bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive control strategy‐based reference model for spacecraft motion trajectory
Authors: Samigulina Zarina , Shiryayeva Olga , Samigulina Galina , Fourati Hassen 
Published: July 2014

SummaryIn aerospace field, the economic realization of a spacecraft is one of the main objectives that should be accomplished by conceiving the optimal propulsion system and the best control algorithms. This paper focuses on the development of a viable adaptive control approach (ACA) for spacecraft motion trajectory (SMT). The proposed strategy involves the nonlinear mathematical model of SMT expressed in the central field, which is linearized by the Taylor expansion, and the second Lyapunov method to offer a high rate and unfailing performance in the functioning. The adaptive control system is composed of the cascade of adaptation loop and feedback control loop. When the spacecraft deviates from its reference trajectory model, the ACA acts on the control system to correct this deviation and follow the optimal reference trajectory. Therefore, when the states of the adjustable model are different from its reference values, then the error signal is provided as an input to the adaptation law, which contains the adaptation algorithm. The output will be the state variable feedback control matrix, which will be used to calculate the new control law vector. The efficiencies of the linearization procedure and the control approach are theoretically investigated through some realistic simulations and tests under MATLAB. The steady‐state errors of control between the reference model and the adjustable model of SMT converge to zero. Copyright © 2014 John Wiley & Sons, Ltd.
Characterizing runs of homozygosity and their impact on risk for psychosis in a population isolate
Authors: Melhem Nadine M. , Lu Cong , Dresbold Cara , Middleton Frank A. , Klei Lambertus , Wood Shawn , Faraone Stephen V. , Vinogradov Sophia , Tiobech Josepha , Yano Victor , Roeder Kathryn , Byerley William , Myles‐Worsley Marina , Devlin Bernie 
Published: July 2014

AbstractAn increased abundance of runs of homozygosity (ROH) has been associated with risk for various diseases, including schizophrenia. Here we investigate the characteristics of ROH in Palau, an Oceanic population, evaluating whether these characteristics are related to risk for psychotic disorders and the nature of this association. To accomplish these aims we evaluate a sample of 203 cases with schizophrenia and related psychotic disorders—representing almost complete ascertainment of affected individuals in the population—and contrast their ROH to that of 125 subjects chosen to function as controls. While Palauan diagnosed with psychotic disorders tend to have slightly more ROH regions than controls, the distinguishing features are that they have longer ROH regions, greater total length of ROH, and their ROH tends to co‐occur more often at the same locus. The nature of the sample allows us to investigate whether rare, highly penetrant recessive variants generate such case–control differences in ROH. Neither rare, highly penetrant recessive variants nor individual common variants of large effect account for a substantial proportion of risk for psychosis in Palau. These results suggest a more nuanced model for risk is required to explain patterns of ROH for this population. © 2014 Wiley Periodicals, Inc.
Effect of bite force and diet composition on craniofacial diversification of Southern South American human populations
Authors: Menéndez Lumila , Bernal Valeria , Novellino Paula , Perez S. Ivan 
Published: July 2014

ABSTRACTEcological factors can be important to shape the patterns of morphological variation among human populations. Particularly, diet plays a fundamental role in craniofacial variation due to both the effect of the nutritional status—mostly dependent on the type and amount of nutrients consumed—on skeletal growth and the localized effects of masticatory forces. We examine these two dimensions of diet and evaluate their influence on morphological diversification of human populations from southern South America during the late Holocene. Cranial morphology was measured as 3D coordinates defining the face, base and vault. Size, form, and shape variables were obtained for 474 adult individuals coming from 12 samples. Diet composition was inferred from carious lesions and δ13C data, whereas bite forces were estimated using traits of main jaw muscles. The spatial structure of the morphological and ecological variables was measured using correlograms. The influence of diet composition and bite force on morphometric variation was estimated by a spatial regression model. Cranial variation and diet composition display a geographical structure, while no geographical pattern was observed in bite forces. Cranial variation in size and form is significantly associated with diet composition, suggesting a strong effect of systemic factors on cranial growth. Conversely, bite forces do not contribute significantly to the pattern of morphological variation among the samples analyzed. Overall, these results show that an association between diet composition and hardness cannot be assumed, and highlight the complex relationship between morphological diversification and diet in human populations. Am J Phys Anthropol 155:114–127, 2014. © 2014 Wiley Periodicals, Inc.
Maintenance of Amyloid β Peptide Homeostasis by Artificial Chaperones Based on Mixed‐Shell Polymeric Micelles
Authors: Huang Fan , Wang Jianzu , Qu Aoting , Shen Liangliang , Liu Jinjian , Liu Jianfeng , Zhang Zhenkun , An Yingli , Shi Linqi 
Published: July 2014

AbstractThe disruption of Aβ homeostasis, which results in the accumulation of neurotoxic amyloids, is the fundamental cause of Alzheimer’s disease (AD). Molecular chaperones play a critical role in controlling undesired protein misfolding and maintaining intricate proteostasis in vivo. Inspired by a natural molecular chaperone, an artificial chaperone consisting of mixed‐shell polymeric micelles (MSPMs) has been devised with tunable surface properties, serving as a suppressor of AD. Taking advantage of biocompatibility, selectivity toward aberrant proteins, and long blood circulation, these MSPM‐based chaperones can maintain Aβ homeostasis by a combination of inhibiting Aβ fibrillation and facilitating Aβ aggregate clearance and simultaneously reducing Aβ‐mediated neurotoxicity. The balance of hydrophilic/hydrophobic moieties on the surface of MSPMs is important for their enhanced therapeutic effect.
Helixförmige Packung von Nanopartikeln, eingeschlossen in zylindrische Domänen einer selbstorganisierten Blockcopolymerstruktur
Authors: Sanwaria Sunita , Horechyy Andriy , Wolf Daniel , Chu Che‐Yi , Chen Hsin‐Lung , Formanek Petr , Stamm Manfred , Srivastava Rajiv , Nandan Bhanu 
Published: July 2014

AbstractAnhand theoretischer Modelle lässt sich vorhersagen, dass eine Vielzahl von durch Selbstorganisation gebildeten Strukturen dicht gepackter kugelförmiger Partikel entstehen kann, wenn diese in zylindrischen Räumen eingeschlossen werden. In der vorliegenden Arbeit demonstrieren wir zum ersten Mal, dass polymerbeschichtete Nanopartikel, die in den selbstorganisierten zylindrischen Domänen eines Blockcopolymers eingeschlossen sind, sich in einer helixförmig gepackten Morphologie anordnen. Es gelang uns, einzelne mit helixförmig angeordneten Nanopartikeln gefüllte Fasern zu isolieren. Dieses Ergebnis eröffnet einzigartige Möglichkeiten sowohl für die Grundlagenforschung als auch für die anwendungsorientierte Forschung.
Flow‐Based Enzymatic Ligation by Sortase A
Authors: Policarpo Rocco L. , Kang Hansol , Liao Xiaoli , Rabideau Amy E. , Simon Mark D. , Pentelute Bradley L. 
Published: July 2014

AbstractSortase‐mediated ligation (sortagging) is a versatile, powerful strategy for protein modification. Because the sortase reaction reaches equilibrium, a large excess of polyglycine nucleophile is often employed to drive the reaction forward and suppress sortase‐mediated side reactions. A flow‐based sortagging platform employing immobilized sortase A within a microreactor was developed that permits efficient sortagging at low nucleophile concentrations. The platform was tested with several reaction partners and used to generate a protein bioconjugate inaccessible by solution‐phase batch sortagging.
Cyclisierende radikalische Carboiodierung, Carbotellurierung und Carboaminoxylierung von Arylaminen
Authors: Hartmann Marcel , Studer Armido 
Published: July 2014

AbstractDie radikalische Carboiodierung verschiedener Arylamine wird vorgestellt. Aryldiazoniumsalze, in situ aus den entsprechenden Arylaminen erzeugt, reagieren dabei mit Bu4NI zu Arylradikalen, welche 5‐exo oder 6‐exo‐Cyclisierungen eingehen. Anschließende I‐Abstraktion liefert die carboiodierten Produkte in guten bis exzellenten Ausbeuten. Bei Zugabe von TEMPO führt die Kaskade zu den entsprechenden carboaminoxylierten Produkten. Läuft die Reaktion in Gegenwart von PhTeTePh ab, so resultieren carbotellurierte cyclische Verbindungen.
Entwicklung eines 18F‐markierten Tetrazins mit vorteilhaften pharmakokinetischen Eigenschaften für die bioorthogonale Positronenemissionstomographie
Authors: Denk Christoph , Svatunek Dennis , Filip Thomas , Wanek Thomas , Lumpi Daniel , Fröhlich Johannes , Kuntner Claudia , Mikula Hannes 
Published: July 2014

AbstractEs wurde ein niedermolekulares 18F‐markiertes Tetrazin entwickelt, das im Bereich der bioorthogonalen Bildgebung mithilfe von PET verwendet werden kann. Durch 18F‐Fluorierung einer geeigneten Vorstufe konnten die Verwendung von prosthetischen Gruppen und die Notwendigkeit mehrerer radiochemischer Syntheseschritte vermieden werden. Die Reaktionskinetik der Cycloaddition mit trans‐Cyclooctenen wurde mithilfe quantenchemischer Rechungen und Stopped‐Flow‐Messungen in humanem Plasma untersucht. Eine hohe Stabilität konnte in vitro und in vivo nachgewiesen werden, während PET/MR‐Untersuchungen an Mäusen eine schnelle homogene Biodistribution offenbarten. Anhand eines In‐vivo‐Experiments konnte die Bioorthogonalität der neuartigen Tetrazinsonde bestätigt werden. Die hervorragenden Eigenschaften dieser bioorthogonalen Sonde zur Lokalisierung und Visualisierung von Dienophil‐markierten Molekülen bilden die Grundlage für viele Anwendungsmöglichkeiten im Bereich der molekularen Bildgebung.
Total Chemical Synthesis of Biologically Active Fluorescent Dye‐Labeled Ts1 Toxin
Authors: Dang Bobo , Kubota Tomoya , Correa Ana M. , Bezanilla Francisco , Kent Stephen B. H. 
Published: July 2014

AbstractTs1 toxin is a protein found in the venom of the Brazilian scorpion Tityus serrulatus. Ts1 binds to the domain II voltage sensor in the voltage‐gated sodium channel Nav and modifies its voltage dependence. In the work reported here, we established an efficient total chemical synthesis of the Ts1 protein using modern chemical ligation methods and demonstrated that it was fully active in modifying the voltage dependence of the rat skeletal muscle voltage‐gated sodium channel rNav1.4 expressed in oocytes. Total synthesis combined with click chemistry was used to label the Ts1 protein molecule with the fluorescent dyes Alexa‐Fluor 488 and Bodipy. Dye‐labeled Ts1 proteins retained their optical properties and bound to and modified the voltage dependence of the sodium channel Nav. Because of the highly specific binding of Ts1 toxin to Nav, successful chemical synthesis and labeling of Ts1 toxin provides an important tool for biophysical studies, histochemical studies, and opto‐pharmacological studies of the Nav protein.
Platinum‐Promoted Ga/Al2O3 as Highly Active, Selective, and Stable Catalyst for the Dehydrogenation of Propane
Authors: Sattler Jesper J. H. B. , Gonzalez‐Jimenez Ines D. , Luo Lin , Stears Brien A. , Malek Andrzej , Barton David G. , Kilos Beata A. , Kaminsky Mark P. , Verhoeven Tiny W. G. M. , Koers Eline J. , Baldus Marc , Weckhuysen Bert M. 
Published: July 2014

AbstractA novel catalyst material for the selective dehydrogenation of propane is presented. The catalyst consists of 1000 ppm Pt, 3 wt % Ga, and 0.25 wt % K supported on alumina. We observed a synergy between Ga and Pt, resulting in a highly active and stable catalyst. Additionally, we propose a bifunctional active phase, in which coordinately unsaturated Ga3+ species are the active species and where Pt functions as a promoter.
Fluorogenic Probes with Substitutions at the 2 and 7 Positions of Cephalosporin are Highly BlaC‐Specific for Rapid Mycobacterium tuberculosis Detection
Authors: Cheng Yunfeng , Xie Hexin , Sule Preeti , Hassounah Hany , Graviss Edward A. , Kong Ying , Cirillo Jeffrey D. , Rao Jianghong 
Published: July 2014

AbstractCurrent methods for the detection of Mycobacterium tuberculosis (Mtb) are either time consuming or require expensive instruments and are thus are not suitable for point‐of‐care diagnosis. The design, synthesis, and evaluation of fluorogenic probes with high specificity for BlaC, a biomarker expressed by Mtb, are described. The fluorogenic probe CDG‐3 is based on cephalosporin with substitutions at the 2 and 7 positions and it demonstrates over 120 000‐fold selectivity for BlaC over TEM‐1 Bla, the most common β‐lactamase. CDG‐3 can detect 10 colony‐forming units of the attenuated Mycobacterium bovis strain BCG in human sputum in the presence of high levels of contaminating β‐lactamases expressed by other clinically prevalent bacterial strains. In a trial with 50 clinical samples, CDG‐3 detected tuberculosis with 90 % sensitivity and 73 % specificity relative to Mtb culture within one hour, thus demonstrating its potential as a low‐cost point‐of‐care test for use in resource‐limited areas.
Copper‐Catalyzed Cyclization/aza‐Claisen Rearrangement Cascade Initiated by Ketenimine Formation: An Efficient Stereocontrolled Synthesis of α‐Allyl Cyclic Amidines
Authors: Xu Hua‐Dong , Jia Zhi‐Hong , Xu Ke , Han Mei , Jiang Sai‐Nan , Cao Jing , Wang Jia‐Cheng , Shen Mei‐Hua 
Published: July 2014

AbstractAn efficient and convenient synthesis of α‐allyl cyclic amidines has been achieved by applying a novel cascade reaction. Copper(I)‐mediated in situ N‐sulfonyl ketenimine formation from the reaction of a terminal alkyne with sulfonyl azide is followed by an intramolecular nucleophilic attack on the central carbon atom by an allylic tertiary amine, and then an aza‐Claisen rearrangement takes place through a chair transition state to furnish the titled amidines with complete stereocontrol.
Access to β‐Lactams by Enantioselective Palladium(0)‐Catalyzed C(sp3)H Alkylation
Authors: Pedroni Julia , Boghi Michele , Saget Tanguy , Cramer Nicolai 
Published: July 2014

Abstractβ‐Lactams are very important structural motifs because of their broad biological activities as well as their propensity to engage in ring‐opening reactions. Transition‐metal‐catalyzed CH functionalizations have emerged as strategy enabling yet uncommon highly efficient disconnections. In contrast to the significant progress of Pd0‐catalyzed CH functionalization for aryl–aryl couplings, related reactions involving the formation of saturated C(sp3)C(sp3) bonds are elusive. Reported here is an asymmetric CH functionalization approach to β‐lactams using readily accessible chloroacetamide substrates. Important aspects of this transformation are challenging C(sp3)C(sp3) and strain‐building reductive eliminations to for the four‐membered ring. In general, the β‐lactams are formed in excellent yields and enantioselectivities using a bulky taddol phosphoramidite ligand in combination with adamantyl carboxylic acid as cocatalyst.
The Evolving Role of Chemical Synthesis in Antibacterial Drug Discovery
Authors: Wright Peter M. , Seiple Ian B. , Myers Andrew G. 
Published: July 2014

AbstractThe discovery and implementation of antibiotics in the early twentieth century transformed human health and wellbeing. Chemical synthesis enabled the development of the first antibacterial substances, organoarsenicals and sulfa drugs, but these were soon outshone by a host of more powerful and vastly more complex antibiotics from nature: penicillin, streptomycin, tetracycline, and erythromycin, among others. These primary defences are now significantly less effective as an unavoidable consequence of rapid evolution of resistance within pathogenic bacteria, made worse by widespread misuse of antibiotics. For decades medicinal chemists replenished the arsenal of antibiotics by semisynthetic and to a lesser degree fully synthetic routes, but economic factors have led to a subsidence of this effort, which places society on the precipice of a disaster. We believe that the strategic application of modern chemical synthesis to antibacterial drug discovery must play a critical role if a crisis of global proportions is to be averted.
Coupling of Titanacyclopentadienes with a Cp Ligand and Elimination of One Substituent
Authors: Mizukami Yuki , Li Haijun , Nakajima Kiyohiko , Song Zhiyi , Takahashi Tamotsu 
Published: July 2014

AbstractTitanacyclopentadienes, prepared from [Cp2TiBu2] and either two equivalents of an alkyne or a diyne, were treated with PMe3 (3 equiv) at 50 °C for 3 h and then with azobenzene at room temperature for 12 h to give 4,5,6‐trisubstituted indene derivatives with the loss of one substituent in good yields. This reaction contrasts sharply with our previously reported reaction for the formation of 4,5,6,7‐tetrasubstituted indene derivatives without the loss of substituents by the treatment of titanacyclopentadienes with azobenzene without PMe3. 13C NMR spectroscopy of the product derived from a 13C‐enriched complex revealed that the five carbon atoms originating from a Cp ligand were arranged linearly in the trisubstituted indene derivatives, in contrast to the 4,5,6,7‐tetrasubsituted indene derivatives, in which the corresponding five carbon atoms are arranged in a ring.
Development of a 18F‐Labeled Tetrazine with Favorable Pharmacokinetics for Bioorthogonal PET Imaging
Authors: Denk Christoph , Svatunek Dennis , Filip Thomas , Wanek Thomas , Lumpi Daniel , Fröhlich Johannes , Kuntner Claudia , Mikula Hannes 
Published: July 2014

AbstractA low‐molecular‐weight 18F‐labeled tetrazine derivative was developed as a highly versatile tool for bioorthogonal PET imaging. Prosthetic groups and undesired carrying of 18F through additional steps were evaded by direct 18F‐fluorination of an appropriate tetrazine precursor. Reaction kinetics of the cycloaddition with trans‐cyclooctenes were investigated by applying quantum chemical calculations and stopped‐flow measurements in human plasma; the results indicated that the labeled tetrazine is suitable as a bioorthogonal probe for the imaging of dienophile‐tagged (bio)molecules. In vitro and in vivo investigations revealed high stability and PET/MRI in mice showed fast homogeneous biodistribution of the 18F‐labeled tetrazine that also passes the blood–brain barrier. An in vivo click experiment confirmed the bioorthogonal behavior of this novel tetrazine probe. Due to favorable chemical and pharmacokinetic properties this bioorthogonal agent should find application in bioimaging and biomedical research.
BiZn Bond Formation in Liquid Ammonia Solution: [BiZnBi]4−, a Linear Polyanion that is Iso(valence)‐electronic to CO2
Authors: Benda Christian B. , Köchner Tobias , Schäper Raphaela , Schulz Stephan , Fässler Thomas F. 
Published: July 2014

AbstractReactions of the zinc(I) complex [Zn2(Mesnacnac)2] (Mesnacnac=[(2,4,6‐Me3C6H2)NC(Me)]2CH) with solid K3Bi2 dissolved in liquid ammonia yield crystals of the compound K4[ZnBi2]⋅(NH3)12 (1), which contains the molecular, linear heteroatomic [BiZnBi]4− polyanion (1 a). This anion represents the first example of a three‐atomic molecular ion of metal atoms being iso(valence)‐electronic to CO2 and being synthesized in solution. The analogy of the discrete [BiZnBi]4− anion and the polymeric ${{{\hfill 1\atop \hfill \infty }}}$[(ZnBi4/2)4−] unit to monomeric CO2 and polymeric SiS2 is rationalized.
Synthesis of Two‐Dimensional Transition‐Metal Phosphates with Highly Ordered Mesoporous Structures for Lithium‐Ion Battery Applications
Authors: Yang Dan , Lu Ziyang , Rui Xianhong , Huang Xiao , Li Hai , Zhu Jixin , Zhang Wenyu , Lam Yeng Ming , Hng Huey Hoon , Zhang Hua , Yan Qingyu 
Published: July 2014

AbstractMaterials with ordered mesoporous structures have shown great potential in a wide range of applications. In particular, the combination of mesoporosity, low dimensionality, and well‐defined morphology in nanostructures may exhibit even more attractive features. However, the synthesis of such structures is still challenging in polar solvents. Herein, we report the preparation of ultrathin two‐dimensional (2D) nanoflakes of transition‐metal phosphates, including FePO4, Mn3(PO4)2, and Co3(PO4)2, with highly ordered mesoporous structures in a nonpolar solvent. The as‐obtained nanoflakes with thicknesses of about 3.7 nm are constructed from a single layer of parallel‐packed pore channels. These uniquely ordered mesoporous 2D nanostructures may originate from the 2D assembly of cylindrical micelles formed by the amphiphilic precursors in the nonpolar solvent. The 2D mesoporous FePO4 nanoflakes were used as the cathode for a lithium‐ion battery, which exhibits excellent stability and high rate capabilities.
Synthesis, Structure, and Reactivity of a Gold Carbenoid Complex That Lacks Heteroatom Stabilization
Authors: Harris Robert J. , Widenhoefer Ross A. 
Published: July 2014

AbstractHydride abstraction from the neutral gold cycloheptatrienyl complex [(P)Au(η1‐C7H7)] (P=P(tBu)2(o‐biphenyl)) with triphenylcarbenium tetrafluoroborate at −80 °C led to the isolation of the cationic gold cycloheptatrienylidene complex [(P)Au(η1‐C7H6)]+ BF4− in 52 % yield, which was characterized in solution and by single‐crystal X‐ray diffraction. This cycloheptatrienylidene complex represents the first example of a gold carbenoid complex that lacks conjugated heteroatom stabilization of the electron‐deficient C1 carbon atom. The cycloheptatrienylidene ligand of this complex is reactive; it can be reduced by mild hydride donors, and converted to tropone in the presence of pyridine N‐oxide.
Aerogels with 3D Ordered Nanofiber Skeletons of Liquid‐Crystalline Nanocellulose Derivatives as Tough and Transparent Insulators
Authors: Kobayashi Yuri , Saito Tsuguyuki , Isogai Akira 
Published: July 2014

AbstractAerogels of high porosity and with a large internal surface area exhibit outstanding performances as thermal, acoustic, or electrical insulators. However, most aerogels are mechanically brittle and optically opaque, and the structural and physical properties of aerogels strongly depend on their densities. The unfavorable characteristics of aerogels are intrinsic to their skeletal structures consisting of randomly interconnected spherical nanoparticles. A structurally new type of aerogel with a three‐dimensionally ordered nanofiber skeleton of liquid‐crystalline nanocellulose (LC‐NCell) is now reported. This LC‐NCell material is composed of mechanically strong, surface‐carboxylated cellulose nanofibers dispersed in a nematic LC order. The LC‐NCell aerogels are transparent and combine mechanical toughness and good insulation properties. These properties of the LC‐NCell aerogels could also be readily controlled.
Nitrite‐Templated Synthesis of Lanthanide‐Containing [2]Rotaxanes for Anion Sensing
Authors: Langton Matthew J. , Blackburn Octavia A. , Lang Thomas , Faulkner Stephen , Beer Paul D. 
Published: July 2014

AbstractThe first anion‐templated synthesis of a lanthanide‐containing interlocked molecule is demonstrated by utilizing a nitrite anion to template initial pseudorotaxane formation. Subsequent stoppering of the interpenetrated assembly allows for the preparation of a lanthanide‐functionalized [2]rotaxane in high yield. Following removal of the nitrite anion template, the europium [2]rotaxane host is demonstrated to recognize and sense fluoride selectively.