bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strontium Niobate for Near‐Infrared Plasmonics
Authors: Dutta Aveek , Wan Dongyang , Yan Bixing , Shalaev Vladimir M. , Venkatesan Thirumalai , Boltasseva Alexandra 
Published: July 2019

AbstractPlasmonics has developed greatly over the past two decades, and a plethora of plasmonic materials has been explored for practical plasmonic devices across various applications. While noble metals such as gold and silver are the most widely used plasmonic materials, other metals such as aluminum, copper, and magnesium have also been proposed as building blocks for plasmonics. Transparent conducting oxides (TCOs) such as aluminum‐ and gallium‐doped zinc oxide and tin‐doped indium oxide have been suggested for plasmonic applications in the near infrared (NIR) spectrum. These materials have lower carrier concentration than noble metals and therefore have lower material losses at the NIR. In this paper, strontium niobate (SNO) is showcased as an addition to the material database for plasmonics in the NIR. SNO plasmonic properties are studied through experimental demonstration of hybrid plasmon resonances in SNO films. Such resonances are characterized by electromagnetic field concentration in a low‐index dielectric, sandwiched between a high‐index dielectric resonator and a plasmonic metal. The results show that although SNO bulk film has an order of magnitude greater carrier concentration than TCOs, its losses are only a few times higher than in TCO materials thus holding a promise for plasmonic applications in the NIR.
Solution‐Processed Perovskite Microdisk for Coherent Light Emission
Authors: Li Xiaojun , Zhang Xuanjun , Li Haifeng , Liu Tanghao , Zhao Dandan , Liang Chao , Xing Guichuan , Tang Zikang 
Published: July 2019

AbstractHigh‐quality semiconductor microdisks (MDs) are of crucial importance for realizing on‐chip coherent light sources. However, the fabrication of all‐inorganic semiconductor circular or circular‐like microdisks (CMDs) with suitable size for optoelectronic applications is still complex and expensive. Herein, a facile ligand‐free antisolvent‐assisted growth method is used to synthesize high‐quality Cs4PbBr6 MDs with tunable size and morphology, which is evolved from rhombohedral to octahedral, hexagonal‐like, and circular‐like MDs based on Cl‐containing antisolvents. Significantly, this is the first time that large semiconductor CMDs are synthesized from solution self‐assembled growth at room temperature. These Cs4PbBr6 MDs show high‐efficient and stable green emission (522 nm), which should be attributed to the first‐order excitonic emission from embedded CsPbBr3 nanocrystals (NCs). The distribution of CsPbBr3 NCs is verified by lattice fringe, crystal data refinement, and time‐resolved photoluminescence analysis. These CsPbBr3‐in‐Cs4PbBr6 CMDs are demonstrated to hold outstanding two‐photon pumped coherent light emission ability with a remarkably low threshold (400 µJ cm−2). These findings suggest CsPbBr3‐in‐Cs4PbBr6 MDs have excellent light emission capability and stability toward practical optoelectronic applications, and their tunable morphology and size indicate that solution method is feasible for the fabrication of semiconductor CMDs.
Further Examination of Interconnection in Conjugated Polymers for Organic Field‐Effect Transistors
Authors: Yang Hau‐Ren , Lai Yu‐Ying , Lee Jey‐Jau 
Published: July 2019

AbstractConventional design principles toward conjugated polymers aiming at high organic field‐effect‐transistor (OFET) mobilities are directed at the establishment of extensive edge‐on π‐order. However, emerging principles state that efficient charge transport can be established through interconnected short‐range‐order polymer crystallites. Fractional side‐chain truncation has been employed to furnish numerous polymers. The electronic structures of the polymers are insensitive to side‐chain variation, whereas the thermal and morphological properties respond to it significantly. As the butyl side chain in the polymer backbone increases in size, the π‐order of the corresponding polymer thin film decreases gradually, while the π‐interconnection is enhanced. Moreover, the π‐anisotropy is transformed from face‐on to isotropy, which can be rationalized by the geometric shape of polymer crystallite. The OFET results disclose the beneficial effect of π‐interconnection to enhance the electron mobility. The significant role of π‐interconnection in the transport is further emphasized. An electron mobility of 0.31 cm2 V−1 s−1 is accomplished, strongly suggesting that the modulation of π‐interconnection by fractional side‐chain truncation can serve as a straightforward approach to improving OFET electron mobility.
Jenseits von Ladungsausgleich: Gegenkationen in der Polyoxometallat‐Chemie
Authors: Misra Archismita , Kozma Karoly , Streb Carsten , Nyman May 
Published: July 2019

AbstractPolyoxometallate (POMs) sind molekulare Metalloxidanionen, die Anwendung in Energiewandlung und ‐speicherung, biomolekularer Chemie sowie Materialdesign und ‐integration finden. Das Wechselspiel von intrinsisch anionischen POMs mit organischen oder anorganischen Gegenionen wird häufig übersehen, ist jedoch essenziell, um die Aggregation, Stabilisierung, Löslichkeit und Funktion von POMs zu verstehen. Jenseits von einfachen Alkalimetall‐ oder Ammoniumkationen können neuartige Anwendungen durch vielseitige Kationen wie Dendrimere, mehrwertige Metallkationen, Metallkomplexe, Amphiphile oder Alkaloidkationen erzielt werden. Dieser Aufsatz gibt einen Überblick über grundlegende POM‐Kation‐Wechselwirkungen in Lösung, die daraus resultierenden Festkörperstrukturen und bespricht neuartige Reaktivitäten und Eigenschaften, die aus diesen Wechselwrkungen resultieren. Wir untersuchen, wie anwendungsnahe Forschung das Kation‐kontrollierte Design neuartiger POM‐Materialien ermöglicht hat, was wiederum den Wunsch nach der Aufklärung der Grundlagen von POM‐Kation‐Wechselwirkungen angeregt hat.
Highly Enantioselective Catalytic Addition of Grignard Reagents to N‐Heterocyclic Acceptors
Authors: Guo Yafei , Harutyunyan Syuzanna R. 
Published: July 2019

AbstractGeneral methods to prepare chiral N‐heterocyclic molecular scaffolds are greatly sought after because of their significance in medicinal chemistry. Described here is the first general catalytic methodology to access a wide variety of chiral 2‐ and 4‐substituted tetrahydro‐quinolones, dihydro‐4‐pyridones, and piperidones with excellent yields and enantioselectivities, utilizing a single catalyst system.
A Threonine‐Forming Oxazetidine Amino Acid for the Chemical Synthesis of Proteins through KAHA Ligation
Authors: Baldauf Simon , Schauenburg Dominik , Bode Jeffrey W. 
Published: July 2019

Abstractα‐Ketoacid‐hydroxylamine (KAHA) ligation allows the coupling of unprotected peptide segments through the chemoselective formation of an amide bond. Currently, the most widely used variant employs a 5‐membered cyclic hydroxylamine that forms a homoserine ester as the primary ligation product. In order to directly form amide‐linked threonine residues at the ligation site, we prepared a new 4‐membered cyclic hydroxylamine building block. This monomer was applied to the synthesis of wild‐type ubiquitin‐conjugating enzyme UbcH5a (146 residues) and Titin protein domain TI I27 (89 residues). Both the resulting UbcH5a and the variant with two homoserine residues showed identical activity to a recombinant variant in a ubiquitination assay.
Drug Design – An experiment for chemistry class during preparation for the A‐levels
Authors: Hoffmann Heiko , Tausch Michael W. , Lühken Arnim 
Published: July 2019

AbstractDie Entwicklung neuer Arzneistoffe ist ein mit Blick auf den Gymnasialunterricht möglicher Kontext mit hohem Lebensweltbezug. Ein Lehrexperiment, basierend auf dem käuflich erhältlichen Modell‐Zielmolekül Trypsin und mehreren Inhibitoren, ist mit in der Schule verfügbaren Methoden auf einfache und robuste Weise durchführbar. Es verdeutlicht den Kern des rationalen Wirkstoffdesigns (rational drug design), nämlich die planvolle Variation der molekularen Struktur zur Erhöhung der Bindungsaffinität an die Substituenten in der Bindetasche des Zielmoleküls, durch Erhöhung der Summe an intermolekularen Wechselwirkungen. Somit wird für Schülerinnen und Schüler nachvollziehbar, wie genau neue Arzneimittel auf molekularer Ebene erdacht bzw. erarbeitet werden.
Bone scan index can be a useful biomarker of survival outcomes in patients with metastatic castration‐resistant prostate cancer treated with radium‐223
Authors: Naito Miki , Ukai Rinzo , Hashimoto Kunihiro 
Published: July 2019

AbstractBackgroundBone metastasis of prostate cancer is associated with pain and reduced overall survival (OS). Radium‐223, which is expected to reduce bone pain and prolong OS, was recently approved in Japan.AimThe aim of this study was to investigate the usefulness of the bone scan index by comparing the outcomes and factors according to response in Japanese patients treated with radium‐223.Methods and resultsTwenty patients receiving radium‐223 were divided into two groups according to whether they did or did not achieve a bone scan index decrease of at least one point (beneficial and non‐beneficial groups, respectively). The clinical characteristics at baseline and after three and six treatment cycles were compared using χ2 tests and Student's t‐tests or Mann–Whitney U tests, and survival was estimated and compared using the Kaplan–Meier method and log‐rank test, respectively. Fourteen (70%) and six patients (30%) were categorized into the beneficial and non‐beneficial groups, respectively. Patients in the former group were significantly more likely to have a higher Eastern Cooperative Oncology Group performance status score and receive a greater number of radium‐223 injections (P < 0.05). Furthermore, patients in the beneficial group had a significantly longer OS (P < 0.05). Regarding safety, one and three patients in the beneficial and non‐beneficial groups, respectively, prematurely discontinued radium‐223 because of an increased prostate‐specific antigen level, decreased hemoglobin level, or femoral fracture.ConclusionRadium‐223 appears generally safe in this population. Patients with good bone scan index response have better performance status, receive more injections of radium‐223, and achieve OS prolongation. Bone scan index is a useful biomarker of survival outcomes and can be a valuable assessment tool in patients with metastatic castration‐resistant prostate cancer who are treated with radium‐223.
Ultrathin Silicon Oxide Film‐Induced Enhancement of Charge Separation and Transport of Nanostructured Titanium(IV) Oxide Photoelectrode
Authors: Akita Atsunobu , Kobayashi Hisayoshi , Tada Hiroaki 
Published: July 2019

AbstractThe development of nanostructured semiconductor electrodes represented by a mesoporous TiO2 nanocrystalline (mp‐TiO2) film is currently bringing great progresses in photoelectrochemical (PEC) devices for solar‐to‐electricity and solar‐to‐chemical conversion. Two serious losses can occur in PEC devices: 1) recombination between the conduction band (CB) electrons and valence band (VB) holes in the bulk and at the surface and 2) back reaction or electron trapping by oxidant in the electrolyte solution during transport to the electron‐collecting electrode. Thus, the major challenge in common with the nanostructured semiconductor photoanodes is to achieve efficient charge separation and electron transport. In this study, an ultrathin SiOx layer was formed on both the external and the internal surface of mp‐TiO2 using an original chemisorption‐calcination technique employing 1,3,5,7‐tetramethyltetrasiloxane as a starting material. The SiOx surface modification of the mp‐TiO2 photoanode drastically prolongs the mean lifetime of CB‐electrons in TiO2 because of enhanced charge separation and electron transport by the negative charge applied in aqueous electrolyte solution. We have demonstrated that the performance of a one‐compartment H2O2‐photofuel cell using mp‐TiO2 as the photoanode is greatly boosted by the surface modification with the SiOx layer. We anticipate that this methodology is widely applicable to nanostructured metal oxide semiconductor electrodes, contributing to the improvement in the performance of PEC devices.
On the resilience of P2P botnet footprints in the presence of legitimate P2P traffic
Authors: Faraji Daneshgar Fateme , Abbaspour Maghsoud 
Published: July 2019

SummaryBotnet is a distributed platform for illegal activities severely threaten the security of the Internet. Fortunately, although their complicated nature, bots leave some footprints during the C&C communication that have been utilized by security researchers to design detection mechanisms. Nevertheless, botnet designers are always trying to evade detection systems by leveraging the legitimate P2P protocol as C&C channel or even mimicking legitimate peer‐to‐peer (P2P) behavior. Consequently, detecting P2P botnet in the presence of normal P2P traffic is one of the most challenging issues in network security. However, the resilience of P2P botnet detection systems in the presence of normal P2P traffic is not investigated in most proposed schemes. In this paper, we focused on the footprint as the most essential part of a detection system and presented a taxonomy of footprints utilized in behavioral P2P botnet detection systems. Then, the resilience of mentioned footprints is analyzed using three evaluation scenarios. Our experimental and analytical investigations indicated that the most P2P botnet footprints are not resilient to the presence of legitimate P2P traffic and there is a pressing need to introduce more resilient footprints.
The freshwater biome gradient framework: predicting macroscale properties based on latitude, altitude, and precipitation
Authors: Dodds Walter K. , Bruckerhoff Lindsey , Batzer Darold , Schechner Anne , Pennock Casey , Renner Elizabeth , Tromboni Flavia , Bigham Kari , Grieger Samantha 
Published: July 2019

AbstractUnderstanding global ecological patterns and processes, from biogeochemical to biogeographical, requires broad‐scale macrosystems context for comparing and contrasting ecosystems. Climate gradients (precipitation and temperature) and other continental‐scale patterns shape freshwater environments due to their influences on terrestrial environments and their direct and indirect effects on the abiotic and biotic characteristics of lakes, streams, and wetlands. We combined literature review, analyses of open access data, and logical argument to assess abiotic and biotic characters of freshwater systems across gradients of latitude and elevation that drive precipitation, temperature, and other variability. We explored the predictive value of analyzing patterns in freshwater ecosystems at the global macrosystems scale. We found many patterns based on climate, particularly those dependent upon hydrologic characteristics and linked to characteristics of terrestrial biomes. For example, continental waters of dry areas will generally be widely dispersed and have higher probability of drying and network disconnection, greater temperatures, greater inorganic turbidity, greater salinity, and lower riparian canopy cover relative to areas with high precipitation. These factors will influence local community composition and ecosystem rates. Enough studies are now available at the continental or global scale to start to characterize patterns under a coherent conceptual framework, though considerable gaps exist in the tropics and less developed regions. We present illustrative global‐scale trends of abiotic, biotic, and anthropogenic impacts in freshwater ecosystems across gradients of precipitation and temperature to further understanding of broad‐scale trends and to aid prediction in the face of global change. We view freshwater systems as occurring across arrays of multiple gradients (including latitude, altitude, and precipitation) rather than areas with specific boundaries. While terrestrial biomes capture some variability along these gradients that influence freshwaters, other features such as, slope, geology, and historical glaciation also influence freshwaters. Our conceptual framework is not so much a single hypothesis as a way to logically characterize patterns in freshwaters at scales relevant to (1) evolutionary processes that give rise to freshwater biodiversity, (2) regulatory units that influence freshwater ecosystems, and (3) the current scope of anthropogenic impacts on freshwaters and the vital ecosystem services they provide.
N‐terminal pro brain natriuretic peptide eliminates the prognostic effect of atrial fibrillation in patients with chronic heart failure
Authors: Schnorbach Johannes , Fröhlich Hanna , Täger Tobias , Corletto Anna , Katus Hugo A. , Frankenstein Lutz 
Published: July 2019

AbstractAimsCo‐morbid atrial fibrillation (AF) increases both mortality and N‐terminal pro brain natriuretic peptide (NT‐proBNP) concentrations in patients with chronic heart failure (CHF). It is unclear whether AF worsens prognosis independently from NT‐proBNP concentrations. If AF was an independent risk factor, NT‐proBNP levels for outcome prediction would need to be adjusted in patients with AF. We aimed to analyse the influence of AF on the prognostic value of NT‐proBNP in patients with CHF.Methods and resultsA total of 2541 consecutive CHF patients with sinus rhythm (SR) or AF were identified in the outpatients' CHF registry of the University of Heidelberg, Germany. Of these, 250 patients with SR were individually matched to 250 patients with AF with respect to NT‐proBNP, New York Heart Association functional class, sex, age, and aetiology of CHF. In the general sample, both AF and NT‐proBNP were associated with all‐cause mortality [hazard ratio (HR) = 1.96, 95% confidence interval (CI) 1.61–2.39, P < 0.001; and HR = 1.03 per 1000 ng/L increase, 95% CI 1.02 to 1.04, P < 0.001, respectively]. After matching, NT‐proBNP retained its prognostic power (HR = 1.13 per 1000 ng/L increase, 95% CI 1.10 to 1.16, P < 0.001), but AF did not (HR = 0.91, 95% CI 0.66 to 1.25, P = 0.56). Despite similar prognosis, matched patients with SR were in more advanced CHF than were AF patients as indicated by a lower left ventricular ejection fraction (30 ± 13% vs. 34 ± 14%, P < 0.001).ConclusionsThe prognostic value of NT‐proBNP in CHF is not influenced by concomitant AF. AF, in return, might be a surrogate of a worse cardiac condition rather than an independent risk factor.
Electrocatalytic and Biosensing Properties of Aerobic Carbon Monoxide Dehydrogenase from Hydrogenophaga Pseudoflava Immobilized on Au Electrode towards Carbon Monoxide Oxidation
Authors: Reginald Stacy Simai , Lee Yoo Seok , Lee Hyeryeong , Jang Nulee , Chang In Seop 
Published: July 2019

AbstractHerein, an enzyme‐electrode based on the oxygen‐insensitive carbon monoxide dehydrogenase (CODH) containing molybdenum (Mo) and copper (Cu), flavin adenine dinucleotide (FAD) and two different [2Fe‐2 S] clusters as cofactors from the aerobic bacterium Hydrogenophaga pseudoflava, is proposed as a platform for dissolved CO concentration monitoring. The immobilized CODHs on Au electrode retain their catalytic activity and demonstrates changes to cyclic voltammetry and amperometry signals upon interactions with various dissolved CO concentrations. Cyclic voltammetry shows that CODHs are capable of direct electron transfer without any mediator use as oxidative current which starts around −0.268 V (vs Ag/AgCl) is observed in the presence of CO. When CO‐saturated standard solution was spiked sequentially into the gas‐tight reactor, amperometry analysis shows current increased accordingly with response time within 5 s. Our study demonstrates that this enzyme‐electrode is promising to serve as platform for developing an on‐line dissolved CO concentration monitoring tool which is essential to fill in the gap for conventional technologies which are limited to off‐line measurement.
Electrochemical Sensor Based on Thioether Oligomer Poly(N‐vinylpyrrolidone)‐modified Gold Electrode for Bisphenol A Detection
Authors: Aberkane Fairouz , Barakat Abdoullatif , Elaissari Abdelhamid , Zine Nadia , Bendaikha Tahar , Errachid Abdelhamid 
Published: July 2019

AbstractPresently, bisphenol A (BPA) has been added to the list of substances of very high concern as endocrine disruptors. According to the literature, exposure to bisphenol A even at low doses may result in adverse health effects. In this study, electrochemical sensor of Bisphenol A based on thioether DDT‐Poly(N‐vinylpyrrolidone) oligomer has been developed. The thioether oligomer, which is capable of recognizing BPA, was prepared and used for gold electrode modification. The characterization of the modified gold electrode and the synthesized thioether oligomer were carried out by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR) and Size exclusion chromatography (SEC). Obtained results indicate that the modified electrode shows good electrochemical activity, good sensitivity and reproducibility for BPA detection. It exhibited a good linear relationship ranging from 1 to 20 pg/mL, and the detection limit was found to be 1.9 pg/mL at S/N=3. Several interfering species such as hydroquinone, phenol and resorcinol were used and their behaviors on the modified gold electrode were investigated.
Voltammetric Label‐free Detection of DNA Hypermethylation Using Polypyrrole‐modified Microelectrode Array
Authors: Meronard Kenton , Josowicz Mira , Saheb Amir 
Published: July 2019

AbstractAn alternative strategy for the label‐free electrochemical detection of DNA hypermethylation using a microelectrode array as an oligodinucleotide (ODN) detector is presented. It relies on the oligonucleotide dependent electrostatic affinity interaction firstly with unmethylated ODN and then follow‐up with methylated DNA. The methylated cytosine status is quantified by monitoring the relative change in the exchange current at the ODN‐detector before and after the bisulfite treated DNA samples. This novel aproach displays unique advantages such as small working volumes of the analytes, low damage to DNA samples, easy integration of oligonucleides on the detector and signal evaluation.
Electrochemical Detection of Droplets in Microfluidic Devices: Simultaneous Determination of Velocity, Size and Content
Authors: Lombardo Teo , Lancellotti Lidia , Souprayen Christelle , Sella Catherine , Thouin Laurent 
Published: July 2019

AbstractMicrofluidic devices were designed to electrochemically detect in a two‐phase flow the velocity, size and content of aqueous droplets containing redox species. The principle of these determinations is based on the analysis of a unique chronoamperometric response recorded during the passage of a droplet over channel microelectrodes. Two configurations of electrochemical cell with different geometries were investigated both theoretically and experimentally. Velocity and size of droplets, as well as internal recirculating convection within droplets, were evaluated from chronoamperometric curves by specific transition times depending on the cell configuration. In addition, the droplet content was probed from the Faradaic current controlled by mass transport and by internal hydrodynamic regime. For droplet velocity and size, experimental data were systematically compared to optical measurements. All the results demonstrated the high performance of the electrochemical detection reached under these conditions. They successfully validate the concept of self‐consistent electrochemical detections of aqueous droplets within microchannels for the simultaneous determination of their velocity, size and content.