bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Adventures in the Synthesis of meso‐Substituted Corroles
Authors: Gryko Daniel T.
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Catalytic Tandem Organic Sequences Through Selective Boron Addition Chemistry
Authors: Fernandez Elena
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Radical Reactions in Aqueous Media: Origins, Reason and Applications
Authors: Perchyonok V. Tamara , Lykakis Ioannis N.
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Efficient Photochemical Electron Transfer Sensitization of Homogeneous Organic Reactions
Authors: Hoffmann Norbert
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Chiral Perazamacrocycles. Synthesis and Applications. Part 2
Authors: Savoia D. , Gualandi A.
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Regeneration of Carbonyl Compounds from the Corresponding Oximes. An Update Until to 2008
Authors: Corsaro Antonino , Chiacchio Maria Assunta , Pistara Venerando
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Fischer‐Type Group 6 Carbene Complexes in the Synthesis of Optically Active Molecules
Authors: Santamaria Javier
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Applications of Zirconium(IV) Compounds in Organic Synthesis
Authors: Zhang Zhan‐Hui , Li Tong‐Shuang
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Recent Development About the Use of Pyrocarbonates as Activator in Organic Synthesis
Authors: Dalpozzo Renato , Bartoli Giuseppe , Bosco Marcella , Melchiorre Paolo , Sambri Letizia
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Product Class 2: Linear Allenes: Synthesis by Substitution
Authors: Ohno H. , Tomioka K.
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Unusually Strained Spiroheterocyclic Ring Systems and Their Exploits in Synthesis
Authors: Duffy Richard J. , Morris Kay A. , Romo Daniel
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Tropan Alkaloids as Medicinally Useful Natural Products and Their Synthetic Derivatives as New Drugs
Authors: Grynkiewicz Grzegorz , Gadzikowska Maria
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Mueller—Rochow Synthesis: The Direct Process to Methylchlorosilanes
Authors: Kalchauer Wilfried , Pachaly Bernd
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Automated Peptide Synthesis
Authors: Lang Eric , Blehaut Jean
Published: September 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Characterization of folded conformations in a tetrapeptide containing two tryptophan residues by vibrational circular dichroism
Authors: Petrovic Ana G. , Polavarapu Prasad L. , Mahalakshmi R. , Balaram P.
Published: September 2009

The intramolecularly hydrogen bonded conformations of the tetrapeptide Boc‐Trp‐Aib‐Gly‐Trp‐OMe (WUGW) are investigated using experimental and quantum chemical predictions of vibrational circular dichroism (VCD) in the 1800–1550 cm−1 region. The predicted VCD spectrum, for a conformation (conformer A) obtained from optimization of crystal structure, reproduced the dominant negative VCD band observed experimentally in CH3OH and CHCl3 solvents. However, the predicted VCD spectrum of Conformation A also has an extra positive band which is not seen in the experimental spectra. This mismatch appears to be due to the lack of solvent influence in the quantum chemical geometry optimizations. However, Conformations I and II, obtained, respectively, from constrained optimization of crystal and NMR structures, mimic the solvent stabilized structures and are predicted to have dominant negative VCD band as found in the experimental spectra. It is noted that, for the peptide investigated here, unconstrained quantum chemical geometry optimizations in vacuum converged to structures that are not the realistic models of conformations found in solution. It is also noted that undertaking quantum chemical vibrational property calculations directly using geometries obtained from crystal data or NMR data resulted in unrealistic vibrational frequencies and descriptions. However, constraining the backbone dihedral angles to those found in condensed medium, and optimizing the remaining geometrical parameters resulted in a better reproduction of the observed VCD in condensed medium. The vibrational origins of bands in all of the predicted VCD spectra for the WUGW‐tetrapeptide have also been presented. Chirality 21:E76–E85, 2009. © 2009 Wiley‐Liss, Inc.
Macroscopic Properties of Phospholipid Vesicles with a Contact Angle between the Membrane Domains
Authors: Božič Bojan , Majhenc Janja
Published: September 2009

Ternary mixtures of a high‐melting lipid, a low‐melting lipid, and cholesterol are known to form domains of a liquid‐ordered and a liquid‐disordered phase in bilayer membranes. We prepare giant vesicles from a sphingomyelin/dioleoylphosphocholine/cholesterol mixture and then examine them using fluorescence microscopy. NBD‐labeled lipid and BODIPY‐labeled cholesterol are used to identify the phase domains of the membrane. A vesicle with only two domains, one in a liquid‐ordered and one in a liquid‐disordered phase, is chosen because of its simple geometry, for convenient comparison of the experimental results with the theoretical predictions. A microinjector is used to gradually decrease and/or increase the volume of the vesicles by changing the osmolarity of the sugar solution. The relevant energy terms of the membrane mechanics are the elastic energies of the domains and the energy of the domain boundary. The elastic energy of the membrane domains can be described by two terms: the bending energy and the Gaussian bending energy. The energy of the domain boundary is proportional to its length. At the boundary between the domains a contact angle is taken into consideration. Then, in order to obtain values for the lateral tension and the contact angle, the areas of the domains and the characteristic dimensions of the shape are determined for different volumes. The best fits were obtained for a line tension of 6±3 pN and a contact angle of 1.4±0.3 rad.
Ensemble Measurement of Diffusion: Novel Beauty and Evidence
Authors: Chmelik Christian , Heinke Lars , Kortunov Pavel , Li Jing , Olson David , Tzoulaki Despina , Weitkamp Jens , Kärger Jörg
Published: September 2009

Recording the evolution of concentration profiles in nanoporous materials opens a new field of diffusion research with particle ensembles. The technique is based on the complementary application of interference microscopy and IR micro‐imaging. Combining the virtues of diffusion measurements with solids and fluids, it provides information of unprecedented wealth and visual power on transport phenomena in molecular ensembles. These phenomena include the diverging uptake and release patterns for concentration‐dependent diffusivities, the mechanisms of mass transfer at the fluid–solid interface and opposing tendencies in local and global concentration evolution.
SERS in Salt Wells
Authors: Kumar G. V. Pavan , Irudayaraj Joseph
Published: September 2009

We report herein a simple, inexpensive fabrication methodology of salt microwells, and define the utility of the latter as nanoparticle containers for highly sensitive surface‐enhanced Raman scattering (SERS) studies. AFM characterization of Ag and Au loaded salt microwells reveal the ability to contain favorable nanostructures such as nanoparticle dimers, which can significantly enhance the Raman intensity of molecules. By performing diffraction‐limited confocal Raman microscopy on salt microwells, we show high sensitivity and fidelity in the detection of dyes, peptides, and proteins, as a proof of our concept. The SERS limit of detection (accumulation time of 1 s) for rhodamine B and TAT contained in salt mircowells is 10 pM and 1 nM, respectively. The Raman characterization measurements of salt microwells with three different laser lines (532 nm, 632.81 nm, 785 nm) reveal low background intensity and high signal‐to‐noise ratio upon nanoparticle loading, which makes them suitable for enhanced Raman detection. SERS mapping of these sub‐femtoliter containers show spatial confinement of the relevant analyte to a few microns, which make them potential candidates for microscale bioreactors.
Cathepsin X cleaves the β2 cytoplasmic tail of LFA‐1 inducing the intermediate affinity form of LFA‐1 and α‐actinin‐1 binding
Authors: Jevnikar Zala , Obermajer Nataša , Pečar‐Fonović Urša , Karaoglanovic‐Carmona Adriana , Kos Janko
Published: September 2009

The motility of T cells depends on the dynamic spatial regulation of integrin‐mediated adhesion and de‐adhesion. Cathepsin X, a cysteine protease, has been shown to regulate T‐cell migration by interaction with lymphocyte function associated antigen‐1 (LFA‐1). LFA‐1 adhesion to the ICAM‐1 is controlled by the association of actin‐binding proteins with the cytoplasmic tail of the β2 chain of LFA‐1. Cleavage by cathepsin X of the amino acid residues S769, E768 and A767 from the C‐terminal of the β2 cytoplasmic tail of LFA‐1 is shown to promote binding of the actin‐binding protein α‐actinin‐1. Furthermore, cathepsin X overexpression reduced LFA‐1 clustering and induced an intermediate affinity LFA‐1 conformation that is known to associate with α‐actinin‐1. Increased levels of intermediate affinity LFA‐1 resulted in augmented cell spreading due to reduced attachment of T cells to the ICAM‐1‐coated surface. Gradual cleavage of LFA‐1 by cathepsin X enables the transition between intermediate and high affinity LFA‐1, an event that is crucial for effective T‐cell migration.
Establishment of nematode infection despite increased Th2 responses and immunopathology after selective depletion of Foxp3+ cells
Authors: Rausch Sebastian , Huehn Jochen , Loddenkemper Christoph , Hepworth Matthew R. , Klotz Christian , Sparwasser Tim , Hamann Alf , Lucius Richard , Hartmann Susanne
Published: September 2009

Here, we show that Treg limit intestinal pathology during nematode infection and that they control the onset and magnitude of the anti‐parasitic Th Th2 response. Using mice expressing the diptheria toxin receptor under the control of the foxp3 locus, we removed Foxp3+ Treg during the early phase of infection with Heligmosomoides polygyrus bakeri. Depletion of Treg in infected animals did not affect adult worm burden, but led to increased pathology at the site of infection. Infected, depleted mice displayed higher frequencies of activated CD4+ T cells and increased levels of the Th2 cytokines IL‐4 and IL‐13. The stronger parasite‐specific Th2 response was accompanied by higher levels of IL‐10. Only a moderate change in Th1 (IFN‐γ) reactivity was detected in worm‐infected, Treg‐depleted mice. Furthermore, we detected an accelerated onset of parasite‐specific Th2 and IL‐10 responses in the transient absence of Foxp3+ Treg. However, adult worm burdens were not affected by the increased Th2‐reactivity in Treg‐depleted mice. Hence, our data show that Treg restrict the onset and strength of Th2 responses during intestinal worm infection, while increasing primary Th2 responses does not necessarily lead to killing of larvae or accelerated expulsion of adult worms.
Critical role of microglial CD40 in the maintenance of mechanical hypersensitivity in a murine model of neuropathic pain
Authors: Cao Ling , Palmer Christopher D. , Malon Jennifer T. , De Leo Joyce A.
Published: September 2009

We recently demonstrated a contributing role of spinal cord infiltrating CD4+ T lymphocytes in the maintenance of mechanical hypersensitivity in a rodent model of neuropathic pain, spinal nerve L5 transection (L5Tx). It has been demonstrated that microglia play a role in the etiology of pain states. We hypothesized that infiltrating CD4+ T lymphocytes communicate with microglia via a CD40‐CD154 interaction. Here, we investigated the role of CD40 in the development of mechanical hypersensitivity post‐L5Tx. CD40 KO mice displayed significantly decreased mechanical sensitivity compared with WT mice starting from day 5 post‐L5Tx. Using bone marrow chimeric mice, we further identified a pro‐nociceptive role of CNS microglial CD40 rather than the peripheral leukocytic CD40. Flow cytometric analysis determined a significant increase of CD40+ microglia in the ipsilateral side of lumbar spinal cord post‐L5Tx. Further, spinal cord proinflammatory cytokine (IL‐1β, IL‐6, IL‐12, and TNF‐α) profiling demonstrated an induction of IL‐6 in both WT and CD40 KO mice post‐L5Tx prior to the increase of microglial CD40 expression, indicating a CD40‐independent induction of IL‐6 following L5Tx. These data establish a novel role of microglial CD40 in the maintenance of nerve injury‐induced behavioral hypersensitivity, a behavioral sign of neuropathic pain.
Membrane protein GARP is a receptor for latent TGF‐β on the surface of activated human Treg
Authors: Stockis Julie , Colau Didier , Coulie Pierre G. , Lucas Sophie
Published: September 2009

Human Treg and Th clones secrete the latent form of TGF‐β, in which the mature TGF‐β protein is bound to the latency‐associated peptide (LAP), and is thereby prevented from binding to the TGF‐β receptor. We previously showed that upon TCR stimulation, human Treg clones but not Th clones produce active TGF‐β and bear LAP on their surface. Here, we show that latent TGF‐β, i.e. both LAP and mature TGF‐β, binds to glycoprotein A repetitions predominant (GARP), a transmembrane protein containing leucine rich repeats, which is present on the surface of stimulated Treg clones but not on Th clones. Membrane localization of latent TGF‐β mediated by binding to GARP may be necessary for the ability of Treg to activate TGF‐β upon TCR stimulation. However, it is not sufficient as lentiviral‐mediated expression of GARP in human Th cells induces binding of latent TGF‐β to the cell surface, but does not result in the production of active TGF‐β upon stimulation of these Th cells.
The importance of scavenging reactive oxygen species in anti‐aging medicine
Authors: Siegel Günter , Schmidt Annette , Schäfer Petra , Malmsten Martin , Ringstad Lovisa , Winkler Karl , Just Sören
Published: September 2009

In a pilot study, we had reported on the beneficial effects of Ginkgo biloba (EGb 761) on arteriosclerotic nanoplaque formation and size in cardiovascular high‐risk patients who had undergone an aortocoronary bypass operation. Briefly, nanoplaque formation and size, the ratio oxLDL/LDL, and the highly atherothrombotic lipoprotein(a) concentration were substantially reduced, while superoxide dismutase activity and the blood concentration of the vasodilating substances cAMP and cGMP were upregulated. Since the arteriosclerosis prophylactic and well‐aging promotive impact of Ginkgo extract has been proven in this pilot study, we wanted to confirm these beneficial effects through a second observational clinical trial. The measurable variables formerly used were additionally supplemented by a wide, novel biomarker spectrum, through which the latest parameters and markers of plaque stability and progression, oxidative stress, and inflammation were available. In eleven patients with metabolic syndrome in the initial stage, the reduction of arteriosclerotic nanoplaque formation amounted to 14.3±2.9% (p<0.0077) and of nanoplaque size to 23.4±3.7% (p<0.0004), respectively, after 2‐months of treatment with Ginkgo biloba extract. Additionally, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were upregulated by 19.6±10.0% (p<0.0785) and 11.6±2.3% (p<0.001), respectively, the quotient oxLDL/LDL lowered by 21.0±4.3% (p<0.002), and lipoprotein(a) concentration decreased by 26.3±4.8% (p<0.001) in the patients' blood. The concentration of cAMP and cGMP was augmented by 43.5±12.0% (p<0.001) and 32.9±10.4% (p<0.001), respectively. Surprisingly, we found a lowering of the serum Ca2+ concentration by 5.4±1.6% (p<0.0076) from 2.37±0.03 to 2.24±0.04 mmol/L (p<0.0069). Apart from an additional vasodilatory effect, the lowered extracellular Ca2+ concentration affects nanoplaque formation restrictively, since this is a Ca2+ driven process. Furthermore, we could show a favourable development of the biomarkers 8‐iso‐PGF2α, oxLDL/LDL, SOD, GPx (oxidative stress), hs‐CRP, MPO, TNFα, TGFβ1 (inflammatory status) and MMP‐9 (plaque stability). The markers selected here are suited to provide a comprehensive risk profile for the prevention of arteriosclerosis. Finally, a multiple regression analysis reveals a basis for a mechanistic explanation of nanoplaque reduction under Ginkgo treatment. The arteriosclerosis inhibiting effect is due to an attenuation of the risk factors oxLDL/LDL, Lp(a), and [Ca2+]o as well as to a significant increase in the vasodilator cAMP and cGMP concentration. Thus, Ginkgo with its pleiotropic effects should be assigned a fixed rank among the anti‐aging medical therapeutics as a prophylactic measure, especially in patients with early‐stage metabolic syndrome.
The technology of the Global HIV Vaccine Research Cryorepository
Authors: Ihmig Frank R. , Shirley Stephen G. , Durst Christopher H. P. , Schulz Julia C. , Briesen Hagen V. , Zimmermann Heiko
Published: September 2009

This paper gives an overview of our developments in the fields of cryotechnology and cryoelectronics for managing biological samples stored over liquid nitrogen, fields that are essential to a central cryostorage facility for AIDS related material used in worldwide collaborative research. As a fundamental part of this project we have developed new electronic cryovials and carrier plates attached to Flash memory chips, so that a redundant and portable set of data is present with each sample. The recovery of peripheral blood mononuclear cells (PBMCs) after cryopreservation in the new cryosubstrates showed, especially for small sample volumes (0.1 ml), an increased viability in comparison to the preservation in standard cryovials. The electronic cryosubstrates interface with a dedicated laboratory workflow management system for reproducible and standardized sample processing. This system can read standard operating procedures (SOPs) stored on each sample's memory chip. Finally, we have developed a polymorphic cryoelectronic infrastructure for sample storage tanks. This cryoelectronic system has been integrated in a hermetic storage and semiautomatic handling environment. The new technologies provide state‐of‐the‐art sample identification, documentation and tracking that brings added value to each sample. The first application of these technologies is in a worldwide collaborative research towards the production of an AIDS vaccine. The functionality and versatility of the technologies will lead to an essential optimization of sample and data exchange for global clinical studies by ensuring a high degree of standardization between laboratories.
Studies on Composite Cathode with Nanostructured Ce0.9Sm0.1O1.95 for Intermediate Temperature Solid Oxide Fuel Cells
Authors: Xiao G. , Jiang Z. , Li H. , Xia C. , Chen L.
Published: September 2009

A kind of nanostructured Ce0.9Sm0.1O1.95 is prepared by a hydrothermal method. It exhibits large Brunauer‐Emmett‐Teller area (>120 m2 g–1), open mesoporous structure and nanocrystalline sheets. This material shows high activity for oxygen reduction. An area specific resistance below 0.6 Ω cm2 at 600 °C is achieved when it is mixed with Ag paste as a composite cathode in a symmetric cell. This is attributed to its large triple phase boundary area and good ionic conducting property. The influences of microstructure, doping, loading effects of silver nanoparticles and the temperature dependence on oxygen reduction kinetics are investigated by the impedance spectroscopy. Although some further optimisations are still required, this special Ce0.9Sm0.1O1.95 material reported here exhibits promising features of applications in the composite electrodes for intermediate temperature solid oxide fuel cells (IT‐SOFCs).
Structural MRI biomarkers for preclinical and mild Alzheimer's disease
Authors: Fennema‐Notestine Christine , Hagler Donald J. , McEvoy Linda K. , Fleisher Adam S. , Wu Elaine H. , Karow David S. , Dale Anders M.
Published: September 2009

Noninvasive MRI biomarkers for Alzheimer's disease (AD) may enable earlier clinical diagnosis and the monitoring of therapeutic effectiveness. To assess potential neuroimaging biomarkers, the Alzheimer's Disease Neuroimaging Initiative is following normal controls (NC) and individuals with mild cognitive impairment (MCI) or AD. We applied high‐throughput image analyses procedures to these data to demonstrate the feasibility of detecting subtle structural changes in prodromal AD. Raw DICOM scans (139 NC, 175 MCI, and 84 AD) were downloaded for analysis. Volumetric segmentation and cortical surface reconstruction produced continuous cortical surface maps and region‐of‐interest (ROI) measures. The MCI cohort was subdivided into single‐ (SMCI) and multiple‐domain MCI (MMCI) based on neuropsychological performance. Repeated measures analyses of covariance were used to examine group and hemispheric effects while controlling for age, sex, and, for volumetric measures, intracranial vault. ROI analyses showed group differences for ventricular, temporal, posterior and rostral anterior cingulate, posterior parietal, and frontal regions. SMCI and NC differed within temporal, rostral posterior cingulate, inferior parietal, precuneus, and caudal midfrontal regions. With MMCI and AD, greater differences were evident in these regions and additional frontal and retrosplenial cortices; evidence for non‐AD pathology in MMCI also was suggested. Mesial temporal right‐dominant asymmetries were evident and did not interact with diagnosis. Our findings demonstrate that high‐throughput methods provide numerous measures to detect subtle effects of prodromal AD, suggesting early and later stages of the preclinical state in this cross‐sectional sample. These methods will enable a more complete longitudinal characterization and allow us to identify changes that are predictive of conversion to AD. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.
Does upward seepage of river water and storm water runoff determine water quality of urban drainage systems in lowland areas? A case study for the Rhine–Meuse delta
Authors: Vermonden Kim , Hermus Marion A. A. , van Weperen Marije , Leuven Rob S. E. W. , van der Velde Gerard , Smolders Alfons J. P. , Roelofs Jan G. M. , Hendriks A. Jan
Published: September 2009

The water quality of urban drainage ditches in lowlands in the Rhine‐Meuse delta was analysed with principal component analysis (PCA) during a dry period and a rain storm, and related to the seepage of polluted river water and effective impervious area (EIA). This was done in order to test the hypothesis that seepage of river water and storm water runoff from impervious areas strongly determine the water quality of urban drainage systems along large lowland rivers.

Our analysis revealed that upward seepage of groundwater originating from rivers Rhine and Meuse was positively correlated with nitrate, potassium, sodium and chloride and negatively correlated with alkalinity, calcium, magnesium and iron. EIA was correlated with very few environmental variables (i.e. phosphate, pH and iron in the dry period and iron during the rain storm). Nickel and zinc concentrations generally exceeded the maximum allowable concentrations (MAC), while lead and phosphorus concentrations were just above the nutrient standards and MAC in a few locations during the rain storm. To optimize water quality in urban water systems, attention should be paid to all sources of pollution and not only to EIA. The impact of local groundwater seepage originating from large rivers in lowlands on the chemistry of urban water systems is often underestimated and should be taken into account when assessing water quality and improving water quality status. Copyright © 2009 John Wiley & Sons, Ltd.
Dynamics of stream nitrate sources and flow pathways during stormflows on urban, forest and agricultural watersheds in central Pennsylvania, USA
Authors: Buda Anthony R. , DeWalle David R.
Published: September 2009

Understanding the influence of storm events on nitrate (NO3−) dynamics is important for efficiently managing NO3− pollution. In this study, five sites representing a downstream progression of forested uplands underlain by resistant sandstone to karst lowlands with agricultural, urban and mixed land‐use were established in Spring Creek, a 201 km2 mixed land‐use watershed in central Pennsylvania, USA. At each site, stream water was monitored during six storm events in 2005 to assess changes in stable isotopes of NO3− (δ15N‐NO3− and δ18O‐NO3−) and water (δ18O‐H2O) from baseflow to peakflow. Peakflow fractions of event NO3− and event water were then computed using two‐component mixing models to elucidate NO3− flow pathway differences among the five sites. For the forested upland site, storm size appeared to affect NO3− sources and flow pathways. During small storms (<35 mm rainfall), greater event NO3− fractions than event water fractions indicated the prevalence of atmospheric NO3− source contributions at peakflow. During larger storms (>35 mm rainfall), event NO3− fractions were less than event water fractions at peakflow suggesting that NO3− was flushed from stored sources via shallow subsurface flow pathways. For the urbanized site, wash‐off of atmospheric NO3− was an important NO3− source at peakflow, especially during short‐duration storms where event water contributions indicated the prevalence of overland flow. In the karst lowlands, very low fractions of event water and even lower fractions of event NO3− at peakflow suggested the dominance of ground water flow pathways during storms. These ground water flow pathways likely flushed stored NO3− sources into the stream, while deep soils in the karst lowlands also may have promoted NO3− assimilation. The results of this study illustrated how NO3− isotopes and δ18O‐H2O could be combined to show key differences in water and NO3− delivery between forested uplands, karst valleys and fully urbanized watersheds. Copyright © 2009 John Wiley & Sons, Ltd.
In vitro synthesis of polyhydroxyalkanoate catalyzed by class II and III PHA synthases: a useful technique for surface coatings of a hydrophobic support with PHA
Authors: Sato Shun , Minato Masayuki , Kikkawa Yoshihiro , Abe Hideki , Tsuge Takeharu
Published: September 2009

In vitro synthesis of polyhydroxyalkanoates (PHAs) on a hydrophobic support, i.e. highly oriented pyrolytic graphite (HOPG), was performed using class II PHA synthase (PhaC1Pp) from Pseudomonas putida and class III PHA synthase (PhaECAv) from Allochromatium vinosum. Using PhaC1Pp and 3‐hydroxyoctanoyl‐CoA, a poly(3‐hydroxyoctanoate) [P(3HO)] film was formed on the hydrophobic support with a thickness of a few nanometers, as revealed by atomic force microscopy (AFM). A poly(3‐hydroxybutyrate) [P(3HB)] film was also formed using PhaECAv and 3‐hydroxybutyryl‐CoA. AFM observations of the HOPG surface during P(3HB) film formation revealed that polymerized P(3HB) covered HOPG surface within the reaction time, resulting in the formation of a homogeneous ultra‐thin film. This method of ultra‐thin PHA film formation on a hydrophobic support may be applicable to the surface‐coating technique of materials with biodegradable, bioabsorbable, and biocompatible PHAs. Copyright © 2009 Society of Chemical Industry
An evaluation of GMCP‐SA as a replacement for ITLC‐SG when measuring the levels of radiochemical impurities in 99mTc radiopharmaceuticals by thin‐layer chromatography
Authors: Millar Alistair M. , Beattie Lynn A. , Craig Fiona , O'Brien Lesley M.
Published: September 2009

Background: The European Pharmacopoeia and radiopharmaceutical manufacturers specify Instant Thin‐Layer Chromatography Silica Gel impregnated glass fibre (ITLC‐SG) as the stationary phase for measuring the radiochemical purity (RCP) of most technetium‐99m (99mTc) radiopharmaceuticals. During 2008, The Pall Corporation stopped manufacturing ITLC‐SG. A replacement is required. Aim: To evaluate Varian's Glass Microfibre Chromatography Paper impregnated with salicic acid (GMCP‐SA) as a replacement. Experimental: Samples of six 99mTc radiopharmaceuticals (albumin nanocolloid, colloidal tin, exametazime, medronate, pentetate and succimer) were prepared containing levels of radiochemical impurities between 0 and 10%. Samples were tested using ITLC‐SG and GMCP‐SA with the mobile phase specified in the pharmacopoeia or by the manufacturer. Analysis was performed by thin‐layer radiochromatogram scanning. Results: For measuring the RCP of albumin nanocolloid, colloidal tin, exametazime and succimer, GMCP‐SA is a suitable replacement for ITLC‐SG. For medronate, GMCP‐SA is suitable for measuring colloidal 99mTc impurity despite producing slightly higher values than ITLC‐SG, but unsuitable for measuring 99mTc pertechnetate impurity due to significant over‐estimation. For pentetate, GMCP‐SA is suitable for measuring colloidal 99mTc impurity but gives slightly higher values for 99mTc pertechnetate impurity than ITLC‐SG. Conclusion: GMCP‐SA is a suitable alternative to ITLC‐SG for analysing some 99mTc radiopharmaceuticals but is not a universal replacement. Copyright © 2009 John Wiley & Sons, Ltd.
Comparative analysis of volatile constituents in Citrus Reticulata Blanco using GC–MS and alternative moving window factor analysis
Authors: Yu Lianfang , Li Xiaoru , Liu Shaoyin , Xu Guangwei , Liang Yizeng
Published: September 2009

The similarities and differences of essential oil components in Album Citri Reticulatae (ACR), Cylindricae Citri Reticulatae (CCR), Folium Citri Reticulatae (FCR), Exocarpium Citri Grandis (ECG), Pericarpium Citri Reticulatae Viride (PCRV) and Pericarpium Citri Reticulatae (PCR) were investigated by GC–MS combined with a chemometric method named alternative moving window factor analysis (AMWFA). And temperature‐programmed retention indices (PTRIs) were used together with mass spectra for identification of the essential oil components. In essential oils of ACR, CCR, FCR, ECG, PCRV and PCR, 28, 26, 61, 62, 52 and 48 components were determined representing 93.13, 94.44, 93.53, 87.67, 99.03 and 98.03% of the total relative content, respectively. Also, the essential oils significantly differed both qualitatively and quantitatively. There were 14 common components among ACR, CCR, FCR, ECG, PCRV and PCR, their abundance varied in the ranges from 32.39% in FCR to 94.66% in PCRV. The results obtained may be helpful to the further study of pharmacological activity for their potential utilization as therapeutical agents.
Direct characterization of aqueous extract of Hibiscus sabdariffa using HPLC with diode array detection coupled to ESI and ion trap MS
Authors: Rodríguez‐Medina Inmaculada C. , Beltrán‐Debón Raúl , Molina Vicente Micol , Alonso‐Villaverde Carlos , Joven Jorge , Menéndez Javier A. , Segura‐Carretero Antonio , Fernández‐Gutiérrez Alberto
Published: September 2009

The phenolic fraction and other polar compounds of the Hibiscus sabdariffa were separated and identified by HPLC with diode array detection coupled to electrospray TOF and IT tandem MS (DAD‐HPLC‐ESI‐TOF‐MS and IT‐MS). The H. sabdariffa aqueous extract was filtered and directly injected into the LC system. The analysis of the compounds was carried out by RP HPLC coupled to DAD and TOF‐MS in order to obtain molecular formula and exact mass. Posterior analyses with IT‐MS were performed and the fragmentation pattern and confirmation of the structures were achieved. The H. sabdariffa samples were successfully analyzed in positive and negative ionization modes with two optimized linear gradients. In positive mode, the two most representative anthocyanins and other compounds were identified whereas the phenolic fraction, hydroxycitric acid and its lactone were identified using the negative ionization mode.
Comparison of the volatile constituents of different parts ofCortex magnolia officinalisby GC‐MS combined with chemometric resolution method
Authors: Xu Xiao‐Na , Tang Zhong‐Hai , Liang Yi‐Zeng , Zhang Liang‐Xiao , Zeng Mao‐Mao , Deng Jia‐Hui
Published: September 2009

Volatile compositions of different parts (stem, branch and root barks) ofCortex magnolia officinalis, cultivated in China, were investigated for the first time by GC‐MS with the help of heuristic evolving latent projection (HELP). Identification of components was conducted by similarity matching to NIST mass library but also assisted by comparison of temperature‐programmed retention indices (PTRIs) with the data web available. A total of 90, 82 and 76 volatile compounds in the essential oils of the three samples taken from the same batch aforementioned were qualitatively and quantitatively determined, representing 84.03, 83.68 and 83.10% of the total content, respectively. Among the constituents determined, there were 50 components coexisting. Eudesmol and its isomers were shown to be the principal compounds in the studied samples, accounting for 47.66, 36.74 and 36.31%, respectively. The three kinds of isomers (α‐, β‐ and γ‐eudesmol) in houpo volatile oils have been tentatively qualified and quantified simultaneously for the first time. By comparative analysis, significant qualitative and semi‐quantitative differences and similarities were observed among the three samples. The results achieved provide a scientific evidence for further exploitation ofMagnoliabark and clinical medication.
Self‐Assembled Polyaniline Nanotubes with Rectangular Cross‐Sections
Authors: Ding Zhongfen , Currier Robert P. , Zhao Yusheng , Yang Dali
Published: September 2009

Nanomaterials made from the conducting polymer polyaniline (PANI) have very unique applications due to their high surface area and ease of processing. The link between synthesis conditions and morphology of PANI nanomaterials has been the subject of numerous investigations in recent years. Formation mechanisms for different morphologies have also been proposed. In this work, we report a self‐assembly method to make high yield PANI nanotubes with rectangular holes and outer contours by qualitatively and purposely controlling reaction rate. We find that aggregation of detectable and separable reaction intermediates is directly correlated with PANI nanotubes formation, consistent with the observation of oligoaniline precipitates reported in the literature. Control over intermediate aggregates morphology is studied systematically. By controlling the reaction rate through adjusting acid and oxidant concentrations, we can slow down the aggregation rate of the intermediates to largely enhance the yield of nanotubes with rectangular cross‐sections. To understand the correlation between the intermediates aggregation and the morphology of the resulting PANI tubes, the morphologies of intermediate aggregates and final nanotubes were characterized using SEM, STEM, and TEM. Open circuit potential (OCP) was used to monitor the polymerization process. Molecular weight distribution results were also obtained for the intermediate aggregates and the final products. Based on our study, we propose a simple PANI nanotube formation mechanism.

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Thermo‐Responsive Copolymers Based on Poly(N‐isopropylacrylamide) and Poly[2‐(methacryloyloxy)ethyl phosphorylcholine]: Light Scattering and Microscopy Experiments
Authors: Cristiano Cláudia M. Z. , Soldi Valdir , Li Chengming , Armes Steven P. , Rochas Cyrille , Pignot‐Paintrand Isabelle , Borsali Redouane
Published: September 2009

Aqueous self‐assembly of thermosensitive triblock copolymers based on poly(N‐isopropylacrylamide) and poly[2‐(methacryloyloxy)ethyl phosphorylcholine] (PNIPAMm–PMPCn–PNIPAMmand PNIPAMm–PMPCn–S–S–PMPCn–PNIPAMm) were studied using light scattering (SLS and DLS), TEM and fluorescence experiments. These techniques were used to investigate the morphological transition as a function of the temperature, below and above the LCST of the PNIPAM, at various triblock copolymer concentrations ranging from dilute to semi‐dilute regimes. Below the LCST and at low concentrations, aqueous solutions show micellar behavior, while above the LCST self‐assembly leading to large nanoparticles stabilized with PMPC chains. Such behavior is the onset of a gel‐like phase transition observed at higher concentrations.

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Poly[ethylene‐co‐(vinyl alcohol)]‐graft‐Poly(ε‐caprolactone) by Reactive Extrusion, 2 – Parameter Analysis
Authors: Zhao Yanchao , Becquart Frédéric , Chalamet Yvan , Chen Jianding D. , Taha Mohamed
Published: September 2009

EVOH‐g‐PCL were prepared by a solvent‐free reactive extrusion process using a co‐rotating twin screw extruder. Kinetic simulations were made of selected reaction conditions at 185 °C. Changes in the screw rotation rate resulted in evolution of the residence time distribution and slightly changed the monomer conversion. An increase of the [OH]0/[Cl]0 ratio made the reactive system more viscous and decreased the overall pumping capacities of the extruder. Increase of the mean residence time, combined with a positive kinetic effect of [OH]0 increase, leaded to an important increase in conversion. For all the conducted experiments, equivalent distribution dispersions and good agreements between calculated conversion and those measured were obtained. An increase in temperature from 185 to 200 °C resulted in total conversion.

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A Solvent‐Assisted Compression Molded of Poly(L‐lactide)/Hydroxyapatite Electrospun Fibers for Robust Engineered Scaffold Systems
Authors: Luong Nguyen Dang , Moon Ik‐Sang , Nam Jae‐Do
Published: September 2009

In an attempt to enhance the biocompatibility and mechanical strength of fibrous polymeric scaffold systems, nanocrystalline hydroxyapatite (HAp) particles were incorporated into the electrospun poly(L‐lactide) (PLLA) fibers and then mechanically interlocked using a vapor‐phase solvent adsorption method. The solvent‐assisted compression molding substantially increased the tensile strength (from 4.61 to 12.63 MPa) and mechanical modulus (from 50.6 to 627.7 MPa) of the fibrous scaffold, which maintained the interstitial space between the fibers to allow the facile transport of nutrients and waste during cell growth and polymer biodegradation. Macrometer‐sized pores (ca. 100–400 µm) were introduced into the scaffolds in a controlled fashion using the salt leaching/gas forming technique to give desired space for a facile cell implantation and growth. Overall, the developed methodology allows the polymer‐based scaffold systems to be tailored for various applications in light of surface characteristics, mechanical strength, and pore size of engineered scaffolds.

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A Magnetically Tunable Colloidal Crystal Film for Reflective Display
Authors: Zhu Cun , Chen Liangshui , Xu Hua , Gu Zhongze
Published: September 2009

A general approach to fabricate a magnetic field responsive colloidal crystal film has been developed. This is carried out by depositing monodisperse Fe3O4/PS composite magnetic nanospheres on the surface of an agarose‐gel coated substrate. The optical properties of the resultant film can be easily controlled by an external magnetic field, which is caused by assembly of the magnetic nanospheres and alteration of the interparticle distance. With the help of a designed array of small magnets, both the color and pattern of the film can be conveniently modulated and the tuning range covers almost the whole visible spectrum. This work will be important for the potential application of monodisperse magnetic nanospheres in fabricating novel sensors, displays and optoelectronic devices.

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Essential tremor — Neurodegenerative or nondegenerative disease towards a working definition of ET
Authors: Deuschl Günther , Elble Rodger
Published: September 2009

Essential tremor (ET) is a syndrome of tremor in posture and movement, but recent studies have revealed additional cerebellar motor disturbances, cognitive disturbances, personality changes, hearing loss, and olfactory deficits. Even dementia and shortened life expectancy were found in one cohort. Recent postmortem studies have found limited Lewy body pathology in some patients and Purkinje cell loss with torpedoes and Bergmann gliosis in others. These findings have led to the hypothesis that ET is a syndrome produced by at least two neurodegenerative diseases with more widespread clinical consequences than previously appreciated. We review the evidence for and against this hypothesis and conclude that studies purporting to support this hypothesis have failed to control for age‐associated comorbidities, depression, medications, and other confounding factors. We propose the alternative hypothesis that abnormal neuronal oscillation is the fundamental abnormality in ET, and the well‐documented cerebellar signs and symptoms, the controversial non‐motor signs, and even the cerebellar pathology of ET could be caused by this oscillation. A major problem for many studies is the lack of a diagnostic gold standard. Lacking such a standard, we propose a subclassification of ET into three categories: hereditary ET, sporadic ET, and senile ET, which we believe will help researchers resolve many of the controversies in this field. © 2009 Movement Disorder Society
Modelling instabilities in triaxial testing on unsaturated soil specimens
Authors: Buscarnera Giuseppe , Nova Roberto
Published: September 2009

The paper presents a theoretical approach to deal with mechanical instabilities in unsaturated soils. Towards this goal, the concept of test controllability is extended to a hydro‐mechanically coupled framework. A constitutive approach based on the introduction of hydraulic generalized stress–strain variables is first adopted, in order to better describe suction effects on the mechanical behaviour of soil. The mathematical consequences of hydro‐mechanical coupling are presented next and two indices are defined to identify the onset of an instability. Possible instability modes linked to saturation processes are discussed. It is shown that the way in which the hydraulic variables are controlled in tests on unsaturated soil specimens is the key factor for the possible occurrence of instabilities and the consequent loss of test controllability. It is shown in particular that unsaturated soil specimens are prone to instability when an externally controlled water flux is injected into the specimen (inundation). This result could in part explain the sudden collapse of soil specimens subjected to wetting under constant applied stresses, which is observed both in the laboratory and in the field. Copyright © 2009 John Wiley & Sons, Ltd.
Iterative strong coupling of dimensionally heterogeneous models
Authors: Leiva Jorge S. , Blanco Pablo J. , Buscaglia Gustavo C.
Published: September 2009

In this article we address decomposition strategies especially tailored to perform strong coupling of dimensionally heterogeneous models, under the hypothesis that one wants to solve each submodel separately and implement the interaction between subdomains by boundary conditions alone. The novel methodology takes full advantage of the small number of interface unknowns in this kind of problems. Existing algorithms can be viewed as variants of the ‘natural’ staggered algorithm in which each domain transfers function values to the other, and receives fluxes (or forces), and vice versa. This natural algorithm is known as Dirichlet‐to‐Neumann in the Domain Decomposition literature. Essentially, we propose a framework in which this algorithm is equivalent to applying Gauss–Seidel iterations to a suitably defined (linear or nonlinear) system of equations. It is then immediate to switch to other iterative solvers such as GMRES or other Krylov‐based method, which we assess through numerical experiments showing the significant gain that can be achieved. Indeed, the benefit is that an extremely flexible, automatic coupling strategy can be developed, which in addition leads to iterative procedures that are parameter‐free and rapidly converging. Further, in linear problems they have the finite termination property. Copyright © 2009 John Wiley & Sons, Ltd.