Alternatives Panels from Waste Plastics Reinforced With Fibers of Pupunha Palm for Use in Civil Construction and Furniture Industry

In order to cooperate in minimizing the problems of the current and growing volume of waste, this work aims at the production of panels made from industrial waste -thermoplastic (Polypropylene - PP; Polyethylene - PE and Acrylonitrile Butadiene Styrene - ABS) reinforced with agro-industrial waste - pupunha palm waste (shells and sheaths). The properties of the panels were evaluated: density, thickness swelling, water absorption and moisture content. It was used the ASTM D1037; EN 317; and ANSI A208.1 standards regarding particle boards. The best results in physical tests were treatments 1 (100% waste plastic), 6 (60% plastic waste and 40% waste of pupunha) and 7 (70% waste plastic and 30% waste of pupunha). The best results in the mechanical tests were treatments 3 (30% de residuos plasticos e 70% de residuos da pupunha), 4 (40% de residuos plasticos c 60% de residuos da pupunha) and 5 (50% de residuos plasticos e 50% de residuos da pupunha). For mechanical tests it was concluded that the results of modulus of rupture and of modulus of elasticity the best treatments were those with more fibers. In the tensile tests perpendicular to the surface, it is clear that using more waste plastics leads to the best results. It was concluded that the waste can be used as raw material for the production of alternative materials mainly in civil construction and furniture industries, and it can be employed in urban or rural environment, given the concept of eco-efficient products.

Pineapple Leaf Fibers for Composites and Cellulose

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Strong infrared spectral broadening in low-loss As-S chalcogenide suspended core microstructured optical fibers

We report the fabrication and characterization of the first guiding chalcogenide As(2)S(3) microstructured optical fibers (MOFs) with a suspended core. At 1.55 mu m, the measured losses are approximately 0.7 dB/m or 0.35 dB/m according to the MOF core size. The fibers have been designed to present a zero dispersion wavelength (ZDW) around 2 mu m. By pumping the fibers at 1.55 mu m, strong spectral broadenings are obtained in both 1.8 and 45-m-long fibers by using a picosecond fiber laser. (C) 2010 Optical Society of America

Microstructured chalcogenide optical fibers from As2S3 glass: towards new IR broadband sources

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Guanidine Affects Differentially the Twitch Response of Diaphragm, Extensor Digitorum Longus and Soleus Nerve-Muscle Preparations of Mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Collagen and reticular fibers in left ventricular muscle in diabetic rats: Physical exercise prevents its changes?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Histochemical study of muscle fiber types in Synbranchus marmoratus Bloch, 1795

The myotomal muscle of Synbranchus marmoratus was investigated using histochemical and immunohistochemical reactions. This musculature is composed of a superficial red compartment, uniformly distributed around the trunk circumferentially and also in the lateral line. The red compartment fibers are small in diameter and have an oxidative metabolism, a high rate of glycogen and a negative reaction to alkaline and acid myofibrillar ATPase (mATPase). The white muscle forms the bulk of the muscle mass. Its fibers are large in diameter and have a glycolytic metabolism, a negative reaction to glycogen, a strong reaction to alkaline mATPase and a negative reaction to acid mATPase. Between these two compartments there is an intermediate layer of fibers presenting a mosaic metabolism pattern with a high rate of glycogen. These fibers stained moderately for alkaline and acid m-ATPase. Several clusters of red muscles were observed inside the white muscle. Each cluster is composed of three fiber types, with a predominance of red and intermediate fibers. Reactivity to anti-MHC BA-D5 was positive only in the intermediate fibers. Reactivity to anti-MHC SC-71 was negative in all fiber types.

Morphological aspects of rabbit masseter muscle after cervical sympathectomy

The objective of this paper was to study the effect of sympathetic innervation on morphological and histochemical aspects of skeletal muscle tissue. Rabbit masseter muscle was studied using histochemical and immunohistochemical methods for periods of up to 18 months post-sympathectomy. The morphological and enzymatic characteristics of control masseter muscles were similar on both the left and right sides. The main features were muscle fibres with a mosaic pattern and a predominance of type IIa fibres, followed by type I. Type IIb fibres showed very low frequency. Sympathectomized animals showed varying degrees of metabolic and morphological alterations, especially 18 months after sympathectomy. The first five groups showed a higher frequency of type I fibres, whilst the oldest group showed a higher frequency of type lib fibres. In the oldest group, a significant variation in fibre diameter was observed. Many fibres showed small diameter, atrophy, hypertrophy, splitting, and necrosis. Areas with fibrosis were observed. Thus cervical sympathectomy induced morphological alterations in the masseter muscles. These alterations were, in part, similar to both denervation and myopathy. These findings indicate that sympathetic innervation contributes to the maintenance of the morphological and metabolic features of masseter muscle fibres.

Mouse extensor digitorum longus and soleus show distinctive ultrastructural changes induced by veratrine

We investigated whether veratrine (5 μl, 10 ng/kg) injected into the mouse extensor digitorum longus (EDL) (fast-twitch) and soleus (SOL) (slow-twitch) muscles provokes distinctive ultrastructural disturbances 15, 30 and 60 min later. The mitochondria in SOL were affected earlier (within 15 min) than in EDL. Swelling of the sarcoplasmic reticulum terminal cisternae was more marked in EDL than in SOL and caused distortion of sarcomeres so that fragmentation of myofilaments was more pronounced in EDL. Hypercontracted sarcomeres were seen mainly in SOL and veratrine caused infoldings of the sarcolemma only in this muscle. In both muscles, the T-tubules remained unaffected and by 60 min after veratrine most of the above alterations had reverted to normal. Pretreatment with tetrodotoxin prevented the alterations induced by veratrine. This suggests that most of the alterations resulted from the enhanced influx of Na+ into muscle fibers. These results emphasize the importance of considering the type of muscle when studying the action of myotoxic agents.

Histoenzymology and morphometry of the masticatory muscles of tufted capuchin monkey (Cebus apella Linnaeus, 1758)

Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.

Collagen fibers in human prostatic lesions: histochemistry and anisotropies

The present study focuses on establishing patterns of collagen fibers distribution in prostatic nodular hyperplasia and adenocarcinomas, in comparison with the normal tissue. Sections of prostatic transurethral resection were subjected to Gömöri's method for collagen fibers and reticulin and analyzed under ordinary and polarized light microscopy. Controls and hyperplastic regions present collagen fibers with variable thickness that run in different directions, establishing a tridimensional network. These fibers exhibit birefringence and dichroism thus demonstrating their fibrillar integrity. On the other hand, increased variability in collagen fiber distribution and anisotropical properties occur in adenocarcinomas evaluated in accordance with the Gleason's score. In some of their areas, a well-defined collagen network delimitates the base of transformed epithelial cells whereas in other areas the collagen fibers are disorganized and do not establish a boundary between the epithelial structures and the stroma. In these areas, collagen is found in the stroma. It was also observed that adenocarcinoma tumor cells rest on a scaffold of thin and dendritic collagen fibers. Collagen fibers of the prostatic stroma of the adenocarcinomas may show a modification in arrangement and fibrillar compactness. In prostatic nodular hyperplasia, there is no change in collagen molecular integrity, since collagen affinity for silver and collagen birefringence are similar to controls. In adenocarcinoma with high dedifferentiation degree, thin and branched strongly argyrophilic and birefringent collagen fibers are detected in regions of cell proliferation. In the adjacent stroma, hyaline plaques are indicative of matrix degradation or remodellation.

Charge density alterations in human hair fibers: An investigation using electrostatic force microscopy

A new method for high-resolution analyses of hair surface charge density under ambient conditions is presented in this paper. Electrostatic force microscopy (EFM) is used here to analyze changes in surface charge density in virgin hair, bleached hair, and hair treated with a cationic polymer. The atomic force microscopy technique is used concomitantly to analyze morphological changes in hair roughness and thickness. The EFM images depict exactly how the polymer is distributed on the surface of the hair fiber. The EFM's powerful analytical tools enabled us to evaluate the varying degrees of interaction between the hair fiber surface charge density and the cationic polymer. The surface charge density and the polymer's distribution in the hair fibers are presented in the light of EFM measurements. © 2006 Society of Cosmetic Scientists and the Socièété Française de Cosmétologie.

Curauá fibers in the automobile industry - a sustainability assessment

Replacing glass fibers with natural fibers in the automobile industry can yield economic, environmental and social benefits. This article evaluates the prospective environmental impacts of automobile applications of curauá fiber (Ananas erectifolius), which nearly equates the physical properties of glass fibers. The study identified economic and social advantages of applying curauá fiber composites in car parts. Besides costing 50% less than fiber glass, the use of curauá fibers can promote regional development in the Amazon region. In order to realize significant environmental benefits, however, the curauá-based composites would have to be lighter than their glass fiber-based counterparts. © 2006 Elsevier Ltd. All rights reserved.

Morphological and histochemical analysis of the human vestibular fold

A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.

Morfologia e morfometria dos tipos de fibras do músculo reto abdominal de cadelas (canis familiaris) durante a gestação

The present paper deals with the evaluation of morphological and morphometric alterations of slow-twist (I) and fast-twitch (II) fibers of rectus abdominis muscle of adult female dog during pregestational phase, at 30 and 60 days of pregnancy and at 30 days after the parturition. At the every phases, using the open biopsy technique, muscle samples were collected. The samples were plunged. Histological sections were cut in a microtome. For general morphology, some sections were stained with HE. Subsequent sections were reacted for myofibrillar ATPase (m-ATPase), after alkaline (pH 10.4) and acid (pH 4.4) pre-incubations, in order to identificate type I and II fibers. In the pre-gestational phase, muscle tissue revealed to be composed by fibers with different diameters, presenting polygonal outlines and one or more periphery nuclei. At 30 days of pregnancy, muscle fiber characteristics were similar. At 60 days, in addition to the existence of normal fibers, polymorphic and small diameter fibers were frequent. At 30 days after the parturation, the morphology of muscle fiber were similar to that observed in the pre-gestational phase. In the four phases, type II fiber diameters were lager than type I. The diameters of both fiber types showed a significant reduction in the 30 days phase and a significative increasing at 60 days. The expansion of the abdominal wall during the pregnancy represents a chronic stimulus, induced changes in the morphology and in the fiber type diameters.