bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethers on Si(001): A Prime Example for the Common Ground between Surface Science and Molecular Organic Chemistry
Authors: Pecher Lisa , Laref Slimane , Raupach Marc , Tonner Ralf 
Published: September 2017

AbstractBy using computational chemistry it has been shown that the adsorption of ether molecules on Si(001) under ultrahigh vacuum conditions can be understood with classical concepts of organic chemistry. Detailed analysis of the two‐step reaction mechanism—1) formation of a dative bond between the ether oxygen atom and a Lewis acidic surface atom and 2) nucleophilic attack of a nearby Lewis basic surface atom—shows that it mirrors acid‐catalyzed ether cleavage in solution. The O−Si dative bond is the strongest of its kind, and the reactivity in step 2 defies the Bell–Evans–Polanyi principle. Electron rearrangement during C−O bond cleavage has been visualized with a newly developed method for analyzing bonding, which shows that the mechanism of nucleophilic substitutions on semiconductor surfaces is identical to molecular SN2 reactions. Our findings illustrate how surface science and molecular chemistry can mutually benefit from each other and unexpected insight can be gained.
Dynamic Molecular Invasion into a Multiply Interlocked Catenane
Authors: Yamada Yasuyuki , Itoh Ryohei , Ogino Sayaka , Kato Tatsuhisa , Tanaka Kentaro 
Published: September 2017

AbstractA multiply interlocked catenane with a novel molecular topology was synthesized; a phthalocyanine bearing four peripheral crown ethers was quadruply interlocked with a cofacial porphyrin dimer bridged with four alkylammonium chains. The supramolecular conjugate has two nanospaces surrounded by a porphyrin, a phthalocyanine, and four alkyl chains to accommodate guest molecules. Because the phthalocyanine can move along the alkyl chains, it acts as an adjustable wall, thus permitting the invasion of large molecules into the nanospaces without spoiling the affinity of the association. The dynamic molecular invasion allowed the intercalation of dianionic porphyrins into both nanospaces with high affinity. A photometric titration experiment revealed the two‐step inclusion phenomenon. The multiply interlocked catenane complexed with three Cu2+ ions, and the spin–spin interaction was switched off by the intercalation of dianionic porphyrins.
An expedient ‘click’ approach for the synthetic evaluation of ester‐triazole‐tethered organosilica conjugates
Authors: Singh Gurjaspreet , Rani Sunita 
Published: September 2017

The present work articulates the synthesis of a new series of organo‐functionalized triethoxysilanes derived from versatile carboxylic acids and 3‐azidopropyltriethoxysilane in excellent yields. A proficient and convenient route implicating the Cu(I)‐catalysed 1,3‐cycloaddition of organic azide with terminal alkynes, labelled as click silylation, has been developed for the generation of ester‐triazole‐linked alkoxysilanyl scaffolds (4a–f). All the synthesized compounds have been thoroughly characterized using elemental analysis and Fourier transform infrared, 1H NMR and 13C NMR spectroscopic techniques. Importantly, the fabricated alkoxysilanes are potentially amenable for an in situ sol–gel condensation reaction with silica nanospheres leading to the incorporation of organic functionality via covalent grafting onto the nanostructured particle system. As a proof of concept, a one‐pot preparation of organic–inorganic hybrid nanoparticles is presented using bis‐silane 4 f. The efficiency and selectivity of the prepared nanocomposite towards metal ions is highlighted using adsorption experiments, and the immobilized nanoparticles present a high sensing efficiency towards Cu2+ and Pb2+ ions while demonstrating better response than that of the bulk material.
Influence of adsorbed and nonadsorbed polymer additives on the viscosity of magnesium oxide suspensions
Authors: Murray Lisa R. , Bice Jason E. , Soltys Emily G. , Perge Christophe , Manneville Sébastien , Erk Kendra A. 
Published: September 2017

ABSTRACTAdsorbed polymer additives have been employed to reduce water content and improve cement workability through lowering viscosity, but the influence of over‐dosage and the presence of nonadsorbed chains have yet to be fully understood. Model magnesium oxide (MgO) suspensions were used to investigate the potential processing effect of “free” chain concentration on cementitious mixtures. The rheological impact of the free chains was measured through incorporation of nonadsorbing poly(ethylene glycol) (PEG) to suspensions stabilized with an adsorbed comb‐polymer superplasticizer. Analyses of the rheological data, that showed viscosity‐increases and viscosity‐reduction due to free PEG concentrations revealed a transition from depletion flocculation to depletion stabilization that contributed to the flow properties of the suspensions. The viscosity‐reduction observed for high concentrations of free chains may be useful for improved mixing of cements with free polymer in addition to the adsorbed polycarboxylate ether‐based superplasticizer. Additionally, the influence of free PEG on the macroscale flow behavior was also examined through local velocity measurements under shear. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 45696.
Sum‐of‐Squares‐Based Finite‐Time Adaptive Sliding Mode Control of Uncertain Polynomial Systems With Input Nonlinearities
Authors: Mardani Mohammad Mehdi , Vafamand Navid , Shokrian Zeini Mostafa , Shasadeghi Mokhtar , Khayatian Alireza 
Published: September 2017

AbstractThis paper proposes a novel adaptive sliding mode control (ASMC) for a class of polynomial systems comprising uncertain terms and input nonlinearities. In this approach, a new polynomial sliding surface is proposed and designed based on the sum‐of‐squares (SOS) decomposition. In the proposed method, an adaptive control law is derived such that the finite‐time reachability of the state trajectories in the presence of input nonlinearity and uncertainties is guaranteed. To do this, it is assumed that the uncertain terms are bounded and the input nonlinearities belong to sectors with positive slope parameters. However, the bound of the uncertain terms is unknown and adaptation law is proposed to effectively estimate the uncertainty bounds. Furthermore, based on a novel polynomial Lyapunov function, the finite‐time convergence of the sliding surface to a pre‐chosen small neighborhood of the origin is guaranteed. To eliminate the time derivatives of the polynomial terms in the stability analysis conditions, the SOS variables of the Lyapunov matrix are optimally selected. In order to show the merits and the robust performance of the proposed controller, chaotic Chen system is provided. Numerical simulation results demonstrate chattering reduction in the proposed approach and the high accuracy in estimating the unknown parameters.
Distributed Consensus‐Based Optimization of Multiple Load Aggregators for Secondary Frequency Control
Authors: Tang Qian , Zhou Hong , Liu Zhi‐Wei , Deng Qi‐Jun 
Published: September 2017

AbstractResponsive loads can act as spinning reserve which is incorporated with the conventional AGC units for the improvement of frequency reliability. In this paper, a distributed consensus‐based optimal strategy of responsive load aggregators and AGC units is presented to provide secondary frequency control in the power system. Specifically, two‐step optimal model is proposed. In the first step, Lambda‐Iteration method is used to yield the total active power command for load group and AGC group. In the second step, the distributed optimal algorithm with θ‐logarithmic barrier cost function is proposed to allocate the active power command to multiple load aggregators and AGC units while guaranteeing consensus among individual incremental costs. In achievement of such a consensus, two virtual pinners are utilized to generate the regulation signal only shared with a part of load aggregators and AGC units, respectively. Moreover, the communication topology among load aggregators is a strongly connected digraph, the same as to the AGC units. Finally, simulation results show that the system frequency can be greatly improved, while the total cost of the whole system can be minimized with both equality and inequality constraints.
Robust Control of Discrete‐time Singular Systems via Integral Sliding Surface
Authors: Bai Jianjun , Lu Renquan , Wu Zhengguang , Zhang Ridong , Zhao Xiaodong , Xue Anke 
Published: September 2017

AbstractIn this paper, the sliding mode control for a class of uncertain discrete‐time singular system with
performance constraint is studied. By taking the singular matrix E into consideration, a new type of integral sliding mode surface is firstly introduced, based on which a sufficient condition is derived to guarantee the sliding mode dynamics admissible with a given γ‐level disturbance attenuation of the unmatched disturbance. A controller law is also given to keep the system trajectory staying in a neighborhood of the ideal sliding surface. Finally, a numerical example is given to show the effectiveness of the proposed approach.
Vorgespannte Holztürme für Windkraftanlagen
Authors: Gräfe Martin , Bert Christopher , Winter Stefan 
Published: September 2017

AbstractIm Rahmen eines Forschungsvorhabens an der TU München wurde eine optimierte Bauweise für Windkrafttürme aus Brettsperrholz entwickelt. Der Turmschaft besteht dabei aus Brettsperrholzplatten in straßentransportfähigen Abmessungen, welche in einer Taktstation am Boden zu vieleckigen Turmabschnitten zusammengefügt und anschließend als vorgefertigte ringförmige Elemente vertikal zu einem Turm verbunden werden. Die horizontalen Verbindungen werden über formschlüssige Kontaktstöße realisiert. Biegezugspannungen in Turmlängsrichtung, vor allem infolge von Windeinwirkungen, werden durch dauerhaft wirksame vertikale Vorspannkräfte überdrückt.Anhand eines Beispielturms mit 100 m Nabenhöhe wurden alle Bauzustände, die Tragfähigkeit und das Langzeitverhalten rechnerisch untersucht. Die Spannkraftverluste sind beherrschbar und liegen nicht wesentlich höher als bei vergleichbaren vertikal vorgespannten Türmen in Spannbetonbauweise.
Relationship altered between functional T1ρ and BOLD signals in bipolar disorder
Authors: Shaffer Joseph J. , Johnson Casey P. , Long Jeffrey D. , Fiedorowicz Jess G. , Christensen Gary E. , Wemmie John A. , Magnotta Vincent A. 
Published: September 2017

AbstractIntroductionFunctional neuroimaging typically relies on the blood‐oxygen‐level–dependent (BOLD) contrast, which is sensitive to the influx of oxygenated blood following neuronal activity. A new method, functional T1 relaxation in the rotating frame (fT1ρ) is thought to reflect changes in local brain metabolism, likely pH, and may more directly measure neuronal activity. These two methods were applied to study activation of the visual cortex in participants with bipolar disorder as compared to controls.MethodsThirty‐nine participants with bipolar disorder and 32 healthy controls underwent functional neuroimaging during a flashing checkerboard paradigm. Functional images were acquired in alternating blocks of BOLD and fT1ρ. Linear mixed‐effect models were used to examine the relationship between these two functional imaging modalities and to test whether that relationship was altered in bipolar disorder.ResultsBOLD and fT1ρ signal were strongly related in visual and cerebellar areas during the task in controls. The relationship between these two measures was reduced in bipolar disorder within the visual areas, cerebellum, striatum, and thalamus.ConclusionsThese results support a distinct mechanisms underlying BOLD and fT1ρ signals. The weakened relationship between these imaging modalities may provide a novel tool for measuring pathology in bipolar disorder and other psychiatric illnesses.
Quantitative muscle ultrasound is useful for evaluating secondary axonal degeneration in chronic inflammatory demyelinating polyneuropathy
Authors: Hokkoku Keiichi , Matsukura Kiyoshi , Uchida Yudai , Kuwabara Midori , Furukawa Yuichi , Tsukamoto Hiroshi , Hatanaka Yuki , Sonoo Masahiro 
Published: September 2017

AbstractIntroductionIn chronic inflammatory demyelinating polyneuropathy (CIDP), exclusion of secondary axonal degeneration is challenging with conventional methods such as nerve conduction study (NCS), needle electromyography, and nerve biopsy. Increased echo intensity (EI) and decreased muscle thickness (MT) identified on muscle ultrasound (MUS) examination represent muscle denervation due to axonal degeneration in neurogenic disorders, suggesting MUS as a new tool to detect secondary axonal degeneration in patients with CIDP.MethodsEI and MT of abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscles were measured in 16 CIDP patients. Raw values were converted into z‐scores using data from 60 normal controls (NCs).ResultsSix of 45 muscles showed abnormally high EI and low MT, suggesting denervation following secondary axonal degeneration. These six muscles belonged to two patients with long disease history, unresponsiveness to treatment, and long interval from onset to initial therapy. There were no significant differences in EI and MT (p = .23 and .67, respectively) between the CIDP and NC groups, although NCS results revealed obvious demyelinating abnormalities in all CIDP patients, suggesting the fact that muscle structures will be preserved, and EI and MT will not change unless secondary axonal degeneration occurs in CIDP.ConclusionMUS is a promising tool for evaluating secondary axonal degeneration in patients with CIDP.
Validation of the American Joint Commission on Cancer (8th edition) changes for patients with stage III gastric cancer: survival analysis of a large series from a Specialized Eastern Center
Authors: Lu Jun , Zheng Chao‐Hui , Cao Long‐Long , Ling Shao‐Wei , Li Ping , Xie Jian‐Wei , Wang Jia‐Bin , Lin Jian‐Xian , Chen Qi‐Yue , Lin Mi , Tu Ru‐Hong , Huang Chang‐Ming 
Published: September 2017

AbstractThe 8th edition of the TNM was released in 2016 and included major revisions, especially for stage III. We aimed to compare the prognostic value of the 7th and 8th editions of the AJCC TNM classification for stage III gastric cancer. Clinical data from 1557 patients operated on for stage III gastric cancer according to the 7th edition between 2007 and 2014 were analyzed and compared using the 7th and 8th TNM classifications. A proposed staging system was established, and the three systems were compared in terms of prognostic performance. The stage shifted for 669 (42.96%) patients. It shifted from IIIA to IIIB (one patient, 0.06%), IIIB to IIIA (230 patients, 14.8%), IIIB to IIIC (94 patients, 6.0%), and IIIC to IIIB (344 patients, 22.1%). However, the new AJCC subgroupings did not prove distinctive for survival levels between T3N3aM0 (stage IIIB) and T3N3bM0 (stage IIIC) or between T4aN3aM0 (stage IIIB) and T4aN3bM0 (stage IIIC) when <30 lymph nodes (LNs) were resected. The performance of the 8th edition (c‐index, 0.614; 95% confidence interval [CI], 0.596–0.633) revealed no relevant improvement compared to the 7th edition (c‐index, 0.624; 95% CI, 0.605–0.643). The proposed staging system generated the best prognostic stratification. The 8th TNM edition may not provide better accuracy in predicting the prognosis of stage III gastric cancer. The proposed staging system, comprised of a combination of the number of LNs harvested and the 7th and 8th AJCC classifications, may improve predictive capacities for stage III gastric cancer.
A Systematic Structure–Activity Study of a New Type of Small Peptidic Transfection Vector Reveals the Importance of a Special Oxo‐Anion‐Binding Motif for Gene Delivery
Authors: Junghänel Sandra , Karczewski Sarah , Bäcker Sandra , Knauer Shirley K. , Schmuck Carsten 
Published: September 2017

AbstractWe discovered a new class of artificial peptidic transfection vectors based on an artificial anion‐binding motif, the guanidiniocarbonylpyrrole (GCP) cation. This new type of vector is surprisingly smaller than traditional systems, and our previous work suggested that the GCP group was important for promoting critical endosomal escape. We now present here a systematic comparison of similar DNA ligands featuring our GCP oxo‐anion‐binding motif with DNA ligands only consisting of naturally occurring amino acids. Structure–activity studies showed that the artificial binding motif clearly outperformed natural amino acids such as histidine, lysine, and arginine. It improved the ability to shuttle foreign genetic material into cells, yet successfully mediated endosomal escape. Also, plasmids that were complexed by our artificial ligands were stabilized against cytosolic degradation to some extent. This resulted in the successful expression of plasmid information (comparable to gold standards such as polyethyleneimine). Hence, our study clearly demonstrates the importance of the tailor‐made GCP anion‐binding site for efficient gene transfection.
Mechanistic Insights into Cyclic Peptide Generation by DnaE Split‐Inteins through Quantitative and Structural Investigation
Authors: Kick Leonhard M. , Harteis Sabrina , Koch Maximilian F. , Schneider Sabine 
Published: September 2017

AbstractInteins carry out protein‐splicing reactions, which are used in protein chemistry, protein engineering and biotechnological applications. Rearrangement of the order of the domains in split‐inteins results in head‐to‐tail cyclisation of the target sequence, which can be used for genetic encoding and expression of libraries of cyclic peptides (CPs). The efficiency of the splicing reaction depends on the target sequence. Here we used mass spectrometry to assess in vivo cyclic peptide formation from different hexameric target sequences by the DnaE split‐inteins from Synechocystis sp. and Nostoc punctiforme, revealing a strong impact of the target sequence and of the intein on the intracellular peptide concentration. Furthermore, we determined the crystal structures of their pre‐splicing complexes, which allowed us to identify F‐block Asp17 as crucial for the DnaE‐mediated splicing reaction.
The toxic alpha‐gliadin peptide 31–43 enters cells without a surface membrane receptor
Authors: Paolella Gaetana , Lepretti Marilena , Martucciello Stefania , Nanayakkara Merlin , Auricchio Salvatore , Esposito Carla , Barone Maria Vittoria , Caputo Ivana 
Published: September 2017

AbstractAlpha‐gliadin peptide 31–43 is considered to be the main peptide responsible for the innate immune response in celiac disease patients. Recent evidence indicates that peptide 31–43 rapidly enters cells and interacts with the early endocytic vesicular compartment. However, the mechanism of its uptake is not completely understood. Our aim is to characterize, isolate and identify possible cell surface proteins involved in peptide 31–43 internalization by Caco‐2 cells. In this study, we used a chemical cross‐linker to block peptide 31–43 on cell surface proteins, and pulled‐down peptide‐proteins complexes using antibodies raised against peptide 31–43. Through this experimental approach, we did not observe any specific complex between cell proteins and peptide 31–43 in Coomassie‐stained denaturating gels or by Western blotting. We also found that type 2 transglutaminase was not necessary for peptide 31–43 internalization, even though it had a regulatory role in the process. Finally, we demonstrated that peptide 31–43 did not behave as a classical ligand, indeed the labeled peptide did not displace the unlabeled peptide in a competitive binding assay. On the basis of these findings and of previous evidence demonstrating that peptide 31–43 is able to interact with a membrane‐like environment in vitro, we conclude that membrane composition and organization, rather than a specific receptor protein, may have a major role in peptide 31–43 internalization by cells.
Dextrocardia with asymptomatic right atrial appendage aneurysm: a case report
Authors: Sate Hossein , Reshadati Najmeh , Aliakbarzadeh Parvaneh , Molazadeh Negin 
Published: September 2017

Key Clinical MessageRight atrial appendage aneurysm (RAAA) is rarely encountered with variable intracardiac anatomy. We report a case of asymptomatic RAAA in a patient with dextrocardia and anomalous origin of RCA from left coronary sinus which was treated successfully by CABG and the aneurysm was completely excised.
Leptospirosis presenting as acute acalculous cholecystitis
Authors: Davies Peter , Aoyagi Yuki 
Published: September 2017

Key Clinical MessageLeptospirosis is the commonest zoonotic infection worldwide but is vastly underreported and extremely heterogeneous in its presentation. Acalculous cholecystitis is an under recognized presentation of acute leptospirosis. In the appropriate clinical context, with a clear exposure history, recognition of this association presents a unifying diagnosis and limits unnecessary surgical interventions.
c.464A>G variation in the GJB2 gene is detected in a Han Chinese family
Authors: Zhu Gang‐Hua , Shu Hong‐Ying , Zhou Hai‐Yan , Chen Yong , Zhou Fei , Ni Bin , Xie Wanqin 
Published: September 2017

Key Clinical MessageWe report two heterozygous carriers of c.464A>G variation in the GJB2 gene in a Chinese pedigree. The proband with hearing loss most likely inherited the c.464A>G variation from his mother who also carries heterozygous c.79G>A variation and has normal hearing. The pathological significance of c.464A>G variation remains to be determined.
Efficient Control of Microbubble Properties by Alcohol Shear Flows in Ceramic Membrane Channels
Authors: Liu Yefei , Han Yang , Li Xiaoli , Jiang Hong , Chen Rizhi 
Published: September 2017

AbstractEfficient control of microbubbles is achieved by alcohol shear flows in ceramic membrane channels. The dependence of hydrodynamic and mass transfer properties of microbubbles on liquid viscosity was investigated in a bubble column. The multichannel ceramic membrane worked as the gas sparger, and the shear flow on the membrane surface controlled the microbubble generation. Oxygen gas and glycerin solutions with different viscosities served as gas phase and liquid phase, respectively. The microbubbles were massively generated at different liquid viscosities. With increasing viscosity, the bubble size first decreased and then increased. The dual effect of viscosity on bubble size was related to bubble coalescence. However, an impact of viscosity on gas holdup was not observed for microbubbles.
Syntheses and Properties of Tin‐Containing Conjugated Heterocycles
Authors: Urrego‐Riveros Sara , Ramirez y Medina Isabel‐Maria , Hoffmann Jonas , Heitmann Anne , Staubitz Anne 
Published: September 2017

AbstractHeterocycles that contain tin atoms can be aromatic in a similar sense to well‐known aromatic compounds such as benzene or thiophene, but such examples are rare. However, due to the low‐lying σ*‐orbitals of the tin‐substituent bond in stannoles, they are capable of σ*–π* conjugation in a way that is exclusive to heavier element containing heterocycles. This makes stannoles very interesting alternatives for purely organic heterocycles in material applications, in which optoelectronic properties are of interest. This Concept article will highlight the synthesis, reactivity and physical properties of stannoles and related fluorenostannoles. At first, a brief introduction to different types of tin‐containing heterocycles is presented, followed by a discussion on different approaches to prepare stannoles, their reactivity and their physical properties. In addition, the first stannole‐containing polymer will be reviewed.