116 research outputs found
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Characterization of the Essential Oil of Holodiscus dumosus (S. Watson) A. Heller (Rosaceae)
Umweltchemische Analysen von Pharma-Produkten: Methodenentwicklung zur Analytik von Benzimidazol-Entwurmungsmitteln und deren Stoffwechselprodukten in SchweinegĂŒlle und damit gedĂŒngten Böden
Benzimidazole anthelmintics enter agricultural land by using manure of treated animals as soil amendment. Efficient analytical methods are required to identify and reliably quantify the residues of these compounds. In this study an analytical method based on liquid chromatographic coupled to tandem mass spectrometry was developed for the simultaneous determination of fenbendazole, flubendazole and 8 of their corresponding metabolites in surface water, liquid pig manure, soil and manured soil. The quantification was conducted using electrospray ionization (ESI) in positive mode. Target compounds were extracted from surface water using solid phase extraction (SPE) at pH 2.3 with recovery rates 84%. For target compound extraction from manure samples, direct solvent extraction using ethyl acetate at pH 9.5 or lyophilization followed by methanol extraction at original pH as well as ultrasound-assisted solvent extraction (USE) of lyophilized manure samples using a methanol/ethyl acetate mixture (1:4, v/v) at pH 9.5, were successfully used. Size exclusion chromatography (SEC) followed by SPE were used to clean-up the raw extracts. For manure samples, the overall recovery rates ranged from 78 to 118 % with relative standard deviations of †19 %. Soil and manured soil samples were treated via direct solvent extraction or USE technique using different solvents and solvent mixtures. At alkaline pH using methanol/ethyl acetate mixture (1:4, v/v), all compounds were efficiently extracted from soil and manured soil with overall recovery rates ranged from 70 to 119 % and relative standard deviations were †21 %. The method detection and quantitation limits ranged from 0.5 to 1 and from 1.6 to 3.1 ”g/kg fresh manure. They were between 0.7 to 2.5 ”g/kg and 2.4 to 7.9 ”g/kg for soil and manured soil samples, respectively. Incubated spiked manure samples for 30 days at 4 and 20 ÂșC, were analyzed in order to check the aging effect on the extractability of the target compounds. Matrix effects were investigated using different calibration approaches. Standard addition method was efficient to compensate these effects. Therefore, it was used to quantify the concentrations of detected compounds in the real samples. Flubendazole and 3 of its metabolites were detected in 7 real manure samples. Confirmation of positive finding was successfully achieved meeting the current requirements of analytical quality assurance in accordance with European Commission Decision 2002/657/EC.Durch Behandlung von Nutztieren mit Benzimidazol-Entwurmungsmitteln gelangen diese Substanzen ĂŒber das Aufbringen von GĂŒlle in Ackerböden. Es sind leistungsfĂ€hige Analysenmethoden nötig um die RĂŒckstĂ€nde der Mittel zuverlĂ€ssig zu bestimmen. In dieser Arbeit wurde eine analytische Methode entwickelt, die auf der FlĂŒssigkeitschromatographie kombiniert mit Tandemmassenspektrometrie (LC/MS/MS) basiert und die Simultanbestimmung von Fenbendazol, Flubendazol und 8 Metaboliten in OberflĂ€chenwasser, SchweinegĂŒlle und gedĂŒngten Böden gestattet. Die Quantifizierung wurde unter Verwendung der LC/MS/MS mittels Elektrospray-Ionisierung (ESI+) durchgefĂŒhrt. Die Zielkomponenten wurden aus OberflĂ€chenwasser mittels Festphasenextraktion (SPE) bei pH 2.3 mit einer Wiederfindungsrate von > 84 % extrahiert.
Bei GĂŒlleproben wurde die direkte FlĂŒssig-Extraktion mit Ethylacetat bei pH 9.5 oder die Gefriertrocknung gefolgt von einer Extraktion mit MeOH bei unverĂ€ndertem pH-Wert sowie die Ultraschallextraktion (USE) gefriergetrockneter GĂŒlleproben mit einer Mischung MeOH/Ethylacetat (1: 4, v/v) bei pH 9.5 eingesetzt. Die Rohextrakte wurden mit der GröĂenausschluĂchromatographie (SEC) gefolgt von der Festphasenextraktion (SPE) gereinigt. Bei den GĂŒlleproben lag die Wiederfindungsrate im Bereich von 78 bis 118 % mit relativen Standardabweichungen von †19 %. Böden bzw. gĂŒllegedĂŒngte Böden wurden ĂŒber die direkte FlĂŒssigextraktion oder mittels Ultraschalltechnik unter Einsatz verschiedener Lösungsmittel bzw. Lösungsmittelgemische extrahiert. Im alkalischen pH-Bereich wurden mit einem MeOH/Ethylacetat-Gemisch (1:4, v/v) alle Komponenten bei einer Wiederfindungsrate von 70 bis 119 % und einer relativen Standardabweichung von †21 % aus den Böden extrahiert. Die Bestimmungsgrenzen reichten von 0.5 bis 1 bzw. 1.6 bis 3.1 ”g/kg fĂŒr frische GĂŒlle. Bei Böden bzw. bei gĂŒllegedĂŒngten Böden wurden 0.7 bis 2.5 ”g/kg und 2.4 bis 7.9 ”g/kg erreicht. Dotierte und anschlieĂend bei 4 °C und 20 °C fĂŒr 30 Tage inkubierte GĂŒlleproben wurden analysiert um Alterungseffekte auf die Extrahierbarkeit der Zielkomponenten zu ĂŒberprĂŒfen. Matrixeffekte, welche durch die Coeluation von Matrixbestandteilen der Proben entstanden, wurden durch Verwendung verschiedener KalibrierungsansĂ€tze untersucht. Mittels einer Standardadditionsmethode konnten die Effekte effizient kompensiert werden. SchlieĂlich wurden Flubendazol und 3 Metabolite in 7 realen GĂŒlleproben bestimmt und die Ergebnisse gemĂ€ss den Richtlinien der analytischen QualitĂ€tssicherung (European Commission Decision 2002/657/EC) bestĂ€tigt
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Biological Activities and Volatile Constituents of Aegle marmelos (L.) CorrĂȘa from Nepal
Aegle marmelos, a deciduous fruit tree that grows in Nepal, has numerous uses in traditional medicine, being used as an anti-inflammatory, antidiarrheal, heart disease treatment, and in birth control. In this study, leaves were collected to obtain, analyze, and examine the bioactivity of the essential oil of A. marmelos, which is often referred to as bael tree in Nepal. The essential oil from leaves was obtained by hydrodistillation. The chemical composition, determined by GC-MS, revealed 82 compounds, with 81 components being identified. The major component was limonene (64.1%), with the other two abundant components being (E)-ÎČ-ocimene (9.7%) and germacrene B (4.7%). Bioassay screening of the essential oil indicated marginal toxicity against MCF-7 human breast adenocarcinoma cells (LC50 = 98.2 ”g mL-1), but good larvicidal activity against mosquitoes (Culex pipiens) (LC50 = 2.15 ”g mL-1), nematocidal activity against Caenorhabditis elegans, (LC50 = 113 ”g mL-) and insecticidal activity against termites (Reticulitermes virginicus), fruit flies (Drosophila melanogaster), and fire ants (Solenopsis invica Ă richteri). The essential oil of A. marmelos showed remarkable brine shrimp lethality. Antimicrobial and antifungal activity of the leaf oil was negligible. Most of the observed biological activity was apparently due to the relatively high level of limonene (64.1%) in the essential of the leaf essential oil from A. marmelos
A hybrid RANS model of wing-body junction flow
This is an accepted manuscript of an article published by Elsevier in European Journal of Mechanics B: Fluids on 26/09/2019, available online: https://doi.org/10.1016/j.euromechflu.2019.09.014
The accepted version of the publication may differ from the final published version.The three-dimensional flow separation over the Rood wing-body junction is an exemplar application of separation affecting many important flows in turbomachinery and aerodynamics. Conventional Reynolds Averaged Navier Stokes (RANS) methods struggle to reproduce the complexity of this flow. In this paper, an unconventional use is made of a hybrid Reynolds Averaged Navier Stokes (RANS) model to tackle this challenge. The hybridization technique combines the Menter â â model with the one equation sub-grid-scale (SGS) model by Yoshizawa through a blending function, based on the wall-normal distance. The hybrid RANS turbulence closure captured most of the flow features reported in past experiments with reasonable accuracy. The model captured also the small secondary vortex at the corner ahead of the wing nose and at the trailing edge. This feature is scarcely documented in the literature.
The study highlights the importance of the spatial resolution near the wing leading edge, where this localised secondary recirculation was observed by the hybrid RANS model. It also provides evidence on the applicability of the hybrid Menter and Yoshizawa turbulence closure to the wing-body junction flows in aircraft and turbomachines, where the flows are characterised by a substantially time-invariant three-dimensional separation
Association of Vitamin D Receptor Gene Polymorphism with Metabolic Syndrome and Type 2 Diabetes Mellitus in a Sample of Egyptian Patients: Submitted: Sep 28, 2018 Accepted: Dec 29, 2018 Published online: 18 Sept, 2019
Background. There are insufficient data on the association of vitamin D receptor (VDR) genes polymorphism and type 2 diabetes mellitus (type 2 DM), and various components of metabolic syndrome among Egyptian patients. The aim of the present study was to study the association of different SNPs of VDR genes BsmI, ApaI, TaqI and FokI and components of metabolic syndrome and type 2 DM among cohort of Egyptian patients. Methods. The study is a case-control study. Patients included in the study were divided into three groups. Group 1 included 78 patients with type 2 DM; group 2 included 72 patients with metabolic syndrome and one hundred age-matched healthy subjects were served as control group. Full biochemical study and serum 25 hydroxy vitamin D (25(OH)D) were done. Purified DNA was subjected to study with polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) for genotyping of SNPs of VDR gene. Data were presented as mean and standard deviation, and were analysed as appropriate by using the one-way ANOVA or paired t-test. Pearson correlation coefficient was used to correlate between variables. Results. Study of VDR genetic polymorphism had shown significant increase in the prevalence of Ff genotypes among diabetic patients and patients with manifestations of metabolic syndrome. There was significant negative correlation between 25(OH)D and total cholesterol, triglyceride, fasting and post-prandial blood glucose levels, waist circumference and diastolic blood pressure. Conclusion. The genetic polymorphism of VDR might play a role in the pathophysiology of type 2 DM and metabolic syndrome., however, more longitudinal studies are still required to support these finding
Turmeric and Its Major Compound Curcumin on Health: Bioactive Effects and Safety Profiles for Food, Pharmaceutical, Biotechnological and Medicinal Applications
Curcumin, a yellow polyphenolic pigment from the Curcuma longa L. (turmeric) rhizome, has been used for centuries for culinary and food coloring purposes, and as an ingredient for various medicinal preparations, widely used in Ayurveda and Chinese medicine. In recent decades, their biological activities have been extensively studied. Thus, this review aims to offer an in-depth discussion of curcumin applications for food and biotechnological industries, and on health promotion and disease prevention, with particular emphasis on its antioxidant, anti-inflammatory, neuroprotective, anticancer, hepatoprotective, and cardioprotective effects. Bioavailability, bioefficacy and safety features, side effects, and quality parameters of curcumin are also addressed. Finally, curcuminâs multidimensional applications, food attractiveness optimization, agro-industrial procedures to offset its instability and low bioavailability, health concerns, and upcoming strategies for clinical application are also covered
Assessment of three mixed arrays dataset for subsurface cavities detection using resistivity tomography as inferred from numerical modelling
Abstract The present study deals with the evaluation of a three-mixed array dataset for the detection of subsurface cavities using conceptual air-filled cavity model sets at different depths. Cavity models were simulated using the forward modelling technique to generate synthetic apparent resistivity data for three common individual arrays. These arrays are dipoleâdipole (DD), poleâdipole (PD), and WennerâSchlumberger (WS). The synthetically apparent resistivity data obtained from two different individual arrays were merged to form a high-resolution single model. Consequently, three possible mixed arrays datasets can be obtained: the dipoleâdipole-WennerâSchlumberger (DD+WS), poleâdipole, and WennerâSchlumberger (PD+WS), and dipoleâdipole and poleâdipole (DD+PD). The synthetically apparent resistivity data for both the individual and mixed arrays were inverted using Res2dinv software based on the robust constrain inversion technique to obtain a 2D resistivity model section. The inverted resistivity sections were evaluated in terms of their recovering ability of the modelâs parameters (e.g. resistivity, and geometry). The results show that the individual arrays can resolve the location and dimensions of the cavity within reasonable accuracy only at a depth not exceeding 6Â m below the surface. On the other hand, a significant resolution enhancement in model resistivity with increasing depth was observed when the mixed arrays were used. The (DD+WS) mixed arrays dataset brings up better model resistivity and shows closer parameters to the true actual model among the other mixed arrays. So it is strongly recommended for cavity detection studies
Chemical Composition and Biological Activities of Essential Oils of Curcuma Species
Members of the genus Curcuma L. have been used in traditional medicine for centuries for treating gastrointestinal disorders, pain, inflammatory conditions, wounds, and for cancer prevention and antiaging, among others. Many of the biological activities of Curcuma species can be attributed to nonvolatile curcuminoids, but these plants also produce volatile chemicals. Essential oils, in general, have shown numerous beneficial effects for health maintenance and treatment of diseases. Essential oils from Curcuma spp., particularly C. longa, have demonstrated various health-related biological activities and several essential oil companies have recently marketed Curcuma oils. This review summarizes the volatile components of various Curcuma species, the biological activities of Curcuma essential oils, and potential safety concerns of Curcuma essential oils and their components
Biological Activities and Safety of Citrus spp. Essential Oils
Citrus fruits have been a commercially important crop for thousands of years. In addition, Citrus essential oils are valuable in the perfume, food, and beverage industries, and have also enjoyed use as aromatherapy and medicinal agents. This review summarizes the important biological activities and safety considerations of the essential oils of sweet orange (Citrus sinensis), bitter orange (Citrus aurantium), neroli (Citrus aurantium), orange petitgrain (Citrus aurantium), mandarin (Citrus reticulata), lemon (Citrus limon), lime (Citrus aurantifolia), grapefruit (Citrus × paradisi), bergamot (Citrus bergamia), Yuzu (Citrus junos), and kumquat (Citrus japonica)
Analytical and CFD Methods Investigating Shroud Blade Tip Leakage.
This study deals with the leakage flow over a shrouded turbine stage, its interaction with the main passage flow, and the associated losses. The study addressed these topics by providing an analytical correlation loss model and detailed CFD simulations.
An analytical model of leakage flow loss over a shrouded turbine stage has been developed. The analytical model uses directly measurable flow quantities to predict the effect of some of the over-shroud design parameters on stage performance. The model displays good predictive ability for the mass leakage fraction and the mixing losses. The model resolves the negative incidence angle induced by mixing the leakage flow with the main stream and predicts the increment in the total mixing loss coefficient at increasing leakage jet injection angles. The main contributions of this model to the leakage jet models documented in the open literature are the effect of the leakage jet injection angle on the mixing loss and the accounting of the effect of the number of fins on the leakage mass fraction in an explicit way. The present model exhibits a good qualitative and quantitative agreement with comparative benchmark data.
An in-house three-dimensional turbomachinery CFD code was developed and validated against six test cases, showing its ability to capture the salient flow features in each test case.
This work makes an innovative use of Detached Eddy Simulation as an advanced Reynolds Averaged Navier-Stokes (RANS) model. A detailed leakage flow structure over the rotor shroud and its interaction with the main passage flow were modeled for seven test cases to investigate the effect of the number of fins, the clearance gap ratio, and the leakage jet injection angle on the flow. The results showed that reducing the injection 90° to 30° leads to a reduction in entropy mixing loss coefficient by up to 24.7% and gives a 0.2% increase in the rotor static to static efficiency and highlighted that reducing the leakage jet injection angle is a promising concept to control most of the adverse effects of the leakage flow
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