bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ammonium Pertechnetate in Mixtures of Trifluoromethanesulfonic Acid and Trifluoromethanesulfonic Anhydride
Authors: Zegke Markus , Grödler Dennis , Roca Jungfer Maximilian , Haseloer Alexander , Kreuter Meike , Neudörfl Jörg M. , Sittel Thomas , James Christopher M. , Rothe Jörg , Altmaier Marcus , Klein Axel , Breugst Martin , Abram Ulrich , Strub Erik , Wickleder Mathias S. 
Published: November 2021

AbstractAmmonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH4)2[TcO(OTf)5]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO3(OTf)], and intermediate TcVI species. 99Tc nuclear magnetic resonance (NMR) has been used to study the TcVII compound and electron paramagnetic resonance (EPR), 99Tc NMR and X‐ray absorption near‐edge structure (XANES) experiments indicate the presence of the reduced technetium species. In moist air, (NH4)2[TcO(OTf)5] slowly hydrolyses under formation of the tetrameric oxidotechnetate(V) (NH4)4[{TcO(TcO4)4}4] ⋅10 H2O. Single‐crystal X‐ray crystallography was used to determine the solid‐state structures. Additionally, UV/Vis absorption and IR spectra as well as quantum chemical calculations confirm the identity of the species.
Synthesis and characterization of a new polyoxometalate nanocluster containing Mo and V as an environmentally green catalyst for oxidative degradation of organic pollutants from aquatic environments
Authors: Naslhajian Hadi , Amini Mojtaba , Hosseinifard Mojtaba , Farnia S. Morteza F. , Janczak Jan 
Published: November 2021

AbstractA water‐insoluble Keggin‐type polyoxomolybdovanadate nanocluster, (Et4N)4[VMo12O40]·MeCN (1) was synthesized and crystallized in acetonitrile. The catalyst was characterized by X‐ray crystallography, UV–Vis, thermogravimetric analysis (TGA), cyclic voltammetry (CV), and FT‐IR techniques. Degradation of organic dyes, Amido black 10B (AB10B) and Methylene blue (MB) was investigated by 1/H2O2 system at room temperature and the influence of different conditions on the decomposition of AB10B and MB dyes such as catalyst dosage, oxidant concentration, pH, radical scavengers, and reusability of 1 were studied.
Heterogeneous esterification of ricinoleic acid with polyol for the synthesis of polyol ricinoleates as biomass‐based lubricant base oil
Authors: Gao Song , Ren Fang‐Yu , Xie Wei‐Hang , He Liang‐Nian , Li Hong‐Ru 
Published: November 2021

AbstractBio‐derived lubricants, especially those derived from vegetable oils, are considered to be promising alternatives to mineral oil‐based lubricants due to the features of sustainability and environmental friendliness. In this work, the polyol ricinoleates were prepared by esterification of ricinoleic acid with trimethylolpropane (TMP), neopentyl glycol (NPG) and pentaerythritol (PE) respectively using Lewis acidic stannous oxide as an efficient heterogeneous catalyst, affording the polyol ricinoleates up to 99.7% yield. Remarkably, the solid catalyst was readily recovered and reused at least for five cycles without significant loss of activity. The resulting polyol ricinoleates products were structurally characterized by Fourier transform infrared spectroscopy (FT‐IR), 1H NMR, 13C NMR, electrospray ionization mass spectra (ESI‐MS); and were stable below 300°C through thermogravimetric analysis (TGA). Furthermore, the physicochemical and lubricating properties of as‐synthesized polyol esters were also evaluated including viscosity at 40 and 100°C, viscosity index (VI), pour point and flash point, thermal stability and wear scar diameter. To our delight, the performance indicators of the target products were comparable or better than the commercial lubricants, showing their potential as lubricant base oil. This work represents an alternative access to useful lubricant products via effective and selective conversion of non‐edible vegetable oil.
Theoretical analysis and numerical modeling of the evolution mechanism of polymer melt unstable flow in two‐dimensional ultrasonic‐assisted micro‐injection molding
Authors: Qiu Zhongjun , Wang Lei 
Published: November 2021

AbstractMicro polymer parts are usually fabricated by ultrasonic‐assisted micro‐injection molding which is an effective and low‐cost method. This method solves some injection molding defects such as short shot by reducing the melt viscosity, and the clarification of its mechanism is a challenge. This article is aimed at studying the evolution mechanism of two‐dimensional ultrasonic vibration on the polymer melt unstable flow. A two‐dimensional ultrasonic vibration, whose displacements components in the‐ and‐directions are large, is applied to the polymer melt. The unstable flow is a flow field with perturbations. The formulas of perturbation stream function and velocity perturbations are established based on the theories of absolute instability and convective instability. The established formulas are verified by numerical analysis. The results show that the flow of polymer melt is convectively unstable and the vortices are formed under the combined actions of shear stress and transverse pressure. The distribution of vortices is bound to affect the mold filling quality. Accordingly, a two‐dimensional ultrasonic vibration with the phase difference of 90° is adopted to make strong vortices occur symmetrically, to improve the uniformity of viscosity field, and to obtain a better melt filling capability during injection molding.
Chitosan‐hydroxycinnamic acid conjugates: Synthesis, photostability and phytotoxicity to seed germination of barley
Authors: Nikalaichuk Viktoryia , Hileuskaya Kseniya , Kraskouski Aliaksandr , Kulikouskaya Viktoryia , Nedved Helen , Kalatskaja Joanna , Rybinskaya Ekaterina , Herasimovich Kanstantsin , Laman Nikolai , Agabekov Vladimir 
Published: November 2021

AbstractChitosan‐caffeic and chitosan‐ferulic acid conjugates are synthesized by carbodiimide method and characterized by UV, FTIR, and NMR spectroscopy. There are two obtained forms of conjugates: freshly synthesized and reconstituted freeze‐dried. A comparative study of the stability of various conjugate forms over time and under UV irradiation has been carried out. It has been shown that the absorption intensity of an aqueous solution of the freshly synthesized chitosan‐caffeic acid conjugate decrease in ~2 times during 20 weeks of storage, while the maximum rate of intensity decrease is observed during the first 40 days. The absorption intensity of the chitosan‐ferulic acid conjugate decrease by 6–7% during the entire storage period. It has been found that freeze‐dried powders of chitosan‐caffeic and chitosan‐ferulic acid conjugates are stable for at least 1 year. It has been established that freeze‐dried chitosan‐caffeic and chitosan‐ferulic acid conjugates are more stable under UV irradiation (in 4–8 and 1.4–1.9 times, respectively) compared to freshly synthesized ones. A comparative study of the influence of conjugates on barley seedlings (Hordeum vulgare L.) growth has been carried out.
Selection of patients for nerve sparing surgery in robot‐assisted radical prostatectomy
Authors: Vis André N. , van den Bergh Roderick C. N. , van der Poel Henk G. , Mottrie Alexander , Stricker Philip D. , Graefen Marcus , Patel Vipul , Rocco Bernardo , Lissenberg‐Witte Birgit , van Leeuwen Pim J. 
Published: November 2021

AbstractContextRobot‐assisted radical prostatectomy (RARP) has become the standard surgical procedure for localized prostate‐cancer (PCa). Nerve‐sparing surgery (NSS) during RARP has been associated with improved erectile function and continence rates after surgery. However, it remains unclear what are the most appropriate indications for NSS.ObjectiveThe objective of this study is to systematically review the available parameters for selection of patients for NSS. The weight of different clinical variables, multiparametric magnetic‐resonance‐imaging (mpMRI) findings, and the impact of multiparametric‐nomograms in the decision‐making process on (side‐specific) NSS were assessed.Evidence acquisitionThis systematic review searched relevant databases and included studies performed from January 2000 until December 2020 and recruited a total of 15 840 PCa patients. Studies were assessed that defined criteria for (side‐specific) NSS and associated them with oncological safety and/or functional outcomes. Risk of bias assessment was performed.Evidence synthesisNineteen articles were eligible for full‐text review. NSS is primarily recommended in men with adequate erectile function, and with low‐risk of extracapsular extension (ECE) on the side‐of NSS. Separate clinical and radiological variables have low accuracy for predicting ECE, whereas nomograms optimize the risk‐stratification and decision‐making process to perform or to refrain from NSS when oncological safety (organ‐confined disease, PSM rates) and functional outcomes (erectile function and continence rates) were assessed.ConclusionsConsensus exists that patients who are at high risk of ECE should refrain from NSS. Several multiparametric preoperative nomograms were developed to predict ECE with increased accuracy compared with single clinical, pathological, or radiological variables, but controversy exists on risk thresholds and decision rules on a conservative versus a less‐conservative surgical approach. An individual clinical judgment on the possibilities of NSS set against the risks of ECE is warranted.Patient summaryNSS is aimed at sparing the nerves responsible for erection. NSS may lead to unfavorable tumor control if the risk of capsule penetration is high. Nomograms predicting extraprostatic tumor‐growth are probably most helpful.
A novel fluorescent probe with aggregation induced emission (AIE) effect based on 1,4‐dihydropyridine and its applications
Authors: Xue Longqi , Wu Liangqiang , Li Yapeng , Yang Qingbiao , Sun Dazhi , Zhang Hao , Xu Hai , Li Yaoxian 
Published: November 2021

AbstractA fluorescent hydrazine hydrate probe (DMA) based on 1,4‐dihydropyridine derivatives was designed and synthesized. The fluorescence emission peak of this probe is in the near‐infrared region (667 nm), which has good selectivity to hydrazine hydrate and low detection limit (11 nM). Importantly, the probe exhibits aggregation‐induced emission (AIE) characteristics. In addition, the probe is prepared with a portable test paper to realize the identification of hydrazine hydrate in the solution and the quantitative detection of hydrazine hydrate gas.
Identification and classification of host cell proteins during biopharmaceutical process development
Authors: Wilson Louisa J. , Lewis Will , Kucia‐Tran Richard , Bracewell Daniel G. 
Published: November 2021

AbstractAs significant improvements in volumetric antibody productivity have been achieved by advances in upstream processing over the last decade, and harvest material has become progressively more difficult to recover with these intensified upstream operations, the segregation of upstream and downstream processing has remained largely unchanged. By integrating upstream and downstream process development, product purification issues are given consideration during the optimization of upstream operating conditions, which mitigates the need for extensive and expensive clearance strategies downstream. To investigate the impact of cell culture duration on critical quality attributes, CHO‐expressed IgG1 was cultivated in two 2 L bioreactors with samples taken on days 8, 10, 13, 15, and 17. The material was centrifuged, filtered and protein A purified on a 1 ml HiTrap column. Host cell protein (HCP) identification by mass spectrometry (MS) was applied to this system to provide insights into cellular behavior and HCP carryover during protein A purification. It was shown that as cultivation progressed from day 8 to 17 and antibody titer increased, product quality declined due to an increase in post‐protein A HCPs (from 72 to 475 peptides detected by MS) and a decrease in product monomer percentage (from 98% to 95.5%). Additionally, the MS data revealed an increase in the abundance of several classes of post‐protein A HCPs (e.g., stress response proteins and indicators of cell age), particularly on days 15 and 17 of culture, which were associated with significant increases in total overall HCP levels. This provides new insight into the specific types of HCPs that are retained during mAb purification and may be used to aid process development strategies.
Iatrogenic tibial arteriovenous fistula after Fogarty balloon catheter graft thrombectomy
Authors: Papadoulas Spyros , Moulakakis Konstantinos , Kouri Natasa , Mulita Francesk , Tsimpoukis Andreas , Seretis Charalampos , Kitrou Panagiotis , Katsanos Konstantinos , Kakkos Stavros K. 
Published: November 2021

AbstractA 75‐year‐old male presented with an immediately threatened grade IIb acute ischemia of the left leg due to thrombosis of a femoro‐infrapopliteal prosthetic bypass graft. After an urgent Computed Tomography Angiography, an urgent graft thrombectomy was performed using a 5 Fr Fogarty catheter, which had a troublesome distal passage, causing a tibial A‐V fistula.
N,N‐Dimethylformamide‐protected Fe2O3 Combined with Pt Nanoparticles: Characterization and Catalysis in Alkene Hydrosilylation
Authors: Nagata Tatsuki , Tanaka Tatsuya , Lin Xianjin , Kondo Ryota , Suzuki Takeyuki , Kanda Yasuharu , Toyao Takashi , Shimizu Ken‐ichi , Obora Yasushi 
Published: November 2021

AbstractWe report a combination of N,N‐dimethylformamide (DMF)‐protected Fe2O3 nanoparticles (NPs) and Pt NPs for the hydrosilylation of various industrially relevant alkenes and tertiary silanes. The DMF‐protected Fe2O3 and Pt NPs catalysts were characterized by transmission electron microscopy, X‐ray absorption spectroscopy, and X‐ray photoelectron spectroscopy. The catalyst of DMF‐protected Fe2O3 NPs combined with Pt NPs can be recycled for five cycles by a simple extraction using hexane/DMF. The developed combination Fe2O3/Pt NPs catalyst is effective up to the 1‐kilogram scale.
Digitales Datenmanagement in der Instandhaltung
Authors: Dittmar Patricia 
Published: November 2021

AbstractDie Instandhaltung in der Produktion steht unter einem enormen Kostendruck und sieht sich ständig mit neuen Herausforderungen wie immer mehr Auflagen und Nachweispflichten, Personalmangel sowie dem Wissensmanagement von Mitarbeitern konfrontiert. Durch die Digitalisierung der Einsatzplanung und Auftragsabwicklung könnten Unternehmen viele der Herausforderungen meistern, doch gibt es immer noch hartnäckige Vorurteile und Einwände, bestehende Prozesse in der Instandhaltung zu digitalisieren und zu optimieren. Die mobileX AG hat sieben Mythen über Instandhaltungssoftware identifiziert und enttarnt:
QoE‐aware traffic monitoring based on user behavior in video streaming services
Authors: Laiche Fatima , Ben Letaifa Asma , Aguili Taoufik 
Published: November 2021

SummaryIn recent years, online video content has gained a lot of popularity and the exponential growth of video traffic continues in every area of the connected world. Thus, understanding the quality of experience (QoE) perceived by end‐users of video streaming services is important for both network operators and over the top providers since estimating end user's QoE has become one of the main points to meet user expectations. However, it is not trivial to ensure an adequate QoE since user experience is affected by various influencing factors (e.g., context factors, human factors, and system factors), and it is still challenging to identify the QoE key influencing factors. To address these challenges, we focused on improving QoE estimation and management strategies by exploiting valuable human and context information because the influence of social contextual information and user behavior on the perceptual quality is often neglected. In this article, we first proposed a classification of influence factors into four categories which are: system factors, human factors, context factors, and social‐behavioral factors. We developed a monitoring web application where video content is played to end‐users so that subjective and objective video metrics are collected. We built a new machine learning (ML) based model for QoE prediction. We used well‐known supervised ML algorithms like decision tree, k‐nearest neighbors, and support vector machine. Finally, we proposed a QoE management approach in the context of software defined network/multi‐access edge computing that implements the proposed QoE prediction model to optimize the video delivery transmission chain.
Research on cross‐hierarchical graph network recommendation algorithm based on random walk and convolutional neural network
Authors: Huang Meng , Sun Guohui 
Published: November 2021

AbstractConvolutional network (CNN) has been widely used in processing various graphics and network data analysis tasks. Therefore, facing the recommendation problem of large‐scale heterogeneous interaction, some studies have raised the problem of whether graph convolution neural network (GCN) can optimize the integration of node features and topology in complex graphs with rich information, but GCN may not be able to adaptively learn some deep related information between topology and node features, Therefore, the ability of GCN in some classification tasks may be seriously hindered. Therefore, this article proposes a heterogeneous network recommendation algorithm based on random walk and convolutional neural network (RW‐CNN), which can not only obtain the deep information of network structure but also aggregate the node representation. The core idea is to use the rule items based on meta‐path similarity to constrain the implicit representation of users and goods and make full use of the rich structural and semantic information of heterogeneous information networks. Then, combined with convolution neural network, the cross‐correlation information between project and user nodes is processed, so as to fully mine the semantic features of nodes. Finally, through the attention mechanism and fully connected network, the global user feature vector and project feature vector of path fusion at different levels are obtained. Finally, the two characteristic matrices are multiplied to obtain the prediction score.
Structural Engineering of Covalent Organic Frameworks Comprising Two Electron Acceptors Improves Photocatalytic Performance
Authors: Zhang Jin , Cao Yuping , Liu Wei , Cao Ting , Qian Jing , Wang Jiemin , Yao Xiaojun , Iqbal Anam , Qin Wenwu 
Published: November 2021

AbstractCovalent organic frameworks (COFs) have recently attracted much attention as potential photocatalysts for hydrogen production. The effective separation of photogenerated charges is a key objective to improve the photocatalytic activity of COFs. Here, four COFs were synthesized through the Schiff‐base reaction to investigate whether the presence (simultaneous or not) of triazine and ketone as acceptors in COFs improved electron‐hole separation efficiency. Evidence indicated that charge separation was more efficient when triazine and ketone were simultaneously present in the COF. The COF comprising two acceptors displayed the highest photocatalytic hydrogen production rate (31.43 μmol h−1; 41.2 and 3.4 times as large as those of the COFs containing only triazine or ketone, respectively). Moreover, the effect of the distance between the two acceptors on the electron‐hole separation was investigated by changing the length of a bridging biphenyl ring. It turned out that the transport distance of a single phenyl group was more favorable for the catalytic reaction. This work affords insight and support for the design of efficient COF photocatalysts.
Secure energy efficient power allocation in massive multiple‐input multiple‐output systems with an eavesdropper using cell division technique
Authors: Gharagezlou Abdolrasoul Sakhaei , Pourrostam Jafar , Nangir Mahdi 
Published: November 2021

SummaryIn this paper, we study energy‐efficient power allocation (PA) to secure the confidential information of massive multiple‐input multiple‐output (MIMO) systems in the presence of an eavesdropper. First a training scheme is presented in the uplink using the MMSE method. Based on the estimated channel state information (CSI), the base station (BS) encrypts the confidential information. Next, the ergodic secret rate is obtained at the downlink. In this paper, in order to maximize the ergodic secrecy rate, the allocation of common power in the uplink and downlink is proposed by considering the constraints such as the transmit power constraint in the uplink, the transmit power constraint in the downlink, and the minimum ergodic secret rate constraint. The objective function in the proposed scenario is a nonconvex problem, which first becomes a convex problem and then, by using the Lagrange dual function method, the problem becomes an unconstraint problem. We also divide the cell into two areas using the cell division method. A practical energy‐efficient PA algorithm is presented which deals with the adverse effect of the eavesdropper. Simulations are carried out to demonstrate the effectiveness of the proposed methods.
Fine‐scale coexistence between Mediterranean mesocarnivores is mediated by spatial, temporal, and trophic resource partitioning
Authors: Ferreiro‐Arias Iago , Isla Jorge , Jordano Pedro , Benítez‐López Ana 
Published: November 2021

Abstract

The partition of the ecological niche can enhance the coexistence of predators due to differences in how they exploit three main resources: food, space, and time, the latter being an axis that often remains unexplored.

We studied niche segregation in a Mediterranean mesocarnivore community composed by Vulpes vulpes, Genetta genetta, Meles meles, and Herpestes ichneumon, addressing simultaneously different niche axes: the temporal, trophic, and spatial axes.

We assessed temporal segregation between mesopredators and prey and between potential competitors, using camera trap data between 2018 and 2020 in a Mediterranean landscape in Southern Spain. We deployed camera traps in 35 stations in three sites with varying vegetation cover within Doñana National Park. We further examined the spatial overlap in activity centers and trophic preferences between potential competitors using diet information from studies performed in the study area.

We found an overall temporal segregation between trophic generalist species, with species showing higher temporal overlap differing in their trophic preferences and/or showing limited spatial overlap. Furthermore, we observed an overall high overlap between the activity patterns of predators and their major prey in the area (the common genet vs. small mammals and the red fox vs. European rabbit).

Our study suggests that coexistence of the different species that compose the mesocarnivore assemblage in Mediterranean landscapes can be facilitated by subtle differences along the three main niche axes, with temporal segregation being a most pronounced mechanism. Our findings reinforce the idea that the coexistence mechanisms underlying community structure are multidimensional.
Palladium‐Catalyzed Intermolecular Dicarbofunctionalization of Unactivated Alkenes: Synthesis of Fluoroalkylated Heterocycles with All‐Carbon Quaternary Centers
Authors: Cheng Jiajia , Zhang Huali , Lv Jinliang , Zheng Jinhua 
Published: November 2021

AbstractThe redox‐neutral palladium‐catalyzed dicarbofunctionalization of unactivated alkenes with a variety of functionalized difluoromethyl and perfluoroalkyl halide is presented here. This transformation proceeds smoothly at low temperatures and enables the assembly of diversified fluoroalkylated pyrrolo[1,2‐a]indole derivatives with one all‐carbon quaternary center in high regioselectivity. Mechanistic studies suggested an operative radical mechanism and the initiation of the inner‐sphere single electron transfer between a dual phosphine ligand‐coordinated palladium(0) species and perfluoroalkyl halides.