bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative analysis of messenger RNA expression of matrix metalloproteinases (MMP‐2 and MMP‐9), tissue inhibitor‐2 of matrix metalloproteinases (TIMP‐2), and steroidogenic enzymes in bovine placentomes during gestation and postpartum
Authors: Takagi M. , Yamamoto D. , Ohtani M. , Miyamoto A.
Published: December 2006

The relationship between the mRNA expression of proteolytic and steroidogenic enzymes in bovine placentomes was examined. Caruncle and cotyledon tissues were collected every 6 hr after spontaneous parturition until the fetal membranes were released. Based on the time of fetal membrane release after parturition, the specimens were classified as follows: (1) the early group, in which the fetal membranes were released within 6 hr after parturition; and (2) the late group, in which the fetal membranes were released 6–12 hr after parturition. The placentomes from a slaughterhouse were additionally collected as samples for the examination of enzymes during the gestation period. The mRNA expression of steroidogenic enzymes in the cotyledon was observed to be higher than that in caruncle tissues; however, the mRNA expression patterns of P450scc and StAR tended to be similar in both placental tissues. On the other hand, although the expression levels of TIMP‐2 mRNA in both caruncle and cotyledon tissues were similar, during gestation and postpartum the expression levels of MMP‐2 and MMP‐9 mRNA were approximately 10 times higher in caruncle than in cotyledon tissue. Marked contrasting changes in mRNA expression patterns between pre‐ and postpartum periods were observed for MMP‐2 and MMP‐9 in caruncle tissues and for MMP‐9 and TIMP‐2 in cotyledon tissues. The present study provides the first evidence that MMP‐2, MMP‐9, and TIMP‐2 mRNAs are expressed in bovine placentomes during the gestational and postpartum periods and suggests that these enzymes, in conjunction with steriodogenic enzymes, mediate fetal membrane detachment after parturition. Mol. Reprod. Dev. 74: 801–807, 2007. © 2006 Wiley‐Liss, Inc.
Expression of LH receptor mRNA splice variants in bovine granulosa cells: changes with follicle size and regulation by FSH in vitro
Authors: Nogueira M.F.G. , Buratini J. , Price C.A. , Castilho A.C.S. , Pinto M.G.L. , Barros C.M.
Published: December 2006

In cattle, most evidence suggests that granulosa cells express LH receptors (LHR) after (or as) the follicle becomes dominant, however there is some suggestion that granulosa cells from smaller pre‐dominant follicles may express several LHR mRNA splice variants. The objective of this study was to measure LHR expression in bovine follicles of defined size and steroidogenic ability, and in granulosa cells from small follicles (<6 mm diameter) undergoing differentiation in vitro. Semiquantitative RT‐PCR demonstrated that LHR mRNA was undetectable in granulosa cells of follicles <7 mm diameter (nondominant follicles), and increased with follicle diameter in follicles >7 mm diameter. Splice variants with deletions of exon 10 and part of exon 11 were detected as previously described, and we detected a novel splice variant with a deletion of exon 3. Cultured granulosa cells contained LHR mRNA, but with significantly greater amounts of variants with deletions of exon 10 and/or exon 11 compared with cells from dominant follicles. FSH increased the abundance of some but not all LHR mRNA splice variants in cultured granulosa cells. The addition of LH to cultured cells did not increase progesterone secretion, despite the presence of LHR mRNA. Collectively, these data suggest that granulosa cells do not acquire functional LHR until follicle dominance occurs. Mol. Reprod. Dev. 74: 680–686, 2007. © 2006 Wiley‐Liss, Inc.
Follicular growth in vitro: detection of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) during in vitro culture of ovine cortical slices
Authors: Mery Lionel , Lefevre Annick , Benchaib Mehdi , Demirci Banu , Salle Bruno , Guerin Jean‐Francois , Lornage Jacqueline
Published: December 2006

Primordial follicles from different mammal species can survive and enter the growth phase in vitro but do not develop beyond the primary stage. The hypothesis was that, in sheep, in vitro follicular growth is arrested because of a lack of secretion of GDF9 and/or BMP15. Cortical slices of 0.3–0.5 mm thickness issued from 5‐ to 6‐month‐old lambs were cultured for 15 days. The pieces were fixed on days 0, 2, 4, 7, 10, and 15 of culture. Follicle morphology, RT‐PCR exploration of GDF9 and BMP15 mRNA, immunohistochemical location of their proteins and their receptor BMPRIB and BMPRII were assessed at different time of culture. The mean percentage of primordial follicles decreased from 58.6% (day 0) to 13.4% (day 15) (P < 0.01), whereas that of primary follicles increased from 3.2% (day 0) to 31.5% on day 4 (P < 0.01), then remained stable until day 15 (35.6%). The percentage of atretic follicles increased from 14.7% (day 0) to 27.1% (day 15) (P < 0.05). A few secondary follicles were observed on days 4 and 10, representing 1.0%, and 2.1% of the total number of follicles. GDF9 and BMP15 mRNAs were detected from harvesting (day 0) up to day 15 following culture. At the same time, positive immunoreactions for GDF9, BMP15 and for BMPRIB and BMPRII were also found in oocyte cytoplasm. In conclusion, expression of GDF9, BMP15 and their receptors BMPRIB and BMPRII are detected during in vitro culture of ovine cortical slices. Mol. Reprod. Dev. 74: 767–774, 2007. © 2006 Wiley‐Liss, Inc.
Membrane progesterone receptor gamma: Tissue distribution and expression in ciliated cells in the fallopian tube
Authors: Nutu Magdalena , Weijdegård Birgitta , Thomas Peter , Bergh Christina , Thurin‐Kjellberg Ann , Pang Yefei , Billig Håkan , Larsson D.G. Joakim
Published: December 2006

Non‐genomic, rapid actions of steroids have long been known, suggesting the possible presence of non‐classical steroid receptors. A membrane receptor for progestins (mPR) was recently described in the spotted seatrout, and transcripts of three related receptors (α, β, and γ) were subsequently identified in other species including human and mouse. To begin exploring the roles of mPRγ in mammals, we have generated an antibody against this receptor. The specificity of the antibody was demonstrated by both overexpression and RNA interference experiments. Using the antibody, we show that mPRγ is expressed in female mouse reproductive tissues such as ovary and fallopian tube, and also in the lung and liver of both sexes. Immunohistochemical studies revealed that mPRγ is associated with the apical membrane of ciliated cells facing the lumen of the fallopian tube. The presence of mPRγ in ciliated cells of the fallopian tube was also demonstrated in human samples. Rapid effects of progesterone on ciliary beat frequency in the fallopian tube have recently been reported. Together, this suggests a common role for mPRγ in the regulation of ciliary activity in the fallopian tube and thus gamete transport in mammals. The presence of mPRγ in lung and liver of mice suggests that the receptor mediates the actions of progesterone outside the reproductive tract as well. Mol. Reprod. Dev. 74: 843–850, 2007. © 2006 Wiley‐Liss, Inc.
Energy dissipation and post‐bifurcation behaviour of granular soils
Authors: Gutierrez M. , Vardoulakis I.
Published: December 2006

Extensive experimental data indicate that plastic flow in granular materials is non‐coaxial (i.e. the principal directions of the plastic strain increment tensor and the stress tensor do not coincide) for loadings involving principal stress rotation. The degree of non‐coaxiality depends on the magnitude of principal stress rotation, hence plastic flow is also incrementally non‐linear. The paper presents an analysis and discussion of the effects of non‐coaxial plastic flow on the post‐bifurcation response of dilatant granular materials. Significant differences are observed between the energy dissipation and stress–dilatancy response of soils before and after shear‐band formation. These differences are attributed to the non‐coaxiality of plastic flow during post‐bifurcation shearing. In turn, the non‐coaxiality is attributed to principal stress rotation within the shear band, which is consistent with the assumption that the materials inside the shear undergo simple shear deformation. Experimental data are presented to support the analytical results. Copyright © 2006 John Wiley & Sons, Ltd.
Analytical formulas for the geometric and inertia quantities of the largest removable blocks around tunnels
Authors: Tonon Fulvio
Published: December 2006

This paper presents algorithms for determining the vertices of the maximum removable block (MB) created by a joint pyramid (JP) around a tunnel when discontinuities are fully persistent. It is shown that an MB cannot be formed by more than 4 discontinuities and this drastically limits the proliferation of rock blocks that need to be analysed. The non‐convex block obtained after the MB is tunnelled through (real maximum block, RMB) is partitioned into a set of tetrahedra, and procedures are given for determining the vertices of these tetrahedra. Geometric and inertia quantities needed for stability analysis and support/reinforcement design are determined as functions of the calculated vertices' co‐ordinates. These quantities are: RMB's volume, face areas, perimeter of the excavated surface, centroid and inertia tensor. The algorithms for their calculation are at least two times faster than other algorithms previously proposed in other applications. It is shown that the formulations presented by Goodman and Shi for translational analysis and by Tonon for rotatability analysis can be used to analyse the RMBs using the geometric quantities presented. A numerical example is presented among those used to verify these analytical procedures and their implementation. Copyright © 2006 John Wiley & Sons, Ltd.
A two‐scale approach for fluid flow in fractured porous media
Authors: Réthoré Julien , Borst René de , Abellan Marie‐Angèle
Published: December 2006

A two‐scale numerical model is developed for fluid flow in fractured, deforming porous media. At the microscale the flow in the cavity of a fracture is modelled as a viscous fluid. From the micromechanics of the flow in the cavity, coupling equations are derived for the momentum and the mass couplings to the equations for a fluid‐saturated porous medium, which are assumed to hold on the macroscopic scale. The finite element equations are derived for this two‐scale approach and integrated over time. By exploiting the partition‐of‐unity property of the finite element shape functions, the position and direction of the fractures is independent from the underlying discretization. The resulting discrete equations are non‐linear due to the non‐linearity of the coupling terms. A consistent linearization is given for use within a Newton–Raphson iterative procedure. Finally, examples are given to show the versatility and the efficiency of the approach, and show that faults in a deforming porous medium can have a significant effect on the local as well as on the overall flow and deformation patterns. Copyright © 2006 John Wiley & Sons, Ltd.
In vitro bone engineering based on polycaprolactone and polycaprolactone–tricalcium phosphate composites
Authors: Zhou Yefang , Hutmacher Dietmar W , Varawan Sae‐Lim , Lim Tit Meng
Published: December 2006

The filling of bone defects in load‐bearing areas requires scaffolds possessing physical properties that are in the range of those of the host bone. In this report, composite scaffolds comprising medical‐grade polycaprolactone and tricalcium phosphate (mPCL‐TCP) (80:20), which have been designed for load‐bearing applications, are characterized and compared with mPCL scaffolds, using in vitro studies. The composite scaffolds exhibited improved hydrophilicity, compressive modulus and strength. Human alveolar osteoblasts (AOs) grown on the composite achieved higher seeding efficiencies and more uniform distribution when compared with mPCL preparations alone. AOs demonstrated better proliferation, denser multilayered cell‐sheets and showed earlier expression of bone matrix‐related proteins on the composite than on mPCL during 28 days in vitro culture. The calcium content in the media decreased in both scaffold/cell constructs. Alkaline phosphatase activity increased significantly in mPCL matrices after osteogenic induction but no distinct change was observed in the composite. Osteocalcin expression was down‐regulated by induction in the composite but was up‐regulated in mPCL at both RNA and protein level. Immuno‐reactive signals for osteopontin and collagen type I, in combination with mineral nodules were found to be stronger in mPCL‐TCP scaffolds. We conclude that the composite scaffolds were more hydrophilic and had improved mechanical properties over mPCL scaffolds. Moreover, the primary AOs achieved better cell proliferation, and showed earlier and different matrix protein expression patterns on the composite scaffolds than on the mPCL scaffolds. Copyright © 2006 Society of Chemical Industry
A novel approach for the preparation of acrylate–siloxane particles with core–shell structure
Authors: Cao Shunsheng , Liu Bailing , Deng Xiaobo , Luo Rong , Chen Hualin
Published: December 2006

It is well known that polysiloxane has excellent properties, such as water repellency, low surface energy, biocompatibility, etc. Its application, however, is subject to some limit due to poor cohesiveness and poor film‐forming properties. Recently, many efforts have been made to overcome such flaws. It is found that polyacrylate is in common consideration for its good cohesiveness and excellent film‐forming properties. This is why there have been so many descriptions of core–shell PSi–PA (PSi, polysiloxane as core; PA, polyacrylate as shell) particles in the literature. Unfortunately, their hydrophobicity is considerably different; therefore, the reversed morphological PA–PSi particles are scarcely available. In the work reported here, core‐shell PA–PSi structures with poly(butyl methacrylate) (PA) as the core and PSi as the shell were successfully prepared by dispersion polymerization. Characterization of the PA–PSi particles was carried out using transmission electron microscopy, particle size analysis, X‐ray photoelectron spectroscopy and static contact angle measurements. Copyright © 2006 Society of Chemical Industry
Fluorescent polyelectrolytes as protein sensors
Authors: Ambade Ashootosh Vasant , Sandanaraj Britto Selvaraj , Klaikherd Akamol , Thayumanavan S
Published: December 2006

This review discusses recent advances in protein sensing using fluorescent polyelectrolytes that are mainly water‐soluble conjugated polymers. A quencher‐labeled substrate or fluorophore‐labeled substrate is generally used as a probe. In the presence of an enzyme, the linker between substrate and quencher/fluorophore is cleaved and fluorescence of the polymer is either ‘turned on’ or ‘turned off’. Fluorescence behavior of these conjugated polymers is highly sensitive to conformation of the polymeric chains. Since upon binding with proteins the conformation is perturbed and fluorescence is affected, these polyelectrolytes have been used to study conformational changes in proteins. The conformation‐dependent fluorescence is also a limitation for these sensors in some cases and non‐conjugated polyelectrolytes have been shown to provide an alternative. Copyright © 2006 Society of Chemical Industry
ABA triblock copolymers with a ring‐opening metathesis polymerization/macromolecular chain‐transfer agent approach
Authors: Switek Karen A. , Chang Kwanho , Bates Frank S. , Hillmyer Marc A.
Published: December 2006

Block copolymers containing polystyrene and polycyclooctene were synthesized with a ring‐opening metathesis polymerization/chain‐transfer approach. Polystyrene, containing appropriately placed olefins, was prepared by anionic polymerization and served as a macromolecular chain‐transfer agent for the ring‐opening metathesis polymerization of cyclooctene. These unsaturated polymers were subsequently converted to the corresponding saturated triblock copolymers with a simple heterogeneous catalytic hydrogenation step. The molecular and morphological characterization of the block copolymers was consistent with the absence of significant branching in the central polycyclooctene and polyethylene blocks [high melting temperatures (114–127 °C) and levels of crystallinity (17–42%)]. A dramatic improvement in both the long‐range order and the mechanical properties of a microphase‐separated, symmetric polystyrene–polycyclooctene–polystyrene block copolymer sample was observed after fractionation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 361–373, 2007
Influence of a reversible addition–fragmentation chain transfer agent in the dispersion polymerization of styrene
Authors: Saikia Prakash J. , Lee Jung Min , Lee Byung H. , Choe Soonja
Published: December 2006

Dispersion polymerization was applied to the controlled/living free‐radical polymerization of styrene with a reversible addition–fragmentation chain transfer (RAFT) polymerization agent in the presence of poly(N‐vinylpyrrolidone) and 2,2′‐azobisisobutyronitrile in an ethanol medium. The effects of the polymerization temperature and the postaddition of RAFT on the polymerization kinetics, molecular weight, polydispersity index (PDI), particle size, and particle size distribution were investigated. The polymerization was strongly dependent on both the temperature and postaddition of RAFT, and typical living behavior was observed when a low PDI was obtained with a linearly increased molecular weight. The rate of polymerization, molecular weight, and PDI, as well as the final particle size, decreased with an increased amount of the RAFT agent in comparison with those of traditional dispersion polymerization. Thus, the results suggest that the RAFT agent plays an important role in the dispersion polymerization of styrene, not only reducing the PDI from 3.34 to 1.28 but also producing monodisperse polystyrene microspheres. This appears to be the first instance in which a living character has been demonstrated in a RAFT‐mediated dispersion polymerization of styrene while the colloidal stability is maintained in comparison with conventional dispersion polymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 348–360, 2007
Poly(L‐lysine) and clay nanocomposite with desired matrix secondary structure: Effects of polypeptide molecular weight
Authors: Hule Rohan A. , Pochan Darrin J.
Published: December 2006

Nanocomposites (NC) were formed using cationic poly(L‐lysine) (PLL), a semicrystalline polypeptide, that was reinforced by sodium montmorillonite (MMT) clay via solution intercalation technique. By varying solution conditions such as pH, temperature, and polypeptide concentration in the presence of clay platelets, the secondary structure of PLL was controllably altered into α‐helical, β‐sheet, and random coil. The high molecular weight polypeptide shows a strong propensity to fold into the β‐sheet structure when cast as films, irrespective of the initial secondary structure in solution. Nanocomposite local morphology confirms intercalated MMT platelets with PLL over a wide range of compositions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 239–252, 2007.
Exploring zipping and assembly as a protein folding principle
Authors: Voelz Vincent A. , Dill Ken A.
Published: December 2006

It has been proposed that proteins fold by a process called “Zipping and Assembly” (Z&A). Zipping refers to the growth of local substructures within the chain, and assembly refers to the coming together of already‐formed pieces. Our interest here is in whether Z&A is a general method that can fold most of sequence space, to global minima, efficiently. Using the HP model, we can address this question by enumerating full conformation and sequence spaces. We find that Z&A reaches the global energy minimum native states, even though it searches only a very small fraction of conformational space, for most sequences in the full sequence space. We find that Z&A, a mechanism‐based search, is more efficient in our tests than the replica exchange search method. Folding efficiency is increased for chains having: (a) small loop‐closure steps, consistent with observations by Plaxco et al. 1998;277;985–994 that folding rates correlate with contact order, (b) neither too few nor too many nucleation sites per chain, and (c) assembly steps that do not occur too early in the folding process. We find that the efficiency increases with chain length, although our range of chain lengths is limited. We believe these insights may be useful for developing faster protein conformational search algorithms. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Effects of acid exposure on the conformation, stability, and aggregation of monoclonal antibodies
Authors: Ejima Daisuke , Tsumoto Kouhei , Fukada Harumi , Yumioka Ryosuke , Nagase Kazuo , Arakawa Tsutomu , Philo John S.
Published: December 2006

Exposure of antibodies to low pH is often unavoidable for purification and viral clearance. The conformation and stability of two humanized monoclonal antibodies (hIgG4‐A and ‐B) directed against different antigens and a mouse monoclonal antibody (mIgG1) in 0.1M citrate at acidic pH were studied using circular dichroism (CD), differential scanning calorimetry (DSC), and sedimentation velocity. Near‐ and far‐UV CD spectra showed that exposure of these antibodies to pH 2.7–3.9 induced only limited conformational changes, although the changes were greater at the lower pH. However, the acid conformation is far from unfolded or so‐called molten globule structure. Incubation of hIgG4‐A at pH 2.7 and 3.5 at 4°C over the course of 24 h caused little change in the near‐UV CD spectra, indicating that the acid conformation is stable. Sedimentation velocity showed that the hIgG4‐A is largely monomeric at pH 2.7 and 3.5 as well as at pH 6.0. No time‐dependent changes in sedimentation profile occurred upon incubation at these low pHs, consistent with the conformational stability observed by CD. The sedimentation coefficient of the monomer at pH 2.7 or 3.5 again suggested that no gross conformational changes occur at these pHs. DSC analysis of the antibodies showed thermal unfolding at pH 2.7–3.9 as well as at pH 6.0, but with decreased melting temperatures at the lower pH. These results are consistent with the view that the antibodies undergo limited conformational change, and that incubation at 4°C at low pH results in no time‐dependent conformational changes. Titration of hIgG4‐A from pH 3.5 to 6.0 resulted in recovery of native monomeric proteins whose CD and DSC profiles resembled those of the original sample. However, titration from pH 2.7 resulted in lower recovery of monomeric antibody, indicating that the greater conformational changes observed at this pH cannot be fully reversed to the native structure by a simple pH titration. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Protein dynamics from X‐ray crystallography: Anisotropic, global motion in diffuse scattering patterns
Authors: Meinhold Lars , Smith Jeremy C.
Published: December 2006

Understanding X‐ray crystallographic diffuse scattering is likely to improve our comprehension of equilibrium collective protein dynamics. Here, using molecular dynamics (MD) simulation, a detailed analysis is performed of the origins of diffuse scattering in crystalline Staphylococcal nuclease, for which the complete diffuse scattering pattern has been determined experimentally. The hydrogen‐atom contribution and the scattering range over which the scattering can be considered to be a sum of solvent and protein scattering are determined. Two models of correlated protein motion are investigated by calculating the model‐derived diffuse scattering and comparing with the scattering calculated directly from MD trajectories. In one model, previously used in diffuse scattering interpretation, the atomic displacement correlations decay isotropically with increasing separation. Model correlation lengths are obtained by refining the model scattering against the simulation‐derived scattering pattern, and are found to be significantly different from those correlation lengths derived directly from the MD trajectories. Furthermore, the convergence between the model‐derived and MD‐derived scattering is poor. The second model, in which the displacement correlations are calculated from the principal components of the MD trajectories, is capable of fully reproducing the MD‐derived diffuse scattering if the ≈50% lowest‐frequency modes are included. However, a small number (≈10) of lowest‐frequency and largest‐amplitude modes dominates the diffuse scattering and thus the correlated protein motions. A detailed analysis of the principal components is performed. In particular, the effective free energy profile associated with each principle mode is analyzed and the eigenfrequency and damping coefficient computed using a model of Brownian dynamics. Those collective modes with effective frequencies below ≈0.5 THz, including those that determine the diffuse scattering, are overdamped. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Comparative high pressure Raman study of individual and bundled single‐wall carbon nanotubes
Authors: Christofilos D. , Arvanitidis J. , Andrikopoulos K. S. , Kourouklis G. A. , Ves S. , Takenobu T. , Iwasa Y.
Published: December 2006

In this work, individual single‐wall carbon nanotubes (i‐SWCNTs) and their parent bundled material (b‐SWCNTs) are investigated by means of high pressure Raman spectroscopy. Pressure application results in the broadening and intensity redistribution of the radial breathing modes (RBMs) in both materials. These changes are more pronounced in the case of bundled SWCNTs as it is also evident by the abrupt increase of the G+ bandwidth at ∼5.5 GPa, in contrast to the smoother pressure response of the individual tubes. Our experimental findings reflect the size dependent cross‐section deformation of carbon nanotubes which evolves differently in the two materials investigated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second‐order Raman study of double‐wall carbon nanotubes under high pressure
Authors: Papagelis K. , Arvanitidis J. , Christofilos D. , Andrikopoulos K. S. , Takenobu T. , Iwasa Y. , Kataura H. , Ves S. , Kourouklis G. A.
Published: December 2006

The high pressure response of the second‐order Raman G ′ band in a high quality bundled double wall carbon nanotube (DWCNT) material has been investigated by means of Raman spectroscopy up to 10 GPa. At ambient conditions two peaks appear, assigned to the inner and outer tubes of DWCNTs. Upon pressure application, the Raman signal of the outer tubes attenuates significantly. This intensity loss is related to the pressure‐induced structural modifications of the outer shells. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tunable laser in 1575 nm–1225 nm range achieved by pressure tuning combined with grating tuning
Authors: Dybala F. , Bercha A. , Adamiec P. , Bohdan R. , Trzeciakowski W.
Published: December 2006

We demonstrated the pressure and external cavity tuning of commercial telecommunication laser, emitting in the 1500 nm band under normal conditions. The laser had AR coatings on the output mirror and highly reflective coating on its back facet. We measured the tuning ranges of the laser operating CW under four different pressures. The experimental setup was in the Littrow configuration. At each pressure the external cavity arrangement enabled the fine tuning in the range of the positive modal gain. We determined the net gain from the Hakki–Paoli method. The combination of pressure tuning with grating allowed us to obtain the 350 nm tuning range (from 1575 nm to 1225 nm). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal stability and pressure‐induced phase transitions in scheelite AWO4 (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding
Authors: Manjón F. J. , Errandonea D. , López‐Solano J. , Rodríguez‐Hernández P. , Radescu S. , Mujica A. , Muñoz A. , Garro N. , Pellicer‐Porres J. , Segura A. , Ferrer‐Roca Ch. , Kumar R. S. , Tschauner O. , Aquilanti G.
Published: December 2006

Recent experimental measurements and ab initio calculations in scheelite CaWO4, SrWO4, BaWO4, PbWO4, EuWO4 and YLiF4 crystals reveal the existence of complex high‐pressure phase diagrams, which present striking differences but also relevant similarities. In this work we show that the high‐pressure structural sequence in the studied scheelites can be understood on the basis of the positions of the different ABX4 compounds in Fukunaga and Yamaoka's diagram and in Bastide's diagram. Our study can help to understand the phase diagrams and high‐pressure phase transitions occurring in ABX4 compounds with scheelite, wolframite, fergusonite, zircon, or pseudoscheelite structures. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐pressure properties and phase diagram of boron
Authors: Shirai Koun , Masago Akira , Katayama‐Yoshida Hiroshi
Published: December 2006

Phase diagram of boron is theoretically studied, with focusing mainly on difference between α and β phases. The melting curve is calculated by the pressure dependence of the bulk modulus of solid. It is found that the gradient of the melting curve is inverted at a high pressure. Based on this finding, a promising method to obtain good‐quality crystals of α phase is proposed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
13C nuclear magnetic resonance spectroscopic analysis of the triacylglycerol composition ofBiota orientalis and carrot seed oil
Authors: Lie Ken Jie Marcel S. F. , Lam C. C. , Pasha Mohammed Khysar
Published: December 2006

13C nuclear magnetic resonance (NMR) spectroscopic analysis of the whole oil (triacylglycerols) ofBiota orientalis seeds confirms the presence of oleate [18:1(9Z)], linoleate [18:2(9Z, 12Z)], linolenate [18:3((9Z, 12Z, 15Z)], 20:3 (5Z, 11Z, 14Z), 20:4(5Z, 11Z, 14Z, 17Z), and saturated fatty acids in the acyl groups by comparing the observed carbon shifts with previously established shift data for model triacylglycerols. This technique shows that the saturated, 20:3 and 20:4 fatty acids are distributed mainly in the α‐acyl positions, whereas oleate, linoleate, and linolenate are randomly acylated to the α‐ and β‐positions of the glycerol “backbone”. Stereospecific hydrolysis of theBiota oil with pancreatic lipase, followed by chromatographic analysis of fatty esters, reveals the presence of trace amounts of 16:0(0.7%), 18:0(0.5%), 20:3 (0.4%), and 20:4 (1.3%) in the β‐position of the glycerol “backbone”, which are undetectable by13C NMR technique on the whole oil. Semiquantitative assessment of the13C NMR signal intensities gives the relative percentages of the fatty acid distribution as: saturated 16:0, 18:0 (12.0% α‐acyl), oleate (7.7% α‐acyl 8.7% β‐acyl), total linoleate and linolenate (31.7% α‐acyl; 24.2% βacyl), total 20:3 and 20:4 (15.7% α‐acyl). The13C NMR spectroscopic analysis of carrot seed oil identifies the presence of saturated (18:0), 18:1(6Z), 18:1(9Z), and 18:2(9Z, 12Z). The saturated fatty acid is found in the α‐acyl positions. Semi‐quantitative assessment of the signal intensities gives the relative percentages of the fatty acids as: 18:0 (4.5% α‐acyl), 18:1(6Z) (49.6% α‐acyl; 19.7% β‐acyl), oleate (6.5% α‐acyl; 8.6% β‐acyl) and linoleate (5.2% α‐acyl; 6.9% β‐acyl).
Quantitation of estolides by Fourier transform infrared spectroscopy
Authors: Erhan Selim M. , Kleiman Robert , Abbott Thomas P.
Published: December 2006

Estolides were produced from meadowfoam oil fatty acids, oleic, linoleic, petroselinic, andcis‐5,cis‐13 docosadienoic acids. Estolide reaction mixtures were quantitated by Fourier transform infrared spectroscopy and compared to the area percentages determined by high‐performance liquid chromatography. The absorbance frequency of estolide carbonyl (1737 cm−1) is different than the lactone carbonyl (1790 cm−1) and the acid carbonyl (1712 cm−1). Estolide standards were obtained by wiped‐film molecular‐still distillations and column chromatography.
The fatty acid composition of the seeds ofGinkgo biloba
Authors: Hierro Maria Teresa G. , Robertson Graeme , Christie William W. , Joh Yong‐Goe
Published: December 2006

The fatty acid composition of seeds ofGinkgo biloba has been examined by a combination of capillary gas chromatography, silver ion high‐performance liquid chromatography and gas chromatography/mass spectrometry. Some of the fatty acids identified are unusual in plants and were rather different from those reported earlier. These include ananteiso‐methyl branched fatty acid, 14‐methylhexadecanoic acid, 5,9‐octadecadienoic acid, and 5,9,12‐octadecatrienoic acid. Fourier‐transform infrared spectroscopy confirmed that all of the double bonds were of thecis‐configuration.
Minor constituents of vegetable oils during industrial processing
Authors: Ferrari R. Ap. , Schulte E. , Esteves W. , Brühl L. , Mukherjee K. D.
Published: December 2006

We report the effects of individual steps of industrial refining, carried out in Brazil, on the alteration of selected minor constituents of oils, such as corn, soybean, and rapeseed oils. Total sterols, determined by capillary gas chromatography (GC), decreased by 18–36% in the fully refined oils, compared with the crude oils. The total steradienes, dehydration products of sterols, were determinedvia a simple clean‐up on a short silica gel column, followed by high‐performance liquid chromatography (HPLC) with ultraviolet detection. The level of steradienes, normally not present in crude oils, increased after each refining step, especially after deodorization. Thus, the content of steradienes increased after deodorization by about 15‐ to 20‐fold in corn and soybean oils, and by about 2‐fold in rapeseed oil. The total steryl esters were also determinedvia clean‐up on a short silica gel column, followed by HPLC with evaporative light scattering mass detection. A minor decrease in the level of steryl esters was observed after complete refining. The individual tocopherols and tocotrienols were determined by HPLC with a fluorescence detector. The level of total tocopherols and tocotrienols decreased by about 2‐fold after complete refining of corn oil and by about 1.5‐fold in soybean and rapeseed oils. In all three cases, maximum reduction of tocopherols was observed after the deodorization step. The level of polymeric glycerides, determinedvia clean‐up on a short silica gel column followed by size‐exclusion HPLC, increased to some extent (0.4–1%) during refining. The level oftrans fatty acids, determined by capillary GC, also increased to a substantial extent (1–4%) after refining.
Progress in table olive debittering: Degradationin vitro of oleuropein and its derivatives byLactobacillus plantarum
Authors: Marsilio V. , Lanza B. , Pozzi N.
Published: December 2006

Oleuropein, a bitter‐tasting secoiridoid glycoside present in olive leaves and fruit (Olea europaea L.), is hydrolyzed by oleuropeinolyticLactobacillus plantarum strains. The work reports the results of a gas‐chromatographic study of the oleuropein derivatives released by incubation withL. plantarum B21, isolated from table olive brines, and byL. plantarum ATCC 8014. Process kinetics indicate that the bacterial strains initially hydrolyze the oleuropein by means of β‐glucosidase action with formation of an aglycone (the first observable intermediate compound). In a second step, this derivative, by means of esterase action, gives rise to 2‐(3,4‐dihydroxyphenyl) ethanol (identified) and elenolic acid (not identified).
Recovered oil from palm‐pressed fiber: A good source of natural carotenoids, vitamin E, and sterols
Authors: Choo Yuen‐May , Yap Soon‐Chee , Ooi Cheng‐Keat , Ma Ah‐Ngan , Goh Swee‐Hock , Ong Augustine Soon‐Hock
Published: December 2006

Recovered fiber from pressed palm fruits, which is normally burned as fuel to provide energy for the palm oil mills, has now been found to be a rich source of carotenoids, vitamin E (tocopherol and tocotrienols), and sterols. Residual oil (5–6% on dry basis) extracted from palm press fibers contains a significant quantity of carotenoids (4000–6000 ppm), vitamin E (2400–3500 ppm), and sterols (4500–8500 ppm). The major identified carotenoids are α‐carotene (19.5%), β‐carotene (31.0%), lycopene (14.1%), and phytoene (11.9%). In terms of vitamin E, α‐tocopherol constitutes about 61% of the total vitamin E present, the rest being tocotrienols (α‐, γ‐, and δ‐). The major sterols present are β‐sitosterol (47%), campesterol (24%), and stigmasterol (15%). The oil extracted from palm‐pressed fiber is contaminated with about 30% of palm kernel oil. The quality of this fiber oil is slightly lower than that of crude palm oil in terms of the content of free fatty acids, peroxide value, and anisidine value.
Temperature‐dependent diffusion coefficient of soluble substances during ethanol extraction of clove
Authors: Myint San , Daud Wan Ramli Wan , Mohamad Abu Bakar , Kadhum Abdul Amir H.
Published: December 2006

The temperature dependence of the diffusion coefficient of ethanol‐soluble substances from ground cloves (particle size 250 μm) during extraction was estimated by fitting batch extraction data at several temperatures (27.8, 40, 50, and 60°C) to a previously developed mass transfer model. The model was based on spherical geometry of particles. Nonlinear regression analysis was used to develop an equation that describes the diffusivity as a function of temperature. The temperature dependence ofDA was of the Arrhenius type.
Comparative nutritional quality of palmstearin‐liquid oil blends and hydrogenated fat (vanaspati)
Authors: Ray S. , Bhattacharyya D. K.
Published: December 2006

An attempt was made to use high‐melting lowdigestible fat palmstearin as a vanaspati substitute by blending it with polyunsaturated fatty acid‐rich liquid oils. This blending produced fat products of zero‐trans fatty acid content and melting points below the human body temperature, so that they can be digested easily. The new blended products were fed to male albino rats (Charles Foster strain); the coefficients of digestibilities were 94.2% for palmstearin and rapeseed oil blend, 95.1% for palmstearin and sunflower oil blend, and 96.2% for palmstearin and soybean oil blend, which were somewhat better than the digestibility coefficient of conventional vanaspati (93.6%). Feeding experiments for three months showed comparable results in terms of serum lipid profiles. The blended products significantly increased the total cholesterol level but not the free cholesterol level in serum and liver of rats when compared with those of the conventional vanaspati group of rats.
Inhibition of malonaldehyde formation by antioxidants from ω3 polyunsaturated fatty acids
Authors: Ogata J. , Hagiwara Y. , Hagiwara H. , Shibamoto T.
Published: December 2006

The inhibitory effect of α‐tocopherol, β‐carotene, 2″‐O‐glycosyl isovitexin (2″‐O‐GIV), and butylated hydroxytoluene (BHT) on malonaldehyde (MA) formation from ω3 polyunsaturated fatty acids (PUFA) was determined by gas chromatography. The levels of MA formed from 1 mg each of octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) upon oxidation with Fenton's reagent were 29.8±1.5, 17.2±1.5, and 22.0±0.7 nmol, respectively. BHT was most effective toward protecting all three ω3 PUFA, whereas β‐carotene did not exhibit any inhibitory effect. 2″‐O‐GIV inhibited MA formation from EPA and DHA by 56 and 43%, respectively, showing the second greatest inhibitory activity after BHT. α‐Tocopherol inhibited MA formation from ODTA and DHA by 67 and 28%, respectively, but it did not show any activity toward EPA oxidation. The naturally occurring antioxidant, 2″‐O‐GIV, may be useful to prevent oxidation of ω3 PUFA.
Transesterification of phospholipids by acetone‐dried cells of aRhizopus species immobilized on biomass support particles
Authors: Hara Fumiko , Nakashima Toshimitsu
Published: December 2006

Acetone‐dried cells of aRhizopus species, immobilized on biomass support particles were applied to the transesterification between phosphatidylcholine and heptadecanoic acid. All eight species ofRhizopus tested exhibited good transesterification performance, with the immobilized cells ofR. niveus, R. delemar, andR. javanicus showing particularly high reaction rates which were equal to or exceeded that of a commercially available immobilized lipase preparation, Lipozyme IM60.
Effect of colony size on the competitive outcome of encrusting colonial organisms
Authors: Nandakumar K. , Tanaka M.
Published: December 2006

The relative importance of colony size ratio of interacting species was studied in Tomioka Bay, Japan. Six encrusting colonial species belonging to the following three different taxonomic groups were tested: Ascidia (three species), Bryozoa (two) and Porifera (one). Colonies of these organisms were grown in the community of sessile organisms developed on plastic panels. Logistic regression analysis was carried out to determine the effect of size ratio on the competitive outcome of interacting colonies. The results between all possible combinations among these six species did not show a significant size effect in competitive outcome (i.e. a larger colony size did not always prove important in the success of a competitive interaction with smaller colonies of other species). On the contrary, competitive success depends on the types of species interacting. Certain species such as Didemnum moseleyi (ascidian) and Haliclona sp. (sponge), in spite of being smaller in colony size, won in competitive interactions with larger colonies of other species such as Diplosoma mitsukurii (ascidian) and Watersipora subovoidea (bryozoan). These results contradict the one reported earlier: that the larger the colony size, the more chance the colony will have to win in competitive interactions.
Individual variation in two host plants of the ladybird beetle, Epilachna pustulosa (Coleoptera: Coccinellidae)
Authors: Fujiyama Naoyuki , Katakura Haruo
Published: December 2006

Individual variation in two species of host plants (thistle, Cirsium kamtschaticum, and blue cohosh, Caulophyllum robustum) of the herbivorous ladybird beetle Epilachna pustulosa was examined under laboratory conditions for their acceptability to adult beetles as a food resource, for adult preference and for larval performance. When clones of these plants were subjected to non‐choice tests using posthibernating female beetles, there was found to be significant intraspecific variation among clones in terms of their acceptability, but interspecific variation was not detected. Significant intraspecific as well as interspecific variation were frequently detected in the two host plants when clones of these plants were subjected to choice tests using posthibernating female beetles; the magnitude of interspecific plant variation for beetle preference is not necessarily larger than that of intraspecific plant variation. Individual variation across plant species with respect to beetle larval performance was also significant. A positive correlation between adult preference and larval performance is suggested across the two taxonomically remote host plant species, thistle and blue cohosh, although this needs further investigation.
Distance effect of co‐occurring tree species on pine wilt disease incidence inPinus densifloraseedlings inoculated withBursaphelenchus xylophilus
Authors: Nakamura Katsunori , Togashi Katsumi , Takahashi Fumiki
Published: December 2006

Field‐grownPinus densifloraseedlings were inoculated withBursaphelenchus xylophilusand the incidence of pine wilt disease was analyzed with respect to the spatial relationships between pine seedlings and adjacent seedlings of other tree species in a pure pine stand and three stands mixed withAlnus sieboldiana, Sarothamus scopariusor naturally associated species. The disease incidence was 60.9% in a 0–40 cm distance class from the nearestA. sieboldianaseedlings and then decreased with increasing minimum distance. The mean minimum distance between pine seedlings andA. sieboldianawas significantly shorter in diseased seedlings than in healthy ones. The highest disease incidence (53.9%) was found in a 0–40 cm distance class from the nearestS. scoparius, although the relationship with minimum distance was blurred by a high incidence in the 80‐cm distance class. The mean minimum distance between pine seedlings was significantly short in diseased seedlings in a pure stand, whereas it was not so short between pine seedlings and other tree species in the two stands mixed withS. scopariusand the naturally associated species. The distance effect on disease incidence was noticeable inA. sieboldianaandP. densifloraat high density. This was not so clear inS. scopariusand was not found in the naturally associated species.
Stand dynamics during a 12‐year period in a second‐growth stand in a cool temperature forest in northern Japan
Authors: Namikawa Kanji , Ishikawa Yukio , Sano Junji
Published: December 2006

In 1981 and 1993, trees over 2 m high were measured and mapped to clarify stand dynamics in two permanent plots of 0.1 ha in a secondary, cool temperate, mixed broadleaf/conifer forest after logging in the Tomakomai Experiment Forest, central Hokkaido, northern Japan. The species could be placed in two groups according to the change in basal area and density, and annual height growth:Quercus mongolica var. grosseserrata, Phellodendron amurense, Prunus sargentii and Tilia japonica (Group I: GI) showed episodic regeneration and/or fast height growth;Acer mono, Acer palmatum var. matsumuae and Sorbus alnifolia (Group II: GII) showed continuous regeneration and/or slow height growth. The age distribution of stems over 10 cm in d.b.h. suggests synchronous regeneration of GI and GII species. Vertical stratification was promoted during the 12‐year period by the difference in annual height growth between the two species groups. Additional tree censuses in both remnant old‐growth stands and second‐growth stands after large scale blowdowns demonstrated that Q. mongolica var. grosseserrata is most dominant in stands varying in the stages of development. Disturbance history and successional trends in dominant species implied that stand‐devastating disturbances were responsible for the regeneration of Q. mongolica var. grosseserrata in the study forest.
The role of weed invasion in controlling sand dune reactivation in abandoned fields in semi‐arid Inner Mongolia, China
Authors: Nemoto Masayuki , Ohkuro Toshiya , Xu Bin
Published: December 2006

The growth of crops and invading weeds were examined at six sites under different cultivation conditions in semi‐arid Inner Mongolia, where sand dune reactivation has been controlled by weed invasion. The soil moisture content was not sufficient for crop growth in over‐cultivated farmland. The shortage of moisture in the soil suppresses the growth of both crops and weeds. Accordingly, farmers carry out weeding to maintain better soil moisture conditions for crop growth. Over‐cultivated farmland is often abandoned when the crop yield decreases to an economically unprofitable level. If weed vegetation before abandonment remains, it becomes a core of vegetation expansion and recovers the entire soil surface. While weedy vegetation is lacking or has been grazed by livestock, sand dune reactivation occurs.