Teaching Story without Struggle: Using Graded Readers and Their Audio Packs in the EFL Classroom

In recent years the support for extensive reading (ER) in English as a second or foreign language (ESL/EFL) programs has been compelling. When practicing extensive reading, the learner reads a wide variety of texts for pleasure and achieves a general understanding of the content while deciphering unknown words through context. This approach contrasts with intensive reading, a more traditional approach based on a slow, careful reading of a text, with goals of complete comprehension and the identification of specific details and information

Photolariats: synthesis, metal ion complexation and photochromism

International audiencePhotolariat development, as an extension to the family of synthetic photochromic crown ether receptors, or photocrowns, is reported. Incorporated additional chelating groups, namely two anisoles or thioanisoles, contribute in completing the metal ion coordination sphere with different affinities and selectivities for a range of ions. Single-crystal X-ray diffraction analysis suggests that the thermally stable trans-form of the receptor is unsuitable for ion binding, consistent with spectrophotometric and NMR titration results, which is largely improved in the cis-form as the basis for the photocontrolled ion coordination/ejection. In terms of the azobenzene-containing receptor photochemistry, a photostationary state highly enriched in the cis-form (94:6, cis-/trans-) is reached, with slow thermal return (1.1-1.4 × 10− 5 s− 1) in the dark, which can undergo multiple cycles without discernable photodegradation

Ultrasensitive electrochemical genosensor for direct detection of specific RNA sequences derived from avian influenza viruses present in biological samples

An electrochemical genosensor based on an epoxyphenanthroline–Fe(III)–NH2-ssDNA layer for the detection of RNA derived from Avian Influenza is presented. The biosensor preparation consists of: (I) modification of gold electrodes with aminoethanethiol, (II) modification of the self-assembled monolayer of aminoethanethiol with 5,6-epoxy-5,6-dihydro-[1,10]-phenanthroline using “click” chemistry, (III) a first step of complexation of Fe(III) by 5,6-epoxy-5,6-dihydro-[1,10]-phenanthroline, (IV) a second step of complexation of Fe(III) by 5,6-epoxy-5,6-dihydro-[1,10]-phenanthroline, (V) immobilization of the single stranded amino-DNA probe via “click” chemistry between epoxy and amino groups. The interactions between the ssDNA probe and RNA targets were explored with Osteryoung Square Wave Voltammetry. The genosensor showed a remarkable detection limit of 3 copies/μL (5 aM) for RNA extracted from A/swan/Poland/305/06 (H5N1) containing a fully complementary sequence. A linear dynamic range for this sequence was observed from 3.0×103 to 3.0×105 [copies/μl]. RNA extracted from A/mallard/Poland/446/09 (H7N7), containing a non-complementary sequence, generated a much weaker response. Moreover, the developed genosensor allows to distinguish RNA present in biological samples having 2, 3 and 4 mismatches. This biosensing approach can become a potential alternative tool for detecting RNA samples in biomedical research and early clinical diagnosis of avian influenza viruses

Immobilization of His-tagged kinase JAK2 onto the surface of a plasmon resonance gold disc modified with different copper (II) complexes.

New surface plasmon resonance (SPR) sensing platforms which consists of copper (II) complexes of a pentetic acid thiol ligand (DPTA-Cu(II)) and of a thiol derivative of dipyrromethene (DPM-Cu(II) created on the surface of gold SPR disc were applied to oriented immobilization of His-tagged Janus kinase 2 (GST-His6-JAK2). This method is based on the covalent bond formation between histidine from a His-tag chain of a protein and Cu(II) centres from the complexes. The kinetic and thermodynamic parameters of the oriented immobilization of GST-His6-JAK2 protein to DPTA-Cu(II) and DPM-Cu(II) complexes attached to the Au surface of a SPR disc were discussed

Pentetic acid (DPTA) Cu(II) monolayer deposited on gold electrode—The base of biosensors for electrochemical screening of kinase JAK2 and potential inhibitor interactions

Here, the new biosensor destined for screening of interactions between kinase JAK2 and compounds which may act as inhibitors was presented. The Cu(II) complex of pentetic acid thiol ligand was applied for immobilization of kinase JAK2 on the gold electrode surface through his-tagged chemistry. The base of the biosensor response was the change of the electrochemical properties of the Cu(II) redox centres upon formation of the kinase JAK2–potential inhibitor complex. The increasing inhibitor concentration caused the decrease of reduction/oxidation Cu(II) current observed with Osteryoung square wave voltammetry. The biosensor usability was checked using known inhibitors, berberines–isoquinolone alkaloids, as well as caffeic acid—a control compound which has no affinity to kinase JAK2. The possible parameters suitable for estimation of the strength of the interactions between kinase JAK2 covalently attached to the Cu(II) complex of pentetic acid thiol ligand deposited on the gold electrode surface and potential inhibitors present in the solution were presented

The application of the click reaction in the synthesis of targeted drugs and MRI contrast agents.

The click reaction is a versatile tool in synthetic chemistry and in this thesis, the applicability of this reaction in the synthesis of targeted drugs and MRI contrast agents has been assessed. In the first part of the research, the reaction was used to construct conjugates of targeting agents and cytotoxic drugs, with applications in cancer treatment. The conclusions in this first part are dual, on one hand, the reaction, on one hand the reaction prevented the synthesis of a number of tirapazamine analogues (most likely due to the formation of insoluble copper complexes), on the other hand, the modular nature of the reaction and its orthogonality with most other reactions proved to enable and facilitate the synthesis of conjugates of RGD mimetics with tubuline polymerization inhibitors and conjugates of an NLS-peptide with a BODIPY PDT probe.In the second part of the thesis, the click reaction as a tool in the synthesis of specific MRI contrast agents has been evaluated. Firstly, the click reaction was used to demonstrate the ease and feasibility of the synthesis of small molecular weight target specific MRI contrast agents. Here, azide substituted target specific probes were fused to an alkyne bearing GdDOTA analogue and the physical and biological properties of the contrast agent proved its effectiveness in vitro.A second type of contrast agents, consisting of a Ru2+ based metallostar contrast agent decorated with RGD-peptides, was constructed. Here, the click reaction s orthogonality enabled the decoration to be postponed to the final step, thus allowing the introduction of the peptides under relatively mild conditions. Due to the modular nature of the click reaction, the scaffold used here could be used as a building block of analogous metallostars decorated with different specific probes.status: publishe