bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal–Organic Framework Supported Palladium Nanoparticles: Applications and Mechanisms
Authors: Yang Qi , Yao Fubing , Zhong Yu , Chen Fei , Shu Xiaoyu , Sun Jian , He Li , Wu Bo , Hou Kunjie , Wang Dongbo , Li Xiaoming 
Published: April 2019

AbstractHeterogeneous palladium (Pd)‐based catalysts are extensively applied to improve the catalytic performance and/or expand the reaction scope in many catalytic processes, involving the cross‐coupling, hydrogenation, reduction, and oxidation reactions. Among them, metal–organic framework (MOF)‐supported Pd nanoparticles (Pd NPs) are becoming the most popular one for their excellent catalytic performance and reusable property. To motivate the development of this technology, the applications of MOF‐supported Pd NPs (Pd NPs/MOFs) in heterogeneous catalysis are critically summarized herein, including the hydrogenation reduction of nitro‐ and polyunsaturated compounds, synthesis of carbon–carbon (CC) bonds compounds, chromium (Cr(VI)) reduction, dehalogenation, alcohol oxidation, CO2 conversion, and CO oxidation. The influences of base, solvents, electron character of substitutes, and type of halogen on the catalytic performance are comprehensively discussed. Finally, the application prospects of Pd NPs/MOFs and existing shortcomings in the catalytic field are proposed.
Equilibrium, affinity, dissociation constants, IC5O: Facts and fantasies
Authors: Barbet Jacques , Huclier‐Markai Sandrine 
Published: April 2019

SUMMARYThe interaction between ligands and receptors is often described in terms of 50% inhibitory concentrations (IC50). However, IC50 values do not accurately reflect the dissociation constants (Kd), and the domain of application and precision of proposed approximations for Kd estimation are unclear. The effect of affinity and of experimental conditions on the differences between IC50 and Kd has been assessed from exact mass action law calculations and from computer simulations. Competitions between [111In]DTPA‐indium and a few metal‐DTPA complexes for binding to a specific antibody are discussed as a practical example. Exact calculations of competition assays have been implemented in Microsoft Excel and performed for a variety of concentrations of receptor, tracer, and competitor. The results are identical to those of software packages. IC50 is found larger than Kd by less than 20% only when tracer concentration is small compared with Kd and to the receptor concentration and when this receptor concentration is small compared with Kd. Otherwise, Kd and IC50 may be very different and approximations proposed in the literature to obtain Kd values from graphically derived IC50 are not acceptable as soon as the concentrations of tracer or of receptor approach Kd. Under most experimental conditions, IC50 values do not reflect Kd values. Using available software packages to determine and report Kd values would allow for more meaningful comparisons of results obtained under different experimental conditions.
Spatio‐temporal variability in underwater light climate in a turbid river‐floodplain system: Driving factors and estimation using Secchi disc
Authors: Mayora Gisela , Devercelli Melina 
Published: April 2019

AbstractThe underwater light climate has important effects on primary producers. The aim of this research was to evaluate its variability in a turbid river‐floodplain system. Photosynthetically active radiation (PAR) was measured in the Middle Paraná River during different hydrological phases to (a) analyse the photosynthetically active radiation attenuation coefficient (k) and euphotic depth (Zeu) as well as their associations with optically active components and (b) develop and evaluate indices and regression models based on Secchi disc (SD) measurements to estimate k and Zeu. Values of k were higher in the fluvial system than in the floodplain and during low‐water stage than high‐water stage. Particulate components controlled the light climate variability. Chromophoric dissolved organic matter and chlorophyll‐a had significant effects during floods. The estimation of k and Zeu was sensitive to temporal but not to spatial variations. The highest prediction accuracy was observed when using specific non‐linear regressions for each hydrological phase, especially for Zeu estimation (low stage: k = 1.76 × SD−0.80, Zeu = 2.62 × 1/SD−0.80; high stage: k = 2.04 × SD−0.53, Zeu = 2.26 × 1/SD−0.53). The indices k × SD and Zeu/SD were significantly different from those proposed for clear water environments. It is concluded that temporal variations should be considered when estimating k and Zeu in turbid river‐floodplain systems because of the temporal heterogeneity in optically active components. Considering that ecological implication of the light climate depends on Zeu:depth ratio, we propose to estimate Zeu instead of k. Finally, indices proposed for clear water environments are not recommended to be applied to turbid environments.
Generation of a Functioning and Self-Renewing Diaphragmatic Muscle Construct
Authors: Trevisan Caterina , Fallas Mario Enrique Alvrez , Maghin Edoardo , Franzin Chiara , Pavan Piero , Caccin Paola , Chiavegato Angela , Carraro Eugenia , Boso Daniele , Boldrin Francesco , Caicci Federico , Bertin Enrica , Urbani Luca , Milan Anna , Biz Carlo , Lazzari Lorenza , De Coppi Paolo , Pozzobon Michela , Piccoli Martina 
Published: April 2019

Abstract
Surgical repair of large muscular defects requires the use of autologous graft transfer or prosthetic material. Naturally derived matrices are biocompatible materials obtained by tissue decellularization and are commonly used in clinical practice. Despite promising applications described in the literature, the use of acellular matrices to repair large defects has been only partially successful, highlighting the need for more efficient constructs. Scaffold recellularization by means of tissue engineering may improve not only the structure of the matrix, but also its ability to functionally interact with the host. The development of such a complex construct is challenging, due to the complexity of the native organ architecture and the difficulties in recreating the cellular niche with both proliferative and differentiating potential during growth or after damage. In this study, we tested a mouse decellularized diaphragmatic extracellular matrix (ECM) previously described by our group, for the generation of a cellular skeletal muscle construct with functional features. The decellularized matrix was stored using different conditions to mimic the off-the-shelf clinical need. Pediatric human muscle precursors were seeded into the decellularized scaffold, demonstrating proliferation and differentiation capability, giving rise to a functioning three-dimensional skeletal muscle structure. Furthermore, we exposed the engineered construct to cardiotoxin injury and demonstrated its ability to activate a regenerative response in vitro promoting cell self-renewal and a positive ECM remodeling. Functional reconstruction of an engineered skeletal muscle with maintenance of a stem cell pool makes this a promising tool toward future clinical applications in diaphragmatic regeneration. Stem Cells Translational Medicine 2019;8:858–869
Economic growth and human development: Evidence from Zambia
Authors: Chikalipah Sydney , Makina Daniel 
Published: April 2019

AbstractIn this paper, we examine the two‐way relationship between economic growth and human development in Zambia over the period 1970 to 2015. By applying the cointegration and vector error correction model techniques, our estimates demonstrate, in the first instance, that economic growth and human development are cointegrated. Second, there is no evidence of two‐way causal effect observable between economic growth and human development in the short run. In marked contrast, we find that economic growth has long‐run effect on human development, with no evidence of reverse causality. This shows that the endless fixation on economic growth has manifestly and consistently proven that GDP growth has had sluggish multiplier effect on inclusive development in Zambia. Finally, we draw country‐specific policy recommendations from our empirical findings.
Effect of deposition temperature on the growth mechanism of chemically prepared CZTGeS thin films
Authors: Shamardin A. , Kurbatov D. , Medvids A. 
Published: April 2019

The Cu2ZnSnGeS4 (CZTGeS) thin films were deposited by the spray pyrolysis method at different substrate temperatures without further sulfurization. The influence of various deposition temperatures on the surface morphology, microstructure, optical properties, chemical, and phase composition were investigated. The substitution mechanism of Sn/Ge in the crystal lattice of CZTGeS depending on deposition temperatures was studied. It was shown that a variation in substrate temperature has a strong effect on the surface morphology of the films. The X‐ray diffractometer (XRD), transmission electron microscope (TEM), and Raman spectroscopy (RS) analysis showed that CZTGeS films were polycrystalline with a kesterite‐type single‐phase structure and a preferential orientation of (112). The RS‐mapping analysis showed the distribution of intensities on the surfaces of the films. Optical measurements showed that CZTGeS films are highly absorbing in the visible region, and the optical band gap is shifted from 1.89 to 1.84 eV.
Effect of Reaction Temperature on the Properties of Polyimide Dielectric Composites
Authors: Mao Xin , Wu Bo , Zhang Fangfang , Wang Chunyan , Deng Ting , Tang Xianzhong 
Published: April 2019

AbstractPolymer dielectric composites are fabricated by blending polyimide (PI) with poly(vinylidene fluoride) (PVDF) base on different temperature conditions. The dielectric and thermal properties of the composites are studied. Experimental results indicate that the dielectric properties of the composites are enhanced by increasing the reaction temperature, while all the resulted composites exhibit excellent thermal stability. Specifically, the sample showing optimized dielectric properties can be obtained at a reaction temperature of 50 °C.
An In Situ Infrared Study of CO2 Hydrogenation to Formic Acid by Using Rhodium Supported on Titanate Nanotubes as Catalysts
Authors: Ruiz‐García Jesús Roberto , Fierro‐Gonzalez Juan Carlos , Handy Brent E. , Hinojosa‐Reyes Laura , De Haro Del Río David A. , Lucio‐Ortiz Carlos J. , Valle‐Cervantes Sergio , Flores‐Escamilla Gerardo A. 
Published: April 2019

AbstractTitanate nanotubes (TiNT) were synthesized by hydrothermal method and used as support of rhodium nanoparticles. Results of X‐Ray diffraction (XRD) and Raman spectroscopy of TiNT revealed its structure of Na2Ti3O7, while the results of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and physisorption of N2 confirmed the multilayer nanotubular morphology with external diameter of ∼12 nm, length > 100 nm and a BET surface area of 195 m2 g−1. The TEM analysis of the rhodium supported sample (Rh/TiNT) showed evidence of small (∼1 nm) and highly dispersed rhodium particles. Results of X‐Ray Photoelectron Spectroscopy (XPS) revealed a strong electronic interaction between TiNT and Rh sites. The catalytic activity of Rh/TiNT for the hydrogenation of CO2 to formic acid at moderate temperature (∼40 °C) and atmospheric pressure was demonstrated as evidenced by results of Mass Spectrometry (MS) and in‐situ Diffuse Reflectance Infrared with Fourier Transform Spectroscopy (DRIFTS). The in‐situ studies showed active surface species bonded to support sites and to rhodium sites. It is proposed that under H2 atmosphere, Na+ cations near to Rh particles promote the conversion of CO2 via dissociated H, allowing the formation of formate species at low temperature. The formate species and the hydride rhodium complexes are considered reaction intermediates.
A Solid‐State‐Emissive 1,8‐Naphthalimide Probe Based on Photoinduced Electron Transfer and Aggregation‐Induced Emission
Authors: Georgiev Nikolai I. , Bakov Ventsislav V. , Bojinov Vladimir B. 
Published: April 2019

AbstractIn this work we focused on the design and synthesis of a fluorescence sensing 4‐chloro‐1,8‐naptalimide derivative operating simultaneously by photoinduced electron transfer (PET) and aggregation induced emission (AIE) mechanisms. Absorption and fluorescence properties of the probe were studied as a function of pH in solution and in solid state as compared to the properties of similar 1,8‐naphthalimide derivatives without a substituent at the 1,8‐naphthalimide C‐4 position. The photoinduced fluorescence enhancement of the probe was FE = 22 after protonation in solution (λF = 405 nm, pKa = 8.50±0.08) and FE = 44 (λF = 472 nm) in solid state after reversible exposure on HCl and ammonia vapours due to the amalgamation of monomer emission and AIE. In solid state on paper support the PET process in the probe was switched “off” in a pH window 2.5‐1.5. Due to the remarkable changes in the fluorescence emission the synthesized compound was successfully applied as a solid‐state chemosensing material for rapid detection of acid‐base vapours and pH in aqueous solutions. The concept proposed herein could drive the classic AIE and PET molecular sensors towards new directions and practical applications.
Synthesis of Flower‐Like Carbon‐Doped Nickel Phosphides Electrocatalysts for Oxygen Evolution Reaction
Authors: Cheng Xian , Zheng Jianfeng , Li Jintang , Luo Xuetao 
Published: April 2019

AbstractMotivated by the challenge to find a low‐cost catalyst with efficient activity for the oxygen evolution reaction (OER), transition metal phosphides (TMPs) recently have been gained attentions as promising earth‐abundant alternatives to nobel metal based electrocatalysts. Here, we present a facile strategy for the synthesis of flower‐like carbon doped nickel phosphides (NiP/C) for OER catalysis, which templated by nickel phenylphosphonate through thermal treatment under H2(5%)/Ar. The phenylphosphonic acid ligand used here has excellent affinity toward metal ions and thus can act as P and C source at the molecular scale. Benefiting from the incorporation of conductive carbon and higher Ni atomic percentage provide more active sites, the sample denoted as NiP/C‐850 exhibits outstanding electrocatalytic activity, with a lower overpotential of 290 mV to achieve the current density of 10 mA⋅cm−2, a small Tafel slope of 74 mV⋅dec−1 and superior durability in 1.0 M KOH solution. This work provides insights for the rich metal organophosphonate chemistry for fabricating carbon doped metal phosphides applied to the electrochemical conversion technologies.
Steric Clashes, Doughnuts and Exploding Cigars: Some Comments on Non‐Covalent Interactions
Authors: Lomas John S. 
Published: April 2019

AbstractIsosurfaces appearing in three‐dimensional Non‐Covalent Interactions (NCI) representations of molecules are attributed to bonding interactions (sign(λ2)*ρ < 0) or to non‐bonding interactions, often referred to as “steric clashes” and typical of ring systems (sign(λ2)*ρ > 0). Since the second eigenvalue of the Hessian of the electron density, λ2, is positive for a ring or a cage critical point and negative for a bond critical point, in many cases NCI isosurfaces simply surround QTAIM critical points, which means that the attribution of positive‐λ2 isosurfaces to steric clashes in rings or cages is not justified. Examples are given for sterically congested hydrocarbons, where isosurfaces associated with C–H…H–C interactions enclose bond and ring critical points. In the same way, their appearance in the absence of critical points can be attributed to a variation of λ2. It is shown that for small, very strained rings, positive‐λ2 isosurfaces are not found when the recommended plot parameters are used.
Enantiospecific Synthesis of 2‐Substituted Piperidine‐4‐carboxylic Acids from α‐Amino Acids
Authors: Ramesh Subbiah , Balakumar Ramadas , Rizzo John R. , Zhang Tony Y. 
Published: April 2019

AbstractA feasible route to access chiral 2‐substituted piperidine‐4‐carboxylic acids as versatile pharmaceutical intermediates was established from easily accessible N‐Cbz amino acids derivatives and Meldrum's acid in simple synthetic sequence. The relatively broad scope was demonstrated by the synthesis of various 2‐substituted piperidine‐4‐carboxylic acids and exemplified in the selective synthesis of AZD6564, a fibrinolysis inhibitor.
Mild Hydrogenation of Urban Biowaste Hydrolysates to Biopolymers with Improved Properties.
Authors: Montoneri Enzo , Fabbri Gloria , Grillo Giorgio , Tabasso Silvia , Cravotto Giancarlo , Quagliotto Pierluigi , Baglieri Andrea , Boero Valter , Negre Michèle 
Published: April 2019

AbstractThis work reports the hydrogenation of soluble biopolymers (SBP) obtained by hydrolysis of municipal biowaste anaerobic digestate (D) and compost (CP). The SBP are mix of heterogenous molecules with 5–750 kDa molecular weight constitued by aliphatic and aromatic C moieties substitued by acid and basic functional groups. They are mutipurpose products for use in the chemical industry as biosurfactants and plastics’ additives, in agriculture and in animal husbandry. Purpose of hydrogenation was to improve SBP properties, while keeping macromolecularity. Hydrogenation was carried out in 4–5% water solution at pH 10 at 100 °C and 35 bar H2 pressure for 2–30 min. Results show hydrogenation of up to 35% SBP C to products containing more aliphatic C and different molecular weight distribution. Relative to pristine SBP, the molecular weight of hydrogenated CP SBP and of D SBP are, respectively, higher and lower. Surfactants properties improve upon hydrogenation. Hydrogenated D SBP are better surfactants than hydrogenated CP SBP. Further improvement and uses of hydrogenated SBP are discussed.
Synthesis and Characterization of Fluorescent Carbon Dots from Tapioca
Authors: Pudza Musa Y. , Abidin Zurina Z. , Abdul‐Rashid Suraya , Yassin Faizah Md. , Noor Ahmad S. M , Abdullah Mohammed 
Published: April 2019

AbstractThis research demonstrates an economical and efficient reduction of carbon foot print. Tapioca powder as a source of organic carbon was utilized in the synthesis of carbon dots through optimization of the synthesis parameters such as temperature, dosage and time. Photoluminescent quantum yield (PLQY) was obtained under the visible region of 340 nm at 34.9%, which was achieved without dopants such as sulfur and nitrogen that are popularly used to increase the value of photoluminescence. The characterization of carbon dots such as FTIR and HrTem, were carried out for the analysis of functional groups, particle sizes (1‐5 nm) and shapes (quasi‐spherical). The high carbon‐carbon bonds and oxygen groups detected in FTIR analysis validates the basis of fluorescence of carbon dots and also presence of hydroxyl (OH), carboxylic acids (COO), and other vital functional groups (C=O, C−O‐C, C−H). These characteristics makes tapioca based carbon dots suitable for application in the fields of environmental studies including sensitive detection and absorbance of pollutants in water and bio imaging in health sciences.
Intrinsically Optimizing Charge Transfer via Tuning Charge/Discharge Mode for Lithium–Oxygen Batteries
Authors: Liu Wei , Shen Yue , Yu Yao , Lu Xia , Zhang Wang , Huang Zhaoming , Meng Jintao , Huang Yunhui , Guo Zaiping 
Published: April 2019

AbstractLithium–oxygen batteries have an ultrahigh theoretical energy density, almost ten times higher than lithium‐ion batteries. The poor conductivity of the discharge product Li2O2, however, severely raises the charge overpotential and pulls down the cyclability. Here, a simple and effective strategy is presented for regular formation of lithium vacancies in the discharge product via tuning charge/discharge mode, and their effects on the charge transfer behavior. The effects of the discharge current density on the lithium vacancies, ionic conductivity, and electronic conductivity of the discharge product Li2O2 are systematically investigated via electron spin resonance, spin‐alignment echo nuclear magnetic resonance, and tungsten nanomanipulators, respectively. The study by density functional theory indicates that the lithium vacancies in Li2O2 generated during the discharge process are highly dependent on the current density. High current can induce a high vacancy density, which enhances the electronic conductivity and reduces the overpotential. Meanwhile, with increasing discharge current, the morphology of the Li2O2 changes from microtoroids to thin nanoplatelets, effectively shortening the charge transfer distance and improving the cycling performance. The Li2O2 grown in fast discharge mode is more easily decomposed in the following charging process. The lithium–oxygen battery cycling in fast‐discharge/slow‐charge mode exhibits low overpotential and long cycle life.
Polyproline Tri‐Helix Macrocycles as Nanosized Scaffolds to Control Ligand Patterns for Selective Protein Oligomer Interactions
Authors: Lin Cin‐Hao , Wen Hsin‐Chuan , Chiang Cheng‐Chin , Huang Jen‐Sheng , Chen Yunching , Wang Sheng‐Kai 
Published: April 2019

AbstractMultivalent ligand–receptor interactions play essential roles in biological recognition and signaling. As the receptor arrangement on the cell surface can alter the outcome of cell signaling and also provide spatial specificity for ligand binding, controlling the presentation of ligands has become a promising strategy to manipulate or selectively target protein receptors. The lack of adjustable universal tools to control ligand positions at the size of a few nanometers has prompted the development of polyproline tri‐helix macrocycles as scaffolds to present ligands in designated patterns. Model lectin Helix pomatia agglutinin has shown selectivity toward the matching GalNAc ligand pattern matching its binding sites arrangement. The GalNAc pattern selectivity is also observed on intact asialoglycoprotein receptor oligomer on human hepatoma cells showing the pattern‐selective interaction can be achieved not only on isolated protein oligomers but also the receptors arranged on the cell surface. As the scaffold design allows convenient creation of versatile ligand patterns, it can be expected as a promising tool to probe the arrangement of receptors on the cell surface and as nanomedicine to manipulate signaling or cell recognition.
Flexible Micropillar Electrode Arrays for In Vivo Neural Activity Recordings
Authors: Du Mingde , Guan Shouliang , Gao Lei , Lv Suye , Yang Siting , Shi Jidong , Wang Jinfen , Li Hongbian , Fang Ying 
Published: April 2019

AbstractFlexible electronics that can form tight interfaces with neural tissues hold great promise for improving the diagnosis and treatment of neurological disorders and advancing brain/machine interfaces. Here, the facile fabrication of a novel flexible micropillar electrode array (µPEA) is described based on a biotemplate method. The flexible and compliant µPEA can readily integrate with the soft surface of a rat cerebral cortex. Moreover, the recording sites of the µPEA consist of protruding micropillars with nanoscale surface roughness that ensure tight interfacing and efficient electrical coupling with the nervous system. As a result, the flexible µPEA allows for in vivo multichannel recordings of epileptiform activity with a high signal‐to‐noise ratio of 252 ± 35. The ease of preparation, high flexibility, and biocompatibility make the µPEA an attractive tool for in vivo spatiotemporal mapping of neural activity.