bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetocaloric Materials with Multiple Instabilities
Authors: Taguchi Yasujiro , Sakai Hideaki , Choudhury Debraj
Published: April 2017

The magnetocaloric effect is a well‐known phenomenon where the temperature of a magnetic material varies upon application or removal of a magnetic field. This effect is anticipated to be applied to magnetic refrigeration technology, which is environmentally benign. For practical applications, it is essential to explore and expand the materials horizon of novel magnets that exhibit giant magnetocaloric effects to achieve sufficient cooling efficiency. In this article, several attempts to enhance the magnetocaloric effect are reviewed from the viewpoint of the competition or cooperation between the ferromagnetic interaction and other magnetic, electronic, and structural instabilities in strongly correlated materials. The results indicate that both the competition and cooperation between them promote the first‐order nature of the magnetic transition, leading to giant magnetocaloric effects. Therefore, exploiting multiple instabilities is a promising strategy for exploring new magnetocaloric materials.
Plasmonic Thermal Emitters for Dynamically Tunable Infrared Radiation
Authors: Kazemi Moridani Amir , Zando Robert , Xie Wanting , Howell Irene , Watkins James J. , Lee Jae‐Hwang
Published: April 2017

Periodic bimetallic microstructures using nickel and gold are fabricated on an elastomeric substrate by use of strain‐induced buckling of the metallic layers, which can be compatible with roll‐to‐roll manufacturing. The intrinsically low emissivity of gold in the midinfrared regime is selectively enhanced by the surface plasmonic resonance at three different midinfrared wavelengths, 4.5, 6.3, and 9.4 µm, respectively, which directly correspond to the structural periodicities of the metallic microstructures. As the thermal emission enhancement effect exists only for the polarization perpendicular to the orientation of the microstructures, substantially polarized thermal emission with an extinction ratio close to 3 is demonstrated. Moreover, the elastically deformed plasmonic thermal emitters demonstrate strain‐dependent emission peaks, which can be applied for future mechano–thermal sensing and dynamic thermal signature modulation.
Multiwavelength Metasurfaces Based on Single‐Layer Dual‐Wavelength Meta‐Atoms: Toward Complete Phase and Amplitude Modulations at Two Wavelengths
Authors: Ding Jun , An Sensong , Zheng Bowen , Zhang Hualiang
Published: April 2017

Since its invention, metasurface has been widely utilized to achieve nearly arbitrary wavefront control based on phase only modulation at single wavelength. To achieve better performance or exotic functions, it is desirable to demonstrate metasurfaces capable of realizing both phase and amplitude modulations. Meanwhile, the wavelength‐dependent behavior of the metasurface is one of the critical limitations in existing metasurface structures. Specifically, single‐layer metasurfaces with the capability to tailor both phase and amplitude at multiple wavelengths have not been reported so far. In this paper, a single‐layer meta‐atom is proposed which can realize ultrathin metasurfaces with complete phase and amplitude modulations at two THz wavelengths. Several dual‐wavelength metalenses and a nondiffractive Airy beam generator operating at two THz wavelengths are numerically demonstrated, the simulated results of which are consistent with the theoretical calculations and design goals. The presented dual‐wavelength meta‐atom can provide a powerful building block in multiwavelength metasurface designs for controlling electromagnetic waves, including focusing, beam steering, beam generations, hologram, etc.
Simple Metal‐Free Direct Reductive Amination Using Hydrosilatrane to Form Secondary and Tertiary Amines
Authors: Varjosaari Sami E. , Skrypai Vladislav , Suating Paolo , Hurley Joseph J. M. , Lio Ashley M. De , Gilbert Thomas M. , Adler Marc J.
Published: April 2017

This work describes the use of cheap, safe, and easy‐to‐handle hydrosilatrane as the reductant in direct reductive amination reactions. This efficient method enables a facile, metal‐free access to secondary and tertiary amines from a wide range of aldehydes and ketones, with the synthesis of tertiary amines requiring no additives at all. This reaction demonstrates excellent functional group tolerance, chemoselectivity, and scalability.

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Organocatalysis and Biocatalysis Hand in Hand: Combining Catalysts in One‐Pot Procedures
Authors: Bisogno Fabricio R. , López‐Vidal Martín G. , de Gonzalo Gonzalo
Published: April 2017

Multi‐step processes catalysed by several catalysts working concurrently have been developed in nature, thus improving reaction efficiency. The quest for novel and improved catalytic systems has led to the development of biocatalytic and later to organocatalytic procedures as very valuable tools in asymmetric synthesis while using mild reaction conditions in the absence of metal catalysts. As a timeless challenge, chemists are facing the need for process designs in which different sorts of catalysts can operate successfully in a one‐pot concurrent fashion. Likewise, such designs bring about the best of each catalyst and, in certain cases, enable us to improve problematic issues, such as reactivity, selectivity, solubility, inhibition, etc. Specifically, to combine these two types of catalysts in one‐pot, achieving high yields and selectivity, is a fascinating aspect of catalysis. This review covers representative advances in this field, in particular those in which biocatalysts and organocatalysts are employed either in sequential reactions or in simultaneous processes.

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Copper‐Catalyzed Carbon‐Nitrogen/Carbon‐Selenium Bonds Formation: Synthesis of 2‐(Organochalcogenyl)‐indolizines
Authors: Goulart Tales A. C. , Back Davi F. , Zeni Gilson
Published: April 2017

The copper‐catalyzed cyclization of propargylpyridines with diorganyl dichalcogenides was applied to the synthesis of 2‐(organochalcogenyl)‐indolizines. A systematic study of the cyclization system revealed that the mutual action between copper(I) iodide and diorganyl dichalcogenides is essential for the formation of indolizines in good yields avoiding the formation of hydrogenated indolizine. The standard reaction conditions were compatible with many functional groups in the substrates, such as methyl, chlorine, fluorine, methoxy and trifluoromethyl. This protocol was efficient with diorganyl diselenides and ditellurides but ineffective with diorganyl disulfides. In addition, the obtained 2‐(organochalcogenyl)‐indolizines were readily transformed into more complex products by reaction with boronic acids using palladium‐catalyzed cross‐coupling conditions.

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Enhancing the Mechanical Durability of an Organic Field Effect Transistor through a Fluoroelastomer Substrate with a Crosslinking‐Induced Self‐Wrinkled Structure
Authors: Shih Chien‐Chung , Lee Wen‐Ya , Lu Chien , Wu Hung‐Chin , Chen Wen‐Chang
Published: April 2017

In this study, a facile method to enhance the ductility of conjugated polymer thin films by using elastomeric substrates with a self‐wrinkled structure is demonstrated. A brittle polymer of poly(selenophene‐alt‐3,6‐dithophene‐2‐yl‐2,5‐bis‐(2‐octyldodecyl)‐2,5‐dihydro‐pyrrolo[3,4‐c]pyrrole‐1,4‐dione) (PSeDPP) is transferred onto a poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP) substrate, which has a wrinkled structure formed during thermal curing. The ductility of the PSeDPP thin film on the fluoroelastomer substrate is significantly improved compared to that on poly(dimethyl siloxane) (PDMS). When the fluoroelastomer is employed in a fully stretchable transistor as the substrate as well as the dielectric layer, the device exhibits ideal transfer characteristics and excellent mechanical robustness. The transistor device with high electrical performance (≈1.51 (cm2 V−1 s−1) mobility, 104 on–off current ratio) can be stretched up to 30% over 2000 cycles and maintain device performance with 7.32 × 10−1 (cm2 V−1 s−1) and ≈104 on–off current ratio. To demonstrate the compatibility of this method with other semiconducting materials, conjugated polymers such as poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) and poly(isoindigo‐bithiophene) (PII2T‐C8C10) are also used as the active layer, and they show similar results to the PSeDPP. Hence, this method demonstrates a general strategy to significantly enhance the ductility of the conjugated polymer thin films, achieving stretchable organic field effect transistors with both high performance and mechanical compliance.
Neonatal characteristics and perinatal complications in neonates with Down syndrome
Authors: Ergaz‐Shaltiel Zivanit , Engel Offra , Erlichman Ira , Naveh Yaron , Schimmel Michael S. , Tenenbaum Ariel
Published: April 2017

The annual rate of Down syndrome (DS) births in Jerusalem is stable, regardless of prenatal screening, and diagnostic measures. We aimed to evaluate our historical cohort for obstetrical characteristics and the neonatal course and complications. We reviewed computerized medical files of neonates with the diagnosis of DS born in the four main hospitals in Jerusalem between the years 2000 and 2010 and evaluated for maternal history and primary neonatal hospitalization. A total of 403 neonates were diagnosed with DS. The average maternal age was 35.6 years, 73% were born via spontaneous vaginal delivery. In all gestational ages, the mean birth weight and head circumference percentiles were significantly lower than the general population (P < 0.001 for both) and at each week the HC percentile was lower than the weight percentile (P < 0.0001), worse among males. Mortality during the primary hospitalization was 3.7%. The most common anomalies were cardiac (79%) with either congenital defects or functional abnormalities, neither influenced the length of hospitalization. The main reasons for prolonged hospitalization were prematurity and anomalies of other (non‐cardiac) organs. Common perinatal complications included respiratory failure or need for oxygen supplementation (32%), hyperbilirubinemia (23%), sepsis (6.4%), and feeding difficulties (13%). About 84% were fed by human milk; of those, two thirds were exclusively breast‐fed and one third were supplemented with infant formula. In conclusion, infants with DS were small for gestational age with relatively reduced head circumference. Despite the increased rate of congenital anomalies and perinatal complications, most infants were discharged home in good medical condition and were exclusively breastfed.
Toughness of the Virunga mountain gorilla (Gorilla beringei beringei) diet across an altitudinal gradient
Authors: Glowacka Halszka , McFarlin Shannon C. , Vogel Erin R. , Stoinski Tara S. , Ndagijimana Felix , Tuyisingize Deo , Mudakikwa Antoine , Schwartz Gary T.
Published: April 2017

The robust masticatory system of mountain gorillas is thought to have evolved for the comminution of tough vegetation, yet, compared to other primates, the toughness of the mountain gorilla diet is unremarkable. This may be a result of low plant toughness in the mountain gorilla environment or of mountain gorillas feeding selectively on low‐toughness foods. The goal of this paper is to determine how the toughness of the mountain gorilla diet varies across their habitat, which spans a large altitudinal range, and whether there is a relationship between toughness and food selection by mountain gorillas. We collected data on the following variables to determine whether, and if so how, they change with altitude: leaf toughness of two plant species consumed by mountain gorillas, at every 100 m increase in altitude (2,600–3,700 m); toughness of consumed foods comprising over 85% of the gorilla diet across five vegetation zones; and toughness of unconsumed/infrequently consumed plant parts of those foods. Although leaf toughness increased with altitude, the toughness of the gorilla diet remained similar. There was a negative relationship between toughness and consumption frequency, and toughness was a better predictor of consumption frequency than plant frequency, biomass, and density. Consumed plant parts were less tough than unconsumed/infrequently consumed parts and toughness of the latter increased with altitude. Although it is unclear whether gorillas select food based on toughness or use toughness as a sensory cue to impart other plant properties (e.g., macronutrients, chemicals), our results that gorillas maintain a consistent low‐toughness dietary profile across altitude, despite toughness increasing with altitude, suggest that the robust gorilla masticatory apparatus evolved for repetitive mastication of foods that are not high in toughness.
Optimizing field and analytical procedures for estimating densities of arboreal and threatened primates in tropical rainforest
Authors: Cavada Nathalie , Ciolli Marco , Barelli Claudia , Rovero Francesco
Published: April 2017

The application of distance sampling to primate density estimation is challenging and susceptible to estimation biases, mainly due to the difficulties of properly accounting for variation in species’ detectability and of accurately sampling the spread of the social groups. We apply a hierarchical distance sampling approach to primate data, to account for a comprehensive set of environmental covariates of both detectability and abundance, and we propose a novel field routine to measure the spread of groups during transect sampling. We confirm the good potential of this approach, given we obtained refined estimates of primate density (as measured by the Akaike Information Criterion) in comparison to estimates from models without covariates.
Multicomponent Reactions with Cyclic Tertiary Amines Enabled by Facile C−N Bond Cleavage
Authors: Zhu Qiming , Yuan Qinghe , Chen Mingwei , Guo Mengping , Huang Hanmin
Published: April 2017

A novel and catalyst‐free multicomponent reaction with cyclic tertiary amines, electron‐deficient aryl halides or heteroaromatic halides, and Na2S enabled by facile C−N bond cleavage of the cyclic tertiary amines was developed. This direct and operationally simple method can be applied with a wide range of functional groups and provides an efficient and rapid approach to potentially drug‐like products containing amine, azaarene, thioether, or phenol ether functionalities in good to excellent yields. The utility of this method was demonstrated by the rapid synthesis of the analgesic ruzadolane.
Transition‐Metal‐Doped NIR‐Emitting Silicon Nanocrystals
Authors: Chandra Sourov , Masuda Yoshitake , Shirahata Naoto , Winnik Françoise M.
Published: April 2017

Impurity‐doping in nanocrystals significantly affects their electronic properties and diversifies their applications. Herein, we report the synthesis of transition metal (Mn, Ni, Co, Cu)‐doped oleophilic silicon nanocrystals (SiNCs) through hydrolysis/polymerization of triethoxysilane with acidic aqueous metal salt solutions, followed by thermal disproportionation of the resulting gel into a doped‐Si/SiO2 composite that, upon HF etching and hydrosilylation with 1‐n‐octadecene, produces free‐standing octadecyl‐capped doped SiNCs (diameter≈3 to 8 nm; dopant <0.2 atom %). Metal‐doping triggers a red‐shift of the SiNC photoluminescence (PL) of up to 270 nm, while maintaining high PL quantum yield (26 % for Co doping).
Ligand Design for Site‐Selective Metal Coordination: Synthesis of Transition‐Metal Complexes with η6‐Coordination of the Central Ring of Anthracene
Authors: Karslyan Eduard E. , Borissova Alexandra O. , Perekalin Dmitry S.
Published: April 2017

A polycyclic aromatic ligand for site‐selective metal coordination was designed by using DFT calculations. The computational prediction was confirmed by experiments: 2,3,6,7‐tetramethoxy‐9,10‐dimethylanthracene initially reacts with [(C5H5)Ru(MeCN)3]BF4 to give the kinetic product with a [(C5H5)Ru]+ fragment coordinated at the terminal ring, which is then transformed into the thermodynamic product with coordination through the central ring. These isomeric complexes have markedly different UV/Vis spectra, which was explained by analysis of the frontier orbitals. At the same time, the calculations suggest that electrostatic interactions are mainly responsible for the site selectivity of the coordination.
Enantioselective Palladium(II)‐Catalyzed Intramolecular Aminoarylation of Alkenes by Dual N−H and Aryl C−H Bond Cleavage
Authors: Zhang Wen , Chen Pinhong , Liu Guosheng
Published: April 2017

An asymmetric palladium‐catalyzed intramolecular oxidative aminoarylation of alkenes has been developed with quinoline–oxazoline chiral ligands and Ag2CO3 as the oxidant. Various indolines containing a quaternary stereogenic center were synthesized in high yield with excellent enantioselectivity. Preliminary mechanistic studies suggest that the addition of a catalytic amount of phenylglyoxylic acid significantly accelerates the reaction and slightly enhances the enantioselectivity.
Proximity‐Based Sortase‐Mediated Ligation
Authors: Wang Hejia Henry , Altun Burcin , Nwe Kido , Tsourkas Andrew
Published: April 2017

Protein bioconjugation has been a crucial tool for studying biological processes and developing therapeutics. Sortase A (SrtA), a bacterial transpeptidase, has become widely used for its ability to site‐specifically label proteins with diverse functional moieties, but a significant limitation is its poor reaction kinetics. In this work, we address this by developing proximity‐based sortase‐mediated ligation (PBSL), which improves the ligation efficiency to over 95 % by linking the target protein to SrtA using the SpyTag–SpyCatcher peptide–protein pair. By expressing the target protein with SpyTag C‐terminal to the SrtA recognition motif, it can be covalently captured by an immobilized SpyCatcher–SrtA fusion protein during purification. Following the ligation reaction, SpyTag is cleaved off, rendering PBSL traceless, and only the labeled protein is released, simplifying target protein purification and labeling to a single step.
Robust Binding between Carbon Nitride Nanosheets and a Binuclear Ruthenium(II) Complex Enabling Durable, Selective CO2 Reduction under Visible Light in Aqueous Solution
Authors: Kuriki Ryo , Yamamoto Muneaki , Higuchi Kimitaka , Yamamoto Yuta , Akatsuka Masato , Lu Daling , Yagi Shinya , Yoshida Tomoko , Ishitani Osamu , Maeda Kazuhiko
Published: April 2017

Carbon nitride nanosheets (NS‐C3N4) were found to undergo robust binding with a binuclear ruthenium(II) complex (RuRu′) even in basic aqueous solution. A hybrid material consisting of NS‐C3N4 (further modified with nanoparticulate Ag) and RuRu′ promoted the photocatalytic reduction of CO2 to formate in aqueous media, in conjunction with high selectivity (approximately 98 %) and a good turnover number (>2000 with respect to the loaded Ru complex). These represent the highest values yet reported for a powder‐based photocatalytic system during CO2 reduction under visible light in an aqueous environment. We also assessed the desorption of RuRu′ from the Ag/C3N4 surface, a factor that can contribute to a loss of activity. It was determined that desorption is not induced by salt additives, pH changes, or photoirradiation, which partly explains the high photocatalytic performance of this material.
Reversible oxidative Addition an Kohlenstoff
Authors: Eichhorn Antonius F. , Fuchs Sonja , Flock Marco , Marder Todd B. , Radius Udo
Published: April 2017

Es wird die Reaktivität N‐heterocyclischer Carbene (NHCs) und cyclischer Alkylaminocarbene (cAACs) gegenüber Arylboronsäureestern vorgestellt. Die Reaktionen mit NHCs führen zur reversiblen Bildung thermisch stabiler Lewis‐Säure‐Base‐Addukte Ar‐B(OR)2⋅NHC (Add1–Add6). Die Umsetzungen von cAACMe mit den Catecholboronsäureestern 4‐R‐C6H4Bcat (R=Me, OMe) liefern die Addukte 4‐R‐C6H4Bcat⋅cAACMe (Add7, R=Me) und (Add8, R=OMe), die bei Raumtemperatur zu den cAACMe‐Ringerweiterungsprodukten RER1 und RER2 reagieren. Die Boronsäureester Ar‐B(OR)2 des Pinakols, Neopentylglykols und Ethylenglykols reagieren bei Raumtemperatur mit cAACMe unter reversibler oxidativer Addition der B‐C‐Bindung an das Carben‐Kohlenstoffatom zu cAACMe(B{OR}2)(Ar) (BCA1–BCA6). NMR‐spektroskopische Untersuchungen an cAACMe(Bneop)(4‐Me‐C6H4) (BCA4) belegen die Reversibilität dieser oxidativen Addition am Kohlenstoffatom.
Fast NMR‐Based Determination of the 3D Structure of the Binding Site of Protein–Ligand Complexes with Weak Affinity Binders
Authors: Wälti Marielle A. , Riek Roland , Orts Julien
Published: April 2017

In early drug discovery approaches, screening hits are often weak affinity binders that are difficult to characterize in structural detail, particularly towards obtaining the 3D structure of protein–ligand complexes at atomic resolution. NMR is the outstanding technique to tackle such problems, yet suffers from a tedious structure calculation process. NMR2 was recently developed to alleviate the laborious element of routine NMR structure calculation procedures and provides the structural information at protein–ligand interaction sites orders of magnitude faster than standard procedures. The NMR2 method was extended to weak binders and applied to the oncoproteins HDM2 and MDMX. The structure of the MDMX‐SJ212 complex is reported with a Kd of approximately 0.7 μm; the complex structure of HDM2 with the mm affinity ligand #845 exhibits a new scaffold.
Domino N‐/C‐Arylation via In Situ Generation of a Directing Group: Atom‐Efficient Arylation Using Diaryliodonium Salts
Authors: Teskey Christopher J. , Sohel Shariar M. A. , Bunting Danielle L. , Modha Sachin G. , Greaney Michael F.
Published: April 2017

Both aryl components of diaryliodonium salts can be used in a domino one‐pot reaction via in situ generation of a directing group. A number of heterocycles undergo N‐arylation which is followed by ruthenium‐catalyzed C‐arylation. Notably the reaction extends well to unsymmetrical diaryliodonium salts with a number of highly selective examples shown.
Intramolecular Benzoin Reaction Catalyzed by Benzaldehyde Lyase from Pseudomonas Fluorescens Biovar I
Authors: Hernández Karel , Parella Teodor , Petrillo Giovanna , Usón Isabel , Wandtke Claudia M. , Joglar Jesús , Bujons Jordi , Clapés Pere
Published: April 2017

Intramolecular benzoin reactions catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I (BAL) are reported. The structure of the substrates envisaged for this reaction consists of two benzaldehyde derivatives linked by an alkyl chain. The structural requirements needed to achieve the intramolecular carbon–carbon bond reaction catalyzed by BAL were established. Thus, a linker consisting of a linear alkyl chain of three carbon atoms connected through ether‐type bonds to the 2 and 2′ positions of two benzaldehyde moieties, which could be substituted with either Cl, Br, or OCH3 at either the 3 and 3′ or 5 and 5′ positions, were suitable substrates for BAL. Reactions with 61–84 % yields of the intramolecular product and ee values between 64 and 98 %, were achieved.
Arrangement of Proteinogenic α‐Amino Acids on a Cyclic Peptide Comprising Alternate Biphenyl‐Cored ζ‐Amino Acids
Authors: Tashiro Shohei , Chiba Masayuki , Shionoya Mitsuhiko
Published: April 2017

Aiming at precisely arranging several proteinogenic α‐amino acids on a folded scaffold, we have developed a cyclic hexapeptide comprising an alternate sequence of biphenyl‐cored ζ‐amino acids and proteinogenic α‐amino acids such as l‐leucine. The amino acids were connected by typical peptide synthesis, and the resultant linear hexapeptide was intramolecularly cyclized to form a target cyclic peptide. Theoretical analyses and NMR spectroscopy suggested that the cyclic peptide was folded into an unsymmetrical conformation, and the structure was likely to be flexible in CHCl3. The optical properties including UV/Vis absorption, fluorescence, and circular dichroism (CD) were also evaluated. Furthermore, the cyclic peptide became soluble in water by introducing three carboxylate groups at the periphery of the cyclic skeleton. This α/ζ‐alternating cyclic peptide is therefore expected to serve as a unique scaffold for arranging several functionalities.
Ambient‐Pressure Stabilization of β‐GdB3O6 by Doping with Bi3+ and Color‐Tunable Emissions by Co‐Doping with Tb3+ and Eu3+: The First Photoluminescence Study of a High‐Pressure Polymorph
Authors: Sun Xiaorui , Jiang Pengfei , Gao Wenliang , Zhou Xianju , Cong Rihong , Yang Tao
Published: April 2017

Rare‐earth borates are good candidates for optical applications. To date, however, the high‐pressure/high‐temperature technique has produced a large number of novel borates with optical properties that have rarely been investigated due to the severe problem of substantial defects. We targeted the high‐pressure polymorph of β‐GdB3O6 and synthesized three solid solutions of β‐Gd0.75−xBi0.25TbxB3O6 (0≤x≤0.75), β‐Gd0.75−yBi0.25EuyB3O6 (0≤y≤0.75), and β‐Gd0.50−zBi0.25Tb0.25EuzB3O6 (0≤z≤0.05) by using typical solid‐state reactions at 820 °C. Here, the function of Bi3+ is to stabilize the high‐pressure phase by lowering the synthetic temperature and being the sensitizer to promote the green and red emissions of Tb3+ and Eu3+. The multiple energy transfer paths were investigated by using lifetime decay experiments and photoluminescent spectra, and both efficiency and mechanism were determined. Eventually, color‐tunable and white emissions were achieved by rational doping of Bi3+, Tb3+, and Eu3+ into β‐GdB3O6, that is, the CIE chromaticity coordinate for β‐Gd0.44Bi0.25Tb0.30Eu0.01B3O6 is (0.318, 0.365) with a correlated color temperature of 6101 K.
Optimization model to start harvesting in stochastic aquaculture system
Authors: Yoshioka Hidekazu , Yaegashi Yuta
Published: April 2017

Establishment of cost‐effective management strategy of aquaculture is one of the most important issues in fishery science, which can be addressed with bio‐economic mathematical modeling. This paper deals with the aforementioned issue using a stochastic process model for aquacultured non‐renewable fishery resources from the viewpoint of an optimal stopping (timing) problem. The goal of operating the model is to find the optimal criteria to start harvesting the resources under stochastic environment, which turns out to be determined from the Bellman equation (BE). The BE has a separation of variables type structure and can be simplified to a reduced BE with a fewer degrees of freedom. Dependence of solutions to the original and reduced BEs on parameters and independent variables is analyzed from both analytical and numerical standpoints. Implications of the analysis results to management of aquaculture systems are presented as well. Numerical simulation focusing on aquacultured Plecoglossus altivelis in Japan validates the mathematical analysis results. Copyright © 2017 John Wiley & Sons, Ltd.
Hydrophobic‐hydrophilic forces in protein folding
Authors: Durell Stewart R. , Ben‐Naim Arieh
Published: April 2017

The process of protein folding is obviously driven by forces exerted on the atoms of the amino‐acid chain. These forces arise from interactions with other parts of the protein itself (direct forces), as well as from interactions with the solvent (solvent‐induced forces). We present a statistical–mechanical formalism that describes both these direct and indirect, solvent‐induced thermodynamic forces on groups of the protein. We focus on 2 kinds of protein groups, commonly referred to as hydrophobic and hydrophilic. Analysis of this result leads to the conclusion that the forces on hydrophilic groups are in general stronger than on hydrophobic groups. This is then tested and verified by a series of molecular dynamics simulations, examining both hydrophobic alkanes of different sizes and hydrophilic moieties represented by polar‐neutral hydroxyl groups. The magnitude of the force on assemblies of hydrophilic groups is dependent on their relative orientation: with 2 to 4 times larger forces on groups that are able to form one or more direct hydrogen bonds.
Association of anti‐gangliosides antibodies and anti‐CMV antibodies in Guillain–Barré syndrome
Authors: Wang Lijuan , Shao Chunqing , Yang Chunjiao , Kang Xixiong , Zhang Guojun
Published: April 2017

Introduction

Numerous types of infection were closely related to GBS, mainly including Campylobacter jejuni, Cytomegalovirus, which may lead to the production of anti‐gangliosides antibodies (AGA). Currently, although there are increased studies on the AGA and a few studies of anti‐CMV antibodies in GBS, the association between them remains poorly documented. Therefore, our research aims to analyze the correlation of anti‐CMV antibodies and AGA in GBS.

Methods

A total of 29 patients with GBS were enrolled in this study. The CMV antibodies were tested by the electrochemiluminescence immunoassay “ECLIA” (Roche Diagnostics GmbH). The serum gangliosides were determined by The EUROLINE test kit.

Results

Of the 29 patients with GBS, 9 (31%) were AGA‐seropositive, in which 22 were CMV‐IgG positive in CSF at the same time, but all 29 samples were CMV‐IgM negative in both serum and CSF. In the AGA‐positive group, the rate of both serum and CSF positive was 87.5% (7/8), higher than 50% (7/14) of the negative group, although no statistical significance was found. In addition, we found that there was a trend of higher ratio of men, a younger age onset, less frequent preceding infection, a higher level of CSF proteins, and less frequent cranial nerve deficits, although the data did not reach a statistical significance.

Conclusion

In spite of no statistical significance association was found between serum AGA and CMV‐IgG in serum and CSF. However, we found that there was a trend of high positive rate of both serum and CSF‐CMV‐IgG in AGA‐positive than the negative group. So we should further expand the sample size to analyze the association between AGA and CMV or other neurotropic virus antibodies in various diseases, to observe whether they could be serological marker of these diseases (especially GBS) or the underlying pathogenesis.
Effects of levodopa/carbidopa intestinal gel versus oral levodopa/carbidopa on B vitamin levels and neuropathy
Authors: Loens Sebastian , Chorbadzhieva Elena , Kleimann Alexandra , Dressler Dirk , Schrader Christoph
Published: April 2017

Objectives

To determine the possible interactions between levodopa therapy and plasma levels of B vitamins in patients with advanced idiopathic Parkinson's disease (IPD) in the context of either oral levodopa therapy or levodopa/carbidopa intestinal gel (LCIG). Secondly, to determine the prevalence of neuropathy and its relation to plasma levels of B vitamins and homocysteine.

Methods

Medication doses, neurographies, and serum levels of pyridoxine, cobalamin, folate, and homocysteine of eight LCIG and 13 orally treated advanced IPD patients matched for age, Hoehn & Yahr stage, and UPRDS III were collected. This data was analyzed for correlation with daily levodopa dose (LDD).

Results

LICG patients had a longer disease duration and higher LDD. All LCIG patients and most orally treated patients had sensorimotor axonal polyneuropathy. Of all plasma vitamin levels, pyridoxine was decreased most and significantly lower in the LCIG group. Cobalamin and folate, however, were within the lower reference range, and homocysteine highly elevated, all without any significant difference between both groups. LDD correlated significantly with pyridoxine deficiency (p = .02) irrespective of the route of application and with hyperhomocysteinemia in the LCIG group (p = .03). At LDDs above 2,000 mg, pyridoxine deficiency was almost always detectable.

Conclusions

Pyridoxine deficiency and hyperhomocysteinemia are dependent on the daily levodopa/carbidopa dose, while levels of cobalamin and folate are not. The mode of application of levodopa/carbidopa has no impact on B‐vitamin levels. Neuropathy is very frequent in advanced IPD; however, it remains to be investigated further whether neuropathy is more frequent in LCIG than in orally levodopa/carbidopa‐treated advanced IPD patients.
Personal experience and critical reflexivity in counselling and psychotherapy research
Authors: Etherington Kim
Published: April 2017

Aims

The aim of this study was to offer a view of how, as a counselling practitioner‐researcher, I use my personal experiences reflexively in research. By ‘showing’ and ‘telling’ about the practices and processes involved, I hope to encourage others to undertake research that values reflexive collaborative engagement and enables participants’ agency in research.

Methods

I address the value of critical reflexivity as a means for including ourselves and our personal experiences in counselling and psychotherapy research. Three excerpts are offered as examples of (a) reflexively contextualising ourselves and our participants, (b) reflexively co‐constructing knowledge and meaning making and (c) a critically reflexive approach to addressing issues of voice in research by highlighting a potential dilemma about choosing which stories should be told.
Cytoskeletal mechanisms in positioning of the second‐division spindles and meiotic restitution in tobacco (Nicotiana tabacum L.) microsporogenesis
Authors: Sidorchuk Yuriy Vladimirovich , Deineko Elena Victorovna
Published: April 2017

Microsporogenesis patterns of the polyploid (2n = 4x = 96) and diploid (2n = 2x = 48) Nicotiana tabacum L. (cv. Havana Petit line SR1) plants have been analyzed and compared. Four types of abnormal positions of the second‐division spindles—tripolar, parallel, proximal, and fused—have been observed. Of these abnormalities, only tripolar (2.4%) and parallel (1.4%) spindles are observable in diploid plants. As for polyploids, the increased ploidy is accompanied by an increase in the incidence of tripolar (22.8%) and parallel (8.1%) spindle orientations and emergence of two remaining abnormalities (proximal and fused spindles, 3.3%). As has been shown, the spindle position abnormalities in diploid plants have no effect on the meiotic products, whereas both dyads and triads are detectable among the tetrads in polyploid plants. Analysis of cytoskeletal remodeling has allowed for the insight into the role of interzonal radial microtubule system in spindle positioning during the second division. The reason underlying the change in spindle positioning is disturbed polymerization–depolymerization processes and interdigitation of microtubule plus ends within the interzonal cytoskeleton system in late telophase I–interkinesis and prophase II. As has been demonstrated, fused second‐division spindles are formed as a result of fused cytoskeletal structures in prophase–prometaphase II in the case when the nuclei are drawn abnormally close to one another.
Hypoglycemia and decreased insulin requirement caused by malignant insulinoma in a type 1 diabetic patient: when the hoof beats are from a zebra, not a horse
Authors: Gjelberg Hilde K. , Hoem Dag , Verbeke Caroline S. , Eide Johan , Cooper John G. , Molven Anders
Published: April 2017

Key Clinical Message

Insulinomas are uncommon tumors, and in patients with diabetes mellitus they are extremely rare. We describe a patient with type 1 diabetes who developed malignant insulinoma. When hypoglycemic episodes persist in a patient with diabetes and treatment‐induced and other causes of hypoglycemia have been ruled out, an insulin‐producing tumor should be considered.
Synthesis of Platinum Nanoparticles by Reductive Crystallization Using Polyethyleneimine
Authors: Nagao Hideyuki , Ichiji Masumi , Hirasawa Izumi
Published: April 2017

Sub‐10‐nm‐sized Pt nanoparticles were synthesized by reducing Pt ions with NaBH4, with the addition of polyethyleneimine (PEI) as a protective reagent. Well‐dispersed Pt nanoparticles with a narrow size distribution were successfully produced. When lowering the pH of the PEI solution, cubic and tetrahedral nanoparticles were observed, while at a higher pH, only spherical nanoparticles were produced. In addition, by selecting a suitable concentration of PEI, the protective reagent itself can reduce Pt ions to generate Pt nanoparticles with diameters in the range of 12.9–70.7 nm. This shows the potential of one‐pot synthesis of Pt nanoparticles by just adding Pt ions and PEI.
Hemilability‐Driven Water Activation: A NiIICatalyst for Base‐Free Hydration of Nitriles to Amides
Authors: Singh Kuldeep , Sarbajna Abir , Dutta Indranil , Pandey Pragati , Bera Jitendra K.
Published: April 2017

The NiIIcomplex1containing pyridyl‐ and hydroxy‐functionalized N‐heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base‐free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen‐bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α‐hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds2and4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds1and3) show substantial activity. The linkage isomer1′where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pKameasurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand‐promoted nucleophilic water addition to a metal‐bound nitrile group. This work reports a Ni‐based catalyst that exhibits functional hemilability for hydration chemistry.
DHMO, die wässrige Gefahr
Authors: Roth Klaus
Published: April 2017

Moleküle und ihre Beziehung zu uns Menschen sollen in dieser Rubrik vorgestellt werden, die daher auch “Moleküle und Menschen” heißt und den Berliner “Molecule Man” des US‐amerikanischen Bildhauers Jonathan Borofsky (*1942) als Logo trägt. Er selbst sagt über sein Kunstwerk: “Für mich steht diese 30 m hohe Aluminium‐Skulptur von drei, sich im Mittelpunkt treffenden Figuren nicht nur für die Leichtigkeit unserer eigenen massiven Körper, sondern die drei, im Zentrum miteinander verbundenen Figuren stehen für die Vereinigung der Moleküle aller Menschen, um unsere Existenz zu erschaffen.” In diesem Aprilheft geht es um Dihydrogenmonoxid .
Schneller als der Arzt erlaubt
Authors: Tetsch Larissa
Published: April 2017

Kegelschnecken [1] lähmen ihre Beutetiere mit Hilfe eines Giftcocktails. Bei den Fische jagenden Landkartenkegelschnecken enthält dieser Insulin, das einen plötzlichen Blutzuckerabfall der Beute verursacht. Im Vergleich zu menschlichem Insulin ist das Schneckeninsulin extrem schnell wirksam, und könnte somit als Leitmolekül für ein neues Diabetespräparat dienen.
f‐Gruppen‐Chemie: Opposition erwünscht
Authors: Groß Michael
Published: April 2017

Das Krebsmedikament cis‐Platin verdankt seinen Namen der Verteilung der quadratisch‐planar angeordneten Liganden, zwei Ammoniakgruppen und zwei Chloridionen. Nur wenn die beiden NH3‐Liganden auf benachbarten Ecken des Quadrats sitzen, also in cis‐Stellung, blockiert der Komplex die Zell‐teilung und ist deshalb gegen Krebs wirksam. Stehen sie sich diagonal gegenüber, so liegt das trans‐Isomere vor, das unwirksam ist. Da trifft es sich gut, dass bei der Synthese des Medikaments der so genannte trans‐Effekt hilft.
Big data and partial least‐squares prediction
Authors: Cook R. Dennis , Forzani Liliana
Published: April 2017

We give a commentary on the challenges of big data for Statistics. We then narrow our discussion to one of those challenges: dimension reduction. This leads to consideration of one particular dimension reduction method—partial least‐squares (PLS) regression—for prediction in big high‐dimensional regressions where the sample size and the number of predictors are both large. We show that in some regression contexts single‐component PLS predictions converge at the usual root‐nrate asregardless of the relationship between the sample sizenand number of predictorsp. Asymptotically, PLS predictions then behave as regression predictions in the usual context wherepis fixed andThese results support the conjecture that PLS regression can be an effective method for prediction in big high‐dimensional regressions.The Canadian Journal of Statistics46: 62–78; 2018 © 2017 Statistical Society of Canada
Experimentelles Zentralabitur in Niedersachsen – Quo Vadis?
Authors: Beeken Marco , Bütergerds Kerstin , Steinhart Martin
Published: April 2017

In den letzten Jahren wurden immer wieder Änderungen bezüglich des Zentralabiturs in Niedersachsen beschlossen. Eine sehr fachspezifische Änderung in der Chemie ist die Einführung des experimentellen Abiturs seit 2013, nach der die Schülerinnen und Schüler wahlweise ein Abitur mit experimentellem Anteil ablegen können, sofern dies von der Schule angeboten wird. In diesem Beitrag wird dieses Konzept umfassend beleuchtet. Zunächst werden die Umsetzung und Organisationen in den Schulen erläutert. Anschließend werden empirische Studien vorgestellt, die mit beteiligten Lehrkräften qualitativ und mit Abiturientinnen und Abiturienten quantitativ geführt wurden, um jeweilige Ergebnisse zu berichten. In diesen werden vor allem die Beweggründe und daraus resultierende Wahltendenzen der Abiturientinnen und Abiturienten mit der Möglichkeit der Ablegung des experimentellen Abiturs vorgestellt, aber auch der Fall beleuchtet, dass es für viele Schulen nicht möglich scheint, ein experimentelles Abitur anzubieten. Aufgrund der sehr gespaltenen Auffassungen zu dem Konzept „Experimentelles Zentralabitur”, schließt der Artikel mit einer ergebnisgeleiteten Diskussion.
Optimal secondary prevention medication use in acute myocardial infarction patients with nonobstructive coronary artery disease is modified by management strategy: insights from the TRIUMPH Registry
Authors: Pitts Reynaria , Daugherty Stacie L. , Tang Fengming , Jones Philip , Ho P. Michael , Tsai Thomas T. , Spertus John , Maddox Thomas M.
Published: April 2017

Background

Patients with acute myocardial infarction (AMI) and nonobstructive coronary artery disease (nonobCAD) may be perceived to be at lower risk for cardiac events, relative to those with obstructive CAD (obCAD), and thus less likely to receive optimal preventive medications in the year following AMI.

Hypothesis

We aimed to determine if AMI patients with nonobCAD, compared to obCAD, received lower rates of prevention medications in the year following AMI.

Methods

We compared optimal prevention medication use at hospital discharge, 1, 6, and 12 months after hospitalization. Optimal medication use was defined as the receipt of all prevention medications for which that patient was eligible (eg, aspirin, clopidogrel, statins, β‐blockers, and angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers). We used multivariable logistic regression analyses to determine the association between nonobCAD to medication use and adjusted for potential confounders.

Results

Three thousand six hundred thirty AMI patients were studied, of whom 200 (5.2%) had nonobCAD. Fewer nonobCAD patients received optimal medication use compared to obCAD patients at discharge (31% vs 65%, P < 0.001), driven primarily by lower rates of clopidogrel use (40.5% vs 83.3%, P < 0.001). After adjustment for percutaneous coronary intervention (PCI), differences in medication use were similar at discharge and 1 year after hospitalization. Stratified analyses by receipt of PCI suggested patients confined to medical management had less optimal medication use, regardless of their CAD burden.

Conclusions

Lower rates of unadjusted optimal medication use were seen in nonobCAD patients, driven by low clopidogrel use among medically managed patients, suggesting improvement efforts should focus on these patients.
Efficacy and feasibility of sorafenib as a maintenance agent after allogeneic hematopoietic stem cell transplantation for Fms‐like tyrosine kinase 3‐mutated acute myeloid leukemia
Authors: Battipaglia Giorgia , Ruggeri Annalisa , Massoud Radwan , El Cheikh Jean , Jestin Matthieu , Antar Ahmad , Ahmed Syed Osman , Rasheed Walid , Shaheen Marwan , Belhocine Ramdane , Brissot Eolia , Dulery Remy , Eder Sandra , Giannotti Federica , Isnard Francoise , Lapusan Simona , Rubio Marie‐Therese , Vekhoff Anne , Aljurf Mahmoud , Legrand Ollivier , Mohty Mohamad , Bazarbachi Ali
Published: April 2017

BACKGROUND

Sorafenib has shown encouraging results in patients with Fms‐like tyrosine kinase 3 (FLT3)‐positive acute myeloid leukemia. Its role after allogeneic stem cell transplantation (HSCT) has been reported in a few cases with encouraging results.

METHODS

The authors describe the use of sorafenib as a maintenance agent after HSCT in 27 patients with FLT3‐positive acute myeloid leukemia.

RESULTS

The median age of the patients was 46 years (range, 15‐57 years). Sorafenib was introduced at a median of 70 days (range, 29‐337 days) after HSCT. The median treatment duration was 8.4 months (range, 0.2‐46 months). Eleven patients experienced treatment toxicities, mainly of grade 1 to 2 (graded according to the National Cancer Institute Common Toxicity Criteria [version 4.0]). Dose reduction or withdrawal was required in 4 patients and 4 patients, respectively. The persistence of toxicity prompted treatment withdrawal in 1 patient. Clinical improvement followed dose modifications. Thirteen patients experienced chronic graft‐versus‐host disease (limited in 9 patients and extensive in 4 patients), resulting in dose reduction in 5 patients followed by withdrawal in 1 of these individuals. At a median follow‐up of 18 months (range, 4‐48 months), 25 patients were alive (all of whom were in complete molecular remission) and 18 were still receiving treatment, with 1‐year overall survival and progression‐free survival rates of 92% ± 6% and 92% ± 5%, respectively.

CONCLUSIONS

Sorafenib treatment after HSCT appears to be feasible and highly effective with dose individualization according to patient tolerability. Further analysis is needed to evaluate the immunomodulating role of sorafenib after HSCT. The data from the current support prospective controlled trials of sorafenib after HSCT. Cancer 2017;123:2867–74. © 2017 American Cancer Society.