bluuebunny/crossref_metadata_2025_split huggingface dataset:
Practical Integration‐Free Episomal Methods for Generating Human Induced Pluripotent Stem Cells
Authors: Kime Cody , Rand Tim A. , Ivey Kathryn N. , Srivastava Deepak , Yamanaka Shinya , Tomoda Kiichiro 
Published: October 2015

AbstractThe advent of induced pluripotent stem (iPS) cell technology has revolutionized biomedicine and basic research by yielding cells with embryonic stem (ES) cell‐like properties. The use of iPS‐derived cells for cell‐based therapies and modeling of human disease holds great potential. While the initial description of iPS cells involved overexpression of four transcription factors via viral vectors that integrated within genomic DNA, advances in recent years by our group and others have led to safer and higher quality iPS cells with greater efficiency. Here, we describe commonly practiced methods for non‐integrating induced pluripotent stem cell generation using nucleofection of episomal reprogramming plasmids. These methods are adapted from recent studies that demonstrate increased hiPS cell reprogramming efficacy with the application of three powerful episomal hiPS cell reprogramming factor vectors and the inclusion of an accessory vector expressing EBNA1. © 2015 by John Wiley & Sons, Inc.
Chemically Defined Culture and Cardiomyocyte Differentiation of Human Pluripotent Stem Cells
Authors: Burridge Paul W. , Holmström Alexandra , Wu Joseph C. 
Published: October 2015

AbstractSince the first discovery that human pluripotent stem cells (hPS cells) can differentiate to cardiomyocytes, efforts have been made to optimize the conditions under which this process occurs. One of the most effective methodologies to optimize this process is reductionist simplification of the medium formula, which eliminates complex animal‐derived components to help reveal the precise underlying mechanisms. Here we describe our latest, cost‐effective and efficient methodology for the culture of hPS cells in the pluripotent state using a modified variant of chemically defined E8 medium. We provide exact guidelines for cell handling under these conditions, including non‐enzymatic EDTA passaging, which have been optimized for subsequent cardiomyocyte differentiation. We describe in depth the latest version of our monolayer chemically defined small molecule differentiation protocol, including metabolic selection–based cardiomyocyte purification and the addition of triiodothyronine to enhance cardiomyocyte maturation. Finally, we describe a method for the dissociation of hPS cell–derived cardiomyocytes, cryopreservation, and thawing. © 2015 by John Wiley & Sons, Inc.
Foehn winds link climate‐driven warming to ice shelf evolution in Antarctica
Authors: Cape M. R. , Vernet Maria , Skvarca Pedro , Marinsek Sebastián , Scambos Ted , Domack Eugene 
Published: October 2015

AbstractRapid warming of the Antarctic Peninsula over the past several decades has led to extensive surface melting on its eastern side, and the disintegration of the Prince Gustav, Larsen A, and Larsen B ice shelves. The warming trend has been attributed to strengthening of circumpolar westerlies resulting from a positive trend in the Southern Annular Mode (SAM), which is thought to promote more frequent warm, dry, downsloping foehn winds along the lee, or eastern side, of the peninsula. We examined variability in foehn frequency and its relationship to temperature and patterns of synoptic‐scale circulation using a multidecadal meteorological record from the Argentine station Matienzo, located between the Larsen A and B embayments. This record was further augmented with a network of six weather stations installed under the U.S. NSF LARsen Ice Shelf System, Antarctica, project. Significant warming was observed in all seasons at Matienzo, with the largest seasonal increase occurring in austral winter (+3.71°C between 1962–1972 and 1999–2010). Frequency and duration of foehn events were found to strongly influence regional temperature variability over hourly to seasonal time scales. Surface temperature and foehn winds were also sensitive to climate variability, with both variables exhibiting strong, positive correlations with the SAM index. Concomitant positive trends in foehn frequency, temperature, and SAM are present during austral summer, with sustained foehn events consistently associated with surface melting across the ice sheet and ice shelves. These observations support the notion that increased foehn frequency played a critical role in precipitating the collapse of the Larsen B ice shelf.
Intercomparison of methods of coupling between convection and large‐scale circulation: 1. Comparison over uniform surface conditions
Authors: Daleu C. L. , Plant R. S. , Woolnough S. J. , Sessions S. , Herman M. J. , Sobel A. , Wang S. , Kim D. , Cheng A. , Bellon G. , Peyrille P. , Ferry F. , Siebesma P. , van Ulft L. 
Published: October 2015

AbstractAs part of an international intercomparison project, a set of single‐column models (SCMs) and cloud‐resolving models (CRMs) are run under the weak‐temperature gradient (WTG) method and the damped gravity wave (DGW) method. For each model, the implementation of the WTG or DGW method involves a simulated column which is coupled to a reference state defined with profiles obtained from the same model in radiative‐convective equilibrium. The simulated column has the same surface conditions as the reference state and is initialized with profiles from the reference state. We performed systematic comparison of the behavior of different models under a consistent implementation of the WTG method and the DGW method and systematic comparison of the WTG and DGW methods in models with different physics and numerics. CRMs and SCMs produce a variety of behaviors under both WTG and DGW methods. Some of the models reproduce the reference state while others sustain a large‐scale circulation which results in either substantially lower or higher precipitation compared to the value of the reference state. CRMs show a fairly linear relationship between precipitation and circulation strength. SCMs display a wider range of behaviors than CRMs. Some SCMs under the WTG method produce zero precipitation. Within an individual SCM, a DGW simulation and a corresponding WTG simulation can produce different signed circulation. When initialized with a dry troposphere, DGW simulations always result in a precipitating equilibrium state. The greatest sensitivities to the initial moisture conditions occur for multiple stable equilibria in some WTG simulations, corresponding to either a dry equilibrium state when initialized as dry or a precipitating equilibrium state when initialized as moist. Multiple equilibria are seen in more WTG simulations for higher SST. In some models, the existence of multiple equilibria is sensitive to some parameters in the WTG calculations.
Mixed norm regularized recursive total least squares for group sparse system identification
Authors: Lim Jun‐seok , Pang Hee‐Suk 
Published: October 2015

SummaryA mixed lp,0‐regularized recursive total least squares (RTLS) algorithm is considered for group sparse system identification. Regularized recursive least squares (RLS) has been successfully applied to group sparse system identification; however, the estimation performance in regularized RLS‐based algorithms deteriorates when both input and output are contaminated by noise (the error‐in‐variables problem). We propose an lp,0‐RTLS algorithm to handle group sparse system identification with errors‐in‐variables. The proposed algorithm is an RLS‐like solution that utilizes lp,0‐regularization. The proposed algorithm provides excellent performance as well as reduces the required complexity by effective inversion matrix handling. Simulations demonstrate the superiority of the proposed lp,0‐regularized RTLS for a group sparse system identification setting. Copyright © 2015 John Wiley & Sons, Ltd.
Microneedles for Transdermal Biosensing: Current Picture and Future Direction
Authors: Ventrelli Letizia , Marsilio Strambini Lucanos , Barillaro Giuseppe 
Published: October 2015

A novel trend is rapidly emerging in the use of microneedles, which are a miniaturized replica of hypodermic needles with length‐scales of hundreds of micrometers, aimed at the transdermal biosensing of analytes of clinical interest, e.g., glucose, biomarkers, and others. Transdermal biosensing via microneedles offers remarkable opportunities for moving biosensing technologies and biochips from research laboratories to real‐field applications, and envisages easy‐to‐use point‐of‐care microdevices with pain‐free, minimally invasive, and minimal‐training features that are very attractive for both developed and emerging countries. In addition to this, microneedles for transdermal biosensing offer a unique possibility for the development of biochips provided with end‐effectors for their interaction with the biological system under investigation. Direct and efficient collection of the biological sample to be analyzed will then become feasible in situ at the same length‐scale of the other biochip components by minimally trained personnel and in a minimally invasive fashion. This would eliminate the need for blood extraction using hypodermic needles and reduce, in turn, related problems, such as patient infections, sample contaminations, analysis artifacts, etc.The aim here is to provide a thorough and critical analysis of state‐of‐the‐art developments in this novel research trend, and to bridge the gap between microneedles and biosensors.
Regulatory Mechanism of the Enantioselective Intramolecular Enone [2+2] Photocycloaddition Reaction Mediated by a Chiral Lewis Acid Catalyst Containing Heavy Atoms
Authors: Wang Hongjuan , Cao Xiaoyan , Chen Xuebo , Fang Weihai , Dolg Michael 
Published: October 2015

AbstractThe asymmetric catalysis of the intramolecular enone [2+2] photocycloaddition has been subject of extensive experimental studies, however theoretical insight to its regulatory mechanism is still sparse. Accurate quantum chemical calculations at the CASPT2//CASSCF level of theory associated with energy‐consistent relativistic pseudopotentials provide a basis for the first regulation theory that the enantioselective reaction is predominantly controlled by the presence of relativistic effects, that is, spin–orbit coupling resulting from heavy atoms in the chiral Lewis acid catalyst.
Metallic Co4N Porous Nanowire Arrays Activated by Surface Oxidation as Electrocatalysts for the Oxygen Evolution Reaction
Authors: Chen Pengzuo , Xu Kun , Fang Zhiwei , Tong Yun , Wu Junchi , Lu Xiuli , Peng Xu , Ding Hui , Wu Changzheng , Xie Yi 
Published: October 2015

AbstractDesigning highly efficient electrocatalysts for oxygen evolution reaction (OER) plays a key role in the development of various renewable energy storage and conversion devices. In this work, we developed metallic Co4N porous nanowire arrays directly grown on flexible substrates as highly active OER electrocatalysts for the first time. Benefiting from the collaborative advantages of metallic character, 1D porous nanowire arrays, and unique 3D electrode configuration, surface oxidation activated Co4N porous nanowire arrays/carbon cloth achieved an extremely small overpotential of 257 mV at a current density of 10 mA cm−2, and a low Tafel slope of 44 mV dec−1 in an alkaline medium, which is the best OER performance among reported Co‐based electrocatalysts to date. Moreover, in‐depth mechanistic investigations demonstrate the active phases are the metallic Co4N core inside with a thin cobalt oxides/hydroxides shell during the OER process. Our finding introduces a new concept to explore the design of high‐efficiency OER electrocatalysts.
Nitrene Insertion into CC and CH Bonds of Diamide Diimine Ligands Ligated to Chromium and Iron
Authors: Heins Spencer P. , Morris Wesley D. , Wolczanski Peter T. , Lobkovsky Emil B. , Cundari Thomas R. 
Published: October 2015

AbstractThe impact of redox non‐innocence (RNI) on chemical reactivity is a forefront theme in coordination chemistry. A diamide diimine ligand, [{‐CHN(1,2‐C6H4)NH(2,6‐iPr2C6H3)}2]n (n=0 to −4), (dadi)n, chelates Cr and Fe to give [(dadi)M] ([1Cr(thf)] and [1Fe]). Calculations show [1Cr(thf)] (and [1Cr]) to have a d4 Cr configuration antiferromagnetically coupled to (dadi)2−*, and [1Fe] to be S=2. Treatment with RN3 provides products where RN is formally inserted into the CC bond of the diimine or into a CH bond of the diimine. Calculations on the process support a mechanism in which a transient imide (imidyl) aziridinates the diimine, which subsequently ring opens.
Particle number and size of polystyrene‐dependent micellar crosslinking polymerization of acrylic acid
Authors: Kim Byungsoo , Hong Daesun , Chang Wenji V. 
Published: October 2015

ABSTRACTThe effect of the number and size of polystyrene particles and the concentration of ammonium persulfate used as the initiator on the micellar crosslinking polymerization of acrylic acid was studied by real‐time monitoring of the storage modulus (G ′), the damping factor (tanδ), and the ratio of the complex modulus (G*) to the maximumG* (G*max) during 1 h of polymerization. The molar ratio (5.83 × 10−4) ofN,N′‐methylenebis‐acrylamide to acrylic acid was fixed. Polystyrene particles were prepared by emulsifier‐free emulsion polymerization. The diameter of the particles ranged from 233 to 696 nm. The results show that crosslinking polymerization was most effective when 1.31 × 1012particles were incorporated into the system, while crosslinking polymerization was less effective in the particle‐filled system than in the unfilled polymerization system if the particle number was 50% lower or higher. Crosslinking was also more effective with the use of uncrosslinked firmer and larger particles at the fixed particle number, except for the anomalous behavior observed with 696 nm polystyrene particles. Increasing the feed concentration of the initiator resulted in more efficient crosslinking up to a limiting concentration of 0.765 mg mL−1(the molar ratio of initiator to monomer was 8.52 × 10−4). When this initiator concentration was doubled, the rate of increase ofG ′ in the deceleration phase was slower after the network was formed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 42851.
Mechanical behavior and failure analysis of recycled polymers by use of miniature punch specimens
Authors: Cuesta Isidro Ivan , Alegre Jesus Manuel , Rodríguez Cristina 
Published: October 2015

ABSTRACTIn today's society, recycling is a priority, and using recycled materials to obtain new 100% reusable materials is an important aspect of some manufacturing sectors. Clearly, the mechanical properties of these new materials can vary considerably from the original material, so it is necessary to carry out a complete mechanical characterization to know its behavior for both standard specimens and final components. One of the common drawbacks is the inability to extract standard size specimens from a final component with a reduced size. In this paper, the use of the small punch test is proposed as a means of solving this problem. At present, this test is used for estimating mechanical properties in those cases when there is not a sufficient amount of material to perform standard tests. The main purpose of this paper is to analyse the feasibility of using miniature punch specimens for the mechanical characterization of recycled polymers. The results are compared with those obtained from standard uniaxial tensile specimens, and a corresponding correlation between the two tests is established. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 42911.
Influence of the coupling agent and graphene oxide on the thermal and mechanical behavior of tea dust–polypropylene composites
Authors: Bari Pravin , Lanjewar Shital , Hansora Dharmesh Parshottam , Mishra Satyendra 
Published: October 2015

ABSTRACTIn this study, the effects of a coupling agent and additive on the physicomechanical (morphological, mechanical, thermal, and swelling) properties of tea dust (TD)–polypropylene (PP) composites were studied. TD–PP composites were prepared with untreated tea dust (UTD) and tetraethylsilane (TES)‐treated TD or silanated tea dust (STD) particles at ratios of 0:100, 10:90, 20:80, 30:70, and 40:60 w/w. Initially, TD particles were grafted by TES as a coupling agent, and these STD particles were then modified with graphene oxide (GO) as an additive to study their effects on the STD–PP composites; these were compared to the STD–PP and UTD–PP composites in accordance with a study of improvements in the mechanical properties. All of the TD–PP composites were analyzed with Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical, thermal, and physical tests. The thermal and mechanical properties of both the STD–PP and GO‐modified STD–PP composites were found to be improved as compared to those of the UTD–PP composites. So, the recycling of a large amount of TD as a waste material could be useful in the preparation of TD–PP composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42927.
Enhanced Electrochemical Performance of Zr‐Modified Layered LiNi1/3Co1/3Mn1/3O2 Cathode Material for Lithium‐Ion Batteries
Authors: Li Xing , Peng Hui , Wang Ming‐Shan , Zhao Xing , Huang Peng‐Xiao , Yang Wei , Xu Jun , Wang Zhi‐Qiang , Qu Mei‐Zhen , Yu Zuo‐Long 
Published: October 2015

AbstractZr‐modified LiNi1/3Co1/3Mn1/3−xZrxO2 samples were prepared through a rheological‐phase method. The results indicate that there is only partial Zr doping into the bulk phase of the LiNi1/3Co1/3Mn1/3O2 particles, whereas the rest of the Zr remained on the surface to form a Li2ZrO3 coating layer during the Zr‐modification process. The Zr‐modified LiNi1/3Co1/3Mn1/3−xZrxO2 samples show lower discharge specific capacities at low rates, however, which exhibit clearly improved rate capabilities than that of pristine LiNi1/3Co1/3Mn1/3O2. Among the Zr‐modified LiNi1/3Co1/3Mn1/3−xZrxO2 samples, LiNi1/3Co1/3Mn1/3−0.01Zr0.01O2 (x=0.01) shows the best rate capability, which exhibts158, 142, and 132 mAh g−1 at 1.0, 2.0, and 3.0 C, respectively. The related results indicate that the doped Zr in pristine LiNi1/3Co1/3Mn1/3O2 could improve the structure stability and the formation of an inactive Li2ZrO3 coating layer which could suppress the interfacial side reaction of LiNi1/3Co1/3Mn1/3O2.
Ruthenium‐Grafted Vinylhelicenes: Chiroptical Properties and Redox Switching
Authors: Srebro Monika , Anger Emmanuel , Moore II Barry , Vanthuyne Nicolas , Roussel Christian , Réau Régis , Autschbach Jochen , Crassous Jeanne 
Published: October 2015

AbstractThe properties of mono‐ and bis‐Ru–vinyl[6]helicene complexes (2 a and 2 b, respectively), recently synthesized by using molecular engineering of helicenes based on the grafting of lateral organometallic substituents on the π‐helical backbone through a vinyl bridge, are presented. These helicene derivatives are thoroughly characterized, with special attention given to their chiroptical properties and redox switching activity. The UV/Vis and electronic circular dichroism (ECD) spectra of P and M enantiopure species, both in the neutral and oxidized states ([2 a].+, [2 b].+, and [2 b]2+), are analyzed with the aid of quantum‐chemical calculations. The extended π‐conjugation facilitated by the vinyl moiety, clearly visible in the electronic structures of 2 a,b, introduces new active bands in the ECD spectra that consequently lead to a significant increase in optical rotation of Ru–vinylhelicenes compared with the organic precursors. The vibrational circular dichroism (VCD) spectra were measured and calculated for both the organic and organometallic species and constitute the first examples of VCD for metal‐based helicene derivatives. Finally, the redox‐triggered chiroptical switching activity of 2 a,b is examined in detail by using ECD spectroscopy. The modifications of the ECD spectra in the UV/Vis and NIR region are well reproduced and rationalized by calculations.
2‐Aminoethanol Extraction as a Method for Purifying Sc3N@C80 and for Differentiating Classes of Endohedral Fullerenes on the Basis of Reactivity
Authors: Sarina Evan A. , Mercado Brandon Q. , Franco Jimmy U. , Thompson Christopher J. , Easterling Michael L. , Olmstead Marilyn M. , Balch Alan L. 
Published: October 2015

AbstractExtraction with 2‐aminoethanol is an inexpensive method for removing empty cage fullerenes from the soluble extract from electric‐arc‐generated fullerene soot that contains endohedral metallofullerenes of the type Sc3N@C2n (n=34, 39, 40). Our method of separation exploits the fact that C60, C70, and other larger, empty cage fullerenes are more susceptible to nucleophilic attack than endohedral fullerenes and that these adducts can be readily extracted into 2‐aminoethanol. This methodology has also been employed to examine the reactivity of the mixture of soluble endohedral fullerenes that result from doping graphite rods used in the Krätschmer–Huffman electric‐arc generator with the oxides of Y, Lu, Dy, Tb, and Gd. For example, with Y2O3, we were able to detect by mass spectrometry several new families of endohedral fullerenes, namely Y3C108 to Y3C126, Y3C107 to Y3C125, Y4C128 to Y4C146, that resisted reactivity with 2‐aminoethanol more than the empty cage fullerenes and the mono‐ and dimetallo fullerenes. The discovery of the family Y3C107 to Y3C125 with odd numbers of carbon atoms is remarkable, since fullerene cages must involve even numbers of carbon atoms. The newly discovered families of endohedral fullerenes with the composition M4C2n (M=Y, Lu, Dy, Tb, and Gd) are unusually resistant to reaction with 2‐aminoethanol. Additionally, the individual endohedrals, Y3C112 and M3C102 (M=Lu, Dy, Tb and Gd), were remarkably less reactive toward 2‐aminoethanol.
A Straightforward Route to Potent Phenolic Chain‐Breaking Antioxidants by Acid‐Promoted Transposition of 1,4‐Benzo[b]oxathiines to Dihydrobenzo[b]thiophenes
Authors: Viglianisi Caterina , Amorati Riccardo , Di Pietro Leonardo , Menichetti Stefano 
Published: October 2015

AbstractThe transformation of simple phenols with limited antioxidant activity into potent chain‐breaking antioxidants was achieved by a three‐step protocol, consisting of the conversion of phenols into 1,4‐benzo[b]oxathiines followed by an unprecedented acid‐promoted transposition to o‐hydroxydihydrobenzo[b]thiophenes, or dihydrobenzo[de]thiochromenes, starting from phenols or naphthols, respectively. These derivatives, bearing a benzo‐fused heterocycle with a sulfide sulfur ortho to the phenolic OH, have a rate constant of reaction with alkylperoxyl radicals (kinh) comparable to that of α‐tocopherol. A solid rationale for the transposition mechanism as well as for the structure‐antioxidant activity relationship is presented.
Efficient Chemical Modification of Carbon Nanotubes with Metallacarboranes
Authors: Cabana Laura , González‐Campo Arántzazu , Ke Xiaoxing , Van Tendeloo Gustaaf , Núñez Rosario , Tobias Gerard 
Published: October 2015

AbstractAs‐produced single‐walled carbon nanotubes (SWCNTs) tend to aggregate in bundles due to π–π interactions. Several approaches are nowadays available to debundle, at least partially, the nanotubes through surface modification by both covalent and noncovalent approaches. Herein, we explore different strategies to afford an efficient covalent functionalization of SWCNTs with cobaltabisdicarbollide anions. Aberration‐corrected HRTEM analysis reveals the presence of metallacarboranes along the walls of the SWCNTs. This new family of materials presents an outstanding water dispersibility that facilitates its processability for potential applications.