bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly fluorescent au nanoclusters: Electrostatically induced phase transfer synthesis for Cu2+ sensing
Authors: Chen Qiansi , Li Yajuan , Xu Shenghao , Tie Weiwei , Wang Nan , He Zhanhang , Liu Pingping , Zhou Huina 
Published: December 2016

AbstractThis paper reports a convenient method for the synthesis of highly fluorescent Au nanoclusters (NCs) via electrostatically induced phase transfer. Furthermore, on the basis of an aggregation‐induced fluorescence quenching mechanism, the potential application for Cu2+ sensing on the fluorescence emission of the Au NCs is discussed. These prepared fluorescent Au NCs offer acceptable sensitivity, high selectivity, and a limit of quantitation of 0.02 μM for the measurement of Cu2+, which is lower than the maximum level (1 ppm, equals to 15.6 μM) of Cu2+ permitted in drinking water in China. This study contributes to the further development of practical applications with fluorescent NCs.
Tools of pathway reconstruction and production of economically relevant plant secondary metabolites in recombinant microorganisms
Authors: Dziggel Clarissa , Schäfer Holger , Wink Michael 
Published: December 2016

AbstractPlant secondary metabolites exhibit a variety of biological activities and therefore serve as valuable therapeutics or flavoring compounds. However, the small amounts isolated from plants often cannot meet market demands. This led to the exploration of other, more profitable methods for their production, including plant cell culture systems, chemical synthesis and biotechnological production in microbial hosts. The biotechnological production can be pursued by reconstructing metabolic pathways in selected microbial systems. But due to their complexity, most of these pathways are not completely understood and require the expression of a multitude of genes in a foreign organism. Recently, next generation sequencing data and advances in gene silencing in plants allowed the elucidation of some biosynthetic pathways in more detail. Thus, the de novo production of some natural products, including morphine, strictosidine, artemisinin, taxol® and resveratrol, in extensively engineered microbial hosts has become feasible. This review highlights the reconstruction of these pathways, missing pieces and novel techniques employed.
Hippocampal atrophy and memory dysfunction associated with physical inactivity in community‐dwelling elderly subjects: The Sefuri study
Authors: Hashimoto Manabu , Araki Yuko , Takashima Yuki , Nogami Kohjiro , Uchino Akira , Yuzuriha Takefumi , Yao Hiroshi 
Published: December 2016

AbstractBackgroundPhysical inactivity is one of the modifiable risk factors for hippocampal atrophy and Alzheimer's disease. We investigated the relationship between physical activity, hippocampal atrophy, and memory using structural equation modeling (SEM).Materials and MethodsWe examined 213 community‐dwelling elderly subjects (99 men and 114 women with a mean age of 68.9 years) without dementia or clinically apparent depression. All participants underwent Mini‐Mental State Examination (MMSE) and Rivermead Behavioral Memory Test (RBMT). Physical activities were assessed with a structured questionnaire. We evaluated the degree of hippocampal atrophy (z‐score—referred to as ZAdvance hereafter), using a free software program—the voxel‐based specific regional analysis system for Alzheimer's disease (VSRAD) based on statistical parametric mapping 8 plus Diffeomorphic Anatomical Registration Through an Exponentiated Lie algebra.ResultsRoutine magnetic resonance imaging findings were as follows: silent brain infarction, n = 24 (11.3%); deep white matter lesions, n = 72 (33.8%); periventricular hyperintensities, n = 35 (16.4%); and cerebral microbleeds, n = 14 (6.6%). Path analysis based on SEM indicated that the direct paths from leisure‐time activity to hippocampal atrophy (β = −.18, p < .01) and from hippocampal atrophy to memory dysfunction (RBMT) (β = −.20, p < .01) were significant. Direct paths from “hippocampus” gray matter volume to RBMT and MMSE were highly significant, while direct paths from “whole brain” gray matter volume to RBMT and MMSE were not significant. The presented SEM model fit the data reasonably well.ConclusionBased on the present SEM analysis, we found that hippocampal atrophy was associated with age and leisure‐time physical inactivity, and hippocampal atrophy appeared to cause memory dysfunction, although we are unable to infer a causal or temporal association between hippocampal atrophy and memory dysfunction from the present observational study.
Engineered ligand‐based VEGFR antagonists with increased receptor binding affinity more effectively inhibit angiogenesis
Authors: Kapur Shiven , Silverman Adam P. , Ye Anne Z. , Papo Niv , Jindal Darren , Blumenkranz Mark S. , Cochran Jennifer R. 
Published: December 2016

AbstractPathologic angiogenesis is mediated by the coordinated action of the vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling axis, along with crosstalk contributed by other receptors, notably αvβ3 integrin. We build on earlier work demonstrating that point mutations can be introduced into the homodimeric VEGF ligand to convert it into an antagonist through disruption of binding to one copy of VEGFR2. This inhibitor has limited potency, however, due to loss of avidity effects from bivalent VEGFR2 binding. Here, we used yeast surface display to engineer a variant with VEGFR2 binding affinity approximately 40‐fold higher than the parental antagonist, and 14‐fold higher than the natural bivalent VEGF ligand. Increased VEGFR2 binding affinity correlated with the ability to more effectively inhibit VEGF‐mediated signaling, both in vitro and in vivo, as measured using VEGFR2 phosphorylation and Matrigel implantation assays. High affinity mutations found in this variant were then incorporated into a dual‐specific antagonist that we previously designed to simultaneously bind to and inhibit VEGFR2 and αvβ3 integrin. The resulting dual‐specific protein bound to human and murine endothelial cells with relative affinities of 120 ± 10 pM and 360 ± 50 pM, respectively, which is at least 30‐fold tighter than wild‐type VEGF (3.8 ± 0.5 nM). Finally, we demonstrated that this engineered high‐affinity dual‐specific protein could inhibit angiogenesis in a murine corneal neovascularization model. Taken together, these data indicate that protein engineering strategies can be combined to generate unique antiangiogenic candidates for further clinical development.
Host‐ and pathogen‐derived adjuvant coatings on protein nanoparticle vaccines
Authors: Chang Timothy Z. , Diambou Ishatou , Kim Jong Rok , Wang Baozhong , Champion Julie A. 
Published: December 2016

AbstractNanoparticulate and molecular adjuvants have shown great efficacy in enhancing immune responses, and the immunogenic vaccines of the future will most likely contain both. To investigate the immunostimulatory effects of molecular adjuvants on nanoparticle vaccines, we have designed ovalbumin (OVA) protein nanoparticles coated with two different adjuvants—flagellin (FliC) and immunoglobulin M (IgM). These proteins, derived from Salmonella and mice, respectively, are representatives of pathogen‐ and host‐derived molecules that can enhance immune responses. FliC‐coated OVA nanoparticles, soluble FliC (sFliC) admixed with OVA nanoparticles, IgM‐coated nanoparticles, and OVA‐coated nanoparticles were assessed for immunogenicity in an in vivo mouse immunization study. IgM coatings on nanoparticles significantly enhanced both antibody and T cell responses, and promoted IgG2a class switching but not affinity maturation. FliC‐coated nanoparticles and FliC‐admixed with nanoparticles both triggered IgG2a class switching, but only FliC‐coated nanoparticles enhanced antibody affinity maturation. Our findings that affinity maturation and class switching can be directed independently of one another suggest that adjuvant coatings on nanoparticles can be tailored to generate specific vaccine effector responses against different classes of pathogens.
Behavior of nucleolus in the tobacco male meiocytes involved in cytomixis
Authors: Mursalimov Sergey , Sidorchuk Yuriy , Deineko Elena 
Published: December 2016

AbstractBehavior of nucleolus during the nuclear migration between plant cells (cytomixis) is studied for the first time in the tobacco male meiosis. As is shown, the nucleolus is located in a nonrandom manner in the migrating nuclei. In the majority of cases, the nucleolus resides on the nuclear pole strictly opposite to the cytomictic channel. Owing to this localization, the nucleolus extremely rare enters the recipient cell, so that the nucleolar material is in most cases undetectable in the micronuclei formed after cytomixis. When a whole nucleus migrates from a donor cell to recipient, the nucleolus can leave the nucleus and remain in the donor cells either alone or with a small amount of chromatin. The causes underlying a nonrandom location of the nucleolus in cytomictic cells are discussed. It is assumed that the nucleolar material contacts the cytoplasmic cytoskeleton, which prevents migration of the nucleolus into another cell within the nucleus. The potential use of cytomixis as a model for studying the nuclear motion is discussed.
Mounier–Kuhn syndrome: a case of tracheal smooth muscle remodeling
Authors: Cook Daniel P. , Adam Ryan J. , Abou Alaiwa Mahmoud H. , Eberlein Michael , Klesney‐Tait Julia A. , Parekh Kalpaj R. , Meyerholz David K. , Stoltz David A. 
Published: December 2016

Key Clinical MessageMounier–Kuhn syndrome is a rare clinical disorder characterized by tracheobronchial dilation and recurrent lower respiratory tract infections. While the etiology of the disease remains unknown, histopathological analysis of Mounier–Kuhn airways demonstrates that the disease is, in part, characterized by cellular changes in airway smooth muscle.
Effects of Extraction Methods on Structure and Valorization of Corn Stover Lignin by a Pd/C Catalyst
Authors: Peng Chang , Chen Qin , Guo Haiwei , Hu Gang , Li Changzhi , Wen Jialong , Wang Haisong , Zhang Tao , Zhao Zongbao Kent , Sun Runcang , Xie Haibo 
Published: December 2016

AbstractWith the significant development of efficient pretreatments of lignocellulosic biomass towards using carbohydrate compositions for biofuel production, the valorization of associated lignin products into valuable chemicals has gained much attention. Four lignins obtained by pretreatment of corn stover with emerging ionic liquid‐based mixed organic electrolytes (ILOE) and alkaline twin‐screw extrusion (ATSE) pretreatment technologies were characterized by gel permeation chromatography (GPC), FTIR, HSQC, 31P NMR spectroscopy, and SEM. These lignins were valorized by using Pd/C under various conditions, followed by an elucidation of the relationship between the lignin structure and valorization efficiency and selectivity. The pretreatment/separation methods have a significant effect on lignin structure and subsequent valorization efficiency. HSQC spectra revealed that corn stover lignin consisted of β‐O‐4, β‐5, β‐1 linkages, and cinnamyl alcohol end groups. The extracted lignins (EL) showed less carbohydrates and β‐O‐4 units than those of enzymatic hydrolytic lignins (EHL). The yields of bio‐oils were 61.7 % and 57.9 % for ATSE‐EL and ILOE‐EL, and 34.2 % and 45.1 % for ATSE‐EHL and ILOE‐EHL under optimal and comparative conditions, respectively. Part of the syringyl (S) units were converted into guaiacyl or p‐hydroxyphenyl (H) units by release of methoxyl groups on the aromatic ring through hydrogenolysis, which led to a decreased proportion of S units and an increased proportion of H units in oil compared with in lignin.
State‐of‐the‐Art Aluminum Porphyrin‐based Heterogeneous Catalysts for the Chemical Fixation of CO2 into Cyclic Carbonates at Ambient Conditions
Authors: Chen Yaju , Luo Rongchang , Xu Qihang , Zhang Wuying , Zhou Xiantai , Ji Hongbing 
Published: December 2016

AbstractA series of metalloporphyrin‐based hyper‐crosslinked polymers (M‐HCPs: M=Al, Co, Fe, Mn) has been directly synthesized through Friedel–Crafts alkylation reactions. The M‐HCPs afforded abundant permanent nanopores, high Brunauer–Emmett–Teller (BET) surface area, and exceptional CO2/N2 adsorptive selectivity. The experimental results suggested that the hollow tubular Al‐HCP exhibited extraordinary catalytic performance in the solvent‐free synthesis of cyclic carbonates from epoxides and CO2 by using tetrabutylammonium bromide as a cocatalyst under mild conditions, which was clearly superior to the corresponding homogeneous analogue. Surprisingly, a high turnover frequency (TOF) value of 14 880 h−1 was achieved with propylene oxide at 100 °C and 3.0 MPa, which was a promising result for industrial production compared with previously reported heterogeneous catalysts. More interestingly, Al‐HCP could smoothly catalyze the cycloaddition reaction, producing the corresponding cyclic carbonates by using simulated flue gas (15 % CO2 and 85 % N2 in volume) as the raw material under ambient conditions. Moreover, Al‐HCP could be readily recycled and efficiently reused more than ten times, exhibiting excellent stability.
Can Biogas Plants Contribute to Lower the Demand for Power Grid Expansion?
Authors: Trommler Marcus , Barchmann Tino , Dotzauer Martin , Cieleit Antje 
Published: December 2016

AbstractFor a stable power grid operation, the appropriateness of several technical parameters is required like voltage bands, transformer and cable loading, losses during operation, and back‐feeding of power into higher voltage level grids. Biogas plants can operate in a flexible mode and in this way influence the above‐mentioned parameters. By using real grid data, different scenarios of flexible biogas plants and their effects on grid related technical parameters are analyzed. Results show that the flexible operation of biogas plants can achieve improvements on such parameters compared to their operation solely orientated at an optimum at the European Power Exchange (EPEX Spot SE). In this way, flexibly operated biogas plants can reduce the need for grid expansion.
Luminescent Metal–Organic Framework Sensor: Exceptional Cd2+ Turn‐On Detection and First In Situ Visualization of Cd2+ Ion Diffusion into a Crystal
Authors: Lim Kwang Soo , Jeong So Yeon , Kang Dong Won , Song Jeong Hwa , Jo Hyuna , Lee Woo Ram , Phang Won Ju , Moon Dohyun , Hong Chang Seop 
Published: December 2016

AbstractWith regard to fluorescence quenching commonly observed during metal‐ion detection, “turn‐on” chemical sensing has been rarely reported, but could be extremely important because it facilitates the selective recognition of target objects of interest against a dark background. A metal–organic framework (MOF) chemosensor has been prepared that serves as an efficient platform for the selective detection of Cu2+ and Cd2+ ions over other metal ions. In particular, this framework shows the highest fluorescence enhancement (≈60‐fold relative to Cd‐free MOF) for the hazardous metal ion Cd2+ among luminescent MOFs and displays excellent reusability in repeated cycles. The direct diffusion of Cd2+ into the crystal pores has also been visualized for the first time.
“On the Dot”—The Timing of Self‐Assembled Growth to the Quantum Scale
Authors: Sonkaria Sanjiv , Ahn Sung‐Hoon , Lee Caroline S. , Khare Varsha 
Published: December 2016

AbstractUnderstanding the complex world of material growth and tunability has mystified the minds of material scientists and has been met with increasing efforts to close the gap between controllability and applicability. The reality of this journey is frustratingly tortuous but is being eased through better conceptual appreciation of metal crystalline frameworks that originate from shape and size dependent solvent responsive growth patterns. The quantum confinement of TiO2 in the range of 0.8–2 nm has been synthetically challenging to achieve but lessons from biomineralization processes have enabled alternative routes to be explored via self‐induced pre‐nucleation events. In driving this concept, we have incorporated many of these key features integrating aspects of low temperature annealing at the interface of complex heterogeneous nucleation between hard and soft materials to arrest the biomimetic amorphous phase of TiO2 to a tunable crystalline quantumized state. The stabilization of metastable states of quantum sized TiO2 driven by kinetic and thermodynamic processes show hallmarks of biomineralized controlled events that suggest the inter‐play between new pathways and interfacial energies that preferentially favor low dimensionality at the quantum scale. This provides the potential to re‐direct synthetic assemblies under tightly controlled parameters to generate a host of new materials with size, shape and anisotropic properties as smart stimuli responsive materials. These new stabilities leading to the growth arrest of TiO2 are discussed in terms of molecular interactions and structural frameworks that were previously inaccessible via conventional routes. There exists an undiscovered parallel between synthetic and biomineralized routes enabling unprecedented access to the availability and tunability of novel quantum confined materials. The parametrics of complex material design at the crossroads of synthetically and biologically driven processes is only now surfacing.
Synthesis and Olfactory Properties of a 6′‐Silasubstituted “Spiro[4.5]‐δ‐Damascone”
Authors: Lovchik Martin A. , Kraft Philip 
Published: December 2016

AbstractThe silicon analogue of the potent spirocyclic δ‐damascone odorant 6 was synthesized from allyltrichlorosilane (15) and but‐2‐en‐1‐ol (16). The latter was transformed to 3‐methylpen‐4‐enenitrile (11) by Saucy–Marbet reaction with ethoxyethane and subsequent treatment with HONH2⋅HCl. The resulting γ,δ‐unsaturated nitrile 11 was silylated with 1‐allyl‐1‐chlorosilolane (14), which was prepared from allyltrichlorosilane (15) and the bis‐Grignard reagent of 1,4‐dichlorobutane. Metathetic ring closure employing the Grubbs I catalyst, followed by DIBAL reduction with non‐aqueous work up, Grignard reaction with prop‐1‐en‐1‐ylmagnesium bromide, and Attenburrow MnO2 oxidation concluded the synthesis. The target compound was found to be olfactorily related to the spiro[4.5]‐δ‐damascone lead, but approximately 900 times weaker. In a type of enol Brook rearrangement, it thermally decomposes however to 3,6‐dihydro‐2H‐1,2‐oxasilocine (20), which surprisingly is a damascone odorant as well; although, 12 000 times weaker.
Double Reduction of 4,4′‐Bipyridine and Reductive Coupling of Pyridine by Two Thorium(III) Single‐Electron Transfers
Authors: Formanuik Alasdair , Ortu Fabrizio , Liu Jingjing , Nodaraki Lydia E. , Tuna Floriana , Kerridge Andrew , Mills David P. 
Published: December 2016

AbstractThe redox chemistry of uranium is burgeoning and uranium(III) complexes have been shown to promote many interesting synthetic transformations. However, their utility is limited by their reduction potentials, which are smaller than many non‐traditional lanthanide(II) complexes. Thorium(III) has a greater redox potential so it should present unprecedented opportunities for actinide reactivity but as with uranium(II) and thorium(II) chemistry, these have not yet been fully realized. Herein we present reactivity studies of two equivalents of [Th(Cp′′)3] (1, Cp′′={C5H3(SiMe3)2‐1,3}) with 4,4′‐bipyridine or two equivalents of pyridine to give [{Th(Cp′′)3}2{μ‐(NC5H4)2}] (2) and [{Th(Cp′′)3}2{μ‐(NC5H5)2}] (3), respectively. As relatively large reduction potentials are required to effect these transformations we have shown that thorium(III) can promote reactions that uranium(III) cannot, opening up promising new reductive chemistry for the actinides.
Distribution of enantiomers of volatile organic compounds in selected fruit distillates
Authors: Vyviurska Olga , Zvrškovcová Helena , Špánik Ivan 
Published: December 2016

AbstractThe enantiomer ratios of chiral volatile organic compounds in fruit distillates were determined by multidimensional gas chromatography using solid‐phase microextraction (SPME) as a sample treatment procedure. Linalool and its oxides, limonene, α‐terpineol, and nerolidol, were present at the highest concentration levels, while significantly lower amounts of β‐citronellol and lactones were found in the studied samples. However, almost all terpenoids mainly occur as a racemic or near‐racemic mixture; enantiomer distribution of some chiral organic compounds in fruit distillates correlated to a botanical origin. In particular, a significant enantiomeric excess of (R)‐linalool and (S)‐α‐terpineol was found only for pear brandy, and likewise the dominance (R)‐limonene and the second eluted enantiomer of nerolidol for Sorbus domestica and strawberry, respectively. The distribution of γ‐lactones stereoisomers was more nonspecific, with a general excess of the R‐enantiomer.
Kölliker–Fuse GABAergic and glutamatergic neurons project to distinct targets
Authors: Geerling Joel C. , Yokota Shigefumi , Rukhadze Irma , Roe Dan , Chamberlin Nancy L. 
Published: December 2016

AbstractThe Kölliker‐Fuse nucleus (KF) is known primarily for its respiratory function as the “pneumotaxic center” or “pontine respiratory group.” Considered part of the parabrachial (PB) complex, KF contains glutamatergic neurons that project to respiratory‐related targets in the medulla and spinal cord (Yokota, Oka, Tsumori, Nakamura, & Yasui, 2007). Here we describe an unexpected population of neurons in the caudal KF and adjacent lateral crescent subnucleus (PBlc), which are γ‐aminobutyric acid (GABA)ergic and have an entirely different pattern of projections than glutamatergic KF neurons. First, immunofluorescence, in situ hybridization, and Cre‐reporter labeling revealed that many of these GABAergic neurons express FoxP2 in both rats and mice. Next, using Cre‐dependent axonal tracing in Vgat‐IRES‐Cre and Vglut2‐IRES‐Cre mice, we identified different projection patterns from GABAergic and glutamatergic neurons in this region. GABAergic neurons in KF and PBlc project heavily and almost exclusively to trigeminal sensory nuclei, with minimal projections to cardiorespiratory nuclei in the brainstem, and none to the spinal cord. In contrast, glutamatergic KF neurons project heavily to the autonomic, respiratory, and motor regions of the medulla and spinal cord previously identified as efferent targets mediating KF cardiorespiratory effects. These findings identify a novel, GABAergic subpopulation of KF/PB neurons with a distinct efferent projection pattern targeting the brainstem trigeminal sensory system. Rather than regulating breathing, we propose that these neurons influence vibrissal sensorimotor function.
Increase in the β‐Sheet Character of an Amyloidogenic Peptide upon Adsorption onto Gold and Silver Surfaces
Authors: Soltani Nima , Gholami Mohammad Reza 
Published: December 2016

AbstractFibrillation of amyloid beta (Aβ) peptide is the hallmark of Alzheimer's disease. Given that interactions at the bio–nano interface affect the fibrillation tendency of this peptide, an understanding of the interactions at Aβ peptide–inorganic surfaces on the microscopic level can help to determine the possible neurotoxicity of nanoparticles. Here, the interactions between a fibril‐forming peptide, Aβ25–35, and (111) and (100) facets of gold and silver surfaces have been studied by conducting atomistic molecular dynamics simulations. The obtained results indicate that the adsorption onto gold and silver surfaces force the peptide into the β‐sheet‐rich conformations, which is prone to aggregation, suggesting a new mechanism for the acceleration of fibril formation upon interaction with nanoparticles. To quantify the β‐sheet content for a single peptide, a new metrics based on the Ramachandran probability distribution is introduced.