bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel 3D Hybrid Nanofiber Aerogels Coupled with BMP‐2 Peptides for Cranial Bone Regeneration
Authors: Weng Lin , Boda Sunil Kumar , Wang Hongjun , Teusink Matthew J. , Shuler Franklin D. , Xie Jingwei 
Published: March 2018

AbstractAn ideal synthetic bone graft is a combination of the porous and nanofibrous structure presented by natural bone tissue as well as osteoinductive biochemical factors such as bone morphogenetic protein 2 (BMP‐2). In this work, ultralight 3D hybrid nanofiber aerogels composed of electrospun PLGA‐collagen‐gelatin and Sr–Cu codoped bioactive glass fibers with incorporation of heptaglutamate E7 domain specific BMP‐2 peptides have been developed and evaluated for their potential in cranial bone defect healing. The nanofiber aerogels are surgically implanted into 8 mm × 1 mm (diameter × thickness) critical‐sized defects created in rat calvariae. A sustained release of E7‐BMP‐2 peptide from the degradable hybrid aerogels significantly enhances bone healing and defect closure over 8 weeks in comparison to unfilled defects. Histomorphometry and X‐ray microcomputed tomography (µ‐CT) analysis reveal greater bone volume and bone formation area in case of the E7‐BMP‐2 peptide loaded hybrid nanofiber aerogels. Further, histopathology data divulged a near complete nanofiber aerogel degradation along with enhanced vascularization of the regenerated tissue. Together, this study for the first time demonstrates the fabrication of 3D hybrid nanofiber aerogels from 2D electrospun fibers and their loading with therapeutic osteoinductive BMP‐2 mimicking peptide for cranial bone tissue regeneration.
Dynamic and Tunable Threshold Voltage in Organic Electrochemical Transistors
Authors: Doris Sean E. , Pierre Adrien , Street Robert A. 
Published: March 2018

AbstractIn recent years, organic electrochemical transistors (OECTs) have found applications in chemical and biological sensing and interfacing, neuromorphic computing, digital logic, and printed electronics. However, the incorporation of OECTs in practical electronic circuits is limited by the relative lack of control over their threshold voltage, which is important for controlling the power consumption and noise margin in complementary and unipolar circuits. Here, the threshold voltage of OECTs is precisely tuned over a range of more than 1 V by chemically controlling the electrochemical potential at the gate electrode. This threshold voltage tunability is exploited to prepare inverters and amplifiers with improved noise margin and gain, respectively. By coupling the gate electrode with an electrochemical oscillator, single‐transistor oscillators based on OECTs with dynamic time‐varying threshold voltages are prepared. This work highlights the importance of electrochemistry at the gate electrode in determining the electrical properties of OECTs, and opens a path toward the system‐level design of low‐power OECT‐based electronics.
Optical and Thermal Switching of Liquid Crystals for Self‐Shading Windows
Authors: Oh Seung‐Won , Kim Sang‐Hyeok , Baek Jong‐Min , Yoon Tae‐Hoon 
Published: March 2018

AbstractA liquid crystal light shutter whose transmittance can be controlled by ambient conditions, such as incident solar UV intensity and outdoor temperature, is demonstrated. Self‐shading by optical or thermal switching between transparent and opaque states is achieved by liquid crystals doped with push–pull azobenzene and can be used for energy‐saving smart windows. The self‐shading light shutter is transparent during cool weather or under weak sunlight, which could save the energy used for heating and lighting, and can be switched from transparent to opaque during warm weather or under strong sunlight, saving energy used for cooling.
Bipolar Membranes Inhibit Product Crossover in CO2 Electrolysis Cells
Authors: Li Yuguang C. , Yan Zhifei , Hitt Jeremy , Wycisk Ryszard , Pintauro Peter N. , Mallouk Thomas E. 
Published: March 2018

AbstractAs electrocatalysts and electrolyzer designs for CO2 reduction continue to improve in terms of current density and product selectivity, product crossover from the cathode to the anode is a loss mechanism that is relatively unexplored. The crossover rates of formate, methanol, and ethanol, which are desirable CO2 reduction products, are compared in electrolyzers containing anion‐exchange membranes and bipolar membranes. The crossover of formate, an anionic CO2 reduction product, occurs by electromigration through anion‐exchange membranes, and its rate increases linearly with current density. Crossover of electroneutral methanol or ethanol through anion‐exchange membranes occurs to a lesser extent through both diffusion and electroosmotic drag, the latter increasing with current density in anion‐exchange membranes. In contrast, the outward fluxes of protons and hydroxide ions generated in bipolar membranes inhibit the crossover of both anionic and neutral products, even with membranes that contain high surface area junctions. Calculated electroosmotic drag coefficients for each of the neutral products confirm the better performance of bipolar membranes in terms of product losses.
Quantum Magnetic Properties in Perovskite with Anderson Localized Artificial Spin‐1/2
Authors: Gunasekera Jagath , Dahal Ashutosh , Chen Yiyao , Rodriguez‐Rivera Jose A. , Harriger Leland W. , Thomas Stefan , Heitmann Thomas W. , Dugaev Vitalii , Ernst Arthur , Singh Deepak K. 
Published: March 2018

AbstractQuantum magnetic properties in a geometrically frustrated lattice of spin‐1/2 magnet, such as quantum spin liquid or solid and the associated spin fractionalization, are considered key in developing a new phase of matter. The feasibility of observing the quantum magnetic properties, usually found in geometrically frustrated lattice of spin‐1/2 magnet, in a perovskite material with controlled disorder is demonstrated. It is found that the controlled chemical disorder, due to the chemical substitution of Ru ions by Co‐ions, in a simple perovskite CaRuO3 creates a random prototype configuration of artificial spin‐1/2 that forms dimer pairs between the nearest and further away ions. The localization of the Co impurity in the Ru matrix is analyzed using the Anderson localization formulation. The dimers of artificial spin‐1/2, due to the localization of Co impurities, exhibit singlet‐to‐triplet excitation at low temperature without any ordered spin correlation. The localized gapped excitation evolves into a gapless quasi‐continuum as dimer pairs break and create freely fluctuating fractionalized spins at high temperature. Together, these properties hint at a new quantum magnetic state with strong resemblance to the resonance valence bond system.
First line treatment of aplastic anemia with thymoglobuline in Europe and Asia: Outcome of 955 patients treated 2001‐2012
Authors: Bacigalupo Andrea , Oneto Rosi , Schrezenmeier Hubert , Hochsmann Britta , Dufour Carlo , Kojima Seiji , Zhu Xiaofan , Chen Xiaojuan , Issaragrisil Surapol , Chuncharunee Suporn , Jeong Dae Chul , Giammarco Sabrina , Van Lint Maria Teresa , Zheng Yizhou , Vallejo Carlos 
Published: March 2018

AbstractThe aim of this study was to assess the outcome of patients with aplastic anemia (AA), receiving rabbit anti‐thymocyte globulin (Thymoglobulin, SANOFI) and cyclosporin, as first line treatment. Eligible were 955 patients with AA, treated first line with Thymoglobulin, between 2001 and 2008 (n = 492), or between 2009 and 2012 (n = 463). The median age of the patients was 21 years (range 1‐84). Mortality within 90 days was 5.7% and 2.4%, respectively in the two time periods (P = .007).The actuarial 10‐year survival for the entire population was 70%; transplant free survival was 64%. Predictors of survival in multivariate analysis, were severity of the disease, patients age and the interval between diagnosis and treatment. Survival was 87% vs 61% for responders at 6 months versus nonresponders (P < .0001). The 10‐year survival of nonresponders at 6 months, undergoing a subsequent transplant (n = 110), was 64%, vs 60% for patient not transplantated (n = 266) (P = .1). The cumulative incidence of response was 37%, 52%, 65% respectively, at 90, 180, and 365 days. In multivariate analysis, negative predictors of response at 6 months, were older age, longer interval diagnosis treatment, and greater severity of the disease. In conclusion, early mortality is low after first line treatment of AA with Thymoglobulin, and has been further reduced after year 2008. Patients age, together with interval diagnosis—treament and severity of the disease, remain strong predictors of response and survival.
Eco‐Friendly Selenoamidation of Alkenes with Sulfamides and Organoseleniums: Rapid access to β‐Amidoselenides
Authors: Liu Yingjie , Li Changhao , Mu Shiqiang , Li Yali , Feng Ranran , Sun Kai 
Published: March 2018

AbstractAn eco‐friendly method has been developed for the 1,2‐selenoamidation of alkenes under metal‐free conditions. The reaction avoids the need for pre‐prepared Se−N regents, providing facile access to a variety of β‐amidoselenides with good regioselectivity and functional group tolerance. The broad substrate scope, good regioselectivity and easy derivation make this reaction attractive for the synthesis of nitrogen‐ and selenium‐containing molecules.
Soft–Hard Acid–Base‐Controlled C−H Trifluoroethoxylation and Trideuteriomethoxylation of Anilides
Authors: Maiti Saikat , Alam Toufique , Mal Prasenjit 
Published: March 2018

AbstractPhenyliodinetrifluoroacetate (PIFA)‐mediated dehydrogenative C−H etherification of anilides is reported for the synthesis of ‐OCH2CF3 and ‐OCD3 incorporated aryl ethers. Nucleophilicity of the added nucleophiles and soft–hard acid–base (SHAB) principle were rationalized to understand those reactions. Anilides and PIFA led to the electrophiles either softer nitrenium ions or harder carbenium ions. The harder nucleophile alcohols exclusively reacted with the carbenium ions to produce aryl ethers.
Heterobimetallic Lanthanide–Sodium Alkoxides Catalyze the Amidation of Esters
Authors: Li Zhao , Wang Chao , Wang Yaorong , Yuan Dan , Yao Yingming 
Published: March 2018

AbstractHeterobimetallic lanthanide–sodium alkoxides Ln2Na8(OCH2CF3)14(THF)6 catalyzed the reaction of esters and amines to produce amides in up to 99 % yields. They showed high catalytic activity for a wide scope of substrates under solvent‐free conditions. The cooperation of lanthanum and sodium alkoxide is proposed to account for the good activity.
The mechanism of blood flow during chest compressions for cardiac arrest is probably influenced by the patient's chest configuration
Authors: Ewy Gordon A. 
Published: March 2018

AimMechanical assist devices are sometimes needed during resuscitation efforts of patients with prolonged cardiac arrest. Two such devices, the AutoPulse and the LUCAS, have different mechanisms of action. We propose that the effectiveness of mechanical assist devices is somewhat dependent on the configuration and compliance of the patient's chest wall.MethodsA previous study of patients with out‐of‐hospital cardiac arrest in Arizona reported that survivors were younger and many were observed to have narrow anterior–posterior chest diameters. These observations suggest that the predominant mechanism of blood flow during cardiopulmonary resuscitation of individuals with primary cardiac arrest is influenced by the patient's anterior–posterior chest diameter and compliance. It is proposed that in older individuals with an increased anterior–posterior chest diameter and decreased chest compliance that the AutoPulse, which works by increasing intrathoracic pressures, may be more effective. In contrast, the LUCAS device, which works predominately by compression of the sternum, is probably more effective in patients with narrower anterior–posterior diameters and a more compliant chest.ResultsThese hypotheses need to be confirmed by researchers who not only have access to the lateral chest roentgenograms of patients with cardiac arrest, to determine their anterior–posterior chest diameter, but also to the type of mechanical device that was used during resuscitation efforts and their patient's survival. If the observations herein proposed are confirmed, hospitals and paramedics may ideally need to have one of each type of mechanical chest compression unit and select the one to use depending on the patient's age and anterior–posterior chest diameter.ConclusionsThe mechanism of blood flow in patients with cardiac arrest is predominantly secondary to cardiac compression in younger patients with narrow anterior chest diameters and predominately secondary to the thoracic pump mechanism in older patients with emphysema.
Electrochemical Oxidative C−H Amination of Phenols: Access to Triarylamine Derivatives
Authors: Tang Shan , Wang Siyuan , Liu Yichang , Cong Hengjiang , Lei Aiwen 
Published: March 2018

AbstractDehydrogenative C−H/N−H cross‐coupling serves as one of the most straightforward and atom‐economical approaches for C−N bond formation. In this work, an electrochemical reaction protocol has been developed for the oxidative C−H amination of unprotected phenols under undivided electrolytic conditions. Neither metal catalysts nor chemical oxidants are needed to facilitate the dehydrogenation process. A series of triarylamine derivatives could be obtained with good functional‐group tolerance. The electrolysis is scalable and can be performed at ambient conditions.
Allosterically Activated Protein Self‐Assembly for the Construction of Helical Microfilaments with Tunable Helicity
Authors: Xu Miaomiao , Liu Lianxiao , Yan Qiang 
Published: March 2018

AbstractProtein allostery, a chemical‐to‐mechanical effect that can precisely regulate protein structure, exists in many proteins. Herein, we demonstrate that protein allostery can be used to drive self‐assembly for the construction of tunable protein architectures. Calmodulin (CaM) was chosen as a model allosteric protein. Ca2+‐mediated contraction of CaM to a closed state can activate CaM and its ligand to self‐assemble into a 1D protein helical microfilament. Conversely, relaxation of CaM to the open state can unwind and further dissociate the helical assemblies. Fine regulation of the protein conformation by tuning the external Ca2+ level allows us to obtain various protein helical nanostructures with tunable helicity. This study offers a new approach toward chemomechanically controlled protein self‐assembly.
Synthesis, Characterization, and Reactivity of Cationic Gold Diarylallenylidene Complexes
Authors: Kim Nana , Widenhoefer Ross A. 
Published: March 2018

AbstractMethoxide abstraction from gold acetylide complexes of the form (L)Au[η1‐C≡CC(OMe)ArAr′] (L=IPr, P(tBu)2(ortho‐biphenyl); Ar/Ar′=C6H4X where X=H, Cl, Me, OMe) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) at −78 °C resulted in the formation of the corresponding cationic gold diarylallenylidene complexes [(L)Au=C=C=CArAr′]+ OTf− in ≥85±5 % yield according to 1H NMR analysis. 13C NMR and IR spectroscopic analysis of these complexes established the arene‐dependent delocalization of positive charge on both the C1 and C3 allenylidene carbon atoms. The diphenylallenylidene complex [(IPr)Au=C=C=CPh2]+ OTf− reacted with heteroatom nucleophiles at the allenylidene C1 and/or C3 carbon atom.
Halogen‐Bond‐Mediated Assembly of a Single‐Component Supramolecular Triangle and an Enantiomeric Pair of Double Helices from 2‐(Iodoethynyl)pyridine Derivatives
Authors: Ng Chun‐Fai , Chow Hak‐Fun , Mak Thomas C. W. 
Published: March 2018

AbstractConstruction of single‐component supramolecular triangle and unprecedented spontaneous resolution of pairs of intertwined supramolecular 31‐ and 32‐double helices by the self‐assembly of achiral 2‐(iodoethynyl)pyridine and its derivatives have been achieved through intermolecular ethynyl C−I⋅⋅⋅⋅N halogen bonds in the crystalline state. Fine‐tuning of the molecular structure of the achiral monomer and choice of solvents for crystallization have a dominant effect on the resultant supramolecular architectures.
Tailoring the d‐Band Centers Enables Co4N Nanosheets To Be Highly Active for Hydrogen Evolution Catalysis
Authors: Chen Zhiyan , Song Yao , Cai Jinyan , Zheng Xusheng , Han Dongdong , Wu Yishang , Zang Yipeng , Niu Shuwen , Liu Yun , Zhu Junfa , Liu Xiaojing , Wang Gongming 
Published: March 2018

AbstractEndowing materials with specific functions that are not readily available is always of great importance, but extremely challenging. Co4N, with its beneficial metallic characteristics, has been proved to be highly active for the oxidation of water, while it is notoriously poor for catalyzing the hydrogen evolution reaction (HER), because of its unfavorable d‐band energy level. Herein, we successfully endow Co4N with prominent HER catalytic capability by tailoring the positions of the d‐band center through transition‐metal doping. The V‐doped Co4N nanosheets display an overpotential of 37 mV at 10 mA cm−2, which is substantially better than Co4N and even close to the benchmark Pt/C catalysts. XANES, UPS, and DFT calculations consistently reveal the enhanced performance is attributed to the downshift of the d‐band center, which helps facilitate the H desorption. This concept could provide valuable insights into the design of other catalysts for HER and beyond.
Investigation of the effect of foaming process parameters on expanded thermoplastic polyurethane bead foams properties using response surface methodology
Authors: Zhao Dong , Wang Guojian , Wang Mouhua 
Published: March 2018

ABSTRACTExpanded thermoplastic polyurethane (ETPU) bead foams were fabricated by batch foaming with supercritical CO2 as blowing agent. On the basis of single factor investigation, the response surface methodology based on Box‐Behnken Design was used to investigate the influences of saturation pressure, temperature, and soaking time and their interactions on foaming behavior of ETPU. The results showed that saturation temperature was the most significant parameter affecting the expansion ratio, shrinkage ratio, and cell morphology of ETPU. Moreover, there was an interaction effect between saturation temperature and soaking time, wherein the expansion ratio of ETPU was more sensitive to change of soaking time at higher temperature. As the soaking time increased, the shrinkage of ETPU increased firstly and then leveled off, and the cell diameter decreased significantly. By applying the response surface methodology optimization, ETPU bead foams with final expansion ratio of 8.04, mean cell diameter of 74.2 μm, and average cell density of 1.46 × 107cell/cm3 can be obtained while the optimum conditions at saturation pressure of 15 MPa, saturation temperature of 100 °C and soaking time for 60 min. In addition, the dual melting peak of ETPU characteristics demonstrated that it is suitable for steam‐chest molding technology. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46327.
Characterization of polypropylene/polystyrene boehmite alumina nanocomposites: Impact of filler surface modification on the mechanical, thermal, and rheological properties
Authors: Malwela Thomas , Khumalo Vincent Mandla , Salehiyan Reza , Ray Suprakas Sinha 
Published: March 2018

ABSTRACTThe influences of surface treatment and the concentration of boehmite alumina (BA) particles on polypropylene and polystyrene (PS) (80/20) blends produced via melt compounding were examined. The results show that p‐toluene sulfonic acid‐treated BA particles yielded the highest stiffness improvement (27.5%), followed by untreated particles (25.7%), and dodecylbenzene sulfonic acid‐treated BA particles (8.5%). Transmission electron microscopy revealed that p‐toluene sulfonic acid‐treated BA particle agglomerates were dispersed in the PS phase, whereas untreated particles formed agglomerations at the interfaces. Dodecylbenzene sulfonic acid‐treated particles were poorly dispersed in both matrices. Differential scanning calorimetry showed that both untreated and p‐toluene sulfonic acid‐treated BA particles acted as nucleating agents in the blend because of the shifting of crystallization peaks to higher temperatures by 12 and 8 °C, respectively. A significant increase in decomposition temperatures occurred upon 7 wt % loading of all types of BA particles into the blend. Heat deflection temperature measurements showed that all types of BA particles improved the thermal properties of the blend. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46376.
Persistence of submerged macrophytes in a drying world: Unravelling the timing and the environmental drivers to produce drought‐resistant propagules
Authors: Calero Sara , Morellato Leonor Patrícia C. , Rodrigo María A. 
Published: March 2018

Abstract

Under a warming scenario many permanent inland water bodies in the Mediterranean region have become temporary ones, so the persistence of submerged macrophytes depends on the timely production of drought‐resistant propagules. Phenological research measures the timing of ecological processes and allows the consequences of disturbances such as climate change to be evaluated.
Among macrophytes, the charophytes are widely distributed benthic macroalgae and are particularly sensitive to environmental variations. The systems in which they live constitute valuable, threatened, and protected habitats (European Habitats Directive code 3140).
This study established a methodological basis for determining which environmental drivers trigger the sexual reproductive phenology of charophytes. For the first time, circular statistics were applied to describe and compare seasonal patterns for submerged macrophytes.
Over a period of 2 years, three charophyte species growing in two Mediterranean brackish ponds were monitored. Most of the sexual reproduction occurred during spring and summer, including the production of drought‐resistant propagules, before the harshest conditions arrived. Each species showed a distinctive phenological pattern, according to specific breeding systems, life cycles, and environmental tolerances and requirements. Deeper conditions and higher salinities delayed reproduction. Different rainfall intensities in autumn produced distinctions between years, as stronger rainfall reduced the salinity stress and stimulated the reproduction of plants.
Interacting factors act as cues for charophyte reproduction and cause antagonistic effects on propagule production. Among them, the heat required for each phenophase peak is essential for understanding the phenology of a population and for predicting its long‐term persistence.
Charophytes appear to be good candidates for tracking climate change in shallow ecosystems. Further phenological studies should consider more species, populations, and long‐term observations in order to predict climate‐change effects on water bodies, and to develop effective plans for management and conservation.
Circular statistics is a potential tool for analysing phenology in the context of global warming, as well as for many other conservation issues.