bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized Polymers from α‐Hydroxyalkylated N‐Vinylcaprolactam
Authors: Schönenberg Lisa , Ritter Helmut 
Published: February 2016

Hydroxyalkylation of N‐vinylcaprolactam (NVCL) in α‐position via ring‐opening reaction of propylene oxide and ε‐caprolactone, respectively, yields in precursors for multifunctional NVCL derivatives. Homo‐ and copolymers of hydroxyfunctionalized NVCL derivatives, synthesized by free radical mechanism, are further investigated regarding their thermoresponsive behavior. Esterification of hydroxypropylated NVCL derivative with methacrylic anhydride is carried out yielding a versatile bifunctional cross‐linker. Networks are obtained either via free radical polymerization of the cross‐linker or anionic polymerization of only the methacrylic function and subsequent polymer analogous cross‐linking of the vinylic side groups. The rheological behavior during and after curing is investigated by oscillatory rheology. Furthermore, N‐vinylcaprolactam anion is used as an initiator for the anionic ring‐opening polymerization of ε‐caprolactone. Copolymerization of poly(ε‐caprolactone) macromonomer with NVCL yields graft copolymers. A polymerizable thermotropic liquid crystalline (LC) derivative is prepared by coupling cholesteryl chloroformate to NVCL. The thermal behavior of LC derivative is investigated by differential scanning calorimetry and polarized light microscopy.
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Simulation Study on the Coil‐Globule Transition and Surface Adsorption of HP Chains
Authors: Wang Qi , Jiang Si‐Jia , Jia Wen , Luo Meng‐Bo 
Published: February 2016

The coil‐globule transition of short hydrophobic‐polar (HP) chains, composed of 24 hydrophilic monomers and 24 polar monomers, in solution and on hydrophobic surface and the adsorption of the HP chain on hydrophobic surface are simulated. The coil‐globule transition point of the HP chain is dependent on sequence of chain but is roughly independent of the surface adsorption strength. Whereas the critical adsorption point of the HP chain is roughly independent of sequence. In addition, the lowest energy states can be obtained for the HP chain in solution or on surface by Monte Carlo simulated annealing method. Results show that the statistical conformation is strongly dependent on the intrachain H‐H attraction strength and the surface adsorption strength.
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New insights into FtsZ rearrangements during the cell division of Escherichia coli from single‐molecule localization microscopy of fixed cells
Authors: Vedyaykin Alexey D. , Vishnyakov Innokentii E. , Polinovskaya Vasilisa S. , Khodorkovskii Mikhail A. , Sabantsev Anton V. 
Published: February 2016

AbstractFtsZ – a prokaryotic tubulin homolog – is one of the central components of bacterial division machinery. At the early stage of cytokinesis FtsZ forms the so‐called Z‐ring at mid‐cell that guides septum formation. Many approaches were used to resolve the structure of the Z‐ring, however, researchers are still far from consensus on this question. We utilized single‐molecule localization microscopy (SMLM) in combination with immunofluorescence staining to visualize FtsZ in Esherichia coli fixed cells that were grown under slow and fast growth conditions. This approach allowed us to obtain images of FtsZ structures at different stages of cell division and accurately measure Z‐ring dimensions. Analysis of these images demonstrated that Z‐ring thickness increases during constriction, starting at about 70 nm at the beginning of division and increasing by approximately 25% half‐way through constriction.
Impact of xanthohumol (a prenylated flavonoid from hops) on DNA stability and other health‐related biochemical parameters: Results of human intervention trials
Authors: Ferk Franziska , Mišík Miroslav , Nersesyan Armen , Pichler Christoph , Jäger Walter , Szekeres Thomas , Marculescu Rodrig , Poulsen Henrik E. , Henriksen Trine , Bono Roberto , Romanazzi Valeria , Al‐Serori Halh , Biendl Martin , Wagner Karl‐Heinz , Kundi Michael , Knasmüller Siegfried 
Published: February 2016

ScopeXanthohumol (XN) is a hop flavonoid found in beers and refreshment drinks. Results of in vitro and animal studies indicate that it causes beneficial health effects due to DNA protective, anti‐inflammatory, antioxidant, and phytoestrogenic properties. Aim of the present study was to find out if XN causes alterations of health‐related parameters in humans.Methods and resultsThe effects of the flavonoid were investigated in a randomized crossover intervention trial (n = 22) in which the participants consumed a XN drink (12 mg XN/P/day). We monitored alterations of the DNA stability in single cell gel electrophoresis assays in lymphocytes and of several health‐related biomarkers. A decrease of oxidatively damaged purines and protection toward reactive oxygen species induced DNA damage was found after the consumption of the beverage; also the excretion of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine and 8‐oxo‐guanosine in urine was reduced. The assumption that the flavonoid causes DNA protection was confirmed in a randomized follow‐up study with pure XN (n = 10) with a parallel design. Other biochemical parameters reflecting the redox‐ and hormonal status and lipid‐ and glucose metabolism were not altered after the intervention.ConclusionTaken together, our data indicate that low doses of XN protect humans against oxidative DNA damage.
Two nonspecific lipid transfer proteins (nsLTPs) from tomato seeds are associated to severe symptoms of tomato‐allergic patients
Authors: Martín‐Pedraza Laura , González Miguel , Gómez Francisca , Blanca‐López Natalia , Garrido‐Arandia María , Rodríguez Rosalía , Torres María J. , Blanca Miguel , Villalba Mayte , Mayorga Cristobalina 
Published: February 2016

ScopeTomato has become one of the most consumed vegetables worldwide, but its intake is often accompanied by an increasing risk of inducing allergic symptoms. The aim of the work was the identification of new seed‐specific allergens associated with severe symptoms in patients allergic to this edible vegetable.Methods and resultsWe used 22 sera from well‐defined tomato‐allergic patients. Tomato seed proteins were purified and analyzed for biochemical and immunological characterization. A mixture of two associated IgE‐binding nsLTPs was purified from tomato seeds. Both allergens, Sola l 7 and Sola l 6, displayed primary structure differences with respect to their counterpart, Sola l 3, from tomato pulp/peel. They retained the ability to bind IgE from 71.4% of patients with severe symptoms. The purified proteins induced positive basophil activation test and skin prick test, and displayed cross‐reactivity with homologous allergens from peanut and sunflower seeds, among others.ConclusionWe herein described two novel allergens from tomato seeds that belong to the nonspecific lipid transfer protein family classes 1 and 2, respectively. This is the first work associating IgE reactivity to these proteins with severe symptoms of certain tomato‐allergic patients. Therefore, they are optimal candidates for clarifying the diagnosis of the tomato allergy.
Three‐dimensional MR spectroscopic imaging using adiabatic spin echo and hypergeometric dual‐band suppression for metabolic mapping over the entire brain
Authors: Esmaeili Morteza , Bathen Tone F. , Rosen Bruce R. , Andronesi Ovidiu C. 
Published: February 2016

PurposeLarge lipid and water signals in MR spectroscopic imaging (MRSI) complicate brain metabolite quantification. In this study, we combined adiabatic hypergeometric dual‐band (HGDB) lipid and water suppression with gradient offset independent adiabatic (GOIA) spin echo to improve three‐dimensional (3D) MRSI of the entire brain.Methods3D MRSI was acquired at 3T with a 32‐channel coil. HGDB pulses were used before excitation and during echo time. A brain slab was selected with GOIA‐W(16,4) pulses, weighted phase encoded stack of spirals, and real‐time motion/shim correction. HGDB alone or in combination with OVS and MEGA (MEscher‐GArwood) was compared with OVS only and no suppression.ResultsThe combined HGDB pulses suppressed lipids to 2%–3% of their full unsuppressed signal. The HGDB lipid suppression was on average 5 times better than OVS suppression. HGDB+MEGA provided 30% more suppression compared with a previously described HGDB+OVS scheme. The number of voxels with good metabolic fits was significantly larger in the HGDB data (91%–94%) compared with the OVS data (59%–80%).ConclusionHGDB pulses provided efficient lipid and water suppression for full brain 3D MRSI. The HGDB suppression is superior to traditional OVS, and it can be combined with adiabatic spin echo to provide a sequence that is robust to B1 inhomogeneity. Magn Reson Med 77:490–497, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Toward a new generation of pelvic floor implants with electrospun nanofibrous matrices: A feasibility study
Authors: Vashaghian Mahshid , Ruiz‐Zapata Alejandra M. , Kerkhof Manon H. , Zandieh‐Doulabi Behrouz , Werner Arie , Roovers Jan Paul , Smit Theo H. 
Published: February 2016

ObjectiveThe use of knitted, polypropylene meshes for the surgical treatment of pelvic organ prolapse (POP) is frequently accompanied by severe complications. Looking for alternatives, we studied the potential of three different electrospun matrices in supporting the adhesion, proliferation, and matrix deposition of POP and non‐POP fibroblasts, the most important cells to produce extracellular matrix (ECM), in vitro.Study designWe electrospun three commonly used medical materials: nylon; poly (lactide‐co‐glycolide) blended with poly‐caprolactone (PLGA/PCL); and poly‐caprolactone blended with gelatin (PCL/Gelatin). The matrices were characterized for their microstructure, hydrophilicity, and mechanical properties. We seeded POP and non‐POP fibroblasts from patients with POP and we determined cellular responses and ECM deposition.ResultsAll matrices had >65% porosity, homogenous microstructures, and close to sufficient tensile strength for pelvic floor repair: 15.4 ± 3.3 MPa for Nylon; 12.4 ± 1.6 MPa for PLGA/PCL; and 3.5 ± 0.9 MPa for PCL/Gelatin. Both the POP and non‐POP cells adhered to the electrospun matrices; they proliferated well and produced ample ECM. Overall, the best in vitro performance appeared to be on nylon, presumably because this was the most hydrophilic material with the thinnest fibers.ConclusionElectrospun nanofibrous matrices show feasible mechanical strength and great biocompatibility for POP and non‐POP fibroblasts to produce their ECM in vitro and, thus, may be candidates for a new generation of implants for pelvic floor repair. Further studies on electrospun nanofibrous matrices should focus on mechanical and immunological conditions that would be presented in vivo. Neurourol. Urodynam. 36:565–573, 2017. © 2016 Wiley Periodicals, Inc.
Glucose‐6‐Phosphate Dehydrogenase Deficiency in Brazilian Children With Sickle Cell Anemia is not Associated With Clinical Ischemic Stroke or High‐Risk Transcranial Doppler
Authors: Belisário André Rolim , Rodrigues Sales Rahyssa , Evelin Toledo Nayara , Velloso‐Rodrigues Cibele , Maria Silva Célia , Borato Viana Marcos 
Published: February 2016

BackgroundStroke is a severe complication of sickle cell anemia (SCA). The role of glucose‐6‐phosphate dehydrogenase (G6PD) deficiency in the development of stroke in children with SCA is controversial.ProcedureThe aim of this study was to investigate the association of clinical ischemic stroke, high‐risk transcranial Doppler measurements (TCD), and hematological features with molecular variants usually linked to G6PD deficiency or with the biochemical activity of G6PD in a cohort of 395 Brazilian children with SCA. G6PD activity was quantitatively determined using an enzymatic‐colorimetric assay. G6PD mutations were determined by PCR‐RFLP and sequencing. Clinical and hematological data were retrieved from the children's records.ResultsThe prevalence of molecularly defined deficiency (hereafter, molecular deficiency) was 4.3% (95% confidence interval: 2.3–6.3%). The mean G6PD activity was 16.88 U/g hemoglobin (Hb) (standard error of the mean [SEM] 0.28) in the group without G6PD molecular deficiency and 8.43 (SEM 1.01) U/g Hb in the group with G6PD A− molecular deficiency. G6PD molecular deficiency was not associated with any hematological features. No effects of G6PD molecular deficiency on clinical ischemic stroke or high‐risk TCD were detected. The mean G6PD activity was similar in children who had clinical ischemic stroke and in those without stroke. Similar results were obtained in analyses comparing children who had high‐risk TCD and those without high‐risk TCD.ConclusionsOur study demonstrated that G6PD molecular deficiency was not associated either with clinical ischemic stroke or high‐risk TCD. Similarly, we found no associations between G6PD enzyme activity and stroke or high‐risk TCD. Small sample size precludes definitive conclusions.
Polybutadiene/polyhedral oligomeric silsesquioxane nanohybrid: investigation of various reactants in polyesterification reaction
Authors: Mirmohammadi Seyed Amin , Nekoomanesh‐Haghighi Mehdi , Mohammadian Gezaz Somayyeh , Bahri‐Laleh Naeimeh 
Published: February 2016

AbstractNano‐sized polyhedral oligomeric silsesquioxane (POSS) diol or ethylene glycol (EG) as diol monomer was incorporated into hydroxyl‐terminated polybutadiene (HTPBD) chain in the presence of fumaryl or thionyl chloride as extenders. Using these polyesterification reactions, two fumarate‐based polyesters and two polyester sulfites were synthesized. Each couple of polyesters and polyester sulfites includes a linear (diol:EG) and a nanohybrid macromer (diol:POSS). Full structural characterization was performed using Fourier transform infrared, 1H NMR and 13C NMR spectroscopies. Gel permeation chromatography was undertaken to study polyesterification mechanisms by deconvolution of the obtained traces. Finally, differential scanning calorimetry, thermogravimetric analysis and cell culture were performed to evaluate the structure–property relationship for the synthesized macromers in comparison with unreacted HTPBD. © 2016 Society of Chemical Industry
Role of lectin microarrays in cancer diagnosis
Authors: Syed Parvez , Gidwani Kamlesh , Kekki Henna , Leivo Janne , Pettersson Kim , Lamminmäki Urpo 
Published: February 2016

The majority of cell differentiation associated tumor markers reported to date are either glycoproteins or glycolipids. Despite there being a large number of glycoproteins reported as candidate markers for various cancers, only a handful are approved by the US Food and Drug Administration. Lectins, which bind to the glycan part of the glycoproteins, can be exploited to identify aberrant glycosylation patterns, which in turn would help in enhancing the specificity of cancer diagnosis. Although conventional techniques such as HPLC and MS have been instrumental in performing the glycomic analyses, these techniques lack multiplexity. Lectin microarrays have proved to be useful in studying multiple lectin–glycan interactions in a single experiment and, with the advances made in the field, hold a promise of enabling glycomic profiling of cancers in a fast and efficient manner.
Heat flow, transport and fluctuations in etched semiconductor quantum wire structures
Authors: Riha Christian , Chiatti Olivio , Buchholz Sven S. , Reuter Dirk , Wieck Andreas D. , Fischer Saskia F. 
Published: February 2016

AbstractLow‐dimensional transport in semiconductor meso‐ and nanostructures is a topical field of fundamental research with potential applications in future quantum devices. However, thermal non‐equilibrium may destroy phase‐coherence and remains to be explored experimentally. Here, we present effects of thermal non‐equilibrium in various implementations of low‐dimensional (non‐interacting) electron systems, fabricated by etching AlGaAs/GaAs heterostructures. These include narrow quasi‐two‐dimensional (2D) channels, quasi‐one‐dimensional (1D) waveguide networks, quantum rings (QRs), and single 1D constrictions, such as quantum point contacts (QPCs). Thermal non‐equilibrium is realized by current heating. The charge carrier temperature is determined by noise thermometry. The electrical conductance and the voltage–noise are measured with respect to bath temperatures, heating currents, thermal gradients, and electric fields. We determine and discuss heat transport processes, electron‐energy loss rates, and electron–phonon interaction, and our results are consistent with the Wiedemann–Franz relation. Additionally, we show how non‐thermal current fluctuations can be used to identify electric conductance anomalies due to charge states.
Annealing of frozen‐in defects in ZnO
Authors: Nirk T. , Lott K. , Seeman V. , Türn L. , Viljus M. , Öpik A. 
Published: February 2016

AbstractHigh temperature electrical conductivity (HTEC) as a function of time after step‐like change of Zn vapor pressure (PZn) at fixed ZnO crystal temperature (TZnO) and after step‐like change of TZnO at fixed PZn was measured in undoped ZnO single crystal and in undoped ZnO ceramic sample. It was found a difference on HTEC relaxation curves in these measurements. Samples were cooled from temperature 1273 K to room temperature. Appearance of asymmetric spectrum with g≈1.96 and disappearance of Mn2+ spectrum were detected in EPR investigations. Then vacuum annealing was applied for these samples and intensity of g≈1.96 EPR spectrum was registered after every vacuum annealing cycles. The change in sample color, the change in g≈1.96 spectrum intensity as well as appearance again of Mn2+ EPR spectrum in the course of vacuum annealing was explained by the model of defect clusters formed during cooling of the crystal. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonant photoluminescence of a positively charged Mn‐doped quantum dot
Authors: Lafuente‐Sampietro A. , Boukari H. , Besombes L. 
Published: February 2016

AbstractWe probe the spin dynamics of an individual magnetic atom (Mn) coupled to carriers in a positively charged quantum dot using resonant photoluminescence. We demonstrate that a p‐doped CdTe/ZnTe quantum dot containing a single Mn atom forms an ensemble of optical Λ systems which can be addressed independently. Performing resonant optical pumping experiment and auto‐correlation of the resonant photoluminescence, we show that these Λ systems are connected through inefficient forbidden spin‐flips. We demonstrate that the spin dynamics of X+‐Mn under resonant excitation is mainly controlled by the electron‐Mn interaction. This coherent dynamics is directly observed in the time domain and is shown to be highly sensitive to the local strain at the Mn location. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Testing particle filters on simple convective‐scale models. Part 2: A modified shallow‐water model
Authors: Haslehner Mylène , Janjić Tijana , Craig George C. 
Published: February 2016

The nonlinearities and stochastic features of atmospheric dynamics pose severe challenges for data assimilation. The particle filter is a method that can potentially address these challenges and has attracted significant interest for convective‐scale applications. Unlike data assimilation techniques used in current numerical weather prediction (NWP), the particle filter does not presuppose Gaussian error statistics but estimates the full probability density function (PDF) with a small number of state vectors (particles). The nudging proposal particle filter operates as a hybrid combination of nudging and sequential importance resampling (SIR). In this article, we investigate a refined nudging proposal particle filter algorithm, the equivalent‐weight particle filter, that combines the nudging proposal particle filter with weight equalization and thus permits an improved representation of the PDF.An idealized, nonlinear, one‐dimensional shallow‐water model is used as a testbed to show that the equivalent‐weight particle filter outperforms both nudging and SIR filters under certain conditions. The selection mechanism of particles during resampling and the effect of nudging on the weights are analyzed. With the help of analytical and experimental results, we identify a numerical quantity that determines whether the equivalent‐weight particle filter can outperform nudging alone and we derive a theoretical criterion for the equivalent‐weight particle filter to outperform nudging. Further, we investigate the effect of equalizing weights on the resampling and the statistical behaviour of the ensemble.
Possible impacts of mega‐El Niño/Southern Oscillation and Atlantic Multidecadal Oscillation on Eurasian heatwave frequency variability
Authors: Zhou Yefan , Wu Zhiwei 
Published: February 2016

Identifying predictability sources of heatwave variations is a scientific challenge and of practical importance. This study investigates the summertime heatwave frequency (HWF) over Eurasia for 1950–2014. The Eurasian HWF is dominated by two distinct modes: the interdecadal (ID) mode, featured by an increasing pattern overall, centred around eastern Europe–central Asia and Mongolia–southwestern China; and the interannual (IA) mode, resembling a tripole anomaly pattern with three centres over western–northern Europe, northeastern Asia and East Asia. The ID mode is found to be influenced by mega‐El Niño/Southern Oscillation (mega‐ENSO) and the Atlantic Multidecadal Oscillation (AMO), and the latter has far more effect, whereas the IA mode is connected with mega‐ENSO.Further analysis suggests that mega‐ENSO variations can incite a Gill‐type response spreading to Eurasia, while the AMO changes cause eastward‐propagating Rossby wave trains toward Eurasia. These two teleconnection patterns together contribute to the large‐scale circulation anomalies of the ID mode, and those related to the IA mode arise from the teleconnection pattern excited by mega‐ENSO. A strong mega‐ENSO triggers subsidence with high pressure anomalies, warms the surface and increases the HWF significantly over northeastern Asia particularly. Likewise, the warm AMO‐induced circulation anomalies engender surface radiative heating and HWF growth in most of the Eurasian continent except some localized Siberian and Asian regions. The situation is opposite for a weak mega‐ENSO and AMO. Those models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) which realistically capture the features of the ID mode can reproduce the AMO‐like sea‐surface temperature anomalies (SSTAs), while signals resembling mega‐ENSO are found in those with favourable capability of simulating the IA mode. On the contrary, these relevant SSTAs linked to the respective modes vanish in the models with little skills. Thus, mega‐ENSO and the AMO might provide two critical predictability sources for heat waves over Eurasia.