6-day Time Research Articles

Enhanced bioremediation of oil-contaminated soil in a slurry bioreactor by H2O2-stimulation of oil-degrading/biosurfactant-generating bacteria: performance optimization and bacterial metagenomics.

Oil-contaminated soil is the main challenge for oil-rich countries, and this study aimed to investigate the performance of the H2O2-stimulated slurry bioreactor for the bioremediation of real oil-contaminated soil. The effect of biomass concentration, soil to water (S/W) ratio, slurry temperature, pH, and H2O2 concentration were optimized for the removal of total petroleum hydrocarbons (TPH) from oil-contaminated soil. TPH removal efficiency, biosurfactants production, and peroxidase and dehydrogenase activities were measured. The optimum conditions for the complete biodegradation of 32 [Formula: see text] in the slurry bioreactor during 6days were biomass of 2250mg/L, S/W ratio of 20%, the temperature of 30°C, pH of 7, and an H2O2 concentration of 120mg/L. The highest peroxidase, dehydrogenase, surfactin, and rhamnolipid formation were also obtained under optimum conditions. The results pointed out that complete biodegradation of 32g/kg of TPH in oil-contaminated soil at a short reaction time of 6days is achievable in the developed process operated under optimum conditions. The GC/FID analysis of solid and liquid phases showed that the bioprocess completely biodegraded the different TPH fractions. H2O2 efficiently stimulated the biosurfactant-generating bacteria to produce peroxidase and thereby accelerating the bioremediation rate. Accordingly, an H2O2-mediated slurry bioreactor inoculated with biosurfactant/peroxidase-generating bacteria is a promising technique for cleaning up oil-contaminated soils.

Application of a Sludge Blanket Reactor for Effluent Treatment: A Laboratory Study

Energy is required in all societies worldwide. This led to a dependency of fossil fuel. During uncertain times fossil fuel supply become highly politically and used as an influencing source. This requires establishing a more environmentally friendly processes to decrease dependency. To produce biogas from municipal, agricultural and industrial waste a laboratory benchtop up-flow sludge blanket reactor with a operating volume of 2850 ml was designed build, started up, and operated using prepared municipal wastewater and separated liquid cow manure at a hydraulic retention time of 1 day, 3 days and 6 days after an 120 h adjustment time prior to testing.
 While using wastewater as influent, the laboratory benchtop up-flow sludge blanket reactor system was not able to reduce the chemical oxygen demand content significantly. Especially at a high volumetric flow rate for the 1-day hydraulic retention time. The produced gas amount decreased from 0.59 ±0.07 (ml/h)/L at a hydraulic retention rate of 6 days to 0.042 ±0.04 (ml/h)/L. The fluctuating influent chemical oxygen demand of 25 ±1 mg/L to 74 ±15 mg/L resulted in a stable effluent concentration of 39 ml/L and 45 ±11 mg/L respectively.
 The laboratory benchtop up-flow sludge blanket reactor system with separated liquid cow manure showed a higher chemical oxygen demand degradation capability but resulted in higher chemical oxygen demand in the effluent. The influent chemical oxygen demand of 308 ±42 mg/L was broken downs to 59 ±1 mg/L at a hydraulic retention time of 6 days and to 114 ±5 mg/L for 1 day retention time. The biogas production result in a stable gas production rate of 0.27 ±0.02 (ml/h)/L through all three hydraulic retention times. For both the wastewater and separated liquid cow manure operation the biogas without carbon dioxide was between 55 and 65%.
 The results show that the laboratory benchtop up-flow sludge blanket reactor system can reduce high chemical oxygen demand in wastewater and separated liquid cow manure. However, a minimum feed level having a minimal chemical oxygen demand above 36 mg/L is needed, otherwise, the active bacterial mass contributes to the effluent level as seen for the influent level below 36 mg/L and 25 mg/L which resulted in a minimum effluent level of 39 mg/L for a hydraulic retention time of 3-days and 6-days.

Factors influencing oral anticoagulant use in patients newly diagnosed with atrial fibrillation.

We investigated factors that influenced oral anticoagulant (OAC) initiation and choice in Australian general practice patients newly diagnosed with AF. Using an Australian nationally representative general practice dataset, MedicineInsight, we identified patients newly diagnosed with AF between January 2009 and April 2019. Logistic regression analyses were used to examine factors associated with OAC initiation and choice. A total of 63212 patients with AF (53.7% males, mean age 72.4years) were identified. Nearly two-thirds of these patients (40854 [64.6%]) were initiated on an OAC, at a median time of 6days after the documented diagnosis date. The proportion of patients who were initiated an OAC increased from 44.8% in 2009 to 72.2% in 2019 (P<.001). High risk of stroke (CHA2 DS2 -VASc, adjusted odds ratio (AOR), 4.39 [95% CI, 3.99-4.83]), low risk of bleeding (ORBIT, AOR, 1.87 [95% CI, 1.72-2.03]), not having a recorded history of dementia (AOR, 1.81 [95% CI, 1.65-1.98]) and male sex (AOR, 1.29 [95% CI, 1.22-1.35]) were independently associated with OAC initiation. Direct-acting oral anticoagulant (DOAC) use increased from 11.9% in 2011 to 94.0% of all OAC initiations in April 2019 (P<.001). The proportion of newly diagnosed patients with AF initiated on OAC increased markedly following the introduction of the DOACs. Of those initiated, 9 in 10 were receiving a DOAC at the end of the study period. There is potential underuse in women and individuals with dementia.

Synthesis of iron nano-catalyst using Acalypha indica leaf extracts for biogas production from mixed liquor volatile suspended solids

ABSTRACTA simple, rapid and eco-friendly procedure was adopted to synthesize iron nano-catalyst (FeNCs) using the leaf extracts of Acalypha indica. The effectiveness of synthesized FeNCs was evaluated for the biogas production from mixed liquor volatile suspended solids (MLVSS). The FeNCs were characterized using UV-Visible spectroscopy, Fourier Transform Infrared spectroscopy, Scanning Electron Microscope and X-Ray Diffraction. The catalytic activity of the synthesized additives of FeNCs during the anaerobic process showed a drastic reduction in the hydraulic retention time of 6days for biogas production 85–90%. This study also showed a significant increase in the total biogas production when MLVSS supplemented with 0.3 g/L FeNCs. The aforementioned additive yielded 0.345 (L/g volatile solids reduced) biogas which is relatively lesser (63%) when compared with the control 0.25 (L/g VS reduced) and their bulk salts 0.055 (L/g VS reduced).

Evidence for photolytic and microbial degradation processes in the dissipation of leptospermone, a natural β-triketone herbicide.

Bioherbicides appear as an ecofriendly alternative to synthetic herbicides, generally used for weed management, because they are supposed to have low side on human health and ecosystems. In this context, our work aims to study abiotic (i.e., photolysis) and biotic (i.e,. biodegradation) processes involved in the fate of leptospermone, a natural β-triketone herbicide, by combining chemical and microbiological approaches. Under controlled conditions, the photolysis of leptospermone was sensitive to pH. Leptospermone has a half-life of 72h under simulated solar light irradiations. Several transformation products, including hydroxy-leptospermone, were identified. For the first time, a bacterial strain able to degrade leptospermone was isolated from an arable soil. Based on its 16S ribosomal RNA (rRNA) gene sequence, it was affiliated to the Methylophilus group and was accordingly named as Methylophilus sp. LS1. Interestingly, we report that the abundance of OTUs, similar to the 16S rRNA gene sequence of Methylophilus sp. LS1, was strongly increased in soil treated with leptospermone. The leptospermone was completely dissipated by this bacteria, with a half-life time of 6days, allowing concomitantly its growth. Hydroxy-leptospermone was identified in the bacterial culture as a major transformation product, allowing us to propose a pathway of transformation of leptospermone including both abiotic and biotic processes.

Effect of fermentation times and extracting solvents on the in vitro immune potentials of the soluble extracts of mucor-fermented Mao-tofu.

Mucor-fermented Mao-tofu at 3-7days was extracted using water (pH 4.5 and pH 6.5) and ethanol solutions (40 and 80%, v/v). At protein concentration of 40μg/mL, all the extracts showed immune activities via activating macrophages, splenocytes, and natural killer cells, which enhances the secretion of interleukin (IL)-2, interferon-γ, tumor necrosis factor-α, IL-1β, IL-6, inducible nitric oxide synthase, and lysozyme, but inhibits the secretion of IL-4. All the extracts exhibited higher activities than that of soybean protein, demonstrating that Mucor-mediated fermentation enhanced the immune potentials of Mao-tofu. Fermentation time of 6days ensured the extracts the highest activities, whereas lower activities were detected. The highest and lowest activities were detected on using a solution of water (pH 6.5) and 40% ethanol, respectively. The extract obtained using water (pH 6.5) contained more Arg and Cys with immune significance, which partially contributed to its high activities. Both fermentation times and extracting solvents were thus proved to affect the immune activities of soluble Mao-tofu extracts.

Quantitative changes in late gadolinium enhancement at cardiac magnetic resonance in the early phase of acute myocarditis

BackgroundThe presence of late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has diagnostic and prognostic value in patients with acute myocarditis (AM). Aim of our study was to quantify the changes in LGE extension (LGE%) early after AM and evaluate its relations with biventricular function and morphology. MethodsWe investigated 76 consecutive patients with AM (acute onset of chest pain/heart failure/ventricular arrhythmias not explained by other causes, and raised troponin) that met CMR criteria based on myocardial oedema at T2-weighted images and LGE on post-contrast images at median time of 6days from onset of symptoms. We quantified LGE% at baseline and after 148days in 49 patients. ResultsMedian left ventricular (LV)-ejection fraction (EF) was 64% (interquartile range [Q1–Q3]: 56–67%), and LGE% 9.4% (Q1–Q3: 7.5–13.2%). LGE% was correlated with LV end-systolic volume index (LV-ESVi; r=+0.34; p=0.003). LGE% was inversely correlated with LV-EF (r=−0.31; p=0.009) and time to CMR scan (r=−0.25; p=0.028). In the 49 patients with a second CMR scan, despite no significant variations in LV-EF, a significant decrease of LGE% was observed (p<0.0001) with a relative reduction of 42% compared with baseline. Patients showing increased LV-ESVi at follow up had a lower decrease of LGE% (p=0.038). ConclusionsIn the acute phase of AM the LGE extension is a dynamic process that reflects impairment of LV function and is time dependent. LGE% appears one of the CMR parameters with the largest relative variations in the first months after AM.

Efficacy of Beauveria bassiana formulations against the fungus gnat Lycoriella ingenua

Lycoriella ingenua Dufour (Diptera: Sciaridae) is a major pest species in commercial mushroom (Agaricus bisporus) production throughout the world. Grower demand for alternative control measures, following the recent withdrawal of a number of chemical control options, led to a label extension for use of the fungal biopesticide BotaniGard® ES, for control of mushroom flies. Semi-field trials were conducted to evaluate the efficacy of BotaniGard® ES, and two alternative formulations of Beauveria bassiana strain GHA (the active ingredient in BotaniGard® ES), for control of L. ingenua, and their effect on crop yield when incorporated at spawning. Data collected from two replicated trials demonstrated that incorporation of B. bassiana was not detrimental to mushroom yield, but was also ineffective in controlling the development of L. ingenua larvae in artificially infested compost. Subsequent laboratory bioassays demonstrated that L. ingenua eggs and larvae were not susceptible to infection by B. bassiana strain GHA whereas pupae were somewhat susceptible (41% mortality). Bioassays conducted on adult L. ingenua using 1h exposure to a surface sprayed with BotaniGard® ES resulted in 100% mortality within 8days and a mean survival time of 6days, which was significantly different from the control population.

A fast Galerkin method with efficient matrix assembly and storage for a peridynamic model

Peridynamic theory provides an appropriate description of the deformation of a continuous body involving discontinuities or other singularities, which cannot be described properly by classical theory of solid mechanics. However, the operators in the peridynamic models are nonlocal, so the resulting numerical methods generate dense or full stiffness matrices. Gaussian types of direct solvers were traditionally used to solve these problems, which requires O(N3) of operations and O(N2) of memory where N is the number of spatial nodes. This imposes significant computational and memory challenge for a peridynamic model, especially for problems in multiple space dimensions. A simplified model, which assumes that the horizon of the material δ=O(N-1), was proposed to reduce the computational cost and memory requirement to O(N). However, the drawback is that the corresponding error estimate becomes one-order suboptimal. Furthermore, the assumption of δ=O(N-1) does not seem to be physically reasonable since the horizon δ represents a physical property of the material that should not depend on computational mesh size.We develop a fast Galerkin method for the (non-simplified) peridynamic model by exploiting the structure of the stiffness matrix. The new method reduces the computational work from O(N3) required by the traditional methods to O(Nlog2N) and the memory requirement from O(N2) to O(N) without using any lossy compression. The significant computational and memory reduction of the fast method is better reflected in numerical experiments. When solving a one-dimensional peridynamic model with 214=16,384 unknowns, the traditional method consumed CPU time of 6days and 11h while the fast method used only 3.3s. In addition, on the same computer (with 128GB memory), the traditional method with a Gaussian elimination or conjugate gradient method ran out of memory when solving the problem with 216=131,072 unknowns. In contrast, the fast method was able to solve the problem with 228=268,435,456 unknowns using 3days and 11h of CPU time. This shows the benefit of the significantly reduced memory requirement of the fast method.