1,977 research outputs found

    Molecular regimes in ultracold Fermi gases

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    The use of Feshbach resonances for tuning the interparticle interaction in ultracold Fermi gases has led to remarkable developments, in particular to the creation and Bose-Einstein condensation of weakly bound diatomic molecules of fermionic atoms. These are the largest diatomic molecules obtained so far, with a size of the order of thousands of angstroms. They represent novel composite bosons, which exhibit features of Fermi statistics at short intermolecular distances. Being highly excited, these molecules are remarkably stable with respect to collisional relaxation, which is a consequence of the Pauli exclusion principle for identical fermionic atoms. The purpose of this review is to introduce theoretical approaches and describe the physics of molecular regimes in two-component Fermi gases and Fermi-Fermi mixtures, focusing attention on quantum statistical effects.Comment: Chapter of the book: "Cold Molecules: Theory, Experiment, Applications" edited by R. V. Krems, B. Friedrich and W. C. Stwalley (publication expected in March 2009

    Effect of cyclooxygenase inhibitors on gentamicin-induced nephrotoxicity in rats

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    The frequent use of nonsteroidal anti-inflammatory drugs (NSAID) in combination with gentamicin poses the additional risk of nephrotoxic renal failure. Cyclooxygenase-1 (COX-1) is the main enzyme responsible for the synthesis of renal vasodilator prostaglandins, while COX-2 participates predominantly in the inflammatory process. Both are inhibited by non-selective NSAID such as indomethacin. Selective COX-2 inhibitors such as rofecoxib seem to have fewer renal side effects than non-selective inhibitors. The objective of the present study was to determine whether the combined use of rofecoxib and gentamicin can prevent the increased renal injury caused by gentamicin and indomethacin. Male Wistar rats (250-300 g) were treated with gentamicin (100 mg/kg body weight, ip, N = 7), indomethacin (5 mg/kg, orally, N = 7), rofecoxib (1.4 mg/kg, orally, N = 7), gentamicin + rofecoxib (100 and 1.4 mg/kg, respectively) or gentamicin + indomethacin (100 and 5 mg/kg, respectively, N = 8) for 5 days. Creatinine clearance and alpha-glutathione-S-transferase concentrations were used as markers of renal injury. Animals were anesthetized with ether and sacrificed for blood collection. The use of gentamicin plus indomethacin led to worsened renal function (0.199 ± 0.019 ml/min), as opposed to the absence of a nephrotoxic effect of rofecoxib when gentamicin plus rofexicob was used (0.242 ± 0.011 ml/min). These results indicate that COX-2-selective inhibitors can be used as an alternative treatment to conventional NSAID, especially in situations in which risk factors for nephrotoxicity are present.Universidade de São Paulo Escola de Enfermagem Laboratório ExperimentalUniversidade de São Paulo Faculdade de Medicina Laboratório de Investigação MédicaUniversidade Federal de São Paulo (UNIFESP) Departamento de Clínica Médica Divisão de NefrologiaUNIFESP, Depto. de Clínica Médica Divisão de NefrologiaSciEL

    Griscelli syndrome-type 2 in twin siblings: case report and update on RAB27A human mutations and gene structure

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    Griscelli syndrome (GS) is a rare autosomal recessive disorder caused by mutation in the MYO5A (GS1, Elejalde), RAB27A (GS2) or MLPH (GS3) genes. Typical features of all three subtypes of this disease include pigmentary dilution of the hair and skin and silvery-gray hair. Whereas the GS3 phenotype is restricted to the pigmentation dysfunction, GS1 patients also show primary neurological impairment and GS2 patients have severe immunological deficiencies that lead to recurrent infections and hemophagocytic syndrome. We report here the diagnosis of GS2 in 3-year-old twin siblings, with silvery-gray hair, immunodeficiency, hepatosplenomegaly and secondary severe neurological symptoms that culminated in multiple organ failure and death. Light microscopy examination of the hair showed large, irregular clumps of pigments characteristic of GS. A homozygous nonsense mutation, C-T transition (c.550C>T), in the coding region of the RAB27A gene, which leads to a premature stop codon and prediction of a truncated protein (R184X), was found. In patient mononuclear cells, RAB27A mRNA levels were the same as in cells from the parents, but no protein was detected. In addition to the case report, we also present an updated summary on the exon/intron organization of the human RAB27A gene, a literature review of GS2 cases, and a complete list of the human mutations currently reported in this gene. Finally, we propose a flow chart to guide the early diagnosis of the GS subtypes and Chédiak-Higashi syndrome.FAPESPCNPq(FAEPA) Fundação de Apoio ao Ensino, Pesquisa e Assistência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão PretoCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Uso Da Casca Do Abacate (persea Americana)na Formulação De Chá: Um Produto Funcional Contendo Compostos Fenólicos E Atividade Antioxidante

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    The peels of avocados, like other fruit peels, are commonly discarded, not knowing their potential use. In order to reuse avocado peel, the chemical and mineral compositions, total phenolic and flavonoid contents as well as antioxidant activities have been investigated by DPPH (1,1-diphenyl-2- picrylhydrazyl) and FRAP(ferric-reducing antioxidant power) methods in in natura and dehydrated avocado peel. Dehydrated avocado-peel tea was manufactured and the antioxidant activity was evaluated, as well as their flavonoid and phenolic compound contents, and compared with other teas marketed. Avocado peel, especially dried avocado peel, contains major phenolic compounds (10,848.27 ± 162.34 mg GAE kg-1) and flavonoids (1,360.34 ± 188.65 mg EQ kg-1). The avocado-peel tea showed antioxidant activity by DPPH (1,954.24 ± 87.92 e 2518.27 ± 192.59 mg TE L-1) and phenolic and flavonoids contents highest than apple tea. The avocado-peel tea showed good antioxidant activity and had good acceptability by sensory analysis as a promising product. © 2016, Eduem - Editora da Universidade Estadual de Maringa. All rights reserved.381232

    Behaviour and performance of lactating sows housed in different types of farrowing rooms during summer

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    AbstractThirty mixed-parity Landrace×Large White sows were used to evaluate the effects of the type of farrowing room on 28-day lactation behaviour under tropical conditions during summer. The sows were allocated in a completely randomised design with three treatments with 10 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of a conventional farrowing room (T1); a conventional farrowing room with floor cooling under the sow (T2); and a semi-outdoor farrowing room without a cage and with access to a fenced field (T3). The sows from T1 and T2 groups were exposed to mean maximum and minimum environmental temperatures of 25.7 and 21.0°C, respectively, and the sows from the T3 group to average maximum and minimum environmental temperatures of 26.5 and 20.7°C, respectively. The feed consumption of T3 sows was numerically higher than the T1 and T2 sows (+9.5% on average). The body-weight loss was influenced at 28days (P<0.10) by treatment, being that the T3 sows gained weight (+4.7kg) while the T1 and T2 sows lost weight (−11.9 and −3.7kg, respectively for T1 and T2). The T3 sows showed a higher percentual litter mortality than the T1 and T2 sows (3.2% vs. 0% vs. 7.8%, respectively for T1, T2 and T3 sows). From farrowing until day 28 of lactation, the T2 and T3 sows showed higher lactation efficiency when compared with the T1 sows (72% vs. 87% vs. 88%, respectively for T1, T2 and T3 sows). The T1 sows showed higher (P<0.01) frequencies of visits to the feeder and drinker (+38% on average). The T3 sows spent more time (P<0.01) at the drinker than T1 and T2 sows (23 vs. 23 vs. 32min, respectively for T1, T2 and T3 sows). The T3 sows showed a higher (P<0.10) frequency of nursing than the other treatments (+15% on average). T1 and T2 sows were found to spend more time (P<0.01) performing other postures during 24h than sows maintained in T3 (50 vs. 51 vs. 22min/d, respectively for T1, T2 and T3). It is concluded that cooling of the floor under the sow in the conventional farrowing room or the use of semi-outdoor farrowing rooms improves the thermal environment and the lactation efficiency of the sows housed in hot ambient temperatures at 28-day lactation in the summer period, indicating an improved welfare

    Ammonia levels on in vitro degradation of fibrous carbohydrates from buffel grass

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    This study was carried out to examine the degradation dynamics of neutral detergent fibre (NDF) and the profile of volatile fatty acids that originate from the fermentation of buffel grass (Cenchrus ciliaris, L.) with various levels of ammonia in the growth medium. The treatments consisted of six levels of ammonia in the growth medium (0, 5, 10, 15, 20 and 30 mg/dL), which were obtained by adding urea. These in vitro incubation times were evaluated in three replicates per time for 0, 3, 6, 9, 12, 24, 36, 48, 72 and 96 hours. Rumen concentrations of acetate and propionate responded quadratically to the ammonia levels. The treatment with 15 mg/dL of ammonia nitrogen in the rumen fluid provided mean acetate and propionate contents of 57.6 mM and 23.1 mM, respectively. Urea addition elevated the degradation rate of potentially degradable fraction of NDF (pdNDF) from 2.5% to 20.1% in comparison with the treatment without urea and to a reduction in estimated discrete lag time from 0.34 to 2.31 hours. Urea supplementation increased the specific microorganism growth rate from 2.6% to 20.1%. At the end of the incubation trial, NDF degradation showed a quadratic response, with maximum value obtained at 17.76 mg/dL of ammonia in the rumen fluid. Urea improves the degradation dynamics of NDF from deferred buffel grass and increases the concentrations of acetate and propionate.Keywords: Cenchrus ciliaris, degradation kinetics, non-protein nitrogen, ure

    Effect of salt concentrations on in vitro rumen fermentation of cellulose, starch, and protein

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    The aim of this study was to evaluate the effects of various concentrations of three salts (sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2)) on the in vitro rumen fermentation of cellulose, starch, and protein substrates. Six salt concentrations were tested, separately, namely 0, 100, 200, 400, 800, and 1600 mg/dL. The experiment was conducted using the completely randomized design in a 6 × 3 × 3 factorial arrangement with main effects of salt concentration and salt type (six levels of three salts (NaCl, MgCl2, or CaCl2) (0, 100, 200, 400, 800, and 1600 mg/dL) into three substrates [starch, cellulose, and glucose]) with three replicates. Cellulose- and glucose-fermenting bacteria were sensitive to NaCl concentrations greater than 400 mg/dL (17.48 decisiemens per metre (dS/m)) and 800 mg/dL (20.55 dS/m) in the media, respectively. In contrast, starch-fermenting bacteria continued to grow in NaCl concentrations up to 1600 mg/dL (29.09 dS/m). Thus, it was concluded that starch-fermenting microorganisms tolerated higher concentrations of NaCl compared with the other microbial groups. Cellulose-fermenting microorganisms are less tolerant to MgCl2 in relation to the other microbial groups. Starch, cellulose-, and glucose-fermenting bacteria from cattle tolerate CaCl2 concentrations of up to 1600 mg/dL (12.26 dS/m). These results suggest that brackish water may be used for ruminants. However, it is important perform an analysis of that water and then to adjust diets to minimize the effects of types of salt and concentrations of salt on rumen microorganisms. Keywords: brackish water, dissolved salts, rumen microbes, water qualit

    Fermentation characteristics and chemical composition of elephant grass silage with ground maize and fermented juice of epiphytic lactic acid bacteria

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    This study aimed to evaluate the microbial populations, fermentation profile, dry matter recovery and chemical composition of elephant grass silage with ground maize (GM) and the fermented juice of epiphytic lactic acid bacteria (FJLB). A factorial design was used with four levels of GM (0 g/kg, 50 g/kg, 100 g/kg and 200 g/kg), untreated or treated with FJLB, in a completely randomized design with five replicates. A pre-experiment was undertaken to determine the optimum level of sucrose to be added to fermented juice for the development of epiphytic microflora. In this pre-experiment, a completely randomized design with three replications was used. The treatments were represented by the levels of sucrose (0 g/kg, 5 g/kg, 10 g/kg, 20 g/kg, 40 g/kg, 60 g/kg and 80 g/kg, fresh matter basis). The microbial populations, dry matter recovery, and effluent losses were affected by the interaction between GM and FJLB. Dry matter (DM) and crude protein (CP) contents increased linearly with the inclusion of GM. The addition of GM enhanced the fermentation process via a reduction in losses, and improvements were identified in the nutritional value of elephant grass silages. The use of fermented juice increased dry matter recovery, and its effect was more pronounced when ground maize was added.Keywords: dry matter recovery, lactic acid, microbiology, Pennisetum purpureu
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