908 resultados para catch-up growth
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SrBi4Ti4O15 (SBTi) thin films were obtained by the polymeric precursor method and crystallized in a domestic microwave oven. For comparison, films were also crystallized in a conventional furnace at 700 degrees C for 2 h. Structural and morphological characterization of the SBTi thin films was investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Using platinum coated silicon substrates configuration, ferroelectric properties of the films were determined with remanent\polarization P-r and a coercive field E-c of 5.1 mu C/cm(2) and 135 kV/cm for the film thermally treated in the microwave oven and 5.4 mu C/cm(2) and 85 kV/cm for the film thermally treated in conventional furnace, respectively. The films thermally treated in the conventional furnace exhibited excellent fatigue-free characteristics up to 10(10) switching cycles indicating that SBTi thin films can be a promise material for use in non-volatile memories. (C) 2007 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of this study was to follow-up the physiological variations in the development of the bone tissue, associating them with the egg production curve. This study was carried out in the facilities of the Faculdade de Medicina Veterinária e Zootecnia of the UNESP, Botucatu, Brazil. Twenty-three families of Ross broiler breeders were used, each family consisting of 13 females and 1 male, distributed in 23 pens of 5.0m² each. The management was that recommended by the genetic company manual (Agroceres Ross, 2003), with daily feeding until 6th week of age; and birds were fed according to a 5:2 schedule (5 days fed, 2 days of fasting) between 7 and 17 weeks of age, returning to daily feeding starting at 18 weeks of age. Birds did not receive afternoon calcium supplementation. on the fourth week of rearing, 84 females were removed for bone analyses of the right tibia and femur, using optical densitometry in radiographic images technique. These analyses were sequentially carried out in 4, 8, 12, 15, 20, 24, 30, 35, 42, 47, and 52 week-old birds. The egg production curve of the birds was followed-up and associated to bone mineral density results. For bone mineral density evaluation (BMD) birds were divided by weight categories as light, intermediate, or heavy within each data age. BMD values of the tibias were not influenced by weight range, but by the age at collection. on the other hand, interactions were found among femur BMD values and weight and age categories. There was no correlation between eggshell quality and femur BMD. A negative correlation (-0.15) was observed between tibia BMD and eggshell percentage. It was possible to conclude that the egg production has little influence on bone mineral density of the birds probably because there was no need of bone mineral mobilization during the production period, since the observed egg production was below that observed under commercial conditions.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Morphological and stereological analyses were used to characterize the growth kinetics of the Wistar rat ventral prostate (VP). Volume density and absolute volume of the epithelium, lumen, smooth muscle cells (SMCs), and nonmuscular stroma were determined by stereology and paired with plasma testosterone levels and different morphometric measurements. The VP shows an initial growth within the first 3 weeks, a resting phase, and the puberal growth. The puberal growth was coincident with the raise in plasma testosterone. Lumen formation occurred within the 3 postnatal weeks. After an expected increase during puberty, the lumen showed a further increase at the 12th week. The volume density of the nonmuscular stroma and of the SMCs decreased slowly postnatally. Absolute volume of the luminal compartment showed three phases of growth (weeks 1-3, 6-9, and 11-12). on the other hand, the increase in the absolute volume of the epithelium was steady up to the 8th week and then showed a marked increase up the 10th week. The increase in epithelial volume was characterized morphologically by the presence of epithelial infoldings and sprouts. The growth of the epithelium showed a 2-week delay as compared to the lumen and occurred only until the 10th week. The epithelial height was variable but could be related to the synthetic activity of the epithelium. In conclusion, the postnatal growth of the VP results from a combination of epithelial proliferation/differentiation and synthesis/accumulation of the secretory products in the lumen.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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OBJETIVO: avaliar as possíveis diferenças no comportamento mandibular em indivíduos Classe I com crescimento vertical e horizontal. MÉTODOS: a amostra desse estudo consistiu de 20 indivíduos Classe I não tratados, sendo o grupo 1 composto por 10 indivíduos com padrão de crescimento vertical e o grupo 2 por 10 indivíduos com padrão de crescimento horizontal, pertencentes aos arquivos do Burlington Growth Center, University of Toronto, no Canadá, acompanhados radiograficamente nas idade de 9, 12 e 21 anos. Determinou-se, por meio de telerradiografias cefalométricas, em norma lateral, os valores médios para a avaliação longitudinal do comportamento da mandíbula utilizando as medidas SNB, Co-Gn, SN.GoMe, altura facial anterior e altura facial posterior. RESULTADOS: o valor de SNB e Co-Gn foram maiores no grupo com crescimento horizontal em todas as idades. A medida Sn.GoMe foi significativamente menor no grupo com crescimento horizontal, a altura facial anterior (AFH) apresentou valores menores nos indivíduos com padrão de crescimento horizontal, e a altura facial posterior (PFH) apresentou valores menores nos indivíduos com crescimento vertical. CONCLUSÃO: as comparações longitudinais das tendências de crescimento de indivíduos Classe I indicam que existe diferenças significativas entre os dois grupos. A mandíbula apresentou tendência à rotação horária no grupo 1. O grupo 2 exibiu tendência à característica de indivíduos braquicefálicos, na forma facial, devido ao déficit no desenvolvimento vertical na altura facial anterior.
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OBJETIVO: demonstrar se ocorre crescimento pulmonar compensatório (CPC) representado pelos conteúdos de proteínas, DNA e RNA no rato adulto jovem, subnutrido, submetido à trilobectomia pulmonar. MÉTODOS: Utilizamos 137 ratos Wistar, machos, distribuídos por sorteio, em 9 grupos, submetidos a três tratamentos (controle, toracotomia, trilobectomia), sacrificados em três momentos (7, 30 e 90 dias). Na trilobectomia foram extirpados os lobos médio, acessório e caudal direitos. Variáveis estudadas: conteúdos pulmonares de proteínas, DNA e RNA. RESULTADOS: No lobo cranial e pulmão esquerdo o conteúdo protéico foi maior nos trilobectomizados. Ocorreu CPC insuficiente para suprir a perda desta variável, sendo menor nos pulmões dos trilobectomizados. O incremento nos conteúdos de DNA do lobo cranial e pulmão esquerdo dos trilobectomizados foram suficientes para compensar a perda desta variável, resultando num conteúdo de DNA dos pulmões semelhante aos controle. O conteúdo de RNA, nos trilobectomizados, foi maior no lobo cranial e pulmão esquerdo, com maior eficiência no primeiro, insuficiente para que se aproximassem aos obtidos nos demais grupos, ficando menores. CONCLUSÃO: Nos trilobectomizados ocorreu CPC, provavelmente com hiperplasia celular e pouca hipertrofia, devido a grande compensação do DNA e pequena do RNA. Esta foi a grande diferença quando comparamos este resultado ao obtido com animais nutridos, que apresentavam hipertrofia pronunciada.
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The effects of triple superphosphate (TS) and liming on macronutrient accumulation and root growth of Pioneer 3072 and Cargill 505 com hybrids were studied. Com plants were grown up to 30 days in pots with 7 L of a dark red Latosol sandy loam (Haplortox). Lime was applied to raise base saturation to 30, 50, and 70%, in two levels of phosphorus (P) fertilization with TS (0 and 200 ppm P). There was an increase in root surface due to lime only in pots without TS, with no effects on plant growth or nutrition. Both com hybrids responded to P fertilization, but Pioneer yielded more dry matter than Cargill. The roots of Cargill were thicker and, when in TS presence, were longer and had a larger surface than Pioneer. There was an increase in macronutrient uptake in the P fertilized pots. Pioneer required more nutrients and showed a higher efficiency in acquiring and utilizing the nutrients from the soil. A higher response of Pioneer in dry matter and nutrient acquisition was more related to the physiological efficiency than to root morphology.
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The phycoerythrin-deficient strain (green phenotype) of Hypnea musciformis (Rhodophyta) originated from a green branch, which had arisen as a spontaneous mutation in a wild plant (brown phenotype) collected from the Brazilian coast. The present study describes the growth responses to irradiance, photoperiod and temperature variations, pigment contents, and photosynthetic characteristics of the brown and green strains of H. musciformis. The results showed that growth rates increased as a function of irradiance (up to 40 mu mol photons m(-2) s(-1)) but, with further increase in irradiance (from 40 to 120 mu mol photons m(-2) s(-1)), became light-saturated and remained almost unchanged. The highest growth rates of the brown and green strains were observed in temperatures of 20-25 degrees C under long (14:10 h LD) and short (10:14 h LD) photoperiods. The brown strain had higher growth rates than the green strain in the short photoperiod, which could be related to the high concentrations of phycobiliproteins. Phycoerythrin was not detected in the green strain. The brown strain had higher concentrations of allophycocyanin and phycoerythrin in the short photoperiod while the green strain had higher concentrations of phycocyanin. The brown strain presented higher photosynthetic efficiency (alpha), and lower saturation parameter (I-k) and compensation irradiance (I-c) than the green strain. The brown strain exhibited the characteristics of shade-adapted plants, and its higher value of photosynthetic efficiency could be attributed to the higher phycoerythrin concentrations. Results of the present study indicate that both colour strains of H. musciformis could be selected for aquaculture, since growth rates were similar (although in different optimal light conditions), as the green strain seems to be adapted to higher light levels than the brown strain. Furthermore, these colour strains could be a useful experimental system to understand the regulation of biochemical processes of photosynthesis and metabolism of light-harvesting pigments in red algae.
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Volume changes of the vitellarium components of the leaf-cutting ant Atta sexdens rubropilosa are reported. The oocyte grew to approximately 409 times of its initial volume and reached a maximum value of 1.2 x 10(7) mu m(3). The follicle increase in size at a more or less constant rate up to the 12(th), showing an elevated growth rate thereafter. The mean number of follicles per ovariole was 16.42 +/- 3.58.
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The prostate of the female gerbil (Meriones unguiculatus) is similar to the human female prostate (Skene gland) and, despite its reduced size, it is functional and shows secretory activity. However, virtually nothing is known about its physiological regulation. This study was thus undertaken to evaluate the behavior of the gerbil female prostate in a hyperandrogenic condition. Adult females received subcutaneous injections of testosterone cypionate (1 mg/kg body weight every 48 h) up to 21 days. Circulating levels of testosterone and estradiol were monitored, and the prostate and ovaries subjected to structural and immunocytochemical analyses. The treatment resulted in sustained high levels of circulating testosterone, and caused a transient increase in estradiol. There was an increase in epithelial cell proliferation accompanied by significant reorganization of the epithelium and an apparent reduction in secretory activity, followed by a progressive increase in luminal volume density and accumulation of secretory products. Immunocytochemistry identified the expression of androgen receptor and a prostate-specific antigen (PSA)-related antigen in prostatic epithelial cells. A circulating PSA-related antigen was also found, and its concentration showed strong negative correlation with circulating estrogen. Epithelial dysplasia was detected in the prostate of treated females. Analysis of the ovaries showed the occurrence of a polycystic condition and stromal cell hyperplasia. The results indicate that testosterone has a stimulatory effect on the female prostate, inducing epithelial cell proliferation, differentiation, secretory activity, and dysplasia. The results also suggest that prostatic growth and activity, polycystic ovaries, and ovarian stromal cell hyperplasia are related to a hyperandrogenic condition in females.
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c-axis oriented Bi3.25La0.75Ti3O12 (BLT) thin films were grown on a RuO2 top electrode deposited on a (100) SiO2/Si substrate by the polymeric precursor method. X-ray diffraction and atomic force microscope investigations indicate that the films exhibit a dense, well crystallized microstructure having random orientations with a rather smooth surface morphology. The electrical properties of preferred oriented Bi3.25La0.75Ti3O12 (BLT) thin films deposited on RuO2 bottom electrode leaded to a large remnant polarization (P-r ) of 17.2 mu C/cm(2) and (V-c ) of 1.8 V, fatigue free characteristics up to 10(10) switching cycles and a current density of 2.2 mu A/cm(2) at 5 V. We found that the polarization loss is insignificant with nine write/read voltages at a waiting time of 10,000 s. Independently of the applied electric field the retained switchable polarization approached a nearly steady-state value after a retention time of 10 s.
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3,4,4'-trichlorocarbanilide (TCC) was rested as a new method of bacterial growth control for S. cerevisiae alcoholic fermentations of diluted high test molasses (HTM). Minimal inhibitory concentration (MIC) was tested to determine the necessary concentration of TCC to control bacterial growth. The fed-batch alcoholic fermentation process was used with cell recycle similar to industrial conditions and Lactobacillus fermentum CCT 1407 was mixed in the first inoculum to grow with the yeast. Yeast extract was added into the must to stimulate bacterial growth. The best results of TCC's MIC to bacterial growth of Lactobacillus fermentum and Leuconostoc mesenteroides (< 0.125-1.0 mu g/ml) and Saccharomyces cerevisiae (16 mu g/ml) occurred when it was combined with sodium dodecylsulphate (SDS) in a 1: 4 TCC/SDS ratio (wt/wt) in distilled water solution. 1.8 g/l TCC entrapped in calcium alginate added to the must with yeast extract inhibited the growth of Lactobacillus fermentum CCT 1407 maintaining a controlled acidity, higher yeast viability and up to 20.8% of improvement in the average of alcoholic efficiency. Addition of 0.075 g/l TCC entrapped in calcium alginate and 1.67 mg/l SDS in the wort with yeast extract (0-5.0 g/l), inhibited and controlled the extensive bacterial contamination for 19 cycles of fermentation. (C) 1998 Published by Elsevier B.V. Ltd.