bluuebunny/crossref_metadata_2025 huggingface dataset:
Immobilization of a functionalized poly(ethylene glycol) onto β‐cyclodextrin‐coated surfaces by formation of inclusion complexes: Application to the coupling of proteins
Authors: Guerrouache M. , Karakasyan C. , Gaillet C. , Canva M. , Millot M. C.
Published: February 2006

The aim of this study was the immobilization of COOH‐modified poly(ethylene glycol) (PEG) layers onto β‐cyclodextrin‐coated surfaces by formation of inclusion complexes, in view of biosensors applications. To this end, PEGs with one phenyladamantyl and one carboxylic end group (Ad‐PEG‐COOH) were prepared according to a three‐step procedure. After modification of PEG with 4‐toluenesulfonylchloride, the reaction of the tosyl intermediate with the alcoholate of 4‐(1‐adamantyl)‐phenol was carried out in tetrahydrofuran to avoid the formation of by‐products. Then, it was shown by high performance liquid chromatography that the association between β‐cyclodextrin cavities and Ad‐PEG‐COOH polymers was not hindered by the presence of the COOH group. Last, the Ad‐PEG‐COOH polymer was immobilized onto β‐cyclodextrin‐coated gold surfaces by formation of inclusion complexes. The immobilization was performed in water, at room temperature, with a rapid kinetics. After activation of COOH groups with N‐hydroxysuccinimide, β‐lactoglobulin was coupled to the biocompatible PEG layer. Functionalization of the gold surface with β‐cyclodextrin cavities, immobilization of Ad‐PEG‐COOH onto the surface, and coupling of the protein to the reactive PEG layer were followed in real time by surface plasmon resonance imaging system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2362–2370, 2006
Synthesis and properties of styrene copolymers. Preparation of film‐modified electrodes to detect Pb2+ ions
Authors: Rivas Bernabé L. , Pooley S. Amalia , Brovelli Francisco , Pereira Eduardo , Basaez Luis , Puentes Jazmín , Moutet Jean‐Claude , Saint‐Aman Eric
Published: February 2006

Organic solvent‐soluble polymers containing different functional groups able to coordinate metal ions from low concentration were synthesized to build complexing polymer film modified electrodes. Poly(acetamide acrylic acid‐co‐styrene) and poly(itaconic acid‐co‐styrene) were synthesized by radical polymerization. The copolymers were characterized by Fourier transform infrared and 1H NMR spectroscopy, electron scanning microscopy, and thermal analysis. The molecular weight and molecular weight distribution were determined by size exclusion chromatography. These complexing polymers have been used in the preparation of complexing modified electrodes (CME) by spin coating. The CME have been tested for the detection of metal ions using the chemical preconcentration‐anodic stripping technique. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2380–2385, 2006
Heat‐resistant hydrophobic–oleophobic coatings
Authors: Uyanik M. , Arpaç E. , Schmidt H. , Akarsu M , Sayilkan F. , Sayilkan H.
Published: February 2006

Thermally and chemically durable hydrophobic oleophobic coatings, containing different ceramic particles such as SiO2, SiC, Al2O3, which can be alternative instead of Teflon, have been developed and applied on the aluminum substrates by spin‐coating method. Polyimides, which are high‐thermal resistant heteroaromatic polymers, were synthesized, and fluor oligomers were added to these polymers to obtain hydrophobic–oleophobic properties. After coating, Al surface was subjected to Taber‐abrasion, adhesion, corrosion, and thermal tests. The effects of the particle size of ceramic powders, organic matrix, and heat on the coating material were investigated. Coating material was characterized by FTIR spectrophotometer. Surface properties and thermal resistance of the coating materials were investigated by SEM and TGA analyses. After thermal curing, contact angles of these coatings with H2O and n‐hexadecane were measured. It was observed that coatings like ceramic particles are more resistant against scratch and abrasion than the other coatings. Also, they are harder than coatings, which do not include ceramic particles. It was seen that coatings, containing Fluorolink D10H, have high‐contact angles with water and n‐hexadecane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2386–2392, 2006
Preparation of novel fluorinated block copolyimide membranes for gas separation
Authors: Niwa M. , Nagaoka S. , Kawakami H.
Published: February 2006

We synthesized novel fluorinated block copolyimides with various diamine compositions and block chain lengths by chemical imidization in a two‐pod procedure. We describe the gas‐transport properties of the novel block copolyimide membranes. We demonstrate that the gas‐transport properties of the copolyimide membranes strongly depended on the block chain lengths. The gas permeabilities of the copolyimide membranes increased with increasing block chain length, and the gas selectivities increased with decreasing lengths. We clarify that the gas diffusivity of the block copolyimide membrane dominated the gas‐transport properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2436–2442, 2006
Effect of rubber reactivity on the morphology of polybenzoxazine blends investigated by atomic force microscopy and dynamic mechanical analysis
Authors: Lee Yu‐Hsin , Allen Douglas J. , Ishida Hatsuo
Published: February 2006

Atomic force microscopy (AFM) is employed to study the hydroxyl‐terminated polybutadiene (HTBD) rubber‐modified polybenzoxazine resin. The morphology exhibits a submicron phase separation when HTBD with low epoxy contents are used. No distinguishable phase separation appears in the blend modified with high epoxy content HTBD. The rubber and resin phases are identified by the change of nanoscale indentation as a function of external load imposed on the cantilever. The existence of an interphase between the glassy matrix and the rubbery domain is shown by comparing the pulling distances from force–distance (F–d) curve measurements. The extent of rubber cavitation is investigated by the particle analysis on the fracture surface and is found to increase with the particle diameter. The amount of dissolved rubber, estimated by the Fox equation, increases with the rubber reactivity, and the data corroborates well with the observed morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2443–2454, 2006
Synthesis of copolymers of tert‐butyl vinyl ether with maleic and citraconic anhydrides
Authors: Denizli Betül Kırcı , Can Hatice Kaplan , Rzaev Zakir M.O. , Güner Ali
Published: February 2006

In the present study, the effects of charge‐transfer complex formation and intramolecular fragmentation (side‐chain lactonization) in radical copolymerization of tert‐butyl vinyl ether (t‐BVE) with anhydrides of maleic (MA) and citraconic (CA) acids and the structure–thermal behavior relationships of the resulting copolymers were examined using the 1H‐NMR, FTIR, DSC, and TGA analysis methods. It was shown that copolymerization under the chosen conditions proceeded through intramolecular fragmentation with the formation of γ‐lactone units. Side‐chain fragmentation of t‐BVE–MA and t‐BVE–CA copolymers also was confirmed by TGA and DSC analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2455–2463, 2006 2006
Thermal stability of polyhydroxyalkanoates
Authors: Carrasco F. , Dionisi D. , Martinelli A. , Majone M.
Published: February 2006

In this study, we examined the thermal decomposition of polyhydroxyalkanoates (PHAs) such as the homopolymer poly(3‐hydroxybutyrate) and the copolymer poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate). They are biodegradable polymers that can replace plastics produced from nonrenewable resources, such as polypropylene. The biopolymers we analyzed were commercial PHAs [obtained by means of pure cultures, with hydroxyvalerate (HV) contents of 0 and 10.4 mol %] and biopolymers produced in our laboratories (by means of an enriched activated sludge at two different organic loads, 8.5 and 20 gCOD/L, with a HV content of 20 mol %). To process these biopolymers, it is important to know their thermal stability. For this reason, thermal degradation in air by means of dynamic thermogravimetry (TG) was carried out. The TG data were adjusted to the nth‐order general analytical equation to evaluate the best order of the reaction, the temperatures of the onset and end of thermal decomposition, and the kinetic parameters. The latter were also calculated by means of other integral and differential methods and compared to those obtained by the general analytical solution. Finally, the influence of the preparation method (pure and mixed cultures and HV content within the biopolymer) on thermal stability was analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2111–2121, 2006
Novel blue‐light‐emitting polymers based on a diphenylanthracene moiety
Authors: Kim Yun‐Hi , Kwon Soon‐Ki
Published: February 2006

New luminescent copolyethers with diphenylanthracene‐emitting segments and electron‐transporting benzoxazole phenyl were successfully synthesized by aromatic nucleophilic substitution. The polymers, characterized by NMR and IR spectroscopy, were obtained in high yields, showed good solubility in various organic solvents, and had high thermal stability with high glass‐transition temperatures (125–129). The number‐average molecular weights of the polymers were 10,000–20,000, and they had polydispersity indices of 1.2–1.4. The optical and electrochemical properties of the polymers were also investigated. The pure blue emission for the polymers (maximum wavelength = 430–440 nm) was obtained with high photoluminescence quantum efficiency (76–78%) in a chloroform solution. The blue electroluminescence for the poly(TDPB) (maximum wavelength = 440 nm) was obtained with a turn‐on voltage of 15–20 V when simple light‐emitting diodes (indium tin oxide/polymer/Al) were fabricated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2151–2157, 2006
Environmentally friendly plasticizers for poly(vinyl chloride)—Improved mechanical properties and compatibility by using branched poly(butylene adipate) as a polymeric plasticizer
Authors: Lindström Annika , Hakkarainen Minna
Published: February 2006

Linear and branched poly(butylene adipate)s (PBA) with molecular weights ranging from 2000 to 10,000 g/mol, and a branching agent content between 0 and 1.8%, were solution cast with poly(vinyl chloride) (PVC) to form 50‐ to 60‐μm thick flexible films. Dry films were analyzed by tensile testing, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and optical microscopy (OM) to study the effects of molecular weight and branching on the plasticizing efficiency of the polyester. PBA formed a semimiscible two‐phase system with PVC, where the amorphous part exhibited a single glass transition temperature. The degree of crystallinity for the polyester, surface composition, and mechanical properties of the films depended on the blend composition, molecular weight, and degree of branching of the polyester. Plasticizing efficiency was improved by higher degree of branching. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2180–2188, 2006
Simulation method for complex permittivities of carbon black/epoxy composites at microwave frequency band
Authors: Kim Jin‐Bong , Kim Tae‐Wook , Kim Chun‐Gon
Published: February 2006

This paper studied the permittivity of carbon black/epoxy composites at microwave frequencies. The measurements were performed for permittivity at a frequency band of 0.5–18 GHz and for DC conductivity to find the percolation threshold of composite samples of 0.0–1.5 wt % of carbon black in epoxy resin. The experimental results show that the complex permittivity of the composite depends strongly on the nature and concentration of the carbon black dispersion. The frequency spectrums of dielectric constants and AC conductivities of composites were investigated by using the descriptions found in percolation theory. A new model, that is a branch of Lichtenecker–Rother formula, is proposed to obtain a rule of mixture to describe the complex permittivity of the composite as function of frequency and concentration of carbon black. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2189–2195, 2006
The characterization of alginate wound dressings with different fiber and textile structures
Authors: Qin Yimin
Published: February 2006

Seven commercially available alginate wound dressings with different polymer, fiber, and nonwoven structures were characterized in this study. The performances of these dressings were compared in terms of their absorbency capacities, gel swelling ratios in water and normal saline, wicking of fluid, and dry and wet strengths. Results show that the absorbency and swelling ratios were strongly affected by the guluronate and mannuronate contents of the alginate, the calcium and sodium contents of the fibers, and the nonwoven structures of the dressing. The different types of alginate wound dressings also had significantly different dry and wet strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2516–2520, 2006
Studies in the utilization of agricultural waste products as filler in natural rubber compounds
Authors: Okieimen F. E. , Imanah J. E.
Published: February 2006

Natural rubber samples were filled with agricultural waste products (cocoa pod husks and rubber‐seed shell) at 50 phr, mixed on a two‐roll mill, and cured using the semiefficient vulcanization system. The physicomechanical properties, tensile strength, modulus at 100% elongation, elongation at break, hardness, abrasion resistance, flex fatigue and compression set, of the agricultural waste products‐filled natural rubber compounds were determined and compared with the values obtained for vulcanisates filled with commercial carbon black (HAF N330). The effect of blending the raw and carbonized agricultural waste products with the commercial grade N330 carbon black on the physicomechanical properties of the natural compounds was studied. It was found that the raw agricultural waste products were ineffective compared with N330 carbon black as reinforcing filler for natural rubber compound mixes and could be classified as semireinforcing fillers. Blends containing up to 40 wt % of the raw agricultural waste products and more than 60 wt % of the carbonized waste products gave natural rubber compounds with comparable physciomechanical properties with compound obtained with N330 carbon black. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2561–2564, 2006
Polymerization of ethyl acrylate using hyperbranched polyglycerol with multi‐RAFT groups as chain transfer agent
Authors: Huang Juan , Wan Decheng , Huang Junlian
Published: February 2006

Surfacing hydroxyl groups of hyperbranched polyglycerol (PG) were transformed into trithiocarbonates (TTC), an efficient multi radical addition‐fragmentation transfer (RAFT) agent, to mediate the polymerization of ethyl acrylate (EA) under controllable conditions, and PG with multiarm PEA was obtained. In this system, PG was a part of Z groups, and trithiolcarbonates were bonded directly to the PG, whereas the growing PEA macroradical was detached. The molecular weight and the molecular weight distribution of the products were in the range of 1.05–3.24 × 104 g/mol and 1.28–1.42, respectively, when the concentration ratio of EA to PG‐TTC was 39.8. The number of the PEA arms was about 16. It was found that the measured molecular weights of the products were deviated from the theoretical value, and the molecular weight distribution was broadened with the conversion due to the termination between the leaving macroradicals. The final and the intermediate products were characterized by NMR in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2203–2209, 2006
New Clerodane Diterpenoids from the Aerial Parts of Pulicaria wightiana
Authors: Das Biswanath , Ramu Ravirala , Venkateswarlu Katta , Rao Yerra Koteswara , Reddy Majjigapu Ravinder , Ramakrishna Kallaganti Venkata Siva , Harakishore Kankipati , Murty Upadhayula Suryanarayana
Published: February 2006

Two new ent‐clerodane‐type diterpenoids, compounds 1 and 2, were isolated from the aerial parts of Pulicaria wightiana, together with three known constituents. Their structures were established based on spectroscopic data, and their antibacterial activities were evaluated (Table 2).
Daturametelins H, I, and J: Three New Withanolide Glycosides from Datura metel L.
Authors: Ma Lei , Xie Chuan‐Ming , Li Jia , Lou Feng‐Chang , Hu Li‐Hong
Published: February 2006

Three new withanolide glycosides named daturametelins H–J (1–3), together with two known ones, daturataturin A (4) and 7,27‐dihydroxy‐1‐oxowitha‐2,5,24‐trienolide (5), were isolated from the MeOH extract of the aerial parts of Datura metel L. (Solanaceae). Their structures were determined mainly by spectroscopic techniques including 2D‐NMR (HMBC, HMQC, 1H,1H‐COSY, NOESY) and MS experiments. Compounds 1–5 were tested for their antiproliferative activity towards the human colorectal carcinoma (HCT‐116) cell line. The nonglycosidic compound 5 exhibited the highest activity of the tested withanolides, with an IC50 value of 3.2±0.2 μM (Table 3).
The Chemical Constituents of the Fungus Stereum sp.
Authors: Li Guo‐Hong , Li Lei , Duan Meng , Zhang Ke‐Qin
Published: February 2006

Four new compounds, including a sesquiterpene and three aromatic compounds, and a known compound were isolated from a culture broth of the fungus Stereum sp. The novel sesquiterpene was determined to be stereumone A ((+)‐2,3,4a,5,6,7,8a,9‐octahydro‐5‐hydroxy‐6,6,9‐trimethyl‐4,8a‐epoxynaphtho[2,3‐b]furan‐8(8H)‐one; 1), and the three new aromatic compounds were elucidated as 3,5‐dihydroxy‐4‐(3‐methylbut‐2‐enyl)benzene‐1,2‐dicarbaldehyde (2), 5,7‐dihydroxy‐6‐(3‐methylbut‐2‐enyl)isobenzofuran‐1(3H)‐one (3), butyl 2,4‐dihydroxy‐6‐methylbenzoate (4), together with the known compound methyl 2,4‐dihydroxy‐6‐methylbenzoate (5). The structures were established by spectroscopic methods including 2D‐NMR techniques. Compounds 2 and 4 showed evident nematicidal activity against nematode Panagrellus redivivus.
Ternary Nickel(II) Complexes as Hydrolytic DNA‐Cleavage Agents
Authors: Reddy Pulimamidi R. , Rao Kandibanda S.
Published: February 2006

A series of small model complexes made from NiII and the ligands ethylenediamine (en), histamine (hist), and histidylleucine (HisLeu) were prepared and studied as potential hydrolytic DNA‐cleavage agents. The stability constants and species‐distribution curves for these complexes were determined as a function of pH. The 1 : 1 : 1 ternary complexes [NiII(en)(HisLeu)] (1) and [NiII(hist)(HisLeu)] (2) were the only major species present at the physiologically relevant pH of 6–7, as further corroborated by ESI‐MS analysis. The complex geometries of 1 and 2 were analyzed by UV/VIS experiments and molecular dynamics (MD) simulations. Both ternary complexes were found to intercalate with DNA, as shown by UV/VIS, thermal‐denaturation, and fluorescence‐titration studies with ethidium bromide (EB). The intrinsic binding constants (Kb) for the bound complexes 1⋅DNA and 2⋅DNA were determined as 150 and 290, resp. Gel‐electrophoresis experiments revealed that 1 and 2 cleave supercoiled (type‐I) to nicked‐circular (type‐II) DNA at physiological pH, with rate constants of 0.64 and 0.75 h−1, resp. A tentative mechanism for this hydrolytic cleavage is proposed.
Outcomes of contrast‐induced nephropathy: Experience in patients undergoing cardiovascular intervention
Authors: McCullough Peter
Published: February 2006

Use of iodinated contrast media for diagnostic and interventional procedures is increasing as computed tomography and percutaneous coronary intervention (PCI) technologies provide increasing patient benefit. Although some complications associated with contrast media are mild and transient, contrast‐induced nephropathy (CIN) can negatively affect long‐term patient morbidity and mortality. The incidence of and outcomes from CIN have been carefully studied in cardiology patients. A number of studies have identified CIN‐associated complications in PCI patients, including bleeding, hematoma, stroke, adult respiratory distress syndrome, electrolyte imbalances, and sepsis. In post‐PCI patients, rates of myocardial infarction and vessel reocclusion are more common in patients with CIN. Therefore, in‐hospital mortality is increased in patients with CIN. In patients requiring dialysis after PCI, several studies have shown the 1‐year mortality rate to be >55%. Even moderate renal dysfunction not requiring dialysis is associated with increased mortality in patients with coronary artery disease. Precautionary measures before, during, and after the use of contrast media that reduce the incidence of CIN, such as discontinuation of nephrotoxic medications, adequate hydration, and use of appropriate volumes and types of contrast media, should be considered in all patients with renal insufficiency or with other risk factors for CIN. © 2006 Wiley‐Liss, Inc.
Focused Libraries of 16‐Substituted Estrone Derivatives and Modified E‐Ring Steroids: Inhibitors of 17ß‐Hydroxysteroid Dehydrogenase Type 1
Authors: Vicker Nigel , Lawrence Harshani R. , Allan Gillian M. , Bubert Christian , Smith Andrew , Tutill Helena J. , Purohit Atul , Day Joanna M. , Mahon Mary F. , Reed Michael J. , Potter Barry V. L.
Published: February 2006

17β‐Hydroxysteroid dehydrogenase type 1 (17β‐HSD1), an oxidoreductase which has a preferential reductive activity using NADPH as cofactor, converts estrone to estradiol and is expressed in many steroidogenic tissues including breast and in malignant breast cells. As estradiol stimulates the growth and development of hormone‐dependent breast cancer, inhibition of the final step of its synthesis is an attractive target for the treatment of this disease. The parallel synthesis of novel focused libraries of 16‐substituted estrone derivatives and modified E‐ring pyrazole steroids as new potent 17β‐HSD1 inhibitors is described. Substituted 3‐O‐sulfamoylated estrone derivatives were used as templates and were immobilised on 2‐chlorotrityl chloride resin to give resin‐bound scaffolds with a multi‐detachable linker. Novel focused libraries of 16‐substituted estrone derivatives and new modified E‐ring steroids were assembled from these immobilised templates using solid‐phase organic synthesis and solution‐phase methodologies. Among the derivatives synthesised, the most potent 17β‐HSD1 inhibitors were 25 and 26 with IC50 values in T‐47D human breast cancer cells of 27 and 165 nm, respectively. Parallel synthesis resulting in a library of C5′‐linked amides from the pyrazole E‐ring led to the identification of 62 with an IC50 value of 700 nM. These potent inhibitors of 17β‐HSD1 have a 2‐ethyl substituent which will decrease their estrogenic potential. Several novel 17β‐HSD1 inhibitors emerged from these libraries and these provide direction for further template exploration in this area. A new efficient diastereoselective synthesis of 25 has also been developed to facilitate supply for in vivo evaluation, and an X‐ray crystal structure of this inhibitor is presented.
Drugs Targeting Protein–Protein Interactions
Authors: Chène Patrick
Published: February 2006

Most biological processes involve permanent and nonpermanent interactions between different proteins, and many protein complexes play a key role in various human diseases. Therefore, molecules that prevent the formation of these protein complexes could be valuable new therapeutic agents to treat these diseases. Protein interfaces have not evolved to bind low‐molecular‐weight molecules, as is the case with enzyme catalytic sites. It is therefore difficult to identify small compounds that inhibit protein–protein interactions. However, there is considerable diversity in the structure of protein interfaces, some of which may be more attractive than others for medicinal chemistry. One of the main challenges in drug discovery is to identify these interfaces and to exploit their properties to make marketable drugs. Herein, the properties of protein interfaces are discussed in light of their use as drug targets.
Ipsilateral connections of the ventral premotor cortex in a new world primate
Authors: Dancause Numa , Barbay Scott , Frost Shawn B. , Plautz Erik J. , Stowe Ann M. , Friel Kathleen M. , Nudo Randolph J.
Published: February 2006

The present study describes the pattern of connections of the ventral premotor cortex (PMv) with various cortical regions of the ipsilateral hemisphere in adult squirrel monkeys. Particularly, we 1) quantified the proportion of inputs and outputs that the PMv distal forelimb representation shares with other areas in the ipsilateral cortex and 2) defined the pattern of PMv connections with respect to the location of the distal forelimb representation in primary motor cortex (M1), primary somatosensory cortex (S1), and supplementary motor area (SMA). Intracortical microstimulation techniques (ICMS) were used in four experimentally naïve monkeys to identify M1, PMv, and SMA forelimb movement representations. Multiunit recording techniques and myelin staining were used to identify the S1 hand representation. Then, biotinylated dextran amine (BDA; 10,000 MW) was injected in the center of the PMv distal forelimb representation. After tangential sectioning, the distribution of BDA‐labeled cell bodies and terminal boutons was documented. In M1, labeling followed a rostrolateral pattern, largely leaving the caudomedial M1 unlabeled. Quantification of somata and terminals showed that two areas share major connections with PMv: M1 and frontal areas immediately rostral to PMv, designated as frontal rostral area (FR). Connections with this latter region have not been described previously. Moderate connections were found with PMd, SMA, anterior operculum, and posterior operculum/inferior parietal area. Minor connections were found with diverse areas of the precentral and parietal cortex, including S1. No statistical difference between the proportions of inputs and outputs for any location was observed, supporting the reciprocity of PMv intracortical connections. J. Comp. Neurol. 495:374–390, 2006. © 2006 Wiley‐Liss, Inc.
Synaptic microcircuitry of tyrosine hydroxylase‐containing neurons and terminals in the striatum of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine‐treated monkeys
Authors: Mazloom Maney , Smith Yoland
Published: February 2006

A population of tyrosine hydroxylase (TH)‐containing neurons that is up‐regulated after lesion of the nigrostriatal dopaminergic pathway has been described in the primate striatum. The goal of this study was to examine the morphology, synaptology, and chemical phenotype of these neurons and TH‐immunoreactive (‐ir) terminals in the striatum of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐treated rhesus monkeys. TH‐ir perikarya were small (10–12 μm), displayed nuclear invaginations, and received very few synaptic inputs. On the other hand, TH‐containing dendrites were typically large in diameter (>1.0 μm) and received scarce synaptic innervation from putative excitatory and inhibitory terminals forming asymmetric and symmetric synapses, respectively. More than 70% of TH‐positive intrastriatal cell bodies were found in the caudate nucleus and the precommissural putamen, considered as the associative functional territories of the primate striatum. Under 10% of these cells displayed calretinin immunoreactivity. TH‐ir terminals rarely formed clear synaptic contacts, except for a few that established asymmetric axodendritic synapses. Almost two‐thirds of TH‐containing boutons displayed γ‐aminobutyric acid (GABA) immunoreactivity in the striatum of parkinsonian monkeys, whereas under 5% did so in the normal striatum. These findings provide strong support for the existence of a population of putative catecholaminergic interneurons in the associative territory of the striatum in parkinsonian monkeys. Their sparse synaptic innervation raises interesting issues regarding synaptic and nonsynaptic mechanisms involved in the regulation and integration of these neurons in the striatal microcircuitry. Finally, the coexpression of GABA in TH‐positive terminals in the striatum of dopamine‐depleted monkeys suggests dramatic neurochemical changes in the catecholaminergic modulation of striatal activity in Parkinson's disease. J. Comp. Neurol. 40:453–469, 2006. © 2006 Wiley‐Liss, Inc.
Alzheimer's disease, estrogens, and clinical trials: a case study in drug development for complex disorders
Authors: Howell Neil , Dykens James , Moos Walter H.
Published: February 2006

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, affecting more than 4 million Americans, and it is a huge drain on health care resources. Moreover, the cost burden of AD will increase substantially without the development of drugs that prevent its onset or slow its progression. At the present time, the available AD drugs provide, at best, temporary cognitive improvement, and cost‐benefit analyses indicate no more than marginal support for their use. AD is a disorder of complex etiology that is characterized by the formation of amyloid plaques and neurofibrillary tangles in the brain. The Amyloid Cascade model of AD neurodegeneration postulates that the primary disease process is the deposition of amyloid plaques and their subsequent effects on cognition. However, as we review here, the emerging evidence argues against simple linear models of neurodegeneration in AD patients, and more complex models of etiology and pathogenesis are needed as part of the drug development process. As one potential therapeutic approach, there is substantial evidence that estrogens are neuroprotective and act on a number of neural pathways, many of which are compromised in AD. A number of studies have shown that estrogens provide clinical benefit in AD patients and in other neurodegenerative disorders. Unfortunately, the negative results of the Women's Health Initiative Memory Study (WHIMS) have overshadowed the positive results from the last four decades. However, as discussed here, there are a number of reasons why the WHIMS results should not be generalized. On balance, estrogens remain a fruitful drug development approach for AD, and other neurodegenerative conditions, and especially those estrogen compounds or analogues that avoid or minimize the complications associated with long‐term use of feminizing hormones in post‐menopausal women. Drug Dev. Res. 66:53–77, 2006. © 2006 Wiley‐Liss, Inc.
Neuroprotective effects of estratriene analogs: structure‐activity relationships and molecular optimization
Authors: Perez Evelyn , Cai Zu Yun , Covey Douglas F. , Simpkins James W.
Published: February 2006

Estrogens are neuroprotectants against a variety of insults, both in vitro and in vivo. Many of these insults involve an oxidative stress component and estrogens are known antioxidants. We (Green et al. [1997b] J Steroid Biochem Mol Biol 63:229–235) and others (Behl et al. [1997] Mol Pharmacol 51:535–541; Moosmann and Behl [1999] Proc Natl Acad Sci USA 96:8867–8872) have determined that the phenolic nature of the A‐ring of the estradiol molecule is essential for neuroprotection. We performed structure‐activity relationship studies using a library of estratriene compounds in well‐established in vitro models for neuroprotection. We tested over 70 compounds in HT‐22 (murine hippocampal) cells for their ability to inhibit cell toxicity against glutamate and iodoacetic acid, at two doses for each insult, and determined EC50 values to ascertain potency comparisons with 17β‐estradiol (E2). We verified that a phenolic A ring was essential for neuroprotection in these models. We also observed that hydrophobicity and planarity affects the ability of estratrienes to protect cells from oxidative stress. This neuroprotection correlated with their ability to inhibit iron‐induced lipid peroxidation in vitro. In contrast, the ability of these estratrienes to bind estrogen receptors was negatively correlated with their ability to protect cells from oxidative stress or inhibit lipid peroxidation. Drug Dev. Res. 66:78–92, 2006. © 2006 Wiley‐Liss, Inc.
Neuroprotection by estrogen in animal models of ischemia and Parkinson's disease
Authors: Merchenthaler Istvan , Shughrue Paul J.
Published: February 2006

Estrogen has been demonstrated to protect against brain injury, neurodegeneration, and cognitive decline. Furthermore, estrogen seems to specifically protect cortical and hippocampal neurons from ischemic injury. Here, the neuroprotective affects of estrogens, selective estrogen receptor modulators (SERMs), and estrogen receptor α‐ and β‐ (ERα and ERβ) selective ligands in animal models of focal and global ischemia are reviewed. In rats and mice, the middle cerebral artery occlusion (MCAO) model has been used as a model representing cerebrovascular stroke, while in gerbils the two‐vessel occlusion model, representing acute heart attack, has been used. Using focal ischemia in ovariectomized ERαKO, ERβKO, and wild type mice, it has been clearly established that the ERα subtype is critical for mediating neuroprotection in this model. The gerbil global ischemia model was used to evaluate the neuroprotective effects of estrogen, SERMs, and ERα‐ and ERβ‐selective compounds in the hippocampus. Analysis of neurogranin mRNA, a marker of viability of hippocampal neurons, with in situ hybridization, revealed that estrogen treatment resulted in complete protection in the dorsal CA1 regions, not only when administered before, but also when given 1 h after occlusion. The neuroprotection conferred by estrogen in an animal model of Parkinson's disease is also discussed. In the model of Parkinson's disease, although estrogen prevented the loss of tyrosine hydroxylase immunoreactivity in the striatum following 1‐methyl‐4‐phenyl‐1,2,3,6 tetrahydropyridine (MPTP) treatment, the lesion and/or the estrogen treatment did not induce the expression of ERs in the striatum or substantia nigra, indicating a non‐ER‐mediating effect of estrogen. Drug Dev. Res. 66:172–181, 2006. © 2006 Wiley‐Liss, Inc.
Modeling and real‐time simulation of UPFC
Authors: Kimura Misao , Takahashi Choei , Kishibe Hideto , Miyazaki Yasuyuki , Noro Yasuhiro , Iio Naotaka
Published: February 2006

We have developed a digital real‐time simulator of Power Electronics Controllers, so‐called FACTS (Flexible AC Transmission Systems) Controllers and/or Custom Power by using MATLABTM/SIMULINKTM and dSPACETM System. This paper describes the modeling and the calculation accuracy of a UPFC (Unified Power Flow Controller) model. Hence, the developed simulator operates at a large time step, in order to improve simulation accuracy, a correction processing of the switching delay is implemented into the UPFC model. Calculation accuracy of the real‐time UPFC model is at the same level as EMTDCTM results. We confirm stable operation of the developed UPFC model by connecting a commercial real‐time digital simulator (RTDSTM). © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 19–26, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20200
Generation of adaptive gait patterns for quadruped robot with CPG network including motor dynamic model
Authors: Son Yurak , Kamano Takuya , Yasuno Takashi , Suzuki Takayuki , Harada Hironobu
Published: February 2006

This paper describes the generation of adaptive gait patterns using new Central Pattern Generators (CPGs) including motor dynamic models for a quadruped robot under various environments. The CPGs act as the flexible oscillators of the joints and adjust joint angles to required values. The CPGs are interconnected with each other and sets of their coupling parameters are adjusted by a genetic algorithm so that the quadruped robot can realize stable and adequate gait patterns. Generation of gait patterns results in the formation of the CPG networks suitable for the formation of not only a straight walking pattern but also of rotating gait patterns. Experimental results demonstrate that the proposed CPG networks are effective for the automatic adjustment of the adaptive gait patterns for the tested quadruped robot under various environments. Furthermore, the target tracking control based on image processing is achieved by combining the general gait patterns. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 35–43, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20225
Heat flux into the substrate and electric power measurement in radio frequency discharge plasma
Authors: Hachiya Kenichiro , Ebe Kentaro , Kato Syouji , Mukaigawa Seiji , Takaki Koichi , Fujiwara Tamiya
Published: February 2006

We performed measurements of the radio frequency power and temperature of electrodes and plasma parameters of rf discharge. The purpose of this research is to check the accuracy of the measurement of energy consumed in plasmas. The heat energy in plasma was obtained by heat flux that was calculated from substrate temperature. The temperature was measured by a laser interferometer using LiNbO3 crystals. In the case of electrode spacings of 2, 3, and 4 cm, the heat energy toward electrodes was 7.7, 5.4, and 4.0 W, respectively. The current and voltage measurement was made at the driven electrode. The input power was 8.2, 5.1, and 7.7 W for electrode spacings of 2, 3, and 4 cm, respectively. The heat energy calculation based on the electron density distribution measured was conducted by estimating the Bohm flux and ambipolar diffusion flux. It was found that the heat energy toward electrodes was 1.4, 1.8, and 1.5 W for electrode spacings of 2, 3, and 4 cm, respectively, and the heat toward the wall was negligible. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 1–8, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20295
Analysis of atmospheric electric field variation signals using digital natural observation method
Authors: Okubo Kan , Chida Masashi , Takeuchi Nobunao
Published: February 2006

As the atmospheric electric field always fluctuates, its observed waveforms are very complicated. It is important to detect the characteristic variation from the observed signals and determine its cause. The natural observation method is adequate for analyzing such nonperiodic signals as the atmospheric electric field signals. In this method the aspectum is proposed as the quantity to estimate the instantaneous power. In this study signal processing by the aspectum was applied to signals of atmospheric electric field variation. It was clarified that a strong correlation exists between the instantaneous fluctuations of atmospheric electric field and the wind speed in the convenient meteorological environment. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 27–34, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20302
Total Synthesis and Olfactory Evaluation of (1R*,3S*,6S*,7S*,8S*)‐ 3‐Hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undecan‐2‐one: A New Synthetic Route to the Patchoulol Skeleton
Authors: Kraft Philip , Weymuth Christophe , Nussbaumer Cornelius
Published: February 2006

The superposition analysis of (–)‐patchoulol (1), the odorous principle of patchouli oil, with the recently discoveredhigh‐impact spirocyclic patchouli odorant (+)‐(1S,4R,5R,9S)‐1‐hydroxy‐1,4,7,7,9‐pentamethylspiro[4.5]decan‐2‐one (2) resulted in the question as to whether a patchoulolderivative in which the gem‐dimethyl group is replacedby a carbonyl function would be a powerful patchouliodorant. The total synthesis of the racemic superstructure (1R*,3S*,6S*,7S*,8S*)‐3‐hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undecan‐2‐one (3) was accomplished in 13 steps from the inexpensive commercial odorant Cyclal C (7) with a total yield of 7 %. Conversion of 7 to the corresponding enamine 8 and subsequent copper‐catalyzed oxidative degradation afforded 2,4‐dimethylcyclohex‐3‐enone (6), which was subjected to a Robinson annulation with 1,4‐dimethoxybutan‐2‐one (9). The carbonyl function of the resulting annulation product 10 was removed by LAH reduction, acylation with Ac2O, and dissolving metal reduction. The deoxygenated methyl enol ether 12 thus obtained was then cleaved by mild hydrolysis with oxalic acid, and the resulting 2,9‐dimethyl‐Δ1‐octalin‐5‐one (5) was hydroxymethylenated by Claisen ester condensation with ethyl formate to provide thecis‐configured (2Z)‐2,3,4,4a,8,8a‐hexahydro‐2‐(hydroxymethylene)‐4a,6‐dimethylnaphthalen‐1(7H)‐one (4). In a novel intramolecular Prins reaction with an equimolar amount of p‐toluenesulfonic acid monohydrate, the ideally preformed precursor 4 cyclized to (1R*,2R*,3S*,7R*,8S*)‐2‐hydroxy‐4,8‐dimethyltricyclo[5.3.1.03,8]undec‐4‐en‐11‐one (13), comprising the complete carbon framework of the target compound 3. A Barton–McCombie deoxygenation of the corresponding O‐phenoxythiocarbonyl derivative, followed by oxidation of the lithium enolate of the resulting ketone 14 with the molybdenum peroxide reagent MoO5–pyridine–DMPU, and the face‐selective hydrogenation of the obtained(1R*,3S*,7S*,8S*)‐3‐hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undec‐5‐en‐2‐one (15) concluded the synthesis of the target molecule 3, which was accompanied by its odorless C‐6 epimer epi‐3 in the ratio 84:16. Both the target structure 3 and its unsaturated precursor 15 possessed pronounced patchouli odors, albeit slightly weaker in threshold than (–)‐patchoulol (1). This proved the superposition analysis of the templates 1 and 2 to be correct and provided novel insight into the structural requirements of patchouli odorants. As 3 was an intermediate in a total synthesis of rac‐1, the synthesis also constitutes a new formal total synthesis of racemic patchoulol (rac‐1). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Physical activity and the risk of colon cancer among women: A prospective cohort study (United States)
Authors: Calton Brook A. , Lacey James V. , Schatzkin Arthur , Schairer Catherine , Colbert Lisa H. , Albanes Demetrius , Leitzmann Michael F.
Published: February 2006

Physical activity has frequently been reported to decrease the risk of colon cancer in men, but data on the relation of physical activity to colon cancer risk in women have generally been less consistent. To further investigate the relationship of physical activity with colon cancer risk in women, we studied a cohort of 31,783 US women participating in the Breast Cancer Detection Demonstration Project Follow‐up Study. Information on daily physical activity over the past year was ascertained using a self‐administered questionnaire at study baseline. The Cox proportional hazards model was used to estimate relative risks (RRs) relating physical activity to the risk of incident colon cancer. During 270,325 person‐years of follow‐up, 243 colon cancer cases were identified. No association was observed between physical activity and the subsequent risk of colon cancer. The multivariable RRs of colon cancer across increasing quintiles of total physical activity were 1.0, 1.45, 1.16, 1.27 and 1.15 (95% CI: 0.76, 1.75; ptrend = 0.77). The multivariable RRs comparing women at the extremes of moderate and vigorous physical activity, respectively, were 1.07 (95% CI: 0.70, 1.62) and 1.10 (95% CI: 0.78, 1.55). The relationship between physical activity and colon cancer risk did not vary by anatomic subsite or across subgroups defined by age, body mass, dietary fiber intake, menopausal status, menopausal hormone use or aspirin use. The results of this large prospective cohort study among women do not support the hypothesis that physical activity is related to a lower incidence of colon cancer. © 2006 Wiley‐Liss, Inc.
Characterization of bulk properties of nanofibrous scaffolds from nanomechanical properties of single nanofibers
Authors: Tan E.P.S. , Lim C.T.
Published: February 2006

This article presents a method of characterizing the macromechanical properties of polymer nanofibrous scaffolds based on the nanomechanical properties obtained for a single nanofiber. Here, we use the example of a poly(L‐lactic acid) (PLLA) nanofibrous scaffold that can be used for tissue engineering application. The elastic modulus of a single nanofiber obtained previously from a nanoscale three‐point bend test performed using atomic force microscopy was used to model the elastic modulus and elastic collapse stress of the bulk scaffold. Various open‐cell solid models are examined for the modeling of bulk scaffold behavior. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Hydroxyapatite growth on anodic TiO2 nanotubes
Authors: Tsuchiya Hiroaki , Macak Jan M. , Müller Lenka , Kunze Julia , Müller Frank , Greil Peter , Virtanen Sannakaisa , Schmuki Patrik
Published: February 2006

In the present work, we study the growth of hydroxyapatite formation on different TiO2 nanotube layers. The nanotube layers were fabricated by electrochemical anodization of titanium in fluoride‐containing electrolytes. To study various nanotube lengths, layers with an individual tube diameter of 100 nm were grown to a thickness of approximately 2 μm or 500 nm. The ability to form apatite on the nanotube layers was examined by immersion tests combined with SEM, XRD and FT‐IR investigations. For reference, experiments were also carried out on compact anodic TiO2 layers. The results clearly show that the presence of the nanotubes on a titanium surface enhances the apatite formation and that the 2‐μm thick nanotube layer triggers deposition faster than the thinner layers. Tubes annealed to anatase, or a mixture of anatase and rutile are clearly more efficient in promoting apatite formation than the tubes in their “as‐formed” amorphous state. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Automated structure verification based on 1H NMR prediction
Authors: Golotvin Sergey S. , Vodopianov Eugene , Lefebvre Brent A. , Williams Antony J. , Spitzer Timothy D.
Published: February 2006

A unique opportunity exists when an experimental NMR spectrum is obtained for which a specific chemical structure is anticipated. A process of Verification—the confirmation of a postulated structure—is now possible, as opposed to Elucidation—the de novo determination of a structure. A method for automated structure verification is suggested, which compares the chemical shifts, intensities and multiplicities of signals in an experimental 1H NMR spectrum with those from a predicted spectrum for the proposed structure. A match factor (MF) is produced and used to classify the spectrum‐structure match into one of three categories, correct, ambiguous, or incorrect. The verification result is also augmented by the spectrum assignment obtained as part of the verification process. This method was tested on a set of synthetic spectra and several sets of experimental spectra, all of which were automatically prepared from raw data. Taking into account even the most problematic structures, with many labile protons present and poor prediction accuracy, 50% of all spectra can still be automatically verified without any false positives or negatives. In a blind test on a typical set of data, it is shown that fewer than 31% of the structures would need manual evaluation. This means that a system is possible whereby 69% of the spectra are prepared and evaluated automatically, and never need to be seen or evaluated by a human. Copyright © 2006 John Wiley & Sons, Ltd.
Fabricating three‐dimensional polymeric photonic structures by multi‐beam interference lithography
Authors: Moon Jun Hyuk , Ford Jamie , Yang Shu
Published: February 2006

The fabrication of true three‐dimensional (3D) microstructures both rapidly and economically over a large area with negligible defects is attractive for a wide range of applications. In particular, multi‐beam interference lithography is one of the promising techniques that can mass‐produce polymeric 3D photonic crystals defect‐free over a large area. This review discusses the relationship between beam geometry and the symmetry of the interference patterns, the lithographic process, and various types of photoresist systems, including thick films of negative‐tone and positive‐tone photoresists, organic‐inorganic hybrids, hydrogels, and holographic polymer‐dispersed liquid crystals. Copyright © 2006 John Wiley & Sons, Ltd.