bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Controllable Reconstruction of Bi‐MOFs for Electrochemical CO2 Reduction through Electrolyte and Potential Mediation
Authors: Yao Dazhi , Tang Cheng , Vasileff Anthony , Zhi Xing , Jiao Yan , Qiao Shi‐Zhang 
Published: July 2021

AbstractMonitoring and controlling the reconstruction of materials under working conditions is crucial for the precise identification of active sites, elucidation of reaction mechanisms, and rational design of advanced catalysts. Herein, a Bi‐based metal–organic framework (Bi‐MOF) for electrochemical CO2 reduction is selected as a case study. In situ Raman spectra combined with ex situ electron microscopy reveal that the intricate reconstruction of the Bi‐MOF can be controlled using two steps: 1) electrolyte‐mediated dissociation and conversion of Bi‐MOF to Bi2O2CO3, and 2) potential‐mediated reduction of Bi2O2CO3 to Bi. The intentionally reconstructed Bi catalyst exhibits excellent activity, selectivity, and durability for formate production, and the unsaturated surface Bi atoms formed during reconstruction become the active sites. This work emphasizes the significant impact of pre‐catalyst reconstruction under working conditions and provides insight into the design of highly active and stable electrocatalysts through the regulation of these processes.
Structure investigation, density functional theory, and biostudy of synthesized dihydrazone incorporating isatin moiety and its homo‐bimetallic complexes
Authors: Shakdofa Mohamad M. E. , Saleem Qaid M. , Shakdofa Adel M. E. 
Published: July 2021

AbstractSeven homo‐bimetallic complexes derived from 3‐(‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)methylene)hydrazono)indolin‐2‐one with Fe3+, Co2+, Cu2+, and UO22+have been prepared and structurally investigated using elemental and thermo‐gravimetric analyses and spectral, magnetic, and molar conductivity measurements. This structural investigation leads us to conclude that the bis‐hydrazone has behaved as neutral tetradentate chelator chelated to the Fe3+, Co2+, Cu2+, and UO22+ions via the carbonyl and azomethine groups adopting distorted octahedral structure for Fe3+, Co2+, and Cu2+complexes (2–5), whereas the Cu2+complexes (6–7) have square planar structures. The structural characterization of bis‐hydrazone and its chelated compounds has been supported by density functional theory calculations. The optimized geometry, global reactivity descriptors, and lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the molecules have been calculated in accordance with the density functional theory (DFT)‐Beckee3eLeeeYangeParr (B3LYP) technique and 6e311G(d,p) basis set. The molecular electrostatic potential image was also drawn by the DFT‐B3LYP technique and 6e311G(d,p) basis set to envision the charge distribution and chemical reactivity on the molecules. The bioeffect of bis‐hydrazone and its chelated compounds was assessed against bacterial strainsBacillus subtilis,Escherichia coli, as well as fungal strainsCanadian albicansandAspergillus niger. The observed data imply encouraging bioeffect of some of these complexes in comparing with the free bis‐hydrazone or amphotericin B (AmB) against all fungalC. albicansandA. niger.
Numerical investigation on deposition rate of mechanically mixed ash particles in an entrained flow reactor
Authors: Wang Yibin , Wang Xiaoxiao , Tan Houzhang , Xu Xinwei 
Published: July 2021

AbstractHomogeneous nucleation and heterogeneous condensation of salt vapors near the wall of superheater or reheater tubes greatly improve the sticky propensity of deposited surfaces or impacting particles and then lead to a fast‐growing rate of initial layer. Based on the deposition experiment of mechanically mixed KCl + SiO2 particles in an entrained flow reactor, a numerical model with considering the salt particle vaporization, salt vapor condensation, and its effect on SiO2 deposition is proposed for simulating impaction and adhesion behavior of molten and solid particles. The results show that deposits are mainly from the impaction of solid and molten particles and the condensation of salt vapors. The condensation rate of salt vapors in the stagnation zone at the windward side of metal probe is maximal. In comparison with the overall deposition rate, although the amount of salt vapors condensed on the probe surface can be negligible, it significantly affects the deposition rate of SiO2 particles. The coupled CFD model over a link between particle sticking and salt vapor condensation could well simulate the deposition behavior of mechanically mixed ash particles under rich‐salt‐vapor atmosphere.
The morphogenesis of porcine femoral head mammillary processes: A structural mechanism of biomechanical stability
Authors: Perrone Jr Ronald Vincent , Williams John Leicester 
Published: July 2021

AbstractThe capital femoral physis is a growth plate located between the head of the femur and femoral neck, which forms a temporary joint where growth plate cartilage is converted to bone by endochondral ossification. The bone‐cartilage‐bone interface develops a unique radial pattern of interdigitating mammillary processes that interlock the femoral head with the metaphysis, increasing biomechanical stability. The arrangement of these mammillary processes may not be a random occurrence and likely serves to provide mechanical mechanisms to enhance biomechanical stability. In this study, we provide a qualitative and quantitative analysis of porcine femoral head mammillary processes and focus on the analysis of six key points of development: the epiphyseal tubercle, epiphyseal cupping, growth plate slope angles, expansion of the epiphyseal subchondral bone plate, epiphyseal elongation, and the emergence of smaller, radially arranged mammillary processes. We introduce a metric of surface roughness analysis to quantify mammillary processes and apply it to analyze the development of the observed radial pattern of peripheral mammillary processes from birth to adolescence. We hypothesized that these processes develop to form a radial pattern with some degree of periodicity beginning relatively early in development of the joint and increase in prominence with age and weight of the animal. These findings may have important implications in the early diagnosis and treatment of the hip disorder slipped capital femoral epiphysis (SCFE). Underdevelopment of femoral head mammillary processes may reduce joint stability and could be a risk factor in SCFE.
Identification of Bioactive Compounds against Aedes aegypti (Diptera: Culicidae) by Bioassays and in Silico Assays
Authors: de Brito Geisiane Amorim , Rocha de Oliveira Paulo Fernando , de Andrade Silva Caliene Melo , de Araújo Neto Moysés Fagundes , Leite Franco Henrique Andrade , Mesquita Paulo Roberto Ribeiro , Mota Tiago Feitosa , Magalhães‐Junior Jairo Torres 
Published: July 2021

AbstractMost of the hematophagous insects act as disease vectors, including Aedes aegypti, responsible for transmitting some of the most critical arboviruses globally, such as Dengue. The use of repellents based on natural products is a promising alternative for personal protection compared to industrial chemical repellents. In this study, the repellent effect of essential oils extracted from Lippia thymoides, Lippia alba, Cymbopogon winterianus, and Eucalyptus globulus leaves was evaluated. Essential oils used showed repellent activity against Ae. aegypti in laboratory bioassays, obtaining protection rates above 70 % from 3.75 mg/mL and higher concentration for all analyzed oils. GC/MS identified 57 constituents, which were used in the ligand‐based pharmacophore model to expose compounds with requirements for repellents that modulate mosquitoes behavior through odorant‐binding protein 1 Ae. aegypti. Ligand‐based pharmacophore model approach results suggested that repellent activity from C. winterianus, L. alba, and L. thymoides essential oils’ metabolites is related to Citronelal (QFIT=26.77), Citronelol (QFIT=11.29), Citronelol acetate (QFIT=52.22) and Geranil acetate (QFIT=10.28) with synergistic or individual activity. E. globulus essential oil's repellent activity is associated with Ledol (0.94 %; QFIT=41.95). Molecular docking was applied to understand the binding mode and affinity of the essential oils’ data set at the protein binding site. According to molecular docking, Citronelol (ChemPLP=60.98) and geranyl acetate (ChemPLP=60.55) were the best‐classified compounds compared to the others and they can be explored to develop new repellents.
Engineered RebH Halogenase Variants Demonstrating a Specificity Switch from Tryptophan towards Novel Indole Compounds
Authors: Sana Barindra , Ho Timothy , Kannan Srinivasaraghavan , Ke Ding , Li Eunice H. Y. , Seayad Jayasree , Verma Chandra S. , Duong Hung A. , Ghadessy Farid J. 
Published: July 2021

AbstractActivating industrially important aromatic hydrocarbons by installing halogen atoms is extremely important in organic synthesis and often improves the pharmacological properties of drug molecules. To this end, tryptophan halogenase enzymes are potentially valuable tools for regioselective halogenation of arenes, including various industrially important indole derivatives and similar scaffolds. Although endogenous enzymes show reasonable substrate scope towards indole compounds, their efficacy can often be improved by engineering. Using a structure‐guided semi‐rational mutagenesis approach, we have developed two RebH variants with expanded biocatalytic repertoires that can efficiently halogenate several novel indole substrates and produce important pharmaceutical intermediates. Interestingly, the engineered enzymes are completely inactive towards their natural substrate tryptophan in spite of their high tolerance to various functional groups in the indole ring. Computational modelling and molecular dynamics simulations provide mechanistic insights into the role of gatekeeper residues in the substrate binding site and the dramatic switch in substrate specificity when these are mutated.
Enhancement of the Catalytic Activity of Hammerhead Ribozymes by Organic Cations
Authors: Nakano Shu‐ichi , Yamashita Hirofumi , Sugimoto Naoki 
Published: July 2021

AbstractCatalytic turnover is important for the application of ribozymes to biotechnology. However, the turnover is often impaired because of the intrinsic high stability of base pairs with cleaved RNA products. Here, organic cations were used as additives to improve the catalytic performance of hammerhead ribozyme constructs that exhibit different kinetic behaviors. Kinetic analysis of substrate cleavage demonstrated that bulky cations, specifically tetra‐substituted ammonium ions containing pentyl groups or a benzyl group, have the ability to greatly increase the turnover rate of the ribozymes. Thermal stability analysis of RNA structures revealed that the bulky cations promote the dissociation of cleaved products and refolding of incorrectly folded structures with small disruption of the catalytic structure. The use of bulky cations is a convenient method for enhancing the catalytic activity of hammerhead ribozymes, and the approach may be useful for advancing ribozyme technologies.
Structure Elucidation of Complex Endotaxially Intergrown Lanthanum Barium Oxonitridosilicate Oxides by Combination of Microfocused Synchrotron Radiation and Transmission Electron Microscopy
Authors: Gamperl Lisa , Neudert Lukas , Schultz Peter , Durach Dajana , Schnick Wolfgang , Oeckler Oliver 
Published: July 2021

AbstractSingle‐crystalline domains in intergrown microcrystalline material of the new compounds Ba22.5+xLa55−x[Si129N240−xOx]O3:Ce3+ and Ba25.5+xLa77−x[Si170N312−xO9+x]O4:Ce3+ were identified by transmission electron microscopy (TEM). Precise diffraction data from these domains were collected with microfocused synchrotron radiation so that crystal structure elucidation of the complex disordered networks became possible. They are composed of two different interconnected slabs of which one is similar in both compounds, which explains their notorious intergrowth. The distribution of Ba and La is indicated by the analysis of bond‐valence sums and by comparison with isostructural Sr28.5+xLa75−x[Si170N312−xO9+x]O4. Ce3+ doping leads to yellow luminescence. This is a showcase that highlights the discovery and accurate characterization of new compounds relevant for luminescence applications from heterogeneous microcrystalline samples by exploiting the capability of the combination of TEM and diffraction using the latest focusing techniques for synchrotron radiation.
Triplet Exciton Upconverting Blue Exciplex Host for Deep Blue Phosphors
Authors: Hui Yun Ju , Lim Junseop , Yeob Lee Jun , Lee Yoonkyoo , Chu Changwoong 
Published: July 2021

AbstractA thermally activated delayed fluorescence (TADF)‐type exciplex host employing a novel electron‐transport type (n‐type) type host managing positive polarons and stabilizing excitons was developed to elongate the device lifetime of deep blue phosphorescent organic light‐emitting diodes (PhOLEDs). The bipolar n‐type host was designed to prevent hole leakage and secure hole stability while being stabilized under excitons by introducing a CN‐modified carbazole moiety as a weak donor. The TADF‐type exciplex host‐based blue PhOLEDs showed high (above 20 %) quantum efficiency with a deep blue color coordinate of (0.14, 0.16) and elongated device lifetime. The device operational lifetime of the blue PhOLEDs bearing the TADF‐type exciplex host was extended by more than twice compared to that of the exciplex‐free unipolar host. This work suggested a design concept of the n‐type host to develop the TADF‐type exciplex host for deep blue phosphors to reach a long lifespan in the deep blue PhOLEDs.
Regioselective trans‐Hydrostannation of Boron‐Capped Alkynes
Authors: Melot Romain , Saiegh Tomas J. , Fürstner Alois 
Published: July 2021

AbstractAlkynyl‐B(aam) (aam=anthranilamidato) derivatives are readily available bench‐stable compounds that undergo remarkably selective reactions with Bu3SnH in the presence of [Cp*RuCl]4 as the catalyst. The addition follows a stereochemically unorthodox trans‐selective course; in terms of regioselectivity, the Bu3Sn‐ unit is delivered with high fidelity to the C‐atom of the triple bond adjacent to the boracyclic head group (“alpha,trans‐addition”). This outcome is deemed to reflect a hydrogen bonding interaction between the protic −NH groups of the benzo‐1,3,2‐diazaborininone ring system and the polarized [Ru−Cl] bond in the loaded catalyst, which locks the substrate in place in a favorable orientation relative to the incoming reagent. The resulting isomerically (almost) pure gem‐dimetalated building blocks are amenable to numerous downstream functionalizations; most remarkable is the ability to subject the −B(aam) moiety to Suzuki‐Miyaura cross coupling without need for prior hydrolysis while keeping the adjacent Bu3Sn‐ group intact. Alternatively, the tin residue can be engaged in selective tin/halogen exchange without touching the boron substituent; the fact that the two ‐NH entities of −B(aam) do not protonate organozinc reagents and hence do not interfere with Negishi reactions of the alkenyl halides thus formed is another virtue of this so far underutilized boracycle. Overall, the ruthenium catalyzed trans‐hydrostannation of alkynyl‐B(aam) derivatives opens a practical gateway to isomerically pure trisubstituted alkenes of many different substitution patterns by sequential functionalization of the 1‐alkenyl‐1,1‐heterobimetallic adducts primarily formed.
An Optimized Protocol for the Synthesis of Peptides Containing trans‐Cyclooctene and Bicyclononyne Dienophiles as Useful Multifunctional Bioorthogonal Probes
Authors: La–Venia Agustina , Dzijak Rastislav , Rampmaier Robert , Vrabel Milan 
Published: July 2021

AbstractDespite the great advances in solid‐phase peptide synthesis (SPPS), the incorporation of certain functional groups into peptide sequences is restricted by the compatibility of the building blocks with conditions used during SPPS. In particular, the introduction of highly reactive groups used in modern bioorthogonal reactions into peptides remains elusive. Here, we present an optimized synthetic protocol enabling installation of two strained dienophiles, trans‐cyclooctene (TCO) and bicyclononyne (BCN), into different peptide sequences. The two groups enable fast and modular post‐synthetic functionalization of peptides, as we demonstrate in preparation of peptide‐peptide and peptide‐drug conjugates. Due to the excellent biocompatibility, the click‐functionalization of the peptides can be performed directly in live cells. We further show that the introduction of both clickable groups into peptides enables construction of smart, multifunctional probes that can streamline complex chemical biology experiments such as visualization and pull‐down of metabolically labeled glycoconjugates. The presented strategy will find utility in construction of peptides for diverse applications, where high reactivity, efficiency and biocompatibility of the modification step is critical.
Hierarchical Nanoporous C/C Composite from Humic Fulvic Acid and Sulfonated Pitch for High‐Energy‐Density EDLC Electrodes
Authors: Chang Panpan , Yang Fan , Cen Yongbing , Zheng Jie , Li Xuguang , Xie Qingruo , Dong Jinshi 
Published: July 2021

AbstractAs a new type of energy storage device, electric double layer capacitors (EDLCs) possess fast charge/discharge speed and good cycling stability. However, the low energy density and high production cost of EDLC electrodes are still big challenges. Herein, a hierarchical nanoporous C/C composite is synthesized by chemical recombination and subsequent activation strategy from low‐cost carbon resources, namely renewable humic fulvic acid (FA) and industrial sulfonated pitch (SP). Profiting from the abundant polycyclic aromatic hydrocarbons in SP and plentiful oxygen‐containing groups in FA, the resultant nanoporous C/C composite has both high e‐conductivity and high specific surface area (SSA). Thus, this porous C/C composite can be directly fabricated as EDLC electrode without any conductive agent. By fully exploiting the synergistic effect between high e‐conductivity and high SSA, it shows excellent electrochemical stability in EMIMBF4 ionic liquid electrolyte. Furthermore, it possesses a higher specific gravimetric capacitance (117 F g−1) than that of pure FA‐based porous carbon (92.5 F g−1) at a current density of 1 A g−1. More importantly, the maximum energy density can be as high as 55.4 Wh kg−1, largely better than commercial activated carbon.
Dose‐dependent effects of aerobic exercise on clinically relevant biomarkers among healthy women at high genetic risk for breast cancer: A secondary analysis of a randomized controlled study
Authors: Ehret Christopher J. , Zhou Shouhao , Tchou Julia C. , Schmitz Kathryn H. , Sturgeon Kathleen M. 
Published: July 2021

AbstractBackgroundExcess adiposity and dysregulated metabolism are associated with increased cancer risk. Triglycerides, cholesterol, glucose, insulin, HOMA‐IR, and VO2max are robust clinical‐metabolic biomarkers of overall health.AimsAerobic exercise may improve clinical‐metabolic biomarkers and decrease cancer risk. This secondary analysis of the WISER Sister randomized controlled trial investigated dose‐dependent effects of aerobic exercise on clinical biomarker levels in women at high genetic risk for breast cancer.Methods and ResultsOne hundred thirty‐nine participants were randomized to: control (<75 min/week), low‐dose (150 min/week), and high‐dose (300 min/week) aerobic exercise intervention groups. Intervention adherence was assessed via heart monitor. Fasting blood draws, cardio‐pulmonary tests, and demographical surveys were taken at baseline and 5 months. Triglyceride, cholesterol, glucose, insulin, and VO2max changes were assessed for 80 of the 122 study completers. Ninety‐six percent of assayed‐completers adhered to >80% of their exercise dose. A significant dose‐dependent increase in VO2max was observed for the low‐dose and high‐dose groups compared to control. No intervention effects were observed for plasma biomarkers. Overweight women (BMI > 25) showed a significant decrease in insulin levels and a trend for decreased triglycerides following exercise intervention. Significant increases in VO2max were independent of BMI stratification.ConclusionWomen at high genetic risk for breast cancer should maintain healthy weights and aerobic capacities through aerobic exercise to achieve measurable benefits on overall health. For overweight women, exercise appears to improve subclinical metabolic dysregulation. However, normal weight women were unaffected by aerobic exercise as their biomarker levels may be below the threshold for improvement. VO2max increases solely quantified the benefits of exercise in already healthy women at high‐risk for breast cancer.
Effect of occlusal anatomy of CAD/CAM feldspathic posterior crowns in the stress concentration and fracture load
Authors: Borges Alexandre Luiz Souto , Tribst João Paulo Mendes , de Lima Aline Lins , Dal Piva Amanda Maria de Oliveira , Özcan Mutlu 
Published: July 2021

AbstractObjectivesThis study evaluated the effect of restoration occlusal design on the maximum fracture load and stress distribution of a feldspathic ceramic crown.Materials and MethodsTwenty dentin analogues were used to simulate a full‐crown preparation. Next, 20 feldspathic crowns were milled according to the occlusal design parameter available in the CAD database (Young or Adult). The crowns were cemented with dual cure resin‐cement and loaded until fracture at 1 mm/min crosshead speed. Data were analyzed by using one‐way ANOVA and Tukey tests (p < 0.05). The same geometry and experimental setup was modeled and exported to the computer aided engineering software and tensile stress concentration was calculated using the finite element method with 300 N occlusal load simulation.ResultsThe occlusal anatomy significantly influenced the load‐to‐fracture (p < 0.05). Adult design showed higher mean values (1149 ± 201 N) than Young design (454 ± 77 N). The maximum principal stress criteria showed similar stress pattern for both designs, however, the highest stress concentration was calculated for Young design (91 MPa) in the occlusal surface.ConclusionsAn anatomy design with reduced cusp angulation and less evident occlusal sulcus can reduce the stress concentration and increase the fracture load for feldspathic CAD/CAM posterior crowns.
A study of the effect of self‐generated pressure gradient sources on the resistive filamentation instability
Authors: Mahdavi Mohammad , Khanzadeh Hengameh 
Published: July 2021

AbstractIn the field of fast ignition scheme, self‐generated magnetic fields via beam resistive filamentation have a significant role in the angular divergence of the relativistic electron beam, which can be affected by the intensity of other self‐generated magnetic fields. In this context, the effects of pressure gradient sources arising from temperature and density gradient of the pellet along the beam flow direction are investigated. The results showed that the resistive filamentation instability can be strongly amplified compared to the fully homogeneous plasma. In this respect, for the distance away from the critical surface, the instability is protected for a longer wave number. Also, the beam and plasma properties such as the beam relativistic factor, the beam number density, and the degree of the plasma temperature anisotropy might be effective.