bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of different surface morphology and roughness on osteoblast‐like cells
Authors: Ball Michael , Grant David M. , Lo Wei‐Jen , Scotchford Colin A.
Published: November 2007

Increased magnitude of biomaterial surface roughness and micromachined‐grooved surfaces has both been shown to stimulate osteoblast activity, but have not been compared in the same study quantitatively. A series of titanium alloy (Ti6Al4V) samples were prepared using simple machining techniques to undertake such a comparison. Samples were either grit blasted (Gb) or shot peened (Sp) to give random discontinuities, or silicon carbide ground (SiC) to produce ordered grooves. These were compared with micropolished samples (Mp). The samples were coated with a 1 μm continuous coating of hydroxyapatite to remove differences in surface chemistry. Human osteoblast‐like cells were seeded onto the materials and metabolic activity, proliferation, alkaline phosphatase activity, and osteocalcin production assessed. Cell responses were highly dependent on the substrate that they were cultured on. Cells cultured on the smooth and ordered (Mp and SiC, respectively) samples had higher metabolic activity and a more elongated morphology than those cultured on the randomly structured Gb or Sp samples. Over 21 days, cell metabolic activity peaked relative to the control between 7 and 14 days on the Mp sample, and between 14 and 21 days on the Gb, Sp, and SiC samples. In common with other researchers, we note that micron scale topography may have potential for influencing osseointegration. More importantly, as the magnitude of the discontinuities on SiC, Gb, and Sp were similar, the differences in cell responses does not appear to lie with the size of the features, but whether the features showed an ordered or disordered structure. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Consil® bioactive glass particles enhance osteoblast proliferation and maintain extracellular matrix production in vitro
Authors: Au Angela Y. , Au Rebecca Y. , Al‐Talib Tala K. , Eves Barbara , Frondoza Carmelita G.
Published: November 2007

Bioactive glasses are used clinically as bone implant materials as they are able to bond directly with bone. Studies in dogs have demonstrated the utility of Consil® Bioglass® synthetic bone graft particulate, a commercially available bioactive glass formulation, as a bone substitute for repair of bony defects. We evaluated the effect of Consil particles (500 μg/mL) on osteoblast proliferation and extracellular matrix (ECM) production at the cellular level in vitro. An osteoblast surrogate MG‐63 cell line was incubated with Consil particles or medium alone for different time periods to determine the effect of Consil particles on proliferation and expression of ECM components. Osteoblasts remained viable and proliferated upon exposure to the particles, as shown by increased total DNA content. Cells incubated with Consil particles maintained expression levels of phenotype markers (type I collagen, osteocalcin, proteoglycans, and alkaline phosphatase) similar to control cells. Levels of secreted type I collagen and osteocalcin were time‐dependent and similar to controls. This study verified the ability of Consil particles to enhance proliferation of osteoblast‐like cells. The particles also maintained ECM production up to 21 days in culture. Our study supports the reported clinical utility of Consil particles for the repair of bony defects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Protein adsorption and separation on amphoteric chitosan/carboxymethylcellulose membranes
Authors: Feng Zhicheng , Shao Zhengzhong , Yao Jinrong , Chen Xin
Published: November 2007

This article reported the preparation of an amphoteric natural polymeric membrane—macroporous chitosan (CS)/carboxymethylcellulose (CMC) blend membrane and the utilization of such a membrane on the membrane chromatography for bioseparation. The membranes were prepared by solution blending of CS and CMC solution, and using silica particles as porogen. Both glutaraldehyde and epichlorohydrin were used as crosslinking agent to increase its chemical stability in aqueous solution. Such a natural polymeric membrane can be served as an amphoteric membrane because of the amino group on CS and the carboxymethyl group on CMC, in which the surface charge can be changed with the environmental pH. Ovalbumin (pI = 4.6) and lysozyme (pI = 11) were selected as model proteins. These two proteins adsorption on different CS/CMC blend membranes with different initial protein concentrations at different pH values were investigated in batch systems. The results indicated that the maximum adsorption for lysozyme and ovalbumin was at pH 9.2 and 4.8 respectively, and the adsorption capacity on the membrane both increased with the increase of initial protein concentration. Though the adsorption mechanism of lysozyme and ovalbumin was found not the same, the maximum adsorption capacity of two proteins on the membranes was quite similar (about 250 mg/g). Moreover, the desorption ratio of both proteins was found to be more than 90% that implied CS/CMC blend membrane could separate proteins by adsorption–desorption process. Finally, both lysozyme and ovalbumin were successfully separated from their binary mixture only by adjusting the pH of the feed and the desorption solution. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Graph classes characterized both by forbidden subgraphs and degree sequences
Authors: Barrus Michael D. , Kumbhat Mohit , Hartke Stephen G.
Published: November 2007

Given a set ${\cal F}$ of graphs, a graph G is ${\cal F}$‐free if G does not contain any member of ${\cal F}$ as an induced subgraph. We say that ${\cal F}$ is a degree‐sequence‐forcing set if, for each graph G in the class ${\cal C}$ of ${\cal F}$‐free graphs, every realization of the degree sequence of G is also in ${\cal C}$. We give a complete characterization of the degree‐sequence‐forcing sets ${\cal F}$ when ${\cal F}$ has cardinality at most two. © 2007 Wiley Periodicals, Inc. J Graph Theory 57: 131–148, 2008
Perfusion‐weighted MRI in evaluating the intranodular hemodynamic characteristics of dysplastic nodules and hepatocellular carcinomas in an experimental rat model
Authors: Xu Hui , Xie Jing‐Xia , Li Xuan , Yang Zheng‐Han , Zheng Zhuo‐Zhao , Wang Bin , Wang Zheng
Published: November 2007

Purpose

To investigate the value of perfusion‐weighted MRI in the evaluation of the intranodular hemodynamic characteristics of dysplastic nodules (DNs) and hepatocellular carcinomas (HCCs) in an experimental rat model.

Materials and Methods

A total of 40 rats with chemically‐induced DNs and HCCs were investigated. Single‐slice gadolinium‐enhanced perfusion‐weighted MRI was performed to evaluate the nodules. Time to peak (Tp), maximal relative signal enhancement (REmax), and the initial slope of signal intensity (SI) vs. time curves of the nodules and cirrhotic liver were evaluated. Nodules precisely corresponding to MRI were examined histologically. Paired Student's t‐tests were used to compare the difference between nodules and cirrhotic liver.

Results

A total of 20 HCCs and 14 DNs were evaluated. HCCs showed a significantly higher REmax, shorter Tp, and higher slope than adjacent cirrhotic liver. The REmax and slope of DNs were significantly lower than adjacent cirrhotic liver parenchyma. Although the Tp of DNs was delayed two to three seconds compared to adjacent cirrhotic liver, there was no significant difference between them.

Conclusion

Perfusion‐weighted MRI detected the intranodular hemodynamic characteristics of DNs and HCCs in an experimental rat model. DNs were hypovascular compared to cirrhotic liver, while HCCs were markedly hypervascular. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Rapid multiplanar abdominal survey using MRI with the steady‐state free‐precession technique
Authors: Dutka Michael V. , Bergin Diane , O'Kane Patrick L. , Frangos Andrea J. , Parker Laurence , Mitchell Donald G.
Published: November 2007

Purpose

To retrospectively evaluate the sensitivity, specificity, and positive and negative predictive values of steady‐state free‐precession (SSFP) survey MRI of the abdomen.

Materials and Methods

A total of 375 consecutive outpatients underwent abdominal MRI at 1.5T. Excluding diffuse metastatic disease, 110 patients had at least one other clinically important finding. The SSFP survey included contiguous 5‐mm‐thick axial, sagittal, and coronal slices (total 90 slices) obtained during a total of 90 seconds of free breathing. Studies were reviewed by two experienced MRI readers independently, randomized, blinded, and at different sittings. The chi‐squared test was used to compare SSFP to full MRI for showing clinically important findings. In a subset of 30 patients, confidence intervals (CI) were calculated to compare the accuracy of SSFP and full MRI as predictors of biopsy result.

Results

SSFP detected 87.3% of clinically important findings and 93.3% of malignancies reported on the full MRI, with a 1.5% false‐positive rate. Significant association was shown between SSFP and full MRI for clinically important findings (P < 0.0001). Compared to biopsy, accuracy of SSFP was high (85% ± 12.7%), though not as high as full MRI (93.3% ± 8.8%).

Conclusion

SSFP provides a rapid survey of the abdomen, with good sensitivity and few false positives. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Abnormal diffusion tensor in nonsymptomatic familial amyotrophic lateral sclerosis with a causative superoxide dismutase 1 mutation
Authors: Ng Man‐Cheuk , Ho Jenny Ting , Ho Shu‐Leong , Lee Raymand , Li Geng , Cheng Tat‐Sun , Song You‐Qiang , Ho Philip Wing‐Lok , Fong Gardian Chung‐Yan , Mak Windsor , Chan Koon‐Ho , Li Leonard Sheung‐Wai , Luk Keith Dip‐Kei , Hu Yong , Ramsden David Boyer , Leong Lilian Ling‐Yee
Published: November 2007

Purpose

To determine whether diffusion abnormalities can be observed in nonsymptomatic family members with a known causative Cu/Zn superoxide dismutase mutation (asymptomatic familial amyotrophic lateral sclerosis; AFALS+SOD1) in a family with autosomal dominant familial amyotrophic lateral sclerosis (ALS) using diffusion tensor imaging (DTI).

Materials and Methods

A total of eight AFALS+SOD1 subjects (aged 17–43 years) were age‐matched with 13 healthy controls (aged 19–45 years) without SOD1 mutations. DTI was carried out on a 1.5T scanner. The diffusion index maps derived were then normalized spatially for voxel‐based analysis. region of interest (ROI)‐based analysis was also carried out.

Results

Our voxel‐based and ROI‐based analysis showed that AFALS+SOD1 subjects have decreased fractional anisotropy (FA) (0.5401 vs. 0.5168, P < 0.05) and increased tensor trace (TT) (2.5854 × 10−3 mm2/second vs. 2.6226 × 10−3 mm2/second, P < 0.04) at the posterior limb of the internal capsule compared to the control subjects. Increased radial diffusivity (E(2,3)/2) was detected on both sides (right = 0.5710 × 10–3 mm2/second vs. 0.5943 × 10–3 mm2/second, P < 0.05; left = 0.5666 × 10–3 mm2/second vs. 0.5872 × 10–3 mm2/second, P < 0.05). No significant change in axial diffusivity (E1) was detected.

Conclusion

Abnormal diffusivity was found at the posterior limb of the internal capsule in AFALS+SOD1 subjects, hitherto unreported. Our results suggest that DTI may detect diffusion abnormalities in AFALS+SOD1 subjects before symptoms develop. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Pesticide analysis in rose wines by micellar electrokinetic chromatography
Authors: Ravelo‐Pérez Lidia M. , Hernández‐Borges Javier , Borges‐Miquel Teresa M. , Rodríguez‐Delgado Miguel Ángel
Published: November 2007

In this work, the determination of 11 pesticides (pirimicarb, metalaxyl, pyrimethanil, procymidone, nuarimol, azoxystrobin, tebufenozide, fenarimol, benalaxyl, penconazole, and tetradifon) in rose wines by micellar EKC (MEKC) using reversed electrode polarity stacking mode (REPSM) as online preconcentration strategy is described. The MEKC buffer consisted of 100 mM sodium tetraborate and 30 mM SDS at pH 8.5 with 6% v/v 1‐propanol. A solid‐phase microextraction (SPME) procedure using PDMS/divinylbenzene (PDMS/DVB) fibers was applied to extract the selected pesticides from the rose wine samples. The comparison between the calibration curves obtained from hydroalcoholic solutions (12% v/v ethanol) and from rose wines (matrix matched calibration) showed the existence of a strong matrix effect. Furthermore, a comparison with calibration curves obtained with white wine samples also showed significant differences for most of the analyzed pesticides. As a result, a matrix matched calibration was developed. Quantitative extraction from spiked wine samples was carried out in triplicate at two levels of concentration (range 0.18–6.00 mg/L). LODs between 0.040 and 0.929 mg/L were achieved, which are below the maximum residue limits (MRLs) established for wine grapes (except for pirimicarb) by the EU and Spain legislation as well as by the Codex Alimentarius. The established method – which is solvent free, cost effective, and fast – was also applied to the analysis of several homemade rose wine samples and a commercial one. Two of the selected pesticides were found in some of the analyzed samples.
Systematic derivation of an asymptotic model for the dynamics of curved viscous fibers
Authors: Panda Satyananda , Marheineke Nicole , Wegener Raimund
Published: November 2007

This paper presents a slender body theory for the dynamics of a curved inertial viscous Newtonian fiber. Neglecting surface tension and temperature dependence, the fiber flow is modeled as a three‐dimensional free boundary value problem in terms of instationary incompressible Navier–Stokes equations. From regular asymptotic expansions in powers of the slenderness parameter, leading‐order balance laws for mass (cross‐section) and momentum are derived that combine the unrestricted motion of the fiber centerline with the inner viscous transport. The physically reasonable form of the one‐dimensional fiber model results thereby from the introduction of the intrinsic velocity that characterizes the convective terms. For the numerical investigation of the viscous, gravitational and rotational effects on the fiber dynamics, a finite volume approach on a staggered grid with implicit upwind flux discretization is applied. Copyright © 2007 John Wiley & Sons, Ltd.
Regulation of placental villous angiopoietin‐1 and ‐2 expression by estrogen during baboon pregnancy
Authors: Albrecht Eugene D. , Babischkin Jeffery S. , Pepe Gerald J.
Published: November 2007

We recently showed an increase in vascular endothelial growth factor (VEGF), decrease in angiopoietin‐1 (Ang‐1) and unaltered Ang‐2 expression by the villous placenta with advancing baboon pregnancy. Moreover, placental VEGF expression was increased by estrogen in early pregnancy. In the present study, we determined whether placental Ang‐1 and Ang‐2 are regulated by estrogen. Ang‐1 and Ang‐2 mRNA and protein were determined by RT‐PCR and immunocytochemistry in the placenta of baboons on Day 60 of gestation (term is 184 days) after administration of estrogen precursor androstenedione on Days 25–59 or on Day 54 after acute estradiol administration. Chronic androstenedione treatment increased serum estradiol levels three‐fold (P < 0.001) and decreased (P < 0.05) villous cytotrophoblast Ang‐1 mRNA to a level (0.36 ± 0.08 relative to 18S rRNA) that was one‐third of that in untreated animals (0.98 ± 0.26). Within 2 hr of estradiol administration, cytotrophoblast Ang‐1 mRNA was decreased to a level (0.24 ± 0.05) one‐fifth (P < 0.05) of that in untreated animals (1.14 ± 0.23). However, Ang‐2 mRNA levels were unaltered. Ang‐1, Ang‐2 and estrogen receptors α and β protein were localized within villous cytotrophoblasts providing a mechanism for estrogen action at this site. In summary, estrogen increased VEGF, decreased Ang‐1, and had no effect on Ang‐2 expression within placental cytotrophoblasts during early baboon pregnancy. We propose that the estrogen‐dependent differential regulation of these angioregulatory factors underpins the unique pattern of neovascularization established within the villous placenta during primate pregnancy. Mol. Reprod. Dev. 75: 504–511, 2008. © 2007 Wiley‐Liss, Inc.
Self‐contact and fictitious domain using a difference convex approach
Authors: Pagano S. , Alart P.
Published: November 2007

A numerical approach of contact or self‐contact of thin structures is performed using a relaxed orientation‐preserving condition inserted in the difference of convex function framework. This method is analyzed on academic examples and cellular media. Copyright © 2007 John Wiley & Sons, Ltd.
A decade comparison of preterm motor performance at age 4
Authors: Sullivan Mary C. , Hawes Katheleen
Published: November 2007

This was a prospective longitudinal study of two cohorts comprised of one full term and three premature infant groups born 10 years apart. Birth cohort, perinatal morbidity, and birth weight effects were investigated at age 4. Cohort 1 (1985–1989) had longer gestation, higher birth weight, and better Apgar scores than Cohort 2 (1996–1999), which had more intraventricular hemorrhage and bronchopulmonary dysplasia. Cohort and perinatal morbidity group, but not birth weight, predicted motor scores. Preterm Cohort 2 children had better oral motor, fine motor, and total motor scores, but lower visual motor integration scores than Cohort 1. Motor problems continue to affect preterm children at age 4, in particular those who experience perinatal morbidity, despite a decade of neonatal intensive care advancements. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:641–654, 2007
Testing a model of contraception use behavior among sexually active female adolescents in Taiwan
Authors: Wang Ruey‐Hsia , Wang Hsiu‐Hung , Cheng Chung‐Ping , Hsu Hsiu‐Yueh , Lin Shu‐Yuan
Published: November 2007

The purpose of this cross‐sectional study was to test a model of contraception use among sexually active Taiwanese female adolescents, using structural equation modeling. Anonymous questionnaires were distributed to 404 female adolescents who had had sexual intercourse in the previous 3 months. A model was produced in which past contraception use, self‐efficacy for contraception use, and decisional balance for using contraception had significant direct effects on current contraception use. Social influences had not only significant direct effects on self‐efficacy and on decisional balance, but also a significant indirect effect on current contraception use. These findings provide a reference for the development of contraceptive intervention programs for sexually active female adolescents in Taiwan. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:628–640, 2007
Noninvasive prenatal diagnosis of aneuploidy using cell‐free nucleic acids in maternal blood: promises and unanswered questions
Authors: Puszyk William M. , Crea Francesco , Old Robert W.
Published: November 2007

The discovery of cell‐free fetal (cff) DNA and RNA in the maternal circulation has driven developments in noninvasive prenatal diagnosis (NIPD) for the past decade. Detection of paternally derived alleles in cff DNA is becoming well established. Now much interest is focussing on NIPD of fetal chromosomal abnormalities, such as trisomy 21, which is a considerable challenge because this demands accurate quantitative measurements of the amounts of specific cff DNA or cff RNA sequences in maternal blood samples. Emerging strategies for distinguishing and quantifying the fetal nucleic acids in the maternal circulation promise continued development of the field, and pose a number of unanswered questions. Copyright © 2007 John Wiley & Sons, Ltd.
Ethylene polymerization and copolymerization with a polar monomer using an α‐iminocarboxamide nickel complex activated by trimethylaluminum
Authors: Carone Carlos L. P. , Bisatto Rubens , Galland Griselda B. , Rojas Rene , Bazan Guillermo
Published: November 2007

An α‐iminocarboxamide nickel complex was activated by trimethylaluminum (TMA) and used in the polymerization of ethylene and its copolymerization with 10‐undecen‐1‐ol. The best activity was observed upon activation with 9 equiv of TMA at a temperature of 26 °C. NMR spectroscopic studies did not show 10‐undecen‐1‐ol incorporation. However, FTIR analyses suggest the incorporation of a very small amount of comonomer, which affects the glass transition temperature, the degree of branching, and the mechanical properties of the materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 54–59, 2008
Homo‐ and copolymerization of ethylene and norbornene with bis(β‐diketiminato) titanium complexes activated with methylaluminoxane
Authors: Li Yongfei , Gao Haiyang , Wu Qing
Published: November 2007

Homo‐ and copolymerization of ethylene and norbornene were investigated with bis(β‐diketiminato) titanium complexes [ArNC(CR3)CHC(CR3)NAr]2TiCl2 (R = F, Ar = 2,6‐diisopropylphenyl 2a; R = F, Ar = 2,6‐dimethylphenyl 2b; R = H, Ar = 2,6‐diisopropylphenyl 2c; R = H, Ar = 2,6‐dimethylphenyl 2d) in the presence of methylaluminoxane (MAO). The influence of steric and electric effects of complexes on catalytic activity was evaluated. With MAO as cocatalyst, complexes 2a–d are moderately active catalysts for ethylene polymerization producing high‐molecular weight polyethylenes bearing linear structures, but low active catalysts for norbornene polymerization. Moreover, 2a–d are also active ethylene–norbornene (E–N) copolymerization catalysts. The incorporation of norbornene in the E–N copolymer could be controlled by varying the charged norbornene. 13C NMR analyses showed the microstructures of the E–N copolymers were predominantly alternated and isolated norbornene units in copolymer, dyad, and triad sequences of norbornene were detected in the E–N copolymers with high incorporated content of norbornene. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 93–101, 2008
NMR study of the nanomorphology in thin films of polymer blends used in organic PV devices: MDMO‐PPV/PCBM
Authors: Mens R. , Adriaensens P. , Lutsen L. , Swinnen A. , Bertho S. , Ruttens B. , D'Haen J. , Manca J. , Cleij T. , Vanderzande D. , Gelan J.
Published: November 2007

The disclosure of the nanomorphology of thin films in organic solar cells, prepared from blends of conjugated polymers and PCBM, is of key importance for a better understanding of the occurring photovoltaic (PV) mechanisms. Hereto solid‐state NMR relaxometry has been evaluated as a complementary technique to traditional microscopic techniques like atomic force microscopy and transmission electron microscopy. It is demonstrated that proton wide‐line solid‐state NMR relaxometry is a useful and innovative tool to study the phase morphology of blends used in semi‐conducting polymer based PV devices. Attention is focused on the influence of the blend composition and casting conditions on the resulting phase morphology. Two different casting techniques, i.e. spincoating and Doctor Blading, were compared. To demonstrate the applicability of NMR relaxometry in this field, MDMO‐PPV/PCBM blends where used, since these are known for their significant phase separation behavior in combination with toluene as solvent. In films prepared from blends in toluene with a PCBM content ≥70 wt %, a fraction of the PCBM is phase separated into crystalline domains, whereas the remaining part remains homogeneously mixed with the MDMO‐PPV. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 138–145, 2008
Targeted delivery of proteins by nanosized carriers
Authors: Solaro Roberto
Published: November 2007

Proteic drug administration poses some additional issues as compared with conventional drugs because of protein high molecular weight and short half‐life in plasma. It is well known that protein delivery canbe significantly improved by using targeted nanocarriers. Among the diverse investigated systems, this overview focuses onliposomes and nanoparticles. Indeed, because of their subcellular size, nanocarriers can cross the fenestration of the vascular epithelium and penetrate tissues. Moreover, nanosystems can be confined at the location of choice by conjugation to molecules that strongly bind the target cells. In spite of the significant progress made in the design and engineering of liposomes and nanoparticles tailored to the targeted delivery of proteins, these nanocarriers seldom succeed in delivering proteins directly inside the cell cytosol. Accordingly, some attention is also paid to virosomes and fusion proteins. These systems have a few advantages over conventional nanocarriers, particularly the ability to cross the cell membrane. They also share the main drawback of being highly immunogenic. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1–11, 2008
Chloroform sorption in nanoporous crystalline and amorphous phases of syndiotactic polystyrene
Authors: Mensitieri Giuseppe , Larobina Domenico , Guerra Gaetano , Venditto Vincenzo , Fermeglia Maurizio , Pricl Sabrina
Published: November 2007

The transport of chloroform in films of atactic polystyrene and of semicrystalline syndiotactic polystyrene in its nanoporous form (δ‐form) has been investigated by gravimetric analysis. Experimental tests have been performed at 35, 49, and 56 °C and at several vapor pressures ranging from 0.5 to 100 Torr. Nonequilibrium lattice fluid prediction of the amorphous sorption behavior was used to enucleate the sorption contribution of the crystalline nanoporous phase from semicrystalline samples. Sorption behavior of the crystalline phase has been interpreted on the basis of Langmuir equation. Moreover, the chloroform sorption at low activities in the crystalline nanoporous phase has been predicted by using Grand Canonical Monte Carlo molecular simulations. Isosteric heats of sorption were also experimentally evaluated for the crystalline phase, and compared with the corresponding prediction of molecular simulation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 8–15, 2008
Morphology development in PS/LLDPE blend during and after elongational deformation
Authors: Starý Zdeněk , Münstedt Helmut
Published: November 2007

The morphology development within a PS/LLDPE blend with 5 wt % of LLDPE at various stages of uniaxial deformation and after cessation of the flow was studied. Under given deformation conditions the dispersed LLDPE particles stretch and form highly elongated fibrils in agreement with a modified capillary number model. The morphology development after deformation was investigated for two different modes—relaxation and recovery. It was found that the stress in the sample is the crucial parameter determining the morphology development. During the first part of relaxation the stress in the sample is sufficient to hold the particles in the highly elongated state and, therefore, Rayleigh breakup takes place according to the Tomotika theory. It results in considerably finer phase structure. Contrary to this, in the absence of the stress in the sample, that is, in the recovery mode, the fibrils start to shrink immediately after the deformation and after a certain time the spherical morphology is restored. During elongation and recovery no evidence of coalescence was observed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 16–27, 2008
Proteome analysis of substantia nigra and striatal tissue in the mouse MPTP model of Parkinson's disease
Authors: Zhao Xin , Li Quan , Zhao Lei , Pu XiaoPing
Published: November 2007

The dopaminergic neurotoxin 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) replicates many of the pathological hallmarks of Parkinson's disease (PD) in mice via selective destruction of dopamine neurons of the substantia nigra and striatum. Although MPTP has been widely used to study downstream effects following the degeneration of dopaminergic neurons, the underlying mechanisms of MPTP action remain poorly understood. To determine the underlying mechanisms of MPTP action at the protein level, a 2‐DE‐based proteomics approach was used to evaluate the changes in protein expression in substantia nigra and striatal tissue in C57BL/6 mice after MPTP administration. We identified nine proteins that were markedly altered and are likely to be involved in mitochondrial function, heat shock protein activity, and which contribute enzyme activities for energy metabolism and protein degradation.
Cancer biomarker discovery via low molecular weight serum proteome profiling – Where is the tumor?
Authors: Davis Michael T. , Auger Paul , Spahr Chris , Patterson Scott D.
Published: November 2007

Time‐course analyses of rapidly processed serum performed in parallel by SELDI and nanoscale LC‐MS/MS have revealed the temporal correlation of several literature‐based disease markers with ex vivo driven events such that their in vivo existence in healthy subjects is questionable. Identification by MS/MS reveals these putative biomarkers to be byproducts of the coagulation cascade and platelet activation and suggests plasmatic analysis may be preferred. In a pilot plasmatic study, a cohort of naïve prostate cancer (PCa) samples were uniformly distinguished from their age‐matched controls (n = 20) on the basis of multiple peptidic components; most notably by a derivative of complement C4 at 1863 m/z (GLEEELQFSLGSKINVK, C41353–1369). The fully tryptic nature of this and other putative PCa discriminants is consistent with the cleavage specificity of common blood proteases and questions the need for tumor‐derived proteolytic activities as has been proposed. In light of the known correlation of disregulated hemostasis with malignant disease, we suggest the underlying differentiating phenomena in these types of analyses may lie in the temporal disparity of sample activation such that the case (patient) samples are preactivated while the control samples are not.
Sequence shuffle controls morphological consequences in a self‐assembling tetrapeptide
Authors: Joshi K. B. , Verma Sandeep
Published: November 2007

Peptide and protein self‐assembly is a well‐studied phenomenon in chemistry and biology, where nanoscopic building blocks exhibit rapid self‐association to reveal supramolecular aggregates of defined structural features. These superstructures are stabilized by hydrophobic interactions, hydrogen bonding and a host of other noncovalent interactions. Thus, amino acid side chains in the primary structure hold importance in dictating secondary structures and preference for particular conformational signatures in peptide aggregates. This report describes contrasting nanoscale morphologies in antamanide‐derived synthetic tetrapeptide mutants, which are composed by shuffling only two amino acids: phenylalanine and proline. Remarkable differences in ultrastructures in primary sequence‐shuffled tetrapeptides suggest dissimilar aggregational pathways due to context‐dependent location of proline and phenylalanine residues with respect to one another. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
In vitro evaluation of leptin fragments activity on the ob receptor
Authors: de Oliveira Vani Xavier , Fázio Marcos Antonio , Santos Edson Lucas , Pesquero João bosco , Miranda Antonio
Published: November 2007

In an attempt to identify regions in the leptin molecule responsible for its bioactivity, we tested six related‐leptin peptide fragments denoted: Ac‐hLEP23–47‐NH2 (I), Ac‐hLEP48–71‐NH2 (II), Ac‐hLEP72–88‐NH2 (III), Ac‐hLEP92–115‐NH2 (IV), Ac‐[Ser117]‐hLEP116–140‐NH2 (V), Ac‐hLEP141–164‐NH2 (VI) and their correspondent disulfide bridged dimer forms. The activity of the fragments was evaluated in comparision to leptin, by their ability to interact with leptin receptor using a cytosensor microphysiometer. Our results indicated that the fragments IV and V and [D‐Leu4]‐OB3 and its human sequence analog were recognized by leptin receptor present in HP‐75 cells, in agreement with the results obtained by other workers, validating that this region of the molecule contain the functional epitope of the leptin molecule. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Simultaneous detection of two types of soot precursor particles using photoionization mass spectrometry
Authors: Baquet Tania Gonzalez , Grotheer Horst‐Henning , Aigner Manfred
Published: November 2007

The soot precursor particles reported in the literature to date may be roughly divided into two classes. Some of their features are very different. Using photoionization mass spectrometry behind premixed atmospheric ethylene/air flames, particle mass distribution functions were measured for these precursor particles. Within a limited C/O range bimodality was found, i.e. two types of particles are formed simultaneously. Through analysis of the photoionization behaviour it was found that the ionization order (IO) is different for these two modes as is the stability of the respective particles. In accordance with earlier measurements, particles with IO = 1 are interpreted as polyaromatic hydrocarbon (PAH) stacks whereas the IO = 2 particles rather seem to be large molecules. This is consistent with the different particle classes mentioned above. Their potential role in soot formation is briefly addressed. Copyright © 2007 John Wiley & Sons, Ltd.
Using calibration approaches to compensate for remaining matrix effects in quantitative liquid chromatography/electrospray ionization multistage mass spectrometric analysis of phytoestrogens in aqueous environmental samples
Authors: Kang Jinguo , Hick Larry A. , Price William E.
Published: November 2007

Signal suppression is a common problem in quantitative liquid chromatography/electrospray ionization multistage mass spectrometric (LC/ESI‐MSn) analysis in environment samples, especially in highly loaded wastewater samples with highly complex matrix. Optimization of sample preparation and improvement of chromatographic separation are prerequisite to improve reproducibility and selectivity. Matrix components are reduced if not eliminated by optimization of sample preparation steps. However, extensive sample preparation may be time‐consuming and risk the significant loss of some trace analytes. The best way to further compensate matrix effects is the use of an internal standard for each analyte. However, in a multi‐component analysis, finding appropriate internal standards for every analyte is often difficult. In this present study, a more practical alternative option was sought. Matrix effects were assessed using the post‐extraction addition method. By comparison of three different calibration approaches, it was found that matrix‐matched calibration combined with one internal standard provides a satisfactory method for compensating for any residual matrix effects on all the analytes. Validating experiments on different sewage treatment plant (STP) influent samples analyzing for a range of phytoestrogens showed that this calibration method provided satisfactory results with concentration ratio 96.1–105.7% compared to those by standard addition. Copyright © 2007 John Wiley & Sons, Ltd.
Association‐based parser for speech understanding systems—details of knowledge and performance evaluation
Authors: Hori Masahiro , Ohsumi Makoto , Ozaki Hiroshi , Mizoguchi Riichiro , Kakusho Osamu
Published: November 2007

In language processing aiming at speech understanding, not only knowledge about the syntax and the semantics, but also knowledge about the context and the control play important roles in dissolving the ambiguity due to the uncertainty in the phoneme recognition. This paper discusses the association‐based parser ASP. Discussions are made especially on the details of the employed knowledges and the result of evaluation experiment, which was performed to verify the usefulness of the association mechanism. In ASP, based on the semantic memory, episode memory, syntactic knowledge and control knowledge, the vocabulary associated with a topic in the sentence is processed with priority, and the control of the search in the intelligent backtrack is performed. In the evaluation experiment, the control knowledge to determine the object of processing from the contending partial solutions, as well as the effect of the order of solution candidates in the phrase, are particularly examined. It was verified as the result that ASP exhibits a performance independent of the order of the solution candidates under a pertinent control strategy, and the correct phrase sequence is identified, based largely on the syntactic and semantic informations, even if there does not exist an appropriate topic.
Application of functional ANOVA models for hazard regression to the Hisayama data
Authors: Kawaguchi Atsushi , Yonemoto Koji , Tanizaki Yumihiro , Kiyohara Yutaka , Yanagawa Takashi , Truong Young K.
Published: November 2007

A methodology for modeling covariate effects on the time‐to‐event data is developed. The covariates are allowed to be time dependent and their effects are modeled using polynomial splines in order to account for possibly non‐linear effects. The methodology is applied to examine the effects on the incidence brain infarction based on a cohort study in Hisayama, Japan. The results indicate that at least two non‐linear effects are significant (body mass index and systolic blood pressure) and there is a time‐varying drug effect. The resulting significant risk factors are assessed by the proposed method that is more flexible and hence less biased than the traditional procedures where linear effects are imposed. These results are extremely important to the local medical investigation. In particular, more insight has been gained by examining the non‐linear effects. Copyright © 2007 John Wiley & Sons, Ltd.
Surgical Management of Gynecomastia—a 10‐year Analysis
Authors: Handschin A. E. , Bietry D. , Hüsler R. , Banic A. , Constantinescu M.
Published: November 2007

Background

Gynecomastia is defined as the benign enlargement of the male breast. Most studies on surgical treatment of gynecomastia show only small series and lack histopathology results. The aim of this study was to analyze the surgical approach in the treatment of gynecomastia and the related outcome over a 10‐year period.

Patients and methods

All patients undergoing surgical gynecomastia corrections in our department between 1996 and 2006 were included for retrospective evaluation. The data were analyzed for etiology, stage of gynecomastia, surgical technique, complications, risk factors, and histological results.

Results

A total of 100 patients with 160 operations were included. Techniques included subcutaneous mastectomy alone or with additional hand‐assisted liposuction, isolated liposuction, and formal breast reduction. Atypical histological findings were found in 3% of the patients (spindle‐cell hemangioendothelioma, papilloma). The surgical revision rate among all patients was 7%. Body mass index and a weight of the resected specimen higher than 40 g were identified as significant risk factors for complications (p < 0.05).

Conclusions

The treatment of gynecomastia requires an individualized approach. Caution must be taken in performing large resections, which are associated with increased complication rates. Histological tissue analysis should be routinely performed in all true gynecomastia corrections, because histological results may reveal atypical cellular pathology.
Abdominal Compartment Syndrome: Current Problems and New Strategies
Authors: Parsak Cem Kaan , Seydaoglu Gulsah , Sakman Gurhan , Acarturk T. Oguz , Karakoc Emre , Hanta Ismail , Alparslan Ali Haydar , Satar Salim
Published: November 2007

Background

Abdominal compartment syndrome (ACS) is a diffucult entity with two main problems during its course: (1) survival of the patient during the early period and (2) closure of the open wounds during the late period. In this study we evaluated the decision to decompress according to the level of intraabdominal pressure (IAP) and analysis of any recurrent or persistent increase in IAP.

Methods

A prospective study was undertaken on 119 patients with increased IAP. The IAP was measured daily by obtaining the bladder pressure. Patients were monitored via a central venous line; and vital signs, arterial blood gases, the Acute Physiology, Age, and Chronic Health Evaluation II (APACHE II) score, and abbreviated mental tests were recorded. The suggestions of Meldrum et al. were taken as a guideline during the treatment. The sensitivity and specifity of IAP and APACHE II scores for different cutoff values were calculated using the receiver operating characteristic curve.

Results

Hospital mortality was 33.6%, which increased with co‐morbidities (p = 0.03). A cutoff value for IAP of 23 mmHg was considered an optimal point predicting mortality. The IAP within the first 3 days for patients who died was higher than the cutoff value. For patients with IAP of 15 to 25 mmHg, nonsurgical therapy increased the rate of mortality (odds ratio 5.2, 95% confidence interval 1.0–27.7; p = 0.03).

Conclusions

In patients with ACS emergency, it is recommended that decompressive laparotomy to be performed even if the IAP falls below 25 mmHg. For patients with IAP levels higher than 25 mmHg, the IAP should be meticolusly brought below the cutoff level during the postoperative period.
Open Onlay Mesh Repair for Major Abdominal Wall Hernias with Selective Use of Components Separation and Fibrin Sealant
Authors: Kingsnorth Andrew N. , Shahid M. Kamran , Valliattu Aby J. , Hadden Robert A. , Porter Christine S.
Published: November 2007

Background

The objective of the study was to reassess the efficacy of the open onlay technique for repair of major incisional hernias, utilizing the modern adjuncts of components separation and fibrin sealant to reduce the principal complications of seroma and recurrence. Major incisional hernias were defined as >10 cm transverse diameter.

Methods

A prospective audit was applied to 116 patients undergoing open onlay incisional hernia repair during a 2‐year period at a single institution. Information was collected concerning operative details, postoperative complications, and recurrence. Clinical review at a median 15.2 months postoperatively was followed by a telephoned structured questionnaire to assess quality of life. All patients with pain or suspected recurrence were recalled for examination.

Results

Fascial closure required components separation in 21 (18.1%) patients when tension‐free fascia reconstruction was not possible, and fibrin sealant was applied in 22 (18.9%) in whom extensive skin flaps were dissected beyond the semilunar line. Postoperatively, there were 11 (9.5%) seromas and 2 (1.7%) deep wound infections. At 15.2 months’ follow‐up there were 4 (3.4%) recurrences.

Conclusions

Open onlay mesh repair for major incisional hernias is a versatile operation applicable to all quadrants of the abdominal wall and gives excellent results when used in association with components separation and fibrin sealant.
Mutation spectrum of glycogen storage disease type Ia in Tunisia: Implication for molecular diagnosis
Authors: Barkaoui E. , Cherif W. , Tebib N. , Charfeddine C. , Ben Rhouma F. , Azzouz H. , Ben Chehida A. , Monastiri K. , Chemli J. , Amri F. , Ben Turkia H. , Abdelmoula M. S. , Kaabachi N. , Abdelhak S. , Ben Dridi M. F.
Published: November 2007

Glycogen storage disease type Ia (GSD Ia; OMIM 232200) is an autosomal recessive disorder of glycogen metabolism caused by a deficiency of the microsomal glucose‐6‐phosphatase (G6Pase). It is characterized by short stature, hepatomegaly, hypoglycaemia, hyperuricaemia, and lactic acidaemia. Various mutations have been reported in the G6Pase gene (G6PC). In order to determine the mutation spectrum in Tunisia, we performed mutation analysis in 22 Tunisian type I glycogen storage disease (GSD I) patients belonging to 18 unrelated families. All patients were clinically classified as GSD Ia. The R83C mutation was found to be the major cause of GSD Ia, accounting for 24 of 36 mutant alleles (66.6%), The R170Q mutation was the second most frequent mutation; it accounts for 10 of 36 mutant alleles (27.7%). The R83C and R170Q mutations could be rapidly detected by PCR/RFLP. Since the majority of Tunisian patients carried R83C and/or R170Q mutations, we propose direct screening of these mutations as a rapid, valuable and noninvasive tool for diagnosis of GSD Ia in Tunisian as well as in Northern African populations.
High-protein diets containing different milk protein fractions differently influence energy intake and adiposity in the rat
Authors: Pichon Lisa , Potier Mylene , Tome Daniel , Mikogami Takashi , Laplaize Benoit , Martin-Rouas Christine , Fromentin Gilles
Published: November 2007

This study was designed to determine whether (1) protein type and (2) the dietary carbohydrate to lipid content affected daily energy intake, body weight and adiposity in rats receiving high-protein diets ad libitum over a 25 d period. Each of the ten groups (n 8) consumed ad libitum one of the diets described below. A normal protein diet (P14C56L30, containing whole milk protein) and nine high-protein diets were used. The composition of the high-protein diets varied in terms of two parameters: macronutrient composition and protein type. Three macronutrient compositions (P55C35L10, P55C15L30 and P55L45) combined with three protein types (Milk, Whey and βLac) allowed us to test nine diets. The results show that both protein type (βLac > Whey > Milk) and the carbohydrate to lipid ratio (P55L45>P55C35L10 or P55C15L30) modulated reductions in energy intake, body weight and adiposity in rats receiving high-protein diets ad libitum, when compared with rats fed a normal diet under the same conditions. By contrast, blood lipid profiles were mainly influenced by the carbohydrate to lipid ratio (P55C15L30>P55L45 or P55C35L10). Moreover, βLac protein was also the most efficient in tending to preserve lean body mass at the expense of fat mass, and improve blood metabolism hormones (insulin, leptin). Taken together, the present results show that whey-derived protein sources, and particularly β-lactoglobulin-enriched fraction, are of considerable value because of their ability to reduce both body weight gain and the adiposity index.
Effect of incremental levels of sunflower-seed oil in the diet on ruminal lipid metabolism in lactating cows
Authors: Shingfield K. J. , Ahvenjärvi S. , Toivonen V. , Vanhatalo A. , Huhtanen P. , Griinari J. M.
Published: November 2007

Based on the potential benefits ofcis-9,trans-11-conjugated linoleic acid (CLA) for human health there is interest in developing sustainable nutritional strategies for enhancing the concentration of this fatty acid in ruminant-derived foods. Most evidence to date suggests that endogenous synthesis is the major source ofcis-9,trans-11 in milk fat and ruminal outflow is limited and largely independent of dietary 18 : 2n-6 supply. Four lactating cows fitted with a rumen cannula were used in a 4 × 4 Latin square with 14 d experimental periods to examine the effects of sunflower-seed oil (SFO) as a source of 18 : 2n-6 on ruminal lipid metabolism. Cows were offered grass silage-based diets supplemented with 0, 250, 500 or 750 g SFO/d. Supplements of SFO had no effect on DM intake, milk fat or protein secretion, but increased linearly (P < 0·01) milk yield and milk lactose output and shifted (P < 0·001) rumen fermentation towards propionate at the expense of acetate. SFO supplements increased linearly (P < 0·05) the flow of 18 : 0, 18 : 1, 18 : 2n-6 and total CLA at the omasum and enhanced ruminalcis-9-18 : 1, 18 : 2n-6 and 18 : 3n-3 metabolism. Flows of all-trans- (Δ4–16) andcis- (Δ9–16) 18 : 1 isomers were elevated, while increases in ruminal CLA outflow were confined totrans-8,trans-10 and geometric 9,11 and 10,12 isomers. It is concluded that supplementing grass silage-based diets with plant oils rich in 18 : 2n-6 enhances ruminal outflow oftrans-11-18 : 1 andcis-9,trans-11-CLA in lactating cows.