bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial Diversity Associated with the Fruit-Piercing and Blood-Feeding Moth Calyptra thalictri (Lepidoptera: Noctuidae)
Authors: Zaspel Jennifer M , Hoy Marjorie A
Published: November 2008

Previous inventories of the diversity of lepidopteran symbionts have been limited to Eubacteria. We conducted a microbial survey of Calyptra thalictri Borkhausen (Lepidoptera: Noctuidae) by using polymerase chain reaction (PCR) primers for 16S rRNA sequences for Eubacteria, and primers for Archaea, fungi including yeast-like organisms, Microsporidia, and Wolbachia. Heads and abdomens of adult males of this fruit-piercing and blood-feeding moth were assayed separately. High-fidelity PCR and subsequent DNA analyses indicated that at least five microorganisms belonging to the α-, β-, and γ-Proteobacteria were present. Two eubacterial sequences, related to a Klebsiella sp. and a Sinorhizobium sp., were detected in the abdomens of all nine individuals sampled, and three additional sequences, two related to species in the genus Alcaligenes and one related to a Rhizobium sp., were found in some of the abdominal samples, suggesting all five could be associated with abdominal structures. No Archaea, fungi including yeast-like organisms, Microsporidia, or Wolbachia were detected. These results document the first microbial associates in a fruit-piercing and blood-feeding moth.
Environmental Conditions Affect Sperm Competition Risk in Japanese Beetles (Coleoptera: Scarabaeidae)
Authors: Switzer Paul V , Enstrom Patrick C , Schoenick Carissa A
Published: November 2008

Males of many species guard their mates to prevent rivals from usurping paternity of the potential offspring. Environmental conditions, such as temperature, may affect a male’s ability to guard a female effectively and consequently the amount of sperm competition that occurs. We tested whether temperature and light affected mating behavior in laboratory experiments on the Japanese beetle, Popillia japonica Newman, a species in which males guard females for minutes to many hours after mating. When tested in groups, under conditions of high temperature and high light, males guarded females for shorter periods of time and males and females both mated with more different individuals. The number of mating pairs observed at any one time, however, was lower under conditions of relatively high temperature and light, which agrees with field data and is likely due to a combination of shorter pair durations and a period of time between successive mates. Contests for females were rare, which indicates that these patterns were due to changes in the behavior of the male and/or female of the pair. To tease apart male versus female roles in these patterns, single males were given dead females for copulation and guarding. When single males mated with the dead female, light and temperature still affected guarding behavior (e.g., the shortest durations were under conditions of relatively high temperature and light), indicating that males play a major part in determining the duration of mate guarding, probably due to a change in the costs the males are incurring. However, the patterns in the dead female experiment were not identical to the patterns in the group experiment, implying that female behavior also plays a role in guarding time. Our results demonstrate that environmental conditions can have a major effect on sperm competition risk and suggest that males would benefit greatly from being able to mitigate, either morphologically, physiologically, or behaviorally, the impact of those conditions.
Lethality of Red Imported Fire Ant Venom to Argentine Ants and Other Ant Species
Authors: Greenberg Les , Kabashima John N , Allison Clinton J , Rust Michael K , Klotz John H , Hurvois Jean-Pierre , Paine Timothy D
Published: November 2008

Using natural venom collected from the red imported fire ant, Solenopsis invicta Buren, we determined the dose of venom necessary to kill 50% of the workers (LD50) of Argentine ants, Linepithema humile (Mayr), and several other ant species that the fire ant may encounter in California. Of the species tested, the Argentine ant was most susceptible to the venom. On a weight-adjusted basis the red imported fire ant was 330 times more resistant to the venom than the Argentine ant. In addition, the native southern fire ant, Solenopsis xyloni McCook, was significantly more susceptible to the venom than S. invicta. Formica perpilosa Wheeler was most resistant to the venom when the LD50 was not adjusted for weight, requiring a dose 684 times higher than that of the Argentine ant. When we tested synthetic venom (solenopsin A, which is the main component of S. xyloni venom) against the Argentine ant, the LD50 value was unchanged. However, both S. invicta and S. xyloni were ≈6 times more susceptible to the synthetic compound than to natural venom. Therefore, S. invicta venom is less toxic to fire ants while being just as toxic to Argentine ants as the simpler, more primitive venom of S. xyloni. Fire ant gaster flagging and venom dabbing applies enough venom to the Argentine ant to be lethal and may help explain the superior interference competition shown by the red imported fire ant.
Functional Perovskites – From Epitaxial Films to Nanostructured Arrays
Authors: Vrejoiu Ionela , Alexe Marin , Hesse Dietrich , Gösele Ulrich
Published: November 2008

Functional perovskite materials gain increasing significance due to their wide spectrum of attractive properties, including ferroelectric, ferromagnetic, conducting and multiferroic properties. Due to the developments of recent years, materials of this type can conveniently be grown, mainly by pulsed laser deposition, in the form of epitaxial films, multilayers, superlattices, and well‐ordered arrays of nanoislands. These structures allow for investigations of preparation–microstructure–property relations. A wide variation of the properties is possible, determined by strain, composition, defect contents, dimensional effects, and crystallographic orientation. An overview of our corresponding work of recent years is given, particularly focusing on epitaxial films, superlattices and nanoisland arrays of (anti)ferroelectric and multiferroic functional perovskites.
Enhanced Two‐Photon Absorption of Organic Chromophores: Theoretical and Experimental Assessments
Authors: Terenziani Francesca , Katan Claudine , Badaeva Ekaterina , Tretiak Sergei , Blanchard‐Desce Mireille
Published: November 2008

Functional organic materials with enhanced two‐photon absorption lead to new technologies in the fields of chemistry, biology, and photonics. In this article we review experimental and theoretical methodologies allowing detailed investigation and analysis of two‐photon absorption properties of organic chromophores. This includes femtosecond two‐photon excited fluorescence experimental setups and quantum‐chemical methodologies based on time‐dependent density functional theory. We thoroughly analyze physical phenomena and trends leading to large two‐photon absorption responses of a few series of model chromophores focusing on the effects of symmetric and asymmetric donor/acceptor substitution and branching.
Particle surface temperature measurements with multicolor band pyrometry
Authors: Lu Hong , Ip Leong‐Teng , Mackrory Andrew , Werrett Luke , Scott Justin , Tree Dale , Baxter Larry
Published: November 2008

A noncontact, color‐band pyrometer, based on widely available, inexpensive digital imaging devices, such as commercial color cameras, and capable of pixel‐by‐pixel resolution of particle‐surface temperature and emissivity is demonstrated and described. This diagnostic instrument is ideally suited to many combustion environments. The devices used in this method include color charge‐coupled device (CCD), or complementary metal oxide semiconductor (CMOS) digital camera, or any other color‐rendering camera. The color camera provides spectrally resolved light intensity data of the image, most commonly for three color bands (Red, Green, and Blue,), but in some cases for four or more bands or for a different set of colors. The CCD or CMOS sensor‐mask combination has a specific spectral response curve for each of these color bands that spans the visible and often near infrared spectral range. A theory is developed, based on radiative heat transfer and camera responsivity that allows quantitative surface temperature distribution calculation, based on a photograph of an object in emitted light. Particle surface temperature calculation is corrected by heat transfer analysis with reflection between the particle and reactor wall for particles located in furnace environments, but such corrections lead to useful results only when the particle temperature is near or below the wall temperatures. Wood particle‐surface temperatures were measured with this color‐band pyrometry during pyrolysis and combustion processes, which agree well with thermocouple measured data. Particle‐surface temperature data simultaneously measured from three orthogonal directions were also mapped onto the surface of a computer generated 3‐D (three‐dimensional) particle model. © 2008 American Institute of Chemical Engineers AIChE J, 2009
Flame retardancy behaviors and structural properties of polypropylene/nano‐SiO2composite textile filaments
Authors: Erdem Nilufer , Cireli Aysun A. , Erdogan Umit H.
Published: November 2008

The number of efforts about modifying the properties of polymeric fibers by organic or inorganic particles has increased recently because of high‐tech applications of textiles. In addition to these attempts, the discovery of nanotechnology also leads to the development of nanoparticles for various end uses such as nanocomposite fibers. In this article, we aimed to produce slow burning or flame retardant polypropylene filaments for carpet pile yarns by incorporating SiO2nanoparticles into polymer. Therefore, we present the preparation of filaments incorporating 0.3, 1, and 3% SiO2nanoparticles and investigate the effects of nanoparticles on the flame retardancy and structural behavior of filaments. Polypropylene and nanoparticles were compounded by melt‐compounding using twin‐screw extruder before spinning. Filaments with trilobal cross sections were spun using pilot melt spinning equipment. The structural properties of nanocomposite fibers were analyzed using X‐ray difractometry, differential scanning calorymetry, scanning electron microscopy, and tensile tests. The flammability behaviors of filaments were evaluated using the oxygen index method. The effect of nanoparticles on structural properties and flame retardancy behaviors of filaments were summarized and discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Novel polymer composites based on a mixture of preformed nanosilica‐filled poly(methyl methacrylate) particles and a diepoxy/diamine thermoset system
Authors: Castrillo P. D. , Olmos D. , González‐Benito J.
Published: November 2008

In this work, a new material based on an epoxy thermoset modified with a thermoplastic filled with silica nanoparticles was investigated. When thermoplastic particles are filled with nanoparticles with unique properties such as high efficiency for absorbing ultraviolet light, electric or magnetic shielding, high electrical conductivity, and high dielectric constants, more than an enhancement of the mechanical properties is expected to be achieved for modified epoxy‐based thermosets. Particles of poly(methyl methacrylate) (PMMA) filled with silica nanoparticles were used to modify a thermoset based on a full reaction between diglycidyl ether of bisphenol A and 3‐(aminomethyl)benzylamine. When the preformed thermoplastic particles were mixed with the reactive constituents of the epoxy system under certain curing conditions in which total miscibility was avoided, uniform particle dispersions could be obtained. The relationships between the composition, morphology (nanoscale and microscale), glass‐transition temperature, mechanical properties, and fracture toughness were considered. Four main results were obtained for consideration of the potential of silica‐filled PMMA as an important modifier of brittle epoxy thermoset systems: (1) a good dispersion of the silica nanoparticles in the PMMA domains, (2) a good dispersion of the silica‐filled PMMA microparticles in the epoxy matrix, (3) the possibility of partial dissolution of the PMMA‐rich domains into the epoxy system, and (4) a slight increase in properties such as the hardness, indentation modulus, and fracture toughness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of side‐chain cholesteric liquid‐crystalline polysiloxanes containing different space groups
Authors: Wang Ji‐Wei , Meng Fan‐Bao , Li Yuan‐Hao , Zhang Bao‐Yan
Published: November 2008

A series of liquid‐crystalline (LC) polysiloxanes were synthesized by two different cholesteric monomers, cholest‐5‐en‐3‐ol(3β)‐10‐undecenoate and cholesteryloxycarbonylmethyl 4‐allyloxybenzoate. The chemical structures and LC properties of the monomers and polymers were characterized by various experimental techniques, including Fourier transform infrared spectroscopy, 1H‐NMR, elemental analysis, differential scanning calorimetry, and polarized optical microscopy. The specific rotation absolute values increased with increasing rigid spacers between the main chain and the mesogens. All of the polymers exhibited thermotropic LC properties and revealed cholesteric phases with very wide mesophase temperature ranges. With a reduction in the soft‐space groups in the series of polymers, the glass‐transition temperature and the isotropic temperature increased slightly on heating cycles. Reflection spectra of the cholesteric mesophase of the series of polymers showed that the reflected wavelength shifted to short wavelengths with decreasing soft‐space groups in the polymers systems, which suggested that the helical pitch became shorter with increasing rigid‐space groups. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Green strength of natural rubber: The origin of the stress–strain behavior of natural rubber
Authors: Amnuaypornsri Sureerut , Sakdapipanich Jitladda , Tanaka Yasuyuki
Published: November 2008

The variation of the green strength of natural rubber (NR) with the preparation method of the film was studied to elucidate the origin of the stress–strain behavior characteristics of NR in connection with the structure of branch points in NR. A rubber film prepared via casting from NR latex showed the highest modulus and green strength in comparison with films prepared via casting from a toluene solution and via the hot pressing of dry rubber. The modulus and green strength of the NR latex‐casting film decreased after the hot‐press treatment of the film. On the other hand, no difference was observed for synthetic cis‐1,4‐polyisoprene rubber with the preparation method of the film or the heat treatment. This stress–strain behavior characteristics of NR can be ascribed to the changes in the branch points of the NR film with the casting method, which may result in differences in entanglement and crystallizability on stretching. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis, Structure, and Application of Self‐Assembled Copper(II) Aqua Complex by H‐Bonding for Acceleration of the Nitroaldol Reaction on Water
Authors: Jammi Suribabu , Ali Md Ashif , Sakthivel Sekarpandi , Rout Laxmidhar , Punniyamurthy Tharmalingam
Published: November 2008

Simple addition: Copper(II) aqua complex 1 can be prepared in a one‐pot synthesis and is self‐assembled by H‐bond interactions. Complex 1 is shown to accelerate the nitroaldol reaction on water, which is a heterogeneous process, requiring no additive or base, and 1 can be recycled without loss of activity.

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Copper(II) aqua complex 1 has been prepared in a one‐pot synthesis. The single crystal X‐ray analysis showed that the complex is self‐assembled through aqua ligands by H‐bond interactions and the copper(II) atoms are pentacoordinated with square pyramidal geometry. Complex 1 has been studied for the acceleration of the nitroalodol reaction on water. It is a clean technological process and the catalyst can be recycled without loss of activity.
Disposable bioprocessing: The future has arrived
Authors: Rao Govind , Moreira Antonio , Brorson Kurt
Published: November 2008

Increasing cost pressures are driving the rapid adoption of disposables in bioprocessing. While well ensconced in lab‐scale operations, the lower operating/ validation costs at larger scale and relative ease of use are leading to these systems entering all stages and operations of a typical biopharmaceutical manufacturing process. Here, we focus on progress made in the incorporation of disposable equipment with sensor technology in bioprocessing throughout the development cycle. We note that sensor patch technology is mostly being adapted to disposable cell culture devices, but future adaptation to downstream steps is conceivable. Lastly, regulatory requirements are also briefly assessed in the context of disposables and the Process Analytical Technologies (PAT) and Quality by Design (QbD) initiatives. Biotechnol. Bioeng. 2009;102: 348–356. © 2008 Wiley Periodicals, Inc.
Whole‐genome transcriptional and physiological responses of Nitrosomonas europaea to cyanide: Identification of cyanide stress response genes
Authors: Park Sunhwa , Ely Roger L.
Published: November 2008

Nitrosomonas europaea (ATCC 19718) is one of several nitrifying species that participate in the biological removal of nitrogen from wastewater by oxidizing ammonia to nitrite, the first step in nitrification. Because nitrification is quite sensitive to cyanide, a compound often encountered in wastewater treatment plants, we characterized the physiological and transcriptional responses of N. europaea cells to cyanide. The cells were extremely sensitive to low concentrations of cyanide, with ${\rm NO}_2^ - $ production and ammonia‐dependent oxygen uptake rates decreasing by 50% within 30 min of exposure to 1 µM NaCN. Whole‐genome transcriptional responses of cells exposed to 1 µM NaCN were examined using Affymetrix microarrays to identify stress‐induced genes. The transcript levels of 35 genes increased more than 2‐fold while transcript levels of 29 genes decreased more than 20‐fold. A gene cluster that included moeZ (NE2353), encoding a rhodanese homologue and thought to be involved in detoxification of cyanide, showed the highest up‐regulation (7‐fold). The down‐regulated genes included genes encoding proteins involved in the sulfate reduction pathway, signal transduction mechanisms, carbohydrate transport, energy production, coenzyme metabolism, and amino acid transport. Biotechnol. Bioeng. 2009;102: 1645–1653. © 2008 Wiley Periodicals, Inc.
Regio‐ and Stereoselective Biomimetic Synthesis of Oligostilbenoid Dimers from Resveratrol Analogues: Influence of the Solvent, Oxidant, and Substitution
Authors: Velu Saraswati S. , Buniyamin Irmaizatussyehdany , Ching Lee Kiew , Feroz Fareeda , Noorbatcha Ibrahim , Gee Lim Chuan , Awang Khalijah , Wahab Ibtisam Abd. , Weber Jean‐Frédéric Faizal
Published: November 2008

Oligostilbenoids are polyphenols that are widely distributed in nature with multifaceted biological activities. To achieve biomimetic synthesis of unnatural derivatives, we subjected three resveratrol analogues to oligomerization by means of one‐electron oxidants. Upon varying the metal oxidant (AgOAc, CuBr2, FeCl3⋅6 H2O, FeCl3⋅6 H2O/NaI, PbO2, VOF3), the solvent (over the whole range of polarities), and the oxygenated substitution pattern of the starting material, stilbenoid oligomers with totally different carbon skeletons were obtained. Here we propose to explain the determinism of the type of skeleton produced with the aid of hard and soft acid/base concepts in conjunction with the solvating properties of the solvents and the preferred alignment by the effect of π stacking.
Ephrin‐A5 regulates the formation of the ascending midbrain dopaminergic pathways
Authors: Cooper Margaret A. , Kobayashi Kazuto , Zhou Renping
Published: November 2008

Dopaminergic neurons from the substantia nigra and the ventral tegmental area of the midbrain project to the caudate/putamen and nucleus accumbens, respectively, establishing the mesostriatal and the mesolimbic pathways. However, the mechanisms underlying the development of these pathways are not well understood. In the current study, the EphA5 receptor and its corresponding ligand, ephrin‐A5, were shown to regulate dopaminergic axon outgrowth and influence the formation of the midbrain dopaminergic pathways. Using a strain of mutant mice in which the EphA5 cytoplasmic domain was replaced with β‐galactosidase, EphA5 protein expression was detected in both the ventral tegmental area and the substantia nigra of the midbrain. Ephrin‐A5 was found in both the dorsolateral and the ventromedial regions of the striatum, suggesting a role in mediating dopaminergic axon‐target interactions. In the presence of ephrin‐A5, dopaminergic neurons extended longer neurites in in vitro coculture assays. Furthermore, in mice lacking ephrin‐A5, retrograde tracing studies revealed that fewer neurons sent axons to the striatum. These observations indicate that the interactions between ephrin‐A ligands and EphA receptors promote growth and targeting of the midbrain dopaminergic axons to the striatum. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Trajectory tracking control of mobile robot by fluid model
Authors: Miyata Junichi , Murakami Toshiyuki
Published: November 2008

This paper describes a fluid model‐based path planning of mobile robot. In previous research, the authors proposed TBSA (Time‐Based Spline Approach) for smooth motion of industrial robots [1]. The TBSA is a powerful method in industrial applications, but the future position and velocity commands must be known to use it. In the general applications of repeat motion, this assumption is acceptable. In the path planning of a mobile robot, however, the future position and velocity commands are unknown. To address the above issue, a strategy to generate the path of a mobile robot based on the fluid model is proposed in this paper. The combination of the TBSA and the generated path by the fluid model brings a smooth motion of mobile robots. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(5): 41–48, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10114
Maximum efficiency control of a system composed of a piezoelectric transformer and cold cathode tube driven by inverter, and its characteristics
Authors: Sugimoto Hidehiko , Shimizu Toshihiro , Morishima Yasuyuki
Published: November 2008

This paper concerns a control method in which cold cathode tube used for liquid crystal display, etc. is made to light at maximum efficiency. In the system composed of inverter, LC circuit, piezoelectric transformer, and cold cathode tube, tube current is controlled at the height of inverter output voltage, and the efficiency is controlled at the frequency. In this way, maximum efficiency control which does not depend on tube current is realized by carrying out tube current control and efficiency control separate. Maximum efficiency control method is deduced, after the characteristics of piezoelectric transformer and cold cathode tube are well examined, and the performance of the control has been confirmed by simulation and experiment. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 82– 93, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20567
Model predictive control based switching of multimodal controllers in switched systems
Authors: Zanma Tadanao , Yamakaji Akira , Ishida Muneaki
Published: November 2008

In real systems, there exist physical constraints such as voltage limitations imposed on actuators or state restriction due to their structure. Violation constraints in systems may cause instability, or in the worst case, result in malfunction. In this paper, a switching algorithm of multimodal controllers in switched systems is proposed. The method is based on the model predictive control. Both simulation and experimental results illustrate the effectiveness of the proposed method. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 73–81, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20702
Effects of output power fluctuation on short‐circuit current of induction‐type wind power generators
Authors: Kumano Teruhisa
Published: November 2008

Effects of the fluctuation inherent in wind speed are studied by a probabilistic method. The random variation in wind speed is responsible for random behavior in output power and internal voltage of a wind power generator. In case of fault occurrence at the instant of high internal voltage, the resultant short‐circuit current will be big, and vice versa. The DC component is also affected.

According to the study, 2.4% and 1.3% increase of short‐circuit current in AC and DC components are observed respectively in a large variation case. This implies that the wind speed variation should be considered for accurate short‐circuit study. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 27–36, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20721
Chemo‐enzymatic synthesis of lipophilic ferulates and their evaluation for antioxidant and antimicrobial activities
Authors: Kanjilal Sanjit , Shanker Kaki Shiva , Rao Kotte Sagar , Reddy Kunduru Konda , Rao Bhamidipati V. S. K. , Kumar Kota B. Shiva , Kantam Mannepalli L. , Prasad Rachapudi B. N.
Published: November 2008

An efficient chemo‐enzymatic synthesis of ferulic acid‐based structured lipids mimicking triacylglycerol with a pendant phenolic moiety was carried out for the first time. Initially, ferulic acid was reduced to coniferyl alcohol, followed by its esterification with fatty acids. The key step in the synthesis was dihydroxylation of the olefinic side chain of coniferyl ester, which was eventually esterified with fatty acids to generate phenolic structured lipids. Two such compounds of varying fatty acid chain lengths were synthesized in good yield. Structural confirmation of both compounds is based on IR, 1H and 13C NMR, and MS techniques. The synthesized compounds were tested for in vitro antioxidant and antimicrobial activities. Both compounds exhibited moderate to good antioxidant activity. The phenolic structured lipid with only shorter‐chain fatty acids showed antibacterial activity. Both compounds did not show any antifungal activity.
Detection of recombinant growth hormone in human plasma by a 2‐D PAGE method
Authors: Kohler Maxie , Püschel Klaus , Sakharov Dimitri , Tonevitskiy Alexander , Schänzer Wilhelm , Thevis Mario
Published: November 2008

Human growth hormone (GH) has several central metabolic functions including bone growth in childhood, and its anabolic and lipolytic effects in particular are assumed reasons for the abuse of GH by athletes. Human endogenous GH consists of a main 22 kDa variant and several isoforms. In contrast, recombinant GH consists of only one variant being identical to the main endogenous isoform. The method presented here separates different isoforms by 2‐D PAGE after isolation of GH from plasma using an immunoaffinity purification system. While samples containing endogenous GH yield up to four isoforms, samples with recombinant GH contain the main 22 kDa spot only. Normalized spot volumes (NSV) are calculated after addition of an internal standard and a discrimination limit was determined at 0.52 for the NSV of the main 22 kDa spot. Above this value, samples containing endogenous GH show at least the main 22 kDa isoform and the 20 kDa splice variant. In contrast, samples with a NSV >0.52 and only one spot are suspicious to contain recombinant GH. This method detects discrete isoforms of GH from plasma and discriminates endogenous GH from its recombinant analog, which makes it useful for doping control purposes.
Volume reconstruction of large tissue specimens from serial physical sections using confocal microscopy and correction of cutting deformations by elastic registration
Authors: Čapek Martin , Brůža Petr , Janáček Jiří , Karen Petr , Kubínová Lucie , Vagnerová Radomíra
Published: November 2008

A set of methods leading to volume reconstruction of biological specimens larger than the field of view of a confocal laser scanning microscope (CLSM) is presented. Large tissue specimens are cut into thin physical slices and volume data sets are captured from all studied physical slices by CLSM. Overlapping spatial tiles of the same physical slice are stitched in horizontal direction. Image volumes of successive physical slices are linked in axial direction by applying an elastic registration algorithm to compensate for deformations because of cutting the specimen. We present a method enabling us to keep true object morphology using a priori information about the shape and size of the specimen, available from images of the cutting planes captured by a USB light microscope immediately before cutting the specimen by a microtome. The errors introduced by elastic registration are evaluated using a stereological point counting method and the Procrustes distance. Finally, the images are enhanced to compensate for the effect of the light attenuation with depth and visualized by a hardware accelerated volume rendering. Algorithmic steps of the reconstruction, namely elastic registration, object morphology preservation, image enhancement, and volume visualization, are implemented in a new Rapid3D software package. Because confocal microscopes get more and more frequently used in scientific laboratories, the described volume reconstruction may become an easy‐to‐apply tool to study large biological objects, tissues, and organs in histology, embryology, evolution biology, and developmental biology. In this work, we demonstrate the reconstruction using a postcranial part of a 17‐day‐old laboratory Wistar rat embryo. Microsc. Res. Tech., 2009. © 2008 Wiley‐Liss, Inc.
Adenoviral‐mediated gene transfer of Gadd45a results in suppression by inducing apoptosis and cell cycle arrest in pancreatic cancer cell
Authors: Li Yunfeng , Qian Haili , Li Xiao , Wang Haijuan , Yu Jing , Liu Yongjun , Zhang Xueyan , Liang Xiao , Fu Ming , Zhan Qimin , Lin Chen
Published: November 2008

Background

The extremely poor prognosis of patients with pancreatic ductal adenocarcinoma indicates the need for novel therapeutic approaches. The growth arrest and DNA damage‐inducible (Gadd) gene Gadd45a is a member of a group of genes that are induced by DNA damaging agents and growth arrest signals.

Methods

We evaluated the biological activity of Gadd45a in pancreatic ductal adenocarcinoma cancer‐derived cell lines and assessed the efficacy of a combined treatment with adenoviral‐mediated expression of Gadd45a (Ad‐G45a) and anticancer drug (Etoposide, cisplatin, 5‐fluorouracil, respectively) for the PANC1 cell line.

Results

Gadd45a is variously expressed in cell lines derived from pancreatic ductal adenocarcinoma cancer and adenoviral‐mediated expression of Gadd45a (Ad‐G45a) in these cells results in apoptosis via caspase activation and cell‐cycle arrest in the G2/M phase. Gadd45a significantly increased the chemosensitivity of PANC1, which may be due to abundant apoptosis induction and cell cycle arrest. By combinational treatment of Ad‐G45a infection and chemotherapeutics, Gadd45a expression was elevated to a higher extent in cancer cells with wild‐type p53 than in that with knocked‐out p53 status, indicating a higher chemosensitivity to cancer chemotherapy.

Conclusions

Gadd45a may be a promising candidate for use in cancer gene therapy in combination with chemotherapeutic agents. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of hydrogen bonding in the vibrational spectra of trans‐cinnamic acid
Authors: Nolasco Mariela M. , Amado Ana M. , Ribeiro‐Claro Paulo J. A.
Published: November 2008

A computationally‐assisted methodology to assign the vibrational spectra of molecular materials (PiMM) has been successfully applied to the Raman and infrared (IR) spectra of trans‐cinnamic acid (t‐CIA) in the solid state. The effects of molecular association through OH···O hydrogen‐bonding in both the wavenumber and the intensity of the bands are accurately described by a single dimer structure. This supports the discrimination between the possible conformers in the solid, the complete evaluation of hydrogen‐bonding effects, and the full assignment of the vibrational spectra of t‐CIA. Copyright © 2008 John Wiley & Sons, Ltd.
Indirect Raman identification of the proton insertion in the high‐temperature [Ba/Sr][Zr/Ti]O3‐modified perovskite protonic conductors
Authors: Slodczyk Aneta , Colomban Philippe , Willemin Stephanie , Lacroix Olivier , Sala Beatrice
Published: November 2008

OH− and H3O+ species in hydrates and simple oxides are rather well characterised from their IR, Raman and inelastic neutron points of view. For the H+ (H2O) species in solid state the variability is well established and assignment remains discussed. The question of the vibrational signature of isolated proton (e.g. the ionic proton, a proton sharing its interaction with more than two acceptors) and its dynamic nature (proton gas, polaron,…) is open. H+‐containing modified perovskites A(Ba,Sr,…) B(Zr,Ce,Ti,…) O3 are potential ceramic membranes for fuel cell and medium temperature water electrolysis (300–800 °C). Comparison studies of the protonated and non‐protonated lanthanide/rare earth‐modified perovskites of type Ba(Sr)Zr(Ti)O3 as well as Al‐modified BaTiO3 show that a broad component centred at 2500 cm−1 is observed after ‘proton insertion’. Its intensity is correlated to the protonic species content as well as to the conductivity of the materials. The mixed nature of this feature is discussed: fluorescence related to the dangling bonds, A, B, C bands or new phenomena related to the ionic protons and associated electronic defect. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of aliphatic amines by cation‐exchange chromatography with suppressed conductivity detection after solid phase extraction*
Authors: Casella Innocenzo G. , Palladino Giacomo A. , Contursi Michela
Published: November 2008

A sensitive method for the determination of underivatized aliphatic amines based on cation exchange chromatography coupled with suppressed conductivity detection scheme and solid phase extraction (SPE) procedure has been developed. A surface modified styrene divinylbenzene polymeric sorbent, based on a reversed‐phase (RP) and strong cation exchange (SCX) mixed mode was used as an active material for the SPE of amines. The conductometric capabilities of several aliphatic mono‐ and polyamines, expressed in terms of molar sensitivity (nS/μM), were determined. The LODs, obtained without the SPE treatment, ranged between 20 and 65 nM for putrescine and 2‐butylamine, respectively. The resulting calibration plots for the aliphatic amines were generally linear over about three orders of magnitude, with correlation coefficients >0.98. The LODs of amines decreased generally by one factor when SPE procedure, using BaCl2/H2SO4 eluents, has been adopted. The proposed SPE procedure, seems to offer good results in terms of preconcentration, recoveries and cleanup of samples. The proposed methodology was successfully tested for the quantitative determination of some biogenic amines in beer and tuna.
Novel Gelling Systems of κ‐, ι‐ and λ‐Carrageenans and their Composite Gels with Cellulose Using Ionic Liquid
Authors: Prasad Kamalesh , Kaneko Yoshiro , Kadokawa Jun‐ichi
Published: November 2008

Gels of three types of carrageenans (κ‐, ι‐ and λ‐), as well as their composite gels with cellulose, were prepared using an ionic liquid, 1‐butyl‐3‐methylimidazolium chloride (BMIMCl), by a heating‐cooling process. κ‐Carrageenan gave the formation of hard gel while the other two carrageenans gave the formation of softer gels with BMIMCl. The gels were characterized by X‐ray diffraction (XRD), thermal analysis (TGA and DSC), scanning electron microscope (SEM) and compressive testing. The results indicated that, among the three types of carrageenans, κ‐ and ι‐carrageenans gave better miscible gels with BMIMCl, followed by λ‐carrageenan. On the other hand, λ‐carrageenan gave a better miscible composite gel with cellulose and BMIMCl, followed by ι‐ and κ‐carrageenans. The stress‐strain curves indicated that the mechanical properties of the above gel systems on the compressive mode were much better than those of the hydrogels of κ‐ and ι‐carrageenans as well as the cellulose gel with BMIMCl.

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Controlled Release of IgG by Novel UV Induced Polysaccharide/Poly(amino acid) Hydrogels
Authors: Tripodo Giuseppe , Pitarresi Giovanna , Cavallaro Gennara , Palumbo Fabio Salvatore , Giammona Gaetano
Published: November 2008

The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti‐TNF‐α monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), α,β‐poly[N‐(2‐hydroxyethyl)‐D,L‐aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, inulin, has been functionalized with methacrylic anhydride and succinic anhydride. The hydrogels were obtained by a short‐time UV irradiation, in physiological‐like conditions, without the use of radical initiators, at low temperature and in the presence or in the absence of PEGDM550 used as a co‐crosslinker in order to evaluate potential differences in terms of physicochemical properties and release profile. The obtained hydrogels were degradable by inulinase, showed a high cell compatibility and the released antibodies, analyzed by SEC and ELISA, retained their biological activity.

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Mechanical Reinforcement of Continuous Flow Spun Polyelectrolyte Complex Fibers
Authors: Granero Alberto J. , Razal Joselito M. , Wallace Gordon G. , in het Panhuis Marc
Published: November 2008

A simple continuous flow wet‐spinning method to achieve mechanical reinforcement of the two oppositely charged biopolymers chitosan and gellan gum is described. The mechanical properties of these biopolymers are influenced by the order of addition. Using a facile method for mechanical reinforcement of gellan gum/chitosan fibers resulted in increases in Young's modulus, tensile strength, and toughness. Spinning gellan gum into chitosan resulted in the strongest fibers. We show that our fibers can provide a mechanical alternative for bio‐fibers without the need of cross‐linking. It is demonstrated that the fibers become ionically conducting in the presence of water vapor.

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Structure and Segmental Motions in a Substituted Polythiophene: A Solid‐State NMR Study
Authors: Le Bouch Nolwenn , Auger Michèle , Leclerc Mario
Published: November 2008

Thermochromic poly[3‐(2‐methyl‐1‐butoxy)‐4‐methylthiophene] has been investigated in the solid state. Some important changes have been observed by UV‐Vis absorption and XRD measurements. Solid‐state NMR spectroscopy, which has the ability to provide information about the structure and dynamics of polymers over a wide range of length scales and time scales, has been utilized to better understand the motion of polythiophene chains during this thermochromic transition. Different solid‐state NMR analyses led to the determination of the relaxation rates for the main chain and the side chain as well as to the characterization of a twisting of the conjugated backbone chain during the thermochromic transition.

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Fluorescence‐Amplifying Assay for Irradiated DNA Lesions Using Water‐Soluble Conjugated Polymers
Authors: Feng Fude , Duan Xinrui , Wang Shu
Published: November 2008

A new platform has been developed for DNA lesion detection using a cationic conjugated polymer (CCP). DNA that contains two adjacent thymine bases is irradiated with ultraviolet light to allow for the formation of cyclobutane pyrimidine dimers and pyrimidine–pyrimidone dimers. The DNA lesions block the primer extension, and the base labeled with fluorescein cannot be incorporated into the DNA strand. Addition of the CCP leads to inefficient fluorescence resonance energy transfer (FRET) from CCP to fluorescein. For the case without DNA lesions, successful primer extension allows for efficient FRET between them. In view of the FRET signal changes, the DNA lesions can be detected. This new protocol offers a convenient detection for DNA lesions in aqueous solution without any isolation and washing steps.

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Polylactide (PLA) and Highly Filled PLA ‐ Calcium Sulfate Composites with Improved Impact Properties
Authors: Murariu M. , Ferreira A. Da Silva , Duquesne E. , Bonnaud L. , Dubois Ph.
Published: November 2008

Summary: Starting from gypsum as by‐product of lactic acid fabrication process, novel high performance composites have been produced by melt‐blending PLA and this filler after a previous specific dehydration performed at 500 °C for min. 1h. Due to PLA sensitivity towards hydrolysis, the utilization of β‐anhydrite II (AII) as filler is a prerequisite. Characterized by attractive mechanical and thermal properties due to good filler dispersion throughout the polyester matrix, these composites are interesting in biodegradable rigid packaging or technical applications. Interestingly, tensile strength of PLA – AII composites proved remarkably high, e.g. higher than 35 MPa at 50 wt‐% filler content. However a decrease of impact properties has been recorded. To increase the toughness of these composites while preserving high stiffness an impact modifier based on ethylene copolymer has been mixed with both the polymer matrix and AII by melt‐compounding. The effectiveness of the impact modifier was confirmed in both neat PLA and AII‐based composites. Addition of 5‐10 wt‐% impact modifier into highly filled composites (30 to 40 wt‐% filler) leads to an attractively threefold increase of impact strength with respect to the compositions without modifier, remarkable thermo‐mechanical performances and good filler dispersion.
Bark Suberin as a Renewable Source of Long‐Chain ω‐Hydroxyalkanoic Acids
Authors: Nilsson Helena , Olsson Ann , Lindström Mikael , Iversen Tommy
Published: November 2008

Summary: Polycondensations of cis‐9,10‐epoxy‐18‐hydroxyoctadecanoic acid, isolated from birch outer bark, were performed at 75 °C in toluene as solvent and at 85 °C in bulk using immobilized Candida antarctica lipase B as catalyst. The polycondensation performed in toluene in presence of molecular sieves gave a polyester with DP 50 after 24 h. The same DP was obtained at much shorter reaction time (3 h) by bulk polymerization in an open vial without any drying agent present.
Degradation Study of Polymers from Renewable Resources and their Compositions in Industrial Composting Pile
Authors: Sikorska Wanda , Dacko Piotr , Sobota Michał , Rydz Joanna , Musioł Marta , Kowalczuk Marek
Published: November 2008

Summary: Polyesters produced from renewable resources and susceptible to hydrolysis under the industrial composting conditions offer ecological advantages as compared to thermoplastics polymers and elastomers produced from fossil carbon sources. In this paper the degradation behaviour of polymer compositions of BTA, PLA and a‐PHB in natural environment of industrial composting pile, consisting of leaves ‐ 40%, branches ‐ 30% and grass ‐ 30%, have been presented. The extend of degradation was monitored by macroscopic observations of sample surfaces, changes of molecular weight, polydispersity and composition of the tested materials and their weight loss.
Supramolecular Structure ‐ A Key Parameter for Cellulose Biodegradation
Authors: Ciolacu Diana , Ciolacu Florin , Popa Valentin I.
Published: November 2008

Summary: Three different cellulosic substrata, like microcrystalline cellulose, cotton cellulose and spruce dissolving pulp, were chosen for biodegradation. The kinetics of the enzymatic hydrolysis of these celluloses by Trichoderma reesei, has been investigated. The experiments proved the fact that both the morphological structure and the crystalline one are crucial to the process and the ratio of the reactions. In addition, in order to obtain the most accessible cellulose substratum it was studied the biodegradation of cellulose allomorphs of spruce dissolving pulp. The insoluble cellulose fraction remaining after enzymatic hydrolysis was examined by X‐ray diffraction method and it was established the degree of crystallinity and the average crystallite size. The enzymatic degradation is also proved by the decrease in the degree of polymerization of hydrolyzed samples.
Non‐invasive tracking of avian development in vivo by MRI
Authors: Hogers Bianca , van der Weerd Louise , Olofsen Hans , van der Graaf Linda M. , DeRuiter Marco C. , Groot Adriana C. Gittenberger‐de , Poelmann Robert E.
Published: November 2008

Conventional microscopic techniques, to study embryonic development, require large numbers of embryos and are invasive, making follow‐up impossible. We explored the use of in vivo MRI to study embryonic development, in general, and cardiovascular development in particular, over time. Wild‐type quail embryos (n = 11) were imaged at embryonic days 3, 5, 7, 9, and 11, covering the main time course of embryonic heart development. On each imaging day cardiac morphology was evaluated and embryonic length was measured. MRI‐embryos as well as control embryos (n = 11) were sacrificed at day 11 and scored for external malformations, while embryonic wet weight and stage were determined. In addition, venous clipped embryos (n = 4), known to develop cardiovascular malformations, were scanned at regular intervals and sacrificed at day 9 for histological analysis ex vivo. We were able to follow heart development of individual quail embryos inside their shell non‐invasively over time, with sufficient detail to study cardiac morphology in vivo. We did not find any adverse effect of the repeated MRI examinations on morphology, length, or weight. Prenatally diagnosed malformations, like ventricular septal defects and aortic arch interruptions were confirmed by histology. In conclusion, micro‐MRI can be used to evaluate in vivo early embryonic development and to diagnose cardiovascular malformations prenatally. Copyright © 2008 John Wiley & Sons, Ltd.
The ATM tumour suppressor gene is down‐regulated in EBV‐associated nasopharyngeal carcinoma
Authors: Bose Shikha , Yap Lee‐Fah , Fung Matthew , Starzcynski Jane , Saleh Amyza , Morgan Susan , Dawson Christopher , Chukwuma Marilyn B , Maina Esther , Buettner Maike , Wei Wenbin , Arrand John , Lim Paul VH , Young Lawrence S , Teo Soo Hwang , Stankovic Tatjana , Woodman Ciaran BJ , Murray Paul G
Published: November 2008

A micro‐array analysis using biopsies from patients with EBV‐positive undifferentiated nasopharyngeal carcinoma (NPC) and from cancer‐free controls revealed down‐regulation of tumour suppressor genes (TSG) not previously associated with this disease; one such gene was the ataxia telangiectasia mutated (ATM) gene. Q‐PCR confirmed down‐regulation of ATM mRNA and ATM protein expression in tumour cells was weak or absent in almost all cases. In NPC cell lines, however, ATM was down‐regulated only in the EBV‐positive line, C666.1, and in none of five EBV‐negative lines. In vitro infection of EBV‐negative NPC cell lines with a recombinant EBV was followed by the down‐regulation of ATM mRNA and protein, and only EBV‐positive cells showed a defective DNA damage response following γ‐irradiation. Our data suggest that loss of ATM function could be an important step in the pathogenesis of NPC, and may have implications for the treatment of this disease. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.