bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microfluidic cell disruption system employing a magnetically actuated diaphragm
Authors: Huh Yun Suk , Choi Jong Hyun , Park Tae Jung , Hong Yeon Ki , Hong Won Hi , Lee Sang Yup 
Published: November 2007

AbstractA microfluidic cell lysis chip equipped with a micromixer and SPE unit was developed and used for quantitative analysis of intracellular proteins. This miniaturized sample preparation system can be employed for any purpose where cell disruption is needed to obtain intracellular constituents for the subsequent analysis. This system comprises a magnetically actuated micromixer to disrupt cells, a hydrophobic valve to manipulate the cell lysate, and a packed porous polymerized monolith chamber for SPE and filtering debris from the cell lysate. Using recombinant Escherichia coli expressing intracellular enhanced green fluorescent protein (EGFP) and lipase as model bacteria, we optimized the cell disruption condition with respect to the lysis buffer composition, mixing time, and the frequency of the diaphragm in the micromixer, which was magnetically actuated by an external magnetic stirrer in the micromixer chamber. The lysed sample prepared under the optimal condition was purified by the packed SPE in the microfluidic chip. At a frequency of 1.96 Hz, the final cell lysis efficiency and relative fluorescence intensity of EGFP after the cell disruption process were greater than 90 and 94%, respectively. Thus, this microfluidic cell disruption chip can be used for the efficient lysis of cells for further analysis of intracellular contents in many applications.
Electrophoresis on a microfluidic chip for analysis of fluorescence‐labeled human rhinovirus
Authors: Kolivoška Viliam , Weiss Victor U. , Kremser Leopold , Gaš Bohuslav , Blaas Dieter , Kenndler Ernst 
Published: November 2007

AbstractWe report the analysis of human rhinovirus serotype 2 (HRV2) on a commercially available lab‐on‐a‐chip instrument. Due to lack of sufficient native fluorescence, the proteinaceous capsid of HRV2 was labeled with Cy5 for detection by the red laser (λex 630 nm) implemented in the instrument. On the microdevice, electrophoresis of the labeled virus was possible in a BGE without stabilizing detergents, which is in contrast to conventional CE; moreover, analysis times were drastically shortened to the few 10 s range. Resolution of the sample constituents (virions, a contaminant present in all virus preparations, and excess dye) was improved upon adaptation of the separation conditions, mainly by adjusting the SDS concentration of the BGE. Purity of fractions from size‐exclusion chromatography after labeling of virus was assessed, and affinity complex formation of the labeled virus with various recombinant very‐low‐density lipoprotein receptor derivatives differing in the number of concatenated V3 ligand binding repeats was monitored. Virus analysis on microchip devices is of particular interest for experiments with infectious material because of easy containment and disposal of samples. Thus, the employment of microchip devices in routine analysis of viruses appears to be exceptionally attractive.
Endostatin inhibits endochondral ossification
Authors: Sipola A. , Ilvesaro J. , Birr E. , Jalovaara P. , Pettersson R. F. , Stenbäck F. , Ylä‐Herttuala S. , Hautala T. , Tuukkanen J. 
Published: November 2007

AbstractBackgroundAngiogenesis is essential for the replacement of cartilage by bone during skeletal growth and regeneration. Vascular endothelial growth factor‐A (VEGF‐A) is a key regulator of angiogenesis whereas endostatin, a potent inhibitor of endothelial cell proliferation and migration, is a natural antagonist of VEGF‐A. The regulatory role of these peptides in angiogenesis and bone formation was investigated using adenoviral gene delivery of VEGF‐A and endostatin in a mouse ectopic ossification model.MethodsBone formation was induced in the hamstring muscles of adult mice with native bone morphogenetic protein (BMP) extract implemented in gelatine gel together with VEGF‐A and endostatin recombinant adenoviral vectors. The mice were sacrificed 1, 2, and 3 weeks after the operation and ectopic bone formation was followed radiographically and histologically.ResultsSignificant bone formation was induced by BMP extract in all treatment groups. VEGF‐A stimulated and endostatin prevented the formation of FVIII‐related antigen‐positive vessels as well as the number of cartilage‐resorbing chondroclasts/osteoclasts. Endostatin alone or in conjugation with VEGF‐A reduced bone formation. Excess of VEGF‐A stimulated and endostatin reduced bone formation, respectively, at the 3‐week time point.ConclusionsOur findings indicate that endostatin retards the cartilage phase in endochondral ossification which subsequently reduces bone formation in our experimental model. We conclude that bone growth and healing, which share features with ectopic bone formation, may be regulated by endostatin. Copyright © 2007 John Wiley & Sons, Ltd.
Incorporation of all‐trans retinoic acid into lipoplexes inhibits nuclear factor κB activation mediated liver injury induced by lipoplexes in mice
Authors: Charoensit Pensri , Kawakami Shigeru , Higuchi Yuriko , Hashida Mitsuru 
Published: November 2007

AbstractBackgroundAll‐trans retinoic acid (ATRA) is a natural derivative of vitamin A, which is well known to suppress inflammatory cytokine production. To date, there have been few reports about the systemic use of ATRA for inflammation because of acute resistance and the highly lipophilic nature of ATRA.MethodsATRA‐lipoplexes were prepared by mixing CMV‐Luc plasmid DNA with ATRA‐incorporated 1,2‐dioleoyl‐3‐trimethylammoniopropane (DOTAP)/cholesterol liposome. After intravenous injection, tissue accumulation, transfection efficacy, NFκB activation, cytokine production, and hepatic toxicity of ATRA‐lipoplexes were evaluated and compared with lipoplexes lacking ATRA.ResultsThe particle size and zeta potential of ATRA‐lipoplexes were similar to those of lipoplexes. After intravenous injection of ATRA‐lipoplexes, tissue accumulation in liver and gene expression in liver and lung were similar to those of lipoplexes, supporting the hypothesis that ATRA incorporation did not affect the delivery and gene transfection efficacy. In addition, ATRA incorporated in ATRA‐lipoplexes was delivered to liver in a manner similar to that for ATRA incorporated in liposomes. In addition, intravenous injection of ATRA‐lipoplexes inhibited the activation of NFκB in liver, and subsequently suppressed the serum levels of tumor necrosis factor‐alpha (TNF‐α) and alanine aminotransferase (ALT) compared with lipoplexes. Liver histology data also demonstrated a low degree of liver injury produced by ATRA‐lipoplexes compared with lipoplexes.ConclusionsATRA‐incorporated lipoplexes effectively suppress NFκB activation, cytokine response and liver injury induced by lipoplexes without affecting gene delivery and transfection efficacy in vivo. Copyright © 2007 John Wiley & Sons, Ltd.
Congo and Korea: a study in divergence
Authors: Garner Phillip 
Published: November 2007

AbstractThe growth experiences of the Democratic Republic of the Congo and South Korea over the last several decades have been polar opposites. Despite this divergence in economic outcomes, the two countries shared some initial similarities including very low income, high population growth rates, harsh colonial regimes, military coups and Cold War politics. There were also important initial differences in population density, ethnolinguistic diversity, natural resource endowments and geography. Given its enormous mineral wealth, economic prospects initially appeared brighter in the Congo than in Korea to most contemporary observers. This paper explores the possible causes of divergences in the two countries by examining initial conditions, economic and demographic trends, geography and governance. Copyright © 2007 John Wiley & Sons, Ltd.
SFM studies of carbon ion induced damages in plasmid DNA
Authors: Brezeanu Mihail , Taucher‐Scholz Gisela , Psonka Katarzyna , Träger Frank , Hubenthal Frank 
Published: November 2007

AbstractIn this study we present for the first time detailed scanning force microscopy (SFM) investigations of carbon ion induced damages in plasmid DNA in order to obtain information about the biological effectiveness of particle radiation. For this purpose, we have combined SFM and gel electrophoresis measurements in a dose range between D = 0 Gy and 5000 Gy. After irradiation with C ions, the percentage of double‐strand breaks (DSBs) increases drastically, i.e. from initially 0% for D = 0 Gy to 38% for D = 5000 Gy. Increasing the dose over the total range is accompanied by a shortening of the average fragment length from 〈L〉 = 1100 nm to 〈L〉 = 575 nm. In addition to our experiments, the average numbers of induced DSBs per irradiated plasmid and per broken plasmid have been calculated from the SFM measurements. The most important among the numerous results is that a significant amount of plasmids has suffered more than two DSBs for all applied doses, indicating multiple DSBs. The number of DSBs per broken plasmid increases from approximately 1.7 after irradiation with a dose of D = 250 Gy to 3.2 after exposure to the highest dose of D = 5000 Gy. The results provide experimental data for the spatially correlated production of DSBs after carbon irradiation, that are relevant to the understanding of its biological effectiveness. Copyright © 2007 John Wiley & Sons, Ltd.
The weed community affects yield and quality of soybean (Glycine max (L.) Merr.)
Authors: Gibson David J , Millar Katherine , Delong Michael , Connolly John , Kirwan Laura , Wood Andrew J , Young Bryan G 
Published: November 2007

AbstractBACKGROUND: The relationship between the weed community and soybean (Glycine max (L.) Merr.) seed yield and quality was assessed in two experiments in Illinois, USA. In one field different proportions of target weeds (Ambrosia trifida L., Amaranthus rudis J. Sauer, and Setaria faberi F. Herrm) were sown into experimental plots, and the other field was naturally infested with these and other weeds. The composition of the weed communities in both fields was compared to soybean yield, biomass, canopy cover and quality (% protein, oil, relative water content, and seed weight) using non‐metric dimensional scaling ordination.RESULTS: In the experimentally sown plots, low yield and low quality soybeans were harvested from plots dominated by the target weeds, particularly A. trifida, and a suite of subordinate volunteers. In the naturally infested field, highest soybean protein was associated with S. faberi early in the season and Ambrosia artemisiifolia and Ipomea hederacea later in the season, and low amounts of A. rudis throughout the growing season.CONCLUSION: Similar results from the two experiments indicate that soybean seed yield and quality are affected by the composition of the weed community. Producers need to manage the weed community to optimize seed quality. Copyright © 2007 Society of Chemical Industry
Physico‐enzymatic production of monoacylglycerols enriched with very‐long‐chain polyunsaturated fatty acids
Authors: Pawongrat Ratchapol , Xu Xuebing , H‐Kittikun Aran 
Published: November 2007

AbstractBACKGROUND: Monoacylglycerols (MAG) containing polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have interesting applications. The enzymatic processing of such MAG directly from fish oils is highly interesting, integrating the processing of MAG and concentration of EPA and DHA. The aim of this study was to develop an efficient enzymatic glycerolysis system together with physical fractionation for the production of PUFA‐MAG from tuna oil.RESULTS: Novozym 435 was eventually selected after evaluation together with immobilized lipase AK in a tertiary alcohol‐based system. A further evaluation of solvent mixtures involving tertiary alcohols was made, taking ease of operation into consideration. It turned out that a number of mixtures gave a similar performance to that of tert‐butanol (TB). Basic reaction parameters were thoroughly evaluated. In the batch reaction system with TB as solvent, the recommended conditions were: glycerol/tuna oil 4:1 (mol/mol), TB/tuna oil 2:1 (wt/wt), 15 wt% Novozym 435, and temperature 40 °C. Under these conditions, the yield of MAG was up to 90% after 3 h incubation. Crude MAG from the production was fractionated to produce MAG with higher EPA and DHA content. Using acetone as solvent at 0 °C led to ca 50% yield of MAG but contained EPA and DHA up to 71% in comparison with ca 30% in tuna oil.CONCLUSION: Potentially practical process steps have been developed for the production of MAG containing a high content of EPA and DHA from natural fish oils with high efficiency and simplicity. Copyright © 2007 Society of Chemical Industry
Growth performance of rats fed raw and extruded African breadfruit‐based complementary diets: A response surface analysis
Authors: Nwabueze Titus U 
Published: November 2007

AbstractBACKGROUND: African breadfruit, from which diverse food forms are produced, is popular in most West African tropical regions. The present study is part of a larger research project aimed at developing appealing, processed, nutritious products from blends of breadfruit, corn and defatted soybean by utilising extrusion cooking using response surface analysis. The study describes the ability or otherwise of raw and extruded African breadfruit‐based diets, similar to weaning diets simulated with rats, to support growth of children and infants.RESULTS: Maximum protein efficiency and net protein ratios of 2.22 and 3.69, respectively, were obtained with rats fed diets made from 40 g 100 g−1 African breadfruit + 5 g 100 g−1 corn + 55 g 100 g−1 soybean extrudates at 18 mL 100 mL−1 feed moisture and 140 rpm screw speed. It compared favourably with a casein standard and was 54–69% and 42–55% higher than those fed raw diets.CONCLUSION: Extrusion cooking significantly improved the nutritional quality of African breadfruit–corn–defatted soybean as reflected in their protein efficiency and net protein values. The superiority in protein quality of diet 1 (containing 40 g 100 g−1 breadfruit, 5 g 100 g−1 corn and 55 g 100 g−1 defatted soybean) over the other experimental diets has serious nutritional implication in dietary diversification to address protein‐energy malnutrition prevalent in Nigeria and other West African countries especially where African breadfruit is known to be highly cultivated as a food resource. Copyright © 2007 Society of Chemical Industry
Determination of lawsone in henna powders by high performance thin layer chromatography
Authors: El‐Shaer Nagwa S. , Badr Jihan M. , Aboul‐Ela Maha A. , Gohar Yousry M. 
Published: November 2007

AbstractThe lawsone content has been evaluated quantitatively in eight commercial henna powders and two collected henna leaves. The phenolic, chloroform‐soluble fraction of the majority of the examined samples showed the presence of lawsone and two other pigments. Here we aimed to optimize high performance thin layer chromatography for the determination of lawsone. Upon using the optimized method the examined samples showed considerable variation in lawsone concentration ranging from 0.004 up to 0.608 wt%, indicating that some samples were almost devoid of lawsone. Some of these products were subjected to preliminary in vivo toxicity studies.
Statistical mixture design – principal component optimization for selective compound extraction from plant material
Authors: Soares Patricia Kaori , Bruns Roy Edward , Scarminio Ieda Spacino 
Published: November 2007

AbstractA simplex centroid design is used to optimize solvent mixtures for selective extraction of compounds from Erythrina speciosa Andrews leaves. Three main groups of compounds characterized by chromatographic retention times of 1.7, 3.1, and 6.6 min were extracted. The chromatographic peak heights registered at 1407 equally spaced times for each design extract were converted into principal components (PCs). Three PCs account for 89.1% of the data variance and have important loading values at the above retention times. Quadratic mixture models were found to adequately describe the response surfaces of their PC score values. Maximizing the first PC scores while minimizing the second and third ones results in an optimum 83% dichloromethane–17% acetone mixture that selectively extracts the group of compounds with retention times around 3.1 min. Maximizing the second PC scores and minimizing the third PC scores leads to a 78% hexane–22% acetone mixture adequate for extracting the 6.6 min retention time compounds as well as other compounds with high retention times. The 1.7 min group of compounds is most efficiently extracted on maximizing the third PC that results in a 50% ethanol–50% acetone mixture. The Derringer–Suich algorithm confirmed the determination of these optimized mixtures.
Prediction of the location of stationary steady‐state zone positions in counterflow isotachophoresis performed under constant voltage in a vortex‐stabilized annular column
Authors: Harrison Schurie L. M. , Ivory Cornelius F. 
Published: November 2007

AbstractA theoretical model is presented and an analytical expression derived to predict the locations of stationary steady‐state zone positions in ITP as a function of current for a straight channel under a constant applied voltage. Stationary zones may form in the presence of a countercurrent flow whose average velocity falls between that of a pure leader zone and of a pure trailer zone. A comparison of model predictions with experimental data from an anionic system shows that the model is able to predict the location of protein zones with reasonable accuracy once the ITP stack has formed. This result implies that an ITP stack can be precisely directed by the operator to specific positions in a channel whence portions of the stack can be removed or redirected for further processing or analysis.
Improved determination of 5‐fluorouracil and its prodrug tegafur in pharmaceuticals by large‐volume sample stacking in CE
Authors: Yang Yanmin , Liu Qian , Tao Wenyan , Nie Lihua , Yao Shouzhuo 
Published: November 2007

AbstractOn‐line determination of the anti‐tumor drug 5‐fluorouracil (5‐FU) and its prodrug, tegafur (TF) was achieved for the first time by capillary electrophoresis with large‐volume sample stacking (CE–LVSS). The optimal electrophoretic buffer consisted of 30 mM phosphate buffer at pH 8.0. Without the LVSS procedure, the limits of detection (LOD) were 600.5 ng/mL and 771.4 ng/mL for 5‐FU and TF, respectively. With the LVSS procedure, the sensitivity was significantly improved by about two orders of magnitude (the LODs of 5‐FU and TF were decreased to 7.9 ng/mL and 6.5 ng/mL, respectively). The %RSD was less than 5%. This method compared favorably with other reported techniques and was applied successfully to the quantitative analysis of anti‐tumor drugs in commercial injection preparations. The results show that the method is simple, fast (less than 3 min), highly selective, and sensitive.
Application of dispersive liquid–liquid microextraction combined with high‐performance liquid chromatography for the determination of methomyl in natural waters
Authors: Wei Guohui , Li Yanyan , Wang Xuedong 
Published: November 2007

AbstractA new method was developed for determination of methomyl in water samples by combining a dispersive liquid–liquid microextraction (DLLME) technique with HPLC–variable wavelength detection (VWD). In this extraction method, 0.50 mL of methanol (as dispersive solvent) containing 20.0 μL of tetrachloroethane (as extraction solvent) was rapidly injected by syringe into a 5.00‐mL water sample containing the analyte, thereby forming a cloudy solution. After phase separation by centrifugation for 2 min at 4000 rpm, the enriched analyte in the settled phase (8 ± 0.2 μL) was at the bottom of the conical test tube. A 5.0‐μL volume of the settled phase was analyzed by HPLC–VWD. Parameters such as the nature and volume of the extraction solvent and the dispersive solvent, extraction time, and the salt concentration were optimized. Under the optimum conditions, the enrichment factor could reach 70.7 for a 5.00‐mL water sample and the linear range, detection limit (S/N = 3), and precision (RSD, n = 6) were 3–5000 ng/mL, 1.0 ng/mL, and 2.6%, respectively. River and lake water samples were successfully analyzed by the proposed method. Comparison of this method with solid‐phase extraction, solid‐phase microextraction, and single‐drop microextraction, indicates that DLLME combined with HPLC–VWD is a simple, fast, and low‐cost method for the determination of methomyl, and thus has tremendous potential in trace analysis of methomyl in natural waters.
Research challenges to ultra‐efficient inorganic solid‐state lighting
Authors: Phillips J.M. , Coltrin M.E. , Crawford M.H. , Fischer A.J. , Krames M.R. , Mueller‐Mach R. , Mueller G.O. , Ohno Y. , Rohwer L.E.S. , Simmons J.A. , Tsao J.Y. 
Published: November 2007

AbstractSolid‐state lighting is a rapidly evolving, emerging technology whose efficiency of conversion of electricity to visible white light is likely to approach 50% within the next several years. This efficiency is significantly higher than that of traditional lighting technologies, giving solid‐state lighting the potential to enable significant reduction in the rate of world energy consumption. Further, there is no fundamental physical reason why efficiencies well beyond 50% could not be achieved, which could enable even more significant reduction in world energy usage. In this article, we discuss in some detail: (a) the several approaches to inorganic solid‐state lighting that could conceivably achieve “ultra‐high,” 70% or greater, efficiency, and (b) the significant research questions and challenges that would need to be addressed if one or more of these approaches were to be realized.
Biomineralized Polysaccharide Beads for Dual‐Stimuli‐Responsive Drug Delivery
Authors: Shi Jun , Liu Lihua , Sun Ximeng , Cao Shaokui , Mano João F. 
Published: November 2007

AbstractBiomineralized polysaccharide‐coated alginate beads containing PNIPAAM were prepared. The resulting beads can be used as carriers for sustained pH/temperature‐sensitive drug delivery. Characterizations using SEM, EDS, FTIR, and POM revealed that the beads were covered by the calcium‐phosphate‐mineralized alginate/chitosan membrane. The drug‐release behavior was examined using indomethacin as a model drug, and the release profile of the developed materials was found to be responsive to pH and temperature. The release profile could be sustained under neutral conditions, indicating that the mineralized polysaccharide membrane could prevent the permeability of the encapsulated drug and reduce the drug release rate.magnified image
Facile Synthesis of Self‐Assembled Polyaniline Nanodisks
Authors: Li Guicun , Zhang Chuanqin , Peng Hongrui 
Published: November 2007

AbstractPolyaniline nanodisks have been synthesized successfully by the chemical oxidation polymerization of aniline by a self‐assembly process without the use of any acid. The thickness and lateral dimensions of the polyaniline nanodisks are in the range of 20–30 nm and 1–2 µm, respectively. The influence of synthetic parameters, such as the concentration of ammonium peroxydisulfate and pH, on the morphologies of polyaniline nanostructures have been investigated.magnified image
Experiences of an action learning set
Authors: Bell Miriam , Coen Eithna , Coyne‐Nevin Ann , Egenton Roisin , Ellis Ann , Moran Liz 
Published: November 2007

AbstractThis paper outlines the background to the establishment of a multidisciplinary action learning set in the Irish Health Service context; describes the action learning set process; explores set members' experiences of set membership and action learning; and concludes by making some recommendations. Copyright © 2007 John Wiley & Sons, Ltd.