bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselective and Regiodivergent Addition of Purines to Terminal Allenes: Synthesis of Abacavir
Authors: Thieme Niels , Breit Bernhard 
Published: January 2017

AbstractThe rhodium‐catalyzed atom‐economic asymmetric N‐selective intermolecular addition of purine derivatives to terminal allenes is reported. Branched allylic purines were obtained in high yields, regioselectivity and outstanding enantioselectivity utilizing a Rh/Josiphos catalyst. Conversely, linear selective allylation of purines could be realized in good to excellent regio‐ and E/Z‐selectivity with a Pd/dppf catalyst system. Furthermore, the new methodology was applied to a straightforward asymmetric synthesis of carbocyclic nucleoside abacavir.
Elasticity in Macrophage‐Synthesized Biocrystals
Authors: Horstman Elizabeth M. , Keswani Rahul K. , Frey Benjamin A. , Rzeczycki Phillip M. , LaLone Vernon , Bertke Jeffery A. , Kenis Paul J. A. , Rosania Gus R. 
Published: January 2017

AbstractSupramolecular crystalline assembly constitutes a rational approach to bioengineer intracellular structures. Here, biocrystals of clofazimine (CFZ) that form in vivo within macrophages were measured to have marked curvature. Isolated crystals, however, showed reduced curvature suggesting that intracellular forces bend these drug crystals. Consistent with the ability of biocrystals to elastically deform, the inherent crystal structure of the principal molecular component of the biocrystals—the hydrochloride salt of CFZ (CFZ‐HCl)—has a corrugated packing along the (001) face and weak dispersive bonding in multiple directions. These characteristics were previously found to be linked to the elasticity of other organic crystals. Internal stress in bent CFZ‐HCl led to photoelastic effects on the azimuthal orientation of polarized light transmittance. We propose that elastic, intracellular crystals can serve as templates to construct functional microdevices with different applications.
Coordination of KrF2 to a Naked Metal Cation, Mg2+
Authors: Lozinšek Matic , Mercier Hélène P. A. , Brock David S. , Žemva Boris , Schrobilgen Gary J. 
Published: January 2017

AbstractExamples of coordination compounds in which KrF2 functions as a ligand are very rare. In contrast, XeF2 provides a rich coordination chemistry with a variety of main‐group and transition metal cations. The reactions of Mg(AsF6)2 and KrF2 in HF or BrF5 solvent have afforded [Mg(KrF2)4(AsF6)2] and [Mg(KrF2)4(AsF6)2]⋅2 BrF5, respectively, the first examples of a metal cation ligated by KrF2. Their X‐ray crystal structures and Raman spectra show that the KrF2 ligands and [AsF6]− anions are F‐coordinated to a naked Mg2+ cation. Quantum‐chemical calculations are consistent with essentially non‐covalent ligand‐metal bonding. These compounds significantly extend the XeF2–KrF2 analogy and the limited chemistry of krypton by introducing a new class of coordination compound in which KrF2 functions as a ligand towards a naked metal cation.
Soluble and electrically conductive polyaniline‐modified polymers: Incorporation of biocompatible polymeric chains through ATRP technique
Authors: Massoumi Bakhshali , Shafagh‐kalvanagh Mostafa , Jaymand Mehdi 
Published: January 2017

ABSTRACTThis article describes the incorporation of biocompatible polymeric chains [poly(2‐hydroxyethyl methacrylate) and poly(N‐isopropylacrylamide)] into the polyaniline backbone through atom transfer radical polymerization technique to produce soluble and electrically conductive polyaniline‐based materials. The chemical structures of all samples as representatives were characterized by means of Fourier transform‐infrared and proton nuclear magnetic resonance spectroscopies. The electroactivity behaviors and electrical conductivities of the synthesized samples were verified under cyclic voltammetric conditions, and the standard four‐probe method, respectively. In addition, the thermal behaviors and morphologies of the synthesized samples were investigated by means of thermogravimetric analysis and scanning electron microscopy, respectively. We envision that the synthesized polyaniline‐modified polymers may be find applications in biomedical fields such as tissue engineering, mainly due to their water solubilities, electrical conductivities, and biocompatibilities. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 44720.
The morphology, rheological, and mechanical properties of wood flour/starch/poly(lactic acid) blends
Authors: Lv Shanshan , Gu Jiyou , Tan Haiyan , Zhang Yanhua 
Published: January 2017

ABSTRACTAn entirely biosourced blend composed of poly(lactic acid) (PLA), starch, and wood flour (WF) was prepared by a co‐extruder with glycerol as a plasticizer. The morphology, rheological properties, and mechanical properties of the WF/starch/PLA blends were comprehensively analyzed. The results showed that with the decrease of the starch/WF ratio, the morphology experienced a large transformation, and the compatibility of the blends was found to be superior to other blends, with a starch/wood flour ratio of 7/3. The dynamic mechanical thermal analysis (DMA) results demonstrated the incompatibility of the components in WF/starch/PLA blends. Following the decrease of the starch/WF ratio, the storage modulus (G″) and the complex viscosity (η*) of the blends increased. The mechanical strength first increased, and then decreased with the increase of the WF concentration. The water absorption results showed that the water resistance of the blends was reduced with the lower starch/WF ratio. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44743.
ZD, ZG and IOL Controllers and Comparisons for Nonlinear System Output Tracking with DBZ Problem Conquered in Different Relative‐Degree Cases
Authors: Li Jian , Mao Mingzhi , Zhang Yunong , Chen Dechao , Yin Yonghua 
Published: January 2017

AbstractThis paper considers the output tracking control of general‐form single‐input single‐output (SISO) nonlinear system, which may encounter the problem of division by zero (DBZ). First, via the Zhang dynamics (ZD) method, a ZD controller is proposed. Then, based on the ZD controller with the aid of gradient dynamics (GD) method, a Zhang‐gradient (ZG) controller is proposed. For comparison, the conventional input‐output linearization (IOL) controller is presented. The ZD, ZG and IOL controllers are compared in different relative‐degree cases (i.e., the standard relative‐degree case, the loose relative‐degree case and the DBZ relative‐degree case). Note that the ZG controller is valid in three relative‐degree cases, while the ZD and IOL controllers are valid only in the standard relative‐degree case and the loose relative‐degree case. In addition, performances of ZD and ZG controllers are guaranteed via theoretical analyses and computer simulations for the output tracking of general‐form nonlinear system with the DBZ problem conquered.
Empirical and modeling analyses of the circulation influences on California precipitation deficits
Authors: Lin Yen‐Heng , Hipps Lawrence E. , Wang S.‐Y. Simon , Yoon Jin‐Ho 
Published: January 2017

AbstractAmplified and persistent ridges in western North America are recurring features associated with drought conditions in California. The recent drought event (2012–2016) lasted through both La Niña and El Niño episodes, suggesting additional climate drivers are important in addition to the commonly perceived El Niño‐Southern Oscillation. Diagnostic analyses presented here suggest that, while the Pacific North American (PNA) and North Pacific Oscillation (NPO) do not directly cause drought in California, the relationships between them and with the upper air circulation pattern do modulate the spatial drought pattern. The positive PNA relative circulation leads drier northern California, and (‐NPO) relative circulation leads southern California to be drier. The types of drought in this region emerge mostly from the combination of two PNA and NPO relative oceanic and atmospheric oscillations. At present, climate model projections do not indicate any significant change in these particular drought‐modulating processes.
The Role of Technology in Managing People Who Have Been Convicted of Internet Child Abuse Image Offences
Authors: Lilley Claire M. 
Published: January 2017

The last 20 years have seen an explosion in the availability, ownership and use of devices used to access the internet. There has been a simultaneous increase in the number of people viewing child abuse images. The ease of access to this material online has removed a key inhibitor for offenders. Technology has facilitated the distribution of child abuse images, but is also used to prevent and identify offending, as well as to manage offenders. There is a range of technological tools currently used in England and Wales to manage those offenders who have been convicted of accessing child abuse images and who are living in the community. Some are specific to the computer as the situation of the crime. This article analyses the evidence base for each. The article concludes that each tool has features which might contribute to the management of internet child sex offenders, but that none have yet been proven or disproven to be effective. Copyright © 2017 John Wiley & Sons, Ltd.‘The ease of access to this material online has removed a key inhibitor for offenders’Key Practitioner Messages

Technology to help manage the risk posed by internet child sex offenders is developing and may offer promise.
None of these technological tools have been proven or disproven to be effective management tools for internet child sex offenders.
Offender managers in the police and probation services should be mindful of this and not be overly reliant on them.
Robust evaluations of these types of technology for these offenders are needed.
‘Technology to help manage the risk posed by internet child sex offenders is developing and may offer promise’
Synthesis of 2,3‐Disubstituted Indoles from α‐Diketones and N‐Substituted Anilines: One‐Pot Pd‐Catalyzed Reductive Amination
Authors: Benitez‐Medina G. Eliad , Amézquita‐Valencia Manuel , Cabrera Armando , Sharma Pankaj 
Published: January 2017

AbstractHerein, we report a new straightforward catalytic synthesis of 2,3‐disubstituted indoles from α‐diketones 1 and N‐substituted anilines 2 by employing a palladium(II) trifluoroacetate/1,1′‐bis(diphenylphosphino)ferrocene ([Pd(tfa)2]/dppf; 1:1.5) under reductive conditions and without an external oxidant. The tandem reaction involves ketoenamine and ketoamine as intermediates and a final dehydration–annulation reaction to obtain the 2,3‐disubstituted indole. New palladium hydride species, which catalyze the reaction, could not be isolated but Pd–H species were observed by NMR and IR spectroscopy and mass spectrometry (FAB+) studies. This work presents a new regioselective route with a plausible mechanism to synthesize 2,3‐disubstituted indoles under reductive conditions.
Improved Void Fraction Correlation for Two‐Phase Flow in Large‐Diameter Annuli
Authors: Wang Ning , Sun Baojiang , Gong Peibin , Wang Zhiyuan 
Published: January 2017

AbstractA flow pattern‐independent void fraction correlation for gas‐liquid two‐phase flow in vertical large‐diameter annuli is established. Two equations are proposed for the parameters of a drift flux model‐based correlation: the distribution parameter and the drift flux velocity. These equations are expressed as a function of two‐phase flow variables including void fraction, fluid properties, pipe geometry, and phase flow rates. Experiments were performed to study the void fraction of vertical air‐water two‐phase flow in large‐diameter annuli. The obtained experimental data along with the literature data of Caetano are used to verify the performance of the proposed void fraction correlation. The accuracy of this correlation is compared with nineteen frequently used correlations in literature. The proposed correlation was found to predict the void fraction consistently with a better accuracy.
Induction of Antibodies Directed Against Branched Core O‐Mannosyl Glycopeptides—Selectivity Complimentary to the ConA Lectin
Authors: Yu Jin , Grant Oliver C. , Pett Christian , Stahl Sabine , Woods Robert J. , Westerlind Ulrika 
Published: January 2017

AbstractMammalian protein O‐mannosylation, initiated by attachment of α‐mannopyranose to Ser or Thr residues, comprise a group of post‐translational modifications (PTMs) involved in muscle and brain development. Recent advances in glycoproteomics methodology and the “SimpleCell” strategy have enabled rapid identification of glycoproteins and specific glycosylation sites. Despite the enormous progress made, the biological impact of the mammalian O‐mannosyl glycoproteome remains largely unknown to date. Tools are still needed to investigate the structure, role, and abundance of O‐mannosyl glycans. Although O‐mannosyl branching has been shown to be of relevance in integrin‐dependent cell migration, and also plays a role in demyelinating diseases, such as multiple sclerosis, a broader understanding of the biological roles of branched O‐mannosyl glycans is lacking in part due to the paucity of detection tools. In this work, a glycopeptide vaccine construct was synthesized and used to generate antibodies against branched O‐mannosyl glycans. Glycopeptide microarray screening revealed high selectivity of the induced antibodies for branched glycan core structures presented on different peptide backbones, with no cross‐reactivity observed with related linear glycans. For comparison, microarray screening of the mannose‐binding lectin concanavalin A (ConA), which is commonly used in glycoproteomics workflows to enrich tryptic O‐mannosyl peptides, showed that the ConA lectin did not recognize branched O‐mannosyl glycans. The binding preference of ConA for short linear O‐mannosyl glycans was rationalized in terms of molecular structure using crystallographic data augmented by molecular modeling. The contrast between the ConA binding specificity and that of the new antibodies indicates a novel role for the antibodies in studies of protein O‐mannosylation.
Glycerol hydrogenolysis using a Ni/Ce‐Mg catalyst for improved ethanol and 1,2‐propanediol selectivities
Authors: Menchavez Russel N. , Morra Matthew J. , He B. Brian 
Published: January 2017

AbstractGlycerol, a byproduct from biodiesel production, is an inexpensive and renewable alternative feedstock for producing valuable chemicals. Hydrogenolysis of glycerol produces ethanol and 1,2‐propanediol (1,2‐PDO) with the help of appropriate catalysts. Commercially available non‐specific Ni‐based catalysts have been reported for use in producing ethanol along with 1,2‐PDO. In this work, a new Ni catalyst on various support materials was developed for the selective production of ethanol and 1,2‐PDO using glycerol hydrogenolysis. The Ni catalyst on CeO2 showed the highest potential for producing both ethanol and 1,2‐PDO. The catalyst with 0.15–0.50 g/g (15–50 wt%) Ni on CeO2 improved glycerol conversion at reaction temperatures of 215–245 °C, however 1,2‐PDO selectivity was unsatisfactory. An improvement in 1,2‐PDO selectivity was attained when Al, Si, Zn, and/or Mg were added as promoters to the Ni catalyst on CeO2, while improvement in the selectivity for ethanol occurred only with the addition of Si or Mg. A variation in Mg content showed that 1,2‐PDO selectivity was favoured at higher Mg content, while ethanol selectivity peaked at 10 % Mg. Systematic investigations found that the catalyst with 0.25 g/g (25 wt%) Ni on a Ce:Mg (4:1 mol:mol) support provided good selectivities for 1,2‐PDO at 68.10 % and ethanol at 9.0 %, respectively.
Synthesis and Cytotoxic Activity of Triterpenoid Thiazoles Derived from Allobetulin, Methyl Betulonate, Methyl Oleanonate, and Oleanonic Acid
Authors: Borkova Lucie , Adamek Richard , Kalina Petr , Drašar Pavel , Dzubak Petr , Gurska Sona , Rehulka Jiri , Hajduch Marian , Urban Milan , Sarek Jan 
Published: January 2017

AbstractA total of 41 new triterpenoids were prepared from allobetulone, methyl betulonate, methyl oleanonate, and oleanonic acid to study their influence on cancer cells. Each 3‐oxotriterpene was brominated at C2 and substituted with thiocyanate; subsequent cyclization with the appropriate ammonium salts gave N‐substituted thiazoles. All compounds were tested for their in vitro cytotoxic activity on eight cancer cell lines and two non‐cancer fibroblasts. 2‐Bromoallobetulone (2 b) methyl 2‐bromobetulonate (3 b), 2‐bromooleanonic acid (5 b), and 2‐thiocyanooleanonic acid (5 c) were best, with IC50 values less than 10 μm against CCRF‐CEM cells (e.g., 3 b: IC50=2.9 μm) as well as 2′‐(diethylamino)olean‐12(13)‐eno[2,3‐d]thiazole‐28‐oic acid (5 f, IC50=9.7 μm) and 2′‐(N‐methylpiperazino)olean‐12(13)‐eno[2,3‐d]thiazole‐28‐oic acid (5 k, IC50=11.4 μm). Compound 5 c leads to the accumulation of cells in the G2 phase of the cell cycle and inhibits RNA and DNA synthesis significantly at 1×IC50. The G2/M cell‐cycle arrest probably corresponds to the inhibition of DNA/RNA synthesis, similar to the mechanism of action of actinomycin D. Compound 5 c is new, active, and nontoxic; it is therefore the most promising compound in this series for future drug development. Methyl 2‐bromobetulonate (3 b) and methyl 2‐thiocyanometulonate (3 c) were found to inhibit nucleic acid synthesis only at 5×IC50. We assume that in 3 b and 3 c (unlike in 5 c), DNA/RNA inhibition is a nonspecific event, and an unknown primary cytotoxic target is activated at 1×IC50 or lower concentration.
Direct numerical simulation of transitional hydrodynamics of the cerebrospinal fluid in Chiari I malformation: The role of cranio‐vertebral junction
Authors: Jain Kartik , Ringstad Geir , Eide Per‐Kristian , Mardal Kent‐André 
Published: January 2017

AbstractObstruction to the cerebrospinal fluid (CSF) outflow caused by the herniation of cerebellar tonsils as a result of Chiari malformation type I leads to altered CSF hydrodynamics. This contribution explores the minutest characteristics of the CSF hydrodynamics in cervical subarachnoid space (SAS) of a healthy subject and 2 Chiari patients by performing highly resolved direct numerical simulation. The lattice Boltzmann method is used for the simulations because of its scalability on modern supercomputers that allow us to simulate up to approximately 109 cells while resolving the Kolmogorov microscales. The results depict that whereas the complex CSF flow remains largely laminar in the SAS of a healthy subject, constriction of the cranio‐vertebral junction in Chiari I patients causes manifold fluctuations in the hydrodynamics of the CSF. These fluctuations resemble a flow that is in a transitional regime rather than laminar or fully developed turbulence. The fluctuations confine near the cranio‐vertebral junction and are triggered due to the tonsillar herniation, which perturbs the flow as a result of altered anatomy of the SAS.
Culturing and Neuronal Differentiation of Human Dental Pulp Stem Cells
Authors: Goorha Sarita , Reiter Lawrence T. 
Published: January 2017

AbstractA major issue in studying human neurogenetic disorders, especially rare syndromes affecting the nervous system, is the ability to grow neuronal cultures that accurately represent these disorders for analysis. Although there has been some success in generating induced pluripotent stem (iPS) cells from both skin and blood, there are still limitations to the collection and production of iPS cells from these biospecimens. We have had significant success in collecting and growing human dental pulp stem (DPS) cells from exfoliated teeth sent to our laboratory by the parents of children with a variety of rare neurogenetic syndromes. This protocol outlines our current methods for the growth and expansion of DPS cells from exfoliated (baby) teeth. These DPS cells can be differentiated into a variety of cell types including osteoblasts, chondrocytes, and mixed neuron and glial cultures. Here we provide our protocol for the differentiation of early passage DPS cell cultures into neurons for molecular studies. © 2017 by John Wiley & Sons, Inc.
Measuring Cognitive Judgement Bias in Rats Using the Ambiguous‐Cue Interpretation Test
Authors: Papciak Justyna , Rygula Rafal 
Published: January 2017

AbstractAn active‐choice, operant, ambiguous‐cue interpretation (ACI) paradigm is described that can be used for measuring cognitive judgement bias in rats. In this behavioral test, animals in an operant conditioning chamber are trained to press a lever to receive a food reward when a specific tone is presented, and to press another lever in response to a different tone to avoid punishment by an electric foot‐shock. The tones, which serve as discriminative stimuli, acquire a positive or negative valence, and the training continues until the rats demonstrate a stable, correct discrimination between these two stimuli. The animals are tested after they have attained stable discrimination performance. The ambiguous‐cue test consists of a discrimination task, as described above, but includes the presentation of additional tones with frequencies that are intermediate between the trained positive and negative tones. The lever‐press response pattern to these ambiguous cues is considered an indicator of the rat's expectation of a positive or negative event; in other words, it is a measure of ‘optimism’ or ‘pessimism’, respectively. © 2017 by John Wiley & Sons, Inc.
Local and landscape drivers of predation services in urban gardens
Authors: Philpott Stacy M. , Bichier Peter 
Published: January 2017

AbstractIn agroecosystems, local and landscape features, as well as natural enemy abundance and richness, are significant predictors of predation services that may result in biological control of pests. Despite the increasing importance of urban gardening for provisioning of food to urban populations, most urban gardeners suffer from high pest problems, and have little knowledge about how to manage their plots to increase biological control services. We examined the influence of local, garden scale (i.e., herbaceous and arboreal vegetation abundance and diversity, ground cover) and landscape (i.e., landscape diversity and surrounding land use types) characteristics on predation services provided by naturally occurring predators in 19 urban gardens in the California central coast. We introduced sentinel pests (moth eggs and larvae and pea aphids) onto greenhouse‐raised plants taken to gardens and assigned to open or bagged (predator exclosure) treatments. We found high predation rates with between 40% and 90% of prey items removed in open treatments. Predation services varied with local and landscape factors, but significant predictors differed by prey species. Predation of eggs and aphids increased with vegetation complexity in gardens, but larvae predation declined with vegetation complexity. Smaller gardens experienced higher predation services, likely due to increases in predator abundance in smaller gardens. Several ground cover features influenced predation services. In contrast to patterns in rural agricultural landscapes, predation on aphids declined with increases in landscape diversity. In sum, we report the relationships between several local management factors, as well as landscape surroundings, and implications for garden management.