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Photo sensitivity

Vahid Goudarzi, Iman Shahabi-Ghahfarrokhi
This paper reports on an experiment in which starch/kefiran/TiO2 (SKT)-based bio-nanocomposite films were developed and modified by photo-chemical reaction. In so doing, film-forming solutions were exposed to ultraviolet A (UV-A) for different times (1, 6, and 12 h). The obtained results indicated that increasing UV-A exposure time brought about an increase (≈14.9%) in the tensile strength of bio-nanocomposites. However, elongation at break and Young's modulus of irradiated film specimen decreased (≈32%, ≈12%, respectively) by increasing UV-A exposure time, and the moisture-sensitive parameters of specimen decreased using UV-A irradiation...
May 21, 2018: International Journal of Biological Macromolecules
Matias Urdampilleta, Cedric Ayela, Pierre-Henri Ducrot, Daniel Rosario-Amorin, Abhishake Mondal, Mathieu Rouzières, Pierre Dechambenoit, Corine Mathonière, Fabrice Mathieu, Isabelle Dufour, Rodolphe Clérac
Incorporating functional molecules into sensor devices is an emerging area in molecular electronics that aims at exploiting the sensitivity of different molecules to their environment and turning it into an electrical signal. Among the emergent and integrated sensors, microelectromechanical systems (MEMS) are promising for their extreme sensitivity to mechanical events. However, to bring new functions to these devices, the functionalization of their surface with molecules is required. Herein, we present original electronic devices made of an organic microelectromechanical resonator functionalized with switchable magnetic molecules...
May 22, 2018: Scientific Reports
Cristina Ocaña, Natalia Abramova, Andrey Bratov, Tom Lindfors, Johan Bobacka
We report here the fabrication of solid-contact calcium-selective electrodes (Ca2+ -SCISEs) made of a polyurethane acrylate ion-selective membrane (ISM) that was covalently attached to the underlying ion-to-electron transducer (solid-contact). Methacrylate-functionalized poly(3,4-ethylenedioxythiophene) (Meth-PEDOT) and Meth-PEDOT films containing either multiwalled carbon nanotubes (MWCNT) or carboxylated MWCNT (cMWCNT) were used as solid contacts. The solid contacts were deposited by drop-casting on screen-printed electrodes and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and potentiometry...
August 15, 2018: Talanta
Daryna Smyrnova, María Del Carmen Marín, Massimo Olivucci, Arnout Ceulemans
A set formed by five reversibly-switchable fluorescent proteins (RSFPs) display spread over 40~nm in absorption maxima and only 18~nm in emission. The five proteins -- Dronpa, rsFastLime, rsKame, Padron(anionic form) and bsDronpa -- carry exactly the same chromophore and differ just in a few mutations. Thus they form an ideal set for mechanistic investigation. Starting with the results of molecular dynamics simulations we use QM/MM calculations to investigate the effects controlling the spectral tuning . In this contribution we show that the models, which are based on CASPT2//CASSCF level of QM theory, reproduce the observed absorption trend with only a limited blue-shift of 4...
May 17, 2018: Journal of Chemical Theory and Computation
Gerard Planes Conangla, Andreas W Schell, Raul A Rica, Romain Quidant
Levitation optomechanics exploits the unique mechanical properties of trapped nano-objects in vacuum in order to address some of the limitations of clamped nanomechanical resonators. In particular, its performance is foreseen to contribute to a better understanding of quantum decoherence at the mesoscopic scale as well as to lead to novel ultra-sensitive sensing schemes. While most efforts have so far focused on optical trapping of low absorbing silica particles, further opportunities arise from levitating objects with internal degrees of freedom like color centers...
May 17, 2018: Nano Letters
Ming Wu, Xinyi Lin, Xionghong Tan, Jiong Li, Zuwu Wei, Da Zhang, Youshi Zheng, Ai-Xian Zheng, Bixing Zhao, Yongyi Zeng, Xiaolong Liu, Jingfeng Liu
Pre-release of RNA molecules than chemotherapeutic drugs with a sufficient interval is a vital prerequisite for RNA/drug co-delivery strategy to overcome multidrug resistance (MDR) of cancer cells, but how to precisely control their release at different time points is still a grand challenge up to now. This study aims to on-demand remotely manipulate RNA and drug release in real time through single delivery system to sequentially play their respective roles for optimizing and enhancing their synergistic antitumor effects...
May 17, 2018: ACS Applied Materials & Interfaces
Marina Saito, Kentaro Miyamoto, Yusuke Uchiyama, Ikuya Murakami
The natural blind spot in the visual field has been known as a large oval region that cannot receive any optical input because it corresponds to the retinal optic disk containing no rod/cone-photoreceptors. Recently, stimulation inside the blind spot was found to enhance, but not trigger, the pupillary light reflex. However, it is unknown whether blind-spot stimulation also affects visual perception. We addressed this question using psychophysical brightness-matching experiments. We found that a test stimulus outside the blind spot was judged as darker when it was accompanied by a consciously unexperienced blue oval inside the blind spot; moreover, the pupillary light reflex was enhanced...
May 15, 2018: Scientific Reports
Álvaro González-Vila, Andreas Ioannou, Médéric Loyez, Marc Debliquy, Driss Lahem, Christophe Caucheteur
Surface plasmon resonance excitation with optical fiber gratings has been typically studied in aqueous solutions. This work describes the procedure to excite a plasmon wave in gaseous media and perform refractive index measurements in these environments. Grating photo-inscription with 193 nm excimer laser radiation allows us to obtain slightly tilted fiber Bragg gratings exhibiting a cladding mode resonance comb along several hundreds of nanometers. Their refractive index sensitive range extends from gases to liquids, so operation in both media is compared...
May 15, 2018: Optics Letters
Hossein Emami, Mohammadreza Hajihashemi, Sayed Ehsan Alavi, Abu Sahmah Mohd Supaat
A microwave photonics instantaneous frequency measurement receiver was conceived and practically demonstrated. The system is based on phase modulation inside a Sagnac loop and therefore needs no bias voltage, resulting in no DC bias drifts. The system provides a DC output whose amplitude is a function of input signal frequency, and thus no high-frequency photo-detector is required. Furthermore, the system exhibits a very good sensitivity without the aid of any sort of electrical noise cancellation techniques, such as lock-in amplification...
May 15, 2018: Optics Letters
Guobin Mao, Chen Liu, Mingyuan Du, Yuwei Zhang, Xinghu Ji, Zhike He
Galactose oxidase is a copper-activated enzyme and have a vital role in metabolism of galactose. Much of the work is focused on determining the amount of galactose in the blood rather than measuring the amount of galactose oxidase to urge the galactosemia patients to restrict milk intake. Here, a simple and effective method was developed for Cu2+ and copper-activated enzyme detection based on homogenous alloyed CdZnTeS quantum dots (QDs). Meso- 2,3-dimercaptosuccinic acid (DMSA) was used as the reducing agent for preparing QDs and the highest quantum yield of CdZnTeS QDs was 69...
August 1, 2018: Talanta
Ekaterina N Zorina-Tikhonova, Aleksandr S Chistyakov, Mikhail A Kiskin, Aleksei A Sidorov, Pavel V Dorovatovskii, Yan V Zubavichus, Eugenia D Voronova, Ivan A Godovikov, Alexander A Korlyukov, Igor L Eremenko, Anna V Vologzhanina
Photoinitiated solid-state reactions are known to affect the physical properties of coordination polymers, such as fluorescence and sorption behaviour, and also afford extraordinary architectures ( e.g. three-periodic structures with polyorganic ligands). However, the construction of novel photo-sensitive coordination polymers requires an understanding of the factors which govern the mutual disposition of reactive fragments. A series of zinc(II) malonate complexes with 1,2-bis(pyridin-4-yl)ethylene and its photo-insensitive analogues has been synthesized for the purpose of systematic analysis of their underlying nets and mutual disposition of N -donor ligands...
May 1, 2018: IUCrJ
Qingming Wang, Yingzi Tan, Nianhua Wang, Zhixiang Lu, Wenling Wang
A fluorescence probe based on thiosemicarbazide has been synthesized and well characterized by 1 H NMR, 13 C NMR, Elemental analysis, Electrospray ionization mass spectra. The probe 1 functions as a multitarget ion sensor, detect biologically and ecologically important Cd2+ , PO4 3- and Cr3+ . Meanwhile, probe 1 displays selectivity for Cd2+ over other metal ions and anions in DMF by emission spectrum. Interestingly, probe 1 has been explored to recognize PO4 3- in CH3 OH-H2 O (v:v = 1:9). The binding stoichiometry of probe 1 with Cd2+ and PO4 3- are 2:1 and 1:1, respectively, which are confirmed by Electrospray ionization mass spectra...
May 7, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Achillefs N Kapanidis, Stephan Uphoff, Mathew Stracy
Protein diffusion is crucial for understanding the formation of protein complexes in vivo, and has been the subject of many fluorescence microscopy studies in cells; however, such microscopy efforts are often limited by low sensitivity and resolution. During the past decade, these limitations have been addressed by new super-resolution imaging methods, most of which rely on single-particle tracking and single-molecule detection; these methods are revolutionizing our understanding of molecular diffusion inside bacterial cells by directly visualizing the motion of proteins and the effects of the local and global environment on diffusion...
May 10, 2018: Journal of Molecular Biology
Xiaohong Wang, Sheng Song, Lei Chen, Christopher M Stafford, Jirun Sun
Resin biostability is of critical importance to the durability of methacrylate-based dental resin restorations. Current methods for evaluating biostability take considerable time, from weeks to months, and provide no short-time kinetics of resin degradation. The objective of this study is to develop a more sensitive method to assess resin biostability over short-time spans (hours to days) that will enhance our understanding of biostability and its resin chemistry. Ultra-flat resin films of equimolar urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA) are produced through photo-curing between two flat surfaces...
May 8, 2018: Acta Biomaterialia
Akanksha Sehgal, Kumari Sita, Kalpna Bhandari, Shiv Kumar, Jitendra Kumar, P V Vara Prasad, Kadambot H M Siddique, Harsh Nayyar
Terminal droughts, along with high temperatures, are becoming more frequent to strongly influence the seed development in cool-season pulses like lentil. In the present study, the lentil plants, growing outdoors under natural environment were subjected to following treatments at the time of seed filling till maturity (a): 28/23°C; day/night temperature as controls. (b): drought-stressed; plants maintained at 50% field capacity, under the same growth conditions as in (a). (c): heat-stressed; 33/28°C; day/night temperature, under the same growth conditions as in (a)...
May 9, 2018: Plant, Cell & Environment
Xiao Xiang, Jihwan Kim, Michael J Escuti
Optical films and surfaces using geometric phase are increasingly demonstrating unique and sometimes enhanced performance compared to traditional elements employing propagation phase. Here, we report on a diffraction grating with wider angular bandwidth and significantly higher average first-order efficiency than the nearest prior art of metasurfaces, volume holographic gratings, and surface-relief gratings configured to achieve a steep deflection angle. More specifically, we demonstrate a liquid crystal (LC) polymer Bragg polarization grating (PG) with large angular bandwidth and high efficiency in transmission-mode for 532 nm wavelength and 400 nm period...
May 8, 2018: Scientific Reports
Longqing Sun, Genlou Sun, Chenxia Shi, Dongfa Sun
BACKGROUND: 337S is a novel bi-pole-photo-thermo-sensitive genic male sterile line in wheat, and sensitive to both long day length/high temperature and short day length/low temperature condition. Although the regulatory function of MicroRNAs (miRNAs) in reproductive development has been increasingly studied, their roles in pre-meiotic and meiotic cells formation of plants have not been clearly explored. Here, we explored the roles of miRNAs in regulating male sterility of 337S at short day length/low temperature condition...
May 8, 2018: BMC Genomics
Maha F Abdel-Ghany, Miriam F Ayad, Mariam M Tadros
Stability-indicating high-performance liquid chromatography (HPLC) and spectrofluorimetric methods were developed for determination of empagliflozin (EGF). EGF was subjected to oxidation, wet heat, photo-degradation, acid hydrolysis and alkali hydrolysis. The alkaline degradation pathway was subjected to a kinetics study as the major product obtained after stress conditions. Arrhenius plots were constructed and the activation energies of the degradation process were calculated. HPLC was used for the kinetic study as it enabled simultaneous determination of EGF and the degradation product while the spectrofluorimetric assay was applied to content uniformity testing due to its higher sensitivity and lower limit of detection (LOD)...
May 7, 2018: Luminescence: the Journal of Biological and Chemical Luminescence
Shun-Wen Cheng, Ting Han, Teng-Yung Huang, Yu-Hsin Chang Chien, Cheng-Liang Liu, Ben Zhong Tang, Guey-Sheng Liou
A novel aggregation enhanced emission (AEE)-active polyamide TPA-CN-TPE with a high photoluminesence characteristic was successfully synthesized by the direct polymerization of 4-cyanotriphenyl diamine (TPA-CN) and tetraphenylethene (TPE)-containing dicarboxylic acid. The obtained luminescent polyamide plays a significant role as the polymer electret layer in organic field-effect transistors (OFET)-type memory. The strong green emission of TPA-CN-TPE under ultraviolet (UV) irradiation can be directly absorbed by the pentacene channel, displaying a light-induced programming and voltage-driven erasing organic phototransistor-based non-volatile memory...
May 7, 2018: ACS Applied Materials & Interfaces
Yung-Kang Peng, Hung-Lung Chou, Shik Chi Edman Tsang
As the chemical state of titanium on the surface of TiO2 can be tuned by varying its host facet and surface adsorbate, improved performance has been achieved in fields such as heterogeneous (photo)catalysis, lithium batteries, dye-sensitized solar cells, etc. However, at present, no acceptable surface technique can provide information about the chemical state and distribution of surface cations among facets, making it difficult to unambiguously correlate facet-dependent properties. Even though X-ray photoelectron spectroscopy (XPS) is regarded as a sensitive surface technique, it collects data from the top few layers of the sample, instead of a specific facet, and hence fails to distinguish small changes in the chemical state of Ti imposed by adsorbates on a facet...
March 7, 2018: Chemical Science
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