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1.
Dig Liver Dis ; 55(9): 1280-1287, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36872200

RESUMO

BACKGROUND: Little is known about the prognosis of colorectal cancer associated with inflammatory bowel disease (CRC-IBD) in a real-world cohort in France. METHODS: We conducted a retrospective observational study including all patients presenting CRC-IBD in a French tertiary center. RESULTS: Among 6510 patients, the rate of CRC was 0.8% with a median delay of 19.5 years after IBD diagnosis (median age 46 years, ulcerative colitis 59%, initially localized tumor 69%). There was a previous exposure to immunosuppressants (IS) in 57% and anti-TNF in 29% of the cases. A RAS mutation was observed in only 13% of metastatic patients. OS of the whole cohort was 45 months. OS and PFS of synchronous metastatic patients was 20.4 months and 8.5 months respectively. Among the patients with localized tumor those previously exposed to IS had a better PFS (39 months vs 23 months; p = 0.05) and OS (74 vs 44 months; p = 0.03). The IBD relapse rate was 4%. No unexpected chemotherapy side-effect was observed CONCLUSIONS: OS of CRC-IBD is poor in metastatic patients although IBD is not associated with under-exposure or increased toxicity to chemotherapy. Previous IS exposure may be associated with a better prognosis.


Assuntos
Neoplasias Colorretais , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Pessoa de Meia-Idade , Doença de Crohn/complicações , Inibidores do Fator de Necrose Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/complicações , Fatores de Risco , Recidiva Local de Neoplasia , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/patologia , Prognóstico , Imunossupressores
2.
Water Sci Technol ; 84(8): 1954-1968, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34695023

RESUMO

This study benchmarks vermifiltration (VF) as secondary wastewater treatment in three nature-based decentralized treatment plants using life-cycle assessment. The comparison is justified by the comparatively easier and cheaper operation of VF when compared to more traditional technologies, including small rate infiltration (SRI), constructed wetlands (CW), and activated sludge (AS). Standard life cycle assessment was used and applied to three case studies located in southern Europe. Material intensity during construction was highest for VF, but impacts during operation were lower, compensating those of the other phases. Impacts during the construction phase far outweigh those of operation and dismantling for facilities using constructed wetlands and activated sludge, when the number of served inhabitants is small, and due to lack of economies of scale. VF used as secondary treatment was shown to contribute to reducing the environmental impacts, mainly in constructed wetlands and activated sludge. The replacement of CW by VF seems to bring important environmental benefits in most impact categories, in particular in the construction phase. The replacement by VF in facilities with SRI seems to result in the improvement of some of the impact categories, in particular in the operation phase. As for dismantling, no conclusive results were obtained.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água , Meio Ambiente , Águas Residuárias , Áreas Alagadas
3.
Environ Manage ; 65(5): 642-664, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32123966

RESUMO

This paper reviews decentralized sanitation technologies comparing dry and wet solutions currently available, discussing their operational requirements, applicability, effluent output quality, efficiencies, environmental impacts, costs, challenges, as well as their advantages and implementation difficulties. Sanitation technologies vary from conventional centralized systems, typically used on urban areas, to decentralized systems, more common in sparse dwellings and small communities of rural areas. Compared with centralized sanitation, decentralized sanitation is being progressively considered as more sustainable solution. Most do not require energy or expensive or sophisticated operation, being easy to adapt to different geographic contexts. A general lack of consistent regulatory control over most dry rudimentary systems and primary treatment systems may compromise water quality and human health. In the future, a mix of new policies and accurate accounting of the location, performance, and degree of failure of such systems should be performed. However, forcing users and communities to face the capital, operational, or repairing costs may be challenging. Since many of the discussed technologies may be important sources of contamination with nutrients, pathogens and toxic chemicals, new opportunities are still open, which include the conversion of dry rudimentary systems into dry controlled systems.


Assuntos
Saneamento , Tecnologia , Meio Ambiente , Humanos , Qualidade da Água
4.
Biochim Biophys Acta Mol Basis Dis ; 1864(6 Pt A): 2183-2198, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29625179

RESUMO

BACKGROUND: Cardiovascular diseases (CVDs) are leading cause of death and primary cause of morbidity and mortality in diabetic population. Epicardial adipose tissue (EAT) covers the heart's surface and is a source of biomolecules regulating heart and blood vessel physiology. The protective activation of the unfolded protein response (UPR) and autophagy allows the cardiomyocyte reticular network to restore energy and/or nutrient homeostasis and to avoid cell death. However, an excessive or prolonged UPR activation can trigger cell death. UPR activation is an early event of diabetic cardiomyopathies and deregulated autophagy is associated with CVDs. RESULTS: An upregulation of UPR markers (glucose-regulated protein 78 KDa, glucose-regulated protein 94 KDa, inositol-requiring enzyme 1α, protein kinase RNA-like ER kinase and CCAAT/-enhancer-binding protein homologous protein (CHOP) gene) in EAT compared to subcutaneous adipose tissue (SAT), was observed as well as the UPR-related apoptosis marker caspase-4/procaspase-4 ratio but not in CHOP protein levels. Additionally, levels of ubiquitin and ubiquitinated proteins were decreased in EAT. Moreover, upregulation of autophagy markers (5' adenosine monophosphate-activated protein kinase, mechanistic target of rapamycin, Beclin 1, microtubule-associated protein light chain 3-II, lysosome-associated membrane protein 2, and PTEN-induced putative kinase 1) was observed, as well as an increase in the apoptotic Bim but not the ratio between Bim and the anti-apoptotic Bcl-2 in EAT. Diabetic patients show alterations in UPR activation markers but not in autophagy or apoptosis markers. CONCLUSION: UPR and autophagy are increased in EAT compared to SAT, opening doors to the identification of early biomarkers for cardiomyopathies and novel therapeutic targets.


Assuntos
Diabetes Mellitus/metabolismo , Cardiomiopatias Diabéticas/patologia , Insuficiência Cardíaca/patologia , Pericárdio/metabolismo , Proteostase , Gordura Subcutânea/metabolismo , Idoso , Apoptose , Autofagia , Biomarcadores , Diabetes Mellitus/patologia , Cardiomiopatias Diabéticas/diagnóstico , Cardiomiopatias Diabéticas/metabolismo , Retículo Endoplasmático/patologia , Estresse do Retículo Endoplasmático , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/metabolismo , Humanos , Masculino , Miócitos Cardíacos/patologia , Pericárdio/citologia , Pericárdio/patologia , Gordura Subcutânea/citologia , Resposta a Proteínas não Dobradas
5.
Water Sci Technol ; 76(5-6): 1188-1195, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28876260

RESUMO

Treatment of the highly polluting and variable textile industry wastewater using aerobic granular sludge (AGS) sequencing batch reactors (SBRs) has been recently suggested. Aiming to develop this technology application, two feeding strategies were compared regarding the capacity of anaerobic-aerobic SBRs to deal with disturbances in the composition of the simulated textile wastewater feed. Both a statically fed, anaerobic-aerobic SBR and an anaerobic plug-flow fed, anaerobic-aerobic SBR could cope with shocks of high azo dye concentration and organic load, the overall chemical oxygen demand and color removal yields being rapidly restored to 80%. Yet, subsequent azo dye metabolite bioconversion was not observed, along the 315-day run. Moreover, switching from a starch-based substrate to acetate in the feed composition deteriorated AGS stability. Overall, the plug-flow fed SBR recovered more rapidly from the imposed disturbances. Further research is needed towards guaranteeing long-term AGS stability during the treatment of textile wastewater.


Assuntos
Reatores Biológicos , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Aerobiose , Compostos Azo , Análise da Demanda Biológica de Oxigênio , Resíduos Industriais , Indústria Têxtil , Têxteis
7.
Neuromuscul Disord ; 24(11): 986-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25047667

RESUMO

Duchenne muscular dystrophy (DMD), a severe and lethal condition, is caused by the absence of muscle dystrophin. Therapeutic trials aiming at the amelioration of muscle function have been targeting the production of muscle dystrophin in affected Duchenne patients. However, how much dystrophin is required to rescue the DMD phenotype remains an open question. We have previously identified two exceptional golden retriever muscular dystrophy (GRMD) dogs with a milder course despite the total absence of muscle dystrophin. Here we report two unusual patients carrying nonsense mutations in the DMD gene and dystrophin deficiency but with an unexpectedly mild phenotype. Three reported polymorphisms, respectively in genes LTBP4, SPP1 and ACTN3 were excluded as possible DMD genetic modifiers in our patients. Finding the mechanisms that protect some rare patients and dogs from the deleterious effect of absent muscle dystrophin is of utmost importance and may lead to new avenues for treatment. Importantly, these observations indicate that it is possible to have a functional large muscle even without dystrophin.


Assuntos
Códon sem Sentido/genética , Distrofina/genética , Distrofia Muscular de Duchenne/genética , Actinas/genética , Adolescente , Feminino , Humanos , Proteínas de Ligação a TGF-beta Latente/genética , Masculino
8.
J Mol Recognit ; 26(2): 104-12, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23334918

RESUMO

Protein stabilization was achieved by a novel approach based on the adsorption and establishment of affinity-like interactions with a biomimetic triazine-scaffolded ligand. A synthetic lead compound (ligand 3'/11, K(a) ≈ 10(4) M(-1)) was selected from a previously screened solid-phase library of affinity ligands for studies of adsorption and stabilization of cutinase from Fusarium solani pisi used as a model system. This ligand, directly synthesized in agarose by a well-established solid-phase synthesis method, was able to strongly bind cutinase and led to impressive half-lives of more than 8 h at 70 °C, and of approximately 34 h at 60 °C for bound protein (a 25- and 57-fold increase as compared with the free enzyme, respectively). The ligand density in the solid matrix was found to be a determinant parameter for cutinase stabilization. It is conceivable that the highly stabilizing effect observed results from the binding of more than one ligand residue to the enzyme, creating specific macromolecular configurations that lock structural mobility thus improving molecular stability.


Assuntos
Hidrolases de Éster Carboxílico/química , Excipientes/síntese química , Proteínas Fúngicas/química , Triazinas/síntese química , para-Aminobenzoatos/síntese química , Adsorção , Sítios de Ligação , Hidrolases de Éster Carboxílico/genética , Dipeptídeos/química , Escherichia coli/genética , Excipientes/química , Proteínas Fúngicas/genética , Fusarium , Meia-Vida , Temperatura Alta , Cinética , Ligantes , Mimetismo Molecular , Ligação Proteica , Estabilidade Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Sefarose/química , Técnicas de Síntese em Fase Sólida , Termodinâmica , Triazinas/química , para-Aminobenzoatos/química
9.
Anal Bioanal Chem ; 404(4): 1211-37, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22644146

RESUMO

Biotechnological processes are crucial to the development of any economy striving to ensure a relevant position in future markets. The cultivation of microorganisms in bioreactors is one of the most important unit operations of biotechnological processes, and real-time monitoring of bioreactors is essential for effective bioprocess control. In this review, published material on the potential application of different spectroscopic techniques for bioreactor monitoring is critically discussed, with particular emphasis on optical fiber technology, reported for in situ bioprocess monitoring. Application examples are presented by spectroscopy type, specifically focusing on ultraviolet-visible, near-infrared, mid-infrared, Raman, and fluorescence spectroscopy. The spectra acquisition devices available and the major advantages and disadvantages of each spectroscopy are discussed. The type of information contained in the spectra and the available chemometric methods for extracting that information are also addressed, including wavelength selection, spectra pre-processing, principal component analysis, and partial least-squares. Sample handling techniques (flow and sequential injection analysis) that include transport to spectroscopic sensors for ex-situ on-line monitoring are not covered in this review.


Assuntos
Bactérias/metabolismo , Reatores Biológicos/microbiologia , Biotecnologia/métodos , Análise Espectral/métodos
10.
J Phys Chem B ; 116(9): 2664-76, 2012 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-22369088

RESUMO

The properties of the light flexible device, ion jelly, which combines gelatin with an ionic liquid (IL) were recently reported being promising to develop safe and highly conductive electrolytes. This article aims for the understanding of the ion jelly conductive mechanism using dielectric relaxation spectroscopy (DRS) in the frequency range 10(-1)-10(6) Hz; the study was complemented with differential scanning calorimetry (DSC) and pulsed field gradient nuclear magnetic resonance (PFG NMR) spectroscopy. The room temperature ionic liquid 1-butyl-3-methylimmidazolium dicyanamide (BMIMDCA) used as received (1.9% w/w water content) and with 6.6% (w/w) of water content and two ion jellies with two different ratios BMIMDCA/gelatin/water % (w/w), IJ1 (41.1/46.7/12.2) and IJ3 (67.8/25.6/6.6), have been characterized. A glass transition was detected by DSC for all materials allowing for classifying them as glass formers. For the ionic liquid, it was observed that the glass transition temperature decreases with the increase of water content. While in subsequent calorimetric runs crystallization was observed for BMIMDCA with negligible water content, no crystallization was detected for any of the ion jelly materials upon themal cycling. To the dielectric spectra of all tested materials, both dipolar relaxation and conductivity contribute; at the lowest frequencies, electrode and interfacial polarization highly dominate. Conductivity, which manifests much more intensity relative to dipolar reorientations, strongly evidences subdiffusive ion dynamics at high frequencies. From dielectric measures, transport properties as mobility and diffusion coefficients were extracted. Data treatment was carried out in order to deconvolute the average diffusion coefficients estimated from dielectric data in its individual contributions of cations (D(+)) and anions (D(-)). The D(+) values thus obtained for IJ3, the ion jelly with the highest IL/gelatin ratio, cover a large temperature range up to room temperature and revealed excellent agreement with direct measurements from PFG NMR, obeying to the same VFT equation. For BMIMDCA(6.6%water), which has the same water amount as IJ3, the diffusion coefficients were only estimated from DRS measurements over a limited temperature range; however, a single VFT equation describes both DRS and PFG NMR data. Moreover, it was found that the diffusion coefficients and mobility are similar for the ionic liquid and IJ3, which points to a role of both water and gelatin weakening the contact ion pair, facilitating the translational motion of ions and promoting its dissociation; nevertheless, it is conceivable the existence of a critical composition of gelatin that leads to those properties. The VFT temperature dependence observed for the conductivity was found to be determined by a similar dependence of the mobility. Both conductivity and segmental motion revealed to be correlated as inferred by the relatively low values of the decoupling indexes. The obtained results show that ion jelly could be in fact a very promising material to design novel electrolytes for different electrochemical devices, having a performance close to the IL but presenting an additional stability regarding electrical measurements and resistance against crystallization relative to the bulk ionic liquid.


Assuntos
Condutividade Elétrica , Íons , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética
11.
Environ Technol ; 29(8): 891-8, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18724644

RESUMO

In the present work ultraviolet (UV)-visible spectra of water samples collected at the outlet of a fuel park wastewater treatment plant, including biological treatment, were acquired and used for the development of partial least squares (PLS) calibration models for the fast and simple estimation of total organic carbon (TOC). Three different PLS models were developed and compared on the basis of a common spectral range. The first model was obtained using spectra of raw samples, the second using spectra of diluted samples, to assess signal saturation in the UV region, and the third using spectra of both diluted and raw samples, in order to expand the narrow interval of TOC concentration values present in the original dataset. The root mean squared error of cross-validation values for the developed PLS models were 2.3, 1.0 and 4.4 mg Cl(-1), respectively, and the validation results where highly satisfactory (root mean squared error of prediction values of 1.8, 0.8 and 4.5 mg Cl(-1), respectively).


Assuntos
Monitoramento Ambiental/métodos , Resíduos Industriais/análise , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Calibragem , Análise dos Mínimos Quadrados , Espectrofotometria Ultravioleta
12.
Artigo em Inglês | LILACS | ID: lil-492205

RESUMO

Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human...


Assuntos
Cólera/epidemiologia , Saúde Pública , Vibrio cholerae/patogenicidade , Poluição da Água
13.
Am J Obstet Gynecol ; 196(4): 352.e1-6, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17403419

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the long-term expression of a transgene and subsequent immune response after the injection of lentiviral vectors in a fetal rats. STUDY DESIGN: Fetal rats were injected in the liver, peritoneal cavity, or lung at E19 (term, E21) with a lentiviral vector expressing enhanced green fluorescent protein and luciferase. Controls received saline solution. After birth, full body bioluminescence was done at weeks 1, 4, 10, and 30 of life; seroconversion for the transgene was assessed. RESULTS: All surviving fetuses that had been injected in the liver (8/9 fetuses), peritoneum (3/3 fetuses), or lung (9/10 fetuses) showed a signal on bioluminescence imaging scan up to 30 weeks. None of the survivors displayed seroconversion against the transgene. CONCLUSION: In the rat model, the administration of lentiviral vectors into the fetal lung and liver resulted in long-term transgene expression without detectable humoral immune response.


Assuntos
Vetores Genéticos/farmacologia , Lentivirus/genética , Prenhez , Transdução Genética , Animais , Modelos Animais de Doenças , Feminino , Feto/imunologia , Feto/patologia , Seguimentos , Técnicas de Transferência de Genes , Terapia Genética/métodos , Imuno-Histoquímica , Fígado/imunologia , Fígado/patologia , Pulmão/imunologia , Pulmão/patologia , Tomografia por Emissão de Pósitrons , Gravidez , Probabilidade , Ratos , Ratos Wistar , Valores de Referência , Sensibilidade e Especificidade , Fatores de Tempo
14.
J. venom. anim. toxins incl. trop. dis ; 13(2): 472-478, 2007. tab
Artigo em Inglês | LILACS | ID: lil-452842

RESUMO

Diseases transmitted by water consists a serious public health problem and enterobacteria are the main group of microorganisms responsible for outbreaks in humans. Such pathogenic bacteria proliferate in water polluted by domestic and industrial sewage and reach the population through seawater contact. The aim of the present work was to study environmental parameters as well as to identify Enterobacteriaceae species and their antimicrobial susceptibility in water samples collected from the estuarine area of São Vicente city (São Paulo State, Brazil). Strains were identified by using traditional biochemical tests described in literature and antimicrobial susceptibility tests were carried out using the disk diffusion method. Out of 26 samples, Escherichia coli was the most frequent species (40.1 percent), followed by Citrobacter, Enterobacter and Klebsiella. The most effective drugs against the tested microorganisms were gentamycin, netilmicin, ciprofloxacin and cefepime. Since these bacteria are commonly found in seashore contaminated by sewage effluents, it can be concluded that estuarine waters of São Vicente are polluted and potentially capable of causing diseases and spreading pathogenic bacteria to human communities.


Assuntos
Enterobacteriaceae , Microbiologia Ambiental , Estuários , Poluição de Estuários , Testes de Sensibilidade Microbiana/métodos
15.
Chemosphere ; 65(5): 786-91, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16650456

RESUMO

In the context of the high application potentials for on-line measurements in wastewater quality monitoring, UV spectroscopy has received recent attention. In the present work UV spectrophotometric analyses were coupled to principal component analysis (PCA) and cluster analysis (CA) to characterize samples taken from a fuel park wastewater treatment plant and to attempt preliminary contaminant identification in the treated wastewater. The score plot resulting from PCA identified two different groups of spectra, one including the influents to the biological reactor and the other the treated wastewater samples. Among the latter, weekday and weekend samples could be further distinguished. The same groups of samples were identified in a dendrogram from CA. The score plot and the dendrogram also allowed the tentative identification of employed process chemicals (lubricant and detergents) as residual contaminants in the treated effluent.


Assuntos
Monitoramento Ambiental/métodos , Resíduos Industriais , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Água/análise , Análise por Conglomerados , Análise de Componente Principal , Espectrofotometria Ultravioleta/métodos , Eliminação de Resíduos Líquidos
16.
Environ Technol ; 24(6): 679-86, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12868522

RESUMO

A great number of the reported examples of azo dye biodegradation comprise two main steps, the reductive cleavage of the azo bond under anaerobic conditions and the subsequent aerobic mineralization of the produced aromatic amines. Based on this possible metabolism a Sequencing Batch Reactor was chosen to study biologicalcolor removal from simulated cotton textile effluents containing a reactive azo dye. In previous studies high color removal levels of the azo dye Remazol Brilliant Violet 5R were achieved (up to 90% with an initial dye concentration of 100 mg l(-1)) during the anaerobic phase of Sequencing Batch Reactor operation. However, HPLC analyses revealed that the aromatic amines formed in the anaerobic phase were not mineralized during the subsequent aerobic phase. In an attempt to promote the aerobic biodegradation of these aromatic amines three different approaches were tested, the increase of the relative duration of the aerobic phase, the increase of the hydraulic retention time through the decrease of the daily fill flow and finally the increase of the dye/carbon source concentration ratio through the decrease of the fed volumetric organic load. The two aromatic amines directly resulting from azo bond reduction were detected by HPLC analysis. However, a third metabolite with significant peak area was also detected with a time profile suggesting an equilibrium with one of the aromatic amines In spite of the conversions occurring between metabolites during the cycles of the tested approaches, no effective biodegradation of these metabolites was observed during the experimental period of over 810 days.


Assuntos
Antraquinonas/metabolismo , Bactérias Aeróbias/fisiologia , Bactérias Anaeróbias/fisiologia , Corantes/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Indústria Têxtil , Eliminação de Resíduos Líquidos , Purificação da Água
17.
J Biotechnol ; 89(2-3): 163-74, 2001 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-11500210

RESUMO

The combination of anaerobic and aerobic periods in the operation cycle of a Sequencing Batch Reactor (SBR) was chosen to study biological color removal from simulated textile effluents containing reactive, sulfonated, monoazo and diazo dyes, respectively, Remazol Brilliant Violet 5R and Remazol Black B. 90% color removal was obtained for the violet dye in a 24-h cycle with a Sludge Retention Time (SRT) of 15 days and an aerated reaction phase of 10 h. For the black dye only 75% color removal was achieved with the same operational conditions and no improvement was observed with the increase of the SRT to 20 days. For the violet dye a reduction of the color removal values from 90 to 75% was observed with the increase of the aerated reaction phase from 10 to 12 h. However, this increase did not promote the aerobic biodegradation of the produced aromatic amines. Abiotic tests were performed with sterilized SBR samples and no color removal was observed in cell-free supernatants. However color removal values of 30 and 12% were observed in the presence of sterilized cells and supernatants with violet and black dye, respectively and could be attributed to the presence of active reducing principles in the sterilized samples.


Assuntos
Reatores Biológicos , Corantes/metabolismo , Naftalenossulfonatos/metabolismo , Têxteis , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão
18.
Biotechnol Bioeng ; 69(3): 286-91, 2000 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-10861408

RESUMO

The operational stability of peroxidases was considerably enhanced by generating hydrogen peroxide in situ from glucose and oxygen. For example, the total turnover number of microperoxidase-11 in the oxidation of thioanisole was increased sevenfold compared with that obtained with continuous addition of H(2)O(2). Coimmobilization of peroxidases with glucose oxidase into polyurethane foams afforded heterogeneous biocatalysts in which the hydrogen peroxide is formed inside the polymeric matrix from glucose and oxygen. The total turnover number of chloroperoxidase in the oxidation of thioanisole and cis-2-heptene was increased to new maxima of 250. 10(3) and 10. 10(3), respectively, upon coimmobilization with glucose oxidase. Soybean peroxidase, which normally shows only classical peroxidase activity, was transformed into an oxygen-transfer catalyst when coimmobilized with glucose oxidase. The combination catalyst mediated the enantioselective oxidation of thioanisole [50% ee (S)] with 210 catalyst turnovers.


Assuntos
Enzimas Imobilizadas , Glucose Oxidase/metabolismo , Peroxidases/metabolismo , Cloreto Peroxidase/metabolismo , Estabilidade Enzimática , Fungos/enzimologia , Glucose/metabolismo , Glucose/farmacologia , Heptanos/química , Heptanos/metabolismo , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Cinética , Oxirredução/efeitos dos fármacos , Oxigênio/metabolismo , Poliuretanos , Soluções , Glycine max/enzimologia , Estereoisomerismo , Sulfetos/química , Sulfetos/metabolismo , terc-Butil Álcool/farmacologia
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