bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of pH‐ and thermoresponsive poly(2‐n‐propyl‐2‐oxazoline) based copolymers
Authors: Boerman Marcel A. , Van der Laan Harry L. , Bender Johan C. M. E. , Hoogenboom Richard , Jansen John A. , Leeuwenburgh Sander C. , Van Hest Jan C. M. 
Published: January 2016

ABSTRACTPolymers that possess lower critical solution temperature behavior such as poly(2‐alkyl‐2‐oxazoline)s (PAOx) are interesting for their application as stimulus‐responsive materials, for example in the biomedical field. In this work, we discuss the scalable and controlled synthesis of a library of pH‐ and temperature‐sensitive 2‐n‐propyl‐2‐oxazoline P(nPropOx) based copolymers containing amine and carboxylic acid functionalized side chains by cationic ring opening polymerization and postpolymerization functionalization strategies. Using turbidimetry, we found that the cloud point temperature (CP) is strongly dependent on both the polymer concentration and the polymer charge (as a function of pH). Furthermore, we observed that the CP decreased with increasing salt concentration, whereas the CP increased linearly with increasing amount of carboxylic acid groups. Finally, turbidimetry studies in PBS‐buffer indicate that CPs of these polymers are close to body temperature at biologically relevant polymer concentrations, which demonstrates the potential of P(nPropOx) as stimulus‐responsive polymeric systems in, for example, drug delivery applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1573–1582
Triple hydrogen‐bonding block copolymers via RAFT polymerization: Synthesis, vesicle formation, and molecule‐recognition behavior
Authors: Wang Shixue , Li Maosheng , Zhang Hang , Yang Xinxiao , Zhang Xiaojie , Tao Youhua , Wang Xianhong 
Published: January 2016

ABSTRACTReversible addition fragmentation chain transfer polymerization afforded triple hydrogen‐bonding block copolymers (PBA‐b‐PDAD) with well‐controlled molecular weight and molecular weight distributions (1.2–1.4). The complexation via specific hydrogen bonding between these block copolymers in CHCl3 provided an unprecedented approach for the formation of spherical vesicles. Atomic force microscopy and dynamic light‐scattering measurements revealed that the resultant polymeric vesicles were about 100 nm in radius. Triple hydrogen‐bonding interactions between maleimide and PBA‐b‐PDAD resulted in the dissociation of these spherical vesicles, facilitating the guest molecule recognition. The hydrogen‐bonding interaction between maleimide and the PBA‐b‐PDAD was further confirmed by 1H NMR and FTIR spectra. These results indicated that these vesicles of triple hydrogen‐bonding block copolymer could be a potential new vehicle for molecular recognition. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1633–1638
Exploration of binding affinity and selectivity of brucine with G‐quadruplex in the c‐myb proto‐oncogene by electrospray ionization mass spectrometry
Authors: Li Huihui , Hai Jinhui , Zhou Jiang , Yuan Gu 
Published: January 2016

RationaleThe c‐myb gene is a potential therapeutic target for human tumors and leukemias. Active ingredients from natural products may be used as drugs in chemotherapy for human cancers. Here, electrospray ionization mass spectrometry (ESI‐MS) was used to probe the formation and recognition of the G‐quadruplex structure from the G‐rich sequence that is found in the c‐myb gene promoter, 5'‐GGGCTGGGCTGGGCGGGG‐3'. The aim of our study is to evaluate a potential binder for the c‐myb gene from natural products, and thereby to modulate c‐myb gene expression.MethodsESI‐MS, as an effective method, was utilized not only to characterize the formation of the G‐quadruplex in the c‐myb oncogene, but also as a tool to probe the binding characteristics of alkaloid molecules with the target G‐quadruplex DNA.ResultsESI‐MS results with the support of circular dichroism (CD) spectra demonstrated the formation of an intramolecular parallel‐stranded G‐quadruplex in the c‐myb oncogene promoter. A screening of six alkaloid molecules showed that brucine (P1) had a strong binding affinity to the c‐myb G‐quadruplex DNA. It is notable that P1 can bind selectively to the c‐myb G‐quadruplex with respect to duplex DNAs, as well as to G‐quadruplexes in other types of gene sequences. According to ESI‐MS results, in which the stability was tested by capillary heating and collision‐induced dissociation, the binding of P1 could thermally stabilize the c‐myb G‐quadruplex DNA.ConclusionsIn this work, brucine (P1), an alkaloid molecule, has been found to bind to the intramolecular parallel G‐quadruplex in the c‐myb oncogene promoter with high affinity and selectivity, and could thermally stabilize the c‐myb G‐quadruplex DNA, indicating that the binding of P1 has the potential to modulate c‐myb gene expression. Copyright © 2015 John Wiley & Sons, Ltd.
Axial spatial distribution focusing: improving MALDI‐TOF/RTOF mass spectrometric performance for high‐energy collision‐induced dissociation of biomolecules
Authors: Belgacem O. , Pittenauer E. , Openshaw M. E. , Hart P. J. , Bowdler A. , Allmaier G. 
Published: January 2016

RationaleFor the last two decades, curved field reflectron technology has been used in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometers, assisting in the generation of post‐source‐decay (PSD) or collision‐induced dissociation (CID) without decelerating precursor ions, producing true high‐energy CID spectra. The result was the generation of product ion mass spectra with product ions typical of high‐energy (10 keV and beyond) collision processes. The disadvantage of this approach was the lack of resolution in CID spectra resulting from the excess laser energy deposition used to generate those MS/MS spectra. The work presented in this study overcomes this limitation and includes comprehensive examples of high‐energy and high‐resolution CID MALDI‐MS/MS spectra of biomolecules.MethodsThe devices used in this study are TOF/RTOF instruments equipped with a high‐vacuum MALDI ion source. High‐resolution and high‐energy CID spectra result from the use of axial spatial distribution focusing (ASDF) in combination with curved field reflectron technology.ResultsA CID spectrum of the P14R1 peptide exhibits product ion resolution in excess of 10,000 (FWHM) but at the same time yields typical high‐energy product ions such as w‐ and [y–2]‐type ion series. High‐energy CID spectra of lipids, exemplified by a glycerophospholipid and triglyceride, demonstrate C–C backbone fragmentation elucidating the presence of a hydroxyl group in addition to double‐bond positioning. A complex high mannose carbohydrate (Man)8(GlcNAc)2 was also studied at 20 keV collision energy and revealed further high‐energy product ions with very high resolution, allowing unambiguous detection and characterization of cross‐ring cleavage‐related ions.ConclusionsThis is the first comprehensive study using a MALDI‐TOF/RTOF instrument equipped with a curved field reflectron and an ASDF device prior to the reflectron. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.
Cover Image, Volume 5, Issue 1
Authors: Xu Xiaofeng , Goswami Santonu , Gulledge Jay , Wullschleger Stan D. , Thornton Peter E. 
Published: January 2016

The cover image, by Xiaofeng Xu et al., is based on the Advanced Review “Interdisciplinary research in climate and energy sciences,”, DOI 10.1002/wene.180.
image
Analysis of Plasmalogen Species in Foodstuffs
Authors: Yamashita Shinji , Kanno Susumu , Honjo Ayako , Otoki Yurika , Nakagawa Kiyotaka , Kinoshita Mikio , Miyazawa Teruo 
Published: January 2016

AbstractEthanolamine plasmalogen (PlsEtn), which is present at high levels in brains, is believed to be involved in neuronal protection. The present study was performed to search for PlsEtn resources in foodstuffs. The foodstuffs examined showed a wide range of PlsEtn contents from 5 to 549 μmol/100 g wet wt. The marine invertebrates, blue mussel, and ascidian had high PlsEtn contents (over 200 μmol/100 g wet wt). Profiling of the molecular species showed that the predominant fatty acids of PlsEtn species were 20:5 (EPA) and 22:6 (DHA) at the sn‐2 position of the glycerol moiety in marine foodstuffs, whereas major PlsEtn species in land foodstuffs were 20:4. Following quantitative analysis by multiple reaction monitoring, the ascidian viscera were shown to contain the highest levels of 18:0/20:5‐PlsEtn and 18:0/22:6‐PlsEtn (86 and 68 μmol/100 g wet wt, respectively). In order to evaluate a neuronal antiapoptotic effect of these PlsEtn species, human neuroblastoma SH‐SY5Y cells were treated with ethanolamine glycerophospholipid (EtnGpl), purified from the ascidian viscera, under serum starvation conditions. Extrinsic EtnGpl from ascidian viscera showed stronger suppression of cell death induced by serum starvation than with bovine brain EtnGpl. The EtnGpl from ascidian viscera strongly suppressed the activation of caspase 3. These results suggest that PlsEtn, especially that containing EPA and DHA, from marine foodstuffs is potentially useful for a therapeutic dietary supplement preventing neurodegenerative diseases, such as Alzheimer's disease (AD).
Numerical studies on the dynamics of an open triangle in a vertically oscillatory flow
Authors: Shao Xueming , Zhang Xiaolong , Yu Zhaosheng , Lin Jianzhong 
Published: January 2016

A direct-forcing fictitious domain method is employed to study the dynamics of an open triangle in a vertically oscillatory flow. The flow structures, the vertical force and the torque on the fixed body are analysed for the stable flow regime in which the flow structures form and evolve exactly in the same way in each period and the unstable regime, respectively. Our results indicate that in the stable flow regime for the body with upright orientation, the steady streaming structure mainly comprises two vortex pairs located respectively above and below the body. Due to up–down asymmetry of the body, the pair below the body produces a larger vertical force on the body than the upper pair, which is mainly responsible for the non-zero average force at relatively high Reynolds numbers. The average force increases with increasing Reynolds number or increasing dimensionless period for the parameter range studied, due to the vortex effects. In the unstable regime, a vortex pair is ejected downward from each body edge. The irregular motion of the emitted vortices below the body leads to the irregular fluctuation of the vertical force. Regarding the torque on a tilted body, in the stable regime, the body experiences a restoring torque when its vertex angle is larger than a critical value being close to (and smaller than) 60°, and otherwise a destructive torque, irrespective of the value of tilt angle. For a fixed vertex angle, the torque magnitude is largest when the tilt angle is around 45°. In the unstable regime, the persistent ejection of the vortex pair during upward flow and corresponding restoring torque are observed for a large tilt angle with one edge aligned close to the horizontal direction, as in the experiment of Liu et al. (Phys. Rev. Lett., vol. 108, 2012, 068103). For a relatively small tilt angle, the emission direction of the vortex pair has intermittency, leading to the intermittency in the direction of torque. The reasons for the above observations are discussed. The predictions on the stable orientation for a hovering body in the stable flow regime and the irregular orientation in the unstable regime are confirmed in the dynamic simulation of a freely moving body. The body with the stable horizontal orientation in case of small vertex angle migrates along the body-shape-diverging direction.
Sex differences in language competence of 3- to 6-year-old children
Authors: LANGE BENJAMIN P. , EULER HARALD A. , ZARETSKY EUGEN 
Published: January 2016

ABSTRACTFor decades, developmental research has involved the study of sex differences in language acquisition. Many studies of these differences have found a slight advantage in competence for females early in life that seems to wane with age. However, because most of these studies have focused on sex differences in mean values, they have mostly neglected sex differences in variance with males being more variable. In the current study, we examined sex differences in language competence in terms of mean values and variance in large samples (N> 10,000) of German children aged 3–6 years. We administered several tests to assess the children's vocabulary, grammar, speech comprehension, pronunciation, and the processing of sentences and nonce words. Girls performed better than boys in all domains, most often to a statistically significant degree, although the effect sizes were small. Differences decreased with age. Boys varied significantly more than girls in their language competence. In response, we discuss explanations for these findings, as well as recommend directions for future research.
Controlling the screening process of a nanoscaled space charge region by minority carriers
Authors: Kloth Philipp , Kaiser Katharina , Wenderoth Martin 
Published: January 2016

AbstractThe miniaturization of future electronic devices is intimately connected to the ability to control electric fields on the atomic scale. In a nanoscopic system defined by a limited number of charges, the combined dynamics of bound and free charges become important. Here we present a model system based on the electrostatic interaction between a metallic tip of a scanning tunnelling microscope and a GaAs(110) semiconductor surface. The system is driven out of equilibrium by optical excitation, which provides ambipolar free charge carriers, and by an optically induced unipolar tunnel current. This combination enables the active control of the density and spatial distribution of free and bound charge in the space-charge region, that is, modifying the screening processes. Temporal fluctuations of single dopants are modified, meaning we are able to control the noise of the system. It is found that free charge carriers suppress the noise level in field-controlled, nanoscopic systems.
Mouse strains to study cold-inducible beige progenitors and beige adipocyte formation and function
Authors: Berry Daniel C. , Jiang Yuwei , Graff Jonathan M. 
Published: January 2016

AbstractCold temperatures induce formation of beige adipocytes, which convert glucose and fatty acids to heat, and may increase energy expenditure, reduce adiposity and lower blood glucose. This therapeutic potential is unrealized, hindered by a dearth of genetic tools to fate map, track and manipulate beige progenitors and ‘beiging’. Here we examined 12 Cre/inducible Cre mouse strains that mark adipocyte, muscle and mural lineages, three proposed beige origins. Among these mouse strains, only those that marked perivascular mural cells tracked the cold-induced beige lineage. Two SMA-based strains, SMA-CreERT2 and SMA-rtTA, fate mapped into the majority of cold-induced beige adipocytes and SMA-marked progenitors appeared essential for beiging. Disruption of the potential of the SMA-tracked progenitors to form beige adipocytes was accompanied by an inability to maintain body temperature and by hyperglycaemia. Thus, SMA-engineered mice may be useful to track and manipulate beige progenitors, beige adipocyte formation and function.
EPR pairing dynamics in Hubbard model with resonant U
Authors: Zhang X. Z. , Song Z. 
Published: January 2016

AbstractWe study the dynamics of the collision between two fermions in Hubbard model with on-site interaction strength U. The exact solution shows that the scattering matrix for two-wavepacket collision is separable into two independent parts, operating on spatial and spin degrees of freedom, respectively. The S-matrix for spin configuration is equivalent to that of Heisenberg-type pulsed interaction with the strength depending on U and relative group velocity vr. This can be applied to create distant EPR pair, through a collision process for two fermions with opposite spins in the case of |vr/U| = 1, without the need for temporal control and measurement process. Multiple collision process for many particles is also discussed.
Integration of genomic, transcriptomic and proteomic data identifies two biologically distinct subtypes of invasive lobular breast cancer
Authors: Michaut Magali , Chin Suet-Feung , Majewski Ian , Severson Tesa M. , Bismeijer Tycho , de Koning Leanne , Peeters Justine K. , Schouten Philip C. , Rueda Oscar M. , Bosma Astrid J. , Tarrant Finbarr , Fan Yue , He Beilei , Xue Zheng , Mittempergher Lorenza , Kluin Roelof J.C. , Heijmans Jeroen , Snel Mireille , Pereira Bernard , Schlicker Andreas , Provenzano Elena , Ali Hamid Raza , Gaber Alexander , O’Hurley Gillian , Lehn Sophie , Muris Jettie J.F. , Wesseling Jelle , Kay Elaine , Sammut Stephen John , Bardwell Helen A. , Barbet Aurélie S. , Bard Floriane , Lecerf Caroline , O’Connor Darran P. , Vis Daniël J. , Benes Cyril H. , McDermott Ultan , Garnett Mathew J. , Simon Iris M. , Jirström Karin , Dubois Thierry , Linn Sabine C. , Gallagher William M. , Wessels Lodewyk F.A. , Caldas Carlos , Bernards Rene 
Published: January 2016

AbstractInvasive lobular carcinoma (ILC) is the second most frequently occurring histological breast cancer subtype after invasive ductal carcinoma (IDC), accounting for around 10% of all breast cancers. The molecular processes that drive the development of ILC are still largely unknown. We have performed a comprehensive genomic, transcriptomic and proteomic analysis of a large ILC patient cohort and present here an integrated molecular portrait of ILC. Mutations in CDH1 and in the PI3K pathway are the most frequent molecular alterations in ILC. We identified two main subtypes of ILCs: (i) an immune related subtype with mRNA up-regulation of PD-L1, PD-1 and CTLA-4 and greater sensitivity to DNA-damaging agents in representative cell line models; (ii) a hormone related subtype, associated with Epithelial to Mesenchymal Transition (EMT) and gain of chromosomes 1q and 8q and loss of chromosome 11q. Using the somatic mutation rate and eIF4B protein level, we identified three groups with different clinical outcomes, including a group with extremely good prognosis. We provide a comprehensive overview of the molecular alterations driving ILC and have explored links with therapy response. This molecular characterization may help to tailor treatment of ILC through the application of specific targeted, chemo- and/or immune-therapies.
Variability of Action Potentials Within and Among Cardiac Cell Clusters Derived from Human Embryonic Stem Cells
Authors: Zhu Renjun , Millrod Michal A. , Zambidis Elias T. , Tung Leslie 
Published: January 2016

AbstractElectrophysiological variability in cardiomyocytes derived from pluripotent stem cells continues to be an impediment for their scientific and translational applications. We studied the variability of action potentials (APs) recorded from clusters of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using high-resolution optical mapping. Over 23,000 APs were analyzed through four parameters: APD30, APD80, triangulation and fractional repolarization. Although measures were taken to reduce variability due to cell culture conditions and rate-dependency of APs, we still observed significant variability in APs among and within the clusters. However, similar APs were found in spatial locations with close proximity and in some clusters formed distinct regions having different AP characteristics that were reflected as separate peaks in the AP parameter distributions, suggesting multiple electrophysiological phenotypes. Using a recently developed automated method to group cells based on their entire AP shape, we identified distinct regions of different phenotypes within single clusters and common phenotypes across different clusters when separating APs into 2 or 3 subpopulations. The systematic analysis of the heterogeneity and potential phenotypes of large populations of hESC-CMs can be used to evaluate strategies to improve the quality of pluripotent stem cell-derived cardiomyocytes for use in diagnostic and therapeutic applications and in drug screening.
Probing the molecular design of hyper-branched aryl polyesters towards lubricant applications
Authors: Robinson Joshua W. , Zhou Yan , Bhattacharya Priyanka , Erck Robert , Qu Jun , Bays J. Timothy , Cosimbescu Lelia 
Published: January 2016

AbstractWe report novel polymeric materials that may be used as viscosity index improvers (VII) for lubricant applications. Our efforts included probing the comb-burst hyper-branched aryl polyester architecture for beneficial viscosity and friction behavior when utilized as an additive in a group I oil. The monomer was designed as to undergo polymerization via polycondensation within the architectural construct (AB2), typical of hyperbranched polymers. The monomer design was comprised of aliphatic arms (12 or 16 methylenes) to provide the necessary lipophilicity to achieve solubility in a non-polar medium. Once polymerized, via catalyst and heat, the surface alcohols were functionalized with fatty acids (lauric and palmitic). Controlling the aliphatic nature of the internal arms and peripheral end-groups provided four unique flexible polymer designs. Changing the reaction time and concentration provided opportunities to investigate the influence of molecular weight and branching density on oil-solubility, viscosity and friction. Oil-solubility was found to decrease with fewer internal carbons, but the number of internal carbons appears to have little influence on the bulk solution viscosity. At concentrations of 2 wt % in a group I base oil, these polymer additives demonstrated an improved viscosity index and reduced friction coefficient, validating the basic approach.
Mercury Isotopes as Proxies to Identify Sources and Environmental Impacts of Mercury in Sphalerites
Authors: Yin Runsheng , Feng Xinbin , Hurley James P. , Krabbenhoft David P. , Lepak Ryan F. , Hu Ruizhong , Zhang Qian , Li Zhonggen , Bi Xianwu 
Published: January 2016

AbstractDuring the past few years, evidence of mass independent fractionation (MIF) for mercury (Hg) isotopes have been reported in the Earth’s surface reservoirs, mainly assumed to be formed during photochemical processes. However, the magnitude of Hg-MIF in interior pools of the crust is largely unknown. Here, we reported significant variation in Hg-MIF signature (Δ199Hg: −0.24 ~ + 0.18‰) in sphalerites collected from 102 zinc (Zn) deposits in China, indicating that Hg-MIF can be recorded into the Earth’s crust during geological recycling of crustal material. Changing magnitudes of Hg-MIF signals were observed in Zn deposits with different formations, evidence that Hg isotopes (especially Hg-MIF) can be a useful tracer to identify sources (syngenetic and epigenetic) of Hg in mineral deposits. The average isotopic composition in studied sphalerites (δ202Hgaverage: −0.58‰; Δ199Hgaverage: +0.03‰) may be used to fingerprint Zn smelting activities, one of the largest global Hg emission sources.