bluuebunny/crossref_metadata_2025_split huggingface dataset:
Post‐Functionalization of Supramolecular Polymers on Surface and the Chiral Assembly‐Induced Enantioselective Reaction
Authors: Li Deng‐Yuan , Zhu Ya‐Cheng , Li Shi‐Wen , Shu Chen‐Hui , Liu Pei‐Nian 
Published: February 2021

AbstractAlthough post‐functionalization is extensively used to introduce diverse functional groups into supramolecular polymers (SPs) in solution, post‐functionalization of SPs on surfaces still remains unexplored. Here we achieved the on‐surface post‐functionalization of two SPs derived from 5,10,15‐tri‐(4‐pyridyl)‐20‐bromophenyl porphyrin (Br‐TPyP) via cross‐coupling reactions on Au(111). The ladder‐shaped, Cu‐coordinated SPs preformed from Br‐TPyP were functionalized through Heck reaction with 4‐vinyl‐1,1′‐biphenyl. In the absence of Cu, Br‐TPyP formed chiral SPs as two enantiomers via self‐assembly, which were functionalized via divergent cross‐coupling reaction with 4‐isocyano‐1,1′‐biphenyl (ICBP). Surprisingly, this reaction was discovered as an enantioselective on‐surface reaction induced by the chirality of SPs. Mechanistic analysis and DFT calculations indicated that after debromination of Br‐TPyP and the first addition of ICBP, only one attack direction of ICBP to the chiral SP intermediate is permissive in the second addition step due to the steric hindrance, which guaranteed the high enantioselectivity of the reaction.
Selective Crystallization of Rare‐Earth Ions into Cationic Metal‐Organic Frameworks for Rare‐Earth Separation
Authors: Yang Huajun , Peng Fang , Schier Danielle E. , Markotic Stipe A. , Zhao Xiang , Hong Anh N. , Wang Yanxiang , Feng Pingyun , Bu Xianhui 
Published: February 2021

AbstractFor rare‐earth separation, selective crystallization into metal‐organic frameworks (MOFs) offers new opportunities. Especially important is the development of MOF platforms with high selectivity toward target ions. Here we report a MOF platform (CPM‐66) with low‐coordination‐number environment for rare‐earth ions. This platform is highly responsive to the size variation of rare‐earth ions and shows exceptional ion‐size selectivity during crystallization. CPM‐66 family are based on M3O trimers (M=6‐coordinated Sc, In, Er‐Lu) that are rare for lanthanides. We show that the size matching between urea‐type solvents and metal ions is crucial for their successful synthesis. We further show that CPM‐66 enables a dramatic multi‐fold increase in separation efficiency over CPM‐29 with 7‐coordinated ions. This work provides some insights into methods to prepare low‐coordinate MOFs from large ions and such MOFs could serve as high‐efficiency platforms for lanthanide separation, as well as other applications.
Effect of Zinc‐Doping on the Reduction of the Hot‐Carrier Cooling Rate in Halide Perovskites
Authors: Wei Qi , Yin Jun , Bakr Osman M. , Wang Ze , Wang Chenhao , Mohammed Omar F. , Li Mingjie , Xing Guichuan 
Published: February 2021

AbstractThe fast hot‐carrier cooling process in the solar‐absorbers fundamentally limits their photon‐conversion efficiencies. It is highly desirable to develop a solar absorber with long‐lived hot‐carriers at sun‐illumination intensity, which can be used to develop the hot‐carrier solar cells with enhanced efficiency. Herein, we reveal that zinc‐doped (0.34 %) halide perovskites have the slower hot‐carrier cooling compared with the pristine sample through the transient absorption spectroscopy measurements and theoretical calculations. The hot‐carrier energy loss rate at the low photoexcitation level of 1017 cm−3 is found to be ≈3 times smaller than that of un‐doped perovskites for T=500 K hot carriers, and up to ten times when the hot‐carrier temperature approaches the lattice temperature. The incorporation of zinc‐dopant into perovskites can reduce the nonadiabatic couplings between conduction bands, which retards the photogenerated hot‐carriers relaxation processes. Our findings present a practical strategy to slow down the hot‐carrier cooling in perovskites at low carrier densities, which would be invaluable for the further development of practical hot‐carrier photovoltaics based on perovskites.
Untersuchung elektroenzymatischer H2‐Produktion mithilfe von Rotierende‐Ring‐Scheiben‐Elektrochemie und Massenspektrometrie**
Authors: Khushvakov Jaloliddin , Nussbaum Robin , Cadoux Cécile , Duan Jifu , Stripp Sven T. , Milton Ross D. 
Published: February 2021

AbstractGas‐verarbeitende Metalloenzyme sind für die Entwicklung biotechnologischer und biologisch inspirierter Anwendungen von großer Wichtigkeit. Im Fokus stehen vor allem Hydrogenasen und Nitrogenasen; beides Enzyme, die durch Reduktion von Protonen (H+) Wasserstoffgas (H2) herstellen. Hier demonstrieren wir, wie mithilfe einer Kombination von Rotierende‐Ring‐Scheiben‐Elektrochemie (RRDE) und Massenspektrometrie (MS) die Produktion von H2 und seiner Isotope HD und D2 nachverfolgt werden kann. Als Modell für H2‐produzierende Metalloenzyme verwenden wir die [FeFe]‐Hydrogenase aus Clostridium pasteurianum. Unsere Technik ermöglicht enzymologische Studien ohne Verwendung chemischer Reduktionsmittel, die unerwünschte Nebenwirkungen haben können. Wir gehen davon aus, dass dieser Ansatz einen wertvollen Beitrag zur Aufklärung des Reaktionsmechanismus H2‐produzierender Metalloenzyme leisten wird und die Entwicklung biologisch inspirierter Katalysatoren für H2‐Produktion und N2‐Fixierung begünstigen kann.
Honeycomb Carbon Nanofibers: A Superhydrophilic O2‐Entrapping Electrocatalyst Enables Ultrahigh Mass Activity for the Two‐Electron Oxygen Reduction Reaction
Authors: Dong Kai , Liang Jie , Wang Yuanyuan , Xu Zhaoquan , Liu Qian , Luo Yonglan , Li Tingshuai , Li Lei , Shi Xifeng , Asiri Abdullah M. , Li Quan , Ma Dongwei , Sun Xuping 
Published: February 2021

AbstractElectrocatalytic two‐electron oxygen reduction has emerged as a promising alternative to the energy‐ and waste‐intensive anthraquinone process for distributed H2O2 production. This process, however, suffers from strong competition from the four‐electron pathway leading to low H2O2 selectivity. Herein, we report using a superhydrophilic O2‐entrapping electrocatalyst to enable superb two‐electron oxygen reduction electrocatalysis. The honeycomb carbon nanofibers (HCNFs) are robust and capable of achieving a high H2O2 selectivity of 97.3 %, much higher than that of its solid carbon nanofiber counterpart. Impressively, this catalyst achieves an ultrahigh mass activity of up to 220 A g−1, surpassing all other catalysts for two‐electron oxygen reduction reaction. The superhydrophilic porous carbon skeleton with rich oxygenated functional groups facilitates efficient electron transfer and better wetting of the catalyst by the electrolyte, and the interconnected cavities allow for more effective entrapping of the gas bubbles. The catalytic mechanism is further revealed by in situ Raman analysis and density functional theory calculations.
Synthesis of a novel lignin‐based epoxy resin curing agent and study of cure kinetics, thermal, and mechanical properties
Authors: Chen Bing , Zhang Qiang , Lu Mangeng , Meng Huifa , Qu Zhencai , Xu Chang'an , Jiao Enxiang 
Published: February 2021

AbstractIn this contribution, first of all, the methoxy groups of organic solvent lignin (OSL) was converted to phenolic hydroxyl groups through demethylation reaction for the purpose of fabricating demethylated organic solvent lignin (DOSL). In addition, the resulting DOSL was utilized as a renewable material to synthesize a novel esterified lignin (EDOSL) by reacting with isobutyryl chloride for curing of epoxy resin. Finally, commercial liquid diglycidyl ether of bisphenol A was cured by EDOSL in the presence of 4‐dimethylaminopyridine (DMAP) used as a catalyst based on dual‐curing mechanism. Dual curing is a processing methodology based upon the alliance of two diverse and compatible polymerization reactions occurring sequentially or simultaneously. According to the FTIR spectra and 1H‐NMR analyses, the demethylation of OSL, esterification of DOSL, and the curing reaction of epoxy resin with EDOSL were successfully conducted. The value of the phenolic hydrogen in the DOSL was approximately 4.89 mmol/g, which increased by 12.64% after demethylation. The thermal and mechanical performances of these cured epoxy samples were measured by DSC, DMA, TGA, and tensile testing. The epoxy system cured by 10%wt esterified lignin with 1%wt DMAP possessed the tensile strength of 71.54 ± 7.50 MPa and the initial degradation temperature (T5%) of 370°C, which can compete fairly with commercial aromatic curing agents or other lignin‐based agents studied currently for the curing of epoxy systems.
Multivariate process trajectories for molecular description of MF thermal curing and correlation with hydrolytic stability
Authors: Weiss Stephanie , Seidl Regina , Kessler Waltraud , Kessler Rudolf W. , Zikulnig‐Rusch Edith M. , Kandelbauer Andreas 
Published: February 2021

AbstractDuring curing of thermosetting resins the technologically relevant properties of binders and coatings develop. However, curing is difficult to monitor due to the multitude of chemical and physical processes taking place. Precise prediction of specific technological properties based on molecular properties is very difficult. In this study, the potential of principal component analysis (PCA) and principal component regression (PCR) in the analysis of Fourier transform infrared (FTIR) spectra is demonstrated using the example of melamine‐formaldehyde (MF) resin curing in solid state. FTIR/PCA‐based reaction trajectories are used to visualize the influence of temperature on isothermal cure. An FTIR/PCR model for predicting the hydrolysis resistance of cured MF resin from their spectral fingerprints is presented which illustrates the advantages of FTIR/PCR compared to the combination differential scanning calorimetry/isoconversional kinetic analysis. The presented methodology is transferable to the curing reactions of any thermosetting resin and can be applied to model other technologically relevant final properties as well.
The influence of poly(3,4‐ethylenedioxythiophene) modification on the transport properties and fuel cell performance of Nafion‐117 membranes
Authors: Stenina Irina A. , Yurova Polina A. , Titova Tatyana S. , Polovkova Marina A. , Korchagin Oleg V. , Bogdanovskaya Vera A. , Yaroslavtsev Andrey B. 
Published: February 2021

AbstractNafion‐117/PEDOT composite membranes were synthesized by in situ chemical polymerization of 3,4‐ethylenedioxythiophene (EDOT) using ammonium persulfate as an oxidant. The polymerization of EDOT in Nafion membranes for various EDOT/oxidant treatment sequences was studied for the first time. PEDOT introduction leads to a slight decrease in both the ion‐exchange capacity and water uptake of the composite membranes, as well as to an increase in cationic transport. Membranes initially treated with an oxidant exhibit better conductivity and lower hydrogen permeability. The effect of both modification of Nafion‐117 membranes by PEDOT and hot‐pressing of hydrogen‐oxygen membrane‐electrode assemblies (MEAs) on the performance of proton‐exchange membrane fuel cells was studied. The maximum power density of the fabricated MEAs increases 1.5‐fold: from 510 (for a pristine Nafion‐117 membrane) to 810 mW cm−2 (for a membrane modified by PEDOT). The current density at a voltage of 0.4 V reaches 1248 and 2246 mA cm−2, respectively.
Improved Stabilities of Labeling Probes for the Selective Modification of Endogenous Proteins in Living Cells and In Vivo
Authors: Lin Kuan‐Yu , Hin Lam Chak , Lin Xin‐Hui , Hsu Jung‐I , Fan Syuan‐Yun , Gupta Nitesh K. , Lin Yu‐Chun , Khoon Tee Boon , Li Jui‐Ping , Chen Jen‐Kun , Tan Kui‐Thong 
Published: February 2021

AbstractTo date, various affinity‐based protein labeling probes have been developed and applied in biological research to modify endogenous proteins in cell lysates and on the cell surface. However, the reactive groups on the labeling probes are also the cause of probe instability and nonselective labeling in a more complex environment, e. g., intracellular and in vivo. Here, we show that labeling probes composed of a sterically stabilized difluorophenyl pivalate can achieve efficient and selective labeling of endogenous proteins on the cell surface, inside living cells and in vivo. As compared with the existing protein labeling probes, probes with the difluorophenyl pivalate exhibit several advantages, including long‐term stability in stock solutions, resistance to enzymatic hydrolysis and can be customized easily with diverse fluorophores and protein ligands. With this probe design, endogenous hypoxia biomarker in living cells and nude mice were successfully labeled and validated by in vivo, ex vivo, and immunohistochemistry imaging.
Changes in the topology of DNA replication intermediates: Important discrepancies between in vitro and in vivo
Authors: Schvartzman Jorge B. , Martínez Víctor , Hernández Pablo , Krimer Dora B. , Fernández‐Nestosa María‐José 
Published: February 2021

AbstractThe topology of DNA duplexes changes during replication and also after deproteinization in vitro. Here we describe these changes and then discuss for the first time how the distribution of superhelical stress affects the DNA topology of replication intermediates, taking into account the progression of replication forks. The high processivity of Topo IV to relax the left‐handed (+) supercoiling that transiently accumulates ahead of the forks is not essential, since DNA gyrase and swiveling of the forks cooperate with Topo IV to accomplish this task in vivo. We conclude that despite Topo IV has a lower processivity to unlink the right‐handed (+) crossings of pre‐catenanes and fully replicated catenanes, this is indeed its main role in vivo. This would explain why in the absence of Topo IV replication goes‐on, but fully replicated sister duplexes remain heavily catenated.
Effects of topological constraints on the alignment and maturation of multinucleated myotubes
Authors: Song Ki‐Young , Correia Jorge C. , Ruas Jorge L. , Teixeira Ana I. 
Published: February 2021

AbstractMicrofluidic‐based technologies enable the development of cell culture systems that provide tailored microenvironmental inputs to mammalian cells. Primary myoblasts can be induced to differentiate into multinucleated skeletal muscle cells, myotubes, which are a relevant model system for investigating skeletal muscle metabolism and physiology in vitro. However, it remains challenging to differentiate primary myoblasts into mature myotubes in microfluidics devices. Here we investigated the effects of integrating continuous (solid) and intermittent (dashed) walls in microfluidic channels as topological constraints in devices designed to promote the alignment and maturation of primary myoblast‐derived myotubes. The topological constraints caused alignment of the differentiated myotubes, mimicking the native anisotropic organization of skeletal muscle cells. Interestingly, dashed walls facilitated the maturation of skeletal muscle cells, as measured by quantifying myotube cell area and the number of nuclei per myotube. Together, our results suggest that integrating dashed walls as topographic constraints in microfluidic devices supports the alignment and maturation of primary myoblast‐derived myotubes.
An antitumor peptide RS17‐targeted CD47, design, synthesis, and antitumor activity
Authors: Wang Xinmin , Wang Ying , Hu Jialiang , Xu Hanmei 
Published: February 2021

AbstractBackgroundCD47 is a widely expressed transmembrane protein located on the surface of somatic cells. It mediates a variety of cellular processes including apoptosis, proliferation, adhesion, and migration. An important role for CD47 is the transmission of a “Don't eat me” signal by interacting with SIRPα on the macrophage surface membrane, thereby preventing the phagocytosis of normal cells. However, cancer cells can take advantage of this autogenous signal to protect themselves from phagocytosis, thus enabling immune escape. Blocking the interaction between CD47 and SIRPα has proven to be effective in removing cancer cells. The treatment of various cancers with CD47 monoclonal antibodies has also been validated.MethodsWe designed and synthesized a peptide (RS17), which can specifically bind to CD47 and block CD47‐SIRPα signaling. The affinity of RS17 for CD47‐expressing tumor cells was determined, while the inhibition of CD47‐SIRPα signaling was evaluated in vitro and in vivo.ResultsThe results indicated that RS17 significantly promotes the phagocytosis of tumor cells by macrophages and had a similar therapeutic effect compared with a positive control (CD47 monoclonal antibodies). In addition, a cancer xenograft mouse model was established using CD47‐expressing HepG2 cells to evaluate the effect of RS17 on tumor growth in vivo. Using ex vivo and in vivo mouse models, RS17 demonstrated a high inhibitory effect on tumor growth.ConclusionsBased on our results, RS17 may represent a novel therapeutic peptide for cancer therapy.
Giant saccular abdominal aortic aneurysm with manifestation of gastric inlet obstruction mimicking a fundal gastrointestinal stromal tumor: A report on an unexpected case
Authors: Maleki Farid , Jahanshahi Fatemeh , Vahedian‐Ardakani Jalal 
Published: February 2021

AbstractWe present an extremely rare report on gastric inlet obstruction due to giant abdominal aortic aneurysm. Despite the rare occurrence of this manifestation, it should be considered in the differential diagnosis of gastric inlet obstructions.
Comparative study between Partial Least Squares and Rational function Ridge Regression models for the prediction of moisture content of woodchip samples using a handheld spectrophotometer
Authors: Mancini Manuela , Taavitsainen Veli‐Matti , Toscano Giuseppe 
Published: February 2021

AbstractThe use of woodchip for energy use is expected to increase in the next years because of the European targets for mitigating climate change and reducing greenhouse gas emissions. The technical standard EN ISO 17225‐4 determines the woodchip quality classes based on different chemical–physical parameters. Among them, moisture content is one of the most important, and its real‐time monitoring could improve the product quality, increase combustion efficiency, and consequently provide a potential decrease of pollutant emissions. Although the lab procedure to determine moisture content is quite simple, it is too long compared to the real needs of power plant operators. A rapid and simple solution may be represented by near‐infrared spectroscopy coupled with chemometric techniques. In detail, two regression methods, that is, Partial Least Squares (PLS) and Rational function Ridge Regression (RRR), have been compared in order to develop a good model for the prediction of moisture content of woodchip samples as arrived at the lab or directly in the power plant. In addition, the prediction performance has been studied as a function of the number of the spectral measurements of the sample. The results showed that handheld instruments could give reliable results by taking enough replicated spectra. According to the estimated measurement uncertainty of moisture measurements, both methods suffer from lack of fit, and the performance could be better if all unknown sources of errors could be eliminated. In general, RRR performs significantly better than PLS, although, as with many nonlinear methods, the risk for outliers in predictions with RRR is higher than with PLS. This could be overpassed performing predictions with both methods, and in cases of big differences, PLS prediction could be chosen.
Experiments and simulation of liquid drainage in oscillating packed beds under roll and heave motions
Authors: Zhang Jian , Larachi Faïçal , Iliuta Ion , Taghavi Seyed M. 
Published: February 2021

AbstractReplication in the laboratory of offshore sea/swell movements is an essential component in the study and design of unit operations commissioned for seagoing vessels. Whether these perturbations affect the internal fluid flow structure inside reactors on‐board ships is yet to be investigated. This study focuses on understanding the phenomenon of liquid drainage of a porous medium submitted to hexapod‐controlled column oscillations. Liquid saturation transients, drainage rate, and drainage velocity were monitored using wire‐mesh sensors in porous media, under forced tilting (roll) and non‐tilting (heave) oscillations. A 3D/transient Eulerian two‐fluid model was also solved in the robot moving reference frame to reproduce the accelerated liquid drainage measured in oscillating columns. Such acceleration was highlighted by unveiling the relationship between the roll amplitude, the wall‐region greater permeability, and the uneven crosswise liquid distribution. Finally, the moving‐frame fictitious acceleration forces stemming from column oscillations were found to be negligibly small compared with the gravity both under heave and roll excitations.
Thromboembolism, mortality, and bleeding in 2,435,541 atrial fibrillation patients with and without cancer: A nationwide cohort study
Authors: Pastori Daniele , Marang Amélie , Bisson Arnaud , Menichelli Danilo , Herbert Julien , Lip Gregory Y. H. , Fauchier Laurent 
Published: February 2021

BackgroundThe number of patients with atrial fibrillation (AF) and cancer is rapidly increasing in clinical practice. The impact of cancer on clinical outcomes in this patient population is unclear, as is the performance of the HAS‐BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol) and CHA2DS2‐VASc (Congestive Heart Failure, Hypertension, Age ≥ 75 years, Diabetes Mellitus, Stroke or Transient Ischemic Attack, Vascular Disease, Age 65 to 74 Years, Sex Category) scores.MethodsThis was an observational, retrospective cohort study including 2,435,541 adults hospitalized with AF. The authors investigated the incidence rates (IRs) of all‐cause and cardiovascular mortality, ischemic stroke, major bleeding, and intracranial hemorrhage (ICH) according to the presence of cancer and cancer types.ResultsOverall, 399,344 (16.4%) had cancer, with the most common cancers being metastatic, prostatic, colorectal, lung, breast, and bladder. During a mean follow‐up of 2.0 years, cancer increased all‐cause mortality (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.99‐2.01). The IR of ischemic stroke was higher with pancreatic cancer (2.8%/y), uterine cancer (2.6%/y), and breast cancer (2.6%/y), whereas it was lower with liver/lung cancer (1.9%/y) and leukemia/myeloma (2.0%/y), in comparison with noncancer patients (2.4%/y). Cancer increased the risk of major bleeding (HR, 1.27; 95% CI, 1.26‐1.28) and ICH (HR, 1.07; 95% CI, 1.05‐1.10). Leukemia, liver cancer, myeloma, and metastatic cancers showed the highest IRs for major bleeding/ICH. Major bleeding and ICH rates progressively increased with the HAS‐BLED score, which showed generally good predictivity with C indexes > 0.70 for all cancer types. The CHA2DS2‐VASc score's predictivity was slightly lower in AF patients with cancer.ConclusionsCancer increased all‐cause mortality, major bleeding, and ICH risk in AF patients. The association between cancer and ischemic stroke differed among cancer types, and in some types, the risk of bleeding seemed to exceed the thromboembolic risk.