bluuebunny/crossref_metadata_2025_split huggingface dataset:
Young WI-38 human fibroblasts apoptosis after to staurosporine exposure: a preliminary assessment
Authors: Leal-Seabra F. , Matos L. , Almeida H. 
Published: August 2009

AbstractHuman fibroblasts cell culture is an important technique for the study of cell biology under various conditions, as exposure to apoptotic stimuli such as UV radiation or hydrogen peroxide administration or chemotherapeutic agent derivatives from staurosporine (STP). STP, isolated from Streptomyces staurospores, is a general inhibitor of protein kinases, and is commonly used to induce apoptosis in a variety of cell in cultures as tumor cell lines, lymphocytes, neurons and osteoblasts. The mechanism by which STP induce cell death is still unkown. Some studies refer that STP induced cell death courses with cytochrome c release, caspase-dependent pathway activation, especially caspase-3, and is inhibited by Bcl-2 overexpression. However cell death still occurs after caspase inhibition by z-VAD-fmk suggesting that caspase independent pathway is also activated.
Ultrastructure of the earthworm calciferous gland. A preliminary study
Authors: Méndez J. , Rodríguez J. B. , Álvarez-Otero R. , Briones M. J. I. , Gago-Duport L. 
Published: August 2009

AbstractThe earthworm species belonging to the Lumbricidae family (Annelida, Oligochaeta) posses a complex oesophageal organ known as “calciferous gland” which secretes a concentrated suspension of calcium carbonate. Previous studies have demonstrated the non-crystalline structure of this calcareous fluid representing an interesting example of biomineralisation.
Copper exposure failed to induce caspase-3 activation in gills of the teleost fish, Oreochromis niloticus
Authors: Calejo M. , Monteiro S. M. , Fontaínhas-Fernandes A. , Sousa M. 
Published: August 2009

AbstractCopper, an essential trace element, becomes toxic when its concentration exceeds certain natural levels. Recent in vitro studies demonstrated that copper overload of cells may induce apoptosis through caspase-3 activation. However, the precise mechanism of copper-induced apoptosis in fish is still unclear, even less in O. niloticus where no studies have been reported so far. Accordingly, the main aim of this study was to find if copper induces apoptosis in Oreochromis niloticus gill, through the caspase pathway. Additionally, we intended to evaluate the potential use of activated caspase-3 expression as a waterborne copper biomarker.
Leaf trichomes of Portuguese Lavandula species: a comparative morphological study
Authors: Zuzarte M. R. , Dinis A. M. , Canhoto J. , Salgueiro L. 
Published: August 2009

AbstractLavandula species are aromatic plants that produce and accumulate essential oils in different types of glandular trichomes. The oils protect the aerial parts of the plant against herbivores and pathogens, and are of great economic value for fragrance, pharmaceutical, food and flavour industries. In Portugal there are five spontaneous species of Lavandula which are included in three different sections: Section Lavandula (L. latifolia), Section Pterostoechas (L. multifida) and Section Stoechas (L. luisieri, L. pedunculata, L. viridis). Our preliminary observations showed that these species have a high diversity of trichomes. This, associated with the fact that trichome morphology is often referred as an useful characteristic for systematic purposes, led us to investigate leaf trichome morphology in the five Portuguese species, using scanning electron microscopy (SEM).
Ultrastructural aspects of a NaCl-adapted potato cell line
Authors: Queirós F. , Almeida D. , Fidalgo F. 
Published: August 2009

AbstractSalinity is one of the major factors limiting plant development and crop productivity. Damage to plants exposed to salinity has been ascribed to ion toxicity, water deficit, nutrient imbalance and oxidative stress. The physiological and biochemical aspects of salt tolerance in plants have attracted considerable interest, but few studies have been carried out to study the ultrastructural changes in plant cells adapted to salinity. These changes may be helpful in elucidating the mechanisms of salt tolerance at cellular level. In plants exposed to salinity, alterations of cell walls and structure of cellular membranes, the swelling of thylakoids and a decrease in the amount of grana stacking in chloroplasts, and the vacuolation of cells have been observed n1, 21.
Fibre types in the skeletal muscle of blackspot seabream (Pagellus bagaraveo, Brunnich) juveniles: a histochemical, immunohistochemical and ultrastructural study
Authors: Silva P. , Valente L. M. P. , Malhão F. , Galante M. H. , Monteiro R. A. F. , Rocha E. 
Published: August 2009

AbstractThe aim of this work was to gain insights into the muscle fibre phenotype and ultrastructure in blackspot seabream juveniles, a potential candidate for Portuguese aquaculture. Firstly, we used a panel of isoform-specific antibodies as well as histochemical staining for myosin ATPase and for SDH enzyme activity (a marker for mitochondrial content and oxidative metabolism) to identify myosin expression. Secondly, muscle fibre types were also identified by their fine structure where powerful approaches contributed to understand the muscle fibre phenotype of blackspot seabream juveniles. We observed that the main part of the musculature consisted of fast-white fibres, with a narrow strip of slow-red fibres situated superficially adjacent to the lateral line. A zone of intermediate-pink muscle fibres was inserted between those muscle domains (Fig.1).
Observation of Hierarchical Porous BaTiO3 Derived from Hard Template
Authors: Hou R. Z. , Ferreira P. , Vilarinho P. M. 
Published: August 2009

AbstractThe morphology control at the mesoscale, via the design of size, shape, surface, interface, porosity and patterning of the meso-components, has gained increasing attention in the recent past and is expected to endue materials with novel functions. Most reports on mesoporous materials are on amorphous silica or simple oxides with amorphous or polycrystalline framework. It is still quite challenging to achieve functional multi-metal-oxides possessing highly porous structure. On the other hand, the synthesis and characterization of nano-sized ferroics has recently become important since it was predicted a dependence, for instance of the ferroelectric response, on the size and morphology. Moreover, the combination of different materials at the nanoscale creating multifunctional nanocomposites, where new properties resulting from scale, interface and defect phenomena are expected, is a new field that requires exploitation. Crystal size, surface area, surface curvature, and charges on the surface singnificantly influence the physical properties of ferroics at the nano-scale. Within our studies of the porous ferroelectrics, we have prepared BaTiO3 crystals with nanoporosity inside with a sol-precipitation process involving polymer or surfactant micelles. In this work, we present the microscopic characterization of porous BaTiO3 derived from hard matrix.
Electron-microscopic observation of BaTiO3 prepared by additive assisted aqueous synthesis
Authors: Maxim F. , Ferreira P. , Vilarinho P. M. , Aimable A. , Bowen P. 
Published: August 2009

AbstractBulk barium titanate (BaTiO3) has found widespread applications especially in multi-layered ceramic capacitors (MLCCs) and embedded decoupling capacitors (EDC). In the last years, the interest in one-dimensional (1D) nanostructured ferroelectric systems (nanotubes, nanowires, nanorods, nanobelts, nanofibers) is increasing. Recently theoretical studies reported an enhancement of ferroelectricity in 1D systems. Although the hydrothermal and aqueous synthesis of equiaxed barium titanate powders have been thoroughly investigated the growth of barium titanate anisotropic nanoparticles still less known. Indeed it is particularly dificult to modify the crystal habit by hydrothermal and related methods. However it is expected that the presence of some additives during the synthesis will change the growth kinetics.
Nanostructure Analysis of Sol-gel PZT Thin Films Derived from Different Chemical Routes
Authors: Wu Aiying , Vilarinho P. M. 
Published: August 2009

AbstractLead zirconate - lead titanate (PZT) materials are commercially important piezoelectric and ferroelectrics in a wide range of applications, such as data storage (dynamic access and ferroelectric random access memories) and sensing and actuating devices. PZT with the morphotropic phase boundary composition offers the highest piezoelectric response and at the present there are no fullydeveloped alternative materials to PZT. The importance of PZT associated with the continuous requirements of device miniaturization, imposes the development of high quality PZT thin films with optimized properties. Concomitantly due to the dependence of the final properties of thin films on the details of the microstructure a thoroughly analysis at the local scale of their microstructure is necessary. Sol-gel method, is one of the Chemical Solution Deposition techniques used to prepare oxide thin films, such as PZT. Starting from a solution, a solid network is progressively formed via inorganic polymerisation reactions. Most metal alkoxides used for sol-gel synthesis are highly reactive towards hydrolysis and condensation. Therefore their chemical reactivity has to be tailored via the chemical modification (or complexation) of metal alkoxides to avoid uncontrolled reactions and precipitation. For PZT sol gel thin film preparation, two chemical routes are frequently used depending on the nature of the molecular precursor, namely methotoxyethanol (MOE) route and diol-route.
Electron microscopy characterization of W-O multilayers
Authors: Parreira N. M. G. , Polcar T. , Pei Y. T. , Galvan D. , De Hosson J. Th. M. , Cavaleiro A. 
Published: August 2009

AbstractIn the decorative field, besides the optical characteristics needed for achieving desired colours, the material should have suitable properties able to assure the daily use of the component without significant degradation. Oxides are well known materials with a high wear and corrosion resistance which make them a preferential choice of coatings for environmental protection. However, the intrinsic colours possible to be achieved in a single oxide system are very limited. For example in W-O system, besides the different tonalities of grey, only the dark blue can be obtained for slightly substochiometric WO3 compound. The pallet of colours exhibited by WO3 coatings is due to interferometric effects. Recently, it was shown that playing with the gradient of the chemical composition of W-O layers it was possible to tune the global colour of the coatings, which made this system an attractive candidate for decorative applications.
Three Dimensional Macroporous Calcium Phosphates Scaffolds for Bone Tissue Engineering
Authors: Teixeira S. , Ferraz M. P. , Monteiro F. J. 
Published: August 2009

AbstractBone tissue engineering is a promising area that aims at developing implants capable of repairing and/ or substituting damaged or lost bone tissue. Ceramics are widely used for bone tissue engineering purposes and in this study, hydroxyapatite porous scaffolds were produced using the polymer replication method. With this method, it was possible to obtain scaffolds with specific demands adequate to tissue engineering purposes namely: macroporosity, microporosity and interconnected porosity. Polyurethane sponges were used as templates and impregnated with a ceramic slurry at different ratios being afterwards sintered following a specific thermal cycle. The characteristics of the hydroxyapatite porous scaffolds were investigated by using scanning electron microscopy and micro computer tomography (μ-CT). Human bone marrow cells (HBMC) were isolated and cultured on the scaffolds for 28 days and SEM was used as a tool to assess cell morphology and distribution.
Microscopic study of bacteria-textile material interaction for hygienic purpose
Authors: Malheiro J. M. M. , Salvado L. R. S. 
Published: August 2009

AbstractUnderwear is the most intimate form of dress, and feminine panties are particularly in close contact with genital mucosa, vulvar skin and perineum area. In fact, despite some controversy, the textile material has been pointed out as promoter of vaginal infection, trough changes on the normal skin physiology. The physiology of vulvar skin is very specific in terms of temperature (≈ 34°C), moisture and pH (< 4.7). This region is also colonized by a very specific microflora that is essential either to protect against pathogenic microorganisms, either to maintain healthy conditions of temperature, moisture and pH.
Nanocomposite Ag Thin Films With Interactive Topography
Authors: Piedade A. P. , Nunes J. , Vieira M. T. 
Published: August 2009

AbstractSynthesis of nanostructures has triggered continuous interest in the nanoscience field due to their potential application such as catalysis and biomaterials. Among these systems the possibility of producing nano- microporous surfaces with various controlled structures and pore sizes has increased the interest in the field owing to a better control over the particle's size and location.
Using SEM techniques for failure analysis of critical aeroengine components
Authors: Silva J. M. , Infante V. , Brito A. S. 
Published: August 2009

AbstractAeroengine components operate under particularly severe conditions, including the combination of both high mechanical stresses and elevated temperatures in chemically aggressive environments. These normal operational requirements will eventually promote both cyclic and time dependent failure mechanisms related with creep-fatigue damages. Therefore, the use of adequate preventive inspection techniques is mandatory in order to maximize safety and reliability levels of these components during service. However, there are some occasional and unpredictable material failures which must be conveniently investigated in order to avoid future hazardous situations. Scanning electron microscopy (SEM) can play a major role in the context of evaluation of failed components, allowing the observation of fracture surfaces and other material's features which are essential to the identification of some particular failure mechanisms.
Intermixing in Ni/Al multilayer thin films
Authors: Simões S. , Viana F. , Ramos A. S. , Vieira M. T. , Vieira M. F. 
Published: August 2009

AbstractSelf-propagating exothermic reactions are known to occur in multilayer films with alternating layers of a transition metal and a light element. The high velocity of these reactions, associated with high heat release rate, convert these systems in a unique heat source. The possibility of tailoring such a heat source to meet the needs of a particular process is very attractive to applications such as brazing or solid-state diffusion bonding. The solid state reactions occurring in Ni and Al multilayer thin films, produced by d.c. magnetron sputtering with bilayer thickness (period) of 5, 14 and 30 nm, were studied by differential scanning calorimetry (DSC). DSC results demonstrated that reaction temperature and heat released increase with the period of Ni/Al multilayer thin films.
Cells spreading on Micro-fabricated Silica Thin film Coatings
Authors: Pelaez-Vargas A. , Ferrell N. , Fernandes M. H. , Hansford D. , Monteiro F. J. 
Published: August 2009

AbstractFrom a biomaterials perspective, it is now understood that success in the osseointegration of a dental implant is conditioned by its “macro”, “micro” and “nano” scale features. Macro-scale roughness is necessary to improve primary stabilization in the post-surgical phase inducing a peri-implant thin fibrous layer. However, the more complex process in the true cell-material interaction is dependent on micro and nano scale phenomena. There is clear evidence that cell adhesion, proliferation, organization and phenotype are modulated at the micro-scale and that protein absorption is fundamentally a process conditioned at nano-scale.
Ferroelectric Domain Structure of PZT Tetragonal Single Crystals Analysed by Scanning Probe Microscopy
Authors: Pérez J. A. , Bdikin I. K. , Senos A. M. R. , Mantas P. Q. , Kholkin A. L. 
Published: August 2009

AbstractFrom the application point of view, the most interesting compositions in the lead zirconate titanate solid solutions, PbZrxTi1-xO3 (PZT), are those near the centre of the phase diagram, where tetragonal and rhombohedral phases are separated by a boundary nearly independent on temperature. The composition of this so-called morphotropic phase boundary (MPB) is approximately 52/48 at room temperature. The piezoelectric coefficients, electromechanical coupling coefficients, dielectric permittivity and remnant polarization measured on ceramic samples reach a maximum in this region, not necessarily at the same composition, which explains why these compositions are technologically so interesting.
Influence of the (citric acid/calcium) ratio on Hap particles synthesis
Authors: Santos C. , Martins M. , Almeida M. M. , Costa M. E. V. 
Published: August 2009

AbstractCalcium phosphate (CaP) particles aimed at specific applications including dental defect filling, bone tissue engineering and drug delivery may be engineered by different methods based on solution chemical precipitation. The understanding of CaP particle morphology evolution during precipitation is of great scientific interest not only from a fundamental point of view but also because morphology directly or indirectly determines the applicability of the particle. Citrate ion, widely known as a minor bone component, plays an important role as crystal habit modifier and crystal growth inhibitor. However the prediction of CaP growth morphologies in presence of citrate ion is still a challenging issue because the mechanism of citrate and CaP interactions is not yet clearly understood.
The joys and perils of recombination - The hotspot conversion paradox and the evolution of recombination
Authors: Pineda-Krch Mario , Redfield Rosemary 
Published: August 2009

AbstractThe contradiction between the long-term persistence of the chromosomal hotspots that initiate meiotic recombination and the self-destructive mechanism by which they act strongly suggests that our understanding of recombination is incomplete. To investigate the requirements for hotspot persistence, Rosemary Redfield and I developed a computer simulation model, hotspot, of their activity and its evolutionary consequences.
Competition between spiders and pitcher plants? Prey availability and trophic interactions in bogs
Authors: Hart Clarisse , Mejia Jonathan , Gotelli Nicholas , Ellison Aaron 
Published: August 2009

AbstractWeb-building spiders (e.g. Frontinella communis and Neriene radiata) and northern pitcher plants (Sarracenia purpurea) are co-occurring sit-and-wait predators that may compete for shared arthropod prey. We evaluated prey availability and capture rates by web-weaving spiders and pitcher plants in a headwater stream box complex (Harvard Pond) in central Massachusetts. We established 40 plots with spider and pitcher plant removal treatments, and collected arthropod prey captured by open pitcher plants, pitfall traps, and sticky traps in those plots. The removal of web-building spiders significantly changed the distribution of prey captured by the pitcher plants (Chi-square test: P = 2.2 × 10-16 at Harvard Pond). Plugging pitcher plants yielded no difference in prey capture by sticky traps or pitfall traps. In pitcher plants, the total number of Odonata, Diptera, and Hemiptera captured more than doubled when web-weaving spiders were removed from the plots. In pitfall traps in web-weaving spider removal plots, the total number of ants decreased by more than 50%. Hunting spider capture by sticky traps showed moderate increase (P = 0.08) when web-weaving spiders were removed, suggesting an unforeseen interaction between these groups of spiders. The increased predation risk of hunting spiders on ants may explain the marked decrease in ant activity when web-weaving spiders were removed.
Decadal-scale changes in seagrass coverage on the Mississippi barrier islands, northern Gulf of Mexico
Authors: Carter Gregory , Criss G. Alan , Blossom Gabriel , Biber Patrick 
Published: August 2009

AbstractSeagrasses provide habitat for a wide variety of aquatic species, and reduce coastal erosion via sediment stabilization. The areal coverage of seagrass beds on the Mississippi barrier islands appears to have declined substantially since the 1960s. However, difficulties in sampling benthic vegetation, differences among previous studies in survey methods, and a lack of data on year-to-year variation in coverage have impeded quantitative study of this decline. Thus, the goal of the present study was to utilize historical remote sensing data to quantitatively determine changes in seagrass (predominantly Halodule wrightii Ascherson) coverage on the Mississippi barrier islands. Analyses were limited to imagery acquired during late summer through autumn, when seagrass canopies remained fully developed and water turbidity was low. Given these conditions, seagrass beds were readily identifiable in older black-and-white to color aerial photographs as well as in more recent multi-spectral imagery.On Horn, the largest Mississippi island, seagrass coverage declined from 77 ha in 1940 to 19 ha in 1971. Coverage had returned to its 1940 value by 2006, but declined again in 2007. Seagrass coverage on Petit Bois, the most rapidly-migrating island, declined from 54 ha in 1940 to an approximately stable 8-19 ha from 1952 through 2007. Petit Bois was the only island for which decline in seagrass coverage corresponded with decline in island land area. On the smallest island, East Ship, seagrass coverage remained nearly constant at 16-19 ha from 1963-2007 despite dramatic reductions in land area during Hurricanes Camille (1969) and Katrina (2005). On West Ship, coverage dropped to zero in 2003 but increased by 2007 to slightly exceed its 1975 value of 18 ha. Data for Cat Island extended only from 2003-2007. Seagrass coverage more than tripled during this period, from 22 ha in 2003 to 71 ha in 2007. Protection from trawling may have been a significant factor in the post-1995 recovery of seagrass on Horn Island. The absence of a similar recovery on Petit Bois may be linked with its rapid westward migration in combination with a nearly 40% reduction in land area from 1940-2007. There was no discernable negative impact of Hurricane Camille or Hurricane Katrina on seagrass coverage. Methodological differences (e.g., mapping potential seagrass habitat rather than existing seagrass beds) are important in explaining the dramatic decline in seagrass coverage that is apparent when recent data are compared with results of earlier surveys.