In this paper, we report a new liquid–liquid microextraction procedure called “nanoparticles decorated with a Schiff's base for the microextraction of Cd, Pb, Ni, and Co in environmental samples”. ...The developed procedure was utilized for the extraction of Cd, Pb, Ni, and Co in environmental samples. The Schiff's base was formed by reacting salicylaldehyde with 3‐aminopropyltriethoxysilane‐functionalized iron oxide nanoparticles. Analyte extraction was conducted in a capillary column system loaded with modified nanoparticles and triton X‐114 as dispersion medium. 1‐Butyl‐3‐methylimidazolium hexafluorophosphate was employed as an extraction solvent. Acidified methanol in ultrasonic bath was used as desorption solvent, and elemental determination was carried out with flame atomic absorption spectrometer. Characterization of modified nanoparticles was performed with FTIR spectroscopy and transmission electron microscopy. Solution pH, nanoparticles amount, dispersant concentration, ionic liquid, and temperature were optimized for the extraction. Detection limits obtained for Cd, Pb, Ni, and Co were 0.183, 0.201, 0.241, and 0.192 μg L−1, respectively, and enhancement factors were 79.1, 86.4, 95.7, and 82.0, respectively. The reproducibility of the developed procedure was in the range of 3.98–5.10%. Validation was checked by applying the developed procedure on certified reference water samples. The microextraction based on nanoparticles decorated with Schiff's base was successfully applied for the extraction of Cd, Pb, Ni, and Co in real environmental water samples.
Tuberculosis (TB) is a dreadful bacterial disease, infecting millions of human and cattle every year worldwide. More than 50 years after its discovery, ethambutol continues to be an effective part of ...the World Health Organization's recommended frontline chemotherapy against TB. However, the lengthy treatment regimens consisting of a cocktail of antibiotics affect patient compliance. There is an urgent need to improve the current therapy so as to reduce treatment duration and dosing frequency. In this study, we have designed a novel anti-TB multifunctional formulation by fabricating graphene oxide with iron oxide magnetite nanoparticles serving as a nano-carrier on to which ethambutol was successfully loaded. The designed nanoformulation was characterised using various analytical techniques. The release of ethambutol from anti-TB multifunctional nanoparticles formulation was found to be sustained over a significantly longer period of time in phosphate buffer saline solution at two physiological pH (7.4 and 4.8). Furthermore, the nano-formulation showed potent anti-tubercular activity while remaining non-toxic to the eukaryotic cells tested. The results of this in vitro evaluation of the newly designed nano-formulation endorse its further development in vivo.
The brown planthopper, Nilaparvata lugens, is a serious pest of rice crops throughout Asia and exhibits wing dimorphism, with brachypterous adults having reduced wings and macropterous adults ...possessing fully developed wings. To understand the reproductive strategies in two wing-morphs of this insect, the transcript encoding the major yolk protein precursor, vitellogenin (Vg), was cloned. The complete mRNA transcript was 6314 bp, which encodes a protein of 2063 residues including an 18-residue putative signal peptide. Analysis of the mature protein revealed two vitellogenin-N (or lipoprotein amino-terminal) domains near the N-terminus and a von Willebrand factor type D domain near the C-terminus. In addition, a highly conserved motif GL/ICG, and a number of cysteine residues were identified near the C-terminus. Northern blot analysis identified a similar to 6.8 kb Vg gene transcript that was expressed exclusively in the adult female fat body cells. The expression profile revealed that the Vg gene starts to be expressed earlier (on day 3) in brachypters as compared to macropters where the mRNA transcript was observed on day 4. However, in both morphs, the amount of Vg mRNA increased to reach high levels during vitellogenic periods from day 4 (in brachypters) and day 5 (in macropters) and onwards. Reflecting the RNA transcription pattern, the Vg signal was detected by immunoblotting on day 3 and day 4 in haemolymph of brachypterous and macropterous females, respectively, and that was increased every day and remained high during the vitellogenic periods. Furthermore, the topical application of juvenile hormone (JH) III had up-regulated the Vg gene expression suggesting that the Vg gene is regulated by JH in N. lugens. In addition, it was demonstrated by Southern blot analysis that there exists a single copy of the gene in the N. lugens genome. A delayed trend in expression (of both the transcript and the protein) demonstrated by macropterous females in the present studies supports the hypothesis of prereproductive long distance migration in this wing-dimorphic species.
The study focused on appraising the influence of exchange rates on returns in the share market: a case of Pakistan. Time-series data spanning 36 years (1980 to 2016) was utilized. To capture the ...impact of exchange rates on returns in the share market, a theory-based model consisting of six sub-models was planned and estimated through the recursive simultaneous-equations econometric estimation technique. As the data was time series, augmented Dickey-Fuller (ADF) tests were employed to assess the stationarity of the considered variables. The autoregressive distributed lag (ARDL) model was chosen due to some variables being found at different levels, such as me (0) and I (1). Bounds tests in the conclusion declared that the value of F-statistics expressed long-run associations among variables. The results revealed that share market returns were positively influenced by the exchange rate. The model also indicated that share market returns were significantly influenced by Foreign Portfolio Investment (FPI). Furthermore, National Savings (NS) demonstrated a positive and significant association with share market returns (SMR). The study's outcomes also illustrated that National Income (NI) had a positive and significant influence on SMR. The study encompassed well-expanded details and estimation techniques of various models and measures required in this type of research, especially when utilizing time-series data. Based on research findings, it was suggested that potential researchers reproduce this research to achieve a better and relatively well-conceived, well-estimated model on the topic. Additionally, it was recommended that public and private sector planners and researchers seek guidance not only on statistically significant exogenous variables but also on other explanatory variables for their effects on the endogenous variables.
Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome is a rare spectrum of retinal vasculitis, aneurysms, and neuroretinitis affecting young individuals in their third ...decade. Most of our current knowledge is based on case reports, case series, and a handful of collaborative studies. There is much diversity in treatment approaches and outcomes in the reported literature. We have aggregated published case reports and case series into quantitative and narrative synthesis to draw evidence-based conclusions toward clinical features, atypical and rare findings, systemic associations, disease course, and treatment outcomes. The analysis suggested the disease mostly affects young individuals with a female predilection. Anterior chamber and vitreous inflammation are common than previously believed. The most prevalent pattern of retinal vasculitis in IRVAN eyes is mixed vasculitis, followed by arteritis and phlebitis. Most eyes at the time of presentation have capillary nonperfusion and require treatment. Most eyes retain good visual acuity; however, treatment is required to maintain visual function. Intravitreal antivascular endothelial growth factors administered as an adjunct to retinal laser photocoagulation are more likely to improve visual outcomes. Besides, we have discussed the different hypotheses on the etiopathogenesis of the disease and stronger evidence suggests an inflammatory origin of the disease.
In this study we present investigations pertaining to structural, elastic, electronic, magnetic and optical properties of RbSrC, RbSrSi and RbSrGe half-Heusler compounds. To carry out this study, ...full potential (FP) linearized augmented plane wave (LAPW), a scheme of calculations developed within the framework of density functional theory (DFT), is employed. To incorporate the exchange correlation (XC) energy and corresponding potential into the total energy calculations, generalized gradient approximation (GGA) parameterized by Wu-Cohen is taken into account. Analysis of band structures and densities of states (DOS) profiles illustrate the conducting nature in spin down state and the semiconducting nature in spin-up state. The bonding nature discussed via electron charge density plot reveals strong ionic bonding character of these compounds. At ambient conditions, calculations for elastic constants (Cij) and their related elastic moduli are also performed which point to their brittle character. The compounds are found to be ferromagnetic with 1μB. The magnetic moment decreases from its integer value at high pressures for these compounds.
•RbSrC, RbSrSi and RbSrGe studied comprehensively using DFT.•All the compounds are half-metals.•Magnetic moment of the materials is 1μB.•The magnetic moment decreases from its integer value at high pressures.•Compounds are elastically stable in brittle nature.
Recent Deep Neural Networks (DNNs) based edge detection methods claim to beat human performance on small scale datasets like BSDS500. But is the problem of edge detection really solved? To answer ...this question, we review the existing dataset limitations as well as the generalization capabilities of the proposed architectures. To this end, we develop a Synthetic Textured Masks Dataset (STMD) that contains 28,000 grayscale images. The performance of several edge detection methods is severely degraded on STMD. To further validate these results we propose a baseline Single Scale Feed Forward Edge Detector (SFED), which is a simple 9-layer feed-forward convolutional neural network with no pooling layers. The performance of SFED is better than most state-of-the-art architectures on BSDS500 and is superior to all the compared architectures on STMD. These results show that most of the architectural advancements of existing architectures are at the cost of generalizability where if we change the dataset set distribution (both training and testset), the performance becomes significantly degraded and therefore the problem of edge detection is still far away from being solved. There are also severe limitations of existing datasets in the field, and STMD provides a framework for designing and testing better edge detection architectures for novel application areas, such as, medical imaging and self-driving cars.
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•A green MTS-SPME method for the speciation and removal of vanadium was developed.•The MWCNT was immobilized with tetraethylenepentamine and packed in micropipette tip-syringe ...system.•The desired method is comparatively excellent replaceable approach of the conventional SPE.•The developed procedure was applied to determine the trace levels of vanadium species in real samples.
Simple, rapid and miniaturized portable micropipette tip-syringe solid phase microextraction method was developed for speciation of vanadium in water and food samples. Tetra ethylene pentamine functionalized multiwalled carbon nanotubes were synthesized and packed in micropipette tip-syringe system. The surface morphology of adsorbent was characterized, and the effective factors that influence the efficiency of developed method such as pH, amount of adsorbent, concentration of acid solution for desorption cycles were studied. The V(V) could be adsorbed on the modified adsorbent surface with tetra ethylene pentamine, while V(IV) could not be retained. The assay of V(IV) was based on subtracting values of V(V), from total vanadium. The extracted total vanadium and V(V) were injected directly into the electrothermal atomic absorption spectrometry for analysis. Enhancement factor and detection limit were found 50 and 0.008μgL−1, respectively. Accuracy of the method was checked by analysis of certified reference materials. The developed method was applied to water and food samples.
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