bluuebunny/crossref_metadata_2025 huggingface dataset:
Eine molekulare Seilbahn für den transmembranären Ionentransport
Authors: Credi Alberto
Published: February 2019

Der kontrollierte Transport molekularer und ionischer Substrate durch Doppelschichtmembranen ist eine grundlegende Aufgabe für die Funktion lebender Organismen. Er stellt außerdem eine äußerst faszinierende und anspruchsvolle Herausforderung für künstliche molekulare Maschinen dar. Der kürzlich veröffentlichte Bericht über einen synthetischen molekularen Transmembranpendler, der Kaliumionen selektiv entlang eines Gradienten abwärts in einem liposomalem System transportieren kann, stellt einen kleinen, aber bedeutenden Schritt zum Erreichen dieses Ziels dar.
A Highly Red‐Emissive Lead‐Free Indium‐Based Perovskite Single Crystal for Sensitive Water Detection
Authors: Zhou Lei , Liao Jin‐Feng , Huang Zeng‐Guang , Wei Jun‐Hua , Wang Xu‐Dong , Li Wen‐Guang , Chen Hong‐Yan , Kuang Dai‐Bin , Su Cheng‐Yong
Published: February 2019

Low‐dimensional luminescent lead halide perovskites have attracted tremendous attention for their fascinating optoelectronic properties, while the toxicity of lead is still considered a drawback. Herein, we report a novel lead‐free zero‐dimensional (0D) indium‐based perovskite (Cs2InBr5⋅H2O) single crystal that is red‐luminescent with a high photoluminescence quantum yield (PLQY) of 33 %. Experimental and computational studies reveal that the strong PL emission might originate from self‐trapping excitons (STEs) that result from an excited‐state structural deformation. More importantly, the in situ transformation between hydrated Cs2InBr5⋅H2O and the dehydrated form is accompanied with a switchable dual emission, which enables it to act as a PL water‐sensor in humidity detection or the detection of traces of water in organic solvents.
Elektronen‐defizitäre Triboran‐ und Tetraboran‐Ringverbindungen: Synthese, Struktur und Bindung
Authors: Himmel Hans‐Jörg
Published: February 2019

Elektronen‐defizitäre kleine Borringe sind einzigartig durch ihre σ‐ und π‐delokalisierten Elektronensysteme sowie die Vermeidung “klassischer” elektronischer Strukturen mit Zwei‐Zentren‐Zwei‐Elektronen‐Bindungen. Diese Ringe sind tolerant gegenüber unterschiedlichen Gerüstelektronen‐Zahlen, wodurch ihre Redox‐Chemie äußerst interessant ist. In den letzten Jahrzehnten wurde eine Reihe stabiler Verbindungen mit verschiedenen Elektronenzahlen in den zentralen B3‐ und B4‐Einheiten synthetisiert. Unter Zuhilfenahme quantenchemischer Rechnungen wurde ihre elektronische Struktur detailliert untersucht. Andererseits ist die Chemie dieser Ringverbindungen weitgehend unerforscht und beschränkt sich bisher auf Protonierungs‐ und Redox‐Reaktionen einiger isolierter Systeme. Die Verknüpfung mehrerer B3‐ und/oder B4‐Ringsysteme sollte zu Verbindungen mit interessanten elektronischen Eigenschaften führen, bis hin zu neuen borbasierten Materialien. In diesem Aufsatz werden wichtige experimentelle und theoretische Resultate zusammengefasst, womit die Basis für die Erforschung der Chemie dieser Ringe gelegt und im Besonderen ihre Integration in höhermolekulare Architekturen vorbereitet werden sollen.
Forming Benzylic Iodides via a Nickel Catalyzed Diastereoselective Dearomative Carboiodination Reaction of Indoles
Authors: Marchese Austin D. , Lind Florian , Mahon Áine E. , Yoon Hyung , Lautens Mark
Published: February 2019

A diastereoselective dearomative carboiodination reaction is reported. We report a novel metal‐catalyzed approach to install reactive secondary benzylic iodides. Utilizing the unique reactivity of nickel, we have expanded the carboiodination reaction to non‐activated aromatic double bonds forming a previously unattainable class of iodides. We also report a broadly applicable method to avoid the use of a metallic reducing agent by utilizing an alkyl phosphite as the ligand. The reaction is thought to proceed through a syn intramolecular carbonickelation across a 2‐substituted indole followed by a diastereoretentive reductive elimination of the carbon−iodine bond. The complex iodinated indolines generated in the reaction were obtained in moderate to good yields and good to excellent diastereoselectivity. The products were easily functionalized by a variety of synthetic methods.
Water Vapor Does Not Catalyze the Reaction between Methanol and OH Radicals
Authors: Chao Wen , Jr‐Min Lin Jim , Takahashi Kaito , Tomas Alexandre , Yu Lu , Kajii Yoshizumi , Batut Sébastien , Schoemaecker Coralie , Fittschen Christa
Published: February 2019

Recent reports [Jara‐Toro et al., Angew. Chem. Int. Ed. 2017, 56, 2166 and PCCP 2018, 20, 27885] suggest that the rate coefficient of OH reactions with alcohols would increase by up to two times in going from dry to high humidity. This finding would have an impact on the budget of alcohols in the atmosphere and it may explain differences in measured and modeled methanol concentrations. The results were based on a relative technique carried out in a small Teflon bag, which might suffer from wall reactions. The effect was reinvestigated using a direct fluorescence probe of OH radicals, and no catalytic effect of H2O could be found. Experiments in a Teflon bag were also carried out, but the results of Jara‐Toro et al. were not reproducible. Further theoretical calculations show that the water‐mediated reactions have negligible rates compared to the bare reaction and that even though water molecules can lower the barriers of reactions, they cannot make up for the entropy cost.
Hohe Block‐Temperatur der Magnetisierung und herausragende Koerzitivfeldstärke im Azafulleren Tb2@C79N mit einer Einelektronen‐Terbium‐Terbium‐Bindung
Authors: Velkos Georgios , Krylov Denis S. , Kirkpatrick Kyle , Spree Lukas , Dubrovin Vasilii , Büchner Bernd , Avdoshenko Stanislav M. , Bezmelnitsyn Valeriy , Davis Sean , Faust Paul , Duchamp James , Dorn Harry C. , Popov Alexey A.
Published: February 2019

Das Azafulleren Tb2@C79N wird als Einzelmolekülmagnet mit einer hohen 100‐s‐Block‐Temperatur der Magnetisierung von 24 K und hoher Koerzitivfeldstärke identifiziert. Die magnetischen Momente von Tb mit magnetischer Vorzugsachsen‐Anisotropie sind durch den ungepaarten Spin der Einelektronenbindung stark gekoppelt. Die Relaxation der Magnetisierung findet in Tb2@C79N bei Temperaturen unter 15 K durch Quantentunneln der Magnetisierung mit einer charakteristischen Relaxationszeit von τQTM=16 462±1230 s statt. Bei höheren Temperaturen folgt die Relaxation dem Orbach‐Mechanismus mit einer Barriere von 757±4 K, was dem angeregten Zustand entspricht, in dem einer der Tb‐Spins umgekehrt wird.
Generation of Nanoparticle, Atomic‐Cluster, and Single‐Atom Cobalt Catalysts from Zeolitic Imidazole Frameworks by Spatial Isolation and Their Use in Zinc–Air Batteries
Authors: Han Xiaopeng , Ling Xiaofei , Wang Ying , Ma Tianyi , Zhong Cheng , Hu Wenbin , Deng Yida
Published: February 2019

The size effect of transition‐metal nanoparticles on electrocatalytic performance remains ambiguous especially when decreasing the size to the atomic level. Herein, we report the spatial isolation of cobalt species on the atomic scale, which was achieved by tuning the zinc dopant content in predesigned bimetallic Zn/Co zeolitic imidazole frameworks (ZnCo‐ZIFs), and led to the synthesis of nanoparticles, atomic clusters, and single atoms of Co catalysts on N‐doped porous carbon. This synthetic strategy allowed an investigation of the size effect on electrochemical behavior from nanometer to Ångström dimensions. Single‐atom Co catalysts showed superior bifunctional ORR/OER activity, durability, and reversibility in Zn–air batteries compared with the other derivatives and noble‐metal Pt/C+RuO2, which was attributed to the high reactivity and stability of isolated single Co atoms. Our findings open up a new avenue to regulate the metal particle size and catalytic performance of MOF derivatives.
Nucleophilic Aromatic Substitution at Benzene with Powerful Strontium Hydride and Alkyl Complexes
Authors: Rösch Bastian , Gentner Thomas Xaver , Elsen Holger , Fischer Christian A. , Langer Jens , Wiesinger Michael , Harder Sjoerd
Published: February 2019

Key to the isolation of the first alkyl strontium complex was the synthesis of a strontium hydride complex that is stable towards ligand exchange reactions. This goal was achieved by using the super bulky β‐diketiminate ligand DIPePBDI (CH[C(Me)N‐DIPeP]2, DIPeP=2,6‐diisopentylphenyl). Reaction of DIPePBDI‐H with Sr[N(SiMe3)2]2 gave (DIPePBDI)SrN(SiMe3)2, which was converted with PhSiH3 into [(DIPePBDI)SrH]2. Dissolved in C6D6, the strontium hydride complex is stable up to 70 °C. At 60 °C, H–D isotope exchange gave full conversion into [(DIPePBDI)SrD]2 and C6D5H. Since H–D exchange with D2 is facile, the strontium hydride complex served as a catalyst for the deuteration of C6H6 by D2. Reaction of [(DIPePBDI)SrH]2 with ethylene gave [(DIPePBDI)SrEt]2. The high reactivity of this alkyl strontium complex is demonstrated by facile ethylene polymerization and nucleophilic aromatic substitution with C6D6, giving alkylated aromatic products and [(DIPePBDI)SrD]2.
Selective and Efficient Removal of Fluoride from Water: In Situ Engineered Amyloid Fibril/ZrO2 Hybrid Membranes
Authors: Zhang Qingrui , Bolisetty Sreenath , Cao Yiping , Handschin Stephan , Adamcik Jozef , Peng Qiuming , Mezzenga Raffaele
Published: February 2019

We report a new strategy for efficient removal of F− from contaminated water streams, and it relies on carbon hybrid membranes made of amyloid fibril/ZrO2 nanoparticles (<10 nm). These membranes exhibit superior selectivity for F− against various competitive ions, with a distribution coefficient (Kd) as high as 6820 mL g−1, exceeding commercial ion‐exchange resins (IRA‐900) by 180 times and outdoing the performance of most commercial carbon‐activated aluminum membranes. At both low and high (ca. 200 mg L−1) F− concentrations, the membrane efficiency exceeds 99.5 % removal. For real untreated municipal tap water (ca. 2.8 mg L−1) under continuous operating mode, data indicates that about 1750 kg water m−2 membrane can be treated while maintaining drinking water quality, and the saturated membranes can be regenerated and reused several times without decrease in performance. This technology is promising for mitigating the problem of fluoride water contamination worldwide.
Selectivity Switch in a Rhodium(II) Carbene Triggered Cyclopentannulation: Divergent Access to Three Polycyclic Indolines
Authors: Liu Hua‐Kui , Wang Sunewang R. , Song Xiang‐Yang , Zhao Liu‐Peng , Wang Lijia , Tang Yong
Published: February 2019

A selectivity switch in a RhII/carbene‐triggered cyclopentannulation with catalytic InCl3 is reported for the first time, affording both diastereomers of the fused spiroindolines and an unusual bridged tetracyclic indoline in high yields with excellent selectivities. Mechanistic studies indicate an intramolecular annulation of the indole with an in situ formed aminocyclopropane. The stepwise thermal conversions from the kinetic spiroindoline to the metastable bridged indoline, and then to the thermodynamic spiroindoline, involving a ring‐opening rearrangement of a cyclopentane, is crucial for selectivity control.
High Blocking Temperature of Magnetization and Giant Coercivity in the Azafullerene Tb2@C79N with a Single‐Electron Terbium–Terbium Bond
Authors: Velkos Georgios , Krylov Denis S. , Kirkpatrick Kyle , Spree Lukas , Dubrovin Vasilii , Büchner Bernd , Avdoshenko Stanislav M. , Bezmelnitsyn Valeriy , Davis Sean , Faust Paul , Duchamp James , Dorn Harry C. , Popov Alexey A.
Published: February 2019

The azafullerene Tb2@C79N is found to be a single‐molecule magnet with a high 100‐s blocking temperature of magnetization of 24 K and large coercivity. Tb magnetic moments with an easy‐axis single‐ion magnetic anisotropy are strongly coupled by the unpaired spin of the single‐electron Tb−Tb bond. Relaxation of magnetization in Tb2@C79N below 15 K proceeds via quantum tunneling of magnetization with the characteristic time τQTM=16 462±1230 s. At higher temperature, relaxation follows the Orbach mechanism with a barrier of 757±4 K, corresponding to the excited states, in which one of the Tb spins is flipped.
Hybrid Organic–Inorganic Thermoelectric Materials and Devices
Authors: Jin Huile , Li Jun , Iocozzia James , Zeng Xin , Wei Pai‐Chun , Yang Chao , Li Nan , Liu Zhaoping , He Jr Hau , Zhu Tiejun , Wang Jichang , Lin Zhiqun , Wang Shun
Published: February 2019

Hybrid organic–inorganic materials have been considered as a new candidate in the field of thermoelectric materials since the last decade owing to their great potential to enhance the thermoelectric performance by utilizing the low thermal conductivity of organic materials and the high Seebeck coefficient, and high electrical conductivity of inorganic materials. Herein, we provide an overview of interfacial engineering in the synthesis of various organic–inorganic thermoelectric hybrid materials, along with the dimensional design for tuning their thermoelectric properties. Interfacial effects are examined in terms of nanostructures, physical properties, and chemical doping between the inorganic and organic components. Several key factors which dictate the thermoelectric efficiency and performance of various electronic devices are also discussed, such as the thermal conductivity, electric transportation, electronic band structures, and band convergence of the hybrid materials.
Improvements in thermal conductivity and mechanical properties of HDPE/nano‐SiC composites by the synergetic effect of extensional deformation and ISBS
Authors: Xiaochun Yin , Yang Li , Di Cheng , Yanhong Feng , Guangjian He
Published: February 2019

A new melt blending method under synergy of extensional deformation and in‐situ bubble stretching for high‐density polyethylene (HDPE) thermally conductive composites filled by nano silicon carbide (nano‐SiC) was reported. Effects of loadings and mixing time of azodicarbonamide (AC) foaming agent on the properties of the composites were experimentally studied. Scanning electron microscopy imaging showed that the nano‐SiC particles dispersed uniformly in the HDPE matrix with the addition of AC. The complex viscosity and storage modulus increased with increasing AC content and decreased with increasing mixing time. The mechanical properties of the composites improved with the addition of AC and proper mixing times. The thermal conductivity of the composites increased from 0.2 to 0.7 W m−1 K−1 without any damage to the mechanical properties when the mixing time increased from 2 to 6 min. These results showed that the new mixing technique enables us to prepare particle‐filled thermally conductive polymer composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47648.
Novel dye for detection of callus embryo by confocal laser scanning fluorescence microscopy
Authors: Kirilova Elena , Mickevica Ilona , Mezaraupe Ligita , Puckins Aleksandrs , Rubenina Ilze , Osipovs Sergejs , Kokina Inese , Bulanovs Andrejs , Kirjusina Muza , Gavarane Inese
Published: February 2019

In the present study a new luminescent dye 3‐N‐(2‐pyrrolidinylacetamido)benzanthrone (AZR) was synthesized. Spectroscopic measurements of the novel benzanthrone 3‐aminoderivative were performed in seven organic solvents showing strong fluorescence. The capability of the prepared dye for visualization has been tested on flax, red clover and alfalfa to determinate the embryo in plant callus tissue cultures. Callus cells were stained with AZR and further analysed utilizing confocal laser scanning fluorescence microscopy. Performed experiments show high visualization effectiveness of newly synthesized fluorescent dye AZR that is efficient in fast and relatively inexpensive diagnostics of callus embryos that are problematic due to in vitro culture specificity.
Utility of bevacizumab in advanced hepatocellular carcinoma: A veterans affairs experience
Authors: Wattenberg Max M. , Damjanov Nevena , Kaplan David E.
Published: February 2019

Hepatocellular carcinoma (HCC) is a challenging to treat malignancy with few available systemic therapies. Angiogenesis has been implicated in the pathogenesis of HCC and prior studies have suggested a role for anti‐VEGF therapy. Prior to FDA approval of second‐line therapy for advanced HCC, from 2008 until 2017, we initiated bevacizumab monotherapy (5‐10 mg/kg every 2‐3 weeks) in 12 patients with intolerance of or progression during sorafenib therapy. Bevacizumab therapy was well tolerated with only 1/12 patients experiencing a grade 3‐4 treatment‐related adverse event (transient ischemic attack) and only 2/12 patients discontinued the therapy due to adverse events. Median overall survival was 20.2 months (IQR, 7.0‐43.5), with a median time to radiologic progression of 10.4 months (IQR, 2.8‐16.1) and a disease control rate of 54%. Taken together, our experience provides rationale for further prospective investigation of bevacizumab for the treatment of advanced HCC.
A role of GCC88 in the retrograde transport of CI‐M6PR and the maintenance of lysosomal activity
Authors: Cui Yi , Yang Zhe , Teasdale Rohan D.
Published: February 2019

GCC88 is a golgin coiled‐coil protein at the trans‐Golgi (TGN) that functions as a tethering factor for the endosome‐derived retrograde transport vesicles. Here, we demonstrate that GCC88 is required for the endosome‐to‐TGN retrograde transport of the cation‐independent mannose 6‐phosphate receptor (CI‐M6PR). The knockout of GCC88 perturbs the retrieval of CI‐M6PR and decreases its cellular level at the steady state, which causes the improper processing of newly synthesized cathepsin‐D, a lysosomal hydrolase dependent on CI‐M6PR for its delivery to lysosomes. At the whole cell level, the knockout of GCC88 reduces the lysosomal proteolytic capacity but does not impair of the efficiency of autophagy within these cells.
Classification scheme for ductal morphology in cyanotic patients with ductal dependent pulmonary blood flow and association with outcomes of patent ductus arteriosus stenting
Authors: Qureshi Athar M. , Goldstein Bryan H. , Glatz Andrew C. , Agrawal Hitesh , Aggarwal Varun , Ligon R. Allen , McCracken Courtney , McDonnell Alicia , Buckey Timothy M. , Whiteside Wendy , Metcalf Christina M. , Petit Christopher J.
Published: February 2019

Objectives

To devise a classification scheme for ductal morphology in patients with ductal dependent pulmonary blood flow (PBF) that can be used to assess outcomes.

Background

The impact of ductal morphology on outcomes following patent ductus arteriosus (PDA) stenting is not well defined.

Methods

Patients <1 year of age who underwent PDA stenting for ductal dependent PBF at the four centers comprising the Congenital Catheterization Research Collaborative (CCRC) were included. A classification scheme for PDA morphology was devised based on a tortuosity index (TI)—Type I (straight), Type II (one turn), and Type III (multiple turns). A subtype classification was used based upon the ductal origin.

Results

One hundred and five patients underwent PDA stenting. TI was Type I in 58, Type II in 24, and Type III in 23 PDAs, respectively. There was a significant association between ductal origin and vascular access site (p < 0.001). Procedure times and need for >1 stent did not differ based on TI. Greater TI was associated with pulmonary artery (PA) jailing (p = 0.003). Twelve (11.4%) patients underwent unplanned reintervention, more commonly with greater TI (p = 0.022) and PA jailing (p < 0.001). At the time of subsequent surgical repair/palliative staging, PA arterioplasty was performed in 32 patients, more commonly when a PA was jailed (p = 0.048). PA jailing did not affect PA size at follow up.

Conclusions

The proposed qualitative and quantitative PDA morphology classification scheme may be helpful in anticipating outcomes in patients with ductal dependent PBF undergoing PDA stenting.
Trends in complete heart block after transcatheter aortic valve replacement: A population based analysis
Authors: Al‐Ogaili Ahmed , Fugar Setri , Okoh Alexis , Kolkailah Ahmed A. , Al Hashemi Nawaf , Ayoub Ali , Russo Mark J. , Kavinsky Clifford J.
Published: February 2019

Objectives

To define the national rate of complete heart block (CHB) after transcatheter aortic valve replacement (TAVR) and its impact on procedural mortality, overall cost, and length of hospital stay.

Background

CHB leading to permanent pacemaker (PPM) implantation is one of the most common complications post TAVR. National data on the temporal trend of CHB post TAVR are lacking.

Methods

We queried the 2012–2014 National Inpatient Sample databases to identify all patients who underwent TAVR. Patients with preoperative pacemakers or implantable cardioverter‐defibrillators were excluded. Association between CHB and outcomes, and overall trends in rate of CHB, PPM implantation, and inpatient mortality were examined.

Results

Of 35,500 TAVR procedures, 3,675 (10.4%) had CHB. Overall, occurrence of CHB significantly increased from 8.4% in 2012 to 11.8% in 2014 (adjusted OR per year: 1.23; 95% confidence interval [CI]: 1.17–1.29, P trend <0.001). During the same period, PPM implantation increased from 9.5 to 13.7% (adjusted OR per year: 1.22; 95% CI: 1.16–1.28, P trend <0.001). Patients with CHB had higher odds of in‐hospital mortality when compared to patients without CHB (5.9% vs. 4.2%, adjusted OR: 1.32; 95% CI: 1.12–1.56; p = 0.001). Moreover, CHB was also associated with longer length of stay (LOS) and higher hospitalization cost.

Conclusions

There was a significant increase in rates of CHB and PPM implantation over the study period. Development of CHB was associated with increased in‐hospital mortality, LOS, and hospitalization cost.
Catalytic Dehydrogenation of Formic Acid with Ruthenium‐PNP‐Pincer Complexes: Comparing N‐Methylated and NH‐Ligands
Authors: Agapova Anastasiya , Alberico Elisabetta , Kammer Anja , Junge Henrik , Beller Matthias
Published: February 2019

Complexes Ru(H)(Cl)(CO)(HN{CH2CH2P(iPr)2}2) 7 and Ru(H)(Cl)(CO)(CH3N{CH2CH2P(iPr)2}2) 8 were compared for the selective dehydrogenation (DH) of formic acid (FA) at different pH values. Remarkably, highest activities were observed in acidic environment (pH 4.5). Under all investigated conditions, the N‐methylated complex 8 showed improved performance compared to 7. These observations can be mechanistically explained with protonation of 4H/3Me being the key step in formic acid DH for both complexes.
Interplay Between Site Activity and Density of BCC Iron for Ammonia Synthesis Based on First‐Principles Theory
Authors: Zhang Bing‐Yan , Su Hai‐Yan , Liu Jin‐Xun , Li Wei‐Xue
Published: February 2019

Site activity and density are two key factors in determining the overall activity of catalysts in heterogeneous catalysis. Combined DFT calculation, Wulff construction and micro‐kinetic analysis, we reveal here a significant interplay between site activity and density of bcc iron catalyzed ammonia synthesis at low coverage regime. It is found that for large size particles, Fe (111) and (311) surfaces that consist of active C7 sites are limited by their low site density, whereas those with the most abundant sites are limited by their low activity. In contrast, Fe (221), (211) and (310) surfaces which consist of active C7 and/or B5 sites and remain abundant, dominate the overall reaction rate, turn‐over‐frequency and mass specific activity. Turn‐over‐frequency of the smaller Fe particles (2–6 nm) decreases by a factor of two or three due to the absence of (221) surface. For the particle size less than 2 nm, the corresponding activity decreases dramatically owing to the absence of all active C7 and/or B5 sites. Interplay of site abundance and intrinsic activity of catalysts is highlighted, and the insights revealed could be used to design and develop better catalysts for ammonia synthesis and other important reactions of technological interest.
Light‐Responsive Arylazopyrazole Gelators: From Organic to Aqueous Media and from Supramolecular to Dynamic Covalent Chemistry
Authors: Chu Chih‐Wei , Stricker Lucas , Kirse Thomas M. , Hayduk Matthias , Ravoo Bart Jan
Published: February 2019

Versatile photoresponsive gels based on tripodal low molecular weight gelators (LMWGs) are reported. A cyclohexane‐1,3,5‐tricarboxamide (CTA) core provides face‐to‐face hydrogen bonding and a planar conformation, inducing the self‐assembly of supramolecular polymers. The CTA core was substituted with three arylazopyrazole (AAP) arms. AAP is a molecular photoswitch that isomerizes reversibly under alternating UV and green light irradiation. The E isomer of AAP is planar, favoring the self‐assembly, whereas the Z isomer has a twisted structure, leading to a disassembly of the supramolecular polymers. By using tailor‐made molecular design of the tripodal gelator, light‐responsive organogels and hydrogels were obtained. Additionally, in the case of the hydrogels, AAP was coupled to the core through hydrazones, so that the hydrogelator and, hence, the photoresponsive hydrogel could also be assembled and disassembled by using dynamic covalent chemistry.
Diverse Role of Solvents in Controlling Supramolecular Chirality
Authors: Xue Shixin , Xing Pengyao , Zhang Jingbo , Zeng Yongfei , Zhao Yanli
Published: February 2019

Supramolecular self‐assembly stands for the spontaneous aggregation of small organic compounds or polymers into ordered structures at any scale. When being induced by inherent molecular chiral centers or ambient asymmetric factors, asymmetric spatial arrangement between building units shall occur, which is defined as supramolecular chirality. Except for molecular design, utilizing external stimulus factors to tune supramolecular chirality is a promising approach. In this Concept article, we particularly discuss the important role of solvents in manipulating the chirality of self‐assembled systems. The impact of solvents on the chirality is generally based on three properties of solvents, i.e., chirality, polarity, and active coassembly with building blocks. Molecular self‐assembly in chiral solvents could undergo the chirality transfer, exhibiting a chiral induction effect. Solvent polarity often determines intermolecular orientation. As a consequence, those building blocks with both polar and apolar segments might change their chirality depending on the solvent polarity. We elaborate the active participation of solvent molecules into ordered structures together with building blocks, where solvents and building blocks exhibit a coassembly manner. By specific treatments such as heating and cooling, solvents could be released or re‐entrapped, allowing a smart control over supramolecular chirality. The solvent effect in manipulating two‐dimensional chiral self‐assemblies is then discussed. The perspective and future development in this research field are presented at last.
Introducing the Chiral Transient Directing Group Strategy to Rhodium(III)‐Catalyzed Asymmetric C−H Activation
Authors: Li Guozhu , Jiang Jijun , Xie Hui , Wang Jun
Published: February 2019

The chiral transient directing group (TDG) strategy has been successfully introduced to the rhodium(III)‐catalyzed asymmetric C−H activation. In the presence of a catalytic amount of a chiral amine and an achiral rhodium catalyst, various chiral phthalides were synthesized from simple aldehydes with high chemoselectivity, regioselectivity, and enantioselectivity (53 examples, up to 73 % yield and >99 % ee). It is noteworthy that the chiral induction model is different from the previously reported chiral TDG system using amino acid derivatives and palladium salts. The imino group generated in situ from chiral amine and aldehyde acts as the monodentate TDG to promote the C−H activation, stereoselectively generating the chiral rhodacycle bearing a chiral metal center. Moreover, the stereogenic center of the product is created and stereocontrolled during the Grignard‐type addition of the C−Rh bond to aldehyde, rather than during the C−H activation step.
Formation and stability of water‐in‐oil nano‐emulsions with mixed surfactant using in‐situ combined condensation‐dispersion method
Authors: Kundu Partha , Arora Kunal , Gu Yongan , Kumar Vimal , Mishra Indra M.
Published: February 2019

Nano‐emulsions (NEs) are non‐equilibrium systems and cannot be formed instantaneously. The small droplet size and high kinetic stability of NEs, compared to conventional emulsions, provide them with advantages for their use in many technological applications. Therefore, energy input, generally from mechanical devices or from the chemical potential of the components, is required for the formation of NEs. In the present work, the formation of water‐in‐oil (w/o) NEs with mixed surfactant (HLB = 9.864) was investigated for enhancing the stability of the water/oil interface. A combined condensation‐dispersion method was used in the present study for the production of NEs. The mechanism of NEs formation was examined and illustrated by observing the droplet size distribution (DSD), polydispersity index (PDI), and kinetic stability of NEs. Highly stable, finely dispersed NEs were produced with smaller droplet sizes and low PDIs. The kinetics of the NEs were studied by observing the variation in droplet size growth with storage time. It was observed that both the mean droplet diameter and the PDI decreases with an increase in the homogenization time and speed (rpm). The Ostwald ripening rate of the NEs increased with a decrease in homogenization time. Polydispersity significantly affects the Ostwald ripening rate of NEs. The IFT and SFT of the w/o NEs were decreased with an increase in the rpm and homogenization time. The decrease in droplet size significantly reduces the IFT and SFT of the NEs. Various instability mechanisms of the NEs were examined by fitting the experimental data to different co‐relations. However, Ostwald ripening was found to be a prominent instability phenomenon over coalescence for the produced NEs. The Ostwald ripening rate was estimated according to the Lifshitz‐Slyozov and Wagner (LSW) theory.
Rationale, design and baseline characteristics of the effect of ticagrelor on health outcomes in diabetes mellitus patients Intervention study
Authors: Bhatt Deepak L. , Fox Kim , Harrington Robert A. , Leiter Lawrence A. , Mehta Shamir R. , Simon Tabassome , Andersson Marielle , Himmelmann Anders , Ridderstråle Wilhelm , Held Claes , Steg Philippe Gabriel ,   on behalf of the THEMIS Steering Committee
Published: February 2019

In the setting of prior myocardial infarction, the oral antiplatelet ticagrelor added to aspirin reduced the risk of recurrent ischemic events, especially, in those with diabetes mellitus. Patients with stable coronary disease and diabetes are also at elevated risk and might benefit from dual antiplatelet therapy. The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS, NCT01991795) is a Phase 3b randomized, double‐blinded, placebo‐controlled trial of ticagrelor vs placebo, on top of low dose aspirin. Patients ≥50 years with type 2 diabetes receiving anti‐diabetic medications for at least 6 months with stable coronary artery disease as determined by a history of previous percutaneous coronary intervention, bypass grafting, or angiographic stenosis of ≥50% of at least one coronary artery were enrolled. Patients with known prior myocardial infarction (MI) or stroke were excluded. The primary efficacy endpoint is a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety endpoint is Thrombolysis in Myocardial Infarction major bleeding. A total of 19 220 patients worldwide have been randomized and at least 1385 adjudicated primary efficacy endpoint events are expected to be available for analysis, with an expected average follow‐up of 40 months (maximum 58 months). Most of the exposure is on a 60 mg twice daily dose, as the dose was lowered from 90 mg twice daily partway into the study. The results may revise the boundaries of efficacy for dual antiplatelet therapy and whether it has a role outside acute coronary syndromes, prior myocardial infarction, or percutaneous coronary intervention.
Structure–Activity Relationship Studies of the Natural Product Gq/11 Protein Inhibitor YM‐254890
Authors: Xiong Xiao‐Feng , Zhang Hang , Boesgaard Michael W. , Underwood Christina R. , Bräuner‐Osborne Hans , Strømgaard Kristian
Published: February 2019

G proteins act as molecular switches in G protein‐coupled receptor signaling pathways and are key mediators for numerous important physiological processes. The natural product, cyclic depsipeptide YM‐254890, together with the structurally similar FR900359, is the only known selective inhibitor of the Gq/11 subfamily of G proteins. We recently reported the first total synthesis of YM‐254890 and FR900359, followed by synthesizing analogues to perform structure–activity relationship studies. However, incomplete information about their structure–activity relationship prevents the further development of potent and structurally simplified analogues. Herein we report the first systematic structure–activity relationship study toward the N‐methyldehydroalanine moiety in YM‐254890, by designing and synthesizing seven new analogues. Pharmacological characterization of the seven compounds for Gq/11‐, Gi/o‐ and Gs‐mediated signaling showed that the simplified analogue YM‐19 is the most potent Gq/11inhibitor among the new analogues. This study provides information for the future design of potent and simplified YM‐254890 analogues.
Simulation of orthodontic force of archwire applied to full dentition using virtual bracket displacement method
Authors: Zhou Xinwen , Gan Yangzhou , Zhao Qunfei , Xiong Jing , Xia Zeyang
Published: February 2019

Objective

Orthodontic force simulation of tooth provides important guidance for clinical orthodontic treatment. However, previous studies did not involve the simulation of orthodontic force of archwire applied to full dentition. This study aimed to develop a method to simulate orthodontic force of tooth produced by loading a continuous archwire to full dentition using finite element method.

Method

A three‐dimensional tooth‐periodontal ligament‐bone complex model of mandible was reconstructed from computed tomography images, and models of brackets and archwire were built. The simulation was completed through two steps. First, node displacements of archwire before and after loading were estimated through moving virtual brackets to drive archwire deformation. Second, the obtained node displacements were loaded to implement the loading of archwire, and orthodontic force was calculated. An orthodontic force tester (OFT) was used to measure orthodontic force in vitro for the validation.

Results

After the simulation convergence, archwire was successfully loaded to brackets, and orthodontic force of teeth was obtained. Compared with the measured orthodontic force using the OFT, the absolute difference of the simulation results ranged from 0.5 to 22.7 cN for force component and ranged from 2.2 to 80.0 cN•mm for moment component, respectively. The relative difference of the simulation results ranged from 2.5% to 11.0% for force component, and ranged from 0.6% to 14.7% for moment component, respectively.

Conclusions

The developed orthodontic force simulation method based on virtual bracket displacement can be used to simulate orthodontic force provided by the archwire applied to full dentition.
pH Dependence ofT1for13C‐Labelled Small Molecules Commonly Used for Hyperpolarized Magnetic Resonance Imaging
Authors: Hundshammer Christian , Grashei Martin , Greiner Alexandra , Glaser Steffen J. , Schilling Franz
Published: February 2019

Hyperpolarization is a method to enhance the nuclear magnetic resonance signal by up to five orders of magnitude. However, the hyperpolarized (HP) state is transient and decays with the spin‐lattice relaxation time (T1), which is on the order of a few tens of seconds. Here, we analyzed the pH‐dependence ofT1for commonly used HP13C‐labelled small molecules such as acetate, alanine, fumarate, lactate, pyruvate, urea and zymonic acid. For instance, theT1of HP pyruvate is about 2.5 fold smaller at acidic pH (25 s, pH 1.7,B0=1 T) compared to pH close to physiological conditions (66 s, pH 7.3,B0=1 T). Our data shows that increasing hydronium ion concentrations shorten theT1of protonated carboxylic acids of most of the analyzed molecules except lactate. Furthermore it suggests that intermolecular hydrogen bonding at low pH can contribute to thisT1shortening. In addition, enhanced proton exchange and chemical reactions at the pKaappear to be detrimental for the HP‐state.
Schwarz lemma for driving point impedance functions and its circuit applications
Authors: Örnek Bülent Nafi , Düzenli Timur
Published: February 2019

In this paper, a boundary version of the Schwarz lemma is investigated for driving point impedance functions and its circuit applications. It is known that driving point impedance function, Z(s)  =  1 + cp(s − 1)p + cp + 1(s − 1)p + 1 + ..., p  >  1, is an analytic function defined on the right half of the s‐plane. Two theorems are presented using the modulus of the derivative of driving point impedance function, |Z′(0)|, by assuming the Z(s) function is also analytic at the boundary point s  =  0 on the imaginary axis with
. In the obtained inequalities, the value of the function at s  =  1 and the derivatives with different orders have been used. Finally, the sharpness of the inequalities obtained in the presented theorems is proved. Simple LC circuits are obtained using the obtained driving point impedance functions.
Comparison of Volumetric and Bead‐Based Counting of CD34 Cells by Single‐Platform Flow Cytometry
Authors: Saraiva Luisa , Wang Lili , Kammel Martin , Kummrow Andreas , Atkinson Eleanor , Lee Ji Youn , Yalcinkaya Burhanettin , Akgöz Muslum , Höckner Jana , Ruf Andreas , Engel Andrea , Zhang Yu‐Zhong , O'Shea Orla , Sassi Maria Paola , Divieto Carla , Lekishvili Tamara , Campbell Jonathan , Liu Yingying , Wang Jing , Stebbings Richard , Gaigalas Adolfas K. , Rigsby Peter , Neukammer Jörg , Vessillier Sandrine
Published: February 2019

Background

Over 2,000 people a year in the United Kingdom need a bone marrow or blood stem cell transplant. It is important to accurately quantify the hematopoietic stem cells to predict whether the transplant will be successful in replenishing the immune system. However, they are present at low frequency, which complicates accurate quantification. The current gold standard method is single‐platform flow cytometry using internal reference counting beads to determine the concentration of CD34 cells. However, volumetric flow cytometers have the ability to measure the acquisition volume, which removes the need for reference beads for calculation of cell concentrations.

Method

In this study, we compared both methods for calculating CD34 cell concentrations in volumetric cytometers, using either the volume reading or the number of reference beads for calculation. In addition, the uncertainty of measurement for each method was estimated.

Results

The results show that both methods have similar uncertainties of measurement. Regression analysis showed low to no statistical difference in CD34 cell concentrations obtained with each method.

Conclusions

Overall, this study suggests that the volumetric method is a valid approach but that the adoption of this technology may be hindered without some form of external calibration of volume readings to increase confidence in the measurement. © 2019 The Authors. Cytometry Part B: Clinical Cytometry published by Wiley Periodicals, Inc. on behalf of International Clinical Cytometry Society.
Method validation and preliminary pharmacokinetic studies on the new designer stimulant 3‐fluorophenmetrazine (3‐FPM)
Authors: Grumann Christina , Huppertz Laura M. , Bisel Philippe , Angerer Verena , Auwärter Volker
Published: February 2019

Pharmaceutical research not only provides the basis for the development of new medicinal products but also for the synthesis of new drugs of abuse. 3‐Fluorophenmetrazine (3‐FPM), a fluorinated derivative of the anorectic phenmetrazine, was first patented in 2011 and appeared on the drug market in 2014. Though invented for potential medical purposes, pharmacokinetic data on this compound, crucial for interpreting forensic as well as clinical cases, are not available. Therefore, a liquid chromatography−electrospray ionization−tandem mass spectrometry (LC−ESI−MS/MS) method for the detection of 3‐FPM in serum, urine, and oral fluid was developed, validated for urine and serum, and used to quantify 3‐FPM in samples obtained during a controlled self‐experiment. The method proved to be linear, selective and sufficiently sensitive. The limits of detection (LODs) were 0.1 ng/mL, 0.2 ng/mL, and 0.05 ng/mL in serum, urine, and oral fluid. Inter‐day precision and intra‐day precision (RSD) in serum samples were below 6.3% and below 8.5%, respectively. The highest serum concentration (cmax) of 210 ng/mL was reached 2.5 hours (tmax) after ingestion. The elimination half‐life and the volume of distribution were calculated to be approx. 8.8 hours and 400 L (5.3 L/kg). 3‐FPM could be detected in serum and urine up to 82 hours and 116 hours, respectively. It was still detected in the last oral fluid sample taken 55 hours after ingestion. 3‐FPM was mainly excreted unchanged. Main metabolic reactions were aryl‐hydroxylation and N‐hydroxylation. Interestingly, the product of oxidative ring opening (2‐amino‐1‐(3‐fluorophenyl)propan‐1‐ol) showed the largest window of detection in the self‐experiment.
The role of fish life histories in allometrically scaled food‐web dynamics
Authors: Bland Stephanie , Valdovinos Fernanda S. , Hutchings Jeffrey A. , Kuparinen Anna
Published: February 2019

Body size determines key ecological and evolutionary processes of organisms. Therefore, organisms undergo extensive shifts in resources, competitors, and predators as they grow in body size. While empirical and theoretical evidence show that these size‐dependent ontogenetic shifts vastly influence the structure and dynamics of populations, theory on how those ontogenetic shifts affect the structure and dynamics of ecological networks is still virtually absent.

Here, we expand the Allometric Trophic Network (ATN) theory in the context of aquatic food webs to incorporate size‐structure in the population dynamics of fish species. We do this by modifying a food web generating algorithm, the niche model, to produce food webs where different fish life‐history stages are described as separate nodes which are connected through growth and reproduction. Then, we apply a bioenergetic model that uses the food webs and the body sizes generated by our niche model to evaluate the effect of incorporating life‐history structure into food web dynamics.

We show that the larger the body size of a fish species respective to the body size of its preys, the higher the biomass attained by the fish species and the greater the ecosystem stability. We also find that the larger the asymptotic body size attained by fish species the larger the total ecosystem biomass, a result that holds true for both the largest fish in the ecosystem and each fish species in the ecosystem.

This work provides an expanded ATN theory that generates food webs with life‐history structure for chosen species. Our work offers a systematic approach for disentangling the effects of increasing life‐history complexity in food‐web models.
Metallocycle‐Supported POM‐Based Metal‐Organic Frameworks Assembled from Isomeric N‐Rich Ligands: Structures and Selective Adsorption and Separation of Cationic Dyes
Authors: Liu Lei , Zhang Hai‐Yan , Wang Hai‐Jun , Chen Song , Wang Jing‐Han , Sun Jing‐Wen
Published: February 2019

Two novel POM‐based metal‐organic frameworks, [Ag7(L1)2·(µ2‐OH)4][H3VW12O40] (1) and [Ag8(L2)4][VW12O40]·4H2O (2) have been isolated by altering the isomeric organic ligands {5‐[n‐(1,2,4‐triazol‐4‐yl)phenyl]‐1H‐tetrazole: n = 3 (HL1); n = 4 (HL2)} under hydrothermal conditions. Due to L1 acts as a V‐shaped linker, compound 1 displays a 3D MOF with three types of metallocycles, in which the Keggin polyanions locat in the largest metallocycle (the size of void ca. 13.31 Å × 13.53 Å). However, when the ligand is replaced by straight ligand L2, compound 2 with a different structure is obtained. Although compound 2 is also a 3D MOF, the types of metallocycle are reduced to one. The Keggin polyanions are seated in the only metallocycle (the size of void ca. 13.6 Å × 13.7 Å). In addition, the adsorption behaviors of the title compounds for organic dyes were investigated in detail. In particular, compound 1 could selectively separate MB+ from the mixture of MB+/RhB+ and MB+/MO– within 5 min, which can be used as a chromatography column for dyes removal.
Sequential Multicomponent Synthesis of 2‐(Imidazo[1,5‐α]pyridin‐1‐yl)‐1,3,4‐Oxadiazoles
Authors: Kurhade Santosh , Konstantinidou Markella , Sutanto Fandi , Kurpiewska Katarzyna , Kalinowska‐Tłuścik Justyna , Dömling Alexander
Published: February 2019

A 21 membered library of 2‐(imidazo[1,5‐α]pyridine‐1‐yl)‐1,3,4‐oxadiazoles is synthesized in an unprecedented short sequence starting from an Ugi tetrazole reaction with a cleavable isocyanide component. The intermediate tetrazole is subjected to an acetic anhydride‐mediated cyclization, followed by a Huisgen‐type rearrangement with acyl chlorides to afford the imidazopyridine‐oxadiazole bis‐heterocycles. The scope and limitations of the methodology were investigated with substitutions on both the oxadiazole and the imidazopyridine rings. The introduced enabling technology for imidazopyridine oxadiazole synthesis combines a short reaction sequence with high scaffold diversity, based on commercially available starting materials and high functional groups tolerance.
Modeling equipment hierarchy and costs for ICT solutions
Authors: Spruytte Jonathan , Van der Wee Marlies , Verbrugge Sofie , Colle Didier
Published: February 2019

In the early 2000s, a large number of companies thrived mainly due to the fast‐paced evolution of network and Internet technologies. A similar trend is now emerging with the rise of the Internet of Things (IoT), using which almost every thing can be part of the Internet. Both groups of companies have important ICT networks as their core assets. In order to validate the feasibility of the business models of such companies, the relevant costs and revenues should be modeled. This publication focuses on the relevant costs, which can be divided into two categories: process costs and equipment costs, the latter being the focus here.

For equipment costs, no formal standard exists. As a result, most studies make use of use case‐specific ad hoc models (typically, a combination of visualization and spreadsheet modeling), which tend to be error‐prone as well as hard to understand and reuse. To solve these issues, we developed the Equipment Coupling Modeling Notation (ECMN), which allows for both visualization and calculation while focusing on simplicity, flexibility, and reusability. ECMN is a flowchart‐like notation based on a small number of building blocks, which allows for hierarchical modeling by means of nesting models (using submodels).

In this study, ECMN was applied to an IoT use case to show its strengths, based on which a comparison was made with various ad hoc models using a set of requirements.