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A comparative study of cobalt ferrite (CoFe2O4) catalysts synthesized via three different methods is presented, aiming to evaluate their catalytic activities in poly(ethylene terephthalate) (PET) chemical depolymerization by glycolysis. The synthesized catalysts have been characterized by X-ray photoelectron spectroscopy, X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and energy dispersive spectroscopy. The conversion of PET into bis(2-hydroxyethyl)terephthalate (BHET) monomer was examined using these cobalt ferrites. The BHET in the reaction mixture was analyzed by FTIR, HPLC, DSC, and TGA and results show the catalyst synthesized by coprecipitation demonstrates the highest BHET yield (95.4%) at a temperature of 200 °C and a pressure of 0.7 bar in 1 h with only 1.0 wt% loading. Hydrothermal synthesized CoFe2O4 and solvent-free synthesized CoFe2O4 both showed lower BHET yields. The catalytic performance of the coprecipitated CoFe2O4 catalyst was influenced by the presence of unintentionally trapped FeCl3 within the catalyst, which resulted in its enhanced activity. The CoFe2O4 catalyst from coprecipitation exhibited acceptable magnetic recoverability and reusability for four consecutive cycles, further highlighting its usefulness and sustainability. [ABSTRACT FROM AUTHOR]

Purpose: Leishmania major is main causative agent and Phlebotomus papatasi is only proven vector of Zoonotic Cutaneous Leishmaniasis (ZCL) in Iran. Human leishmaniasis is mostly susceptible to climatic conditions and molecular variations of Leishmania parasites within sandflies. Methods: L. major was analyzed based on geographical, environmental, climatic changes and haplotype variations within P. papatasi. Molecular tools and different geographical aspects were employed using Arc-GIS software for mapping the geographic distribution of samples and other statistics tests. Fragments of ITS-rDNA, k-DNA, and microsatellite genes of Leishmania were used for PCR, RFLP, sequencing, and phylogenetic analyses. Results: Totally 81 out of 1083 female P. papatasi were detected with Leishmania parasites: 70 and five were L. major and L. turanica, respectively. Golestan and Fars provinces had the highest (13.64%) and lowest (4.55%) infection rates, respectively. The infection rate among female P. papatasi collected from gerbil burrows was significantly higher (15.15%) than animal shelters, yards, and inside houses (4.48%) (P < 0.0%). Microsatellite was more sensitive (22.72%) than k-DNA (18.8%) and ITS-rDNA (7.48%). More molecular variations of L. major were found in Isfahan province. Conclusions: Arc-GIS software and other statistics tests were employed to find Leishmania positive and haplotype variations among sand flies. Geographical situations, altitude, climate, precipitation, humidity, temperature, urbanization, migrations, regional divergences, deforestation, global warming, genome instability, ecology, and biology of the sand flies intrinsically, and the reservoir hosts and neighboring infected locations could be reasons for increasing or decreasing the rate of Leishmania infection and haplotype variations. [ABSTRACT FROM AUTHOR]

Scientific communities are motivated to schedule their large-scale data analysis workflows in heterogeneous cluster environments because of privacy and financial issues. In such environments containing considerably diverse resources, efficient resource allocation approaches are essential for reaching high performance. Accordingly, this research addresses the scheduling problem of workflows with bag-of-task form to minimize total runtime (makespan). To this aim, we develop a mixed-integer linear programming model (MILP). The proposed model contains binary decision variables determining which tasks should be assigned to which nodes. Also, it contains linear constraints to fulfill the tasks requirements such as memory and scheduling policy. Comparative results show that our approach outperforms related approaches in most cases. As part of the post-optimality analysis, some secondary preferences are imposed on the proposed model to obtain the most preferred optimal solution. We analyze the relaxation of the makespan in the hope of significantly reducing the number of consumed nodes. [ABSTRACT FROM AUTHOR]

An electrochemical aptamer-based sensor was designed to detect tetracycline (Tet) in chicken ham. First, polyacrylonitrile (PAN) polymer was used to prepare electrospun PAN nanofibers. PAN nanofibers were heat treated to form electrospun carbon nanofiber (CNF) mat. The electrospun CNF mat electrode was modified with Au and the aptamer of Tet was placed on the mat electrode. Raman spectroscopy and scanning electron microscopy equipped with energy-dispersive spectroscopy were used to identify the structure and morphology of electrospun CNFs, respectively. The behavior of CNF mat electrode was evaluated via cyclic voltammetry. The designed aptamer biosensor had a good repeatability, reproducibility, stability, and specific function for the detection of Tet in chicken ham. This biosensor was able to detect the Tet in the linear range of 1 × 10–9 M to 1 × 10–4 M with the detection limit of 1.2 × 10–10 M and preserve about 95% of its primary response after 20 days. In addition, the recoveries of Tet were achieved ranging from 96.92 to 104.31%. [ABSTRACT FROM AUTHOR]

In this research, DNA-modified carbon dots (CDs) were exploited to construct a fluorescence assay for breast cancer genes (BRCA1, a potential marker for cancer diagnosis) detection. For this purpose, water-soluble synthesized CDs were functionalized with 19 mer-modified oligonucleotides (capture probe). By adding the DNA target, the specific binding between the DNA probe and DNA target causes fluorescence quenching. The assay displayed a fine capability of sensing the BRCA1 gene with a linear range (R2 = 0.9918) of 36 attomolar (aM) to 532 femtomolar (fM) and a detection limit of 2 attomolar. This homogeneous process does not need additional separation and washing steps of un-hybridized DNA. To assess the selectivity, the prepared biosensor responses were evaluated in solutions containing single-base mismatched DNA sequences, three-base mismatched DNA sequences, or non-complementary DNA sequences, separately. To demonstrate the practical application of the designed biosensor, the extracted DNA from blood samples of breast cancer patients was utilized as real samples. When the CDs-DNA bioassay was exploited in the imaging of MCF-7 cancer cells, strong fluorescence emission was observed. After incubation times, both the cells' size and shape remained unchanged. The results validated that the CDs are an extremely great bioimaging candidate in disease diagnosis, biomedicine investigation, and managing cancer diseases. [ABSTRACT FROM AUTHOR]

The development of pharmaceutical analytical techniques is one of the most crucial steps in drug development and quality control. The pharmaceuticals serve their intent only if their content is labeled, free from impurities, and are administered in an appropriate amount. Thus, an accurate, selective, low-cost, and fast analytical tool is highly required. Carbon nanodots (CDs), as emerging luminescent nanomaterials in analytical applications, play a significant role in offering low detection limit, superior selectivity, high sensitivity, low-cost precursors, biocompatible, and facile preparation protocols. Recently, many papers have been reported on the quantification and detection of various active pharmaceutical ingredients using CDs. Owing to the luminescence of CDs, a big concern is given to fluorescence-based probes. This review article highlights the physical and chemical properties of CDs, their synthesis approaches, surface functionalization, detection mechanisms, and several detection platforms, such as fluorescence, electrochemical, electrochemiluminescence, colorimetry, and surface plasmon resonance for pharmaceutical analysis based on CDs. [ABSTRACT FROM AUTHOR]

Over the last decade, the size and complexity of real-world problems have grown dramatically, necessitating more effective tools. Nature-inspired metaheuristic algorithms have proven to be a promising tool for solving such problems due to their performance in a variety of fields. JAYA algorithm is a novel population-based algorithm which could have been able to present reliable results. This is because it does not need any parameters to be set other than the population size and the maximum number of iteration. Despite its positive feedbacks, this algorithm should be modified to witness more efficiency. This paper aims to amend the original version of Jaya to present a high-efficiency version named Powerful Enhanced Jaya (PEJAYA). In other words, the methodology of updating position in Jaya is modified to enhance the convergence and search capabilities. This approach is assessed according to solve 20 well-known benchmark functions, feature selection, and statistical tests. The output results of proposed optimization algorithm are then evaluated by comparing it with other recent algorithms including crow search algorithm (CSA), standard version of JAYA, particle swarm optimization (PSO), dragonfly algorithm (DA), grasshopper optimization algorithm (GOA), moth-flame optimization (MFO) and sine–cosine algorithm (SCA). Solving a real-world problem is another way of checking the efficiency of this approach with other published works. Prompt escape from local minima, superior convergence, and stability demonstrate that the suggested approach is a very powerful instrument that may be employed in a variety of optimization situations. [ABSTRACT FROM AUTHOR]

Herein, we designed a sensitive and selective "Turn-On" fluorescence nanosensor using water-soluble carbonaceous fluorescent nanomaterials (CFNs) functionalized with thiourea (CFNs-Thiourea) for efficient detection of trace concentrations of arsenic (III) in aqueous samples. The CFNs and CFNs-Thiourea were characterized by transmission electron microscopy (TEM), UV–visible spectroscopy (UV-vis) and fourier transformed infrared spectroscopy (FTIR). The emission peak intensity of proposed nanosensor at 425 nm was gradually enhanced on arsenite addition in a wide detection range (3.3–828.5 µg L−1) attributed to the binding of arsenite species with sulfur groups of CFNs-Thiourea. The limit of detection (LOD) was 0.48 µg L−1 being much lower than the World Health Organization (WHO) recommended threshold value of 10 µg L−1. Furthermore, the as-prepared CFNs-Thiourea exhibited a superb selectivity for As (III) compared to various cations and anions, such as; NO3−, NO2−, F−, Ni2+, Fe3+, Cu2+, Ca2+, Mg2+, Zn2+, Fe2+, Hg2+, Pb2+, F−, Cl−, Mn2+, Cr3+, Co2+, Cd2+, Bi3+, Al3+ and As (V) at 100 folds concentration of As (III). The turn on fluorescence nanosensor was successfully exploited for quantification of arsenic in spiked water samples with acceptable efficiencies. [ABSTRACT FROM AUTHOR]

One of the most controversial issues among rheumatologists is the best approach to managing a rheumatic patient (RP) with coronavirus disease 2019 (COVID-19). This study aims to evaluate the prevalence of COVID-19 in RPs compared to the general population and to relatively assess the potential role of RPs' treatment regimen against COVID-19. In a cross-sectional study, all RPs with an updated medical record between December 1, 2019, and February 29, 2020, at the rheumatology clinic of Shahid Beheshti Hospital, Qom, Iran were included (as the case group), and the prevalence of COVID-19 was compared to the paired control group-individuals without RDs, randomly selected from the Qom Health Network's database. Qom was the first city in Iran in which COVID-19 was identified and spread rapidly. Both groups were paired regarding sex, age, and underlying severe conditions. The prevalence of COVID-19 was lower in RPs than the control group (p = 0.028). Moreover, patients who were under treatment with disease-modifying anti-rheumatic drugs (DMARDs) and biologic agents seemed to possess a lower risk for COVID-19. Two RPs died from COVID-19, both of whom had granulomatosis and polyangiitis (GPA). The prevalence of COVID-19 in the RPs was lower than the control group, which could be associated with more adherence to the quarantine and social distancing rules by RPs and stricter routine follow-ups than the general population. Besides, taking DMARDs, such as leflunomide, might possess a protective effect against severe COVID-19, probably as a result of preventing cytokine storm. [ABSTRACT FROM AUTHOR]

There is always a need to develop new, fast and non-complicated microextraction methods that consume small amounts of organic solvents. In this study, a new mode of liquid phase microextraction method, termed as continuous sample drop flow-based microextraction (CSDF−ME), was developed for the enrichment and determination of cobalt in water samples. To attain the appropriate conditions for the CSDF−ME, experimental parameters such as pH, type and volume of extraction solvent, concentration of chelating agent, salting effect, sample flow rate and sample volume, needle diameter were examined. The enrichment factor was 167 for 20 mL sample solution. The calibration graph was linear in the concentration range of 5–200 μg/L with the correlation coefficient of 0.999. The limit of detection was 1.3 μg/L. The reliability of the recommended procedure was verified by analysis of real water samples (including tap, mineral and river water) and synthetic sample spiked with known amount of cobalt, and the obtained recoveries of spiked samples have demonstrated accuracy and applicability of the proposed method. [ABSTRACT FROM AUTHOR]

A practical technique was applied to fabricate MoWS2 nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. The characterization of MoWS2 nanocomposite was investigated by several techniques to identify the size, crystal structure, and elemental composition. MoWS2 nanocomposite exhibited a unique and well-defined hierarchical structure with neatly and densely piled nanopetals acting as the active sites in the electrocatalytic reactions. A carbon screen-printed electrode (CSPE) modified with interesting MoWS2 nanopetals (MoWS2/CSPE) was constructed. Subsequently, the electrochemical oxidation of morphine on fabricated MoWS2/CSPE was studied. Experimental results confirm that under optimized conditions, the maximum oxidation current of morphine occurs at 275 mV in the case of MoWS2/CSPE that is around 100 mV more negative than that observed in the case of the unmodified CSPE and about 2.6 times increase was observed for the oxidation peak current. The analytical approach was obtained by differential pulse voltammetry in accordance with the relationship between the oxidation peak current and the morphine concentration. The oxidation peak currents for morphine were found to vary linearly with its concentrations in the range of 4.8 × 10−8–5.05 × 10−4 M with the detection limit of 1.44 × 10−8 M. Two completely separated signals occured at the potentials of 275 mV and 920 mV for oxidation of morphine and tramadol at the surface of MoWS2/CSPE which are sufficient for determination of morphine in the presence of tramadol. The presence of morphine was also detected in real samples using the introduced approach. [ABSTRACT FROM AUTHOR]

Rationale: Autism spectrum disorder (ASD), the fastest growing neurodevelopmental disorder, is characterized by social deficits, repetitive/stereotypic activity, and impaired verbal and nonverbal communication and is commonly diagnosed at early stages of life. Based on the excitatory-inhibitory imbalance theory of autism, some recent animal experiments have reported amelioration in autistic-like phenotypes in adult animals following acute treatment of NMDA antagonists. However, we suggested the neonatal period as a critical period for NMDA antagonist intervention. Objectives: This experiment was designed to determine the role of postnatal MK-801, an NMDA receptor blocker, in the prenatal valproic acid (VPA) rat model of ASD. Methods: The model of autism was induced by subcutaneous administration of valproic acid (600 mg/kg) to pregnant rats at gestational day 12.5. The effects of MK-801 (0.03 mg/kg, from postnatal day 6–10) in correcting ASD-associated behaviors in male offspring were assessed by open-field, three-chambered social interaction tests. Moreover, the nociceptive threshold was measured by tail flick and hot plate. Behavioral tests were performed on PND 55–60. Nissl staining was performed to confirm the safety of 0.03 mg/kg MK-801 for the brain. Results: We reported that MK-801 rescued social deficits, repetitive behaviors (self-grooming), anxiety-related behavior, and the low nociceptive threshold in the VPA-treated rats. Further, histological examination showed that there were no significant differences among all the groups in terms of the neuronal survival rate. Conclusions: Our results showed that postnatal low-dose MK-801 improved ASD-associated behaviors in the VPA-treated rats and that early exposure to NMDA antagonist resulted in permanent changes in adult behavior. [ABSTRACT FROM AUTHOR]

An oversimplified and sensitive sensor based on MoWS2-modified screen-printed electrode (MoWS2/SPE) was designed in this study for detecting gliclazide (GLZ) and glibenclamide (GLB) that are two widespread employed drugs in treating noninsulin-dependent diabetes mellitus. MoWS2 exhibited very good electrocatalytic activities toward oxidation of GLZ and GLB in comparison with bare SPE in 0.1 M PBS, and the isolated capacities of oxidation peak assured concurrent determination of GLZ with widespread linear range between 0.06 and 500.0 μM. Determination limit of GLZ has been 18.0 nM (S/N = 3). MoWS2/SPE has good steadiness, repeatability, and reproducibility. This procedure has had a successful application in detecting GLZ and GLB in their biological and pharmaceutical specimens with acceptable recovery. [ABSTRACT FROM AUTHOR]

Scientific communities are motivated to schedule the data-intensive scientific workflows in multi-cloud environments, where considerable diverse resources are provided by multiple clouds and resource limitation imposed by individual clouds is overcome. However, this scheduling involves two conflicting objectives: minimizing cost and makespan. In general, dealing with such conflicting criteria is a difficult task. But fortunately recent efficient methods for solving multi-objective optimization problems motivated us to provide a multi-objective model considering minimization of cost and makespan as objectives. For solving this model, we use different scalarization procedures such as weighted-sum, Benson's scalarization and weighted min–max under different scenarios. Moreover, we investigate the stability of obtained solutions and propose a new approach for determining the most stable solution related to weighted-sum and weighted min–max as post-optimality analysis. Results indicate that our proposed weighted-sum approach outperforms the previously developed methods in terms of hypervolume. [ABSTRACT FROM AUTHOR]

Bulk modification of carbon paste electrode (CPE) with graphene oxide nanoribbon and 3-(4′-amino-3′-hydroxy-biphenyl-4-yl) -acrylic acid (3,4′-AA-GONR/CPE) was used to develop a new electro-chemical sensor for sensitive determination of droxidopa and carbidopa at physiological pH. Chronoamperometry, differential pulse voltammetry, and cyclic voltammetry were employed to evaluate electro-chemical responses of as-prepared modified electrodes. A linear dependence of oxidation peak current on the concentration of droxidopa within a range between 0.02 and 300.0 μM was also observed with determination limit of 10.0 nM (S/N = 3). Desirable reproducibility, stability, and selectivity were seen in as-prepared 3,4′-AA-GONR/CPE, implying hopeful uses for concurrent detection of droxidopa and carbidopa. [ABSTRACT FROM AUTHOR]

A novel and improved version of continuous-flow microextraction known as continuous sample drop flow-based microextraction has been utilized for the first time in extraction and preconcentration of sodium dodecyl sulfate (SDS) from detergent samples prior to spectrophotometric determination. In this paper, some effective parameters for determination of SDS, such as the needle diameter, flow rate, concentration of the methylene blue and pH, were optimized. Under optimized conditions, a good linearity for SDS was obtained in the range of 30–400 ng mL−1 with R2 = 0.999. A practical detection limit of 8.2 ng mL−1 was calculated according to a signal-to-noise ratio of three. The enrichment factor of the method was 122.2. The method was employed for determination of total anionic surfactants in shampoo, hand washing liquid and clothes washing liquid. Satisfactory recoveries in the range of 97.9–100.8% for real samples confirmed the good accuracy and applicability of the present method. Afterward, the samples were analyzed by standard method as well and there was no any difference between the standard and the proposed method. [ABSTRACT FROM AUTHOR]

Given that multi-cloud environments contain considerably diverse resources, scheduling workflows in these environments significantly reduces financial costs and overcomes the resource limitations imposed by commercial cloud providers. Accordingly, this study addressed the problem of scientific workflow scheduling in multi-cloud settings under deadline constraint to minimize associated financial costs. To this end, we proposed integer linear programming models that can be solved in a reasonable time by available solvers. In a mathematical model, the objective of a problem and real and physical constraints or restrictions are formulated using exact mathematical functions. Such formulation enabled us to comprehensively understand the system under evaluation, consider secondary preferences and post-optimality analysis and apply useful revisions to inappropriately selected input data. We analyzed the treatment of optimal cost under variations in deadline and workflow size. As part of the post-optimality analysis, sensitivity analysis and deadline revision were implemented. Results indicated that our proposed approach outperforms previously developed methods in terms of financial cost reduction. [ABSTRACT FROM AUTHOR]

The authors describe a colorimetric method for highly selective determination of cystamine using silver nanoparticles capped with thiomalic acid (TMA-AgNPs). The TMA-AgNPs exhibit a strong surface plasmon resonance absorption band at 395 nm. After the addition of cystamine to their yellow colloidal solution, the absorption maximum at 395 nm decreases gradually, and a new absorption peak appears at around 560 nm. This is accompanied by a color change, first to green and then to purple. The aggregation of NPs induced by cystamine is assumed to be due to the electrostatic interaction between capped NPs and cystamine. Aggregation was confirmed by UV-vis absorptiometry and transmission electron microscopy. A linear correlation was obtained between the ratio of absorbances at 560 and 395 nm and the cystamine concentration in the range between 0.2 μM and 10.0 μM. The limit of detection is 46 nM. The method was successfully applied to the determination of cystamine in spiked human serum and urine samples. Recoveries ranged between 94.0 % and 100.9 %, and relative standard deviations are <9.50 % (for n = 3). [ABSTRACT FROM AUTHOR]

A fast, selective and sensitive colorimetric method was developed for the determination of creatinine. It is based on the finding that creatinine causes the aggregation of silver nanoparticles capped with 2,2-thiodiacetic acid, while other biomolecules do not exert an effect. As a result, the color of the solution changes from yellow to green which can be detected visually or by spectrophotometry. The aggregation of the AgNPs was confirmed by UV-vis absorptiometry and transmission electron microscopy. This colorimetric probe allows creatinine to be rapidly quantified with a 3.0 nM limit of detection. The ratio of absorptions at 560 and 390 nm is linearly correlated to the concentration of creatinine in the 0.01 to 1.0 μM range. The method was successfully applied to the determination of creatinine in (spiked) human serum plasma and urine samples and gave recoveries that ranged from 89.4 to 102.1 %. The method was also validated by using the Jaffe standard method. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This short review (with 72 refs.) summarizes the state of the art in fluorometric methods for targeted imaging of cancer cells and tumor tissues in order to differentiate between normal cells and cancer cells. Following an introduction into the field and after presenting an overview on the most commonly used carbon dots and graphene quantum dots, we describe methods based on peptide based targeting, aptamer based targeting, antibody based targeting, and ligand-based targeting. A concluding section summarizes the current state and challenges, and discusses future perspectives. Graphical abstract An overview is given on the applications of carbon dots (CDs) in target-specific imaging and differentiation of cancerous cells from normal cells. Several classes of ligands (including aptamers, peptides, antibodies), especially small molecules (such as FA)) have been reported for functionalizing of CDs. [ABSTRACT FROM AUTHOR]

A fluorometric method is presented for sensitive deternination of microRNA. It is making use of carbon dots (C-dots) loaded with a DNA probe as fluorophore and MnO2 nanosheets as the quenching agent. The blue-green fluorescence of the DNA-loaded C-dots is quenched by the MnO2 nanosheets, but restored on binding target microRNA-155. The maximum excitation wavelength and the maximum emission wavelength of C-dots are at 360 nm and 455 nm, respectively. Fluorescence correlates linearly with the log of the microRNA-155 concentration in two ranges, viz. from 0.15 to 1.65 aM and from 1.65 to 20 aM. The detection limit is as low as 0.1 aM. The assay can discriminate between fully complementary and single-base mismatch microRNA. The assay displayed high specificity when used to detect MCF-7 breast cancer cells which can be detected in concentrations from 1000 to 45,000 cells·mL−1, with a 600 cells·mL−1 detection limit. The method was applied to the analysis of serum samples spiked with microRNA, and satisfactory results were acquired.Schematic of a fluorometric sensing platform for miRNA-155. The method relies on a FRET process between C-dots and MnO2 nanosheets. This strategy has a practical application for detection of miRNA in cell lines and biological fluids. [ABSTRACT FROM AUTHOR]

Silica boron-sulfuric acid nanoparticles (SBSANs) as a solid Lewis-protic acid have been found to be an efficient heterogeneous catalyst in the synthesis of xanthene and acridine derivatives. The SBSAN-catalyzed reaction between carbonyl compound (aldehyde/ketone/ethyl orthoformate) and 5,5-dimethyl-1,3-cyclohexanedione (dimedone) for synthesis of xanthene derivatives is performed under mild conditions with the excellent isolated yield. Also, we can apply a broad scope of carbonyl compounds and amines for efficient synthesis of various acridine derivatives in the presence of SBSAN catalyst. In these multicomponent approaches the SBSAN catalyst can be reused for several times without any treatment in its catalytic activity. [ABSTRACT FROM AUTHOR]