bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructing numerically stable Kalman filter‐based algorithms for gradient‐based adaptive filtering
Authors: Kulikova M. V. , Tsyganova J. V. 
Published: March 2015

SummaryThis paper addresses the numerical aspects of adaptive filtering (AF) techniques for simultaneous state and parameters estimation arising in the design of dynamic positioning systems in many areas of research. The AF schemes consist of a recursive optimization procedure to identify the uncertain system parameters by minimizing an appropriate defined performance index and the application of the Kalman filter (KF) for dynamic positioning purpose. The use of gradient‐based optimization methods in the AF computational schemes yields to a set of the filter sensitivity equations and a set of matrix Riccati‐type sensitivity equations. The filter sensitivities evaluation is usually carried out by the conventional KF, which is known to be numerically unstable, and its derivatives with respect to unknown system parameters. Recently, a novel square‐root approach for the gradient‐based AF by the method of the maximum likelihood has been proposed. In this paper, we show that various square‐root AF schemes can be derived from only two main theoretical results. This elegant and simple computational technique replaces the standard methodology based on direct differentiation of the conventional KF equations (with their inherent numerical instability) by advanced square‐root filters (and its derivatives as well). As a result, it improves the robustness of the computations against round off errors and leads to accurate variants of the gradient‐based AFs. Additionally, such methods are ideal for simultaneous state estimation and parameter identification because all values are computed in parallel. The numerical experiments are given. Copyright © 2015 John Wiley & Sons, Ltd.
Chemical Remodeling of Cell‐Surface Sialic Acids through a Palladium‐Triggered Bioorthogonal Elimination Reaction
Authors: Wang Jie , Cheng Bo , Li Jie , Zhang Zhaoyue , Hong Weiyao , Chen Xing , Chen Peng R. 
Published: March 2015

AbstractWe herein report a chemical decaging strategy for the in situ generation of neuramic acid (Neu), a unique type of sialic acid, on live cells by the use of a palladium‐mediated bioorthogonal elimination reaction. Palladium nanoparticles (Pd NPs) were found to be a highly efficient and biocompatible depropargylation catalyst for the direct conversion of metabolically incorporated N‐(propargyloxycarbonyl)neuramic acid (Neu5Proc) into Neu on cell‐surface glycans. This conversion chemically mimics the enzymatic de‐N‐acetylation of N‐acetylneuramic acid (Neu5Ac), a proposed mechanism for the natural occurrence of Neu on cell‐surface glycans. The bioorthogonal elimination was also exploited for the manipulation of cell‐surface charge by unmasking the free amine at C5 to neutralize the negatively charged carboxyl group at C1 of sialic acids.
η3‐Allylkoordination an Zinn(II) – Reaktivität gegenüber Alkinen und Benzonitril
Authors: Krebs Kilian M. , Wiederkehr Jessica , Schneider Julia , Schubert Hartmut , Eichele Klaus , Wesemann Lars 
Published: March 2015

AbstractWir berichten über die Synthese und Charakterisierung eines Allyl‐SnII‐Komplexes, der eine η3‐Koordination in Lösung und im Festkörper aufweist. Zwei Beispiele für die Reaktivität des Allylderivates werden vorgestellt: Die Reaktion mit terminalen Alkinen ergibt tricyclische Verbindungen, während die Umsetzung mit Benzonitril über eine C‐H‐Aktivierung zu einem 16 Atome umfassenden Ringsystem führt.
Plasma vs heart tissue concentration in humans – literature data analysis of drugs distribution
Authors: Tylutki Zofia , Polak Sebastian 
Published: March 2015

AbstractLittle is known about the uptake of drugs into the human heart, although it is of great importance nowadays, when science desires to predict tissue level behavior rather than to measure it. Although the drug concentration in cardiac tissue seems a better predictor for physiological and electrophysiological changes than its level in plasma, knowledge of this value is very limited. Tissue to plasma partition coefficients (Kp) come to rescue since they characterize the distribution of a drug among tissues as being one of the input parameters in physiologically based pharmacokinetic (PBPK) models. The article reviews cardiac surgery and forensic medical studies to provide a reference for drug concentrations in human cardiac tissue. Firstly, the focus is on whether a drug penetrates into heart tissue at a therapeutic level; the provided values refer to antibiotics, antifungals and anticancer drugs. Drugs that directly affect cardiomyocyte electrophysiology are another group of interest. Measured levels of amiodarone, digoxin, perhexiline and verapamil in different sites in human cardiac tissue where the compounds might meet ion channels, gives an insight into how these more lipophilic drugs penetrate the heart. Much data are derived from postmortem studies and they provide insight to the cardiac distribution of more than 200 drugs. The analysis depicts potential problems in defining the active concentration location, what may indirectly suggest multiple mechanisms involved in the drug distribution within the heart. Copyright © 2015 John Wiley & Sons, Ltd.
Involvement of microsomal NADPH‐cytochrome P450 reductase in metabolic reduction of drug ketones
Authors: Lehr Matthias , Fabian Jörg , Hanekamp Walburga 
Published: March 2015

AbstractRecently, it was found that the carbonyl group of 1‐[3‐(4‐phenoxyphenoxy)‐2‐oxopropyl]indole‐5‐carboxylic acid (5), an inhibitor of the pro‐inflammatory enzyme cytosolic phospholipase A2α, is easily reduced by rat liver S9 fractions in vitro. Determination of the inhibitory potency of certain putative inhibitors of carbonyl reducing enzymes on the transformation of the ketone derivative 5 to its alcohol 6 by recombinant microsomal NADPH‐cytochrome P450 reductase and by recombinant cytosolic carbonyl reductase‐1 now reveals that these compounds show a lack of specificity for these two enzymes in part. Thus, an assignment of the roles of different carbonyl reductases in metabolic keto reduction by the use of inhibitors is problematic. In addition, the ability of NADPH‐cytochrome P450 reductase and carbonyl reductase‐1 to reduce the ketone groups of the drugs haloperidol and daunorubicin was examined. Under the conditions applied, a pronounced reductive metabolism was only observed for daunorubicin in the presence of microsomal NADPH‐cytochrome P450 reductase. Similarly, in rat liver S9 fractions a marked reduction of daunorubicin was seen, while haloperidol was only slightly metabolized to its alcohol. After separation of the S9 homogenate into a microsomal and a cytosolic fraction, it became evident that the ketone groups of daunorubicin, haloperidol and compound 5 were mainly reduced by cytosolic enzymes. However, since microsomes also catalysed these carbonyl reductions to some extent, it can be concluded that microsomal NADPH‐cytochrome P450 reductase can contribute to metabolic keto reductions in xenobiotics. Copyright © 2015 John Wiley & Sons, Ltd.
Application of a method used to deconstruct a single dose pharmacokinetic profile from multiple dose data
Authors: Stockmann Chris , Spigarelli Michael G. , Healy Daniel P. , Gottschlich Michele M. , Kagan Richard , Balch Alfred H. , Sherwin Catherine 
Published: March 2015

AbstractWith traditional non‐compartmental methods, it is challenging to deconstruct plasma concentration versus time curves to assess the influence of individual doses. This study describes the application of a mathematical approach used to deconstruct a single dose curve using data derived from the second, third, fourth or nth dosing interval. Using data from a prospective clinical trial it is demonstrated that this approach reliably estimates pharmacokinetic parameters measured following two doses of zolpidem tartrate. Additionally, the study demonstrates the application of this approach using previously published data from a single‐ and multiple‐dose pharmacokinetic study of the antibiotic gatifloxacin. Copyright © 2015 John Wiley & Sons, Ltd.
Randomized clinical trial of laparoscopic colectomy with or without natural-orifice specimen extraction
Authors: Wolthuis A M , Fieuws S , Van Den Bosch A , de Buck van Overstraeten A , D'Hoore A 
Published: March 2015

Abstract

Background
Although conventional laparoscopic colectomy is a validated technique, laparoscopic natural-orifice specimen extraction (NOSE) colectomy might improve outcome. This randomized clinical trial compared analgesia requirements, postoperative pain, anorectal function, inflammatory response and cosmesis in laparoscopic NOSE colectomy and conventional laparoscopic colectomy.

Methods
Patients were randomly assigned to undergo laparoscopic NOSE colectomy or conventional laparoscopic colectomy for left-sided colonic disease. The primary endpoint was analgesia requirement. Secondary endpoints were operative outcome, inflammatory response, anorectal function and cosmesis.

Results
Forty patients were enrolled in the study, 20 in each group (15 with diverticulitis and 5 with colorectal cancer in each group). A significant difference was observed in morphine analogue requirements (1 of 20 patients in the NOSE group versus 10 of 20 in the conventional group; P = 0·003). Patient-controlled epidural analgesia was lower in the NOSE group (mean 116 ml versus 221 ml in the conventional group; P &lt; 0·001), as was paracetamol use (mean 11·0 versus 17·0 g respectively; P &lt; 0·001). Postoperative pain scores were lower in the NOSE group: mean maximum visual analogue score of 3·5 versus 2·1 (P &lt; 0·001). One week after hospital discharge, pain scores remained higher in the conventional group: 15 of 20 patients in the conventional group reported pain, compared with one of 20 in the NOSE group (P &lt; 0·001). Inflammatory responses were greater in patients undergoing NOSE colectomy: higher peak C-reactive protein and interleukin 6 levels were observed on postoperative day 2 (P &lt; 0·001) and day 1 (P = 0·002) respectively. Postoperative anorectal function, complications and hospital stay were similar in the two groups.

Conclusion
Laparoscopic NOSE colectomy was associated with less pain and lower analgesia requirements than the conventional laparoscopic extraction. Registration number: NCT01033838 (http://www.clinicaltrials.gov).
Application of a UPLC‐MS/MS method for the analysis of alosetron in human plasma to support a bioequivalence study in healthy males and females
Authors: Chaudhary Darshan V. , Patel Daxesh P. , Shah Jaivik V. , Shah Priyanka A. , Sanyal Mallika , Shrivastav Pranav S. 
Published: March 2015

ABSTRACTA simple, rapid and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed and validated for the determination of alosetron (ALO) in human plasma. The assay method involved solid‐phase extraction of ALO and ALO 13C‐d3 as internal standard (IS) on a LichroSep DVB‐HL (30 mg, 1 cm3) cartridge. The chromatography was performed on an Acquity UPLC BEH C18 (50 × 2.1 mm, 1.7 µm) column using acetonitrile and 2.0 mm ammonium formate, pH 3.0 adjusted with 0.1% formic acid (80:20, v/v) as the mobile phase in an isocratic mode. For quantitative analysis, the multiple reaction monitoring transitions studied were m/z 295.1/201.0 for ALO and m/z 299.1/205.1 for IS in the positive ionization mode. The method was validated over a concentration range of 0.01–10.0 ng/mL for ALO. Post‐column infusion experiment showed no positive or negative peaks in the elution range of the analyte and IS after injection of extracted blank plasma. The extent of ion‐suppression/enhancement, expressed as IS‐normalized matrix factor, varied from 0.96 to 1.04. The assay recovery was within 97–103% for ALO and IS. The method was successfully applied to support a bioequivalence study of 1.0 mg alosetron tablets in 28 healthy Indian male and female subjects. Copyright © 2015 John Wiley & Sons, Ltd.
Functional network mediates age‐related differences in reaction time: a replication and extension study
Authors: Gazes Yunglin , Habeck Christian , O'Shea Deirdre , Razlighi Qolamreza R. , Steffener Jason , Stern Yaakov 
Published: March 2015

AbstractIntroductionA functional activation (i.e., ordinal trend) pattern was previously identified in both young and older adults during task‐switching performance, the expression of which correlated with reaction time. The current study aimed to (1) replicate this functional activation pattern in a new group of fMRI activation data, and (2) extend the previous study by specifically examining whether the effect of aging on reaction time can be explained by differences in the activation of the functional activation pattern.MethodA total of 47 young and 50 older participants were included in the extension analysis. Participants performed task‐switching as the activation task and were cued by the color of the stimulus for the task to be performed in each block. To test for replication, two approaches were implemented. The first approach tested the replicability of the predictive power of the previously identified functional activation pattern by forward applying the pattern to the Study II data and the second approach was rederivation of the activation pattern in the Study II data.ResultsBoth approaches showed successful replication in the new data set. Using mediation analysis, expression of the pattern from the first approach was found to partially mediate age‐related effects on reaction time such that older age was associated with greater activation of the brain pattern and longer reaction time, suggesting that brain activation efficiency (defined as “the rate of activation increase with increasing task difficulty” in Neuropsychologia 47, 2009, 2015) of the regions in the Ordinal trend pattern directly accounts for age‐related differences in task performance.DiscussionThe successful replication of the functional activation pattern demonstrates the versatility of the Ordinal Trend Canonical Variates Analysis, and the ability to summarize each participant's brain activation map into one number provides a useful metric in multimodal analysis as well as cross‐study comparisons.
Terpenoids from Rhizomes of Alpinia japonica Inhibiting Nitric Oxide Production
Authors: Li Qiang‐Ming , Luo Jian‐Guang , Yang Ming‐Hua , Kong Ling‐Yi 
Published: March 2015

AbstractA new sesquiterpenoid, 1, and three new diterpenoids, 3–5, along with five known compounds, 2 and 6–9, were isolated from rhizomes of Alpinia japonica. The structures of the new compounds were determined as (1R,4R,6S,7S,9S)‐4α‐hydroxy‐1,9‐peroxybisabola‐2,10‐diene (1), methyl (12E)‐16‐oxolabda‐8(17),12‐dien‐15‐oate (3), (12R)‐15‐ethoxy‐12‐hydroxylabda‐8(17),13(14)‐dien‐16,15‐olide (4), and methyl (11E)‐14,15,16‐trinorlabda‐8(17),11‐dien‐13‐oate (5) by means of spectroscopic data. The absolute configurations at C(4) in 1 and C(12) in 4 were deduced from the circular dichroism (CD) data of the in situ‐formed [Rh2(CF3COO)4] complexes. Inhibitory effects of the isolates on NO production in lipopolysaccharide‐induced RAW264.7 macrophages were evaluated, and 2–4, 6, and 7 were found to exhibit inhibitory activities with IC50 values between 14.6 and 34.3 μM.
Bioactive Diphenyl Ether Derivatives from a Gorgonian‐Derived Fungus Talaromyces sp.
Authors: Chen Min , Han Lei , Shao Chang‐Lun , She Zhi‐Gang , Wang Chang‐Yun 
Published: March 2015

AbstractThree new diphenyl ether derivatives, talaromycins A–C (1–3, resp.), together with six known analogs, 4–9, were isolated from a gorgonian‐derived fungus, Talaromyces sp. The structures of the new compounds were determined by analysis of extensive NMR spectroscopic data. All of the isolated metabolites, 1–9, were evaluated for their cytotoxic and antifouling activities. Compound 4 exhibited pronounced cytotoxicity against the tested human cell lines with the IC50 values ranging from 4.3 to 9.8 μM. Compounds 3, 5, 8, and 9 showed potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite with the EC50 values ranging from 2.2 to 4.8 μg/ml.
Surface Modification of Carbon Nitride Polymers by Core–Shell Nickel/Nickel Oxide Cocatalysts for Hydrogen Evolution Photocatalysis
Authors: Zhang Guigang , Li Guosheng , Wang Xinchen 
Published: March 2015

AbstractNi/NiO core–shell cocatalysts have been prepared on the surface of graphitic carbon nitride by a facile in situ immersion strategy to promote photocatalytic H2 evolution activity under the light irradiation of the conjugated polymer. The physicochemical properties of the as‐prepared hybridized materials were characterized by several techniques, which include XRD, UV‐Raman spectroscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, X‐ray photoelectron spectroscopy, and high‐resolution transmission electron microscopy, to investigate the composition, texture, surface properties, and optical properties of the samples. In comparison with an unmodified carbon nitride polymer, the Ni/NiO‐decorated sample shows an increased photocatalytic H2 evolution rate and good durability because of the promoted surface kinetics that increase the charge‐transfer rate and reduce the overpotential for H2 evolution dramatically.
Photoinduced Formation of an Azobenzene‐Based CD‐Active Supramolecular Cyclic Dimer
Authors: Sogawa Hiromitsu , Terada Kayo , Miyagi Yu , Shiotsuki Masashi , Inai Yoshihito , Masuda Toshio , Sanda Fumio 
Published: March 2015

AbstractA series of new photo‐responsive amino acid‐derived azobenzenedicarboxylic acid derivatives (S)‐1 a–e were synthesized. Compound (S)‐1 a in the trans form exhibited no circular dichroism (CD) signal in DMF under ambient conditions, whereas intense Cotton effects were observed upon UV irradiation, indicating the formation of a chiral supramolecular structure in the cis form. The CD signals disappeared when trifluoroacetic acid (TFA) was added to the solution. The ester counterpart [(S)‐1 a′] showed no CD signal. Hydrogen bonding between the carboxy groups seemed necessary for constructing the supramolecular structure. The kinetic studies of cis to trans isomerization of (S)‐1 a demonstrated that the formation of a chiral supramolecule enhances the stability of the cis‐azobenzene structure. The ESI mass spectrum of stilbenedicarboxylic acid (S)‐4, an analogue of (S)‐1 b, confirmed the formation of a dimer. A theoretical CD study revealed that (S)‐1 a in the cis form should be present as a cyclic chiral dimer.
Luminescent Nitridophosphates CaP2N4:Eu2+, SrP2N4:Eu2+, BaP2N4:Eu2+, and BaSr2P6N12:Eu2+
Authors: Pucher Florian J. , Marchuk Alexey , Schmidt Peter J. , Wiechert Detlef , Schnick Wolfgang 
Published: March 2015

AbstractNitridophosphates MP2N4:Eu2+ (M=Ca, Sr, Ba) and BaSr2P6N12:Eu2+ have been synthesized at elevated pressures and 1100–1300 °C starting from the corresponding azides and P3N5 with EuCl2 as dopant. Addition of NH4Cl as mineralizer allowed for the growth of single crystals. This led to the successful structure elucidation of a highly condensed nitridophosphate from single‐crystal X‐ray diffraction data (CaP2N4:Eu2+ (P63, no. 173), a=16.847(2), c=7.8592(16) Å, V=1931.7(6) Å3, Z=24, 2033 observed reflections, 176 refined parameters, wR2=0.096). Upon excitation by UV light, luminescence due to parity‐allowed 4f6(7F)5d1→4f7(8S7/2) transition was observed in the orange (CaP2N4:Eu2+, λmax=575 nm), green (SrP2N4:Eu2+, λmax=529 nm), and blue regions of the visible spectrum (BaSr2P6N12:Eu2+ and BaP2N4:Eu2+, λmax=450 and 460 nm, respectively). Thus, the emission wavelength decreases with increasing ionic radius of the alkaline‐earth ions. The corresponding full width at half maximum values (2240–2460 cm−1) are comparable to those of other known Eu2+‐doped (oxo)nitrides emitting in the same region of the visible spectrum. Following recently described quaternary Ba3P5N10Br:Eu2+, this investigation represents the first report on the luminescence of Eu2+‐doped ternary nitridophosphates. Similarly to nitridosilicates and related oxonitrides, Eu2+‐doped nitridophosphates may have the potential to be further developed into efficient light‐emitting diode phosphors.
Formation of an Imino‐Stabilized Cyclic Tin(II) Cation from an Amino(imino)stannylene
Authors: Ochiai Tatsumi , Franz Daniel , Irran Elisabeth , Inoue Shigeyoshi 
Published: March 2015

AbstractThe novel amino(imino)stannylene 1 was prepared by conversion of HNIPr (NIPr=bis(2,6‐diisopropylphenyl)imidazolin‐2‐imino) with one equivalent of Lappert’s tin reagent (Sn[N(SiMe3)2]2). Treatment of 1 with DMAP (4‐dimethylaminopyridine) yields its Lewis acid–base adduct 2. The reaction of 1 with one equivalent of trimethylsilyl azide results in replacement of the amino group at the tin center by an N3 substituent with concomitant elimination of N(SiMe3)3 to afford dimeric [N3SnNIPr]2 (3). Remarkably, the reaction of 1 with B(C6F5)3 produces the novel tin(II) monocation 4+[MeB(C6F5)3]− comprising a four‐membered stannacycle through methyl‐abstraction from the trimethylsilyl group.
Trifluoromethylation‐Initiated Remote Cross‐Coupling of Carbonyl Compounds to Form Carbon–Heteroatom/Carbon Bonds
Authors: Huang Lin , Zheng Sheng‐Cai , Tan Bin , Liu Xin‐Yuan 
Published: March 2015

AbstractBy involving the reversal of conventional reactivity expectations without external oxidants, we describe a novel and convenient protocol of remote cross‐coupling of carbonyl compounds with a series of common and simple nucleophiles. This cross‐coupling is triggered by radical trifluoromethylation of alkenes, thereby achieving highly selective remote difunctionalization of alkenes and α‐position of the carbonyl group for facile access to trifluoromethyl α‐halo‐ and α‐cyanocarbonyl compounds. The reaction exhibits a broad substrate scope with excellent functionality tolerance and many different types of nucleophiles; further synthetic applicability of the obtained compounds proved to be suitable, thus showing great potential for synthetic utility.
Catalytic Asymmetric Addition of Meldrum’s Acid, Malononitrile, and 1,3‐Dicarbonyls to ortho‐Quinone Methides Generated In Situ Under Basic Conditions
Authors: Caruana Lorenzo , Mondatori Martina , Corti Vasco , Morales Sara , Mazzanti Andrea , Fochi Mariafrancesca , Bernardi Luca 
Published: March 2015

AbstractA new approach to the utilization of highly reactive and unstable ortho‐quinone methides (o‐QMs) in catalytic asymmetric settings is presented. The enantioselective reactions are catalysed by bifunctional organocatalysts, and the o‐QM intermediates are formed in situ from 2‐sulfonylalkyl phenols through base‐promoted elimination of sulfinic acid. The use of mild Brønsted basic conditions for transiently generating o‐QMs in catalytic asymmetric processes is unprecedented, and allows engaging productively in the reactions nucleophiles such as Meldrum’s acid, malononitrile and 1,3‐dicarbonyls. The catalytic transformations give new and general entries to 3,4‐dihydrocoumarins, 4H‐chromenes and xanthenones. These frameworks are recurring structures in natural product and medicinal chemistry, as testified by the formal syntheses of (R)‐tolterodine and (S)‐4‐methoxydalbergione from the catalytic adducts.
ChemInform Abstract: Pentacoordinate Phosphorus in a High‐Pressure Polymorph of Phosphorus Nitride Imide P4N6(NH).
Authors: Baumann Dominik , Schnick Wolfgang 
Published: March 2015

AbstractThe title γ‐P4N6(NH) polymorph is obtained by high‐temperature high‐pressure synthesis using P3N5 and NH4Cl in the molar ratio of 4:1 (multianvil cell, 14 GPa, 1200 °C, 3 h).
ChemInform Abstract: Three Structure Types and Intermediate Cerium Valence in the Solid Solution CeRu1—xNixSn.
Authors: Niehaus Oliver , Abdala Paula M. , Touzani Rachid St. , Fokwa Boniface P. T. , Poettgen Rainer 
Published: March 2015

AbstractSingle crystals of the solid solutions CeRu1‐xNixSn (x = 0.12—1) are obtained by melting stoichiometric mixtures of the elements (arc welded Nb ampoules, 1670 K, 5 min; controlled cooling).