bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalyst‐ and Reagent‐Free Electrochemical Azole C−H Amination
Authors: Qiu Youai , Struwe Julia , Meyer Tjark H. , Oliveira João C. A. , Ackermann Lutz 
Published: June 2018

AbstractCatalyst‐ and chemical oxidant‐free electrochemical azole C−H aminations were accomplished via cross‐dehydrogenative C−H/N−H functionalization. The catalyst‐free electrochemical C−H amination proved feasible on azoles with high levels of efficacy and selectivity, avoiding the use of stoichiometric oxidants under ambient conditions. Likewise, the C(sp3)−H nitrogenation proved viable under otherwise identical conditions. The dehydrogenative C−H amination featured ample scope, including cyclic and acyclic aliphatic amines as well as anilines, and employed sustainable electricity as the sole oxidant.
Existing Self‐Replicators Can Direct the Emergence of New Ones
Authors: Altay Yigit , Altay Meniz , Otto Sijbren 
Published: June 2018

AbstractThe study of the interplay between different self‐replicating molecules constitutes an important new phase in the synthesis of life and in unravelling the origin of life. Here we show how existing replicators can direct the nature of a newly formed replicator. Starting from the same building block, 6‐ring replicators formed when the mixture was exposed to pre‐existing 6‐membered replicators, while pre‐formed 8‐membered replicators funneled the building block into 8‐ring replicators. Not only ring size, but also the mode of assembly of the rings into stacks was inherited from the pre‐existing replicators. These results show that the nature of self‐replicating molecules can be strongly influenced by the interplay between different self‐replicators, overriding preferences innate to the structure of the building block.
In Situ Generation of Oxazole Ylide and Interception with Sulfonamide: Construction of Amidines Using Two Diazo Molecules
Authors: Chen Jijun , Long Wenhao , Zhao Yanwei , Li Haiyan , Zheng Yonggao , Lian Pengcheng , Wan Xiaobing 
Published: June 2018

AbstractA novel generation of oxazole ylide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper‐catalyzed four‐component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.
Cover Picture: Anionic Copolymerization of Carbonyl Sulfide with Epoxides via Alkali Metal Alkoxides (Chin. J. Chem. 7/2018)
Authors: Zhang Cheng‐Jian , Yang Jia‐Liang , Hu Lan‐Fang , Zhang Xing‐Hong 
Published: June 2018

The cover picture shows a protocol of an anionic copolymerization of carbonyl sulfide (COS) with epoxides via alkali metal alkoxides. COS is an analogue of carbon dioxide (CO2), and can be converted to CO2 via the carbonic anhydride enzymes widely existing in nature. It causes acid rain, ozonosphere damage and haze by a series of photochemical reactions. Very simple and low‐cost alkali metal alkoxides are shown as effective catalysts, affording highly transparent poly(monothiocarbonate)s with 100% alternating degree, >99% tail‐to‐head (T‐H) content, high number‐average molecular weights with narrow molecular weight distributions. This is an environment‐friendly and atom‐economic process for making sulfur‐containing polymers. More details are discussed in the article by Zhang et al. on page 625–629.
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Automated classification of Wuyi rock tealeaves based on support vector machine
Authors: Lin Li‐Hui , Li Cheng‐Hsuan , Yang Sheng , Li Shao‐Zi , Wei Yi 
Published: June 2018

SummaryThis paper describes a new automated classification method for Wuyi rock tealeaves based on the best penalty parameter selection for the support vector machine with RBF (Radial Basis Function) kernel. A total of 3590 fresh tealeaf images of the representative Rou Gui and Shui Hsien varieties of Wuyi rock tea are collected in their natural habitat. Fourteen image features are extracted in terms of the leaf shape and texture. The automatic selection method is used to find the optimum RBF kernel parameter sigma, which is then applied to design an automatic parameter selection method to screen the best penalty parameter C for the classification of Wuyi rock tealeaves. In this study, the SVM classifier is used for the automated classification and recognition of the 14 image features. The contribution of the various features to the recognition rate of fresh tealeaves is evaluated to identify the key features for the classification and recognition of fresh Wuyi rock tealeaf images. The experimental results show that the proposed method improves the recognition rate of fresh tealeaves to 91.00%.
Synthesis and Characterization of Carboxyethylated Lignosulfonate
Authors: Bahrpaima Khatereh , Fatehi Pedram 
Published: June 2018

AbstractLignosulfonate is a byproduct of the sulfite pulping process and has limited use in industry. The main objective of this study was to investigate the carboxyethylation of lignosulfonate to increase its charge density to broaden its applications. The carboxyethylation of lignosulfonate was optimized under the conditions of 30 wt % NaOH, 2.0 mol mol−12‐chloropropinic acid/lignosulfonate, 90 °C, 0.5 h, and 0.03 mol 2‐chloropropinic acid, which produced carboxyethylated lignosulfonate with a charge density and molecular weight of −3.51 meq g−1and 46 493 g mol−1, respectively. The mechanism of the carboxyethylation reaction using 2‐chloropropinic acid by an SN1 pathway in an alkaline solution was discussed. Methylation was also used to mask the phenolic hydroxide groups of lignosulfonate to investigate if carboxyethylation occurred on aliphatic hydroxide groups of lignosulfonate. The produced carboxyethylated lignosulfonate was characterized by using FTIR spectroscopy, NMR spectroscopy, gel permeation chromatography, and elemental and functional group analyses. Basic1H‐1H 2 D COSY NMR spectroscopy was used to record the coupled spins of the carboxyethyl group on carboxyethylated lignosulfonate. The information from 1 D1H NMR and 2 D NMR COSY spectroscopy provided evidence for the existence of a 1‐carboxyethyl group on the carboxyethylated lignosulfonate structure.
A novel energy‐aware routing mechanism for SDN‐enabled WSAN
Authors: Al‐Hubaishi Mohammed , Çeken Celal , Al‐Shaikhli Ali 
Published: June 2018

SummaryEnergy consumption is one of the most important design constraints when building a wireless sensor and actuator network since each device in the network has a limited battery capacity, and prolonging the lifetime of the network depends on saving energy. Overcoming this challenge requires a smart and reconfigurable network energy management strategy. The Software‐Defined Networking (SDN) paradigm aims at building a flexible and dynamic network structure, especially in wireless sensor networks. In this study, we propose an SDN‐enabled wireless sensor and actuator network architecture that has a new routing discovery mechanism. To build a flexible and energy‐efficient network structure, a new routing decision approach that uses a fuzzy‐based Dijkstra's algorithm is developed in the study. The proposed architecture can change the existing path during data transmission, which is the key property of our model and is achieved through the adoption of the SDN approach. All the components and algorithms of the proposed system are modeled and simulated using the Riverbed Modeler software for more realistic performance evaluation. The results indicate that the proposed SDN‐enabled structure with fuzzy‐based Dijkstra's algorithm outperforms the one using the regular Dijkstra's and the ZigBee‐based counterpart, in terms of the energy consumption ratio, and the proposed architecture can provide an effective cluster routing while prolonging the network lifetime.
Towards providing optimal energy‐efficiency and throughput for IEEE 802.11 WLANs
Authors: Tuysuz Mehmet Fatih 
Published: June 2018

SummaryIEEE 802.11 wireless network standard has become one of the most used wireless networking technologies for smart devices as it offers mobility support and low cost deployment. However, these devices deeply rely on the energy provided by their batteries, which results in limited running time. IEEE 802.11 network standard provides stations with carrier sense multiple access with collision avoidance for the medium access. Yet it results in stations to consume an important amount of power. Therefore, minimizing WiFi‐based energy consumption in smart devices has been received substantial attention in both academia and industry. Accordingly, this paper proposes a novel beacon‐based energy‐efficient collision‐free medium access control protocol for any type of IEEE 802.11 stations, regardless of being stationary or mobile, or having different amount of traffic flow, transmission rates, or traffic types. The proposed scheme is valid for all types of low or wide bandwidth, single or multiuser multiple‐input multiple‐output WLAN channels, such as IEEE 802.11a\b\g\n\ac. In the proposed scheme, energy saving is achieved, enabling stations to transmit on the right time and maintaining stations in the doze state during a predetermined sleep_time interval after each successful frame transmission, by making use of modified control and management frames of the standard IEEE 802.11 protocol. The proposed scheme reduces the probability of collisions and may allow stations to enter the collision‐free state, regardless of the number of stations on the channel and their traffic types. Widespread simulations have been executed to validate the efficiency of the proposed method. The results demonstrate that the proposed method significantly increases overall throughput and reduces power consumption of stations over IEEE 802.11 WLANs.
Diradical Character and Second Hyperpolarizability of Alkaline Earth Metal Inverse Sandwich Complexes Involving Cyclopentadienyl and Cyclooctatetraene Ligands
Authors: Takamuku Shota , Nakano Masayoshi 
Published: June 2018

AbstractInvited for the cover of this issue are Shota Takamuku and Masayoshi Nakano from the group of Masayoshi Nakano, Graduate School of Engineering Science, Osaka University, Japan. The cover image shows a real inverse sandwich between two kinds of alkaline earth metal inverse sandwich model complexes.
Label‐free Electrochemical Bisphenol A Aptasensor Based on Designing and Fabrication of a Magnetic Gold Nanocomposite
Authors: Baghayeri Mehdi , Ansari Reza , Nodehi Marzieh , Razavipanah Iman , Veisi Hojat 
Published: June 2018

AbstractThe present study focuses on designing and fabricating an electrochemical aptasensor for the label free detection of bisphenol A (BPA) using gold nanoparticles (Au NPs) immobilized on functional cupper magnetic nanoparticles (CuFe2O4‐SH) and multiwall carbon nanotubes (MWCNTs) modified with aptamer and 6‐mercapto‐1‐hexanol (MCH). A number of analysis techniques were used to characterize the nanocomposite, including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, elemental mapping analysis and energy dispersive x‐ray diffraction. The results of the analyses revealed that the fabricated aptasensor had an acceptable linearity index (0.05‐9 nM) with an ultralow detection limit (25.2 pM) when used to determine BPA. Electrochemical experiments were conducted using a [Fe(CN)6]3−/[Fe(CN)6]4− redox system. The results of the electrochemical tests indicated that the existence of Au NPs along with magnetic nanoparticles and MWCNTs in nanocomposite led to a synergistic augmentation on the surface of the modified electrode, thus facilitating the efficient sensing of BPA. This method is highly selective, sensitive and environmentally friendly. Moreover, proposed aptasensor has valuable potential applications in medical diagnostics and food industries where a fast and reliable detection of BPA is of paramount importance for the health of the public.
Validation of the Caregiver Skills (CASK) scale in Catalonia: Concordance between caregivers in attitudes and behaviours
Authors: Vintró‐Alcaraz Cristina , Mestre‐Bach Gemma , Steward Trevor , Lozano‐Madrid María , Agüera Zaida , Jiménez‐Murcia Susana , Pedraza Anna M. , Serrano‐Troncoso Eduardo , Ortiz García Ana E. , Rangil Teresa , Lorán Eulalia , Soriano‐Pacheco Jose , Medrano‐Puigdollers Laura , Bujalance‐Arguijo Sara , Badia Gina , Luque Maria , Tràfach Gloria , Gómez Osane , Peña Joan , Fabra Carme , Plana Maria Teresa , Raspall Reyes , Sánchez Isabel , Riesco Nadine , Granero Roser , Carretero‐Jardí Cristina , Treasure Janet , Fernández‐Aranda Fernando 
Published: June 2018

AbstractObjectiveThe aim of this study was to validate a Spanish version of the Caregiver Skills scale (CASK) in a sample of eating disorder (ED) caregivers. A further aim was to examine the concordance/discrepancy between them (namely, between the mothers and fathers of ED patients).MethodTwo hundred sixty‐five ED caregivers were recruited from ED centers in Catalonia, Spain. Confirmatory factor analyses was used to test the factorial structure of the CASK scale. Cronbach's α was used to measure internal consistency of the CASK scales. A comparison of the CASK measures between respondents (mothers and fathers) was conducted using generalized estimating equations.ResultsConfirmatory factor analysis of the Spanish version of the CASK corroborated the strong factorial validity of the 6 factors of the original CASK questionnaire. Mothers and fathers did not differ significantly on CASK overall and subscale scores. There was however less concordance between parents on the bigger picture (ICC = 0.28) and biting your tongue (ICC = 0.08) subscales.ConclusionsThe CASK is a valid tool to assess ED‐related attitudes in Spanish‐speaking caregivers. Furthermore, caregivers and patients alike could stand to benefit from interventions focused on improving areas such as ED beliefs, effective communication, quality of life, and emotional distancing.
Eating disorders and non‐suicidal self‐injury: Structural equation modelling of a conceptual model
Authors: Vieira Ana Isabel , Machado Bárbara C. , Moreira Célia S. , Machado Paulo P.P. , Brandão Isabel , Roma‐Torres António , Gonçalves Sónia 
Published: June 2018

AbstractEvidence suggests several risk factors for both eating disorders (ED) and nonsuicidal self‐injury (NSSI), but the relationships between these factors are not well understood. Considering our previous work and a conceptual model, this cross‐sectional study aimed to assess the relationships among distal and proximal factors for the presence of NSSI in ED. We assessed 245 ED patients with the Oxford Risk Factor Interview for ED. Structural equation modelling revealed that both distal and proximal factors were related to the presence of NSSI in ED, disclosing a mediating role of the proximal factors. Stressful life events mediated the relationship between childhood sexual abuse, peer aggression, and both ED and NSSI. Childhood physical abuse was related to ED and NSSI via substance use, negative self‐evaluation, and suicide attempts. Findings provided support for the conceptual model and highlight the possible mechanisms by which psychosocial factors may lead to ED and NSSI.
On the rapid discharge of subsea accumulators: remarks on the normed design method and proposal of improvement
Authors: Cipollone Roberto , Fatigati Fabio , Di Battista Davide , Allara Paolo , Carini Nicola 
Published: June 2018

AbstractThis study is focused on the design of the subsea accumulators currently used to deliver a pressurized fluid whose function is to actuate safety operations on a subsea well. API 16D, whose specifications regulate the design method of a bank of accumulators, was revised, discussed, and resumed in terms of a nomogram whose engineering value is useful for designers. An additional nomogram was derived allowing to perform the verification process which is suggested by the norm, in order to verify the fulfillment of the actuations requested to the accumulators. This verification phase caught the interest of the Authors: API 16D assumes for the design that the Functional Volume Requirement (FVR) – the sum of the quantities of pressurized fluid to be delivered for different sequenced‐in‐time functions – is delivered at the Minimum Operating Pressure (MOP) requested by the last actuation. This hypothesis simplifies the design, but the result cannot fulfill the previous functions because of the pressure lack (energy content in the pressurized propelling gas) which can happen. The use of the two nomograms proposed simplifies the application of the design procedure and allow to discuss main sensitivities of the variables involved (FVRs & MOPs), evidencing which variables deserve more attention and accuracy. In particular, the use of the second nomogram permits to verify that the right volumes of fluid during the actuations are delivered above a minimum pressure level, so guaranteeing the fulfillment of the function. It is based on a thermo‐fluid‐dynamic discharge modeling of the accumulators. The paper outlines a design direction which minimizes the number of accumulators and opens the way to a different design approach, based on a fully physical discharge process description.
A multi‐scale approach interpreting sediment processes and distribution from desert sand colour in central Saudi Arabia
Authors: Bradley Andrew V. , McLaren Sue J. , Al‐Dughairi Ahmed , Khalaf Nadia 
Published: June 2018

AbstractIn central Saudi Arabia the redness of sands observed on satellite imagery, often related to iron oxide amount, was used to better interpret geomorphic processes operating in the area. To compare variations between dune and interdune morphology, linear and dome dunes, and an ephemeral river partly buried under a sand sea, Nafud Al‐Thuwayrat, a multi‐scale approach was used to identify the spatial variation in causes of iron oxide amounts and colour. Macro‐scale mapping of Image Spectral Redness identified that the extent and intensity of colour grading across the orientation of well‐defined linear and dome dune types, interdunes and the Wadi Al‐Rimah, indicated sediment mixing of different provenance. Meso‐scale chemical, physical and colour analysis of surface samples indicated that iron oxide coated grains were present within all the samples and was not the sole control on Image Spectral Redness. The reddest sediments were the best sorted medium‐to fine‐quartz sands with iron oxide bearing chemistry and the paler sediments contained coarser sands with additional feldspars, calcite and gypsum. Micro‐scale analysis of grain characteristics found dune–interdune contrasts and that the reddest sands with iron coatings were of aeolian origin and the paler sands contained larger fluvial material mixed with reworked aeolian deposits. Dust in the area consists of high amounts of iron oxide and appears to be a major contributor to redness in the sand dunes. These controls on colour show the sand seas are paler westwards because a major river and local drainage systems deliver fluvial sediments from the carbonate and sandstone bedrock into the quartz‐rich aeolian material from the linear dunes. Evaporite deposits dominate in the paler interdunes, and south of the Wadi the dome dunes are the reddest as they are not migrating but building up. This multi‐scale approach has provided a modern analogy of processes for palaeoenvironmental studies. © 2018 John Wiley & Sons, Ltd.
A Simulation‐Based Method for Finding the Optimal Number of Options for Multiple‐Choice Items on a Test
Authors: Guo Hongwen , Zu Jiyun , Kyllonen Patrick 
Published: June 2018

AbstractFor a multiple‐choice test under development or redesign, it is important to choose the optimal number of options per item so that the test possesses the desired psychometric properties. On the basis of available data for a multiple‐choice assessment with 8 options, we evaluated the effects of changing the number of options on test properties (difficulty, reliability, and score comparability) using simulation. Using 2 criteria (low frequency and poor discrimination) to remove nonfunctioning options and 2 schemes (random and educated guessing) to model hypothetical response behavior for the removed options, we found that decreasing the number of options (from 8) created an easier test form but that a test form with reduced options could be more reliable if low‐discriminating options were removed and an educated guessing strategy were assumed. We present a rationale for the optimal number of options for this test being approximately 5, which would result in a shorter test while preserving its psychometric quality. Simulation methods discussed in this report could be applied to any test to compare the effects of changing the number of options.
Statistics for X‐chromosome associations
Authors: Özbek Umut , Lin Hui‐Min , Lin Yan , Weeks Daniel E. , Chen Wei , Shaffer John R. , Purcell Shaun M. , Feingold Eleanor 
Published: June 2018

AbstractIn a genome‐wide association study (GWAS), association between genotype and phenotype at autosomal loci is generally tested by regression models. However, X‐chromosome data are often excluded from published analyses of autosomes because of the difference between males and females in number of X chromosomes. Failure to analyze X‐chromosome data at all is obviously less than ideal, and can lead to missed discoveries. Even when X‐chromosome data are included, they are often analyzed with suboptimal statistics. Several mathematically sensible statistics for X‐chromosome association have been proposed. The optimality of these statistics, however, is based on very specific simple genetic models. In addition, while previous simulation studies of these statistics have been informative, they have focused on single‐marker tests and have not considered the types of error that occur even under the null hypothesis when the entire X chromosome is scanned. In this study, we comprehensively tested several X‐chromosome association statistics using simulation studies that include the entire chromosome. We also considered a wide range of trait models for sex differences and phenotypic effects of X inactivation. We found that models that do not incorporate a sex effect can have large type I error in some cases. We also found that many of the best statistics perform well even when there are modest deviations, such as trait variance differences between the sexes or small sex differences in allele frequencies, from assumptions.