1,535 research outputs found
Amphiphile Adsorption on Rigid Polyelectrolytes
A theory is presented which quantitatively accounts for the cooperative
adsorption of cationic surfactants to anionic polyelectrolytes. For high salt
concentration we find that the critical adsorption concentration (CAC) is a
bilinear function of the polyion monomer and salt concentrations, with the
coefficients dependent only on the type of surfactant used. The results
presented in the paper might be useful for designing more efficient gene
delivery systems
Influence of abiotic factors on the chemical composition of copaiba oil (Copaifera multijuga Hayne): soil composition, seasonality and diameter at breast height
Copaiba oils are important medicinal products used primarily for their healing and anti-inflammatory activities. Consisting of sesquiterpenes and diterpenes, these oils have variable composition which, according to the literature, may originate from several factors. In order to analyze the relationship between chemical composition and abiotic factors such as seasonality, diameter at breast height (DBH) and soil composition, sixteen of oilresin samples of Copaifera multijuga Hayne, from the Ducke Forest Reserve (Manaus City, Amazon State, Brazil), were analyzed by gas chromatography with flame ionization detection (GC-FID) and coupled with mass spectrometry (GC-MS). Thirty-five compounds were identified and the results evaluated by multivariate analysis (hierarchical cluster analysis (HCA) and principal component analysis (PCA)), allowing differentiation of the samples into two groups with different compositions. One of them presented β-caryophyllene as the major constituent, while the other presented caryophyllene oxide. This variation in composition appears to depend on soil type. Other factors previously described as essential for defining the chemical composition of copaiba oils, such as seasonality and DBH, showed no significant influence on the chemical composition of oils of this species
The Arabidopsis SR45 splicing factor, a negative regulator of sugar signaling, modulates SNF1-related protein kinase 1 (SnRK1) stability
The deposited article is a post-print version and has been submitted to peer review.This publication hasn't any creative commons license associated.This deposit is composed by the main article, and it hasn't any supplementary materials associated.The ability to sense and respond to sugar signals allows plants to cope with environmental and metabolic changes by adjusting growth and development accordingly. We previously reported that the SR45 splicing factor negatively regulates glucose signaling during early seedling development in Arabidopsis thaliana Here, we show that under glucose-fed conditions, the Arabidopsis sr45-1 loss-of-function mutant contains higher amounts of the energy-sensing SNF1-Related Protein Kinase 1 (SnRK1) despite unaffected SnRK1 transcript levels. In agreement, marker genes for SnRK1 activity are upregulated in sr45-1 plants, and the glucose hypersensitivity of sr45-1 is attenuated by disruption of the SnRK1 gene. Using a high-resolution RT-PCR panel, we found that the sr45-1 mutation broadly targets alternative splicing in vivo, including that of the SR45 pre-mRNA itself. Importantly, the enhanced SnRK1 levels in sr45-1 are suppressed by a proteasome inhibitor, indicating that SR45 promotes targeting of the SnRK1 protein for proteasomal destruction. Finally, we demonstrate that SR45 regulates alternative splicing of the Arabidopsis 5PTase13 gene, which encodes an inositol polyphosphate 5-phosphatase previously shown to interact with and regulate the stability of SnRK1 in vitro, thus providing a mechanistic link between SR45 function and the modulation of degradation of the SnRK1 energy sensor in response to sugars.Fundação para a Ciência e a Tecnologia grants: (PTDC/BIA-PLA/3937/2012, PTDC/BIA-PLA/1084/2014, SFRH/BPD/80073/2011, SFRH/BPD/94796/2013); EMBO Installation Program: (EMBO-Proj.1984); Scottish Government Rural and Environment Science and Analytical Services (RESAS).info:eu-repo/semantics/publishedVersio
THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL
Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni
Coping with antidepressants in a changing ocean: behavioural implications in juvenile meagre (Argyrosomus regius) exposed to venlafaxine.
Na publicação: FABIOLA FOGAÇA
Determinação das frações volumétricas de ferrita e martensita em função da temperatura de têmpera intercrírtica para o aço 1011 ao Si e Mn
Com a grande procura por parte das indústrias automobilísticas em melhorar o desempenho e diminuir a poluição, vem se desenvolvendo pesquisas para a redução de peso de seus automóveis. Uma das linhas de pesquisas é aquela envolvendo os aços bifásicos, estes aços possuem uma boa conformabilidade, uma boa resistência mecânica, uma boa tenacidade e um alto índice de encruamento. Estas propriedades são oriundas de sua microestrutura formada pelas fases ferrita e martensita. Neste trabalho foi determinada a faixa de temperatura para tratamentos térmicos intercríticos, via simulação numérica e por metalografia quantitativa. As simulações numéricas foram realizadas utilizando o software THERMOCALC e considerando um aço com 0,11% de carbono e seus principais elementos de liga. Utilizando a faixa de temperatura determinada pela simulação numérica, foram realizadas têmperas a partir de diferentes temperaturas com o objetivo de se obter microestruturas com diferentes frações volumétricas de ferrita e martensita. As têmperas intercríticas foram realizadas a cada 10 oC, cobrindo toda a faixa de temperatura determinada pela simulação computacional. As frações volumétricas de ferrita e martensita, em cada amostra temperada, foram determinadas por meio de metalografia quantitativa. Os resultados mostraram que a faixa de temperatura para tratamento térmicos intercriticos (698 oC a 833 oC) e as frações volumétricas de ferrita e martensita obtidas pela simulação numérica estão de acordo com aquelas obtidas por metalografia quantitativa
The emergence of arboviruses changes the profile of viral meningitis in Salvador, Bahia: A case series
Background: Recently, different arboviruses became endemic in Brazil mostlycausing acute febrile illnesses, however, neurological manifestations have alsobeen reported. This study aimed to investigate which viruses were involved inthe meningitis etiology and the contribution of the circulating arboviruses inSalvador, Bahia, Brazil.Methods: From June 2014 to February 2016, 170 patients with suspected viralmeningitis were identified in Couto Maia Hospital, Salvador-BA, Brazil. TheirCSF samples were investigated for possible viral etiology by reversetranscription-PCR (RT-PCR) for different arboviruses: DENV, ZIKV and CHIKV;and for the EV; and by PCR for the HHV1-5 complex (HSV1-2, VZV, EBV andCMV). Also, ELISA was carried out in a subgroup of remaining samples fordetection of DENV IgM and NS1 antigen, CHIKV IgM and ZIKV IgM.Results: Thirty-seven patients were PCR or ELISA positive for at least one of thestudied viruses (overall positivity 21.8%). EV was the agent most frequentlydetected (10 cases; 27.0%), along with all four DENV serotypes (10 cases;27.0%); followed by CHIKV (6 cases; 16.2%), ZIKV (6 cases; 16.2%), and Varicellazoster virus (VZV) (1 case; 2.7%). Four cases (10.8%) presented viral co-infectiondetected: DENV1 + CHIKV, DENV1 + EV, DENV4 + ZIKV, and CHIKV + ZIKV.Arboviruses (DENV, CHIKV and ZIKV) accounted for the great majority of cases(26 cases; 70.3%) of all single and co-infections: DENV has been the mostfrequently detected arbovirus (13 cases; 35.1%). Among non-arboviralmeningitis,the most common etiology was the EV (11 cases; 29.7%).Conclusions: Arboviruses accounted for the majority of identified virusesamong patients with suspected viral meningitis. In areas where they areendemic it is crucial to increase viral surveillance and consider them in thedifferential diagnosis of meningitis.Fil: Dias, Tamiris T.. Fundación Oswaldo Cruz; BrasilFil: Tauro, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Macêdo, Lara E. N.. Fundación Oswaldo Cruz; BrasilFil: Brito, Liz O.. Fundación Oswaldo Cruz; BrasilFil: Ribeiro, Victor H. O.. Fundación Oswaldo Cruz; BrasilFil: Santos, Cleiton S.. Fundación Oswaldo Cruz; BrasilFil: Jacob-Nascimento, Leile C.. Fundación Oswaldo Cruz; BrasilFil: Vilas-Boas, Letícia S.. Fundación Oswaldo Cruz; BrasilFil: Amado, Caio. Fundación Oswaldo Cruz; BrasilFil: Barbosa, Paula S.. Fundación Oswaldo Cruz; BrasilFil: Reis, Joice N.. Fundación Oswaldo Cruz; BrasilFil: Soares Campos, Gubio. Fundación Oswaldo Cruz; BrasilFil: Ribeiro, Guilherme S.. Fundación Oswaldo Cruz; BrasilFil: Siqueira, Isadora C.. Fundación Oswaldo Cruz; BrasilFil: Silva, Luciano K.. Fundación Oswaldo Cruz; BrasilFil: Reis, Mitermayer G.. Fundación Oswaldo Cruz; Brasi
Inhibitory action of Lippia gracilis Schauer essential oil on pathogenic bacteria and its effects as a growth promoter on quail
Aim of the study: To examine the in vitro sensitivity of Salmonella sp. and Escherichia coli strains to the microbial activity of Lippia gracilis Schauer essential oil (LGSEO) and to determine the optimal level of LGSEO as a growth promoter in diets for Japanese quail up to 35 days of age.Area of study: São Cristovão, Sergipe, Brazil.Material and methods: A total of 504 female Japanese quails (Coturnix coturnix japonica) at an initial average body weights of 6.80±0.10 g was allotted to one of six treatments (0, 100, 200, 300, 400 mg/kg of LGSEO and a diet containing 500 mg/kg of bacitracin methylene disalicylate) in 7 replicates, using 12 birds per experimental unit.Main results: In the age period of 21 to 35 days, feed intake declined linearly (p=0.04) and feed efficiency improved (p<0.01), whereas no changes were observed in production performance (p>0.05). The estimated (p=0.01) maximum relative weights of proventriculus and pancreas were obtained at the LGSEO inclusion levels of 196.5 and 251 mg/kg, respectively. Inclusion of 100 to 300 mg/kg of LGSEO in the diet reduced the total Salmonella sp. bacterial count.Research highlights: The use of 196.5 mg/kg of LGSEO in the diet of Japanese quail improved production performance and organ development and demonstrated potential antimicrobial capacity against Salmonella sp. bacteria. Due its pharmacological composition, LGSEO can potentially substitute to antimicrobials, because contains thymol and carvacrol as main active constituents
Maternal Melatonin Programs the Daily Pattern of Energy Metabolism in Adult Offspring
Background: Shift work was recently described as a factor that increases the risk of Type 2 diabetes mellitus. In addition, rats born to mothers subjected to a phase shift throughout pregnancy are glucose intolerant. However, the mechanism by which a phase shift transmits metabolic information to the offspring has not been determined. Among several endocrine secretions, phase shifts in the light/dark cycle were described as altering the circadian profile of melatonin production by the pineal gland. The present study addresses the importance of maternal melatonin for the metabolic programming of the offspring. Methodology/Principal Findings: Female Wistar rats were submitted to SHAM surgery or pinealectomy (PINX). The PINX rats were divided into two groups and received either melatonin (PM) or vehicle. The SHAM, the PINX vehicle and the PM females were housed with male Wistar rats. Rats were allowed to mate and after weaning, the male and female offspring were subjected to a glucose tolerance test (GTT), a pyruvate tolerance test (PTT) and an insulin tolerance test (ITT). Pancreatic islets were isolated for insulin secretion, and insulin signaling was assessed in the liver and in the skeletal muscle by western blots. We found that male and female rats born to PINX mothers display glucose intolerance at the end of the light phase of the light/dark cycle, but not at the beginning. We further demonstrate that impaired glucose-stimulated insulin secretion and hepatic insulin resistance are mechanisms that may contribute to glucose intolerance in the offspring of PINX mothers. The metabolic programming described here occurs due to an absence of maternal melatonin because the offspring born to PINX mothers treated with melatonin were not glucose intolerant. Conclusions/Significance: The present results support the novel concept that maternal melatonin is responsible for the programming of the daily pattern of energy metabolism in their offspring.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)CNPq (Conselho Nacional de Aperfeicoameno Cientifico)CNPq (Conselho Nacional de Aperfeicoameno Cientifico
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