bluuebunny/crossref_metadata_2025 huggingface dataset:
Voltammetric Characterization of Micro‐ and Submicrometer‐Electrode Arrays of Conical Shape for Electroanalytical Use
Authors: Daniele Salvatore , De Faveri Eddy , Kleps Irina , Angelescu Anca
Published: August 2006

Densely packed micro‐ and submicrometer electrode arrays of platinum and gold (the nominal number, N, of electrodes in each array varies between 225 and 3600) are fabricated by photolithographic technique and vapor deposition processes of metal films. The electrodes are conical‐shaped and only their apexes are exposed to the electrolytic solution. The electrode arrays are characterized electrochemically in Ru(NH3)6Cl3 aqueous solutions by using cyclic voltammetry at low scan rates, to establish the number of electrochemically active electrodes (Nac) in each array; the geometric characterization is performed by scanning electron microscopy. All the investigated arrays provide steady‐state voltammograms, indicating diffusionally independent behavior of each microelectrode. The number of microelectrodes that are active in the fabricated arrays depends on microelectrode density. In particular, for the arrays with N=3600 and N=225, the fraction of active sites is about 45% and 90%, respectively. The analytical performance of some of the Pt version of the arrays is tested in hydrogen peroxide solutions, allowing verifying that linear calibration plots over the concentration range (0.1–20 mM) are obtained. This dynamic range is larger than that typically recorded at smooth polycrystalline platinum electrodes (0.5–5 mM), and the better performance is attributed to both the higher aspect ratio of the cone geometry and the higher mass transport associated to each microelectrode of the array. Reproducibility (within 3.5%, r.s.d.) and long‐term stability (within 5%, r.s.d., after 8 h continuous use) of the electrode systems are satisfactory. A low detection limit, based on the signal to noise ratio equal to 3, of 0.05 mM is found, which is adequate for a rapid monitoring of H2O2 in real samples and industrial processes.
Tagging of Model Amphetamines with Sodium 1,2‐Naphthoquinone‐4‐sulfonate: Application to the Indirect Electrochemical Detection of Amphetamines in Oral (Saliva) Fluid
Authors: Goodwin Alexander , Banks Craig E. , Compton Richard G.
Published: August 2006

Proof‐of‐concept is shown for the indirect electrochemical detection of model amphetamines, D‐amphetamine sulfate and pseudoephedrine, based on the labeling of the amphetamine models with sodium 1,2‐naphthoquinone‐4‐sulfonate (NQS). The presence of the amphetamine models is monitored via either the reduction in the magnitude of the voltammetric peak corresponding to the electrochemical reduction of the quinone functionality of the sodium 1,2‐naphthoquinone‐4‐sulfonate or via growth of a new voltammetric peak related to reaction between the amphetamine model and NQS, both of which are well resolved from one another. The protocol is shown to be successful in artificial saliva and authentic human oral (saliva) fluid. Such a protocol may be particularly attractive for roadside testing of amphetamines in drug drivers.
Collagen‐Like Peptide as a Matrix for Enzyme Immobilization in Electrochemical Biosensors
Authors: Yemini Miri , Xu Peng , Kaplan David L. , Rishpon Judith
Published: August 2006

An efficient enzyme immobilization technique is described in which well‐organized collagen peptide monolayers are used as a scaffold upon which horseradish peroxidase is anchored on gold electrode surfaces. The resulting electrode presents reproducible amperometric responses at an applied potential of −0.1 V with a range of linearity for peroxides. These results suggest that triple helical collagen can be used for specific immobilization of HRP with advantages of low price, simplicity and biocompatibility. The results are significant for the control of biomolecular self‐assembly in the intrinsic electric devices.
Iron(III) Oxide Graphite Composite Electrodes: Application to the Electroanalytical Detection of Hydrazine and Hydrogen Peroxide
Authors: Šljukić Biljana , Banks Craig E. , Crossley Alison , Compton Richard G.
Published: August 2006

Composite electrodes based on iron(III) oxide, Fe2O3, carbon powder and epoxy resin have been prepared and characterized using electrochemical methods and X‐ray photoelectron spectroscopy (XPS). Initially composite electrodes were made by mixing micron sized carbon powder surface with iron(III) oxide. However, the voltammetric responses were unsatisfactory. Therefore, a new type of composite electrodes was made using carbon powder modified with iron(III) oxide via a wet impregnation procedure. This technique involves saturation of the carbon powder with iron(III) nitrate followed by thermal treatment at ca. 623 K forming iron(III) oxide on the surface of the carbon powder.
Genetic mutation analysis by CE with LIF detection using inverse‐flow derivatization of DNA fragments
Authors: Sang Fuming , Ren Haixia , Ren Jicun
Published: August 2006

Inverse‐flow derivatization is a novel approach to obtain fluorescent DNA derivatives in DNA analysis based on CE with LIF detection. In the present work, we want to explore the feasibility of the application of this method into the mutation detection based on constant denaturant capillary electrophoresis (CDCE) and SSCP analysis. The DNA fragments were first amplified by PCR using a pair of common primers without fluorescent label, and then the mutations were determined by CDCE or SSCP analysis based on CE‐LIF with inverse‐flow derivatization of DNA fragments. The experimental conditions were investigated systematically, and different labeling modes including inverse‐flow derivatization, on‐column derivatization and fluorescent labeled primer technique were compared. The inverse‐flow derivatization was successfully used in the detection of C677T mutation in the methylenetetrahydrofolate reductase gene by CDCE or SSCP analysis. Our preliminary results demonstrate that inverse‐flow derivatization is very simple, inexpensive and sensitive and well suitable for the genetic analysis in clinical diagnosis.
Alkaline leaching of printed circuit board sludge
Authors: Hu S.H. , Wu J.Y. , Yen F.S. , Tsai M.S.
Published: August 2006

The purpose of this study was to develop a treatment procedure for processing aluminum‐contaminated sludge produced from the coagulation/flocculation process of wastewater treatment in the manufacture of printed circuit boards (PCBs). In this study, the reagent sodium hydroxide (2 N) was used to leach the heavy metal sludge and the dissolution of sludge's aluminum content was roughly 70%. The weight loss of the heavy metal sludge was caused by the dissolution of aluminum content of nearly 20%. Although dissolution of a small amount of copper occurred simultaneously during this leaching process, the dissolution of copper content was restricted within 0.72% in the leaching operation and the copper content was concentrated in the residue to increase the copper level.

The large amounts of sodium hydroxide and Al3+ remaining in the leachate were recycled as neutralization and coagulation agents in wastewater treatment. Synthetic heavy metal wastewater was neutralized with the preceding leachate to estimate the reuse feasibility of recovered coagulant. The heavy metal concentration of the effluent met regulation standards after neutralization and precipitation. The settling rate could be significantly enhanced by the addition of 100 ppm supplemental polyacrylamide (PAM). © 2006 American Institute of Chemical Engineers Environ Prog, 2006
Practical seismic upgrade strategy for substation equipment based on performance indices
Authors: Shumuta Yoshiharu
Published: August 2006

This paper presents an upgrade strategy for substation equipment under seismic risk. In Japan, existing old equipment does not often meet the present seismic design standards and the seismic damage is concentrated on such old equipment. This problem is widely recognized as a typical feature of advanced countries. The proposed method helps managerial decisions pertaining to the prioritizing of upgrading the huge number of existing equipment. In order to prioritize the equipment to be upgraded, practitioners have discussed it from various points of view including earthquake resistant capacity of equipment, seismic performance of whole power system and cost effectiveness of equipment upgrading. Thus, the proposed method consists of four different performance indices to quantitatively evaluate these factors. For numerical examples, the proposed method is applied to a hypothetical power system to discuss the advantages and disadvantages of the proposed indices. Copyright © 2006 John Wiley & Sons, Ltd.
Correlating specific conductivity with total hardness in gypsum karst waters
Authors: Krawczyk Wiesława Ewa , Ford Derek C.
Published: August 2006

Modern digital conductivity meters are readily portable, robust, cheap, and give precisely reproducible values of specific electrical conductivity (SpC, in µS cm−1). Here we investigate the accuracy of their estimates of the amounts of gypsum dissolved in waters collected in gypsum karst terrains, expressed as total hardness (TH) in mg L−1 of CaSO4·2H2O (GYP). Total dissolved solid concentrations (TDS) are also considered. Curves obtained with the program PHREEQC, for the dissolution of pure gypsum in water at 25 C, are compared with 574 comprehensive water chemical analyses selected from gypsum karst studies in Europe and the Americas. Principal common and foreign ions encountered are the BNC group (bicarbonates, nitrates, chlorides). It is found that GYP = 1·12·SpC + 62 where BNC < 33% (Cl− < 5%), with one standard error <5% for waters with SpC > 2400 µS cm−1; GYP = 0·74·SpC + 777 where BNC < 33% (5% ≤ Cl− < 15%), with one standard error <10% for waters with SpC > 3100 µS cm−1; GYP = 0·97·SpC − 209 where BNC < 33% and Cl− ≥ 15%, with one standard error <10% for samples with SpC > 4300 µS cm−1. There are similar results for the more complex waters found in gypsum karsts where much carbonate rock or salt is also present, to the limit of BNC < 50% for what may reasonably be defined as ‘gypsum waters’. Values of R2 for linear correlations of different subsets of the water samples range from 0·69 to 0·96, the majority being >0·8. Copyright © 2006 John Wiley & Sons, Ltd.
Compensatory activations in patients with multiple sclerosis during preserved performance on the auditory N‐back task
Authors: Forn Cristina , Barros‐Loscertales Alfonso , Escudero Joaquín , Benlloch Vicente , Campos Salvador , Antònia Parcet Maria , Ávila César
Published: August 2006

Recent fMRI studies have suggested that multiple sclerosis (MS) patients show adaptive cortical changes (i.e., compensatory mechanisms) during motor and cognitive tasks to limit the clinical impact of tissue injury. In this study, we investigated the activation pattern during the auditory n‐back working memory (WM) paradigm in a group of 17 MS patients and 10 healthy controls with preserved performance in WM tasks. Compared with healthy controls, MS patients showed significantly greater bilateral activation in prefrontal cortex (BA 44), and the insula. These findings were similar to those obtained in previous studies showing that compensatory mechanisms during WM tasks in MS may be based on the use of prefrontal areas adjacent to those involved in the task. Hum. Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.
Peginterferon alpha-2b plus adefovir induce strong cccDNA decline and HBsAg reduction in patients with chronic hepatitis B
Authors: Wursthorn Karsten , Lutgehetmann Marc , Dandri Maura , Volz Tassilo , Buggisch Peter , Zollner Bernhard , Longerich Thomas , Schirmacher Peter , Metzler Frauke , Zankel Myrga , Fischer Conrad , Currie Graeme , Brosgart Carol , Petersen Joerg
Published: August 2006

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is responsible for persistent infection of hepatocytes. The aim of this study was to determine changes in intrahepatic cccDNA in patients with chronic hepatitis B (CH-B) during 48 weeks of antiviral therapy and its correlation to virological, biochemical, and histological parameters. Twenty-six HBsAg-positive CH-B patients received combination treatment with pegylated interferon alpha-2b (peg-IFN) and adefovir dipivoxil (ADV) for 48 weeks. Paired liver biopsies from before and at the end of treatment were analyzed for intrahepatic HBV-DNA. Median serum HBV-DNA had decreased by −4.9 log10 copies/mL at the end of treatment and was undetectable in 13 individuals (54%). Median intrahepatic total HBV-DNA and cccDNA had decreased by −2.2 and −2.4 log10, respectively. Changes in intracellular HBV-DNA positively correlated with HBsAg serum reduction and were accompanied by a high number of serological responders. Eight of 15 HBeAg-positive patients lost HBeAg, and five developed anti-HBe antibodies during treatment. These eight patients exhibited lower cccDNA levels before and at the end of therapy than did patients without HBeAg loss. Four patients developed anti-HBs antibodies. ALT normalized in 11 patients. The number of HBs-antigen- and HBc-antigen-positive hepatocytes was significantly lower after treatment, suggesting the involvement of cytolytic mechanisms.

In conclusion

, combination therapy with peg-IFN and ADV led to marked decreases in serum HBV-DNA and intrahepatic cccDNA, which was significantly correlated with reduced HBsAg.
Intrahepatic injection of adenovirus reduces inflammation and increases gene transfer and therapeutic effect in mice
Authors: Crettaz Julien , Berraondo Pedro , Mauleón Itsaso , Ochoa Laura , Shankar Vijay , Barajas Miguel , van Rooijen Nico , Kochanek Stefan , Qian Cheng , Prieto Jesús , Hernández-Alcoceba Rubén , González-Aseguinolaza Gloria
Published: August 2006

Recombinant adenoviruses (Ad) are among the most extensively used vectors for liver gene transfer. One of the major limitations for the clinical application of these vectors is the inflammatory immune response associated with systemic administration of high dose of virus. We evaluated the effect of Ad administration route on the inflammatory immune response and liver transgene expression. We compared direct intrahepatic injection (IH) with the systemic administration via tail vein (IV). IH injection of Ad resulted in a lower inflammatory response and a higher transgene expression. When a relatively low dose of virus was used, IV administration resulted in no detectable protein expression but production of proinflammatory cytokines. In contrast, IH administration induced high levels of transgene expression and no inflammation, although we detected a transient hypertransaminemia, which fully resolved within days. Furthermore, IH injection resulted in a faster protein expression being more intense at the site of injection, whereas IV administration caused slower but diffuse liver expression. IH injection also reduced the spreading of the virus to other organs. Independently of the route, depletion of Kupffer cells significantly enhanced the transduction efficiency of Ad. This effect was stronger when using IV injection, indicating that IH injection partially overcomes Kupffer cell phagocytic activity. Moreover, the antitumor efficacy of high-capacity-Ad encoding murine interleukin-12 (IL-12) was significantly greater when the vector was administered by IH injection than when given IV.

In conclusion

, IH injection of adenovirus represents a safe and efficient administration route for clinical applications of gene therapy targeting the liver.
pH-independent entry and sequential endosomal sorting are major determinants of hepadnaviral infection in primary hepatocytes
Authors: Funk Anneke , Mhamdi Mouna , Hohenberg Heinz , Will Hans , Sirma Hueseyin
Published: August 2006

Entry and intracellular transport of hepatitis B viruses have several unusual, largely unknown aspects. In this study, we explored the mode of virus entry using the duck hepatitis B virus (DHBV) and the primary hepatocyte infection model. Upon internalization, viral particles were enriched in an endosomal compartment, as revealed by biochemical and ultrastructural analysis. Virus-containing vesicles harbored early endosome markers. Kinetic analysis revealed time-dependent partial translocation of viral DNA from endosomes into the cytosol. This was strongly reduced by inhibition of vacuolar ATPase; (vATPase) activity with bafilomycin A1 and resulted in abortive infection and prevention of cccDNA formation. Inactivation of vATPase induced accumulation and stabilization of incoming viral particles in endosomes, presumably by blocking endosomal carrier vesicle–mediated cargo transport and sorting. Although neutralization of the endomembrane organelles alone led to stabilization of incoming viral particles, it did not inhibit virus infection. In line with this, a pH-dependent ectopic virus fusion at the plasma membrane could not be artificially induced. This provided further evidence for a pH-neutral translocation mechanism. Endosomal membrane potential was required for viral infection because cotreatment of cells with monensin partially overcame the inhibitory effect of bafilomycin A1.

In conclusion

, hepatitis B viral infection is mediated by a novel cellular entry mechanism with features different from that of all other known viruses.

Supplementary material for this article can be found on the HEPATOLOGY website
(http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
Patterns of viral decline during PEG-interferon alpha-2b therapy in HBeAg-positive chronic hepatitis B: Relation to treatment response
Authors: ter Borg Martijn J. , van Zonneveld Monika , Zeuzem Stefan , Senturk Hakan , Akarca Ulus S. , Simon Christopher , Hansen Bettina E. , Haagmans Bart L. , de Man Robert A. , Schalm Solko W. , Janssen Harry L.A.
Published: August 2006

In chronic hepatitis B, it is difficult to predict an early therapeutic response. We investigated the viral decline during therapy with pegylated interferon alpha-2b (PEG-IFN) with or without lamivudine in 266 HBeAg-positive chronic hepatitis B patients. In patients treated with PEG-IFN and lamivudine, a uniform biphasic viral decline pattern was found during therapy and there were no marked differences in viral load between those who lost HBeAg at the end of follow-up (response) or not. In contrast, those treated with PEG-IFN monotherapy exhibited different viral decline patterns. A delayed decline of at least two log from baseline HBV DNA after week 4 but before week 32 was associated with the highest response rate (63%). In comparison, response was 52% for patients with an early decline (week 0-4), 38% for a late decline (week 32-52), 27% for a posttreatment decline (week 52-78) and 11% for patients with no substantial decline. The HBsAg loss was 22% in the delayed decline pattern compared to 4% for those with early decline and none for other decline patterns.

In conclusion

, different patterns of decline in viral load during treatment with PEG-IFN monotherapy were associated with different rates of HBeAg and HBsAg loss at the end of follow-up. Since there was a considerable response, even in patients with a late or posttreatment decline pattern, prediction of response based on viral decline during the first months of therapy was difficult.
Matrix metalloproteinase-9 is an important factor in hepatic regeneration after partial hepatectomy in mice
Authors: Olle Eric W. , Ren Xiaodan , McClintock Shannon D. , Warner Roscoe L. , Deogracias Michael P. , Johnson Kent J. , Colletti Lisa M.
Published: August 2006

Partial hepatectomy triggers hepatocyte proliferation, hepatic matrix remodeling, and hepatocyte apoptosis, all of which are important processes in the regenerating liver. Previous studies have shown an increase in the levels of matrix metalloproteinases gelatinase A (MMP-2) and gelatinase B (MMP-9) after partial hepatectomy. The goal of this study was to investigate the role of MMP-9 in liver regeneration after partial hepatectomy. A 70% hepatectomy or sham laparotomy was performed in wild-type or MMP-9–deficient (MMP-9−/−) mice. Hepatic regeneration was determined by liver weight/total body weight ratios and BrdU staining, which was used to a calculate mitotic index at several times postoperatively. Cytokine and growth factor expression was evaluated by Luminex™ bead–based ELISA and Western blots. Finally, the effect of MMP-9 on apoptosis was measured using TUNEL and caspase expression. The MMP-9−/− animals had a delayed hepatic regenerative response when compared with wild-type controls. The MMP-9–deficient animals expressed significantly less VEGF, HGF, and TNF-α between days 2 and 3 post-hepatectomy. Apoptosis, as measured by TUNEL staining and caspase expression, was decreased in the MMP-9−/−.

In conclusion

, MMP-9 plays an important role in liver regeneration after partial hepatectomy by affecting matrix remodeling, as well as cytokine, growth factor, and caspase expression.

Supplementary material for this article can be found on the HEPATOLOGY website
(http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
HLA class II alleles, genotypes, haplotypes, and amino acids in primary biliary cirrhosis: A large-scale study
Authors: Donaldson Peter T. , Baragiotta Anna , Heneghan Michael A. , Floreani Annarosa , Venturi Carla , Underhill James A. , Jones David E.J. , James Oliver F.W. , Bassendine Margaret F.
Published: August 2006

Twin and family studies suggest there is a significant genetic component to primary biliary cirrhosis (PBC). However, the inability to replicate reported associations has been a recurring problem, with the only consistently reported genetic association that between PBC and HLA-
DRB1*0801

. However, recently even this has been questioned, and a number of novel associations have also been reported. We reinvestigated HLA class II

DRB1, DQA1,

and

DQB1

alleles and haplotypes in a total of 492 well-characterized PBC patients, 412 from the United Kingdom and an additional 80 patients from northern Italy. There was a clear and significant association with HLA

-DRB1*0801

in both groups of patients compared to population-specific healthy controls (12% versus 4% in the UK patients,

P

= .00087, OR = 3.05; and 18% versus 6% in the Italian patients,

P

= .021, OR = 3.15). There were also significant protective associations with

DRB1*11

in the Italian patients (28% versus 47%,

P

= .0071, OR = 0.42), but not in the UK patients (8% versus 8%) and a protective association with

DRB1*13

in both series (14% versus 20%,

P

= .042, OR = 0.65 in the UK patients; and 10% versus 31%,

P

= .00092, OR = 0.25 in the Italian patients).

In conclusion

, a complex relationship exists between HLA and PBC, and some genetic associations may be population specific.
Solution NMR and X‐Ray Structural Studies on Phthalocyaninatoiron Complexes
Authors: Fernández Ignacio , Pregosin Paul S. , Albinati Alberto , Rizzato Silvia , Spichiger‐Keller Ursula E. , Nezel Tomas , Fernández‐Sánchez Jorge F.
Published: August 2006

The addition of primary amines as solubilizing reagents for phthalocyaninatoiron complexes is shown to afford six‐coordinate bis(amine)phthalocyaninato complexes, i.e., [Fe(amine)2(pc)] 2 (amine = decan‐1‐amine) and 3 (amine = benzylamine), with the two new N‐donors occupying the trans‐axial positions. The new complexes were characterized by extensive NMR measurements in THF solution. For complex 3 with the benzylamine ligand, the solid‐state structure was determined by X‐ray diffraction methods. Complex 2 is sufficiently labile in THF solution to exchange one amine ligand against CO (gas) affording an equilibrium mixture containing [Fe(amine)(CO)(pc)] 4.
Chiral Phosphino‐ and (Phosphinooxy)‐Substituted N‐Heterocyclic Carbene Ligands and Their Application in Iridium‐Catalyzed Asymmetric Hydrogenation
Authors: Nanchen Steve , Pfaltz Andreas
Published: August 2006

Enantiomerically pure iridium complexes with phosphino‐ and (phosphinooxy)‐substituted N‐heterocyclic carbene (NHC) ligands were synthesized. Investigation of their electronic properties showed a similar trans influence of the phosphino (or phosphinooxy) and the NHC units. The complexes were tested in iridium‐catalyzed hydrogenation. While low conversions were observed with unfunctionalized olefins, the catalysts proved to be suitable for hydrogenation of the α,β‐unsaturated ester 20, allylic alcohol 21, and imine 22. The enantioselectivities were, however, moderate.
Ab initio Emulsion Polymerization by RAFT (Reversible Addition–Fragmentation Chain Transfer) through the Addition of Cyclodextrins
Authors: Apostolovic Bojana , Quattrini Francesca , Butté Alessandro , Storti Giuseppe , Morbidelli Massimo
Published: August 2006

A novel process to produce homo‐ and copolymers by RAFT polymerization in emulsion is presented. It is known that RAFT‐controlled radical polymerization can be conducted in emulsion polymerization without disturbing the radical segregation characteristic of this process, thus leading to polymerization rates identical to those encountered in the corresponding nonliving systems. However, RAFT agents are often characterized by very low water solubility and, therefore, they diffuse very slowly from the monomer droplets, where they are initially solubilized, to the reaction loci, i.e., the polymer particles. Accordingly, when used in emulsion polymerization, they are practically excluded from the reaction. In this work, we show that cyclodextrins, well‐known for their ability to form water‐soluble complexes with hydrophobic molecules, facilitate the transport across the H2O phase of the RAFT agent to the polymer particles. Accordingly, chains grow through the entire process in a controlled way. This leads to the production of low‐polydispersity polymers with well‐defined structure and end functionalities as well as to the possibility of synthesizing block copolymers by a radical mechanism.
Insertion Reactions of 1,2‐Disubstituted Olefins with an α‐Diimine Palladium(II) Complex
Authors: Carfagna Carla , Gatti Giuseppe , Mosca Luca , Paoli Paola , Guerri Annalisa
Published: August 2006

The migratory insertions of cis or trans olefins CH(X)CH(Me) (X = Ph, Br, or Et) into the metal–acyl bond of the complex [Pd(Me)(CO)(iPr2dab)]+ [B{3,5‐(CF3)2C6H3}4]− (1) (iPr2dab = 1,4‐diisopropyl‐1,4‐diazabuta‐1,3‐diene = N,N′‐(ethane‐1,2‐diylidene)bis[1‐methylethanamine]) are described (Scheme 1). The resulting five‐membered palladacycles were characterized by NMR spectroscopy and X‐ray analysis. Experimental data reveal some important aspects concerning the regio‐ and stereochemistry of the insertion process. In particular, the presence of a Ph or Br substituent at the alkene leads to the formation of highly regiospecific products. Moreover, in all cases, the geometry of the substituents in the formed palladacycle was the same as in the starting olefin, as a consequence of a cis addition of the Pd–acyl fragment to the CC bond. Reaction with CO and MeOH of the five‐membered complex derived from trans‐β‐methylstyrene (= [(1E)‐prop‐1‐enyl]benzene) insertion, yielded the 2,3‐substituted γ‐keto ester 9 with an (2RS,3SR)‐configuration (Scheme 3).
Synthesis of 3‐Acyl‐4‐alkenylpyrrolidines by Platinum‐Catalyzed Hydrative Cyclization of Allenynes
Authors: Matsuda Takanori , Kadowaki Sho , Murakami Masahiro
Published: August 2006

A series of nitrogen‐tethered allenynes (‘5‐aza‐1,2‐dien‐7‐ynes’) 1 were transformed to the corresponding 3‐acyl‐4‐alkenylpyrrolidines 3 when treated with a catalytic amount of PtCl2 in MeOH at 70°. Initial Pt‐promoted cyclization forms a nonclassical carbocationic intermediate. In contrast to the cycloisomerization in toluene, which produced the bicyclic cyclobutenes 2, the intermediate is intercepted by addition of an oxygen nucleophile to achieve the formal hydrative cyclization.
Statistical Approach for the Determination of the Stereoregularity of Optically Active Propylene–CO Copolymers
Authors: Bronco Simona
Published: August 2006

A two‐parameter statistic model was applied to analyze the NMR spectra of a series of stereoregular propylene–CO copolymers synthesized by catalytic polymerization in the presence of various transition‐metal complexes containing chiral ligands. The concentration of the different pentads, estimated to be recognizable in the spectra, was determined. A tentative assignment of the nature of the different peaks composing the signal of the CO group in the 13C‐NMR spectra is proposed.
Influence of bone quality on the strength of internal and external fixation of tibial plateau fractures
Authors: Ali Ahmad M. , Saleh Michael , Eastell Richard , Wigderowitz Carlos A. , Rigby Alan S. , Yang Lang
Published: August 2006

We studied the influence of different parameters of bone quality on the fixation strength of bicondylar tibial plateau fractures and examined the relationship between these parameters. Bone quality was measured in the plateau of 16 cadaveric tibias using three modalities: dual‐energy X‐ray absorptiometry (DXA), peripheral quantitative computer tomography (pQCT), and spectral analysis of digitized radiographs (SADR). The tibias were divided into two groups by the median bone mineral density (BMD) and randomized to receive either dual plating or external fixator for the stabilization of a standardized bicondylar tibial fracture. The fixed fractures were subjected to axial compression until failure. DXA BMD correlated most significantly with the failure load (r ≥ 0.79, p < 0.001), followed by the pQCT parameters of cancellous bone (0.52 ≥ r ≥ 0.73, p < 0.01). Similar strong correlations were also evident in both fixation methods. For parameters derived from SADR, only those including both longitudinal and transverse trabecular orientations had modest correlation with the fixation strength (0.53 ≥ r ≥ 0.71, p < 0.01). The failure loads of the two fixation techniques were not significantly different (mean ± SD = 3522 ± 1386 N and 3710 ± 1356 N, respectively, p = 0.78). However, BMD in the dual‐plating group influenced the failure load significantly (p = 0.03), whereas in the external fixation group this was less evident (p = 0.100). The majority of bone quality parameters that correlated with fixation strength were also strongly correlated with each other, particularly the BMDs measured by DXA and pQCT. This is the first study that relates fixation strength of bicondylar tibial plateau fractures to bone quality assessed at the same anatomical site. BMD around the fracture site had the best correlation with the failure load regardless of the fixation technique. The two fixation methods tested performed equally well, and the choice between them depends on the soft tissue condition and surgeon preference. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2080–2086, 2006
Effect of naringin on bone cells
Authors: Wong R.W.K. , Rabie A.B.M.
Published: August 2006

Statin, a HMG‐CoA reductase inhibitor, was shown to increase BMP‐2 gene expression for bone formation, by blocking the mevalonate pathway in cholesterol production. We investigated the effect of naringin, a flavonoid available commonly in citrus fruits, which was also a HMG‐CoA reductase inhibitor, in UMR 106 osteoblastic cell line in vitro. The control group consisted of cells cultured without any intervention for different time intervals (24 h, 48 h, and 72 h), whereas the experimental (naringin) group consisted of cells cultured with naringin of different concentrations (0.001 µmol/L, 0.01 µmol/L, and 0.1 µmol/L) for the same time intervals of the control. Colorimetric Tetrazolium (MTT) assay, total protein content assay, and alkaline phosphatase activity were used to measure the cellular activities. Results for the naringin group showed an increase in MTT assay compared with the control and the effect was dose dependent. At high concentration (0.1 µmol), the increases ranged from 60% to 80%. In the total protein content assay, naringin also showed an increase compared with control and the effect was also dose dependent. At high concentration (0.1 µmol), the increases ranged from 9% to 20%. In the alkaline phosphatase activity assay, naringin at high concentration (0.1 µmol) significantly increased the activity up to 20%. In conclusion, naringin significantly increased bone cell activities in vitro. This is the first study specifically attempted to investigate the effect of naringin on bone cell activities. Besides statin, this provided another example of mevalonate pathway blockage in the cholesterol production pathway by HMG‐CoA reductase inhibition will increase the bone cell activities. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2045–2050, 2006
Inferences about winter temperatures and summer rains from the late Quaternary record of C4 perennial grasses and C3 desert shrubs in the northern Chihuahuan Desert
Authors: Holmgren Camille A. , Norris Jodi , Betancourt Julio L.
Published: August 2006

Late Quaternary histories of two North American desert biomes—C4 grasslands and C3 shrublands—are poorly known despite their sensitivity and potential value in reconstructing summer rains and winter temperatures. Plant macrofossil assemblages from packrat midden series in the northern Chihuahuan Desert show that C4 grasses and annuals typical of desert grassland persisted near their present northern limits throughout the last glacial–interglacial cycle. By contrast, key C3 desert shrubs appeared somewhat abruptly after 5000 cal. yr BP. Bioclimatic envelopes for select C4 and C3 species are mapped to interpret the glacial–interglacial persistence of desert grassland and the mid‐to‐late Holocene expansion of desert shrublands. The envelopes suggest relatively warm Pleistocene temperatures with moist summers allowed for persistence of C4 grasses, whereas winters were probably too cold (or too wet) for C3 desert shrubs. Contrary to climate model results, core processes associated with the North American Monsoon and moisture transport to the northern Chihuahuan Desert remained intact throughout the last glacial–interglacial cycle. Mid‐latitude effects, however, truncated midsummer (July–August) moisture transport north of 35° N. The sudden expansion of desert shrublands after 5000 cal. yr BP may be a threshold response to warmer winters associated with increasing boreal winter insolation, and enhanced El Niño–Southern Oscillation variability. Published in 2006 by John Wiley & Sons, Ltd.
The post harvest sensory and chemical characteristics of cold‐stored pineapples pretreated with different Fruitone concentrations
Authors: Othman Zaulia , Madom Mohammed Selamat , Osman Azizah , Mohamed Suhaila
Published: August 2006

The effects of Fruitone CPA [2‐(3‐chlorophenoxy)propionic acid] (0‐44 ppm) on post‐harvest storage, chemical characteristics and sensory evaluation of pineapples for fresh consumption after storage at 10 ± 1 °C were studied. Pre‐harvest Fruitone treatment beneficially affected the physical characteristics of pineapples, namely increased fruit weight, reduced texture loss, reduced crown size and delayed ripening, but adversely affected their chemical characteristics. Almost all parameters analysed (total soluble solid, titratable acidity, pH and sugars) showed that Fruitone concentrations between 35.2 and 44 ppm were most effective in delaying the ripening of pineapples compared to other concentrations. At these concentrations, Fruitone significantly (P < 0.05) reduced the total soluble solid and pH, but significantly (P < 0.05) increased the titratable acidity. Fruitone treatment was effective in maintaining the TSS and reduced the fluctuation of sugar and the sugar–acid ratio during storage and between fruits. Sensory scores showed that there was a slight increase in the score for odour after 3 weeks of storage between Fruitone‐treated pineapples and control pineapples, while all other sensory attributes (sourness, sweetness, flavour and overall acceptability) were insignificantly different. All sensory attributes correlated positively with pH and sucrose at low concentrations of Fruitone (0–8.8 ppm and 0–26.4 ppm, respectively); with glucose at intermediate Fruitone concentration (17.6–26.4 ppm); with total soluble solid at higher Fruitone concentrations (35.2–44 ppm); and with sugar–acid ratio at all concentrations (except at 44 ppm Fruitone). Copyright © 2006 Society of Chemical Industry
Volatile odour components and sensory quality of fresh and processed mandarin juices
Authors: Pérez‐López Antonio J , Carbonell‐Barrachina Ángel A
Published: August 2006

Twelve volatile compounds were quantified by gas chromatography/mass spectrometry in juices from two Spanish mandarin varieties, Fortuna and Clemenules. Fresh Clemenules juice contained a higher amount of total volatile compounds (61.1 ± 1.1 mg L−1) than fresh Fortuna juice (48.8 ± 2.5 mg L−1), with D‐limonene (97.1%), myrcene (1.7%), sabinene (0.5%), α‐pinene (0.3%) and linalool (0.3%) being the predominant compounds. Pasteurisation of the mandarin juices (20 s at 98 °C) caused a significant reduction (∼12%) in vitamin C concentration. On the other hand, vitamin C was stable during storage of the juices for 60 days in aseptic tanks at 2 °C. Volatile compounds, however, were more affected by storage in aseptic refrigerated tanks (2 °C) than by heat treatment. Pasteurisation caused a mean decrease in the total concentration of volatile compounds of about 18%, while, after a storage time of 60 days, 36% of total volatiles present in the juices after pasteurisation were lost from both Fortuna and Clemenules juices. Significant reductions in the concentrations of D‐limonene, myrcene, sabinene, α‐pinene and linalool were found, while those of α‐terpineol and terpinen‐4‐ol increased. Copyright © 2006 Society of Chemical Industry
A Rapid Process for Producing Cellulose Multi‐Filament Fibers from a NaOH/Thiourea Solvent System
Authors: Ruan Dong , Zhang Lina , Lue Ang , Zhou Jinping , Chen Hui , Chen Xuming , Chu Benjamin , Kondo Tetsuo
Published: August 2006

Summary: Cellulose was dissolved rapidly in 9.5 wt.‐% NaOH and 4.5 wt.‐% thiourea aqueous solution pre‐cooled to −5 °C to prepare a transparent solution. Novel cellulose multi‐filament fibers were spun successfully, for the first time, from the cellulose dope on an extended laboratory scale. The results from 13C NMR, scanning electron microscopy and wide angle X‐ray diffraction (WAXD) patterns indicated that the fibers exhibited cellulose II character and possessed a circular cross‐section and smooth surface. The tensile strength of the novel fibers reached 1.9–2.2 cN · dtex−1. 2D WAXD and SAXS patterns revealed that, with a drawing progress, the orientation factor increased and mechanical properties were improved.

SEM micrographs of the novel multi‐filament fibers spun from cellulose solution in a NaOH/thiourea aqueous system pre‐cooled to −5 °C on an extended laboratory scale.

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SEM micrographs of the novel multi‐filament fibers spun from cellulose solution in a NaOH/thiourea aqueous system pre‐cooled to −5 °C on an extended laboratory scale.
Synthesis of PEDOT Nanoparticles and Vesicles by Dispersion Polymerization in Alcoholic Media
Authors: Mumtaz Muhammad , de Cuendias Anne , Putaux Jean‐Luc , Cloutet Eric , Cramail Henri
Published: August 2006

Summary: The synthesis of PEDOT nanoparticles and vesicles by dispersion polymerization in a methanol/water mixture (3/2, v/v) is reported, using either ammonium persulfate or iron(III) p‐toluenesulfonate as oxidants and α‐EDOT‐PEO as a reactive stabilizer. The influence of the oxidant as well as the α‐EDOT‐PEO molar mass and concentration on the core‐shell particle morphology and conductivity properties have been investigated. PEDOT particles with conductivities up to 1.5 × 10−2 S · cm−1 have been obtained in high yield.

TEM image of PEDOT vesicles prepared using PEO‐based stabilizers of 25 000 g · mol−1 in water/methanol mixture (2:3 v/v) at room temperature using ammonium persulfate as an oxidant.

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TEM image of PEDOT vesicles prepared using PEO‐based stabilizers of 25 000 g · mol−1 in water/methanol mixture (2:3 v/v) at room temperature using ammonium persulfate as an oxidant.
Simple Patterning of Cells on a Biocompatible Nonchemically Amplified Resist
Authors: Kim Jin‐Baek , Ganesan Ramakrishnan , Yoo So Young , Choi Jae‐Hak , Lee Sang Yup
Published: August 2006

Summary: A simple lithographic process in conjunction with a novel biocompatible nonchemically amplified photoresist material was successfully used for cell patterning. UV light irradiation on selected regions of the nonchemically amplified resist film renders the exposed regions hydrophilic by the formation of carboxylic groups. Mouse fibroblast cells were found to be preferentially aligned and proliferated on the UV light exposed regions of the nonchemically amplified resist film where carboxylic groups were present.

Schematic representation of the simplified lithographic process used for cell patterning.

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Schematic representation of the simplified lithographic process used for cell patterning.
Nitroxide‐Mediated Radical Dispersion Polymerization of Styrene in Supercritical Carbon Dioxide Using a Poly(dimethylsiloxane‐block‐styrene) Alkoxyamine as Initiator and Stabilizer
Authors: McHale Ronan , Aldabbagh Fawaz , Zetterlund Per B. , Okubo Masayoshi
Published: August 2006

Summary: Nitroxide‐mediated dispersion polymerization of styrene in supercritical carbon dioxide has been performed successfully at 110 °C using a new polymeric so‐called inistab species, which fulfils the dual functions of an initiator and a colloidal stabilizer. The inistab species comprised a poly(dimethylsiloxane) block and a polystyrene block end‐capped with the nitroxide N‐tert‐N‐butyl‐N‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)] nitroxide (SG1). The dispersion polymerization resulted in sub‐micron sized polymer particles and polymers of narrow polydispersity.

TEM micrograph of PS particles prepared in the dispersion polymerization of S in scCO2 in the presence of PDMS(\overline M _{\rm n} = 6 500)‐b‐PS(\overline M _{\rm n} = 4 500)‐SG1 at 110 °C.

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TEM micrograph of PS particles prepared in the dispersion polymerization of S in scCO2 in the presence of PDMS(\overline M _{\rm n} = 6 500)‐b‐PS(\overline M _{\rm n} = 4 500)‐SG1 at 110 °C.
Preparation of Well‐Defined Poly[(ethylene oxide)‐block‐(sodium 2‐acrylamido‐2‐methyl‐1‐propane sulfonate)] Diblock Copolymers by Water‐Based Atom Transfer Radical Polymerization
Authors: Paneva Dilyana , Mespouille Laetitia , Manolova Nevena , Degée Philippe , Rashkov Iliya , Dubois Philippe
Published: August 2006

Summary: Well‐defined poly[(ethylene oxide)‐block‐(sodium 2‐acrylamido‐2‐methyl‐1‐propane sulfonate)] diblock copolymers [P(EOm‐b‐AMPSn)], have been obtained by water‐based ATRP using α‐methoxy‐ω‐(2‐methylbromoisobutyrate) poly(ethylene oxide)s (MeO‐P[EO]m‐BriB with m ranging from 12 to 113) and CuBr · 2Bpy (Bpy for 2,2′‐bipyridyl) as macroinitiator and catalytic complex, respectively. Compared to direct polymerization in water, it has been demonstrated that the water/methanol (3:1, v/v) mixture is better suited for predicting the final number‐average molar mass from the initial monomer‐to‐macroinitiator molar ratio and achieving a quite narrow polydispersity, even at high monomer conversion ($\overline M _{\rm w} /\overline M _{\rm n}$ ≈ 1.4 at 80% conversion). The effect of temperature, solvent mixture composition and addition of NaCl salt on the polymerization rate and extent of control over the copolymer molecular parameters have been highlighted as well.

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Effect of rivastigmine on tremor in patients with Parkinson's disease and dementia
Authors: Gurevich Tanya Y. , Shabtai Herzel , Korczyn Amos D. , Simon Ely S. , Giladi Nir
Published: August 2006

The purpose of this study was to assess whether rivastigmine, a cholinergic agent, affects tremor features when given to improve cognition in demented Parkinson's disease (PD) patients. Demented PD patients (n = 26; Mini‐Mental State Examination score, 13–25; age, 75.2 ± 4.9 yr) were given rivastigmine (mean dose, 8.0 mg/day) for 12 weeks. They underwent tremor assessment before and during treatment. Global Tremor Score (GTS) was based on eight items specific to tremor in the Unified Parkinson's Disease Rating Scale. Tremor amplitude was also measured using accelerometers during the ON state in both hands in 19 patients. Drug therapy for other PD symptoms was unchanged. The mean group baseline GTS was 1.2 ± 1.6 points, increasing to 1.6 ± 2.4 points after treatment (mean increase, 0.4 ± 1.2 points; P > 0.05). The GTS increased by 3.2 ± 1.9 points (range, 1–5) in 7 patients (26.9%) and decreased by 1 ± 0 points in 3 patients (11.5%). Accelerometric assessment showed a significant increase of the average tremor amplitude in the right hand (0.08 ± 0.03 xg at baseline; 0.12 ± 0.02 xg at Week 12 of treatment, P = 0.02). Left‐hand tremor amplitude did not change. Rivastigmine caused only slight worsening of tremor in demented PD patients, while improving cognition. © 2006 Movement Disorder Society
123I‐Ioflupane SPECT in the diagnosis of suspected psychogenic Parkinsonism
Authors: Gaig Carles , Martí Maria José , Tolosa Eduardo , Valldeoriola Francesc , Paredes Pilar , Lomeña Francisco Juan , Nakamae Fernando
Published: August 2006

Psychogenic Parkinsonism (PsyP) can be clinically difficult to differentiate from Parkinson's disease (PD). Striatal dopamine transporter (DAT) imaging could be helpful in differentiating them. We performed 123I‐Ioflupane single‐photon emission computed tomography (SPECT) in 9 patients with suspected PsyP. In 1 patient, 123I‐Ioflupane SPECT disclosed bilateral decrease of striatal tracer uptake that indicated nigrostriatal degeneration. In this patient, a parkin gene mutation was detected. In the other 8 patients, 123I‐Ioflupane SPECT was normal and supported the initial suspicion of PsyP. Normal DAT imaging supports the diagnosis of PsyP, whereas reduced striatal tracer uptake suggests an underlying neurodegenerative Parkinsonism and should encourage the search for additional causes for the syndrome. © 2006 Movement Disorder Society
Jaw tremor: Prevalence and clinical correlates in three essential tremor case samples
Authors: Louis Elan D. , Rios Eileen , Applegate LaKeisha M. , Hernandez Nora C. , Andrews Howard F.
Published: August 2006

The spectrum of involuntary movements seen in essential tremor (ET) is limited. Jaw tremor is one such movement. The prevalence and clinical correlates of jaw tremor have not been studied in detail. The objective of this study was to estimate the prevalence and examine the clinical correlates of jaw tremor in ET using ET cases from three distinct settings (population, tertiary‐referral center, brain repository). All ET cases underwent a videotaped tremor examination in which tremors (including limb, head, voice, and jaw) were assessed. The prevalence [95% confidence interval (CI)] of jaw tremor was lowest in the population sample (7.5%; 3.9%–14.2%), intermediate in the tertiary‐referral center (10.1%; 6.8%–14.7%), and highest in the brain repository (18.0%; 12.3%–25.5%; P = 0.03). Jaw tremor was associated with older age (P < 0.001), more severe action tremor of the arms (P < 0.001), and presence of head and voice tremor (P < 0.001). Jaw tremor was present in 4/14 (28.6%) ET cases with consistent rest tremor vs. 15/193 (7.8%) cases without rest tremor (odds ratio = 4.8; 95% CI = 1.3–7.0; P = 0.009). The prevalence of jaw tremor was 7.5% to 18.0% and was dependent on the mode of ascertainment, being least prevalent in a population‐based sample. ET cases with jaw tremor had a more clinically severe and more topographically widespread disorder. The association in our study between jaw tremor and rest tremor, along with the published observation that jaw tremor can occur in Parkinson's disease (PD), raises the question whether jaw tremor in ET is a marker for subsequent conversion to PD. © 2006 Movement Disorder Society