Recently, porous polymer-ceramic composites have been developed and represent promising scaffolds to be used as synthetic extracellular matrix in bone tissue engineering since they combine the advantages of these two types of materials. On the other hand bioactive glasses (BG) have been used as ceramic fillers to promote bioactivity and to enhance mechanical properties and osteoblast functions. Among all the requirements, these 3D porous structures should have a controllable average pore size larger than 100 μm as well as good pore interconnectivity to allow vascularization and tissue ingrowth. The goal of this study is to investigate the effect of the addition of a bioactive glass on the porous structure development of the scaffolds prepared by thermally induced phase-separation and also to test the bioactivity of these composite scaffolds. Poly (L-lactic) acid (PLLA) was chosen as the polymer matrix because of its well-known biocompatibility and adjustable physical and mechanical properties. Micron-sized (<10 μm) glass from the 3CaO.P2O5-MgO-SiO2 system was produced in our laboratory and used as the bioactive ceramic filler.

Owing to its chemical similarity to the mineral phase of human bone and to its biological performance, synthetic hydroxyapatite (HA, Ca10(PO4)6(OH)2) has long been recognized as an important bone substitute material in orthopaedics, dentistry and artificial implants. HA ceramics have also been studied as drug delivery systems components where an appropriate porosity for ensuring a high ability forcarryingand delivering drugs in a controlled manner is required. For some emerging applications demanding nanoscale structured systems endowed with novel potentialities HA nanoparticles may be addressed as alternative components ensuring a large surface area for adsorbing the pharmacological substance of interest. Moreover particle porosity may offer new possibilities for drug or nutrient delivery, or for biocompatible and bioresobable structural reinforcements in osteologic implants, coatings and adhesives. Mesostructured porous calcium phosphate based systems have been synthesized at macro- and micro-scale, but well established methods for the specific synthesis of porous HA nanoparticles have not been reported so far. Yao et al. reported a successful synthesis of HA mesoporous micron-sized rods 0.5-1 μm in length and 50-100 nm in thickness but having low porosity. A new synthesis challenge for producing nano-sized particles of high surface area and having ordered mesopores is thus addressed.

The importance of surface analysis of materials has been increasing. The available techniques are complementary. Nuclear techniques, which are non-destructive, provide analysis for a few microns near the surface. Using low energy ion beams of a few MeV, applications have been made to several areas. Nuclear reactions and elastic scattering are the more precise nuclear techniques for obtaining absolute values of concentrations in surface analysis. Nuclear reactions provide, not only high sensitivities for detection of light elements in heavy substrates, but also discrimination of isotopes. We consider the “energy analysis method”, where a spectrum is acquired of ions from the target for a single energy of an incident ion beam. The spectrum inherently contains target composition and concentration profile information. A computational procedure has been developed for predicting such energy spectra, where elastic scattering is a particular and important case. The model mainly accounts for: target parameters, such as composition and concentration profiles; energy spread of the incident ion beam; geometric factors and target rotation; stopping power; differential cross section; energy straggling; detector resolution. An option permits inclusion of effects such as: multiple scattering; incident beam size and angular divergence; detector angular aperture. Computer simulated spectra are compared to experimental data. The chi-square is calculated, to evaluate the goodness of fit. Through variation of target parameters, so as to fit experimental data, target composition and concentration profiles are obtained.

Laser ablation has been extensively studied in polymers because of their considerable utility in diverse fields such as medicine, microelectronics, photonics, etc. As a result, laser ablation of polymers has generated considerable interest in research during the past two decades. Among the many aspects of laser ablation of polymers, several authors have reported the formation and growth of conical structures during laser processing with UV laser radiation. Although this aspect of laser ablation has been investigated since the 1980s, only a few applications of these structures have been reported. In the present paper, we study the development of conical structures on polyimide treated with KrF laser radiation as a function of the radiation fluence, and its effect on the wettability of the polymer.

Mortars are common and essential elements of masonry historical buildings and are composed by a binder, aggregates and eventually, some additives. The binder provides consistency to this composite material, and until the emergence of Portland cement in the 19th century, lime was the main binder used. The aggregates are normally sand or rock fragments with variable sizes. The whole set is morphologically very similar to a sedimentary clastic rock with carbonate cementing. Following an old tradition of microscope use in this kind of rocks, it is not surprising the application of optical microscopy to mortars as also happened with concrete.

High temperatures in Solid Oxide Fuel Cells (SOFCs) place stringent requirements on the cell components materials which result in high material costs for interconnects and insulation and cause the degradation of the system. The development of Intermediate Temperature SOFCs (IT-SOFCs) will require electrolyte materials with higher ionic conductivity at moderate temperatures than the conventional yttria-stabilised zirconia (YSZ). Recently, lanthanum silicates with an apatite-like structure (La9,33Si6O26) have attracted considerable interest as potential materials for low cost electrolyte. Some of these materials show conductivities at 875 K comparable to, or better than, YSZ; their high level of oxide ion mobility was related to the presence of oxygen channels along the c axis which facilitate the diffusion of the anionic species (O2− for SOFCs applications). Another way to fulfil IT-SOFCs requirements is to decrease the electrolyte thickness to the micrometer range and, therefore, the ohmic drop at the electrolyte. Magnetron sputtering has already been used to synthesize thin film electrolytes for SOFCs owing to its versatility for depositing complex materials as well as its ability to control their composition and morphology. The manufacturing of thin film lanthanum silicate electrolytes by magnetron sputtering, with thicknesses in the micrometer range, can be achieved through the previous deposition of La-Si films and subsequent thermal oxidation. The present study focuses on the characterization of the morphological and structural changes upon oxidation of La-Si films deposited by magnetron sputtering.

Ni-Ti Shape Memory Alloys (SMAs) have been attracting attention as smart materials because they can work as sensors and actuators at the same time. Miniaturization of mechanical devices is evolving toward sub-micron dimensions raising important questions in the properties of Ni-Ti films. In thin films it is essential to investigate the microstructure to understand the origin of the thickness limit. The design of functionally graded films has also been considered but for their successful development it is important to characterize the variations in crystalline structure.

Friction stir welding (FSW) is a solid-state joining technique initially developed for aluminium alloys. The heat generated by a rotating tool softens the material in the vicinity of the tool. The material undergoes intense plastic deformation following quite complex paths around the tool, depending on the tool geometry, process parameters and material to be welded. The comprehension of the material flow is essential to prevent voids and other internal defects which may form during welding. Several techniques have been used for tracking material flow during FSW such as metallography, the use of a marker material as a tracer or the flow visualization by FSW of dissimilar materials or even the X-ray and computer tomography. Some of these techniques are useless in the analysis of welds in homogenous materials or welds between materials of the same group. The aim of this investigation is tracking the material flow in FSW between 1mm thick sheets in aluminium alloys AA 5182-H111 and AA 6016-T4, currently used in automotive industry.

Arraiolos tapestries are probably one of the richest artistic Portuguese expressions in terms of textile heritage. It is difficult to date the beginning of the production of rugs in Arraiolos (Southern Portugal), but they were already produced in the late 1600's as they are listed in the inventories of Portuguese aristocratic households in the beginning of the 18th century. Sensitive detection techniques play an increasing role in the chemical investigation of historical objects since the knowledge derived from the chemical composition of materials is of upmost importance for textile conservation and restoration purposes. Textiles deteriorate due to natural causes like heat, radiation, mechanical stress, moisture, microbiological and enzymatic attack. Deterioration of materials causes breakdown of the molecular structure and results in a loss of strength, extensibility and durability, discoloration and fading which affects the appearance of the textiles.

The alkali-silica reaction (ASR) and internal sulfatic reaction (ISR), normally both referred as internal expansive reactions, are among the most common causes of concrete structures deterioration worldwide. These reactions, which could be present simultaneously, origin products those are responsible for expansive stresses in the cement-based building materials, leading to severe cracking and loss of strength. The reaction products are also often amorphous or badly crystallized, or even present in very low content that they are very difficult to identify by current analytical physico-chemical techniques. The main macroscopic evidence of these degradation phenomena in concrete structures are the superficial occurrence of map-cracking, pop-outs and exudates (figure 1). Nevertheless, these symptoms are not exclusive and enough to establish a correct diagnosis.

Small vessels of the penis are very sensitive to structural and functional changes, and small disturbances can conduce to any degree of erectile dysfunction (ED). For this motive, ED is now considered as an early manifestation of atherosclerosis and consequently a precursor of systemic vascular disease. Ageing, diabetes and hipogonadic states are recognized risk factors for ED, contributing together to vascular damage of penile tissue. Penile trabeculae of corpus cavernosum in the rat, constituted by connective tissue with abundant collagen fibrils, scarce fibroblasts and fibroelastic components, support smooth muscle fibers in subendothelium location. Corpus cavernosum structural elements act in concert, allowing increase of intra-cavernous arterial flow and smooth muscle relaxing, processes which are fundamental to penis erection. The purpose of this study is to clarify ultrastructural organization of corpus cavernosum of experimental rat models of known ED-risk factors.

A key factor limiting the success of Assisted Reproduction Techniques (ART) is oocyte and embryo quality, usually assessed by their morphologic appearance. Due to the subjectivity and inaccuracy of such criteria, other predictors of oocyte and embryo quality would be welcome. Cumulus oophorus (c.o.) cells are eligible as oocyte quality predictors, due to their direct contact with it. In addition, ART success was also related to oxidative stress, whose effects in the porcine and bovine oocytes may be prevented by the presence of c.o. cells. Yet, it is unknown if a similar effect exists in humans due to the scarcity of studies employing human c.o. cells.

Adrenocorticotropic hormone (ACTH) is the most potent stimulator of adrenal cortex, acting through the Melanocortin-2 receptor (MC2R). ACTH induces secretion of steroid hormones, critical for the normal stress response and plays also an important role on cell proliferation and differentiation. MC2R is a classical G-Protein coupled receptor (GPCR), thus activating Protein Kinase A (PKA). However, many studies suggested a cross-talk between different signalling pathways and a more complex intracellular network. In fact, in adrenocortical Y1 tumour cell line, ACTH may activate Extracellular Regulated Kinases 1/2 (ERK 1/2), which belong to the Mitogen-Activated Protein Kinases (MAPKs) family. In addition, this pathway was implicated in in vivo proliferation and steroidogenesis as shown by our group. In order to further explore and clarify ACTH signalling mechanisms, we made the present work to establish a model of primary cultures of rat adrenal cells.

The structure of human oocytes at the different maturation stages is known based on descriptive studies of its ultrastructural composition. The tridimensional quantitative ultrastructural analysis of human oocytes would be important for understanding folliculogenesis and establishing adequate methods of in vitro oocyte maturation. In this study, stereological methods were applied to quantify the distribution of mitochondria (M) and smooth endoplasmic reticulum (SER) in oocytes at the germinal vesicle (VG) stage of prophase I.

Aging is the major known risk factor for Alzheimer's disease (AD) and Parkinson's disease (PD), but genetic deffects have been associated with familial cases. Huntington's disease (HD) is a purely genetic neurodegenerative disorder, where mutations in the IT15 gene, encoding for the protein huntingtin, determine the development of the disease. The Prion diseases differ from these other disorders because they can also have infections origin.

The first step in quality control of herbal drugs is ensuring the correct identification of the plant intended for use. The required analytical procedures (macroscopic characterization of the entire or fragmentized material, microscopic characterization after pulverization of the plant material and chemical characterization), are usually described on quality monographs reported in authoritarian texts such as the European 6th Pharmacopoeia. Further information related to the name of the each herbal drug, the herbal drug definition, purity tests and assay are also provided.

Hakea sericeae Schrader and H. salicifolia (Vent.) B. L. Burtt. are perennials, which belong to the Proteaceae family. Native to dry tropical zones from South Australia, they became aggressive species, particulary in damaged, dried and windy areas and are now considered invaders in some places of mainland Portugal. With no natural predators, the use of chemical control is the main way to manage these plants but they both show a small foliar area, therefore usually little success has been achieved.

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that together with their tissue inhibitors (TIMPs) are important modulators of normal lung development and harmful mediators of lung damage. Several studies support the role for an imbalance of MMPs and TIMPs homeostasis in the pathogenesis of paediatric lung failure. It was verified that MMP-9 and MMP-9/TIMP-1 ratio increases in the broncho-alveolar lavage of patients with bronchopulmonary dyspasia (BPD). Maternal administration of vitamin A, once the period of retinoid-induced teratogenesis is over, results in an enhancement of lung foetal organogenesis, an increase in the lung's elastic fibres, and an increase in VEGF pulmonary and plasma levels.

In mammals it is well known the role of the elastic fibres in the lung development and its fundamental importance in the process of distending and recoil of the organ as a whole. The bird's lungs are compact and virtually non-expansible.

After morphological studies on elastic fibres distribution and quantification by image analysis we carried out a study on biochemical methods to quantify elastin in the avian lung, using domestic fowl (Gallus gallus) as an experimental model. We made use of two analytical methods for the elastin determination in these animal lungs from the 14th day of hatching until the 42nd day after hatchling.

Nowadays, environmental moulds are often being referred as also being the cause of superficial mycosis. Keratinophilic activity is one of the characteristics involved in the infectious process of some fungal species. With these findings some problems appear: 1) Do these species really act on keratinized tissues?; 2) How do these fungi perform their keratinophilic activity?; 3) Should we validate the results as positives in the case of isolating from the lesions only species considered as environmental? To answer to these questions, the in vitro hair perforation test was performed in 60 different species, including dermatophytes and environmental isolates. In vitro perforation capability, believed to be one of the characteristics involved in some fungal infectious processes, was assessed with aid of optic-, fluorescence-, electron scanning- and transmission-microscopy, followed by calculation of keratinophilic activity. According to Ali-Shtayeh et al., each hair degradation factor has a specific weight in a keratinolytic activity intensity index called “IKA”, which ranges between 0 and 100%. Changes in the hair structure may occur in the two following different ways: (a) Superficial Erosion, where there is an even hair degradation from the outside to the inside (b) Radial Penetration where there is a localized degradation of hair surface, often in a pocket-like structure. Different types of hyphæ are observed: of narrow diameter called boring hyphæ, of larger diameter called wider boring hyphæ) and swollen boring hyphæ (with dilated tips). Hyphæ may also produce highly specialized perforation organs.