bluuebunny/crossref_metadata_2025 huggingface dataset:
Fusarium species: The occurrence and the importance in agriculture of Serbia
Authors: Levic Jelena , Stankovic Slavica , Krnjaja Vesna , Bocarov-Stancic Aleksandra
Published: May 2009

Fusarium species have been isolated from over 100 plant species in Serbia. From the economic aspect, they have been and still are the most important for the production and storage of small grains and maize, and are exceptionally important for some other species. Total of 63 species, 35 varieties (var.) and 19 specialised forms (f. sp.) of basic species, particularly of F. oxysporum (4 var. and 12 f. sp.) and F. solani (7 var. and 3 f. sp.) were identified. Species F. langsethiae and F. thapsinum, recently identified, have been isolated from wheat and s o r g h u m seeds, respectively. F. graminearum is the most important pathogen for wheat, barely and maize, while F. poae is also important for wheat and barely. Furthermore, species of the section Liseola (F. verticillioides, F. subglutinans and F. proliferatum) are important for maize and sorghum. In recent years, species of the section Liseola have been increasingly occurring in wheat and barley. The June-October period in Serbia is the most critical period for quality maintenance of stored maize, as the abundance and frequency of fungi, particularly of toxigenic species of the genus Fusarium, are the greatest during that period. In general, there is a lack of data about fusarioses of industrial crops in Serbia. There are mere descriptions of specific cases in which the development of Fusarium species was mostly emphasised by agroecological conditions. The presence of recently determined Fusarium species in kernels of these plant species indicates their importance from the aspect of the yield reduction and grain quality debasement and the mycotoxin contamination. Root rot and plant wilt are characteristic symptoms of fusarioses for forage and vegetable crops, while pathological changes in fruits provoked by Fusarium species are less frequent. F. oxysporum and its specialised forms prevail in these plant species.
Mycotoxins in wine with special attention on ochratoxin A
Authors: Jovic Slobodan , Petrovic Aleksandar , Markovic Nebojsa
Published: May 2009

Wine quality is a complex, multi - layered conception consisting of numerous factors such as sensory characteristics, chemical composition, legislation, market - consumer, with hygienic - toxicological factor being of special importance due to growing demands for health safe foods. This paper shows the results of studies carried out up till now concerning the mycotoxins in wine (Aflatoxins, Trichothecens, Patulin), with special attention paid to ochratoxin A, most frequently present in grapes, must and wine, and to the influence of certain technological operations and processes during wine making. Due to its high toxicity, the presence of ochratoxin A has been limited to 2 ?g/l by EU EG regulation 123/2005.
Influence of Allium ampeloprasum L. and Allium cepa L. essential oils on the growth of some yeasts and moulds
Authors: Kocic-Tanackov Suncica , Dimic Gordana , Tepic Aleksandra , Vujicic Biserka
Published: May 2009

Essential oils extracted from spices, as natural antimicrobial agents, attract particular attention due to their possible role in food protection from microorganisms, and their nontoxicity, in contrast to the synthetic preservatives. In this work, inhibitory effect of Allium ampeloprasum and two onions (Allium cepa), Junski srebrnjak and Kupusinski jabucar, essential oils in different concentrations (1, 4, 7 and 10%) on three yeasts (Saccharomyces cerevisiae, Candida tropicalis and Rhodotorula sp.) and three moulds (Aspergillus tamarii, Penicillium griseofulvum and Eurotium amstelodami) was investigated. All three essential oils showed the strongest inhibitory effect against S. cerevisiae in concentration of only 1%. Among onions, Kupusinski jabucar essential oil had stronger influence to C. tropicalis, while Allium ampeloprasum essential oil did not show any influence on this yeast. Rhodotorula sp. was influenced only by Allium ampeloprasum essential oil. The strongest inhibitory effect on A. tamarii showed Kupusinski jabucar (57% of inhibition, in concentration of 10%), while on P. griseofulvum, the strongest influence showed Allium ampeloprasum essential oil (78.3% of inhibition, in concentration of 10%). Junski srebrnjak and Kupusinski jabucar essential oils, in concentrations of 7 and 10% respectively, completely inhibited the growth of E. amstelodami.
Morphological and pathogenic characteristics of Colletotrichum trifolii Bain et Essary, the alfalfa anthracnose inducer
Authors: Vasic Tanja , Ivanovic Mirko , Trkulja Vojislav , Radovic Jasmina , Gajic Sanja , Andjelkovic Bojan
Published: May 2009

During summer and autumn, easily recognizable diseased plants can be detected in alfalfa fields. Diseased plants have characteristically curved apical part, commonly known as 'shepard's hook'. Using the standard mycological methods, several fungi isolates were obtained. Four of these isolates were used for further study. Two standard mycological methods were used for determination of pathogenicity of Colletotrichum spp. isolates: with and without damaging of the stems. During these studies, it was determined that all of the isolates were causing the symptoms of alfalfa anthracnose. All of the selected isolates form germinative bodies - acervulae - on mycelium. Acervulae can be grouped or scattered across the colony area. Their size in the culture was 100-250 mm. Conidia were short, cylindrical, relatively broad, with both end obtuse 7,85 x 3,85 mm. Appressoria were ovate to obovoid, pale to medium brown 7,5-16,5 x 5,5-8,9 ?m.
Influence of structural features on immunostimulating activity of glucans extracted from Agaricus blazei mushroom
Authors: Kozarski Maja , Klaus Anita , Niksic Miomir
Published: May 2009

High molecular weight b-D-glucans derived from Basidiomycetes cell walls are able to specifically activate cellular and humoral components of the host immune system. The aim of this paper was to examine immunomodulating activity of native, chemically and enzimatically modified glucans from Agaricus blazei mushroom and to determine which structural features are of primary importance for their stimulation referring to humane immune cells. The immunomodulating activities were tested in vitro, by stimulation of peripheral blood mononuclear cells (PBMCs) and measuring of interferon-gamma (IFN-g) production by enzyme linked immunosorbent assay (ELISA). Measurements of immunomodulatory capacity of Agaricus blazei native glucans showed their expressive immunostimulating effect on activated PBMCs and synthesis of IFN-g. The results obtained after the stimulation of cells with 1M H2SO4 and 1M NaOH, the treated glucans showed that primary structure is of more importance than the tertiary structure of the triple helix for their immunostimulating activity and synthesis of IFN-g. Glucans of lower molecular weight obtained after acid hydrolysis appeared as effective immunostimulators of PBMC's. The results obtained after the incubation of cells with 1,6 b-glucanase modified glucans suggest that b-(1,6) binding of glucose monomers probably has no importance for the production of imunostimulating effects, in vitro. This confirmed that b-(1,3) bonds are the primary determinants of immunomodulatory activities and stimulation of IFN-g synthesis.
Macrofungi of the Zasavica special nature reserve
Authors: Cvijanovic Marko , Stankovic Mihajlo , Matavulj Milan , Lolic Svjetlana , Pjanic Branko
Published: May 2009

In the frame of biodiversity investigation of the Republic of Serbia, the investigation of the presence and the diversity of macrofungi of the Zasavica Special Nature Reserve (North Serbia) has been undertaken. Relatively poor generic diversity of macrofungi was recorded with domination of ecological group of wood-decaying species. Even though being preliminary, our results point to the necessity of conservation and protection of recent fungal diversity but, in our opinion, not by making a so-called 'Red list of endangered species', which, due to the lack of information and very poor evidence on this group of organisms in our country, are extremely unreliable and therefore disputable, but rather through the very short list of a few not endangered species, conditionally called 'White list of not endangered fungal species', if such species recently exist et all.
The influence of technological parameters on malt quality produced from different triticale varieties
Authors: Grujic Olgica , Pejin Jelena , Dencic Srboljub
Published: May 2009

The analysis of eight different triticale varieties, from selective experiments, crop 2007, from Rimski Sancevi (Serbia) location was performed. On the basis of results obtained from triticale and produced triticale malt analysis as well as during micromalting, technological quality of investigated triticale varieties was evaluated. The aim of the work was to determine if the gibberellic acid added during the germination phase had a positive influence on the degradation of triticale grain during micromalting. Based on the obtained results it was concluded that triticale variety has the most important influence on the quality of produced triticale malt.
Voices of Youth: Podcasting as a Means for Inquiry-Based Community Engagement
Authors: Bruce Bertram (Chip) , Lin Ching-Chiu
Published: May 2009

A youth community informatics (YCI) research project intersected an inquiry learning model with the making of audiovisual podcasts to foster personal growth and community engagement in a group of Mexican American youth enrolled in an afterschool program. Specifically, the article describes the cycle of inquiry together with the development of a project that embraced community inquiry as the core value for community building. Based on the project outcomes, it then recommends ways that community leaders could adopt a collaborative approach to creating spaces in which youth have fun learning new media, enjoy creative expression, take action for community needs, and develop potential for civic engagement by serving their family, friends, and communities.
A Guide to Interpretation of Studies Investigating Subgroups of Responders to Physical Therapy Interventions
Authors: Hancock Mark , Herbert Robert D. , Maher Christopher G.
Published: May 2009

Many researchers and clinicians believe the effectiveness of existing physical therapy interventions can be improved by targeting the provision of specific interventions at patients who respond best to that treatment. Although this approach has the potential to improve outcomes for some patients, it needs to be implemented carefully because some methods used to identify subgroups can produce biased or misleading results. The aim of this article is to assist readers in assessing the validity and generalizability of studies designed to identify subgroups of responders to physical therapy interventions. The key messages are that subgroups should be identified using high-quality randomized controlled trials, the investigation should be limited to a relatively small number of potential subgroups for which there is a plausible rationale, subgroup effects should be investigated by formally analyzing statistical interactions, and findings of subgroups should be subject to external validation.
The Role of Theory in Increasing Adherence to Prescribed Practice
Authors: Sirur Ruth , Richardson Julie , Wishart Laurie , Hanna Steven
Published: May 2009

Purpose: The purpose of this article is to apply theoretical frameworks to adherence behaviour and to guide the development of an intervention to increase adherence to prescribed home programmes.

Summary of Key Points: Delivering an effective intervention requires establishing one that is evidence based and of adequate dosage. Two-thirds of patients who receive home exercise prescriptions do not adhere to their home programme, which may contribute to their physiotherapy's being ineffective. The mediating concepts of self-efficacy (SE) and outcome expectations (OE) are common to the five relevant theories used to explain adherence to exercise: the health belief model, protection motivation theory, theory of reasoned action, theory of planned behaviour, and social cognitive theory.

Conclusion/Recommendations: Few intervention studies with any theoretical underpinning have examined adherence to exercise. Even fewer have been designed to affect and measure change in the theoretical mediators of SE and OE in patient populations. Physiotherapists must consider increasing adherence as a component of effective physiotherapy. Ongoing research is needed to increase our understanding of adherence to prescribed home programmes and to design interventions to affect theoretical mediators for increasing adherence.
Valparaíso: su geografía, su historia y su identidad como Patrimonio de la Humanidad
Authors: Sánchez M. Alfredo , Bosque M. Joaquín , Jiménez V. Cecilia
Published: May 2009

Valparaíso fue declarado Patrimonio de la Humanidad en el año 2003, por su importancia histórica, belleza natural y una arquitectura única. Este artículo analiza los detalles de este proceso iniciado en 1998 y que culminó con el reconocimiento de UNESCO. La importancia de esta decisión beneficia también a la población de la ciudad, por cuanto se preserva y propende a la conservación del valor cultural propio de la ciudad. Este proceso tiene un segundo aspecto positivo, en términos de los cambios en materia de políticas, sociales, culturales y económicos, como en caso del turismo para que incluyan el valor de la ciudad en su propio desarrollo.
Medida de ruido electroquímico para el estudio de procesos de corrosión de aleaciones metálicas
Authors: Sánchez-Amaya J. M. , Bethencourt M. , Gonzalez-Rovira L. , Botana F. J.
Published: May 2009

El ruido electroquímico (electrochemical noise, EN) es una técnica que permite estimar la velocidad y los mecanismos de corrosión de aleaciones metálicas mediante la medida y análisis de las fluctuaciones de corriente y potencial. Su principal ventaja frente a otras técnicas electroquímicas es que el proceso de medida no perturba externamente el sistema corrosivo, por lo que el sistema se mantiene en el potencial natural de corrosión. Las dos etapas necesarias para utilizar esta técnica son la medida y el análisis de las señales de ruido electroquímico. En este artículo, se revisan exclusivamente los conceptos más importantes de la etapa de medida, describiéndose la metodología necesaria para generar y registrar señales de ruido electroquímico. Los parámetros de análisis de señales más empleados en la bibliografía se describirán en otro artículo de revisión. En el presente trabajo se describen, en primer lugar, los dispositivos experimentales utilizados habitualmente para medir señales de EN. Posteriormente, se estudian las propiedades más importantes de las señales de EN. Finalmente, se analizan las fuentes de ruido instrumental que pueden afectar a las señales de ruido electroquímico del sistema corrosivo estudiado.
Sintesis autopropagada a alta temperatura (SHS) del masteralloy Fe(TiMo)C utilizando ferroaleaciones
Authors: Erauskin J. I. , Sargyan A. , Arana J. L.
Published: May 2009

El carburo simple de titanio TiC es muy duro, estable, tanto a baja como a alta temperatura y, relativamente, fácil de sintetizar por SHS a partir de sus elementos. Sin embargo, debido a su baja mojabilidad por parte del acero fundido, este carburo es difícilmente aplicable, como material aleante, en el refuerzo de los aceros fabricados mediante el proceso de la metalurgia líquida. Para este propósito resulta más adecuada, por su mayor mojabilidad, la utilización de una aleación madre formada por el carburo complejo (TiMo)C aglomerado en hierro. La manera más económica y sencilla de elaborar esta aleación madre Fe(TiMo)C es también la del SHS y, además, utilizando como materias primas ferroaleaciones comerciales FeTi y FeMo en vez de los elementos individuales hierro, titanio y molibd eno. En el presente trabajo se describe dicho proceso, así como las características de la aleación madre obtenida.
Conductive Core–Sheath Nanofibers and Their Potential Application in Neural Tissue Engineering
Authors: Xie Jingwei , MacEwan Matthew R. , Willerth Stephanie M. , Li Xiaoran , Moran Daniel W. , Sakiyama‐Elbert Shelly E. , Xia Younan
Published: May 2009

Conductive core–sheath nanofibers are prepared by a combination of electrospinning and aqueous polymerization. Specifically, nanofibers electrospun from poly(ε‐caprolactone) (PCL) and poly(L‐lactide) (PLA) are employed as templates to generate uniform sheaths of polypyrrole (PPy) by in‐situ polymerization. These conductive core–sheath nanofibers offer a unique system to study the synergistic effect of different cues on neurite outgrowth in vitro. It is found that explanted dorsal root ganglia (DRG) adhere well to the conductive core–sheath nanofibers and generate neurites across the surface when there is a nerve growth factor in the medium. Furthermore, the neurites can be oriented along one direction and enhanced by 82% in terms of maximum length when uniaxially aligned conductive core–sheath nanofibers are compared with their random counterparts. Electrical stimulation, when applied through the mats of conductive core–sheath nanofibers, is found to further increase the maximum length of neurites for random and aligned samples by 83% and 47%, respectively, relative to the controls without electrical stimulation. Together these results suggest the potential use of the conductive core–sheath nanofibers as scaffolds in applications such as neural tissue engineering.
Electroluminescence and Laser Emission of Soluble Pure Red Fluorescent Molecular Glasses Based on Dithienylbenzothiadiazole
Authors: Huang Ju , Liu Quan , Zou Jian‐Hua , Zhu Xu‐Hui , Li Ai‐Yuan , Li Jun‐Wen , Wu Sha , Peng Junbiao , Cao Yong , Xia Ruidong , Bradley Donal D. C. , Roncali Jean
Published: May 2009

Soluble molecular red emitters 1a/1b are synthesized by Stille coupling from 2‐(3,5‐di(1‐naphthyl)phenyl)thiophene precursors. The compounds show emission maxima at ca. 610 nm in CH2Cl2 solution and 620 nm in solid films. Replacing the n‐hexyl substituent by 4‐sec‐butoxyphenyl produces a marked increase of glass transition temperature (Tg) from 82 °C to 137 °C and increases the solubility in toluene and p‐xylene, thus improving the film‐forming properties. Cyclic voltammetry shows that the compounds can be reversibly oxidized and reduced around +1.10 and −1.20 V, respectively. A two‐layered electroluminescent device based on 1b produces a pure red light emission with CIE coordinates (0.646, 0.350) and a maximal luminous efficiency of 2.1 cd A−1. Furthermore, when used as a solution‐processed red emitter in optically pumped laser devices, compound 1b successfully produces a lasing emission at ca. 650 nm.
Structure and properties of polypropylene‐wrapped carbon nanotubes composite
Authors: Li Wen‐Hua , Chen Xiao‐Hua , Yang Zhi , Xu Long‐Shan
Published: May 2009

By means of in situ graft method, polypropylene (PP)‐wrapped carbon nanotubes (CNTs) composite were prepared. Infrared spectroscopy (IR) results showed that there was covalent linkage between PP and CNTs via maleic anhydride (MAH) grafting. Owing to the uniform dispersion of CNTs and covalent adhesion between PP and CNTs, the tensile strength of PP‐wrapped CNTs composite was higher than that for neat PP by 110%, and a 74% increase as compared to the CNTs/PP (with the same CNTs content) composite. The further test showed a strong mechanical behavior with up to 113% increase in Young's modulus of the neat PP. Based on the uniform dispersion of CNTs, the electrical conductivity of PP‐wrapped CNTs composite increased sharply by up to seven orders of magnitude with 4 wt % CNT fillers. As a result, the volume resistivity was decreased with increase in the CNT content that could be governed in a percolation‐like power law with a relatively low percolation threshold. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fracture behaviors of metallocene catalyzed polyethylene elastomer via peroxide crosslinking
Authors: Lai S.‐M. , Liu J.‐L. , Hu S.‐H. , Huang C.‐H. , Wang S.‐J. , Chien S.‐C.
Published: May 2009

Peroxide cured metallocene catalyzed polyethylene (mPE) has been prepared to form an elastomer. mPEs with two different levels of comonomer contents have been cured with various amounts of dicumyl peroxide. “Threshold” fracture energy is roughly proportional to the reciprocal square root of Young's modulus. The values of tear strength are generally two orders of magnitude larger than the results from cutting measurements. The cutting strength of mPE vulcanizates gives an intermediate value compared with crystalline plastics and conventional elastomers and is comparable with other evaluations of cutting strength for different crosslinking types of mPE and different types of materials, which further signifies the importance of crystalline yielding even in the nanofracture zone of deformation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Highly thermally stable novolac derivatives and their properties in epoxy composites
Authors: Wu Hsin Ho , Chu Peter P.
Published: May 2009

Two diazo‐coupling novolac derivative resins (carbonyl phenyl azo novolac resin and carbonyl phenol–biphenylene azo novolac resin) were used as flame retardants. The cured resins exhibited elevated glass‐transition temperatures from 115°C (blank) to 195 and 167°C, respectively. The char yield at 800°C was increased, which elaborated the effectiveness of flame retardancy with evaluated limiting oxygen indices around 36 to 40. This was mainly attributed to the increased crosslink densities and highly aromatic contents in the modified phenol novolac derivative resins, which exhibited higher thermal degradation energies. Furthermore, the more effective flame retardancy was expected because of the loss of nitrogen during combustion. Through the evaluation of the cooperative flame retardancy in the organic/inorganic hybrid with char yield and increasing limiting oxygen index percentage, the effects of the filler showed cooperative flame retardancy only with the appropriate addition and with a difference in the crosslinking densities. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Injectable and thermosensitive poly(organophosphazene) hydrogels for a 5‐fluorouracil delivery
Authors: Lee Sun Mi , Chun Chang Ju , Heo Jeong Yun , Song Soo‐Chang
Published: May 2009

The drug solubility and its release profiles of an anticancer drug from an injectable thermosensitive poly(organophosphazene) hydrogel bearing hydrophobic L‐isoleucine ethyl ester and hydrophilic α‐amino‐ω‐methoxy‐poly(ethylene glycol) with and without hydrolysis‐sensitive glycyl lactate ethyl ester or functional glycyl glycine have been investigated. 5‐Fluorouracil (5‐FU) was used as a model anticancer drug. The aqueous solutions of 5‐FU incorporated poly(organophosphazenes) were an injectable fluid state at room temperature and formed a transparent gel at body temperature. The poly(organophosphazene) solution could enhance the solubility of 5‐FU and its solubility (34.26 mg/mL) was increased up to 10‐fold compared to that in phosphate‐buffered saline (3.39 mg/mL, pH 7.4, 4°C). The in vitro drug release profiles from poly(organophosphazene) hydrogels were established in phosphate‐buffered saline at pH 7.4 at 37°C and the release of 5‐FU was significantly affected by the diffusion‐controlled stage. The results suggest that the injectable and thermosensitive poly(organophosphazene) hydrogel is a potential carrier for 5‐FU to increase its solubility, control a relatively sustained and localized release at target sites and thus decrease systemic side effects. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Concentration profile of glass fiber bundles in epoxy‐based gradient composites during centrifugation
Authors: Hashmi S. A. R. , Dwivedi U. K. , Chand Navin
Published: May 2009

The short fiber bundles separated from the machining waste of a printed circuit board (PCB) manufacturing plant were used in preparing functionally graded composites using polysulfide‐modified epoxy resin. The graded material was developed using centrifugation technique. The centrifugation time was varied to obtain different gradient profiles. The concentration profile was then compared with the theoretical HD model (Hashmi‐Dwivedi model), which was modified to accommodate the changes in the shape of suspending particles. A shape factor was introduced in terminal velocity estimation. The simulated results are in agreement with the experimental trends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Architectonic Subdivisions of Neocortex in the Tree Shrew (Tupaia belangeri)
Authors: Wong Peiyan , Kaas Jon H.
Published: May 2009

Tree shrews are small mammals that bear some semblance to squirrels, but are actually close relatives of primates. Thus, they have been extensively studied as a model for the early stages of primate evolution. In this study, subdivisions of cortex were reconstructed from brain sections cut in the coronal, sagittal, or horizontal planes, and processed for parvalbumin, SMI‐32‐immunopositive neurofilament protein epitopes, vesicle glutamate transporter 2 (VGluT2), free ionic zinc, myelin, cytochrome oxidase, and Nissl substance. These different procedures revealed similar boundaries between areas, suggesting the detection of functionally relevant borders and allowed a more precise demarcation of cortical areal boundaries. Primary cortical areas were most clearly revealed by the zinc stain, because of the poor staining of layer 4, as thalamocortical terminations lack free ionic zinc. Area 17 (V1) was especially prominent, as the broad layer 4 was nearly free of zinc stain. However, this feature was less pronounced in primary auditory and somatosensory cortex. In primary sensory areas, thalamocortical terminations in layer 4 densely express VGluT2. Auditory cortex consists of two architectonically distinct subdivisions, a primary core region (Ac), surrounded by a belt region (Ab) that had a slightly less developed koniocellular appearance. Primary motor cortex (M1) was identified by the absence of VGluT2 staining in the poorly developed granular layer 4 and the presence of SMI‐32‐labeled pyramidal cells in layers 3 and 5. The presence of well‐differentiated cortical areas in tree shrews indicates their usefulness in studies of cortical organization and function. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Probing the Initial Stages of Molecular Organization of Oligo(p‐phenylenevinylene) Assemblies with Monolayer Protected Gold Nanoparticles
Authors: Kumar Vattakattu R. Rajeev , Sajini Vadukumpulli , Sreeprasad Theruvakkattil S. , Praveen Vakayil K. , Ajayaghosh Ayyappanpillai , Pradeep Thalappil
Published: May 2009

Tapes, fibrils, and fibers: Thiol‐protected gold nanoparticles have been used to probe the initial stages of the molecular organization of oligo(p‐phenylenevinylene) gelators. The oligo(p‐phenylenevinylene) molecules self‐assemble to form tapes. Further self‐assembly leads to the formation of fibrils, which in turn self‐assemble to form fibers. The existence of these forms has been confirmed by nanoparticle marking.

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Thiol‐protected gold nanoparticles (GNPs) have been used to probe the initial stages of the molecular organization of oligo(p‐phenylenevinylene) (OPV) gelators. The hybrid materials prepared by the self‐assembly of OPVs and GNPs are characterized by optical microscopy, fluorescence microscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. GNPs are located preferentially on the sides of the OPV structures, which implies the presence of alkyl chains at the edges, which makes the assemblies hydrophobic. TEM analyses at the early stages of self‐assembly show tapes that have a width of 4 nm, which upon further self‐assembly, form fibrils through hydrogen bonding. The experiment was performed with GNPs protected with dodecane and octadecane thiols. The existence of tapes, ribbons, fibrils, and fibers were confirmed by nanoparticle marking. Based on the experimental data, we have proposed a hierarchical model for the self‐assembly of OPV molecules. The presence of nanoparticles does not alter the morphology or electronic properties of the OPV structures, as revealed by microscopic and spectroscopic studies.
Robust optimization for multiple responses using response surface methodology
Authors: He Zhen , Wang Jing , Oh Jinho , Park Sung H.
Published: May 2009

Typically in the analysis of industrial data for product/process optimization, there are many response variables that are under investigation at the same time. Robustness is also an important concept in industrial optimization. Here, robustness means that the responses are not sensitive to the small changes of the input variables. However, most of the recent work in industrial optimization has not dealt with robustness, and most practitioners follow up optimization calculations without consideration for robustness. This paper presents a strategy for dealing with robustness and optimization simultaneously for multiple responses. In this paper, we propose a robustness desirability function distinguished from the optimization desirability function and also propose an overall desirability function approach, which makes balance between robustness and optimization for multiple response problems. Simplex search method is used to search for the most robust optimal point in the feasible operating region. Finally, the proposed strategy is illustrated with an example from the literature. Copyright © 2009 John Wiley & Sons, Ltd.
A multipurpose capacitive biosensor for assay and quality control of human immunoglobulin G
Authors: Labib Mahmoud , Hedström Martin , Amin Magdy , Mattiasson Bo
Published: May 2009

We report a flow‐injection biosensor system with a capacitive transducer for assay and quality control of human immunoglobulin G (hIgG). The sensing platform is based on self‐assembled monolayers (SAMs) of carboxylic acid terminated alkyl‐thiols with covalently attached concanavalin A. The electrochemical characteristics of the sensor surface were assessed by cyclic voltammetry using a permeable redox couple (potassium ferricyanide). The developed biosensor proved capable of performing a sensitive label‐free assay of hIgG with a detection limit of 1.0 µg mL−1. The capacitance response depended linearly on hIgG concentration over the range from 5.0 to 100 µg mL−1, in a logarithmic plot. Typical measurements were performed in 15 min and up to 18 successive assays were achieved without significant loss of sensitivity using a single electrode. In addition, the biosensor can detect hIgG aggregates with concentrations as low as 0.01% of the total hIgG content (5.0 µg mL−1). Hence, it represents a potential post‐size‐exclusion chromatography–UV (post‐SEC–UV) binding assay for in‐process quality control of hIgG, which cannot be detected by SEC–UV singly at concentrations below 0.3% of the total hIgG content. Biotechnol. Bioeng. 2009; 104: 312–320 © 2009 Wiley Periodicals, Inc.
Induction of mammalian cell death by simple shear and extensional flows
Authors: Tanzeglock Timm , Soos Miroslav , Stephanopoulos Gregory , Morbidelli Massimo
Published: May 2009

In this work we investigated whether the type of shear flow, to which cells are exposed, influences the initiation of cell death. It is shown that mammalian cells, indeed, distinguish between discrete types of flow and respond differently. Two flow devices were employed to impose accurate hydrodynamic flow fields: uniform steady simple shear flow and oscillating extensional flow. To distinguish between necrotic and apoptotic cell death, fluorescence activated cell sorting and the release of DNA in the culture supernatant was used. Results show that Chinese Hamster Ovaries and Human Embryonic Kidney cells will enter the apoptotic pathway when subjected to low levels of hydrodynamic stress (around 2.0 Pa) in oscillating, extensional flow. In contrast, necrotic death prevails when the cells are exposed to hydrodynamic stresses around 1.0 Pa in simple shear flow or around 500 Pa in extensional flow. These threshold values at which cells enter the respective death pathway should be avoided when culturing cells for recombinant protein production to enhance culture longevity and productivity. Biotechnol. Bioeng. 2009; 104: 360–370 © 2009 Wiley Periodicals, Inc.
The generation of stable, high MAb expressing CHO cell lines based on the artificial chromosome expression (ACE) technology
Authors: Kennard Malcolm L. , Goosney Danika L. , Monteith Diane , Zhang Lin , Moffat Mark , Fischer David , Mott John
Published: May 2009

The manufacture of recombinant proteins at industrially relevant levels requires technologies that can engineer stable, high expressing cell lines rapidly, reproducibly and with relative ease. Commonly used methods incorporate transfection of mammalian cell lines with plasmid DNA containing the gene of interest. Identifying stable high expressing transfectants is normally laborious and time consuming. To improve this process, the ACE System has been developed based on pre‐engineered artificial chromosomes with multiple recombination acceptor sites. This system allows for the targeted transfection of single or multiple genes and eliminates the need for random integration into native host chromosomes. To illustrate the utility of the ACE System in generating stable, high expressing cell lines, CHO based candidate cell lines were generated to express a human monoclonal IgG1 antibody. Candidate cell lines were generated in under 6 months and expressed over 1 g/L and with specific productivities of up to 45 pg/cell/day under non‐fed, non‐optimized shake flask conditions. These candidate cell lines were shown to have stable expression of the monoclonal antibody for up to 70 days of continuous culture. The results of this study demonstrate that clonal, stable monoclonal antibody expressing CHO based cell lines can be generated by the ACE System rapidly and perform competitively with those cell lines generated by existing technologies. The ACE System, therefore, provides an attractive and practical alternative to conventional methods of cell line generation. Biotechnol. Bioeng. 2009; 104: 540–553 © 2009 Wiley Periodicals, Inc.
Auditioning of CHO host cell lines using the artificial chromosome expression (ACE) technology
Authors: Kennard Malcolm L. , Goosney Danika L. , Monteith Diane , Roe Susanna , Fischer David , Mott John
Published: May 2009

In order to maximize recombinant protein expression in mammalian cells many factors need to be considered such as transfection method, vector construction, screening techniques and culture conditions. In addition, the host cell line can have a profound effect on the protein expression. However, auditioning or directly comparing host cell lines for optimal protein expression may be difficult since most transfection methods are based on random integration of the gene of interest into the host cell genome. Thus it is not possible to determine whether differences in expression between various host cell lines are due to the phenotype of the host cell itself or genetic factors such as gene copy number or gene location. To improve cell line generation, the ACE System was developed based on pre‐engineered artificial chromosomes with multiple recombination acceptor sites. This system allows for targeted transfection and has been effectively used to rapidly generate stable CHO cell lines expressing high levels of monoclonal antibody. A key feature of the ACE System is the ability to isolate and purify ACEs containing the gene(s) of interest and transfect the same ACEs into different host cell lines. This feature allows the direct auditioning of host cells since the host cells have been transfected with ACEs that contain the same number of gene copies in the same genetic environment. To investigate this audition feature, three CHO host cell lines (CHOK1SV, CHO‐S and DG44) were transfected with the same ACE containing gene copies of a human monoclonal IgG1 antibody. Clonal cell lines were generated allowing a direct comparison of antibody expression and stability between the CHO host cells. Results showed that the CHOK1SV host cell line expressed antibody at levels of more than two to five times that for DG44 and CHO‐S host cell lines, respectively. To confirm that the ACE itself was not responsible for the low antibody expression seen in the CHO‐S based clones, the ACE was isolated and purified from these cells and transfected back into fresh CHOK1SV cells. The resulting expression of the antibody from the ACE newly transfected into CHOK1SV increased fivefold compared to its expression in CHO‐S and confirmed that the differences in expression between the different CHO host cells was due to the cell phenotype rather than differences in gene copy number and/or location. These results demonstrate the utility of the ACE System in providing a rapid and direct technique for auditioning host cell lines for optimal recombinant protein expression. Biotechnol. Bioeng. 2009; 104: 526–539 © 2009 Wiley Periodicals, Inc.
Fluorescence optical detection in situ for real‐time monitoring of cytochrome P450 enzymatic activity of liver cells in multiple microfluidic devices
Authors: Sung Jong Hwan , Choi Jong‐ryul , Kim Donghyun , Shuler Michael L.
Published: May 2009

We describe an in situ fluorescence optical detection system to demonstrate real‐time and non‐invasive detection of reaction products in a microfluidic device while under perfusion within a standard incubator. The detection system is designed to be compact and robust for operation inside a mammalian cell culture incubator for quantitative detection of fluorescent signal from microfluidic devices. When compared to a standard plate reader, both systems showed similar biphasic response curves with two linear regions. Such a detection system allows real‐time measurements in microfluidic devices with cells without perturbing the culture environment. In a proof‐of‐concept experiment, the cytochrome P450 1A1/1A2 activity of a hepatoma cell line (HepG2/C3A) was monitored by measuring the enzymatic conversion of ethoxyresorufin to resorufin. The hepatoma cell line was embedded in MatrigelTM construct and cultured in a microfluidic device with medium perfusion. The response of the cells, in terms of P450 1A1/1A2 activity, was significantly different in a plate well system and the microfluidic device. Uninduced cells showed almost no activity in the plate assay, while uninduced cells in MatrigelTM with perfusion in a microfluidic device showed high activity. Cells in the plate assay showed a significant response to induction with 3‐Methylcholanthrene while cells in the microfluidic device did not respond to the inducer. These results demonstrate that the system is a potentially useful method to measure cell response in a microfluidic system. Biotechnol. Bioeng. 2009; 104: 516–525 © 2009 Wiley Periodicals, Inc.
Interpreting Experimental Data by Using Molecular Simulation Instead of Model Building
Authors: Gattin Zrinka , Schwartz Julian , Mathad Raveendra I. , Jaun Bernhard , van Gunsteren Wilfred F.
Published: May 2009

A proper description of the conformational equilibrium of polypeptides or proteins is essential for a correct description of their function. The conformational ensembles from 16 molecular dynamic simulations of two β‐ heptapeptides were used to interpret the primary NMR data, which were also compared to a set of NMR model structures (see graphic).

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One of the most used spectroscopic techniques for resolving the structure of a biomolecule, such as a protein or peptide, is NMR spectroscopy. Because only NMR signal intensities and frequencies are measured in the experiment, a conformational interpretation of the primary data, that is, measured data, is not straightforward, especially for flexible molecules. It is hampered by the occurrence of conformational and/or time‐averaging, by insufficient number of experimental data and by insufficient accuracy of experimental data. All three problematic aspects of structure refinement based on NMR nuclear Overhauser effect (NOE) intensities and 3J coupling data are illustrated by using two β‐heptapeptides in methanol as an example. We have performed 16 molecular dynamics (MD) simulations between 20 to 100 ns in length of unrestrained and NOE distance‐restrained cases (instantaneous and time‐averaged) of two β‐heptapeptides with a central β‐HAla(α‐OH) amino acid in methanol at two different temperatures using two different GROMOS force‐field parameter sets, 45 A3 and 53 A6. The created conformational ensembles were used to interpret the primary NMR data on these molecules. They also were compared to a set of NMR model structures derived by single‐structure refinement in vacuo by using standard techniques. It is shown that the conformational interpretation of measured experimental data can be significantly improved by using unrestrained, instantaneous and time‐averaged restrained MD simulations of the peptides by using a thermodynamically calibrated force field and by explicitly including solvent degrees of freedom.
The Steric Nature of the Bite Angle
Authors: van Zeist Willem‐Jan , Visser Ruud , Bickelhaupt F. Matthias
Published: May 2009

Twisted! We show, based on DFT analyses, that the well‐known dependence of a catalyst's activity in bond activation on the ligand–metal–ligand angle, or bite angle, has a primarily steric origin, not an electronic one. Thus, by bending or twisting the catalyst a priori, one avoids unfavorable nonbonded interactions with the substrate (see figure).

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A Multicomponent Reaction Towards N‐(Cyanomethyl)amides
Authors: Elders Niels , Ruijter Eelco , de Kanter Frans J. J. , Janssen Elwin , Lutz Martin , Spek Anthony L. , Orru Romano V. A.
Published: May 2009

Diversity‐oriented synthesis: The multicomponent reaction of α‐isocyano amides, aldehydes or ketones, and amines affords N‐(cyanomethyl)amides, presenting the fourth class of products from this combination of reagents (see scheme). The scope of the reaction is very broad and various functional groups are tolerated. The outcome of the reaction can also be directed to the formation of 2H‐2‐imidazolines by AgI catalysis.

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Molecular Layer Chemistry via Parylenes
Authors: Senkevich Jay J. , Wang Pei‐I
Published: May 2009

Communication: Parylene polymers have a main‐chain phenyl group, which possesses a high in‐plane electronic polarizability and allows for strong molecule‐to‐molecule interaction. This chemistry is far more robust than traditional self‐assembled monolayers since no special surface treatment is needed and these molecular layers are room temperature chemical vapor deposited. Parylene molecular layers are particularly useful for nanotechnology driven applications where manufacturability is important.
Automated quantification of DNA demethylation effects in cells via 3D mapping of nuclear signatures and population homogeneity assessment
Authors: Gertych Arkadiusz , Wawrowsky Kolja A. , Lindsley Erik , Vishnevsky Eugene , Farkas Daniel L. , Tajbakhsh Jian
Published: May 2009

Today's advanced microscopic imaging applies to the preclinical stages of drug discovery that employ high‐throughput and high‐content three‐dimensional (3D) analysis of cells to more efficiently screen candidate compounds. Drug efficacy can be assessed by measuring response homogeneity to treatment within a cell population. In this study, topologically quantified nuclear patterns of methylated cytosine and global nuclear DNA are utilized as signatures of cellular response to the treatment of cultured cells with the demethylating anti‐cancer agents: 5‐azacytidine (5‐AZA) and octreotide (OCT). Mouse pituitary folliculostellate TtT‐GF cells treated with 5‐AZA and OCT for 48 hours, and untreated populations, were studied by immunofluorescence with a specific antibody against 5‐methylcytosine (MeC), and 4,6‐diamidino‐2‐phenylindole (DAPI) for delineation of methylated sites and global DNA in nuclei (n = 163). Cell images were processed utilizing an automated 3D analysis software that we developed by combining seeded watershed segmentation to extract nuclear shells with measurements of Kullback‐Leibler's (K‐L) divergence to analyze cell population homogeneity in the relative nuclear distribution patterns of MeC versus DAPI stained sites. Each cell was assigned to one of the four classes:similar,likely similar,unlikely similar, anddissimilar. Evaluation of the different cell groups revealed a significantly higher number of cells with similar or likely similar MeC/DAPI patterns among untreated cells (approximately 100%), 5‐AZA‐treated cells (90%), and a lower degree of same type of cells (64%) in the OCT‐treated population. The latter group contained (28%) of unlikely similar or dissimilar (7%) cells. Our approach was successful in the assessment of cellular behavior relevant to the biological impact of the applied drugs, i.e., the reorganization of MeC/DAPI distribution by demethylation. In a comparison with other metrics, K‐L divergence has proven to be a more valuable and robust tool for categorization of individual cells within a population, with potential applications in epigenetic drug screening. © 2009 International Society for Advancement of Cytometry
BMI, body composition, and the energy requirement for body weight gain in patients with anorexia nervosa
Authors: Yamashita Sakino , Kawai Keisuke , Yamanaka Takeharu , Inoo Takehiro , Yokoyama Hiroaki , Morita Chihiro , Takii Masato , Kubo Chiharu
Published: May 2009

Objective

Theories abound about the energy requirements for body weight gain in anorexia nervosa (AN). We hypothesized that malnutrition status affects the energy requirements.

Method

On admission, 97 AN patients were measured for body composition by dual‐energy X‐ray absorptiometry. The relationship between body mass index (BMI) and body composition was investigated. In addition, 21 patients who completed our treatment program were tested for energy intake and body weight.

Results

The relationship between BMI and both fat‐free mass and fat mass (FM) on admission was curvilinear. The weight gain per excess energy was greater in the group of patients with FM < 4 kg or BMI < 14 kg/m2 than in the group with FM ≥ 4 kg or BMI ≥ 14 kg/m2 (p = .037, p = .055, respectively).

Discussion

The energy requirements for weight gain in AN patients are related to the initial FM and BMI. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
Palladium‐Catalysed Cross‐Coupling and Related Processes: Some Interesting Observations That Have Been Exploited in Synthetic Chemistry
Authors: McGlacken Gerard P. , Fairlamb Ian J. S.
Published: May 2009

Palladium‐catalysed cross‐coupling reactions are routinely used in the synthesis of important organic and organometallic compounds, including advanced materials and natural products. Industry and academia depend heavily on these ubiquitous transformations. Their success is quite remarkable, but not without their share of problematic and sometimes unusual observations, which continue to probe our fundamental understanding of these reactions. Through an identification of side‐reactions, our train of thought of a well‐known reaction can be challenged. In this review we identify exemplary processes and show how they have been exploited in synthetic chemistry. A deeper insight into well‐established processes is provided, which alerts us to new synthetic transformations. On one hand, it is of significant interest to understand how to minimise unwanted reactions and their side‐products, but on the other, one can seek to exploit such reaction pathways and develop new synthetic methodologies. Either way, synthetic chemists only stand to benefit from such findings, which, more often than not, stimulate further research into this ever‐expanding field. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)