Caracterização física e mecânica de argamassas à base de cimento Portland e cinza de casca de arroz residual

Rice husk, employed as an energy source at milling industries in Brazil generates, after burning, a dark ash. This residue is not yet conveniently disposed, being currently dumped on large areas, causing environmental problems. This research intended to evaluate the applications of residual rice husk ashes (RHA) as a partial replacement of cement for mortar production. Rice husk ash was chemically characterized through X-ray fluorescence, determination of carbon content, X-ray diffraction, and laser granulometric analysis. Mortar specimens were submitted to two different exposure conditions: internal and external environments at a maximum period of five months. Physical-mechanical testing were compressive strength and ultrasonic pulse velocity (UPV). Although presenting good mechanical performance, the mortar based on ash (RHA) did not present pozolanicity but it can be employed in cement matrices as inert material (filler).

Are skeletally mature female rats a suitable model to study osteoporosis?

OBJECTIVE: To analyze if female Wistar rats at 56 weeks of age are a suitable model to study osteoporosis. MATERIALS AND METHODS: Female rats with 6 and 36 weeks of age (n = 8 per group) were kept over a 20-week period and fed a diet for mature rodents complete in terms of Ca, phosphorous, and vitamin D. Excised femurs were measured for bone mass using dual-energy x-ray absorptiometry, morphometry, and biomechanical properties. The following serum mar-kers of bone metabolism were analyzed: parathyroid hormone (PTH), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor Κappa B ligand (RANKL), C-terminal peptides of type I collagen (CTX-I), total calcium, and alkaline phosphatase (ALP) activity. RESULTS: Rats at 56 weeks of age showed important bone metabolism differences when compared with the younger group, such as, highest diaphysis energy to failure, lowest levels of OC, CTX-I, and ALP, and elevated PTH, even with adequate dietary Ca. CONCLUSION: Rats at 26-week-old rats may be too young to study age-related bone loss, whereas the 56-week-old rats may be good models to represent the early stages of age-related changes in bone metabolism.

Tua imensa torcida e bem feliz... da relação torcedor com o clube

Universidade Estadual de Campinas . Faculdade de Educação Física

Modelo para análise do ataque no futebol = : A model to analyze soccer offensive phase

Universidade Estadual de Campinas . Faculdade de Educação Física

Efeito da ingestão de cafeina sobre o deficit acumulado de oxigenio, sinal eletromiografico dos musculos superficiais do quadriceps e desempenho fisico de ciclistas

Universidade Estadual de Campinas . Faculdade de Educação Física

Effect of different cleansers on the surface of removable partial denture

Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey’s test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.

Variabilidade amostral das séries mensais de precipitação pluvial em duas regiões do Brasil: Pelotas-RS e Campinas-SP

O presente trabalho avaliou a variabilidade amostral dos parâmetros da distribuição gama, relativos a séries mensais de precipitação pluvial, nas regiões de Campinas-SP e Pelotas-RS, que têm dados para os períodos de 1890-2006 e 1890-2005, respectivamente. Assim, os espaços amostrais considerados foram de 58, 39 e 29 anos para Campinas e 58 e 29 anos para Pelotas. As análises foram feitas usando o teste da razão da máxima verossimilhança. Os resultados apontaram significativas alterações amostrais. Não houve indicações de tendências contínuas (redução ou aumento) no regime mensal de precipitação pluvial na região de Campinas-SP. Em contrapartida, esse teste indicou, para a localidade de Pelotas-RS, tendência de elevação no regime desse elemento meteorológico ocorrida entre as amostras relativas aos anos de 1948 a 1976 e 1977 a 2005.

Origin of successive cambia on stem in three species of Menispermaceae

The lianas observed in this study, Abuta convexa (Vell.) Diels, Abuta imene (Mart.) Eichler, and Chondrodendron platiphyllum (A. St.-Hil.) Miers, all have successive cambia in their stems. The terminology applied to stem histology in species with successive cambia is as diverse as the interpretations of the origins of this cambial variant. Therefore, this study specifically investigates the origin of successive cambia through a developmental analysis of the above-mentioned species, including an analysis of the terminology used to describe this cambial variation. For the first time, we have identified several developmental stages giving rise to the origins of successive cambia in this family. First, the pericycle originates in 1-3 layers of conjunctive tissue. After the differentiation of the first ring, the conjunctive tissue undergoes new divisions, developing approximately 10 rows of parenchyma cells. In the middle portion, a layer of sclereids is formed, again subdividing the conjunctive tissue into two parts: internal and external. New cambia originate in the internal part, from which new secondary vascular strands will originate, giving rise to the second successive vascular ring of the stem. The external part remains parenchymatous during the installation of the second ring and will undergo new periclinal division, repeating the entire process. New cambia will originate from the neoformed strands, which will form only rays. In the literature, successive cambia are formed by a meristem called "diffuse lateral meristem."However, based on the species of Menispermaceae studied in this report, it is demonstrated that the diffuse lateral meristem is the pericycle itself.

An unusual, dwarf new species of Neotropical freshwater stingray, Plesiotrygon nana sp. nov., from the upper and mid Amazon basin: the second species of Plesiotrygon (Chondrichthyes: Potamotrygonidae)

A new species of the relatively poorly known Neotropical freshwater stingray genus Plesiotrygon Rosa, Castello & Thorson, 1987 is described from the main channel and smaller tributaries (Ríos Itaya and Pachitea) of the upper Amazon basin in Peru. The first specimen to be collected, however, was from much farther east in Rio Solimões in 1996, just down-river from Rio Purus (specimen unavailable for this study). Plesiotrygon nana sp. nov., is a very distinctive and unusually small species of freshwater stingray (Potamotrygonidae), described here mostly from three specimens representing different size classes and stages of sexual maturity. Plesiotrygon nana sp. nov., is distinguished from its only congener, P. iwamae Rosa, Castello & Thorson, 1987, by numerous unique features, including: dorsal coloration composed of very fine rosettes or a combination of spots and irregular ocelli; very circular disc and snout; very small and less rhomboidal spiracles; short snout and anterior disc region; narrow mouth and nostrils; denticles on dorsal tail small, scattered, not forming row of enlarged spines; adult and preadult specimens with significantly fewer tooth rows; fewer caudal vertebrae; higher total pectoral radials; very small size, probably not surpassing 250 mm disc length or width, males maturing sexually at around 180 mm disc length and 175 mm disc width; distal coloration of tail posterior to caudal stings usually dark purplish-brown; and features of the ventral lateral-line canals (hyomandibular canal very narrow, infraorbital and supraorbital canals not undulated, supraorbital and infraorbital loops small and narrow, supraorbital loop very short, not extending posteriorly to level of mouth, jugular and posterior infraorbital canals short, not extending caudally to first gill slits, subpleural loop very narrow posteriorly; absence of anterior and posterior subpleural tubules). To provide a foundation for the description of P. nana sp. nov., morphological variation in P. iwamae was examined based on all type specimens as well as newly collected and previously unreported material. Two specimens topotypic with the male paratype of P. nana sp. nov., referred to here as Plesiotrygon cf. iwamae, are also reported. Relationships of the new species to P. iwamae are discussed; further characters indicative of Plesiotrygon monophyly are proposed, but the genus may still not be valid. Plesiotrygon nana sp. nov., is commercialized with some regularity in the international aquarium trade from Iquitos (Peru), an alarming circumstance because nothing is known of its biology or conservation requirements.

Trichomycterus dali: a new highly troglomorphic catfish (Silurifomes: Trichomycteridae) from Serra da Bodoquena, Mato Grosso do Sul State, Central Brazil

Trichomycterus dali, new species, is described from flooded limestone caves in Serra da Bodoquena karst area, State of Mato Grosso do Sul, Central Brazil. The new species is diagnosed by a unique character in the genus, the presence of conspicuous, ridge-like adipose folds lining dorsally throughout the body. Trichomycterus dali can be further distinguished readily from epigean congeners by the reduction of eyes and skin pigmentation (except for T. gorgona), and from remaining congeners (i.e., all hypogean plus T. gorgona) by the total loss of eyes, not visible externally (except for T. sandovali and T. spelaeus). Other diagnostic features includes very long barbels, especially the nasal (99.3-143.5% HL) and the maxillary (97.0-131.3% HL), pectoral-fin ray count reaching I,9 and a unique cranial fontanel with a conspicuous constriction on the meeting point of supraoccipital and the two frontal bones. The troglobitic status of the species is suggested by the presence of troglomorphisms on an advanced degree, especially the reduction of skin pigmentation, the total loss of eyes and the enlarged barbels. In addition, the presence of a well developed adipose fold in adults may indicate a distinctive adaptation acquired by neoteny to withstand the food scarce conditions of its hypogean habitat.

A new species of Pimelodus La Cépède, 1803 (Siluriformes: Pimelodidae) from rio Ribeira de Iguape basin, Brazil

Pimelodus multicratifer, a new species, is described from the rio Ribeira de Iguape basin. The new species differs from the other Pimelodus species by the following features: 26 to 30 gill rakers on the first branchial arch; a combination of three to six rows of dark spots regularly or irregularly scattered on the flanks and several small dark spots irregularly scattered on the dorsal surface of head, supraoccipital process, and sometimes on the dorsal and caudal fins; striated lips; maxillary barbels reaching between posterior tip of the pelvic-fin rays and posterior tip of the middle caudal-fin rays.

Ituglanis mambai, a new subterranean catfish from a karst area of Central Brazil, rio Tocantins basin (Siluriformes: Trichomycteridae)

Ituglanis mambai, new species, is described from a cave in the Mambaí karst area, State of Goiás, Central Brazil. The new species distinguishes from epigean and cave congeners by the combination of the following characteristics: posterior supraoccipital fontanel absent; pectoral-fin rays usually i,7; six pleural ribs; total vertebrae 37-38 behind Weberian apparatus; shorter predorsal length (65.1-70.8% SL); shorter caudal peduncle length (8.4-11.9% SL); shorter dorsal-fin base length (7.7-11.3% SL); wider interobital width (29.2-36.5% HL); larger mouth width (43.4-64.0% HL); intermediate between epigean and other cave Ituglanis species as regards to both eyes (diameter varying from 0.5 to1.0 mm in adults, 7.8-10.1 % HL) and pigmentation, composed by irregular light brown spots along the body. The latter indicate the troglobitic status for I. mambai. In addition, this species has the maxillae with a discrete medial-posterior projection; fronto-lacrimal one half-length of the maxillae and pointed backwards; posterior process of palatine half its length, with a tenuous medial concavity; 14 dorsal and 12 ventral procurrent rays. In the natural habitat, I. mambai displayed cryptobiotic habits, trying to hide in the graveled bottom or under boulders when disturbed, apparently showing a negative response to light. It was observed a preference to slow-moving waters. Recent flood marks were observed in the stream conduit in March/April 2007 (end of the rainy season) when less individuals were observed on 300 m of the subterranean stream compared to September 2004 (end of the dry season).

Two new species of Moenkhausia Eigenmann (Characiformes: Characidae) from Serra do Cachimbo, Pará, Northern Brazil

Two new species of Moenkhausia, one from the rio Tapajós and the other from the rio Xingu basins are described as apparently endemics of the Serra do Cachimbo. Both species, along with M. petymbuaba, share a distinct color pattern composed of large conspicuous dark blotches on the base of the body scales. Moenkhausia chlorophthalma, from rio Treze de Maio, a tributary to rio Curuá (rio Xingu basin), is distinguished by the presence of a proximal well delimited black area on the adipose fin and a green eye in life. Moenkhausia plumbea of the headwaters of tributaries of the rio Braço Norte, rio Tapajós basin is diagnosed by the presence of a dark longitudinal stripe across the eye and six branched pelvic-fin rays (vs. seven). Relationships of the new species with other Moenkhausia are discussed.

Expression of SMAD proteins, TGF-beta/activin signaling mediators, in human thyroid tissues

OBJECTIVE: To investigate the expression of SMAD proteins in human thyroid tissues since the inactivation of TGF-β/activin signaling components is reported in several types of cancer. Phosphorylated SMAD 2 and SMAD3 (pSMAD2/3) associated with the SMAD4 induce the signal transduction generated by TGF-β and activin, while SMAD7 inhibits this intracellular signaling. Although TGF-β and activin exert antiproliferative roles in thyroid follicular cells, thyroid tumors express high levels of these proteins. MATERIALS AND METHODS: The protein expression of SMADs was evaluated in multinodular goiter, follicular adenoma, papillary and follicular carcinomas by immunohistochemistry. RESULTS: The expression of pSMAD2/3, SMAD4 and SMAD7 was observed in both benign and malignant thyroid tumors. Although pSMAD2/3, SMAD4 and SMAD7 exhibited high cytoplasmic staining in carcinomas, the nuclear staining of pSMAD2/3 was not different between benign and malignant lesions. CONCLUSIONS: The finding of SMADs expression in thyroid cells and the presence of pSMAD2/3 and SMAD4 proteins in the nucleus of tumor cells indicates propagation of TGF-β/activin signaling. However, the high expression of the inhibitory SMAD7, mostly in malignant tumors, could contribute to the attenuation of the SMADs antiproliferative signaling in thyroid carcinomas.

Controle da adipogênese por ácidos graxos

A obesidade é um dos principais problemas de saúde pública. Indivíduos obesos são mais suscetíveis a desenvolver doenças cardiovasculares e diabetes melito tipo 2. A obesidade resulta do aumento no tamanho e no número de adipócitos. O balanço entre adipogênese e adiposidade determina o grau de obesidade do indivíduo. Adipócitos maduros secretam adipocinas, tais como TNFα, IL-6, leptina e adiponectina, e lipocina, o ácido palmitoleico ω-7. A produção de adipocinas é maior na obesidade, o que contribui para o estabelecimento de resistência periférica à insulina. O conhecimento dos eventos moleculares que regulam a diferenciação dos pré-adipócitos e de células-tronco mesenquimais em adipócitos (adipogênese) é importante para o entendimento da gênese da obesidade. A ativação do fator de transcrição PPARγ é essencial na adipogênese. Certos ácidos graxos são ligantes de PPARγ e podem, assim, controlar a adipogênese. Além disso, alguns ácidos graxos atuam como moléculas sinalizadoras em adipócitos, regulando sua diferenciação ou morte. Dessa forma, a composição lipídica da dieta e os agonistas de PPARγ podem regular o balanço entre adipogênese e morte de adipócitos e, portanto, a obesidade.