bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium‐Aminopyridine Catalyzed C−H Oxygenation: Probing the Nature of Metal Based Oxidant
Authors: Lubov Dmitry P. , Bryliakova Anna A. , Samsonenko Denis G. , Sheven Dmitriy G. , Talsi Evgenii P. , Bryliakov Konstantin P. 
Published: September 2021

AbstractA mechanistic study of direct selective oxidation of benzylic C(sp3)−H groups with peracetic acid, catalyzed by palladium complexes with tripodal amino‐tris(pyriylmethyl) ligands, is presented. The oxidation of arylalkanes having secondary and tertiary benzylic C−H groups, predominantly yields, depending on the substrate and conditions, either the corresponding ketones or alcohols. One of the three 2‐pyriylmethyl moieties, which is pending in the starting catalyst, apparently, facilitates the active species formation and takes part in stabilization of the high‐valent Pd center in the active species, occupying the axial coordination site of palladium. The catalytic, as well as isotopic labeling experiments, in combination with ESI‐MS data and DFT calculations, point out palladium oxyl species as possible catalytically active sites, operating essentially via C−H abstraction/oxygen rebound pathway. For the ketones formation, O−H abstraction/в‐scission mechanism has been proposed.
Electrocatalytic and stoichiometric reactivity of 2D layered siloxene for high‐energy‐dense lithium–sulfur batteries
Authors: Kang Hui‐Ju , Park Jae‐Woo , Hwang Hyun Jin , Kim Heejin , Jang Kwang‐Suk , Ji Xiulei , Kim Hae Jin , Im Won Bin , Jun Young‐Si 
Published: September 2021

AbstractLithium–sulfur batteries (LSBs) have emerged as promising power sources for high‐performance devices such as electric vehicles. However, the poor energy density of LSBs owing to polysulfide shuttling and passivation has limited their further market penetration. To mitigate this challenge, two‐dimensional (2D) siloxene (2DSi), a Si‐based analog of graphene, is utilized as an additive for sulfur cathodes. The 2DSi is fabricated on a large scale by simple solvent extraction of calcium disilicide to form a thin‐layered structure of Si planes functionalized with vertically aligned hydroxyl groups in the 2DSi. The stoichiometric reaction of 2DSi with polysulfides generates a thiosulfate redox mediator, secures the intercalation pathway, and reveals Lewis acidic sites within the siloxene galleries. The 2DSi utilizes the corresponding in‐situ‐formed electrocatalyst, the 2D confinement effect of the layered structure, and the surface affinity based on Lewis acid–base interaction to improve the energy density of 2DSi‐based LSB cells. Combined with the commercial carbon‐based current collector, 2DSi‐based LSB cells achieve a volumetric energy density of 612 Wh Lcell−1 at 1 mA cm−2 with minor degradation of 0.17% per cycle, which rivals those of state‐of‐the‐art LSBs. This study presents a method for the industrial production of high‐energy‐dense LSBs.
Stabilization of Dynamic Covalent Architectures by Multivalence
Authors: Chen Yixin , Lei Ye , Tong Lu , Li Hao 
Published: September 2021

AbstractThe formation of imine bond is reversible. This feature has been taken advantage of by chemists for accomplishing high yielding self‐assembly. On the other hand, it also jeopardizes the intrinsic stability of these self‐assembled products. However, some recent discoveries demonstrate that some of these imine bond containing molecules could be rather stable or kinetically inert. A deep investigation indicated that such enhanced stability results from, at least partially, multivalence. Such results also inspire chemists to use imine condensation for self‐assembly in water, a solvent that is considered not compatible with imine bond for a long time.
Titanium Vacancies in TiO2 Nanofibers Enable Highly Efficient Photodriven Seawater Splitting
Authors: Zhang Yan‐Xiang , Wu Si‐Ming , Tian Ge , Zhao Xiao‐Fang , Wang Li‐Ying , Yin Yi‐Xia , Wu Lu , Li Qian‐Ni , Zhang Yue‐Xing , Wu Jin‐Song , Janiak Christoph , Ozoemena Kenneth I. , Shalom Menny , Yang Xiao‐Yu 
Published: September 2021

AbstractInvited for the cover of this issue are Xiao‐Yu Yang and co‐workers at Wuhan University of Technology, Heinrich‐Heine‐Universität Düsseldorf, University of the Witwatersrand, and Ben‐Gurion University of the Negev. The image depicts Ti vacancies in TiO2 as powerful drivers of photo‐ and photo‐electrocatalytic seawater splitting for hydrogen production. Read the full text of the article at 10.1002/chem.202101817.
Remote Radical Desaturation of Unactivated C−H Bonds in Amides
Authors: Xia Yong , Jana Kalipada , Studer Armido 
Published: September 2021

AbstractDesaturation of inert aliphatic C−H bonds in alkanes to form the corresponding alkenes is challenging. In this communication, a new and practical strategy for remote site‐selective desaturation of amides via radical chemistry is reported. The readily installed N‐allylsulfonylamide moiety serves as an N radical precursor. Intramolecular 1,5‐hydrogen atom transfer from an inert C−H bond to the N‐radical generates a translocated C‐radical which is subsequently oxidized and deprotonated to give the corresponding alkene. The commercially available methanesulfonyl chloride is used as reagent and a Cu/Ag‐couple as oxidant. The remote desaturation is realized on different types of unactivated sp3‐C−H bonds. The potential synthetic utility of this method is further demonstrated by the dehydrogenation of natural product derivatives and drugs.
Electrochemical Recycling of Photovoltaic Modules to Recover Metals and Silicon Wafers
Authors: Modrzynski Christian , Blaesing Luisa , Hippmann Sebastian , Bertau Martin , Bloh Jonathan Z. , Weidlich Claudia 
Published: September 2021

AbstractAn electrochemical‐assisted leaching process using boron‐doped diamond (BDD) electrodes was developed to recover valuable metals from photovoltaic modules. With BDD electrodes peroxydisulfate is generated from sulfuric acid to oxidatively dissolve copper, tin and silver from solar cell contacts. Since the oxidant is regenerated in the developed process, no additional hazardous and volatile chemicals are required, and the process can be operated solely by electricity. In addition, the dissolved metals can be electrochemically recovered at the cathode of the same cell.
Parallel and accurate k‐means algorithm on CPU‐GPU architectures for spectral clustering
Authors: He Guanlin , Vialle Stephane , Baboulin Marc 
Published: September 2021

Summaryk‐Means is a standard algorithm for clustering data. It constitutes generally the final step in a more complex chain of high‐quality spectral clustering. However, this chain suffers from lack of scalability when addressing large datasets. This can be overcome by applying also the k‐means algorithm as a preprocessing task to reduce the input data instances. We propose parallel optimization techniques for the k‐means algorithm on CPU and GPU. Particularly we use a two‐step summation method with package processing to handle the effect of rounding errors that may occur during the phase of updating cluster centroids. Our experiments on synthetic and real‐world datasets containing millions of instances exhibit a speedup up to 7 for the k‐means iteration time on GPU versus 20/40 CPU threads using AVX units, and achieve double‐precision accuracy with single‐precision computations.
Optimization of service addition in multilevel index model for edge computing
Authors: Gu Jiayan , Wu Yan , Anjum Ashiq , Panneerselvam John , Lu Yao , Yuan Bo 
Published: September 2021

AbstractWith the development of edge computing and artificial intelligence (AI) technologies, edge devices are witnessed to generate data at unprecedented volume. The edge intelligence (EI) has led to the emergence of edge devices in various application domains. The EI can provide efficient services to delay‐sensitive applications, where the edge devices are deployed as edge nodes to host the majority of execution, which can effectively manage services and improve service discovery efficiency. The multilevel index model is a well‐known model used for indexing service, such a model is being introduced and optimized in the edge environments to efficiently services discovery while managing large volumes of data. However, effectively updating the multilevel index model by adding new services timely and precisely in the dynamic edge computing environments is still a challenge. Addressing this issue, this article proposes a designated key selection method to improve the efficiency of adding services in the multilevel index models. Our experimental results show that in the partial index and the full index of multilevel index model, our method reduces the service addition time by around 84% and 76%, respectively when compared with the original key selection method and by around 78% and 66%, respectively when compared with the random selection method. Our proposed method significantly improves the service addition efficiency in the multilevel index model, when compared with existing state‐of‐the‐art key selection methods, without compromising the service retrieval stability to any notable level.
Multi‐perspective business process discovery from messaging systems: State‐of‐the art
Authors: Elleuch Marwa , Laga Nassim , Alaoui Ismaili Oumaima , Gaaloul Walid 
Published: September 2021

SummaryAt the stage of identifying and modeling business processes (BP), traditional methods for collecting business expertise are time consuming since they mainly rely on physical communication. Moreover, there are some BP with no formal documentation and their execution relies on implicit knowledge of workers. Therefore, analyzing the logs data generated by messaging systems allowing workers to share such implicit knowledge has been a research area of growing interest. BP knowledge introduced by workers in emails could actually cover multiple BP perspectives that would vary from activity, actors, and data perspectives. This article gives an overview of the current state‐of‐the‐art in multi‐perspective BP discovery from messaging systems as well as the main existing research questions. Different approaches are presented, discussed, and compared against each other on a qualitative level deduced from the defined set of research questions. The resulting overview covers both advantages and disadvantages of current techniques and the research questions that have not been addressed to date. This should provide a solid basis for further research.
UV Excitation of Carotenoid Binding Proteins OCP and HCP: Excited‐State Dynamics and Product Formation
Authors: Khan Tuhin , Kuznetsova Valentyna , Dominguez‐Martin Maria Agustina , Kerfeld Cheryl A. , Polívka Tomáš 
Published: September 2021

AbstractOver the last decade the orange carotenoid protein (OCP) gained attention due to its role in photoprotection in cyanobacteria. Recently, other carotenoid binding proteins such as helical carotenoid proteins (HCPs) have been identified and characterized, although the function of the HCPs is not yet clarified. Here we have examined OCP1 and two HCPs, HCP2 and HCP3, from Tolypothrix PCC 7601 by ultrafast spectroscopy after excitation of both carotenoid canthaxanthin and amino acids tryptophan and tyrosine in UV at 275 nm. We find that the canthaxanthin S1 lifetime remains the same 3.5 ps as for excitation of the carotenoid S2 state, but the S* signal is significantly amplified by UV excitation. In contrast to the S2 excitation, we observe a formation of the canthaxanthin radical cation at 900 nm for all three proteins after 275 nm excitation. In OCP1, UV light also enhances the amplitude of spectral band centered at 550 nm at longer delays. This band likely corresponds to the first photoproduct of the OCP photocycle, suggesting that excess energy excitation and/or direct excitation of amino acids can enhance the product formation.
Deep learning for wireless modulation classification based on discrete wavelet transform
Authors: Al‐Makhlasawy Rasha M. , Ghanem Hanan S. , Kassem Hossam M. , Elsabrouty Maha , Hamed Hesham F. A. , Abd El‐Samie Fathi E. , Salama Gerges M. 
Published: September 2021

SummaryIn the presence of noise in communication systems, constellation diagram points are scattered to the extent that may make the modulation classification a difficult task. With the plethora of applications of machine and deep learning, several communication systems have adopted machine and deep learning to solve some classical detection and classification problems. Casting the modulation order detection as a pattern classification of the constellation images opens the door for application of mature machine learning and image processing tools to solve the classification problem, efficiently. This paper presents a system based on a wavelet‐aided convolutional neural network (CNN) classifier to efficiently detect the modulation type and order in the presence of noise. The proposed system depends on a pretrained CNN setup, which is trained with a set of constellation diagrams for each modulation scheme and used after that for testing. In addition, discrete wavelet transform (DWT) is investigated to generate representative patterns from constellation diagrams to be used for the training and testing tasks as well. The wavelet approximation images and their corresponding wavelet sub‐bands across all predefined scales are used in the dataset. Several pretrained networks including AlexNet, VGG‐16, and VGG‐19 are used as classifiers for the modulation type from the DWTs for different constellation diagrams. Several simulation experiments are presented in this paper to compare different scenarios for modulation classification at different signal‐to‐noise ratios (SNRs).
Naphthyl‐ and Quinoline‐Appended o‐Carboranyl Luminophores: Intramolecular Charge Transfer‐Based Radiative Decay Controlled by Structural Geometry around C−C Bond Axis
Authors: Ryu Chan Hee , Lee Seok Ho , Yi Sanghee , Hong Ju Hyun , Im Sehee , Lee Kang Mun 
Published: September 2021

AbstractNaphthyl‐ and quinoline‐appended o‐carboranyl compounds, NCB and QCB, respectively, were prepared and characterized by multinuclear nuclear magnetic resonance spectroscopy, elemental analysis, and single crystal X‐ray diffraction. Although both the compounds were non‐emissive in the solution state at 298 K, they were photoluminescent in the rigid state (in THF at 77 K and film state) in the region 450–550 nm. Theoretical calculation of the optimized structure in the S1 state suggested that the low‐energy emissive bands for NCB and QCB were attributed to intramolecular charge transfer (ICT) transition. Intriguingly, the C−C bond axis of the o‐carborane in NCB in the solid state was more orthogonal to the plane of the appended aromatic group than that in QCB, indicating relatively high delocalization between the o‐carborane and aromatic moieties of NCB. The quantum efficiency and radiative decay constant of the ICT‐based emission of NCB in the film state were much higher than those of QCB. These findings imply that the structural geometry around the C−C bond axis of the o‐carborane is a decisive factor in accelerating the ICT‐based radiative decay in the o‐carbonyl luminophores in the rigid state.
Drought imprints on crops can reduce yield loss: Nature's insights for food security
Authors: Fu Peng , Jaiswal Deepak , McGrath Justin M. , Wang Shaowen , Long Stephen P. , Bernacchi Carl J. 
Published: September 2021

AbstractThe Midwestern “Corn‐Belt” in the United States is the most productive agricultural region on the planet despite being predominantly rainfed. In this region, global climate change is driving precipitation patterns toward wetter springs and drier mid‐ to late‐summers, a trend that is likely to intensify in the future. The lack of precipitation can lead to crop water limitations that ultimately impact growth and yields. Young plants exposed to water stress will often invest more resources into their root systems, possibly priming the crop for any subsequent mid‐ or late‐season drought. The trend toward wetter springs, however, suggests that opportunities for crop priming may lessen in the future. Here, we test the hypothesis that early season dry conditions lead to drought priming in field‐grown crops and this response will protect crops against growth and yield losses from late‐season droughts. This hypothesis was tested for the two major Midwestern crop, maize and soybean, using high‐resolution daily weather data, satellite‐derived phenological metrics, field yield data, and ecosystem‐scale model (Agricultural Production System Simulator) simulations. The results from this study showed that priming mitigated yield losses from a late season drought of up to 4.0% and 7.0% for maize and soybean compared with unprimed crops experiencing a late season drought. These results suggest that if the trend toward wet springs with drier summers continues, the relative impact of droughts on crop productivity is likely to worsen. Alternatively, identifying opportunities to breed or genetically modify pre‐primed crop species may provide improved resilience to future climate change.
Textural and sensory characteristics of sugar‐free biscuit formulated with quinoa flour, isomalt, and maltodextrin
Authors: Nadian Narges , Azizi Mohammad Hossain , Abbastabar Ahangar Hossein , Aarabi Aazam 
Published: September 2021

AbstractA low‐calorie biscuit formulation containing quinoa flour (cultivars TTKK), isomalt, and maltodextrin was optimized using response surface methodology. Optimized samples were evaluated in terms of total phenolic compounds (TPC), sensory properties, and nutritional value while samples containing only wheat flour (Pishgam var.) and sucrose were used as control. Morphology of isolated starch from quinoa was also investigated. The results showed that with increasing amounts of quinoa, isomalt, and maltodextrin ΔE and Browning index increased, whereas hardness and L values decreased. The formulation containing 25% quinoa flour, 3.5% maltodextrin, and 10% isomalt was found to be optimal with an overall desirability value of 0.95. The sensory evaluation showed that replacement of wheat flour with 25 g/100 g quinoa flour in biscuits was acceptable. TPC of the optimal biscuit (1,180.34 ± 0.02 μg GAE/g) was higher than that of the control sample (729.95 ± 0.007 μg GAE/g). In addition, the optimized biscuit had more protein (8.36 ± 0.035%) and dietary fiber (2.14 ± 0.035%) content compared with the control sample (7.01 ± 0.007% and 1.66 ± 0.028%, respectively). The consumption of 100 g of optimized quinoa biscuits supplies the daily requirement of Fe, Mg, Ca, and Zn at 2.43%, 44.81%, 19.46% and 1.12%, respectively.
Aberrant DNA methylation patterns in microsatellite stable human colorectal cancers define a new marker panel for the CpG island methylator phenotype
Authors: Gebhard Claudia , Mulet‐Lazaro Roger , Glatz Dagmar , Schwarzfischer‐Pfeilschifter Lucia , Schirmacher Peter , Gaedcke Jochen , Weichert Wilko , Reuschel Edith , Dietmaier Wolfgang , Rehli Michael 
Published: September 2021

AbstractA distinct group of colorectal carcinomas (CRCs) referred to as the “CpG island methylator phenotype” (CIMP) shows an extremely high incidence of de novo DNA methylation and may share common pathological, clinical or molecular features. However, there is limited consensus about which CpG islands (CGIs) define a CIMP, particularly in microsatellite stable (MSS) carcinomas. To study this phenotype in a systematic manner, we analyzed genome‐wide CGI DNA methylation profiles of 19 MSS CRC using methyl‐CpG immunoprecipitation (MCIp) and hybridization on 244K CGI oligonucleotide microarrays, determined KRAS and BRAF mutation status and compared disease‐related DNA methylation changes to chromosomal instability as detected by microarray‐based comparative genomic hybridization. Results were validated using mass spectrometry analysis of bisulfite‐converted DNA at a subset of 76 individual CGIs in 120 CRC and 43 matched normal tissue samples. Both genome‐wide profiling and CpG methylation fine mapping segregated a group of CRC showing pronounced and frequent de novo DNA methylation of a distinct group of CGIs that only partially overlapped with previously established classifiers. The CIMP group defined in our study revealed significant association with colon localization, either KRAS or BRAF mutation, and mostly minor chromosomal losses but no association with known histopathological features. Our data provide a basis for defining novel marker panels that may enable a more reliable classification of CIMP in all CRCs, independently of the MS status.
Comparative analysis of the potential of the secretomes of cardiac resident stromal cells and fibroblasts
Authors: Lino Jhonatan Basso , Robert Anny Waloski , Stimamiglio Marco Augusto , de Aguiar Alessandra Melo 
Published: September 2021

AbstractThe secretome of different cell types has been applied on in vitro and in vivo assays, indicating considerable therapeutic potential. However, the choice of the ideal cell type and culture conditions for obtaining the best set of soluble factors, as well as the assays to assess specific effects, remain subjects of vigorous debate. In this study, we used mass spectrometry to characterize the secretomes of ventricle derived‐cardiac resident stromal cells (vCRSC) and human dermal fibroblasts (HDFs) and evaluate them in an effort to understand the niche specificity of biological responses toward different cellular behaviors, such as cell proliferation, adhesion, migration, and differentiation. It was interesting to note that the HDF and vCRSC secretomes were both able to induce proliferation and cardiac differentiation of H9c2 cells, as well as to increase the adhesion activity of H9c2 cells and human umbilical vein endothelial cells. Analysis of the secretome composition showed that the vCRSCs derived from different donors secreted a similar set of proteins. Despite the differences, almost half of the proteins identified in conditioned medium were common to both HDF and vCRSC. Consequently, a high number of common biological processes were identified in the secretomes of the two cell types, which could help to explain the similar results observed in the in vitro assays. We show that soluble factors secreted by both HDF and vCRSC are able to promote proliferation and differentiation of cardiomyoblasts in vitro. Our study indicates the possible use of vCRSC or HDF secretomes in acellular therapies for regenerative medicine.
SHP2: The protein tyrosine phosphatase involved in chronic pulmonary inflammation and fibrosis
Authors: Chang Chun‐Jung , Lin Chiou‐Feng , Chen Bing‐Chang , Lin Pei‐Yun , Chen Chia‐Ling 
Published: September 2021

AbstractChronic respiratory diseases (CRDs), including pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), lung cancer, and asthma, are significant global health problems due to their prevalence and rising incidence. The roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) in controlling tyrosine phosphorylation of targeting proteins modulate multiple physiological cellular responses and contribute to the pathogenesis of CRDs. Src homology‐2 domain‐containing PTP2 (SHP2) plays a pivotal role in modulating downstream growth factor receptor signaling and cytoplasmic PTKs, including MAPK/ERK, PI3K/AKT, and JAK/STAT pathways, to regulate cell survival and proliferation. In addition, SHP2 mutation and activation are commonly implicated in tumorigenesis. However, little is known about SHP2 in chronic pulmonary inflammation and fibrosis. This review discusses the potential involvement of SHP2 deregulation in chronic pulmonary inflammation and fibrosis, as well as the therapeutic effects of targeting SHP2 in CRDs.