bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioinspired Nanocomposites: Ordered 2D Materials Within a 3D Lattice
Authors: Giosia Matteo Di , Polishchuk Iryna , Weber Eva , Fermani Simona , Pasquini Luca , Pugno Nicola M. , Zerbetto Francesco , Montalti Marco , Calvaresi Matteo , Falini Giuseppe , Pokroy Boaz
Published: May 2016

Composites, materials composed of two or more materials—metallic, organic, or inorganic—usually exhibit the combined physical properties of their component materials. The result is a material that is superior to conventional monolithic materials. Advanced composites are used in a variety of industrial applications and therefore attract much scientific interest. Here the formation of novel carbon‐based nanocomposites is described via incorporation of graphene oxide (GO) into the crystal lattice of single crystals of calcite. Incorporation of a 2D organic material into single‐crystal lattices has never before been reported. To characterize the resulting nanocomposites, high‐resolution synchrotron powder X‐ray diffraction, electron microscopy, transmission electron microscopy, fluorescence microscopy and nanoindentation tests are employed. A detailed analysis reveals a layered distribution of GO sheets incorporated within the calcite host. Moreover, the optical and mechanical properties of the calcite host are altered when a carbon‐based nanomaterial is introduced into its lattice. Compared to pure calcite, the composite GO/calcite crystals exhibits lower elastic modulus and higher hardness. The results of this study show that the incorporation of a 2D material within a 3D crystal lattice is not only feasible but also can lead to the formation of hybrid crystals exhibiting new properties.
Toward Ultrahigh‐Capacity V2O5 Lithium‐Ion Battery Cathodes via One‐Pot Synthetic Route from Precursors to Electrode Sheets
Authors: Lee Jung Han , Kim Ju‐Myung , Kim Jung‐Hwan , Jang Ye‐Ri , Kim Jeong A , Yeon Sun‐Hwa , Lee Sang‐Young
Published: May 2016

Acquisition of high‐energy density is the highest priority requirement and unending challenge in energy storage systems including lithium‐ion batteries (LIBs). One theoretically preferable way to reach this goal is the use of cathode active materials such as vanadium pentoxide (V2O5) that relies on multielectron insertion/extraction reactions. Application of V2O5 to LIB cathodes, however, has been mostly focused on V2O5 materials themselves with little emphasis on V2O5‐incorporated cathode sheets. Here, as an unusual electrode‐architecture approach to achieve ultrahigh‐capacity V2O5 cathode sheets, a new class of self‐standing V2O5 cathode sheets is demonstrated based on V2O5/multiwalled carbon tubes (MWNTs) mixtures spatially besieged by polyacrylonitrile nanofibers (referred to as “VMP cathode sheets”). Notably, the VMP cathode sheet is fabricated directly via one‐pot synthetic route starting from V2O5 precursor (i.e., through concurrent electrospraying/electrospinning followed by calcination), without metallic foil current collectors/carbon powders/polymeric binders. The one‐pot synthesis allows dense packing of V2O5 nanoparticles in close contact with MWNT electronic networks and also formation of well‐developed interstitial void channels (ensuring good electrolyte accessibility). This material/architecture uniqueness of the VMP cathode sheet eventually enables significant improvements in cell performance (particularly, gravimetric/volumetric capacity of cathode sheets) far beyond those accessible with conventional electrode technologies.
Small Upconverting Fluorescent Nanoparticles for Biosensing and Bioimaging
Authors: Tan Guang‐Rong , Wang Menghan , Hsu Chin‐Ying , Chen Nanguang , Zhang Yong
Published: May 2016

Rapid progress in biological sensing and imaging technologies offers new and exciting opportunities to identify biochemical changes fundamental to preclinical research that may develop into the next generation of point‐of‐care devices. Small upconverting fluorescent nanoparticles (UCNPs) are a special class of lanthanide‐doped, optically active, microscopic particles that fluoresce upon near‐infrared light activation. With the additional advantages of deep penetration, minimal photodamage, and low background fluorescence in biological tissues, biosensors incorporating these lanthanide nanoparticles are rapidly emerging as serious contenders to rival the traditional downconversion‐based fluorescence nanoparticles. Emphasizing on two application areas, namely biosensing and bioimaging, the recent developments in lanthanide‐based UCNP design for optimum upconversion efficiency are reviewed. The article discusses the use of UCNPs in biosensing and bioimaging, highlights the challenges that hamper further applications, and concludes with future directions.
Broadband Solar Thermal Absorber Based on Optical Metamaterials for High‐Temperature Applications
Authors: Han Sunwoo , Shin Ju‐Hyeon , Jung Pil‐Hoon , Lee Heon , Lee Bong Jae
Published: May 2016

In this work, a tandem grating solar absorber is proposed, which can be easily fabricated on a wafer scale and is thermally stable up to 800 K. The base of the solar thermal absorber consists of a tungsten substrate, SiO2 spacer, and 2D tungsten nanohole array filled with SiO2. On top of the base structure, a 2D tungsten nanodisc array is coated with an additional SiO2 spacer, forming the tandem grating structure. The outside area of the nanodisc array is also filled with SiO2; thus, the proposed solar absorber is geometrically flat. In the solar spectrum from 0.3 to 2.0 μm, the total absorptance of the fabricated sample is measured to be 90%. On the other hand, in the mid‐infrared region from 3 to 15 μm, the total emittance is measured to be 23% at 800 K, which greatly suppresses the thermal emission loss. Finite‐difference time‐domain simulation suggests that the magnetic resonance and Rayleigh anomaly are responsible for the enhanced absorption of solar radiation. It is also shown that the spectral absorptance of the proposed solar absorber is nearly insensitive to the polarization angle as well as to the incidence angle in the spectrum of solar radiation.
On optimal sensing and actuation design for an industrial scale steam methane reformer furnace
Authors: Kumar Ankur , Baldea Michael , Edgar Thomas F.
Published: May 2016

The spatial temperature distribution in the highly energy‐intensive furnace unit in a steam reforming‐based hydrogen manufacturing plant determines the energy efficiency of the plant. While the fuel distribution among the burners can be manipulated to control the furnace temperature distribution, adequate temperature measurements is a prerequisite. Typical furnaces have hundreds of tubes and burners, and economic considerations dictate that the number of temperature sensors and flow actuators required for automatic temperature optimization be minimized. In this article, we investigate several formulations for the design of the optimal sensor and actuation configurations for an industrial furnace. We initially formulate the optimal sensor placement problem as a bi‐level optimization problem, and exploit the problem structure to obtain an equivalent mixed‐integer linear program formulation. We then provide an extension to the combined sensor and actuator placement. We demonstrate the efficacy of our approach through simulation case studies based on industrial data. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3225–3237, 2016
The effect of shear‐thickening on the stability of slot‐die coating
Authors: Khandavalli Sunilkumar , Rothstein Jonathan P.
Published: May 2016

Slot‐die coating is an economical roll‐to‐roll processing technique with potential to revolutionize the fabrication of nano‐patterned thin films at high throughput. In this study, the impact of shear‐thickening of the coating fluid on the stability of slot‐die coating was investigated. For the coating fluid, a model system fumed silica nanoparticles dispersed in polypropylene glycol was chosen. These dispersions exhibit shear and extensional thickening characterized through steady shear and capillary break‐up measurements. The critical web velocity for the onset of coating defect for different flow rates was measured, while the type of coating defect was visualized using a high speed camera. For the shear thickening particle dispersions, the coating failed through the onset of a ribbing instability. The critical web velocity for the onset of coating defect was found to decrease with increasing particle concentration and increasing fluid viscosity. The minimum wet thickness was studied as a function of capillary number for the particle dispersions and compared with a series of Newtonian fluids with similar viscosities. In all cases, shear‐thickening behavior was found to stabilize coating by reducing the minimum wet coating thickness when compared against a Newtonian fluid with similar viscosity at the same capillary number. Conversely, the shear‐thinning fluids tested destabilized the coating by increasing the minimum wet thickness when compared against a Newtonian at the same capillary number. The impact of shear‐thickening on slot‐die coating was further studied by quantifying the evolution of the ribbing instability with increasing web speed and by conducting tests over a wide range of coating gaps. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4536–4547, 2016
Study on dynamic behavior adjustment of nonlinear chemical processes
Authors: Jiang Hao , Chen Bingzhen
Published: May 2016

In nonlinear chemical processes, many economically desirable operating conditions are located in unstable regions, leading to product quality degradation and safety problems. Therefore, determining how to adjust the dynamic behavior to make the process stable within its desired operational range is a topic of common interest within industrial and academic communities. This article presents a dynamic behavior adjustment method based on a washout filter‐aided controller with an improved parameter‐tuning algorithm to stabilize parts of the equilibrium manifold of chemical processes. In addition, applying this method to industrial toluene liquid‐phase catalytic oxidation shows that, by combining a conventional proportional‐integral (PI) controller with the proposed improved washout filter‐aided controller, the performance of set‐point tracking is improved for cases with parameter uncertainty. In general, the proposed dynamic behavior adjustment method will be effective for most chemical processes. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3189–3198, 2016
Polymorph selection by continuous crystallization
Authors: Farmer Thomas C. , Carpenter Corinne L. , Doherty Michael F.
Published: May 2016

This article is motivated by a remarkable observation reported recently by Myerson, Trout, and co‐workers that continuous crystallization is capable of producing metastable polymorphs in stable steady‐state operation. We explain why this phenomenon occurs and give simple design rules for reproducing it in other polymorphic systems. A linear stability analysis gives simple functions of parameters for which one can continuously produce thermodynamically metastable products based only on the relative polymorph dynamics. We demonstrate agreement with two sets of experimental data; L‐glutamic acid grown from aqueous solution and p‐aminobenzoic acid also grown from aqueous solution. For many polymorphic compounds, engineering a process to produce a desired polymorph is as simple as finding a reasonable operating point for the continuous mixed‐suspension mixed‐product removal crystallization process (temperature, residence time, initial supersaturation, etc.) according to the rules reported in this article. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3505–3514, 2016
Incidence, etiology, and outcome of pleural effusions in allogeneic hematopoietic stem cell transplantation
Authors: Modi Dipenkumar , Jang Hyejeong , Kim Seongho , Deol Abhinav , Ayash Lois , Bhutani Divaya , Lum Lawrence G. , Ratanatharathorn Voravit , Manasa Richard , Mellert Kendra , Uberti Joseph P.
Published: May 2016

Pleural effusion is a known entity in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT); however, the incidence, risk factors, and morbidity−mortality outcomes associated with pleural effusions remain unknown. We retrospectively evaluated pleural effusions in 618 consecutive adult patients who underwent allogeneic HSCT from January 2008 to December 2013 at our institution. Seventy one patients developed pleural effusion at a median of 40 days (range, 1 − 869) post‐HSCT with the cumulative incidence of 9.9% (95% CI, 7.7 − 12.5%) at 1 year. Infectious etiology was commonly associated with pleural effusions followed by volume overload and serositis type chronic GVHD. In multivariate analysis, higher comorbidity index (P = 0.03) and active GVHD (P = 0.018) were found to be significant independent predictors for pleural effusion development. Higher comorbidity index, very high disease risk index, ≤7/8 HLA matching, and unrelated donor were associated with inferior overall survival (OS) (P < 0.03). More importantly, patients with pleural effusion were noted to have poor OS in comparison to patients without pleural effusion (P < 0.001). Overall, pleural effusion is a frequently occurring complication after allogeneic HSCT, adding to morbidity and mortality and hence, early identification is required. Am. J. Hematol. 91:E341–E347, 2016. © 2016 Wiley Periodicals, Inc.
Malnutrition and body composition in urban and rural schoolchildren: A cross‐sectional study in San Rafael, Mendoza (Argentina)
Authors: Garraza Mariela , Cesani María F. , Navone Graciela T. , Oyhenart Evelia E.
Published: May 2016

Objectives

The aim of the present study was to analyze the nutritional status and body composition of children from San Rafael, Mendoza, avoiding urban and rural categorization by generating subpopulations as a function of their socio‐environmental characteristics.

Methods

A cross‐sectional study was performed in 3,596 schoolchildren from 4.0 to 13.9 years of age. Body weight, height, upper arm circumference, and triceps skinfold were measured. Body mass index, total muscle, and fat areas of the arm were calculated. To estimate nutritional status and body composition, the NHANES III reference was used. The socio‐environmental variables were surveyed using a structured questionnaire. These variables were processed by categorical principal‐component analysis (catPCA).

Results

The catPCA allowed the differentiation of four groups, three with urban characteristics (high urban, medium urban, impoverished urban), and a rural group. Stunting occurred at a higher rate in the impoverished urban group, and the occurrence of underweight children was higher in the rural group. The prevalence of excess weight varied in the range of 20–26%. The latter value corresponded to children of the high urban group, who also did not show reduced muscle mass.

Conclusion

Children from San Rafael presented differences in nutritional condition and body composition associated with pronounced socio‐environmental heterogeneity. Thus, we could observe a gradient from the “high urban” group, with better social, economic, and sanitation conditions and at the same time a more obesogenic environment to the “impoverished urban” and “rural” groups, whose vulnerability reflected a higher prevalence of child undernutrition and the association with excess weight and reduced muscle mass. Am. J. Hum. Biol. 28:796–803, 2016. © 2016Wiley Periodicals, Inc.
Directional asymmetry of upper limbs in a medieval population from Poland: A combination of linear and geometric morphometrics
Authors: Kubicka Anna Maria , Lubiatowski Przemysław , Długosz Jan Dawid , Romanowski Leszek , Piontek Janusz
Published: May 2016

Objectives

Degrees of upper‐limb bilateral asymmetry reflect habitual behavior and activity levels throughout life in human populations. The shoulder joint facilitates a wide range of combined motions due to the simultaneous motion of all three bones: clavicle, scapula, and humerus. Accordingly, we used three‐dimensional geometric morphometrics to analyze shape differences in the glenoid cavity and linear morphometrics to obtain the degree of directional asymmetry in a medieval population.

Methods

To calculate directional asymmetry, clavicles, humeri, and scapulae from 100 individuals (50 females, 50 males) were measured. Landmarks and semilandmarks were placed within a three‐dimensional reconstruction of the glenoid cavity for analysis of shape differences between sides of the body within sexes.

Results

Linear morphometrics showed significant directional asymmetry in both sexes in all bones. Geometric morphometrics revealed significant shape differences of the glenoid cavity between sides of the body in females but not in males. Both indicators of directional asymmetry (%DA and %AA) did not show significant differences between sexes. PLS analysis revealed a significant correlation between glenoid shape and two humeral head diameters only in females on the left side of the body.

Conclusions

The studied population, perhaps due to a high level of activity, exhibited slightly greater upper‐limb bone bilateral asymmetry than other agricultural populations. Results suggest that the upper limbs were involved in similar activity patterns in both sexes but were characterized by different habitual behaviors. To obtain comprehensive results, studies should be based on sophisticated methods such as geometric morphometrics as well as standard measurements. Am. J. Hum. Biol. 28:817–824, 2016. © 2016Wiley Periodicals, Inc.
The interaction of cultural consonance and a polymorphism in the 2A serotonin receptor in relation to depression in Brazil: failure to replicate previous findings
Authors: Dressler William W. , Balieiro Mauro C. , de Araújo Luiza Ferreira , Silva Wilson A. , dos Santos José ERNESTO
Published: May 2016

Objectives

To replicate a previously identified gene‐environment interaction between a genetic polymorphism in the serotonin 2A receptor and cultural consonance in family life in relation to depressive symptoms (Dressler et al., 2009).

Methods

A sample of 402 individuals in a sample drawn from four different economic strata in Ribeirão Preto, Brazil was interviewed and genotyped.

Results

Cultural consonance in family life has an inverse association with depressive symptoms (beta = −0.439, P < 0.001) and with high depressive symptoms (OR = 2.36, P < 0.001), but the interaction with genotype was not statistically significant.

Conclusion

The previously identified gene‐environment interaction was not replicated. Limitations of the study are discussed. Am. J. Hum. Biol. 28:936–940, 2016. © 2016Wiley Periodicals, Inc.
Selektive katalytische Synthesen mit Kohlendioxid und Wasserstoff: Katalyse‐Schach an der Nahtstelle zwischen Energie und Chemie
Authors: Klankermayer Jürgen , Wesselbaum Sebastian , Beydoun Kassem , Leitner Walter
Published: May 2016

Dieser Aufsatz diskutiert die Chancen und Herausforderungen für die Nutzung der Kombination aus Kohlendioxid und Wasserstoff als C1‐Synthon in katalytischen Reaktionen und Prozessen. Die Transformationen werden anhand des Reduktionsgrades und der Bindungsknüpfung geordnet, wobei die chemische Wertschöpfungskette von großvolumigen Grundchemikalien bis hin zu komplexen Molekülen mit biologischer Wirkung abgedeckt wird. Die chemischen Transformationen erlauben zum einen die Speicherung und Nutzung von erneuerbaren Energien in stofflichen Produkten und bieten gleichzeitig Möglichkeiten für ressourcenschonende und umweltfreundliche Herstellungsprozesse. Interdisziplinäre Grundlagenforschung von Chemikern und Ingenieuren kann so zu nachhaltigen Technologien an der Schnittstelle von Energie und Chemie beitragen. Der Aufsatz lädt den Leser dazu ein, das “katalytische Schachbrett” der Nutzung von CO2 und H2 kennenzulernen und vielleicht selbst einige Partien darauf zu beginnen.
Pd4+ in oxoanionischer Umgebung: Die XeF2‐unterstützte Synthese von [Pd(S2O7)3]2−
Authors: Bruns Jörn , van Gerven David , Klüner Thorsten , Wickleder Mathias S.
Published: May 2016

Erstmalig wurde eine Verbindung synthetisiert, in der Pd4+‐Kationen ausschließlich von einfachen Oxoanionen koordiniert werden. Die Stabilisierung des vierwertigen Palladiums erfolgt durch Bildung des Komplexanions [Pd(S2O7)3]2−, in dem das Metallatom von drei chelatisierenden Disulfatgruppen umgeben wird. Interessanterweise wird das Salz K2[Pd(S2O7)3] nur dann erhalten, wenn die Reaktion von K2[PdCl6] und reinem SO3 in Gegenwart von XeF2 durchgeführt wird.
A General Method for Growing Two‐Dimensional Crystals of Organic Semiconductors by “Solution Epitaxy”
Authors: Xu Chunhui , He Ping , Liu Jie , Cui Ajuan , Dong Huanli , Zhen Yonggang , Chen Wei , Hu Wenping
Published: May 2016

Two‐dimensional (2D) crystals of organic semiconductors (2DCOS) have attracted attention for large‐area and low‐cost flexible optoelectronics. However, growing large 2DCOS in controllable ways and transferring them onto technologically important substrates, remain key challenges. Herein we report a facile, general, and effective method to grow 2DCOS up to centimeter size which can be transferred to any substrate efficiently. The method named “solution epitaxy” involves two steps. The first is to self‐assemble micrometer‐sized 2DCOS on water surface. The second is epitaxial growth of them into millimeter or centimeter sized 2DCOS with thickness of several molecular layers. The general applicability of this method for the growth of 2DCOS is demonstrated by nine organic semiconductors with different molecular structures. Organic field‐effect transistors (OFETs) based on the 2DCOS demonstrated high performance, confirming the high quality of the 2DCOS.
A Modular Synthetic Approach to Monocyclic 1,4‐Azaborines
Authors: Liu Xuguang , Zhang Yuanzhe , Li Bo , Zakharov Lev N. , Vasiliu Monica , Dixon David A. , Liu Shih‐Yuan
Published: May 2016

A simple and general method for the synthesis of a wide range of monocyclic 1,4‐azaborines, including the first examples containing B heteroatoms is described. Post‐heterocycle‐formation olefin isomerization was employed as a key strategy. This new synthetic method provides fundamental insight into the resonance stabilization and photophysical properties of 1,4‐azaborines.
Using Single‐Cell Amperometry To Reveal How Cisplatin Treatment Modulates the Release of Catecholamine Transmitters during Exocytosis
Authors: Li Xianchan , Dunevall Johan , Ewing Andrew G.
Published: May 2016

The pretreatment of cultured pheochromocytoma (PC12) cells with cis‐diamminedichloroplatinum (cisplatin), an anti‐cancer drug, influences the exocytotic ability of the cells in a dose‐dependent manner. Low concentrations of cisplatin stimulate catecholamine release whereas high concentrations inhibit it. Single‐cell amperometry reflects that 2 μm cisplatin treatment increases the frequency of exocytotic events and reduces their duration, whereas 100 μm cisplatin treatment decreases the frequency of exocytotic events and increases their duration. Furthermore, the stability of the initial fusion pore that is formed in the lipid membrane during exocytosis is also regulated differentially by different cisplatin concentrations. This study thus suggests that cisplatin influences exocytosis by multiple mechanisms.
Os2–Os4 Switch Controls DNA Knotting and Anticancer Activity
Authors: Fu Ying , Romero María J. , Salassa Luca , Cheng Xi , Habtemariam Abraha , Clarkson Guy J. , Prokes Ivan , Rodger Alison , Costantini Giovanni , Sadler Peter J.
Published: May 2016

Dinuclear trihydroxido‐bridged osmium–arene complexes are inert and biologically inactive, but we show here that linking dihydroxido‐bridged OsII–arene fragments by a bridging di‐imine to form a metallacycle framework results in strong antiproliferative activity towards cancer cells and distinctive knotting of DNA. The shortened spacer length reduces biological activity and stability in solution towards decomposition to biologically inactive dimers. Significant differences in behavior toward plasmid DNA condensation are correlated with biological activity.
Super‐heptazethrene
Authors: Zeng Wangdong , Sun Zhe , Herng Tun Seng , Gonçalves Théo P. , Gopalakrishna Tullimilli Y. , Huang Kuo‐Wei , Ding Jun , Wu Jishan
Published: May 2016

The challenging synthesis of a laterally extended heptazethrene molecule, the super‐heptazethrene derivative SHZ‐CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ‐CF3 exhibits an open‐shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo‐terrylene SHZ‐2H was also obtained during the synthesis. This study provides a new synthetic method to access large‐size quinoidal polycyclic hydrocarbons with unique physical properties.
A Selective C−H Deprotonation Strategy to Access Functionalized Arynes by Using Hypervalent Iodine
Authors: Sundalam Sunil K. , Nilova Aleksandra , Seidl Thomas L. , Stuart David R.
Published: May 2016

Described here is an efficient method to access highly functionalized arynes from unsymmetrical aryl(mesityl)iodonium tosylate salts. The iodonium salts are prepared in a single pot from either commercially available aryl iodides or arylboronic acids. The aryne intermediates are generated by ortho‐C−H deprotonation of aryl(mesityl)iodonium salt with a commercially available amide base and trapped in a cycloaddition reaction with furan in moderate to good yields. Coupling partners for the aryne intermediates beyond furan are also described, including benzyl azide and alicyclic amine nucleophiles. The regio‐ and chemoselectivity of this reaction is discussed and evidence for the spectator aryl ligand of the iodonium salt as a critical control element in selectivity is presented.
Ein zweikerniger 1,1′‐Bis(boratabenzol)‐Komplex: beispiellose intramolekulare Metall‐Metall‐Kommunikation durch eine B‐B‐Bindung
Authors: Braunschweig Holger , Demeshko Serhiy , Ewing William C. , Krummenacher Ivo , Macha Bret B. , Mattock James D. , Meyer Franc , Mies Jan , Schäfer Marius , Vargas Alfredo
Published: May 2016

Der erste 1,1′‐Bis(boratabenzol)‐Komplex wurde durch eine Tetrabromdiboran(4)‐induzierte Ringerweiterung von Cobaltocen erhalten. Um [{(η5‐C5H5)Co}2{μ:η6,η6‐(BC5H5)2}] zu gewinnen, werden sechs Cobaltocen‐Äquivalente benötigt, da Cobaltocen als Reagens wie auch als Reduktionsmittel fungiert. Die formal dianionische Bis(boratabenzol)‐Einheit im Komplex mit einer B‐B‐Einfachbindung kann als symmetrisches Dimer des entsprechenden Boratabenzol‐Anions oder auch als erstes Beispiel eines Dibor‐Analogons von Biphenyl betrachtet werden. Elektrochemische Messungen in Lösung zeigen, dass die Verbindung vier schrittweise Redoxprozesse eingeht, was auf eine merkliche intramolekulare Wechselwirkung der beiden Cobalt‐Ionen über die Bis(boratabenzol)‐Einheit schließen lässt. Die durch temperaturabhängige SQUID‐Messungen bestimmten magnetischen Eigenschaften deuten auf eine schwache intramolekulare antiferromagnetische Wechselwirkung hin. DFT‐Rechnungen untermauern die experimentellen Befunde und geben Einblick in die elektronischen Zustände des Komplexes.
3D SERS Imaging Using Chemically Synthesized Highly Symmetric Nanoporous Silver Microparticles
Authors: Vantasin Sanpon , Ji Wei , Tanaka Yoshito , Kitahama Yasutaka , Wang Mengfan , Wongravee Kanet , Gatemala Harnchana , Ekgasit Sanong , Ozaki Yukihiro
Published: May 2016

3D surface‐enhanced Raman scattering (SERS) imaging with highly symmetric 3D silver microparticles as a SERS substrate was developed. Although the synthesis method is purely chemical and does not involve lithography, the synthesized nanoporous silver microparticles possess a regular hexapod shape and octahedral symmetry. By using p‐aminothiophenol (PATP) as a probe molecule, the 3D enhancement patterns of the particles were shown to be very regular and predictable, resembling the particle shape and exhibiting symmetry. An application to the detection of 3D inhomogeneity in a polymer blend, which relies on the predictable enhancement pattern of the substrate, is presented. 3D SERS imaging using the substrate also provides an improvement in spatial resolution along the Z axis, which is a challenge for Raman measurement in polymers, especially layered polymeric systems.
Unusual Formation of CoSe@carbon Nanoboxes, which have an Inhomogeneous Shell, for Efficient Lithium Storage
Authors: Hu Han , Zhang Jintao , Guan Buyuan , Lou Xiong Wen (David)
Published: May 2016

Hybrid hollow nanostructures with tailored shell architectures are attractive for electrochemical energy storage applications. Starting with metal–organic frameworks (MOFs), we demonstrate a facile formation of hybrid nanoboxes with complex shell architecture where a CoSe‐enriched inner shell is intimately confined within a carbon‐enriched outer shell (denoted as CoSe@carbon nanoboxes). The synthesis is realized through manipulation of the template‐engaged reaction between Co‐based zeolitic imidazolate framework (ZIF‐67) nanocubes and Se powder at elevated temperatures. By virtue of the structural and compositional features, these unique CoSe@carbon nanoboxes manifest excellent lithium‐storage performance in terms of high specific capacity, exceptional rate capability, excellent cycling stability, and high initial Coulombic efficiency.
The Preparation of Complexes of Germanone from a Germanium μ‐Oxo Dimer
Authors: Sinhababu Soumen , Yadav Dhirendra , Karwasara Surendar , Sharma Mahendra Kumar , Mukherjee Goutam , Rajaraman Gopalan , Nagendran Selvarajan
Published: May 2016

Complexes of germanone containing formal Ge=O→M bonds (M=Zn, B, Ge, Sn) were isolated and characterized. The compounds were prepared through a novel synthetic route using a germanium μ‐oxo dimer 3 as the starting material. This method circumvents the need to employ germanones to prepare complexes of germanones.
Infinite Polyiodide Chains in the Pyrroloperylene–Iodine Complex: Insights into the Starch–Iodine and Perylene–Iodine Complexes
Authors: Madhu Sheri , Evans Hayden A. , Doan‐Nguyen Vicky V. T. , Labram John G. , Wu Guang , Chabinyc Michael L. , Seshadri Ram , Wudl Fred
Published: May 2016

We report the preparation and X‐ray crystallographic characterization of the first crystalline homoatomic polymer chain, which is part of a semiconducting pyrroloperylene–iodine complex. The crystal structure contains infinite polyiodide I∞δ−. Interestingly, the structure of iodine within the insoluble, blue starch–iodine complex has long remained elusive, but has been speculated as having infinite chains of iodine. Close similarities in the low‐wavenumber Raman spectra of the title compound and starch–iodine point to such infinite polyiodide chains in the latter as well.
Modulation of the E. coli rpoH Temperature Sensor with Triptycene‐Based Small Molecules
Authors: Barros Stephanie A. , Yoon Ina , Chenoweth David M.
Published: May 2016

Regulation of the heat shock response (HSR) is essential in all living systems. In E. coli, the HSR is regulated by an alternative σ factor, σ32, which is encoded by the rpoH gene. The mRNA of rpoH adopts a complex secondary structure that is critical for the proper translation of the σ32 protein. At low temperatures, the rpoH gene transcript forms a highly structured mRNA containing several three‐way junctions, including a rare perfectly paired three‐way junction (3WJ). This complex secondary structure serves as a primitive but highly effective strategy for the thermal control of gene expression. In this work, the first small‐molecule modulators of the E. coli σ32 mRNA temperature sensor are reported.
Palladium(IV) in an Oxoanionic Environment: The XeF2 Assisted Synthesis of [Pd(S2O7)3]2−
Authors: Bruns Jörn , van Gerven David , Klüner Thorsten , Wickleder Mathias S.
Published: May 2016

For the first time tetravalent palladium is detected, coordinated exclusively by simple oxoanions. Stabilization was achieved by formation of the [Pd(S2O7)3]2− complex in which three chelating disulfate groups surround the metal atom. The salt K2[Pd(S2O7)3] could only be obtained if the reaction of K2[PdCl6] and neat SO3 was performed in the presence of XeF2.
Short, Enantioselective Total Synthesis of Highly Oxidized Taxanes
Authors: Yuan Changxia , Jin Yehua , Wilde Nathan C. , Baran Phil S.
Published: May 2016

In the realm of natural product chemistry, few isolates have risen to the level of fame justifiably accorded to Taxol (1) and its chemical siblings. This report describes the most concise route to date for accessing the highly oxidized members of this family. As representative members of taxanes containing five oxygen atoms, decinnamoyltaxinine E (2) and taxabaccatin III (3), have succumbed to enantioselective total synthesis for the first time in only 18 steps from a simple olefin starting material. The strategy holistically mimics nature's approach (two‐phase synthesis) and features a carefully choreographed sequence of stereoselective oxidations and a remarkable redox‐isomerization to set the key trans‐diol present in 2 and 3. This work lays the critical groundwork necessary to access even higher oxidized taxanes such as 1 in a more practical fashion, thus empowering a medicinal chemistry campaign that is not wedded to semi‐synthesis.
Dissecting Hofmeister Effects: Direct Anion–Amide Interactions Are Weaker than Cation–Amide Binding
Authors: Balos Vasileios , Kim Heejae , Bonn Mischa , Hunger Johannes
Published: May 2016

Whereas there is increasing evidence for ion‐induced protein destabilization through direct ion–protein interactions, the strength of the binding of anions to proteins relative to cation–protein binding has remained elusive. In this work, the rotational mobility of a model amide in aqueous solution was used as a reporter for the interactions of different anions with the amide group. Protein‐stabilizing salts such as KCl and KNO3 do not affect the rotational mobility of the amide. Conversely, protein denaturants such as KSCN and KI markedly reduce the orientational freedom of the amide group. Thus these results provide evidence for a direct denaturation mechanism through ion–protein interactions. Comparing the present findings with results for cations shows that in contrast to common belief, anion–amide binding is weaker than cation–amide binding.
A Long‐Lived Mononuclear Cyclopentadienyl Ruthenium Complex Grafted onto Anatase TiO2 for Efficient CO2 Photoreduction
Authors: Huang Haowei , Lin Jinjin , Zhu Gangbei , Weng Yuxiang , Wang Xuxu , Fu Xianzhi , Long Jinlin
Published: May 2016

This work shows a novel artificial donor–catalyst–acceptor triad photosystem based on a mononuclear C5H5‐RuH complex oxo‐bridged TiO2 hybrid for efficient CO2 photoreduction. An impressive quantum efficiency of 0.56 % for CH4 under visible‐light irradiation was achieved over the triad photocatalyst, in which TiO2 and C5H5‐RuH serve as the electron collector and CO2‐reduction site and the photon‐harvester and water‐oxidation site, respectively. The fast electron injection from the excited Ru2+ cation to TiO2 in ca. 0.5 ps and the slow backward charge recombination in half‐life of ca. 9.8 μs result in a long‐lived D+–C–A− charge‐separated state responsible for the solar‐fuel production.
Polyvalent Catalysts Operating on Polyvalent Substrates: A Model for Surface‐Controlled Reactivity
Authors: McKay Craig S. , Finn M. G.
Published: May 2016

Unusually fast rates of nucleophilic catalysis of hydrazone ligation were observed when polyvalent anthranilic acid catalysts operating on polyvalent aldehyde substrates were used with PAMAM dendrimers as the common platform. When presented in this way, the catalyst has a strong accelerating effect at concentrations 40–400 times lower than those required for similar monovalent catalysts and displays unique kinetic parameters. We attribute these properties to polyvalent engagement between the dendrimer surface groups, and a potential “rolling” effect leading to fast interparticle kinetic turnover. The phenomenon is sensitive to the density of functional groups on each dendrimer, and insensitive to factors that promote or inhibit nonspecific particle aggregation. These findings constitute a rare experimental example of an underappreciated phenomenon in biological and chemical systems that are organized on interacting surfaces.
BSA imprinted polyethylene glycol grafted calcium alginate hydrogel microspheres
Authors: Liu Jiangquan , Ying Xiaoguang , Wang Hongxun , Li Xiao , Zhang Weiying
Published: May 2016

Polyethylene glycol grafted calcium alginate hydrogel microspheres are synthesized by ring‐opening and addition reaction of epoxy chloropropane. FTIR, 13C NMR, optical microscope, SEM, TG, and DSC are used for characterization. Swelling behaviors are studied and it is found that polyethylene glycol grafted calcium alginate microspheres are improved in anti‐swelling properties. Protein‐imprinted polyethylene glycol grafted calcium alginate hydrogel microspheres exhibit enhanced specific rebinding quantity (11.16 mg/g) and selective recognition properties (4.71 against BHb), towards target molecule in the presence of competing protein, compared with that of the unmodified samples (4.96 mg/g and 1.75, respectively). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43617.
Conducting polymerized high‐internal‐phase emulsion/single‐walled carbon nanotube nanocomposite foams: Effect of the aqueous‐phase surfactant type on the morphology and conductivity
Authors: Karimian Hossein , Moghbeli Mohammad Reza
Published: May 2016

Poly(styrene‐co‐divinylbenzene)/single‐walled carbon nanotubes (SWCNTs) polymerized high‐internal‐phase emulsion (polyHIPE) nanocomposite foams were successfully synthesized with various types of aqueous‐phase surfactants. The effects of anionic, cationic, nonionic, and mixed surfactants on the morphology and electrical conductivity of the resulting nanocomposite foams were investigated. The use of an anionic surfactant, sodium dodecylbenzesulfonate (SDBS), did not completely result in the typical polyHIPE nanocomposite foam microstructure because of the partial instability of the high‐internal‐phase emulsion. The nanocomposite foams synthesized by nonionic surfactants, that is, Pluronic F127 and Triton X‐100, and the cationic/anionic mixture, cetyltrimethylammonium bromide/SDBS, exhibited the proper morphology, but the resulting nanocomposite foams were electrically insulators. Interestingly, the use of a Gemini‐like surfactant, sodium dioctylsulfosuccinate (SDOSS), significantly improved both the typical morphology and electrical properties of the resulting nanocomposite foams because of the probable stronger interactions of SDOSS molecules with SWCNTs. The typical morphology of the nanocomposite foam synthesized with the SDOSS/F127 mixed surfactant was significantly improved, but the electrical conductivity decreased to some extent compared with the SDOSS‐synthesized nanocomposite foams. This behavior was attributed to an increase in the tunneling length of the electrons between adjacent SWCNTs. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43883.
Functional modification of poly(vinyl alcohol) by copolymerizing with a hydrophobic cationic double alkyl‐substituted monomer
Authors: Ma Jiaojiao , Yin Xiande , Xiao Hongqin , Li Ying , Bao Jianjun
Published: May 2016

In this paper, a hydrophobic monomer (HM) that has a cationic double alkyl‐substituted group bonded to the nitrogen atom was first synthesized. Then a hydrophobic poly(vinyl alcohol) (PVA) was prepared by a radical solution copolymerization of vinyl acetate (VAc) with the HM followed by an alcoholysis reaction in alkaline conditions. The structures of HM and hydrophobically modified PVA (H‐PVA) were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The effect of hydrophobic cationic segments on crystallization behaviors, mechanical properties, morphology, solution viscosity, and hydrophobic property were investigated. The results indicated that the crystallinity decreased from 37.2% of pure PVA to the minimum 23.2% of H‐PVA with the incorporation of 1.15 mol % HM. The thermal decomposition temperature of H‐PVA increased by about 50 °C compared with that of pure PVA. The viscosity of the H‐PVA solution was several times higher than that of the corresponding unmodified PVA solution over the whole shear rate range, which demonstrated that the H‐PVA had good shear‐resistance ability. Furthermore, the contact angle was significantly increased from 55.1° to 115° with the incorporation of only 0.83% HM, which illustrated that the H‐PVA had high hydrophobicity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43888.
Enhancing the thermo‐oxidative stability of PLA through the use of hybrid organic–inorganic coatings
Authors: Toselli Maurizio , Saccani Andrea
Published: May 2016

PLA samples have been coated with organic–inorganic hybrid films containing SiO2 as inorganic phase and two different types of organic phase PEO or PCL. Sol–gel solutions, spin coating deposition, and mild thermal treatments have been used to form thin protective coatings. Coated and uncoated PLA samples have been submitted to accelerated thermo‐oxidative stresses at 120 °C in air up to about 400 h. The extent of the damage induced by this treatment has been evaluated by different techniques. Coated samples of both compositions are able to increase the resistance to thermo‐oxidation of PLA as proved by the smaller reduction of molecular weight. This effect is probably deriving from the reduced oxygen permeability, as well as from the constrained outward diffusion and recombination of the cyclic oligomers produced by intramolecular transesterification reactions of polyester chains. Data so far collected underline also a long‐term stability and adherence of the hybrid coatings during the entire aging process and hint at the possibility of using PLA in more demanding applications than that of packaging (i.e., electric industry, automotive field, or housewares). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43897.
Prediction of diffusion in a ternary solvent–solvent–polymer blend by means of binary diffusion data: Comparison of experimental data and simulative results
Authors: Siebel David , Scharfer Philip , Schabel Wilhelm
Published: May 2016

Multicomponent diffusion of solvents in polymeric systems is not completely understood, despite many scientific contributions to the topic. Literature scarcely offers measurement data on diffusion for model validation in such systems. In this work, the ternary systems consisting of poly(vinyl acetate) and the solvents toluene and methanol was investigated experimentally and numerically. By means of inverse micro Raman spectroscopy (IMRS) concentration gradients in drying thin films have been measured. Initial composition of the samples has been varied systematically in order to detect mutual influence of the solvents' diffusive behavior. It was shown that the mobility of the different species is increased in the presence of other solvents as predicted by theory. This experimental data is provided for model validation. A new expression to calculate the diffusion coefficients in ternary mixtures is proposed which only requires binary data. This expression is tested by means of a model‐based simulation to predict the drying of ternary polymer solutions in terms of concentration profiles and residual solvent content. The results are in very good agreement with the experiments. Cross terms diffusion coefficients and thermodynamic factors were not found to be necessary for a satisfying prediction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43899.
Recent Advances in Transition‐Metal‐Free Oxygenation of Alkene C=C Double Bonds for Carbonyl Generation
Authors: Wan Jie‐Ping , Gao Yong , Wei Li
Published: May 2016

Carbonyl‐forming reactions are a class of fundamental transformations in organic chemistry. Guided by the current importance of environmentally benign metal‐free catalysis and synthesis, herein we review recent advances in carbonyl‐generation reactions based on alkene C=C double oxygenation as well as related cascade reactions in the synthesis of diverse organic products. The content of this focus review consists of two important but different reaction models: oxygenation based on full C=C double‐bond cleavage and oxygenation based on partial C=C double‐bond cleavage.
Fault‐Tolerant Control for Flutter of Airfoil Subject to Input Saturation
Authors: Luo Mengxiang , Gao Mingzhou , Cai Guoping
Published: May 2016

In this paper, a fault tolerant control is studied for a two‐dimensional airfoil with input saturation and actuator fault. The dynamic equation of airfoil flutter is firstly established, in which the cubic hard spring nonlinearity of pitch stiffness is considered. Then, an adaptive sliding mode fault tolerant control is derived by using an on‐line updating law to estimate the bound of the actuator fault such that no information about the fault is needed. Furthermore, an auxiliary design system is introduced to resolve actuator saturation in control. Next, Lyapunov stability analysis is carried out to prove that the system is asymptotically stable. Finally, the effectiveness of the proposed controller is verified through numerical simulations. Simulation results indicate that the adaptive sliding mode fault tolerant controller is effective in suppressing airfoil flutter under partial loss of actuator effectiveness performance and input saturation.
Exponential Stability Analysis for Stochastic Delayed Differential Systems with Impulsive Effects: Average Impulsive Interval Approach
Authors: Yao Fengqi , Cao Jinde , Qiu Li , Cheng Pei
Published: May 2016

This paper is concerned with the exponential stability analysis of stochastic delayed systems with impulsive effects. By using the average impulsive interval approach, and together with comparison lemma and Razumikhin techniques, sufficient conditions ensuring the moment exponential stability of the systems under consideration are established. A stability criterion for non‐delayed stochastic systems with impulses is also derived as a corollary. Compared with the existing stability results in the literature, which are usually based on the supremum or infimum of impulsive intervals, the results reported in this paper are less conservative. Two illustrative examples are provided to validate the effectiveness and advantages of our theoretical results.
Biologically Inspired Control Of A Fleet Of Uavs With Threat Evasion Strategy
Authors: El Ferik Sami , Thompson Olapido Raphael
Published: May 2016

In this paper, navigation algorithms for a fleet of multiple nonholonomic UAVs capable of evading a chasing predator and also pursuing a desired target are proposed. The proposed biologically‐inspired navigation algorithms are used to define path planning trajectories which are tracked by a designed backstepping tracking controller. We implement the group of nonholonomic UAVs in an adaptive network, specifically inspired by the relationship between a school of fish and a predator. This approach approximately simulates an air combat field. To put this in context, the aim is to use a biologically inspired algorithm along with a designed controller to achieve both target pursuance and effective evasion from a predator. This is equivalent to having multiple UAVs on the same mission of attacking a target, while also aware of a predator on pursuit. The UAVs aim to maneuver and evade the predator while also coordinating their movement and behaviors in a cooperative and coherent manner.