.In this study, the salivary glands of the carnivorous cephalaspidean Philinopsis depicta were observed by light microscopy using semithin sections and by transmission electron microscopy. A central duct runs along the length of these thin ribbon-shaped glands dividing them in two halves, each formed by a single row of tubules perpendicularly attached to the central duct. The simple epithelium of the central duct and lateral tubes contains ciliated cells and two types of secretory cells, named granular cells and cells with apical vacuole (Fig. 1). A very thin outer layer of connective tissue covers the epithelium (Fig. 1). The ciliated cells are numerous but very thin, forming small clusters between secretory cells. The nucleus, several mitochondria and a few lysosomes are located in the apical region were the cells are wider. A very thin cytoplasmic stalk reaches the base of the epithelium and contains bundles of filaments in addition to some mitochondria.
Gender and aging in the liver: preliminary data using design-based stereological methods
Authors: Marcos Ricardo , Malhão Fernanda , Monteiro Rogério , Rocha Eduardo 
Published: August 2009

AbstractDifferent epidemiological studies demonstrated that male gender and age are risk factors for the progression of liver disease. Regarding age, it has been associated with liver mass and blood flow reduction, whereas in gender, the estradiol has revealed protective roles in models of liver fibrosis and of trauma-hemorrhage in rats. So far, most of the studies on aging focused their attention in hepatocyte (HEP) structure and function and few data exists pertaining to other liver cell subpopulations, including hepatic stellate cells (HSC) and Kupffer cells (KC). To the best of our knowledge, an integrative analysis (with modern stereology) of the liver cell populations, throughout aging and gender, has never been performed.
Electrical and mechanical probing of nanostructures with transmission electron microscopy
Authors: Costa P. M. F. J. , Bando Y. , Golberg D. 
Published: August 2009

AbstractRecent developments in the design of holders for transmission electron microscopes (TEM) have enabled widespread property analysis of nanostructures with unprecedented spatial resolution. It is now possible to routinely and reliably test the mechanical and electrical characteristics of a single carbon nanotube (CNT), for instance. Furthermore, due to the multitasking capability of TEMs, the study can even integrate simultaneous imaging and spectroscopical analysis. The combination of real-time gathering of structural, chemical, electrical and mechanical information provides an outstanding view of the materials' reactions when subjected to external stimulus such as current or heat.
Electron scanning microscopy analysis of fracture surfaces in laser welded samples of hardmetals
Authors: Miranda R. M. , Silva R. J. C. 
Published: August 2009

AbstractHardmetals of tungsten carbides in a cobalt matrix have been attempted to weld in similar joints by Nd/YAG laser in continuous wave mode. The combination of mechanical and thermo-physical properties of these materials poses a significant difficulty in welding these materials, especially for grades with low Co content, as 6 to 12% in volume. However, grades with higher Co content also showed a poor weldability. In fact, when welding hardmetals with a Co content of 25% in volume, a large amount of pores was observed on the fracture surface. Analysis under scanning electron microscopy showed these pores were coated with a thin film.Observations with energy dispersive spectroscopy (SEM-EDS) revealed this film is rich in cobalt and is highly unstable. Figure 1 shows the characteristics of the film around a pore evidencing its corrugated aspect originated during rapid cooling conditions verified during laser welding.
CVD diamond/substrate interface FIB preparation of cutting tools
Authors: Peripolli S. B. , Almeida F. A. , Gomes L. S. , Oliveira F. J. , Silva R. F. , Achete C. A. 
Published: August 2009

AbstractCVD diamond coated cutting tools are used for machining of abrasive and hard materials such as Al-Si alloys and tungsten carbide. The knowledge of the mechanisms governing the diamond/substrate interfacial strength is crucial in cutting tools design. The most adequate substrate material for maximizing the adhesion of diamond films is the silicon nitride (Si3N4) ceramic that possesses a thermal expansion coefficient similar to that of diamond. Buchkremer-Hermanns and co-workers consider the formation of a SiC interlayer between diamond and Si3N4, which may favour chemical bonding to diamond, although they could not detect it by glazing incidence X-Ray diffraction. They believed that insufficient detection sensitivity for very thin films, texture effects or presence of amorphous layers are possible reasons. In the case of TiN substrates, a graded interlayer of amorphous TiCN of only 8 Å was suggested by Contreras, as observed by HRTEM images and EDS measurements. Due to the difficulty in the detection of such layers, which can be in the order of a few angstrons, a definite evidence of their nature is yet to be demonstrated.
Biodegradation assessment of a 16th century fresco from Southern Portugal
Authors: Martins R. , Fialho S. , Lima M. , Tavares D. , Mirão J. , Valadas S. , Candeias A. E. 
Published: August 2009

AbstractThis work reports the study of the frescoes from the Casa de Fresco dos Sanches Baena in Vila Viçosa (Southeast Portugal) to allow their material characterisation, to identify the different microorganism populations and to assess their role in the deterioration of these paintings. The Casa de Fresco dos Sanches Baena is a small semi-underground building constructed in a Palace garden over a well and used as a cool refreshing place by the owners. The frescoes that cover the ceilings (composed of 4 panels) present rich mythological scenes and have other decorative elements, which make them an unusual example of this art form. Unfortunately, due to partial abandonment the paintings are in an advanced state of degradation exhibiting partial detachment of paint layers and mortars, salt efflorescences and abundant biological colonisations (Fig.1).
Microstructure and reaction mechanisms at γ-TiAl brazed interfaces
Authors: Guedes A. , Pinto A. M. P. , Sequeiros E. W. , Vieira M. F. , Viana F. 
Published: August 2009

AbstractTitanium aluminide alloys based on the γ-TiAl intermetallic compound are emerging as potential materials for high performance applications on aircraft engines components, aerospace vehicles and automotive engines, owing to their low density, high specific stiffness, excellent strength retention at high temperature and good creep and oxidation resistance. The development of adequate techniques to join γ-TiAl alloys, either to themselves or to other materials, is a key issue regarding the effective use of these alloys. Understanding of the reaction mechanisms that promote bonding is mandatory when optimization of the joining procedure is envisaged.
Joining of TiAl alloys using Ni/Al multilayers
Authors: Simões S. , Viana F. , Ventzke V. , Koçak M. , Ramos A. S. , Vieira M. T. , Vieira M. F. 
Published: August 2009

AbstractThe development of joining processes for TiAl alloys is fundamental to integrate them into functional structures and to widen their application field. Diffusion bonding has become the most reported technique for joining TiAl alloys but have the disadvantage of requiring high temperature stages. Diffusion bonding of TiAl at the 950-1200°C temperature range has been reported to produce defect-free bonds. Çam et al., successfully joined TiAl at 950 °C/30 MPa/3 h and 1000 °C/30 MPa/1 h, however, the bond interfaces were clearly visible.
Defect formation and microstructural changes in friction stir welds between pure copper and a brass alloy
Authors: Leal Rui M. , Leitão Carlos , Loureiro Altino , Rodrigues Dulce M. 
Published: August 2009

AbstractSeveral attempts have been made in the last few years for joining similar pure copper and brass alloys using the solid state friction stir welding (FSW) process. For both material types, all the works performed reported that the production of defect free welds is largely dependent on the correct choice of process parameters. It was also observed that, despite grain refinement occurred in the centre of all the welds, the welds in copper showed a slight reduction in strength, when compared to that of the base material, as opposed to welds in brass alloys, for which an increase in strength was observed. Regardless of the encouraging results obtained in similar FWS of these materials, in the knowledge of the authors, few reports exist concerning dissimilar joints between them. In his work, dissimilar welds between Cu DHP cooper plates and Cu-Zn 37 brass plates, both of 1 mm thickness, with the brass plate positioned in the advancing side of the tool, were analysed. Welds were carried out with a solid tool made of high speed steel. Tool geometry was characterized by a tool shoulder of 10 mm in diameter, containing a conical cavity of 6 degrees, and a threaded probe of 3 mm in diameter. Welds were done in a milling machine, in position control, using the working parameters indicated in table 1.
Imaging characterization of friction stir welds in the AA 5182-H111 aluminium alloy
Authors: Leal Rui M. , Leitão Carlos , Loureiro Altino , Rodrigues Dulce M. 
Published: August 2009

AbstractThe environmentally friendly friction stir welding (FSW) process is being increasingly used in joining similar and dissimilar aluminium and copper alloys and other soft materials. In this process a rotating tool promotes significant shear strain and frictional heating of the base materials, in order to stir them into a highly plasticized weld region, at the trailing side of the tool. Due to the intense plastic deformation, complex material flow patterns, such as vortices, swirls and whorls occur during welding. In dissimilar welds, these patterns are readily revealed by differential etching and the respective microstructures characterized. However, in similar welds, such as the welds between plates of AA 5182-H111 aluminium alloy, it is hard to distinguish the different features in the welds and characterize their microstructures. Fig. 1 illustrates optical and TEM micrographs of a weld in this alloy. In the optical image of the weld, at the top of the image, it is possible to distinguish three main areas signalized by numbers: the weld nugget (1), with a very fine grain structure with 2.8 um mean grain size, and a transition region (2) between the nugget and the base material (3), which is usually called the Thermomechanical Affected Zone (TMAZ).
Surface Analysis by MeV Ion Beams and Microscopy
Authors: de Carvalho José A. R. Pacheco , Pacheco Cláudia F. F. P. R. , Reis António D. 
Published: August 2009

AbstractMaterial analysis, specially surface analysis of materials, has been increasingly important. A wide range of surface analysis techniques is available. The techniques are, generally, complementary. There are nuclear and non-nuclear techniques, e.g. microscopy. Nuclear techniques, which are nondestructive, permit analysis for a few microns near the surface. They have been applied to areas such as scientific, technologic, industry, arts and medicine, using MeV ion beams. Nuclear reactions permit to achieve high sensitivities for detection of light elements in heavy substrates and also discrimination of isotopes. We use ion-ion nuclear reactions, elastic scattering and the energy analysis method, where an energy spectrum is obtained of ions from the target for a chosen energy of the incident ion beam. The target composition and concentration profile information contained in the spectrum is computationally obtained through a computer program that has been developed for predicting such energy spectra. Predicted spectra obtained for variations of target parameters are compared with experimental data, giving that information. SEM and TEM are also used.
Dispersion mechanisms of nanoclays in a polymer matrix by electron microscopy
Authors: Almeida M. F. , Machado A. V. , Covas J. A. , Larocca N. M. , Pessan L. A. 
Published: August 2009

AbstractThis work investigates the dispersion of nanoclays in polymer/montmorillonite (MMT) nanocomposites. Nanocomposites were prepared in a twin screw extruder and the collected samples were analyzed by SEM and TEM. It was possible to study the dispersion of the nanoclays and moreover understand its effect as compatibilizer.
Phase inversion phenomena of EPDM/PP - based TPVs by Electronic Microscopy
Authors: Antunes C. F. , Machado A. V. , van Duin M. 
Published: August 2009

AbstractMorphology development during phase inversion is a very complex and not well understood process. EPDM/PP -based TPVs were prepared and characterize by different electronic microscopy techniques. Using a low Mw-EPDM, morphology development during phase inversion was successfully followed by scanning electron microscopy with a back scattered electron detector.