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Herein, highly recoverable, and stable, nitrogen-doped Ti 3 C 2 T x -based sensors are developed for ammonia detection at room-temperature. Ti 3 C 2 T x MXene as a room-temperature gas sensor has two main drawbacks: weak recovery and resistance drift. In this work; Ti 3 C 2 T x nano-sheets were derived from the pre-synthesized Ti 3 AlC 2 by selective aluminum etching using HF acid. The sensors fabricated using pristine Ti 3 C 2 T x had high response toward polar gases, particularly ammonia. The sensors' response to 100 ppm ammonia was 10%. However, they experienced incomplete recovery and baseline resistance drift. To overcome these problems, we introduced a novel method, in which, before fabricating the gas sensors, the surface of synthesized Ti 3 C 2 T x MXene was modified by a nitrogen treatment strategy. In this method, the MXene layers were doped with nitrogen using NH 3 gas at 500 °C for 2 h. In nitrogen-doped Ti 3 C 2 T x -based sensors, both recovery and drift problems disappeared. The response of the nitrogen-doped Ti 3 C 2 T x is 3.7% toward 100 ppm ammonia, which is a notable response for a stable, recoverable, room-temperature gas sensor. [ABSTRACT FROM AUTHOR]

[Display omitted] • A magnetic ionic liquid catalyst containing SbBr 4 − introduced for PET glycolysis. • Magnetic supported catalyst shows higher activity compared to unsupported catalyst. • PET depolymerized to BHET with 96.4% yield using 6 wt% of the new catalyst. • The catalyst can be easily recovered and reused in consecutive glycolysis reactions. In a previous study, we demonstrated the efficient depolymerization of polyethylene terephthalate (PET) through glycolysis using antimony (III) oxide, a commonly used catalyst in PET synthesis. In the present research, we introduce a novel approach involving the synthesis of a magnetic bifunctional ionic liquid, Fe 3 O 4 @PMIM.SbBr 4 , containing only 2.2 wt% of antimony. The aim is to reduce the required antimony dosage for the reaction and enable its facile recovery and reuse. By employing this catalyst in PET chemical recycling through glycolysis to generate bis (2-hydroxyethyl) terephthalate (BHET) monomer, we achieved 100% PET conversion with a 96.4% yield and selectivity for BHET. This outcome was obtained using a catalyst loading of 6.0 wt% at 200 °C and 0.6 bar in a high-pressure reactor. We explored the impact of catalyst loading on BHET yield and conducted a comparative assessment of the Fe 3 O 4 @PMIM.SbBr 4 catalyst against antimony (III) bromide, and another synthesized unsupported antimony-containing ionic liquid. Our results revealed the superior catalytic activity of the magnetic ionic liquid catalyst in PET glycolysis. The utilization of this catalyst offers promising potential for PET glycolysis due to its effortless separation using an external magnet, ability to produce highly pure BHET, and recyclability for repetitive use. [ABSTRACT FROM AUTHOR]

The effectiveness of cancer treatment and reducing cancer-related deaths strongly depends on the early diagnosis of cancer cells or related markers. Different nanomaterials have been applied for diagnosis, treatment and management of cancers. Between these, carbon dots (CDs) have unique properties. These include: low cost for synthesis/fabrication, high brightness, cell permeability and photostability, good intracellular solubility, high affinity and specificity to targets, high surface area and nontoxicity. They are used not only as an ideal fluorescent probe or electrochemical platform for biosensing but also they can be applied as a novel label for bioimaging. In this review, we considered recently developed electrochemical and spectroscopic biodevices for cancer markers and cancer cells analysis. Furthermore, the application of CDs as specific emerging fluorescent probe in bio-imaging of cells was also highlighted. This review opens new windows for synergistic efforts of researches in chemistry, biology and medicine for management and diagnostic of cancers. • Cancer markers detection and cancer cell analysis is a difficult analytical challenge. • Different nanomaterials were used for cancer cell analysis and treatment. • Application of CDs for development of novel tumor marker biosensors presented. • Bio-imaging of different cancer cells with various CDs discussed. • Advantageous and future applications of CDs in cancer management are also considered. [ABSTRACT FROM AUTHOR]

In recent years, investment in solar energy has increased substantially across countries. Thus, selecting convenient locations for solar farms has become a fundamental problem when determining the investment required due to differences in climatic factors, the type and availability of land, transportation infrastructures, and the quality of power lines. Multi-Criteria Evaluation approaches based on crisp data are generally used in the selection process of optimal locations. However, despite being crisp, the data available when considering the evaluation criteria of the different alternatives constitute a discrete approximation performed on a spatial grid of potential locations. Thus, we introduce a three-stage fuzzy evaluation framework designed to account for the imprecision inherent to the evaluations when identifying the most convenient location for constructing solar power farms. First, we implement ANFIS (Adaptive Neuro-Fuzzy Inference System) on the set of grid intersection crisp data points and derive a coherent set of approximations per each potential discrete location and evaluation criterion. Then, the fuzzy AHP (Analytic Hierarchy Process) method is used to determine the weights of the different criteria considered from the linguistic evaluations provided by different experts. Finally, we define a set of if-then rules combining the different ANFIS evaluation criteria and their weights within a FIS (Fuzzy Inference System) whose output is used to determine the most convenient location for constructing a solar power farm. The efficacy of the proposed evaluation framework is demonstrated through its application to the Iranian regions of Kerman and Yazd. [ABSTRACT FROM AUTHOR]

Functionalized graphite nano-platelets (FGNP) were combined with tripolyphosphate (TPP) to gain a hybrid nano-particle (FGNP-TPP) with homogenous dispersion in epoxy, resulting in an excellent anti-corrosion coating for carbon steel substrate. Characterization analyses of the hybrid nano-particle were performed by FT-IR, SEM, XRD and TEM. TPP was linked to FGNP nano-particles by hydrogen bondings. Different epoxy coatings formulated with 1 wt.% of FGNP, FGNP-TPP and TPP were evaluated. Electrochemical investigations, salt spray and pull-off tests showed that the hybrid nano-particle can provide long-term corrosion protection compared to FGNP and TPP due to synergistic effect between FGNP as an accelerator and TPP as a corrosion inhibitor to produce a uniform and stable iron-phosphate passive film with high surface coverage. [ABSTRACT FROM AUTHOR]

In this study polyethylene terephthalate (PET) waste from drinking water bottles was converted to bis(2-hydroxyethyl) terephthalate (BHET) in the presence of antimony (III) oxide (Sb 2 O 3) as the catalyst and excess ethylene glycol (EG). The yield of BHET, using 0.5 wt% of the catalyst, under 200°C and 2.1 bar was 97.5%, achieved in only 1 h. The crude of the reaction and the purified monomer was characterized by differential scanning calorimetry, infrared spectroscopy, high pressure liquid chromatography, thermogravimetric analysis, and nuclear magnetic resonance. The influences of reaction parameters, such as the catalyst loading, reaction time, EG:PET weight ratio, and reaction pressure on the yield of BHET was investigated. In addition, the activity of this catalyst was compared to zinc acetate, antimony (III) acetate, and antimony (V) oxide, demonstrating the highest catalytic activity of Sb 2 O 3 for PET glycolysis. Since Sb 2 O 3 is one of the catalysts for the industrial synthesis of PET, the results from this work can open up a venue for the synthesis of repolymerized PET from waste PET in the same glycolysis reactor. [Display omitted] [ABSTRACT FROM AUTHOR]

Functionalized graphite nanoplatelets (FGNP) were modified with tripolyphosphate (TPP) as a thermal oxidation inhibitor. The hybride nano-particles (FGNP-TPP) effects on improvement of fire retardant properties of a traditional intumescent fire retardant (IFR) formulation were investigated. FT-IR results showed that TPP was linked to FGNP nano-particle by hydrogen bondings. TEM image showed homogenous dispersion of FGNP-TPP nano-particles in epoxy. Thermogravimetric analysis (TGA) in air showed the oxidation onset temperature of FGNP was increased by approximately 125 °C in the presence of TPP. Incorporation of 2 wt.% of FGNP-TPP into the traditional IFR coating increased the LOI value from 27.1 to 32. Also, a crack free char with high adhesion to the metal substrate was observed in bunsen burner test which increased the time of failure from 43 to 94 min. The results showed the hybrid nano-particles can improve the thermal oxidation stability of the IFR coating at higher temperatures (900–1000 °C) leading to improved char strength, char adhesion, char morphology, residual weight and fire protection properties. [ABSTRACT FROM AUTHOR]

A new selective, simple, fast and sensitive method is developed for sensing assay of Bi (III) using pyridine-2,6-dicarboxylic acid or dipicolinic acid (DPA) modified silver nanoparticles (DPA–AgNPs). Silver nanoparticles (AgNPs) were synthesized by reducing silver nitrate (AgNO 3 ) with sodium borohydride (NaBH 4 ) in the presence of DPA. Bismuth detection is based on color change of nanoparticle solution from yellow to red that is induced in the presence of Bi (III). Aggregation of DPA–AgNPs has been confirmed with UV–vis absorption spectra and transmission electron microscopy (TEM) images. Under the optimized conditions, a good linear relationship (correlation coefficient r = 0.995) is obtained between the absorbance ratio (A 525 /A 390 ) and the concentration of Bi (III) in the 0.40–8.00 μM range. This colorimetric probe allows Bi (III) to be rapidly quantified with a 0.01 μM limit of detection. The present method successfully applied to determine bismuth in real water and drug samples. Recoveries of water samples were in the range of 91.2–99.6%. [ABSTRACT FROM AUTHOR]

Abstract: A new electrochemical sensor for the determination of norepinephrine (NE), acetaminophen (AC) and tryptophan (TRP) is described. The sensor is based on carbon paste electrode (CPE) modified with 5-mino-3′,4′-dimethyl-biphenyl-2-ol (5ADB) and takes the advantages of carbon nanotubes (CNTs), which makes the modified electrode highly sensitive for the electrochemical detection of these compounds. Under the optimum pH of 7.0, the oxidation of NE occurs at a potential about 170mV less positive than that of the unmodified CPE. Also, square wave voltammetry (SWV) was used for the simultaneous determination of NE, AC and TRP at the modified electrode. [Copyright &y& Elsevier]

Abstract: Background and aim: Adiponectin, is an adipose tissue-specific adipokine, that circulates in human plasma at high levels, although lower levels are noted with insulin resistance and atherosclerosis. We investigated the relationship of adiponectin concentrations with dietary factors and some of the cardiovascular risk factors in patients with T2DM. Methods and results: Totally 107 patients with T2DM were recruited from the out patients clinic of Shariati Hospital, Tehran, Iran. Patients were evaluated for laboratory and anthropometric measurements including serum adiponectin, fasting insulin, FPG, OGTT, HbA1c, HOMA-IR, hsCRP, weight, height, BMI and WHR. Nutrients intakes were obtained via 24-h recall from each patient in three successive days. Nutrients and data analysis were done using FPII and SPSS version 13 softwares. The mean of log10-transformed serum adiponectin concentration was 0.79±0.27μg/ml. The univariate linear regression analysis could not show any significant relation between the log of serum adiponectin and dietary factors. In multivariate linear regression after multiple adjustment, the log of serum adiponectin was independently associated with WHR (P =0.02, t =−2.33), HDL-C (P =0.050, t =2.03) and markedly but not significantly with age of patients (P =0.058, t =1.92). Conclusions: Our findings showed that WHR, one of the important cardiovascular risk factors, can modulate independently adiponectin levels of T2DM patients in inverse manner. Also, the age of patients and HDL-C levels have marked positive effect on circulating levels of this adipocytokine. Thus, adiponectin might be a useful biomarker to prevent developing CVD in type 2 diabetes. [Copyright &y& Elsevier]

Abstract: Aim: The discovery of new adipokine, visfatin can significantly enhance our knowledge of insulin resistance and diabetes mellitus. We explored the relation of visfatin concentrations to cardiovascular risk factors, adiponectin and insulin resistance criteria in patients with type 2 diabetes mellitus (T2DM). Materials and Methods: Fifty-eight patients with T2DM were recruited from the out patients clinic of Shariati Hospital. Laboratory and anthropometric measurements include FBG, OGTT, HbA1c, fasting serum visfatin, insulin and adiponectin, HOMA-IR and hsCRP, weight, height, BMI and WHR were performed in all participants. All of the statistical data were analyzed using the SPSS15 software. Results: The log10-transformed (log) plasma visfatin concentration was in significant positive correlation with age (r =0.286, p =0.033). Patients were divided in two groups by median log visfatin (0.85ng/mL): group I had low values and group II had high values. In group I the log visfatin was in significant positive correlation with age (r =0.436, p =0.018) and in group II log visfatin was in significant negative correlation with FPG and HbA1c (r >0.4, p <0.05). Conclusion: In conclusion high circulating levels of visfatin could be in healthy relations with cardiovascular risk factors, insulin resistance status and adiponectin in diabetic patients. [Copyright &y& Elsevier]

In this study, a simple and effective green in situ solvothermal reduction method of multi-layered Graphene oxide (MLGO) was developed using acetonitrile (at 70 °C) for preparing a hydrophobic and corrosion-resistant epoxy coating on carbon steel. FT-IR, TGA, Raman spectroscopy and mapping EDX analysis showed a successful solvothermal reduction of MLGO by acetonitrile. The long-term salt spray and EIS study showed superior corrosion protection of reduced multi-layered Graphene oxide (RMLGO)/epoxy nano-coating compared to MLGO/epoxy. The water contact angle test on the pure epoxy, MLGO/epoxy, and RMLGO/epoxy coatings were 66.66°, 72.18°, and 91.66°, respectively that confirmed the hydrophobic property of the RMLGO/epoxy coating. Also, TEM images showed high-quality dispersion of the RMLGO prepared by in-situ solvothermal reduction compared to ex-situ solvothermal reduction. [Display omitted] • In-situ solvothermal reduction of MLGO was performed by acetonitrile. • EIS study showed superior corrosion protection of RMLGO/epoxy. • The wet adhesion results of RMLGO/epoxy was better than MLGO/epoxy • Contac angle test showed hydrophobic property of RMLGO/epoxy. • TEM images showed uniform distribution of RMLGO in epoxy. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a carbon paste electrode modified with carbon nanotubes and 5-amino-3′,4′-dimethyl-biphenyl-2-ol (5ADB) was used to prepare a novel electrochemical sensor. The objective of this novel electrode modification was to seek new electrochemical performances for the detection of isoproterenol (IP) in the presence of acetaminophen (AC) and N-acetylcysteine (NAC). The peak potentials recorded in a phosphate buffer solution (PBS) of pH 7.0 were 265, 445 and 950mV vs. Ag/AgCl/KCl (3.0M) for IP, AC and NAC, respectively. Under the optimum pH of 7.0, the oxidation of IP occurred at a potential about 215mV less positive than that of the unmodified CPE. The response of catalytic current with IP concentration showed a linear relation in the range from 4.0×10−7 to 9.0×10−4 M with a detection limit of 2.0×10−7 M. [Copyright &y& Elsevier]

Abstract: We used novel synthetic conditions of precipitation polymerization to obtain uniformly sized molecularly imprinted nanospheres of dipyridamole for application in the design of new drug delivery systems. In addition, the morphology, drug release, and binding properties of molecularly imprinted polymers (MIPs) were studied, and the effects of morphology on other properties were investigated. The MIPs prepared by acetonitrile/chloroform (19:1, v/v) were uniformly sized nanospheres with an average mean diameter of approximately 88nm at a wetted state, 50nm at a dry state, and a polydispersity index of 0.062. The imprinted nanospheres showed excellent binding properties and had 62.7% of template binding compared with 17.1% of its blank polymer. The imprinted nanospheres with 67.5 (mg template/of polymer) of binding capacity had better imprinting efficiency than the 50.5% of binding capacity shown by irregularly shaped MIP particles that were prepared by chloroform. The molecular binding abilities of imprinted nanospheres in human serum were evaluated by HPLC analysis (binding about 77% of dipyridamole). Results from release experiments of MIPs showed a very slow, controlled, and satisfactory release of dipyridamole. The loaded drug was released up to 99% in 17days for nanospheres and 22days for irregularly shaped particles. [Copyright &y& Elsevier]