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61.
Specimens of Astyanax scabripinnisfrom three different altitudes (1920, 1800 and 700?m) along the Ribeirão Grande stream in the Campos do Jordão region (São Paulo State, Brazil) were investigated. The same diploid number, 2n?=?50, was detected in the three populations, with the following karyotypic constitution: 6M, 22SM, 10ST and 12A. The populations located at 1920 and 1800?m altitude presented a high incidence of B chromosomes varying in number (0–2), shape (meta- and submetacentrics), size (large and small) and sex-related frequency (they were more frequent among females). The two morphologically variant B chromosomes probably evolved from a metacentric macrochromosome, which is the most commonly observed B chromosome in several A. scabripinnispopulations. 相似文献
62.
van Dijken JP Bauer J Brambilla L Duboc P Francois JM Gancedo C Giuseppin ML Heijnen JJ Hoare M Lange HC Madden EA Niederberger P Nielsen J Parrou JL Petit T Porro D Reuss M van Riel N Rizzi M Steensma HY Verrips CT Vindeløv J Pronk JT 《Enzyme and microbial technology》2000,26(9-10):706-714
To select a Saccharomyces cerevisiae reference strain amenable to experimental techniques used in (molecular) genetic, physiological and biochemical engineering research, a variety of properties were studied in four diploid, prototrophic laboratory strains. The following parameters were investigated: 1) maximum specific growth rate in shake-flask cultures; 2) biomass yields on glucose during growth on defined media in batch cultures and steady-state chemostat cultures under controlled conditions with respect to pH and dissolved oxygen concentration; 3) the critical specific growth rate above which aerobic fermentation becomes apparent in glucose-limited accelerostat cultures; 4) sporulation and mating efficiency; and 5) transformation efficiency via the lithium-acetate, bicine, and electroporation methods. On the basis of physiological as well as genetic properties, strains from the CEN.PK family were selected as a platform for cell-factory research on the stoichiometry and kinetics of growth and product formation. 相似文献
63.
64.
Ana Sílvia Franco Pinheiro Moreira José Pires de Lemos Filho Gerhard Zotz Rosy Mary dos Santos Isaias 《Flora》2009,204(8):604-611
This study compares photosynthetic and structural features of Dichaea cogniauxiana and Epidendrum secundum leaves and roots. The diurnal titratable acidity fluctuations indicated crassulacean acid metabolism (CAM) in E. secundum leaves, associated with anatomical features like thick cuticle, large and vacuolated cells, and reduced stomata size and frequency. Roots of both species had chloroplasts in their cortical parenchyma. However, neither the roots nor D. cogniauxiana leaves did show tissue sap acidity fluctuations. This indicates C3 metabolism in these organs. This lack of oscillation of organic acids in Epidendrum roots was at odds with a CAM-like 13C ratio, suggesting that in spite of active CO2 fixation in roots during the day, the bulk of carbon is imported from the leaves. Roots of both species showed Fv/Fm, ΔF/Fm′, ETR values similar to reports from other non-foliar photosynthetic organs. Besides reducing root carbon cost, root photosynthesis may also be important by alleviating potential hypoxia, since water-saturated velamen severely impedes the gas exchange between radicular cortex. 相似文献
65.
Diet and exercise improve chemoreflex sensitivity in patients with metabolic syndrome and obstructive sleep apnea 下载免费PDF全文
Cristiane Maki‐Nunes Edgar Toschi‐Dias Felipe X. Cepeda Maria Urbana P.B. Rondon Maria‐Janieire N. N. Alves Raffael F. Fraga Ana Maria F. W. Braga Adriana M. Aguilar Aline C. Amaro Luciano F. Drager Geraldo Lorenzi‐Filho Carlos E. Negrão Ivani C. Trombetta 《Obesity (Silver Spring, Md.)》2015,23(8):1582-1590
66.
Lara Saraiva Alanna Silva Reis Jeronimo Marteleto Nunes Rugani Agnes Ant?nia Sampaio Pereira Felipe Dutra Rêgo Ana Cristina Vianna Mariano da Rocha Lima Célia Maria Ferreira Gontijo José Dilermando Andrade Filho 《PloS one》2015,10(8)
Brazil is one of the most important endemic areas for leishmaniasis worldwide. Protected areas that are tourist attractions likely present an important risk of transmission of cutaneous leishmaniasis (CL). Furthermore, with the geographical expansion of visceral leishmaniasis (VL), several studies have recorded the occurrence of its vector, Lutzomyia longipalpis, and cases of human and canine VL in such tourist areas. The Parque Estadual do Sumidouro is an environmentally protected area located in the Brazilian Cerrado biome and in an important area endemic for leishmaniasis in the state of Minas Gerais. The purpose of this study was to monitor the sand fly fauna in areas of tourist activity in the park. Sampling was performed every month, from September 2011 to August 2013, using CDC light traps at six sites of differing environmental characteristics. Sampled specimens were identified following Galati (2003), and females were submitted to molecular techniques for the detection and identification of Leishmania DNA. A total of 4,675 sand fly specimens of 25 species belonging to nine genera were collected. The most abundant species were Micropygomyia quinquefer, Lutzomyia renei and Pintomyia pessoai, although only Pi. pessoai is implicated in the transmission of Leishmania braziliensis. The species accumulation curve reached saturation on the 16th sampling event. Species richness, diversity and evenness differed among the sampled areas. The seasonal curve was not determined by a single unique species, and no single species was the most abundant in all environments sampled. The main vector of Leishmania (Leishmania) infantum, Lutzomyia longipalpis, accounted for only 5.35% of the specimens collected. Proven or suspected vectors of Leishmania (Viannia) braziliensis were recorded, and one female of the cortellezzii complex tested positive for Le. braziliensis DNA. Even with a low infection rate (0.62%), these data indicate the circulation of the parasite and reinforce the need for entomological and epidemiological surveillance in the park and its surroundings. 相似文献
67.
Karla F.A.S. Silva Miguel Michereff‐Filho Maria E.N. Fonseca José G. Silva‐Filho Ana C.A. Texeira Antônio Williams Moita Jorge B. Torres Rafael Fernández‐Muñoz Leonardo S. Boiteux 《Entomologia Experimentalis et Applicata》2014,151(3):218-230
Advances in tomato breeding for pest resistance have been achieved via gene introgression from wild Solanum (section Lycopersicon) species (Solanaceae). Ninety‐nine F3 families derived from an interspecific cross using as parental lines Solanum lycopersicum L. ‘LAM‐148' (susceptible standard) and Solanum pimpinellifolium L. ‘TO‐937‐15’ (multiple pest resistance accession with type IV glandular trichomes and acylsugar accumulation) were evaluated for their resistance against the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B in free‐choice and no‐choice tests for oviposition and adult colonization. The parental lines and eight F3 families with contrasting levels of resistance against the whitefly were selected and investigated in additional assays, which included the estimation of trichome densities and foliar acylsugar levels. The F3 families BTR‐302 and BTR‐331 exhibited low amounts of eggs of whitefly and transgressive segregation for type IV glandular trichome density with values greater than that of TO‐937‐15 plants. However, the tested families did not surpass the total foliar acylsugar content found in TO‐937‐15. BTR‐331 exhibited low colonization in the free‐choice test and it was the least preferred F3 family in the no‐choice test. The higher resistance levels of BTR‐331 were associated with a positive combination of higher type IV trichome density and higher acylsugar levels. Some F3 families displayed reduced fruit set due to the presence of flowers with style exertion of the antheridial‐cone. Fruit weight at harvest stage of the selected families (from 4.9 to 14.5 g) was lower than that of LAM‐148 (139.5 g) but higher than that of TO‐937‐15 plants (1.3 g). Therefore, although difficult to reach due to the simultaneous segregation of many polygenic traits, the combination of high B. tabaci resistance levels with superior horticultural traits is feasible. These results confirm TO‐937‐15 as a source of biotype B resistance. From the breeding standpoint, the genetic similarity between S. lycopersicum and S. pimpinellifolium would allow a more efficient resistance introgression by facilitating recombination and minimizing the potentially undesirable linkage drag associated with this trait. 相似文献
68.
Carolina G. Fernandes Guilhian Leipnitz Bianca Seminotti Alexandre U. Amaral Ângela Zanatta Carmen R. Vargas Carlos S. Dutra Filho Moacir Wajner 《Cellular and molecular neurobiology》2010,30(2):317-326
High levels of phenylalanine (Phe) are the biochemical hallmark of phenylketonuria (PKU), a neurometabolic disorder clinically
characterized by severe mental retardation and other brain abnormalities, including cortical atrophy and microcephaly. Considering
that the pathomechanisms leading to brain damage and particularly the marked cognitive impairment in this disease are poorly
understood, in the present study we investigated the in vitro effect of Phe, at similar concentrations as to those found in
brain of PKU patients, on important parameters of oxidative stress in the hippocampus and cerebral cortex of developing rats.
We found that Phe induced in vitro lipid peroxidation (increase of TBA-RS values) and protein oxidative damage (sulfhydryl
oxidation) in both cerebral structures. Furthermore, these effects were probably mediated by reactive oxygen species, since
the lipid oxidative damage was totally prevented by the free radical scavengers α-tocopherol and melatonin, but not by L-NAME,
a potent inhibitor of nitric oxide synthase. Accordingly, Phe did not induce nitric oxide synthesis, but significantly decreased
the levels of reduced glutathione (GSH), the major brain antioxidant defense, in hippocampus and cerebral cortex supernatants.
Phe also reduced the thiol groups of a commercial GSH solution in a cell-free medium. We also found that the major metabolites
of Phe catabolism, phenylpyruvate, phenyllactate and phenylacetate also increased TBA-RS levels in cerebral cortex, but to
a lesser degree. The data indicate that Phe elicits oxidative stress in the hippocampus, a structure mainly involved with
learning/memory, and also in the cerebral cortex, which is severely damaged in PKU patients. It is therefore presumed that
this pathomechanism may be involved at least in part in the severe cognitive deficit and in the characteristic cortical atrophy
associated with dysmyelination and leukodystrophy observed in this disorder. 相似文献
69.
Raquel Cristine Kuhn Francisco Maugeri Filho 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(22):2023-2028
Recent studies have shown that the chromatographic separation of mixtures of monosaccharides and disaccharides may be improved by employing Y zeolites, a procedure which holds promise in the separation of oligosaccharides. In the present study, a column packed with zeolite was employed to study the separation of fructooligosaccharides (FOS). FOS were produced by an enzyme isolated from Rhodotorula sp., which produces GF2 (kestose), GF3 (nystose) and GF4 (frutofuranosyl nystose). The identification and quantification of the sugars were carried out by ion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The separation of fructooligosaccharides was carried out using a fixed bed column packed with Ba2+-exchange Y zeolites. The effects of temperature (40–50 °C), injected volume per bed volume (2.55–7.64%), superficial velocity (0.1–0.15 cm min−1) and eluent composition (40–60% ethanol) were investigated using a fractionary factorial design with separation efficiency as the response. The results showed that the most favorable conditions for the separation of the oligosaccharide–glucose mixture were 60% ethanol as eluent, temperature of 50 °C, superficial velocity of 0.1 cm min−1 and 2.55% injection volume per bed volume of injection mixture, using two columns in series. The values for separation efficiency were 0.60 for oligosaccharide–glucose, 1.00 for oligosaccharide–fructose, 0.22 for oligosaccharide–sucrose, 0.43 for glucose–fructose, 0.82 for glucose–sucrose and 1.23 for fructose–sucrose. 相似文献
70.
Toyama MH Toyama DO Torres VM Pontes GC Farias WR Melo FR Oliveira SC Fagundes FH Diz Filho EB Cavada BS 《The protein journal》2010,29(8):567-571
Low molecular weight fragments of sulfated galactans (Boc-5 and Boc-10) from the red algae Botryocladia occidentalis significantly inhibited Crotalus durissus cascavella sPLA2 enzymatic activity. Equimolar ratios of sPLA2 to Boc-5 or Boc-10 resulted in allosteric inhibition of sPLA2. Under
the conditions tested, we observed that both Boc-5 and Boc-10 strongly decreased edema, myonecrosis, and neurotoxicity induced
by native sPLA2. 相似文献