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An X-ray analysis of exfoliated MoS2, produced by means of microwave-assisted liquid-phase exfoliation (LPE) from bulk powder in 1-methyl-2-pyrrolidone (NMP) or acetonitrile (ACN) + 1-methyl-2-pyrrolidone (NMP) solvents, has revealed distinct structural differences between the bulk powder and the microwave-exfoliated samples. Specifically, we performed X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements to identify the elements of our exfoliated sample deposited on a Si substrate by drop-casting, as well as their chemical state and its structural crystalline phase. In the exfoliated sample, the peaks pattern only partially resemble the theoretical Miller indices for MoS2. In contrast, the bulk powder's spectrum shows the characteristic peaks of the 2H polytype of MoS2, but with some broadening. Notable is the retention of partial crystallinity in the post-exfoliation phases, specifically in the normal-to-plane orientation, thus demonstrating the effectiveness of microwave-assisted techniques in producing 2D MoS2 and attaining desirable properties for the material. XPS measurements confirm the success of the exfoliation procedure and that the exfoliated sample retains its original structure. The exfoliation process has been optimized to maintain the structural integrity of MoS2 while enhancing its surface area and electrochemical performance, thereby making it a promising material for advanced electronic and optoelectronic applications ranging from energy storage to sensing devices under ambient conditions. [ABSTRACT FROM AUTHOR]

Screen-printed electrodes (SPEs) are reliable, portable, affordable, and versatile electrochemical platforms for the real-time analytical monitoring of emerging analytes in the environmental, clinical, and agricultural fields. The aim of this study was to evaluate the electrochemical behavior of gold screen-printed electrodes (SPGEs) modified with molecules containing amino (Tr-N) or α-aminophosphonate (Tr-P) groups for the selective and sensitive detection of the toxic metal ions Pb2+ and Hg2+ in aqueous samples. After optimizing the analytical parameters (conditioning potential and time, deposition potential and time, pH and concentration of the supporting electrolyte), anodic square wave stripping voltammetry (SWASV) was used to evaluate and compare the electrochemical performance of bare or modified electrodes for the detection of Hg2+ and Pb2+, either alone or in their mixtures in the concentration range between 1 nM and 10 nM. A significative improvement in the detection ability of Pb2+ ions was recorded for the amino-functionalized gold sensor SPGE-N, while the presence of a phosphonate moiety in SPGE-P led to greater sensitivity towards Hg2+ ions. The developed sensors allow the detection of Pb2+ and Hg2+ with a limit of detection (LOD) of 0.41 nM and 35 pM, respectively, below the legal limits for these heavy metal ions in drinking water or food, while the sensitivity was 5.84 µA nM−1cm−2 and 10 µA nM−1cm−2, respectively, for Pb2+ and Hg2+. The reported results are promising for the development of advanced devices for the in situ and cost-effective monitoring of heavy metals, even in trace amounts, in water resources. [ABSTRACT FROM AUTHOR]

Potassium channels have recently emerged as suitable target for the treatment of epileptic diseases. Among potassium channels, KCNT1 channels are the most widely characterized as responsible for several epileptic and developmental encephalopathies. Nevertheless, the medicinal chemistry of KCNT1 blockers is underdeveloped so far. In the present review, we describe and analyse the papers addressing the issue of KCNT1 blockers' development and identification, also evidencing the pros and the cons of the scientific approaches therein described. After a short introduction describing the epileptic diseases and the structure–function of potassium channels, we provide an extensive overview of the chemotypes described so far as KCNT1 blockers, and the scientific approaches used for their identification. [ABSTRACT FROM AUTHOR]

The one-pot synthesis of N-doped graphene quantum dots (GQDs), capped with a positively charged polyamine (trien), has been realized through a microwave-assisted pyrolysis on solid L-glutamic acid and trien in equimolar amounts. The resulting positively charged nanoparticles are strongly emissive in aqueous solutions and are stable for months. The interaction with the anionic tetrakis(4-sulphonatophenyl)porphyrin (TPPS4) has been investigated at neutral and mild acidic pH using a combination of UV/vis absorption spectroscopy together with static and time-resolved fluorescence emission. At pH = 7, the experimental evidence points to the formation of a supramolecular adduct mainly stabilized by electrostatic interactions. The fluorescence emission of the porphyrin is substantially quenched while GQDs remain still emissive. On decreasing the pH, protonation of TPPS4 leads to formation of porphyrin J-aggregates through the intermediacy of the charged quantum dots. [ABSTRACT FROM AUTHOR]

This review offers an overview of the synthesis of phosphonated isoxazolidinyl nucleosides, a new class of interesting and potentially antiviral/antitumor agents. The synthetic methodology relies on a 1,3-dipolar cycloaddition reaction as a key step. The cycloaddition process involves substituted nitrones, phosphonated nitrones, or nitrones containing functional groups easily convertible into a phosphonated group. Biological assays are presented, which show that phosphonated isoxazolidinyl nucleosides represent a new promising template of nucleoside analogues. [ABSTRACT FROM AUTHOR]

A series of spiro[isoindole-1,5-isoxazolidin]-3(2 H )-ones has been synthesized by 1,3-dipolar cycloaddition of N -benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9-22 μM. Biological tests suggest that the antitumor activity could be linked to the inhibition of the protein-protein p53-MDM2 interaction. Docking measurements support the biological data.

Objective: To investigate the role of body composition and oxidative stress measured by total thiol groups (TTG) levels in prostate specimens of patients affected by benign prostatic hyperplasia (BPH) or prostate cancer (PCa)., Patients and Methods: From January 2011 to January 2013, a cohort of 150 consecutive male patients who underwent first prostate biopsy were enrolled. Twelve-core needle biopsy was performed as standard procedure, while twelve more needle tissue cores matched with the previous group were also collected for glutathione determination. After definitive diagnosis, measurement of glutathione was performed in the correspondent one matched prostatic sample where PCa or BPH were identified. A day after the prostatic biopsy, body composition was estimated by air plethysmography (BOD POD®)., Results: A significant difference of TTG was observed in BPH and PCa patients; 34 nanomole (nmol) reagent sulfihydrylc (RSH)/ mg protein vs. 1.1 nmol RSH/ mg protein respectively (p<0.05). In BPH patients, a negative correlation was found between TTG and age (r=-0.46; p<0.05), while, in PCa patients, a positive correlation was observed between TTG and fat mass (FM) (r=0.76; p<0.01) and waist circumference (WC) (r=0.49; p<0.05). Multivariate linear regression analysis showed TTG to be negatively associated with age (β-coefficient=-0.4; p<0.05) in BPH patients and positively with FM (β-coefficient=3.4; p<0.01) and WC (β-coefficient=2.7; p<0.05) in PCa patients., Conclusion: Aging determines a progressive reduction of TTG in BPH patients, while in PCa subjects glutathione concentrations are significantly lower and FM and WC are associated with an unbalance of its levels., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)