bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid Switches: Stimuli‐Responsive Liposomes through Conformational Isomerism Driven by Molecular Recognition
Authors: Lou Jinchao , Zhang Xiaoyu , Best Michael D. 
Published: August 2018

AbstractAdvancements in the field of liposomal drug carriers have culminated in greatly improved delivery properties. An important aspect of this work entails development of designer liposomes for release of contents triggered by environmental changes. The majority of these systems are driven by chemical reactions in the presence of different stimuli. However, a promising new paradigm instead focuses on molecular recognition events as the impetus for content release. In certain cases, these platforms exploit synthetic lipid switches designed to undergo conformational changes upon binding to target ions or molecules that perturb membrane assembly, thereby triggering cargo release. Examples of this approach reported thus far showcase how rational design of lipid switches can result in dramatic changes in lipid assembly properties. These strategies show great promise for opening up new pathophysiological stimuli that can be harnessed for programmed content release in drug delivery applications.
Homo‐ and Heteroleptic Coordination Polymers and Oxido Clusters of Bismuth(III) Vinylsulfonates
Authors: Wrobel Lydia , Rüffer Tobias , Korb Marcus , Krautscheid Harald , Meyer Jens , Andrews Philip C. , Lang Heinrich , Mehring Michael 
Published: August 2018

AbstractThe synthesis and characterization of six homo‐ and heteroleptic coordination polymers and oxido clusters of bismuth(III) vinylsulfonates are reported. The solvent‐mediated reaction of BiPh3 and vinylsulfonic acid in ethanol produces [{Ph2Bi(O3SCH=CH2)}n] (1), which crystallizes as a one‐dimensional coordination polymer as a result of bridging sulfonato ligands accompanied by intermolecular Bi⋅⋅⋅ π(arene) London dispersion interactions. In solution, compound 1 equilibrates to give [{PhBi(O3SCH=CH2)2}n] (2) and BiPh3. Compound 2 is obtained as a single product by the reaction of BiPh3 with vinylsulfonic acid in acetonitrile and crystallizes as a one‐dimensional coordination polymer. The homoleptic vinylsulfonate [{Bi(O3SCH=CH2)3}n] (3) was isolated as a two‐dimensional coordination polymer, which is quite moisture sensitive, but did not provide a distinct polynuclear bismuth oxido cluster upon hydrolysis. However, by treatment of [Bi6O4(OH)4(NO3)6]⋅H2O or [Bi38O45(OMc)24(dmso)9(H2O)2]⋅2 DMSO⋅5 H2O (OMc=methacrylate) with vinylsulfonic acid, such a cluster, namely, [Bi9O7(OH)(O3SCH=CH2)11(dmso)11](O3SCH=CH2)⋅3 DMSO (4), is available as the main product. Starting from the hexanuclear bismuth oxido nitrate, another cluster, [Bi38O45(NO3)8(O3SCH=CH2)14(dmso)18](O3SCH=CH2)2⋅2 DMSO (5), was observed as a co‐crystallizing side product, which upon further hydrolysis afforded [Bi38O45(NO3)6(OH)4(O3SCH=CH2)12(dmso)23(H2O)2](O3SCH=CH2)2⋅2 H2O (6).
Light‐Triggered Transformation of Molecular Baskets into Organic Nanoparticles
Authors: Border Sarah E. , Pavlović Radoslav Z. , Zhiquan Lei , Gunther Michael J. , Wang Han , Cui Honggang , Badjić Jovica D. 
Published: August 2018

AbstractDiscovering novel and functional photoresponsive materials is of interest for improving controlled release of molecules and scavenging toxic compounds for cleaning our environment or designing chemosensors. In this study, we report on the photoinduced decarboxylation of basket 16−, containing three glutamic acids at its rim. This concave compound is, in an aqueous environment (30 mm phosphate buffer at pH 7.0), monomeric (1H NMR DOSY, DLS) with glutamic acid residues randomly oriented about its rim (1H NMR and MM‐OPLS3). The irradiation (300 nm) of 16− leads to the exclusive removal of its α‐carboxylates to give amphiphilic 23− possessing γ‐carboxylates. The photochemical transformation is a consecutive reaction with mono‐ and bis‐decarboxylated products observed with 1H NMR spectroscopy and ESI mass spectrometry. Amphiphilic 23− is a preorganized molecule (MM‐OPLS3) that, in water, aggregates into organic nanoparticles (ca. 50–200 nm in diameter; DLS, TEM and cryo‐TEM) having a critical aggregation concentration of 12 μm (UV/Vis). As the transition of monomeric 16− into nanoparticulate 23− is triggered with light, we reasoned that stimuli‐responsive formation of the soft material lends itself to nanotechnology applications such as controlled release or scavenging of targeted compounds.
Host–Guest Binding Hierarchy within Redox‐ and Luminescence‐Responsive Supramolecular Self‐Assembly Based on Chalcogenide Clusters and γ‐Cyclodextrin
Authors: Ivanov Anton A. , Falaise Clément , Abramov Pavel A. , Shestopalov Michael A. , Kirakci Kaplan , Lang Kamil , Moussawi Mhamad A. , Sokolov Maxim N. , Naumov Nikolay G. , Floquet Sébastien , Landy David , Haouas Mohamed , Brylev Konstantin A. , Mironov Yuri V. , Molard Yann , Cordier Stéphane , Cadot Emmanuel 
Published: August 2018

AbstractInvited for the cover of this issue are Anton A. Ivanov, Mohamed Haouas, Stéphane Cordier, Pavel Abramov, Emmanuel Cadot, and co‐workers involved within the CLUSPOM‐CNRS International Laboratory, including the Nikolaev Institute of Inorganic Chemistry (Novosibirsk, Russia) University of Versailles Saint Quentin and University of Rennes 1 (France). The image has been designed by Mrs. Alice Gronier (UVSQ) from an original idea of Dr. Pavel Abramov (NIIC). The cover picture depicts redox and luminescent octahedral clusters [Re6Q8(CN)6]4− that interact through supramolecular host–guest process, with biocompatible macrocycles such as γ‐cyclodextrin. Read the full text of the article at 10.1002/chem.201802102.
The High‐Pressure Oxide Tb3O5 and its Non‐Centrosymmetric Low‐Temperature Polymorph–A Comprehensive Study
Authors: Glätzle Matthias , Janka Oliver , Svitlyk Volodymyr , Chernyshov Dmitry , Bartsch Manfred , Zacharias Helmut , Pöttgen Rainer , Huppertz Hubert 
Published: August 2018

AbstractIn this article, the first thoroughly characterized mixed‐valent binary rare earth oxide synthesized under high‐pressure/high‐temperature conditions, and its low‐temperature polymorph are reported. Crystalline HT‐HP‐Tb3O5 has been prepared from an equimolar mixture of Tb4O7 and Tb2O3 under reaction conditions of 8 GPa and 1323 K. Single‐crystal X‐ray structure determination showed that HT‐HP‐Tb3O5 crystallizes in the orthorhombic space group Pnma, isopointal to the β‐Yb5Sb3‐type structure. Temperature‐dependent measurements of the magnetic susceptibility showed that HT‐HP‐Tb3O5 is a Curie–Weiss paramagnet. The observed effective magnetic moment of μeff=9.21(2) μB per formula unit fits well to the calculated moment of μcalc=9.17 μB. Low‐field measurements revealed antiferromagnetic ordering at TN=3.6(1) K. Heat capacity measurements indicated an intrinsic structural phase transition of HT‐HP‐Tb3O5 at low temperature, which was confirmed by synchrotron X‐ray powder diffraction data recorded at 2 K. The metastable high‐pressure modification HT‐HP‐Tb3O5 undergoes a translationengleiche transition from space group Pnma to Pn21a (non‐standard setting of Pna21), leading to the low‐temperature polymorph LT‐HP‐Tb3O5 by loss of a mirror plane (displacive phase transition).
Iodine(III)‐Mediated Electrochemical Trifluoroethoxylactonisation: Rational Reaction Optimisation and Prediction of Mediator Activity
Authors: Möckel Robert , Babaoglu Emre , Hilt Gerhard 
Published: August 2018

AbstractA new electrochemical iodine(III)‐mediated cyclisation reaction for the synthesis of 4‐(2,2,2‐trifluoroethoxy)isochroman‐1‐ones is presented. Based on this reaction design of experiments and multivariate linear regression analysis were used to demonstrate their first application in an electrochemical reaction. The broad applicability of these reaction conditions could be shown by a range of substrates and an extensive compatibility test.
Simultaneous chiral separation of tramadol and methadone in tablets, human urine, and plasma by capillary electrophoresis using maltodextrin as the chiral selector
Authors: Naghdi Elahe , Fakhari Ali Reza 
Published: August 2018

AbstractThe stereoselective analysis and separation of racemic drugs play an important role in pharmaceutical industry to eliminate the unwanted isomer and find the right therapeutic control for the patient. Present study suggests a maltodextrin‐modified capillary electrophoresis method for a single‐run chiral separation of two closely similar opiate pain relief drugs: tramadol (TRA) and methadone (MET). The best separation method possible for the both enantiomers was achieved on an uncoated fused‐silica capillary at 25°C using 100 mM phosphate buffer (pH 8.0) containing 20% (w v−1) maltodextrin with dextrose equivalent of 4–7 and an applied voltage of 16 kV. Under optimal conditions, the baseline resolution of TRA and MET enantiomers was obtained in less than 12 minutes. The relative standard deviations (n = 3) of 20 μg mL−1 TRA and MET were 2.28% and 3.77%, respectively. The detection limits were found to be 2 μg mL−1 for TRA and 1.5 μg mL−1 for MET. This method was successfully applied to the measurement of drugs concentration in their tablets, urine, and plasma samples.
Die Untersuchung von Lidocainhydrochlorid – analytische Methoden im Zusammenspiel
Authors: Habekost Achim 
Published: August 2018

AbstractEs werden verschiedene analytische Verfahren zur qualitativen und quantitativen Analyse des Arzneimittels Lidocainhydrochlorid vorgestellt. Der Schwerpunkt liegt dabei auf elektrochemischen Verfahren. Die Experimente können in einem Hochschulpraktikum, teilweise auch im Chemieunterricht durchgeführt werden.
A noninvasive method for the determination of in vivo mitral valve leaflet strains
Authors: Rego Bruno V. , Khalighi Amir H. , Drach Andrew , Lai Eric K. , Pouch Alison M. , Gorman Robert C. , Gorman Joseph H. , Sacks Michael S. 
Published: August 2018

AbstractAssessment of mitral valve (MV) function is important in many diagnostic, prognostic, and surgical planning applications for treatment of MV disease. Yet, to date, there are no accepted noninvasive methods for determination of MV leaflet deformation, which is a critical metric of MV function. In this study, we present a novel, completely noninvasive computational method to estimate MV leaflet in‐plane strains from clinical‐quality real‐time three‐dimensional echocardiography (rt‐3DE) images. The images were first segmented to produce meshed medial‐surface leaflet geometries of the open and closed states. To establish material point correspondence between the two states, an image‐based morphing pipeline was implemented within a finite element (FE) modeling framework in which MV closure was simulated by pressurizing the open‐state geometry, and local corrective loads were applied to enforce the actual MV closed shape. This resulted in a complete map of local systolic leaflet membrane strains, obtained from the final FE mesh configuration. To validate the method, we utilized an extant in vitro database of fiducially labeled MVs, imaged in conditions mimicking both the healthy and diseased states. Our method estimated local anisotropic in vivo strains with less than 10% error and proved to be robust to changes in boundary conditions similar to those observed in ischemic MV disease. Next, we applied our methodology to ovine MVs imaged in vivo with rt‐3DE and compared our results to previously published findings of in vivo MV strains in the same type of animal as measured using surgically sutured fiducial marker arrays. In regions encompassed by fiducial markers, we found no significant differences in circumferential(P = 0.240) or radial (P = 0.808) strain estimates between the marker‐based measurements and our novel noninvasive method. This method can thus be used for model validation as well as for studies of MV disease and repair.
Sigmoid colon perforation after postoperative hypofractionated intensity‐modulated radiation therapy in a cervical cancer patient
Authors: Kim Hakyoung , Park Won , Choi Yoon‐La , Lee Jeong‐Won 
Published: August 2018

AbstractBackgroundRadiation‐induced complication occurs in two phases: acute and chronic toxicities. Bowel perforation is regarded as a chronic toxicity associated with injury to vascular and connective tissue. It is usually noted a few months to several years after radiation treatment (RT).CaseHerein, we present a case of sigmoid colon perforation relatively early after completion of RT. A 70‐year‐old woman was treated with laparoscopic radical hysterectomy and postoperative hypofractionated intensity‐modulated RT for clinical stage IB1 cervical cancer. RT was delivered with a total dose 4000 cGy in 16 fractions to whole pelvis once a day. Sigmoid colon perforation was found 40 days after completion of RT without any typical signs of perforated viscera. Emergency exploratory laparotomy was performed. Pathology revealed chronic inflammation with mucosal ulceration and submucosal fibrosis, a typical radiation effect.ConclusionAlthough the cause of perforation remains unclear, early‐onset sigmoid colon perforation as an effect of irradiation can occur. We should keep in mind the possibility of perforation in the care of radiated patients who present abdominal pain with atypical presentation regardless of satisfaction of dose constraint for radiotherapy.
Improvement of Anticancer Drug Release by Cobalt Ferrite Magnetic Nanoparticles through Combined pH and Temperature Responsive Technique
Authors: Dey Chaitali , Ghosh Arup , Ahir Manisha , Ghosh Ajay , Goswami Madhuri Mandal 
Published: August 2018

AbstractThis work reports the application possibilities of cobalt ferrite (CoFe2O4) magnetic nanoparticles (CFMNPs) for stimuli responsive drug delivery by magnetic field induced hyperthermia technique. The CFMNPs were characterized by X‐ray diffraction (XRD) with Rietveld analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), fourier transform infrared spectroscopy (FTIR), thermogravimetry and differential thermal analysis (TG‐DTA), vibrating sample magnetometer (VSM) and superconducting quantum interference device (SQUID) magnetometry. Particles were functionalized with folic acid (FA) by EDC‐NHS coupling method and loaded with anticancer drug (DOX) by activated folate ions. The drug release was studied as a function of time at two different temperatures (37 and 44 °C) under pH∼5.5 and 7. It was observed that the drug release rate is higher at elevated temperature (44 °C) and acidic pH∼5.5 as compared to our normal body temperature and pH∼7 using the CFMNPs. This way, we have developed a pH and temperature sensitive drug delivery system, which can release the anticancer drug selectively by applying ac magnetic field as under ac field particles are heated up. We have calculated the amount of heat generation by the particles around 1.67 °C per second at ∼600 Hz frequency. By MTT assay on cancer cell and normal cell, it was confirmed that CFMNPs are nontoxic and biocompatible in nature, which assures that our synthesized particles can be successfully used in localized cancer treatment by stimuli responsive drug delivery technique.
Ultrafast Charge Dynamics in Mixed Cation – Mixed Halide Perovskite Thin Films
Authors: Minda Iulia , Horn Jonas , Ahmed Essraa , Schlettwein Derck , Schwoerer Heinrich 
Published: August 2018

AbstractPerovskite based photovoltaic devices are popularised by the rapid increase in their efficiencies. Understanding the fundamental physics and chemistry processes occurring upon excitation is key. We monitored the temporal evolution of the population and depopulation dynamics of various electronic states in FA0.85MA0.15PbI2.55Br0.45 by means of ultrafast transient absorption spectroscopy in the visible and near infrared spectral regions in order to build a fully consistent charge dynamics model of the initial photoprocesses. Upon photoexcitation with 3.2 eV photon energy, hot electrons and holes are generated in the lowest conduction and highest valence bands, away from the bandgap, and cool to the band edges with a time constant of 500 fs. Geminate recombination of excitons occurs with a time constant of 66 ps, which increases to approximately 130 ps at the optical bandgap. From a systematic study of the excited state population dynamics and its dependence on charge carrier density, we determined the nonlinear recombination rate constants characteristic to FA0.85MA0.15PbI2.55Br0.45. The coefficient describing the non‐geminate recombination of free electrons and holes is independent of the k vector as well as the charge carrier density and equal to 1×10−10 s−1 cm3, while the Auger recombination coefficient decreases with increasing charge carrier density in the range of (2–50)×10−32 s−1 cm6.
Structure, Conformational Equilibria, and Weak Hydrogen Bonding in the CH2F2−CF3CH2F Dimer
Authors: Lu Tao , Chen Junhua , Zhang Jiaqi , Gou Qian , Xia Zhining , Feng Gang 
Published: August 2018

AbstractTo probe the multiple configurations of a weakly bound intermolecular complex, the difluoromethane and 1,1,1,2‐tetrafluoroethane dimer was investigated by using pulsed jet Fourier transform microwave spectroscopy coupled with quantum chemical calculations. Three isomers were detected in the supersonic jet. Spectroscopic assignments, ab initio calculations and quantum theory of atoms in molecules (QTAIM) analyses prove that all the observed isomers are stabilized through a net of three weak C−H⋅⋅⋅F−C interactions. The interaction energies are estimated to be within 12–13 kJ mol−1, dominated by electrostatic and dispersion according to Symmetry‐Adapted Perturbation Theory (SAPT) analysis. The spectroscopic measurements were also extended to three and two 13C isotopologues in natural abundance for the isomers II and III, respectively, which lead to precisely structural determinations of these two isomers. The comparison of the relative intensity of these isomers measured in the carrier gases of argon and helium evidenced that isomer II is the global minimum, while the intensities measured in helium suggested that the population of the three isomers in the jet to be NI/NII/NIII≈1/11/4.
Atomic Force Microscopy Study of the Influence of the Synthesis Conditions on the Single‐Crystal Surface of Interdigitated Metal‐Organic Frameworks
Authors: Kamakura Yoshinobu , Hosono Nobuhiko , Terashima Aya , Kitagawa Susumu , Yoshikawa Hirofumi , Tanaka Daisuke 
Published: August 2018

AbstractThe front cover artwork is provided by the groups of Mr. Y. Kamakura, Prof. Dr. H. Yoshikawa and Prof. Dr. D. Tanaka (Kwansei Gakuin University, Japan) as well as Dr. N. Hosono, Ms. A. Terashima and Prof. Dr. S. Kitagawa (Institute for Integrated Cell‐Material Sciences (WPI‐iCeMS), Kyoto University Institute for Advanced Study (KUIAS), Japan). The image shows the competition between solvent molecules and ligands under crystal growth and the observation of the step edge on a metal–organic framework (MOF) crystal surface by atomic force microscopy. Read the full text of the Communication at 10.1002/cphc.201800439.
Yolk‐Shell‐Mesostructured Silica‐Supported Dual Molecular Catalyst for Enantioselective Tandem Reactions
Authors: Wu Liang , Li Yilong , Meng Jingjing , Jin Ronghua , Lin Jingrong , Liu Guohua 
Published: August 2018

AbstractYolk‐shell‐mesostructured silica was used as a support in the development of an active‐site‐isolated bifunctional catalyst that can mediate a sequential organic transformation. Herein, through immobilization, the location of two catalytic species is controlled: a base functionality is anchored in the channels of the outer silica shell and a chiral ruthenium/diamine functionality is anchored on the inner silica yolk. The result is a yolk‐shell‐mesostructured silica‐supported active‐site‐isolated dual molecule catalyst. Structural analysis through solid‐state carbon 13C NMR spectroscopy reveals its well‐defined single‐site dual active centers. Electron microscopy investigations disclose its uniformly distributed mesoporous nanoparticles. As envisaged, this bifunctional catalyst enables a controllable aza‐Michael addition/asymmetric transfer hydrogenation catalytic sequence, where the base‐catalyzed aza‐Michael addition of enones and amines to aryl‐substituted
‐secondary amino ketones is followed by a Ru‐catalyzed asymmetric transfer hydrogenation. Various aryl‐substituted γ‐secondary amino alcohols are obtained in high yields and enantioselectivities via this one‐pot enantioselective organic transformation. Furthermore, the heterogeneous catalyst can be applied in a continuous‐flow process, which was shown to be particularly attractive for the practical preparation of aryl‐substituted γ‐secondary amino alcohols in an environmentally friendly medium.
Utilizing Miniature Fluorescence Microscopy to Image Hippocampal Place Cell Ensemble Function in Thy1.GCaMP6f Transgenic Mice
Authors: Indersmitten Tim , Berdyyeva Tamara , Aluisio Leah , Lovenberg Timothy , Bonaventure Pascal , Wyatt Ryan M. 
Published: August 2018

AbstractImaging neuronal activity in awake behaving mice with miniature fluorescence microscopes requires the implementation of a variety of procedures. Surgeries are performed to gain access to the cell population of interest and to implant microscope components. After a recovery period, mice are trained to exhibit a desired behavior. Finally, neuronal activity is imaged and synchronized with that behavior. To take full advantage of the technology, selection of the calcium indicator and experimental design must be carefully considered. In this article, we explain the procedures and considerations that are critical for obtaining high‐quality calcium imaging data. As an example, we describe how to utilize miniature fluorescence microscopy to image hippocampal place cell activity during linear track running in Thy1.GCaMP6f transgenic mice. © 2018 by John Wiley & Sons, Inc.
Yeast Two‐Hybrid Assay to Identify Interacting Proteins
Authors: Paiano Aurora , Margiotta Azzurra , De Luca Maria , Bucci Cecilia 
Published: August 2018

AbstractThis article describes the general method to perform the classical two‐hybrid system. Although it has already been more than 25 years since this technique was developed, it still represents one of the best and most inexpensive, time saving, and straightforward methods to identify and study protein‐protein interactions. Indeed, this system can be easily used to identify interacting proteins for a given protein, to check interactions between two known proteins, or to map interacting domains. Most of the interactions revealed using the two‐hybrid assay have been proven to be binary direct interactions. Data comparison with other systems, such as mass spectrometry, have demonstrated that this system is at least as reliable. In fact, its use is increasing with time, and at present numerous variants of the yeast two‐hybrid assay have been developed, including high‐throughput systems that promote the generation of a proteome‐scale map of protein‐protein interactions in specific system. © 2018 by John Wiley & Sons, Inc.