bluuebunny/crossref_metadata_2025_split huggingface dataset:
Divergent Reactivity of In Situ Generated Metal Azides: Reaction with N,N‐Bis(oxy)enamines as a Case Study
Authors: Zhmurov Petr A. , Khoroshutina Yulia A. , Novikov Roman A. , Golovanov Ivan S. , Sukhorukov Alexey Yu. , Ioffe Sema L. 
Published: February 2017

AbstractInvited for the cover of this issue is the group of Alexey Sukhorukov at the N. D. Zelinsky Institute of Organic Chemistry. The image depicts the reaction pathways taken by metal azides as a “chemical billiard” game. Read the full text of the article at 10.1002/chem.201605390.
Effect of the Metal Ion on the Enantioselectivity and Linkage Isomerization of Thiosemicarbazone Helicates
Authors: Romero María J. , Suárez Vanesa , Fernández‐Fariña Sandra , Maneiro Marcelino , Martínez‐Núñez Emilio , Zaragoza Guillermo , González‐Noya Ana M. , Pedrido Rosa 
Published: February 2017

AbstractThe effect of the metal ion and ligand design on the enantioselectivity and linkage isomerization of neutral cobalt and zinc bisthiosemicarbazone metallohelicates has been investigated in this work. The electrochemical synthesis has afforded the enantioselective formation of chirally pure cobalt helicates, and the ΛΛ isomer of a single enantiomer has been crystallized as only product for the cobalt methyl‐substituted thiosemicarbazone helicate. Interestingly linkage isomers have been formed from zinc ethyl‐substituted thiosemicarbazone helicate enantiomers for the first time. The co‐existence of these isomers has been evaluated from the point of view of both experimental results and computational calculations.
Dinickel–Salphen Complexes as Binders of Human Telomeric Dimeric G‐Quadruplexes
Authors: Zhou Chun‐Qiong , Liao Ting‐Cong , Li Zi‐Qi , Gonzalez‐Garcia Jorge , Reynolds Matthew , Zou Min , Vilar Ramon 
Published: February 2017

AbstractThree new polyether‐tethered dinickel–salphen complexes (2 a–c) have been synthesized and fully characterized by NMR spectroscopy, mass spectrometry, and elemental analyses. The binding affinity and selectivity of these complexes and of the parent mono‐nickel complex (1) towards dimeric quadruplex DNA have been determined by UV/Vis titrations, fluorescence spectroscopy, CD spectroscopy, and electrophoresis. These studies have shown that the dinickel–salphen complex with the longest polyether linker (2 c) has higher binding affinity and selectivity towards dimeric quadruplexes (over monomeric quadruplexes) than the dinickel–salphen complexes with the shorter polyether linkers (2 a and 2 b). Complex 2 c also has higher selectivity towards human telomeric dimeric quadruplexes with one TTA linker than the monometallic complex 1. Based on the spectroscopic data, a possible binding mode between complex 2 c and the dimeric G‐quadruplex DNA under study is proposed.
An investigation of dimensional scaling using cervical spine motion segment finite element models
Authors: Singh Dilaver , Cronin Duane S. 
Published: February 2017

AbstractThe paucity of experimental data for validating computational models of different statures underscores the need for appropriate scaling methods so that models can be verified and validated using experimental data. Scaling was investigated using 50th percentile male (M50) and 5th percentile female (F05) cervical spine motion segment (C4‐C5) finite element models subject to tension, flexion, and extension loading. Two approaches were undertaken: geometric scaling of the models to investigate size effects (volumetric scaling) and scaling of the force‐displacement or moment‐angle model results (data scaling). Three sets of scale factors were considered: global (body mass), regional (neck dimensions), and local (segment tissue dimensions).Volumetric scaling of the segment models from M50 to F05, and vice versa, produced correlations that were good or excellent in both tension and flexion (0.825‐0.991); however, less agreement was found in extension (0.550‐0.569). The reduced correlation in extension was attributed to variations in shape between the models leading to nonlinear effects such as different time to contact for the facet joints and posterior processes. Data scaling of the responses between the M50 and F05 models produced similar trends to volumetric scaling, with marginally greater correlations.Overall, the local tissue level and neck region level scale factors produced better correlations than the traditional global scaling. The scaling methods work well for a given subject, but are limited in applicability between subjects with different morphology, where nonlinear effects may dominate the response.
Planarizable Push–Pull Probes: Overtwisted Flipper Mechanophores
Authors: Macchione Mariano , Chuard Nicolas , Sakai Naomi , Matile Stefan 
Published: February 2017

AbstractPlanarizable push–pull fluorescent probes, also referred to as flipper probes, have been introduced as conceptually innovative mechanophores that report on forces in their local environment in lipid bilayer membranes. The best flipper probes respond to a change from liquid disordered to solid ordered membranes with a red shift in excitation of 50–90 nm. A simultaneous increase in fluorescence lifetime and negligible background fluorescence from the aqueous phase qualifies these fluorescent probes for meaningful imaging in live cells. Here, we report that the replacement of methyl with isobutyl substituents along the scaffold of a dithienothiophene dimer strongly reduces fluorescence intensity but increases solvatochromism slightly. These trends imply that the large substituents in “leucine flippers” hinder the planarization in the first excited state to result in twisted intramolecular charge transfer (TICT). As a result of this overtwisting, the leucine flippers form interesting fluorescent micelles in water but fail to respond to changes in membrane order. These dramatic changes in function provide one of the most impressive illustrations for the hypersensitivity of fluorescent membrane probes toward small changes in their structure.
Utility of BRCA1‐associated protein 1 immunoperoxidase stain to differentiate benign versus malignant mesothelial proliferations in cytologic specimens
Authors: McCroskey Zulfia , Staerkel Gregg , Roy‐Chowdhuri Sinchita 
Published: February 2017

BackgroundLoss of BAP1 has recently been described as a highly specific marker for distinguishing malignant mesotheliomas (MM) from benign mesothelial proliferations (BMP). The aim of this study was to evaluate the utility of BAP1 in cytospin and cell block (CB) preparations.MethodsWe searched the database at our institution for cases of MM (n = 21) and BMP (n = 11). A Papanicolaou stained cytospin preparation and CB section from each case were selected for BAP1 staining. The results were scored as nuclear BAP1 staining, absent or present. Positive staining in non‐neoplastic cells was noted as internal control.ResultsIn the study group, MM cells showed a loss of BAP1 staining in 18/21(86%) cytospin and 19/21(90%) CB preparations. All cytospins showed appropriate positive nuclear staining in the “internal control” inflammatory cells. However, only 17/21(81%) of CB sections showed good internal control with positive nuclear staining in inflammatory cells. The intensity of BAP1 nuclear staining varied across cases. Overall, the intensity of staining was higher in cytospins, providing sharper contrast between the malignant cells with loss of stain and the benign inflammatory cells with retained stain in cases of MM. Sensitivity/specificity for cytospins when compared with CB was 86/100 and 88/100%, respectively.ConclusionsCytospin preparations have comparable sensitivity and specificity to CB with greater intensity and better contrast between negative and positive nuclei making the interpretation easier. We advise to interpret BAP1 IPOX stain results with caution with careful attention to staining of background nonmalignant “internal control” cells. Diagn. Cytopathol. 2017;45:312–319. © 2016 Wiley Periodicals, Inc.
Complex variation in habitat selection strategies among individuals driven by extrinsic factors
Authors: Raynor Edward J. , Beyer Hawthorne L. , Briggs John M. , Joern Anthony 
Published: February 2017

AbstractUnderstanding behavioral strategies employed by animals to maximize fitness in the face of environmental heterogeneity, variability, and uncertainty is a central aim of animal ecology. Flexibility in behavior may be key to how animals respond to climate and environmental change. Using a mechanistic modeling framework for simultaneously quantifying the effects of habitat preference and intrinsic movement on space use at the landscape scale, we investigate how movement and habitat selection vary among individuals and years in response to forage quality–quantity tradeoffs, environmental conditions, and variable annual climate. We evaluated the association of dynamic, biotic forage resources and static, abiotic landscape features with large grazer movement decisions in an experimental landscape, where forage resources vary in response to prescribed burning, grazing by a native herbivore, the plains bison (Bison bison bison), and a continental climate. Our goal was to determine how biotic and abiotic factors mediate bison movement decisions in a nutritionally heterogeneous grassland. We integrated spatially explicit relocations ofGPS‐collared bison and extensive vegetation surveys to relate movement paths to grassland attributes over a time period spanning a regionwide drought and average weather conditions. Movement decisions were affected by foliar crude content and low stature forage biomass across years with substantial interannual variation in the magnitude of selection for forage quality and quantity. These differences were associated with interannual differences in climate and growing conditions from the previous year. Our results provide experimental evidence for understanding how the forage quality–quantity tradeoff and fine‐scale topography drives fine‐scale movement decisions under varying environmental conditions.
Immigration ensures population survival in the Siberian flying squirrel
Authors: Brommer Jon E. , Wistbacka Ralf , Selonen Vesa 
Published: February 2017

AbstractLinking dispersal to population growth remains a challenging task and is a major knowledge gap, for example, for conservation management. We studied relative roles of different demographic rates behind population growth in Siberian flying squirrels in two nest‐box breeding populations in western Finland. Adults and offspring were captured and individually identifiable. We constructed an integrated population model, which estimated all relevant annual demographic rates (birth, local [apparent] survival, and immigration) as well as population growth rates. One population (studied 2002–2014) fluctuated around a steady‐state equilibrium, whereas the other (studied 1995–2014) showed a numerical decline. Immigration was the demographic rate which showed clear correlations to annual population growth rates in both populations. Population growth rate was density dependent in both populations. None of the demographic rates nor the population growth rate correlated across the two study populations, despite their proximity suggesting that factors regulating the dynamics are determined locally. We conclude that flying squirrels may persist in a network of uncoupled subpopulations, where movement between subpopulations is of critical importance. Our study supports the view that dispersal has the key role in population survival of a small forest rodent.
Covalently Anchored p‐Aminobenzene Sulfonate Multilayer on a Graphite Pencil Lead Electrode: A Highly Selective Electrochemical Sensor for Dopamine
Authors: Devaramani Samrat , Sreeramareddygari Muralikrishna , Reddy M. Radhakrishna , Thippeswamy Ramakrishnappa 
Published: February 2017

AbstractAn electrochemical sensor for dopamine (DA) has been developed based on the electrografting of 4‐aminobenzene sulfonic acid (4‐ABSA) onto the graphite pencil lead electrode (GPLE). The process of covalent anchoring and presence of 4‐ABSA on the GPLE was studied using cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical behaviour of the sensor towards DA, ascorbic acid (AA), and uric acid (UA) was studied in detail in phosphate buffer of pH 7. After optimizing the various parameters that influence the differential pulse voltammetric (DPV) signal for DA, the sensor exhibited a linear response over the 0.5 – 10 μmol⋅L‐1concentration range with a limit of detection, 0.095 μmol⋅L‐1 (at an S/N of 3). The sensor can selectively quantify DA even in the presence of 1 mmol⋅L‐1 AA. Distinct DPV signals were obtained for DA (at 0.191 mV vs. Ag/AgCl) and for UA (at 0.343 mV vs. Ag/AgCl). The sensor is highly selective, sensitive and stable. It was applied to the quantification of DA in injections and urine. Recovery studies were done by spiking both the real samples with a known quantity of DA.
Gold Nano Particle and Reduced Graphene Oxide Composite Modified Carbon Paste Electrode for the Ultra Trace Detection of Arsenic (III)
Authors: Sahoo Srikant , Sahoo Prasanta Kumar , Satpati Ashis Kumar 
Published: February 2017

AbstractGold nanoparticles (AuNPs) and reduced graphene oxide (RGO) composite modified carbon paste electrode (CPE) was prepared by electrodepositing AuNPs over the reduced graphene oxide (RGO) modified carbon paste electrode. The composite material was characterised using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. The nano composite modified electrode was applied for the determination of total As and for the inorganic speciation of As(III) and As(V) in environmental samples. The linear dynamic range was obtained for the determination of As(III) in the present method from 1μgL−1 to 20 μgL−1 and the limit of detection(LOD) in the standard solution was found to be 0.13 μgL−1 for the 300 sec deposition time in 10 mL supporting electrolyte solution. This method was applied for the determination of As (III) in water and soil samples. The results were agreed well with the result obtained from the hydride generation atomic absorption spectrometry.
A Disposable Homemade Screen Printed Electrochemical Sensor for Vitamin B1 Determination in Multivitamin Ampoules: Potentiometric and Surface Morphology Studies
Authors: Issa Yousry M. , Sherif Omaima E. , Dena Ahmed S. Abo 
Published: February 2017

AbstractThiamine chloride hydrochloride (TCH) is one of the B‐complex vitamins which resemble a very biologically important group of biomolecules. The first screen‐printed graphite ion‐selective sensor for the determination of TCH was prepared and characterized. The sensor is based on TCH‐tetraphenylborate as electrode material. A number of parameters such as the type of solvent mediator, weight percent of the ion‐exchanger, test solution temperature and possible interferences were extensively studied. Moreover, the surface morphology of the prepared sensor was studied using scanning electron microscopy. The sensor shows a Nernstian slope of 30.60±0.07 mV/decade, a low LOD of 5.08×10−6 mol/L and a wide applicability range of 5.96×10−6‐1.00×10−2 mol/L. The sensing graphite ink remains usable for at least one month. Fast potentiometric response was obtained within 5 s and remains stable for at least 60 s. The sensor was applied to the analysis of TCH in pure solutions and multivitamin ampoules from the Egyptian market using the standard addition method and high recovery values of 97–102 % were obtained. Low %RSD values (0.27‐1.30) indicate high precision of the proposed sensor. Our sensor provides the advantages of disposability, simple preparation procedures, sensitivity and easy storage and transportation.
Electrochemical Measurement of the Dissolved Oxygen Concentration in Water in the Absence of Deliberately Added Supporting Electrolyte
Authors: Clark Richard O. D. , Ngamchuea Kamonwad , Batchelor‐McAuley Christopher , Compton Richard G. 
Published: February 2017

AbstractIt is commonly assumed that the use and application of electrochemical techniques to natural surface waters requires the presence of high electrolyte concentrations prior to measurement, so limiting the applicability of the technique. We report that even for the complex case of oxygen reduction, an analytically useful electrochemical signal is obtainable using a carbon fibre microcylinder electrode. It is shown to be the case even when using voltammetric signals recorded in potable water that has not been pre‐treated or had the addition of any ionic material. The magnitude of the redox wave gives a reliable measure of the oxygen content of these solutions which contain only few millimolar of ions and contains no pH buffer.
Capturing the spatiotemporal variability of bedload transport: A time‐lapse imagery technique
Authors: Redolfi Marco , Guidorizzi Luca , Tubino Marco , Bertoldi Walter 
Published: February 2017

AbstractMonitoring sediment transport in morphologically complex and labile channels remains a difficult task, even at the laboratory scale. To address this challenge, a fully automated imagery technique for continuously mapping the spatial and temporal variability of bedload transport is proposed. This method uses differentiated time‐lapse imagery taken from a fixed camera to detect bed variations induced by grain displacement. The technique is not based on tracking the individual particles; rather, it evaluates macroscopic colour changes within a region that contains several grains, which depend on the occurrence and intensity of the bedload transport. Image‐derived data were compared with the sediment flux measured during four flume experiments, and produced good correspondence. The method provides continuous tracking of the location of the transporting channels, and enables estimation of local variations in the magnitude of the bedload flux. Moreover, the spatial extent of the monitoring area offers an unprecedented opportunity to aggregate spatially dense and continuous data at the reach scale, as needed to properly capture the full range of variability of morphologically complex and rapidly evolving gravel‐bed rivers. Despite being limited to laboratory‐scale physical experiments, the method provides useful data to investigate fundamental morphodynamic processes such as bar migration, bank erosion, anabranches opening/closure, and the associate spatial and temporal scales. Further, the data obtained have the potential to enhance numerical model calibration and improve our understanding of the complex dynamics of real‐world settings. Copyright © 2017 John Wiley & Sons, Ltd.
A sweet taste receptor‐dependent mechanism of glucosensing in hypothalamic tanycytes
Authors: Benford Heather , Bolborea Matei , Pollatzek Eric , Lossow Kristina , Hermans‐Borgmeyer Irm , Liu Beihui , Meyerhof Wolfgang , Kasparov Sergey , Dale Nicholas 
Published: February 2017

AbstractHypothalamic tanycytes are glial‐like glucosensitive cells that contact the cerebrospinal fluid of the third ventricle, and send processes into the hypothalamic nuclei that control food intake and body weight. The mechanism of tanycyte glucosensing remains undetermined. While tanycytes express the components associated with the glucosensing of the pancreatic β cell, they respond to nonmetabolisable glucose analogues via an ATP receptor‐dependent mechanism. Here, we show that tanycytes in rodents respond to non‐nutritive sweeteners known to be ligands of the sweet taste (Tas1r2/Tas1r3) receptor. The initial sweet tastant‐evoked response, which requires the presence of extracellular Ca2+, leads to release of ATP and a larger propagating Ca2+ response mediated by P2Y1 receptors. In Tas1r2 null mice the proportion of glucose nonresponsive tanycytes was greatly increased in these mice, but a subset of tanycytes retained an undiminished sensitivity to glucose. Our data demonstrate that the sweet taste receptor mediates glucosensing in about 60% of glucosensitive tanycytes while the remaining 40% of glucosensitive tanycytes use some other, as yet unknown mechanism.
Translational readthrough generates new astrocyte AQP4 isoforms that modulate supramolecular clustering, glial endfeet localization, and water transport
Authors: De Bellis Manuela , Pisani Francesco , Mola Maria Grazia , Rosito Stefania , Simone Laura , Buccoliero Cinzia , Trojano Maria , Nicchia Grazia Paola , Svelto Maria , Frigeri Antonio 
Published: February 2017

AbstractRegulation of water homeostasis is a central feature of central nervous system pathophysiology. In this context, several lines of evidence suggest a crucial role for the water channel aquaporin‐4 (AQP4) and its plasma membrane supramolecular organization as the key element. Here, we demonstrate the expression in tissues of additional isoforms of AQP4 characterized by a C‐terminal extension generated by programmed translational readthrough. These extended isoforms (AQP4ex) display a perivascular polarization and expression in dystrophin‐dependent pools. AQP4ex reduces supramolecular clustering tendency and allows AQP4 interactions with syntrophin. Furthermore, site‐directed mutagenesis of two serines in the extended C‐terminus of AQP4ex showed potential regulation of water permeability by phosphorylation. Finally, AQP4ex expression can be positively modulated by gentamicin treatment, demonstrating the possibility of regulating the AQP4 translational readthrough frequency. This novel regulatory mechanism could have important pathophysiological implications for conditions in which alternations have been reported in AQP4 structure.
Predictive modeling of EEG time series for evaluating surgery targets in epilepsy patients
Authors: Steimer Andreas , Müller Michael , Schindler Kaspar 
Published: February 2017

AbstractDuring the last 20 years, predictive modeling in epilepsy research has largely been concerned with the prediction of seizure events, whereas the inference of effective brain targets for resective surgery has received surprisingly little attention. In this exploratory pilot study, we describe a distributional clustering framework for the modeling of multivariate time series and use it to predict the effects of brain surgery in epilepsy patients. By analyzing the intracranial EEG, we demonstrate how patients who became seizure free after surgery are clearly distinguished from those who did not. More specifically, for 5 out of 7 patients who obtained seizure freedom (= Engel class I) our method predicts the specific collection of brain areas that got actually resected during surgery to yield a markedly lower posterior probability for the seizure related clusters, when compared to the resection of random or empty collections. Conversely, for 4 out of 5 Engel class III/IV patients who still suffer from postsurgical seizures, performance of the actually resected collection is not significantly better than performances displayed by random or empty collections. As the number of possible collections ranges into billions and more, this is a substantial contribution to a problem that today is still solved by visual EEG inspection. Apart from epilepsy research, our clustering methodology is also of general interest for the analysis of multivariate time series and as a generative model for temporally evolving functional networks in the neurosciences and beyond. Hum Brain Mapp 38:2509–2531, 2017. © 2017 Wiley Periodicals, Inc.