Gli autori si desidera ringraziare il sostegno fornito a Morgan Philp attraverso un australiano governo ricerca formazione programma di borsa di studio.

1. preparazione delle soluzioni di reagente Test colore
Nota: Pesare 0,12 g di nitrato di rame triidrato in un becher da mL 100 asciutto. Aggiungere 30 mL di acqua deionizzata (DI) e accuratamente di turbinio a temperatura ambiente per sciogliere tutti i solidi. Versare questa soluzione in un matraccio tarato da 100 mL e riempire fino alla tacca calibrata con dell'acqua distillata. Questa soluzione preparata è il reagente 1. Nota: Reagente 1 possa essere preparato con altri sali di rame (II), per esempio cloruro di rame (II).
<ol><li>Peso 0,11 g di emiidrato 2,9-dimetil-1,10-fenantrolina (Neocuproina) in un becher da mL 100 asciutto. Aggiungere 50 mL di 0.10 mol/L di acido cloridrico (HCl) e utilizzare un bacchetta di vetro per promuovere la dissoluzione dei solidi a temperatura ambiente. Versare questa soluzione in un matraccio tarato da 100 mL e riempire fino alla tacca calibrata con 0.10 mol/L HCl. Questa soluzione preparata è reagente 2. Attenzione: Neocuproina è acutamente tossico può provocare irritazioni cutanee e gravi lesioni oculari. Indossare guanti e occhiali di sicurezza durante la manipolazione per ridurre al minimo il rischio di esposizione. Nota: Neocuproina è solo leggermente solubile in acqua, pertanto, acido diluito viene utilizzata per preparare questo reagente e garantire che tutti i solidi si dissolvono.</li>
	<li>Pesare 16,4 g di acetato di sodio in un becher da mL 100 asciutto. Aggiungere 50 mL di acqua deionizzata e utilizzare un bacchetta di vetro per favorire la dissoluzione dei solidi a temperatura ambiente. Versare questa soluzione in un matraccio tarato da 100 mL e riempire fino alla tacca calibrata con dell'acqua distillata. Questa soluzione preparata è Reagente 3. Nota: Il protocollo può essere messo in pausa qui. I reagenti sono altamente stabili e possono essere memorizzati fino a 12 mesi a temperatura ambiente.</li>
</ol>2. colore test
<ol><li>Raccogliere una porcellana pulito posto piatto, tre pipette monouso, tre soluzioni di reagenti preparate al punto 2.1, una spatola pulita, una piastra elettrica e il campione/sequestrato materiale da testare.</li>
	<li>Utilizzando la spatola, posizionare una piccola, testa di spillo dimensioni quantità (circa 0.1-0.2 mg) del campione sconosciuto in tre separati pozzetti di una piastra di porcellana spot. Lasciare tre pozzetti adiacenti vuote (controllo in bianco) e un altro tre pozzi con uguali quantità di HCl 4-methylmethcathinone (4-MMC), un campione di riferimento di catinone sintetico (controllo positivo). Nota: La superficie di prova preferito è un piatto di porcellana spot. Se questi non sono disponibili, utilizzare piastre microtiter plastica o semi micro provette.</li>
	<li>Utilizzando una pipetta monouso, aggiungere 5 gocce della soluzione di nitrato di rame (Reagente 1) in ciascun pozzetto del campione, oltre i pozzetti di controllo vuoto e positivo.</li>
	<li>Utilizzando una pipetta monouso seconda, aggiungere 2 gocce della soluzione Neocuproina (Reagente 2) ad ogni pozzetto campione, oltre i pozzetti di controllo vuoto e positivo.</li>
	<li>Utilizzando una pipetta monouso terza, aggiungere 2 gocce di soluzione di acetato di sodio (Reagente 3) per ogni pozzetto, oltre ai pozzetti di controllo vuoto e positivo del campione. Nota: Il soluzione diventa blu chiaro.</li>
	<li>Posizionare la porcellana piatto posto direttamente su una piastra elettrica impostata a 80 ° C. Nota: Non riscaldare piastre microtiter plastica direttamente sulla piastra riscaldante. Preparare un bagno di acqua bollente poco profonde per impostare la piastra di plastica. Calore semi-micro provette in un piccolo bagno d'acqua bollente. Il preciso tempo necessario per osservare che un cambiamento di colore dipenderà lo spessore e la composizione del piatto posto. Attenzione: fare attenzione durante la movimentazione piastre piatte per evitare ustioni.</li>
	<li>Dopo il riscaldamento per 10 min, osservare ad occhio nudo e si noti il cambiamento di colore finale o scattare una foto della modifica del colore finale. Nota: Utilizzare uno sfondo bianco per meglio visualizzare i cambiamenti di colore.</li>
</ol>

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M., Al-Tamrah, S. A., Aly, F. A., Alwarthan, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+(S)(&#8722;)-cathinone+by+spectrophotometric+detection.">Determination of (S)(&#8722;)-cathinone by spectrophotometric detection.</a> J Pharmaceut Biomed. 17 (2), 321-326 (1998).</li><li>Namera, A., Kawamura, M., Nakamoto, A., Saito, T., Nagao, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comprehensive+review+of+the+detection+methods+for+synthetic+cannabinoids+and+cathinones.">Comprehensive review of the detection methods for synthetic cannabinoids and cathinones.</a> Forensic Toxicol. 33 (2), 175-194 (2015).</li><li>Isaacs, R. C. 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Gli autori non hanno nulla a rivelare.

Questo protocollo di prova colore è stato adattato da lavoro sperimentale pubblicato da Al-Omari et al. 18 in cui gli autori hanno dimostrato un cambiamento di colore si verifica in presenza di catinone estratte dalla pianta del khat. Modifiche al protocollo pubblicato sono state necessarie per prevedere la sua applicazione nella diagnosi presuntiva di droghe illecite. La considerazione più importante era quello di ridurre la scala della reazione. Il protocollo descritto nel presente do...

Il mercato delle droghe illecite opera alla stregua di un esercizio commerciale tradizionale continuando ad evolversi e adattarsi a un mercato in evoluzione. Avanzamenti nella tecnologia moderna, in particolare, la proliferazione globale di comunicazione potente ha visto aumentato gli acquisti online via il buio netto1 e vasta conoscenza condivisione tra gli utenti tramite forum online2. In combinazione con gli avanzamenti nella chimica, il rapido emergere di nuove sostanze psicoattive (NPS) creata una seria sfida per il controllo della droga nazionale ed internazionale.
NPS sono potenzialmente pericolose sostanze d'abuso che hanno effetti simili alle droghe sotto controllo internazionale. Inizialmente commercializzato come alternative "legali", 739 NPS sono stati segnalati all'ufficio delle Nazioni Unite su droghe e crimine (UNODC) tra il 2009 e il 20163. Secondo la più recente relazione annuale, un numero record di NPS sono stato sequestrato alla frontiera australiana, con la maggior parte di quelli analizzati, ulteriormente identificato come sintetico cathinones4. Su scala globale, sequestri di cathinones sintetici sono in costante aumento dal primo segnalato nel 2010 e sono uno dei più comunemente sequestrati NPS5.
Le sfide posate dalla NPS sono state un argomento largamente pubblicato di discussione6,7. Laboratori forensi e forze dell'ordine sono stati lasciati in una situazione di svantaggio senza metodi adeguati per rilevare e identificare dei criteri di rete durante la loro emersione rapida. Ricerca approfondita per la rilevazione di NPS, inclusa cathinones sintetico, nel materiale sequestrato, ha impiegato la spettrometria della cromatografia-massa del gas (GC-MS)8 e liquido cromatografia-alta risoluzione spettrometria di massa (LC-HRMS)9 per analisi di conferma. La crescente domanda di preparazione minima del campione ha visto infrarossi e Raman spettroscopia10 studi, nonché analisi spettrometria di massa, ionizzazione ambientale, quali analisi diretta in tempo reale spettrometria di massa (DART-MS)11, 12. la necessità per l'analisi rapida e precisa nel campo ha visto anche l'incorporazione di carta spray ionizzazione-spettrometria totale (PSI-MS) in dispositivi portatili per uso di applicazione della legge13. Molte tecniche strumentali offrono analisi di conferma con rivelazione sensibile e risultati quantitativi. Tuttavia, per analisi di alto-rendimento, possono essere che richiede tempo, a causa della preparazione del campione, tempi di esecuzione e strumento formazione e manutenzione.
Presuntiva colore test sono progettati per suggerire la presenza o l'assenza di alcune classi di farmaci in un campione di prova14. Il gruppo di lavoro scientifico per l'analisi di farmaci sequestrati (SWGDRUG) classifica colore test come la tecnica di potere più basso discriminante, al fianco di spettroscopia ultravioletta e test immunologici15. Tuttavia, sono ancora ampiamente impiegati da forze dell'ordine e altro personale di sicurezza come un mezzo per fornire risultati in tempi rapidi ad un costo significativamente inferiore rispetto ad altre tecniche. Il vantaggio principale offerto da macchia di colore metodi di prova è la capacità di eseguire tali operazioni nel campo usando i corredi della prova portatile.
La selettività delle prove colore si basa su singole reazioni chimiche che avvengono tra il reagente e la classe di farmaco di interesse per creare un cambiamento di colore. Protocolli di prova presuntivi attuali mancano un particolare test per la rilevazione sintetica cathinones solo; i reagenti comunemente usati che mancano di specificità e contengono sostanze pericolose sono spesso impiegati. Altri reagenti consigliati non sono stati proiettati su un gran numero di possibili catinone sintetico sostanze16.
Lo scopo di questo lavoro è di presentare un protocollo di test semplice di colore che possa essere facilmente impiegato dalle parti interessate per lo screening preliminare di cathinones sintetico in sostanze illecite di composizione sconosciuta. Parti interessate dovrebbe includere forze dell'ordine, agenzie di protezione del bordo, laboratori forensi e altro personale di sicurezza pertinenti. I metodi proposti impiegano una reazione di riduzione-ossidazione che si verificano tra il reagente complesso rame accettare elettroni e le molecole di droga catinone sintetico ricco di elettroni. Utilizzando questi metodi chimici sviluppati, si può applicare a loro sotto forma di una prova presuntiva colore per suggerire la presenza di cathinones sintetico.

color spot test as a presumptive tool for the rapid detection of synthetic cathinones

Cathinones sintetici sono una vasta classe di nuove sostanze psicoattive (NPS) che sono sempre più diffusi in sequestri di droga fatti da forze dell'ordine e altre autorità di protezione di frontiera a livello globale. Colore test è una tecnica di identificazione presuntiva che indica la presenza o l'assenza di una classe particolare farmaco utilizzando metodi chimici rapidi e senza complicazioni. A causa della loro emersione relativamente recente, una prova di colore per l'identificazione specifica di cathinones sintetico non è attualmente disponibile. In questo studio, presentiamo un protocollo per l'identificazione presuntiva di cathinones sintetico, impiegando tre soluzioni reagenti acquosi: nitrato di rame (II), 2,9-dimetil-1,10-fenantrolina (Neocuproina) e sodio acetato. Dimensioni capocchia piccola quantità (circa 0.1-0.2 mg) dei farmaci sospetti vengono aggiunti ai pozzetti di una porcellana spot piastra e ciascun reagente viene quindi aggiunto goccia a goccia in sequenza prima di riscaldamento su una piastra riscaldante. Un cambiamento di colore da blu molto chiaro a giallo-arancio dopo 10 min indica la probabile presenza di cathinones sintetico. Il reagente di prova altamente stabile e specifica ha il potenziale per uso nella selezione presuntiva dei campioni sconosciuti per sintetico cathinones in un laboratorio forense. Tuttavia, il fastidio di una fase di Riscaldamento aggiunto per il risultato del cambiamento di colore limita il test per applicazioni di laboratorio e diminuisce la probabilità di una semplice traduzione di prove sul campo.

Il protocollo dei test è stato convalidato attraverso diversi studi, i cui risultati sono descritti in Philp et al. 17. il metodo di prova di colore è in grado di riconoscere presuntivamente sintetico cathinones in un campione sconosciuto attraverso un colore cambiare dal blu chiaro al giallo-arancio (Figura 1). Il colore arancione e giallo cambia occuring dopo il periodo di riscaldamento sono considerati risultati positivi ...

Watch this Scientific Journal Video about Color Spot Test As a Presumptive Tool for the Rapid Detection of Synthetic Cathinones at JoVE.com

Color Spot Test As a Presumptive Tool for the Rapid Detection of Synthetic Cathinones

Colore Spot Test come strumento presuntivo per la rilevazione rapida di Cathinones sintetico

Qui presentiamo un protocollo di test posto chimico semplice, poco costoso e selettiva per l'individuazione di cathinones sintetico, una classe delle nuove sostanze psicoattive. Il protocollo è adatto ad uso in varie aree di applicazione della legge che incontrano materiale illecito.

Synthetic cathinones are a large class of new psychoactive substances (NPS) that are increasingly prevalent in drug seizures made by law enforcement and ...

color-spot-test-as-presumptive-tool-for-rapid-detection-synthetic

Universidad San Sebastian

Research

JoVE Journal

Chemistry

24.5K Views.  University of Technology Sydney (UTS). Qui presentiamo un protocollo di test posto chimico semplice, poco costoso e selettiva per l'individuazione di cathinones sintetico, una classe delle nuove sostanze psicoattive. Il protocollo è adatto ad uso in varie aree di applicazione della legge che incontrano materiale illecito.

Video: Color Spot Test As a Presumptive Tool for the Rapid Detection of Synthetic Cathinones

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing and maintaining primary and pluripotent stem cell derived hepatocytes. While biological matrices are useful, they permit short term culture of hepatocytes, limiting their widespread application. We have attempted to overcome the limitations using a synthetic polymer coating. Polymers represent one of the broadest classes of biomaterials and possess a wide range of mechanical, physical and chemical properties, which can be fine-tuned for purpose. Importantly, such materials can be scaled to quality assured standards and display batch-to-batch consistency. This is essential if cells are to be expanded for high through-put screening in the pharmaceutical testing industry or for cellular based therapy. Polyurethanes (PUs) are one group of materials that have shown promise in cell culture. Our recent progress in optimizing a polyurethane coated surface, for long-term culture of human hepatocytes displaying stable phenotype, is presented and discussed.

This article will focus on developing polymer coated surfaces for long-term, stable culture of stem cell derived human hepatocytes.

Stabilizzazione epatocellulare Fenotipo Utilizzando superfici sintetiche ottimizzati

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing ...

Ricerca

Chimica

Optimization of Synthetic Proteins: Identification of Interpositional Dependencies Indicating Structurally and/or Functionally Linked Residues

Protein alignments are commonly used to evaluate the similarity of protein residues, and the derived consensus sequence used for identifying functional units (e.g., domains). Traditional consensus-building models fail to account for interpositional dependencies &#8211; functionally required covariation of residues that tend to appear simultaneously throughout evolution and across the phylogentic tree. These relationships can reveal important clues about the processes of protein folding, thermostability, and the formation of functional sites, which in turn can be used to inform the engineering of synthetic proteins. Unfortunately, these relationships essentially form sub-motifs which cannot be predicted by simple &#8220;majority rule&#8221; or even HMM-based consensus models, and the result can be a biologically invalid &#8220;consensus&#8221; which is not only never seen in nature but is less viable than any extant protein. We have developed a visual analytics tool, StickWRLD, which creates an interactive 3D representation of a protein alignment and clearly displays covarying residues. The user has the ability to pan and zoom, as well as dynamically change the statistical threshold underlying the identification of covariants. StickWRLD has previously been successfully used to identify functionally-required covarying residues in proteins such as Adenylate Kinase and in DNA sequences such as endonuclease target sites.

Synthetic protein sequences based on consensus motifs typically ignore co-evolving residues, that imply interpositional dependencies (IPDs). IPDs can be essential to activity, and designs that disregard them may result in suboptimal results. This protocol uses StickWRLD to identify IPDs and help inform rational protein design, resulting in more efficient results.

Ottimizzazione di proteine ​​sintetiche: identificazione di interposizione Dipendenze Indicazione Strutturalmente e / o residui funzionalmente collegate

Protein alignments are commonly used to evaluate the similarity of protein residues, and the derived consensus sequence used for identifying functional ...

A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants

We demonstrate a method to fabricate highly sensitive surface-enhanced Raman spectroscopic (SERS) substrates using a filter syringe system that can be applied to the detection of various chemical contaminants. Silver nanoparticles (Ag NPs) are synthesized via reduction of silver nitrate by sodium citrate. Then the NPs are aggregated by sodium chloride to form nanoclusters that could be trapped in the pores of the filter membrane. A syringe is connected to the filter holder, with a filter membrane inside. By loading the nanoclusters into the syringe and passing through the membrane, the liquid goes through the membrane but not the nanoclusters, forming a SERS-active membrane. When testing the analyte, the liquid sample is loaded into the syringe and flowed through the Ag NPs coated membrane. The analyte binds and concentrates on the Ag NPs coated membrane. Then the membrane is detached from the filter holder, air dried and measured by a Raman instrument. Here we present the study of the volume effect of Ag NPs and sample on the detection sensitivity as well as the detection of 10 ppb ferbam and 1 ppm ampicillin using the developed assay.

A procedure for fabrication and performing the filter-based surface enhanced Raman spectroscopic (SERS) assay for the detection of chemical contaminants (i.e., pesticide ferbam and antibiotic ampicillin) is presented.

Una Superficie-filtro basato avanzata Raman spettroscopica Assay per Rapid individuazione dei contaminanti chimici

We demonstrate a method to fabricate highly sensitive surface-enhanced Raman spectroscopic (SERS) substrates using a filter syringe system that can be ...

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin

Vanillin (4-hydoxy-3-methoxybenzaldehyde) is the main component of the extract of vanilla bean. The natural vanilla scent is a mixture of approximately 200 different odorant compounds in addition to vanillin. The natural extraction of vanillin (from the orchid Vanilla planifolia, Vanilla tahitiensis and Vanilla pompon) represents only 1% of the worldwide production and since this process is expensive and very long, the rest of the production of vanillin is synthesized. Many biotechnological approaches can be used for the synthesis of vanillin from lignin, phenolic stilbenes, isoeugenol, eugenol, guaicol, etc., with the disadvantage of harming the environment since these processes use strong oxidizing agents and toxic solvents. Thus, eco-friendly alternatives on the production of vanillin are very desirable and thus, under current investigation. Porous coordination polymers (PCPs) are a new class of highly crystalline materials that recently have been used for catalysis. HKUST-1 (Cu3(BTC)2(H2O)3, BTC = 1,3,5-benzene-tricarboxylate) is a very well known PCP which has been extensively studied as a heterogeneous catalyst. Here, we report a synthetic strategy for the production of vanillin by the oxidation of trans-ferulic acid using HKUST-1 as a catalyst.

The conversion of trans-ferulic acid to vanillin was achieved by heterogeneous catalysis. HKUST-1 was employed in this synthesis and the essential step in the catalytic process was the generation of unsaturated metal sites. Thus, when the catalyst was activated under vacuum, full vanillin conversion (yield of 95%) was obtained.

HKUST-1 come catalizzatore eterogeneo per la sintesi di vanillina

Vanillin (4-hydoxy-3-methoxybenzaldehyde) is the main component of the extract of vanilla bean. The natural vanilla scent is a mixture of approximately ...

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic acids containing three to six carbons), such as malate and citrate, are critical to the proper functioning of many biological systems, where they function in cellular respiration and can serve as indicators of cell health. In foods, organic acid content can have significant impact on taste, with increased SCCA levels resulting in a sour or &#34;acid&#34; taste. Because of this, methods for the rapid analysis of organic acid levels are of particular interest to the food and beverage industries. Unfortunately, however, most methods used for SCCA quantification are dependent on time-consuming protocols requiring the derivatization of samples with hazardous reagents, followed by costly chromatographic and/or mass spectrometric analyses. This method details an alternate method for the detection and quantification of organic acids from plant material and food samples using free zonal capillary electrophoresis (CZE), sometimes simply referred to as capillary electrophoresis (CE). CZE provides a cost-effective method for measuring SCCAs with a low limit of detection (0.005 mg/ml). This article details the extraction and quantification of SCCAs from plant samples. While the method provided focuses on measurement of SCCAs from coffee beans, the method provided can be applied to multiple plant-based food materials.

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

This article presents a method for the detection and quantification of organic acids from plant material using free zonal capillary electrophoresis. An example of the potential application of this method, determining the effects of a secondary fermentation on organic acid levels in coffee seeds, is provided.

Usando elettroforesi capillare per quantificare Acidi organici da tessuti vegetali: un banco di prova d&#39;esame<em&gt; Coffea arabica</em&gt; Semi

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic ...

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements

The western diet is poor in n-3 fatty acids, therefore the consumption of fish oil supplements is recommended to increase the intake of these essential nutrients. The objective of this work is to demonstrate the qualitative and quantitative analysis of encapsulated fish oil supplements using high-resolution 1H and 13C NMR spectroscopy utilizing two different NMR instruments; a 500 MHz and an 850 MHz instrument. Both proton (1H) and carbon (13C) NMR spectra can be used for the quantitative determination of the major constituents of fish oil supplements. Quantification of the lipids in fish oil supplements is achieved through integration of the appropriate NMR signals in the relevant 1D spectra. Results obtained by 1H and 13C NMR are in good agreement with each other, despite the difference in resolution and sensitivity between the two nuclei and the two instruments. 1H NMR offers a more rapid analysis compared to 13C NMR, as the spectrum can be recorded in less than 1 min, in contrast to 13C NMR analysis, which lasts from 10 min to one hour. The 13C NMR spectrum, however, is much more informative. It can provide quantitative data for a greater number of individual fatty acids and can be used for determining the positional distribution of fatty acids on the glycerol backbone. Both nuclei can provide quantitative information in just one experiment without the need of purification or separation steps. The strength of the magnetic field mostly affects the 1H NMR spectra due to its lower resolution with respect to 13C NMR, however, even lower cost NMR instruments can be efficiently applied as a standard method by the food industry and quality control laboratories.

Here, high-resolution 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy was used as a rapid and reliable tool for quantitative and qualitative analysis of encapsulated fish oil supplements.

Spettroscopia NMR come uno strumento robusto per la rapida valutazione del profilo lipidico di olio di pesce integratori

The western diet is poor in n-3 fatty acids, therefore the consumption of fish oil supplements is recommended to increase the intake of these essential ...

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

This article shows how the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) or the "reaction microscope" technique can be used to distinguish between enantiomers (stereoisomers) of simple chiral species on the level of individual molecules. In this approach, a gaseous molecular jet of the sample expands into a vacuum chamber and intersects with femtosecond (fs) laser pulses. The high intensity of the pulses leads to fast multiple ionization, igniting a so-called Coulomb Explosion that produces several cationic (positively charged) fragments. An electrostatic field guides these cations onto time- and position-sensitive detectors. Similar to a time-of-flight mass spectrometer, the arrival time of each ion yields information on its mass. As a surplus, the electrostatic field is adjusted in a way that the emission direction and the kinetic energy after fragmentation lead to variations in the time-of-flight and in the impact position on the detector.
Each ion impact creates an electronic signal in the detector; this signal is treated by high-frequency electronics and recorded event by event by a computer. The registered data correspond to the impact times and positions. With these data, the energy and the emission direction of each fragment can be calculated. These values are related to structural properties of the molecule under investigation, i.e. to the bond lengths and relative positions of the atoms, allowing to determine molecule by molecule the handedness of simple chiral species and other isomeric features.

For small chiral species, Coulomb Explosion Imaging provides a new approach to determine the handedness of individual molecules.

Formazione immagine di esplosione Coulombiana come uno strumento per distinguere tra stereoisomeri

This article shows how the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) or the "reaction microscope" technique can be used to distinguish ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). In the case of fast reversible electrochemical processes, current is predominantly affected by the rate of diffusion, which is the slowest and limiting stage. EIS is a powerful technique that allows separate analysis of stages of charge transfer that have different AC frequency response. The capability of the method was used to extract the value of charge transfer resistance, which characterizes the rate of charge exchange on the electrode-solution interface. The application of this technique is broad, from biochemistry up to organic electronics. In this work, we are presenting the method of analysis of organic compounds for optoelectronic applications.

Electrochemical impedance spectroscopy (EIS) of species that undergo reversible oxidation or reduction in solution was used for determination of rate constants of oxidation or reduction.

Spettroscopia di impedenza elettrochimica come uno strumento per la stima della costante tasso elettrochimica

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...

A Facile Synthetic Method to Obtain Bismuth Oxyiodide Microspheres Highly Functional for the Photocatalytic Processes of Water Depuration

Bismuth oxyhalide (BiOI) is a promising material for sunlight-driven-environmental photocatalysis. Given that the physical structure of this kind of materials is highly related to its photocatalytic performance, it is necessary to standardize the synthetic methods in order to obtain the most functional architectures and, thus, the highest photocatalytic efficiency. Here, we report a reliable route to obtain BiOI microspheres via the solvothermal process, using Bi(NO3)3 and potassium iodide (KI) as precursors, and ethylene glycol as a template. The synthesis is standardized in a 150 mL autoclave, at 126 &#176;C for 18 h. This results in 2-3 &#181;m-sized mesoporous microspheres, with a relevant specific surface area (61.3 m2/g). Shortening the reaction times in the synthesis results in amorphous structures, while higher temperatures lead to a slight increase in the porosity of the microspheres, with no effect in the photocatalytic performance. The materials are photo-active under UV-A/visible light irradiation for the degradation of the antibiotic ciprofloxacin in water. This method has demonstrated to be effective in interlaboratory tests, obtaining similar BiOI microspheres in Mexican and Chilean research groups.

This article describes a synthetic method to obtain bismuth oxyiodide microspheres, which are highly functional to perform the photocatalytic removal of organic pollutants, such as ciprofloxacin, in water under UV-A/visible light irradiation.

Un Facile metodo sintetico per ottenere bismuto Oxyiodide microsfere altamente funzionale per i processi fotocatalitici di depurazione delle acque

Bismuth oxyhalide (BiOI) is a promising material for sunlight-driven-environmental photocatalysis. Given that the physical structure of this kind of ...

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The cholesteric LC is composed of a nematic LC 4&#39;-pentyloxy-4-cyanobiphenyl (5OCB), redox-responsive chiral dopant (FcD), and a supporting electrolyte 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIm-OTf). The most important component is FcD. This molecule changes its helical twisting power (HTP) value in response to redox reactions. Therefore, in situ electrochemical redox reactions in the LC mixture allow for the device to change its reflection color in response to electrical stimuli. The LC mixture was introduced, by a capillary action, into a sandwich-type ITO glass cell comprising two glass slides with patterned indium tin oxide (ITO) electrodes, one of which was coated with poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol) doped with perchlorate (PEDOT+). Upon application of +1.5 V, the reflection color of the device changed from blue (467 nm) to green (485 nm) in 0.4 s. Subsequent application of 0 V made the device recover the original blue color in 2.7 s. This device is characterized by its fastest electrical response and lowest operating voltage among any previously reported cholesteric LC device. This device could pave the way for the development of next generation reflective displays with low energy consumption rates.

A protocol for the fabrication of a reflective cholesteric liquid crystalline display device containing a redox-responsive chiral dopant allowing quick and low-voltage operation is presented.

Un dispositivo cristallino liquido colesterico elettrochimico per la modulazione di colori veloce e bassa tensione

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The ...