bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rechargeable Hydrogen Storage System Based on the Dehydrogenative Coupling of Ethylenediamine with Ethanol
Authors: Hu Peng , Ben‐David Yehoshoa , Milstein David 
Published: July 2015

AbstractA novel and simple hydrogen storage system was developed, based on the dehydrogenative coupling of inexpensive ethylenediamine with ethanol to form diacetylethylenediamine. The system is rechargeable and utilizes the same ruthenium pincer catalyst for both hydrogen loading and unloading procedures. It is efficient and uses a low catalyst loading. Repetitive reversal reactions without addition of new catalyst result in excellent conversions in both the dehydrogenation and hydrogenation procedures in three cycles.
Protein‐Induced Color Shift of Carotenoids in β‐Crustacyanin
Authors: Gamiz‐Hernandez Ana P. , Angelova Iva Neycheva , Send Robert , Sundholm Dage , Kaila Ville R. I. 
Published: July 2015

Abstractβ‐Crustacyanin (β‐CR) is a pigment protein responsible for the blue color of lobsters. We show using correlated ab initio calculations how the protein environment tunes the chromophores of β‐CR through electrostatic and steric effects.
Semiconducting Polymer Nanoparticles with Persistent Near‐Infrared Luminescence for In Vivo Optical Imaging
Authors: Palner Mikael , Pu Kanyi , Shao Shirley , Rao Jianghong 
Published: July 2015

AbstractMaterials with persistent luminescence are attractive for in vivo optical imaging since they have a long lifetime that allows the separation of excitation of fluorophores and image acquisition for time‐delay imaging, thus eliminating tissue autofluorescence associated with fluorescence imaging. Persistently luminescent nanoparticles have previously been fabricated from toxic rare‐earth metals. This work reports that nanoparticles made of the conjugated polymer MEH‐PPV can generate luminescence persisting for an hour upon single excitation. A near‐infrared dye was encapsulated in the conjugated polymer nanoparticle to successfully generate persistent near‐infrared luminescence through resonance energy transfer. This new persistent luminescence nanoparticles have been demonstrated for optical imaging applications in living mice.
From Mesomorphic Phosphine Oxide to Clustomesogens Containing Molybdenum and Tungsten Octahedral Cluster Cores
Authors: Cîrcu Viorel , Molard Yann , Amela‐Cortes Maria , Bentaleb Ahmed , Barois Philippe , Dorcet Vincent , Cordier Stéphane 
Published: July 2015

AbstractNew clustomesogens (i.e., metal atom clusters containing liquid crystalline (LC) materials) have been obtained by grafting neutral cyanobiphenyl (CB)‐ or cholesteryl‐containing tailor‐made dendritic mesomorphic triphenylphosphine oxide ligands on luminescent (M6Cli8)4+ octahedral cluster cores (M=Mo, W). The LC properties were studied by a combination of polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X‐ray powder diffraction analyses. While the organic ligands showed various mesophase types ranging from nematic, SmA columnar (SmACol), SmA, and SmC phases, it turned out that the corresponding clustomesogens formed layered phases (SmA) over a wide range of temperatures that depend on the nature and density of mesogenic groups employed. Intrinsic luminescence properties of the cluster precursors are preserved over the entire range of LC phase existence.
Diphenyliodonium‐Catalyzed Fluorination of Arynes: Synthesis of ortho‐Fluoroiodoarenes
Authors: Zeng Yuwen , Li Guangyu , Hu Jinbo 
Published: July 2015

AbstractDescribed is a one‐pot vicinal fluorination‐iodination of arynes at room temperature. The diphenyliodonium salt proved to be a privileged catalyst for this nucleophilic fluorination process using CsF as a fluorine source, and a subsequent facile electrophilic iodination with C4F9I was also found to be crucial to ensure the efficient fluorination. This new synthetic protocol has a broad substrate scope under mild reaction conditions.
Synthesis and Evaluation of GdIII‐Based Magnetic Resonance Contrast Agents for Molecular Imaging of Prostate‐Specific Membrane Antigen
Authors: Banerjee Sangeeta Ray , Ngen Ethel J. , Rotz Matthew W. , Kakkad Samata , Lisok Ala , Pracitto Richard , Pullambhatla Mrudula , Chen Zhengping , Shah Tariq , Artemov Dmitri , Meade Thomas J. , Bhujwalla Zaver M. , Pomper Martin G. 
Published: July 2015

AbstractMagnetic resonance (MR) imaging is advantageous because it concurrently provides anatomic, functional, and molecular information. MR molecular imaging can combine the high spatial resolution of this established clinical modality with molecular profiling in vivo. However, as a result of the intrinsically low sensitivity of MR imaging, high local concentrations of biological targets are required to generate discernable MR contrast. We hypothesize that the prostate‐specific membrane antigen (PSMA), an attractive target for imaging and therapy of prostate cancer, could serve as a suitable biomarker for MR‐based molecular imaging. We have synthesized three new high‐affinity, low‐molecular‐weight GdIII‐based PSMA‐targeted contrast agents containing one to three GdIII chelates per molecule. We evaluated the relaxometric properties of these agents in solution, in prostate cancer cells, and in an in vivo experimental model to demonstrate the feasibility of PSMA‐based MR molecular imaging.
A Morphological Transition of Inverse Mesophases of a Branched‐Linear Block Copolymer Guided by Using Cosolvents
Authors: La Yunju , An Tae Hyun , Shin Tae Joo , Park Chiyoung , Kim Kyoung Taek 
Published: July 2015

AbstractWe report here a strategy for influencing the phase and lattice of the inverse mesophases of a single branched‐linear block copolymer (BCP) in solution which does not require changing the structure of the BCP. The phase of the self‐assembled structures of the block copolymer can be controlled ranging from bilayer structures of positive curvature (polymersomes) to inverse mesophases (triply periodic minimal surfaces and inverse hexagonal structures) by adjusting the solvent used for self‐assembly. By using solvent mixtures to dissolve the block copolymer we were able to systematically change the affinity of the solvent toward the polystyrene block, which resulted in the formation of inverse mesophases with the desired lattice by self‐assembly of a single branched‐linear block copolymer. Our method was also applied to a new solution self‐assembly method for a branched‐linear block copolymer on a stationary substrate under humidity, which resulted in the formation of large mesoporous films. Our results constitute the first controlled transition of the inverse mesophases of block copolymers by adjusting the solvent composition.
A Versatile Approach Towards Nucleobase‐Modified Aptamers
Authors: Tolle Fabian , Brändle Gerhard M. , Matzner Daniel , Mayer Günter 
Published: July 2015

AbstractA novel and versatile method has been developed for modular expansion of the chemical space of nucleic acid libraries, thus enabling the generation of nucleobase‐modified aptamers with unprecedented recognition properties. Reintroduction of the modification after enzymatic replication gives broad access to many chemical modifications. This wide applicability, which is not limited to a single modification, will rapidly advance the application of in vitro selection approaches beyond what is currently feasible and enable the generation of aptamers to many targets that have so far not been addressable.
Self‐Assembled Nanocomposite Organic Polymers with Aluminum and Scandium as Heterogeneous Water‐Compatible Lewis Acid Catalysts
Authors: Miyamura Hiroyuki , Sonoyama Arisa , Hayrapetyan Davit , Kobayashi Shū 
Published: July 2015

AbstractWhile water‐compatible Lewis acids have great potential as accessible and environmentally benign catalysts for various organic transformations, efficient immobilization of such Lewis acids while keeping high activity and without leaching of metals even under aqueous conditions is a challenging task. Self‐assembled nanocomposite catalysts of organic polymers, carbon black, aluminum reductants, and scandium salts as heterogeneous water‐compatible Lewis acid catalysts are described. These catalysts could be successfully applied to various CC bond‐forming reactions without leaching of metals. Scanning transmission electron microscopy analyses revealed that the nanocomposite structure of Al and Sc was fabricated in these heterogeneous catalysts. It is noted that Al species, which are usually decomposed rapidly in the presence of water, are stabilized under aqueous conditions.
Fine Tuning of β‐Peptide Foldamers: a Single Atom Replacement Holds Back the Switch from an 8‐Helix to a 12‐Helix
Authors: Altmayer‐Henzien Amandine , Declerck Valérie , Farjon Jonathan , Merlet Denis , Guillot Régis , Aitken David J. 
Published: July 2015

AbstractCyclic homologated amino acids are important building blocks for the construction of helical foldamers. N‐aminoazetidine‐2‐carboxylic acid (AAzC), an aza analogue of trans‐2‐aminocyclobutanecarboxylic acid (tACBC), displays a strong hydrazino turn conformational feature, which is proposed to act as an 8‐helix primer. tACBC oligomers bearing a single N‐terminal AAzC residue were studied to evaluate the ability of AAzC to induce and support an 8‐helix along the oligopeptide length. While tACBC homooligomers assume a dominant 12‐helix conformation, the aza‐primed oligomers preferentially adopt a stabilized 8‐helix conformation for an oligomer length up to 6 residues. The (formal) single‐atom exchange at the N terminus of a tACBC oligomer thus contributes to the sustainability of the 8‐helix, which resists the switch to a 12‐helix. This effect illustrates atomic‐level programmable design for fine tuning of peptide foldamer architectures.
Synergistic Effect between Metal–Nitrogen–Carbon Sheets and NiO Nanoparticles for Enhanced Electrochemical Water‐Oxidation Performance
Authors: Wang Jun , Li Kai , Zhong Hai‐xia , Xu Dan , Wang Zhong‐li , Jiang Zheng , Wu Zhi‐jian , Zhang Xin‐bo 
Published: July 2015

AbstractIdentifying effective means to improve the electrochemical performance of oxygen‐evolution catalysts represents a significant challenge in several emerging renewable energy technologies. Herein, we consider metal–nitrogen–carbon sheets which are commonly used for catalyzing the oxygen‐reduction reaction (ORR), as the support to load NiO nanoparticles for the oxygen‐evolution reaction (OER). FeNC sheets, as the advanced supports, synergistically promote the NiO nanocatalysts to exhibit superior performance in alkaline media, which is confirmed by experimental observations and density functional theory (DFT) calculations. Our findings show the advantages in considering the support effect for designing highly active, durable, and cost‐effective OER electrocatalysts.
Specific Photochemical Dehydrocoupling of N‐Heterocyclic Phosphanes and Their Use in the Photocatalytic Generation of Dihydrogen
Authors: Puntigam Oliver , Könczöl László , Nyulászi László , Gudat Dietrich 
Published: July 2015

AbstractN‐Heterocyclic phosphanes react under UV irradiation in a highly selective dehydrocoupling reaction to diphosphanes and H2. Computational studies suggest that the product formation is initiated by the formation of dimeric molecular associates whose electronic excitation yields H2 and a diphosphane. Combining the dehydrocoupling of sterically demanding phosphanes with Mg‐reduction of the formed diphosphanes allows constructing a reaction cycle for the photocatalytic reductive generation of H2 from Et3NH+.
RhIII‐Catalyzed CH Activation with Pyridotriazoles: Direct Access to Fluorophores for Metal‐Ion Detection
Authors: Kim Ju Hyun , Gensch Tobias , Zhao Dongbing , Stegemann Linda , Strassert Cristian A. , Glorius Frank 
Published: July 2015

AbstractThe first CH bond activation with pyridotriazoles as coupling partners is presented using a RhIII catalyst. The pyridotriazoles can be used as new carbene precursors in CH activation for direct access to novel fluorescent scaffolds. These tunable fluorophores can be applied for the detection of metal ions.
Enantioselective Total Synthesis of (−)‐Hosieine A
Authors: Ouyang Jie , Yan Rui , Mi Xianwei , Hong Ran 
Published: July 2015

AbstractThe first total synthesis of (−)‐hosieine A was accomplished and features an unprecedented nitroso–ene cyclization to construct the 2‐azabicyclo[3.2.1]octane ring system. Phosphine‐enabled stereoselective bromohydrination provided interesting mechanistic insights into the anti‐Markovnikov process. Also noteworthy is the retention of stereochemistry at C9 in the facile radical debromination initiated by Et3B/air.
Nickel‐Catalyzed Cyclopropanation with NMe4OTf and nBuLi
Authors: Künzi Stefan A. , Sarria Toro Juan Manuel , den Hartog Tim , Chen Peter 
Published: July 2015

AbstractNickel was identified as a catalyst for the cyclopropanation of unactivated olefins by using in situ generated lithiomethyl trimethylammonium triflate as a methylene donor. A mechanistic hypothesis is proposed in which the generation of a reactive nickel carbene explains several interesting observations. Additionally, our findings shed light on a report by Franzen and Wittig published in 1960 that had been retracted later owing to irreproducibility, and provide a rational basis for the systematic development of the reaction for preparative purposes as an alternative to diazomethane or Simmons–Smith conditions.
Foaming behavior of bio‐based blends based on thermoplastic gelatin and poly(butylene succinate)
Authors: Oliviero Maria , Sorrentino Luigi , Cafiero Livia , Galzerano Barbara , Sorrentino Andrea , Iannace Salvatore 
Published: July 2015

ABSTRACTBiodegradable thermoplastic gelatin/poly(butylene succinate) (TPG/PBS) foams were prepared by melt mixing and subsequent batch foaming with supercritical CO2. Shear viscosity and calorimetric properties of the various blends were investigated using a rotational rheometer and a differential scanning calorimeter, respectively. TPG/PBS blends show poor miscibility at all blend ratios. The addition of PBS reduced the melt viscosity and increased both the CO2 diffusivity and the thermal stability of TPG. Results from foaming experiments show that the blend foams exhibit smaller cell size and higher cell density compared to the neat TPG foam due to the lower melt viscosity and to their lower gas barrier. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42704.
Effects of pore morphology and size on antimicrobial activity of chitosan/poly(ethylene glycol) diacrylate macromer semi‐IPNhydrogels
Authors: Bedel Nazlı Sokmen , Tezcan Melek , Ceylan Ozgur , Gurdag Gulten , Cicek Huseyin 
Published: July 2015

ABSTRACTThe objective of this study was to obtain antibacterial active chitosan/poly(ethylene glycol) diacrylate macromere (CS/PEGM) semi‐IPN hydrogels near a neutral pH level by changing their pore size and morphology. These hydrogels were prepared from CS and PEGM with different molecular weights in the presence of pore‐forming agents, poly (ethylene glycol) (PEG) or sodium bicarbonate (NaHCO3), by using two different initiator system, namely chemical or UV. A combination of CS with PEG or NaHCO3in the presence of PEGM could be able to create desired pore formation in both initiator systems. The antibacterial activity of hydrogels changed with the molecular weight (g/mol) of PEGM in the order 2000>400>8000. A chemical initiation system was found more suitable than the UV initiation system for antibacterial activity. Hydrogels showing the highest antibacterial activity onStaphylococcus aureusandEscherichia colihave medium or distributed pore size and interconnected pores. Hydrogels prepared with PEGM (Mn: 2000 g/mol) were proposed for antibacterial wound dressing and soft tissue regeneration applications owing to their antibacterial activity and elastic modulus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42707.
Impact of Total Knee Arthroplasty as Assessed Using Patient‐Reported Pain and Health‐Related Quality of Life Indices: Rheumatoid Arthritis Versus Osteoarthritis
Authors: Dusad Anand , Pedro Sofia , Mikuls Ted R. , Hartman Curtis W. , Garvin Kevin L. , O'Dell James R. , Michaud Kaleb 
Published: July 2015

ObjectiveTo assess and compare the impact of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA).MethodsPatients with rheumatologist‐diagnosed arthritis undergoing primary TKA during 1999–2012 were identified. Indices of pain (overall, index knee, and contralateral knee) and health‐related quality of life (HRQOL) were obtained in 3 consecutive 6‐month intervals: preoperative (baseline), perioperative, and postoperative (recovery). Descriptive statistics and one‐way analysis of variance were used to compare TKA outcomes by diagnosis. Effect sizes and standardized response means (SRMs) were calculated between baseline and recovery.ResultsOf the participating 18,897 patients, 834 of those with RA (5.3%) and 315 of those with OA (10.2%) had undergone index TKA at similar mean ages (65 and 68 years). Post‐TKA, significant improvements were observed for most domains of pain, function, and HRQOL within both disease groups, with greater impact in OA. Based on the SRM, the maximum improvement was shown in index knee pain (SRM −1.33 in RA and −1.34 in OA; effect size −1.75 and −1.94, respectively). The Health Assessment Questionnaire II and the Short Form 36 physical component summary were the most responsive HRQOL indices in detecting post‐TKA improvement in RA. A diagnosis of RA, lower income, and preoperative anxiety were independently associated with a lower degree of improvement in index knee pain following TKA.ConclusionTKA is highly effective in reducing clinically relevant knee pain (to a greater extent than its effect on other subjective HRQOL indices in patients with RA), although this improvement is less marked as compared to that among patients with OA. TKA serves as a “time machine” via which patients can return to a lifestyle with less disability, before the arthritis process catches up in RA.
Phase I/II trial of capecitabine, oxaliplatin, and irinotecan in combination with bevacizumab in first line treatment of metastatic colorectal cancer
Authors: Bazarbashi Shouki , Aljubran Ali , Alzahrani Ahmad , Mohieldin Ahmed , Soudy Hussein , Shoukri Mohammed 
Published: July 2015

AbstractPhase III studies have demonstrated the efficacy of FOLFOXIRI regimens (5‐fluorouracil/leucovorin, oxaliplatin, irinotecan) with/without bevacizumab in metastatic colorectal cancer (mCRC). Capecitabine is an orally administered fluoropyrimidine that may be used instead of 5‐fluorouracil/leucovorin. We evaluated a triple‐chemotherapy regimen of capecitabine, oxaliplatin, and irinotecan, plus bevacizumab in 53 patients with mCRC. A Phase I study identified the maximum tolerated dose of irinotecan as 150 mg/m2. Median follow‐up in a subsequent Phase II study using this dose was 28 months (74% progressed). For all patients, a complete response was achieved in 4% and a partial response in 60%; median progression‐free survival (PFS) was 16 months and median overall survival (OS) was 28 months. Median PFS was longer for patients with an early treatment response (28 vs. 9 months for others; P = 0.024), or early tumor shrinkage (25 vs. 9 months for others; P = 0.006), or for patients suitable for surgical removal of metastases with curative intent (median not reached vs. 9 months for others; P = 0.001). Median OS was longer for patients with early tumor shrinkage (median not reached vs. 22 months for others; P = 0.006) or surgery (median not reached vs. 22 months for others, P = 0.002). K‐ras mutations status did not influence PFS (P = 0.88) or OS (P = 0.82). Considerable Grade 3/4 toxicity was encountered (36% for diarrhea, 21% for vomiting and 17% for fatigue). In conclusion, the 3‐weekly triple‐chemotherapy regimen of capecitabine, oxaliplatin, and irinotecan, plus bevacizumab, was active in the first‐line treatment of mCRC, although at the expense of a high level of toxicity.
A Review on Gas Separation Applications of Supported Ionic Liquid Membranes
Authors: Karkhanechi Hanyeh , Salmani Saeide , Asghari Morteza 
Published: July 2015

AbstractThe selection of the separation process is a critical issue in the chemical industries. Among different conventional methods for the separation processes, supported liquid membrane (SLM)‐based separation processes have been predicted as a promising option. However, the industrial use of supported liquid membranes based on conventional liquids is limited by their relative instability and short lifetime. The use of ionic liquids as a liquid membrane phase results in the stabilization of the SLMs due to their negligible vapor pressure, possibility of minimizing their solubility in the surrounding phases and greater capillary force associated with their high viscosity, which can reduce the displacement of liquids from micron pores under pressure. In this review, recent advances in supported membranes based on ionic liquids including issues such as methods of synthesis IL, methods of preparation of supported ionic liquid membranes and application of supported ionic liquid membranes in gas separation are presented.
A One‐Step Staining Probe for Phosphatidylethanolamine
Authors: Hou Songwang , Johnson Steven E. , Zhao Ming 
Published: July 2015

AbstractPhosphatidylethanolamine (PE) is an abundant phospholipid in cellular membranes, but relatively little is known about the kinetics of PE in biological membrane systems. Characterizing PE on a cellular level has been challenging owing to a lack of proper molecular tools. The lantibiotic duramycin and its structural analogue, cinnamycin, are currently the only known polypeptides that have an established stereospecific structure for binding membrane PE with high affinity and high specificity. These lantibiotics are recognized for their potential as molecular probes for studying PE kinetics in various membranes. However, owing to their antibiotic nature, duramycin and cinnamycin exhibit appreciable levels of cytotoxicity at low micromolar concentrations in cultured mammalian cells by inducing membrane distortion and possible PE redistribution. These issues can potentially complicate study design and data interpretation. Here, we report the construction of a molecular probe consisting of duramycin attached to the C terminus of green fluorescent protein (GFP) by a PEG linker at a stoichiometry of 1. The construct retained specific binding toward PE and essentially no cytotoxicity compared to native duramycin. The biological utilities of this probe were demonstrated in a number of cellular staining studies involving PE dynamics. The availability of a one‐step, nontoxic molecular probe for PE will enable characterization of the biology of this important phospholipid.
Efficient Photochemical Synthesis of Peptide‐α‐Phenylthioesters
Authors: Pardo Andrew , Hogenauer Tyrone J. , Cai Zhefeng , Vellucci Julian A. , Castillo Efrain M. , Dirk Carl W. , Franz Andreas H. , Michael Katja 
Published: July 2015

AbstractLow yields and substantial epimerization of peptide‐α‐thioesters often compromise the overall efficiency of native chemical ligation (NCL). Peptide arylthioesters are more reactive than peptide alkylthioesters in NCL, but are also more difficult to handle due to their propensity to hydrolyze, and are therefore often generated in situ. However, pre‐prepared peptide arylthioesters are required for some NCL applications. Here we present a 7‐nitroindoline‐based photochemical method that generates protected peptide phenylthioesters under neutral reaction conditions via their activated esters from photoreactive peptide precursors in high isolated yields, and with low levels of epimerization. This method is fully compatible with Fmoc‐strategy solid‐phase peptide synthesis. Global deprotection with trifluoroacetic acid furnishes peptide phenylthioesters for NCL. Photoreactive peptide precursors can also be converted into their hydrazides in two steps by this method.