oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 21 )

2018 ( 23 )

2017 ( 27 )

2016 ( 27 )

Custom range...

Search Results: 1 - 10 of 15333 matches for " Luz Jr "
All listed articles are free for downloading (OA Articles)
Page 1 /15333
Display every page Item
Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilhéus, Bahia
Luz, JR.;Boehs, G.;
Brazilian Journal of Biology , 2011, DOI: 10.1590/S1519-69842011000400012
Abstract: the aim of this study was to characterize the reproductive cycle of anomalocardia brasiliana, typical of the estuarine region of the cachoeira river, ilhéus, bahia, brazil. for this purpose, 20 specimens were collected biweekly between august 2005 and august 2006 on an intertidal bank (14o 48' 23" s and 39o 02' 47" w). the animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in davidson's solution. subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with harris hematoxylin and eosin (he). the slides were examined under a light microscope. the water temperature at the site ranged from 24 to 30.5 oc (mean: 27.4 oc; sd ± 1.9), salinity from zero to 23 (mean: 13.7; sd ± 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). the sample (n = 478) showed a sex ratio (m: f) of 1: 1.2 (p < 0.05) and no cases of hermaphroditism. there was no sexual dimorphism. males and females showed reproductive synchrony. the reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. these results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes.
Desidrata??o de etanol sobre material nanoestruturado do tipo LaSBA-15
Luz Jr, Geraldo E.;Melo, Ana C. R.;Lima, Stevie H.;Araujo, Ant?nio S.;Fernandes Jr., Valter J.;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000800005
Abstract: la-incorporated sba-15 mesopourous molecular sieves (lasba-15) were directly synthesized with aim to convert ethanol to ethylene. the samples were characterized by xrd, xrf, nitrogen sorption and acidity, by thermodesorption of n-buthylamine. the results have indicated that all the samples have showed high ordered mesostructure with a large average pore size, and that the lanthanum incorporation has caused an increase in the acidity of the sba-15. the lasba-15 samples have improved, with low deactivation rate, the conversion of the ethanol to water, ether, acetaldehyde and ethylene. in addition, they have increased the ethylene selectivity.
Myiasis by Screw Worm Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) in a Wild Maned Wolf Chrysocyon brachyurus (Mammalia: Canidae), in Brasília, Brazil
Cansi, ER;Bonorino, R;Ataíde, HS;Pujol-Luz, JR;
Neotropical Entomology , 2011, DOI: 10.1590/S1519-566X2011000100025
Abstract: in april 2009, a wild maned wolf, chrysocyon brachyurus, was captured in an area of cerrado in brasília, df, brazil, with screw worm maggots in external wounds. fifty larvae were bred in the laboratory and eight adults of cochliomyia hominivorax (coquerel) emerged 10 days after pupation. this is the first report of a myiasis by c. hominivorax in a free-living maned wolf in brazil.
Microestrutura e propriedades mecanicas de compósitos de polipropileno refor?ado com celulose de baga?o e palha de cana
Luz, Sandra M. da;Gon?alves, Adilson R.;Del'Arco Jr, Ant?nio P.;
Matéria (Rio de Janeiro) , 2006, DOI: 10.1590/S1517-70762006000200004
Abstract: composites utilizing vegetable fibers as reinforcement have demonstrated attracted increasing interest ofcrescent advantages from the scientific and industrial communities. sugarcane bagasse and straw are renewable materials and when used as reinforcement in thermoplastic matrix can give origin to composite materials with low cost, low density and interesting mechanical properties. this work aimed to evaluate the mechanical and morphological properties of polypropylene composites reinforced with cellulose from sugarcane bagasse and straw. the cellulose was obtained through naoh/aq pulping process at 170oc for 3.5 h. the composites reinforced with 20 and 30 % wt of fibers were preparated utilizing a dryser mixer. after ground and injection molding, these materials were analyzed by tensile and flexural tests, optical microscopy (om) and scanning electron microscopy (sem). the tensile strength of composites reinforced with fibers (20 wt.%) was similar to that of pure polypropylene, however, it decreased with the increase increasing amount of reinforcement. the tensile and flexural elasticity moduli increased up to 79.4 and 81.7 %, respectively, due to the high modulus of the fibers inserted inside the polymeric matrix. the composite surface analysis by om showed homogeneous distribution of fibers inside the matrix and variable length and shape of the fibers. the cellulosic fibers from straw were also smaller than those from bagasse. sem analysis of fractured composites exhibited pullout displacement of the fiber in with respect to thematrix and a typical behavior of brittle fracture. cellulosic fibers obtained from sugarcane bagasse and straw resulted in composites with similar mechanical and morphological properties and provided rigidity to thematrix.
Progress?o da espessura corneana do ponto mais fino em dire??o ao limbo: estudo de uma popula??o normal e de portadores de ceratocone para cria??o de valores de referência
Luz, Allan;Ursulio, Mário;Casta?eda, Daniel;Ambrósio Jr, Renato;
Arquivos Brasileiros de Oftalmologia , 2006, DOI: 10.1590/S0004-27492006000400023
Abstract: purpose: to study the variation and progression of the pachymetric values from the thinnest point towards the limbus in normal and keratoconic corneas; to establish reference curves for this parameter. methods: one hundred eyes with normal corneas and twenty-five eyes with mild keratoconus (stages i and ii - krumeich) were analyzed using the orbscan. concentric circles were drawn on the thinnest point of the cornea with increasing radii from 1 to 7 mm. the average results of each circle were calculated and inserted in an excel table in order to arrange a progression chart for each case starting on the thinnest point. the spss software was also used for statistical analysis. student's t test was then used to compare the found values. results: the average values on the thinnest point in normal patients was 511.6 μm (standard deviation 30.6). the average values of the thinnest point in patients with keratoconus was 424.4 μm (standard deviation 56.57). statistically significant different values were reported (p<0.01) for all circles, and for 6 and 7 mm radii p=0.01. conclusion: there is a greater pachymetric variability in patients with keratoconus. keratoconic corneas also have a faster progression of pachymetric values than healthy eyes. pachymetric progression complements traditional single point evaluation of corneal thickness and must be considered for the screening at refractive candidates. this parameter may represent an indirect index of the biomechanics of corneal tissue but this hypothesis still needs further studies.
Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain
Luz-Agostinho, KDG.;Agostinho, AA.;Gomes, LC.;Júlio-Jr., HF.;Fugi, R.;
Brazilian Journal of Biology , 2009, DOI: 10.1590/S1519-69842009000300004
Abstract: flood pulses affect floodplain enrichment via the incorporation of nutrients and terrestrial biomass. as a result, they positively affect the body condition of aquatic organisms. this paper evaluates whether the absence of floods (resulting from dam control) affects the feeding activity and body condition of piscivorous fish. in addition, whether piscivores respond similarly to alterations in the flooding regime was assessed. five piscivorous species were selected (acestrorhynchus lacustris, hoplias aff. malabaricus, plagioscion squamosissimus, rhaphiodon vulpinus, and salminus brasiliensis). the fish were captured in four distinct years and in three river subsystems with differentiated water level fluctuations (ivinheira = not regulated; baía = regulated by the paraná river level; paraná = regulated by dams). feeding activity and body condition were evaluated using the mean values of the standard residuals generated by regression models between body and stomach weights and standard length and body weight (all log-transformed). differences among years and subsystems were evaluated via two-way analysis of variance. pearson and spearman correlations were performed between flooding attributes (duration, amplitude, timing, and daily variability) and feeding activity and body condition. feeding activity differed across subsystems, whereas body condition varied across years, depending on the subsystem. hoplias aff malabaricus (an ambusher adapted to starvation) presented feeding activity independent of the flooding regime and also presented better body condition in times of high water levels. rhaphidon vulpinus exhibited variations in feeding activity but did not present alterations in body condition. the other species presented poorer body condition in years or subsystems with regular floods. correlations identified that the duration and timing of floods had negative effects on body condition, whereas amplitude and mean annual water level improved feeding activity. there
Functional and morphological effects of resistance exercise on disuse-induced skeletal muscle atrophy
Nicastro, H.;Zanchi, N.E.;da Luz, C.R.;Lancha Jr., A.H.;
Brazilian Journal of Medical and Biological Research , 2011, DOI: 10.1590/S0100-879X2011007500125
Abstract: abstract the reduction of skeletal muscle loss in pathological states, such as muscle disuse, has considerable effects in terms of rehabilitation and quality of life. since there is no currently effective and safe treatment available for skeletal muscle atrophy, the search for new alternatives is necessary. resistance exercise (re) seems to be an important tool in the treatment of disuse-induced skeletal muscle atrophy by promoting positive functional (strength and power) and structural (hypertrophy and phenotypic changes) adaptive responses. human and animal studies using different types of resistance exercise (flywheel, vascular occlusion, dynamic, isometric, and eccentric) have obtained results of great importance. however, since re is a complex phenomenon, lack of strict control of its variables (volume, frequency, intensity, muscle action, rest intervals) limits the interpretation of the impact of the manipulation on skeletal muscle remodeling and function under disuse. the aim of this review is to critically describe the functional and morphological role of resistance exercise in disuse-induced skeletal muscle atrophy with emphasis on the principles of training.
Coronary fat content evaluated by morphometry in patients with severe atherosclerosis has no relation with serum lipid levels
Braz Jr., D.J.;Gutierrez, P.S.;Luz, P.L. da;
Brazilian Journal of Medical and Biological Research , 2007, DOI: 10.1590/S0100-879X2007000400004
Abstract: the relationship between lipid serum levels and coronary atherosclerotic plaque fat content was studied in 51 necropsy patients. serum lipids were measured by standard techniques, during life, in the absence of lipid-lowering drugs. intima, intimal fat and media areas were measured using a computerized system in cryosections of the odd segments of the right, anterior descending and circumflex coronary arteries stained with sudan-iv. mean intimal and lipid areas were 5.74 ± 1.98 and 1.22 ± 0.55 mm2 (22.12 ± 8.48%) in 26 cases with high cholesterol (3200 mg/dl) and 4.98 ± 1.94 and 1.16 ± 0.66 mm2 (22.75 ± 9.06%) in 25 cases with normal cholesterol (<200 mg/dl; p > 0.05). patients with high levels of low-density lipoprotein (3130 mg/dl, n = 15) had a higher intima/media area ratio than those with normal levels of low-density lipoprotein (<130 mg/dl, n = 13, p < 0.01). no significant difference in the morphometrical variables was found in groups with high or low serum levels of triglycerides (3200 mg/dl, n = 13 vs <200 mg/dl, n = 36) or high-density lipoprotein (335 mg/dl, n = 11 vs <35 mg/dl, n = 17). the association between the morphological measurements and serum levels of cholesterol, its fractions, and triglycerides was also tested and the correlation coefficients were low. although high cholesterol is a risk factor, we show here that in patients with severe atherosclerosis blood cholesterol and triglyceride levels seem to have little influence on coronary lipid content, indicating that other factors may contribute to arterial lipid deposition and plaque formation.
Selective cyclooxygenase-2 inhibition protects against myocardial damage in experimental acute ischemia
Carnieto Jr., Alberto;Dourado, Paulo Magno Martins;Luz, Protásio Lemos da;Chagas, Antonio Carlos Palandri;
Clinics , 2009, DOI: 10.1590/S1807-59322009000300016
Abstract: background: acute myocardial infarction is associated with tissue inflammation. early coronary reperfusion clearly improves the outcome but may help propagate the inflammatory response and enhance tissue damage. cyclooxygenase-2 is an enzyme that catalyzes the initial step in the formation of inflammatory prostaglandins from arachidonic acid. cyclooxygenase-2 levels are increased when ischemic cardiac events occur. the overall function of cox-2 in the inflammatory process generated by myocardial ischemic damage has not yet been elucidated. goal: the objective of this study was to determine whether a selective cyclooxygenase-2 inhibitor (rofecoxib) could alter the evolution of acute myocardial infarction after reperfusion. methods and results: this study was performed with 48 mongrel dogs divided into two groups: controls and those treated with the drug. all animals were prepared for left anterior descending coronary artery occlusion. the dogs then underwent 180 minutes of coronary occlusion, followed by 30 minutes of reperfusion. blood samples were collected from the venous sinus immediately before coronary occlusion and after 30 minutes of reperfusion for measurements of cpk-mb, cpk-mbm and troponin i. during the experiment we observed the mean blood pressure, heart rate and coronary flow. the coronary flow and heart rate did not change, but in the control group, there was blood pressure instability, in addition to maximal levels of cpk-mb post-infarction. the same results were observed for cpk-mbm and troponin i. conclusion: in a canine model of myocardial ischemia-reperfusion, selective inhibition of cyclooxygenase-2 with rofecoxib was not associated with early detrimental effects on the hemodynamic profile or the gross extent of infarction; in fact, it may be beneficial by limiting cell necrosis.
The genera Boiruna and Clelia (serpentes: pseudoboini) in Paraguay and Argentina
Scott Jr., Norman J.;Giraudo, Alejandro R.;Scrocchi, Gustavo;Aquino, Aida Luz;Cacciali, Pier;Motte, Martha;
Papéis Avulsos de Zoologia (S?o Paulo) , 2006, DOI: 10.1590/S0031-10492006000900001
Abstract: snakes of the pseudoboine genera clelia, which is probably polyphyletic, and boiruna are distributed from southern argentina, southern brazil, and uruguay northwards into central méxico. six members occur in paraguay and argentina: b. maculata, clelia bicolor, c. clelia, c. plumbea, c. quimi, and c. rustica. historically, there has been taxonomic confusion among the larger species (b. maculata, c. clelia, c. plumbea, and c. rustica) and between the small species (c. bicolor and c. quimi). all of the species except c. rustica have distinct ontogenetic color changes. species can be distinguished on the bases of size, color, hemipenial spines, and loreal, supralabial, and ventral scale counts. much of the morphological evolutionary differentiation in boiruna and clelia seems to have taken place in the snout region, as evidenced by the differing proportions of the scales of the loreal region. boiruna maculata has the widest ecological amplitude. it is broadly distributed in most vegetation types north of the 38th parallel in central argentina, being absent only from the deltaic sediments of buenos aires province, argentina and the broad valleys and rolling hills of eastern paraguay. clelia bicolor is most common in the paraguay and paraná river valleys, with a few records from the andean foothills in northern argentina. clelia clelia is distributed along the río paraguay and the lower paraná, and is also found throughout much of eastern paraguay. clelia plumbea is apparently parapatric with c. clelia along the río paraná in southeastern paraguay and misiones province, argentina. the ranges of c. quimi to the east and c. bicolor in the west about in this same region without apparent overlap. there are no vouchered records of clelia rustica from paraguay. in argentina, it is a species of temperate climates; north of the 30th parallel, it occurs in the andean foothills and the wet forests of misiones province. southwards, it is widely distributed to beyond the 40th paralle
Page 1 /15333
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.