bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total Synthesis of Phenanthropiperidine Alkaloids by Sequential Alkylation of N,N‐Dibenzylaminoacetonitrile
Authors: Bouvry Christelle , Franzetti Milène , Cupif Jean‐François , Hurvois Jean‐Pierre 
Published: October 2021

AbstractTwo representative members of the phenanthropiperidine alkaloid family, tylophorine (1) and cryptopleurine (2), were synthesized by a bidirectional alkylation strategy employing dibenzylaminoacetonitrile as a substrate. This approach relies on the unprecedented condensation of metallated α‐aminonitriles with bromomethylphenanthrenes to provide fully substituted α‐aminonitriles, which are subjected to a NaBH4‐mediated reductive decyanation process to form homobenzylic amines. From these intermediates, a terminal leaving group was introduced by simple chemical manipulation, and its displacement by a free primary amine under two favorable cyclization processes led to the formation of the future E‐ring of both alkaloids in high yields. Finally, a late Pictet‐Spengler cyclization ensured the formation of a D‐ring for the alkaloids 1 and 2.
Gold Nanocatalysts Towards Digital Sensing Probes with Electrochemiluminescence Based Micro Electrodes Array
Authors: Nagano Kohei , Terada Yuhei , Araki Akiko , Osaki Shuto , Saito Masato , Tamiya Eiichi 
Published: October 2021

AbstractThe authors have found that gold nanoparticles (AuNP) function as nanocatalysts for the generation of reactive oxygen species such as hydrogen peroxide from dissolved oxygen in coexistence with tris(hydroxymethyl)aminomethane (Tris) or N‐[tris(hydroxymethyl) methyl]glycine (Tricine) chemicals, and that these can be evaluated by luminol electrochemi‐luminescence (ECL). In the present study, we investigated the effects of reaction time, particle concentration, and temperature on the catalytic properties of gold nanoparticles. Unlike biocatalysts such as enzymes, the gold nanoparticles showed an Arrhenius plot‐like increase in activity with temperature without inactivation. In addition, the catalytic activity of the gold nanoparticles varied with the size and shape of the nanoparticles for spherical gold nanoparticles of different sizes (5, 15, 30, 50 and 400 nm) and the activity per nanoparticle increased with the size and surface area. When compared activity per surface area, 15 nm nanoparticles showed higher activity. We prepared gold nanoparticles with nanoflower (AuNF) structure of approx.200 nm in size which showed higher activity per particle than 400 nm spherical particles. The increase in surface area and the difference in surface condition may have influenced these results. We also prepared microelectrode arrays capable of holding small amounts of nl‐pL test reagents. They showed the possibility of imaging ECL of the activity of gold nanoparticles at the level of tens of nanoparticles which could lead to nanocatalysts as probes for digital analysis.
Perspective for removing volatile organic compounds during solar‐driven water evaporation toward water production
Authors: Ma Jiaxiang , Xu Ying , Sun Feiyun , Chen Xiaodong , Wang Wei 
Published: October 2021

AbstractSolar evaporation has attracted considerable interest to alleviate the shortage of water resources in the past few years. Lots of works have been done focusing on evaporation materials, rate, and efficiency, however, little attempts have been made to remove the harmful volatile organic compounds (VOCs), a kind of contamination that inevitably evaporate and condense alongside with water, which seriously affect the distilled water quality. This perspective puts forward some technical ideas utilizing chemical or physicochemical methods, aiming at the development of multifunctional composite materials, and forming an integrated evaporation system, which manage to remove VOCs in situ at the interface of photothermal evaporation.image
A Woodbury solution method for efficient seismic collapse analysis of space truss structures based on hybrid nonlinearity separation
Authors: Yu Ding‐Hao , Li Gang , Li Hong‐Nan 
Published: October 2021

AbstractThis study presents a fast algorithm for collapse behavior simulation of space truss structures under extreme earthquake excitation by introducing the Woodbury formula to efficiently solve the structural response caused by material and geometric nonlinearity (hybrid nonlinearity). The Woodbury formula, which is an efficient tool in mathematics for solving low‐rank perturbation problems, has successfully been used to improve the efficiency of local material nonlinear analysis but still has difficulties with seismic collapse analysis in which geometric nonlinearity should be considered. In this study, by implementing stiffness matrix decomposition according to the unchanged reference configuration, the effects of hybrid nonlinearity on the change in tangent stiffness of truss structures are uniformly formulated in the form of hybrid nonlinear perturbation to the reference elastic stiffness. Thus, a hybrid nonlinearity separated governing equation can be established, in which the hybrid nonlinear behaviors are depicted by the additional nonlinear degrees of freedom (NLDOFs) separated from the reference system. This allows for employing the Woodbury formula to perform seismic collapse analysis of space truss structures for avoiding the repeated updating of the global stiffness. To overcome the adverse effect of the large NLDOF number caused by the global characteristics of geometric nonlinearity on the efficiency advantages of the Woodbury formula during seismic collapse analysis, an element state judgment strategy and an adaptive restart mechanism are presented to activate only a small number of NLDOFs within critical local regions. The accuracy and efficiency of the proposed method are verified by two numerical examples.
A novel decentralized cross‐domain identity authentication protocol based on blockchain
Authors: Zhao Gang , Di Bingbing , He Hui 
Published: October 2021

AbstractIn the context of cloud computing, the interaction between clients in different application domains becomes more frequent, which makes cross‐domain identity authentication safely and efficiently become an important research topic. Public key infrastructure (PKI) is a technology to solve cross‐domain authentication. However, there are problems such as difficulty in mutual trust between multiple certificate authority nodes (CA), failure of single point, and low efficiency in the traditional PKI method. Blockchain is a promising technology for decentralized trust management by providing consistent data storage, which gives impetus to the further development of cross‐domain identity authentication. Thus, this article apply blockchain to cross‐domain identity authentication. To solve the defects of the traditional PKI method, the design requirements are analyzed firstly, based on the analysis result, we proposed a double‐layer cross‐domain identity authentication model by constructing a consortium blockchain which is comprised of authentication server nodes (AS) and some internal blockchain, the model can highly improve the scalability of the PKI system without changing the internal architecture. Then a novel authentication protocol was put forward. The protocol can improve the efficiency of online cross‐domain identity authentication transactions by verifying the hash instead of the signature of their certificate. By putting the generation process of the blockchain certificate and the storage process of its hash in the registration operation and reducing the authentication process for AS and CA, the efficiency is further improved. Finally, the protocol was evaluated by security and performance analysis. The results display our protocol can guarantee security and has an excellent performance in cross‐domain identity authentication transactions.
Inter‐cloud secure data sharing and its formal verification
Authors: Lu Jintian , Zhang Yunyi , Yang Likun , Jin Shuyuan 
Published: October 2021

AbstractWith the development of cloud computing, data sharing and collaboration have become increasing among cloud‐oriented organizations. In addition to trivial management work, data providers face many difficulties in managing access control policies in cloud data sharing, to prevent permission abuse and information leakage. This article mainly answers the following question: is it possible to achieve verifiably secure inter‐cloud data sharing? This article proposes an inter‐cloud data sharing (ICDS) approach based on ciphertext‐policy attribute‐based encryption (CP‐ABE) to ensure the security of ICDS. The security properties that ICDS holds are formally verified, where the information flow rules are defined and used in the verification. The information flow of the proposed ICDS is firstly modeled by use of high‐level Petri nets (HLPN) formally, then being represented in Z language, and at last the security properties of ICDS are verified by the Z3 solver. The formal analysis proves that the ICDS holds the security properties of confidentiality, authenticity, and collusion‐resistance.
GC characterization and erectogenic enzyme inhibitory effect of essential oils from tangerine and lemon peels: A comparative study
Authors: Idowu Oyeleye Sunday , Ajayi Oluwasegun E. , Ademosun Ayokunle O. , Oboh Ganiyu 
Published: October 2021

AbstractThis study comparatively evaluated inhibitory effect of essential oils (EOs) from tangerine and lemon peels on some enzymes [angiotensin‐converting enzyme (ACE), acetylcholinesterase (AChE), arginase, monoamine oxidase (MAO), phosphodiesterase‐5 (PDE‐5), adenosine deaminase (ADA) and 5’‐nucleotidase] related to erectile dysfunction (ED), as well as thiobarbituric acid reactive species (TBARs) level in isolated Wistar albino rats’ penile homogenate. In addition, the chemical compositions of these EOs were characterized via gas chromatography coupled with flame ionization detector (GC‐FID). The result revealed that the studied EOs were able to inhibit these erectogenic enzymes and TBARs level in a dose‐dependent manner. The EOs were found to be rich in monoterpenes hydrocarbon. However, the major constituent in both oils was D‐limonene, 45.48% and 34.99% abundance in lemon and tangerine EOs, respectively. Other phytoconstituents detected in substantial amounts include the following: 4‐Vinyl‐2‐methoxyphenol (5.42% and 2.97%), N‐methyl‐D3‐Aziridine (6.58% and 10.01%) and Xanthotoxin (12.055 and 18.7%) for lemon and tangerine EOs, respectively. It is suggestive that these EOs owe their exceptional inhibitory capacities to the availability of these phytochemicals. Hence, their ability to inhibit ACE, AChE, arginase, MAO, PDE‐5, ADA and 5’‐nucleotidase activities, and TBARs level could be the possible mechanism by which the studied EOs exert their therapeutic potentials in the management of ED.
Comparison of the immersion chilling and freezing and traditional air freezing on the quality of beef during storage
Authors: Ren Wanyu , Yuan Guoqiang , Lin Xueer , Guo Xiaohui , Wang Zengli 
Published: October 2021

AbstractCompared to traditional air freezing, immersion chilling and freezing shows an improvement in the freezing effect on meat quality, but it is not known whether this advantage persists over longer storage periods. Therefore, the objective of the current study was to compare the effects of immersion chilling and freezing (ICF) and traditional air freezing (TAF) on the physical and chemical indexes in beef longissimus muscle during a storage period of 150 days. In the current study, the longissimus muscle from Luxi cattle (aged 20–24 months) was analyzed, with samples independently frozen by ICF and TAF. After the core temperature was frozen to below −18 degrees by the two chilling methods, samples were transferred to a −18 degrees cold room for further storage. During the storage period, physical and chemical indexes, mainly including color and texture qualities, total volatile base nitrogen (TVB‐N) and peroxide value (POV) were measured and comparatively analyzed at several fixed time points. A higher freezing rate was observed in ICF (5.124 cm/h) than in TAF (0.194 cm/h), and better microstructure was observed in ICF treatment. Besides, peak force values and total energy values were significantly lower in the TAF group than in the ICF group during the first 45 days of freezing storage time (p < .05). ICF also showed better color quality due to higher L* values than TAF samples during the first 75 days of frozen storage (p < .05). In addition, the thawing loss (after 75 days of storage), total volatile base nitrogen, and peroxide value (in the 30 to 75 days of storage period) were lower in the ICF than in the TAF group. In conclusion, the immersion chilling and freezing is more conducive to the quality of beef during storage at −18 degrees compared to traditional air freezing.
Design, manufacturing, and operation of movable 2 × 10 kW size rSOC system
Authors: Saarinen V. , Pennanen J. , Kotisaari M. , Thomann O. , Himanen O. , Iorio S. Di , Hanoux P. , Aicart J. , Couturier K. , Sun X. , Chen M. , Sudireddy B. R. 
Published: October 2021

AbstractReversible solid oxide cell (rSOC) technology enables both electricity generation for local demands and electricity conversion into hydrogen with high power‐to‐gas (AC to H2) efficiency. This work describes modeling and implementation of movable “10‐feet container” size rSOC system in a pilot demonstration scale (10 kW SOEC/2 kW SOFC). The selected two‐stack two‐module system layout is the simplest option to investigate multi‐module rSOC systems in various operation modes and conditions. Special attention is also paid to heat integration: heat losses are minimized with optimized BoP component design, placement, and insulation. Reversibility, dynamic operation, and methods for efficient transitions between SOFC and SOEC modes are investigated at a system level. The developed system is highly instrumented enabling detailed system analysis, for example, the calculation of enthalpy flows and efficiencies of all BoP components. Analyses of key parameters on the performance and efficiency are presented. To explore upscaling of rSOC systems, the effects of size and structure of stack modules on the reliability and maintenance of the entire system are investigated, and as a conclusion, the construction of multi‐MW scale rSOC systems are recommended to be implemented with approximately 100 kW size stack modules.
Piecewise linear double barrier options
Authors: Lee Hangsuck , Ha Hongjun , Lee Minha 
Published: October 2021

AbstractA piecewise linear double barrier option generalizes classical double barrier options because of its versatility in designing various double boundaries. This paper discusses how to price piecewise linear double barrier options. To this purpose, we derive the probability that an underlying process does not cross a given piecewise linear double barrier, where the underlying process follows the Brownian motion of piecewise constant drift. Using the established non‐crossing probability, we provide the explicit pricing formulas of piecewise linear double barrier options and show how the shape of a double barrier affects the option prices through extensive numerical experiments.
Effect of surface weathering on portable X‐Ray fluorescence analysis of artefacts: Evidence from Tasmanian hornfels
Authors: Theys Jeff , Webb John 
Published: October 2021

AbstractHornfels was commonly utilised by Aboriginal people in southeastern Tasmania for stone artefact manufacture. Sourcing of hornfels artefacts in this region using pXRF analysis is potentially compromised by the weathering patina generally present on this lithology. To understand the impact of weathering on hornfels composition, the mineralogy and chemical composition of weathered and unweathered hornfels were analysed, and weathering was simulated in column experiments. The results demonstrate that the cordierite and, to a lesser extent, plagioclase present in the hornfels transform very rapidly into kaolinite, which is the dominant component of the pale, porous weathering patina. Weathering simulation experiments and isocon comparisons of major and trace element analyses show that this alteration is accompanied by a substantial loss of Mg, Na and Ca (≥50%). For the trace elements, 25%–35% are removed (except Zr, which is relatively immobile), with the remainder retained in unaltered minerals or adsorbed to the neoformed kaolinite. Rb and Nb are more stable than Sr, which demonstrates the highest absolute mobility, but even this element shows relatively little loss, provided that the weathering patina is <1 mm thick. For Rb, Sr, Y, Zn and Nb, the percentage loss during weathering is similar (25%–35%), so bivariate plots of these trace elements show a spread due to weathering, but with a more or less constant ratio. As a result, pXRF analyses of these elements can be used to successfully differentiate hornfels artefacts from different sites in southeastern Tasmania. This study showed that Rb, Sr, Y and Nb, which are commonly used to source igneous artefacts, are also effective in sourcing hornfels, even though they are mobile during weathering. This study also demonstrated the importance of isocon plots in identifying the trace elements best suited to artefact sourcing using pXRF, if the analyses are affected by chemical weathering.
REHE: Fast variance components estimation for linear mixed models
Authors: Yue Kun , Ma Jing , Thornton Timothy , Shojaie Ali 
Published: October 2021

AbstractLinear mixed models are widely used in ecological and biological applications, especially in genetic studies. Reliable estimation of variance components is crucial for using linear mixed models. However, standard methods, such as the restricted maximum likelihood (REML), are computationally inefficient in large samples and may be unstable with small samples. Other commonly used methods, such as the Haseman–Elston (HE) regression, may yield negative estimates of variances. Utilizing regularized estimation strategies, we propose the restricted Haseman–Elston (REHE) regression and REHE with resampling (reREHE) estimators, along with an inference framework for REHE, as fast and robust alternatives that provide nonnegative estimates with comparable accuracy to REML. The merits of REHE are illustrated using real data and benchmark simulation studies.
Robust estimates of heritable coronary disease risk in individuals with type 2 diabetes
Authors: Grace Christopher , Hopewell Jemma C. , Watkins Hugh , Farrall Martin , Goel Anuj 
Published: October 2021

AbstractType 2 diabetes (T2D) is an important heritable risk factor for coronary artery disease (CAD), the risk of both diseases being increased by metabolic syndrome (MS). With the availability of large‐scale genome‐wide association data, we aimed to elucidate the genetic burden of CAD risk in T2D predisposed individuals within the context of MS and their shared genetic architecture. Mendelian randomization (MR) analyses supported a causal relationship between T2D and CAD [odds ratio (OR) = 1.13 per log‐odds unit 95% confidence interval (CI): 1.10–1.16; p = 1.59 × 10−17]. Simultaneously adjusting MR analyses for the effects of the T2D instrument including blood pressure, dyslipidaemia, and obesity attenuated the association between T2D and CAD (OR = 1.07, 95% CI: 1.04–1.11). Bayesian locus‐overlap analysis identified 44 regions with the same causal variant underlying T2D and CAD genetic signals (FDR < 1%) at a posterior probability >0.7; five (MHC, LPL, ABO, RAI1 and MC4R) of these regions contain genome‐wide significant (p < 5 × 10−8) associations for both traits. Given the small effect sizes observed in genome‐wide association studies for complex diseases, even with 44 potential target regions, this has implications for the likely magnitude of CAD risk reduction that might be achievable by pure T2D therapies.
Mendelian randomization in the multivariate general linear model framework
Authors: Allman Phillip H. , Aban Inmaculada , Long Dustin M. , Patki Amit , MacKenzie Todd , Irvin Marguerite R. , Lange Leslie A. , Lange Ethan , Cutter Gary , Tiwari Hemant K. 
Published: October 2021

AbstractMendelian randomization (MR) is an application of instrumental variable (IV) methods to observational data in which the IV is a genetic variant. MR methods applicable to the general exponential family of distributions are currently not well characterized. We adapt a general linear model framework to the IV setting and propose a general MR method applicable to any full‐rank distribution from the exponential family. Empirical bias and coverage are estimated via simulations. The proposed method is compared to several existing MR methods. Real data analyses are performed using data from the REGARDS study to estimate the potential causal effect of smoking frequency on stroke risk in African Americans. In simulations with binary variates and very weak instruments the proposed method had the lowest median [Q1, Q3] bias (0.10 [−3.68 to 3.62]); compared with 2SPS (0.27 [−3.74 to 4.26]) and the Wald method (−0.69 [−1.72 to 0.35]). Low bias was observed throughout other simulation scenarios; as well as more than 90% coverage for the proposed method. In simulations with count variates, the proposed method performed comparably to 2SPS; the Wald method maintained the most consistent low bias; and 2SRI was biased towards the null. Real data analyses find no evidence for a causal effect of smoking frequency on stroke risk. The proposed MR method has low bias and acceptable coverage across a wide range of distributional scenarios and instrument strengths; and provides a more parsimonious framework for asymptotic hypothesis testing compared to existing two‐stage procedures.
Late Triassic granites (ca. 230 Ma) from Cairi area in eastern Qiangtang subterrane, central Tibet: Product of a mid‐oceanic ridge subduction
Authors: He Haiyang , Li Yalin , Wang Tingting , Xiao Siqi , Wang Zhengqing , Chen Liang , Feng Zhigang , Han Shili , Liu Shan , Zhang Yuqian , Tang Zhenping 
Published: October 2021

Although a large number of Triassic magmatism were found in the Qiangtang terrane, central Tibet, the tectonic evolution of the Shuanghu Palaeo‐Tethys Ocean remains controversial. In this study, we present the zircon U–Pb age and major‐ and trace‐element data for the Late Triassic pluton from the Cairi area in the eastern Qiangtang terrane. Zircon U–Pb dating indicates that the samples were emplaced at ca. 230 Ma. The magmatism from the Cairi area primarily consists of granites (SiO2 = 67.28–77.74), with the characteristics of medium‐K calc‐alkaline, metaluminous, and peraluminous. The Cairi granites are enriched light rare earth elements ([La/Yb]N = 5.01–10.56), with obvious Eu anomaly (Eu/Eu* = 0.32–0.47). The Cairi granites are characterized by low 1,000 × Ga/Al (2.10–2.64), FeO*/MgO (3.41–5.03), Ce (57.95–114.36 ppm), Y (27.30–45.19 ppm), and negative correlation between P2O5 and SiO2. These geochemical features reveal that the Cairi granites are calc‐alkaline, I‐type granites. The four samples show relatively restricted (87Sr/86Sr)i ratios (0.70598–0.70724), 143Nd/144Nd ratios (0.51192–0.51196), and εNd(t) of −8.19 to −7.54. Based on the variations of Rb–Sr–Ba and Th–La–Nb and the zircon saturation of temperatures (806–868°C), we suggest that the primary magmas of the Cairi granites were generated through various degrees of mixing between sediments and mantle‐derived components. Petrological and geochemical characteristics, as well as regional geological characteristics indicate that the Cairi granites formed in a continental volcanic arc setting. Our results, in combination with the coeval granites and elcogite, indicate that the generation of Late Triassic (ca. 230 Ma) Cairi granites is related to ocean ridge subduction and subsequent development of a slab window.