bluuebunny/crossref_metadata_2025_split huggingface dataset:
Devulcanization of ethylene‐propylene‐diene monomer rubber waste. Effect of diphenyl disulfide derivate as devulcanizing agent on vulcanization, and devulcanization process
Authors: Gschwind Larissa , Jordan Carmen‐Simona , Vennemann Norbert 
Published: January 2022

AbstractA systematic study was performed to understand the effects of the devulcanizing agent dibenzamido diphenyl disulfide (DBD) on the vulcanization and devulcanization process of a sulfur‐cured ethylene‐propylene‐diene monomer (EPDM) rubber. The influence of DBD on vulcanization was investigated by mixing DBD with virgin rubber and curative system. The devulcanization of rubber waste was achieved with varying amounts of DBD ranging from 0.4 to 13.8 wt% and temperatures from 150 to 200°C. The quality of vulcanizates and devulcanizates was evaluated by rheometer tests, temperature scanning stress relaxation measurements, and analysis of mechanical properties. During vulcanization, DBD acts as an accelerator in the presence of sulfur. When accelerators are added, the scorch time increases, and the cure rate decreases. Thus, DBD acts as a retarder. In the presence of activators, DBD leads to a significant reduction of crosslink density. This results in composites with high elongation at break and poor compression set values. The efficiency of the devulcanization of rubber waste depends strongly on DBD concentration and temperature. The monosulfidic crosslinks are cleaved by low concentrations of DBD, while polysulfidic crosslinks require higher concentrations. These results show that DBD is effective as a devulcanizing agent and degrades the network below 200°C.
Fluorescent ABC‐Triblock Polymer Nanocarrier for Cisplatin Delivery to Cancer Cells
Authors: Kulkarni Bhagyashree , Malhotra Mehak , Jayakannan Manickam 
Published: January 2022

AbstractMonitoring intracellular administration of non‐luminescent anticancer drugs like cisplatin is a very challenging task in cancer research. Perylenebisimide (PBI) chromophore tagged fluorescent ABC‐triblock polycaprolactone (PCL) nanoscaffold was engineered having carboxylic acid blocks for the chemical conjugation of cisplatin at the core and hydrophilic PEG blocks at the periphery. The amphiphilic ABC triblock Pt‐prodrug was self‐assembled into <200 nm nanoparticles and exhibited excellent shielding against drug detoxification by the glutathione (GSH) species in the cytosol. In vitro drug release studies confirmed that the Pt‐prodrug was stable at extracellular conditions and the PCL block exclusively underwent lysosomal‐enzymatic biodegradation at the intracellular level to release the cisplatin drug in the active‐form for accomplishing more than 90% cell growth inhibition. Confocal microscopic imaging of the red‐fluorescence signals from the perylene chromophores established the simultaneous monitoring and delivery aspects of the Pt‐prodrug, and the proof‐of‐concept was successfully demonstrated in breast and cervical cancer cell lines.
Hysteresis Nanoarchitectonics with Chiral Gel Fibers and Achiral Gold Nanospheres for Reversible Chiral Inversion
Authors: Xu Hui , Zhang Qi , Gan Jia‐An , Wang Zhuo , Chen Meng , Shan Yahan , Chen Shaoyu , Tong Fei , Qu Da‐Hui 
Published: January 2022

AbstractIntelligent control over the handedness of circular dichroism (CD) is of special significance in self‐organized biological and artificial systems. Herein, we report a chiral organic molecule (R1) containing a disulfide unit self‐assembles into M‐type helical fibers gels, which undergoes chirality inversion by incorporating gold nanospheres due to the formation of Au−S bonds between R1 and gold nanospheres. Upon heating at 80 °C, the aggregation of gold nanospheres results in a disappearance of the Au−S bond, allowing the reversible switching back to M‐type helical fibers. The original chirality of M‐type fibers could also be retained by adding anisotropic gold nanorods. A series of characterization methods, involving CD, Raman, Infrared spectroscopy, electric microscopy, and small‐angle X‐ray scattering (SAXS) measurements were used to investigate the mechanism of chiral evolutions. Our results provide a facile way of fabricating hysteresis nanoarchitectonics to achieve dynamic supramolecular chirality using inorganic metallic nanoparticles.
Localizing flares to understand stellar magnetic fields and space weather in exo‐systems
Authors: Ilin Ekaterina , Poppenhäger Katja , Alvarado‐Gómez Julián D. 
Published: January 2022

AbstractStars are uniform spheres, but only to first order. The way in which stellar rotation and magnetism break this symmetry places important observational constraints on stellar magnetic fields, and factors in the assessment of the impact of stellar activity on exoplanet atmospheres. The spatial distribution of flares on the solar surface is well known to be nonuniform, but elusive on other stars. We briefly review the techniques available to recover the loci of stellar flares, and highlight a new method that enables systematic flare localization directly from optical light curves. We provide an estimate of the number of flares we may be able to localize with the Transiting Exoplanet Survey Satellite, and show that it is consistent with the results obtained from the first full sky scan of the mission. We suggest that nonuniform flare latitude distributions need to be taken into account in accurate assessments of exoplanet habitability.
A systematic review of geospatial representation of United States community water systems
Authors: McDonald Yolanda J. , Anderson Kayla M. , Caballero Mariah D. , Ding Ke Jack , Fisher Douglas H. , Morkel Caroline P. , Hill Elaine L. 
Published: January 2022

AbstractThis study presents a state‐level systematic review of geospatial representation of Community Water Systems (CWSs) in the United States. We conducted online searches and contacted government, water industry, and academic representatives to obtain these data. CWS geospatial data were characterized by vector type, methodological approaches, data sources, availability to the public, entities involved in creation and maintenance of data, and CWS map requirements by primacy agency. We found that 24 states and the District of Columbia had geospatial representation of CWS estimated service area boundary (ESAB) (i.e., polygons), which were harmonized to construct a geospatial database representative of available CWS ESABs. Our findings aim to prompt discussion among myriad stakeholders on the need to create, standardize, and maintain CWS ESABs to ensure water justice for all communities.
Bioassay Directed Fractionation of Petroleum Ether Extract of Aerial Parts of Ceriops tagal: Isolation of Lupeol as the Nematicidal Agent against Cyst Nematode Heterodera zeae
Authors: Ahmad Ateeq , Siddiqui Pirzada J. A. , Fayyaz Shahina , Khan Kehkashan , Iqbal Erum Y. , Rasheed Munawwer , Muzafar Wajeeha , Faizi Shaheen 
Published: January 2022

AbstractPlant parasitic cyst nematode Heterodera zeae is a pest, causing substantial economic losses in agriculture. Organic pesticides, based on plant products have emerged as eco‐benign nematicidal agents. Ceriops tagal is a well‐known marine medicinal plant which has not been evaluated against any nematode. Petroleum ether extract of the aerial parts of the plant (CTP), exhibited promising activity against infective stage larvae of H. zeae. On subjecting to classical solvent‐solvent separation, it afforded petroleum ether soluble (CTP‐S), methanol soluble (CTPMS‐1, CTPMS‐2) and insoluble (CTPM‐IN‐2) fractions, which exhibited activity against the cyst nematode within 24 h exposure. GC, GC/MS and HR‐ESI‐MS analyses of CTPMS‐1 and CTPMS‐2 fractions resulted in the identification of a number of compounds, including pentacyclic triterpenoids, lupeol (1), betunal (2), betulin (3), lupenone (4), betulonaldehyde (5), betulonic acid (7), methyl 3‐acetoxy‐27‐O‐(3,4‐dihydroxy‐E‐cinnamoyl)‐20(29)‐lupen‐28‐oate (8) and β‐amyrin, along with phenylpropanoid esters, fatty acids and their derivatives, benzamide, and indole derivatives. CTPM‐IN‐2 which mainly contained lupeol (1) exhibited maximum nematicidal activity, with 91 % and 93 % mortality of the larvae of H. zeae, after exposure for 72 h at the concentration of 0.5 % and 1 %, respectively. Its fractionation and purification through column chromatography resulted in the isolation and identification of four lupane‐type triterpenoids 1, 3, 4 and betulinic acid (6). One of its most abundant column fractions CC‐9‐18 (145 mg) which exhibited substantial activity, with 81 % mortality at the lowest concentration of 0.125 % after 48 h of incubation mainly contained lupeol. It seems lupeol, a wide spread bio‐privileged triterpenoid is the nematicidal principle of the plant as its authentic sample showed LC50 value of 0.061 after 72 h exposure. It is for the first time that nematicidal activity is reported for any part of C. tagal and that of lupeol against H. zeae. Pentacyclic triterpenoids 1–8 are biosynthetically related. Of the twenty‐four compounds isolated or identified in the present investigation only five constituents 1, 3, 6, 7 and palmitic acid have been isolated previously from C. tagal.
A Heterogenized Copper Phenanthroline System to Catalyze the Oxygen Reduction Reaction
Authors: van der Ham Cornelis J. M. , Zwagerman Damy N. H. , Wu Longfei , Hofmann Jan P. , Hetterscheid Dennis G. H. 
Published: January 2022

AbstractUpon the electrochemical reduction of an in situ generated 5‐diazo‐1,10‐phenanthroline ion, phenanthroline was covalently attached to a gold electrode. The grafted molecules act as a ligand when brought in contact with a copper‐containing electrolyte solution. As the ligands are limited in spatial movement, the exclusive formation of the active species with only one phenanthroline ligand coordinated was expected. The in situ generated complexes have been investigated for activity in the oxygen reduction reaction, for which an overpotential of 800 mV is observed. During catalysis, initially a thick copper layer is formed on top of an organic layer that is still present on the gold surface. Upon deterioration of the organic layer underneath the copper over time, the amount of copper on the electrode and thereby the electrocatalytic activity decreases.
Rhodium‐Catalyzed C−H Methylation and Alkylation Reactions by Carbene‐Transfer Reactions
Authors: Empel Claire , Jana Sripati , Langletz Tim , Koenigs Rene M. 
Published: January 2022

AbstractIn this combined computational and experimental study, the C−H functionalization of 2‐phenyl pyridine with diazoalkanes was investigated. Initial evaluation by computational methods allowed the evaluation of different metal catalysts and diazoalkanes and their compatibility in this C−H functionalization reaction. With these findings, suitable reaction conditions for the C−H methylation reactions were quickly identified by using highly reactive TMS diazomethane and C−H alkylation reactions with donor/acceptor diazoalkanes, which is applied to a broad scope on alkylation reactions of 2‐aryl pyridines with TMS diazomethane and donor/acceptor diazoalkane (51 examples, up to 98 % yield).
Survey regarding students’ confidence in their experimental capabilities
Authors: Rautenstrauch Hanne , Busker Maike 
Published: January 2022

AbstractExperimentieren ist eine der zentralen Tätigkeiten im Chemieunterricht. Schüler:innen sollen im Rahmen ihrer Schulausbildung u. a. lernen, Hypothesen zu formulieren und Experimente zu entwickeln, mit denen aufgestellte Hypothesen überprüft werden können. Sie sollen Sicherheitsaspekte beim Experimentieren beachten und ihre Durchführungen, Beobachtungen und Auswertungen protokollieren können [1, 2]. Das Erwerben experimenteller Fähigkeiten ist somit eines der zentralen Bildungsziele im Chemieunterricht. Doch wie groß ist das Zutrauen der Schüler:innen in ihre eigenen experimentellen Fähigkeiten? Zeigen sich Unterschiede zwischen Schüler:innen unterschiedlicher Schularten und im Naturwissenschafts‐ bzw. Chemieunterricht? In diesem Beitrag wird eine Schüler:innenbefragung vorgestellt, welche sich mit den experimentellen Selbstwirksamkeitserwartungen von Schüler:innen befasst und den gestellten Fragen nachgeht.
Final esthetic result of ceramic restorations cemented with different colors of cement
Authors: Gomes Catarina , Martins Francisco , Reis José Alexandre , Albacete‐Martinez Carlos Pérez , Maurício Paulo Durão 
Published: January 2022

AbstractObjectiveThe purpose of this study is to evaluate the color changes of lithium disilicate ceramics when cemented with different brands of cement by varying the thickness of the ceramic.Materials and MethodsForty ceramic discs, shade A2, were fabricated with 0.5 and 0.8 mm thickness. Forty composite resin discs, shade A3, were also produced. The ceramic samples were cemented to the composite resin discs, with two colors of resin cement, Neutral and Warm. A spectrophotometer evaluation was made. Translucency and color change analysis was performed by calculating the ΔE. A two‐way analysis of variance test and multiple comparisons were performed using the Bonferroni method with a 95% confidence interval.ResultsThere are statistically significant differences between the two ceramic thicknesses with different brands of cement (p < .001). In addition, using the translucency analysis it was found that there are statistically significant differences between the two ceramic thicknesses in both types of cement (p < .001).ConclusionsThe use of different cementation materials on lithium disilicate ceramics appears to have little visible influence at the clinical level. Different ceramic thicknesses have a clinically visible influence on the final restoration color.
The 21N‐moment multi‐temperature collision coefficients for Zhdanov closure
Authors: Raghunathan M. , Marandet Y. , Bufferand H. , Ciraolo G. , Ghendrih Ph. , Tamain P. , Serre E. 
Published: January 2022

AbstractWe provide the 21N‐moment multi‐temperature collision coefficients for the Boltzmann collision operator using the Sonine‐Hermite polynomial ansatz in the style of Zhdanov et al. First, we outline the general derivation method. Then, we provide the collision coefficients in the most general form in terms of the Chapman‐Cowling integrals for any potential of interaction for the 21N‐moment approximation. Then, we provide the collision coefficients for the specific case of the approximated Coulomb potential cross‐section with Debye cutoff. These coefficients help in order to find easy implementation in current scrape‐off layer/edge fluid packages, which currently implement the 21N‐moment single‐temperature coefficients. This provides the completion of a missing link in the current literature.
Development and application of novel BiFC probes for cell sorting based on epigenetic modification
Authors: Mendonca Agnes , Sánchez Oscar , Zhao Han , Lin Li , Min Alan , Yuan Chongli 
Published: January 2022

AbstractThe epigenetic signature of cancer cells varies with disease progression and drug treatment, necessitating the study of these modifications with single cell resolution over time. The rapid detection and sorting of cells based on their underlying epigenetic modifications by flow cytometry can enable single cell measurement and tracking to understand tumor heterogeneity and progression warranting the development of a live‐cell compatible epigenome probes. In this work, we developed epigenetic probes based on bimolecular fluorescence complementation (BiFC) and demonstrated their capabilities in quantifying and sorting cells based on their epigenetic modification contents. The sorted cells are viable and exhibit distinctive responses to chemo‐therapy drugs. Notably, subpopulations of MCF7 cells with higher H3K9me3 levels are more likely to develop resistance to Doxorubicin. Subpopulations with higher 5mC levels, on the other hand, tend to be more responsive. Overall, we report for the first time, the application of novel split probes in flow cytometry application and elucidated the potential role of 5mC and H3K9me3 in determining drug responses.
Understory evapotranspiration rates in a coast redwood forest
Authors: Kassuelke Shelby R. , Dymond Salli F. , Feng Xue , Savage Jessica A. , Wagenbrenner Joseph W. 
Published: January 2022

AbstractIn forests where the overstorey canopy has been disturbed by timber harvest or other means, evapotranspiration (ET) by the understorey may be the main flux of water back to the atmosphere. However, little research has been apportioned to directly measuring understorey water use, and the technology to do so is thus limited. Here, we used a portable chamber to quickly and directly measure understorey ET by measuring the water flux from the soil and vegetation enclosed by the chamber. This method was used in a third‐growth coast redwood forest to measure ET rates from individuals of five species commonly found in the understorey: Sequoia sempervirens (coast redwood) sprouts, Notholithocarpus densiflorus (tanoak) sprouts, Vaccinium ovatum (evergreen huckleberry) sprouts, Polystichum munitum (sword fern) and Struthiopteris spicant (deer fern). Measurements were conducted in four small watersheds which were harvested to varying intensities ranging from 0% to 75% targeted reduction in preharvest overstory basal area. Mean understorey ET rate was highest in the watershed with the lowest residual basal area (x̅ = 0.036 ± 0.024 mm/h) and lowest in the unharvested control watershed (x̅ = 0.013 ± 0.0078 mm/h). Multiple regression modelling on resprouting species indicated that the difference in ET rate between watersheds was related to soil and light resources. These results imply that understorey water use can be significant, particularly in harvested watersheds, and should be quantified at the landscape scale.
Myocardial strain to identify benefit from beta‐blockers in patients with heart failure with reduced ejection fraction
Authors: Park Chan Soon , Park Jin Joo , Hwang In‐Chang , Park Jun‐Bean , Park Jae‐Hyeong , Cho Goo‐Yeong 
Published: January 2022

AbstractAimsNot all patients with heart failure with reduced ejection fraction (HFrEF) benefit equally from beta‐blockers. Previous studies suggest that myocardial strain that reflects myocardial deformation may have a better prognostic value than the left ventricular ejection fraction. We aimed to evaluate the differential effect of beta‐blockers according to the global longitudinal strain (GLS) in patients with HFrEF.Methods and resultsOf the 4312 patients in the Strain for Risk Assessment and Therapeutic Strategies in Patients with Acute Heart Failure registry, we included 2126 HFrEF patients whose data on beta‐blocker use and GLS were available. Patients were categorized into two groups: one group of patients had GLS ≥ 10%, and the other group had GLS < 10%. The primary outcome was 5 year all‐cause mortality according to beta‐blocker use. Of the 2126 patients with HFrEF, 526 (24.7%) and 1600 (75.3%) patients had GLS ≥ 10% and <10%, respectively. Overall, 1399 patients (65.8%) received beta‐blockers, and 864 (40.6%) patients died during the 5 year follow‐up. Beta‐blocker use was associated with improved survival in patients with GLS < 10% in both the inverse probability treatment‐weighted (hazard ratio 0.70, 95% confidence interval 0.59–0.83, P < 0.001) and Cox regression analyses (hazard ratio 0.69, 95% confidence interval 0.59–0.81; P < 0.001). However, beta‐blocker use was not associated with better survival in patients with GLS ≥ 10% in the inverse probability treatment‐weighted and Cox regression analyses (both P > 0.05).ConclusionsBeta‐blocker use appears to be associated with improved survival in patients with HFrEF and GLS < 10%, but this is not the case in patients with GLS ≥ 10%. Therefore, GLS may be used to identify patients who have attenuated benefits from beta‐blockers in HFrEF.Clinical Trial Registration: ClinicalTrials.gov: NCT03513653 (https://clinicaltrials.gov/ct2/show/NCT03513653).
Impact of instantaneous solar irradiance on refrigeration characteristics of household PCM storage air conditioning directly driven by distributed photovoltaic energy
Authors: Xu Yongfeng , Li Ming 
Published: January 2022

AbstractMature and inexpensive ice thermal storage was employed to replace battery bank in energy storage, and photovoltaic directly driven technology was also combined in this paper. A 3HP household air conditioning assisted with ice thermal storage was investigated in four operating conditions. First, directly driven by photovoltaic arrays, the (COP)rs were almost 6.31% than that of refrigerator driven by power grid for the instantaneous solar irradiance, and the stored cooling capacity decreased 18.63% under the intermittent influence of solar irradiance. Moreover, the (COP)r of refrigerator operating in out‐of‐box mode was about 1.38 times that of operating in ice storage mode. Next, the inevitable compress motor fluctuation, caused by instantaneous solar irradiance, was investigated by experiment and simulation. In three typical weathers, compressor fluctuating time was approximately 65.22 s, 197.05 s, and 270.48 s in full irradiance range. When the lower solar irradiance limit was optimized from 150 to 80 Wm−2, refrigerator operated stably and continuously in any weather conditions. The ice production and the (COP)r were improved by 40.91% and 12.36%, respectively.
An adaptive central‐upwind scheme on quadtree grids for variable density shallow water equations
Authors: Ghazizadeh Mohammad A. , Mohammadian Abdolmajid 
Published: January 2022

AbstractMinimizing computational cost is one of the major challenges in the modeling and numerical analysis of hydrodynamics, and one of the ways to achieve this is by the use of quadtree grids. In this article, we present an adaptive scheme on quadtree grids for variable density shallow water equations. A scheme for the coupled system is developed based on the work of [M.A. Ghazizadeh, A. Mohammadian, and A. Kurganov,Computers & Fluids, 208 (2020)]. The scheme is capable of exactly preserving “lake‐at‐rest” steady states. A continuous piecewise bi‐linear interpolation of the bottom topography function is used to achieve higher‐order in space in order to preserve the positivity of water depth for the point values of each computational cell. Necessary conditions are checked to be able to preserve the positivity of water depth and density, and to ensure the achievement of a stable numerical scheme. At each timestep, local gradients are examined to find new seeding points to locally refine/coarsen the computational grid.