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1.
PLoS One ; 15(12): e0237283, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33259486

RESUMO

Antibiotic resistant bacteria (ARB) and their genes (ARGs) have become recognised as significant emerging environmental pollutants. ARB and ARGs in sewage sludge can be transmitted back to humans via the food chain when sludge is recycled to agricultural land, making sludge treatment key to control the release of ARB and ARGs to the environment. This study investigated the fate of antibiotic resistant Escherichia coli and a large set of antibiotic resistance genes (ARGs) during full scale anaerobic digestion (AD) of sewage sludge at two U.K. wastewater treatment plants and evaluated the impact of thermal hydrolysis (TH) pre-treatment on their abundance and diversity. Absolute abundance of 13 ARGs and the Class I integron gene intI1 was calculated using single gene quantitative (q) PCR. High through-put qPCR analysis was also used to determine the relative abundance of 370 ARGs and mobile genetic elements (MGEs). Results revealed that TH reduced the absolute abundance of all ARGs tested and intI1 by 10-12,000 fold. After subsequent AD, a rebound effect was seen in many ARGs. The fate of ARGs during AD without pre-treatment was variable. Relative abundance of most ARGs and MGEs decreased or fluctuated, with the exception of macrolide resistance genes, which were enriched at both plants, and tetracyline and glycopeptide resistance genes which were enriched in the plant employing TH. Diversity of ARGs and MGEs decreased in both plants during sludge treatment. Principal coordinates analysis revealed that ARGs are clearly distinguished according to treatment step, whereas MGEs in digested sludge cluster according to site. This study provides a comprehensive within-digestor analysis of the fate of ARGs, MGEs and antibiotic resistant E. coli and highlights the effectiveness of AD, particularly when TH is used as a pre-treatment, at reducing the abundance of most ARGs and MGEs in sludgeand preventing their release into the environment.


Assuntos
Anaerobiose/genética , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Esgotos/microbiologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Genes Bacterianos/genética , Genes MHC Classe I/genética , Humanos , Hidrólise/efeitos dos fármacos , Integrons/genética , Sequências Repetitivas Dispersas/genética , Macrolídeos/farmacologia , Águas Residuárias/microbiologia
2.
Ecol Evol ; 10(17): 9132-9143, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32953051

RESUMO

Social network analyses allow studying the processes underlying the associations between individuals and the consequences of those associations. Constructing and analyzing social networks can be challenging, especially when designing new studies as researchers are confronted with decisions about how to collect data and construct networks, and the answers are not always straightforward. The current lack of guidance on building a social network for a new study system might lead researchers to try several different methods and risk generating false results arising from multiple hypotheses testing. Here, we suggest an approach for making decisions when starting social network research in a new study system that avoids the pitfall of multiple hypotheses testing. We argue that best edge definition for a network is a decision that can be made using a priori knowledge about the species and that is independent from the hypotheses that the network will ultimately be used to evaluate. We illustrate this approach with a study conducted on a colonial cooperatively breeding bird, the sociable weaver. We first identified two ways of collecting data using different numbers of feeders and three ways to define associations among birds. We then evaluated which combination of data collection and association definition maximized (a) the assortment of individuals into previously known "breeding groups" (birds that contribute toward the same nest and maintain cohesion when foraging) and (b) socially differentiated relationships (more strong and weak relationships than expected by chance). This evaluation of different methods based on a priori knowledge of the study species can be implemented in a diverse array of study systems and makes the case for using existing, biologically meaningful knowledge about a system to help navigate the myriad of methodological decisions about data collection and network inference.

3.
Bioresour Technol ; 267: 732-742, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30076074

RESUMO

Managing organic waste streams is a major challenge for the agricultural industry. Anaerobic digestion (AD) of organicwastes is a preferred option in the waste management hierarchy, as this processcangenerate renewableenergy, reduce emissions from wastestorage, andproduce fertiliser material.However, Nitrate Vulnerable Zone legislation and seasonal restrictions can limit the use of digestate on agricultural land. In this paper we demonstrate the potential of cultivating microalgae on digestate as a feedstock, either directlyafter dilution, or indirectlyfromeffluent remaining after biofertiliser extraction. Resultant microalgal biomass can then be used to produce livestock feed, biofuel or for higher value bio-products. The approach could mitigate for possible regional excesses, and substitute conventional high-impactproducts with bio-resources, enhancing sustainability withinacircular economy. Recycling nutrients from digestate with algal technology is at an early stage. We present and discuss challenges and opportunities associated with developing this new technology.


Assuntos
Microalgas , Gerenciamento de Resíduos , Agricultura , Anaerobiose , Biocombustíveis , Biomassa
4.
Bioresour Technol ; 257: 164-171, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29500950

RESUMO

A biological methanation system based on nutrient recycling via mixed culture microbial catabolism was investigated at mesophilic (37 °C) and thermophilic (55 °C) temperatures. At mesophilic temperatures, the formation of biofilms on two different types of material was assessed. Results showed that with intense mixing the biofilm reactors presented methanogenic capacities (per working volume) 50% higher than the ones operated with suspended cultures. Gas feeding rates of 200 L/L/d were achieved at a H2/CO2 to CH4 conversion efficiency of above 90% by linking two reactors in series. Furthermore the robustness of the cultures was assessed under a series of inhibitory conditions that simulated possible process interferences at full scale operation. Full recovery after separate intense oxygenation and long starvation periods was observed within 2-5 days.


Assuntos
Reatores Biológicos , Metano , Euryarchaeota , Reciclagem , Temperatura
5.
Bioresour Technol ; 245(Pt A): 1049-1057, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28946387

RESUMO

The integration of a biomethanation system within a wastewater treatment plant for conversion of CO2 and H2 to CH4 has been studied. Results indicate that the CO2 could be utilised to produce an additional 13,420m3/day of CH4, equivalent to approximately 133,826kWh of energy. The whole conversion process including electrolysis was found to have an energetic efficiency of 66.2%. The currently un-optimised biomethanation element of the process had a parasitic load of 19.9% of produced energy and strategies to reduce this to <5% are identified. The system could provide strategic benefits such as integrated management of electricity and gas networks, energy storage and maximising the deployment and efficiency of renewable energy assets. However, no policy or financial frameworks exist to attribute value to these increasingly important functions.


Assuntos
Metano , Águas Residuárias , Purificação da Água , Biocombustíveis , Estudos de Viabilidade , Água
6.
Santarém; s.n; set. 2017. 74 p.
Tese em Português | BDENF - Enfermagem | ID: biblio-1382130

RESUMO

Foi desenvolvido o diagnóstico de situação, mediante o Perfil e o Plano local de Saúde da Unidade de Saúde Pública do ACES Lezíria, que alertam para uma prevalência de determinantes de risco de tumores do cólon do reto e doenças cerebrovasculares associados com a alimentação e baixa literacia em saúde. Com a USP foi desenvolvido um projeto denominado "Promoção da literacia em Saúde ­ Leitura dos rótulos alimentares", junto das ajudantes de lar de idosos, grupo alvo com o qual esta unidade já se encontrava a intervir. O objetivo do projeto foi capacitar para a leitura do rótulo alimentar, mediante intervenções de educação para a saúde, com o contributo do Modelo de Promoção da Saúde de Pender e o recurso à metodologia do Planeamento em Saúde. A revisão sistemática da literatura através da metodologia PI[C]O evidenciou a importância da intervenção por parte dos profissionais de saúde, através de programas de promoção da saúde e da literacia na área da nutrição, considerando essencial fornecer ferramentas às pessoas ao nível da rotulagem e do marketing social


The situation diagnosis was developed according to the Local Public Health Unit (USP) of ACES Lezíria Local Profile and Plan. These alert towards a prevalence of risk factors like colon and rectum tumours and cerebrovascular diseases associated with eating habits and low health literacy. A project called "Promotion of Health Literacy ­ Reading Food Labels" was developed along with the USP, aiming towards the elderly home helpers, the target group in which this unit was already working with. The aim of this project was to enable the target group to read food labels, trough health education interventions, with the Pender's framework for Health Promotion and the use of the Health Planning methodology. The systematic review of literature through the PI[C]O method highlighted the importance of the health professionals' intervention. Made through health promotion programmes and literacy in the nutrition domain, considering essential to provide tools to people on the labelling and social marketing domains Keywords: literacy


Assuntos
Letramento em Saúde , Rotulagem de Produtos , Educação em Saúde
7.
Mater Sci Eng C Mater Biol Appl ; 76: 13-24, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28482497

RESUMO

In this paper, the biomineralization potential and cellular response of novel blend films of the anionic sulfated polysaccharides kappa-carrageenan (KCG) and fucoidan (FUC) derived from seaweeds with semi-crystalline polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHBV), respectively, were analyzed. The incorporation of KCG and FUC into PHB and PHBV, which has been studied here for the first time, led to an overall decrease in crystallinity, enhanced surface hydrophilicity, reduced brittleness and faster degradation of the polymer blend films. All PHB/KCG, PHBV/KCG and PHBV/FUC films exhibited a two-stage mass loss profiles with pH stabilization. PHBV/KCG film showed the highest biomineralization activity due the presence of sulfate groups on the surface of the films. NIH3T3 cells attached and proliferated well on all blend films on account of enhanced surface hydrophilicity and improved flexibility. PHBV/KCG led to a promoted cellular activity compared to PHBV/FUC, presumably due to phase separation and higher amount of biopolymer on the film surface that was a consequence of the immiscibility of the polymers in the blend films.


Assuntos
Calcificação Fisiológica , Animais , Carragenina , Camundongos , Células NIH 3T3 , Poliésteres , Polissacarídeos
8.
Bioresour Technol ; 232: 380-388, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28259068

RESUMO

Ammonia inhibition mitigation in anaerobic digestion of high solids content of thermally hydrolysed secondary sewage sludge by the NH4+ affinitive clinoptilolite and a strong acid type ion-exchange resin S957 was investigated. Continuous NH4+-N removal was achieved through ion-exchanging at both temperatures with average removals of 50 and 70% for the clinoptilolite and resin dosed reactors, respectively. Approximate 0.2-0.5unit of pH reduction was also observed in the dosed reactors. The synergy of NH4+-N removal and pH reduction exponentially decreased free NH3 concentration, from 600 to 90mg/L at 43°C, which mitigated ammonia inhibition and improved methane yields by approximately 54%. Microbial community profiling suggested that facilitated by ammonia removal, the improvement in methane production was mainly achieved through the doubling in bacterial density and a 6-fold increase in population of the Methanosarcinaceae family, which in turn improved the degradation of residual volatile fatty acids, proteins and carbohydrates.


Assuntos
Amônia/isolamento & purificação , Bactérias/metabolismo , Metano/biossíntese , Esgotos/microbiologia , Ácido Acético/análise , Compostos de Amônio/isolamento & purificação , Anaerobiose , Bactérias/genética , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Carboidratos/análise , Ácidos Graxos Voláteis/análise , Dosagem de Genes , Concentração de Íons de Hidrogênio , Troca Iônica , Metano/metabolismo , Propionatos/análise , Resinas Sintéticas/química , Temperatura , Zeolitas/química
9.
Bioresour Technol ; 227: 93-101, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28013141

RESUMO

A novel eco-engineered mixed anaerobic culture was successfully demonstrated for the first time to be capable of continuous regeneration in nutrient limiting conditions. Microbial catabolism has been found to support a closed system of nutrients able to enrich a culture of lithotrophic methanogens and provide microbial cell recycling. After enrichment, the hydrogenotrophic species was the dominating methanogens while a bacterial substratum was responsible for the redistribution of nutrients. q-PCR results indicated that 7% of the total population was responsible for the direct conversion of the gases. The efficiency of H2/CO2 conversion to CH4 reached 100% at a gassing rate of above 60v/v/d. The pH of the culture media was effectively sustained at optimal levels (pH 7-8) through a buffering system created by the dissolved CO2. The novel approach can reduce the process nutrient/metal requirement and enhance the environmental and financial performance of hydrogenotrophic methanogenesis for renewable energy storage.


Assuntos
Biotecnologia/métodos , Metano/metabolismo , Microbiota , Anaerobiose , Reatores Biológicos/microbiologia , Biotecnologia/instrumentação , Dióxido de Carbono/metabolismo , Catálise , Meios de Cultura/metabolismo , Desenho de Equipamento , Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Microbiota/genética , Reação em Cadeia da Polimerase , Reciclagem
10.
J Biomed Mater Res B Appl Biomater ; 105(6): 1667-1684, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27080439

RESUMO

Bone tissue engineering based on scaffolds is quite a complex process as a whole gamut of criteria needs to be satisfied to promote cellular attachment, proliferation and differentiation: biocompatibility, right surface properties, adequate mechanical performance, controlled bioresorbability, osteoconductivity, angiogenic cues, and vascularization. Third generation scaffolds are more of composite types to maximize biological-mechanical-chemical properties. In the present review, our focus is on the performance of micro-organism-derived polyhydroxyalkanoates (PHAs)-polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHBV)-composite scaffolds with ceramics and natural polymers for tissue engineering applications with emphasis on bone tissue. We particularly emphasize on how material properties of the composites affect scaffold performance. PHA-based composites have demonstrated their biocompatibility with a range of tissues and their capacity to induce osteogenesis due to their piezoelectric properties. Electrospun PHB/PHBV fiber mesh in combination with human adipose tissue-derived stem cells (hASCs) were shown to improve vascularization in engineered bone tissues. For nerve and skin tissue engineering applications, natural polymers such as collagen and chitosan remain the gold standard but there is scope for development of scaffolds combining PHAs with other natural polymers which can address some of the limitations such as brittleness, lack of bioactivity and slow degradation rate presented by the latter. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1667-1684, 2017.


Assuntos
Poli-Hidroxialcanoatos/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Humanos , Proibitinas , Pele/citologia , Pele/metabolismo
11.
Water Res ; 100: 267-276, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27206055

RESUMO

The extracellular polymeric substances and microbial cytoplasmic contents seem to hold inorganic ions and organic products, such as proteins and carbohydrates that are of critical importance for the metabolism of hydrolytic and acidogenic anaerobic microorganisms. The addition of soluble microbially recovered nutrients from thermally treated digestate sludge, for the fermentation of thermally hydrolysed waste activated sludge, resulted in higher volatile fatty acids yields (VFAs). The yield of VFAs obtained from the recovered microbial nutrients was 27% higher than the no micronutrients control, and comparable to the yield obtained using a micronutrients commercial recipe. In addition, the use of a low pH resulting from a high sucrose dose to select spore forming acidogenic bacteria was effective for VFA production, and yielded 20% higher VFAs than without the pH shock and this associated with the addition of recovered microbial nutrients would overcome the need to thermally pre-treat the inoculum.


Assuntos
Micronutrientes , Esgotos/química , Reatores Biológicos/microbiologia , Ácidos Graxos Voláteis/metabolismo , Fermentação , Hidrólise
12.
Bioresour Technol ; 163: 287-94, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24835740

RESUMO

External stress factors in the form of ionic species or temperature increases have been shown to produce a stress response leading to enhanced PHA production. The effect of five different NaCl concentrations, namely 3.5, 6.5, 9, 12 and 15 g/l NaCl on PHA productivity using Cupriavidus necator has been investigated alongside a control (no added NaCl). A dielectric spectroscopy probe was used to measure PHA accumulation online in conjunction with the chemical offline analysis of PHA. The highest PHA production was obtained with the addition of 9 g/l NaCl, which yielded 30% higher PHA than the control. Increasing the addition of NaCl to 15 g/l was found to inhibit the production of PHA. NaCl addition can therefore be used as a simple, low cost, sustainable, non toxic and non reactive external stress strategy for increasing PHA productivity.


Assuntos
Cupriavidus necator/metabolismo , Poli-Hidroxialcanoatos/biossíntese , Cloreto de Sódio/química , Meios de Cultura , Cupriavidus necator/crescimento & desenvolvimento
13.
Bioresour Technol ; 147: 345-352, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23999264

RESUMO

The production of polyhydroxyalkanoates (PHAs) using digestate liquor as culture media is a novel application to extend the existing uses of digestates. In this study, two micro-filtered digestates (0.22 µm) were evaluated as a source of complex culture media for the production of PHA by Cupriavidus necator as compared to a conventional media. Culture media using a mixture of micro-filtered liquors from food waste and from wheat feed digesters showed a maximum PHA accumulation of 12.29 g/l PHA, with 90% cell dry weight and a yield of 0.48 g PHA/g VFA consumed, the highest reported to date for C. necator studies. From the analysis of the starting and residual media, it was concluded that ammonia, potassium, magnesium, sulfate and phosphate provided in the digestate liquors were vital for the initial growth of C. necator whereas copper, iron and nickel may have played a significant role in PHA accumulation.


Assuntos
Cupriavidus necator/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Cromatografia Líquida , Meios de Cultura , Ácidos Graxos Voláteis/metabolismo , Filtração
14.
Bioresour Technol ; 140: 234-42, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23707910

RESUMO

Microbial populations in a full-scale anaerobic digester fed on food waste were monitored over an 18-month period using qPCR. The digester exhibited a highly dynamic environment in which methanogenic populations changed constantly in response to availability of substrates and inhibitors. The methanogenic population in the digester was dominated by Methanosaetaceae, suggesting that aceticlastic methanogenesis was the main route for the production of methane. Sudden losses (69%) in Methanosaetaceae were followed by a build-up of VFAs which were subsequently consumed when populations recovered. A build up of ammonium inhibited Methanosaetaceae and resulted in shifts from acetate to hydrogen utilization. Addition of trace elements and alkalinity when propionate levels were high stimulated microbial growth. Routine monitoring of microbial populations and VFAs provided valuable insights into the complex processes occurring within the digester and could be used to predict digester stability and facilitate digester optimization.


Assuntos
Reatores Biológicos/microbiologia , Metano/metabolismo , Methanosarcinales/crescimento & desenvolvimento , Methanosarcinales/metabolismo , Eliminação de Resíduos/instrumentação , Gerenciamento de Resíduos , Álcalis/farmacologia , Compostos de Amônio/farmacologia , Anaerobiose/efeitos dos fármacos , Calibragem , Ácidos Graxos Voláteis/metabolismo , Hidrogênio/metabolismo , Methanosarcinales/efeitos dos fármacos , Esgotos/microbiologia , Oligoelementos
15.
Bioresour Technol ; 134: 143-50, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23500571

RESUMO

In this study, dielectric spectroscopy was utilised to evaluate and define the optimum harvesting time for polyhydroxyalkanoates (PHA) production. It is essential to harvest PHA at the optimum time during fermentation for maximum yield, otherwise cells start degrading. Two carbon sources (acetic and butyric acids) were used in laboratory based experiments and a number of samples were measured ex situ for PHA production. The real-time measured capacitance in addition of identifying the cells growth phase, it correlated very well with ex situ measured PHA produced within the cells. The probe has proven to be a useful tool to assess process kinetics, to monitor real-time cell growth, PHA produced and defining the optimum harvesting time.


Assuntos
Sistemas Computacionais , Cupriavidus necator/metabolismo , Espectroscopia Dielétrica/métodos , Poli-Hidroxialcanoatos/biossíntese , Ácido Acético/farmacologia , Aerobiose/efeitos dos fármacos , Técnicas de Cultura Celular por Lotes , Biomassa , Ácido Butírico/farmacologia , Cupriavidus necator/efeitos dos fármacos , Cupriavidus necator/crescimento & desenvolvimento , Capacitância Elétrica , Ácidos Graxos Voláteis/análise , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Cinética , Oxigênio/metabolismo
16.
Bioresour Technol ; 133: 398-404, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23454801

RESUMO

This study investigates the use of Hotelling's T(2) control charts as the basis of a process monitor for sewage sludge anaerobic digestion. Fourier transform near infrared spectroscopy was used to produce partial least squares regression models of volatile fatty acids, bicarbonate alkalinity and volatile solids. These were utilised in a series of principle component analysis models along with spectral data from digestate and feedstock samples to produce a pseudo steady state model, which was then used with an independent test set to evaluate the system. The system was able to identify disturbances to the digester due to a temporary alteration of the type of feedstock to the digester and separately, halving of the hydraulic retention time of the digester. It could also provide advance warning of disturbances to the digester. This technique could be used to improve the performance of sewage sludge anaerobic digesters by enabling optimisation of the process.


Assuntos
Reatores Biológicos/microbiologia , Análise de Componente Principal/métodos , Esgotos/microbiologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Anaerobiose , Biodegradação Ambiental , Calibragem , Análise dos Mínimos Quadrados
17.
Bioresour Technol ; 131: 235-45, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23353037

RESUMO

Environmental burdens for the production and utilisation of biomethane vehicle fuel or a biohydrogen/biomethane blend produced from food waste or wheat feed, based on data from two different laboratory experiments, have been compared. For food waste treated by batch processes the two stage system gave high hydrogen yields (84.2l H2kg(-1) VS added) but a lower overall energy output than the single stage system. Reduction in environmental burdens compared with diesel was achieved, supported by the diversion of waste from landfill. For wheat feed, the semi continuously fed two stage process gave low hydrogen yields (7.5l H2kg(-1) VS added) but higher overall energy output. The process delivers reduction in fossil fuel burdens, and improvements in process efficiencies will lead to reduction in CO2 burdens compared with diesel. The study highlights the importance of understanding and optimising biofuel production parameters according to the feedstock utilised.


Assuntos
Bactérias Anaeróbias/metabolismo , Biocombustíveis/microbiologia , Conservação de Recursos Energéticos/métodos , Gasolina/microbiologia , Hidrogênio/metabolismo , Metano/metabolismo , Triticum/microbiologia , Microbiologia de Alimentos , Hidrogênio/isolamento & purificação , Metano/isolamento & purificação , Esgotos/microbiologia
18.
Bioresour Technol ; 102(15): 7313-23, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21616662

RESUMO

A life cycle assessment has been completed of potential biogas infrastructures on a regional scale. Centralised and distributed infrastructures were considered along with biogas end uses of Combined Heat and Power (CHP) and injection to the gas grid for either transport fuel or domestic heating end uses. Damage orientated (endpoint) life cycle impact assessment method identified that CHP with 80% heat utilisation had the least environmental impact, followed by transport fuel use. Utilisation for domestic heating purposes via the gas grid was found to perform less well. A 32% difference in transportation requirement between the centralised and distributed infrastructures was found to have a relatively small effect on the overall environmental impact. Global warming impacts were significantly affected by changes in methane emissions at upgrading stage, highlighting the importance of minimising operational losses.


Assuntos
Biocombustíveis/análise , Biotecnologia/instrumentação , Eliminação de Resíduos , Meios de Transporte
19.
Rev. bras. hematol. hemoter ; 30(5): 426-429, set.-out. 2008. ilus, graf
Artigo em Português | LILACS | ID: lil-512162

RESUMO

A macroglobulinemia de Waldenstrõm (MW) é uma patologia rara dos linfócitos B caracterizada pela produção monoclonal de IgM, e que pode manifestar-se clinicamente com fadiga, astenia, perda de peso, sangramento de mucosas e do trato gastrintestinal, lifonodonomegalias, hepatoesplenomegalia e alterações neurológicas. A doença é mais comum em pacientes idosos, e seus sintomas são decorrentes da hiperviscosidade sangüínea. Na MW observa-se hipergamaglobulinemia com pico monoclonal na eletroforese de proteínas séricas, níveis elevados de IgM e demais imunoglobulinas normais ou diminuídas, imunofenotipagem com linfócitos B CD19+, CD20+ e CD24+, aspirado de medula óssea hipercelular, e biópsia de medula óssea hipercelular com infiltração difusa de linfócitos, linfócitos plasmocitóides e plasmócitos. Atualmente, anticorpos monoclonais estão sendo usados na terapêutica da MW com grande sucesso. O rituximabe, anticorpo monoclonal anti -CD20, tem mostrado excelentes resultados no tratamento da MW, inclusive naqueles indivíduos que não obtiveram resposta adequada ao tratamento convencional. Nós reportamos o caso de uma mulher de 78 anos de idade com história de fadiga, astenia, anorexia, sonolência, inquietação, urticária, dificuldade para deambular e perda excessiva de peso, aproximadamente 22 kg em um período de cinco meses, cujo tratamento foi realizado com rituximabe. O objetivo deste relato é apresentar uma paciente com diagnóstico de MW e revisar aspectos clínicos e terapêutico atual da doença.


Waldenstrõm's macroglobulinemia is a rare pathology of B lymphocytes characterized by the production of monoclonal IgM, causing clinical manifestations which may include fatigue, asthenia, weight loss, bleeding of the mucosa and intestinal tract, lymphadenomegaly, hepatosplenomegaly and neurological alterations. The disease is more frequent among elderly patients and its symptoms are a result of the hyperviscosity of blood. Waldenstrõm's macroglobulinemia presents hypergammaglobulinemia with a monoclonal peak of serum proteins seen by electrophoresis, high IgM levels and other normal or diminished immunoglobulin levels, immunophenotyping with CD19+, CD20+ and CD24+ B lymphocytes aspirated from hypercellular bone marrow and hypercellular bone marrow biopsy with diffuse infiltration of lymphocytes, plasmocytoid lymphocytes and plasmocytes. Currently, monoclonal antibodies are successfully being used in the treatment of Waldenstrõm's macroglobulinemia. Rituximab, an anti-CD20 monoclonal antibody, has shown excellent results in the treatment of Waldenstrõm's macroglobulinemia even for individuals who did not obtain satisfactory responses to conventional treatment. This work reports the case of a 78-year-old woman with a history of fatigue, asthenia, anorexia, somnolence, restlessness, urticaria, difficulties in walking, and excessive weight loss (approximately 22 Kg within a period of 5 months) who was successfully treated using rituximab. The objective of this report is to present the case of this patient and to review current clinical and therapeutic aspects of the disease.


Assuntos
Humanos , Feminino , Idoso , Hipergamaglobulinemia , Imunossupressores , Macroglobulinemia de Waldenstrom
20.
Water Res ; 42(16): 4379-85, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18757074

RESUMO

The IWA Anaerobic Digestion Model No.1 (ADM1) has been extensively used in recent years. However, its application to non-methanogenic systems is limited by the use of constant-stoichiometry to describe product formation from carbohydrate fermentation. This study presents a modification of the ADM1 using a variable stoichiometry approach, derived from experimental information. The biomass and product yields from glucose degradation are assumed to be dynamically depending on the total concentration of undissociated acids in the reactor. Experimental data from an 11 L mesophilic continuous bio-hydrogen reactor fed with 20, 40, 50 and 10 g/L of sucrose, were used to validate the approach. The modified model achieved good predictions of the experimental data, using the standard ADM1 parameter values, without any parameter fitting beyond the implementation of the variable stoichiometry. The modification approach proposed extends the applicability of the ADM1 to non-methanogenic fermentative systems and in particular to continuous bio-hydrogen production.


Assuntos
Reatores Biológicos , Hidrogênio/química , Hidrogênio/metabolismo , Anaerobiose , Bactérias/metabolismo , Fontes de Energia Bioelétrica , Fermentação , Concentração de Íons de Hidrogênio , Modelos Biológicos
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