Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Sci Total Environ ; 857(Pt 1): 159343, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36228791

RESUMEN

Cyanobacteria have been identified as promising organisms to reuse nutrients from waste effluents and produce valuable compounds such as lipids, polyhydroxyalkanoates (PHAs), and pigments. However, almost all studies on cyanobacterial biorefineries have been performed under lab scale and short cultivation periods. The present study evaluates the cultivation of the cyanobacterium Synechocystis sp. in a pilot scale 30 L semi-continuous photobioreactor fed with secondary effluent for a period of 120 days to produce phycobiliproteins, polyhydroxybutyrate (PHB) and lipids. To this end, the harvested biomass from the semi-continuous photobioreactor was transferred into 5 L vertical column batch photobioreactors to perform PHB and lipid accumulation under nutrient starvation. Three hydraulic retention times (HRT) (6, 8 and 10 days) were tested in the semi-continuous photobioreactor to evaluate its influence on biomass growth and microbial community. A maximum biomass concentration of 1.413 g L-1 and maximum productivity of 173 mg L-1 d-1 was reached under HRT of 8 days. Microscopy analysis revealed a shift from Synechocystis sp. to Leptolyngbya sp. and green algae when HRT of 6 days was used. Continuous, stable production of phycobiliproteins in the semi-continuous photobioreactor was obtained, reaching a maximum content of 7.4%dcw in the biomass. In the batch photobioreactors a PHB content of 4.8%dcw was reached under 7 days of nitrogen and phosphorus starvation, while a lipids content of 44.7%dcw was achieved under 30 days of nitrogen starvation. PHB and lipids production was strongly dependent on the amount of nutrients withdrawn from the grow phase. In the case of lipids, their production was stimulated when there was only phosphorus depletion. While Nitrogen and phosphorus limitation was needed to enhance the PHB production. In conclusion, this study demonstrates the feasibility of cultivating cyanobacteria in treated wastewater to produce bio-based valuable compounds within a circular bioeconomy approach.


Asunto(s)
Microalgas , Synechocystis , Ficobiliproteínas , Biomasa , Aguas Residuales , Fósforo , Nitrógeno , Lípidos
2.
Bioresour Technol ; 247: 513-519, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28972904

RESUMEN

In this study, microalgae digestate and secondary effluent were used to grow microalgae in a tertiary wastewater treatment, and then, the biomass was co-digested for biogas generation. A 30L closed-photobioreactor was used for microalgae cultivation. The biomass, mainly composed by Scenedesmus sp., reached and maintained a concentration of 1.1gTSS/L during 30days. A complete removal of N-NH4+ and P-PO43- and high nitrates and organic matter removals were achieved (58% N-NO3- and 70% COD) with 8d of HRT. The potential biogas production of the cultivated microalgae was determined in batch tests. To improve their biodegradability, a novel method combining their co-digestion with activated sludge after a simultaneous autohydrolysis co-pretreatment was evaluated. After the co-pretreatment, the methane yield increased by 130%. Thus, integrating microalgae tertiary treatment into activated sludge systems is a promising and feasible solution to recover energy and nutrients from waste, improving wastewater treatment plants sustainability.


Asunto(s)
Microalgas , Aguas Residuales , Anaerobiosis , Biocombustibles , Biomasa , Metano , Aguas del Alcantarillado
3.
Cochrane Database Syst Rev ; (5): CD006899, 2016 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-27223580

RESUMEN

BACKGROUND: Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors with the potential to improve the healing of chronic wounds. This is the first update of a review first published in 2012. OBJECTIVES: To determine whether autologous PRP promotes the healing of chronic wounds. SEARCH METHODS: In June 2015, for this first update, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library): Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched for ongoing and unpublished clinical trials in the WHO International Clinical Trials Registry Platform (ICTRP) (searched January 2015). We did not impose any restrictions with respect to language, date of publication, or study setting. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults. We did not apply any date or language restrictions. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology, including two reviewers independently selecting studies for inclusion, extracting data, and assessing risk of bias. MAIN RESULTS: The search identified one new RCT, making a total of 10 included RCTs (442 participants, 42% women). The median number of participants per RCT was 29 (range 10 to 117). Four RCTs recruited people with a range of chronic wounds; three RCTs recruited people with venous leg ulcers, and three RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range 8 to 40 weeks).It is unclear whether autologous PRP improves the healing of chronic wounds generally compared with standard treatment (with or without placebo) (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.95 to 1.50; I(2) = 27%, low quality evidence, 8 RCTs, 391 participants). Autologous PRP may increase the healing of foot ulcers in people with diabetes compared with standard care (with or without placebo) (RR 1.22, 95% CI 1.01 to 1.49; I(2) = 0%, low quality evidence, 2 RCTs, 189 participants). It is unclear if autologous PRP affects the healing of venous leg ulcers (RR 1.02, 95% CI 0.81 to 1.27; I(2) = 0% ). It is unclear if there is a difference in the risk of adverse events in people treated with PRP or standard care (RR 1.05, 95% CI 0.29 to 3.88; I(2) = 0%, low quality evidence from 3 trials, 102 participants). AUTHORS' CONCLUSIONS: PRP may improve the healing of foot ulcers associated with diabetes, but this conclusion is based on low quality evidence from two small RCTs. It is unclear whether PRP influences the healing of other chronic wounds. The overall quality of evidence of autologous PRP for treating chronic wounds is low. There are very few RCTs evaluating PRP, they are underpowered to detect treatment effects, if they exist, and are generally at high or unclear risk of bias. Well designed and adequately powered clinical trials are needed.


Asunto(s)
Pie Diabético/terapia , Transfusión de Plaquetas/métodos , Plasma Rico en Plaquetas , Úlcera Varicosa/terapia , Cicatrización de Heridas , Adulto , Transfusión de Sangre Autóloga/métodos , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto
4.
Cochrane Database Syst Rev ; 10: CD006899, 2012 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-23076929

RESUMEN

BACKGROUND: Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors and has the potential to aid wound healing. OBJECTIVES: To determine whether autologous PRP promotes the healing of chronic wounds. SEARCH METHODS: We searched the Cochrane Wounds Group Specialised Register (searched 15 August 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8); Ovid MEDLINE (1950 to August Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, August 14, 2012); Ovid EMBASE (1980 to 2012 Week 32); EBSCO CINAHL (1982 to 10 August 2012) and International Clinical Trials Registry Platform (ICTRP)(accessed 22 August 2012). No date or language restrictions were applied. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed each study against the inclusion criteria, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD) and time to wound healing was analysed as survival data using the hazard ratio (HR). We considered heterogeneity as significant when I(2) was >75%. MAIN RESULTS: Nine eligible RCTs were included, with a total of 325 participants of whom 44% were women. The median number of participants per RCT was 26 (range 10 to 86). Four RCTs recruited people with mixed chronic wounds (there were participants with wounds caused by more than one aetiology and participants who had wounds of several aetiologies in the same trial), three RCTs recruited people with venous leg ulcers and two RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range eight to 40 weeks).One study was at low risk of bias, three studies were at high risk of bias with the remainder being at overall unclear risk of bias. The proportion of completely healed chronic wounds was reported in seven RCTs that compared PRP with standard treatment or placebo, with no statistically significant difference between the groups, in diabetic foot ulcers (RR 1.16; 95% CI 0.57 to 2.35), in venous leg ulcers (pooled RR 1.02; 95% CI 0.81 to 1.27; I(2)=0% ) and in mixed chronic wounds (pooled RR 1.85; 95% CI 0.76 to 4.51; I(2)=42%). The total area epithelialised at the end of the intervention was reported in three RCTs of mixed chronic wounds, there was no statistically significant difference between the groups (pooled MD -1.94 cm(2); 95% CI -4.74 to 0.86; I(2)=47%). The percentage of wound area healed was reported in two RCTs of mixed chronic wounds, and results were statistically significant in favour of the PRP group (RR 51.78%; 95% CI 32.70 to 70.86; I(2)= 0%). Wound complications like infection or necrosis were reported by three RCTs, and there was no statistically significant difference between groups (RR 1.08; 95% CI 0.31 to 3.73). Adverse effects were reported by three studies and there was no statistically significant difference between people treated with PRP and those not given PRP (pooled RR 1.07; 95% CI 0.32 to 3.58; I(2)=0%). AUTHORS' CONCLUSIONS: There is currently no evidence to suggest that autologous PRP is of value for treating chronic wounds. However, current evidence is based on a small number of RCTs, most of which are either at high or unclear risk of bias. Well-designed and adequately powered clinical trials are needed.


Asunto(s)
Pie Diabético/terapia , Transfusión de Plaquetas/métodos , Plasma Rico en Plaquetas , Úlcera Varicosa/terapia , Cicatrización de Heridas , Adulto , Transfusión de Sangre Autóloga/métodos , Enfermedad Crónica , Femenino , Humanos , Masculino , Ensayos Clínicos Controlados Aleatorios como Asunto
5.
Water Res ; 45(12): 3579-89, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21601904

RESUMEN

The effect of both the type of primary treatment (hydrolitic up-flow sludge blanket (HUSB) reactor and conventional settling) and the flow regime (batch and continuous) on clogging development in subsurface flow constructed wetlands (SSF CWs) was studied. Clogging indicators (such as accumulated solids, hydraulic conductivity and drainable porosity) were determined in an experimental plant with three treatment lines. Correlations were encountered between the solids accumulated and both saturated hydraulic conductivity and drainable porosity reduction over time (74.5% and 89.2% of correlation, respectively). SSF CW implemented with a HUSB reactor accumulated ca. 30% lower sludge (1.9 kg DM/m(2)) than a system with a settler (2.5-2.8 kg DM/m(2)). However, no significant differences were recorded among treatment lines concerning hydraulic parameters (such as hydraulic conductivity or porosity). Root system development contributed to clogging. Accordingly, planted wetlands showed between 30% and 40% and 10% lower hydraulic conductivity and porosity reduction, respectively, than non-planted wetlands.


Asunto(s)
Reología , Purificación del Agua/métodos , Humedales , Raíces de Plantas/metabolismo , Poaceae/metabolismo , Porosidad , Aguas del Alcantarillado , Suelo/química , Factores de Tiempo , Eliminación de Residuos Líquidos , Agua , Purificación del Agua/instrumentación
6.
Water Res ; 45(2): 573-82, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20932543

RESUMEN

Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (<2000 population equivalent). The performance of full-scale STW was characterised during 2 years. Sludge dewatering increased total solids (TS) concentration by 25%, while sludge biodegradation lead to volatile solids around 45% TS and DRI(24h) between 1.1 and 1.4 gO(2)/kgTS h, suggesting a partial stabilisation of biosolids. In the economic and environmental assessment, four scenarios were considered for comparison: 1) STW with direct land application of biosolids, 2) STW with compost post-treatment, 3) centrifuge with compost post-treatment and 4) sludge transport to an intensive wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities.


Asunto(s)
Ambiente , Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodos , Humedales , Biodegradación Ambiental , Biomasa , Aguas del Alcantarillado/química , Suelo , España , Eliminación de Residuos Líquidos/economía , Purificación del Agua/métodos
7.
Proc Natl Acad Sci U S A ; 107(13): 5762-7, 2010 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-20231433

RESUMEN

Here we report the discovery of a new late Lower Pleistocene site named Vallparadís (Barcelona, Spain) that produced a rich archeological and paleontological sequence dated from the upper boundary of the Jaramillo subchron to the early Middle Pleistocene. This deposit contained a main archeological layer with numerous artifacts and a rich macromammalian assemblage, some of which bore cut marks, that could indicate that hominins had access to carcasses. Paleomagnetic analysis, electron spin resonance-uranium series (ESR-US), and the biostratigraphic chronological position of the macro- and micromammal and lithic assemblages of this layer reinforce the proposal that hominins inhabited Europe during the Lower Pleistocene. The archeological sequence provides key information on the successful adaptation of European hominins that preceded the well-known fossil population from Atapuerca and succeeded the finds from Orce basin. Hence, this discovery enables us to close a major chronological gap in the early prehistory of Iberia. According to the information in this paper and the available data from these other sites, we propose that Mediterranean Western Europe was repeatedly and perhaps continuously occupied during the late Matuyama chron.


Asunto(s)
Fósiles , Hominidae , Animales , Arqueología , Historia Antigua , Humanos , Mamíferos , Paleontología , España
8.
Menopause ; 17(2): 303-8, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19934777

RESUMEN

OBJECTIVE: This study aimed to compare the efficacy and safety of a multibotanical (Nutrafem) with those of placebo for the treatment of menopausal vasomotor symptoms. METHODS: In this phase III, double-blind, randomized, placebo-controlled study, 159 postmenopausal women experiencing at least 21 vasomotor symptoms per week were treated with Nutrafem (Bionutra Pte Ltd, Singapore) or a matched placebo for 12 weeks. Treatment outcome was evaluated by the change from baseline in the average weekly number of vasomotor symptoms. RESULTS: At the end of the study, Nutrafem reduced the number of vasomotor symptoms by 46% from baseline, and this is significantly superior to placebo (26% from baseline; P = 0.020). Forty-three percent of women taking Nutrafem experienced an at least 50% reduction in the number of symptoms compared with 6% of women taking placebo (P = 0.021; number needed to treat = 2.7). There were no group differences in adverse events, laboratory values, and gynecological data. CONCLUSIONS: Nutrafem is an effective botanical treatment for vasomotor symptoms in postmenopausal women.


Asunto(s)
Medicamentos Herbarios Chinos/uso terapéutico , Sofocos/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Posmenopausia , Sistema Vasomotor/efectos de los fármacos , Administración Oral , Método Doble Ciego , Eucommiaceae , Fabaceae , Femenino , Humanos , Persona de Mediana Edad , Extractos Vegetales/farmacología , Hojas de la Planta , Semillas , Singapur , Resultado del Tratamiento
9.
Bioresour Technol ; 100(17): 3882-90, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19369066

RESUMEN

Optimization of sludge management can help reducing sludge handling costs in wastewater treatment plants. Sludge drying reed beds appear as a new and alternative technology which has low energy requirements, reduced operating and maintenance costs, and causes little environmental impact. The objective of this work was to evaluate the efficiency of three full-scale drying reed beds in terms of sludge dewatering, stabilization and hygienisation. Samples of influent sludge and sludge accumulated in the reed beds were analysed for pH, Electrical Conductivity, Total Solids (TS), Volatile Solids (VS), Chemical Oxygen Demand, Biochemical Oxygen Demand, nutrients (Total Kjeldahl Nitrogen (TKN) and Total Phosphorus (TP)), heavy metals and faecal bacteria indicators (Escherichiacoli and Salmonella spp.). Lixiviate samples were also collected. There was a systematic increase in the TS concentration from 1-3% in the influent to 20-30% in the beds, which fits in the range obtained with conventional dewatering technologies. Progressive organic matter removal and sludge stabilization in the beds was also observed (VS concentration decreased from 52-67% TS in the influent to 31-49% TS in the beds). Concentration of nutrients of the sludge accumulated in the beds was quite low (TKN 2-7% TS and TP 0.04-0.7% TS), and heavy metals remained below law threshold concentrations. Salmonella spp. was not detected in any of the samples, while E. coli concentration was generally lower than 460MPN/g in the sludge accumulated in the beds. The studied systems demonstrated a good efficiency for sludge dewatering and stabilization in the context of small remote wastewater treatment plants.


Asunto(s)
Desecación , Restauración y Remediación Ambiental/métodos , Poaceae/metabolismo , Aguas del Alcantarillado/química , Agua/química , Bacterias/aislamiento & purificación , Biodegradación Ambiental , Conductividad Eléctrica , Heces/microbiología , Concentración de Iones de Hidrógeno , Metales Pesados/análisis , Nitrógeno/análisis , Compuestos Orgánicos/aislamiento & purificación , Oxígeno , Fósforo/análisis , Aguas del Alcantarillado/microbiología , España , Volatilización , Purificación del Agua
10.
Transfusion ; 49(1): 44-56, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18954394

RESUMEN

BACKGROUND: Autologous plasma rich in platelets (PRP) is a derived blood product whose application in clinical practice is growing. A systematic review was conducted to evaluate its efficacy and safety. STUDY DESIGN AND METHODS: A search was performed in electronic databases. Randomized controlled clinical trials (RCTs) in adult patients were included and assessed for methodologic quality. The main outcomes were "tissue regeneration" and "safety." Relative risks (RRs) and standardized mean differences (SMDs) were calculated to show pooled estimates for these outcomes. When the results heterogeneity was more than 50 percent, a sensitivity analysis was performed. RESULTS: Twenty RCTs were included (11 of oral and maxillofacial surgery, 7 of chronic skin ulcers, and 2 of surgery wounds). Four RCTs evaluated the depth reduction in gingival recession in chronic periodontitis; the SMD was 0.54 (95% confidence interval [CI], 0.16 to 0.92) mm, favorable to PRP. Three RCTs evaluated the clinical attachment level in chronic periodontitis; the SMD was 0.33 (95% CI, -0.71 to 1.37) mm. Six RCTs assessed the complete skin epithelialization in wound ulcers; the RR was 1.40 (95% CI, 0.85 to 2.31). Only 6 RCTs reported adverse effects without differences between groups. CONCLUSIONS: PRP improves the gingival recession but not the clinical attachment level in chronic periodontitis. In the complete healing process of chronic skin ulcers, the results are inconclusive. There are little data about PRP safety. There are several methodologic limitations and, consequently, future research should focus on strong and well-designed RCTs that assess the efficacy and safety of PRP.


Asunto(s)
Transfusión de Sangre Autóloga , Transfusión de Plaquetas , Seguridad , Cicatrización de Heridas , Enfermedad Crónica , Periodontitis Crónica/cirugía , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Úlcera Cutánea/terapia , Cirugía Bucal/métodos
11.
Artículo en Inglés | MEDLINE | ID: mdl-15921294

RESUMEN

The objective of this article is to evaluate the effect of water depth on organic matter removal efficiency in horizontal subsurface flow constructed wetlands (SSFs). Experiments were carried out in a pilot plant comprising eight parallel SSF of almost equal surface area (54-56 m2 each) and treating urban wastewater. Each SSF differs from the others in the aspect ratio or the size of the granular medium or the water depth. During a period of two years, the shallow SSFs (0.27 m water depth) removed more chemical oxygen demand (COD) (72-81%), biochemical oxygen demand (BOD)5 (72-85%), ammonia (35-56%), and dissolved reactive phosphorus (DRP) (8-23%) than deep SSFs (0.5 m water depth) (59-64% for COD; 51-57% for BOD5; 18-29% for ammonia; and 0-7% for DRP). Experiments carried out during the summer indicated that sulphate reduction accounted for a clearly higher organic matter removal in the deep SSFs than in the shallow ones. Denitrification seemed to be a significant mechanism for organic matter removal to occur in shallow SSFs. The results suggest that the relative contribution of different metabolic pathways varies with depth.


Asunto(s)
Ecosistema , Nitrógeno/metabolismo , Eliminación de Residuos Líquidos/métodos , Compuestos Orgánicos , Oxígeno/metabolismo , Fósforo/análisis , Fósforo/química , Plantas , Estaciones del Año , Movimientos del Agua
12.
Water Res ; 38(7): 1669-78, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15026221

RESUMEN

This study evaluates the effect of hydraulic loading rate (HLR), aspect ratio, granular medium size and water depth on the removal of selected contaminants during the start up of horizontal subsurface flow reed beds (HFRBs). Experiments were carried out in a pilot-scale HFRB system comprising four pairs of lined beds of almost equal surface area (54-56 m(2) each bed), with the following aspect ratios: 1:1, 1.5:1, 2:1 and 2.5:1. The size of the granular medium of each pair varied from coarse granitic gravel ( D(60) = 10mm, C(u) = 1.6) to small granitic gravel (D(60) = 3.5 mm, C(u) = 1.7). The beds of the pair with longest aspect ratio were made shallower (0.27 m) than the rest (0.5m) The system was sampled weekly from May 2001 to January 2002. The results indicate that HLR and water depth are determining factors in the performance of the HFRBs. Beds with a water depth of 0.27 m removed more COD (70-80%), BOD(5) (70-85%), ammonia (40-50%) and dissolved reactive phosphorus (DRP) (10-22%) than beds with a depth of 0.5m (60-65% for COD, 50-60% for BOD(5), 25-30% for ammonia, and 2-10% for DRP). The higher efficiency observed shallower beds was related to their less reducing conditions (average redox potential (E) ranging from -351 to -338 mV) than beds with a depth of 0.5m (-390 to -358 mV). The difference in E status between two bed types seems to lead to differences in the biochemical processes. In fact, denitrification was estimated to be a significant reaction in shallower beds.


Asunto(s)
Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Biodegradación Ambiental , Ciudades , Ecosistema , Filtración , Nitrógeno/análisis , Nitrógeno/aislamiento & purificación , Oxígeno/análisis , Fósforo/análisis , Fósforo/aislamiento & purificación , Plantas , Movimientos del Agua
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA