823 research outputs found
Life-cycle assessment of microalgae biodiesel: a review
Microalgae are an attractive way to produce biofuels due to the ability to accumulate lipids and very high photosynthetic yields. This article presents a review of life-cycle assessment studies of microalgae biodiesel production, including an analysis of modeling choices and assumptions. A high variation in GHG emissions (between -0.75 and 2.9 kg CO2eq MJ-1) was found and the main causes were investigated, namely modeling choices (e.g. the approach used to deal with multifunctionality), and a high parameter uncertainty in microalgae cultivation, harvesting and oil extraction processes
Composition and antioxidant activity of thymus vulgaris volatiles: comparison between supercritical fluid extraction and hydrodistillation
Supercritical fluid extraction (SEE) of the volatile oil from Thymus vulgaris L. aerial flowering parts was performed under different conditions of pressure, temperature, mean particle size and CO2 flow rate and the correspondent yield and composition were compared with those of the essential oil isolated by hydrodistillation (HD). Both the oils were analyzed by GC and GC-MS and 52 components were identified. The main volatile components obtained were p-cymene (10.0-42.6% for SFE and 28.9-34.8% for HD), gamma-terpinene (0.8-6.9% for SFE and 5.1-7.0% for HD), linalool (2.3-5.3% for SFE and 2.8-3.1% for HD), thymol (19.5-40.8% for SFE and 35.4-41.6% for HD), and carvacrol (1.4-3.1% for SFE and 2.6-3.1% for HD). The main difference was found to be the relative percentage of thymoquinone (not found in the essential oil) and carvacryl methyl ether (1.0-1.2% for HD versus t-0.4 for SFE) which can explain the higher antioxidant activity, assessed by Rancimat test, of the SFE volatiles when compared with HD. Thymoquinone is considered a strong antioxidant compound
Avaliação de alternativas aos revestimentos com alcatrão de hulha para estruturas de aço total ou parcialmente imersas em estuário e água do mar
Na procura de revestimentos anticorrosivos para protecção de estruturas de aço total ou parcialmente imersas em estuário e água do mar, que sejam alternativas mais ecológicas aos revestimentos com alcatrão de hulha ainda utilizados, foi desenvolvido um projecto no qual se comparam revestimentos epoxÃdicos comerciais com um revestimento de alcatrão de hulha epoxÃdico de referência, também comercial. Este trabalho inclui, para além da avaliação da protecção anticorrosiva dos revestimentos envolvidos no projecto, quer em laboratório, quer em exposição natural em estuário (rios Sado e Tejo) e em mar (Sines) durante quatro anos, a caracterização laboratorial das tintas integradas nos diferentes esquemas de pintura que deram origem aos revestimentos em estudo. Os resultados da avaliação no fim de dois anos de exposição natural, complementados com os ensaios em laborató permitiram concluir que dois dos quatro revestimentos alternativos estudados apresentaram melhor comportamento anticorrosivo do que o revestimento com alcatrão de hulha epoxÃdico usado como referência
Exantema após vacinação do sarampo: análise laboratorial de casos notificados em São Paulo
OBJECTIVE: The clinical differential diagnosis of rash due to viral infections is often difficult, and misdiagnosis is not rare, especially after the introduction of measles and rubella vaccination. A study to determine the etiological diagnosis of exanthema was carried out in a group of children after measles vaccination. METHODS: Sera collected from children with rash who received measles vaccine were reported in 1999. They were analyzed for IgM antibodies against measles virus, rubella virus, human parvovirus B19 (HPV B19) using ELISA commercial techniques, and human herpes virus 6 (HHV 6) using immunofluorescence commercial technique. Viremia for each of those viruses was tested using a polimerase chain reaction (PCR). RESULTS: A total of 17 cases of children with exanthema after measles immunization were reported in 1999. The children, aged 9 to 12 months (median 10 months), had a blood sample taken for laboratory analysis. The time between vaccination and the first rash signs varied from 1 to 60 days. The serological results of those 17 children suspected of measles or rubella infection showed the following etiological diagnosis: 17.6% (3 in 17) HPV B19 infection; 76.5% (13 in 17) HHV 6 infection; 5.9% (1 in 17) rash due to measles vaccine. CONCLUSIONS: The study data indicate that infection due to HPV B19 or HHV 6 can be misdiagnosed as exanthema due to measles vaccination. Therefore, it is important to better characterize the etiology of rash in order to avoid attributing it incorrectly to measles vaccine.OBJETIVO: O diagnóstico diferencial de doenças exantemáticas causadas por vÃrus é geralmente difÃcil, e equÃvocos não são raros, especialmente depois da introdução da vacina contra o sarampo e a rubéola. Um estudo laboratorial foi conduzido com o objetivo de estabelecer o diagnóstico etiológico de casos de exantema em crianças que receberam a vacina contra o sarampo. MÉTODOS: Soros de casos de exantema em crianças que receberam vacina contra o sarampo, em 1999, foram analisados para anticorpos IgM contra os vÃrus do sarampo, da rubéola e do parvovÃrus humano B19 (HPV B19), por técnicas comerciais de Elisa, e o herpes vÃrus humano tipo 6 (HHV 6), por técnica comercial de imunofluorecência. A viremia para cada um desses vÃrus foi testada pela reação em cadeia da polimerase (PCR). RESULTADOS: Foram notificados, em 1999, 17 casos de crianças com exantema pós-vacinal. A idade das crianças era de nove a 12 meses (mediana, dez meses). Uma amostra de sangue colhida para investigação laboratorial foi obtida para cada criança. O tempo decorrido entre a aplicação da vacina e o aparecimento do exantema variou de um a 60 dias. Os resultados da sorologia das 17 crianças sugeriram o seguinte diagnóstico etiológico para o exantema: 17,6% (três em 17) infecção pelo HPV B19; 76,5% (13 em 17) infecção pelo HHV 6; 5,9% (um em 17) exantema originado pela vacina do sarampo. CONCLUSÃO: Os resultados indicaram que a infecção pelo HPV B19 ou pelo HHV 6 pode ser diagnosticada como sarampo de origem vacinal. Portanto, é fundamental incluir esses vÃrus no diagnóstico laboratorial para corretamente apontar a etiologia das doenças exantemáticas, evitando, assim, atribuir à vacina do sarampo efeito colateral
Linhagem celular RC-IAL: sensibilidade de crescimento do vÃrus da rubéola
OBJECTIVE: The rapid growth of the rubella virus in RC-IAL² with development of cytopathic effect, in response to rubella virus infection, is described. For purposes of comparison, the rubella virus RA-27/3 strain was titered simultaneously in the RC-IAL, Vero, SIRC and RK13 cell lines. METHODS: Rubella virus RA-27/3 strain are inoculated in the RC-IAL cell line (rabbit Kidney, Institute Adolfo Lutz). Plates containing 1.5x10(5) cells/ml of RC-IAL line were inoculated with 0.1ml s RA-27/3 strain virus containing 1x 10(4)TCID50/0.1ml. A 25% cytopathic effect was observed after 48 hours and 100% after 96 hours. The results obtained were compared to those observed with the SIRC, Vero and RK13 cell lines. Rubella virus was detected by immunohistochemistry. RESULTS: With the results, it was possible to conclude that the RC-IAL cell line is a very good substrate for culturing rubella virus. The cells inoculated with rubella virus were examined by phase contrast microscopy and showed the characteristic rounded, bipolar and multipolar cells. The CPE in RC-IAL was observed in the first 48 hours and the curve of the increased infectivity was practically the same as observed in other cell lines. CONCLUSIONS: These findings are important since this is one the few cell lines described in the literature with a cytopathic effect. So it can be used for antigen preparation and serological testing for the diagnosis of specific rubella antibodies.OBJETIVO: Descreve-se o crescimento do vÃrus-padrão da rubéola RA-27/3 na linhagem celular RC-IAL, com desenvolvimento de efeito citopático em resposta à infecção viral. Para este propósito, o vÃrus-padrão foi titulado simultaneamente nas linhagens celulares Vero, SIRC e RK13. MÉTODOS: O vÃrus-padrão da rubéola RA-27/3 foi inoculado na linhagem celular RC-IAL (rim de coelho, Instituto Adolfo Lutz). Placas contendo 1,5x10(5) células/ml foram inoculadas com 0,1 ml do vÃrus contendo 1x10(4) DICT50/0,1 ml. O efeito citopático correspondente a 25% foi observado após 48 h e 100% após 96 h. Os resultados obtidos foram comparados com o crescimento do vÃrus nas linhagens celulares SIRC, Vero e RK13. O vÃrus da rubéola na linhagem celular RC-IAL foi detectado por imuno-histoquÃmica. RESULTADOS: As células inoculadas com o vÃrus da rubéola apresentaram efeito citopático nas primeiras 48h. As células apresentaram aspecto arredondado, com formação de alguns prolongamentos citoplasmáticos e sincÃcios, produzindo células multinucleadas. A curva do crescimento da infectividade do vÃrus foi praticamente a mesma que a observada nas outras linhagens celulares. CONCLUSÃO: Os resultados obtidos mostram que a linhagem celular RC-IAL é um ótimo substrato para crescimento do vÃrus da rubéola, pois poucas linhagens celulares descritas na literatura apresentam efeito citopático considerável e podem ser utilizadas para preparação de antÃgenos e nos testes de diagnóstico sorológico para o vÃrus da rubéola
Unassisted and carbon dioxide-assisted hydro- and Steam-distillation: modelling kinetics, energy consumption And chemical and biological activities of volatile oils
The demand for more suitable eco-friendly extraction processes has grown over the last few
decades and driven research to develop efficient extraction processes with low energy consumption
and low costs, but always assuring the quality of the volatile oils (VOs). The present study estimated
the kinetic extraction and energy consumption of simultaneous hydro- and steam-distillation (SHSD),
and SHSD assisted by carbon dioxide (SHSDACD), using an adopted modelling approach. The two
isolation methods influenced the VOs yield, chemical composition and biological activities, namely,
antioxidant, anti-glucosidase, anti-acetylcholinesterase and anti-inflammatory properties. SHSDACD
provided higher VOs yields than the SHSD at a shorter extraction time: 2.8% at 30 min vs. 2.0% at
120 min, respectively, for Rosmarinus officinalis, 1.5% at 28 min vs. 1.2% at 100 min, respectively, for
Lavandula angustifolia, and 1.7% at 20 min vs. 1.6% at 60 min, respectively, for Origanum compactum.
The first order and sigmoid model fitted to SHSD and SHSDACD, respectively, with R2 value at 96%
and with mean square error (MSE) < 5%, where the k distillation rate constant of SHSDACD was
fivefold higher and the energy consumption 10 times lower than the SHSD. The rosemary SHSD
and SHSDACD VOs chemical composition were similar and dominated by 1,8-cineole (50% and
48%, respectively), and camphor (15% and 12%, respectively). However, the lavender and oregano
SHSDACD VOs were richer in linalyl acetate and carvacrol, respectively, than the SHSD VOs. The
SHSDACD VOs generally showed better capacity for scavenging the nitric oxide and superoxide
anions free radicals as well as for inhibiting α-glucosidase, acetylcholinesterase, and lipoxygenase.info:eu-repo/semantics/publishedVersio
Determining factors of functioning in hemodialysis patients using the international classification of functioning, disability and health
Background: Hemodialysis (HD) treatment affects functioning, physical activity level, clinical biomarkers, and body
composition. However, the association between these variables with functioning, considering International Classification
of Functioning, Disability and Health (ICF) domains remains unclear. Thus, the aim of this study was to investigate
the possible association between physical activity, biomarkers, and body composition with functioning in HD patients
in reference to the ICF.
Methods: Eighty HD patients performed different tests grouped according to ICF domain: Body structure and function
– handgrip strength (HS), 5-repetition sit-to-stand test, and 60-s sit-to-stand test (5-STS, 60-STS, respectively);
Activity – short physical performance battery (SPPB); and Participation – participation scale questionnaire. Physical
activity [Human Activity Profile questionnaire (HAP)], body composition (Dual-energy X-ray absorptiometry), Parathormone
(PTH), and alkaline phosphatase were analyzed as possible variables associated with ICF domains. Data analyses
were performed using simple and multiple regression models adjusted for age, duration of HD, and diuresis volume.
Results: In the body structure and function domain, appendicular lean mass, PTH level, and age were associated
with HS (
R2 = 0.558); HAP and PTH were associated with 5-STS (
R2 = 0.263); and HAP, PTH, duration of HD, and age
were associated with 60-STS (
R2 = 0.337). In the activity domain, HAP, PTH, alkaline phosphatase, duration of HD, age,
and body fat were associated with SPPB (
R2 = 0.689). Finally, only HAP was associated with the participation scale
(
R2 = 0.067).
Conclusion: Physical activity and PTH levels are determinant protagonists of functioning in all ICF domains in hemodialysis
patients
Chemical composition and antibacterial activity of essential oils from the medicinal plant Mentha cervina L. grown in Portugal
Mentha cervina is a medicinal plant traditionally
used in Portugal in folk medicine, in different gastric
disorders and inflammations of the respiratory tract. In
order to validate those traditional uses, M. cervina essential
oils (EOs) were characterized by GC and GC–MS and their
antimicrobial activity was tested against 23 bacterial strains
(including multiresistant strains). The EOs were dominated
by the monoterpenes pulegone (52–75%), isomenthone
(8–24%), limonene (4–6%), and menthone (1–2%). The
antibacterial activity of these EOs was compared to that of
the main components standards. The most effective antibacterial
activity was expressed by the EOs against the
Gram-negative bacteria, Escherichia coli and Acinetobacter
baumanni, with MIC values of 1 mg/ml. The EOs complex mixtures were more active than the individual
aromatic components supporting the hypothesis that the
EOs antibacterial activity is a function of the synergistic
effect of their different aromatic components. These results
show the potential role of M. cervina EOs as antibacterial
agents and validate the traditional use of this plant
- …