bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micromachining‐Compatible, Facile Fabrication of Polymer Nanocomposite Spin Crossover Actuators
Authors: Manrique‐Juárez María D. , Mathieu Fabrice , Laborde Adrian , Rat Sylvain , Shalabaeva Victoria , Demont Philippe , Thomas Olivier , Salmon Lionel , Leichle Thierry , Nicu Liviu , Molnár Gábor , Bousseksou Azzedine 
Published: May 2018

Abstract[FeII(Htrz)2(trz)](BF4) spin crossover particles of 85 nm mean size are dispersed in an SU‐8 polymer matrix and spray‐coated onto silicon microcantilevers. The subsequent photothermal treatment of the polymer resist leads to micrometer thick, smooth, and homogeneous coatings, which exhibit well‐reproducible actuation upon the thermally induced spin transition. The actuation amplitude as a function of temperature is accurately determined by combining integrated piezoresistive detection with external optical interferometry, which allows for the assessment of the associated actuation force (9.4 mN), stress (28 MPa), strain (1.0%), and work density (140 mJ cm−3) through a stratified beam model. The dynamical mechanical characterization of the films evidences an increase of the resonance frequency and a concomitant decrease of the damping in the high‐temperature phase, which arises due to a combined effect of the thickness and mechanical property changes. The spray‐coating approach is also successfully extended to scale up the actuators for the centimeter range on a polymer substrate providing perspectives for biomimetic soft actuators.
Reducing Bacterial Infections and Biofilm Formation Using Nanoparticles and Nanostructured Antibacterial Surfaces
Authors: Mi Gujie , Shi Di , Wang Mian , Webster Thomas J. 
Published: May 2018

AbstractWith the rapid spreading of resistance among common bacterial pathogens, bacterial infections, especially antibiotic‐resistant bacterial infections, have drawn much attention worldwide. In light of this, nanoparticles, including metal and metal oxide nanoparticles, liposomes, polymersomes, and solid lipid nanoparticles, have been increasingly exploited as both efficient antimicrobials themselves or as delivery platforms to enhance the effectiveness of existing antibiotics. In addition to the emergence of widespread antibiotic resistance, of equal concern are implantable device‐associated infections, which result from bacterial adhesion and subsequent biofilm formation at the site of implantation. The ineffectiveness of conventional antibiotics against these biofilms often leads to revision surgery, which is both debilitating to the patient and expensive. Toward this end, micro‐ and nanotopographies, especially those that resemble natural surfaces, and nonfouling chemistries represent a promising combination for long‐term antibacterial activity. Collectively, the use of nanoparticles and nanostructured surfaces to combat bacterial growth and infections is a promising solution to the growing problem of antibiotic resistance and biofilm‐related device infections.
Nearly 100% Horizontal Dipole Orientation and Upconversion Efficiency in Blue Thermally Activated Delayed Fluorescent Emitters
Authors: Byeon Sung Yong , Kim Jongchan , Lee Dong Ryun , Han Si Hyun , Forrest Stephen R. , Lee Jun Yeob 
Published: May 2018

AbstractThe relationship between anisotropic orientation and molecular structure of thermally activated delayed fluorescent (TADF)‐based organic light emitting devices (OLEDs) is studied using TADF emitters with carbazole, biscarbazole, and triscarbazole donor units. The bicarbazole and triscarbazole donors are more effective than the carbazole donor in driving the anisotropic orientation of the TADF molecules. A near‐perfect in‐plane orientation of the TADF dipole moment is demonstrated using the triscarbazole donor. In addition, the triscarbazole donor based OLED shows high photoluminescence quantum yield and an upconversion efficiency close to 100%. As a consequence, an external quantum efficiency >30% is obtained.
Phototriggered Selective Actuation and Self‐Oscillating in Dual‐Phase Liquid Crystal Photonic Actuators
Authors: Wei Wanyuan , Zhang Zhewei , Wei Jie , Li Xiaofeng , Guo Jinbao 
Published: May 2018

AbstractAmong different kinds of photoactuators available, those based on liquid‐crystal polymer networks (LCNs) are gathering a great deal of attention due to their fast response and versatility of structural design. However, only a few reports have focused on the phototriggered LCN actuators for complex actuation and multifunction properties. Here, a phototriggered LCN‐based photonic actuator with quasi‐bilayer structure that exhibits fast and reversible shape changes is created by infiltrating a LCN precursor–graphene oxide mixture into a silica opal template, ultraviolet photopolymerization, and removing the template. Particularly, the phototriggered selective actuation behavior is achieved in dual‐phase LCN‐based photonic actuators with macroscopically alternating nematic (N) and isotropic (I) phase, which enables versatile actuation modes and allows multiple shape changes. In addition, a two‐segmented, dual‐phase LCN‐based photonic actuator exhibits self‐oscillating motion when a responsive N‐phase region as localized active point is irradiated, which arises from the self‐shadowing of the passive I‐phase region. To demonstrate the potential application of this self‐oscillating motion behavior, a photoelectric energy conversion device that is capable of converting light energy to electric energy is constructed.
Synthesis of a Bolm's 2,2′‐Bipyridine Ligand Analogue and Its Applications
Authors: Bednářová Eva , Dračínský Martin , Malatinec Štefan , Císařová Ivana , Lamaty Frédéric , Kotora Martin 
Published: May 2018

AbstractA new method of synthesis of an analogue of Bolm's 2,2′‐bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1‐halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2‐bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)‐2 was then tested as a chiral ligand in metal‐catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama‐aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents.magnified image
Self‐employed individuals performing different types of work have different occupational safety and health problems
Authors: Park Jungsun , Han Boyoung , Kim Yangho 
Published: May 2018

AbstractIntroductionWe assessed the occupational safety and health (OSH) issues of self‐employed individuals in Korea.MethodsThe working conditions and OSH issues in three groups were analyzed using the Korean Working Conditions Survey of 2014.ResultsAmong self‐employed individuals, “Physical work” was more common among males, whereas “Emotional work” was more common among females. Self‐employed individuals performing “Mental work” had more education, higher incomes, and the lowest exposure to physical/chemical and ergonomic hazards in the workplace. In contrast, those performing “Physical work” were older, had less education, lower incomes, greater exposure to physical/chemical and ergonomic hazards in the workplace, and more health problems. Individuals performing “Physical work” were most vulnerable to OSH problems.ConclusionThe self‐employed are a heterogeneous group of individuals. We suggest development of specific strategies that focus on workers performing “Physical work” to improve the health and safety of self‐employed workers in Korea.
Highly Efficient Syntheses of C−N Axially Chiral 1‐(ortho‐hydroxyaryl)uracil using a Chiral Auxiliary and a Chiral Base
Authors: Hasegawa Futoshi , Yasukawa Yoshifumi , Kawamura Kazushi , Tsuchikawa Hiroshi , Murata Michio 
Published: May 2018

AbstractWe achieved a highly diastereoselective synthesis of 1‐aryl‐6‐aminouracils, which are C−N atropisomeric compounds, through the combined use of a chiral auxiliary and a chiral base under mild conditions. We found that the (R)‐5‐allyl‐2‐oxabicyclo[3.3.0]oct‐1‐yl group is a good chiral auxiliary that, when combined with quinidine, efficiently affords 1‐aryl‐6‐aminouracils with high diastereoselectivity (up to 98 % ee after isolation). The chiral alcohol moiety in quinidine appears to be crucial for achieving stereoselectivity during cyclization. Furthermore, the chiral auxiliary was easily removed from the product under acidic conditions to provide the atropisomer with high enantiomeric excess (up to 96 % ee). The developed method is an efficient diastereoselective‐cyclization method for the generation of C−N axial chirality.
Thermally Twistable, Photobendable, Elastically Deformable, and Self‐Healable Soft Crystals
Authors: Gupta Poonam , Karothu Durga Prasad , Ahmed Ejaz , Naumov Panče , Nath Naba K. 
Published: May 2018

AbstractThe first example of a smart crystalline material, the 2:1 cocrystal of probenecid and 4,4′‐azopyridine, which responds reversibly to multiple external stimuli (heat, UV light, and mechanical pressure) by twisting, bending, and elastic deformation without fracture is reported. This material is also able to self‐heal on heating and cooling, thereby overcoming the main setbacks of molecular crystals for future applications as crystal actuators. The photo‐ and thermomechanical effects and self‐healing capabilities of the material are rooted in reversible trans–cis isomerization of the azopyridine unit and crystal‐to‐crystal phase transition. Fairly isotropic intermolecular interactions and interlocked crisscrossed molecular packing secure high elasticity of the crystals.
Isolierung und Charakterisierung von kristallinen, neutralen Diboran(4)‐Radikalen
Authors: Seufert Jens , Welz Eileen , Krummenacher Ivo , Paprocki Valerie , Böhnke Julian , Hagspiel Stephan , Dewhurst Rian D. , Tacke Reinhold , Engels Bernd , Braunschweig Holger 
Published: May 2018

AbstractBei der Umsetzung von Diaryldihalogendiboranen(4) mit Bis(amidinato)‐ und Bis(guanidinato)silylenen wurden die ersten neutralen Diboran‐zentrierten Radikale erhalten. Diese formal nicht‐aromatischen 5π‐Elektronen‐Systeme sind sowohl im Festkörper, als auch in Lösung stabil und wurden mittels Einkristallstrukturanalyse, hochauflösender Massenspektrometrie und ESR‐Spektroskopie charakterisiert. Die Reaktivität eines dieser Radikale mit dem Oxidationsmittel 1,4‐Benzoquinon führte zur Ringöffnung und B‐O‐Bindungsbildung.
Silylarenhydrierung – ein strategischer Ansatz für einen direkten Zugang zu silylierten gesättigten Carbo‐ und Heterocyclen
Authors: Wiesenfeldt Mario P. , Knecht Tobias , Schlepphorst Christoph , Glorius Frank 
Published: May 2018

AbstractEin Verfahren zur Umwandlung leicht zugänglicher silylierter Arene in silylierte gesättigte Carbo‐ und Heterocyclen mittels Arenhydrierung wurde entwickelt. Die Substratbreite umfasst Alkoxy‐ und Halogensilylgruppen. Silylgruppen können in eine Vielzahl von funktionellen Gruppen umgewandelt werden und finden Anwendung in der Synthese, der Materialwissenschaft sowie der pharmazeutischen, agrochemischen und Duftstoff‐Forschung. Silylierte gesättigte (Hetero)cyclen sind mit anderen Methoden nur schwer zugänglich. Die Ausbeute der Hydrierung hängt von der Menge des Kieselgel‐Additivs ab. Dieser SiO2‐Effekt ermöglicht ebenfalls eine signifikante Verbesserung des zuvor berichteten Verfahrens für die Hydrierung hochfluorierter Arene (z. B. zu all‐cis‐C6H6F6).
Silylarene Hydrogenation: A Strategic Approach that Enables Direct Access to Versatile Silylated Saturated Carbo‐ and Heterocycles
Authors: Wiesenfeldt Mario P. , Knecht Tobias , Schlepphorst Christoph , Glorius Frank 
Published: May 2018

AbstractWe report a method to convert readily available silylated arenes into silylated saturated carbo‐ and heterocycles by arene hydrogenation. The scope includes alkoxy‐ and halosilyl substituents. Silyl groups can be derivatized into a plethora of functionalities and find application in organic synthesis, materials science, and pharmaceutical, agrochemical, and fragrance research. However, silylated saturated (hetero‐ ) cycles are difficult to access with current technologies. The yield of the hydrogenation depends on the amount of the silica gel additive. This silica effect also enables a significant improvement of a previously disclosed method for the hydrogenation of highly fluorinated arenes (e.g., to all‐cis‐C6H6F6).
Water Molecules Gating a Photoinduced One‐Electron Two‐Protons Transfer in a Tyrosine/Histidine (Tyr/His) Model of Photosystem II
Authors: Chararalambidis Georgios , Das Shyamal , Trapali Adelais , Quaranta Annamaria , Orio Maylis , Halime Zakaria , Fertey Pierre , Guillot Régis , Coutsolelos Athanassios , Leibl Winfried , Aukauloo Ally , Sircoglou Marie 
Published: May 2018

AbstractWe investigate a biomimetic model of a TyrZ/His190 pair, a hydrogen‐bonded phenol/imidazole covalently attached to a porphyrin sensitizer. Laser flash photolysis in the presence of an external electron acceptor reveals the need for water molecules to unlock the light‐induced oxidation of the phenol through an intramolecular pathway. Kinetics monitoring encompasses two fast phases with distinct spectral properties. The first phase is related to a one‐electron transfer from the phenol to the porphyrin radical cation coupled with a domino two‐proton transfer leading to the ejection of a proton from the imidazole–phenol pair. The second phase concerns conveying the released proton to the porphyrin N4 coordinating cavity. Our study provides an unprecedented example of a light‐induced electron‐transfer process in a TyrZ/His190 model of photosystem II, evidencing the movement of both the phenol and imidazole protons along an isoenergetic pathway.
Direct Real‐Time Monitoring of Prodrug Activation by Chemiluminescence
Authors: Gnaim Samer , Scomparin Anna , Das Sayantan , Blau Rachel , Satchi‐Fainaro Ronit , Shabat Doron 
Published: May 2018

AbstractThe majority of theranostic prodrugs reported so far relay information through a fluorogenic response generated upon release of the active chemotherapeutic agent. A chemiluminescence detection mode offers significant advantages over fluorescence, mainly due to the superior signal‐to‐noise ratio of chemiluminescence. Here we report the design and synthesis of the first theranostic prodrug monitored by a chemiluminescence diagnostic mode. As a representative model, we prepared a prodrug from the chemotherapeutic monomethyl auristatin E, which was modified for activation by β‐galactosidase. The activation of the prodrug in the presence of β‐galactosidase is accompanied by emission of a green photon. Light emission intensities, which increase with increasing concentration of the prodrug, were linearly correlated with a decrease in the viability of a human cell line that stably expresses β‐galactosidase. We obtained sharp intravital chemiluminescent images of endogenous enzymatic activity in β‐galactosidase‐overexpressing tumor‐bearing mice. The exceptional sensitivity achieved with the chemiluminescence diagnostic mode should allow the exploitation of theranostic prodrugs for personalized cancer treatment.
Development of microsatellite markers for Primula oreodoxa (Primulaceae), a distylous‐homostylous species
Authors: Yuan Shuai , Zeng Gui , Zhang Dianxiang 
Published: May 2018

Premise of the StudyMicrosatellite markers were developed for a distylous‐homostylous species, Primula oreodoxa (Primulaceae), to investigate the mating patterns and gene flow in the species.Methods and ResultsUsing RAD sequencing, 42,777 contigs were generated. A total of 1566 putative simple sequence repeat (SSR) loci were identified by MISA, and 1433 primer sets were designed. After initial screening of 107 SSR loci, 24 loci displayed polymorphism. The number of alleles per locus detected ranged from one to 11 in the sampled populations of P. oreodoxa. Levels of observed and expected heterozygosity for each locus ranged from 0 to 0.917 and 0 to 0.816, respectively. Fifteen and 13 of these loci could be successfully amplified in the two congeneric species P. obconica and P. heucherifolia, respectively.ConclusionsThe SSR markers developed here will be valuable for genetic analysis and elucidation of mating patterns in P. oreodoxa.
Pharmacokinetic and pharmacodynamic model for analysis of adalimumab administered for Crohn's disease
Authors: Kimura Koji , Yoshida Atsushi , Takayanagi Risa , Yamada Yasuhiko 
Published: May 2018

AbstractAdalimumab (ADA) is used as a therapeutic agent for Crohn's disease (CD). Although the dosage regimen has been established through clinical trial experience, it has not been analysed theoretically. The present study analysed of sequential changes in the Crohn's disease activity index (CDAI) after repeated administrations of adalimumab using a pharmacokinetic and pharmacodynamic model. In addition, we analysed the validity of the dosage regimen, and the potential efficacy gained by increasing the dose and reducing the interval of administration. The sequential changes in CDAI values obtained with our model were in good agreement with observed CDAI values, which is considered to show the validity of our analysis. We consider that our results showed the importance of a loading dose of adalimumab to obtain remission in an early stage of active CD. In addition, we showed that patients who have an incomplete response to adalimumab can obtain similar efficacy from increasing the dose and reducing the dose interval. In conclusion, our results showed that the present model may be applied to predict the CDAI values of adalimumab for CD. They indicate the validity of the dosage regimen, as well as the efficacy of increasing the dose and reducing the dose interval.
A label‐free fluorescence method for detection of ureC gene and diagnosis of Helicobacter pylori infection
Authors: Zhang Leiyi , Cao Ding , Tang Tenglong , Zuo Zhongkun , Huang Jiangsheng , Duan Lunxi 
Published: May 2018

AbstractThe feasibility of using a polymerase chain reaction (PCR)‐based label‐free DNA sensor for the detection of Helicobacter pylori is investigated. In particular, H. pylori ureC gene, a specific H. pylori nucleic acid sequence, was selected as the target sequence. In the presence of ureC gene, the target DNA could be amplified to dsDNA with much higher detectable levels. After added the SYBR green I (SGI), the sensing system could show high fluorescence. Thus, the target DNA can be detected by monitoring the change of fluorescence intensity of sensing system. The clinical performance of this method was determined by comparing it with another conventional technique urea breath test (UBT). The result also showed good distinguishing ability between negative and positive patient, which was in good agreement with that obtained by the UBT. It suggests that the label‐free fluorescence‐based method is more suitable for infection confirmation test of H. pylori. This approach offers great potential for simple, sensitive and cost‐effective identification of H. pylori infection.
Antidiuretic hormone release associated with increased intracranial pressure independent of plasma osmolality
Authors: Keller William J. , Mullaj Elda 
Published: May 2018

AbstractObjectiveIntroduce and evaluate a new model which explains the release of brain antidiuretic hormone (ADH) independent of plasma osmolality.MethodsSystematic review and critical analysis of the professional literature.ResultsPrimary electronic database searches using key terms revealed 57,432 hits. Secondary searches with application of specific inclusion and exclusion criteria and manual inspection for completeness reduced the total number of studies to fourteen (N = 14). Twelve (N = 12) studies investigated human subjects in the hospital settings, and two (N = 2) studies investigated animals (rhesus monkeys and dog) under invasive experimental conditions. All fourteen studies included direct or indirect indicators of intracranial pressure (ICP), measurements of plasma ADH, and plasma osmolality or urine osmolality. Findings, in brief, reveal a stable and positive association between increased intracranial pressure (ICP) and increased ADH release, in patients with low or normal blood osmolality. Findings are reliable and reproducible across human and animal populations.ConclusionsFindings support the proposed model, which explains increase secretion of brain ADH when plasma osmolality is low or within normal limits. Mechanical pressures exerted on hypothalamic nuclei, especially paraventricular and supra‐optic nuclei, as a consequence of increased intracranial pressure, produce release of ADH, independent of plasma osmolality. The mechanical pressure model explains release of ADH previously unexplained by traditional plasma osmolality models. Findings have important clinical implications for the medical and surgical management of patients.
Alterations of brain network hubs in reflex syncope: Evidence from a graph theoretical analysis based on DTI
Authors: Park Bong Soo , Lee Yoo Jin , Park Jin‐Han , Kim Il Hwan , Park Si Hyung , Lee Ho‐Joon , Park Kang Min 
Published: May 2018

AbstractObjectiveWe evaluated global topology and organization of regional hubs in the brain networks and microstructural abnormalities in the white matter of patients with reflex syncope.MethodsTwenty patients with reflex syncope and thirty healthy subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on extracted DTI data, using DSI Studio. We then investigated differences in the network measures between the patients with reflex syncope and the healthy subjects. We also analyzed microstructural abnormalities of white matter using tract‐based spatial statistics analysis (TBSS).ResultsMeasures of global topology were not different between patients with reflex syncope and healthy subjects. However, in reflex syncope patients, the strength measures of the right angular, left inferior frontal, left middle orbitofrontal, left superior medial frontal, and left middle temporal gyrus were lower than in healthy subjects. The betweenness centrality measures of the left middle orbitofrontal, left fusiform, and left lingual gyrus in patients were lower than those in healthy subjects. The PageRank centrality measures of the right angular, left middle orbitofrontal, and left superior medial frontal gyrus in patients were lower than those in healthy subjects. Regarding the analysis of the white matter microstructure, there were no differences in the fractional anisotropy and mean diffusivity values between the two groups.ConclusionsWe have identified a reorganization of network hubs in the brain network of patients with reflex syncope. These alterations in brain network may play a role in the pathophysiologic mechanism underlying reflex syncope.