bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Rapid Exfoliation and Subsequent Restacking of Layered Titanates Driven by an Acid–Base Reaction
Authors: Yuan Huiyu , Dubbink David , Besselink Rogier , ten Elshof Johan E. 
Published: June 2015

AbstractTwo‐dimensional (2D) (hydro)oxide materials, that is, nanosheets, enable the preparation of advanced 2D materials and devices. The general synthesis route of nanosheets involves exfoliating layered metal (hydro)oxide crystals. This exfoliation process is considered to be time‐consuming, hindering their industrial‐scale production. Based on in situ exfoliation studies on the protonated layered titanate H1.07Ti1.73O4⋅H2O (HTO), it is now shown that ion intercalation‐assisted exfoliation driven by chemical reaction provides a viable and fast route to isolated nanosheets. Contrary to the general expectation, data indicate that direct exfoliation of HTO occurs within seconds after mixing of the reactants, instead of proceeding via a swollen state as previously thought. These findings reveal that ion intercalation‐assisted exfoliation driven by chemical reaction is a promising exfoliation route for large‐scale synthesis.
Acid‐Triggered Degradable Reagents for Differentiation of Adaptive and Innate Immune Responses to Leishmania‐Associated Sugars
Authors: Roychoudhury Rajarshi , Martinez Pedro A. , Grinnage‐Pulley Tara , Schaut Robert G. , Petersen Christine A. , Pohl Nicola L. B. 
Published: June 2015

AbstractLipopolysaccharides (LPS) of Leishmania spp are known to alter innate immune responses. However, the ability of these sugars to specifically alter adaptive T‐cell responses is unclear. To study cap sugar–T‐cell interactions, pathogen mimics (namely glycodendrimer‐coated latex beads with acid‐labile linkers) were synthesized. Upon lysosomal acidification, linker breakdown releases glycodendrimers for possible loading on antigen presenting molecules to induce T‐cell growth. T‐cell proliferation was indeed higher after macrophage exposure to mannobioside or ‐trioside‐containing glycodendrimers than to non‐functionalized beads. Yet, blocking phagolysosomal acidification only reduced T‐cell proliferation with macrophages exposed to beads with an acid‐labile‐linker and not to covalently‐linked beads. These sugar‐modified reagents show that oligosaccharides alone can drive T‐cell proliferation by acidification‐requiring presentation, most significantly in NKT receptor (CD160)‐restricted T cells.
Eine universelle Herstellungsmethode für extrem kleine magneto‐fluoreszierende Nanohybride
Authors: Feld Artur , Merkl Jan‐Philip , Kloust Hauke , Flessau Sandra , Schmidtke Christian , Wolter Christopher , Ostermann Johannes , Kampferbeck Michael , Eggers Robin , Mews Alf , Schotten Theo , Weller Horst 
Published: June 2015

AbstractDie Saat‐Emulsionspolymerisation ist eine effiziente Herstellungsmethode für nanoskalige multifunktionale Hybridmaterialien. In einem zweistufigen Prozess wurden zunächst Eisenoxidnanopartikel mit einer Hülle aus Polystyrol verkapselt. Diese wurden anschließend mit Quantenpunkten in Quantenstäben (QDQRs) belegt, sodass Nanohybride mit Eisenoxidkern und QDQR‐Satelliten resultierten. Die Synthese einer nahtlosen Polystyrolhülle ermöglicht sowohl die Fixierung des Konstruktes als auch die Steuerung seiner Zusammensetzung. Dadurch bleiben die Fluoreszenzeigenschaften der QDQRs und die magnetischen Eigenschaften des Eisenoxids unverändert, was mittels Einzelpartikeluntersuchung, Messung der Fluoreszenzabklingzeit und Relaxometrie nachgewiesen werden kann. Die Biofunktionalisierung erfolgte direkt durch Copolymerisation von entsprechenden Affinitätsmolekülen. Die Anwendbarkeit der Methode auf verschiedenartige Nanopartikel wurde demonstriert.
Copper‐Catalyzed Regioselective Hydroalkylation of 1,3‐Dienes with Alkyl Fluorides and Grignard Reagents
Authors: Iwasaki Takanori , Shimizu Ryohei , Imanishi Reiko , Kuniyasu Hitoshi , Kambe Nobuaki 
Published: June 2015

AbstractCopper complexes generated in situ from CuCl2, alkyl Grignard reagents, and 1,3‐dienes play important roles as catalytic active species for the 1,2‐hydroalkylation of 1,3‐dienes by alkyl fluorides through CF bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3‐diene regioselectively, thus giving rise to the branched terminal alkene product.
Thiophene, Selenophene, and Tellurophene‐based Three‐Dimensional Organic Frameworks
Authors: Li Peng‐Fei , Schon Tyler B. , Seferos Dwight S. 
Published: June 2015

Abstract3D frameworks are important because of their potential to combine the advantageous properties of porous materials with those associated with polymers. A series of novel 3D aromatic frameworks are presented that incorporate the heterocycles thiophene, selenophene, and tellurophene. The specific surface area and pore width of frameworks depends on the element that is used to build the framework. Optoelectronic properties are element‐dependent, with heavy atoms red‐shifting the optical properties and decreasing the energy gap of the solid. The metalloid nature of tellurophene allows the properties of this material to be tuned based on its oxidation state, even as an insoluble solid. The incorporation of the optoelectronic active thiophene, selenophene, and tellurophene units and the effect that they have on properties was studied. A supercapcitor device was fabricated using these frameworks, showing that these 3D frameworks are promising for optoelectronic uses.
A Photoactivatable AIE Polymer for Light‐Controlled Gene Delivery: Concurrent Endo/Lysosomal Escape and DNA Unpacking
Authors: Yuan Youyong , Zhang Chong‐Jing , Liu Bin 
Published: June 2015

AbstractEndo/lysosomal escape of gene vectors and the subsequent unpacking of nucleic acids in cytosol are two major challenges for efficient gene delivery. Herein, we report a polymeric gene delivery vector, which consists of a photosensitizer (PS) with aggregation‐induced emission (AIE) characteristics and oligoethylenimine (OEI) conjugated via an aminoacrylate (AA) linker that can be cleaved by reactive oxygen species (ROS). In aqueous media, the polymer could self‐assemble into bright red fluorescent nanoparticles (NPs), which can efficiently bind to DNA through electrostatic interaction for gene delivery. Upon visible light irradiation, the generated ROS can break the endo/lysosomal membrane and the polymer, resulting in light‐controlled endo/lysosomal escape and unpacking of DNA for efficient gene delivery. The smart polymer represents the first successful gene vector to simultaneously address both challenges with a single light excitation process.
Ruthenium‐Catalyzed Monoalkenylation of Aromatic Ketones by Cleavage of Carbon–Heteroatom Bonds with Unconventional Chemoselectivity
Authors: Kondo Hikaru , Akiba Nana , Kochi Takuya , Kakiuchi Fumitoshi 
Published: June 2015

AbstractRuthenium‐catalyzed selective monoalkenylation of ortho CO or CN bonds of aromatic ketones was achieved. The reaction allowed the direct comparison of the relative reactivities of the cleavage of different carbon‐heteroatom bonds, thus suggesting an unconventional chemoselectivity, where smaller, more‐electron‐donating groups are more easily cleaved. Selective monofunctionalization of CO bonds in the presence of ortho CH bonds was also achieved.
Cp*RhIII‐katalysierte Arylierung von C(sp3)‐H‐Bindungen
Authors: Wang Xiaoming , Yu Da‐Gang , Glorius Frank 
Published: June 2015

AbstractDie erste Cp*RhIII‐katalysierte Arylierung nichtaktivierter C(sp3)‐H‐Bindungen wird vorgestellt. Nichtaktivierte primäre C(sp3)‐H‐Bindungen von 2‐Alkylpyridinen können mit RhIII aktiviert und mit Triarylboroxinen umgesetzt werden, um neue C(sp3)‐Aryl‐Bindungen zu knüpfen. Die entwickelte Methode erlaubt auch die einfache Synthese unsymmetrischer Triarylmethane durch RhIII‐katalysierte C(sp3)‐H‐Arylierung von Diarylmethanen.
Effective Formylation of Amines with Carbon Dioxide and Diphenylsilane Catalyzed by Chelating bis(tzNHC) Rhodium Complexes
Authors: Nguyen Thanh V. Q. , Yoo Woo‐Jin , Kobayashi Shū 
Published: June 2015

AbstractThe reductive formylation of amines using CO2 and hydrosilanes is an attractive method for incorporating CO2 into valuable organic compounds. However, previous systems required either high catalyst loadings or high temperatures to achieve high efficiency, and the substrate scope was mostly limited to simple amines. To address these problems, a series of alkyl bridged chelating bis(NHC) rhodium complexes (NHC=N‐heterocyclic carbene) have been synthesized and applied to the reductive formylation of amines using CO2 and Ph2SiH2. A rhodium‐based bis(tzNHC) complex (tz=1,2,3‐triazol‐5‐ylidene) was identified to be highly effective at a low catalyst loading and ambient temperature, and a wide substrate scope, including amines with reducible functional groups, were compatible.
Total Synthesis and Structural Revision of Antibiotic CJ‐16,264
Authors: Nicolaou K. C. , Shah Akshay A. , Korman Henry , Khan Tabrez , Shi Lei , Worawalai Wisuttaya , Theodorakis Emmanuel A. 
Published: June 2015

AbstractThe total synthesis and structural revision of antibiotic CJ‐16,264 is described. Starting with citronellal, the quest for the target molecule featured a novel bis‐transannular Diels–Alder reaction that casted stereoselectively the decalin system and included the synthesis of six isomers before demystification of its true structure.
Asymmetric Construction of Spirooxindoles by Organocatalytic Multicomponent Reactions Using Diazooxindoles
Authors: Wu Ming‐Yue , He Wei‐Wei , Liu Xin‐Yuan , Tan Bin 
Published: June 2015

AbstractThe first highly diastereo‐ and enantioselective multicomponent reaction of diazooxindoles, nitrosoarenes, and nitroalkenes using a newly developed hydrogen‐bond catalyst has been successfully developed for the efficient construction of a series of spirooxindole derivatives with excellent functional‐group tolerance. Spirooxindoles are formed in excellent yields and stereoselectivities, and the method represents an unprecedented approach for trapping the active intermediate with a nitroalkene to form biologically important compounds having three contiguous stereogenic centers with excellent asymmetric induction.
Visible‐Light‐Activated Molecular Switches
Authors: Bléger David , Hecht Stefan 
Published: June 2015

AbstractThe ability to influence key properties of molecular systems by using light holds much promise for the fields of materials science and life sciences. The cornerstone of such systems is molecules that are able to reversibly photoisomerize between two states, commonly referred to as photoswitches. One serious restriction to the development of functional photodynamic systems is the necessity to trigger switching in at least one direction by UV light, which is often damaging and penetrates only partially through most media. This review provides a summary of the different conceptual strategies for addressing molecular switches in the visible and near‐infrared regions of the optical spectrum. Such visible‐light‐activated molecular switches tremendously extend the scope of photoswitchable systems for future applications and technologies.
Folding of the Tau Protein on Microtubules
Authors: Kadavath Harindranath , Jaremko Mariusz , Jaremko Łukasz , Biernat Jacek , Mandelkow Eckhard , Zweckstetter Markus 
Published: June 2015

AbstractMicrotubules are regulated by microtubule‐associated proteins. However, little is known about the structure of microtubule‐associated proteins in complex with microtubules. Herein we show that the microtubule‐associated protein Tau, which is intrinsically disordered in solution, locally folds into a stable structure upon binding to microtubules. While Tau is highly flexible in solution and adopts a β‐sheet structure in amyloid fibrils, in complex with microtubules the conserved hexapeptides at the beginning of the Tau repeats two and three convert into a hairpin conformation. Thus, binding to microtubules stabilizes a unique conformation in Tau.
The Radiative Lifetime in Near‐IR‐Luminescent Ytterbium Cryptates: The Key to Extremely High Quantum Yields
Authors: Doffek Christine , Seitz Michael 
Published: June 2015

AbstractA powerful strategy for the improvement of near‐IR lanthanoid luminescence has been successfully employed for the first time, which involves the rational and deliberate shortening of the radiative luminescence lifetimes τrad in molecular ytterbium complexes. In this context, the bidentate chelating unit 2,2′‐bipyridine‐N,N′‐dioxide has been identified as being responsible for decreasing τrad substantially in macrobicyclic Yb cryptates. This strategy, when combined with conventional approaches, yields unprecedented absolute near‐IR quantum yields of up to 12 %. This extraordinary efficiency represents the highest value measured for any molecular lanthanoid near‐IR emitter. The proof‐of‐concept for the implementation of the new strategy opens up entirely new prospects for the field of lanthanoid luminescence.
1,5‐Di(nitramino)tetrazole: High Sensitivity and Superior Explosive Performance
Authors: Fischer Dennis , Klapötke Thomas M. , Stierstorfer Jörg 
Published: June 2015

AbstractHighly energetic 1,5‐di(nitramino)tetrazole and its salts were synthesized. The neutral compound is very sensitive and one of the most powerful non‐nuclear explosives to date. Selected nitrogen‐rich and metal salts were prepared. The potassium salt can be used as a sensitizer in place of tetracene. The obtained compounds were characterized by low‐temperature X‐ray diffraction, IR and Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and DSC. Calculated energetic performances using the EXPLO5 code based on calculated (CBS‐4M) heats of formation and X‐ray densities support the high energetic performances of the 1,5‐dinitraminotetrazolates as energetic materials. The sensitivities towards impact, friction, and electrostatic discharge were also explored.
Selective Aryl–Fluoride Reductive Elimination from a Platinum(IV) Complex
Authors: Dubinsky‐Davidchik Ina , Goldberg Israel , Vigalok Arkadi , Vedernikov Andrei N. 
Published: June 2015

AbstractA difluoro(mesityl)platinum(IV) complex underwent highly selective reductive elimination of 2‐fluoromesitylene upon heating in toluene. Kinetic analysis and DFT calculations suggest that the CF coupling involves a five‐coordinate PtIV transient intermediate resulting from the rate‐limiting dissociation of the pyridine ligand.
Cp*RhIII‐Catalyzed Arylation of C(sp3)H Bonds
Authors: Wang Xiaoming , Yu Da‐Gang , Glorius Frank 
Published: June 2015

AbstractThe first Cp*RhIII‐catalyzed arylation of unactivated C(sp3)H bonds is presented. The unactivated primary C(sp3)H bond of 2‐alkylpyridines can be activated by RhIII and further reacts with triarylboroxines to efficiently build new C(sp3)aryl bonds. The methodology also provides a facile and efficient synthesis of unsymmetrical triarylmethanes by RhIII‐catalyzed C(sp3)H arylation of diarylmethanes.
Experimental investigation of moisture diffusion in short‐glass‐fiber‐reinforced polyamide 6,6
Authors: Zhang Shi , Huang Zhigao , Zhang Yun , Zhou Huamin 
Published: June 2015

ABSTRACTMoisture diffusion in polyamide 6,6 (PA66) and its short glass fiber‐reinforced composites has a great influence on their mechanical properties and service lives under hydrothermal environments. Hence, the moisture diffusion in neat PA66 and its composites was studied comprehensively in this study with the general Fickian model. To systematically investigate the effects of the fiber content, humidity, temperature, and humidity–temperature coupling effect on the diffusion coefficient and equilibrium concentration, gravimetric experiments for the PA66 composites were carried out under different hydrothermal conditions. The results show that the equilibrium moisture concentration depended on the relative humidity and fiber content but only depended weakly on temperature. The diffusion velocity was affected by the three aforementioned factors with different trends. The analysis of variance demonstrated that the humidity–temperature coupling effect played an important role in the diffusion process. The regression analysis gave the corresponding quadratic regression equations. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42369.
Current progress in the production of PLA–ZnO nanocomposites: Beneficial effects of chain extender addition on key properties
Authors: Murariu Marius , Paint Yoann , Murariu Oltea , Raquez Jean‐Marie , Bonnaud Leila , Dubois Philippe 
Published: June 2015

ABSTRACTPoly(lactic acid) (PLA) nanocomposites characterized by multifunctional end‐use properties are of high interest as new biosourced materials for the production of smart films, fibers, and injection‐molded components. In this work, PLA–ZnO nanocomposites designed for the extrusion of films were obtained by melt‐compounding PLA with up to 5 wt % ZnO rod‐like nanoparticles, nanofiller previously surface‐treated with a specific silane (triethoxycaprylylsilane). To improve the processing and performances of nanocomposites such as their stability at high temperature, the addition of a selected chain‐extender (CE) was considered. It was revealed that the co‐addition of nanofiller (ZnO) and epoxy functional styrene‐acrylate oligomeric CE (Joncryl® ADR 4300F) leads to a very significant enhancement of the properties (molecular, rheological, thermal, etc.) of PLA–ZnO nanocomposites. After addition of 1% CE into nanocomposites, the PLA molecular weights were found to be nearly twofold higher, while the isothermal tests (at 220 and 240°C) confirmed a significant increase in thermal stability. Because the CE plays a key role in limiting the degrading effects of ZnO, due to a gain in melt viscosity and increased molecular mass, a better ability to process nanocomposites by extrusion was found. The good nanofiller dispersion and specific end‐use characteristics owing to the presence of ZnO nanoparticles (such as UV shielding) were again confirmed on extruded films. These developments are being viewed as a promising approach that can open new perspectives in the application of PLA–ZnO nanocomposites with specific end‐use properties (UV protection, antibacterial, gas‐barrier, and self‐cleaning) at larger scale. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42480.
Investigation of the thermostability of poly(ethylene terephthalate)–hemp fiber composites: Extending natural fiber reinforcements to high‐melting thermoplastics
Authors: Talla Aimé Sylvain Fotso , Erchiqui Fouad , Kaddami Hamid , Kocaefe Duygu 
Published: June 2015

ABSTRACTThe thermal stability of poly(ethylene terephthalate) reinforced with 1, 5, 10, 15, and 20% hemp fibers was investigated with the aim of extending the applications of biocomposites to high‐melting thermoplastics. The material was injection‐molded following compounding with a torque‐based Rheomix at 240, 250, and 260°C. A combination of thermogravimetric methods at 5, 10, and 20°C/min, Liu and Yu's collecting temperature method, and Friedman's kinetic method were used for testing and analysis. A significant thermostability for all formulations was observed below 300°C; this demonstrated their potential for successful melt processing. Moreover, two degradation steps were observed in the temperature ranges 313–390 and 390–490°C. The associated apparent activation energies within the temperature ranges were determined as 150–262 and 182–242 kJ/mol, respectively. We found that the thermostability was significantly affected by the heating rates; however, the effect of the temperature of the mixing chamber was negligible. These findings suggest that the successful melt processing of high‐melting thermoplastics reinforced with natural fibers is possible with limited fiber thermodegradation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42500.
Largely toughening biodegradable poly(lactic acid)/thermoplastic polyurethane blends by adding MDI
Authors: Zhao Fei , Huang Han‐Xiong , Zhang Shui‐Dong 
Published: June 2015

ABSTRACTThis work focuses on largely toughening poly(lactic acid)/thermoplastic polyurethane (PLA/TPU) blend with lower content (20 wt %) of TPU using appropriate contents of 4,4‐methylene diphenyl diisocyanate (MDI) via simple melt blending. Both scanning electron micrographs and differential scanning calorimetry curves suggest little change of the compatibility between the PLA and TPU phases by adding the MDI. Dynamic rheological test demonstrates that a reaction occurs between the TPU phase and MDI during melt blending. Combining the rheological behaviors and gel contents of the blends, it can be speculated that adding the MDI extends the TPU chains and forms branched and crosslinked structure in the TPU chains sequentially. Toughening mechanism is analyzed and different impact strengths for the blends with different MDI contents are explained based on combined effects of the decreased crystallinities for the PLA matrix and the extended, branched and crosslinked structure in the TPU chains. A 0.8 wt % MDI content is optimal in terms of the impact strength (100.6 kJ/m2) and the elongation at break (392.4%). The former is about 1.9 and 32.5 times of that for the blend without MDI and the PLA, respectively. Moreover, the MDI results in some increase in the tensile strength of the blends. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42511.
Environmental flow releases trigger spawning migrations by Australian grayling Prototroctes maraena, a threatened, diadromous fish
Authors: Amtstaetter Frank , O'connor Justin , Pickworth Andrew 
Published: June 2015

Abstract

Monitoring fish movement can test the effectiveness of environmental flow releases when they are used to trigger spawning behaviour. Environmental flow releases have been used to enhance Australian grayling (Prototroctes maraena) spawning in regulated rivers in south‐eastern Australia and resource managers require knowledge of the effectiveness on the conservation of this threatened species.
Australian grayling movement was monitored in the Thomson River, south‐eastern Australia using acoustic telemetry to determine whether the species undergoes a spawning migration, where they migrate and timing in relation to environmental flow releases. Drift netting was used to verify whether spawning took place.
Adult Australian grayling undertook downstream spawning migrations (up to 140 km) to the lower Thomson River, coinciding with environmental flow releases.
The findings of this study support the use of environmental flow releases to trigger spawning migrations by Australian grayling. In addition, they provide managers of other species with an example of the potential effectiveness of environmental flow releases in triggering fish migration or spawning that can assist in rationalizing this management intervention.
Copyright © 2015 John Wiley & Sons, Ltd.