bluuebunny/crossref_metadata_2025 huggingface dataset:
Níveis de irrigação na germinação das sementes de cenoura
Authors: Lima Júnior Francisco de Assis , Guerra Hugo Orlando Carvallo , Metri José Elias da Cunha
Published: November 2006

Este trabalho foi desenvolvido na fazenda Cazuzinha, no Município de Sumé, Estado da Paraíba, com o propósito de se estudar o efeito de cinco níveis de água (irrigar diariamente com 20, 40, 60, 80 e 100% da evaporação medida no tanque "Classe A") durante o período de germinação das cultivares de cenoura Tropical e Brasília. As parcelas experimentais foram irrigadas com regadores comuns e o plantio realizado conforme as recomendações dos produtores locais. O delineamento estatístico foi o de blocos casualizados com arranjo fatorial (5x2) e três repetições. O efeito dos níveis de irrigação foi estatisticamente significativo a nível de 1% de probabilidade e a curva que melhor ajustou sua regressão foi: y = -15,82 + 1,0542x - 0,00562x². Destacaram-se os tratamentos de 100 e 80% da evaporação no Tanque "Classe A" como os que proporcionaram as maiores germinações de semente, e o tratamento de 20% como o que produziu a menor germinação; nenhum efeito significativo foi observado para os tratamentos de cultivar, blocos e interação níveis versus cultivar. Para se obter boa germinação das cultivares Brasília e Tropical, quando cultivadas na microrregião homogênea do Cariri Ocidental paraibano, recomenda-se adotar níveis de irrigação com base em pelo menos 80% da evaporação medida no tanque "Classe A".
A Scaleable and Defined System for Generating Neural Stem Cells from Human Embryonic Stem Cells
Authors: Joannides Alexis J. , Fiore-Hériché Christelle , Battersby Alysia A. , Athauda-Arachchi Pandula , Bouhon Isabelle A. , Williams Lydia , Westmore Kristine , Kemp Paul J. , Compston Alastair , Allen Nicholas D. , Chandran Siddharthan
Published: November 2006

The ability to differentiate human ESCs (hESCs) to defined lineages in a totally controlled manner is fundamental to developing cell-based therapies and studying human developmental mechanisms. We report a novel, scaleable, and widely applicable system for deriving and propagating neural stem cells from hESCs without the use of animal products, proprietary formulations, or genetic manipulation. This system provides a definitive platform for studying human neural development and has potential therapeutic implications.
Local scour due to free overfall jet
Authors: Ghodsian M. , Melville B. , Tajkarimi D.
Published: November 2006

A study was conducted to determine how the tailwater depth beneath a free-falling water jet affects the dimensions of local scour. Available data on scouring in uniform bed material due to circular and rectangular outflow jets were compiled and analysed. It was found that the scour hole geometry (i.e. maximum depth of scour, width of scour hole, length of scour hole and height of ridge formed downstream of the scour hole) is a function of the densimetric Froude number and the ratio of tailwater depth to drop height. The effect of tailwater on scour was investigated and limiting values for tailwater are introduced. It was observed that at low values of tailwater depth, increasing tailwater depth is associated with increasing scour hole dimensions, while at high values of tailwater depth the reverse trend occurs. For low tailwater conditions, the densimetric Froude number has little or no effect on the ridge height downstream of the scour hole, which is affected only by tailwater depth. New empirical equations for the prediction of scour hole geometry and ridge height are presented.
A short proof of Eilenberg and Moore’s theorem
Authors: Nogin Maria
Published: November 2006

In this paper we give a short and simple proof the following theorem of S. Eilenberg and J.C. Moore: the only injective object in the category of groups is the trivial group.
Hypolipidemic effect of a pro-drug containing nicotinic acid in rats
Authors: Filip Cristiana , Albu Elena , Gheorghita Nastasia , Ghitler Nicolae , Mocanu Georgeta , Nechifor Mihai
Published: November 2006

We studied the release of nicotinic acid from a macromolecular pro-drug containing niacin bound to a polymeric support of dextran. Using a modified High-performance Liquid Chromatography (HPLC) method to provide an improved separation between nicotinic acid and its metabolites, we compared the plasma levels of nicotinic acid 24 h after administration of the pro-drug or a similar dose of unbound nicotinic acid to rats. Nicotinic acid exerts a number of pharmacological activities among which is the hypolipidemic effect. To determine the hypolipidemic effect of the pro-drug, we measured the triglyceride levels and examined the correlation with the plasma levels of nicotinic acid.Starting 6 h after administration of the pro-drug, the plasma levels of nicotinic acid were high enough to cause a decrease in the triglyceride level. These results suggest that nicotinic acid was gradually released from the polymeric support, leading to the sustained presence of the active substance and, therefore, a reduction in the level of triglycerides.
Methodological issues regarding confounding and exposure misclassification in epidemiological studies of occupational exposures
Authors: Blair Aaron , Stewart Patricia , Lubin Jay H. , Forastiere Francesco
Published: November 2006

Background

Confounding and exposure misclassification are issues that concern epidemiologists because of their potential to bias results of studies and complicate interpretations. In occupational epidemiology both are routinely raised to argue that an observed result is either a false positive or a false negative finding. Although it is important to consider the potential for limitations of epidemiologic investigations, judgment regarding their importance should be based on their actual likelihood of occurrence.

Methods

This paper is based on our experience in epidemiologic analyses and a brief review of the literature regarding confounding and exposure misclassification.

Results

Examples of substantial confounding are rare in occupational epidemiology. In fact, even for studies of occupational exposures and lung cancer, tobacco‐adjusted relative risks rarely differ appreciably from the unadjusted estimates. This is surprising because it seems the perfect situation for confounding to occur. Yet, despite the lack of evidence that confounding is a common problem, nearly every epidemiologic paper includes a lengthy discussion on uncontrolled or residual confounding. On the other hand, exposure misclassification probably occurs in all studies. The only question is, how much? The direction and magnitude of nondifferential exposure misclassification (the type most likely to occur in cohort studies) on estimates of relative risks can be largely predicted given knowledge on the degree of misclassification, that is, relatively small amounts of misclassification can bias relative risks substantially towards the null. The literature, however, is full of discussions implying that misclassification of exposure is an explanation for a positive finding.

Conclusions

These comments are not to suggest that all potential limitations for epidemiologic studies should not be considered and evaluated. We do believe, however, that the likelihood of occurrence and the direction and magnitude of the effect should be more carefully and realistically considered when making judgments about study design or data interpretation. Am. J. Ind. Med. 50: 199–207, 2007. © 2006 Wiley‐Liss, Inc.
Identification and characterization of Kentucky self‐employed occupational injury fatalities using multiple sources, 1995–2004
Authors: Bunn Terry , Costich Julia , Slavova Svetla
Published: November 2006

Background

Identification and characterization of occupational injury fatalities in self‐employed workers typically relies on a single data source and thus may miss some cases.

Methods

Kentucky self‐employed worker injury fatalities were identified using Fatality Assessment and Control Evaluation (FACE) program data (1995–2004) and compared to non self‐employed worker data. Occupations and industries listed on death certificates were compared to those in which the decedent was actually engaged.

Results

Of 1,281 Kentucky worker injury deaths, 28% were self‐employed. Death certificates failed to identify 31% of these deaths as work‐related; industry and occupation were incorrectly identified in 27% and 16%, respectively. Fifty‐seven percent of the deaths were in agriculture, primarily tractor‐related. For Kentucky, the self‐employed crude death rate was higher (27.6/100,000) than the non self‐employed worker (5.4/100,000) rate or the US (11.5/100,000) self‐employed rate.

Conclusions

Multiple information sources improve identification of self‐employed status in work‐related injury fatalities. Effective prevention requires accurate surveillance and examination of contributing factors. Self‐employed worker injuries in high‐risk industries should be more fully examined for development of effective injury prevention programs. Am. J. Ind. Med. 2006. © 2006 Wiley‐Liss, Inc.
Synthesis of poly(amide‐ester)s by microwave methods
Authors: Borriello Anna , Nicolais Luigi , Fang Xiaomei , Huang Samuel J. , Scola Daniel A.
Published: November 2006

The polycondensation of sebacic acids and ω‐amino alcohols by microwave irradiation was studied. The results were compared to those obtained from conventional melt polycondensation of poly(amide‐ester)s. It was found that the reaction proceeded at a much higher rate upon microwave irradiation. A high yield of thermally stable poly(amide‐ester)s was obtained. The microwave‐synthesized compounds were fully characterized by FTIR and 1H‐NMR spectroscopy, gel permeation chromatography, and a solubility test. The thermal properties of the poly(amide‐ester)s also were investigated. The results showed that the chemical‐physical properties of the polymers were in good agreement with those of polymers obtained by conventional synthesis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1952–1958, 2007
Thermal and crystalline properties of water‐borne polyurethanes based on IPDI, DMPA, and PEBA/HNA
Authors: Zhang Shubiao , Jiang Huiming , Xu Yingmei , Zhang Donghui
Published: November 2006

A series of water‐borne polyurethanes (WPUs) with different soft segments, various COOH contents, and various hard segment contents were prepared through a prepolymerization process. Thermal and crystalline properties of their films were studied by the measurement of differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and thermogravimetry (TG), respectively. Two Tg areas in DSC of WPUs with polyethylene‐butylene adipate glycol (PEBA) as the soft segment were found; an endothermic peak at ∼ 33°C was also found with polyhexane neopentyl adipate glycol (HNA) as the soft segment. The DSC of WPUs with the mixture of PEBA/HNA as soft segment was investigated to show similarity to those from HNA, but with a relatively smaller endothermic peak at ∼ 34°C. Three sharp diffraction peaks at 2θ = 20.50°, 21.72°, and 24.54° in XRD of water‐borne PUs from HNA were found to indicate the crystallization of soft segments, which was disrupted by the addition of polyacrylate (PA), as evidenced by the amorphous shoulder at ∼ 2θ = 20°. TG analysis and differential thermogravimetric (DTG) analysis were measured to indicate that the films lost weight in two stages, and the decomposition temperatures of the films depended on the COOH content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1936–1941, 2007
Gas‐phase‐assisted surface polymerization of methyl methacrylate with Fe(0)/TsCl initiator system
Authors: Andou Yoshito , Yasutake Mikio , Jeong Jae‐Mun , Kaneko Masao , Nishida Haruo , Endo Takeshi
Published: November 2006

To obtain a high polymer coated Fe(0) surface, gas‐phase‐assisted surface polymerization (GASP) of methyl methacrylate (MMA) was investigated using a zero‐valent iron (Fe(0))/p‐toluene sulfonylchloride (TsCl) initiator system, resulting in successful high polymer production on the solid surface. GASP was found to be initiated by radical species that might have been generated via redox reactions with Fe(0), Fe(II), Fe(III), and TsCl. From 1H‐NMR analysis, the p‐toluene sulfonyl group was found at one end of the polymer chain. The molecular weight of obtained PMMA drastically decreased with increase in the composition ratio of Fe(0) in the initiator system, and increased with increase in polymer yield. From the results, it was assumed that the physically controlled polymerization of MMA proceeded by immobilized active species at gas–solid interfaces. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1879–1886, 2007
Binding properties of polyamidoamine dendrimers
Authors: Klajnert B. , Pastucha A. , Shcharbin D. , Bryszewska M.
Published: November 2006

Dendrimers are globular, hyperbranched polymers possessing a high concentration of surface functional groups and internal cavities. These unique features make them good host molecules for small ligands. To reveal relationships between dendrimer size and its encapsulating properties, the interactions of the fourth and the sixth generations of polyamidoamine dendrimers (PAMAM G4 and PAMAM G6) with a fluorescent dye 1‐anilinonaphthalene‐8‐sulfonate (ANS) were studied. Because ANS is a fluorescent molecule and its fluorescence is very sensitive to changes in its microenvironment, it was possible to use spectrofluorometric methods to evaluate the interactions with dendrimers. A double fluorometric titration method was used to estimate a binding constant and the number of binding centers. There were two types of dendrimer binding centers characterized by different affinity towards ANS. For PAMAM G4, the values of Kb and n for low‐affinity and high‐affinity sites equaled to 2.6 × 105, 0.60 and 3.70 × 106, 0.34, respectively, whereas in the case of PAMAM G6, these values equaled to 1.2 × 105, 76.34 and 1.38 × 106, 22.73. It was observed that the size of the dendrimer had a strong impact on the number of ANS molecules that interacted with dendrimers and their location within the macromolecule. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2036–2040, 2007
Curing behavior and thermal properties of multifunctional epoxy resin with methylhexahydrophthalic anhydride
Authors: Liu Yanfang , Du Zhongjie , Zhang Chen , Li Congju , Li Hangquan
Published: November 2006

The curing behavior and thermal properties of bisphenol A type novolac epoxy resin (bisANER) with methylhexahydrophthalic anhydride (MHHPA) at an anhydride/epoxy group ratio of 0.85 was studied with Fourier‐transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetry. The results showed that the FTIR absorption intensity of anhydride and epoxide decreased during the curing reaction, and the absorption peak of ester appeared. The dynamic curing energies were determined as 48.5 and 54.1 kJ/mol with Kissinger and Flynn–Wall–Ozawa methods, respectively. DSC measurements showed that as higher is the curing temperature, higher is the glass transition. The thermal degradation of the cured bisANER/MHHPA network was identified as two steps: the breaking or detaching of OH, CH2, CH3, OCO and COC, etc., taking place between 300 and 450°C; and the carbonizing or oxidating of aromatic rings occurring above 450°C. The kinetics of the degradation reaction was studied with Coats–Redfern method showing a first‐order process. In addition, vinyl cyclohexene dioxide (VCD) was employed as a reactive diluent for bisANER (VCD/bisANER = 1 : 2 w/w) and cured with MHHPA, and the obtained network had a higher Tg and a slight lower degradation temperature than the undiluted system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2041–2048, 2007
Stability and copolymerization of concentrated emulsion of styrene and butyl acrylate in the presence of polyurethane macromonomer
Authors: Zhang Hongtao , Duan Lingli , Chen Li , Huang He
Published: November 2006

A study has been made of the stability and copolymerization of concentrated emulsion of styrene (St) and butyl acrylate (BA) in the presence of polyurethane macromonomer (DPUA), which contains CC at one end. First, the DPUA macromonomer was synthesized from the appropriate amount of 2,4‐diisocyanate (TDI), polypropylene glycol (PPG), 2‐hydroxyethyl methylacrylate (HEMA), dimethylolpropionic acid (DMPA), and triethylamine (TEA) by four steps. Then, the DPUA was dissolved in St‐BA monomer mixtures. The DPUA/St‐BA concentrated emulsion copolymerization using sodium dodecyl sulfate/cetyl alcohol (SDS/CA) as composite surfactant and polyvinyl alcohol (PVA) as liquid film reinforcer, and ammonium persulfate/sodium hydrogen sulfate (APS/SHS) as redox initiator system was carried out at 30°C. The effect of NCO/OH molar ratio, surfactants' concentration, mass ratio of DPUA/St‐BA, initiators' concentration, volume fraction of the monomer phase (Φ), and temperature on the stability or the copolymerization of the concentrated emulsion of DPUA/St‐BA were investigated. The average size and distribution of the latex particles obtained under different conditions were also analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1992–1999, 2007
Chitosan phosphate induced better thermal characteristics to cotton fabric
Authors: Abou‐Okeil A. , El‐Shafie A. , Hebeish A.
Published: November 2006

Chitosan phosphate was prepared and applied at different concentrations with and without low formaldehyde N‐methylol finishing agent (resin) to cotton fabrics. Chitosan phosphate was characterized by FTIR, nitrogen content, and phosphorus content. The so‐treated fabrics were monitored for thermogravimetric analysis (maximum decomposition temperature and residue contents after decomposition), nitrogen content, phosphorus content, tensile strength, and elongation at break. Results indicate that extent of reaction of chitosan phosphate with the cotton fabric relies on concentration of the former; increasing the concentration of the resin has practically no effect on this reaction though the resin functions as a chemical bridge between the chitosan phosphate and the cotton fabric. On the other hand, the nitrogen of the resin and the phosphorus of chitosan undergo synergetic effect and enhance the thermal properties of the treated cotton. Strength properties display higher values in the presence than in the absence of chitosan phosphate when the latter was used along with the resin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2021–2026, 2007
Preparation of polyacrylonitrile and cellulose acetate blend fibers through wet‐spinning
Authors: Barani H. , Bahrami S. H.
Published: November 2006

Fibers containing both polyacrylonitrile (PAN) and cellulose acetate (CA) were prepared through wet‐spinning by using N,N‐dimethylformamide (DMF) as a solvent. Compatibility of PAN and cellulose acetate blend (PCB) fibers was investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and infrared (IR) spectrophotometry. The absorptive capacity and mechanical properties of the fibers were measured. It was observed that the surface and the cross section of PAN fibers were quite smooth and free from voids and microcracks, whereas cracks and voids were present on the surface and cross section of blend fibers, which increased with the incorporation of CA in the blend. Moisture regains of blend fibers were quite high while their tensile properties showed a partial decrease. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2000–2005, 2007
Flow and thermal characteristics of cationic dyeable nylon 6/cationic dyeable poly(ethylene terephthalate) polyblended polymers and filaments
Authors: Shu Yao‐Chi , Hsiao Kai‐Jen
Published: November 2006

Cationic dyeable nylon 6 (CD‐N6) and cationic dyeable poly(ethylene terephthalate) (CD‐PET) polymers were extruded (in the proportions of 75/25, 50/50, 25/75) from one melt twin‐screw extruders to prepare three CD‐N6/CD‐PET polyblended polymers and then spin filaments. The molar ratio of 5‐sodium sulfonate dimethyl isophthalate (5‐SSDMI) for CD‐N6 and CD‐PET polymers were 2.01% and 2.04%, respectively. This study investigated the flow and thermal characteristics of CD‐N6/CD‐PET polyblended polymers and filaments using gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), potentiometer, a rheometer, the density gradient, wide‐angle X‐ray diffraction (WAXD), and extension stress–strain measurement. Flow behavior of CD‐N6/CD‐PET polyblended polymers exhibited negative‐deviation blends (NDB), and the 50/50 blend of CD‐N6/CD‐PET showed a minimum value of the melt viscosity. Experimental results of the DSC indicated CD‐N6 and CD‐PET molecules formed an immiscible system. Particularly, a double endothermic peak was observed from CD‐N6, CD‐PET and their polyblended filaments. The tenacity of CD‐N6/CD‐PET polyblended filaments decreased initially and then increased as the CD‐PET content increased. Crystallinities and densities of CD‐N6/CD‐PET polyblended filaments were the linear relation with the blend ratio. The miscibility parameter μ values of CD‐N6/CD‐PET all samples were less than zero. It indicated the electrostatic repulsion was evident between CD‐N6 and CD‐PET molecules. From the experimental data, the CD‐N6 and CD‐PET polymers were identified to be immiscible. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2049–2056, 2007
Blends of high density polyethylene and ethylene/1‐octene copolymers: Structure and properties
Authors: Adhikari Rameshwar , Godehardt Reinhold , Lebek Werner , Michler Goerg H.
Published: November 2006

The morphology formation in the blends comprising a high density polyethylene (HDPE) and selected ethylene/1‐octene copolymers (EOCs) was studied with variation of blend compositions using atomic force microscopy (AFM). The binary HDPE/EOC blends studied showed well phase‐separated structures (macrophase separation) in consistence with individual melting and crystallization behavior of the blend components. For the blends comprising low 1‐octene content copolymers, the lamellar stacks of one of the phases were found to exist side by side with that of the another phase giving rise to leaflet vein‐like appearance. The formation of large HDPE lamellae particularly longer than in the pure state has been explained by considering the different melting points of the blend components. The study of strain induced structural changes in an HDPE/EOC blend revealed that at large strains, the extensive stretching of the soft EOC phase is accompanied by buckling of HDPE lamellar stack along the strain axis and subsequent microfibrils formation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1887–1893, 2007
Insect dispersal does not limit the biological recovery of streams from acidification
Authors: Masters Zoe , Peteresen Irene , Hildrew Alan G. , Ormerod S.J.
Published: November 2006

The ecological recovery of streams from large‐scale perturbations, such as acidification, requires aquatic insects to disperse between catchments. While adults can usually fly, dispersal is seldom observed directly. Catches of insects in transects of traps perpendicular from streams suggest that lateral adult dispersal is limited. This paper evaluates whether this could explain limited biological recovery in streams recovering chemically from acidification.

At the replicate Llyn Brianne experimental catchments (Wales), Malaise traps (2000) and benthic sampling (1985–2005) were used to appraise inter‐catchment dispersal in acid‐sensitive Ephemeroptera, Plecoptera and Trichoptera. The results provide direct evidence for inter‐catchment dispersal: eight species from three Orders were caught as adults alongside acid streams where larvae never occurred in 21 years' benthic sampling.

These data refute the hypothesis that limited dispersal per se explains delayed biological recovery from acidification in Welsh streams. Other factors affecting colonization (e.g. ‘propagule pressure’, mating or oviposition behaviour) and persistence (e.g. continued acid episodes) must be involved, with the first of these possibilities still poorly understood. These data add to a growing body of literature illustrating insect dispersal between catchments, and they have wider relevance to the recovery and restoration of river ecosystems following basin‐scale impacts.

Copyright © 2006 John Wiley & Sons, Ltd.
An assessment of the usability of an Internet‐based education system in a cross‐cultural environment: The case of the Interreg crossborder program in Central Europe
Authors: Blažič Borka Jerman , Law Effie Lai‐Chong , Arh Tanja
Published: November 2006

In this article, we assess the usability in an Internet‐based system for e‐learning in a cross‐cultural environment. The context of the evaluation and testing was a training program launched with the intention of introducing and promoting a new way of learning about and understanding the emerging technologies in regions with a low educational level and a high unemployment rate. The aim of the study was to assess the usability of the e‐learning system with different methods and approaches to get a good assessment of its learnability and applicability in various circumstances.
Cover Picture: Metallomacrocycles That Incorporate Cofacially Aligned Diimide Units (Chem. Asian J. 5/2006)
Authors: Khoshbin Meisa S. , Ovchinnikov Maxim V. , Salaita Khalid S. , Mirkin Chad A. , Stern Charlotte L. , Zakharov Lev N. , Rheingold Arnold L.
Published: November 2006

The weak‐link approach is illustrated by the reaction of hemilabile phosphinoalkyl thioether ligands that contain incorporated pyromellitic and naphthalene diimide moieties with [Cu(CH3CN)4]PF6 or [{Rh(norbornadiene)Cl}2]. As a consequence, the two diimide units become cofacially aligned, as shown in the cover picture, within a supramolecular macrocyclic architecture. The introduction of ancillary ligands to the intermediates causes the weak thioether–metal bonds to break, thus generating a large macrocycle in which the distance between diimide units is significantly larger than for the intermediates. For more information, see the Full Paper by C. A. Mirkin and co‐workers on page 686 ff.
Comparing different fractions of a factorial design: a metal cutting case study
Authors: Mønness E. , Linsley M. J. , Garzon I. E.
Published: November 2006

Full factorial designs of a significant size are very rarely performed in industry due to the number of trials involved and unavailable time and resources. The data in this paper were obtained from a six‐factor full factorial (26) designed experiment that was conducted to determine the optimum operating conditions for a steel milling operation. Fractional‐factorial designs 2 (one‐eighth) and 2 (one‐fourth, using a fold‐over from the one‐eighth) are compared with the full 26 design. Four of the 2 are de‐aliased by adding four more runs. In addition, two 12‐run Plackett–Burman experiments and their combination into a fold‐over 24‐run experiment are considered.

Many of the one‐eighth fractional‐factorial designs reveal some significant effects, but the size of the estimates varies much due to aliasing. Adding four more runs improves the estimation considerably. The one‐quarter fraction designs yield satisfactory results, compared to the full factorial, if the ‘correct’ parameterization is assumed. The Plackett–Burman experiments, estimating all main effects, always perform worse than the equivalent regular designs (which have fewer runs). When considering a reduced model many of the different designs are more or less identical. The paper provides empirical evidence for managers and engineers that the choice of an experimental design is very important and highlights how designs of a minimal size may not always result in productive findings. Copyright © 2006 John Wiley & Sons, Ltd.
The relation between reduced serum melatonin levels and zinc in rats with induced hypothyroidism
Authors: Belviranli Muaz , Baltaci Abdulkerim Kasim
Published: November 2006

The objective of the study was to explore the changes in melatonin and zinc levels in rats with induced hypothyroidism. Thirty adult male rats used in the study were allocated to three groups with equal numbers. Group 1: General control group which was not subjected to any procedure. Group 2: Sham‐hypothyroidism group to which was administered 10 mg kg−1 intraperitoneal (i.p.) physiologic saline (0.09% NaCl) for 4 weeks. Group 3: Hypothyroidism group which was supplemented with intraperitoneal 10 mg kg−1 propylthiouracil (PTU) for 4 weeks. Blood samples collected from all animals at the end of the study by decapitation were analysed for serum Total T4 (TT4), Total T3 (TT3), Free T4 (FT4), Free T3 (FT3) (ELISA) as well as for melatonin (RIA) hormones and zinc levels (atomic emission). Comparison of the study groups in terms of thyroid hormones, melatonin and zinc levels showed that TT4, TT3, FT4, FT3, melatonin and zinc levels in group 3 were lower than those in groups 1 and 2 ( p < 0.01). These parameters were not different in groups 1 and 2. The results of the study demonstrate that PTU supplementation for 4 weeks results in a significant inhibition in both melatonin and zinc levels. Inhibited melatonin levels may result from the decrease in zinc levels. Copyright © 2006 John Wiley & Sons, Ltd.
The direct chiral separations of fungicide enantiomers on amylopectin based chiral stationary phase by HPLC
Authors: Wang Peng , Liu Donghui , Jiang Shuren , Gu Xu , Zhou Zhiqiang
Published: November 2006

Amylopectin‐tris(phenylcarbamate) was synthesized and coated to aminopropylsilica to prepare chiral stationary phase. The chiral separations of fungicide enantiomers were performed by the CSP using high‐performance liquid chromatography. Mobile phase was n‐hexane and isopropanol, and flow rate was 1.0 ml/min. Detection wavelength was 230 nm. The influence of the percentage of isopropanol in the mobile phase on the separations was studied. Twelve chiral fungicides were tested and seven of them were found to show stereoselectivity on the CSP. The enantiomers of metalaxyl and benalaxyl got near baseline separations and myclobutanil, hexconazole, tebuconazole, uniconazole, and paclobutrazol enantiomers were completely separated. The decreasing percentage of isopropanol in the mobile phase resulted in better separation and longer analysis time. The enantiomers were identified by a circular dichroism (CD) detector and the CD spectra of the individual enantiomers were also studied by online scanning. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Helicobacter pylori‐negative gastric mucosa‐associated lymphoid tissue lymphoma
Authors: Nakamura Shotaro , Matsumoto Takayuki , Ye Hongtao , Nakamura Shigeo , Suekane Hiroshi , Matsumoto Hiroshi , Yao Takashi , Tsuneyoshi Masazumi , Du Ming‐Qing , Iida Mitsuo
Published: November 2006

BACKGROUND.

The majority of gastric mucosa‐associated lymphoid tissue (MALT) lymphoma develops in Helicobacter pylori‐associated chronic gastritis. Little is still known regarding the clinicopathologic features of gastric MALT lymphoma not associated with H. pylori infection.

METHODS.

One hundred thirty‐seven patients with gastric MALT lymphoma, in whom H. pylori status was evaluated using at least both serology and histology, were enrolled. Clinical, histopathologic, and molecular findings were compared between H. pylori‐negative group (n = 12; 9%) and H. pylori‐positive group (n = 125; 91%). t(11;18)(q21;q21) was investigated by reverse‐transcription polymerase chain reaction and interphase fluorescence in situ hybridization.

RESULTS.

In cases without diffuse large B‐cell lymphoma (DLBCL) component, H. pylori‐negative lymphomas located more frequently in the proximal stomach (70%), less frequently appeared as superficial type (40%), and frequently invaded the submucosa or beyond (70%). Histologically, lymphoepithelial lesions (57%), lymphoid follicles (43%), and background mucosal atrophy (50%) in the H. pylori‐negative group were less frequent than in the H. pylori‐positive group (91%, 93%, and 100%, respectively). The frequencies of t(11;18)(q21;q21) (100%) and BCL10 nuclear expression (100%) in the H. pylori‐negative group were significantly higher than in the H. pylori‐positive group (2% and 27%, respectively). Response to antibiotic treatment was observed not only in the H. pylori‐positive group (75%), but also in the H. pylori‐negative group (2 of 7 patients, 29%). In cases with a DLBCL component, such differences were not observed between the 2 groups.

CONCLUSIONS.

H. pylori‐negative gastric MALT lymphoma is characterized by frequent t(11;18)(q21;q21). Antibiotic treatment should be considered also for this disease, although cases with t(11;18)(q21;q21) may need additional strategies. Cancer 2006. © 2006 American Cancer Society.
Evaluation of denaturing high‐performance liquid chromatography as a rapid detection method for identification of epidermal growth factor receptor mutations in nonsmall‐cell lung cancer
Authors: Cohen Victor , Agulnik Jason S. , Jarry Jonathan , Batist Gerald , Small David , Kreisman Harvey , Adriana Tejada Neely , Miller Wilson H. , Chong George
Published: November 2006

BACKGROUND.

Somatic mutations of the epidermal growth factor receptor (EGFR) gene in nonsmall‐cell lung cancer (NSCLC) may predict responsiveness to tyrosine kinase inhibitors. These mutations are commonly identified using DNA sequencing methods. Although considered the gold standard, this approach is time‐consuming. In addition, this approach requires large diagnostic specimens and a high ratio of tumor‐to‐normal‐tissue DNA for optimal results. The use of denaturing high‐performance liquid chromatography (dHPLC) as a method to screen for the 2 predominant EGFR mutations is reported.

METHODS.

Clinical specimens from 104 NSCLC patients were analyzed for EGFR mutations in exons 19 and 21. After DNA extraction and polymerase chain reaction (PCR), both direct sequencing and dHPLC were performed and the results were compared.

RESULTS.

Sequencing revealed a total of 7 mutations: 3 deletion mutations in exon 19 and 4 missense mutations in exon 21. dHPLC showed the presence of genomic alterations in 23 samples, including the 7 identified by sequencing plus 16 additional samples (10 in exon 19 and 1 in exon 21). dHPLC fractions were isolated, reamplified, and sequenced to confirm the results. In serial dilution studies, dHPLC was able to detect mutations in samples containing as little as 1.6% to 6.25% mutated DNA, whereas direct sequencing required at least 30%.

CONCLUSIONS.

dHPLC is an efficient and more sensitive method for screening for genomic alterations in exons 19 and 21 of the EGFR gene compared with direct sequence analysis. These data suggest that dHPLC should be implemented as a screening tool for detection of EGFR mutations. Cancer 2006. © 2006 American Cancer Society.
How corporate social responsibility is defined: an analysis of 37 definitions
Authors: Dahlsrud Alexander
Published: November 2006

Despite numerous efforts to bring about a clear and unbiased definition of CSR, there is still some confusion as to how CSR should be defined. In this paper five dimensions of CSR are developed through a content analysis of existing CSR definitions. Frequency counts are used to analyse how often these dimensions are invoked. The analysis shows that the existing definitions are to a large degree congruent. Thus it is concluded that the confusion is not so much about how CSR is defined, as about how CSR is socially constructed in a specific context. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Cages on Surfaces: Thiol Functionalisation of CoIII Sarcophagine Complexes
Authors: Harrowfield Jack M. , Koutsantonis George A. , Kraatz Heinz‐Bernhard , Nealon Gareth L. , Orlowski Grzegorz A. , Skelton Brian W. , White Allan H.
Published: November 2006

A number of new (sarcophagine)cobalt compounds containing oligopeptide substituents terminated by a mercaptoethylamide unit, [Co(R)(R′)sar]26+ (R = NH2, CH3; R′ = NHpeptideCONHCH2CH2S–), have been prepared utilising the carboxymethyl complexes [Co(R){N(CH2CO2H)}sar]3+ (R = NH2, CH3), and subsequently characterised. The amino acid residues, terminating with cystamine groups, were introduced into the carboxymethyl complexes using standard peptide coupling chemistry. The solid‐state structures of [Co(CH3){N(CH2CO2H)}sar]Cl4·H2O, [Co(CH3){N(CH2CO2H)2}sar]Cl3·2H2O and [Co(CH3){N(CH2CO2)2}sar]Cl·6.5H2O were determined by single‐crystal X‐ray diffraction experiments, the first two forming lattices containing homochiral sheets of cations in planes parallel to [0,0,1]. In the structure of [Co(CH3){N(CH2CO2H)}sar]Cl4·H2O, the cations are of the same absolute configuration, but this alternates from one sheet tothe next. In the dihydrate, [Co(CH3){N(CH2CO2H)2}sar]Cl3·2H2O, the structure appears to be very similar. The sheet alternation is different from the structure of the monohydrate, [Co(CH3){N(CH2CO2H)}sar]Cl4·H2O. The deprotonated imidodiacetate complex, [Co(CH3){N(CH2CO2)2}sar]Cl·6.5H2O, was prepared in an unrelated reaction; the structure displays hydogen‐bonding interactions involving the carboxylate groups and coordinated NH units. The solution electrochemistry of these compounds has been investigated using both cyclic voltammetry and differential pulse voltammetry. The compounds exhibited pH‐dependent, quasi‐reversible redox behaviour. A monolayer was prepared by the interaction of [Co(R)sar(GlyNHCH2CH2S–)]26+ and a gold microelectrode using both conventional “self assembly” (SAM) and electrodeposition (EDM) techniques. Surface cyclic voltammograms were measured, which, after a period of induction associated with surface reorganisation, were typical of an ordered monolayer. The monolayer was characterised by XPS, showing peaks assigned to the presence of S, Co, N, O and C. Ellipsometry gave a film thickness of 7 ± 1 Å, consistent with the formation of a mono‐ rather than a multi‐layer. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Alkylmono(cyclopentadienyl)titanium Complexes Containing the 2,2′‐Methylenebis(6‐tert‐butyl‐4‐methylphenoxido) Ligand – Studies on the Nature of the Catalytic Species Present in α‐Olefin Polymerisation Processes
Authors: González‐Maupoey Marta , Cuenca Tomás , Frutos Luis Manuel , Castaño Obis , Herdtweck Eberhardt , Rieger Bernhard
Published: November 2006

The mono(alkyl)bis(phenoxido)titanium complexes [TiR′(η5‐C5R5)(η2‐mbmp)] [R = H, R′ = Me (4), CH2Ph (5), Ph (6), CH2SiMe3 (7); R = Me, R′ = Me (8), CH2Ph (9), CH2SiMe3 (10); η2‐mbmp = 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenoxido)] have been prepared in good yields by reaction of the appropriate alkylating reagent with the corresponding chlorido(cyclopentadienyl)bis(phenoxido)titanium derivative. Compound 6 reacts in toluene with traces of water to afford the μ‐oxidotitanium complex {Ti(η5‐C5H5)(η2‐mbmp)}2(μ‐O) (11). Compounds 8, 9 and 11 have been characterised by single‐crystal X‐ray crystallography, and density functional calculations have been performed in order to elucidate the energetic and structural properties of these compounds. The activity of these complexes in the presence of methylaluminoxane (MAO), B(C6F5)3 or [Ph3C][B(C6F5)4] as co‐catalysts in the polymerisation of propylene and styrene has been studied. In an effort to model the nature of the catalytic species generated from these precursors, the reactions of the mono(cyclopentadienyl)bis(phenoxido)chlorido‐ and‐alkyltitanium derivatives with Lewis acids were examined. B(C6F5)3 reacts with the neutral complexes [TiR′(η5‐C5R5)(η2‐mbmp)] by abstraction of the alkyl group R′ to give the highly stable species [Ti(η5‐C5H5)(η2‐mbmp)][MeB(C6F5)3] (12), [Ti(η5‐C5H5)(η2‐mbmp)][(PhCH2)B(C6F5)3] (13), [Ti(η5‐C5Me5)(η2‐mbmp)][MeB(C6F5)3] (14) and [Ti(η5‐C5Me5)(η2‐mbmp)][(PhCH2)B(C6F5)3] (15), which are inactive in propylene and styrene polymerisation. In contrast, the reaction between the neutral alkyl derivatives and [CPh3][B(C6F5)4] affords species that are active in α‐olefin polymerisation. Treatment of the mono(chlorido) compound [TiCl(η5‐C5H5)(η2‐mbmp)] with 1 equiv. of AlMe3 affords the methyl derivative 4 as essentially the only reaction product. When an excess of AlMe3 is used, transmetallation reactions of the bis(phenoxido) ligand from titanium to aluminium are observed. Reactions of the bis(phenol) mbmpH2 with AlMe3 or AlClMe2 yield [AlMe(mbmp)]2 (16) and [AlCl(mbmp)]2 (17). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
R(Ar)O–N2+ vs. R(Ar)–N2O+: Are Alkoxy‐(Aryloxy‐)diazonium Ions or Alkyl‐(Aryl‐)N‐nitroso‐onium Ions Formed in the Gas‐Phase Reactions of N2O with H+, Me+, Ph+, PhCH2+, Tr+ and PhCO+?
Authors: Cabrini Liliane G. , Benassi Mario , Eberlin Marcos N. , Okazaki Takao , Laali Kenneth K.
Published: November 2006

Gas‐phase reactions of N2O with H+, Me+, Ph+, PhCH2+, Tr+ (the tropylium ion) and PhCO+ were studied by pentaquadrupole mass spectrometry. Collision‐induced dissociation (CID) of the product ions establishes that, in the diluted solvent and counterion‐free MS environment, gaseous Me+ and Ph+ ions form preferentially Me(Ph)O–N2+ (electrophilic attack at oxygen), whereas PhCH2+ forms preferentially PhCH2–N2O+ (electrophilic attack at nitrogen). The nascent phenoxydiazonium ion PhO–N2+ dissociates promptly by N2 loss to form PhO+ as the observable addition product. The PhCO+ and Tr+ ions are unreactive towards addition to N2O. The CID and ion/molecule chemistry of [N2O + H]+ are inconclusive with regard to connectivity, because the ion is rather resistant towards dissociation and reacts essentially as a proton donor species. Gaseous MeO–N2+ is not only efficient as a methylating agent towards ethers, heteroaromatics and nitriles, but also displays a rich chemistry that includes polar [4+2+] stepwise cycloadditions with representative dienes and polar transacetalization with cyclic acetals. Relative energies and geometries of various RO–N2+/R–N2O+ isomeric pairs were evaluated by MP2 and DFT calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of a Benzolactone Collection using Click Chemistry
Authors: Ritschel Jan , Sasse Florenz , Maier Martin E.
Published: November 2006

A collection of benzotriazoles consisting of seven compounds was prepared from the propynyl‐substituted benzolactone 1 and various azides using click chemistry. The lactone 1 was obtained through a short route by direct esterification of the allylbenzoic acid 9 with the alkynol 7 giving the benzoate 2. The homopropargyl alcohol 7 in turn was obtained by opening the epoxide 6 with triisopropylsilyl acetylide. Ring‐closing metathesis of the ester 2 using Grubbs catalyst II followed by removal of the silicon protecting group furnished the lactone 1. Two of the benzotriazoles, 17a and 17b, were also converted into the corresponding phenols to probe the role of the phenolic OH on the biological activity. All nine benzotriazoles showed cytotoxic activity in a L929 mouse fibroblast assay with IC50 values in the low micromolar range. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
α‐Haloenol Acetates: Versatile Reactants for Oxetan‐2‐one, Azetidin‐2‐one and Isoxazolidin‐5‐one Synthesis
Authors: Bejot Romain , Anjaiah Siddam , Falck J. R. , Mioskowski Charles
Published: November 2006

New ketene equivalents, namely α‐haloenol acetates, are investigated as both nucleophilic and electrophilic reactants in a tandem aldol–lactonization reaction. Diethylaluminum ethoxide proves to be an efficient promoter for the aldol reaction with a wide range of substrates, including inter alia, aldehydes, ketones, imines, nitrones and oximes, leading to oxetan‐2‐ones, azetidin‐2‐ones and isoxazolidin‐5‐ones. The resultant heterocyclic adducts are common structural elements in numerous compounds of interest as well as key intermediates in the preparation of other functionalities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Mit dem Laser gegen Blitz und Donner
Authors: Wöste Ludger H. , Sauerbrey Roland
Published: November 2006

Mit den ultrakurzen Lichtblitzen eines Hochleistungslasers lassen sich ausgedehnte Plasmakanäle in der Luft erzeugen. Sie können nicht nur in der Atmosphärenforschung helfen, sondern auch den Gewitterschutz verbessern
Ist die deutsche Hochschulmedizin so schlecht wie ihr Ruf?
Authors: Schölmerich Jürgen
Published: November 2006

Der Klinischen Forschung fehlen mehr Respekt für das Engagement des Nachwuchses, längerfristige Karrierechancen, größere Transparenz bei der Mittelzuweisung
Vom großen Nutzen kleinster Partikel
Authors: Odenbach Stefan
Published: November 2006

Mithilfe magnetischer Felder können Kräfte auf Ferrofluide ausgeübt werden. Dies macht sich auch die biomedizinische Forschung zunutze. So werden neuartige Therapieformen zur Bekämpfung von Krebserkrankungen unterstützt
Molecular characterization of a t(9;12)(p21;q13) balanced chromosome translocation in combination with integrative genomics analysis identifies C9orf14 as a candidate tumor‐suppressor
Authors: Pujana Miguel Angel , Ruiz Anna , Badenas Cèlia , Puig‐Butille Josep‐Anton , Nadal Marga , Stark Mitchell , Gómez Laia , Valls Joan , Solé Xavier , Hernández Pilar , Cerrato Celia , Madrigal Irene , de Cid Rafael , Aguilar Helena , Capellá Gabriel , Cal Santiago , James Michael R. , Walker Graeme J. , Malvehy Josep , Milà Montserrat , Hayward Nicholas K. , Estivill Xavier , Puig Susana
Published: November 2006

A large number of nevi (LNN) is a high risk phenotypic trait for developing cutaneous malignant melanoma (CMM). In this study, the breakpoints of a t(9;12)(p21;q13) balanced chromosome translocation were finely mapped in a family with LNN and CMM. Molecular characterization of the 9p21 breakpoint identified a novel gene C9orf14 expressed in melanocytes disrupted by the translocation. Integrative analysis of functional genomics data was applied to determine the role of C9orf14 in CMM development. An analysis of genome‐wide DNA copy number alterations in melanoma tumors revealed the loss of the C9orf14 locus, located proximal to CDKN2A, in approximately one‐fourth of tumors. Analysis of gene expression data in cancer cell lines and melanoma tumors suggests a loss of C9orf14 expression in melanoma tumorigenesis. Taken together, our results indicate that C9orf14 is a candidate tumor‐suppressor for nevus development and late stage melanoma at 9p21, a region frequently deleted in different types of human cancers. © 2006 Wiley‐Liss, Inc.
Family‐based association analysis with ordered categorical phenotypes, covariates and interactions
Authors: Baksh M. Fazil , Balding David J. , Vyse Timothy J. , Whittaker John C.
Published: November 2006

Genetic association analyses of family‐based studies with ordered categorical phenotypes are often conducted using methods either for quantitative or for binary traits, which can lead to suboptimal analyses. Here we present an alternative likelihood‐based method of analysis for single nucleotide polymorphism (SNP) genotypes and ordered categorical phenotypes in nuclear families of any size. Our approach, which extends our previous work for binary phenotypes, permits straightforward inclusion of covariate, gene‐gene and gene‐covariate interaction terms in the likelihood, incorporates a simple model for ascertainment and allows for family‐specific effects in the hypothesis test. Additionally, our method produces interpretable parameter estimates and valid confidence intervals. We assess the proposed method using simulated data, and apply it to a polymorphism in the c‐reactive protein (CRP) gene typed in families collected to investigate human systemic lupus erythematosus. By including sex interactions in the analysis, we show that the polymorphism is associated with anti‐nuclear autoantibody (ANA) production in females, while there appears to be no effect in males.Genet. Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.