bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyether polyurethanes: Synthesis, characterization, and thermoresponsive shape memory properties
Authors: Merline J. Dyana , Nair C. P. Reghunadhan , Gouri C. , Bandyopadhyay G. G. , Ninan K. N.
Published: December 2007

Thermoresponsive shape memory polymers based on polyurethane with soft segment consisting of poly (tetramethylene oxide) (PTMO) and hard segment arising from urethane reaction of tolylene diisocyanate with OH terminal of PTMO and 1,4 butane diol (BD) were synthesized by a two‐ step process. The molar ratios of the reactants were varied to get polymers of different soft – hard segment contents. These were characterized by DSC, IR, DMTA, XRD, SEM analyses, and mechanical properties. The shape memory behavior was evaluated by cyclic tensile tests. PTMO served as the switching segments whose crystalline melting was responsible for the switching behavior. As the hard segment‐content increased, transition temperature (Ttrans) diminished and so did the elongation and tensile strength of the polyurethane. Higher glassy/rubbery modulus ratio observed for higher hard segment‐content polymer was conducive to better shape recovery properties. The influence of hard/soft segments on the thermal, mechanical, damping and shape memory properties of the copolymers are presented and correlated to their phase morphology, as investigated by FTIR and SEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Hydrophilic microporous PES membranes prepared by PES/PEG/DMAc casting solutions
Authors: Li Jing‐Feng , Xu Zhen‐Liang , Yang Hu , Feng Cui‐Ping , Shi Jiang‐Huan
Published: December 2007

Microporous poly(ether sulfones) (PES) membranes were prepared via phase inversion using poly (ethylene glycol) (PEG) as additive and N,N‐dimethylacetamide (DMAc) as solvent. Thermodynamic of the casting solutions was studied by coagulation value while precipitation rate was observed by light transmittance measurement. It was found that casting solution with PEG200 as additive was thermodynamically less stable than those with PEG400 and PEG600 as additive and easier to cause phase separation in exposure time. With the increase of PEG200 concentration, the casting solution became thermodynamically less stable and easier to cause phase separation in exposure time, but precipitation rate during immersion precipitation decreased because of the increased viscosities. ATR‐FTIR spectra and TGA curves showed that the membranes prepared using PEG200 as additive had less PEG residual than those of PEG400 and PEG600, but it showed better permeation performance than that prepared using PEG400 and PEG600 as additive. With the increase of PEG200 concentration from 30 to 70 wt %, the cross section structure changed from macrovoid to sponge‐like, micropores with a mean pore size around 0.1 μm began to form on the top surface. When the PEG200 concentration is 60 wt %, the pure water flux was 1845 L m−2 h−1 bar−1, which is the highest value. As the PEG200 concentration increased from 30 to 60 wt %, the contact angles decreased from 82.1° to 58.2°. As the addition amount of PEG200 increased, the residual PEG made the prepared membranes more hydrophilic. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of Y2 Receptor Deletion on Whole Bone Structural Behavior in Mice
Authors: Mikic Borjana , Zhang Mimi , Webster Eidan , Rossmeier Kerri
Published: December 2007

Recent evidence has shown that mice deficient in the NPY Y2 receptor have an increase in trabecular bone volume as well as cortical bone mass due to increased osteoblast activity. However, the mechanical phenotype of Y2 −/− bone has not yet been assessed. Thus, the aim of the present study was to examine the effect of Y2 deletion on murine cortical bone structural behavior, as well as to assess the material and geometric contributions to that behavior. The results of this study indicate that Y2 −/− mice on a 129 SV × Balb/c background strain are smaller in body mass and have smaller bones than wild‐type controls. As expected based on smaller bone cross‐sectional properties, cortical bone structural strength was lower in −/− animals. Surprisingly, the structural stiffness of −/− bones was comparable to that of +/+ bones despite their smaller cross‐sectional geometry. Comparable structural stiffness appeared to be achieved by means of an elevated effective shear modulus, which was associated with a small, but statistically significant, higher ash content in Y2 −/− bones. These data represent the first comprehensive characterization of the effect of Y2 deletion on cortical bone structural and material behavior to date. Anat Rec, 291:14–18, 2007. © 2007 Wiley‐Liss, Inc.
Bridging Mucosal Vessels Associated with Rhythmically Oscillating Blood Flow in Murine Colitis
Authors: Turhan Aslihan , Konerding Moritz A. , Tsuda Akira , Ravnic Dino J. , Hanidziar Dusan , Lin Miao , Mentzer Steven J.
Published: December 2007

Oscillatory blood flow in the microcirculation is generally considered to be the result of cardiopulmonary influences or active vasomotion. In this report, we describe rhythmically oscillating blood flow in the bridging vessels of the mouse colon that appeared to be independent of known biological control mechanisms. Corrosion casting and scanning electron microscopy of the mouse colon demonstrated highly branched bridging vessels that connected the submucosal vessels with the mucosal plexus. Because of similar morphometric characteristics (19 ± 11 μm vs. 28 ± 16 μm), bridging arterioles and venules were distinguished by tracking fluorescent nanoparticles through the microcirculation using intravital fluorescence videomicroscopy. In control mice, the blood flow through the bridging vessels was typically continuous and unidirectional. In contrast, two models of chemically induced inflammation (trinitrobenzenesulfonic acid and dextran sodium sulfate) were associated with a twofold reduction in flow velocity and the prominence of rhythmically oscillating blood flow. The blood oscillation was characterized by tracking the bidirectional displacement of fluorescent nanoparticles. Space–time plots and particle tracking of the oscillating segments demonstrated an oscillation frequency between 0.2 and 5.1 cycles per second. Discrete Fourier transforms demonstrated a power spectrum composed of several base frequencies. These observations suggest that inflammation‐inducible changes in blood flow patterns in the murine colon resulted in both reduced blood flow velocity and rhythmic oscillations within the bridging vessels of the mouse colon. Anat Rec, 291:74–82, 2007. © 2007 Wiley‐Liss, Inc.
Paläogene Vögel. Die Vogelschar vor Fink und Star
Authors: Mayr Gerald
Published: December 2007

Zahlreiche Neufunde der vergangenen Jahre belegen eine wenig wahrgenommene Vielfalt paläogener Vögel. Anhand von Beispielen aus marinen und terrestrischen Ökosystemen wird ein kurzer Überblick gegeben und dargelegt, dass sich die paläogene Vogelwelt deutlich von der heutigen unterschied. Eine detaillierte Kenntnis der Fossilgeschichte der Vögel ist nicht nur entscheidend für ein Verständnis der Vogelevolution, sondern trägt aufgrund der vielfältigen ökologischen Wechselbeziehungen zwischen Vögeln und anderen Lebewesen auch zu einem besseren Verständnis der Evolution von Ökosystemen im Allgemeinen bei.
Überraschende kognitive Leistungen bei Elefantenrüsselfischen
Authors: Feil Sylvia
Published: December 2007

Seine Stromstöße töten nicht, sie verraten dem Elefantenrüsselfisch Gnathonemus petersii jedoch vieles über seine Umgebung. Er zählt zu den schwach elektrischen Fischen und ortet aktiv elektrosensorisch lebendes Futter oder unbelebte Objekte, die ihm als Landmarken den Weg zu seinem Versteck weisen. Darüber hinaus zeigt eine aktuelle Studie, dass die Fische abstrahieren können.
Riesige “Klaue” enthüllt größten bekannten Gliederfüßer
Authors: Poschmann Markus , Braddy Simon J. , Tetlie Erik O.
Published: December 2007

Im Gegensatz zu der relativen Kleinwüchsigkeit heutiger Arthropoden (Gliederfüßer) zeigen uns Fossilien, dass einige Repräsentanten dieser Gruppe geradezu gigantische Ausmaße erreichten. In der Eifel wurde nun die Chelicere eines Seeskorpions aus dem Unterdevon gefunden, der vermutlich 2,46 m lang war.
Die Antikörperfabrik: Antikörper für jedes Protein
Authors: Schirrmann Thomas , Hust Michael , Dübel Stefan
Published: December 2007

Antikörper sind unersetzliche Werkzeuge für die Analyse von Proteinen und damit Schlüsselreagenzien für eine Hauptaufgabe der Genomforschung – der Zuordnung von Funktionen zu der noch riesigen Zahl von uncharakterisierten Gensequenzen und den dazu gehörigen Genprodukten. Zur Bewältigung dieser Aufgabe entwickelt die Antikörperfabrik (Antibody Factory) Verfahren, mit denen spezifische Antikörper in einem weit höherem Durchsatz als bisher generiert werden können. Als zentrale Technologie wird hierfür das Antikörper‐Phagen‐Display eingesetzt, mit dem Antikörper vollständig ohne Versuchstiere aus menschlichen Antikörper‐Genbibliotheken isoliert werden können.
Ion‐Conduction Pathways in Self‐Organised Ureidoarene–Heteropolysiloxane Hybrid Membranes
Authors: Michau Mathieu , Barboiu Mihail , Caraballo Rémi , Arnal‐Hérault Carole , Perriat Pascal , van der Lee Arie , Pasc A.
Published: December 2007

This paper reports on hybrid organic–inorganic dense membrane materials in which protons and ions are envisioned to diffuse along the hydrophilic pathways. The hierarchical generation of functional hybrid materials was realised in two steps. First, the self‐assembling properties of 3‐(ureidoarene)propyltriethoxysilane compounds1–5in aprotic solvents were determined, revealing the formation of supramolecular oligomers. Compounds1–5generate organogels in chloroform or in acetone, leading in a second sol–gel transcription step to hybrid membrane materials on a nanoscopic scale. The crystal structures of1–5indicate that the arrangement is mainly defined by periodic parallel sheets, resulting from the alignment of hydrophobic organic and inorganic silica layers. Hybrid materialsMB 1–MB 4, with a similar lamellar structure, define particularly attractive functional transport devices; they are oriented along the organic layers and sandwiched between the two siloxane layers. These systems have been employed successfully to design solid dense membranes and illustrate how the self‐organised hybrid materials perform interesting and potentially useful functions.
Manipulative therapy of secondary lymphedema in the presence of locoregional tumors
Authors: Pinell Ximena A. , Kirkpatrick Stephanie H. , Hawkins Kennedy , Mondry Tammy E. , Johnstone Peter A. S.
Published: December 2007

BACKGROUND.

Complete decongestive therapy (CDT), including manual lymphatic drainage (MLD) is a manipulative intervention of documented benefit to patients with lymphedema (LE). Although the role of CDT for LE is well described, to the authors' knowledge there are no data regarding its efficacy for patients with LE due to tumor masses in the draining anatomic bed. Traditionally, LE therapists are wary of providing therapy to such patients with ‘malignant’ LE for fear of exacerbating the underlying cancer, and that the obstruction will render therapy less effective. In the current study, the authors' experience providing CDT for such patients is discussed.

METHODS.

Cancer survivors with LE were referred to therapists at 2 Atlanta‐area clinics. CDT consists of treatment (Phase 1) and maintenance phases (Phase 2). During Phase 1, the patient undergoes manipulative therapy and bandaging daily until the LE reduction plateaus; at that point, Phase 2 (self‐care) begins. At the beginning and end of Phase 1, LE is quantified and differences in girth volume calculated. The results for patients completing Phase 1 therapy for LE in the presence of locoregional masses were compared with results for patients with LE in the absence of such disease. Both volume reduction of the affected limb and number of treatments to plateau were analyzed.

RESULTS.

Between January 2004, and March 2007, LE of 82 limbs in 72 patients was treated with CDT and Phase 1 was completed. The median number of treatments to plateau was 12 (range, 4–23 treatments); the median limb volume reduction was 22% (range, −23 to 164%). Nineteen limbs (16 patients) with associated chest wall/axillary or pelvic/inguinal tumors had nonsignificant difference in LE reduction (P = .75) in the presence of significantly more sessions to attain plateau (P = .0016) compared with 63 limbs in 56 patients without such masses.

CONCLUSIONS.

Patients with LE may obtain relief with CDT regardless of whether they have locoregional disease contributing to their symptoms. However, it will likely take longer to achieve that effect. Manipulative therapy of LE should not be withheld because of persistent or recurrent disease in the draining anatomic bed. Cancer 2008. © 2007 American Cancer Society.
Repopulation of cochlear macrophages in murine hematopoietic progenitor cell chimeras: The role of CX3CR1
Authors: Sato Eisuke , Shick H. Elizabeth , Ransohoff Richard M. , Hirose Keiko
Published: December 2007

Cochlear macrophages have been shown to accumulate in the murine cochlea following acoustic trauma. This investigation was performed to determine whether cochlear macrophages could be replaced by donor transplantation of bone marrow precursors. Lethally irradiated C57BL/6 mice were transplanted with hematopoietic precursors from CX3CR1GFP/GFP fetal mice. CX3CR1GFP/GFP mice express green fluorescent protein (GFP) in monocytes and macrophages and possess no functional CX3CR1. Donor monocytes and macrophages can be easily traced in the wild‐type recipient with fluorescent microscopy. We studied mice at 2–16 weeks after transplantation to assess repopulation of cochlear macrophages. A separate group of chimeras was exposed to octave band noise (8–16 kHz for 2 hours) 2 weeks after transplantation to evaluate the migration properties of donor hematopoietic precursors. We found that macrophages derived from donor hematopoietic precursors appeared in cochlea 3–4 weeks after transplantation and increased week by week. Noise exposure induced a massive accumulation of leukocytes, particularly in the spiral ligament of the basal turn. There was no difference between CX3CR1GFP/GFP donor/wild‐type recipient chimeras and the wild‐type donor/wild‐type recipient chimeras in hearing thresholds, accumulation of cochlear macrophages, or tissue injury after noise exposure. These data indicate that cochlear macrophages are derived from bone marrow precursors and that they are an exchanging and migratory population. Furthermore, CX3CR1 in hematopoietic precursors is not necessary for macrophage migration into cochlea and when deleted in this cell population, the absence of CX3CR1 does not substantially effect the outcomes after noise. J. Comp. Neurol. 506:930–942, 2008. © 2007 Wiley‐Liss, Inc.
Using the proper vocabulary
Authors: Kagan Jerome
Published: December 2007

This paper makes three points. First, inferences from biological and psychological evidence pertaining to psychological constructs must use distinct vocabularies because they represent different phases of a cascade of processes. Second, there are necessarily indeterminate relations between phases of the cascade that begins with an incentive evoking a brain state which, in turn, may generate a psychological reaction and/or action. Finally, all biological and psychological phenomena occur in particular species and specific contexts; hence it is useful to append to every conclusion information on the agent and the setting in which the evidence was gathered. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 4–8, 2008.
Body sway and sensory motor coupling adaptation in children: Effects of distance manipulation
Authors: Godoi Daniela , Barela José A.
Published: December 2007

The purpose of this investigation was to examine coupling between visual information and body sway in children and young adults at various distances from a moving room front wall. Sixty children (from 4 to 14 years old) and 10 young adults stood upright inside a moving room that was oscillated at .2 and .5 Hz, at distances of .25, .5, 1, and 1.5 m from a front wall. Visual information induced body sway in all participants in all conditions. Young children swayed more than older participants, whether the moving room was oscillated or not. Coupling between visual information and body sway became stronger and the room movement influence became weaker with age. Up to the age of 10, coupling strength between visual information and body sway and the room movement influence were distance dependent. Postural control development appears to be dependent on how children reweight the contribution of varying sensory cues available in environment in order to control body sway. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 77–87, 2008.
Critical role for IFN‐γ in natural killer cell‐mediated protection from diabetes
Authors: Lee I‐Fang , Qin Huilian , Priatel John J. , Tan Rusung
Published: December 2007

Autoimmune diabetes in nonobese diabetic (NOD) mice can be prevented by a single injection of complete Freund's adjuvant (CFA), but the mechanisms mediating protection remains unclear. We previously showed that NOD mice immunized with CFA have a markedly reduced incidence of diabetes that is associated with a significant decrease in the number of β‐cell‐specific, autoreactive cytotoxic T lymphocytes and, furthermore, that the effect of CFA is mediated by natural killer (NK) cells. In this study, we report one mechanism by which NK cells regulate the onset of diabetes. Administration of CFA produced a rapid increase in NK cell frequency and function, including cytotoxicity and IFN‐γ secretion. By co‐transferring NK cells from IFN‐γ‐deficient (or wild‐type) NOD mice and spleen cells from diabetic NOD mice to NOD/SCID recipients, we show that IFN‐γ secretion by NK cells significantly influences the effect of CFA protection. In contrast, NK cytotoxicity does not appear to participate in CFA‐mediated protection from diabetes. Our findings demonstrate that NK cells mediate the protective effects of CFA through secretion of IFN‐γ.
Metal–Organic Frameworks Containing Flexible Bis(benzimidazole) Ligands
Authors: Jiang Hui , Ma Jian‐Fang , Zhang Wen‐Li , Liu Ying‐Ying , Yang Jin , Ping Guang‐Ju , Su Zhong‐Min
Published: December 2007

Eleven coordination polymers constructed from three structurally related flexible bis(benzimidazole) ligands, 1,1′‐(1,4‐butanediyl)bis(2‐methylbenzimidazole) (L1), 1,1′‐(1,4‐butanediyl)bis(2‐ethylbenzimidazole) (L2), and 1,1′‐(1,4‐butanediyl)bis(2‐benzylbenzimidazole) (L3), have been synthesized: [Zn(cin)2(L1)]·H2O (1), [Zn(cin)2(L2)] (2), [Cd(cin)2(L1)]·H2O (3), [Cd(cin)2(L2)] (4), [Ag(MES)(L1)0.5] (5), [Ag(MES)(L2)0.5]·H2O (6), [Zn(adi)(L1)]·H2O (7), [Zn(adi)(L2)0.5] (8), [Cd(adi)(L1)]·2H2O (9), [Cd(adi)(L2)] (10), and [Cd(adi)(L3)]·2H2O (11), where cin = cinnamate anion, MES = 2‐(N‐morpholino)ethanesulfonate anion, and adi = adipate dianion. For compounds 1–4, the cin anions are coordinated to metal ions in monodentate mode or bidentate chelating mode, and metal cations are bridged by L1 or L2 ligands to form 1‐D chain structures. Compound 5 shows a 1‐D chain structure which comprises a dimeric unit that is built from two silver ions and two MES anions. In compound 6, silver ions are bridged by MES anions and L2 ligands to form a 2‐D (6, 3) network while compounds 7–9 possess 2D (4, 4) networks. In the structure of compound 8, there exists a dimeric unit which is built from two zinc ions bridged by four carboxylate groups. Compound 10 exhibits a fourfold interpenetrating diamondoid net, and compound 11 displays a noninterpenetrating diamondoid framework. The luminescent properties for 1–11 are also discussed in detail.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Efficient Synthesis of Substituted 3‐Iodofurans by Electrophilic Cyclization of Propargylic Oxirane Derivatives
Authors: Xie Yong‐Xin , Liu Xue‐Yuan , Wu Lu‐Yong , Han Yao , Zhao Lian‐Biao , Fan Ming‐Jin , Liang Yong‐Min
Published: December 2007

The electrophilic cyclization of various propargylic oxirane compounds and I2 offers an efficient and straightforward route to highly substituted iodofurans under mild reaction conditions. Further functionalization has demonstrated that the iodo derivatives obtained are potential synthetic intermediates for the amplification of molecular complexity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrophoresis of a charge‐regulated toroid normal to a large disk
Authors: Hsu Jyh‐Ping , Kuo Chao‐Chung , Ku Ming‐Hong
Published: December 2007

The electrophoresis of a charge‐regulated toroid (doughnut‐shaped entity) normal to a large disk is investigated under the conditions of low surface potential and weak applied electric field. The system considered is capable of modeling the electrophoretic behavior of various types of biocolloids such as bacterial DNA, plasmid DNA, and anabaenopsis near a perfectly conducting planar wall. The influences of the size of the toroid, the separation distance between the toroid and the disk, the charged conditions on the surfaces of the toroid and the disk, and the thickness of electric double layer on the electrophoretic mobility of the toroid are discussed. The results of numerical simulation reveal that under typical conditions the electrophoretic behavior of the toroid can be different from that of an integrated entity. For instance, if the surface of the toroid carries both acidic and basic functional groups, its mobility may have a local maximum as the thickness of double layer varies. We show that the electrophoretic behavior of the toroid is different, both qualitatively and quantitatively, from that of the corresponding integrated particle (particle without hole).
Signal modelization for improved precision of assessment of minimum and mean telomere lengths
Authors: Ponsot Elodie , Kadi Fawzi
Published: December 2007

Telomere length is an important measure of cell and tissue regenerative capacities. The mean telomere length is classically used as global indicator of a tissue telomere length. In skeletal muscle, which is made of postmitotic myonuclei and satellite cells (muscle stem cells), minimum telomere length is also used to assess the telomere length of satellite cells and newly incorporated myonuclei. At present, the estimation of the method reproducibility during the assessment of mean and minimum telomere length using Southern blot analysis has never been documented. The aim of this report is to describe a signal modelization for improved precision of assessment of minimum and mean telomere lengths and to document the method reproducibility. Telomeres are assessed using a Southern technique where the gel is directly hybridized with the specific probe without the membrane‐transferring step in order to prevent telomeric low signal loss. We found that the improved signal analysis for determination of telomere length is associated with coefficients of variation ranging from 1.37 to 4.29% for the mean telomeric restriction fragment (TRF) length and from 2.04 to 4.95% for the minimum TRF length. Improved method reproducibility would allow saving time and biological material as duplicate and triplicate measurement of the same sample is no longer required.
Nanoliter‐volume protein enrichment, tryptic digestion, and partial separation based on isoelectric points by CE for MALDI mass spectral analysis
Authors: Nesbitt Chandra A. , Jurcic Kristina , Yeung Ken K.‐C.
Published: December 2007

Sequence‐specific proteolysis is an important part of protein identification by MS. Digestion of protein is commonly performed in‐solution, in sample vials with volumes ranging from milli‐ to microliters. When digestion is performed with a sample volume below 1 μL, handling of solution and potential sample loss via adsorption become significant issues. In this report, a proof of concept for the digestion of a small volume protein solution inside a capillary was demonstrated using a discontinuous buffer system previously studied (Nesbitt, C. A., et al. J. Chromatogr. A 2005, 1073, 175–180). Upon voltage application, a pH junction was created by the discontinuous buffer. Using myoglobin as an example, the protein molecules were enriched at the junction with an estimated volume of a few nanoliters. A protease, trypsin, was then introduced to myoglobin at the junction by coenrichment to induce in‐capillary digestion. The voltage application was then suspended to provide the necessary time (2 h) for the proteolysis to proceed. When completed, voltage application was resumed, and the discontinuous buffer reconcentrated the peptides formed from digestion. Importantly, the refocused peptides appeared to roughly elute according to their pIs, resulting in a partial separation. Direct sample deposition from capillary was performed to facilitate mass spectral analysis by MALDI. The partial separation, according to pI, offered the potential benefits of MALDI MS signal enhancement and provided supplementary pI information for peptide identity assignment.
CE coupled with amperometric detection using a boron‐doped diamond microelectrode: Validation of a method for endogenous norepinephrine analysis in tissue
Authors: Quaiserová‐Mocko Veronika , Novotný Martin , Schaefer Luther S. , Fink Gregory D. , Swain Greg M.
Published: December 2007

The level of endogenous norepinephrine (NE) in several tissue types was determined by CE with amperometric detection. We report herein on the method validation by HPLC using both amperometric and coulometric detection (CD). Keys to the method were the use of a diamond microelectrode for detection and off‐line SPE for sample preparation. The run buffer was a 250 mM borate solution adjusted to pH 8.8 with potassium hydroxide. The diamond microelectrode exhibited a low and stable background current, and a low peak‐to‐peak noise ≤0.65 pA at the detection potential of +0.86 V versus Ag/AgCl. For standard solutions, the detector signal (i.e., oxidation current) changed linearly with the NE concentration (r2 = 0.999) between 60 and 1000 nmol/L with an estimated LOD of 51 nmol/L (S/N = 3) and a response variability of 4.5% (RSD, n = 5). An Oasis MCX sorbent was used for SPE and the procedure produced an NE recovery of 95.1 ± 5.6% (n = 6) from tissue homogenates. NE levels in the spleen, small intestine, and heart of a normotensive rat were found to be in the range of 0.77–0.97, 0.22–0.32, and 0.29–0.45 μg/g tissue (n = 3), respectively.
A numerical strategy for the direct 3D simulation of the expansion of bubbles into a molten polymer during a foaming process
Authors: Bruchon J. , Coupez T.
Published: December 2007

In the framework of the foam process modelling, this paper presents a numerical strategy for the direct 3D simulation of the expansion of gas bubbles into a molten polymer. This expansion is due to a gas overpressure. The polymer is assumed to be incompressible and to behave as a pseudo‐plastic fluid. Each bubble is governed by a simple ideal gas law. The velocity and the pressure fields, defined in the liquid by a Stokes system, are subsequently extended to each bubble in a way of not perturbing the interface velocity. Hence, a global velocity–pressure‐mixed system is solved over the whole computational domain, thanks to a discretization based on an unstructured first‐order finite element. Since dealing with an Eulerian approach, an interface capturing method is used to follow the bubble evolution. For each bubble, a pure advection equation is solved by using a space–time discontinuous‐Galerkin method, coupled with an r‐adaptation technique. Finally, the numerical strategy is achieved by considering a global mesh expansion motion, which conserves the amount of liquid into the computational domain during the expansion. The expansion of one bubble is firstly considered, and the simulations are compared with an analytical model. The formation of a cellular structure is then investigated by considering the expansion of 64 bubbles in 2D and the expansion of 400 bubbles in 3D. Copyright © 2007 John Wiley & Sons, Ltd.
Numerical study of coupled fluid–structure interaction for combustion system
Authors: Khatir Z. , Pozarlik A. K. , Cooper R. K. , Watterson J. W. , Kok J. B. W.
Published: December 2007

The computation of fluid–structure interaction (FSI) problems requires solving simultaneously the coupled fluid and structure equations. A partitioned approach using a volume spline solution procedure is applied for the coupling of fluid dynamics and structural dynamics codes. For comparative study, two commercial packages for combustion and structural analysis are used. Results of numerical investigations of FSI between unsteady flow and vibrating liner in a combustion chamber are presented and show good agreement with experimental data. Copyright © 2007 John Wiley & Sons, Ltd.
An MPDATA‐based solver for compressible flows
Authors: Smolarkiewicz Piotr K. , Szmelter Joanna
Published: December 2007

The theory of the high‐resolution multidimensional positive‐definite advection transport algorithm (MPDATA) has been extensively developed since its invention in the early eighties. Many successful applications for geophysical flows followed. This paper introduces the original development of an MPDATA solver operating on a classical set of conservation laws, applicable to high‐speed compressible flows. The solver belongs to a general class of the second‐order nonoscillatory forward‐in‐time schemes. Theoretical considerations are supported with numerical examples. An elementary three‐dimensional spherical wave‐propagation problem illustrates that MPDATA correctly captures signal transfer in acoustic flows. Copyright © 2007 John Wiley & Sons, Ltd.
Nanopatterning of fibronectin and the influence of integrin clustering on endothelial cell spreading and proliferation
Authors: Slater John H. , Frey Wolfgang
Published: December 2007

Investigating stages of maturation of cellular adhesions to the extracellular matrix from the initial binding events to the formation of small focal complexes has been challenging because of the difficulty in fabricating the necessary nanopatterned substrates with controlled biochemical functionality. We present the fabrication and characterization of surfaces presenting fibronectin nanopatterns of controlled size and pitch that provide well‐defined cellular adhesion sites against a nonadhesive polyethylene glycol background. The nanopatterned surfaces allow us to control the number of fibronectin proteins within each adhesion site from 9 to 250, thereby limiting the number of integrins involved in each cell–substrate adhesion. We demonstrate the presence of fibronectin on the nanoislands, while no protein was observed on the passivated background. We show that the cell adheres to the nanopatterns with adhesions that are much smaller and more evenly distributed than on a glass control. The nanopattern influences cellular proliferation only at longer times, but influences spreading at both early and later times, indicating adhesion size and adhesion density play a role in controlling cell adhesion and signaling. However, the overall density of fibronectin on all patterns is far lower than on homogeneously coated control surfaces, showing that the local density of adhesion ligands, not the average density, is the important parameter for cell proliferation and spreading. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 87A: 176–195, 2008
Targeted folic acid‐PEG nanoparticles for noninvasive imaging of folate receptor by MRI
Authors: Chen Ting‐Jung , Cheng Tsan‐Hwang , Hung Yu‐Chin , Lin Kuei‐Tang , Liu Gin‐Chung , Wang Yun‐Ming
Published: December 2007

The surface of superparamagnetic iron oxide nanoparticles (SPIO) with different molecular weight of poly(ethylene glycol) (PEG) and folic acid (FA) were synthesized. The SPIO‐PEG‐FA nanoparticles are well‐dispersed and have good stability in various pH solutions. The lack of hysterestis and remanence at ambient temperatures is characteristic of superparamagnetic materials for SPIO‐PEG‐FA. The uptake by macrophage for SPIO‐PEG‐FA is lower than that of Feridex I.V. even at higher concentration. Internalization of SPIO‐PEG‐FA in targeted cells (KB cells) was observed by flow‐cytometric analysis and in vitro MR imaging. The intensity change of positive KB cell tumor (−20 to 25%) is significantly lower than that of negative HT‐1080 cell tumor from precontrast to postcontrast images of the tumor by in vivo MR imaging. These preliminary results demonstrated that SPIO‐PEG‐FA have the ability to target folate receptor. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 87A: 165–175, 2008
A novel porous collagen scaffold around an implantable biosensor for improving biocompatibility. I. In vitro/in vivo stability of the scaffold and in vitro sensitivity of the glucose sensor with scaffold
Authors: Ju Young Min , Yu Bazhang , Koob Thomas J. , Moussy Yvonne , Moussy Francis
Published: December 2007

A new 3D porous and biostable collagen scaffold has been developed to improve the biocompatibility of implantable glucose sensors by minimizing tissue reactions while stimulating angiogenesis around the sensors. The novel collagen scaffold was crosslinked using nordihydroguaiaretic acid (NDGA) to enhance biostability. NDGA‐treated collagen scaffolds were stable without physical deformation in the subcutaneous tissue of rats for 4 weeks. In contrast, glutaraldehyde (GA)‐treated collagen scaffolds were extremely damaged following implantation. Both types of scaffolds (NDGA‐ and GA‐crosslinked) were stable in vitro in the presence of collagenase with 70% retention of original weight after 4 weeks of incubation. The response current (i.e. sensitivity) of sensors with porous scaffolds was not significantly changed when compared with control sensors (no scaffold), while the response time (T95%) was slightly delayed after a glucose concentration increase from 5 to 15 mM. Above this range, the sensors coated with scaffolds had only a slightly lower sensitivity than the control sensors. These results indicate that we have developed a stable NDGA‐crosslinked collagen scaffold for biosensors, and that the scaffold does not impair the function of our sensor. We plan to use this scaffold to enhance the function and lifetime of the implantable biosensors by providing a controlled local environment around the sensors with the help of various drugs and growth factors (dexamethasone, VEGF, PDGF). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Synthetic zeolites as a new tool for drug delivery
Authors: Rimoli Maria G. , Rabaioli Maria R. , Melisi Daniela , Curcio Annalisa , Mondello Sandro , Mirabelli Rosella , Abignente Enrico
Published: December 2007

Synthetic zeolites were studied in order to investigate their ability to encapsulate and to release drugs. In particular, a zeolite X and a zeolitic product obtained from a cocrystallization of zeolite X and zeolite A were examined. These materials were characterized by chemical analyses (ICP‐AES), X‐ray diffraction, nitrogen adsorption isotherm, scanning electron microscopy, laser diffraction, and infrared spectroscopy. Since ketoprofen was chosen as a model drug for the formulation of controlled‐release dosage forms, it was encapsulated into these two types of synthetic zeolites by a soaking procedure. Drug‐loaded matrices were then characterized for entrapped drug amount and thermogravimetric behavior. In both types of activated zeolites, the total amount of ketoprofen (800 mg) was encapsulated in 2 g of matrix. By using HPLC measurements, ketoprofen release studies were done at different pH conditions so as to mimick gastrointestinal fluids. The absence of release in acid conditions and a double phased release, at two different pH values (5 and 6.8), suggest that after activation these materials offer good potential for a modified release delivery system of ketoprofen. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Micromechanical properties of human trabecular bone: A hierarchical investigation using nanoindentation
Authors: Norman Jonathan , Shapter Joe G. , Short Ken , Smith Lachlan J. , Fazzalari Nicola L.
Published: December 2007

The ability to assess the risk of fracture, evaluate new therapies, predict implant success and assess the influence of bone remodeling disorders requires specific measurement of local bone micromechanical properties. Nanoindentation is an established tool for assessing the micromechanical properties of hard biological tissues. In this study, elastic modulus and hardness were quantified using nanoindentation for human trabecular bone from the intertrochanteric region of the proximal femur. These properties were demonstrated to be heterogeneous and highly correlated at the intraspicule, interspicule, and interspecimen levels. The results of this study have important implications for current understanding of structure–function relationships throughout the trabecular bone structural hierarchy. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Mass spectrometry analysis of gliadins in celiac disease
Authors: Ferranti Pasquale , Mamone Gianfranco , Picariello Gianluca , Addeo Francesco
Published: December 2007

In recent years, scientific research on wheat gluten proteins has followed three main directions aimed at (1) finding relationships between individual genetic alleles coding for gliadins, high or low molecular weight glutenin subunits, and the viscoelastic dough properties of flour‐derived products such as pasta and bread; (2) identifying prolamins and derived peptides involved in celiac disease, a pathological condition in which the small intestine of genetically predisposed individuals is reversibly damaged; and (3) developing and validating sensitive and specific methods for detecting trace amounts of gluten proteins in gluten‐free foods for celiac disease patients. In this review, the main aspects of current and perspective applications of mass spectrometry and proteomic technologies to the structural characterization of gliadins are presented, with focus on issues related to detection, identification, and quantification of intact gliadins, as well as gliadin‐derived peptides relevant to the biochemical, immunological, and toxicological aspects of celiac disease. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of synthetic antioxidants on stored maize grain mycoflora in situ
Authors: Nesci Andrea , Ferrari Luciana , Etcheverry Miriam
Published: December 2007

BACKGROUND: The influence of a mixture of butylated hydroxyanisole (BHA) and propyl paraben (PP) (each at a concentration of 20 mmol L−1) on mycoflora and Aspergillus section Flavi populations in stored maize grain was evaluated. A survey of 120 maize samples was carried out from June to November 2005.

RESULTS: The predominant populations in non‐treated (control) maize between the first and sixth sampling periods were Aspergillus section Flavi and Penicillium. Aspergillus flavus was the fungus most frequently isolated from both control and antioxidant‐treated kernels. All samples of control and antioxidant‐treated maize kernels were negative for aflatoxins during the 6 month storage period. Aspergillus flavus and A. parasiticus strains showed a variable ability to produce aflatoxins. The contribution of the strains to silo community toxigenicity was higher for A. flavus L (large) and S (small) strains in the fourth sampling period.

CONCLUSION: Antioxidant treatment negatively affected natural maize mycoflora and Aspergillus section Flavi populations between the second and sixth months of storage. Copyright © 2007 Society of Chemical Industry
Retroperitoneoscopic adrenalectomy: Lateral versus dorsal approach
Authors: Agha Ayman , von Breitenbuch Philipp , Gahli Nabil , Piso Pompiliu , Schlitt Hans J.
Published: December 2007

Background

For tumours of the adrenal gland different surgical retroperitoneal approaches have been established, including the lateral and the dorsal approach. It is still unclear if the lateral or the dorsal approach should be preferred.

Patients and Methods

A retrospective comparison between 21 patients who underwent retroperitoneoscopic adrenalectomy in lateral position (LRA) and 24 patients who underwent a retroperitoneoscopic adrenalectomy in dorsal position (DRA).

Results

There were no significant differences with regard to the age, sex, tumour localisation, and the size of the tumour. The body‐mass‐index as well as the operation time was significantly higher of patients who underwent surgery in lateral position. Complications were comparable in both groups.

Conclusion

The dorsal and the lateral retroperitoneal approach are ideal approaches for patients having had an intraabdominal surgery before. Due to the missing intraabdominal pressure the lateral approach is advantageous for patients with high body‐mass‐index (>35) and is indicated for patients with a tumour >6 cm due to the small retroperitoneal space. J. Surg. Oncol. 2008;97:90–93. © 2007 Wiley‐Liss, Inc.
LD pumped Yb:YAG regenerative amplifier for high average power short-pulse generation
Authors: Sueda K , Kawato S , Kobayashi T
Published: December 2007

A diode pumped Yb:YAG regenerative amplifier has been developed for short pulse generation. High gain and efficient cooling characteristics were achieved in the laser gain module using a thin square-rod laser structure. Average output power of 10 W was realized at a pulse repetition rate of 100 kHz with 6.2 ps pulse width.
A fundamental mode miniature acousto-optically Q-switched Nd:YVO4 laser with short pulse width at high repetition rates
Authors: Wang Y , Huang L , Zhang H , Yan X , Liu Q , Gong M
Published: December 2007

A miniature, high repetition rate, short pulse width acousto-optically Q-switched Nd:YVO4 laser in fundamental mode is presented. Miniature solid-state lasers have the characteristics of short cavity length and small mode area in the cross section, which, on the one hand, benefits high gain, high repetition rate and short pulse width, on the other hand, makes it difficult to achieve high mode-matching efficiency and causes higher order modes oscillation. The thermal lens in Nd:YVO4 is treated as thick lens under high pump intensity. The mode-matching efficiency is analyzed with the thermal lens being equivalent to a thin lens array. In high repetition rate Q-switching operation, 3.6 ns pulses at 500 kHz repetition rate with 20 mm cavity length and 4.1 kW peak power are achieved, without active control of pump beam quality. The laser beam quality factors were measured to be Mx
2 = 2.03, My
2 = 2.46. By improving the pump beam quality and utilizing the optimal pump beam waist radius and location, the mode-matching efficiency and laser beam quality are improved. 4.0 ns pulses at 500 kHz with 2.5 kW peak power are produced. The beam quality factors were measured to be Mx
2 = 1.31, My
2 = 1.43.
Antitumor activity of 3,5,4′‐trimethoxystilbene in COLO 205 cells and xenografts in SCID mice
Authors: Pan Min‐Hsiung , Gao Jia‐Hui , Lai Ching‐Shu , Wang Ying‐Jan , Chen Wen‐Ming , Lo Chih‐Yu , Wang Mingfu , Dushenkov Slavik , Ho Chi‐Tang
Published: December 2007

Resveratrol (R‐3), a trihydroxy trans‐stilbene from grape, inhibits multistage carcinogenesis in animal models. Here we report that 3,5,4′‐trimethoxystilbene (MR‐3), the permethylated derivative of R‐3 was more potent against the growth of human cancer cells (HT‐29, PC‐3, COLO 205) with estimated IC50 values of 81.31,42.71, and 6.25 µM, respectively. We further observed that MR‐3 induced apoptosis in COLO 205 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of MR‐3‐induced apoptosis, preceding cytochrome‐c release, caspase activation, and DNA fragmentation. Significant therapeutic effects were demonstrated in vivo by treating severe combined immune deficiency (SCID) mice bearing COLO 205 tumor xenografts with MR‐3 (50 mg/kg ip). Assays on DNA fragmentation and caspase activation were performed and demonstrated that apoptosis occurred in tumor tissues treated with MR‐3. The appearance of apoptotic cells, as shown by Hematoxylin and Eosin (H&E) staining, and an increase in p21 and decrease in proliferating cell nuclear antigen (PCNA) protein by immuno‐histochemistry were observed in tumor tissues under MR‐3 treatment. Our study identifies the novel mechanisms of the antitumor effects of MR‐3 and indicates that these results may have significant applications for cancer chemotherapy. © 2007 Wiley‐Liss, Inc.
Phenolic compounds: Evidence for inhibitory effects against obesity and their underlying molecular signaling mechanisms
Authors: Hsu Chin‐Lin , Yen Gow‐Chin
Published: December 2007

Phenolic compounds are widely present in the plant kingdom. Many epidemiological studies have indicated that consumption of some plant‐derived foodstuffs with high phenolic content is associated with the prevention of some diseases and that these compounds may have similar properties to antioxidants, antimutagenic agents, antithrombotic agents, anti‐inflammatory agents, anti‐HIV‐1, and anticancer agents. However, obesity is an important topic in the world of public health and preventive medicine. Relationships between body mass index, waist circumference, or waist‐to‐hip ratio and the risk of development of some diseases (such as heart disease, dyslipidemia, hypertension, non‐alcoholic fatty liver disease, diabetes, kidney failure, cancer, stroke, osteoarthritis, and sleep apnea) have been observed. Evidence that phenolic compounds have beneficial effects in fighting obesity is increasingly being reported in the scientific literature. These in vitro and in vivo effects of phenolic compounds on the induction of pre‐adipocytic and adipocytic apoptosis and inhibition of adipocytic lipid accumulation are considered in detail here. This review presents evidence of their inhibitory effects on obesity and their underlying molecular signaling mechanisms.
1H NMR metabolite profiling of feces as a tool to assess the impact of nutrition on the human microbiome
Authors: Jacobs Doris M. , Deltimple Nancy , van Velzen Ewoud , van Dorsten Ferdi A. , Bingham Max , Vaughan Elaine E. , van Duynhoven John
Published: December 2007

Current research increasingly recognizes the human gut microbiome as a metabolically versatile biological ‘digester’ that plays an essential role in regulating the host metabolome. Gut microbiota recover energy and biologically active molecules from food that would otherwise be washed out of the intestinal tract without benefit. In this study, a protocol for NMR‐based metabolite profiling has been developed to access the activity of the microbiome. The physicochemical properties of fecal metabolites have been found to strongly affect the reproducibility and coverage of the profiles obtained. Metabolite profiles generated by water and methanol extraction of lyophilized feces are reproducible and comprise a variety of different compounds including, among others, short‐chain fatty acids (e.g. acetate, propionate, butyrate, isobutyrate, isovalerate, malate), organic acids (e.g. succinate, pyruvate, fumarate, lactate), amino acids, uracil, trimethylamine, ethanol, glycerol, glucose, phenolic acids, cholate, and lipid components. The NMR profiling approach was validated on fecal samples from a double‐blinded, placebo‐controlled, randomized cross‐over study, in which healthy human subjects consumed a placebo and either a grape juice extract or a mix of grape juice and wine extract over a period of 4 weeks, each. The considerable inter‐ and intra‐individual variability observed originates in the first instance from variable metabolite concentrations rather than from variable metabolite compositions, suggesting that different colonic flora share general biochemical characteristics metabolizing different substrates to specific metabolic patterns. Whereas the grape juice extract did not induce changes in the metabolite profiles as compared with the placebo, the mixture of grape juice and wine extract induced a reduction in isobutyrate, which may indicate that polyphenols are able to modulate the microbial ecology of the gut. Copyright © 2007 John Wiley & Sons, Ltd.