bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Morphology and Electronic Structure Modulation on Atomic Iron‐Nitrogen‐Carbon Catalysts for Highly Efficient Oxygen Reduction
Authors: Xin Cuncun , Shang Wenzhe , Hu Jinwen , Zhu Chao , Guo Jingya , Zhang Jiangwei , Dong Haopeng , Liu Wei , Shi Yantao 
Published: September 2021

AbstractAtomic transition‐metal‐nitrogen‐carbon catalysts (M‐N‐Cs) hold great promise as Pt‐group‐metal‐free candidates for electrochemical reactions, yet their rational design and controllable synthesis remain fundamental challenges. Here, the molten‐salts mediated pyrolysis is demonstrated to be an effective and facile strategy for simultaneous morphology and electronic structure modulation of prototypical Fe‐N‐C materials, which functions as efficient oxygen reduction electrocatalysts. Taking advantage of the strong polarity and salt templating effects, the as‐obtained Fe‐N/C‐single atom catalyst (SAC) possesses hierarchical porous nanosheet morphology with an impressive specific surface area of 2237 m2 g−1 and unique FeN4Cl moieties as isolated active centers. The Fe‐N/C‐SAC delivers remarkable alkaline oxygen reduction reaction (ORR) activity with a half‐wave potential of 0.91 V and record kinetic current density up to 55 mA cm−2, outperforming the benchmark Pt/C. By virtue of dechlorination treatment, it is experimentally identified that the enhanced ORR activities are essentially governed by the axially bound Cl. Theoretical calculations rationalize this finding and demonstrate that the well‐defined fivefold‐coordinated configuration accelerates 4e− pathway kinetics through near‐optimal adsorption of the *OH intermediates and tunes the potential determining step from *OH reduction to *OOH formation. This study provides fundamental insights into the coordination‐engineered strategy in single‐atom catalysis.
Highly Nonlinear Optical Organic Crystals for Efficient Terahertz Wave Generation, Detection, and Applications
Authors: Kim Seung‐Jun , Kang Bong Joo , Puc Uros , Kim Won Tae , Jazbinsek Mojca , Rotermund Fabian , Kwon O‐Pil 
Published: September 2021

AbstractOrganic π‐conjugated crystals with second‐order optical nonlinearity are considerably attractive materials for diverse terahertz (THz) wave photonics. An overview of the research of organic nonlinear optical (NLO) crystals for THz wave generation, detection, and applications is provided here. First, the status of organic NLO crystals compared to other alternative THz materials is described. Second, the basic theory and requirements for organic THz generators and detectors are explained. Third, with a primary focus on the organic NLO crystals that have been developed during the last decade, various molecular engineering approaches are discussed from the perspective of THz photonics. Finally, various types of high‐power broadband coherent THz sources and their applications in THz nonlinear optics are discussed.
Structure of nanoparticle‐polyelectrolyte complexes: Effects of polyelectrolyte characteristics and charge ratio
Authors: Holkar Advait , Toledo Jesse , Srivastava Samanvaya 
Published: September 2021

AbstractWe present structural and turbidimetric characterizations of aqueous dispersions of oppositely charged nanoparticles and polyelectrolytes that undergo complexation and flocculation to form particle‐rich agglomerates over a wide range of polyelectrolyte and nanoparticle concentrations with varying polyelectrolyte sizes and persistence lengths. Compaction of nanoparticles in the polyelectrolyte–nanoparticle complexes, signified by decreasing internanoparticle spacing until they are brought in near‐contact, is observed upon increasing screening of interparticle repulsion arising from adsorption of polyelectrolytes on the nanoparticle surfaces. We identify the ratio of charge borne by the polyelectrolytes and the nanoparticles as a key parameter dictating the compaction of nanoparticles into complexes as well as densification of complexes into agglomerates. Moreover, the emergence of turbidity in solution is shown to correlate with the initiation of nanoparticle compaction by polyelectrolytes but failing to describe further structural evolution of the complexes, emphasizing the need for alternate characterization techniques.
Semianalytical method of two‐phase liquid transport in shale reservoirs and its application in fracture characterization
Authors: Zhang Fengyuan , Emami‐Meybodi Hamid 
Published: September 2021

AbstractThis study presents a new semi‐analytical method to simulate the two‐phase liquid transport in hydraulic fractures (HF) and matrix system, which can be applied to characterize HF attributes and dynamics using the flowback data from hydraulically fractured shale oil wells. The proposed approach includes a fracture model for HF properties calculation and a matrix model capable of considering multiple liquid transport mechanisms in shale nanopores. The proposed method is first validated with the numerical simulation then applied to a field example in Eagle Ford shale. The numerical validation confirms that our method can accurately characterize fracture attributes and closure dynamics by closely estimating the initial fracture permeability, pore‐volume, compressibility, and permeability modulus. Furthermore, the analysis results from numerical simulation and a field example both indicate a clear flow enhancement and deficit for oil and water transport, respectively, due to the slippage effect and variation of fluid properties inside nanopores.
Tuneable Time Delay in the Burst Release from Oxidation‐Sensitive Polymersomes Made by PISA
Authors: Sobotta Fabian H. , Kuchenbrod Maren T. , Gruschwitz Franka V. , Festag Grit , Bellstedt Peter , Hoeppener Stephanie , Brendel Johannes C. 
Published: September 2021

AbstractReactive polymersomes represent a versatile artificial cargo carrier system that can facilitate an immediate release in response to a specific stimulus. The herein presented oxidation‐sensitive polymersomes feature a time‐delayed release mechanism in an oxidative environment, which can be precisely adjusted by either tuning the membrane thickness or partial pre‐oxidation. These polymeric vesicles are conveniently prepared by PISA allowing the straightforward and effective in situ encapsulation of cargo molecules, as shown for dyes and enzymes. Kinetic studies revealed a critical degree of oxidation causing the destabilization of the membrane, while no release of the cargo is observed beforehand. The encapsulation of glucose oxidase directly transforms these polymersomes into glucose‐sensitive vesicles, as small molecules including sugars can passively penetrate their membrane. Considering the ease of preparation, these polymersomes represent a versatile platform for the confinement and burst release of cargo molecules after a precisely adjustable time span in the presence of specific triggers, such as H2O2 or glucose.
Two new Cu (II) complexes based on 5‐fluorouracil‐1‐yl acetic acid and N‐donor ligands: Investigation of their interaction with DNA and anticancer activity
Authors: Xi Yun‐Hong , Yan Xin , Bigdeli Fahime , Zhang Qianwen , Esrafili Leili , Hanifehpour Younes , Zhang Wei‐Bing , Hu Mao‐Lin , Morsali Ali 
Published: September 2021

AbstractTwo new Cu (II) complexes [Cu (bpy)2L1] BF4.CH3OH (Z3) and [Cu (phen)2L1] BF4·H2O (Z9), L1 = 5‐Fluorouracil‐1‐yl Acetic Acid, were synthesized based on 5‐Fluorouracil‐1‐yl Acetic Acid and 2,2′‐Bipyridine or 1,10‐phenanthroline ligands and their anticancer activity toward human cancer cell lines investigated. The complexes were characterized by infrared (IR) spectra, elemental analysis, and X‐ray crystallography. The interaction of the complexes with CT‐DNA was investigated by UV–vis absorption and fluorescence spectroscopies, and cyclic voltammetry; cell viability (%) was studied using the absorbance amount of the samples. The interaction mode of the complexes with DNA is electrostatic, and the complexes displayed good anticancer activity against HCT 116 (human colorectal cancer cells) and MDA‐MB‐231 (MD Anderson‐metastatic breast) cell lines with best IC50 amount of 11.31 ± 0.74 μM for Z9. The results showed that the nature of the nitrogen‐donor ligand is very effective in the anticancer activity of the complexes.
Granitic quarry waste as a dual functional filler for high density polyethylene‐based composites: Mechanical and microwave absorbing properties
Authors: de Moura Luanna C. R. , Soares Bluma G. , Indrusiak Tamara , Neumann Reiner , Tavares Luís Marcelo 
Published: September 2021

AbstractCost‐effective polymeric composites were successfully prepared by melt blending granitic quarry waste (GQW) with high‐density polyethylene (HDPE). The GQW is a waste generated during the production of manufacture fine aggregates (MFA) from crushed gneiss rock and contains significant amount of mica with iron in its structure. Different sieving and milling procedures were employed. The materials were characterized by mechanical and dynamic‐mechanical properties and scanning electron microscopy. Moreover, the influence of the GQW on the microwave absorbing properties in the X‐band frequency range was investigated. The presence of mica and iron compound in the GQW provides a dual function to the filler: toughening agent with microwave absorbing capacity. Indeed, the addition of 5 wt% of GQW previously sieved and milled by dry or wet‐grinding approach resulted in composites with outstanding toughness, modulus and elongation at break. Simulated RL studies revealed electro‐magnetic attenuation of −25 dB at 8.7 GHz. Such successful use of a waste generated in the production of a concentrate (MFA) not only contributes to the economics of the quarrying operation, but also to its environmental sustainability, since it replaces disposal of this product, which could lead to dust emissions, given its fine size and low moisture content.
Influence of rigid particles on thermal conductivity enhancement of polydimethylsiloxane composite during spatial confining forced network assembly
Authors: Zhang Xiaowen , Guo Yang , Zhang Hao , Guo Mengli , Liu Ying , Wu Daming , Chen Ning , Sun Jingyao 
Published: September 2021

AbstractIn order to meet the heat dissipation requirements of electronic equipment, a variety of methods for preparing thermally conductive polymer composites have been proposed. In this article, highly thermal conductive polydimethylsiloxane (PDMS) composites were prepared by combining the spatial confining forced network assembly (SCFNA) method with adding rigid particles (RPs). The orthogonal experiments were designed to verify the effects of short carbon fiber (SCF) content, glass bubble (GB) content, GB particle size and composite thickness on the thermal conductivity (λ) of SCF‐GB/PDMS composite. In addition, the λ and shapes of different RPs (including GB, SiO2, AlN, glass fiber [GF]) also play vital roles in λ enhancements of SCF‐RP/PDMS composites. The mechanical properties of SCF‐RP/PDMS composites were different with various RPs contents, and the SCF‐GB/PDMS composite presented the largest elongation at break (70%) and the best mechanical flexibility. The SCF‐GB/PDMS composite with a low GB content of 5 vol% can not only greatly improve the λ, but also ensure its excellent mechanical properties.
In‐situ polymerization of polyaniline in PDADMAC/PSS complex membranes: Effect of the polyelectrolyte stoichiometry
Authors: Luangaramvej Pimchaya , Wijitsettakun Pisut , Plengplung Pha‐sita , Dubas Stephan Thierry 
Published: September 2021

AbstractThe direct polymerization of a polymer in a polyelectrolyte complex membrane is a quick and simple method to enhance the properties and add functionality to a pre‐formed membrane. Here, polyelectrolyte complex membrane (PECs) of poly (diallyl dimethyl ammonium chloride) (PDADMAC) [P+] and poly (styrene sulfonate) [P−] were modified by the in‐situ polymerization of aniline monomer into polyaniline (PANI). The initial PECs were prepared by the co‐precipitation of polyelectrolytes with various [P+]: [P−] molar ratio and were formed into 100 micron thin membranes by compression molding. The in‐situ polymerization of PANI was achieved by sequential dipping of the PECs in ammonium peroxydisulfate solution to load the oxidant and in the aniline monomer solution to initiate the polymerization. Both the polyelectrolyte stoichiometry and the NaCl concentration used during the formation of the complex were found to have a profound effect on the polymerization reaction. UV–visible spectroscopy, X‐ray diffraction, and infrared spectroscopy were used to characterize the changes in color of the PANI membranes and to confirm the synthesis of PANI. Scanning electron microscopy revealed the presence of a dense coating of PANI at the surface of the PEC.
Effects of interval‐based inpatient treatment for anorexia nervosa: An observational study
Authors: Peters Kathrin , Meule Adrian , Voderholzer Ulrich , Rauh Elisabeth 
Published: September 2021

AbstractObjectiveAfter inpatient treatment for anorexia nervosa (AN), many patients relapse and need to be readmitted. To obtain a sustained improvement, a pre‐planned multistep inpatient procedure might help to improve the patient's skills in dealing with symptoms and transdiagnostic problems, thus decreasing symptoms of AN. However, no data have been reported for such interval treatment yet. Therefore, this study examined effects of interval treatment in inpatients with AN.MethodData of adult women with AN (N = 304) who received inpatient treatment and either received interval treatment (n = 179) or not (n = 125) were analyzed. Of these, 225 patients completed a follow up measurement after an average of 25 months. Treatment outcome variables were body mass index and subscales of the Eating Disorder Inventory‐2 at admission, discharge, and follow up.ResultsAcross measurements, the interval treatment group had larger increases in body mass index and larger decreases in drive for thinness and binge/purge symptoms than the no interval treatment group. These differences did not seem to be driven by longer treatment duration.DiscussionOur data suggest that interval treatment for AN is effective and may even be superior to conventional single inpatient treatment. Given the observational nature of this study, however, controlled studies are necessary to corroborate these findings.
Harnessing P450 Enzyme for Biotechnology and Synthetic Biology
Authors: Zhang Libo , Wang Qian 
Published: September 2021

AbstractCytochrome P450 enzymes (P450s, CYPs) catalyze the oxidative transformation of a wide range of organic substrates. Their functions are crucial to xenobiotic metabolism and steroid transformation in humans and other organisms. The enzymes are promising for synthetic biology applications but limited by several drawbacks including low turnover rates, poor stability, the dependance of expensive cofactors and redox partners, and the narrow substrate scope. To conquer these obstacles, emerging strategies including substrate engineering, usage of decoy and decoy‐based small molecules auxiliaries, designing of artificial enzyme cascades and the incorporation of materials have been explored based on the unique properties of P450s. These strategies can be applied to a wide range of P450s and can be combined with protein engineering to improve the enzymatic activities. This minireview will focus on some recent developments of these strategies which have been used to leverage P450 catalysis. Remaining challenges and future opportunities will also be discussed.
On the Weak Binding and Spectroscopic Signature of SARS‐CoV‐2 nsp14 Interaction with RNA
Authors: Hassan Ayaz , Sedenho Graziela C. , Vitale Phelipe A. M. , Oliviera Mona N. , Crespilho Frank N. 
Published: September 2021

AbstractThe SARS‐CoV‐2 non‐structural protein 14 (nsp14), known as exoribonuclease is encoded from the large polyprotein of viral genome and is a major constituent of the transcription replication complex (TRC) machinery of the viral RNA synthesis. This protein is highly conserved among the coronaviruses and is a potential target for the development of a therapeutic drug. Here, we report the SARS‐CoV‐2 nsp14 expression, show its structural characterization, and ss‐RNA exonuclease activity through vibrational and electronic spectroscopies. The deconvolution of amide‐I band in the FTIR spectrum of the protein revealed a composition of 35 % α‐helix and 25 % β‐sheets. The binding between protein and RNA is evidenced from the spectral changes in the amide‐I region of the nsp14, showing protein conformational changes during the binding process. A value of 20.60±3.81 mol L−1 of the binding constant (KD) is obtained for nsp14/RNA complex. The findings reported here can motivate further studies to develop structural models for better understanding the mechanism of exonuclease enzymes for correcting the viral genome and can help in the development of drugs against SARS‐CoV‐2.
The E2 state of FeMoco: Hydride Formation versus Fe Reduction and a Mechanism for H2 Evolution
Authors: Thorhallsson Albert Th. , Bjornsson Ragnar 
Published: September 2021

AbstractThe iron‐molybdenum cofactor (FeMoco) is responsible for dinitrogen reduction in Mo nitrogenase. Unlike the resting state, E0, reduced states of FeMoco are much less well characterized. The E2 state has been proposed to contain a hydride but direct spectroscopic evidence is still lacking. The E2 state can, however, relax back the E0 state via a H2 side‐reaction, implying a hydride intermediate prior to H2 formation. This E2→E0 pathway is one of the primary mechanisms for H2 formation under low‐electron flux conditions. In this study we present an exploration of the energy surface of the E2 state. Utilizing both cluster‐continuum and QM/MM calculations, we explore various classes of E2 models: including terminal hydrides, bridging hydrides with a closed or open sulfide‐bridge, as well as models without. Importantly, we find the hemilability of a protonated belt‐sulfide to strongly influence the stability of hydrides. Surprisingly, non‐hydride models are found to be almost equally favorable as hydride models. While the cluster‐continuum calculations suggest multiple possibilities, QM/MM suggests only two models as contenders for the E2 state. These models feature either i) a bridging hydride between Fe2 and Fe6 and an open sulfide‐bridge with terminal SH on Fe6 (E2‐hyd) or ii) a double belt‐sulfide protonated, reduced cofactor without a hydride (E2‐nonhyd). We suggest both models as contenders for the E2 redox state and further calculate a mechanism for H2 evolution. The changes in electronic structure of FeMoco during the proposed redox‐state cycle, E0→E1→E2→E0, are discussed.
Efficient Near‐Infrared Electrochemiluminescence from Au18 Nanoclusters
Authors: Hesari Mahdi , Ding Zhifeng 
Published: September 2021

AbstractBright, near‐infrared electrochemiluminescence (NIR–ECL) of Au18 nanoclusters is reported herein. Spooling ECL and photoluminescence spectroscopy were used to track and link NIR emissions at 832 and 848 nm to three emissive species, Au180*, Au181+* and Au182+*, with a considerably high ECL efficiency of 5.5 relative to that of the gold standard Ru(bpy)32+/TPrA (with 5–6 % reported ECL efficiency). The unprecedentedly high efficiency is due to the overlapped oxidation potentials of Au180 and tri‐n‐propylamine as co‐reactant, the exposed facets of Au180 gold core, and electrocatalytic loops. These discoveries will add a new member to the efficient NIR‐ECL gold nanoclusters family and bring more potential applications.
Life‐years lost due to cancer among solid organ transplant recipients in the United States, 1987 to 2014
Authors: Noone Anne‐Michelle , Pfeiffer Ruth M. , Schaubel Douglas E. , Dorgan Joanne F. , Magder Laurence S. , Bromberg Jonathan S. , Lynch Charles F. , Morris Cyllene R. , Pawlish Karen S. , Engels Eric A. 
Published: September 2021

BackgroundSolid organ transplant recipients have an elevated risk of cancer. Quantifying the life‐years lost (LYL) due to cancer provides a complementary view of the burden of cancer distinct from other metrics and may identify subgroups of transplant recipients who are most affected.MethodsLinked transplant and cancer registry data were used to identify incident cancers and deaths among solid organ transplant recipients in the United States (1987‐2014). Data on LYL due to cancer within 10 years posttransplant were derived using mean survival estimates from Cox models.ResultsAmong 221,962 transplant recipients, 13,074 (5.9%) developed cancer within 10 years of transplantation. During this period, the mean LYL due to cancer were 0.16 years per transplant recipient and 2.7 years per cancer case. Cancer was responsible for a loss of 1.9% of the total life‐years expected in the absence of cancer in this population. Lung recipients had the highest proportion of total LYL due to cancer (0.45%) followed by heart recipients (0.29%). LYL due to cancer increased with age, from 0.5% among those aged birth to 34 years at transplant to 3.2% among those aged 50 years and older. Among recipients overall, lung cancer was the largest contributor, accounting for 24% of all LYL due to cancer, and non‐Hodgkin lymphoma had the next highest contribution (15%).ConclusionsTransplant recipients have a shortened lifespan after developing cancer. Lung cancer and non‐Hodgkin lymphoma contribute strongly to LYL due to cancer within the first 10 years after transplant, highlighting opportunities to reduce cancer mortality through prevention and screening.
Anion⋅⋅⋅Anion Interactions Involving σ‐Holes of Perrhenate, Pertechnetate and Permanganate Anions
Authors: Daolio Andrea , Pizzi Andrea , Terraneo Giancarlo , Frontera Antonio , Resnati Giuseppe 
Published: September 2021

AbstractIn this communication experimental and theoretical results are reported affording strong evidence that interactions between electron rich atoms and the metal of tetroxide anions of group 7 elements are a new case of attractive and σ‐hole interactions. Single crystal X‐ray analyses, molecular electrostatic potentials, quantum theory of atoms‐in‐molecules, and noncovalent interaction plot analyses show that in crystalline permanganate and perrhenate salts the metal in Mn/ReO4− anion can act as electron acceptors, the oxygen of another Mn/ReO4− anion can act as the donor and supramolecular anionic dimers or polymers are formed. The name matere bond (MaB) is proposed to categorize these noncovalent interactions and to differentiate them from the classical metal‐ligand coordination bond.
Influence of Reaction Conditions on Hydrothermal Carbonization of Fructose
Authors: Modugno Pierpaolo , Titirici Maria‐Magdalena 
Published: September 2021

AbstractHydrothermal carbonization is a powerful way to convert cellulosic waste into valuable platform chemicals and carbonaceous materials. In this study, to optimize the process, fructose was chosen as the carbon precursor and the influence of reaction time, acid catalysis, feed gas and pressure on the conversion products is evaluated. 5‐hydroxymethylfurfural (HMF) is produced in high amounts in relatively short time. Both strong and weak acids accelerate fructose conversion. Levulinic acid (LevA) formation is faster than that of hydrothermal (HT) carbon in acidic conditions. Strong acid catalysts should be considered to target preferentially LevA production, whereas milder conditions should be preferred for HMF production. Moreover, a slight initial overpressure of the reactor is always beneficial in terms of conversion. FT‐IR and 13C ss‐NMR spectroscopy and SEM showed that HT carbon evolves through time from a furanic‐based structure with alkylic linkers to an increasingly cross‐linked condensed structure. MALDI‐ToF mass spectrometry showed the existence of a series of oligomers in a mass range within 650 Da and 1500 Da formed by condensation of repeating units.