| 1. |
- Pinheiro, V. E., et al.
(författare)
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Anaerobic digestion of cornmeal : the effect of crude enzyme extract and co-digestion with cow manure
- 2021
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Ingår i: Biofuels, Bioproducts and Biorefining. - : John Wiley and Sons Ltd. - 1932-104X .- 1932-1031.
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the effect of a crude enzyme extract, containing mainly starch-degrading enzymes, on cornmeal (Zea mays) hydrolysis. This was followed by an investigation of the effect of enzymatic treatment for the anaerobic digestion of this biomass. Cornmeal and cow manure were also co-digested, and both batch and semi-continuous experiments were performed. The enzymatic pretreatment of cornmeal resulted in a yield of 65 ± 5% reducing sugars, with 1:10 w/v (grams of dry substrate per mililiters of enzyme extract) enzyme load at 45 °C for 48 h. There was an 8% enhancement of methane production observed during the batch assays, both when cornmeal hydrolysate was digested and when enzymes were added directly to the digester. Synergetic effects were found when co-digesting cornmeal and cow manure, leading to higher methane yield (280 NmL gVS–1) than that (200 NmL gVS–1) calculated based on the methane potential of the individual substrates. Regarding long-term effects, the laboratory-scale semi-continuous experiments also demonstrated that the co-digestion of cornmeal and cow manure (1:1 volatile solid (VS) basis) led to a stable process reaching an organic loading rate of 3 g VS L day–1 and achieving a daily methane production of 1280.12 ± 99.4 NmL CH4/day. However, when cornmeal was investigated in mono-digestion, and the enzyme extract was directly added during semi-continuous digestion of cornmeal, volatile fatty acid (VFA) accumulation was observed, leading to a decrease in pH, and no significant enhancement of the conversion into methane was observed. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd
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| 2. |
- Pinheiro, V. E., et al.
(författare)
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Screening and cocktail optimization using experimental mixture design : enzymatic saccharification as a biological pretreatment strategy
- 2021
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Ingår i: Biofuels, Bioproducts and Biorefining. - : John Wiley & Sons. - 1932-104X .- 1932-1031.
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Tidskriftsartikel (refereegranskat)abstract
- Biofuels contribute environment-friendly, renewable energy, minimizing dependence on fossil energy. The pretreatment of biomass is a practical step that accelerates and facilitates the hydrolysis of complex materials. This work aimed to screen, select, and study cocktail formulations for biomass hydrolysis, where the enzymes were provided both from a commercial source (Trichoderma reesei, Novozymes®) and through the cultivation of Aspergillus brasiliensis and Aspergillus tamarii Kita. Experimental mixture designs were used to optimize the enzymatic conversion of substrates into simple sugars. A crude extract rich in amylase (AAB) had a significant favorable influence on cornmeal hydrolysis by maximizing the yield of reducing sugars (RS) (173 μmol mL–1). Celluclast™, rich in cellulase, significantly affected the hydrolysis of banana peel, maximizing the RS yield (175 μmol mL–1). Variable degrees of enzyme synergism were evident from statistical analysis of the biomass hydrolysis.
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| 3. |
- Saberniak, Jorg, et al.
(författare)
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Vigorous physical activity impairs myocardial function in patients with arrhythmogenic right ventricular cardiomyopathy and in mutation positive family members
- 2014
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Ingår i: European Journal of Heart Failure. - : Wiley. - 1879-0844 .- 1388-9842. ; 16:12, s. 1337-1344
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Tidskriftsartikel (refereegranskat)abstract
- AimsExercise increases risk of ventricular arrhythmia in subjects with arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed to investigate the impact of exercise on myocardial function in ARVC subjects. Methods and ResultsWe included 110 subjects (age 4217years), 65 ARVC patients and 45 mutation-positive family members. Athletes were defined as subjects with 4h vigorous exercise/week [1440 metabolic equivalents (METsxminutes/week)] during a minimum of 6 years. Athlete definition was fulfilled in 37/110 (34%) subjects. We assessed right ventricular (RV) and left ventricular (LV) myocardial function by echocardiography, and by magnetic resonance imaging (MRI). The RV function by RV fractional area change (FAC), RV global longitudinal strain (GLS) by echocardiography, and RV ejection fraction (EF) by MRI was reduced in athletes compared with non-athletes (FAC 34 +/- 9% vs. 40 +/- 11%, RVGLS -18.3 +/- 6.1% vs. -22.0 +/- 4.8%, RVEF 32 +/- 8% vs. 43 +/- 10%, all P<0.01). LV function by LVEF and LVGLS was reduced in athletes compared with non-athletes (LVEF by echocardiography 50 +/- 10% vs. 57 +/- 5%, LVEF by MRI 46 +/- 6% vs. 53 +/- 8%, and LVGLS -16.7 +/- 4.2% vs. -19.4 +/- 2.9%, all P<0.01). The METsxminutes/week correlated with reduced RV and LV function by echocardiography and MRI (all P<0.01). The LVEF by MRI was also reduced in subgroups of athlete index patients (46 +/- 7% vs. 54 +/- 10%, P=0.02) and in athlete family members (47 +/- 3% vs. 52 +/- 6%, P<0.05). ConclusionAthletes showed reduced biventricular function compared with non-athletes in ARVC patients and in mutation-positive family members. The amount and intensity of exercise activity was associated with impaired LV and RV function. Exercise may aggravate and accelerate myocardial dysfunction in ARVC.
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| 4. |
- Sečenji, M, et al.
(författare)
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Differences in root functions during long-term drought adaptation : comparison of active gene sets of two wheat genotypes
- 2010
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Ingår i: Plant Biology. - : Wiley-Blackwell. - 1435-8603 .- 1438-8677. ; 12:6, s. 871-882
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to shed light on the role of root systems in differential responses of wheat genotypes to long-term water limitation, transcriptional differences between two wheat genotypes (Triticum aestivum L., cv. Plainsman V and landrace Kobomugi) were identified during adaptation to moderate water stress at the tillering stage. Differences in organ sizes, water-use efficiency and seed production were detected in plants grown in soil, and root functions were characterised by expression profiling. The molecular genetic background of the behaviour of the two genotypes during this stress was revealed using a cDNA macroarray for transcript profiling of the roots. During a 4-week period of moderate water deficit, a set of up-regulated genes displaying transiently increased expression was identified in young plantlets, mostly in the second week in the roots of Kobomugi, while transcript levels remained constantly high in roots of Plainsman V. These genes encode proteins with various functions, such as transport, protein metabolism, osmoprotectant biosynthesis, cell wall biogenesis and detoxification, and also regulatory proteins. Oxidoreductases, peroxidases and cell wall-related genes were induced significantly only in Plainsman V, while induction of stress- and defence-related genes was more pronounced in Kobomugi. Real-time qPCR analysis of selected members of the glutathione S-transferase gene family revealed differences in regulation of family members in the two genotypes and confirmed the macroarray results. The TaGSTZ gene was stress-activated only in the roots of Kobomugi.
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| 5. |
- Yarsur, E., et al.
(författare)
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Methane yield of paper industry waste in the presence of two compounds from alcohol and aldehyde groups during thermophilic anaerobic digestion
- 2023
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Ingår i: Environmental Research and Technology. - : Yildiz Technical University. - 2636-8498. ; , s. 54-59
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Konferensbidrag (refereegranskat)abstract
- In this study, effect of two chemical compounds (i.e., 1-octanol and hexanal) respectively from the alcohol and aldehyde groups on thermophilic (55±2 °C) anaerobic process digesting the waste produced at a paper industry was investigated. In this scope, possible inhibition was monitored by the cumulative methane (CH4) yields in the batch reactors digesting the paper waste as the feedstock at concentrations of 0.005%, 0.05%, and 0.5% for each compound. Comparing the effects of the two different groups with the control reactor having only the paper waste as the substrate, the results revealed that adding 1-octanol and hexanal up to 0.05% concentrations had some synergistic effect on biogas yield (i.e., from 3% to 12% enhancement). Accordingly, the highest methane yields were 550 and 567 mL/g-VSfed, respectively on average in the presence of 1-octanol and hexanal at a concentration of 0.05% while the cumulative methane yield was observed as 490 mL/g-VSfed for the control reactor. With the exception of 1-octanol at 0.5%, adding both compounds at each investigated concentration was beneficial for the digestion in the batch process. Therefore, the selected alcohol and aldehyde sources did not cause the expected detrimental effect on the methanogens even at the maximum amounts added in this study. Nevertheless, since the effect of the chemical compounds on methane generation has been generally concentration-dependent, the toxic effects of 1-octanol and hexanal would be better observed at higher concentrations (>0.5%), especially when their threshold levels are exceeded in anaerobic reactors digesting paper wastes.
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