bluuebunny/crossref_metadata_2025 huggingface dataset:
DISTRIBUTION OF THE HEPATIC BLOOD VESSELS OF THE GROUND SQUIRREL (SPERMOPHILUS CITELLUS)
Authors: BLAGOJEVIĆ Miloš , NEŠIĆ Ivana , ĐORĐEVIĆ Milena , NEDIĆ Drago , ZDRAVKOVIĆ Marija , TOŠKOVIĆ Borislav , NIKOLIĆ Zora
Published: May 2019

The aim of this paper was to study distribution of the hepatic artery and portal vein of theportal system of the liver in ground squirrels (Spermophilus citellus) and compare these data withthose concerning the rats, rabbits, guinea pigs and nutrias. The liver of the ground squirrel receivesthe oxygen and nutrients through blood from two large blood vessels: portal vein and hepatic artery(a. hepatica propria). The portal vein is formed by the confluence of three main venous bloodvessels: v. gastropancreaticoduodenalis, v. gastrolienalis and v. mesenterica cranialis. It collectsvenous blood from the stomach, pancreas, spleen and all of intestines except the rectum. The portalvein enters the porta hepatis on the liver together with the hepatic artery. Five venous branches ofdifferent size separate from the portal vein and ramify into the respective liver lobes.Blood leaves the liver through the hepatic veins that start with the central veins. Three large hepaticveins and two venous trunks drain lobes of the liver and enter the caudal vena cava as it passesthrough the liver.A. hepatica propria supplies the liver and gallbladder with oxygenated blood. It raises from thehepatic artery (a. hepatica) wich is the third branch of the celiac artery. A. hepatica propria in theportal fissure is divided into two branches, of which the left branch brings arterial blood to the lefthepatic lobe, and the right branch brings it into other liver lobes.
Reducing Acrylamide Exposure: A Review of the Application of Sulfur-Containing Compounds - A Caribbean Outlook
Authors: Augustine Dahryn A. , Bent Grace-Anne
Published: May 2019

Acrylamide, a known neurotoxin, reproductive toxin, genotoxin, probable carcinogen, hepatotoxin, and immunotoxin, has sparked intense curiosity due to its prominent presence in thermally processed, carbohydrate-rich foods. Acrylamide formation occurs via the Maillard reaction at temperatures ≥100ºC. Thorough investigations on acrylamide mitigation through the application of sulfur-containing compounds to raw materials, and during food processing have been conducted. Although prominent results in acrylamide reduction have been observed, limitations are considered. These limitations involve the social and economic challenges of a population, such as the Caribbean. This study seeks to answer just how effective the application of sulfur-containing compounds is in reducing acrylamide exposure, especially when this applies to a developing region.
Printing Life‐Inspired Subcellular Scale Compartments with Autonomous Molecularly Crowded Confinement
Authors: Arrabito Giuseppe , Cavaleri Felicia , Porchetta Alessandro , Ricci Francesco , Vetri Valeria , Leone Maurizio , Pignataro Bruno
Published: May 2019

A simple, rapid, and highly controlled platform to prepare life‐inspired subcellular scale compartments by inkjet printing has been developed. These compartments consist of fL‐scale aqueous droplets (few µm in diameter) incorporating biologically relevant molecular entities with programmed composition and concentration. These droplets are ink‐jetted in nL mineral oil drop arrays allowing for lab‐on‐chip studies by fluorescence microscopy and fluorescence life time imaging. Once formed, fL‐droplets are stable for several hours, thus giving the possibility of readily analyze molecular reactions and their kinetics and to verify molecular behavior and intermolecular interactions. Here, this platform is exploited to unravel the behavior of different molecular probes and biomolecular systems (DNA hairpins, enzymatic cascades, protein‐ligand couples) within the compartments. The fL‐scale size induces the formation of molecularly crowded confined shell structures (hundreds of nanometers in thickness) at the droplet surface, allowing discovery of specific features (e.g., heterogeneity, responsivity to molecular triggers) that are mediated by the intermolecular interactions in these peculiar environments. The presented results indicate the possibility of using this platform for designing nature‐inspired confined reactors allowing for a deepened understanding of molecular confinement effects in living subcellular compartments.
Ultrasmall Quantum Dots with Broad‐Spectrum Metal Doping Ability for Trimodal Molecular Imaging
Authors: Tian Rui , Shen Zheyu , Zhou Zijian , Munasinghe Jeeva , Zhang Xue , Jacobson Orit , Zhang Mingxi , Niu Gang , Pang Dai‐Wen , Cui Ran , Zhu Shoujun , Chen Xiaoyuan
Published: May 2019

Development of efficient targeting nanomaterials is extremely challenging due to the nonspecific accumulation in immune tissues, such as the liver and the spleen. Ultrasmall nanoparticles (USNPs) could possess small molecule‐like in vivo pharmacokinetic profiles, coupled with integrated functions capacity, improving the molecular imaging efficiency, particularly in oncology. For nuclear imaging, radiometals are often incorporated into the structures of USNPs using chelator and chelator‐free strategies. However, the incorporated chelator may change the surface properties and in vivo behavior of UNSPs, while chelator‐free labeling strategies either involve complicated resynthesis or rely on the active properties of the metal ions. Herein, a novel chelator‐free and postsynthetic strategy for broad‐spectrum metal ion attachment is reported. The ultrasmall Ag2Se quantum dots (QDs) are developed with an active oxygen layer on the surface, allowing for facile incorporation of both active and inert metals with high labeling efficiency. The particles enable fluorescence, magnetic resonance imaging, and positron emission tomography (PET) trimodality imaging. After conjugation with targeting peptide, the probe yields a high tumor‐to‐muscle ratio of nine in PET imaging. Importantly, the QDs are predominantly excreted from body through the renal route within 12 h. This chelator‐free strategy opens an avenue for exploring broad‐spectrum radiometal isotope labeling and USNP‐based renal‐excreting imaging probes.
Ag Thin Film Dewetting Prevention by Ion Implantation
Authors: Chi Longxing , Bassim Nabil
Published: May 2019

Ion implantation is applied here to prevent metallic silver (Ag) thin films from dewetting on a sapphire substrate during annealing. In these experiments, silicon (Si) and indium (In) atoms are implanted into Ag thin films grown directly on sapphire, which are then annealed for different time periods to introduce film dewetting. It is observed that trace amounts of 1014 cm−2 dopants significantly retard the film grain growth, alter the film surface wetting features, and trivially influence the electrical and optical performance of the original film. A grain growth model with the presence of solute species is introduced here, combined with a thermodynamic simulation of film dewetting. It is found that doping ions introduce solute drag into Ag grains thereby significantly retarding the grain growth by generating a limiting grain size. The shrunken grains then alter the film surface energy distribution, transferring the most stable state from the dewetting phase to the wetting phase. The approach provides a novel strategy to suppress metallic thin films from dewetting with high stability, durability, and insignificant impact on the film performance without using an adhesion layer and also potentially expands the thermal processing window for metallic thin films.
WNT10B variants in split hand/foot malformation: Report of three novel families and review of the literature
Authors: Brunelle Perrine , Jourdain Anne‐Sophie , Escande Fabienne , Martinovic Jelena , Dupont Juliette , Busa Tiffany , Moncla Anne , Frénois Frédéric , Stichelbout Morgane , Manouvrier‐Hanu Sylvie , Petit Florence
Published: May 2019

Split‐hand/foot malformation (SHFM) is a genetically heterogeneous congenital limb malformation typically limited to a defect of the central rays of the autopod, presenting as a median cleft of hands and feet. It can be associated with long bone deficiency or included in more complex syndromes. Among the numerous genetic causes, WNT10B homozygous variants have been recently identified in consanguineous families, but remain still rarely described (SHFM6; MIM225300). We report on three novel SHFM families harboring WNT10B variants and review the literature, allowing us to highlight some clinical findings. The feet are more severely affected than the hands and there is a frequent asymmetry without obvious side‐bias. Syndactyly of third–fourth fingers was a frequent finding (62%). Polydactyly, which was classically described in SHFM6, was only present in 27% of patients. No genotype–phenotype correlation is delineated but heterozygous individuals might have mild features of SHFM, suggesting a dose‐effect of the WNT10B loss‐of‐function.
Training in clinical genetics and genetic counseling in Asia
Authors: Cutiongco‐de la Paz Eva Maria , Chung Brian Hon‐Yin , Faradz Sultana M. H. , Thong Meow‐Keong , David‐Padilla Carmencita , Lai Poh San , Lin Shuan‐Pei , Chen Yin‐Hsiu , Sura Thanyachai , Laurino Mercy
Published: May 2019

The status of training in clinical genetics and genetic counseling in Asia is at diverse stages of development and maturity. Most of the training programs are in academic training centers where exposure to patients in the clinics or in the hospital is a major component. This setting provides trainees with knowledge and skills to be competent geneticists and genetic counselors in a variety of patient care interactions. Majority of the training programs combine clinical and research training which provide trainees a broad and integrated approach in the diagnosis and management of patients while providing opportunities for research discoveries that can be translated to better patient care. The background on how the training programs in clinical genetics and genetic counseling in Asia evolved to their current status are described. Each of these countries can learn from each other through sharing of best practices and resources.
The Prague Rules: Problem Detected, but Imperfectly Solved
Authors: Sessler Anke , Stein Max
Published: May 2019

The Rules on the Efficient Conduct of Proceedings in International Arbitration (“Prague Rules”) were launched on Dec. 14, 2018, after several rounds of drafts, comments and redrafting, with the involvement of more than 40 highly regarded, mostly European practitioners.
Time‐Bar Defenses in Enforcement Proceedings: Analyzing the Rusoro Decision by the Paris Court of Appeals
Authors: d'Esclapon Pierre F. de Ravel
Published: May 2019

Venezuela's 2011 nationalization of its gold‐mining industry resulted in three arbitral awards, all grounded in the Canada‐Venezuela Bilateral Investment Treaty and rendered by tribunals constituted according the ICSID Additional Facility, a set of arbitration, conciliation and fact‐finding rules for parties that fall outside of the International Centre for Settlement of Investment Disputes' Convention.
Boosting Solid‐State Diffusivity and Conductivity in Lithium Superionic Argyrodites by Halide Substitution
Authors: Adeli Parvin , Bazak J. David , Park Kern Ho , Kochetkov Ivan , Huq Ashfia , Goward Gillian R. , Nazar Linda F.
Published: May 2019

Developing high‐performance all‐solid‐state batteries is contingent on finding solid electrolyte materials with high ionic conductivity and ductility. Here we report new halide‐rich solid solution phases in the argyrodite Li6PS5Cl family, Li6−xPS5−xCl1+x, and combine electrochemical impedance spectroscopy, neutron diffraction, and 7Li NMR MAS and PFG spectroscopy to show that increasing the Cl−/S2− ratio has a systematic, and remarkable impact on Li‐ion diffusivity in the lattice. The phase at the limit of the solid solution regime, Li5.5PS4.5Cl1.5, exhibits a cold‐pressed conductivity of 9.4±0.1 mS cm−1 at 298 K (and 12.0±0.2 mS cm−1 on sintering)—almost four‐fold greater than Li6PS5Cl under identical processing conditions and comparable to metastable superionic Li7P3S11. Weakened interactions between the mobile Li‐ions and surrounding framework anions incurred by substitution of divalent S2− for monovalent Cl− play a major role in enhancing Li+‐ion diffusivity, along with increased site disorder and a higher lithium vacancy population.
Size‐Independent Fast Ion Intercalation in Two‐Dimensional Titania Nanosheets for Alkali‐Metal‐Ion Batteries
Authors: Yang Jinlin , Xiao Xu , Gong Wenbin , Zhao Liang , Li Guohui , Jiang Kun , Ma Renzhi , Rummeli Mark H. , Li Feng , Sasaki Takayoshi , Geng Fengxia
Published: May 2019

Compared to lithium ions, the fast redox intercalation of large‐radius sodium or potassium ions into a solid lattice in non‐aqueous electrolytes is an elusive goal. Herein, by regulating the interlayer structure of stacked titania sheets through weakened layer‐to‐layer interactions and a robustly pillared gallery space, the two‐dimensional channel between neighboring sheets was completely open to guest intercalation, allowing fast intercalation that was practically irrespective of the carrier‐ion sizes. Regardless of employing regular Li or large‐radius Na and K ions, the material manifested zero strain‐like behavior with no significant change in both host structure and interlayer space, enabling comparable capacities for all tested ions along with excellent rate behaviors and extraordinarily long lifetimes, even with 80‐μm‐thick electrodes. The result highlights the importance of interlayer structural features for unlocking the electrochemical activity of a layered material.
Semi‐heterogene duale Nickel‐/Photokatalyse mit Kohlenstoffnitriden: Veresterung von Carbonsäuren mit Arylhalogeniden
Authors: Pieber Bartholomäus , Malik Jamal A. , Cavedon Cristian , Gisbertz Sebastian , Savateev Aleksandr , Cruz Daniel , Heil Tobias , Zhang Guigang , Seeberger Peter H.
Published: May 2019

Kreuzkupplungen durch duale Nickel‐/Photokatalyse sind aus Synthesesicht vielversprechend, jedoch werden meist teure, nicht wiederverwendbare Edelmetallkomplexe als Photokatalysatoren verwendet. Heterogene Halbleiter bieten hier eine nachhaltige Alternative. Graphitische Kohlenstoffnitride sind eine Klasse metallfreier Halbleiter mit großem Potenzial für photokatalytische organische Umwandlungen. Wir zeigen, dass graphitische Kohlenstoffnitride im Zusammenspiel mit Nickelkatalyse selektive C‐O‐Kreuzkupplungen von Carbonsäuren mit Arylhalogeniden induzieren können und die jeweiligen Arylester in hervorragender Ausbeute und Selektivität liefern. Dieser eingesetzte organische Halbleiter ist kompatibel mit einem breiten Substratspektrum, in der Lage, grünes Licht zu nutzen, und kann mehrfach wiederverwendet werden. Um die Kupplung bei verschiedenen Wellenlängen und Ansatzgrößen zu untersuchen, wurde zur Aufzeichnung des Reaktionsverlaufes eine In‐situ‐FTIR‐Methode entwickelt.
Catechol Oxidase versus Tyrosinase Classification Revisited by Site‐Directed Mutagenesis Studies
Authors: Prexler Sarah M. , Frassek Martin , Moerschbacher Bruno M. , Dirks‐Hofmeister Mareike E.
Published: May 2019

Catechol oxidases (COs) and tyrosinases (TYRs) are both polyphenol oxidases (PPOs) that catalyze the oxidation of ortho‐diphenols to the corresponding quinones. By the official classification, only TYRs can also catalyze the hydroxylation of monophenols to ortho‐diphenols. Researchers have been trying to find the molecular reason for the mono‐/diphenolase specificity for decades. However, the hypotheses for the lack of monophenolase activity of plant COs are only based on crystal structures so far. To test these hypotheses, we performed site‐directed mutagenesis studies and phylogenetic analyses with dandelion PPOs offering high phylogenetic diversity, the results of which refute the structure‐based hypotheses. While plant PPOs of phylogenetic group 2 solely exhibit diphenolase activity, plant PPOs of phylogenetic group 1 unexpectedly also show monophenolase activity. This finding sheds new light upon the molecular basis for mono‐/diphenol substrate specificity and challenges the current practice of generally naming plant PPOs as COs.
A Rutile TiO2 Electron Transport Layer for the Enhancement of Charge Collection for Efficient Perovskite Solar Cells
Authors: Wang Yongling , Wan Jiawei , Ding Jie , Hu Jin‐Song , Wang Dan
Published: May 2019

Interfacial charge collection efficiency has demonstrated significant effects on the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Herein, crystalline phase‐dependent charge collection is investigated by using rutile and anatase TiO2 electron transport layer (ETL) to fabricate PSCs. The results show that rutile TiO2 ETL enhances the extraction and transportation of electrons to FTO and reduces the recombination, thanks to its better conductivity and improved interface with the CH3NH3PbI3 (MAPbI3) layer. Moreover, this may be also attributed to the fact that rutile TiO2 has better match with perovskite grains, and less trap density. As a result, comparing with anatase TiO2 ETL, MAPbI3 PSCs with rutile TiO2 ETL delivers significantly enhanced performance with a champion PCE of 20.9 % and a large open circuit voltage (VOC) of 1.17 V.
Viskoelastische konjugierte polymere Fluide
Authors: Shinohara Akira , Pan Chengjun , Guo Zhenfeng , Zhou Liyang , Liu Zhonghua , Du Lei , Yan Zhichao , Stadler Florian J. , Wang Lei , Nakanishi Takashi
Published: May 2019

Optoelektronische Funktionen in viskoelastischen Polymeren öffnet den Zugang zu neuartigen, hochentwickelten weichen Materialien, die für biomedizinische und robotische Anwendungen erforderlich sind. Es ist jedoch schwierig, sowohl viskoelastisches Verhalten als auch hervorragende optoelektronische Eigenschaften zu erreichen, da eine große Konzentration von π‐konjugierten Anteilen in der Hauptkette diese drastisch versteift. Hier führen wir ein neuen Konzept zur Herstellung von additivfreien viskoelastischen konjugierten Polymeren (VE‐CPs) bei Raumtemperatur ein, das über voluminöse, flexible Alkylseitenketten als “interne Weichmacher” bei intakter π‐konjugierter Hauptkette erreicht wird. Je nach genauer chemischer Struktur der Haupt‐ und Seitenketten dieser Polymere zeigen diese ein gel‐ und elastomerähnliches rheologisches Verhalten ohne Vernetzung oder Verschlaufung. Außerdem zeigen binäre Mischungen dieser VE‐CPs eine neuartige dynamische Mischbarkeit mit selbstheilenden und mechanisch induzierten Fluoreszenzfarbänderungen.
Porphyrin Nanocage‐Embedded Single‐Molecular Nanoparticles for Cancer Nanotheranostics
Authors: Yu Guocan , Cen Tian‐Yong , He Zhimei , Wang Shu‐Ping , Wang Zhantong , Ying Xin‐Wen , Li Shijun , Jacobson Orit , Wang Sheng , Wang Lei , Lin Li‐Sen , Tian Rui , Zhou Zijian , Ni Qianqian , Li Xiaopeng , Chen Xiaoyuan
Published: May 2019

Single molecular nanoparticles (SMNPs) integrating imaging and therapeutic capabilities exhibit unparalleled advantages in cancer theranostics, ranging from excellent biocompatibility, high stability, prolonged blood lifetime to abundant tumor accumulation. Herein, we synthesize a sophisticated porphyrin nanocage that is further functionalized with twelve polyethylene glycol arms to prepare SMNPs (porSMNPs). The porphyrin nanocage embedded in porSMNPs can be utilized as a theranostic platform. PET imaging allows dynamic observation of the bio‐distribution of porSMNPs, confirming their excellent circulation time and preferential accumulation at the tumor site, which is attributed to the enhanced permeability and retention effect. Moreover, the cage structure significantly promotes the photosensitizing effect of porSMNs by inhibiting the π–π stacking interactions of the photosensitizers, ablating of the tumors without relapse by taking advantage of photodynamic therapy.
Phosphazenylphosphine: Die elektronenreichsten ungeladenen Brønsted‐ und Lewis‐Phosphor‐Basen
Authors: Ullrich Sebastian , Kovačević Borislav , Xie Xiulan , Sundermeyer Jörg
Published: May 2019

Wir entdeckten, dass Phosphazenylphosphine (PAPs) stärkere P‐Superbasen darstellen als ihre korrespondierenden Schwesinger‐Phosphazen‐N‐Superbasen. Ein einfacher synthetischer Zugang zu diesen PR3‐Derivaten sowie ihre Homologisierung, XRD‐Strukturen, Protonenaffinitäten (PA) und Gasphasenbasizitäten (GB), berechnete wie auch experimentelle pK
‐Werte werden beschrieben. Im Gegensatz zu ihren N‐basischen Verwandten entpuppen PAPs sich darüber hinaus als privilegierte Liganden in der Übergangsmetallchemie. Tatsächlich stellen sie die stärksten bislang bekannten P‐Donorliganden dar und überragen sowohl etablierte als auch kürzlich eingeführte Liganden, wie PtBu3 oder Imidazolin‐2‐ylidenaminophosphine (IAPs), hinsichtlich niedrigerer elektronischer Tolman‐Parameter (TEP) und größerer Kegelwinkel.
Highly Reproducible Formation of a Polymer Single‐Molecule Junction for a Well‐Defined Current Signal
Authors: Harashima Takanori , Hasegawa Yusuke , Kaneko Satoshi , Kiguchi Manabu , Ono Tomoya , Nishino Tomoaki
Published: May 2019

Single‐molecule devices attract much interest in the development of nanoscale electronics. Although a variety of functional single molecules for single‐molecule electronics have been developed, there still remains the need to implement sophisticated functionalization toward practical applications. Given its superior functionality encountered in macroscopic materials, a polymer could be a useful building block in the single‐molecule devices. Therefore, a molecular junction composed of polymer has now been created. Furthermore, an automated algorithm was developed to quantitatively analyze the tunneling current through the junction. Quantitative analysis revealed that the polymer junction exhibits a higher formation probability and longer lifetime than its monomer counterpart. These results suggest that the polymer provides a unique opportunity to design both stable and highly functional molecular devices for nanoelectronics.
Spatial Positioning and Chemical Coupling in Coacervate‐in‐Proteinosome Protocells
Authors: Booth Richard , Qiao Yan , Li Mei , Mann Stephen
Published: May 2019

The integration of molecularly crowded microenvironments into membrane‐enclosed protocell models represents a step towards more realistic representations of cellular structure and organization. Herein, the membrane diffusion‐mediated nucleation of either negatively or positively charged coacervate microdroplets within the aqueous lumen of individual proteinosomes is used to prepare nested hybrid protocells with spatially organized and chemically coupled enzyme activities. The location and reconfiguration of the entrapped droplets are regulated by tuning the electrostatic interactions between the encapsulated coacervate and surrounding negatively charged proteinosome membrane. As a consequence, alternative modes of a cascade reaction involving membrane‐ and coacervate‐segregated enzymes can be implemented within the coacervate‐in‐proteinosome protocells.
Fabrication of Photoactuators: Macroscopic Photomechanical Responses of Metal–Organic Frameworks to Irradiation by UV Light
Authors: Shi Yi‐Xiang , Zhang Wen‐Hua , Abrahams Brendan F. , Braunstein Pierre , Lang Jian‐Ping
Published: May 2019

Photoreactive olefinic species are incorporated into a metal–organic framework (MOF), [Zn(bdc)(3‐F‐spy)] (1). Single crystals of 1 are shown to undergo three types of photomechanical macroscopic deformation upon illumination by UV light. To demonstrate the practical potential of this system, the inclusion of 1 in a PVA (polyvinyl alcohol) composite membrane, by exploiting hydrogen‐bonding interactions, is presented. Using this composite membrane, the amplification of mechanical stress to achieve macroscopic actuation behavior is demonstrated. These results pave the way for the generation of MOF‐based soft photoactuators that produce clearly defined mechanical responses upon irradiation with light. Such systems are anticipated to have considerable potential in photomechanical energy harvesting and conversion systems.
Photoswitchable Dissipative Two‐Dimensional Colloidal Crystals
Authors: Vialetto Jacopo , Anyfantakis Manos , Rudiuk Sergii , Morel Mathieu , Baigl Damien
Published: May 2019

Control over particle interactions and organization at fluid interfaces is of great importance both for fundamental studies and practical applications. Rendering these systems stimulus‐responsive is thus a desired challenge both for investigating dynamic phenomena and realizing reconfigurable materials. Here, we describe the first reversible photocontrol of two‐dimensional colloidal crystallization at the air/water interface, where millimeter‐sized assemblies of microparticles can be actuated through the dynamic adsorption/desorption behavior of a photosensitive surfactant added to the suspension. This allows us to dynamically switch the particle organization between a highly crystalline (under light) and a disordered (in the dark) phase with a fast response time (crystallization in ≈10 s, disassembly in ≈1 min). These results evidence a new kind of dissipative system where the crystalline state can be maintained only upon energy supply.
Endlich homoleptisch: Synthese und vollständige Charakterisierung stabiler Salze des Mangantetranitrosylkations
Authors: Bohnenberger Jan , Derstine Brandon , Daub Michael , Krossing Ingo
Published: May 2019

Trotz der Ähnlichkeit zu Kohlenmonoxid ist die Chemie von homoleptischen Stickstoffmonoxidkomplexen im Unterschied zu ihren Carbonylanaloga bislang grundlegend unerforscht. Hier beschreiben wir die Synthese des ersten echten homoleptischen Übergangsmetallnitrosylkomplexes als Salz der schwach koordinierenden Anionen (WCAs) [Al(ORF)4]− und [F{Al(ORF)3}2]− (RF=C(CF3)3). Diese Salze sind in guten Ausbeuten phasenrein zugänglich und wurden vollständig durch IR/Raman‐, NMR‐ und UV/Vis‐Spektroskopie sowie mittels Einkristallstrukturanalyse und Pulverdiffraktometrie charakterisiert. Sie könnten als bisher beispiellose Modellsysteme für theoretische und experimentelle Studien zu Nitrosylkomplexen fungieren.
Optimierung der Größe von Platin‐Nanopartikeln für eine erhöhte Massenaktivität der elektrochemischen Sauerstoffreduktion
Authors: Garlyyev Batyr , Kratzl Kathrin , Rück Marlon , Michalička Jan , Fichtner Johannes , Macak Jan M. , Kratky Tim , Günther Sebastian , Cokoja Mirza , Bandarenka Aliaksandr S. , Gagliardi Alessio , Fischer Roland A.
Published: May 2019

Eine Aktivitätserhöhung der Sauerstoffreduktion (ORR) gilt als der Schlüssel zu zahlreichen Energieanwendungen. Durch die Kombination von Theorie und Experiment werden Pt‐Nanopartikel mit optimaler Größe für die effiziente ORR in Protonenaustauschmembran‐Brennstoffzellen hergestellt. Optimale Nanopartikelgrößen werden durch rechnergestütztes Screening in der Nähe von 1, 2 und 3 nm vorhergesagt. Um die Ergebnisse der Rechnungen zu bestätigen, synthetisierten wir ca. 1 nm große Pt‐Nanopartikel mit einem Templatansatz basierend auf Metall‐organischen Gerüsten. Der Elektrokatalysator wurde durch HR‐TEM und XPS charakterisiert, und seine Aktivität in der ORR wurde unter Verwendung einer rotierenden Scheibenelektrode gemessen. Die beobachtete Massenaktivität liegt nahe an der rechnerischen Vorhersage. Wir verzeichnen die aktuell höchste Massenaktivität unter reinen Pt‐Katalysatoren für die ORR im vergleichbaren Größenbereich. Die Massen‐ sowie die spezifische Aktivität waren zweimal so hoch wie die des kommerziellen Tanaka‐Katalysators.
Carboxylate‐Assisted Oxidative Addition to Aminoalkyl PdII Complexes: C(sp3)−H Arylation of Alkylamines by Distinct PdII/PdIV Pathway
Authors: Whitehurst William G. , Blackwell J. Henry , Hermann Gary N. , Gaunt Matthew J.
Published: May 2019

Reported is the discovery of an approach to functionalize secondary alkylamines using 2‐halobenzoic acids as aryl‐transfer reagents. These reagents promote an unusually mild carboxylate‐assisted oxidative addition to alkylamine‐derived palladacycles. In the presence of AgI salts, a decarboxylative C(sp3)−C(sp2) bond reductive elimination leads to γ‐aryl secondary alkylamines and renders the carboxylate motif a traceless directing group. Stoichiometric mechanistic studies were effectively translated to a Pd‐catalyzed γ‐C(sp3)−H arylation process for secondary alkylamines.
Visualizing Microglia with a Fluorescence Turn‐On Ugt1a7c Substrate
Authors: Kim Beomsue , Fukuda Masahiro , Lee Jung‐Yeol , Su Dongdong , Sanu Srikanta , Silvin Aymeric , Khoo Audrey T. T. , Kwon Taejoon , Liu Xiao , Chi Weijie , Liu Xiaogang , Choi Sejong , Wan Diana S. Y. , Park Sung‐Jin , Kim Jin‐Soo , Ginhoux Florent , Je H. Shawn , Chang Young‐Tae
Published: May 2019

Microglia, the brain‐resident macrophage, are involved in brain development and contribute to the progression of neural disorders. Despite the importance of microglia, imaging of live microglia at a cellular resolution has been limited to transgenic mice. Efforts have therefore been dedicated to developing new methods for microglia detection and imaging. Using a thorough structure–activity relationships study, we developed CDr20, a high‐performance fluorogenic chemical probe that enables the visualization of microglia both in vitro and in vivo. Using a genome‐scale CRISPR‐Cas9 knockout screen, the UDP‐glucuronosyltransferase Ugt1a7c was identified as the target of CDr20. The glucuronidation of CDr20 by Ugt1a7c in microglia produces fluorescence.
Synergy between Plasmonic and Electrocatalytic Activation of Methanol Oxidation on Palladium–Silver Alloy Nanotubes
Authors: Huang Lin , Zou Jiasui , Ye Jin‐Yu , Zhou Zhi‐You , Lin Zhang , Kang Xiongwu , Jain Prashant K. , Chen Shaowei
Published: May 2019

Localized surface plasmon resonance (LSPR) excitation of noble metal nanoparticles has been shown to accelerate and drive photochemical reactions. Here, LSPR excitation is shown to enhance the electrocatalysis of a fuel‐cell‐relevant reaction. The electrocatalyst consists of PdxAg alloy nanotubes (NTs), which combine the catalytic activity of Pd toward the methanol oxidation reaction (MOR) and the visible‐light plasmonic response of Ag. The alloy electrocatalyst exhibits enhanced MOR activity under LSPR excitation with significantly higher current densities and a shift to more positive potentials. The modulation of MOR activity is ascribed primarily to hot holes generated by LSPR excitation of the PdxAg NTs.
From Polyhalides to Polypseudohalides: Chemistry Based on Cyanogen Bromide
Authors: Schmidt Benjamin , Schröder Benjamin , Sonnenberg Karsten , Steinhauer Simon , Riedel Sebastian
Published: May 2019

Pseudohalogens are defined as molecular entities that resemble the halogens in their chemistry. While our understanding of polyhalogen chemistry has increased over the last years, research on polypseudohalogen compounds is lacking. The pseudohalogen BrCN possesses a highly pronounced σ‐hole at the bromine side of the molecule, inducing strong halogen bonding. This allows the synthesis and characterization of new polypseudohalogen anions, as shown by the single‐crystal X‐ray diffraction of [PNP][Br(BrCN)] and [PNP][Br(BrCN)3]. Both the nearly linear anion [Br(BrCN)]− and the distorted pyramidal anion [Br(BrCN)3]− were characterized by Raman spectroscopy and quantum‐chemical calculations. The behavior of the polypseudohalogen compounds in solution and as room‐temperature ionic liquids (RT‐ILs) using the [NBu4]+ cation was studied by 13C and 15N NMR spectroscopy. These types of ILs are capable of dissolving elemental gold and offer themselves as promising compounds in metal recycling.
A Very Strong Methylation Agent: [Me2Cl][Al(OTeF5)4]
Authors: Hämmerling Sebastian , Thiele Günther , Steinhauer Simon , Beckers Helmut , Müller Carsten , Riedel Sebastian
Published: May 2019

A new chloronium‐containing salt, [Me2Cl][Al(OTeF5)4], was synthesized on multigram scale by means of a simple one‐pot procedure. The isolated product can be handled at room temperature and used as a strong electrophilic methylation agent. This is demonstrated by the methylation of the very weak bases P(CF3)3, PF3, MeI, and MeBr.
Copper (II) complexes of 3,5‐di‐tert‐butyl‐2‐hydroxybenzoylhydrazones of 2‐formylpyridine and 2‐acetylpyridine, with tautomeric azine‐scaffold‐based architecture: Synthesis, crystal structures, the effect of counteranions on complexation, and their anti‐microbial and anti‐tuberculosis evaluation
Authors: Hegde Ganesh S. , Netalkar Sandeep P. , Revankar Vidyanand K.
Published: May 2019

A series of air‐ and moisture‐stable copper (II) complexes of 3,5‐di‐tert‐butyl‐2‐hydroxy‐N′‐(pyridin‐2‐ylmethylene)benzohydrazide (L1H) and 3,5‐di‐tert‐butyl‐2‐hydroxy‐N′‐(1‐(pyridin‐2‐yl)ethylidene)benzohydrazide (L2H) were synthesized. The two newly designed hydrazone Schiff base ligands with the tautomeric azine‐scaffold involving N, N and O ligating architecture were derived from the condensation of 3,5‐di‐tert‐butyl‐2‐hydroxybenzoylhydrazide with 2‐formylpyridine and 2‐acetylpyridine, respectively. The resultant ligands and their copper complexes were characterized using various spectro‐analytical techniques, like infrared (IR), 1H‐NMR, 13C‐NMR, electron paramagnetic resonance, electronic spectroscopy, thermogravimetric analysis and conductance measurements. The interesting inter‐convertible E/Z geometrical isomeric forms of the ligand L1H was established by NMR and IR spectra. In addition, the molecular structures of L2H, C3 and C4 were unambiguously established using the single‐crystal X‐ray diffraction technique. The dichlorido‐bridged dinuclear square pyramidal complexes, with the [Cu2(μ‐Cl)2L2] type of core units, were resulted for the complexes C1 and C3, whereas z‐in compressed mononuclear 1:2 (M:L) octahedral complex geometries resulted for C2, C4 and the rest of the complexes even when various copper (II) precursor salts with different counteranions were used. The ligands and their complexes were investigated for the anti‐microbial activities against gram‐positive and gram‐negative bacteria. The ligand L2H and its complexes C3 and C4 exhibited better anti‐tuberculosis activity than the controls.
Templating effect of carbon nanoforms on highly cross‐linked imidazolium network: Catalytic activity of the resulting hybrids with Pd nanoparticles
Authors: Campisciano Vincenzo , Calabrese Carla , Liotta Leonarda Francesca , La Parola Valeria , Spinella Alberto , Aprile Carmela , Gruttadauria Michelangelo , Giacalone Francesco
Published: May 2019

Two different carbon nanoforms (CNFs), namely multi‐walled carbon nanotubes (MWCNTs) and carbon nanohorns (CNHs), have been chosen as support for the direct polymerization of a bis‐vinylimidazolium salt. Transmission electron microscopy analyses revealed a templating effect of the CNFs on the growth of the polymeric network, which perfectly covers their whole surfaces creating a cylindrical or spherical coating for MWCNTs and CNHs, respectively. Subsequently, the CNFs‐polyimidazolium have been used as stabilizers for Pd nanoparticles (Pd NPs), and the obtained materials have been characterized by means of analytical and spectroscopic techniques and then employed as easily recoverable and recyclable catalysts for Suzuki and Heck reactions. Quantitative conversions have been obtained in almost all the explored reactions, even employing low loading of catalyst (down to 0.007 mol%). Suzuki reactions were carried out in pure water under aerobic conditions. Both materials showed excellent activity and recyclability for the investigated C‐C coupling reactions, with the CNHs‐based material resulting slightly more active than the MWCNTs‐based one due to a higher superficial exposure of Pd NPs.
Free‐radical emulsion copolymerization of styrene with butadiene and vinyl triethoxysilane with a cumene hydroperoxide redox initiator
Authors: Yin Changjie , Zhang Qiuyu , Zhang Zhuorui , Zhu Chengyuan , Liu Jianxun
Published: May 2019

The emulsion free‐radical copolymerization of vinyl triethoxysilane (VTES) with styrene (St) and butadiene (Bd) was initiated by cumene hydroperoxide and ferrous sulfate at 0 °C. The effects of VTES on the copolymerization conversion, reaction time, gel content, latex particle size, thermal stability, and mechanical properties were thoroughly investigated. The success of this reaction was confirmed by the peaks attributed to both Si─O─Si groups at 1065 cm−1 and the Si─O─C bond at 1046 cm−1. A kinetics analysis showed that the conversion decreased with increasing VTES mass in the monomer feed. Compared with that in the St–Bd copolymer, the latex particle size increased slightly with increasing VTES mass. The Mooney viscosity and gel content results show that a large fraction of precrosslinking molecular chains was formed in the rubber particles. The thermogravimetric analysis results indicate that the thermal stability of the copolymers increased with increasing VTES concentration. The 300% modulus and tensile strength of the St–Bd–VTES copolymer increased with the mass of VTES at first and then decreased after 3 phr VTES, whereas the elongation at break decreased with increasing VTES mass. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47896.
HLA Alleles Associated With Risk of Ankylosing Spondylitis and Rheumatoid Arthritis Influence the Gut Microbiome
Authors: Asquith Mark , Sternes Peter R. , Costello Mary‐Ellen , Karstens Lisa , Diamond Sarah , Martin Tammy M. , Li Zhixiu , Marshall Mhairi S. , Spector Timothy D. , le Cao Kim‐Anh , Rosenbaum James T. , Brown Matthew A.
Published: May 2019

Objective

HLA alleles affect susceptibility to more than 100 diseases, but the mechanisms that account for these genotype–disease associations are largely unknown. HLA alleles strongly influence predisposition to ankylosing spondylitis (AS) and rheumatoid arthritis (RA). Both AS and RA patients have discrete intestinal and fecal microbiome signatures. Whether these changes are the cause or consequence of the diseases themselves is unclear. To distinguish these possibilities, we examined the effect of HLA–B27 and HLA–DRB1 RA risk alleles on the composition of the intestinal microbiome in healthy individuals.

Methods

Five hundred sixty‐eight stool and biopsy samples from 6 intestinal sites were collected from 107 healthy unrelated subjects, and stool samples were collected from 696 twin pairs from the TwinsUK cohort. Microbiome profiling was performed using sequencing of the 16S ribosomal RNA bacterial marker gene. All subjects were genotyped using the Illumina CoreExome SNP microarray, and HLA genotypes were imputed from these data.

Results

Associations were observed between the overall microbial composition and both the HLA–B27 genotype and the HLA–DRB1 RA risk allele (P = 0.0002 and P = 0.00001, respectively). These associations were replicated using the stool samples from the TwinsUK cohort (P = 0.023 and P = 0.033, respectively).

Conclusion

This study shows that the changes in intestinal microbiome composition seen in AS and RA are at least partially due to effects of HLA‐B27 and HLA–DRB1 on the gut microbiome. These findings support the hypothesis that HLA alleles operate to cause or increase the risk of these diseases through interaction with the intestinal microbiome and suggest that therapies targeting the microbiome may be effective in preventing or treating these diseases.
Novel Carbazole‐Based N‐Heterocyclic Carbene Ligands to Access Synthetically Relevant Stilbenes in Pd‐Catalyzed Coupling Processes
Authors: Girase Tejpalsingh Ramsingh , Kapdi Anant R.
Published: May 2019

A series of new carbazole‐based N‐heterocyclic carbene (NHC) ligands have been synthesized in a simple and facile synthetic route and subsequently used in a Pd/carbazole‐based NHC catalytic system, which was found to be effective in catalyzing Heck reactions to provide substituted stilbene derivatives in good yields. Several bioactive stilbenes, including pterostilbene, pinosylvin, trimethoxy resveratrol, and resveratrol, were synthesized in good yields, and a 10 mmol scale‐up was also performed for trimethoxy resveratrol. The synthetic application was also extended by performing a double‐tandem chemoselective Heck reaction followed by Miyaura borylation in a one‐pot procedure to give single‐step access to synthetically useful stilbenyl boronate esters. Similarly, a unique triple‐tandem protocol of a chemoselective Heck reaction/Miyaura borylation/Suzuki–Miyaura coupling reaction sequence was performed for the one‐pot modification of biologically relevant molecules.
PI‐PD controller design for time delay systems via the weighted geometrical center method
Authors: Ozyetkin Munevver Mine , Onat Cem , Tan Nusret
Published: May 2019

In this study, a PI‐PD controller tuning method is presented using the weighted geometrical center method, which is based on the calculation of the weighted geometric center of the stability region obtained by the stability boundary locus method. The proposed method for tuning of PI‐PD controller parameters (kd,kf,kp and ki) is performed in three steps. In the first step, the (kd,kf) parameter region for the inner loop with PD controller is obtained, and then the weighted geometric center of this region is calculated. In the second step, the inner PD loop is reduced to a single block using the numerical values of (kd,kf) that are obtained in the first step. Then, the (kp,ki) values of the external loop with PI controller are determined by the same procedure. This tuning method has some advantages over other tuning methods in terms of simplicity and robustness. The simulation examples show that a PI‐PD controller designed using the proposed method provides good performance results when compared to other tuning methods presented in the literature.
Veränderung des Frost‐ und Frost‐Tausalzwiderstands von Hochleistungsbeton in Abhängigkeit vom Betonalter
Authors: Palecki Susanne
Published: May 2019

Beton ist in der Praxis verschiedenen Umwelteinflüssen wie z. B. einem Frost‐Tausalzangriff ausgesetzt, der je nach Zusammensetzung die Dauerhaftigkeit unterschiedlich stark beeinflussen kann. Für eine entsprechende Überprüfung der Eignung einer Betonmischung vor deren Einsatz in der Praxis stehen verschiedene Laborprüfverfahren zur Verfügung, die aus Konformitätsgründen ein Prüfalter von 28 Tagen vorschreiben, obwohl in der Praxis Bauteile häufig erst zu einem späteren Zeitpunkt Frost‐Tau‐Wechseln ausgesetzt sind. Die Erfahrungen zeigen, dass besonders bei Betonen mit Zusatzstoffen, wie sie bei hochfesten Betonen eingesetzt werden, eine Beeinflussung der Prüfergebnisse vom Zeitpunkt der Frost‐Tausalzprüfung gegeben ist. Hier wird sowohl die innere als auch äußere Schädigung mit zunehmendem Prüfalter negativ verändert. Als Ursache können in erster Linie Änderungen innerhalb der Gefügestruktur sowie der gefrierbaren Wassermenge genannt werden.

Im Rahmen eines Forschungsprojekts wurde dieser Sachverhalt an mehreren Reihen hochfester Betonmischungen unterschiedlichster Zusammensetzung über einen Zeitraum von bis zu drei Jahren systematisch überprüft. Die Untersuchungen erfolgten dabei sowohl an labor‐ als auch freigelagerten Proben. Ziel des Projekts war eine Beschreibung der Schädigungs‐ und Transportmechanismen unter Frost‐/Frost‐Tausalzeinwirkung in Abhängigkeit von der Zeit und den Umgebungsbedingungen unter Berücksichtigung der sich verändernden Materialparameter.
Kriechen und mechanische Eigenschaften von Straßenbetonen nach AKR‐provozierender Lagerung
Authors: Mielich Oliver , Reinhardt Hans‐Wolf , Özkan Hasan
Published: May 2019

Vier Straßenbetone wurden mit der am F.A. Finger‐Institut für Baustoffkunde der Bauhaus‐Universität Weimar entwickelten FIB‐Klimawechsellagerung einer AKR‐provozierenden Lagerung unterzogen. Es wurden Dehnungen, Druckfestigkeit, Elastizitätsmodul, Kriechen und Schwinden bestimmt. Die Ergebnisse zeigen, dass der AKR‐bedingte Schädigungsprozess wie folgt beschrieben werden kann: AKR‐verursachte Mikrorissbildung in der Zementmatrix ist für die Druckfestigkeit des Betons eher nebensächlich. Löseprozesse und Rissbildungen in der Gesteinskörnung setzen die Steifigkeit des Betons (E‐Modul) herab, nicht jedoch die Druckfestigkeit. Die Risse, die bei langsam reagierenden Gesteinskörnungen ihren Ursprung im Gesteinskorn haben, setzen sich in die Matrix fort. Bei größerem Matrixvolumen und vermehrter Rissbildung wird das Kriechen vergrößert. Ungeschädigter Beton zeigt, wenn auch nur marginal, unter Einfluss einer Natriumchloridlösung (NaCl‐Lösung) ein erhöhtes Kriechen, was auf einen chemischen Einfluss der Matrix hinweist.
Parallel experimental evolution reveals a novel repressive control of GalP on xylose fermentation in Escherichia coli
Authors: Kurgan Gavin , Sievert Christian , Flores Andrew , Schneider Aidan , Billings Thomas , Panyon Larry , Morris Chandler , Taylor Eric , Kurgan Logan , Cartwright Reed , Wang Xuan
Published: May 2019

Efficient xylose utilization will facilitate microbial conversion of lignocellulosic sugar mixtures into valuable products. In Escherichia coli, xylose catabolism is controlled by carbon catabolite repression (CCR). However, in E. coli such as the succinate‐producing strain KJ122 with disrupted CCR, xylose utilization is still inhibited under fermentative conditions. To probe the underlying genetic mechanisms inhibiting xylose utilization, we evolved KJ122 to enhance its xylose fermentation abilities in parallel and characterized the potential convergent genetic changes shared by multiple independently evolved strains. Whole‐genome sequencing revealed that convergent mutations occurred in the galactose regulon during adaptive laboratory evolution potentially decreasing the transcriptional level or the activity of GalP, a galactose permease. We showed that deletion of galP increased xylose utilization in both KJ122 and wild‐type E. coli, demonstrating a common repressive role of GalP for xylose fermentation. Concomitantly, induced expression of galP from a plasmid repressed xylose fermentation. Transcriptome analysis using RNA sequencing indicates that galP inactivation increases transcription levels of many catabolic genes for secondary sugars including xylose and arabinose. The repressive role of GalP for fermenting secondary sugars in E. coli suggests that utilization of GalP as a substitute glucose transporter is undesirable for conversion of lignocellulosic sugar mixtures.
Essential Features of Electrolyte Solvents that Enable High‐Performance LiS Batteries
Authors: Kang Jin Kyeong , Kim Tae Jeong , Park Jong Won , Jung Yongju
Published: May 2019

In a lithium‐ion battery, the organic solvent in the electrolyte simply acts as a medium that facilitates ionic charge transfer, whereas for the lithium‐sulfur (Li—S) battery, the choice of the electrolyte is critical as it influences the chemical nature of the soluble polysulfides and the cycling stability of the lithium metal anode. Li‐S batteries currently use ether‐based electrolytes with high polysulfide solubility. Until now, however, the necessary requirements and the roles of the electrolytes have been inconclusive. This work elucidates the essential features and functions of the electrolyte based on an intensive investigation into 17 variants of solvents. Furthermore, examples of electrolytes for high performance, rechargeable Li—S batteries are suggested. The three major study procedures are (1) analyzing the chemical stability of reactive polysulfide species and lithium metal in the solvents of choice, (2) inspecting the chemical reactivity of lithium metal in a polysulfide solution, and (3) evaluating the influences of the solvent on the performance of Li—S cells. Based on the chemical and electrochemical test results, we suggest that the stability of the active materials (i.e., lithium metal and lithium polysulfides) should be ensured in an electrolyte for the proper operation of Li—S cells, that chemical reactions between the polysulfide species and lithium metal should be negligible during the charge–discharge process. In addition, we have confirmed that the high polysulfide solubility is essential for high rate performance.