bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioinspired Synthesis of Monolithic and Layered Aerogels
Authors: Han Xiao , Hassan Khalil T. , Harvey Alan , Kulijer Dejan , Oila Adrian , Hunt Michael R. C. , Šiller Lidija 
Published: April 2018

AbstractAerogels are the least dense and most porous materials known to man, with potential applications from lightweight superinsulators to smart energy materials. To date their use has been seriously hampered by their synthesis methods, which are laborious and expensive. Taking inspiration from the life cycle of the damselfly, a novel ambient pressure‐drying approach is demonstrated in which instead of employing low‐surface‐tension organic solvents to prevent pore collapse during drying, sodium bicarbonate solution is used to generate pore‐supporting carbon dioxide in situ, significantly reducing energy, time, and cost in aerogel production. The generic applicability of this readily scalable new approach is demonstrated through the production of granules, monoliths, and layered solids with a number of precursor materials.
3D Printed Functional and Biological Materials on Moving Freeform Surfaces
Authors: Zhu Zhijie , Guo Shuang‐Zhuang , Hirdler Tessa , Eide Cindy , Fan Xiaoxiao , Tolar Jakub , McAlpine Michael C. 
Published: April 2018

AbstractConventional 3D printing technologies typically rely on open‐loop, calibrate‐then‐print operation procedures. An alternative approach is adaptive 3D printing, which is a closed‐loop method that combines real‐time feedback control and direct ink writing of functional materials in order to fabricate devices on moving freeform surfaces. Here, it is demonstrated that the changes of states in the 3D printing workspace in terms of the geometries and motions of target surfaces can be perceived by an integrated robotic system aided by computer vision. A hybrid fabrication procedure combining 3D printing of electrical connects with automatic pick‐and‐placing of surface‐mounted electronic components yields functional electronic devices on a free‐moving human hand. Using this same approach, cell‐laden hydrogels are also printed on live mice, creating a model for future studies of wound‐healing diseases. This adaptive 3D printing method may lead to new forms of smart manufacturing technologies for directly printed wearable devices on the body and for advanced medical treatments.
Regio‐ und chemoselektive Oxo‐Azidierung von Vinylarenen, katalysiert durch Kupfer(II) und sichtbares Licht
Authors: Hossain Asik , Vidyasagar Adiyala , Eichinger Christian , Lankes Christian , Phan Jenny , Rehbein Julia , Reiser Oliver 
Published: April 2018

AbstractDie photokatalytische Oxo‐Azidierung von Vinylarenen mit Trimethylsilylazid und Luftsauerstoff als stöchiometrischem Oxidationsmittel gelingt in Gegenwart von [Cu(dap)2]Cl oder [Cu(dap)Cl2], im Unterschied zu etablierten Photokatalysytoren auf Basis von Iridium oder Ruthenium oder organischen Farbstoffen. Eine Erklärung hierfür sind der leichte Ligandenaustausch sowie die Möglichkeit zur Rückbindung der intermediär gebildeten Radikale an Kupferzentren. Als katalytisch aktive Spezies wird ein CuII‐Azid‐Komplex postuliert, der eine durch sichtbares Licht beschleunigte Cu‐N‐Bindungshomolyse eingeht und dabei CuI sowie Azidradikale bildet. Dieses Aktivierungsprinzip (CuII‐X→CuI+X.) eröffnet neue Möglichkeiten für die Kupfer‐basierte Photokatalyse.
Electron‐Catalyzed Cross‐Coupling of Arylboron Compounds with Aryl Iodides
Authors: Okura Keisho , Teranishi Tsuyoshi , Yoshida Yuto , Shirakawa Eiji 
Published: April 2018

AbstractArylboroxines in combination with zinc chloride and potassium tert‐butoxide were found to undergo the electron‐catalyzed cross‐coupling with aryl iodides to give the corresponding biaryls without the aid of transition‐metal catalysis.
Visible‐Light‐Accelerated Copper(II)‐Catalyzed Regio‐ and Chemoselective Oxo‐Azidation of Vinyl Arenes
Authors: Hossain Asik , Vidyasagar Adiyala , Eichinger Christian , Lankes Christian , Phan Jenny , Rehbein Julia , Reiser Oliver 
Published: April 2018

AbstractThe visible‐light‐accelerated oxo‐azidation of vinyl arenes with trimethylsilylazide and molecular oxygen as stoichiometric oxidant was achieved. In contrast to photocatalysts based on iridium, ruthenium, or organic dyes, [Cu(dap)2]Cl or [Cu(dap)Cl2] were found to be unique for this transformation, which is attributed to their ability to interact with the substrates through ligand exchange and rebound mechanisms. CuII is proposed as the catalytically active species, which upon coordinating azide will undergo light‐accelerated homolysis to form CuI and azide radicals. This activation principle (CuII‐X→CuI+X.) opens up new avenues for copper‐based photocatalysis.
Facile Stabilization of the Sodium Metal Anode with Additives: Unexpected Key Role of Sodium Polysulfide and Adverse Effect of Sodium Nitrate
Authors: Wang Huan , Wang Chuanlong , Matios Edward , Li Weiyang 
Published: April 2018

AbstractSodium metal is an attractive anode for next‐generation energy storage systems owing to its high specific capacity, low cost, and high abundance. Nevertheless, uncontrolled Na dendrite growth caused by the formation of unstable solid electrolyte interphase (SEI) leads to poor cycling performance and severe safety concerns. Sodium polysulfide (Na2S6) alone is revealed to serve as a positive additive or pre‐passivation agent in ether electrolyte to improve the long‐term stability and reversibility of the Na anode, while Na2S6‐NaNO3 as co‐additive has an adverse effect, contrary to the prior findings in the lithium anode system. A superior cycling behavior of Na anode is first demonstrated at a current density up to 10 mA cm−2 and a capacity up to 5 mAh cm−2 over 100 cycles. As a proof of concept, a high‐capacity Na‐S battery was prepared by pre‐passivating the Na anode with Na2S6. This study gives insights into understanding the differences between Li and Na systems.
Highly Selective Directed Iridium‐Catalyzed Hydrogen Isotope Exchange Reactions of Aliphatic Amides
Authors: Valero Mégane , Weck Remo , Güssregen Stefan , Atzrodt Jens , Derdau Volker 
Published: April 2018

AbstractFor the first time, we describe highly selective homogeneous iridium‐catalyzed hydrogen isotope exchange (HIE) of unactivated C(sp3) centers in aliphatic amides. When using the commercially available Kerr catalyst, the HIE with a series of common antibody–drug conjugate (ADC) linker side chains proceeds with high yields, high regioselectivity, and with deuterium incorporation up to 99 %. The method is fully translatable to the specific requirements of tritium chemistry and its effectiveness was demonstrated by direct tritium labelling of a maytansinoid. The scope of the method can be extended to simple amino acids, with high HIE activity observed for glycine and alanine. In di‐ and tripeptides, a very interesting protecting‐group‐dependent tunable selectivity was observed. DFT calculations gave insight into the energies of the transition states, thereby explaining the observed selectivity and the influence of the amino acid protecting groups.
Influence of Water Deficit in Bioactive Compounds of Olive Paste and Oil Content
Authors: Sena‐Moreno Estela , Cabrera‐Bañegil Manuel , Pérez‐Rodríguez Juan M. , De Miguel Concepción , Prieto María H. , Martín‐Vertedor Daniel 
Published: April 2018

AbstractThe main objective of this study was to evaluate the effect of different deficit irrigation treatments (control, regulated deficit irrigation [RDI]‐1, RDI‐2, and RDI‐3) on the phenolic profile of the olive paste and oil content. Irrigation treatments with more stress water led to a considerable increase in the phenolic compounds of olive paste, especially in oleuropein (60.24%), hydroxytyrosol (82%), tyrosol (195%), and verbascoside (223%) compared to control. A significant increase in the content of total flavonoids and phenolic acids was also observed for these samples. In virgin olive oils (VOO) elaborated from the most stressed olive trees (RDI‐2 and RDI‐3), a noticeable increase in phenolic substances with antioxidant properties (oleuropein, hydroxytyrosol, tyrosol, secoiridoid derivatives, and o‐vanillin) was observed. Consequently, water stress conditions improved antioxidant activity of VOO.
Processing Parameters on the Extraction of Olive Pomace Oil and Its Bioactive Compounds: A Kinetic and Thermodynamic Study
Authors: Chanioti Sofia , Tzia Constantina 
Published: April 2018

AbstractThe effect of temperature (40–60 °C), solid/liquid ratio (1/4–1/12 g mL−1), and agitation speed (AS) (100–800 rpm) on the extraction yield of olive pomace oil and on the recovery of its unsaponifiable matter (USM) during extraction were studied. Two kinetic models were tested to correlate the experimental data; the first proposed by So and Macdonald and the second by Sulaiman et al. The two models adequately describe the extraction process of both oil and USM. Higher extraction temperatures, solid to liquid ratios, and AS led to increased oil yield and favored USM in the extracted oil, and also increased the calculated mass transfer coefficients of the extraction. Changes in enthalpy and entropy were found to be positive while change in free energy was negative, indicating that the process was endothermic, irreversible, and spontaneous. Under equilibrium conditions, the oil yield was increased by a factor of approximately 1.096 and 1.054 for the model of So and Macdonald and Sulaiman et al., respectively, for every 10 °C rise in temperature.
Pharmacological characterization of a β‐adrenergic‐like octopamine receptor in Plutella xylostella
Authors: Huang Qing‐Ting , Ma Hai‐Hao , Deng Xi‐Le , Zhu Hang , Liu Jia , Zhou Yong , Zhou Xiao‐Mao 
Published: April 2018

AbstractThe β‐adrenergic‐like octopamine receptor (OA2B2) belongs to the class of G‐protein coupled receptors. It regulates important physiological functions in insects, thus is potentially a good target for insecticides. In this study, the putative open reading frame sequence of the Pxoa2b2 gene in Plutella xylostella was cloned. Orthologous sequence alignment, phylogenetic tree analysis, and protein sequence analysis all showed that the cloned receptor belongs to the OA2B2 protein family. PxOA2B2 was transiently expressed in HEK‐293 cells. It was found that PxOA2B2 could be activated by both octopamine and tyramine, resulting in increased intracellular cyclic AMP (cAMP) levels, whereas dopamine and serotonin were not effective in eliciting cAMP production. Further studies with series of PxOA2B2 agonists and antagonists showed that all four tested agonists (e.g., naphazoline, clonidine, 2‐phenylethylamine, and amitraz) could activate the PxOA2B2 receptor, and two of tested antagonists (e.g., phentolamine and mianserin) had significant antagonistic effects. However, antagonist of yohimbine had no effects. Quantitative real‐time polymerase chain reaction analysis showed that Pxoa2b2 gene was expressed in all developmental stages of P. xylostella and that the highest expression occurred in male adults. Further analysis with fourth‐instar P. xylostella larvae showed that the Pxoa2b2 gene was mainly expressed in Malpighian tubule, epidermal, and head tissues. This study provides both a pharmacological characterization and the gene expression patterns of the OA2B2 in P. xylostella, facilitating further research for insecticides using PxOA2B2 as a target.
Aqueous biphasic systems in the separation of food colorants
Authors: Santos João H. P. M. , Capela Emanuel V. , Boal‐Palheiros Isabel , Coutinho João A. P. , Freire Mara G. , Ventura Sónia P. M. 
Published: April 2018

AbstractAqueous biphasic systems (ABS) composed of polypropylene glycol and carbohydrates, two benign substances are proposed to separate two food colorants (E122 and E133). ABS are promising extractive platforms, particularly for biomolecules, due to their aqueous and mild nature (pH and temperature), reduced environmental impact and processing costs. Another major aspect considered, particularly useful in downstream processing, is the “tuning” ability for the extraction and purification of these systems by a proper choice of the ABS components. In this work, our intention is to show the concept of ABS as an alternative and volatile organic solvent‐free tool to separate two different biomolecules in a simple way, so simple that teachers can effectively adopt it in their classes to explain the concept of bioseparation processes. Informative documents and general information about the preparation of binodal curves and their use in the partition of biomolecules is available in this work to be used by teachers in their classes. In this sense, the students use different carbohydrates to build ABS, then study the partition of two food color dyes (synthetic origin), thus evaluating their ability on the separation of both food colorants. Through these experiments, the students get acquainted with ABS, learn how to determine solubility curves and perform extraction procedures using colorant food additives, that can also be applied in the extraction of various (bio)molecules. © 2018 by The International Union of Biochemistry and Molecular Biology, 46:390–397, 2018.
A Simple Glycolipid Mimic of the Phosphatidylinositol Mannoside Core from Mycobacterium tuberculosis Inhibits Macrophage Cytokine Production
Authors: Mosaiab Tamim , Boiteux Sandra , Zulfiker Abu Hasanat Md , Wei Ming Q. , Kiefel Milton J. , Houston Todd A. 
Published: April 2018

AbstractGlycolipids from Mycobacterium tuberculosis have a profound impact on the innate immune response of the host. Macrophage‐inducible C‐type lectin (Mincle) is a pattern‐recognition receptor that has been shown to bind trehalose dimycolate (TDM) from the mycobacterium and instigate intracellular signalling in the immune cell. There are structural similarities between the structures of TDM and phosphatidyl inositol mannoside (PIM). We thus hypothesized that these latter structures might also modulate an immune response in a similar manner. To test this, we synthesized a series of new mannose derivatives modified with fatty esters at the 6‐position and assessed the release of inflammatory cytokines in human U937 macrophages under the induction of lipopolysaccharides (LPS) after glycolipid treatment. The results showed that the amount of two major cytokines—tumour necrosis factor (TNF)‐α and interleukin (IL)‐6—released from LPS‐stimulated U937 cells decreased significantly when compared to a control upon treatment with the prepared glycolipids, thus indicating a reduction in cytokine production by the macrophages.
Design of a Cost‐Reduced Flexible Plant for Supercritical Fluid‐Assisted Applications
Authors: Cassanelli Mattia , Prosapio Valentina , Norton Ian , Mills Thomas 
Published: April 2018

AbstractA novel batch plant for supercritical CO2 applications is proposed which is not equipped with expensive components, such as high‐pressure pumps, making it particularly suitable for bench‐scale use. For the first time, the use of a hanging scale is suggested to weigh the amount of CO2 required for the experiment and the use of the thermodynamics to reach the working conditions. The rig is able to cover different applications, e.g., aerogel drying, impregnation, and extraction, showing high flexibility. An approximate cost analysis has been performed considering as a reference a 150‐mL vessel. It has been calculated that both the setup and running costs are considerably lower than the common batch and semicontinuous rigs.
Fault detection based on difference locality preserving projections for the semiconductor process
Authors: Guo Jinyu , Zhong Lulu , Li Yuan 
Published: April 2018

AbstractSome existing fault detection methods for the semiconductor process, such as principal component analysis and locality preserving projections (LPP), are linear algorithms, so they degrade the performance of fault detection in a nonlinear process. In addition, they are not effective for fault detection in a multimodal process. To solve the problems caused by nonlinear and multimodal characteristics in the semiconductor process, a new difference (DIF) pre‐processing strategy is proposed to normalize the nonlinear and multimodal data. After detailed analysis of DIF, a new method called DIF‐LPP is developed for fault detection in the semiconductor process. The nonlinear and multimodal data can be transformed into data sets that follow a Gaussian and single mode distribution, respectively. The proposed method contains a model without prior knowledge of the nonlinear and multimodal process. To demonstrate the proposed method's effectiveness, it is applied to 2 numerical examples and the semiconductor process. Simulation results verify that the proposed method is effective for fault detection in the nonlinear and multimodal process.
Elemental fingerprint profiling with multivariate data analysis to classify organic chocolate samples
Authors: Junior Airton C.M. , Maione Camila , Barbosa Rommel M. , Gallimberti Matheus , Paulelli Ana Carolina C. , Segura Fabiana R. , Souza Vanessa C.O. , Batista Bruno L. , Barbosa Fernando 
Published: April 2018

AbstractChocolate is an appreciated food derived from cacao fruit. The flavonoids and minerals present in the chocolate have benefits to health, and some specific minerals are known to be toxic. Because of differences in their production systems, organic chocolate has a distinguishable pattern in mineral concentrations than conventional chocolate. Aiming for authenticity and study of the toxic elements in organic chocolate, we present in this work a simple method to classify organic chocolate samples based on elemental fingerprint profiling and multivariate data analysis. Thirty‐eight elements (toxic and essential) were determined in 36 chocolate samples (organic and conventional) by using inductively coupled plasma mass spectrometry to establish reference ranges and to identify differences in patterns of elements in both type of samples. Our results showed that Al, Zn, Mn, Cu, and Ba are the most present components for both types of chocolate, and higher concentrations of essential elements Fe, Zn, and Mg are found in conventional type, opposing the idea that organic food is rich in essential elements. Principal component analysis and linear discriminant analysis were used for multivariate data analysis, and sample differentiation was possible with 83% accuracy.
Selective Synthesis of Perfluoroalkylated Corannulenes and Investigation of their Structural, Dynamic and Electrochemical Behavior
Authors: Haupt Axel , Keller Lisa‐Marie , Kutter Maximilian , Lentz Dieter 
Published: April 2018

AbstractHerein we report general methods allowing the synthesis of various perfluoroalkylated corannulenes with a specific substitution pattern. Variable temperature NMR spectroscopic investigations revealed dynamic behavior which was analyzed by line shape analysis. The activation parameters of these dynamic processes were determined. For a tetrasubstituted compound it was possible to observe through space scalar coupling. The packing motifs were elucidated by X‐ray crystallography, showing that the substitution pattern as well as the size of substituents strongly influence intermolecular π‐stacking. The reduction potentials of the perfluoroalkylated compounds were determined by cyclic voltammetry.
A DNA Nanotube–Peptide Biocomplex for mRNA Detection and Its Application in Cancer Diagnosis and Targeted Therapy
Authors: Ji Xiaoting , Lv Haoyuan , Guo Jiayi , Ding Caifeng , Luo Xiliang 
Published: April 2018

AbstractA biocomplex of DNA nanotube–peptide, consisting of six concatenated DNA strands, three locked DNA strands, and a cell‐penetrating peptide, is reported. The barrel‐structured DNA nanotube–peptide was successfully applied as a codrug‐delivery system for targeting cancer therapy. The mucin 1 protein (MUC‐1) aptamer is part of a DNA nanotube that can specifically recognize MUC‐1 protein on the surface of MCF‐7 cells. Cyclo (Arg‐Gly‐Asp‐d‐Phe‐Lys; cRGD), as a cell‐penetrating peptide, facilitates recruitment and uptake of targeting drugs by binding to integrin receptors (αvβ3) of the cytomembrane surface. Anticancer drugs doxorubicin (DOX) and paclitaxel (PTX) were loaded into the capsulated DNA nanotube–peptide (CDNP), which was used as codrug cargo models. The as‐prepared biocomplex can be utilized not only to deliver drugs, but also to achieve anticancer effects in vivo. Experimental results suggested that the treatment efficacy of the codrug delivery platform (CDNP/DOX/PTX) was better than that of a single‐drug delivery platform (CDNP/DOX or CDNP/PTX). This system, which is composed of DNA strands and peptide, has good biocompatibility and biodegradability. Furthermore, the system can readily detect target mRNA in MCF‐7 cells in vitro. The detection limits of mRNA are 9.7×10−8 and 1.8×10−8 m with CDNP/DOX and CDNP/PTX–FITC (FITC=fluorescein isothiocyanate), respectively, as probes.
Chiral Lithium Amido Zincates for Enantioselective 1,2‐Additions: Auto‐assembling Reagents Involving a Fully Recyclable Ligand
Authors: Rouen Mathieu , Chaumont Pauline , Barozzino‐Consiglio Gabriella , Maddaluno Jacques , Harrison‐Marchand Anne 
Published: April 2018

AbstractA methodology consisting in carrying out enantioselective nucleophilic 1,2‐additions (ee values up to 97 %) from cheap, easily accessible, and never described before, chiral lithium amido zincates is presented. These multicomponent reactants auto‐assemble when mixing, in a 1:1 ratio, a homoleptic diorganozinc (R2Zn) with a chiral lithium amide (CLA). The latter, obtained after a single reductive amination, plays the role of the chiral inductor and is fully recoverable thanks to a simple acid–base wash, allowing being recycled and re‐use without loss of stereochemical information.
Substituent effects on chiral resolutions of derivatized 1‐phenylalkylamines by heptakis(2,3‐di‐O‐methyl‐6‐O‐tert‐butyldimethylsilyl)‐β‐cyclodextrin GC stationary phase
Authors: Issaraseriruk Natthapol , Sritana‐anant Yongsak , Shitangkoon Aroonsiri 
Published: April 2018

AbstractChiral resolutions of trifluoroacetyl‐derivatized 1‐phenylalkylamines with different type and position of substituent were investigated by capillary gas chromatography by using heptakis(2,3‐di‐O‐methyl‐6‐O‐tert‐butyldimethylsilyl)‐β‐cyclodextrin diluted in OV‐1701 as a chiral stationary phase. The influence of column temperature on retention and enantioselectivity was examined. All enantiomers of meta‐substituted analytes as well as fluoro‐substituted analytes could be resolved. Temperature had a favorable influence on enantioselectivity for small amines with substituents at the ortho‐position. The type of substituent at the stereogenic center of amines also had a crucial effect as the ethyl group led to poor enantioseparation. Among all analytes studied, trifluoroacetyl‐derivatized 1‐(2′‐fluorophenyl)ethylamine exhibited baseline resolution with the shortest analysis time.
Robust precision matrix estimation via weighted median regression with regularization
Authors: Chun Hyonho , Lee Myung Hee , Kim Sung‐Ho , Oh Jihwan 
Published: April 2018

AbstractA precision matrix is an important parameter of interests because its elements describe useful association information among multiple variables, which has a wide variety of applications. For example, it is used for inferring gene regulation networks in genomic studies and stock association networks in financial studies. However, in many cases, the precision matrix needs to be robustly estimated due to the presence of outliers. We propose estimating a sparse scaled precision matrix via weighted median regression with regularization. Our weighted median regression approach is consistent under various distributional assumptions including multivariate t‐ or contaminated Gaussian distributions. This fact is illustrated with simulation studies and a real data analysis with monthly stock return data.The Canadian Journal of Statistics 46: 265–278; 2018 © 2018 Statistical Society of Canada