bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cognitive testing of an instrument to evaluate acceptability and use of pre‐exposure prophylaxis products among women
Authors: Zissette Seth , Atujuna Millicent , Tolley Elizabeth E. , Okumu Eunice , Auerbach Judith D. , Hodder Sally L. , Aral Sevgi O. , Adimora Adaora A. 
Published: July 2019

SummaryGiven the range of pre‐exposure prophylaxis (PrEP) products currently being tested to prevent HIV in women, a standardized Acceptability and Use of PrEP Products Among Women Tool may facilitate comparisons of product acceptability and use across different geographies, trials, and users. We conducted three rounds of cognitive interviewing over 2 months in 2016, with 28 South African women who had experience participating in a range of PrEP product trials. The final instrument contained 41 items, including five new items that improved construct validity and 22 items modified for clarity. Changes were made due to unclear wording, difficulty answering, participant embarrassment, low response variability, and administrative formatting. Cognitive interviewing provided a means to address issues that would have inhibited this tool's ability to accurately collect data otherwise. This rapid, low‐cost study provided valuable insight into participants' understanding of questions and demonstrated the utility of cognitive interviewing in international clinical trials.
Comparison of Ultrasound Features of Major Salivary Glands in Sarcoidosis, Amyloidosis, and Sjögren's Syndrome
Authors: Law Shing T. , Jafarzadeh S. Reza , Govender Praveen , Sun Xianbang , Sanchorawala Vaishali , Kissin Eugene Y. 
Published: July 2019

ObjectiveWhile salivary gland ultrasound (SGU) has gained prominence for evaluating Sjögren's syndrome, little information exists on SGU appearance of sarcoidosis and amyloidosis, potential mimics of Sjögren's syndrome. Our goal in this study was to estimate the diagnostic accuracy of major SGU features in differentiating Sjögren's syndrome from sarcoidosis, amyloidosis, and controls.MethodsWe enrolled consecutive adult ambulatory patients with a clinical diagnosis of Sjögren's syndrome fulfilling the 2016 American College of Rheumatology (ACR) classification criteria; we also enrolled patients with a clinical diagnosis of sarcoidosis or systemic immunoglobulin light chain (AL) amyloidosis, with histologic confirmation from any tissue, and rheumatology outpatients without diagnoses affecting salivary glands. Subjects underwent major SGU using the Hočevar protocol, with resulting video clips reviewed blind to clinical diagnosis.ResultsSjögren's syndrome SGU scores were greater than in patients from the other groups, but there were no distinguishing salivary gland features from AL amyloidosis or sarcoidosis. None of the patients in the control group scored higher than 17, a cutoff previously suggested for Sjögren's syndrome, but 27% of patients with AL amyloidosis and 19% with sarcoidosis scored higher than 17. Adding Hočevar SGU scores of ≥17 to the 2016 ACR/European League Against Rheumatism criteria in a parallel scheme increased the sensitivity for Sjögren's syndrome from 87% to 98%, while combining the 2 criteria in series increased specificity from 81% to 98%.ConclusionSjögren's syndrome, sarcoidosis, and AL amyloidosis share common SGU features that can help distinguish these conditions from patients without systemic rheumatologic disease. Clinicians should carefully consider these potential mimics when interpreting salivary gland US results.
Structurally Ordered Low‐Pt Intermetallic Electrocatalysts toward Durably High Oxygen Reduction Reaction Activity
Authors: Wang Zhongxiang , Yao Xiaozhang , Kang Yongqiang , Miao Linqing , Xia Dongsheng , Gan Lin 
Published: July 2019

AbstractCarbon‐supported low‐Pt ordered intermetallic nanoparticulate catalysts (PtM3, M = Fe, Co, and Ni) are explored in order to enhance the oxygen reduction reaction (ORR) activity while achieving a high stability compared to previously reported Pt‐richer ordered intermetallics (Pt3M and PtM) and low‐Pt disordered alloy catalysts. Upon high‐temperature thermal annealing, ordered PtCo3 intermetallic nanoparticles are successfully prepared with minimum particle sintering. In contrast, the PtFe3 catalyst, despite the formation of ordered structure, suffers from obvious particle sintering and detrimental metal–support interaction, while the PtNi3 catalyst shows no structural ordering transition at all but significant particle sintering. The ordered PtCo3 catalyst exhibits durably thin Pt shells with a uniform thickness below 0.6 nm (corresponding to 2–3 Pt atomic layers) and a high Co content inside the nanoparticles after 10 000 potential cycling, leading to a durably compressive Pt surface and thereby both high activity (fivefold vs a commercial Pt catalyst and 1.7‐fold vs an ordered PtCo intermetallic catalyst) and high durability (5 mV loss in half‐wave potential and 9% drop in mass activity). These results provide a new strategy toward highly active and durable ORR electrocatalysts by rational development of low‐Pt ordered intermetallics.
Real‐Time Imaging of Nanoscale Redox Reactions over Bimetallic Nanoparticles
Authors: Tan Shu Fen , Chee See Wee , Baraissov Zhaslan , Jin Hongmei , Tan Teck Leong , Mirsaidov Utkur 
Published: July 2019

AbstractThe catalytic performance of bimetallic nanoparticles (NPs) strongly depends on their structural and compositional changes under reaction conditions. At the fundamental level, these changes are driven by redox reactions that occur on the surface of the NPs. The degree of complexity in the redox reactions is further amplified in bimetallic NPs because both metals can have their own reactions with the reactant molecules, in addition to any synergistic effects between the metal nanocatalysts and their reducible oxides. Here, the gas phase oxidation and reduction reactions, and the oxidation of carbon monoxide (CO) over Pt–Ni rhombic dodecahedron NPs with segregated Pt frames and Pt–Ni alloy NPs are investigated using in situ gas cell transmission electron microscopy. The real‐time observations show that NiO shell formation and Pt segregation are two important features during the oxidation and reduction of Pt–Ni NPs, respectively. Moreover, the two types of NPs evolved in different ways. By combining high‐resolution imaging, mass spectroscopy, and modeling, it is shown that the evolution of NP morphology and composition during redox reactions plays an important role in controlling the catalytic activity of the NPs.
A Biomimetic Soft Lens Controlled by Electrooculographic Signal
Authors: Li Jinrong , Wang Yang , Liu Liwu , Xu Sheng , Liu Yanju , Leng Jinsong , Cai Shengqiang 
Published: July 2019

AbstractThanks to many unique features, soft robots or soft machines have been recently explored intensively to work collaboratively with human beings. Most of the previously developed soft robots are either controlled manually or by prewritten programs. In the current work, a novel human–machine interface is developed to use electrooculographic signals generated by eye movements to control the motions and the change of focal length of a biomimetic soft lens. The motion and deformation of the soft lens are achieved by the actuation of different areas of dielectric elastomer films, mimicking the working mechanisms of the eyes of human and most mammals. The system developed in the current study has the potential to be used in visual prostheses, adjustable glasses, and remotely operated robotics in the future.
Tailoring the Molecular Properties with Isomerism Effect of AIEgens
Authors: Chen Ming , Liu Junkai , Liu Feng , Nie Han , Zeng Jiajie , Lin Gengwei , Qin Anjun , Tu Mei , He Zikai , Sung Herman H. Y. , Williams Ian D. , Lam Jacky W. Y. , Tang Ben Zhong 
Published: July 2019

AbstractIt is challenging to achieve precise control on the properties of organic π‐functional materials to widen their practical applications. On the other hand, the study of aggregation‐induced emission luminogens (AIEgens) helps achieve such goals because of inherent relationships between their luminescence behaviors and conformational variations that allow for the visual monitoring of the changes in the material properties. Inspired by this, in this work, three AIE isomers are fabricated in structures consisting of tetraphenylpyrazine and triphenylethene units with para‐, meta‐, and ortho‐position linkages, respectively. The isomerism effect brings about significantly decreased luminescence efficiency, subtly blueshifted emission, basically reduced AIE effect but boosted porosity in the aggregate state as the conformation of AIEgens evolves from an extended to a folded one. Based on the distinct properties, their respective use in blue organic light‐emitting diodes, nanofluorescent probes, and molecule‐capturing porous crystals are investigated. This work not only achieves precise property control by using the isomerism effect of AIEgens but also provides useful information on the future design of π‐conjugated materials with advanced functionalities.
Substrate‐Dependent Spin–Orbit Coupling in Hybrid Perovskite Thin Films
Authors: Zhang Qi , Yu Haomiao , Zhao Fenggui , Pei Liying , Li Jinpeng , Wang Kai , Hu Bin 
Published: July 2019

AbstractSolution‐processing hybrid metal halide perovskites are promising materials for developing flexible thin‐film devices. This work reports the substrate effects on the spin–orbit coupling (SOC) in perovskite films through thermal expansion under thermal annealing. X‐ray diffraction (XRD) measurements show that using a flexible polyethylene naphthalate (PEN) substrate introduces a smaller mechanical strain in perovskite MAPbI3−xClx films, as compared to conventional glass substrates. Interestingly, the linear/circular photoexcitation‐modulated photocurrent studies find that decreasing mechanical strain gives rise to a weaker orbit–orbit interaction toward decreasing the SOC in the MAPbI3−xClx films prepared on flexible PEN substrates relative to rigid glass substrates. Simultaneously, decreasing the mechanical strain causes a reduction in the internal magnetic parameter inside the MAPbI3−xClx films, providing further evidence to show that introducing mechanical strain can affect the SOC in hybrid perovskite films upon using flexible substrates toward developing flexible perovskite thin‐film devices. Furthermore, thermal admittance spectroscopy indicates that the trap states are increased in the perovskite films prepared on flexible PEN substrates as compared to glass substrates. Consequently, PEN and rigid glass substrates lead to shorter and longer photoluminescence lifetimes, respectively. Clearly, these findings provide an insightful understanding on substrate effects on optoelectronic properties in flexible perovskite thin‐film devices.
Inkjet Printing of Patterned, Multispectral, and Biocompatible Photonic Crystals
Authors: Li Wenyi , Wang Yu , Li Meng , Garbarini Logan P. , Omenetto Fiorenzo G. 
Published: July 2019

AbstractPatterning of photonic crystals to generate rationally designed color‐responsive materials has drawn considerable interest because of promising applications in optical storage, encryption, display, and sensing. Here, an inkjet‐printing based strategy is presented for noncontact, rapid, and direct approaches to generate arbitrarily patterned photonic crystals. The strategy is based on the use of water‐soluble biopolymer‐based opal structures that can be reformed with high resolution through precise deposition of fluids on the photonic crystal lattice. The resulting digitally designed photonic lattice formats simultaneously exploit structural color and material transience opening avenues for information encoding and combining functions of optics, biomaterials, and environmental interfaces in a single device.
Sandwich‐Like Ultrathin TiS2 Nanosheets Confined within N, S Codoped Porous Carbon as an Effective Polysulfide Promoter in Lithium‐Sulfur Batteries
Authors: Huang Xia , Tang Jiayong , Luo Bin , Knibbe Ruth , Lin Tongen , Hu Han , Rana Masud , Hu Yuxiang , Zhu Xiaobo , Gu Qinfen , Wang Dan , Wang Lianzhou 
Published: July 2019

AbstractAs the lightest member of transition metal dichalcogenides, 2D titanium disulfide (2D TiS2) nanosheets are attractive for energy storage and conversion. However, reliable and controllable synthesis of single‐ to few‐layered TiS2 nanosheets is challenging due to the strong tendency of stacking and oxidation of ultrathin TiS2 nanosheets. This study reports for the first time the successful conversion of Ti3C2Tx
MXene to sandwich‐like ultrathin TiS2 nanosheets confined by N, S co‐doped porous carbon (TiS2@NSC) via an in situ polydopamine‐assisted sulfuration process. When used as a sulfur host in lithium–sulfur batteries, TiS2@NSC shows both high trapping capability for lithium polysulfides (LiPSs), and remarkable electrocatalytic activity for LiPSs reduction and lithium sulfide oxidation. A freestanding sulfur cathode integrating TiS2@NSC with cotton‐derived carbon fibers delivers a high areal capacity of 5.9 mAh cm−2 after 100 cycles at 0.1 C with a low electrolyte/sulfur ratio and a high sulfur loading of 7.7 mg cm−2, placing TiS2@NSC one of the best LiPSs adsorbents and sulfur conversion catalysts reported to date. The developed nanospace‐confined strategy will shed light on the rational design and structural engineering of metal sulfides based nanoarchitectures for diverse applications.
Polymernetzwerke: Von Kunststoffen und Gelen zu porösen Gerüsten
Authors: Gu Yuwei , Zhao Julia , Johnson Jeremiah A. 
Published: July 2019

AbstractPolymernetzwerke sind Materialien, die aus vielen kleineren Komponenten aufgebaut sind, die als “Vernetzungspunkte” und “Stränge” bezeichnet werden und über kovalente oder nichtkovalente/supramolekulare Wechselwirkungen miteinander verknüpft sind. Sie gehören zu den vielseitigsten, am häufigsten eingesetzten und wichtigsten Materialien. Von den ersten kommerziellen Polymeren über die Kunststoffrevolution des 20. Jahrhunderts bis in die Gegenwart gibt es nahezu keine Aspekte des modernen Lebens, die nicht von Polymernetzwerken beeinflusst werden. Dennoch müssen noch viele Herausforderungen in Angriff genommen werden, um ein vollständiges Verständnis dieser Materialien zu ermöglichen und ihre Entwicklung für künftige Anwendungen zu fördern, die von Energie‐Harvesting und Energiespeicherung bis zur Gewebezüchtung und additiven Fertigung reichen. Hier geben wir einen Überblick über die Grundlagen der Synthese, Struktur und Eigenschaften von Polymernetzwerken, unter Einbeziehung aktueller Trends auf dem Gebiet. Wir werden außerdem die neuesten Fortschritte bei der Anwendung des Moleküldesigns und der Steuerung der Topologie aufzeigen, um zu demonstrieren, wie ein tiefgehendes Verständnis der Struktur‐Eigenschaft‐Beziehungen zu hochentwickelten Netzwerken mit außergewöhnlichen Eigenschaften führen kann.
Electrochemically Gated Long‐Distance Charge Transport in Photosystem I
Authors: López‐Martínez Montse , López‐Ortiz Manuel , Antinori Maria Elena , Wientjes Emilie , Nin‐Hill Alba , Rovira Carme , Croce Roberta , Díez‐Pérez Ismael , Gorostiza Pau 
Published: July 2019

AbstractThe transport of electrons along photosynthetic and respiratory chains involves a series of enzymatic reactions that are coupled through redox mediators, including proteins and small molecules. The use of native and synthetic redox probes is key to understanding charge transport mechanisms and to the design of bioelectronic sensors and solar energy conversion devices. However, redox probes have limited tunability to exchange charge at the desired electrochemical potentials (energy levels) and at different protein sites. Herein, we take advantage of electrochemical scanning tunneling microscopy (ECSTM) to control the Fermi level and nanometric position of the ECSTM probe in order to study electron transport in individual photosystem I (PSI) complexes. Current–distance measurements at different potentiostatic conditions indicate that PSI supports long‐distance transport that is electrochemically gated near the redox potential of P700, with current extending farther under hole injection conditions.
Perquinoline A–C: neuartige bakterielle Tetrahydroisochinoline mit einer bemerkenswerten Biosynthese
Authors: Rebets Yuriy , Nadmid Suvd , Paulus Constanze , Dahlem Charlotte , Herrmann Jennifer , Hübner Harald , Rückert Christian , Kiemer Alexandra K. , Gmeiner Peter , Kalinowski Jörn , Müller Rolf , Luzhetskyy Andriy 
Published: July 2019

AbstractDie Analyse des metabolischen Profils von Streptomyces sp. IB2014/ 016‐6 führte zur Identifizierung der drei neuen Tetrahydroisochinolin‐Naturstoffe Perquinoline A–C (1–3). Durch Fütterungsexperimente mit angereicherten Vorläuferverbindungen und Klonen des pqr‐Biosynthesegenclusters wurde entdeckt, dass 1–3 unter Wirkung einiger ungewöhnlicher Enzyme synthetisiert werden. Die Biosynthese startet mit der Kondensation von Succinyl‐CoA und l‐Phenylalanin, katalysiert durch PqrA, einem Enzym mit Ähnlichkeit zur Amino‐7‐oxononanoatsynthase. Diese Reaktion ist innerhalb der Naturstoffchemie selten anzufinden. Die zweite Kondensation und der Ringschluss wird von PqrG, ein acyl‐CoA Ligase‐ähnliches Enzym, durchgeführt. Die Biosynthese wird durch den Transfer einer Aminobuttersäure‐ bzw. einer β‐Alaningruppe durch die ATP‐grasp RimK‐ähnliche Ligase PqrI abgeschlossen. Der entdeckte Verlauf repräsentiert ein neues Beispiel für die Zusammensetzung von Naturstoffen mit einem Tetrahydroiso‐chinolin‐Kern.
The Case of Formic Acid on Anatase TiO2(101): Where is the Acid Proton?
Authors: Tabacchi Gloria , Fabbiani Marco , Mino Lorenzo , Martra Gianmario , Fois Ettore 
Published: July 2019

AbstractCarboxylic‐acid adsorption on anatase TiO2is a relevant process in many technological applications. Yet, despite several decades of investigations, the acid‐proton localization—either on the molecule or on the surface—is still an open issue. By modeling the adsorption of formic acid on top of anatase(101) surfaces, we highlight the formation of a short strong hydrogen bond. In the 0 K limit, the acid‐proton behavior is ruled by quantum delocalization effects in a single potential well, while at ambient conditions, the proton undergoes a rapid classical shuttling in a shallow two‐well free‐energy profile. This picture, supported by agreement with available experiments, shows that the anatase surface acts like a protecting group for the carboxylic acid functionality. Such a new conceptual insight might help rationalize chemical processes involving carboxylic acids on oxide surfaces.
Asymmetric Synthesis of Enantioenriched 2‐Aryl‐2,3‐Dihydrobenzofurans by a Lewis Acid Catalyzed Cyclopropanation/Intramolecular Rearrangement Sequence
Authors: Pandit Rameshwar Prasad , Kim Seung Tae , Ryu Do Hyun 
Published: July 2019

AbstractA cyclopropanation/intramolecular rearrangement initiated by the Michael addition of in situ generated ortho‐quinone methides (o‐QMs) has been developed for the enantioselective synthesis of 2‐aryl‐2,3‐dihydrobenzofurans containing two consecutive stereogenic centers, including a quaternary carbon atom. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction proceeded in excellent yields (up to 95 %) with excellent stereoselectivity (up to >99 ee, up to >20:1 d.r.).
Mineralization‐Inspired Synthesis of Magnetic Zeolitic Imidazole Framework Composites
Authors: Terzopoulou Anastasia , Hoop Marcus , Chen Xiang‐Zhong , Hirt Ann M. , Charilaou Michalis , Shen Yang , Mushtaq Fajer , del Pino Angel Pérez , Logofatu Constantin , Simonelli Laura , de Mello Andrew J. , Doonan Christian J. , Sort Jordi , Nelson Bradley J. , Pané Salvador , Puigmartí‐Luis Josep 
Published: July 2019

AbstractMetal–organic frameworks (MOFs) capable of mobility and manipulation are attractive materials for potential applications in targeted drug delivery, catalysis, and small‐scale machines. One way of rendering MOFs navigable is incorporating magnetically responsive nanostructures, which usually involve at least two preparation steps: the growth of the magnetic nanomaterial and its incorporation during the synthesis of the MOF crystals. Now, by using optimal combinations of salts and ligands, zeolitic imidazolate framework composite structures with ferrimagnetic behavior can be readily obtained via a one‐step synthetic procedure, that is, without the incorporation of extrinsic magnetic components. The ferrimagnetism of the composite originates from binary oxides of iron and transition metals such as cobalt. This approach exhibits similarities to the natural mineralization of iron oxide species, as is observed in ores and in biomineralization.
Kopplung von Solarenergie und Wärmeenergie zur Kohlendioxidreduktion: Aktueller Stand und Perspektiven
Authors: Wang Zhou‐jun , Song Hui , Liu Huimin , Ye Jinhua 
Published: July 2019

AbstractDie Reduktion von Kohlendioxid (CO2) durch die Nutzung verschiedener Antriebskräfte wie Wärme, Strom und Strahlung ist Gegenstand intensiver Forschung. Die effiziente CO2‐Reduktion ist jedoch aufgrund der langsamen Kinetik nach wie vor eine Herausforderung. Jüngste Pionierarbeiten aus mehreren Arbeitsgruppen, darunter auch unsere, haben gezeigt, dass die Kopplung von Solarenergie und Wärmeenergie als neuartige und vielversprechende Strategie zur Förderung der Aktivität und/oder der Manipulation der Selektivität bei der CO2‐Reduktion dienen kann. Hier werden wir die Definition und die Prinzipien der Kopplung von Solarenergie und Wärmeenergie klar definieren und den aktuellen Stand und die Perspektiven der CO2‐Reduktion durch Kopplung von Solarenergie und Wärmeenergie evaluieren. Katalysatordesign, Reaktorkonfiguration, photovermittelte Aktivität/Selektivität und Mechanismusstudien zur photothermischen CO2‐Reduktion werden hervorgehoben. Ziel dieses Aufsatzes ist es, das Verständnis für die CO2‐Aktivierung zu fördern und Leitlinien für die Entwicklung neuer Katalysatoren für eine effiziente CO2‐Reduktion zu liefern.
Enantioselective Total Syntheses of Pallambins A–D
Authors: Zhang Xiwu , Cai Xinxian , Huang Bin , Guo Lei , Gao Zhongrun , Jia Yanxing 
Published: July 2019

AbstractThe first enantioselective total syntheses of (−)‐pallambins A–D have been achieved in 15 or 16 steps from a known chiral cyclohexenone. Salient features of the syntheses include a palladium‐catalyzed oxidative cyclization to assemble the [3.2.1]bicyclic moiety, an Eschenmoser–Claisen rearrangement/lactone formation sequence to construct the C ring, an intramolecular Wittig reaction to form the D ring, and individual transformations of pallambins C and D to generate pallambins A and B. The described synthesis avoids protecting‐group manipulations through the design of highly chemo‐ and stereoselective transformations. During the course of this work, a palladium‐catalyzed method for the dehydrobromination of α‐bromoketones was developed, and the scope of this transformation was also investigated.
Magnetic Alignment of Polymer Macro‐Nanodiscs Enables Residual‐Dipolar‐Coupling‐Based High‐Resolution Structural Studies by NMR Spectroscopy
Authors: Ravula Thirupathi , Ramamoorthy Ayyalusamy 
Published: July 2019

AbstractExperimentally measured residual dipolar couplings (RDCs) are highly valuable for atomic‐resolution structural and dynamic studies of molecular systems ranging from small molecules to large proteins by solution NMR spectroscopy. Here we demonstrate the first use of magnetic‐alignment behavior of lyotropic liquid‐crystalline polymer macro‐nanodiscs (>20 nm in diameter) as a novel alignment medium for the measurement of RDCs using high‐resolution NMR. The easy preparation of macro‐nanodiscs, their high stability against pH changes and the presence of divalent metal ions, and their high homogeneity make them an efficient tool to investigate a wide range of molecular systems including natural products, proteins, and RNA.