bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carotenoid production from Chlorococcum littorale in photoautotrophic cultures with downstream supercritical fluid processing
Authors: Ota Masaki , Watanabe Hiromoto , Kato Yoshitaka , Watanabe, Masaru , Sato Yoshiyuki , Smith Richard Lee , Inomata Hiroshi 
Published: June 2009

AbstractCarotenoid production from highly CO2 tolerant microalga Chlorococcum littorale in photoautotrophic cultures with downstream supercritical fluid processing was studied. Increasing temperature, increasing light intensity and decreasing CO2 and O2 gas concentrations enhanced growth rate under nitrate‐rich conditions. Carotenoid content was insensitive to nitrate concentration, temperature and gas composition, but was greatly promoted by light intensity. Growth rate and carotenoid content had an optimum light intensity of ca. 120 μmol‐photon·m–2s–1. Separation of two sample cultures was studied by applying supercritical fluid extraction with CO2 and 10 mol% ethanol co‐solvent. Extraction yield of carotenoids was 90% with 10 mol% ethanol at 333 K and 30 MPa. Selectivity of a sample with less lipid content (12.9 wt%) was five‐fold higher than that with higher lipid content (29.4 w%).
Profiling of polar metabolites in biological extracts using diamond hydride‐based aqueous normal phase chromatography
Authors: Callahan Damien L. , Souza David De , Bacic Antony , Roessner Ute 
Published: June 2009

AbstractHighly polar metabolites, such as sugars and most amino acids are not retained by conventional RP LC columns. Without sufficient retention low concentration compounds are not detected due ion suppression and structural isomers are not resolved. In contrast, hydrophilic interaction chromatography (HILIC) and aqueous normal phase chromatography (ANP) retain compounds based on their hydrophilicity and therefore provides a means of separating highly polar compounds. Here, an ANP method based on the diamond hydride stationary phase is presented for profiling biological small molecules by LC. A rapid separation system based upon a fast gradient that delivers reproducible chromatography is presented. Approximately 1000 compounds were reproducibly detected in human urine samples and clear differences between these samples were identified. This chromatography was also applied to xylem fluid from soyabean (Glycine max) plants to which 400 compounds were detected. This method greatly increases the metabolite coverage over RP‐only metabolite profiling in biological samples. We show that both forms of chromatography are necessary for untargeted comprehensive metabolite profiling and that the diamond hydride stationary phase provides a good option for polar metabolite analysis.
Sequestering carbon in soils of arid ecosystems
Authors: Lal R. 
Published: June 2009

AbstractRecent increase in atmospheric concentration of CO2 and decrease in land‐based sink capacity are attributed to numerous anthropogenic activities including increase in severity and extent of soil degradation and desertification. There is a strong link between desertification and global warming with positive feedback of mutual reinforcement. The biophysical process is also driven by social, economic, political, and cultural factors such as overgrazing by local Bedouin population. Soil carbon (C) sequestration, through conversion to a restorative land use and adoption of recommended management practices, is more in cooler than warmer and higher in wetter than drier climates, and larger in clayey than sandy soils. It ranges from 0 to 200 kg C ha−1 y−1 in soils of semi‐arid climate to 200–500 kg ha−1 y−1 in those of sub‐humid climates. The rates may range from negative to a high of 1500 kg ha−1 y−1. In contrast, the rate of SIC sequestration as secondary carbonates are low and range from 1·5 to 15 kg C ha−1 y−1. In addition to proven technologies (e.g., low stocking rate, afforestaion, soil, and water conservation), there are numerous opportunities for using the modern innovations involving nanotechnology, biotechnology, and information technology. Trading of C credits, through Kyoto's CDM or World Bank's BioCarbon Fund and other mechanisms, opens new opportunities for promoting the use of terrestrial sinks. In this regards, desertified ecosystems in Africa/Asia and elsewhere may benefit through C‐sequestration programs because rehabilitation of degraded lands is an urgent matter of global importance. Copyright © 2009 John Wiley & Sons, Ltd.
Correlation between friction and flow of lubricating greases in a new tribometer device
Authors: Heyer Patrick , Läuger Jörg 
Published: June 2009

AbstractA tribometer requires speed and normal force control, as well as a torque measurement, to acquire tribological data. An air bearing‐supported rotational rheometer allows the measurement of the same variables, but in a broader range and with better accuracy. This and the intension to measure Stribeck curves, as well as the static friction with one single instrument, led to the idea to design an accessory turning a rheometer into a high‐resolution tribometer based on a ball on pyramid principle. Speed ramp and static friction measurements of oil‐lubricated systems illustrate the performance of the rheo‐tribometer. The flow behaviour of greases is more complex, and extensive rheological and tribological testing was performed on three greases of the American National Lubrication Grease Institute classes 0, 1 and 2 at the temperatures of 25 and −40°C. The influence of temperature could be monitored, and a correlation between rheology and tribology was found. To link the model system with real applications for greases, a ball bearing fixture for the tribological accessory has been designed for which first results are presented. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and Characterization of Low Viscosity Aromatic Hyperbranched Poly(trimellitic anhydride ethylene glycol) Ester Epoxy Resin
Authors: Zhang Daohong , Jia Demin , Chen Sufang 
Published: June 2009

AbstractFrom carboxyl‐ended hyperbranched poly(trimellitic anhydride ethylene glycol) ester (HTM) and epichlorohydrin, low viscosity (1 000–1 250 cp) aromatic HTM epoxy resin (HTME) was synthesized. Molar mass of the HTM was calculated from its acid value with a “Recursive Probability Approach”, and its degree of branching (0.63–0.70) was characterized by model compounds and 1H NMR‐minus spectrum technology. HTME has an epoxy equivalent weight of <470 g/mol; it is an ellipsoid‐like molecule with a size of <8.65 nm. This low viscosity novel epoxy resin has important applications in the field of “no‐solvent” coatings.magnified image
Kinetics of Complex Formation between DNA and Cationically Charged Cylindrical Brush Polymers Observed by Stopped Flow Light Scattering
Authors: Kuehn Frauke , Fischer Karl , Schmidt Manfred 
Published: June 2009

AbstractThe complex formation of pUC19 DNA and a cylindrical brush polymer with quaternized poly(vinyl pyridinium) side chains is investigated by stopped flow light scattering (LS). In highly dilute solutions up to two kinetic processes are observable, depending on the mole fraction of anionic charges, xanion. For xanion < 0.2 and xanion > 0.4–0.5 only one kinetic process was identified leading to the largest complexes at xanion = 0.4 well below charge stoichiometry. For 0.2 < xanion < 0.4 two kinetic growth processes were identified: The initially formed complexes on the time scale of a few hundred milliseconds keep growing by an unusual fractal growth process until after several minutes they become stable. This last fractal process does not follow the classical Smoluchowski coagulation theory as monitored by LS up to 90 s after mixing.magnified image
Surface Coatings Based on Polysilsesquioxanes: Solution‐Processible Smooth Hole‐Injection Layers for Optoelectronic Applications
Authors: Kessler Daniel , Lechmann Maria C. , Noh Seunguk , Berger Rüdiger , Lee Changhee , Gutmann Jochen S. , Theato Patrick 
Published: June 2009

AbstractOptoelectronic devices usually consist of a transparent conductive oxide (TCO) as one electrode. Interfacial engineering between the TCO electrode and the overlying organic layers is an important method for tuning device performance. We introduce poly(methylsilsesquioxane)–poly(N,N‐di‐4‐methylphenylamino styrene) (PMSSQ–PTPA) as a potential hole‐injection layer forming material. Spin‐coating and thermally induced crosslinking resulted in an effective planarization of the anode interface. HOMO level (−5.6 eV) and hole mobility (1 × 10−6 cm2 · Vs−1) of the film on ITO substrates were measured by cyclovoltammetry and time‐of‐flight measurement demonstrating the hole injection capability of the layer. Adhesion and stability for further multilayer built‐up could be demonstrated. Contact angle measurements and tape tests after several solvent treatments proved the outstanding film stability.magnified image
Synthesis of Dendronized Diblock Copolymers via Click Chemistry: The Effect of Dendronization on Phase Separation Behaviour
Authors: Fleischmann Sven , Kiriy Anton , Bocharova Vera , Tock Christian , Komber Hartmut , Voit Brigitte 
Published: June 2009

AbstractA novel route towards the synthesis of well‐defined linear–dendronized diblock copolymers is reported. Precursor alkyne containing diblock copolymers were modified in a highly efficient cycloaddition reaction with dendritic azides of different generation. The dendronization has been shown to be selective and could be driven to completion under ambient conditions. The phase separation of such dendronized diblock copolymers was investigated in dependence of the generation size being attached. Compared to a linear–linear diblock copolymer as starting material the dendronization yielded in a pronounced phase separation. The nanoscaled features observed in thin films strongly depended on the dendron size and a variety of morphologies could be identified. Hence, the unique combination of controlled radical polymerization and click chemistry allows for the triggering of structured surfaces in the nanometer‐regime.magnified image
Progress in Cellulose Research in the Reflection of the Zellcheming Cellulose Symposium
Authors: Philipp Burkart , Schempp Walter 
Published: June 2009

AbstractSummary:Within the general topic “Structure and Properties of Cellulose” this presentation covers some principle issues of cellulose research during the recent 50 years and their reflection in the lecture and discussion program of the “Rundgespräch” since 1959. The goal of this “Rundgespräch” was a get together of fundamental research and industrial practice for exchange of information and for cooperation, realizing an interdisciplinary approach of chemistry, physics and technology in cellulosics, supplemented later by environmental problems and aspects of biology and medicine. An especially profitable area of joint activities was found in the analytics of cellulosics, experiencing the entry of modern instrumental methods in cellulose research and the growing relevance of distribution spectra of various structural parameters. With respect to the “renaissance of the viscose process” during the decades after World War II, activities of the “Rundgespräch” were at first centred on the complex sequence of reactions of viscose preparation, including the evaluation of dissolving pulps, and also around the chemistry and the colloid chemistry of filament formation in the spinning process. Further central topics in the following decades were classical and new solvents for cellulose and the states of solution obtained as well as the theoretical meaning and experimental comprehension of cellulose reactivity during chemical processing. Additionally, hemicelluloses were included in the program as well as cellulosic specialties like membranes, cellulose powders, or bead cellulose. Within an integration process of cellulose research into polymer science, composites of cellulose with synthetic polymers gained more relevance in recent years.Finally, 3 highlights during the 50 years of the “Rundgespräch” are mentioned, i.e.,a survey of German cellulose research after the re‐unificationa presentation of the stimulating results of the large DFG‐project on molecular and supramolecular structure of cellulosicsthis year's program with its really “international flair” and its wide span from the history to actual topics and further to a vision of future development.
The Applicability of Enzymes in Cellulose Ether Analysis
Authors: Adden Roland , Melander Claes , Brinkmalm Gunnar , Knarr Matthias , Engelhardt Jürgen , Mischnick Petra 
Published: June 2009

AbstractSummary: Six methyl cellulose (MC) samples, one with a DS of 1.32 and five with a DS between 1.83 and 1.88, were degraded with five different enzymes or enzyme preparations containing endoglucanases. The main goal was to investigate whether enzymes could be used for determination of heterogeneity of the substituent distribution along the cellulose chain. To obtain information about the heterogeneity it was necessary to gather information on how the enzymes affect hydrolysis. Monomer composition and methyl distribution in the polymer chain were analyzed after total or partial random hydrolysis and appropriate derivatization by GC and MS, respectively, and used as reference data for the evaluation of the enzymatic hydrolysis. Size exclusion chromatography with multi angle light scattering and refractive index detection (SEC‐MALLS/RI) was used to estimate molar mass distribution of the MCs before and after hydrolysis. Electrospray and matrix assisted laser desorption/ionization (ESI and MALDI) in combination with various MS analyzers were compared with respect to quantification of the degradation products directly and after perdeuteromethylation. Methyl group distribution in the oligomeric fractions and the average DS/DP were calculated from ESI mass spectra. With help of the reference analysis, patterns could be corrected for the unspecific contribution of end groups. By labelling and ESI‐MSn, our knowledge about the tolerance of the enzyme's sub‐sites with respect to the number of methyl groups could be improved. A novel standard addition method in combination with electrospray ionization ion trap mass spectrometry (ESI‐IT MS) was used to determine the amount of formed oligomers.
Reactivity of Dissolving Pulp for Processing Viscose
Authors: Fischer Klaus , Schmidt Ingeborg , Fischer Steffen 
Published: June 2009

AbstractSummary: Pulp reactivity is a kinetic term and is always connected with a certain derivatization process. The quality and hence the market value of the pulp is determined by such characteristics as α‐ cellulose content, solubility, brightness, ash content, as well as the amount of soluble material in dichloromethane. However, solubility data, especially S18 and S10 values do not characterise dissolving pulp reactivity. These are indicative of pulp solubility and provide some information regarding losses of material during pulp processing. One way by which the pulp reactivity for viscose making can be characterised is the investigation of the mercerisation step. Following the mercerisation kinetics by help of the molecular weight distribution of cellulose II the behaviour especially of the high molecular weight cellulose gives information regarding the accessibility and therefore, about the reactivity of the pulp aside from losses in low molecular weight cellulose. This behaviour will be shown on different pulps and the physicochemical background will be discussed in relation to results obtained from wide angle X‐ray scattering and Raman investigations. The influence of the behaviour of the pulp during mercerising on the viscose process, and the molecular weight distribution of the viscose including the distribution of the xanthogenate groups along the chain was investigated and will also be discussed.
Nanocellulose Materials – Different Cellulose, Different Functionality
Authors: Klemm Dieter , Schumann Dieter , Kramer Friederike , Heßler Nadine , Koth Daniel , Sultanova Barno 
Published: June 2009

AbstractSummary: Nanocelluloses combine in a very exciting manner important properties of cellulose with amazing features of nano‐scale materials. With a view to the increasing discussion on the potential risks of nanoparticles and nanotechnology to human health and the environment, it is important to point out that the nanocellulose fibers are irreversibly networked in the supramolecular cellulose structure. This contribution assembles the current knowledge in research, development, and application in the field of nanocelluloses through examples. The topics combine selected results on nanocelluloses from bacteria and wood as well as the formation and in situ shaping of cellulose bodies, the coating of materials with nanosized cellulose networks/supports, and the preparation of nanocellulose composites as well as the use of bacterial cellulose as novel type of medical implants.
Novel Cellulose Ethers: Synthesis and Structure Characterization of 3‐Mono‐O‐(3′‐hydroxypropyl) Cellulose
Authors: Schumann Kristin , Pfeifer Annett , Heinze Thomas 
Published: June 2009

AbstractSummary: The synthesis of 3‐mono‐O‐(3′‐hydroxypropyl) cellulose via 3‐mono‐O‐allyl‐2,6‐di‐O‐thexyldimethylsilyl cellulose was studied. Conversion of the double bond with 9‐borabicyclo[3.3.1]nonane and subsequent alkaline oxidation lead to the 3′‐hydroxypropyl group. Finally, the treatment with tetrabutylammonium fluoride trihydrate yields the complete cleavage of the protecting groups. The structure of the polymer was confirmed by one‐ and two dimensional NMR spectroscopic techniques. 3‐mono‐O‐(3′‐hydroxypropyl) cellulose is soluble in water and aprotic‐dipolar organic media.
Regioselectively Oxidized Cellulose Ethers
Authors: Yin Xueqiong , Koschella Andreas , Heinze Thomas 
Published: June 2009

AbstractSummary: 3‐Mono‐O‐(2‐methoxyethyl) cellulose (MEC) was selectively oxidized with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy radical (TEMPO)/NaBr/ NaOCl. According to 1D and 2D NMR measurements, the primary hydroxyl group was completely oxidized without affecting the secondary one at position 2. Size‐exclusion chromatography revealed high tendency of 3‐mono‐O‐(2‐methoxyethyl)‐6‐carboxyl cellulose (MECO) to aggregate. Viscosity measurement and gelation of MECO upon interaction with chitosan and Cu2+ ions confirmed the introduction of anionic ions into the polymer backbone. Both MEC and MECO expressed the property of surface activity hence decreasing the surface tension of water (72 mN/m), being 45.0 and 56.8 mN/m, respectively.
Application of Modified Bead Cellulose as a Carrier of Active Ingredients
Authors: Volkert Bert , Wolf Bertram , Fischer Steffen , Li Ning , Lou Chenhua 
Published: June 2009

AbstractSummary: A new kind of very fine disperse porous bead cellulose is modified by chemical treatments to 2,3‐dialdehyde cellulose, carboxymethyl and dihydrogenphosphate cellulose. Model drugs like benzocaine and prazosin are coupled to these modified bead celluloses by covalent and ionic linkage, respectively and compressed to tablets. Compression mixtures with low loaded benzocaine conjugates release with medium rate. Linkage of prazosin cation to the anionic derivatives of bead cellulose leads to fast release of poor soluble ionic drug.
The affect of the base rate on the extreme dependency score
Authors: Primo Cristina , Ghelli Anna 
Published: June 2009

AbstractThe Extreme Dependency Score (EDS) has been introduced in the verification of rare events because it does not vanish as other standard scores do. The EDS can be written as a function of the base rate and the hit rate. This paper analyses its dependency on the base rate. It is also shown how the score encourages hedging. Guidelines are provided to make proper use of the EDS when verifying the performance of a forecasting system. Copyright © 2009 Royal Meteorological Society
NMR quantification of trace components in complex matrices by band‐selective excitation with adiabatic pulses
Authors: Rastrelli Federico , Schievano Elisabetta , Bagno Alessandro , Mammi Stefano 
Published: June 2009

AbstractThe use of band‐selective excitation with adiabatic pulses to rapidly obtain NMR spectra of trace components in the presence of strong signals is described, along with qualitative and quantitative examples from food matrices like olive oil and honey. Copyright © 2009 John Wiley & Sons, Ltd.
Aurora kinase B modulates chromosome alignment in mouse oocytes
Authors: Shuda Kristy , Schindler Karen , Ma Jun , Schultz Richard M. , Donovan Peter J. 
Published: June 2009

AbstractThe elevated incidence of aneuploidy in human oocytes warrants study of the molecular mechanisms regulating proper chromosome segregation. The Aurora kinases are a well‐conserved family of serine/threonine kinases that are involved in proper chromosome segregation during mitosis and meiosis. Here we report the expression and localization of all three Aurora kinase homologs, AURKA, AURKB, and AURKC, during meiotic maturation of mouse oocytes. AURKA, the most abundantly expressed homolog, localizes to the spindle poles during meiosis I (MI) and meiosis II (MII), whereas AURKB is concentrated at kinetochores, specifically at metaphase of MI (Met I). The germ cell‐specific homolog, AURKC, is found along the entire length of chromosomes during both meiotic divisions. Maturing oocytes in the presence of the small molecule pan‐Aurora kinase inhibitor, ZM447439 results in defects in meiotic progression and chromosome alignment at both Met I and Met II. Over‐expression of AURKB, but not AURKA or AURKC, rescues the chromosome alignment defect suggesting that AURKB is the primary Aurora kinase responsible for regulating chromosome dynamics during meiosis in mouse oocytes. Mol. Reprod. Dev. 76: 1094–1105, 2009. © 2009 Wiley‐Liss, Inc.
Evidence for in vivo macrophage mediated tumor uptake of paramagnetic/fluorescent liposomes
Authors: Castelli Daniela Delli , Terreno Enzo , Cabella Claudia , Chaabane Linda , Lanzardo Stefania , Tei Lorenzo , Visigalli Massimo , Aime Silvio 
Published: June 2009

AbstractDysprosium (Dy)‐loaded liposomes act as excellent T2‐susceptibility agents at high magnetic field strength. The R2‐enhancement increases with the size of the liposomes and the concentration of entrapped paramagnetic metal complexes. Neuro‐2a tumor cells are readily labeled when Dy‐loaded liposomes, suitably functionalized with glutamine residues (Gln), are added to the culture medium as glutamine receptors are highly expressed in such proliferating tumor cells. By using fluorescent liposomes doped with fluorescent dyes (either incorporated in the membrane or included in the inner cavity), confocal microscopy experiments showed that targeted liposomes are taken up much more avidly than non‐targeted vesicles. In vivo studies showed that glutamine‐functionalized and non‐functionalized liposomes accumulate in the tumor region to a similar extent. Confocal images of the excised tumor showed extensive co‐localization of liposomes and macrophages in both cases. It is suggested that the loss of tumor specificity, shown by Gln‐functionalized liposomes in vivo, has to be associated with the efficient removal of liposomes operated by the RES (reticulo endoplasmatic system) or tumor associated macrophages. Copyright © 2009 John Wiley & Sons, Ltd.
Well‐conditioned matrices for numerical treatment of Fredholm integral equations of the second kind
Authors: Mastroianni Giuseppe , Milovanović Gradimir V. 
Published: June 2009

AbstractIn the cases A=[−1, 1] and A=[0,+∞), with \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$w(x)=(1-x)^{\alpha}(1+x)^{\beta},\,\alpha,\beta{>}-1,\,{\rm{and}}\,w(x)=x^{\alpha}e^{{-x}^{\beta}},\,\alpha{>}-1,\,\beta{>}\frac{1}{2}$\end{document}, respectively, in this paper we consider the corresponding Fredholm integral equations of the second kind

in the spaces of continuous functions equipped with certain uniform weighted norms. Assuming the continuity of the kernel k(x,y) we use Nyström methods and prove the stability, the convergence and the well conditioning of the corresponding matrices. The last property is derived only from the continuity of the kernel and not from its special form. Error estimates and numerical tests are also included. Copyright © 2009 John Wiley & Sons, Ltd.