Simultaneous determination of 75 abuse drugs including amphetamines,benzodiazepines, cocaine,opioids, piperazines,zolpidem and metabolites in human hair samples using liquid chromatography–tandem mass spectrometry

A liquid chromatography–tandem mass spectrometric method for the simultaneous determination of 75 abuse drugs and metabolites, including 19 benzodiazepines, 19 amphetamines, two opiates, eight opioids, cocaine, lysergic acid diethylamide, zolpidem, three piperazines and 21 metabolites in human hair samples, was developed and validated. Ten‐milligram hair samples were decontaminated, pulverized using a ball mill, extracted with 1 mL of methanol spiked with 28 deuterated internal standards in an ultrasonic bath for 60 min at 50°C, and purified with Q‐sep dispersive solid‐phase extraction tubes. The purified extracts were evaporated to dryness and the residue was dissolved in 0.1 mL of 10% methanol. The 75 analytes were analyzed on an Acquity HSS T3 column using gradient elution of methanol and 0.1% formic acid and quantified in multiple reaction monitoring mode with positive electrospray ionization. Calibration curves were linear (r ≥ 0.9951) from the lower limit of quantitation (2–200 pg/mg depending on the drug) to 2000 pg/mg. The coefficients of variation and accuracy for intra‐ and inter‐assay analysis at three QC levels were 4.3–12.9% and 89.2–109.1%, respectively. The overall mean recovery ranged from 87.1 to 105.3%. This method was successfully applied to the analysis of 11 forensic hair samples obtained from drug abusers.     

Self‐emulsion polymerization of amphiphilic monomers—a green route to synthesis of polymeric nanoscaffolds

Self‐emulsion polymerization (SEP), a green route developed by us for the polymerization of amphiphilic monomers, does not require any emulsifier or an organic solvent except that the water‐soluble initiators such as 2,2′‐azobis[2‐(2‐imidazolin‐2‐yl)propane]dihydrochloride (VA‐044) and potassium persulfate (KPS) are only used. We report here the polymer nanoscaffolds from a number of amphiphilic monomers, which can be used for in situ encapsulation of a variety of nanoparticles. As a demonstration of the efficacy of these nanoscaffolds, the synthesis of a biocompatible hybrid nanoparticle (nanohybrid), prepared by encapsulating Fe₃O₄ magnetic nanoparticle (Fe₃O₄ MNPs) in poly(2‐hydroxyethyl methacrylate) in water, for MRI application is presented. The nanohybrid prepared following the SEP in the form of an emulsion does not involve the use of any stabilizing agent, crosslinker, polymeric emulsifier, or surfactant. This water‐soluble, spherical, and stable nanohybrid containing Fe₃O₄ MNPs of average size 10 ± 2 nm has a zeta potential value of ?41.89 mV under physiological conditions. Magnetic measurement confirmed that the nanohybrid shows typical magnetic behavior having a saturation magnetization (Ms) value of 32.3 emu/g and a transverse relaxivity (r2) value of 29.97 mM^?1 s^?1, which signifies that it can be used as a T2 contrast agent in MRI. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019     

Solution-Processable Low Voltage Organic Transistors of Thieno[3,2-b]thiophene-Based Conducting Polymer

A low-operating voltage and high performance polymeric field effect transistors using octadecylphosphonic acid-treated high-k AlOx and HfO₂ hybrid dielectrics were demonstrated. High-k metal oxide hybrid dielectrics were prepared by oxygen plasma treatment of deposited Al film for AlOx and by spin coating of solution-processable HfO₂ sol-gel solution for HfO₂ in combination with phosphoric acid-based self-assembled monolayer (SAM), resulting in high capacitance (10 nF/cm² for SiO₂, 600 nF/cm² for AlOx and 580 nF/cm² for HfO₂). With phosphoric acid-based SAM on high-k metal oxide and thermal annealing of thieno[3,2-b]thiophene-based conducting polymer, the device performance was significantly enhanced. The highest mobility of the transistors using ODPA-treated AlOx as a gate dielectric is 2.3 × 10^?2 cm² V^?1 s^?1 in the saturation region with the source-drain of ?2 V. In ODPA-treated HfO₂ hybrid dielectric, the saturated mobility is 1.1 × 10^?2 cm² V^?1 s^?1 and the threshold voltage was measured to be ?0.31 V, which is at least one order lower than SiO₂ hybrid dielectric (?3 V).     

Mapped WENO schemes based on a new smoothness indicator for Hamilton–Jacobi equations

In this paper, we introduce an improved version of mapped weighted essentially non-oscillatory (WENO) schemes for solving Hamilton–Jacobi equations. To this end, we first discuss new smoothness indicators for WENO construction. Then the new smoothness indicators are combined with the mapping function developed by Henrick et al. (2005) [31]. The proposed scheme yields fifth-order accuracy in smooth regions and sharply resolve discontinuities in the derivatives. Numerical experiments are provided to demonstrate the performance of the proposed schemes on a variety of one-dimensional and two-dimensional problems.     

Negative-pressure wound therapy induces endothelial progenitor cell mobilization in diabetic patients with foot infection or skin defects

Non healing chronic wounds are difficult to treat in patients with diabetes and can result in severe medical problems for these patients and for society. Negative-pressure wound therapy (NPWT) has been adopted to treat intractable chronic wounds and has been reported to be effective. However, the mechanisms underlying the effects of this treatment have not been elucidated. To assess the vasculogenic effect of NPWT, we evaluated the systemic mobilization of endothelial progenitor cells (EPCs) during NPWT. Twenty-two of 29 consecutive patients who presented at the clinic of Seoul National Universty Hospital between December 2009 and November 2010 who underwent NPWT for diabetic foot infections or skin ulcers were included in this study. Peripheral blood samples were taken before NPWT (pre-NPWT) and 7–14 days after the initiation of NPWT (during-NPWT). Fluorescence-activated cell sorting (FACS) analysis showed that the number of cells in EPC-enriched fractions increased after NPWT, and the numbers of EPC colony forming units (CFUs) significantly increased during NPWT. We believe that NPWT is useful for treating patients with diabetic foot infections and skin ulcers, especially when these conditions are accompanied by peripheral arterial insufficiency. The systemic mobilization of EPCs during NPWT may be a mechanism for healing intractable wounds in diabetic patients with foot infections or skin defects via the formation of increased granulation tissue with numerous small blood vessels.     

Characterizing affinity epitopes between prion protein and β-amyloid using an epitope mapping immunoassay

Cellular prion protein, a membrane protein, is expressed in all mammals. Prion protein is also found in human blood as an anchorless protein, and this protein form is one of the many potential sources of misfolded prion protein replication during transmission. Many studies have suggested that β-amyloid_1–42 oligomer causes neurotoxicity associated with Alzheimer''s disease, which is mediated by the prion protein that acts as a receptor and regulates the hippocampal potentiation. The prevention of the binding of these proteins has been proposed as a possible preventative treatment for Alzheimer''s disease; therefore, a greater understanding of the binding hot-spots between the two molecules is necessary. In this study, the epitope mapping immunoassay was employed to characterize binding epitopes within the prion protein and complementary epitopes in β-amyloid. Residues 23–39 and 93–119 in the prion protein were involved in binding to β-amyloid_1–40 and _1–42, and monomers of this protein interacted with prion protein residues 93–113 and 123–166. Furthermore, β-amyloid antibodies against the C-terminus detected bound β-amyloid_1–42 at residues 23–40, 104–122 and 159–175. β-Amyloid epitopes necessary for the interaction with prion protein were not determined. In conclusion, charged clusters and hydrophobic regions of the prion protein were involved in binding to β-amyloid_1–40 and _1–42. The 3D structure appears to be necessary for β-amyloid to interact with prion protein. In the future, these binding sites may be utilized for 3D structure modeling, as well as for the pharmaceutical intervention of Alzheimer''s disease.     

Cytotoxic 5‐Hydroxyindole Alkaloids from the Marine Sponge Scalarispongia sp.

Three new 5‐hydroxyindole alkaloids ( 1 , 2 , 3 ) along with seven known analogs ( 4 , 5 , 6 , 7 , 8 , 9 , 10 ) were isolated from a Dokdo marine sponge Scalarispongia sp. The elucidation of the structures of the new compounds by spectroscopic analyses indicated that these compounds were an indole glyoxylate ( 1 ), a mono‐indole analog of hyrtinadine A ( 2 ), and a symmetrical bis‐indole with pyridine linker ( 3 ). The comparison of IC₅₀ values for obtained compounds against a human leukemia cell line revealed that the bis‐indole structure is a requirement for cytotoxicity.     

In Vitro and In Silico Screening and Characterization of Antimicrobial Napin Bioactive Protein in Brassica juncea and Moringa oleifera

The study aimed to investigate the antibacterial activity of Mustard (Brassica juncea) and Moringa (Moringa oleifera) leaf extracts and coagulant protein for their potential application in water treatment. Bacterial cell aggregation and growth kinetics studies were employed for thirteen bacterial strains with different concentrations of leaf extracts and coagulant protein. Moringa oleifera leaf extract (MOS) and coagulant protein showed cell aggregation against ten bacterial strains, whereas leaf extract alone showed growth inhibition of five bacterial strains for up to 6 h and five bacterial strains for up to 3 h. Brassica juncea leaf extract (BJS) showed growth inhibition for up to 6 h, and three bacterial strains showed inhibition for up to 3 h. The highest inhibition concentration with 2.5 mg/mL was 19 mm, and furthermore, the minimum inhibitory concentration (MIC) (0.5 mg/mL) and MBC (1.5 mg/mL) were determined to have a higher antibacterial effect for <3 KDa peptides. Based on LCMS analysis, napin was identified in both MOS and BJS; furthermore, the mode of action of napin peptide was determined on lipoprotein X complex (LpxC) and four-chained structured binding protein of bacterial type II topoisomerase (4PLB). The docking analysis has exhibited moderate to potent inhibition with a range of dock score −912.9 Kcal/mol. Thus, it possesses antibacterial-coagulant potential bioactive peptides present in the Moringa oleifera purified protein (MOP) and Brassica juncea purified protein (BJP) that could act as an effective antimicrobial agent to replace currently available antibiotics. The result implies that MOP and Brassica juncea purified coagulant (BJP) proteins may perform a wide degree of antibacterial functions against different pathogens.