bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gold‐Catalyzed Dual Annulation of Homopropargyl Alcohols with Nitrones: Synthesis of Tetrahydropyrano[4,3‐b]indole Scaffolds
Authors: Wei Hanlin , Zhou Su , Qiu Lihua , Qian Yu , Hu Wenhao , Xu Xinfang 
Published: May 2019

AbstractAn unprecedented gold‐catalyzed dual annulation of homopropargyl alcohols with nitrones has been developed, which provides an effective access to the 1,3,4,5‐tetrahydropyrano[4,3‐b]indole derivatives in good to high yields. Mechanistically, this one‐pot three‐step cascade reaction is initiated by a gold‐catalyzed alkyne oxoarylation, followed by an intramolecular cyclodehydration and terminated with an intermolecular cyclization with aldehyde which is a leaving species in the early stage of this cascade process.magnified image
Iron and Nitrogen Co‐Doped Mesoporous Carbon‐Based Heterogeneous Catalysts for Selective Reduction of Nitroarenes
Authors: Wang Jitao , Yu Xiaochun , Shi Chongyang , Lin Dajie , Li Jun , Jin Huile , Chen Xian , Wang Shun 
Published: May 2019

AbstractA facile fabrication of Fe and N co‐doped mesoporous carbon (MC), as an efficient heterogeneous catalyst for the highly selective reduction of nitroarenes, is described. The Fe and N co‐doped MC nanosheets are easily synthesized via a hydrothermal reaction between citrate acid and magnesium citrate, followed by calcination in the presence of melamine and potassium ferrocyanide. The Fe−N complex provides a unique active site for the selective reduction of 1‐chloro‐4‐nitrobenzene, leading to the production of (E)‐1,2‐bis(4‐chlorophenyl)diazene with a selectivity of >96%, in <40 mins. Control experiments based on non‐doped, N‐doped, and Fe‐doped MC nanosheets demonstrate that selectivity greatly depends on the catalyst active component type, and that non‐doped MC significantly contributes to the high efficiencies observed in the selective synthesis of azoxy compound intermediates. A broad range of substrates, including extra‐functional groups on the nitroarenes rings, were successfully converted to the corresponding azo compounds at mild conditions with high selectivity.magnified image
General Methodology to Identify the Minimum Alphabet Size for Heteropolymer Design
Authors: Cardelli Chiara , Nerattini Francesca , Tubiana Luca , Bianco Valentino , Dellago Christoph , Sciortino Francesco , Coluzza Ivan 
Published: May 2019

AbstractUnderstanding how to design the structure of heteropolymers through their monomer sequence will have a significant impact on the creation of novel artificial materials. According to mean‐field theories, the minimum number—or alphabet—of distinct monomers necessary to achieve such designability is directly related to the conformational entropy ω of compact polymer structures. Here, a computational strategy to calculate this conformational entropy is introduced and thus predict the minimum alphabet to achieve designability, for a generalized heteropolymer model. The comparison of the predictions with previous results proves the robustness of the approach. It is quantified for the first time how the number of directional interactions is critical for achieving the designability. The methodology that is introduced can be easily generalized to models representing specific polymers. A comparison between conventional polymers monomers are provided, and it is predicted that polyurea, polyamide, and polyurethane residues are optimal candidates to be functionalized for the experimental synthesis of designable heteropolymers. As such, our method can guide the engineering of new types of self‐assembling modular polymers, that will open new possibilities for polymer‐based materials with unmatched versatility and control.
A Compromise Reveals Buckling Resistance Strategy of a Naturally Slender Tibia
Authors: Xing Yun , Yang Jialing 
Published: May 2019

AbstractIn nature, slender tibiae of stick insects have an excellent performance in resisting buckling, which raises the questions why the natural evolution chooses the pentagonal shape as the tibiae's cross section to resist buckling? Why is the proximal base round but the distal end pentagonal in adult tibiae? In this study, 3D geometrical models of the tibiae in stick insects are reconstructed aimed at investigating the buckling resistance strategy of the biological composite with different polygonal cross sections. The numerical result is consistent with the experimental observation. Based on large deflection theory, corresponding mechanical models proposed herein can accurately predict the structural response and mechanical behavior at buckling (including both Euler buckling and local buckling). Eventually, with the help of numerical and theoretical analysis, this article might have found the reason for the tibiae of stick insects naturally evolving to form the cross section with a pentagonal shape. In conclusion, the nature's choice of pentagon (S5) cross section could be a best compromise strategy to balance both Euler buckling and local buckling resistance capability. The knowledge gained from this work will inspire the designs of new advanced materials and structures.
Are there gross motor coordination spurts during mid‐childhood?
Authors: dos Santos Marcos A. M. , Baxter‐Jones Adam , Reyes Ana C. , Freitas Duarte , Henrique Rafael S. , Chaves Raquel N. , Bustamante Alcibíades , Tani Go , Katzmarzyk Peter T. , Maia José 
Published: May 2019

AbstractObjectivesThe aims of this study were (1) to identify the timing of the mid‐growth spurt (MGS) in stature in children and (2) to identify gross motor coordination (GMC) spurts when aligned by the age of attainment of the MGS (aMGS).MethodsStature, weight, and GMC were measured in 245 Portuguese children followed annually from 6 to 10 years. GMC was assessed and to estimate children's MGS in stature as well as GMC spurts in each of the four tests aligned by aMGS, we used a nonsmoothed polynomial methodology.ResultsIn boys, the aMGS was attained at 7.8 years, whereas in girls it was 8.0 years. In boys, the peak MGS was 6.2 cm∙yr−1 and in girls it was 6.4 cm∙yr−1. In boys, the peak for walking backwards (WB) occurred 18 months before aMGS (14.9‐points∙yr−1), jumping sideways (JS) was 12 months after aMGS (13.5‐points∙yr−1), hopping on one leg (HO) was 18 months before aMGS (11.7‐points∙yr−1), and shifting platform (SP) was 12 months before aMGS (6.8‐points∙yr−1). In girls, WB spurts occurred 12 months after aMGS (13.3‐points∙yr−1), JS was 12 months before aMGS (10.5‐points∙yr−1), HO was coincident with aMGS (10.4‐points∙yr−1), and SP was 18 as well as 12 months before aMGS (7.2‐points∙yr−1). No differences were observed in the mean peak spurts between sexes in the GMC tests.ConclusionsBoys and girls reached their MGS in stature at about the same chronological age. Spurts in GMC did not express themselves in the same biological timing relative to aMGS in stature, and there are sex differences.
Influence of Base on a Surfactant‐Assisted Heterogeneous Sonogashira Reaction
Authors: Ortega Kenneth J. , Hostier Thomas , Hayman Alan R. 
Published: May 2019

AbstractWe herein report a simple method for the interrogation of the influence of the bases (sodium hydroxide and various tertiary amines) on the surfactant‐assisted Sonogashira reaction utilizing a palladium on carbon catalyst. Of the bases evaluated, triethylamine (TEA) gave the best yields. The efficiency of the reaction was found to be highly dependent on surfactant concentration when using sodium hydroxide. In contrast, the reaction efficiency was found to be independent of surfactant concentration when using TEA. It was also determined that the surfactant not only facilitates the bulk transport of reactants and products within the medium, but also influences the transport and accessibility of the base to the palladium bound alkyne. The role of tertiary amines as auxiliary additives was explored in the reaction systems using NaOH as the principle base. The maximal efficiency in this case was achieved with a long‐chain tertiary amine auxiliary, N,N‐dimethylhexadecylamine (C16NMe2).
Wide range humidity sensors printed on biocomposite films of cellulose nanofibril and poly(ethylene glycol)
Authors: Syrový Tomáš , Maronová Stanislava , Kuberský Petr , Ehman Nanci V. , Vallejos María E. , Pretl Silvan , Felissia Fernando E. , Area María C. , Chinga‐Carrasco Gary 
Published: May 2019

ABSTRACTCellulose nanofibril (CNF) films were prepared from side streams generated by the sugarcane industry, that is, bagasse. Two fractionation processes were utilized for comparison purposes: (1) soda and (2) hot water and soda pretreatments. 2,2,6,6‐Tetramethylpiperidinyl‐1‐oxyl‐mediated oxidation was applied to facilitate the nanofibrillation of the bagasse fibers. Poly(ethylene glycol) (PEG) was chosen as plasticizer to improve the ductility of CNF films. The neat CNF and biocomposite films (CNF and 40% PEG) were used for fabrication of self‐standing humidity sensors. CNF‐based humidity sensors exhibited high change of impedance, within four orders of magnitude, in response to relative humidity (RH) from 20 to 90%. The use of plasticizer had an impact on sensor kinetics. While the biocomposite film sensors showed slightly longer response time, the recovery time of these plasticized sensors was two times shorter in comparison to sensors without PEG. This study demonstrated that agroindustrial side streams can form the basis for high‐end applications such as humidity sensors, with potential for, for example, packaging and wound dressing applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47920.
Wet‐spinning and carbonization of graphene/PAN‐based fibers: Toward improving the properties of carbon fibers
Authors: Sayyar Sepidar , Moskowitz Jeremy , Fox Bronwyn , Wiggins Jeffrey , Wallace Gordon 
Published: May 2019

ABSTRACTGraphene/polyacrylonitrile (PAN)‐based composite fibers, as monofilaments, multifilaments, and yarns, were prepared through a facile solution mixing and wet‐spinning method. The PAN‐based (PANb) precursor was synthesized via reversible addition–fragmentation chain transfer polymerization with N‐isopropylacrylamide as a comonomer. Following wet‐spinning, the PANb yarns were carbonized at 900 °C. Scanning electron microscopy images confirmed the presence of a homogenous dispersion of graphene nanosheets inside the polymer matrix. It has been shown that the addition of graphene not only enhanced the thermal and mechanical properties of the PANb fibers, but also improved their graphitic structure after heat treatment. Tensile strength and Young's modulus of the PANb yarns were increased by 28 and 20%, respectively, on addition of 0.5 wt % graphene. Raman spectra demonstrated improvement in the graphitic structure of the carbonized yarns even at low graphene content. These graphene/ PANb fibers show potential as a suitable precursor for the development of next generation carbon fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47932.
Estimation of energy dissipation caused by odd order difference schemes for an unstable planetary boundary layer
Authors: Kitamura Yuji , Nishizawa Seiya 
Published: May 2019

AbstractNumerical error by an odd order difference approximation in the advection term dissipates energy in the resolved motion. We propose a method to estimate the energy dissipation rate derived from the numerical error to clarify its effect on the energy budget. The energy dissipation rate in Large‐Eddy Simulations for an ideal unstable boundary layer is analysed. The proposed method reveals that the imbalance of the energy budget can be ascribed to the non‐conservative property with respect to kinetic energy of the discretised advection terms, while the net energy dissipation in the resolved field is almost insensitive to the origins of the energy dissipation. However, the magnitude of the momentum and temperature fluxes is sensitive to the difference scheme; the numerical error in the advection term reduces these fluxes in the resolved part. A subgrid scheme should be designed so as to compensate decrease of the resolved flux when an odd order difference is applied to the advection term.
Development of air‐assisted dispersive micro‐solid‐phase extraction‐based supramolecular solvent‐mediated Fe3O4@Cu–Fe–LDH for the determination of tramadol in biological samples
Authors: Ezoddin Maryam , Adlnasab Laleh , Afshari Kaveh Akram , Karimi Mohammad Ali , Mahjoob Behnaz 
Published: May 2019

AbstractA simple method, air‐assisted dispersive micro‐solid‐phase extraction‐based supramolecular solvent was developed for the preconcentration of tramadol in biological samples prior to gas chromatography–flame ionization detection. A new type of carrier liquid, supramolecular solvent based on a mixture of 1‐dodecanol and tetrahydrofuran was combined with layered double hydroxide coated on a magnetic nanoparticle (Fe3O4@SiO2@Cu–Fe–LDH). The supramolecular solvent was injected into the solution containing Fe3O4@SiO2@Cu–Fe–LDH in order to provide high stability and dispersion of the sorbent without any stabilizer agent. Air assisted was applied to enhance the dispersion of the sorbent and solvent. A number of analytical techniques such as Fourier transform‐infrared spectrometry, field emission scanning electron microscope, energy‐dispersive X‐ray spectroscopy and X‐ray diffraction measurements were applied to assess the surface chemical characteristics of Fe3O4@SiO2@Cu–Fe–LDH nanoparticles. The effects of important parameters on the extraction recovery were also investigated. Under optimized conditions, the limits of detection and quantification were obtained in the range of 0.9–2.4 and 2.7–7.5 μg L−1 with preconcentration factors in the range of 450–472 in biological samples. This method was used for the determination of tramadol in biological samples (plasma, urine and saliva samples) with good recoveries.
Risk factors for chemotherapy‐induced peripheral neuropathy in patients receiving taxane‐ and platinum‐based chemotherapy
Authors: Molassiotis Alex , Cheng Hui Lin , Leung Kwun To , Li Yu Chung , Wong Kam Hung , Au Joseph Siu Kie , Sundar Raghav , Chan Alexandre , Ng Terrence Rong De , Suen Lorna K. P. , Chan Choi Wan , Yorke Janelle , Lopez Violeta 
Published: May 2019

AbstractBackgroundChemotherapy‐induced peripheral neuropathy (CIPN) is a significant and difficult to manage side effect of neurotoxic chemotherapies. Several risk factors for CIPN have been identified to date, but inconsistencies and methodological limitations exist in past research. Also, a limited number of potential risk factors has been investigated in the past.AimThe objective of this study was to assess the relative contribution of a wider range of risk factors in the development of CIPN.MethodsThis analysis used the 6‐month data after starting chemotherapy from a larger prospective observational study on CIPN risk, prevalence, and quality of life. Patients were assessed at recruitment for possible CIPN risk factors, including prior history of neuropathies, current/past infectious diseases; neurotoxic medication history; personal and treatment characteristics; smoking history, alcohol use, and vegetable/fruit intake. Neuropathy was assessed at 6‐months after starting chemotherapy with the neuropathy (motor/sensory) items of the NCI‐CTCAE scale and the WHO criterion for neuropathy. Data on symptom burden were also collected.ResultsData were available from 255 patients from three cancer centers in Hong Kong, Singapore, and UK. The use of different scales did not always identify the same predictor variables. Key risk factors in multivariate regression models included older age (highest OR = 1.08, p < 0.01 with the WHO scale), chemotherapy (platinum‐based chemotherapy had OR = 0.20–0.27 in developing CIPN compared to taxane‐based chemotherapy), history of neuropathy (for motor CIPN only, OR = 8.36, p < 0.01), symptom burden (OR = 1.06, p < 0.05), number of chemotherapy cycles received (OR = 1.19–1.24, p < 0.01), and alcohol intake (OR = 0.32, p < 0.05). In univariate analysis, the use of statins was implicated with CIPN (p = 0.03–0.04 with different assessments) and diabetes showed a trend (p = 0.09) in the development of CIPN.ConclusionThis study confirmed the CIPN risk related to certain variables and identified new ones. This knowledge can assist with treatment decisions and patient education.
Cyanobacteria as an eco‐friendly resource for biofuel production: A critical review
Authors: Farrokh Parisa , Sheikhpour Mojgan , Kasaeian Alibakhsh , Asadi Hassan , Bavandi Roya 
Published: May 2019

AbstractCyanobacteria are photosynthetic microorganisms which can be found in various environmental habitats. These photosynthetic bacteria are considered as promising feedstock for the production of the third‐ and the fourth‐generation biofuels. The main subject of this review is highlighting the significant aspects of the biofuel production from cyanobacteria. The most recent investigations about the extraction or separation of the bio‐oil from cyanobacteria are also adduced in the present review. Moreover, the genetic engineering of cyanobacteria for improving biofuel production and the impact of bioinformatics studies on the designing better‐engineered strains are mentioned. The large‐scale biofuel production is challenging, so the economic considerations to provide inexpensive biofuels are also cited. It seems that the future of biofuels is strongly dependent to the following items; understanding the metabolic pathways of the cyanobacterial species, progression in the construction of the engineered cyanobacteria, and inexpensive large‐scale cultivation of them.
Polygon method: A systematic margin assessment for breast conservation
Authors: Ichihara Shu , Moritani Suzuko , Nishimura Rieko , Oiwa Mikinao , Morita Takako , Hayashi Takako , Kato Aya , Endo Tokiko , Kada Akiko , Ito Noriko , Kuroishi Tetsuo , Sato Yasuyuki 
Published: May 2019

AbstractBackgroundRadiation therapy (RT) for women with ductal carcinoma in situ (DCIS) undergoing breast‐conserving surgery (BCS) may be overtreatment for some, especially for those in which DCIS is eradicated, and ipsilateral breast tumor recurrence (IBTR) risk approaches the contralateral breast cancer (CBC) level. The aim of this study was to clarify whether the polygon method, a new systematic method of en face (tangential, shaved) margin assessment, can identify a subset of DCIS that can be safely treated by BCS alone.MethodsA key tool of the polygon method is an adjustable mold that prevents the “pancake phenomenon” (flattening) of breast tissue after surgical removal so that the specimen is fixed in the shape of a polygonal prism. This preanalytical procedure enables us to command a panoramic view of entire en face margins 3‐5‐mm deep from the real peripheral cut surfaces. Competing risk analysis was used to quantify rates of IBTR and CBC and to evaluate risk factors.ResultsFrom 2000 to 2013, we identified 146 DCIS patients undergoing BCS with a contralateral breast at risk. In 100 DCIS patients whose margin was negative by the polygon method, 5 IBTR (3 DCIS and 2 invasive ductal carcinoma [IDC]) and 10 CBC (6 DCIS and 4 IDC) cases were identified during a median follow‐up of 7.6 years (range, 0.9‐17.4). Five‐ and 10‐year cumulative incidence rates were 3.0% and 5.3% for IBTR, and 7.1% and 13.3% for CBC, respectively. Thus, patients with a negative margin consistently showed at least twofold lower IBTR than CBC despite omission of RT.ConclusionsJapanese women classified with a negative margin by the polygon method show a very low risk of IBTR and account for approximately half of CBC cases. In this subset of DCIS patients, additional RT is not beneficial.
Tobacco hookah smoking‐induced carbon monoxide poisoning: A case report of non‐ambient exposure
Authors: Maalem Reem , Alali Abdulaziz , Alqahtani Saeed 
Published: May 2019

AbstractCarbon monoxide (CO) toxicity should be considered in patients presenting to the emergency department with any acute vague manifestations after hookah smoking; furthermore, smoking in an open space does not eliminate the risk of CO toxicity. High‐flow supplemental oxygen should be provided immediately while further investigations and management options are considered.
Variant form of hairy cell leukemia
Authors: Wiber Margaux , Maitre Elsa , Cornet Edouard , Salaün Véronique , Naguib Dina , Troussard Xavier 
Published: May 2019

AbstractMature lymphoid B‐cell proliferations with hairy cells represent heterogeneous entities where specific diagnosis is difficult but important since it impacts therapeutic management. The clinical cases of variant hairy cell leukemia reported herein illustrate the persistence of a clear interest in the use of splenectomy as a therapeutic alternative. Furthermore, ibrutinib appears to be a promising treatment in patients with relapsed/refractory disease.
Optimization of the Impeller Design for Mesenchymal Stem Cell Culture on Microcarriers in Bioreactors
Authors: Loubière Céline , Delafosse Angélique , Guedon Emmanuel , Toye Dominique , Chevalot Isabelle , Olmos Eric 
Published: May 2019

AbstractWhen agitating mesenchymal stem cells adhered on microcarriers in bioreactors, a compromise has to be found between sufficient particle suspension and limitation of hydromechanical stresses. The present study proposes a strategy to improve the design of an ‘elephant ear' impeller at the just‐suspended state by varying its relative size, blade slope angle, and position in the reactor. To do that, computational fluid dynamics simulations were coupled with multi‐objective optimization to minimize the hydromechanical stress encountered by the microcarriers. Two minimization criteria were considered: (P/V)@p and the energy dissipation function EDC. On the basis of 31 conditions, an optimal impeller geometry is proposed.
Modeling Oxygen Gas Diffusion Electrodes for Various Technical Applications
Authors: Kubannek Fabian , Turek Thomas , Krewer Ulrike 
Published: May 2019

AbstractIn gas diffusion electrodes (GDEs), electrocatalysts are in contact with gas and electrolyte ensuring a large active three‐phase boundary. GDEs are used for important technical applications in energy transformation and chemical synthesis. This review gives an introduction into the vast range of existing models for GDEs and their specific purpose, with an emphasis on oxygen reduction electrodes. After introducing the processes occurring in GDEs, modeling approaches are described according to their dimensionality (from 0D to 3D to multiscale) and perspectives for future research are discussed.
Dynamic Modeling of Reversible Solid Oxide Cells
Authors: Wehrle Lukas , Wang Yuqing , Banerjee Aayan , Brandon Nigel , Deutschmann Olaf 
Published: May 2019

AbstractReversible solid oxide cells (rSOCs) are highly efficient devices, which allow either the generation of electric power or the storage of energy via fuel production. In this paper, the characteristics of the mode switch are investigated by applying a dynamic 3D stack model. The responses of temperature, current density, and species mole fractions regarding a switch from storage (SOEC) to generation mode (SOFC) are examined in detail. Additionally, the impact of using excess air and continuous voltage variations to limit temperature gradients and fluctuations during the mode switch are analyzed.