bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenolic compounds in the brown seaweed Ascophyllum nodosum: distribution and radical‐scavenging activities
Authors: Audibert Laetitia , Fauchon Marilyne , Blanc Nathalie , Hauchard Didier , Ar Gall Erwan 
Published: March 2010

AbstractIntroduction – Phenolic compounds are metabolites exhibited at high levels in Phaeophyceae. Although several studies have been conducted on total phenol contents, no one to our knowledge has dealt with the contents of phenolic compounds and antioxidant activities on purified fractions.Objective – The purpose of this study was the extraction and purification of phenolic compounds from the brown seaweed Ascophylllum nodosum, to determine both their distribution and their radical‐scavenging activities, and to obtain a sufficiently purified oligophenolic fraction to perform an RP‐HPLC analysis on molecules with a molecular weight (MW) < 2 kDa.Methodology –Phenolic compounds were separated and purified by liquid–liquid extraction, tangential ultrafiltration and dialysis. Then, the contents of both phenolic compounds and radical‐scavenging activities were measured by the Folin–Ciocalteu reagent, and DPPH and ABTS assays. NMR analysis was performed to validate the process. RP‐HPLC with a C18 column was performed on the oligophenolic fraction, using a novel method developed in this study.Results – Seven fractions were obtained as a function of polarity and molecular weight. Among them, the fraction containing phenolic compounds with a MW ≥ 50 kDa appeared to be the most active, correlated with the content of phenolic compounds.Conclusion – This work constitutes a step forward in the separation and purification of bioactive phlorotannins and represents a prerequisite for further investigations into their structural characterisation and distribution in A. nodosum.
Extraction and characterisation of hemicelluloses from maize stem
Authors: Sun Xiao‐Feng , Fowler Paul , Rajaratnam Mohanathas , Zhang Guangcheng 
Published: March 2010

AbstractIntroduction – Extraction and characterisation of hemicelluloses are very important for converting them into functional materials and chemicals.Objective – To develop a method for isolation of hemicelluloses from all cell walls.Methodology – Sequential steps using 90% dioxane, 80% acidic dioxane, 100% dimethyl sulphoxide and 8% NaOH were used for extraction of the hemicellulosic preparations (H1, H2, H3 and H4) from maize stem. Advanced NMR techniques were used for the analysis of native hemicelluloses.Results – Hemicelluloses with high yieldd were isolated from all cell walls, and contained arabinoxylan as the major polysaccharide. H3 was substituted by α‐l‐arabinofuranose, α‐d‐xylopyranose, and acetyl groups (degree of saturation = 0.12/0.09) at O‐3/O‐2 of xylan. H4 had a long continuous side chain of arabinose residues, and associated closely with non‐cellulosic glucose. The hemicelluloses formed more linkages with guaiacyl lignins, and some p‐coumaric acids built a bridge between hemicelluloses and lignin in maize stem.Conclusion – This modified method is successful for the isolation of hemicelluloses with high yields from all cell walls of maize stem. Copyright © 2010 John Wiley & Sons, Ltd.
Development and Validation of a Micellar Electrokinetic Chromatography Method for Quantitative Determination of Butenolides in Piper malacophyllum (C. Presl) C. DC.
Authors: de Oliveira Alberto , Silva Claudinei A. , Silva Adalberto M. , Tavares Marina F.M. , Kato Massuo J. 
Published: March 2010

AbstractIntroduction – A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination.Objective – To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species.Methodology – The extracts were analysed in an uncoated fused‐silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line.Results – A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0–50.0 µg/mL (r2 = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 µg/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 ± 1.4% of recovery.Conclusions – A novel high‐performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts. Copyright © 2010 John Wiley & Sons, Ltd.
A nitromethane‐based HPLC system alternative to acetonitrile for carotenoid analysis of fruit and vegetables
Authors: Sandmann Gerhard 
Published: March 2010

AbstractAcetonitrile‐based HPLC systems are the most commonly used for carotenoid analysis from different plant tissues. Because of the acetonitrile shortage, an HPLC system for the separation of carotenoids on C18 reversed‐phase columns was developed in which an acetonitrile–alcohol‐based mobile phase was replaced by nitromethane. This solvent comes closest to acetonitrile with respect to its elutrophic property. Our criterion was to obtain similar separation and retention times for a range of differently structured carotenoids. This was achieved by further increase in the lipophilicity with ethylacetate. For all the carotenoids which we tested, we found co‐elution only of β‐cryptoxanthin and lycopene. By addition of 1% of water, separation of this pair of carotenoids was also achieved. The final recommended mobile phase consisted of nitromethane : 2‐propanol : ethyl acetate : water (79 : 10 : 10 : 1, by volume). On Nucleosil C18 columns and related ones like Hypersil C18, we obtained separation of carotenes, hydroxyl, epoxy and keto derivatives, which resembles the excellent separation properties of acetonitrile‐based mobile phases on C18 reversed phase columns. We successfully applied the newly developed HPLC system to the separation of carotenoids from different vegetables and fruit. Copyright © 2010 John Wiley & Sons, Ltd.
Preparative separation of chlorogenic acid by centrifugal partition chromatography from highbush blueberry leaves (Vaccinium corymbosum L.)
Authors: Kim Sang‐Min , Shang Ya Fang , Um Byung‐Hun 
Published: March 2010

AbstractIntroduction – Blueberries (genus Vaccinium) have gained worldwide focus because of the high anthocyanin content of their fruits. In contrast, the leaves of blueberry have not attracted any attention, even though they contain large quantities of chlorogenic acid, a strong antioxidant compound.Objective – The aim of this investigation was the quantification and preparative isolation of chlorogenic acid (5‐caffeoylquinic acid, 5‐CQA) from blueberry leaves using a new separation scheme, centrifugal partition chromatography (CPC).Methodology – A water fraction containing a high concentration of 5‐CQA (14.5% of dry weight extract) was obtained by defatting a crude methanol extract from blueberry leaves. CPC was applied to isolate 5‐CQA from this water fraction using a two‐phase solvent system of ethyl acetate–ethanol–water at a volume ratio 4:1:5 (v/v/v). The flow‐rate of mobile phase was 2 mL/min with the ascending mode while rotating at 1200 rpm. The eluate was monitored at 330 nm. The structure of chlorogenic acid in the CPC fraction was confirmed with HPLC, UV, ESI/MS and NMR spectra.Results – The HPLC chromatogram showed that the fractions collected by CPC contained chlorogenic acid with 96% purity based on peak area percentage. The total amount of chlorogenic acid isolated from 0.5 g of a water fraction was 52.9 mg, corresponding to 10.6% of the water fraction. The isolated compound was identified successively as 5‐CQA with MS (parent ion at m/z 355.1 [M + H]+) and 1H NMR spectra [caffeoyl moiety in the down field (δ 6.0–8.0 ppm) and quinic acid moiety in the up field (δ 2.0–5.5 ppm)].Conclusion – 5‐CQA was successfully isolated from blueberry leaves by the CPC method in a one‐step procedure, indicating a further potential use for blueberry leaves. Copyright © 2010 John Wiley & Sons, Ltd.
Superheated water extraction of essential oils from Cinnamomum zeylanicum (L.)
Authors: Jayawardena Bimali , Smith Roger M. 
Published: March 2010

AbstractIntroduction – Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored.Objective – To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.) bark and leaves as typical plant materials to determine if this extraction method can yield a higher quality oil.Methodology – Samples of cinnamon bark or leaves were extracted at 200°C with water under pressure. The essential oils were obtained from the aqueous solution using a solid phase extraction cartridge and were then examined by GC‐MS.Results – Using superheated water extraction, cinnamon bark oil with over 80% cinnamaldehyde and cinnamon leaf oil containing up to 98% eugenol were obtained. Alternative solvent extraction methods were also studied but led to emulsion formation apparently because of the presence of cellulose breakdown products.Conclusion – Superheated water extraction offers a cheap, environmentally friendly technique with a shorter extraction time than hydrodistillation and yielded a higher quality oil with a higher proportion of eugenol than hydrodistillation. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of lanthanum oxide (La2O3) on the structure and crystallization of poly(vinylidene fluoride)
Authors: Song Jianbin , Lu Chunhua , Xu Dan , Ni Yaru , Liu Yujian , Xu Zhongzi , Liu Jianxun 
Published: March 2010

AbstractRare earth polymers, due to their excellent luminescence, fluorescence, laser protective, optical and magnetic properties, have attracted much research attention in recent years. However, little attention has been paid to the effect of rare earths on the structure and crystallization of polymers, which is of important significance in the development of functional polymers. X‐ray diffraction and differential scanning calorimetry were used to investigate the structure and crystallization behavior of a poly(vinylidene fluoride) (PVDF)/lanthanum oxide (La2O3) composite. The results showed that the degree of perfection, crystal size, crystallization rate and isothermal crystallization activation energy of PVDF in the composite decreased, compared with pure PVDF. The spherulite nucleation and growth for PVDF and PVDF composite were analyzed in detail using the Lauritzen‐Hoffman equation. The modified Avrami equation and the Mo equation were used to study the non‐isothermal crystallization kinetics. The addition of La2O3 did not change the crystal structure and nucleation process for PVDF, but it decreased markedly the crystal growth rate and led to the formation of unstable crystals. This was attributed to the fact that too much La2O3 prevented PVDF molecular chains from moving and arranging in an orderly manner into crystals. Copyright © 2010 Society of Chemical Industry
Garlic as an inhibitor of Pseudomonas aeruginosa quorum sensing in cystic fibrosis—a pilot randomized controlled trial
Authors: Smyth Alan R. , Cifelli Paramita M. , Ortori Catharine A. , Righetti Karima , Lewis Sarah , Erskine Penny , Holland Elaine D. , Givskov Michael , Williams Paul , Cámara Miguel , Barrett David A. , Knox Alan 
Published: March 2010

AbstractPseudomonas aeruginosa forms biofilms in the cystic fibrosis lung. Quorum sensing (QS) controls biofilm maturation, immune evasion, antibiotic tolerance and virulence factor production. Garlic shows QS inhibitory activity in vitro and in animal models. We report the first clinical trial in man of a QS inhibitor.We randomized 34 patients to garlic or olive oil capsules (both 656 mg daily). Clinical outcomes and safety bloods were measured at baseline and after 8 weeks treatment. In this exploratory study, analysis was per protocol.Eight patients withdrew, leaving 26 for analysis (13 garlic). With placebo, there was a greater decline in mean (SD) percentage change from baseline FEV1 [−3.6% (11.3)] than with garlic [−2.0% (12.3)]. This was not significant (mean difference = 1.6, 95% CI −12.7 to 15.9, P = 0.8). The mean (SD) increase in weight was greater with garlic [1.0% (2.0)] than with placebo [0.6% (2.0)]—non‐significant (mean difference = 0.4%, 95% CI −1.3 to 2.0, P = 0.6). The median (range) change in clinical score with garlic was −1 (−3 to 5) and 1 (−1 to 4) with placebo (negative score means improvement). This was non‐significant [median difference = −1 (−3 to 0), P = 0.16]. In the garlic group, seven patients had IV antibiotics versus five placebo. There was a highly significant correlation between plasma and sputum measurements of the QS molecule 3‐oxo‐C12‐HSL (Pearson correlation coefficient = 0.914, P = 0.004). At the end of treatment five patients in each group had abnormal liver function or triglycerides and five garlic patients (one placebo) reported minor adverse effects.Garlic capsules were well tolerated. Although there was no significant effect of garlic compared to placebo in this pilot study, there was a suggestion of improvement with garlic which should be investigated in a larger trial. Pediatr Pulmonol. 2010; 45:356–362. © 2010 Wiley‐Liss, Inc.
A functional polymorphism in MSMB gene promoter is associated with prostate cancer risk and serum MSMB expression
Authors: Xu Bin , Wang JinFeng , Tong Na , Mi YuanYuan , Min ZhiChao , Tao Jun , Li PengChao , Cheng Gong , Li JiuMing , Wang MeiLin , Tang JiaLin , Song NingHong , Zhang ZhengDong , Zhang Wei , Wu HongFei , Hua LiXin , Feng NingHan 
Published: March 2010

AbstractBACKGROUNDTo explore the reported association of SNP marker rs10993994 with prostate cancer identified by two independent in two genome‐wide association studies (GWAS) further, we performed a case–control study in southern Chinese Han population. Consequently, we detected the serum levels of MSMB expression with different genotypes in the cases and controls to characterize the functional consequences of rs10993994.MATERIALS AND METHODSTwo hundred fifty‐one prostate cancer and 258 control subjects were included in the cancer association study and 90 serum samples were used to test the expression of the MSMB by Enzyme‐linked immunosorbent assay (ELISA).RESULTSWe found that the T allele displayed an increased prevalence of prostate cancer compared with the C allele (OR = 1.30, 95% CI = 1.01–1.67, P = 0.040). Moreover, the prostate cancer patients carrying CT/TT genotype had significantly decreased serum MSMB levels compared to those with CC genotype (16.32 ± 3.98 µg/L vs. 19.33 ± 4.27 µg/L, P = 0.022).CONCLUSIONSrs10993994 in MSMB promoter affects serum MSMB expression, contributes to the genetic predisposition to prostate cancer in southern Chinese Han population. Prostate 70: 1146–1152, 2010. © 2010 Wiley‐Liss, Inc.
Energy‐resolved STM maps of finite carbon nanotubes and the role of surface–tube interactions
Authors: De Menech Mario , Saalmann Ulf , Garcia Martin E. 
Published: March 2010

AbstractThe influence of the supporting surface on the standing wave electronic modes of finite metallic carbon nanotubes (CNTs) is discussed. The charge distribution of the states is visualized by simulating the energy resolved scanning tunneling spectroscopy (STS) maps. The Fourier transform of the spatial patterns exhibited by the STS maps allows to reconstruct the dispersion relation, whose definiteness is smeared out for increasing surface–tube interaction strengths. The scattering of the modes in the tube due to the interaction with the surface causes distortions of the simulated maps. For example, the reflection symmetry with respect to the mirror plane perpendicular to the tube axis appears to be broken for modes in the case of narrow tubes, when the interaction with the surface is strong enough.Breaking of the reflection symmetry: STS map for a (4,4) carbon nanotube of length 50a0 near the Fermi level placed at 2.5 Å (upper tube) and 3.0 Å (lower tube) away from an Au(111) surface. Red, green, and blue colored regions refer to large, intermediate and low values of the current, respectively.magnified image
Effect of post‐implantation anneal on the current‐voltage characteristics of IR photodiodes based on p‐CdxHg1‐xTe
Authors: Vishnyakov A. V. , Varavin V. S. , Garifullin M. O. , Predein A. V. , Remesnik V. G. , Sabinina I. V. , Sidorov G. Yu. 
Published: March 2010

AbstractCurrent–voltage characteristics of IR photodiodes and carriers distributions in n+–n– –p ‐structures based on p ‐type CdxHg1‐xTe films with x = 0.22 were examined. 3D numerical modelling of the distribution of charge carriers after photodiode implantation and annealing was performed. The obtained distribution was used to calculate the current–voltage characteristics. The calculations predict that large tunnel currents in diodes after implantation can result from an increased donor concentration (more than 1015 cm‐3) in the n–‐layer, which enhances tunnelling by decreasing the thickness of the space charged region of the n –p ‐junction. Another possible reason is the small (less than 3 μm) depth of the p –n ‐junction. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of molecular beam epitaxy‐grown HgCdTe structures with potential wells
Authors: Ivanov‐Omskii V. I. , Mynbaev K. D. , Bazhenov N. L. , Smirnov V. A. , Mikhailov N. N. , Sidorov G. Yu. , Remesnik V. G. , Varavin V. S. , Dvoretsky S. A. 
Published: March 2010

AbstractPhotoconductivity and photoluminescence of HgCdTe‐based nanostructures with 50 to 200 nm‐wide potential wells were studied. The structures were grown by molecular beam epitaxy on GaAs substrates, and emitted light with wavelengths 2.8–3.8 μm at 300 K. The luminescence properties of the nanostructures at low temperatures were found to be strongly affected by the effect of alloy disorder, which led to a substantial red‐shift of the emission spectrum in relation to energy gap of the wells. This effect could be reduced by post‐growth annealing of the structures, which also increased the luminescence intensity. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of CdS:Mn nanoparticle properties caused by pH of colloid solution and ultrasound irradiation
Authors: Savchuk A. I. , Rudko G. Yu. , Fediv V. I. , Voloshchuk A. G. , Gule E. G. , Ivanchak S. A. , Makoviy V. V. 
Published: March 2010

AbstractThe effects of pH value and precursors concentrations in the growth solution as well as of ultrasound irradiation on the properties of CdS:Mn nanoparticles in PVA matrix are studied. Analysis of the photoluminescence spectra indicates that the increase of the pH value in the growth solution leads to the increase of the density of surface electron states that participate in radiative transitions and to the enlargement of CdS:Mn nanoparticles.We discuss a stabilization of the sizes of CdS:Mn nanoparticles at pH=6 and change of nanoparticle size with decreasing pH value at elevated concentrations of ions HS‐. It is shown that in the ultrasound‐treated samples the size of the particles does not depend on pH value. The effects of ultrasound result primarily from acoustic cavitation. It is demonstrated that the action of two external factors (the value of the medium pH and ultrasound treatment) on the characteristics of nanoparticles is correlated. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive variable structure state estimation for uncertain systems with persistently bounded disturbances
Authors: Wu Huai‐Ning , Shi Peng 
Published: March 2010

AbstractThis paper develops an adaptive state estimator design methodology for nonlinear systems with unknown nonlinearities and persistently bounded disturbances. In the proposed estimation scheme, the boundary layer strategy in variable structure techniques is utilized to design a continuous state estimator such that the undesirable chattering phenomenon is avoided; and the adaptive bounding technique is used for online estimation of the unknown bounding parameter. The existence condition of the adaptive estimators is provided in terms of linear matrix inequality (LMI). Since the orthogonal projection of the state estimation error onto the null space of the linear measurement distribution matrix is used in the derivation process, the update law of bounding parameter estimate is represented in terms of the available measurement error. The proposed estimator can ensure that the state estimation error is uniformly ultimately bounded (UUB) with an ultimate bound. Furthermore, using the existing LMI optimization technique, a suboptimal adaptive state estimator can be obtained in the sense of minimizing an upper bound of the peak gains in the ultimate bound. Finally, a simulation example is given to illustrate the effectiveness of the proposed design method. Copyright © 2010 John Wiley & Sons, Ltd.
Exploratory inspection—a user‐based learning method for improving open source software usability
Authors: Zhao Luyin , Deek Fadi P. , McHugh James A. 
Published: March 2010

AbstractThe increasingly widespread use of open source software (OSS) is an indication of its success. However, as a software development model OSS still has shortcomings that need to be resolved. In particular, the question of usability and its improvement in an OSS context remains a significant ongoing issue that demands further investigation. This is especially so given the unique manner in which OSS diverges from traditional software development models. Current experience with OSS does not favor the existence of a positive relation between the standard OSS development paradigm and good usability practice. We believe that addressing the inadequacy of usability expertise in the OSS community will improve the quality of its products and enhance their competitiveness. Motivated by the unique user‐driven character of the OSS model, we propose an exploratory method for inspection which is intended to assist OSS users in contributing to open source usability inspection. This method provides an effective adaptation of the ‘learning‐by‐doing’ approach to the domain of usability inspection. This is accomplished by innovatively applying usability patterns to guide usability exploration, incorporating strategies for ‘outlining knowledge’ and ‘exploration freedom’ and implementing both techniques in an integrated inspection environment. The results of an experiment involving a group of OSS users inspecting an open source project called dotproject demonstrate that this method outperforms traditional heuristics‐based inspection. The paper also considers the applicability of the usability method and tool developed to usability improvement in the context of traditional proprietary development. Copyright © 2010 John Wiley & Sons, Ltd.