In this paper, we summarize the sample preparation methods currently used at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. We also report on a series of ...results with regards to the graphitization protocol. Tests with different temperatures and baking times were performed, and carbon stable isotope ratios of graphite were measured by an EA–IRMS (elemental analyzer coupled with an isotopic ratio mass spectrometer) to infer the completeness of the graphitization reaction. We monitored the muffle furnace temperature using an independent thermocouple and found a −60°C offset, which may have caused the lower graphitization yields (detected from the large isotopic fractionation on several reference materials targets). At a temperature of 520°C, the isotopic fractionation in the graphitization reaction was systematically lower (−5‰ in average) and the overall scattering was reduced. As long as isotopic fractionation corrections are made using the online stable isotopes ratios provided by the AMS system, the accuracy of the 14C results should be maintained.
A HoBi-like pestivirus was first described in 2004 in a Brazilian fetal bovine serum that was exported to Germany. Nevertheless, it is believed that the virus had been present since the 1990’s, when ...it was detected in buffalos of Brazilian origin. Reproductive and respiratory diseases have been reported since 2001 in cattle, and more recently, diseases accompanied by a clinical presentation of mucosal disease-like (MD-like lesions have been reported as well. In the present study, the authors reported the oldest case of MD--like in cattle, associated with a HoBi-like pestivirus infection. Diarrhea, anorexia, nasal discharge, hypersalivation, and weakness were observed in 20 calves. For two of the animals, clinical follow-ups were performed. Following their death, necropsy was performed on these two calves. The main gross alterations observed were ulcers and erosions in the upper and lower digestive tract and interdigital dermatitis. Clinical history, gross findings, histopathological examination, immunohistochemistry, RT-PCR, and virus isolation were determined as suitable tools for the diagnosis of a MD-like outbreak, caused by a HoBi-like pestivirus.
•The clinical and pathological features between BVDV and HoBi-like pestivirus infections are indistinguishable.•HoBi-like pestivirus isolates classified as genetic group 3a, as in this case, seem to be typical, and endemic in Brazil.•This is the oldest report of an occurrence of mucosal disease by HoBi-like pestivirus in calves.
The generation of active chlorine on Ti/Sn(1-x)Ir x O2 anodes, with different compositions of Ir (x = 0.0,0.0,0.10 and 0.30 ), was investigated by controlled current density electrolysis. Using a low ...concentration of chloride ions (0.05 mol L) and a low current density (5 mA cm) it was possible to produce up to 60 mg L of active chlorine on a Ti/Sn0.99Ir0.01O2 anode. The feasibility of the discoloration of a textile acid azo dye, acid red 29 dye (C.I. 16570), was also investigated with in situ electrogenerated active chlorine on Ti/Sn(1-x)Ir x O2 anodes. The best conditions for 100% discoloration and maximum degradation (70% TOC reduction) were found to be: NaCl pH 4, 25 mA cm and 6 h of electrolysis. It is suggested that active chlorine generation and/or powerful oxidants such as chlorine radicals and hydroxyl radicals are responsible for promoting faster dye degradation. Rate constants calculated from color decay versus time reveal a zero order reaction at dye concentrations up to 1.0 X 10 mol L. Effects of other electrolytes, dye concentration and applied density currents also have been investigated and are discussed.
Hydrogen sulphide (H2S) is a gasotransmitter that participates in various physiological and pathophysiological processes within the gastrointestinal tract. We studied the effects and possible ...mechanism of action of H2S in secretory diarrhoea caused by cholera toxin (CT). The possible mechanisms of action of H2S were investigated using an intestinal fluid secretion model in isolated intestinal loops on anaesthetized mice treated with CT. NaHS and Lawesson's reagent and l-cysteine showed antisecretory activity through reduction of intestinal fluid secretion and loss of Cl− induced by CT. Pretreatment with an inhibitor of cystathionine-γ-lyase (CSE), dl-propargylglycine (PAG), reversed the effect of l-cysteine and caused severe intestinal secretion. Co-treatment with PAG and a submaximal dose of CT increased intestinal fluid secretion, thus supporting the role of H2S in the pathophysiology of cholera. CT increased the expression of CSE and the production of H2S. Pretreatment with PAG did not reverse the effect of SQ 22536 (an AC inhibitor), bupivacaine (inhibitor of cAMP production), KT-5720 (a PKA inhibitor), and AICAR (an AMPK activator). The treatment with Forskolin does not reverse the effects of the H2S donors. Co-treatment with either NaHS or Lawesson's reagent and dorsomorphin (an AMPK inhibitor) did not reverse the effect of the H2S donors. H2S has antisecretory activity and is an essential molecule for protection against the intestinal secretion induced by CT. Thus, H2S donor drugs are promising candidates for cholera therapy. However, more studies are needed to elucidate the possible mechanism of action.
•Cholera toxin induces an increase in the expression of CSE in mice.•H2S displayed antidiarrheal activity in secretory diarrhoea induced by cholera toxin in mice.•Antisecretory effect of H2S occurs by a mechanism independent of AC/cAMP/PKA and AMPK.•H2S donors have potential in cholera therapy.
Hydrogen sulphide (H
S) is a gasotransmitter that participates in various physiological and pathophysiological processes within the gastrointestinal tract. We studied the effects and possible ...mechanism of action of H
S in secretory diarrhoea caused by cholera toxin (CT). The possible mechanisms of action of H
S were investigated using an intestinal fluid secretion model in isolated intestinal loops on anaesthetized mice treated with CT. NaHS and Lawesson's reagent and l-cysteine showed antisecretory activity through reduction of intestinal fluid secretion and loss of Cl
induced by CT. Pretreatment with an inhibitor of cystathionine-γ-lyase (CSE), dl-propargylglycine (PAG), reversed the effect of l-cysteine and caused severe intestinal secretion. Co-treatment with PAG and a submaximal dose of CT increased intestinal fluid secretion, thus supporting the role of H
S in the pathophysiology of cholera. CT increased the expression of CSE and the production of H
S. Pretreatment with PAG did not reverse the effect of SQ 22536 (an AC inhibitor), bupivacaine (inhibitor of cAMP production), KT-5720 (a PKA inhibitor), and AICAR (an AMPK activator). The treatment with Forskolin does not reverse the effects of the H
S donors. Co-treatment with either NaHS or Lawesson's reagent and dorsomorphin (an AMPK inhibitor) did not reverse the effect of the H
S donors. H
S has antisecretory activity and is an essential molecule for protection against the intestinal secretion induced by CT. Thus, H
S donor drugs are promising candidates for cholera therapy. However, more studies are needed to elucidate the possible mechanism of action.
Infection by Rhodococcus equi is considered one of the major health concerns for foals worldwide. In order to better understand the disease’s clinical and pathological features, we studied twenty ...cases of natural infection by R. equi in foals. These cases are characterized according to their clinical and pathological findings and immunohistochemical aspects. Necropsy, histologic examination, bacterial culture, R. equi and Pneumocystis spp. immunohistochemistry were performed. The foals had a mean age of 60 days and presented respiratory signs (11/20), hyperthermia (10/20), articular swelling (6/20), prostration (4/20), locomotor impairment (3/20) and diarrhea (3/20), among others. The main lesions were of pyogranulomatous pneumonia, seen in 19 foals, accompanied or not by pyogranulomatous lymphadenitis (10/20) and pyogranulomatous and ulcerative enterocolitis (5/20). Pyogranulomatous osteomyelitis was seen in 3 foals, one of which did not have pulmonary involvement. There was lymphoplasmacytic (4/20), lymphoplasmacytic and neutrophilic (1/20) or pyogranulomatous arthritis (1/20), affecting multiple or singular joints. Immunohistochemistry revealed to be a valuable tool for the detection of R. equi, confirming the diagnosis in all cases. Furthermore, pulmonary immunostaining for Pneumocystis spp. demonstrates that a coinfection with R. equi and this fungal agent is a common event in foals, seen in 13 cases.
RESUMO: Infecção por Rhodococcus equi é considerado um dos maiores problemas sanitários para potros em todo o mundo. Para melhor compreender a apresentação clínica e patológica da enfermidade, foram avaliados vinte casos de infecção natural por R. equi em potros. Os casos são caracterizados de acordo com seus achados clínicos e patológicos e aspectos imuno-histoquímicos. Foram realizados exames de necropsia, histologia, bacteriologia e imuno-histoquímica para R. equi e Pneumocystis spp. Os potros tinham idade media de 60 dias e apresentaram sinais respiratórios (11/20), hipertermia (10/20), aumento de volume articular (6/20), prostração (4/20), distúrbios locomotores (3/20) e diarreia (3/20), entre outros. As lesões mais importantes eram pneumonia piogranulomatosa, vista em 19 potros, acompanhada ou não por linfadenite piogranulomatosa (10/20) e enterocolite ulcerativa (5/20). Osteomielite piogranulomatosa foi constatada em três potros, um dos quais não apresentava envolvimento pulmonar. Artrites afetando uma ou múltiplas articulações eram caracterizadas por infiltrado linfoplasmocítico (4/20), linfoplasmocítico e neutrofílico (1/20) e piogranulomatoso (1/20). A imuno-histoquímica demonstrou ser uma ferramenta valiosa na detecção de R. equi, permitindo confirmar o diagnóstico em todos os casos avaliados. Além disso, a imuno-histoquímica para Pneumocystis spp. demonstra que a coinfecção por R. equi e o agente fúngico é um evento frequente em potros, constatado em 13 casos.
This study evaluated the effect of the supplementation of total dietary fiber from apple, banana or passion fruit processing by-products on the post-acidification, total titratable acidity, bacteria ...counts and fatty acid profiles in skim milk yoghurts co-fermented by four different probiotics strains: Lactobacillus acidophilus L10 and Bifidobacterium animalis subsp. lactis BL04, HN019 and B94. Apple and banana fibers increased the probiotic viability during shelf-life. All the fibers were able to increase the short chain and polyunsaturated fatty acid contents of yoghurts compared to their respective controls. A synergistic effect between the type of fiber and the probiotic strain on the conjugated linoleic acid content was observed, and the amount of α-linolenic acid was increased by banana fiber. The results of this study demonstrate, for the first time, that fruit fibers can improve the fatty acid profile of probiotic yoghurts and point out the suitability of using fibers from fruit processing the by-products to develop new high value-added fermented dairy products.
► Apple and banana fibers increased the probiotic viability during shelf-life. ► Fibers increased the short chain and polyunsaturated fatty acid contents. ► Fiber type and probiotic strain had synergistic effect on conjugated linoleic acid content. ► The amount of α-linolenic acid was increased by banana fiber.
Radiocarbon measurements at LAC-UFF: Recent performance Linares, Roberto; Macario, Kita D.; Santos, Guaciara M. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
10/2015, Letnik:
361
Journal Article
Recenzirano
In 2012 a single stage accelerator mass spectrometer from NEC was installed at the Radiocarbon Laboratory of Universidade Federal Fluminense (LAC-UFF), Niterói, Brazil. Here, we present a status ...report of our facility. We discuss some modifications applied to our combustion protocol in an attempt to reduce our procedural blank, mostly to processed organic samples. Measurements of reference materials indicate low precision and accuracy that are partially related to beam optics through the acceleration tube. We observed that once the beam current intensity increases the measured 13C+/12C+ becomes erratic. Therefore, in order to maintain the AMS-δ13C values within reasonable values, so that fractionation corrections using the spectrometer 13C+/12C+ values does not affect the final 14C results, we are forced to limit the 12C− beam intensity to ⩽30μA. This requirement was confirmed during our accuracy tests, when measuring selected annual tree-rings wood samples from a Parana pine (Araucaria angustifolia) between 1927 and 1997 previously measured at the Keck Carbon Cycle AMS Facility (KCCAMS), at the University of California, Irvine (UCI). At the LAC-UFF tree-ring wood samples were processed and measured in 4 different batches during a period of about 5months. The 14C results were later compared to the high-precision data obtained at KCCAMS/UCI and reached a good agreement. Recently a problem associated with graphitization yield were finally identified and new measurements with secondary standards are promising.
This radiocarbon study aims to physically verify the critical analysis of the Torah scrolls from the National Museum of Brazil collection. Although the manuscript was formerly believed to be as old ...as the 10th century, the paleographic and stylistic study of the books of Genesis and Deuteronomy revealed features that could be associated to the year 1560AD. Radiocarbon analysis was performed and a phase model limited by a Historical boundary was applied. The results are in agreement with the critical analysis of the manuscript that it is not older than the 16th century.
Among other zooarchaeological remains, terrestrial snails’ shells from the Thaumastus and Megalobulimus genera are found in some Brazilian shellmounds, presenting a potential substitute for charcoal ...in radiocarbon dating analyses, as reliable representatives of the atmospheric carbon isotopic ratio. In this paper, we present statistically similar results of both charcoal and land snails samples from the same archaeological contexts in three settlements on the coast of Rio de Janeiro. The Manitiba I shellmound results range from 4.2 to 3.7 ka cal BP (95.4%), contemporary with the Saquarema shellmound, occupied during the period from 4.3 to 3.6 ka cal BP (95.4%). For the Usiminas shellmound, two groups of samples revealed different periods of time for two occupational layers from 2.3 to 2.1 ka cal BP (95.4%) and from 1.6 and 1.3 ka cal BP (95.4%). A model constraining each group of samples to within a single phase has a general agreement of 97% with only two outliers out of 22 dates, yielding minimum individual agreement of 74% and 7% posterior outlier probability for Saquarema shells. These are good examples of sites in which the occupation chronology can be successfully obtained by the radiocarbon dating of land snails.
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