bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental assessment of diazotroph responses to elevated seawater pCO2 in the North Pacific Subtropical Gyre
Authors: Böttjer Daniela , Karl David M. , Letelier Ricardo M. , Viviani Donn A. , Church Matthew J. 
Published: May 2014

AbstractWe examined short‐term (24–72 h) responses of naturally occurring marine N2 fixing microorganisms (termed diazotrophs) to abrupt increases in the partial pressure of carbon dioxide (pCO2) in seawater during nine incubation experiments conducted between May 2010 and September 2012 at Station ALOHA (A Long‐term Oligotrophic Habitat Assessment) (22°45′N, 158°W) in the North Pacific Subtropical Gyre (NPSG). Rates of N2 fixation, nitrogenase (nifH) gene abundances and transcripts of six major groups of cyanobacterial diazotrophs (including both unicellular and filamentous phylotypes), and rates of primary productivity (as measured by 14C‐bicarbonate assimilation into plankton biomass) were determined under contemporary (~390 ppm) and elevated pCO2 conditions (~1100 ppm). Quantitative polymerase chain reaction (QPCR) amplification of planktonic nifH genes revealed that unicellular cyanobacteria phylotypes dominated gene abundances during these experiments. In the majority of experiments (seven out of nine), elevated pCO2 did not significantly influence rates of dinitrogen (N2) fixation or primary productivity (two‐way analysis of variance (ANOVA), P > 0.05). During two experiments, rates of N2 fixation and primary productivity were significantly lower (by 79 to 82% and 52 to 72%, respectively) in the elevated pCO2 treatments relative to the ambient controls (two‐way ANOVA, P < 0.05). QPCR amplification of nifH genes and gene transcripts revealed that diazotroph abundances and nifH gene expression were largely unchanged by the perturbation of the seawater pCO2. Our results suggest that naturally occurring N2 fixing plankton assemblages in the NPSG are relatively resilient to large, short‐term increases in pCO2.
Kovalente Oberflächenmodifikationen von Oxiden
Authors: Pujari Sidharam P. , Scheres Luc , Marcelis Antonius T. M. , Zuilhof Han 
Published: May 2014

AbstractDie Modifizierung von Oberflächen durch robuste Abscheidung einer Deckschicht bietet eine hervorragende Möglichkeit, die Eigenschaften eines sterisch anspruchsvollen Substrats auf die eigenen Interessen abzustimmen. Eine solche Kontrolle über die Oberflächeneigenschaften gewinnt immer mehr an Bedeutung mit der stetigen Verkleinerung aktiver Bestandteile in allen möglichen optoelektronischen Geräten ebenso wie mit dem entsprechend größeren Oberfläche/Volumen‐Verhältnis. Eine relevante einzustellende Eigenschaft ist z. B. das Ausmaß, in dem eine Oberfläche durch Wasser oder Öl benetzt wird. Zudem besteht für Anwendungen in der Biosensorik ein wachsendes Interesse an “romantischen Oberflächen” – Oberflächen, die alle möglichen biologischen Entitäten abweisen, mit einer Ausnahme, die von ihnen stark gebunden wird. Solche Systeme erfordern eine nachhaltige wie auch hochspezifische Einstellung der Oberflächeneigenschaften. Dieser Aufsatz erläutert eine Vorgehensweise für die Herstellung widerstandsfähiger Oberflächenmodifikationen an Oxiden, nämlich die kovalente Anbindung von Monoschichten.
Nickel(0)‐ und Platin(0)‐Bis‐NHC‐Chelatkomplexe
Authors: Brendel Matthias , Braun Carolin , Rominger Frank , Hofmann Peter 
Published: May 2014

Abstractd10‐ML2‐Fragmente sind seit langem für ihr Potenzial bekannt, unreaktive Bindungen durch oxidative Addition zu aktivieren. Bei der Entwicklung aktiverer Spezies haben sich zwei Ansätze bewährt: Der Einsatz von starken σ‐Donorliganden, die zu elektronenreichen Metallzentren führen, sowie von Chelatliganden, die eine gewinkelte Koordinationsgeometrie erzeugen. Wir haben beide Strategien kombiniert und Nickel(0)‐ sowie erstmals Platin(0)‐Bis‐NHC‐Chelatkomplexe synthetisiert. Bis(1,5‐Cyclooctadien)nickel(0) und ‐platin(0) reagieren mit in situ deprotonierten Bisimidazoliumsalzen bei Raumtemperatur zu tetraedrischen oder trigonal‐planaren Bis‐NHC‐Chelat‐Olefinkomplexen. Die Synthese und Charakterisierung dieser Komplexe sowie ein erstes Beispiel einer C‐C‐Bindungsaktivierung mit diesen Systemen werden beschrieben. Wegen der erzwungenen cis‐Anordnung zweier NHCs eröffnen diese Verbindungen interessante Perspektiven für Bindungsaktivierungen und Katalyse.
Single‐Cell Chemical Proteomics with an Activity‐Based Probe: Identification of Low‐Copy Membrane Proteins on Primary Neurons
Authors: Xu Fei , Zhao Han , Feng Xiaojun , Chen Linhai , Chen Dongjuan , Zhang Yang , Nan Fajun , Liu Jianfeng , Liu Bi‐Feng 
Published: May 2014

AbstractWe propose a novel single‐cell chemical proteomics (SCCP) strategy to profile low‐abundance membrane proteins in single cells. In this approach, the membrane protein GB1 and its splicing variants were targeted on cultured cell lines and primary neurons using a specifically designed activity‐based probe. The functionally labeled single cells were encapsulated in individual buffer droplets on a PDMS microwell array, and were further picked up one at a time and loaded into a capillary electrophoresis system for cell lysis, separation, and laser‐induced fluorescence detection of the targeted proteins. The results revealed the expression of GB1 splicing variants in HEK and MEF cells, which was previously only suggested at the transcriptional level. We further applied this method to investigate single primary cells and observed significant heterogeneity among individual mouse cerebellar granule neurons. Interference experiments with GB1 antagonist and agonist validated this observation.
Oxidationsbeobachtung mit Fluoreszenzspektroskopie offenbart das Alter von Fingerabdrücken
Authors: van Dam Annemieke , Schwarz Janina C. V. , de Vos Judith , Siebes Maria , Sijen Titia , van Leeuwen Ton G. , Aalders Maurice C. G. , Lambrechts Saskia A. G. 
Published: May 2014

AbstractEs gibt keine forensische Methode, die das Alter von Fingerspuren am Tatort zuverlässig ermitteln kann. Informationen über die Zeit, die seit dem Entstehen des Fingerabdrucks vergangen ist, sind wünschenswert, weil hierdurch zwischen deliktsbezogenen und irrelevanten Fingerabdrücken unterschieden werden kann. Wir stellen eine kontaktlose Methode vor, mit der das Alter von Fingerabdrücken geschätzt werden kann. Fingerabdrücke wurden hierbei als Protein‐Lipid‐Gemisch behandelt, und ein Modell zur Altersschätzung wurde entwickelt, das auf Protein‐Lipid‐Oxidationsreaktionen basiert. Zwei Messgrößen eines Fingerabdrucks sind erforderlich, um dessen Alter zu berechnen: die relative Menge an fluoreszierenden Oxidationsprodukten und die Geschwindigkeit, mit der diese Produkte gebildet werden. Fluoreszenzspektroskopie wurde eingesetzt, um diese Messgrößen zu erhalten. Wir haben die Methode an 44 Fingerabdrücken getestet und konnten das Alter bei 55 % der männlichen Fingerabdrücke bis zu einem Alter von drei Wochen mit einer Unsicherheit von 1.9 Tagen ermitteln.
Palladium‐Catalyzed Oxidative Difunctionalization of Alkenes with α‐Carbonyl Alkyl Bromides Initiated through a Heck‐type Insertion: A Route to Indolin‐2‐ones
Authors: Fan Jian‐Hong , Wei Wen‐Ting , Zhou Ming‐Bo , Song Ren‐Jie , Li Jin‐Heng 
Published: May 2014

AbstractThe oxidative interception of various σ‐alkyl palladium(II) intermediates with additional reagents for the difunctionalization of alkenes is an important research area. A new palladium‐catalyzed oxidative difunctionalization reaction of alkenes with α‐carbonyl alkyl bromides is described, in which the σ‐alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp2)H bond. This method can be applied to various α‐carbonyl alkyl bromides, including primary, secondary, and tertiary α‐bromoalkyl esters, ketones, and amides.
Synthetic Disialyl Hexasaccharides Protect Neonatal Rats from Necrotizing Enterocolitis
Authors: Yu Hai , Lau Kam , Thon Vireak , Autran Chloe A. , Jantscher‐Krenn Evelyn , Xue Mengyang , Li Yanhong , Sugiarto Go , Qu Jingyao , Mu Shengmao , Ding Li , Bode Lars , Chen Xi 
Published: May 2014

AbstractTwo novel synthetic α2–6‐linked disialyl hexasaccharides, disialyllacto‐N‐neotetraose (DSLNnT) and α2–6‐linked disialyllacto‐N‐tetraose (DS′LNT), were readily obtained by highly efficient one‐pot multienzyme (OPME) reactions. The sequential OPME systems described herein allowed the use of an inexpensive disaccharide and simple monosaccharides to synthesize the desired complex oligosaccharides with high efficiency and selectivity. DSLNnT and DS′LNT were shown to protect neonatal rats from necrotizing enterocolitis (NEC) and are good therapeutic candidates for preclinical experiments and clinical application in treating NEC in preterm infants.
Enhancement of Lithium Storage Performance of Carbon Microflowers by Achieving a High Surface Area
Authors: Li Yao , Xiao Ying , Wang Xia , Cao Minhua 
Published: May 2014

AbstractHigh‐surface‐area, nitrogen‐doped carbon microflowers (A‐NCFs‐4) assembled from porous nanosheets are prepared in a three‐step process: soft‐templating self‐assembly, thermal decomposition, and KOH activation. The hydrazine hydrate used in our experiment serves not only as a structure‐directing agent, but also as a nitrogen source. The resultant A‐NCFs‐4 has a hierarchical porous structure and its specific surface area is as high as 2309 m2 g−1. When used as anode, it exhibits a reversible capacity as high as 807 mAh g−1 at 300 mA g−1 after 100 cycles, and an excellent rate capability of 200 mAh g−1 at a high current density of 8 A g−1. Compared with unactivated counterpart, A‐NCFs‐4 exhibits a significantly improved lithium storage capacity and rate capability; this can be attributed to its unique structural characteristics and high surface area. The hierarchical micro‐/mesopore structure, high surface area, and nitrogen doping of A‐NCFs‐4 could guarantee fast mass transport for lithium species, enhance the A‐NCFs‐4/electrolyte contact area, shorten the lithium‐ion diffusion length, and accommodate strain induced by volume changes during the electrochemical reaction. The results indicate that the as‐prepared A‐NCFs‐4 could be a promising candidate as a high‐performance anode for lithium‐ion batteries.
Disilanyl Double‐Pillared Bisternaphthyl (SiDPBT): Synthesis and Interfused Packing Structures with Herringbone and π‐Stack Motifs
Authors: Nakanishi Waka , Matsuyama Naoto , Hara Daisuke , Saeki Akinori , Hitosugi Shunpei , Seki Shu , Isobe Hiroyuki 
Published: May 2014

AbstractA silacyclophane molecule with two disilanyl pillars and two oligoarylene units was synthesized. The molecule was packed in a single crystal with a new motif interfusing π‐stack and herringbone packing structures. The hole transporting ability of the solid was revealed by using the flash‐photolysis time‐resolved microwave conductivity method. The molecular structure, albeit a singly‐bonded arylene macrocycle, was rigidified by the unique packing array, which favorably contributed to the hole transporting ability of the solid via the small reorganization energy through the charge transport.
Active Disturbance Rejection Control Applied To A Delta Parallel Robot In Trajectory Tracking Tasks
Authors: Ramírez‐Neria Mario , Sira‐Ramírez Hebertt , Luviano‐Juárez Alberto , Rodrguez‐Ángeles Alejandro 
Published: May 2014

AbstractIn this article, the problem of robust trajectory tracking, for a parallel robot is tackled via an observer‐based active disturbance rejection controller. The proposed design method is based on purely linear disturbance observation and linear feedback control techniques modulo nonlinear input gain injections and cancellations. The estimations are carried out through Generalized Proportional Integral (GPI) observers, endowed with output integral injection to ease the presence of possible zero mean measurement noise effects. As the lumped (both exogenous and endogenous) disturbance inputs are estimated, they are being used in the linear controllers for on‐line disturbance cancellation, while the phase variables are being estimated by the same GPI observer. The estimations of the phase variables are used to complete a linear multivariable output feedback controller. The proposed control scheme does not need the exact knowledge of the system, which is a good alternative to classic control schemes such as computed torque method, reducing the computation time. The estimation and control method is approximate, ensuring small as desired reconstruction and tracking errors. The reported results, including laboratory experiments, are better than the results provided by the classical model‐based techniques, shown to be better when the system is subject to endogenous and exogenous uncertainties.
Investigation of Binding‐Site Homology between Mushroom and Bacterial Tyrosinases by Using Aurones as Effectors
Authors: Haudecoeur Romain , Gouron Aurélie , Dubois Carole , Jamet Hélène , Lightbody Mark , Hardré Renaud , Milet Anne , Bergantino Elisabetta , Bubacco Luigi , Belle Catherine , Réglier Marius , Boumendjel Ahcène 
Published: May 2014

AbstractTyrosinase is a copper‐containing enzyme found in plants and bacteria, as well as in humans, where it is involved in the biosynthesis of melanin‐type pigments. Tyrosinase inhibitors have attracted remarkable research interest as whitening agents in cosmetology, antibrowning agents in food chemistry, and as therapeutics. In this context, commercially available tyrosinase from mushroom (TyM) is frequently used for the identification of inhibitors. This and bacterial tyrosinase (TyB) have been the subjects of intense biochemical and structural studies, including X‐ray diffraction analysis, and this has led to the identification of structural homology and divergence among enzymes from different sources. To better understand the behavior of potential inhibitors of TyM and TyB, we selected the aurone family—previously identified as potential inhibitors of melanin biosynthesis in human melanocytes. In this study, a series of 24 aurones with different hydroxylation patterns at the A‐ and B‐rings were evaluated on TyM and TyB. The results show that, depending on the hydroxylation pattern of A‐ and B‐rings, aurones can behave as inhibitors, substrates, and activators of both enzymes. Computational analysis was performed to identify residues surrounding the aurones in the active sites of both enzymes and to rationalize the interactions. Our results highlight similarities and divergence in the behavior of TyM and TyB toward the same set of molecules.
Artificial Plasmid Labeled with 5‐Bromo‐2′‐deoxyuridine: A Universal Molecular System for Strand Break Detection
Authors: Zylicz‐Stachula Agnieszka , Polska Katarzyna , Skowron Piotr , Rak Janusz 
Published: May 2014

AbstractDNA strand breaks (SBs) are among the most cytotoxic forms of DNA damage, and their residual levels correlate directly with cell death. Hence, the type and amount of SBs is directly related to the efficacy of a given anticancer therapy. In this study, we describe a molecular tool that can differentiate between single (SSBs) and double (DSBs) strand breaks and also assess them quantitatively. Our method involves PCR amplification of a linear DNA fragment labeled with a sensitizing nucleotide, circularization of that fragment, and enzymatic introduction of supercoils to transform the circular relaxed form of the synthesized plasmid into a supercoiled one. After exposure of the molecule to a damaging factor, SSB and DSB levels can be easily assayed with gel electrophoresis. We applied this method to prepare an artificial plasmid labeled with 5‐bromo‐2′‐deoxyuridine and to assay SBs photoinduced in the synthesized plasmid.
A New Chemical Probe for Phosphatidylinositol Kinase Activity
Authors: Sherratt Allison R. , Nasheri Neda , McKay Craig S. , O'Hara Shifawn , Hunt Ashley , Ning Zhibin , Figeys Daniel , Goto Natalie K. , Pezacki John Paul 
Published: May 2014

AbstractPhosphatidylinositol kinases (PIKs) are key enzymatic regulators of membrane phospholipids and membrane environments that control many aspects of cellular function, from signal transduction to secretion, through the Golgi apparatus. Here, we have developed a photoreactive “clickable” probe, PIK‐BPyne, to report the activity of PIKs. We investigated the selectivity and efficiency of the probe to both inhibit and label PIKs, and we compared PIK‐BPyne to a wortmannin activity‐based probe also known to target PIKs. We found that PIK‐BPyne can act as an effective in situ activity‐based probe, and for the first time, report changes in PI4K‐IIIβ activity induced by the hepatitis C virus. These results establish the utility of PIK‐BPyne for activity‐based protein profiling studies of PIK function in native biological systems.
Periprocedural and long‐term outcomes of endovascular abdominal aortic aneurysm repair in cardiology practice
Authors: Basoor Abhijeet , Patel Kiritkumar C. , Halabi Abdul R. , Todorov Mina , Senthilvadivel Prashanth , Choksi Nishit , Phan Thanh , LaLonde Thomas , Yamasaki Hiroshi , DeGregorio Michele 
Published: May 2014

BackgroundEndovascular repair of abdominal aortic aneurysm (AAA) has recently been made a class I indication in the treatment of AAA. In comparison to the conventional open surgical treatment, endovascular AAA repair (EVAR) is associated with equivalent long‐term morbidity and mortality rates. Vascular surgeons perform majority of EVAR. There are no reports for the long‐term results of this intervention performed by interventional cardiologists. We present one of the first reports of periprocedural and long‐term outcomes of EVAR performed by interventional cardiologists.MethodsRetrospective chart review on patients with attempted EVAR between September 2005 and January 2011 was performed. Included cases were all consecutive patients who had attempted EVAR by interventional cardiologists.ResultsDuring the study period EVAR was attempted in 170 patients, with 27% being women. The mean age was 74 years (range 52–93). The endovascular graft placement was successful in 96% (163/170) of patients. Procedure failures were more common in women (6 of 46 vs 1 of 124, P = 0.003). The 30‐day mortality was 1.8 % (3 of 170). In patients with successful EVAR the mean follow‐up was 30 months and mean length of hospital stay was 3.5 ± 3.2 days. Major periprocedural complications were noted in 9% patients (15 of 167). During follow‐up, six patients (3.5%) required re‐intervention and additional 16 patients died with no aneurysm related deaths.ConclusionEVAR primarily performed by interventional cardiologists demonstrates high periprocedural and long‐term success rates. A higher EVAR failure rate has been observed in women. © 2014 Wiley Periodicals, Inc.
Insights into the AIEE of 1,8‐Naphthalimides (NPIs): Inverse Effects of Intermolecular Interactions in Solution and Aggregates
Authors: Mukherjee Sanjoy , Thilagar Pakkirisamy 
Published: May 2014

AbstractSystematic structural perturbation has been used to fine‐tune and understand the luminescence properties of three new 1,8‐naphthalimides (NPIs) in solution and aggregates. The NPIs show blue emission in the solution state and their fluorescence quantum yields are dependent upon their molecular rigidity. In concentrated solutions of the NPIs, intermolecular interactions were found to quench the fluorescence due to the formation of excimers. In contrast, upon aggregation (in THF/H2O mixtures), the NPIs show aggregation‐induced emission enhancement (AIEE). The NPIs also show moderately high solid‐state emission quantum yields (ca. 10–12.7 %). The AIEE behaviour of the NPIs depends on their molecular rigidity and the nature of their intermolecular interactions. The NPIs 1–3 show different extents of intermolecular (π–π and CH⋅⋅⋅O) interactions in their solid‐state crystal structures depending on their substituents. Detailed photophysical, computational and structural investigations suggest that an optimal balance of structural flexibility and intermolecular communication is necessary for achieving AIEE characteristics in these NPIs.
Thermally Induced Twin Polymerization of 4H‐1,3,2‐Benzodioxasilines
Authors: Kempe Patrick , Löschner Tina , Auer Alexander A. , Seifert Andreas , Cox Gerhard , Spange Stefan 
Published: May 2014

AbstractThe twin monomer 2,2′‐spirobi[4H‐1,3,2‐benzodioxasiline] (1) can be polymerized to nanostructured SiO2/phenolic‐resin composite material by thermally induced twin polymerization. Thermally induced twin polymerization represents a way to produce nanocomposites simply by thermal induction of twin monomers. Besides 1, the thermal reaction of several related salicylic (2‐oxybenzylic) silicon molecules has been investigated. The thermal cleavage of the molecules is studied by using several trapping reagents (e.g., vinyl compounds). A significant occurrence of quinone methide adducts indicates that the thermal mechanism proceeds not only by a ring opening at the oxymethylene position, but also with the ortho‐quinone methide as a central or alternative intermediate. This is supported by product analyses of thermally initialized reactions of 1 and its substituted analogues as well as by quantum chemical calculations.
Ergoline‐Derived Inverse Agonists of the Human H3 Receptor for the Treatment of Narcolepsy
Authors: Auberson Yves P. , Troxler Thomas , Zhang Xuechun , Yang Charles R. , Fendt Markus , Feuerbach Dominik , Liu Yu‐Chih , Lagu Bharat , Lerchner Andreas , Perrone Mark , Lei Lijun , Zhang Chao , Wang Chunxiu , Wang Tie‐Lin , Bock Mark G. 
Published: May 2014

AbstractErgoline derivative (6aR,9R)‐4‐(2‐(dimethylamino)ethyl)‐N‐phenyl‐9‐(pyrrolidine‐1‐carbonyl)‐6,6a,8,9‐tetrahydroindolo[4,3‐fg]quinoline‐7(4H)‐carboxamide (1), a CXCR3 antagonist, also inhibits human histamine H3 receptors (H3R) and represents a structurally novel H3R inverse agonist chemotype. It displays favorable pharmacokinetic and in vitro safety profiles, and served as a lead compound in a program to explore ergoline derivatives as potential drug candidates for the treatment of narcolepsy. A key objective of this work was to enhance the safety and efficacy profiles of 1, while minimizing its duration of action to mitigate the episodes of insomnia documented with previously reported clinical candidates during the night following administration. Modifications to the ergoline core at positions 1, 6 and 8 were systematically investigated, and derivative 23 (1‐((4aR,8R,9aR)‐8‐(hydroxymethyl)‐1‐(2‐((R)‐2‐methylpyrrolidin‐1‐yl)ethyl)‐4,4a,7,8,9,9a‐hexahydroindolo[1,14‐fg]quinolin‐6(1H)‐yl)ethanone) was identified as a promising lead compound. Derivative 23 has a desirable pharmacokinetic profile and demonstrated efficacy by enhancing brain concentrations of tele‐methylhistamine, a major histamine metabolite. This validates the potential of the ergoline scaffold to serve as a template for the development of H3R inverse agonists.