bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Aortic and Carotid Arterial Stiffness Parameters in Patients With Verified Coronary Artery Disease
Authors: Gaszner Balázs , Lenkey Zsófia , Illyés Miklós , Sárszegi Zsolt , Horváth Iván G. , Magyari Balázs , Molnár Ferenc , Kónyi Attila , Cziráki Attila
Published: November 2011

Background:

Arterial stiffness parameters are commonly used to determine the development of atherosclerotic disease. The independent predictive value of aortic stiffness has been demonstrated for coronary events.

Hypothesis:

The aim of our study was to compare regional and local arterial functional parameters measured by 2 different noninvasive methods in patients with verified coronary artery disease (CAD). We also compared and contrasted these stiffness parameters to the coronary SYNTAX score in patients who had undergone coronary angiography.

Methods:

In this study, 125 CAD patients were involved, and similar noninvasive measurements were performed on 125 healthy subjects. The regional velocity of the aortic pulse wave (PWVao) was measured by a novel oscillometric device, and the common carotid artery was studied by a Doppler echo‐tracking system to determine the local carotid pulse wave velocity (PWVcar). The augmentation index (AIx), which varies proportionately with the resistance of the small arteries, was recorded simultaneously.

Results:

In the CAD group, the PWVao and aortic augmentation index (Alxao) values increased significantly (10.1 ± 2.3 m/sec and 34.2% ± 14.6%) compared to the control group (9.6 ± 1.5 m/sec and 30.9% ± 12%; P < 0.05). We observed similar significant increases in the local stiffness parameters (PWVcar and carotid augmentation index [Alxcar]) in patients with verified CAD. Further, we found a strong correlation for PWV and AIx values that were measured with the Arteriograph and those obtained using the echo‐tracking method (r = 0.57, P < 0.001 for PWV; and r = 0.65, P < 0.001 for AIx values).

Conclusions:

Our results indicate that local and regional arterial stiffness parameters provide similar information on impaired arterial stiffening in patients with verified CAD. © 2011 Wiley Periodicals, Inc.

This study was supported by the Hungarian National Research Foundation (OTKA) No.78480. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Vectorial color
Authors: Worthey James A.
Published: November 2011

A set of orthonormal color matching functions is developed, in which the first is an all‐positive achromatic function, the second is red–green, and the third can be loosely described as blue–yellow. The achromatic function, proportional to the familiar
$ \bar y $, is a sum of red and green cones. The red–green function uses the same cone sensitivities, but subtracted, with coefficients so that it is orthogonal to the achromatic one. The third function involves all three cones, but is primarily a blue sensitivity. Using this basis to compute the tristimulus vectors of narrow‐band lights at unit power gives Jozef Cohen's locus of unit monochromats, (LUM) an invariant shape now graphed in a space where the axes have intuitive meaning. The extreme points of the LUM reveal the wavelengths that act most strongly in mixtures, a close approximation to William Thornton's Prime Colors. In effect, decades of research converge in three functions and a vectorial schema, demystifying such issues as color rendering and the selection of additive primaries. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011.
Probing the Effects of One‐Electron Reduction and Protonation on the Electronic Properties of the Fe‐S Clusters in the Active‐Ready Form of [FeFe]‐Hydrogenases. A QM/MM Investigation.
Authors: Greco Claudio , Bruschi Maurizio , Fantucci Piercarlo , Ryde Ulf , De Gioia Luca
Published: November 2011

A QM/MM investigation of the active‐ready (Hox) form of [FeFe]‐hydrogenase from D. desulfuricans, in which the electronic properties of all Fe‐S clusters (H, F and F′) have been simultaneously described using DFT, was carried out with the aim of disclosing a possible interplay between the H‐cluster and the accessory iron‐sulfur clusters in the initial steps of the catalytic process leading to H2 formation. It turned out that one‐electron addition to the active‐ready form leads to reduction of the F′‐cluster and not of the H‐cluster. Protonation of the H‐cluster in Hox is unlikely, and in any case it would not trigger electron transfer from the accessory Fe4S4 clusters to the active site. Instead, one‐electron reduction and protonation of the active‐ready form trigger electron transfer within the protein, a key event in the catalytic cycle. In particular, protonation of the H‐cluster after one‐electron reduction of the enzyme lowers the energy of the lowest unoccupied molecular orbitals localized on the H‐cluster to such an extent that a long‐range electron transfer from the F′‐cluster towards the H‐cluster itself is allowed.
Transparency of GaN substrates in the mid‐infrared spectral range
Authors: Welna M. , Kudrawiec R. , Motyka M. , Kucharski R. , Zając M. , Rudziński M. , Misiewicz J. , Doradziński R. , Dwiliński R.
Published: November 2011

Transparency of truly bulk GaN substrates obtained by ammonothermal method was measured in the mid infrared spectral range by Fourier spectroscopy. The same measurements were performed for GaN templates grown by meatlorganic vapour phase epitaxy on sapphire and SiC substrates. It has been clearly observed that truly bulk GaN substrates are transparent up to ∼7 µm whereas GaN templates grown on sapphire and SiC are transparent only up to ∼6.5 and ∼5.5 µm, respectively, due to non‐transparency of sapphire and SiC in this spectral range. It has been shown that the transparency “cut off” at ∼7 µm for GaN crystals results from the absorption of light by the second harmonic of optical phonons, which is very significant due to the strong electron‐phonon coupling in this material. Also it has been clearly presented that the absorption “cut‐off” in the infrared spectral region can be easily tuned by increasing of free carrier concentration in GaN. It was observed that the infrared transparency can be shifted from ∼7 to ∼2 µm or even shorter wavelengths when the electron concentration is increased up to ∼1019 cm‐3. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Substituent and solvent effects on UV‐visible absorption spectra of liquid crystalline disubstituted biphenylcyclohexane derivatives – a computational approach
Authors: Lakshmi Praveen P. , Ojha D. P.
Published: November 2011

A computational approach has been carried out on liquid crystalline disubstituted biphenylcyclohexanes (BCHs) of general formula R‐C6H10‐C6H4‐C6H4‐X with R: C3H7; X: H (BCH30) and R: C5H11; X: CN (BCH5CN) using the CNDO/S + CI and INDO/S + CI methods. These methods have been employed to calculate and analyze the spectral shifts, and absorbance measurements in UV‐visible range of the systems. The electronic transitions, absorption wavelength, HOMO (Highest Occupied Molecular Orbital), and LUMO (Lowest Unoccupied Molecular Orbital) energies have been calculated. Further, ultraviolet (UV) stability of the molecules has been discussed in the light of absorption wavelength and electronic transition oscillator strength (f). The effect of different solvent media and substituents on transition energies, oscillator strength, and other absorption parameters has also been reported. The present article provides valuable information regarding enhancing the UV stability of molecules by marinating their conductivity. Further, these absorption spectra will provide valuable data base for future computational studies, and the other experimental investigations. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
When once is not enough: accounting for CO2 recycling in EOR operations
Authors: Marston Philip M.
Published: November 2011

Funding for carbon capture and storage (CCS) demonstration projects is currently under lots of pressure. Phillip Marston puts forward the case that CO2‐based enhanced oil recovery (EOR) offers a potential solution. To really make this work for captured anthropogenic CO2, we need to come up with an accepted accounting protocol for dealing with recycling of CO2 during EOR.
The presumed atypical chemokine receptor CXCR7 signals through Gi/o proteins in primary rodent astrocytes and human glioma cells
Authors: Ödemis Veysel , Lipfert Jana , Kraft Robert , Hajek Peter , Abraham Getu , Hattermann Kirsten , Mentlein Rolf , Engele Jürgen
Published: November 2011

SDF‐1/CXCL12 binds to the chemokine receptors, CXCR4 and CXCR7, and controls cell proliferation and migration during development, tumorigenesis, and inflammatory processes. It is currently assumed that CXCR7 would represent an atypical or scavenger chemokine receptor which modulates the function of CXCR4. Contrasting this view, we demonstrated recently that CXCR7 actively mediates SDF‐1 signaling in primary astrocytes. Here, we provide evidence that CXCR7 affects astrocytic cell signaling and function through pertussis toxin‐sensitive Gi/o proteins. SDF‐1‐dependent activation of Gi/o proteins and subsequent increases in intracellular Ca2+ concentration persisted in primary rodent astrocytes with depleted expression of CXCR4, but were abolished in astrocytes with depleted expression of CXCR7. Moreover, CXCR7‐mediated effects of SDF‐1 on Erk and Akt signaling as well as on astrocytic proliferation and migration were all sensitive to pertussis toxin. Likewise, pertussis toxin abolished SDF‐1‐induced activation of Erk and Akt in CXCR7‐only expressing human glioma cell lines. Finally, consistent with a ligand‐biased function of CXCR7 in astrocytes, the alternate CXCR7 ligand, I‐TAC/CXCL11, activated Erk and Akt through β‐arrestin. The demonstration that SDF‐1‐bound CXCR7 activates Gi/o proteins in astrocytes could help to explain some discrepancies previously observed for the function of CXCR4 and CXCR7 in other cell types. © 2011 Wiley Periodicals, Inc.
Exploiting salivary miR‐31 as a clinical biomarker of oral squamous cell carcinoma
Authors: Liu Chung‐Ji , Lin Shu‐Chun , Yang Cheng‐Chieh , Cheng Hui‐Wen , Chang Kuo‐Wei
Published: November 2011

Background

Oral carcinoma is an important malignancy throughout the world. MicroRNAs (miRNAs) are endogenously expressed, non‐coding RNAs that regulate post‐transcriptional levels of targeted mRNAs. MiRNA‐31(miR‐31) is significantly upregulated in oral carcinoma tissues and plays oncogenic roles in oral carcinogenesis.

Methods

We analyzed the levels of miR‐31 in saliva of patients with oral carcinoma (n = 45), oral verrucous leukoplakia (n = 10), and control healthy individuals (n = 24) by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR).

Results

Salivary miR‐31 was significantly increased in patients with oral carcinoma at all clinical stages, including very small tumors. However, our preliminary analysis showed no increase of salivary miR‐31in patients with oral verrucous leukoplakia relative to controls. The miR‐31 was more abundant in saliva than in plasma, suggesting salivary miR‐31 was a more sensitive marker for oral malignancy. After excision of oral carcinoma, salivary miR‐31 was remarkably reduced, indicating that most of the upregulated salivary miR‐31 came from tumor tissues.

Conclusion

Our results point to a potential application of salivary miR‐31 as a biomarker for early detection and postoperative follow‐up of oral carcinoma. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Radical Cyclization of Fluorinated 1,3‐Dicarbonyl Compounds with Dienes Using Manganese(III) Acetate and Synthesis of Fluoroacylated 4,5‐Dihydrofurans
Authors: Yılmaz Mehmet , Yılmaz E. Vildan Burgaz , Pekel A. Tarık
Published: November 2011

Radical cyclizations of fluorinated 1,3‐dicarbonyl compounds with dienes mediated by Mn(OAc)3 afforded 4,5‐dihydrofurans containing difluoroacetyl, trifluoroacetyl, or heptafluorobutanoyl groups in good‐to‐excellent yields. Additionally, 2‐(difluoromethyl)‐4,5‐dihydrofurans and a 4,7‐dihydrooxepin derivative were obtained as unexpected products in the reaction of 4,4‐difluoro‐1‐phenylbutane‐1,3‐dione with 1,3‐diphenylbuta‐1,3‐diene. The radical cyclization of symmetrical dienes such as 2,3‐dimethylbuta‐1,3‐diene and 1,4‐diphenylbuta‐1,3‐diene with 1,3‐diketones furnished the corresponding products in low yields. However, treatment of 1‐phenylbuta‐1,3‐diene with 1,3‐dicarbonyl compounds afforded 4,5‐dihydrofurans containing fluoroacyl groups. The radical cyclizations with 3‐methyl‐1‐phenylbuta‐1,3‐diene and 1,3‐diphenylbuta‐1,3‐diene led to 4,5‐dihydrofurans in good yields, since Me and Ph groups at C(3) of these dienes increase the stability of the radical intermediate.
Euphane Triterpenes from the Bark of Broussonetia papyrifera
Authors: Zhong Han‐Ting , Li Fu , Chen Bin , Wang Ming‐Kui
Published: November 2011

Four new euphane triterpenes, (3β)‐3‐(acetyloxy)eupha‐7,25‐dien‐24‐one (1), (3β,24R)‐3‐(acetyloxy)eupha‐7,25‐dien‐24‐ol (2), (3β,24S)‐eupha‐7,25‐diene‐3,24‐diol (3), and (3β,24R)‐eupha‐7,25‐diene‐3,24‐diol (4) were isolated from the barks of Broussonetia papyrifera, a tree whose roots, barks, and fruits were used as herbal drugs in China. The structures of 1–4 were elucidated on the basis of spectroscopic evidence and chemical methods.
The Synthesis of Epiboxidine and Related Analogues as Potential Pharmacological Agents
Authors: Kulu Irem , Ocal Nuket
Published: November 2011

Methyl epiboxidine‐N‐carboxylate (8) was synthesized from 7 under reductive Heck conditions (Scheme 2). The CC coupling of the new epiboxidine analog 9 with aryl and heteroaryl halides gave by hydroarylation C‐aryl, N‐(3‐methylisoxazol‐5‐yl)‐substituted tricyclic imides 10a–10f (Table). The [3+2] cycloaddition of 9 with nitrile oxides yielded the bridged dihydroisoxazole derivatives 11a–11d with potential biological activity (Scheme 4).
Acylated Triterpene Saponins from Atroxima libericaStapf
Authors: Tabopda Turibio Kuiate , Mitaine‐Offer Anne‐Claire , Miyamoto Tomofumi , Tanaka Chiaki , Mirjolet Jean‐François , Duchamp Olivier , Ngadjui Bonaventure Tchaleu , Lacaille‐Dubois Marie‐Aleth
Published: November 2011

The four new acylated triterpene saponins 1–4, isolated as two pairs of isomers and named libericosides A1/A2 and B1/B2, one pair of isomers 5/6, the (Z)‐isomer libericoside C2 (5) being new, one new sucrose ester, atroximoside (7), and eight known compounds were isolated from the roots of Atroxima liberica by repeated MPLC and VLC on normal and reversed‐phase silica gel. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR studies (1H‐ and 13C‐NMR, DEPT, COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3‐O‐β‐D‐glucopyranosylpresenegenin 28‐{O‐α‐L‐arabinopyranosyl‐(1→3)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]‐β‐D‐fucopyranosyl} ester (1) and its (Z)‐isomer 2, 3‐O‐β‐D‐glucopyranosylpresenegenin 28‐{O‐α‐L‐arabinopyranosyl‐(1→4)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[O‐β‐D‐xylopyranosyl‐(1→3)‐β‐D‐glucopyranosyl‐(1→3)]‐4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]‐β‐D‐fucopyranosyl} ester (3) and its (Z)‐isomer 4, 3‐O‐β‐D‐glucopyranosylpresenegenin 28‐{O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[6‐O‐acetyl‐β‐D‐glucopyranosyl‐(1→3)]‐4‐O‐[(Z)‐3,4‐dimethoxycinnamoyl]‐β‐D‐fucopyranosyl} ester (5), and 3‐O‐[(Z)‐feruloyl]‐β‐D‐fructofuranosyl α‐D‐glucopyranoside (7). Compounds 1–6 and the known saponins 8/9 were evaluated against the human colon cancer cells HCT 116 and HT‐29 and showed moderate to weak cytotoxicity.
Two New Prenylated Xanthones from the Pericarp of Garcinia mangostana (Mangosteen)
Authors: Zhou Xiaojun , Huang Riming , Hao Jing , Huang Huijuan , Fu Manqin , Xu Zhifang , Zhou Yongmei , Li Xu‐E , Qiu Samuel X. , Wang Bin
Published: November 2011

Two new prenylated xanthones (=9H‐xanthen‐9‐ones), garcimangosxanthones D (1) and E (2), together with the six known xanthones 3–8, were isolated from the pericarp of Garcinia mangostana. Their structures were determined by analysis of their spectroscopic data. All of the isolated compounds were biologically evaluated for their in vitro cytotoxic activity against A549, Hep‐G2, and MCF‐7 human‐cancer cell lines and antioxidant activity. Compound 1 exhibited moderate cytotoxicity against Hep‐G2 (IC50=19.2 μM) and weak cytotoxicity against MCF‐7 (IC50=62.8 μM) cell lines, and compound 2 showed moderate cytotoxicity against A549, Hep‐G2, and MCF‐7 cell lines with IC50 values of 12.5–20.0 μM (Table 2). Both compounds 1 and 2 demonstrated a weak antioxidant activity with ferric reducing antioxidant power (FRAP) values of 41±7 and 130±4 μmol/g, respectively (Table 3).
Bruceines K and L from the Ripe Fruits of Brucea javanica
Authors: Zhao Ming , Lau Sin Ting , Zhang Xiao Qi , Ye Wen Cai , Leung Po Sing , Che Chun‐Tao , Lin Zhi‐Xiu
Published: November 2011

Bruceine K (1), a pentacyclic C20‐quassinoid bearing a unique 12,20‐epoxy moiety, and bruceine L (2), along with the ten known compounds (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one (3 and 4, resp.), cleomiscosins A–C, luteoline, quercetine, bruceantinol, pinoresinol, and thevetiaflavone, were isolated from the ripe fruits of Brucea javanica. Bruceines K (1) and L (2) were determined to be (1β,2α,11β,12β,14ξ,15β)‐12,20‐epoxy‐1,2,11,13,14,15‐hexahydroxypicras‐3‐en‐16‐one and (1β,2α,11β,12β,15β)‐13,20‐epoxy‐1,2,11,12‐tetrahydroxy‐16‐oxo‐15‐(senecioyloxy)picras‐3‐en‐21‐oic acid methyl ester (senecioic acid=3‐methylbut‐2‐enoic acid), respectively, on the basis of NMR (1H‐ and 13C‐NMR, DEPT, 1H,1H‐COSY, NOESY, HMQC, and HMBC) and ESI‐MS data. Among the known compounds, (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one (3 and 4, resp.), cleomiscosin C, luteoline, quercetine, and thevetiaflavone were isolated for the first time from the Brucea plants.
Stereochemical Investigation of Macrocyclic Bisbibenzyls with a Stereogenic Center at One of the Ethylene Bridges
Authors: Xie Chun‐Feng , Zhu Rong‐Xiu , Qu Jian‐Bo , Wang Li‐Ning , Guo Dong‐Xiao , Yu Wen‐Tao , Liu Cheng‐Bu , Lou Hong‐Xiang
Published: November 2011

7′‐Hydroxyriccardin C (1) and marchantin E (2), two macrocyclic bisbibenzyls with a stereogenic center at the ethylene bridge from Chinese liverworts, were investigated stereochemically. Compound 1 was found to be optically active and occurred as a pair of dynamically interchangeable atropisomers at room temperature due to the low barrier of rotation around the biaryl bond, while 2 was a racemic mixture, which was successfully resolved by chiral HPLC into two enantiomers. Their absolute configurations were unequivocally assigned by analysis of temperature‐dependent NMR spectra, X‐ray crystallographic diffraction, and comparison of experimental and calculated ECD data.
Nepethalates A and B: Two New Phthalate Derivatives from Nepeta clarkei
Authors: Hussain Javid , Rehman Najeeb Ur , Hussain Hidayat , Ali Liaqat , Al‐Harrasi Ahmed , Ahmad Viqar Uddin
Published: November 2011

The structure elucidation of two new phthalate derivatives named nepethalates A (1) and B (2) is reported. Both of these secondary metabolites were isolated from the MeOH extract of Nepeta clarkei. HR‐EI‐MS, IR and UV absorption spectrometry, and NMR experiments including COSY, HMQC, and HMBC were used for the determination of the structures and complete 1H‐ and 13C‐NMR assignments.
Synthesis of 2‐Aryl‐2,3‐dihydro‐3‐sulfanyl‐1H‐isoindol‐1‐ones by Pummerer‐Type Cyclization of N‐Aryl‐2‐(sulfinylmethyl)benzamides
Authors: Kobayashi Kazuhiro , Hashimoto Hiroo , Suzuki Teruhiko , Konishi Hisatoshi
Published: November 2011

An efficient method for the synthesis of 2‐aryl‐2,3‐dihydro‐3‐sulfanyl‐1H‐isoindol‐1‐ones 1 via Pummerer‐type cyclization of N‐aryl‐2‐(sulfinylmethyl)benzamides 2 is described. Thus, treatment of these sulfinyl‐benzamides 2, easily prepared from 2‐(bromomethyl)benzoates 3 in three steps, with Ac2O at ca. 100° resulted in the formation of the desired isoindolones 1 in generally good yields.
Improved Large‐Scale Liquid‐Phase Synthesis and High‐Temperature NMR Characterization of Short ­(F‐)PNAs
Authors: Plöger Tobias A. , von Kiedrowski Günter
Published: November 2011

We report on a large‐scale synthesis of F‐PNA trimer 10 and PNA trimer 11. The key improvement is the facile two‐step synthesis of (2,4‐difluoro‐5‐methylphenyl)acetic acid (2). Water solubility of the corresponding F‐PNA oligomer 10 was achieved by synthesizing solubility enhancer 5a, which is twofold positively charged and only consists of inherent structural elements of PNA. Protected and unpaired PNA n‐mers exist in a mixture of 2n conformers undergoing slow exchange and leading to complicated NMR spectra. Structure analysis was improved by recording 1H‐ and 13C‐NMR spectra at elevated temperatures above the coalescence point. Fully protected backbone derivatives show sharp resonances where expected, and spectra of protected PNAs are remarkably simplified, thereby allowing an interpretation for the first time. Both trimers 10 and 11 are considered as building blocks for a self‐replicating system based on PNA.
Modification of poly(ether urethane) with fluorinated phosphorylcholine polyurethane for improvement of the blood compatibility
Authors: Tan Dongsheng , Zhang Xiaoqing , Li Jiehua , Tan Hong , Fu Qiang
Published: November 2011

In order to improve the blood compatibility, poly(ether urethane) (PEU) and fluorinated phosphorylcholine polyurethane (P‐HFPC) were used to prepare PU/P‐HFPC blends by solution mixing. The hemocompatibility in vitro was evaluated with protein adsorption and platelet‐rich plasma (PRP) contact tests. It was found that the amount of adsorbed protein on surface was decreased by 87%, and almost no platelet adhesion and activation was observed on the surface of blends when P‐HFPC content was above 5 wt %. After adding P‐HFPC, the blends basically kept favorable mechanical properties of PEU though the content of P‐HFPC rises to 20 wt %. To better understand the relationship between structure and properties, the phase structure and surface property of the blend films were further investigated via differential scanning calorimetry, dynamic mechanical analysis, atomic force microscopy, X‐ray photoelectron spectroscopy, and contact angle measurements. The results indicated that the fluorinated phosphorylcholine units could be easily enriched on the surface of blend films due to the phase separation between the PEU and P‐HFPC. Therefore, ordinary poly(ether urethane)s can obtain both satisfactory blood compatibility and good mechanical properties just by blending with small amount of P‐HFPC. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Valorization of residual woody biomass (Olea europaea trimmings) based on aqueous fractionation
Authors: Requejo Ana , Peleteiro Susana , Rodríguez Alejandro , Garrote Gil , Parajó Juan Carlos
Published: November 2011

BACKGROUND: Olive tree trimmings, a widely available agricultural residue lacking added value applications, were subjected to treatments with hot, compressed water under a variety of operational conditions. As a result of treatments, hemicelluloses were solubilized, and the treated solids were enriched in cellulose and lignin. Spent solids from autohydrolysis were assayed as substrates for enzymatic hydrolysis and for bioethanol production by simultaneous saccharification and fermentation.

RESULTS: Liquors from the aqueous fractionation stage resulted in the formation of soluble hemicellulose‐derived saccharides (mainly of oligomeric nature) at yields up to 26.2 g per 100 g oven‐dry raw material. Enzymatic hydrolysis of spent solids from the aqueous fractionation step led to solutions containing up to 58.8 g glucose L−1 (corresponding to cellulose to glucose conversions up to 83.2%). Simultaneous saccharification and fermentation assays using spent solids as substrates enabled the production of media containing up to 38.2 g ethanol L−1, corresponding to 72% of the stoichiometric amount.

CONCLUSION: Aqueous (or hydrothermal) processing is a technology enabling the recovery of hemicelluloses (as soluble saccharides) and the production of spent solids with high susceptibility to enzymatic hydrolysis (suitable for bioethanol production by simultaneous saccharification and fermentation). Copyright © 2011 Society of Chemical Industry
Chemical composition of ripe fruits of Rubus chamaemorus L. grown in different habitats
Authors: Jaakkola Mari , Korpelainen Ville , Hoppula Kalle , Virtanen Vesa
Published: November 2011

BACKGROUND: Cloudberry (Rubus chamaemorus L.) is one of the most valuable berry‐producing plants because of its nutritional properties. The chemical composition and crop yield of ripe fruits of cloudberry grown wild in 10 habitats in northern Finland was analysed over two consecutive summers. For comparison, two clones of cultivated cloudberries were studied as well.

RESULTS: The concentrations of citric and malic acids, α‐tocopherol, anthocyanins and β‐carotene had notable variations between habitats. In particularly, cloudberries grown on open habitats had higher content of citric acid and less α‐tocopherol compared to those grown on shaded sites. In a colder and rainy summer the content of anthocyanins and the unsaturation level of fatty acids were significantly higher than in a warmer and drier summer. Crop yields were higher in the warmer summer, except in open sites where yields were quite equal.

CONCLUSION: Cloudberries grown in open habitats showed notable differences in chemical composition when compared to those grown on shaded sites. Results suggest that the amount of sunlight and temperature levels could be the main factors affecting crop yield and chemical composition of cloudberry. In addition, the amount of rainfall may have an effect on anthocyanin concentrations. Copyright © 2011 Society of Chemical Industry
HILIC‐MS/MS method development for targeted quantitation of metabolites: Practical considerations from a clinical diagnostic perspective
Authors: Rappold Brian A. , Grant Russell P.
Published: November 2011

The development of targeted assays for polar molecules is a persistent challenge in quantitative metabolite measurement. In addressing these challenges, hydrophilic interaction liquid chromatography (HILIC) has proved to be a valuable, though under‐used and poorly understood chromatographic technique. This work has addressed a number of components that are intrinsic in development of a high‐throughput, specific and sensitive assay for metabolites using HILIC‐MS/MS. Generally accepted HILIC doctrine, such as addition of water to all mobile phases and re‐equilibration time, was shown to be flawed under gradient HILIC mode. The effect of non‐classical mobile phase additives on HILIC‐MS/MS specificity, sensitivity and assay throughput was shown for endogenous metabolites. A broad evaluation of columns and mobile phases for the retention of varied molecular classes was performed, elucidating the empirical nature of HILIC method development. Application of the empirical evaluations performed in the paper was demonstrated by detailing a method development cycle for methylmalonic acid to achieve a highly selective and sensitive HILIC‐MS/MS quantitation capable of high‐throughput analysis for clinical utility.
Separation and purification of isorhamnetin 3‐sulphate from Flaveria bidentis (L.) Kuntze by counter‐current chromatography comparing two kinds of solvent systems
Authors: Xie Qianqian , Yin Li , Zhang Guoliang , Wei Yun
Published: November 2011

The first preparative separation of a flavonoid sulphate isorhamnetin 3‐sulphate from Flaveria bidentis (L.) Kuntze by counter‐current chromatography (CCC) was presented. Two kinds of solvent systems were used. A conventional organic/aqueous solvent system n‐butanol–ethyl acetate–water (4:1:5, v/v) was used, yielding isorhamnetin 3‐sulphate 2.0 mg with a purity of 93.4% from 83 mg of pre‐enriched crude extract obtained from 553 mg ethanol extract by macroporous resin. A one‐component organic/salt‐containing system composed of n‐butanol–0.25% sodium chloride aqueous solution (1:1, v/v) was also used, and the LC column packed with macroporous resin has been employed for desalination of the target compound purified from CCC. As a result, 2.1 mg of isorhamnetin 3‐sulphate with a purity of over 97% has been isolated from 402 mg of crude extract without pre‐enrichment. Compared with the conventional organic/aqueous system, the one‐component organic/salt‐containing aqueous system was more suitable for the separation of isorhamnetin 3‐sulphate, and purer target compound was obtained from the crude extract without pre‐enrichment using the new solvent system. The chemical structure was confirmed by ESI‐MS and 1H, 13C NMR. In summary, our results indicated that CCC using one‐component organic/salt‐containing aqueous solution is very promising and powerful for high‐throughput purification of isorhamnetin 3‐sulphate from Flaveria bidentis (L.) Kuntze.
Electromembrane extraction of peptides – Fundamental studies on the supported liquid membrane
Authors: Seip Knut Fredrik , Stigsson Jeanette , Gjelstad Astrid , Balchen Marte , Pedersen‐Bjergaard Stig
Published: November 2011

A large screening of different components in the supported liquid membrane (SLM) in electromembrane extraction (EME) was performed to test the extraction efficiency on eight model peptides. Electromembrane extraction from a 500 μL acidified aqueous sample containing the model peptides in the concentration 10 μg/mL was used. Extraction time was 5 min with an electric potential of 10 V and 900 rpm agitation of the sample vial. The samples were extracted through a hollow fiber‐based SLM with different compositions of organic solvents and carriers. A small volume of acidified acceptor solution (25 μL) was after extraction analyzed directly, or with some dilution, on CE or HPLC. This article has identified mono‐ or di‐substituted phosphate groups as the prominent group of carrier molecules needed to obtain acceptable recoveries. For the organic solvents, primary alcohols and ketones have shown promise regarding recovery and reproducibility, with some differences in selectivity. A new composition of the SLM, namely 2‐octanone and tridecyl phosphate (90:10 w/w) has proved to give higher extraction recoveries and lower standard deviation than SLMs previously reported in the literature.
Determination of quinine in beverages by online coupling capillary isotachophoresis to capillary zone electrophoresis with UV spectrophotometric detection
Authors: Mikuš Peter , Maráková Katarína , Veizerová Lucia , Piešt'anský Juraj
Published: November 2011

The present study illustrates the possibilities of capillary isotachophoresis (CITP) online coupled with capillary zone electrophoresis (CZE) and hyphenated with fiber‐based spectrophotometric diode array detection (DAD) for the direct, highly reliable, and ultrasensitive determination of quinine (QUI) in real multicomponent ionic matrices (beverages). Here, the CITP provided an effective online sample pretreatment (preseparation and preconcentration) prior to the CZE separation. Due to the CITP sample preconcentration, a simple UV–visible absorbance spectrophotometric detection was sufficient for obtaining very low concentration limits of detection (∼2.3 ng/mL). Enhanced separation selectivity due to the combination of different separation mechanisms (CITP vs. CZE) enabled to obtain a pure analyte zone, suitable for its detection and quantitation in the directly injected real samples. The spectrophotometric DAD, unlike single wavelength UV detection, enabled to characterize the purity (i.e. spectral homogeneity) of the analyte zone and preliminary data indicate structurally related compounds via characteristic spectra recorded in the interval of 200–600 nm. The proposed CITP–CZE–DAD method was characterized by favorable performance parameters (sensitivity, linearity, precision, recovery, accuracy, robustness, and selectivity) and successfully applied to the control of QUI and potential QUI impurities in commercial beverages. This method is proposed as a routine automatized method for the highly reliable quality food control.
Determination of hydrate inhibitor in crude oil by nanoextraction–gas chromatography
Authors: Mokhtari Bahram , Pourabdollah Kobra
Published: November 2011

This work focused on the quantitation of methanol as a hydrate inhibitor in crude oil. The novelty is nanoextraction of a polar compound from a complex non‐polar matrix and selection of the proper fiber with maximum selectivity, loading percent, and lifetime. This approach not only does not require specific instrumentation, such as multiple columns and selective detectors, but also has eliminated the use of organic solvent and avoids the insertion of water inside the GC columns. The objective is optimization of extraction conditions, GC adjustments, and data processing. Experiments were conducted on the real sample of Iranian offshore crude oil by a carboxen/PDMS fiber via GC equipped with a cross‐linked polyethylene glycol column and flame ionization detector. The results revealed that this fiber adsorbed the alcohols among other light non‐polar compounds of crude oil. Moreover, the interference effects of ethanol were solved by proper selection of the thermal program. The LOD, LOQ, and linear range of this approach were determined to be 3.9, 12.9, and 14–229 ppm for methanol, respectively. Using the standard calibration and the standard addition methods, the relative errors of 1.6–7.2 and 5.3–14.0% were determined.
Catechol‐O‐methyltransferase Val158Met and the risk of dyskinesias in Parkinson's disease
Authors: de Lau Lonneke M.L. , Verbaan Dagmar , Marinus Johan , Heutink Peter , van Hilten Jacobus J.
Published: November 2011

Background:

The A‐allele of the catechol‐O‐methyltransferase (COMT) Val158Met polymorphism is associated with decreased enzymatic activity and higher dopamine availability.

Methods:

We studied 219 patients with PD who were free of dyskinesias at baseline and underwent thorough annual examinations.

Results:

The A‐allele of the COMT Val158Met polymorphism was related to an increased risk of developing dyskinesias during follow‐up, in a dose‐dependent manner (adjusted hazard ratios for the AG and AA genotypes [compared to GG]: 2.09 [95% confidence interval (CI), 1.07–4.06] and 2.81 [CI, 1.43–5.54], respectively).

Conclusions:

This finding suggests that genetic factors may affect susceptibility to dyskinesias in PD. © 2011 Movement Disorder Society
A new radar‐based storm identification and warning technique
Authors: Li Nan , Wei Ming , Niu Ben , Mu Xiyu
Published: November 2011

A new storm identification and warning technique is proposed which exclusively uses radar data as input. The new identification method assembles contiguous storm points to constitute 2D storm components and improve the vertical association of storm components to construct 3D storms, which can overcome the deficiencies existing in traditional identification methods. Based on the evolution properties and characteristic distributions, strong storms and general storms are specified to train support vector machines (SVMs) which then can be used to discriminate storms. The performance of the SVM shows that it can indicate the intensity and development of a storm, providing an important aid in severe weather warning. Copyright © 2011 Royal Meteorological Society
Accelerated phase‐contrast cine MRI using k‐t SPARSE‐SENSE
Authors: Kim Daniel , Dyvorne Hadrien A. , Otazo Ricardo , Feng Li , Sodickson Daniel K. , Lee Vivian S.
Published: November 2011

Phase‐contrast (PC) cine MRI is a promising method for assessment of pathologic hemodynamics, including cardiovascular and hepatoportal vascular dynamics, but its low data acquisition efficiency limits the achievable spatial and temporal resolutions within clinically acceptable breath‐hold durations. We propose to accelerate PC cine MRI using an approach which combines compressed sensing and parallel imaging (k‐t SPARSE‐SENSE). We validated the proposed 6‐fold accelerated PC cine MRI against 3‐fold accelerated PC cine MRI with parallel imaging (generalized autocalibrating partially parallel acquisitions). With the programmable flow pump, we simulated a time varying waveform emulating hepatic blood flow. Normalized root mean square error between two sets of velocity measurements was 2.59%. In multiple blood vessels of 12 control subjects, two sets of mean velocity measurements were in good agreement (mean difference = −0.29 cm/s; lower and upper 95% limits of agreement = −5.26 and 4.67 cm/s, respectively). The mean phase noise, defined as the standard deviation of the phase in a homogeneous stationary region, was significantly lower for k‐t SPARSE‐SENSE than for generalized autocalibrating partially parallel acquisitions (0.05 ± 0.01 vs. 0.19 ± 0.06 radians, respectively; P < 0.01). The proposed 6‐fold accelerated PC cine MRI pulse sequence with k‐t SPARSE‐SENSE is a promising investigational method for rapid velocity measurement with relatively high spatial (1.7 mm × 1.7 mm) and temporal (∼35 ms) resolutions. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Ultrahigh field systems and applications at 7 T and beyond: Progress, pitfalls, and potential
Authors: Bandettini Peter A. , Bowtell Richard , Jezzard Peter , Turner Robert
Published: November 2011

About 150 researchers around the world convened at the Chateau Lake Louise on February 20–23, 2011 to present and discuss the latest research in human and animal imaging and spectroscopy at field strengths of 7 T or above (termed ultrahigh field) at the third ISMRM‐sponsored high field workshop. The clear overall message from the workshop presentations and discussion is that ultrahigh field imaging is gaining momentum with regard to new clinically relevant findings, anatomic and functional MRI results, susceptibility contrast advancements, solutions to high field‐related image quality challenges, and to generally push the limits of resolution and speed of high field imaging. This meeting report is organized in a manner reflecting the meeting organization itself, covering the seven sessions that were approximately titled: (1) high field overview from head to body to spectroscopy; (2) susceptibility imaging; (3) proffered session on susceptibility, ultrafast imaging, unique contrast at 7 T, and angiography; (4) neuroscience applications; (5) proffered session on coils, shimming, parallel imaging, diffusion tensor imaging, and MRI‐PET fusion; (6) high field animal imaging and spectroscopy, as well as a vendor overview, and (7) Cutting edge technology at 7 T. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Robust discrimination of glioblastomas from metastatic brain tumors on the basis of single‐voxel 1H MRS
Authors: Vellido A. , Romero E. , Julià‐Sapé M. , Majós C. , Moreno‐Torres À. , Pujol J. , Arús C.
Published: November 2011

This article investigates methods for the accurate and robust differentiation of metastases from glioblastomas on the basis of single‐voxel 1H MRS information. Single‐voxel 1H MR spectra from a total of 109 patients (78 glioblastomas and 31 metastases) from the multicenter, international INTERPRET database, plus a test set of 40 patients (30 glioblastomas and 10 metastases) from three different centers in the Barcelona (Spain) metropolitan area, were analyzed using a robust method for feature (spectral frequency) selection coupled with a linear‐in‐the‐parameters single‐layer perceptron classifier. For the test set, a parsimonious selection of five frequencies yielded an area under the receiver operating characteristic curve of 0.86, and an area under the convex hull of the receiver operating characteristic curve of 0.91. Moreover, these accurate results for the discrimination between glioblastomas and metastases were obtained using a small number of frequencies that are amenable to metabolic interpretation, which should ease their use as diagnostic markers. Importantly, the prediction can be expressed as a simple formula based on a linear combination of these frequencies. As a result, new cases could be straightforwardly predicted by integrating this formula into a computer‐based medical decision support system. This work also shows that the combination of spectra acquired at different TEs (short TE, 20–32 ms; long TE, 135–144 ms) is key to the successful discrimination between glioblastomas and metastases from single‐voxel 1H MRS. Copyright © 2011 John Wiley & Sons, Ltd.
The effect of an educational intervention on meperidine use in Nova Scotia, Canada: a time series analysis
Authors: Fisher Judith E. , Zhang Ying , Sketris Ingrid , Johnston Grace , Burge Fred
Published: November 2011

Purpose

To evaluate the impact of a prescriber focused individual educational and audit–feedback intervention undertaken by the Nova Scotia Prescription Monitoring Program (NSPMP) in March/April 2007 to reduce meperidine use.

Method

The NSPMP records all prescriptions for controlled substances dispensed in community pharmacies in Nova Scotia, Canada. Oral meperidine use from 1 July 2005 to 31 December 2009 was examined using NSPMP data. Monthly totals for the following were obtained: number of individual patients who filled at least one meperidine prescription, number of prescriptions, and number of tablets dispensed. Data were analyzed graphically to observe overall trends. The intervention effect was estimated on the logarithmic scale with autocorrelations over time modeled by an integrated autoregressive moving average model for each outcome measure.

Results

An overall trend toward decreasing use from July 2005 to December 2009 was apparent for all three outcome measures. The intervention was associated with a statistically significant reduction in meperidine use, after adjusting for the overall long‐term trend. Compared with the pre‐intervention period, the monthly number of patients declined by 12% (p < 0.001; 95% confidence interval [CI] = 5%–18%), prescriptions by 10% (p < 0.001; 95%CI = 3%–17%), and tablets by 13.5% (p < 0.001, 95%CI = 6%–29%) in the post‐intervention period.

Conclusion

Given the risks associated with meperidine, determining that this intervention successfully reduced meperidine use is encouraging. This study highlights the potential for using population data such as the NSPMP to evaluate the effectiveness of population‐level interventions to improve medication use, including professional, organizational, financial, and regulatory initiatives. Copyright © 2011 John Wiley & Sons, Ltd.
Formation of poly(octadecyl acrylate) brushes on a silicon wafer surface
Authors: Öztürk Esra , Turan Eylem , Caykara Tuncer
Published: November 2011

To introduce an ultrahydrophobic polymeric phase onto a silicon wafer, an initiator‐modified silicon wafer was prepared with 2‐bromopropionyl bromide and then surface‐initiated atom transfer radical polymerization of octadecyl acrylate was carried out from the initiator‐grafted silicon wafer using CuBr and N,N,N′,N″‐pentamethyldiethylenetriamine as catalyst precursors. The resultant poly(octadecyl acrylate) [poly(ODA)] brushes were characterized by ellipsometry, X‐ray photoelectron spectroscopy, grazing angle Fourier transform infrared spectroscopy, atomic force microscopy, gel permeation chromatography and water contact angle measurements. Wettability of the poly(ODA) brushes was found to depend on the surface coverage (Γ) and the root mean square roughness. The most hydrophobic surface (Γ = 25.35 mg m−2 and root mean square roughness 11.9 nm) exhibited a water contact angle of 171.1 ± 0.2°. Copyright © 2011 Society of Chemical Industry
Transparent conductive oxide‐less three‐dimensional cylindrical dye‐sensitized solar cell fabricated with flexible metal mesh electrode
Authors: Usagawa Jun , Pandey Shyam S. , Ogomi Yuhei , Noguchi Sho , Yamaguchi Yoshihiro , Hayase Shuzi
Published: November 2011

A cylindrical transparent conductive oxide‐less dye‐sensitized solar cell (DSSC) consisting of glass tube/stainless steel mesh–TiO2–dye/gel electrolytes/Pt‐Ti rod having capability of self‐light trapping is reported. Replacing the glass tube with heat‐shrinkable tube to reduce electrolyte gap and optical loss due to light transmission and reflection led to the enhancement in the power conversion efficiency from 2.61% to 3.91%. Profiling of the current distribution measured by laser beam‐induced current exhibited nearly the same current in the axial and radial directions, suggesting that light reflection on a cylindrical DSSC does not affect the efficiency seriously. Optimized best DSSC in this novel device architecture gave a short‐circuit current density of 11.94 mA/cm2, an open‐circuit voltage of 0.71 V and a fill factor of 0.66 leading to the power conversion efficiency of 5.58% at AM 1.5 under simulated solar irradiation. Copyright © 2011 John Wiley & Sons, Ltd.
Quadratic corrections to three‐point functions
Authors: Arnaudov D. , Rashkov R.C.
Published: November 2011

Following the recent progress on the calculation of three‐point correlators with two “heavy” (with large quantum numbers) and one “light” states at strong coupling, we compute the logarithmic divergent terms of leading bosonic quantum corrections to correlation functions with “heavy” operators corresponding to simple string solutions in AdS5 × S5. The “light” operator is chosen to be the dilaton. An important relation connecting the corrections to both the dimensions of “heavy” states, and the structure constants is recovered.
Asthma management: stop, think and review before moving to step 3
Authors: Haughney John , Holmes Steve , Scullion Jane
Published: November 2011

In this Expert Panel Discussion the participants discuss the factors that should be considered before a patient is moved from step 2 to step 3 of asthma therapy. Copyright © 2011 Wiley Interface Ltd
Antibacterial Compounds from the Mushroom Ganoderma colossum from Nigeria
Authors: Ofodile L. N. , Uma N. , Grayer R. J. , Ogundipe O. T. , Simmonds M. S. J.
Published: November 2011

Three colossolactones (colossolactone E, colossolactone B and 23‐hydroxycolossolactone E) were isolated and characterized from an n‐hexane:dichloromethane (2:7) extract of Ganoderma colossum using chromatographic techniques. The antimicrobial activity of the three compounds was then tested against Gram‐positive and Gram‐negative bacteria. The activity was evaluated by the thin‐layer chromatography agar overlay method. The results showed that colossolactone E and 23‐hydroxycolossolactone E were active against Bacillus subtilis and Pseudomonas syringae. Colossolactone B was not active against the bacteria. Their structures were elucidated by spectroscopic methods. Potency of the compounds against bacteria tested supports the use of this mushroom in therapeutic medicine. Copyright © 2011 John Wiley & Sons, Ltd.
A linear mixed model for predicting a binary event from longitudinal data under random effects misspecification
Authors: Albert Paul S.
Published: November 2011

The use of longitudinal data for predicting a subsequent binary event is often the focus of diagnostic studies. This is particularly important in obstetrics, where ultrasound measurements taken during fetal development may be useful for predicting various poor pregnancy outcomes. We propose a modeling framework for predicting a binary event from longitudinal measurements where a shared random effect links the two processes together. Under a Gaussian random effects assumption, the approach is simple to implement with standard statistical software. Using asymptotic and simulation results, we show that estimates of predictive accuracy under a Gaussian random effects distribution are robust to severe misspecification of this distribution. However, under some circumstances, estimates of individual risk may be sensitive to severe random effects misspecification. We illustrate the methodology with data from a longitudinal fetal growth study. Copyright © 2011 John Wiley & Sons, Ltd.