bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemically Reduced Graphene Oxide for the Assessment of Food Quality: How the Electrochemical Platform Should Be Tailored to the Application
Authors: Chng Chu'Er , Ambrosi Adriano , Chua Chun Kiang , Pumera Martin , Bonanni Alessandra 
Published: December 2016

AbstractGraphene platforms have been drawing considerable attention in electrochemistry for the detection of various electroactive probes. Depending on the chemical composition and properties of the probe, graphene materials with diverse structural features may be required to achieve an optimal electrochemical performance. This work comprises a comparative study on three chemically modified graphenes, obtained from the same starting material and with different oxygen functionalities and structural defects (graphene oxide (GO), chemically reduced graphene oxide (CRGO), and thermally reduced graphene oxide (TRGO)) towards the electrochemical detection of quinine, an important flavoring agent present in tonic‐based beverages. In general, the reduced graphenes, namely CRGO and TRGO, showed enhanced performance in terms of calibration sensitivity and selectivity, due to the improved heterogeneous electron‐transfer rates on their surfaces. In particular, CRGO provided the best overall electrochemical performance, which can be attributed to its higher density of structural defects and reduced amount of oxygen functionalities. For this reason, CRGO was employed for the electrochemical detection of quinine in commercial tonic drink samples, showing high sensitivity and selectivity, and therefore representing a valid low‐cost alternative to more complicated and time consuming traditional analytical methods.
A Bio‐Chemosynthetic Approach to Superparamagnetic Iron Oxide–Ansamitocin Conjugates for Use in Magnetic Drug Targeting
Authors: Wang Liang‐Liang , Balakrishnan Asha , Bigall Nadja‐Carola , Candito David , Miethe Jan Frederick , Seidel Katja , Xie Yu , Ott Michael , Kirschning Andreas 
Published: December 2016

AbstractA combination of mutasynthesis using a mutant strain of A. pretiosum blocked in the biosynthesis of amino‐hydroxybenzoic acid (AHBA) and semisynthesis relying on a Stille cross‐coupling step provided access to new ansamitocin derivatives of which one was attached by a thermolabile linker to nanostructured iron oxide particles. When exposed to an oscillating electromagnetic field the resulting iron oxide/ansamitocin conjugate 19 heats up in an aqueous suspension and the ansamitocin derivative 16 is released by means of a retro‐Diels–Alder reaction. It exerts strong antiproliferative activity (IC50=4.8 ng mg−1) in mouse fibroblasts. These new types of conjugates have the potential for combating cancer through hyperthermia and chemotherapy using an electromagnetic external trigger.
Computational Prediction and Rationalization, and Experimental Validation of Handedness Induction in Helical Aromatic Oligoamide Foldamers
Authors: Liu Zhiwei , Hu Xiaobo , Abramyan Ara M. , Mészáros Ádám , Csékei Márton , Kotschy András , Huc Ivan , Pophristic Vojislava 
Published: December 2016

AbstractMetadynamics simulations were used to describe the conformational energy landscapes of several helically folded aromatic quinoline carboxamide oligomers bearing a single chiral group at either the C or N terminus. The calculations allowed the prediction of whether a helix handedness bias occurs under the influence of the chiral group and gave insight into the interactions (sterics, electrostatics, hydrogen bonds) responsible for a particular helix sense preference. In the case of camphanyl‐based and morpholine‐based chiral groups, experimental data confirming the validity of the calculations were already available. New chiral groups with a proline residue were also investigated and were predicted to induce handedness. This prediction was verified experimentally through the synthesis of proline‐containing monomers, their incorporation into an oligoamide sequence by solid phase synthesis and the investigation of handedness induction by NMR spectroscopy and circular dichroism.
The Assembly of an All‐Inorganic Porous Soft Framework from Metal Oxide Molecular Nanowires
Authors: Zhang Zhenxin , Sadakane Masahiro , Noro Shin‐ichiro , Hiyoshi Norihito , Yoshida Akihiro , Hara Michikazu , Ueda Wataru 
Published: December 2016

AbstractAn all‐inorganic soft framework is rare but interesting for both fundamental research and practical applications. Here, an all‐inorganic soft framework based on a transition metal oxide is reported. The periodic connection of a one‐dimensional anionic tungstoselenate molecular wire building block with a CoII ion is used to construct the crystalline material. The crystal structure of the material was determined by high‐angle annular dark‐field scanning transmission electron microscopy combined with several characterization techniques. The soft framework of the material enables water adsorption/desorption with a change in its structure, leading to a high level of water adsorption. The framework of the material is flexible, and the structure of the molecular wire building block is stable during the water adsorption/desorption process.
Three‐Dimensional Metal–Organic Framework as Super Heat‐Resistant Explosive: Potassium 4‐(5‐Amino‐3‐Nitro‐1H‐1,2,4‐Triazol‐1‐Yl)‐3,5‐Dinitropyrazole
Authors: Li Chuan , Zhang Man , Chen Qishan , Li Yingying , Gao Huiqi , Fu Wei , Zhou Zhiming 
Published: December 2016

AbstractA new super heat‐resistant explosive, potassium 4‐(5‐amino‐3‐nitro‐1H‐1,2,4‐triazol‐1‐yl)‐3,5‐dinitropyrazole (KCPT, 1), featuring a three‐dimensional (3D) energetic metal–organic framework (MOF) was synthesized and fully characterized. The new 3D MOF was found to be extremely heat‐resistant, having a high decomposition temperature of 323 °C. In addition, KCPT exhibits the best calculated detonation performance (vD=8457 m s−1, p=32.5 GPa) among the reported super heat‐resistant explosives or energetic potassium salts while retaining a suitable impact sensitivity of 7.5 J, which makes it one of the most promising heat‐resistant explosives.
Gold(I) Fluorohalides: Theory and Experiment
Authors: Baya Miguel , Pérez‐Bitrián Alberto , Martínez‐Salvador Sonia , Casas José M. , Menjón Babil , Orduna Jesús 
Published: December 2016

AbstractThe anionic trifluoromethylgold(I) derivatives [CF3AuX]−, which have been prepared and isolated as their [PPh4]+ salts in good yield, undergo thermally induced difluorocarbene extrusion in the gas phase, giving rise to the mixed gold(I) fluorohalide complexes [F−Au−X]− (X=Cl, Br, I). These triatomic species have been detected by tandem mass spectrometry (MS2) experiments and their properties have been analyzed by DFT methods. The CF2 extrusion mechanism from the Au−CF3 moiety serves as a model for the CF2 insertion into the Au−F bond, since both reactivity channels are connected by the microreversibility principle.
Using chiral peptide substitutions to probe the structure function relationship of a key residue of Aβ42
Authors: Warner Christopher J.A. , Dutta Subrata , Foley Alejandro R. , Chen Eefei , Kliger David S. , Raskatov Jevgenij A. 
Published: December 2016

AbstractAmyloid beta‐protein 42 plays an important role in the onset and progression of Alzheimer's disease. Familial mutations have identified the glutamate residue 22 as a hotspot with regard to peptide neurotoxicity. We introduce an approach to study the influence of systematic sidechain modification at this residue, employing chirality as a structural probe. Circular dichroism experiments reveal that charge‐preserving alterations of the amino acid sidechain attenuate the characteristic random coil to β‐sheet transition associated with the wildtype peptide. Removal of the negative charge from residue 22, a trait observed with all known familial mutations at this residue, gives rise to a peptide with limited random coil propensity and high β‐sheet characteristics. Our approach can be extended to other residues of Aβ, as well as further amyloidogenic peptides.
Modelling mitral valvular dynamics–current trend and future directions
Authors: Gao Hao , Qi Nan , Feng Liuyang , Ma Xingshuang , Danton Mark , Berry Colin , Luo Xiaoyu 
Published: December 2016

AbstractDysfunction of mitral valve causes morbidity and premature mortality and remains a leading medical problem worldwide. Computational modelling aims to understand the biomechanics of human mitral valve and could lead to the development of new treatment, prevention and diagnosis of mitral valve diseases. Compared with the aortic valve, the mitral valve has been much less studied owing to its highly complex structure and strong interaction with the blood flow and the ventricles. However, the interest in mitral valve modelling is growing, and the sophistication level is increasing with the advanced development of computational technology and imaging tools. This review summarises the state‐of‐the‐art modelling of the mitral valve, including static and dynamics models, models with fluid‐structure interaction, and models with the left ventricle interaction. Challenges and future directions are also discussed.
Supramolecular Nanofibers as Ambient Stable Wide Voltage Window Electrolyte for Micro‐Supercapacitors
Authors: Mogera Umesha , Gedda Murali , George Subi J. , Kulkarni Giridhar U. 
Published: December 2016

AbstractIn this paper, we explore the use of supramolecular nanofibers as an electrolyte for in‐plane micro‐supercapacitors. The supramolecular nanofibers obtained from the self‐assembly of donor–acceptor (D‐A) molecules, coronene tetracarboxylate salt (CS) and dodecyl methyl viologen (DMV), carrying positive and negative ionic charges, respectively, were drop‐coated onto metal gap electrodes using an aqueous dispersion to form the device. Under dry conditions (<35 % relative humidity, RH), the device exhibited a stack capacitance of 160 F cm−3 with energy and power densities comparable to high‐performance micro‐supercapacitors. Although the electrolyte has aqueous origin, in dry conditions, it is capable of operating in a voltage window of 0–3 V. This supramolecular micro‐supercapacitor device (micro‐SS) was fabricated only with metal electrodes without using electrode material in it, thanks to the ability of the nanofiber to provide extended surface area for charge storage. The 1D face‐to‐face arrangement of D‐A molecules seems to provide an efficient pathway for the diffusion of ions across the electrodes. The present study not only provides a new approach to obtain an ambient stable electrolyte with wide operating voltage window but also gives a low‐cost method of fabricating micro‐supercapacitors with reasonably high energy and power densities.
Multiconfigurational Effects in Theoretical Resonance Raman Spectra
Authors: Ma Yingjin , Knecht Stefan , Reiher Markus 
Published: December 2016

AbstractWe analyze resonance Raman spectra of the nucleobase uracil in the short‐time approximation calculated with multiconfigurational methods. We discuss the importance of static electron correlation by means of density‐matrix renormalization group self‐consistent field (DMRG‐SCF) calculations. Our DMRG‐SCF results reveal that a minimal active orbital space that leads to a qualitatively correct description of the resonance Raman spectrum of uracil should encompass parts of the σ/σ* bonding/anti‐bonding orbitals of the pyrimidine ring. We trace these findings back to the considerable entanglement between the σ/σ* bonding/anti‐bonding as well as valence π/π* orbitals in the excited‐state electronic structure of uracil, which indicates non‐negligible non‐dynamical correlation effects that are less pronounced in the electronic ground state.
Mass Cytometry Analytical Approaches Reveal Cytokine‐Induced Changes in Natural Killer Cells
Authors: Vendrame Elena , Fukuyama Julia , Strauss‐Albee Dara M. , Holmes Susan , Blish Catherine A. 
Published: December 2016

BackgroundNatural killer (NK) cells have antiviral and antitumor activity that could be harnessed for the treatment of infections and malignancies. To maintain cell viability and enhance antiviral and antitumor effects, NK cells are frequently treated with cytokines. Here they performed an extensive assessment of the effects of cytokines on the phenotype and function of human NK cells.MethodsThey used cytometry by time‐of‐flight (CyTOF) to evaluate NK cell repertoire changes after stimulation with interleukin (IL)‐2, IL‐15 or a combination of IL‐12/IL‐15/IL‐18. To analyze the high dimensional CyTOF data, they used several statistical and visualization tools, including viSNE (Visualization of t‐Distributed Stochastic Neighbor Embedding), Citrus (Cluster identification, characterization, and regression), correspondence analysis, and the Friedman–Rafsky test.ResultsAll three treatments (IL‐2, IL‐15, and IL‐12/IL‐15/IL‐18) increase expression of CD56 and CD69. The effects of treatment with IL‐2 and IL‐15 are nearly indistinguishable and characterized principally by increased expression of surface markers including CD56, NKp30, NKp44, and increased expression of functional markers, such as perforin, granzyme B, and MIP‐1β. The combination of IL‐12/IL‐15/IL‐18 induces a profound shift in the repertoire structure, decreasing expression of CD16, CD57, CD8, NKp30, NKp46, and NKG2D, and dramatically increasing expression of IFN‐γ.ConclusionsCyTOF provides insights into the effects of cytokines on the phenotype and function of NK cells, which could inform future research efforts and approaches to NK cell immunotherapy. There are several analytical approaches to CyTOF data, and the appropriate method should be carefully selected based on which aspect of the dataset is being explored. © 2016 International Clinical Cytometry Society
From adolescent to elder rats: Motivation for palatable food and cannabinoids receptors
Authors: Amancio‐Belmont Octavio , Romano‐López Antonio , Ruiz‐Contreras Alejandra Evelin , Méndez‐Díaz Mónica , Prospéro‐García Oscar 
Published: December 2016

ABSTRACTTo analyze motivation, food self‐administration and decision‐making were evaluated in adolescent, adult, and aged rats. Subjects were trained to press a lever (fixed ratio, FR1 and FR5) in an operant chamber, to obtain chocolate flavor pellets. They assessed the progressive ratio (PR), extinction, and reinstatement of the behavior. To estimate decision‐making for food, rats were trained in the conditioned place preference (CPP) paradigm: (a) associating one compartment with lab chow (LCh) one day and the other compartment with rice krisspies (RK), the next day. (b) Training similar to (a) but on the day RK was the reinforcer, it was delivered with a progressive delay. In addition, CB1 and CB2 receptor expression in the nucleus accumbens (NAcc) and prefrontal cortex (PFC) was estimated by means of Western blot. Adolescent rats consumed higher amounts of RK/body weight than adult and aged rats during FR1, FR5, and PR. Extinction was more prolonged for adolescent rats than for adult and aged rats. First CPP condition, all three groups of rats preferred the RK‐associated compartment. Second CPP condition, adolescent rats developed equal preference to both compartments, while adult and aged rats preferred the RK‐associated compartment. Rats per group ate a similar amount of either reinforcer. Adolescent rats exhibited low expression of CB1R in the NAcc and low expression of both CB1R and CB2R in the PFC compared with adult and aged rats. Adolescent rats display higher motivation for palatable food and an indiscriminate seeking behavior suggesting involvement of both homeostatic and hedonic systems in their decision‐making processes. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 917–927, 2017
Relative importance of abiotic, biotic, and disturbance drivers of plant community structure in the sagebrush steppe
Authors: Mitchell Rachel M. , Bakker Jonathan D. , Vincent John B. , Davies G. Matt 
Published: December 2016

AbstractAbiotic conditions, biotic factors, and disturbances can act as filters that control community structure and composition. Understanding the relative importance of these drivers would allow us to understand and predict the causes and consequences of changes in community structure. We used long‐term data (1989–2002) from the sagebrush steppe in the state of Washington, USA, to ask three questions: (1) What are the key drivers of community‐level metrics of community structure? (2) Do community‐level metrics and functional groups differ in magnitude or direction of response to drivers of community structure? (3) What is the relative importance of drivers of community structure? The vegetation in 2002 was expressed as seven response variables: three community‐level metrics (species richness, total cover, compositional change from 1989 to 2002) and the relative abundances of four functional groups. We used a multi‐model inference framework to identify a set of top models for each response metric beginning from a global model that included two abiotic drivers, six disturbances, a biotic driver (initial plant community), and interactions between the disturbance and biotic drivers. We also used a permutational relative variable importance metric to rank the influence of drivers. Moisture availability was the most important driver of species richness and of native forb cover. Fire was the most important driver of shrub cover and training area usage was important for compositional change, but disturbances, including grazing, were of secondary importance for most other variables. Biotic drivers, as represented by the initial plant communities, were the most important driver for total cover and for the relative covers of exotics and native grasses. Our results indicate that the relative importance of drivers is dependent on the choice of metric, and that drivers such as disturbance and initial plant community can interact.
Shifts in intertidal zonation and refuge use by prey after mass mortalities of two predators
Authors: Gravem Sarah A. , Morgan Steven G. 
Published: December 2016

AbstractRecent mass mortalities of two predatory sea star species provided an unprecedented opportunity to test the effect of predators on rocky intertidal prey. Mass mortalities provide insight that manipulative experiments cannot because they alter ecosystems on a larger scale, for longer time periods, and remove both organisms and their cues from the environment. We examined shifts in population size structure, vertical zonation, and use of emersed refuge habitats outside tidepools by the abundant herbivorous black turban snail Tegula funebralis, both before and after the successive mortalities of two predatory sea stars. The small cryptic predator Leptasterias spp. suffered a localized but extreme mortality event in November 2010, followed by two mass mortalities of the keystone predator Pisaster ochraceus in August 2011 and autumn 2013. After the local extinction of Leptasterias, the population size of Tegula more than doubled. Also, since Leptasterias primarily inhabited only mid to low intertidal tidepools at this site, small and medium sized snails (which are preferred by Leptasterias) shifted lower in the intertidal and into tidepools after the mortality of Leptasterias. After the mortality of Pisaster in August 2011, large snails did not shift lower in the intertidal zone despite being preferred by Pisaster. Small and medium sized snails became denser in the higher zone and outside tidepools, which was not likely due to Pisaster mortality. Previous studies concluded that Pisaster maintained vertical size gradients of snails, but our data implicate the overlooked predator Leptasterias as the primary cause. This natural experiment indicated that (1) predators exert top‐down control over prey population sizes and lower limits, (2) vertical zonation of prey are dynamic and controlled in part by prey behavior, and (3) predators exert the strongest effects on more vulnerable individuals, which typically inhabit stressful habitats higher on the shore or outside tidepools to avoid predation. Because the mass mortalities of two predators drastically reduced both the predation pressure and the chemical cues of predators in the environment, we were able to investigate both the effects of predators on prey populations and the effects on mobile prey behavior.
When can we infer mechanism from parasite aggregation? A constraint‐based approach to disease ecology
Authors: Wilber Mark Q. , Johnson Pieter T. J. , Briggs Cheryl J. 
Published: December 2016

AbstractFew hosts have many parasites while many hosts have few parasites. This axiom of macroparasite aggregation is so pervasive it is considered a general law in disease ecology, with important implications for the dynamics of host–parasite systems. Because of these dynamical implications, a significant amount of work has explored both the various mechanisms leading to parasite aggregation patterns and how to infer mechanism from these patterns. However, as many disease mechanisms can produce similar aggregation patterns, it is not clear whether aggregation itself provides any additional information about mechanism. Here we apply a “constraint‐based” approach developed in macroecology that allows us to explore whether parasite aggregation contains any additional information beyond what is provided by mean parasite load. We tested two constraint‐based null models, both of which were constrained on the total number of parasites P and hosts H found in a sample, using data from 842 observed amphibian host–trematode parasite distributions. We found that constraint‐based models captured ~85% of the observed variation in host‐parasite distributions, suggesting that the constraints P and H contain much of the information about the shape of the host‐parasite distribution. However, we also found that extending the constraint‐based null models can identify the potential role of known aggregating mechanisms (such as host heterogeneity) and disaggregating mechanisms (such as parasite‐induced host mortality) in constraining host‐parasite distributions. Thus, by providing robust null models, constraint‐based approaches can help guide investigations aimed at detecting biological processes that directly affect parasite aggregation above and beyond those that indirectly affect aggregation through P and H.
Synthesis and Electrochemical Properties of Hierarchically Porous Zn(Co1−xMnx)2O4 Anodes for Li‐Ion Batteries
Authors: Wong Wei‐Ting , Chen Bing‐Hong , Maggay Irish Valerie B. , Liu Chang , Duh Jenq‐Gong , Liu Wei‐Ren 
Published: December 2016

AbstractA hierarchically porous Zn(Co1−xMnx)2O4 anode is synthesized through a hydrothermal method. XRD measurements indicate that ZnCo2O4, ZnCo1.5Mn0.5O4, ZnCoMnO4, ZnCo0.5Mn1.5O4, and ZnMn2O4 are isostructural in solid solution. Through analysis of X‐ray photoelectronic spectra and EPMA and EDX mapping of Zn(Co1−xMnx)2O4, it is confirmed that the valance of Mn is 3+ only, and that the Mn cation is distributed homogeneously in the ZnCo2O4‐based structure. Interestingly, the pore‐size distributions of these spinel‐based anodes are tunable by changing the substituting content of Mn in the ZnCo2O4 host. Compared with nanoporous ZnCo2O4 and macroporous ZnMn2O4, the as‐synthesized ZnCoMnO4 nanospheres exhibit a high capacity of 823 mAh g−1 with excellent cycling retention of more than 80 cycles without decay. The excellent cyclability might be attributed to the nanosized particles and the nature of the hierarchical pore‐size distribution. The results indicate that ZnCoMnO4 is a good candidate as an anode for application in lithium‐ion batteries.