bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring groundwater storage changes in complex basement aquifers: An evaluation of the GRACE satellites over East Africa
Authors: Nanteza J. , de Linage C. R. , Thomas B. F. , Famiglietti J. S. 
Published: December 2016

AbstractAlthough the use of the Gravity Recovery and Climate Experiment (GRACE) satellites to monitor groundwater storage changes has become commonplace, our evaluation suggests that careful processing of the GRACE data is necessary to extract a representative signal especially in regions with significant surface water storage (i.e., lakes/reservoirs). In our study, we use cautiously processed data sets, including GRACE, lake altimetry, and model soil moisture, to reduce scaling factor bias and compare GRACE‐derived groundwater storage changes to in situ groundwater observations over parts of East Africa. Over the period 2007–2010, a strong correlation between in situ groundwater storage changes and GRACE groundwater estimates (Spearman's ρ = 0.6) is found. Piecewise trend analyses for the GRACE groundwater estimates reveal significant negative storage changes that are attributed to groundwater use and climate variability. Further analysis comparing groundwater and satellite precipitation data sets permits identification of regional groundwater characterization. For example, our results identify potentially permeable and/or shallow groundwater systems underlying Tanzania and deep and/or less permeable groundwater systems underlying the Upper Nile basin. Regional groundwater behaviors in the semiarid regions of Northern Kenya are attributed to hydraulic connections to recharge zones outside the subbasin boundary. Our results prove the utility of applying GRACE in monitoring groundwater resources in hydrologically complex regions that are undersampled and where policies limit data accessibility.
Total Synthesis of (±)‐Dihydroisosubamol
Authors: Pflästerer Daniel , Rudolph Matthias , Yates Brian F. , Ariafard Alireza , Hashmi A. Stephen K. 
Published: December 2016

AbstractWe herein report the first total synthesis of the dibenzocycloheptanoide (±)‐dihydroisosubamol. The key step includes a recently developed gold‐catalysed hydroarylation reaction for the construction of the dibenzocycloheptene motif. Additional steps are a Suzuki‐Miyaura cross coupling, a palladium‐catalysed hydroxylation and an allylic oxidation. To access the saturated seven‐membered ring system an iridium‐catalysed hydrogenation proved to be successful.magnified image
Can Housing and Service Interventions Reduce Family Separations for Families Who Experience Homelessness?
Authors: Shinn Marybeth , Brown Scott R. , Gubits Daniel 
Published: December 2016

AbstractFamily break‐up is common in families experiencing homelessness. This paper examines the extent of separations of children from parents and of partners from each other and whether housing and service interventions reduced separations and their precursors among 1,857 families across 12 sites who participated in the Family Options Study. Families in shelters were randomized to offers of one of three interventions: permanent housing subsidies that reduce expenditures for rent to 30% of families’ income, temporary rapid re‐housing subsidies with some services directed at housing and employment, and transitional housing in supervised facilities with extensive psychosocial services. Each group was compared to usual care families who were eligible for that intervention but received no special offer. Twenty months later, permanent housing subsidies almost halved rates of child separation and more than halved rates of foster care placements; the other interventions did not affect separations significantly. Predictors of separation were primarily homelessness and drug abuse (all comparisons), and alcohol dependence (one comparison). Although housing subsidies reduced homelessness, alcohol dependence, intimate partner violence, and economic stressors, the last three variables had no association with child separations in the subsidy comparison; thus subsidies had indirect effects via reductions in homelessness. No intervention reduced partner separations.
Natural selection and type 2 diabetes‐associated mortality in an isolated indigenous community in the valley of Oaxaca, southern Mexico
Authors: Little Bertis B. , Peña Reyes Maria Eugenia , Malina Robert M. 
Published: December 2016

AbstractObjectiveThis study tests the hypothesis that natural selection is associated with type 2 diabetes (T2D)‐associated mortality and fertility in a rural isolated Zapotec community in the Valley of Oaxaca, southern Mexico.Participants and MethodsMortality data and related demographic and genealogic information were linked with data for fertility, prereproductive mortality and family history of mortality attributed to T2D. Physician verified T2D mortality (n = 27) between 1980 and 2009 and imputed T2D (n = 70) from cardiovascular mortality (68% random sample) and renal failure (44% random sample). Bootstrapping was used to obtain a robust variance estimate in survival analysis and multivariate analysis of variance.ResultsEstimated maximum natural selection by Crow's Index occurred circa 1930 and was relaxed after this time in the study population. Cox‐regression survival analysis of T2D mortality with covariates (family history of T2D, cardiovascular disease, renal failure) indicated a significant hazard ratio (HR = 5.95, 95% CI: 1.38–25.67, p < .008) for the increase in T2D in 2000 to 2009. Survival analysis of imputed T2D resulted in a significant HR of 2.03 (95% CI: 1.08–3.85, p = .01) for the increase in T2D in the 2000 to 2009 cohort (reference group: 1980–1989). Mean number of live born offspring was lower among T2D (n = 27, 4.04 ± 3.85 SD) compared to non‐T2D (n = 199, 5.30 ± 3.48) groups (p < .08). Mean number of live born offspring was lower (p = .003) among imputed T2D compared to non‐T2D groups (4.10 ± 3.44 vs. 5.62 + 3.50).DiscussionT2D‐associated mortality increased in frequency as natural selection decreased, and favored offspring survival of non‐T2D descedants. The results indicated statistically significant directional selection against T2D and imputed T2D to this population isolate.
Dynamic mechanical analysis of ethylene/1‐hexene copolymers: The effect of the catalyst type on the short‐chain branching distribution and properties of the amorphous and crystalline phases
Authors: Shundrina Inna K. , Matsko Mikhail A. , Baskakova Kseniya I. , Echevskaya Ludmila G. , Nikolaeva Marina I. , Shundrin Leonid A. , Zakharov Vladimir A. 
Published: December 2016

ABSTRACTDynamic mechanical analysis was used to study ethylene/1‐hexene copolymers with different compositions, molecular weight distributions, and profiles of short‐chain branching (SCB) versus molecular weight. These copolymers were produced over a highly active supported titanium–magnesium catalyst (TMC), a highly active supported vanadium–magnesium catalysts (VMC), and a supported zirconocene catalyst. A higher fraction of the crystalline phase in the copolymers prepared with VMC was shown to result in higher elastic modulus values. β relaxation was found to be sensitive to the SCB distribution versus the molecular weight. The copolymers prepared with the zirconocene catalyst and VMC were characterized by more uniform SCB distributions and higher temperatures of β relaxation compared to the copolymers prepared with TMC. The mobility of the polymer chains at room temperature in the amorphous phase obtained by the spin‐probe method rose with increasing branch content in the copolymers and was not sensitive to different SCB distribution profiles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44638.
Facet‐Dependent Electrical Conductivity Properties of Silver Oxide Crystals
Authors: Tan Chih‐Shan , Chen Ying‐Jui , Hsia Chi‐Fu , Huang Michael H. 
Published: December 2016

AbstractAg2O cubes, truncated octahedra, rhombic dodecahedra, and rhombicuboctahedra were synthesized in aqueous solution. Two tungsten probes were brought into contact with a single particle for electrical conductivity measurements. Strongly facet‐dependent electrical conductivity behaviors have been observed. The {111} faces are most conductive. The {100} faces are moderately conductive. The {110} faces are nearly non‐conductive. When electrodes contacted two different facets of a rhombicuboctahedron, asymmetrical I–V curves were obtained. The {111} and {110} combination gives the best I–V curve expected for a p‐n junction with current flowing in one direction through the crystal but not in the opposite direction. Density of states (DOS) plots for varying number of different lattice planes of Ag2O match with the experimental results, suggesting that the {111} faces are most electrically conductive. The thicknesses of the thin surface layer responsible for the facet‐dependent properties of Ag2O crystals have been determined.
Temperature‐dependent molecular dynamics study reveals an ionic liquid induced 310‐ to α‐helical switch in a neurotoxin
Authors: Sajeevan Karuna Anna , Roy Durba 
Published: December 2016

AbstractThermal melting and recooling of AuIB, a neurotoxic conopeptide and a highly potent nonaddictive pain reliever is investigated thoroughly in water and an ionic liquid (IL) 1‐butyl‐3‐methylimidazolium Chloride, [Im41][Cl] by classical molecular dynamics simulations. Structural evolution of AuIB in water and the IL is observed at different temperatures between 305 and 400 K, to explore how highly viscous ionic solvents affect the peptide structure as compared to conventional solvent water. At 305 K, unlike water, the coercive effect of IL frustrates AuIB secondary structural motifs significantly. As the temperature is raised, a very interesting IL induced conformational transition from 310‐ to α‐helix is noticed in the peptide, presumably triggered by a significant restructuring of the peptide H‐bond network. The backbone length distributions of the peptide indicate that the IL induced conformational switching is accompanied by a reduction of the axial rise of the helical region, encompassing the residues Pro‐6 to Ala‐10. Further, we estimated the void space available to the peptide for its structural relaxation within the first solvation shell of ∼5 Å in water as well as in IL. A temperature increase by 100 K, opens up an estimated void volume of ∼70 Å3, equivalent to the volume of approximately six water molecules, around the peptide in IL. Cooling simulations of AuIB point to the crucial interplay between thermodynamically favored AuIB conformers and their kinetic control. This study provides a comprehensive understanding of the ionic solvation of biomolecules reinforcing previous experimental findings.
Single‐step purification of cyclotides using affinity chromatography
Authors: Uddin Shaikh Jamal , Muhammad Taj , Shafiullah Md , Slazak Blazej , Rouf Razina , Göransson Ulf 
Published: December 2016

AbstractCyclotides are considered promising scaffolds for drug development owing to their inherent host defence activities and highly stable structure, defined by the cyclic cystine knot. These proteins are expressed as complex mixtures in plants. Although several methods have been developed for their isolation and analysis, purification of cyclotides is still a lengthy process. Here, we describe the use of affinity chromatography for the purification of cyclotides using polyclonal IgG antibodies raised in rabbits against cycloviolacin O2 and immobilized on NHS‐activated Sepharose columns. Cycloviolacin O2 was used as a model substance to evaluate the chromatographic principle, first as a pure compound and then in combination with other cyclotides, that is, bracelet cyclotide cycloviolacin O19 and Möbius cyclotide kalata B1, and in a plant extract. We demonstrate that single‐step purification of cyclotides by affinity chromatography is possible but cross reactivity may occur between homologue cyclotides of the bracelet subfamily.
Metabolic profiles revealed synergistically antidepressant effects of lilies and Rhizoma Anemarrhenae in a rat model of depression
Authors: Du Hongli , Zhao Hongxia , Lai Xueli , Lin Qishan , Zhu Zhenyu , Chai Yifeng , Lou Ziyang 
Published: December 2016

AbstractDepression is a major cause of illness and disability. We applied untargeted metabolomics using mass spectrometry to identify metabolic signatures associated with depression in serum and explored the antidepressant effects of lilies and Rhizoma Anemarrhenae on an experimental model of chronic unpredictable mild stress (CUMS). Meanwhile metabolomics based on UHPLC‐Q‐TOF‐MS was used to study the change in metabolites in CUMS rat serum and to evaluate the effects of Rhizoma Anemarrhenae and lilies (alone and in combination). Partial least squares‐discriminant analysis identified 30 metabolites as decisive marker compounds that discriminated the CUMS rats and the control rats. The majority of these metabolites were involved in amino acid metabolism, the tricarboxylic acid cycle, and phosphoglyceride metabolism. The reliability of the metabolites was evaluated by the administration of lilies, Rhizoma Anemarrhenae, fluoxetine and the combination of lilies and Rhizoma Anemarrhenae to the CUMS rats. Behavior studies demonstrated that treatment with the combination of lilies and Rhizoma Anemarrhenae resulted in optimal antidepressant effects. The combination treatment was almost as effective as fluoxetine. Our results suggest that lilies and Rhizoma Anemarrhenae demonstrate synergistically antidepressant effects in CUMS via the regulation of multiple metabolic pathways. These findings provide insight into the pathophysiological mechanisms underlying CUMS and suggest innovative and effective treatments for this disorder.
Rapid determination of oxindole alkaloids in cat's claw by HPLC using ionic liquid‐based microwave‐assisted extraction and silica monolithic column
Authors: Chang Chih‐Wei , Yeh Yu‐Ying , Chang Li‐Ching , Hsu Mei‐Chich , Wu Yu‐Tse 
Published: December 2016

AbstractCat's claw is a large woody vine with hook‐like thorns, and has been traditionally used to treat inflammatory disorders in South and Central America. In this study, a rapid, validated high‐performance liquid chromatographic (HPLC) method using a silica monolithic column was developed for the simultaneous determination of oxindole alkaloids, namely rhynchophylline, pteropodine, isomitraphylline and isopteropodine, in cat's claw. The ionic liquid‐based microwave‐assisted extraction (ILMAE), considered as an environmentally friendly and powerful tool, was first applied in the extraction of oxindole alkaloids. To optimize the HPLC method, the stationary phases, pH values of mobile phase and flow rates were investigated. The validated HPLC method using a Monolithic RP18e column (100 × 4.6 mm) enables these analytes to be separated almost twice as fast as with a conventional particulate column (~16 vs ~30 min) with limits of quantification and detection of 0.5 and 0.15 μg/mL, respectively. The ILMAE conditions were optimized by the Taguchi orthogonal array design. In comparison with conventional water boiling extraction, ILMAE offers almost four times higher yields within an extremely short extraction time. The developed HPLC coupled with ILMAE method could be efficient and practical for rapid determination of oxindole alkaloids in cat's claw.
Cortical interactions during the resolution of information processing demands in autism spectrum disorders
Authors: Denisova Kristina , Zhao Guihu , Wang Zhishun , Goh Suzanne , Huo Yuankai , Peterson Bradley S. 
Published: December 2016

AbstractIntroductionOur flexible and adaptive interactions with the environment are guided by our individual representation of the physical world, estimated through sensation and evaluation of available information against prior knowledge. When linking sensory evidence with higher‐level expectations for action, the central nervous system (CNS) in typically developing (TD) individuals relies in part on distributed and interacting cortical regions to communicate neuronal signals flexibly across the brain. Increasing evidence suggests that the balance between levels of signal and noise during information processing may be disrupted in individuals with Autism Spectrum Disorders (ASD).MethodsParticipants with and without ASD performed a visuospatial interference task while undergoing functional Magnetic Resonance Imaging (fMRI). We empirically estimated parameters characterizing participants’ latencies and their subtle fluctuations (noise accumulation) over the 16‐min scan. We modeled hemodynamic activation and used seed‐based analyses of neural coupling to study dysfunction in interference‐specific connectivity in a subset of ASD participants who were nonparametrically matched to TD participants on age, male‐to‐female ratio, and magnitude of movement during the scan.ResultsStochastic patterns of response fluctuations reveal significantly higher noise‐to‐signal levels and a more random and noisy structure in ASD versus TD participants, and in particular ASD adults who have the greatest clinical autistic deficits. While individuals with ASD show an overall weaker modulation of interference‐specific functional connectivity relative to TD individuals, in particular between the seeds of Anterior Cingulate Cortex (ACC) and Inferior Parietal Sulcus (IPS) and the rest of the brain, we found that in ASD, higher uncertainty during the task is linked to increased interference‐specific coupling between bilateral anterior insula and prefrontal cortex.ConclusionsSubtle and informative differences in the structure of experiencing information exist between ASD and TD individuals. Our findings reveal in ASD an atypical capacity to apply previously perceived information in a manner optimal for adaptive functioning, plausibly revealing suboptimal message‐passing across the CNS.
Activation of the glmS Ribozyme Confers Bacterial Growth Inhibition
Authors: Schüller Anna , Matzner Daniel , Lünse Christina E. , Wittmann Valentin , Schumacher Catherine , Unsleber Sandra , Brötz‐Oesterhelt Heike , Mayer Christoph , Bierbaum Gabriele , Mayer Günter 
Published: December 2016

AbstractThe ever‐growing number of pathogenic bacteria resistant to treatment with antibiotics call for the development of novel compounds with as‐yet unexplored modes of action. Here, we demonstrate the in vivo antibacterial activity of carba‐α‐d‐glucosamine (CGlcN). In this mode of action study, we provide evidence that CGlcN‐mediated growth inhibition is due to glmS ribozyme activation, and we demonstrate that CGlcN hijacks an endogenous activation pathway, hence utilizing a prodrug mechanism. This is the first report describing antibacterial activity mediated by activating the self‐cleaving properties of a ribozyme. Our results open the path towards a compound class with an entirely novel and distinct molecular mechanism.
Horseradish‐Peroxidase‐Catalyzed Tyrosine Click Reaction
Authors: Sato Shinichi , Nakamura Kosuke , Nakamura Hiroyuki 
Published: December 2016

AbstractThe efficiency of protein chemical modification on tyrosine residues with N‐methylluminol derivatives was drastically improved by using horseradish peroxidase (HRP). In the previous method, based on the use of hemin and H2O2, oxidative side reactions such as cysteine oxidation were problematic for functionalization of proteins selectively on tyrosine residues. Oxidative activation of N‐methylluminol derivatives with a minimum amount of H2O2 prevented the occurrence of oxidative side reactions under HRP‐catalyzed conditions. As probes for HRP‐catalyzed protein modification, N‐methylluminol derivatives showed much higher efficiency than tyramide without inducing oligomerization of probe molecules. Tyrosine modification also proceeded in the presence of β‐nicotinamide adenine dinucleotide (NADH, H2O2‐free conditions).
Palladium‐Catalyzed Aerobic Synthesis of Terminal Acetals from Vinylarenes Assisted by π‐Acceptor Ligands
Authors: Matsumura Satoko , Sato Ruriko , Nakaoka Sonoe , Yokotani Wakana , Murakami Yuka , Kataoka Yasutaka , Ura Yasuyuki 
Published: December 2016

AbstractTerminal acetals were synthesized from various vinylarenes and 1,2‐ or 1,3‐diols using a simple PdCl2(MeCN)2/methoxy‐p‐benzoquinone (MeOBQ)/CuCl catalyst system and 1 atm of O2 under mild reaction conditions by the anti‐Markovnikov nucleophilic attack of an oxygen nucleophile on the coordinated vinylarenes. Cyclic α,β‐unsaturated carbonyl compounds such as MeOBQ and N‐phenylmaleimide were especially effective as additives to afford higher yields of the desired terminal acetals. Kinetic experiments indicated that MeOBQ operates as a π‐acceptor ligand for Pd to accelerate the reaction and that the dissociation of a chloride ion from Pd precedes the rate‐determining step.
Deep Eutectic Solvent Compatible Metallic Catalysts: Cationic Pyridiniophosphine Ligands in Palladium Catalyzed Cross‐Coupling Reactions
Authors: Marset Xavier , Khoshnood Abbas , Sotorríos Lia , Gómez‐Bengoa Enrique , Alonso Diego A. , Ramón Diego J. 
Published: December 2016

AbstractCationic pyridiniophosphine ligands have been synthetized in an attempt to develop a deep eutectic solvents (DESs) compatible catalytic systems. These ligands, in combination with PdCl2, have been successfully applied to different palladium‐catalyzed cross coupling reactions, such as Suzuki–Miyaura, Sonogashira, or Heck couplings. While traditional palladium ligands in DES medium failed to reproduce the results obtained in VOC solvents, these cationic phosphines improved the catalytic activity of palladium as no other traditional ligand could in such a polar medium. In addition, the recyclability of these processes was studied, allowing us to reuse both, catalyst and solvent up to 5 times in Suzuki and Sonogashira reactions without a significant drop in the catalytic activity. Regarding the structure of the Pd catalysts, titration, NMR, and DFT studies have clearly demonstrated the coordination properties of the DES‐compatible cationic phosphine ligands.
Electrochemical Formation of FeV(O) and Mechanism of Its Reaction with Water During O−O Bond Formation
Authors: Pattanayak Santanu , Chowdhury Debarati Roy , Garai Bikash , Singh Kundan K. , Paul Amit , Dhar Basab B. , Gupta Sayam Sen 
Published: December 2016

AbstractA detailed electrochemical investigation of a series of iron complexes (biuret‐modified tetraamido iron macrocycles FeIII‐bTAML), including the first electrochemical generation of FeV(O), and demonstration of their efficacy as homogeneous catalysts for electrochemical water oxidation (WO) in aqueous medium are reported. Spectroelectrochemical and mass spectral studies indicated FeV(O) as the active oxidant, formed due to two redox transitions, which were assigned as FeIV(O)/FeIII(OH2) and FeV(O)/FeIV(O). The spectral properties of both of these high‐valent iron oxo species perfectly match those of their chemically synthesised versions, which were thoroughly characterised by several spectroscopic techniques. The O−O bond‐formation step occurs by nucleophilic attack of H2O on FeV(O). A kinetic isotope effect of 3.2 indicates an atom–proton transfer (APT) mechanism. The reaction of chemically synthesised FeV(O) in CH3CN and water was directly probed by electrochemistry and was found to be first‐order in water. The pKa value of the buffer base plays a critical role in the rate‐determining step by increasing the reaction rate several‐fold. The electronic effect on redox potential, WO rates, and onset overpotential was studied by employing a series of iron complexes. The catalytic activity was enhanced by the presence of electron‐withdrawing groups on the bTAML framework. Changing the substituents from OMe to NO2 resulted in an eightfold increase in reaction rate, while the overpotential increased threefold.