Synthesis of (−)-elemoxide,a commercially important fragrance compound

(?)-Elemoxide, a fragrant compound was synthesised using commercially available elemol in four steps with overall yield of 32%. The cyclic ether skeleton was constructed via intramolecular hydroalkoxylation using I₂ and PhSiH₃ catalytic system. Also, intramolecular oxymercuration-demercuration was employed as an alternate approach for cyclization. The various regioselective strategies involving epoxidation of alkene, reduction of epoxide and intramolecular cyclization were the highlights of the work. The key intermediate diol serves as a versatile intermediate for the synthesis of elemoxide and elemene.     

Voltammetric determination of 17β-estradiol in human urine and buttermilk samples using a simple copper(II) oxide-modified carbon paste electrode

This paper reports the voltammetric determination of 17β-estradiol in urine and buttermilk samples using a simple detector based on a carbon paste electrode (CPE) modified with copper(II) oxide (CuO). The CuO was obtained by the Pechini method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive (EDS), Fourier transform infrared (FTIR), and Raman spectroscopies. Cyclic voltammetry (CV) and square-wave voltammetry (SWV) demonstrated that the CuO-modified carbon paste electrode (CuO/CPE detector) displayed much higher electrocatalytic activity in the 17β-estradiol oxidation reaction than the CPE without modification, exhibiting a low detection limit of 21.0 nmol L^?1 with a wide linear range from 60.0 to 800.0 nmol L^?1 (R = 0.998). Satisfactory results were obtained for the determination of 17β-estradiol in human urine and buttermilk samples. The proposed electrochemical detector offers high repeatability, stability, fast response, low cost, and potential for practical application in the quantification of this hormone.

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How a single photon can mediate entanglement between two others

We describe a novel quantum information protocol, which probabilistically entangles two distant photons that have never interacted. Different from the entanglement swapping protocol, which requires two pairs of maximally entangled photons as the input states, as well as a Bell-state measurement (BSM), the present scheme only requires three photons: two to be entangled and another to mediate the correlation, and no BSM, in a process that we call “entanglement mediation”. Furthermore, in analyzing the paths of the photons in our arrangement, we conclude that one of them, the mediator, exchanges information with the two others simultaneously, which seems to be a new quantum-mechanical feature.     

Turbulence in microfluidics: Cleanroom-free,fast, solventless,and bondless fabrication and application in high throughput liquid-liquid extraction

This paper addresses an important breakthrough in the deployment of ultra-high adhesion strength microfluidic technologies to provide turbulence at harsh flow rate conditions. This paper is only, to our knowledge, the second reporting on the generation of high flow rate-assisted turbulence in microchannels. This flow solves a crucial bottleneck in microfluidics: the generation of high throughput homogeneous mixings. We focused on the fabrication of bulky polydimethylsiloxane (PDMS) microchips (without any interfaces) rather than the laborious surface modifications that were employed in the first reporting about turbulence-assisted microfluidics. The fabrication is cleanroom-free, simple, low-cost, fast, solventless, and bondless requiring only a laboratory oven. More specifically, our method relies on the shaping of a nylon scaffold, cure of PDMS with embedded nylon, and removal of this scaffold. The scaffold was obtained by manually wrapping nylon threads. The withdrawing out of the scaffold was completed in few seconds using only a plier. Such microchannels endured flow rates of up to 60.0 mL min⁻¹ with a strikingly low elastic deformation. The importance in producing turbulence into microscale channels was successfully shown in liquid-liquid extractions. The great energy dissipation rate relative to the turbulence created high throughput and efficient extractions in microfluidics for the first time. The residence time was only 0.01 s at 25.0 mL min⁻¹ (total flow rate of the immiscible phases). In addition, the partition coefficient determined in a single run was similar to that obtained by the conventional batch shake-flask method that was realized in triplicate.     

Simple HPLC‐UV for the quantification of a new leishmanicidal candidate (E)‐1‐4(trifluoromethyl) benzylidene)‐5‐(2‐4‐dichlorozoyl) carbonylhydrazine (LASSBio‐1736) in rat plasma for pharmacokinetics assessment

In this study, a sensitive HPLC‐UV assay was developed and validated for the determination of LASSBio‐1736 in rat plasma with sodium diclofenac as internal standard (IS). Liquid–liquid extraction using acetonitrile was employed to extract LASSBio‐1736 and IS from 100 μL of plasma previously basified with NaOH 0.1 M. Chromatographic separation was carried on Waters Spherisorb^®S5 ODS2 C₁₈ column (150 × 4.6 mm, 5 μm) using an isocratic mobile phase composed by water with triethylamine 0.3% (pH 4), methanol and acetonitrile grade (45:15:40, v/v/v) at a flow rate of 1 mL/min. Both LASSBio‐1736 and IS were eluted at 4.2 and 5 min, respectively, with a total run time of 8 min only. The lower limit of quantification was 0.2 μg/mL and linearity between 0.2 and 4 μg/mL was obtained, with an R² > 0.99. The accuracy of the method was >90.5%. The relative standard deviations intra and interday were <6.19 and <7.83%, respectively. The method showed the sensitivity, linearity, precision, accuracy and selectivity required to quantify LASSBio‐1736 in preclinical pharmacokinetic studies according to the criteria established by the US Food and Drug Administration and European Medicines Agency. Copyright © 2016 John Wiley & Sons, Ltd.