bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Direct One‐Pot Modification of β‐Cyclodextrin via the Ugi‐Five‐Component Reaction
Authors: Schneider Rebekka V. , Sehlinger Ansgar , Meier Michael A. R. 
Published: September 2020

AbstractStarch‐derived β‐cyclodextrins (β‐CDs) are used in pharmacy or the food and cosmetic industry as drug deliverers, separating agents, catalysts, detergents, or viscosity modifiers. However, solubility issues often restrict their potential applications. Here, we report a straightforward and direct one‐pot synthesis for the modification of β‐CDs based on the Ugi‐five‐component reaction (Ugi‐5CR). The Ugi‐5CR requires to react an amine, an aldehyde, an isocyanide, carbon dioxide and the β‐CD, which serves as alcohol component. Overall, five modified β‐CDs containing carbamate moieties were synthesized at room temperature in a high pressure reactor (10 bar) within 24 hours. The successful modifications are verified by mass spectrometry, nuclear magnetic resonance, and infrared spectroscopy, indicating one to three reacted primary hydroxyl groups per β‐CD. Additionally, we report altered solubility behavior of two of the five modified β‐CDs.
A Perspective on Synthesis and Applications of Fluorenones
Authors: Patel Sagarkumar , Rathod Bhagyashri , Regu Siddulu , Chak Shivam , Shard Amit 
Published: September 2020

AbstractFluorenones are important constituents in material, medical and chemical sciences with potential applications in various domains. The key factors responsible for the diverse usage of fluorenones in material sciences are their intriguing and tunable photo, as well as physico‐chemical properties. Besides this, the presence of conjugated poly‐(en)ynes in the fluorenones makes them molecules of interest in material sciences. Fluorenones show various biological activities like antibiotics, anticancer, antiviral, and neuromodulatory, etc. Organic chemists are developing various protocols for the synthesis of fluorenones. Despite several protocols developed for their synthesis since 1931, there is no review covering their entire synthetic protocols. This review includes several classical and novel synthetic approaches for the synthesis of fluorenones. Furthermore, we delineated the mechanism by which they have been synthesized.
Maghnite‐H+ Catalytic Synthesis and Characterization of Polyindenes and Oxidized Derivatives
Authors: Marref Mohamed , Berenguer Raúl , Morallón Emilia , Meghabar Rachid 
Published: September 2020

AbstractThis work presents a comprehensive study on the physico‐chemical and electrochemical properties of polyindenes (PIns) synthesized by Maghnite‐H+‐catalysed polymerization of indene (benzocyclopentadiene) in CH2Cl2 at different temperatures, and their oxidative derivatives by subsequent treatment with FeCl3. The polymers are characterized by TG, FT‐IR, XPS and UV‐vis spectroscopies, as well as electrical conductivity and voltammetric measurements, analysing the influence of synthesis temperature and post‐oxidation. Results show that the PIns synthesized at different temperatures present quite similar thermogravimetric behavior and UV spectra. Nevertheless, FTIR and XPS reveal significant differences in chemical composition and polymer structure depending on this temperature. At higher temperatures, indenyl coupling proceeds via 1,2 carbon atoms to obtain more compact and less defective PIns with higher yields. At lower temperatures, polymerization through 1,3 carbon atoms may also occur, leading to polymers with a larger number of defects and oxygen functionalities and lower yields. FeCl3 treatment causes the introduction of some oxygen functionalities in the compact PIn60 and PIn80 polymers, without significantly affecting their molecular structure and electrical conductivity. Finally, cyclic voltammetry demonstrates that, despite not electro‐active, these partially oxidized PIns show enough electrical conductivity for different applications.
Importance of Chloride Addition on Arsenite Removal by Aluminium Electrocoagulation
Authors: Syam Babu Davuluri , Kadaverugu Rakesh , Veetil Nidheesh Puthiya , Suresh Kumar Manukonda 
Published: September 2020

AbstractEffect of chloride addition on arsenite removal by electrocoagulation process was carried out in this study. Electrocoagulation experiments were executed in a 5 L capacity rectangular tank equipped with 7 anodes and 7 cathodes. Addition of chloride significantly enhanced the arsenite removal efficiency of electrocoagulation process and the removal is purely by the separation process, rather than the oxidation of arsenite to arsenate by electrolytically generated active chlorine. 250 mg L−1 of chloride was found as optimal, and more than 99 % of arsenite were removed from its initial concentration of 1 mg L−1 at pH 6, applied voltage of 5 V, and 60 min of electrolysis. Sludge produced after electrocoagulation treatment was analyzed by scanning electron microscopy (SEM) / energy dispersive X‐ray analysis (EDAX), X‐ray diffraction (XRD), and Fourier transforms infrared (FTIR) techniques.
Synthesis and Evaluation of New 2‐Mercaptomethyl Benzimidazole Scaffolds as Potential Antibacterial, Antioxidant and Cytotoxic Agents
Authors: Khalifa Mohamed E. 
Published: September 2020

AbstractNovel series of benzimidazole derivatives are developed based on the key compound 2‐mercaptomethyl benzimidazole 1. The reactivity of the precursor compound 1 towards nucleophilic reagents enabled us to produce new series with expected bioactivity. The synthesized benzimidazole scaffolds are structurally authenticated and fully characterized by their spectral properties. They exhibit antimicrobial efficiency against selected pathogenic bacteria strains (Gram +ve & ‐ve bacteria) using disc diffusion method, the inhibition clear zones (mm) and MIC are recorded as well. The compounds are also assessed for their cytotoxicity, antioxidant and antitumor activity against HEP−G2 human hepatoma cell line, showing gradient efficiencies related to the chemical structure.
Tunable Surface Selenization on MoO2‐Based Carbon Substrate for Notably Enhanced Sodium‐Ion Storage Properties
Authors: Zeng Fanyan , Yu Maohui , Cheng Wanting , He Wenxiu , Pan Yang , Qu Yaohui , Yuan Cailei 
Published: September 2020

AbstractTransition metal chalcogenides with high theoretical capacity are promising conversion‐type anode materials for sodium ion batteries (SIBs), but often suffer from unsatisfied cycling stability (hundreds of cycles) caused by structural collapse and agglomerate. Herein, a rational strategy of tunable surface selenization on highly crystalline MoO2‐based carbon substrate is designed, where the sheet‐like MoSe2 can be coated on the surface of bundle‐like N‐doped carbon/granular MoO2 substrate, realizing partial transformation from MoO2 to MoSe2, and creating b‐NC/g‐MoO2@s‐MoSe2‐10 with robust hierarchical MoO2@MoSe2 heterostructures and strong chemical couplings (MoC and MoN). Such well‐designed architecture can provide signally improved reaction kinetics and reinforced structural integrity for fast and stable sodium‐ion storage, as confirmed by the ex situ results and kinetic analyses as well as the density functional theory calculations. As expected, the b‐NC/g‐MoO2@s‐MoSe2‐10 delivers splendid rate capability and ultralong cycling stability (254.2 mAh g−1 reversible capacity at 5.0 A g−1 after 6000 cycles with ≈89.0% capacity retention). Therefore, the tunable surface strategy can provide new insights for designing and constructing heterostructures of transition metal chalcogenides toward high‐performance SIBs.
Achieving High‐Performance Perovskite Photovoltaic by Morphology Engineering of Low‐Temperature Processed Zn‐Doped TiO2 Electron Transport Layer
Authors: Wu Ming‐Chung , Lin Yen‐Tung , Chen Shih‐Hsuan , Jao Meng‐Huan , Chang Yin‐Hsuan , Lee Kun‐Mu , Lai Chao‐Sung , Chen Yang‐Fang , Su Wei‐Fang 
Published: September 2020

AbstractPerovskite solar cells (PSCs) have become one of the most promising renewable energy converting devices. However, in order to reach a sufficiently high power conversion efficiency (PCE), the PSCs typically require a high‐temperature sintering process to prepare mesostructured TiO2 as an efficient electron transport layer (ETL), which prohibits the PSCs from commercialization in the future. This work investigates a low‐temperature synthesis of TiO2 nanocrystals and introduces a two‐fluid spray coating process to produce a nanostructured ETL for the following deposition of perovskite layer. The temperature during the whole deposition process can be maintained under 150 °C. Compared to the typical planar TiO2 layer, the perovskite layer fabricated on a nanostructured TiO2 layer shows uniform compactness, preferred orientation, and high crystallinity, leading to reproducible and promising device performance. The detail mechanisms are revealed by the contact angle test, morphology characterization, grazing incident wide angle X‐Ray scattering measurement, and space charge limited currents analysis. Finally, optimized device performance can be achieved through adequate Zn doping in the TiO2 layer, demonstrating an average PCE of 19.87% with champion PCE of 21.36%. The efficiency can maintain over 80% of its original value after 3000 h storage in ambient atmosphere. This study suggests a promising approach to offer high‐efficiency PSCs using the low‐temperature process.
Influence of nano silica on compressive strength, durability, and microstructure of high‐volume slag and high‐volume slag–fly ash blended concretes
Authors: Hosan Anwar , Shaikh Faiz Uddin Ahmed 
Published: September 2020

AbstractThis study investigated the influence of nano silica (NS) addition on the early‐ and later‐age compressive strengths and durability properties such as sorptivity, drying shrinkage, volume of permeable voids, and rapid chloride permeability, along with microstructural changes, of high‐volume slag (HVS) and high‐volume slag–fly ash (HVS‐FA) blended concrete. The results showed that the addition of NS improved the early‐age (3 days) compressive strength of HVS and HVS‐FA concretes significantly by 34 and 45%, respectively. In addition, the HVS concrete containing 78% blast furnace slag (BFS) gained considerable compressive strengths at later age due to the addition of 2% NS than the control HVS concrete with 80% BFS and showed comparable compressive strengths to ordinary Portland cement (OPC) concrete. On the other hand, the compressive strengths of HVS‐FA concrete containing 67% BFS‐FA blend and 3% NS surpassed OPC concrete at 28 days and exhibited superior strengths at later ages than the OPC concrete. Significant reduction in sorptivity of both HVS and HVS‐FA concretes is observed at 28 and 91 days, respectively, due to the addition of NS. Similar substantial reduction of drying shrinkage, chloride ion permeability, and volume of permeable voids are also witnessed in both HVS and HVS‐FA concretes due to the inclusion of NS than their respective control concretes without NS, and these exhibited better performance than control OPC concrete on most occasions. A denser and compacted interfacial transition zone (ITZ) is also found in the HVS and HVS‐FA concretes due to the addition of a small amount of NS.
Computational techniques for parameter estimation of gravitational wave signals
Authors: Meyer Renate , Edwards Matthew C. , Maturana‐Russel Patricio , Christensen Nelson 
Published: September 2020

AbstractSince the very first detection of gravitational waves from the coalescence of two black holes in 2015, Bayesian statistical methods have been routinely applied by LIGO and Virgo to extract the signal out of noisy interferometric measurements, obtain point estimates of the physical parameters responsible for producing the signal, and rigorously quantify their uncertainties. Different computational techniques have been devised depending on the source of the gravitational radiation and the gravitational waveform model used. Prominent sources of gravitational waves are binary black hole or neutron star mergers, the only objects that have been observed by detectors to date. But also gravitational waves from core‐collapse supernovae, rapidly rotating neutron stars, and the stochastic gravitational‐wave background are in the sensitivity band of the ground‐based interferometers and expected to be observable in future observation runs. As nonlinearities of the complex waveforms and the high‐dimensional parameter spaces preclude analytic evaluation of the posterior distribution, posterior inference for all these sources relies on computer‐intensive simulation techniques such as Markov chain Monte Carlo methods. A review of state‐of‐the‐art Bayesian statistical parameter estimation methods will be given for researchers in this cross‐disciplinary area of gravitational wave data analysis.This article is categorized under:Applications of Computational Statistics > Signal and Image Processing and CodingStatistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)Statistical Models > Time Series Models
Adaptation of evidence‐based suicide prevention strategies during and after theCOVID‐19 pandemic
Authors: Wasserman Danuta , Iosue Miriam , Wuestefeld Anika , Carli Vladimir 
Published: September 2020

Suicide is preventable. Nevertheless, each year 800,000 people die of suicide in the world. While there is evidence indicating that suicide rates de‐crease during times of crises, they are expected to increase once the immediate crisis has passed. The COVID‐19 pandemic affects risk and pro‐tective factors for suicide at each level of the socio‐ecological model. Economic downturn, augmented barriers to accessing health care, increased access to suicidal means, inappropriate media reporting at the societal level; deprioritization of mental health and preventive activities at the community level; interpersonal conflicts, neglect and violence at the relationship level; unemployment, poverty, loneliness and hopelessness at the individual level: all these variables contribute to an increase of depression, anxiety, post‐traumatic stress disorder, harmful use of alcohol, substance abuse, and ultimately suicide risk. Suicide should be prevented by strengthening universal strategies directed to the entire population, including mitigation of unemployment, poverty and inequalities; prioritization of access to mental health care; responsible media reporting, with information about available support; prevention of increased alcohol intake; and restriction of access to lethal means of suicide. Selective interventions should continue to target known vulnerable groups who are socio‐economically disadvantaged, but also new ones such as first responders and health care staff, and the bereaved by COVID‐19 who have been deprived of the final contact with loved ones and funerals. Indicated preventive strategies targeting individuals who display suicidal behaviour should focus on available pharmacological and psychological treatments of mental disorders, ensuring proper follow‐up and chain of care by increased use of telemedicine and other digital means. The scientific community, health care professionals, politicians and decision‐makers will find in this paper a systematic description of the effects of the pandemic on suicide risk at the society, community, family and individual levels, and an overview of how evidence‐based suicide preventive interventions should be adapted. Research is needed to investigate which adaptations are effective and in which con‐texts.
Zoo‐housed mammals do not avoid giving birth on weekends
Authors: Hosey Geoff , Ward Samantha J. , Ferguson Amanda , Jenkins Hannah , Hill Sonya P. 
Published: September 2020

AbstractThere is evidence that zoo visitor presence can influence the behaviour and, in some cases, adrenal response of zoo animals, and can sometimes compromise animal welfare. In some laboratory studies, significantly more primate births have been reported on weekends, when fewer people are working there, compared with weekdays when staffing levels are at their highest. Here, we investigate whether there is evidence of a “weekend effect” on births in zoo animals as a result of visitor numbers. Unlike laboratories, zoos are typically busier with visitors on weekends than on weekdays, although staffing levels remain fairly consistent across days of the week. If zoo animal parturition is sensitive to human presence, then fewer births would be expected on weekends compared with weekdays. We tested this using birth data and visitor numbers on the entrance gate from zoo records across 16 species representing artiodactyls, perissodactyls, carnivores and primates at four British zoos, to see whether there is an association between mean daily birth rates and average visitor numbers. We predict that, if there is a visitor effect, daily births should be lower on weekends than weekdays and should correlate with mean daily visitor numbers. Results showed that births for all 16 species were randomly distributed through the week, and there was no significant decline in births on weekends. We conclude that the “weekend effect”, if such a thing exists, does not appear to be a feature of zoo births, suggesting that elevated weekend visitor numbers are not sufficiently stressful to trigger delayed parturition.
Improving the surface quality of friction stir welds using reinforcement learning and Bayesian optimization
Authors: Hartl R. , Hansjakob J. , Zaeh M. F. 
Published: September 2020

AbstractFriction stir welding is an advanced joining technology that is particularly suitable for aluminum alloys. Various studies have shown a significant dependence of the welding quality on the welding speed and the rotational speed of the tool. Frequently, an inappropriate setting of these parameters can be detected through an examination of the resulting surface defects, such as increased flash formation or surface galling. In this work, two different learning-based algorithms were applied to improve the surface topography of friction stir welds. For this purpose, the surface topographies of 262 welds, which were performed as part of ten studies, were evaluated offline. The aim was to use reinforcement learning and Bayesian optimization approaches to determine the most appropriate settings for the welding speed and the rotational speed of the tool. The optimization problem was solved using reinforcement learning, specifically value iteration. However, the value iteration algorithm was not efficient, since all actions and states had to be iterated over, i.e., each possible parameter combination had to be evaluated, to find the best policy. Instead, it was better to solve the optimization problem directly using the Bayesian optimization. Two approaches were applied: both an approach in which the information from the other studies was not used and an approach in which the information from the other studies was used. On average, both the Bayesian optimization approaches found suitable welding parameters significantly faster than a random search algorithm, and the latter approach improved the result even further compared with the former approach. Future research will aim to show that optimization of the surface topography also leads to an increase in the ultimate tensile strength.
An approach for performance evaluation of SBS/RS with shuttle vehicles serving multiple tiers of multiple-deep storage rack
Authors: Eder Michael 
Published: September 2020

AbstractThis paper presents a method for determining the performance of shuttle-based storage and retrieval systems (SBS/RS) with tier-captive, single-aisle shuttles serving various numbers of tiers of multiple-deep storage. The use of this approach takes place in the design process of SBS/RS. The proposed approach considers the real operating characteristics of the shuttle and lifts. The basis of this calculation method is a continuous-time, open-queueing system with limited capacity. The cycle times of the lifts and shuttles, determined by a spatial value approach, can be used directly in the presented method with an assumed uniform distribution of storage locations and a probability-based model of storage depth. This approach is validated by a comparison with a discrete-event simulation. Finally, an example based on a system provided by a European material handling provider is presented to outline how this calculation model can be used for designing SBS/RS that fulfill predefined requirements. The result of this example is a decrease in the needed ground space with an increasing number of tiers served by each shuttle and with increasing storage depth.
Mercury in traditionally foraged species of fungi (macromycetes) from the karst area across Yunnan province in China
Authors: Falandysz Jerzy , Mędyk Małgorzata , Saba Martyna , Zhang Ji , Wang Yuanzhong , Li Tao 
Published: September 2020

Abstract
The objective of this study is to better quantify the occurrence, intake, and potential risk from Hg in fungi traditionally foraged in SW China. The concentrations and intakes of Hg were measured from 42 species including a “hard” flesh type polypore fungi and a” soft” flesh type edible species that are used in traditional herbal medicine, collected during the period 2011–2017. Three profiles of forest topsoil from the Zhenyuan site in 2015 and Changning and Dulong sites in 2016 were also investigated. The concentrations of Hg in composite samples of polypore fungi were usually below 0.1 mg kg−1 dry weight (dw) but higher levels, 0.11 ± 0.01 and 0.24 ± 0.00 mg kg−1 dw, were noted in Ganoderma applanatum and Amauroderma niger respectively, both from the Nujiang site near the town of Lanping in NW Yunnan. Hg concentrations in Boletaceae species were usually well above 1.0 mg kg−1 dw and as high as 10 mg kg−1 dw. The quality of the mushrooms in this study in view of contamination with Hg showed a complex picture. The “worst case” estimations showed probable intake of Hg from 0.006 μg kg−1 body mass (bm) (“hard” type flesh) to 0.25 μg kg−1 bm (“soft” flesh) on a daily basis for capsulated products, from 17 to 83 μg kg−1 bm (“soft” flesh) in a meal (“hard” type flesh mushrooms are not cooked while used in traditional herbal medicine after processing), and from 0.042 to 1.7 and 120 to 580 μg kg−1 bm on a weekly basis, respectively.

Graphical abstract

Key points
• Polypore species were slightly contaminated with Hg.
• Hg maximal content in the polypore was < 0.25 mg kg−1dry weight.
• Many species from Boletaceae family in Yunnan showed elevated Hg.
• Locals who often eat Boletus may take Hg at a dose above the daily reference dose.
Three-dimensional analysis of the heart function and effect cholinergic agonists in the cockroach Gromphadorhina portentosa
Authors: Claros-Guzmán Alfonso , Rodríguez Martín G. , Heredia-Rivera Birmania , González-Segovia Rodolfo 
Published: September 2020

AbstractMany relevant aspects of mammal’s cardiac physiology have been mainly investigated in insect models such as Drosophila melanogaster and Periplaneta americana. Cardiac function has been poorly studied in the cockroach Gromphadorhina portentosa, which has some advantages for experimental purposes such as an easier culture, bigger organs and a robust physiology. On the other hand, the study of cardiac physiology in insects has been largely improved since the arrival of digital imaging technologies for recording purposes. In the present work, we introduce a methodology of video recording coupled to an isotonic transducer for a three-dimensional analysis of the heart and intracardiac valves of G. portentosa. We used this methodology for assessing the physiological responses of the cockroach heart upon the application of different cholinergic neurotransmitters (acetylcholine, nicotine and muscarine). We recorded in detail the relationship between intracardiac valves movement, hemolymph flow, diastole and systole. Acetylcholine and nicotine induced a biphasic effect on the cardiac frequency. Acetylcholine increased the diastolic opening. Nicotine at high concentration caused paralysis. Muscarine induced no major effects. These findings suggest a combined action of cholinergic agonists for a finely tuned the cardiac frequency, intracardiac valves function and cardiac cycle.