bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Survey for Cloud Computing Based Nature-Inspired Algorithms Optimization Scheduling
Authors: Yahia Hazha Saeed , Zeebaree Subhi R. M. , Sadeeq Mohammed A. M. , Salim Nareen O. M. , Kak Shakir Fattah , AL-Zebari Adel , Salih Azar Abid , Hussein Helat Ahmed 
Published: May 2021

Many applications in the real world include optimizing specific targets, such as cost minimization, energy conservation, climate, and maximizing production, efficiency, and sustainability. The optimization problem is strongly non-linear with multifunctional landscapes under several dynamic, non-linear constraints in some instances. It is challenging to address those issues. Also, with the increasing strength of modern computers, simplistic brute force methods are still inefficient and unwanted. Practical algorithms are also vital for these implementations whenever possible.
Cloud computing has become an essential and popular emerging computing environment that supports on-demand services and provides internet-based services. Cloud computing allows a range of services and tools to be easily accessed from anywhere in the world. Since cloud computing has global access to its services, there will always be threats and challenges facing its servers and services, such as; task scheduling, security, energy efficiency, network load, and other challenges. In the research area, many algorithms have been addressed to solve these problems. This paper investigates relevant analysis and surveys on the above topics, threats, and outlooks. This paper offers an overview of nature-inspired algorithms, their applications, and valuation, emphasizing cloud computing problems. Many problems in science and engineering can be viewed as optimization problems with complex non-linear constraints. Highly nonlinear solutions typically need advanced optimization algorithms, and conventional algorithms can have difficulty addressing these issues. Because of its simplicity and usefulness, nature-inspired algorithms are currently being used. There are nevertheless some significant concerns with computing and swarming intelligence influenced by evolution.
Scanning Electron Microscopic Evaluation of Marginal Adaptation of Three Endodontic Sealers: An Ex-Vivo Study
Authors: Padmawar Neeta , Moapagr Viddyasagar , Vadvadgi Vinay , Vishwas Jayshree , Joshi Sourabh , Padubidri Meghna 
Published: May 2021

Introduction: To avoid the entry of micro-organism or their products, sealer should completely adapt to the root canal wall so that no gaps will be present. AH plus is the most routinely used sealer. EndoRez is methacrylate resin-based self as well as light cured sealer. Endosequence BC RCS is the recently introduced bioceramic based sealer.
Aim: To evaluate the marginal adaptation of Endosequence BS RCS, EndoRez and AH plus as a root canal sealer to root dentin under electron scanning microscope.
Methods: Total 75 freshly extracted permanent maxillary central incisors with single canal were included in this study. All the teeth were decoronated till twelve millimeter and access cavity was prepared. All the teeth were prepared with rotary protaper till# F3 with intermediate copious irrigation with 3% sodium hypochlorite and 17%EDTA.Teeth were randomly divided into three groups according to sealers and were obturated- Endosequence BC RCS, Ah Plus and EndoRez. Access cavity was restored with glass ionomer type II in all the groups. After seven days, teeth were vertically sectioned and evaluated under electron scanning microscope for marginal adaptation.
Results: Marginal gaps were present in all groups. Maximum number of gaps were present in Ah plus group. Endosequence BC RCS group showed least number of gaps.
Discussion: Marginal adaptation of sealer depends upon the properties like flow, viscosity, presence or absence of smear layer etc. Better adaptation of Endosequence BC RCS to root dentin is due to formation of mineral infiltration zone which results in formation of calcific tags in dentine.
Conclusion: Within the limitation of present study, newly introduced Endosequence BC RCS showed better marginal adaptability to root dentine. Further studies are required to evaluate and corelate these findings with other properties of these sealers.
Monte Carlo study of TG‐43 dosimetry parameters of GammaMed Plus high dose rate 192Ir brachytherapy source using TOPAS
Authors: Wu Jianan , Xie Yaoqin , Ding Zhen , Li Feipeng , Wang Luhua 
Published: May 2021

AbstractPurposeTo develop a simulation model for GammaMed Plus high dose rate 192Ir brachytherapy source in TOPAS Monte Carlo software and validate it by calculating the TG‐43 dosimetry parameters and comparing them with published data.MethodsWe built a model for GammaMed Plus high dose rate brachytherapy source in TOPAS. The TG‐43 dosimetry parameters including air‐kerma strength SK, dose‐rate constant Λ, radial dose function gL(r), and 2D anisotropy function F(r,θ) were calculated using Monte Carlo simulation with Geant4 physics models and NNDC 192Ir spectrum. Calculations using an old 192Ir spectrum were also carried out to evaluate the impact of incident spectrum and cross sections. The results were compared with published data.ResultsFor calculations using the NNDC spectrum, the air‐kerma strength per unit source activity SK/A and Λ were 1.0139 × 10‐7 U/Bq and 1.1101 cGy.h−1.U−1, which were 3.56% higher and 0.62% lower than the reference values, respectively. The gL(r) agreed with reference values within 1% for radial distances from 2 mm to 20 cm. For radial distances of 1, 3, 5, and 10 cm, the agreements between F(r,θ) from this work and the reference data were within 1.5% for 15° < θ < 165°, and within 4% for all θ values. The discrepancies were attributed to the updated source spectrum and cross sections. They caused deviations of the SK/A of 2.90% and 0.64%, respectively. As for gL(r), they caused average deviations of −0.22% and 0.48%, respectively. Their impact on F(r,θ) was not quantified for the relatively high statistical uncertainties, but basically they did not result in significant discrepancies.ConclusionA model for GammaMed Plus high dose rate 192Ir brachytherapy source was developed in TOPAS and validated following TG‐43 protocols, which can be used for future studies. The impact of updated incident spectrum and cross sections on the dosimetry parameters was quantified.
Genetically Encoding Light‐Responsive Protein‐Polymers Using Translation Machinery for the Multi‐Site Incorporation of Photo‐Switchable Unnatural Amino Acids
Authors: Israeli Bar , Strugach Daniela S. , Gelkop Sigal , Weber Shir , Gozlan Dor S. , Amiram Miriam 
Published: May 2021

AbstractA general and versatile technology to engineer light‐responsive protein‐based biomaterials can enable the manipulation and interrogation of proteins, pathways, and cells, and it will assist the design of “smart” light‐responsive biomaterials. This study reports the evolution of chromosomal aminoacyl‐tRNA synthetases (aaRSs) for azobenzene‐bearing unnatural amino acids (uAAs) with up to ≈40‐fold increased protein production and improved fidelity, as compared with a previously described aaRS. The evolved translation systems enable efficient and accurate incorporation of up to 10 instances of the various light‐responsive uAAs in elastin‐like polypeptides (ELPs). Azobenzene‐containing ELPs are capable of isothermal, reversible, light‐mediated soluble‐to‐insoluble phase transition, with up to a 12  °C difference in the ELP transition temperature upon cis‐to‐trans azobenzene isomerization. Furthermore, the incorporation of azobenzene‐uAAs in ELP diblock‐copolymers enables the creation of light‐responsive self‐assembled nanostructures. Finally, light‐responsive resilin‐inspired polymers are also generated by multi‐site azobenzene‐incorporation. The translation machinery evolved in this study can be used for the multi‐site incorporation of azobenzene moieties at the polypeptide level and constitute a universal methodology for the design of light‐responsive proteins and additional families of protein‐based biomaterials with customized and tunable light‐responsive behavior.
Brønsted Base‐Catalyzed Tandem [2+4] Annulation/Tautomerization/Aromatization Reaction of α‐Alkylidene Succinimides with 5‐Alkenyl Thiazolones
Authors: Yuan Chunhao , Yang Huimin , Gong Qi , Luo Shan , Gu Jing , Ge Yanqing , Guo Hongchao , Xie Lei 
Published: May 2021

AbstractA Brønsted base‐catalyzed tandem [2+4] annulation/tautomerization/aromatization reaction of α‐alkylidene succinimides with 5‐alkenyl thiazolones has been developed for synthesis of functionalized thiazolo pyrones under mild conditions. The prepared thiazolo pyrones show fluorescent properties.magnified image
Thermal and Humidity Stability of Mixed Spacer Cations 2D Perovskite Solar Cells
Authors: Yu Huayang , Xie Yulin , Zhang Jia , Duan Jiashun , Chen Xu , Liang Yudong , Wang Kai , Xu Ling 
Published: May 2021

AbstractIn this article, two different types of spacer cations, 1,4‐butanediamonium (BDA2+) and 2‐phenylethylammonium (PEA+) are co‐used to prepare the perovskite precursor solutions with the formula of (BDA)1‐a(PEA2)aMA4Pb5X16. By simply mixing the two spacer cations, the self‐assembled polycrystalline films of (BDA)0.8(PEA2)0.2MA4Pb5X16 are obtained, and BDA2+ is located in the crystal grains and PEA+ is distributed on the surface. The films display a small exciton binding energy, uniformly distributed quantum wells and improved carrier transport. Besides, utilizing mixed spacer cations also induces better crystallinity and vertical orientation of 2D perovskite (BDA)0.8(PEA2)0.2MA4Pb5X16 films. Thus, a power conversion efficiency (PCE) of 17.21% is achieved in the optimized perovskite solar cells with the device structure of ITO/PEDOT:PSS/Perovskite/PCBM/BCP/Ag. In addition, the complementary humidity and thermal stability are obtained, which are ascribed to the enhanced interlayer interaction by BDA2+ and improved moisture resistance by the hydrophobic group of PEA+. The encapsulated devices are retained over 95% or 75% of the initial efficiency after storing 500 h in ambient air under 40 ± 5% relative humidity or 100 h in nitrogen at 60 °C.
Mechanophore activation enhanced by hydrogen bonding of diarylurea motifs: An efficient supramolecular force‐transducing system
Authors: Kida Jumpei , Aoki Daisuke , Otsuka Hideyuki 
Published: May 2021

AbstractMacromolecules are efficient as mechanical transducers for mechanically induced chemical bond cleavage reactions. Although various classes of polymers have been studied as effective mechanical‐force transducers for mechanophores, alternatives to polymer chains, that is, small molecules, have rarely been studied. In this paper, the role of hydrogen bonding as small‐molecule mechanical‐force transducers for the activation of mechano‐responsive molecular units (mechanophores) in the bulk is investigated. The introduction of diarylurea linkage motifs, which are known as strong hydrogen bonding groups, enhances the mechanochemical activation of the fluorescent mechanophore tetraarylsuccinonitrile (TASN) as effectively as the attachment of a typical macromolecular transducer. Electron paramagnetic resonance measurements of mechanically activated TASN with diphenyl urea motifs demonstrate its higher carbon–carbon bond dissociation ratio compared to that of TASN without diphenyl urea motifs. This efficient supramolecular‐force‐transducing system represents a new concept in the field of mechanochemistry, namely, the enhancement of mechanochemical bond scission by simply changing the substituents of a mechanophore, even in small molecules.
Comprehensive Analysis of Binding Sites in Tubulin
Authors: Mühlethaler Tobias , Gioia Dario , Prota Andrea E. , Sharpe May E. , Cavalli Andrea , Steinmetz Michel O. 
Published: May 2021

AbstractTubulin plays essential roles in vital cellular activities and is the target of a wide range of proteins and ligands. Here, using a combined computational and crystallographic fragment screening approach, we addressed the question of how many binding sites exist in tubulin. We identified 27 distinct sites, of which 11 have not been described previously, and analyzed their relationship to known tubulin–protein and tubulin–ligand interactions. We further observed an intricate pocket communication network and identified 56 chemically diverse fragments that bound to 10 distinct tubulin sites. Our results offer a unique structural basis for the development of novel small molecules for use as tubulin modulators in basic research applications or as drugs. Furthermore, our method lays down a framework that may help to discover new pockets in other pharmaceutically important targets and characterize them in terms of chemical tractability and allosteric modulation.
Head‐to‐Tail Oligomerization by Silylene‐Tethered Sonogashira Coupling on Ag(111)
Authors: Sun Kewei , Sagisaka Keisuke , Peng Lifen , Watanabe Hikaru , Xu Feng , Pawlak Rémy , Meyer Ernst , Okuda Yasuhiro , Orita Akihiro , Kawai Shigeki 
Published: May 2021

AbstractOn‐surface synthesis is a powerful method for the fabrication of π‐conjugated nanomaterials. Herein, we demonstrate chemoselective Sonogashira coupling between (trimethylsilyl)ethynyl and chlorophenyl groups in silylethynyl‐ and chloro‐substituted partially fluorinated phenylene ethynylenes (SiCPFPEs) on Ag(111). The desilylative Sonogashira coupling occurred with high chemoselectivity up to 75 %, while the competing Ullmann and desilylative Glaser homocoupling reactions were suppressed. A combination of bond‐resolved scanning tunneling microscopy/atomic force microscopy (STM/AFM) and DFT calculations revealed that the oligomers were obtained by the formation of intermolecular silylene tethers (‐Me2Si‐) through CH3−Si bond activation at 130 °C and subsequent elimination of the tethers at an elevated temperature of 200 °C.
Formulating the Electrolyte Towards High‐Energy and Safe Rechargeable Lithium–Metal Batteries
Authors: Ma Qiang , Yue Junpei , Fan Min , Tan Shuang‐Jie , Zhang Juan , Wang Wen‐Peng , Liu Yuan , Tian Yi‐Fan , Xu Quan , Yin Ya‐Xia , You Ya , Luo An , Xin Sen , Wu Xiong‐Wei , Guo Yu‐Guo 
Published: May 2021

AbstractRechargeable lithium–metal batteries with a cell‐level specific energy of >400 Wh kg−1 are highly desired for next‐generation storage applications, yet the research has been retarded by poor electrolyte–electrode compatibility and rigorous safety concerns. We demonstrate that by simply formulating the composition of conventional electrolytes, a hybrid electrolyte was constructed to ensure high (electro)chemical and thermal stability with both the Li‐metal anode and the nickel‐rich layered oxide cathodes. By employing the new electrolyte, Li∥LiNi0.6Co0.2Mn0.2O2 cells show favorable cycling and rate performance, and a 10 Ah Li∥LiNi0.8Co0.1Mn0.1O2 pouch cell demonstrates a practical specific energy of >450 Wh kg−1. Our findings shed light on reasonable design principles for electrolyte and electrode/electrolyte interfaces toward practical realization of high‐energy rechargeable batteries.
Discovery of a Low Thermal Conductivity Oxide Guided by Probe Structure Prediction and Machine Learning
Authors: Collins Christopher M. , Daniels Luke M. , Gibson Quinn , Gaultois Michael W. , Moran Michael , Feetham Richard , Pitcher Michael J. , Dyer Matthew S. , Delacotte Charlene , Zanella Marco , Murray Claire A. , Glodan Gyorgyi , Pérez Olivier , Pelloquin Denis , Manning Troy D. , Alaria Jonathan , Darling George R. , Claridge John B. , Rosseinsky Matthew J. 
Published: May 2021

AbstractWe report the aperiodic titanate Ba10Y6Ti4O27 with a room‐temperature thermal conductivity that equals the lowest reported for an oxide. The structure is characterised by discontinuous occupancy modulation of each of the sites and can be considered as a quasicrystal. The resulting localisation of lattice vibrations suppresses phonon transport of heat. This new lead material for low‐thermal‐conductivity oxides is metastable and located within a quaternary phase field that has been previously explored. Its isolation thus requires a precisely defined synthetic protocol. The necessary narrowing of the search space for experimental investigation was achieved by evaluation of titanate crystal chemistry, prediction of unexplored structural motifs that would favour synthetically accessible new compositions, and assessment of their properties with machine‐learning models.
Degradation in Order: Simple and Versatile One‐Pot Combination of Two Macromolecular Concepts to Encode Diverse and Spatially Regulated Degradability Functions
Authors: Fuoco Tiziana 
Published: May 2021

AbstractThe clever one‐pot combination of two macromolecular concepts, ring‐opening polymerization (ROP) and step‐growth polymerization (SGP), is demonstrated to be a simple, yet powerful tool to design a library of sequence‐controlled polymers with diverse and spatially regulated degradability functions. ROP and SGP occur sequentially at room temperature when the organocatalytic conditions are switched from basic to acidic, and each allows the encoding of specific degradable bonds. ROP controls the sequence length and position of the degradability functions, while SGP between the complementary vinyl ether and hydroxyl chain‐ends enables the formation of acetal bonds and high‐molar‐mass copolymers. The result is the rational combination of cleavable bonds prone to either bulk or surface erosion within the same macromolecule. The strategy is versatile and offers higher chemical diversity and level of control over the primary structure than current aliphatic polyesters or polycarbonates, while being simple, effective, and atom‐economical and having potential for scalability.
Rational Design and Engineering of One‐Dimensional Hollow Nanostructures for Efficient Electrochemical Energy Storage
Authors: Fang Yongjin , Luan Deyan , Gao Shuyan , Lou Xiong Wen (David) 
Published: May 2021

AbstractThe unique structural characteristics of one‐dimensional (1D) hollow nanostructures result in intriguing physicochemical properties and wide applications, especially for electrochemical energy storage applications. In this Minireview, we give an overview of recent developments in the rational design and engineering of various kinds of 1D hollow nanostructures with well‐designed architectures, structural/compositional complexity, controllable morphologies, and enhanced electrochemical properties for different kinds of electrochemical energy storage applications (i.e. lithium‐ion batteries, sodium‐ion batteries, lithium‐sulfur batteries, lithium‐selenium sulfur batteries, lithium metal anodes, metal‐air batteries, supercapacitors). We conclude with prospects on some critical challenges and possible future research directions in this field. It is anticipated that further innovative studies on the structural and compositional design of functional 1D nanostructured electrodes for energy storage applications will be stimulated.
1,1,2‐Ethenetriol: The Enol of Glycolic Acid, a High‐Energy Prebiotic Molecule
Authors: Mardyukov Artur , Keul Felix , Schreiner Peter R. 
Published: May 2021

AbstractAs low‐temperature conditions (e.g. in space) prohibit reactions requiring large activation energies, an alternative mechanism for follow‐up transformations of highly stable molecules involves the reactions of higher energy isomers that were generated in a different environment. Hence, one working model for the formation of larger organic molecules is their generation from high‐lying isomers of otherwise rather stable molecules. As an example, we present here the synthesis as well as IR and UV/Vis spectroscopic identification of the previously elusive 1,1,2‐ethenetriol, the higher energy enol tautomer of glycolic acid, a rather stable and hence unreactive biological building block. The title compound was generated in the gas phase by flash vacuum pyrolysis of tartronic acid at 400 °C and was subsequently trapped in argon matrices at 10 K. The spectral assignments are supported by B3LYP/6–311++G(2d,2p) computations. Upon photolysis at λ=180–254 nm, 1,1,2‐ethenetriol rearranges to glycolic acid and ketene.
Azacalix[3]triazines: A Substructure of Triazine‐Based Graphitic Carbon Nitride Featuring Anion‐π Interactions
Authors: Gong Hao , Zhang Cheng , Ogaki Takuya , Inuzuka Hiroyuki , Hashizume Daisuke , Miyajima Daigo 
Published: May 2021

AbstractGraphitic carbon nitride (GCN) has garnered broad research interest due to its unique catalytic properties. However, GCN, prepared by general methods, possesses myriad structural defects and it has been difficult to elucidate their intrinsic physical properties. We report the development of azacalix[3]triazines (AC3Ts), a substructure of triazine‐based GCN (Tz‐GCN). Despite the electron‐deficient natures of triazine, AC3Ts capture protons as organic superbases. We reveal the unique anion‐π interactions of AC3Ts that alters the ionization potentials of AC3Ts. To the best of our knowledge, these features have not yet been recognized for Tz‐GCN. These unveiled features of AC3Ts are expected to expand the usage scope and possibilities for GCNs.
Dioxygen Activation and Pyrrole α‐Cleavage with Calix[4]pyrrolato Aluminates: Enzyme Model by Structural Constraint
Authors: Sigmund Lukas Maximilian , Ehlert Christopher , Enders Markus , Graf Jürgen , Gryn'ova Ganna , Greb Lutz 
Published: May 2021

AbstractThe present work describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin‐forbidden process. Despite a negligible spin–orbit coupling constant, the intersystem crossing (ISC) is facilitated by singlet and triplet state degeneracy and spin–vibronic coupling. The formed peroxides are stable toward external substrates but undergo an unprecedented oxidative pyrrole α‐cleavage by ligand aromatization/dearomatization‐initiated O−O σ‐bond scission. A detailed comparison of the calix[4]pyrrolato aluminates with dioxygen‐related enzymology provides insights into the ISC of metal‐ or cofactor‐free enzymes. It substantiates the importance of structural constraint and element–ligand cooperativity for the functions of aerobic life.
Monumental funerary landscapes of Dhar Tagant (south‐eastern Mauritania): Towards ethical satellite remote sensing in the West African Sahel
Authors: Linares Matás Gonzalo J. , Lim Jonathan S. 
Published: May 2021

AbstractThe remembrance of the dead is a ubiquitous dimension of most human societies, and the spatial dimension of mortuary practices actively constitutes an essential element of the cultural significance of certain places in the landscape. The visual prominence of stone‐built funerary monuments in dry upland areas is particularly conducive to their multiscalar study through above‐ground remote sensing methods. In this paper, we characterize the nature and distribution of Late Holocene drystone funerary monuments in the Dhar Tagant region of south‐eastern Mauritania using freely available, very high‐resolution (VHR) satellite imagery. We contextualize them in relation to the monumental mortuary records of Senegal and Mali within the West African Sahel, exploring their similarities and differences with other monumental funerary landscapes in semi‐arid environments. Ethical considerations and a self‐reflective attitude must be at the forefront of archaeological research, and we discuss the ethics of remote sensing research in the study of funerary practices in Africa, as well as the opportunities and challenges for remote collaborative engagement with local communities in the context of fieldwork restrictions.