bluuebunny/crossref_metadata_2025 huggingface dataset:
A geometric mass‐preserving redistancing scheme for the level set function
Authors: Ausas Roberto F. , Dari Enzo A. , Buscaglia Gustavo C.
Published: February 2010

In this paper we describe and evaluate a geometric mass‐preserving redistancing procedure for the level set function on general structured grids. The proposed algorithm is adapted from a recent finite element‐based method and preserves the mass by means of a localized mass correction. A salient feature of the scheme is the absence of adjustable parameters. The algorithm is tested in two and three spatial dimensions and compared with the widely used partial differential equation (PDE)‐based redistancing method using structured Cartesian grids. Through the use of quantitative error measures of interest in level set methods, we show that the overall performance of the proposed geometric procedure is better than PDE‐based reinitialization schemes, since it is more robust with comparable accuracy. We also show that the algorithm is well‐suited for the highly stretched curvilinear grids used in CFD simulations. Copyright © 2010 John Wiley & Sons, Ltd.
Velocity–pressure coupling in finite difference formulations for the Navier–Stokes equations
Authors: Zogheib B. , Barron R. M.
Published: February 2010

A new numerical procedure for solving the two‐dimensional, steady, incompressible, viscous flow equations on a staggered Cartesian grid is presented in this paper. The proposed methodology is finite difference based, but essentially takes advantage of the best features of two well‐established numerical formulations, the finite difference and finite volume methods. Some weaknesses of the finite difference approach are removed by exploiting the strengths of the finite volume method. In particular, the issue of velocity–pressure coupling is dealt with in the proposed finite difference formulation by developing a pressure correction equation using the SIMPLE approach commonly used in finite volume formulations. However, since this is purely a finite difference formulation, numerical approximation of fluxes is not required. Results presented in this paper are based on first‐ and second‐order upwind schemes for the convective terms. This new formulation is validated against experimental and other numerical data for well‐known benchmark problems, namely developing laminar flow in a straight duct, flow over a backward‐facing step, and lid‐driven cavity flow. Copyright © 2010 John Wiley & Sons, Ltd.
A Voronoi‐based ALE solver for the calculation of incompressible flow on deforming unstructured meshes
Authors: Norris S. E. , Were C. J. , Richards P. J. , Mallinson G. D.
Published: February 2010

An Arbitrary Lagrangian–Eulerian method for the calculation of incompressible Navier–Stokes equations in deforming geometries is described. The mesh node connectivity is defined by a Delaunay triangulation of the nodes, whereas the discretized equations are solved using finite volumes defined by the Voronoi dual of the triangulation.

For prescribed boundary motion, an automatic node motion algorithm provides smooth motion of the interior nodes. Changes in the connectivity of the nodes are made through the use of local transformations to maintain the mesh as Delaunay. This allows the nodes and their associated Voronoi finite volumes to migrate through the domain in a free manner, without compromising the quality of the mesh.

An MAC finite volume solver is applied on the Voronoi dual using a cell‐centred non‐staggered formulation, with cell‐face velocities being calculated by the Rhie–Chow momentum interpolation. Advective fluxes are approximated with the third‐order QUICK differencing scheme.

The solver is demonstrated via its application to a driven cavity flow, and the flow about flapping aerofoil geometries. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical simulation of 2D lid‐driven cavity flow with CLEARER algorithm on extremely highly skewed grids at high Reynolds numbers
Authors: Cheng Y. P. , Lee T. S. , Sui Y. , Wang L. P.
Published: February 2010

It is crucial to deal with the grid non‐orthogonality effectively in solving the flow in complex geometries, especially at high Reynolds numbers. In this study, the newly proposed Coupled and Linked Equations Algorithm Revised‐ER (CLEARER) algorithm is adopted to solve this problem successfully. In CLEARER algorithm the second relaxation factor is introduced in constructing the contravariant interface velocities, by setting it to a low value. CLEARER algorithm can overcome the severe grid non‐orthogonality and non‐linearity of equations effectively. After the numerical results with CLEARER are validated with the benchmark solutions, this algorithm is used to solve the lid‐driven flow in inclined cavity with inclination angles varying from 10 to 170∘, and Reynolds numbers varying from 5000 to 15 000. The streamlines and the centerline velocity distributions are provided in detail for all cases, which may offer some guidance for the study in this area. Copyright © 2010 John Wiley & Sons, Ltd.
Transient two‐layer thin‐film flow
Authors: Pandher Ramanjit S. , Khayat Roger E.
Published: February 2010

The transient two‐layer thin‐film planar flow is investigated theoretically in this study. The interplay among inertia, viscous and surface/interfacial tension is emphasized. It is found that the film and interface profiles, as well as the flow field, are strongly influenced by the viscosity ratio, velocity and film thickness ratios at inception, and the surface‐to‐interfacial tension ratio. The nonlinear stability of the steady state reveals the formation of a solitary wave after flow inception, which propagates in the form of a convective instability, with the steady state recovered only in the tail (upstream) region of the wave. In the presence of surface/interfacial tension, surface modulation appears, which grows in wavelength and amplitude with position. The flow is found to be particularly stable for higher viscosity of the lower film layer. Copyright © 2010 John Wiley & Sons, Ltd.
A direct‐forcing pressure‐based lattice Boltzmann method for solving fluid–particle interaction problems
Authors: Lin San‐Yih , Lin Chin‐Tien , Chin Ya‐Hsien , Tai Yuan‐Hung
Published: February 2010

A direct‐forcing immersed boundary‐lattice Boltzmann method (IB–LBM) is developed to simulate fluid–particle interaction problems. This method uses the pressure‐based LBM to solve the incompressible flow field and the immersed boundary method to handle the fluid–particle interactions. The pressure‐based LBM uses the pressure distribution functions instead of the density distribution functions as the independent dynamic variables. The main idea is to explicitly eliminate the compressible effect due to the density fluctuation. In the IB method, a direct‐forcing method is introduced to capture the particle motion. It directly computes an IB force density at each lattice grid from the differences between the pressure distribution functions obtained by the LBM and the equilibrium pressure distribution functions computed from the particle velocity. By applying this direct‐forcing method, the IB–LBM becomes a purely LBM version. Also, by applying the Gauss theorem, the formulas for computing the force and the torque acting on the particle from the flows are derived from the volume integrals over the particle volume instead of from the surface integrals over the particle surface. The order of accuracy of the IB–LBM is demonstrated on the errors of velocity field, wall stress, and gradients of velocity and pressure. As a demonstration of the efficiency and capabilities of the new method, sedimentation of a large number of spherical particles in an enclosure is simulated. Copyright © 2010 John Wiley & Sons, Ltd.
Comments on ‘Adiabatic shock capturing in perfect gas hypersonic flows’
Authors: Tezduyar Tayfun E.
Published: February 2010

Some comments are provided on the shock‐capturing techniques and stabilization parameters used in a recent paper (B.S. Kirk, Int. J. Numer. Meth. Fluids 2009; DOI: 10.1002/fld.2195) in conjunction with the SUPG formulation of compressible flows. Copyright © 2010 John Wiley & Sons, Ltd.
Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells Using In situ Modified Carbon Papers with Multi‐walled Carbon Nanotubes Nanoforest
Authors: Stuckey P. A. , Lin J. F. , Kannan A. M. , Ghasemi‐Nejhad M. N.
Published: February 2010

Gas diffusion layers (GDLs) in the proton exchange membrane fuel cells (PEMFCs) enable the distribution of reactant gases to the reaction zone in the catalyst layers by controlling the water in the pore channels apart from providing electrical and mechanical support to the membrane electrode assembly (MEA). In the present work, we report the in situ growth of carbon nanotubes nanoforest (CNN) directly onto macro‐porous carbon paper substrates. The surface property as analysed by a Goniometer showed that the CNN/carbon paper surface is highly hydrophobic. CNN/carbon paper was employed as a GDL in an MEA using Nafion‐212 membrane as an electrolyte and evaluated in single cell PEMFCs. While the GDLs prepared by wire‐rod coating process have major performance losses at lower humidities, the in situ CNN/carbon paper, developed in this work, shows very stable performance at all humidity conditions demonstrating a significant improvement for fuel cell performance. The CNN/carbon‐based MEAs showed very stable performance with power density values of ∼1,100 and 550 mW cm–2, respectively, both using O2 and air as oxidants at ambient pressure.
Synthesis and Characterisation of Sulphonated Poly(arylene sulphone) Terpolymers with Triphenylphosphine Oxide Moieties for Proton Exchange Membrane Fuel Cells
Authors: Titvinidze G. , Kaltbeitzel A. , Manhart A. , Meyer W. H.
Published: February 2010

For application in fuel cells, a series of sulphonated poly(phenylene sulphone) terpolymers with triphenylphosphine oxide moieties as constitutional units in the polymer backbone have been prepared. The synthesis of the terpolymers represents a two‐step process including: (i) an aromatic nucleophilic substitution polycondensation of three difluoro monomers with varying ratios, i.e. 3,3′‐disulphonate‐4,4′‐difluorodiphenylsulphone, 4,4′‐difluorodiphenylsulphone and bis(4‐fluorophenyl)phenyl phosphine oxide (BFPPO), with 4,4′‐thiobisbenzenethiol yielding sulphonated poly(phenylene sulphide) terpolymers (sPPSPO) and (ii) their following oxidation with hydrogen peroxide in acidic solution to yield sulphonated poly(phenylene sulphone) terpolymers (sPPSO2PO). The structures and molecular compositions were confirmed by 1H and 13C NMR spectroscopy. The ion exchange capacity (IEC) was adjusted at will choosing the appropriate ratio of sulphonated and unsulphonated monomers. Terpolymers with 1.72 ≤ IEC ≤ 2.32 have been obtained. Sulphonated poly(arylene) ionomers containing only sulphone (–SO2–) linkages and phosphine oxide (–PO–) units rather than ether or sulphide in the backbone reveal a high thermal and oxidative stability. Membranes were cast either from dimethylformamide (DMF) or from dimethyl sulphoxide (DMSO) solutions. For all terpolymers some general characteristic trends were observed, such as an increase of the proton conductivity with increasing IEC, water uptake and temperature. The series of sPPSO2PO membranes offered high conductivities at high humidification, however, their performance strongly depends on the relative humidity.

The mechanical properties of sulphonated poly(phenylene sulphone)s have been considerably improved by means of terpolymerisation with phenylene oxide moieties. Even under high humidification the terpolymers form clear, flexible membranes the stress at break of some membranes exceeds that of Nafion® under the same conditions by 40%.
A note on the relationship between the variability of the hedge ratio and hedging performance
Authors: Lien Donald
Published: February 2010

This note provides an analysis to examine the conjecture about the monotonic relationship between hedge ratio variability and hedging performance. Specific conditions are characterized to sustain the conjecture. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark
Single‐stage repair of subglottic stenosis using the radial forearm free flap as a vascularized carrier
Authors: Prasad Kumar G. , Varvares Mark A. , Odell Michael J.
Published: February 2010

Background.

We present a case report of a patient with history of subglottic carcinoma who underwent chemoradiation and subsequently developed subglottic stenosis (SGS).

Methods and Results.

She was treated with an anterior cricoid split maintained by septal cartilage wrapped in a partially deepithelialized radial forearm free flap (RFFF). To date, with a follow‐up of 6 months, the patient has been fully decannulated and has not experienced airway collapse or any other complications.

Conclusions.

Upper airway reconstruction using a single‐stage autogenous cartilage graft wrapped in a vascularized carrier is a real option for those patients with extensive SGS in the setting of an irradiated and devascularized tissue bed. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Outcome of sinonasal melanoma: Clinical experience and review of the literature
Authors: Roth Thomas N. , Gengler Carole , Huber Gerhard F. , Holzmann David
Published: February 2010

Background.

Primary sinonasal malignant melanoma (SNMM) is a rare clinical entity. There is neither a classification nor a staging system nor an evidence‐based treatment concept established. Our objective was to find potential risk factors predicting the outcome.

Methods.

Twenty‐five patients with histologically confirmed SNMM were consecutively included and retrospectively analyzed. Staging methods were nasal endoscopy, CT, MRI, and positron emission tomography (PET) scan. Patients were selected for a curative or palliative concept. All patients had postoperative follow‐up with control‐MRI at 3 and 6 months. Restaging was performed when local recurrence occurred.

Results.

Nineteen patients underwent primary surgery with curative intention; in 16 cases with tumor free margins. Thirteen patients (68%) had transnasal endoscopic surgery, 4 lateral rhinotomy, and 2 transfacial approach with orbital exenteration. Six patients (32%) had palliative therapy and 7 patients (37%) had adjuvant radiotherapy. Despite radical operations, 6 patients (37%) showed local recurrence and 8 patients (50%) developed distant metastasis. In 2 patients with incomplete surgery, regional metastasis was noted. The median disease‐free interval was 18 months, and the median overall survival rate was 23 months.

Conclusion.

SNMMs of the ethmoid and maxillary sinuses have a worse prognosis than other localizations in the nasal cavity; infiltration into the skull base, orbit, or facial soft tissue correlates with a very poor outcome corresponding to the palliative situations. Furthermore, local recurrence insinuates aggressive disease with short survival rate. A main difference from its cutaneous counterpart seems to be a primary tendency to hematogenic spread. Further research is needed to confirm these findings. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Correlation between reduced expression of the spindle checkpoint protein BubR1 and bad prognosis in tonsillar carcinomas
Authors: Hannisdal Kirsten , Burum‐Auensen Espen , Schjølberg Aasa , De Angelis Paula M. , Clausen Ole Petter F.
Published: February 2010

Background.

Spindle checkpoint proteins such as Mad2 and BubR1 are important for chromosome segregation during mitosis. The aim of the present study was to examine their possible impact on prognosis in tonsillar carcinomas and their relation to clinical variables, the prevalence of human papillomavirus (HPV), p53 status, and Ki‐67 positivity.

Methods.

We examined the expression of Mad2 and BubR1 by immunohistochemistry on tissue microarrays from 105 patients with tonsillar carcinomas.

Results.

BubR1 and Mad2 were both expressed in tonsillar carcinomas. Expression of BubR1 was a significant prognostic factor in univariate survival analysis. In multivariate analyses, BubR1 was a significant prognostic factor together with stage, age, and HPV statusp< .01), whereas Mad2 did not show any significant correlations.

Conclusion.

We have shown that BubR1 expression is a novel and strong prognostic factor in tonsillar carcinomas, giving additional information to the TNM stage and other known prognostic factors. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Misses and near‐misses after postoperative radiation therapy for head and neck cancer: Comparison of IMRT and non‐IMRT techniques in the CT‐simulation era
Authors: Chen Allen M. , Farwell D. Gregory , Luu Quang , Chen Leon M. , Vijayakumar Srinivasan , Purdy James A.
Published: February 2010

Background.

The purpose of this study was to compare the patterns of failure focusing on the distribution of local‐regional recurrence among patients treated postoperatively with conventional radiotherapy (RT) and intensity‐modulated radiotherapy (IMRT) for head and neck cancer.

Methods.

The records of 130 patients treated by surgery and postoperative radiation therapy for squamous cell carcinoma of the head and neck were reviewed. Seventy‐eight patients (60%) were treated using conventional RT and 52 patients (40%) were treated using IMRT.

Results.

The 3‐year estimates of local‐regional control were 70% and 73% among patients treated by conventional RT and IMRT, respectively (p = .33). Among the local‐regional recurrences in the IMRT group, 9 were in‐field recurrences occurring within the physician‐designated clinical target volume (CTV), and 4 were marginal recurrences involving the contralateral neck adjacent to the spared parotid gland (3 patients) and the retropharyngeal/retrostyloid lymph node region (1 patient).

Conclusion.

Our study showed that conventional RT and IMRT result in similar rates of local‐regional control. The implications for CTV design are discussed herein. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Induction of laryngeal cancer cell death by Ent‐11‐hydroxy‐15‐oxo‐kaur‐16‐en‐19‐oic acid
Authors: Vlantis Alexander C. , Lo Chun Shan , Chen George G. , Ci Liang Nian , Lui Vivian W. Y. , Wu Kefeng , Deng Yi Feng , Gong Xianling , Lu Yingnian , Tong Michael C. F. , van Hasselt C. Andrew
Published: February 2010

Background.

Ent‐11‐hydroxy‐15‐oxo‐kaur‐16‐en‐19‐oic acid (5F) is known to exhibit antitumor activity, but its mechanism is not completely understood. 5F has not been tested in laryngeal cancer.

Methods.

Two laryngeal cancer cell lines were treated with 5F. Cell death was analyzed by MTT [3‐(4,5‐dimethylthiozol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] and Annexin V assay. Nuclear factor kappa beta (NF‐κB)– and apoptosis‐related molecules were examined.

Results.

5F induced laryngeal cancer cell death in a dose‐dependent manner. The Annexin V assay and the measurement of cleavage of procaspase‐3 and poly(ADP‐ribose) polymerase demonstrated that the 5F‐induced cell death was mainly apoptotic. 5F slightly reduced the basal level of NF‐κB, but significantly suppressed the inducible NF‐κB by reducing its transcriptional activity, protecting its inhibitory subunit IκBα from degradation, and suppressing its level in the nucleus. 5F also inhibited pro‐proliferative and anti‐apoptotic molecules but promoted pro‐apoptotic Bax.

Conclusions.

5F induces apoptosis of laryngeal cancer cells by inhibiting NF‐κB activation/induction, suppressing pro‐proliferative and anti‐apoptotic molecules, and promoting pro‐apoptotic Bax. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
The involvement of hypophyseal‐gonadal and hypophyseal‐adrenal axes in arsenic‐mediated ovarian and uterine toxicity: Modulation by hCG
Authors: Chattopadhyay Sandip , Ghosh Debidas
Published: February 2010

This study evaluated the involvement of hypophyseal‐gonadal and hypophyseal‐adrenal axes as a possible mechanism of sodium arsenite toxicity in ovary and uterus by the coadministration of hCG. Subchronic treatment of 0.4 ppm of sodium arsenite/(100 g body weight day) via drinking water for seven estrous cycles significantly suppressed the plasma levels of leutinizing hormone, follicle‐stimulating hormone, and estradiol along with sluggish ovarian activities of Δ5,3β‐hydroxysteroid dehydrogenase and 17β‐hydroxysteroid dehydrogenase followed by a reduction in gonadal tissue peroxidase activities in mature female rats at diestrous phase. Noticeable weight loss of the ovary and uterus along with prolonged diestrous phase and increased deposition of arsenic in the plasma and in these reproductive organs were also demonstrated following the ingestion of arsenic. Follicular atresia and thinning of the uterine luminal diameter were evident after sodium arsenite treatment. Effective protection of gonadal weight loss, suppressed ovarian steroidogenesis, and altered ovarian and uterine peroxidase activities were noticed when 1.0 IU hCG/(100 g body weight day) is given in arsenic‐intoxicated rats. Normal estrous cyclicity was restored toward the control level after hCG coadministration, though the elimination of elementary arsenic from the plasma and gonadal tissues was impossible. A significant recovery in the restoration of ovarian and uterine histoarchitecture was prominent after hCG treatment. Adrenal hypertrophy and steroidogenic arrest of the adrenal gland along with altered level of brain monoamines in the midbrain and diencephalons following arsenic intoxication were also ameliorated after hCG coadministration. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:29–41, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20309
Antihyperlipidemic activity of 3‐hydroxymethyl xylitol, a novel antidiabetic compound isolated fromCasearia esculenta(Roxb.) root, in streptozotocin‐diabetic rats
Authors: Chandramohan Govindasamy , Al‐Numair Khalid S. , Sridevi Muruhan , Pugalendi Kodukkur Viswanathan
Published: February 2010

Casearia esculentaroot (Roxb.) is widely used in traditional system of medicine to treat diabetes in India. An active compound, 3‐hydroxymethyl xylitol (3‐HMX), has been isolated, and its optimum dose has been determined in a short duration study and patented. In addition, the long‐term effect of 3‐HMX in type 2 diabetic rats on carbohydrate metabolism was investigated, and its antihyperglycemic effect was shown previously (Chandramohan et al.,Eur J Pharmacol2008;590:437–443). In this study we investigated the effect of 3‐HMX on plasma and tissue lipid profiles in streptozotocin‐induced diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180–200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. The normal and diabetic rats were treated with 3‐HMX (40 mg/kg BW/day) for 45 days. The levels of total cholesterol, triglycerides, free fatty acids, and phospholipids were assayed in the plasma besides lipoprotein‐cholesterol (high‐density lipoprotein‐cholesterol (HDL‐C), low‐density lipoprotein‐cholesterol (LDL‐C), and very low density lipoprotein‐cholesterol (VLDL‐C)) and tissues (liver, kidney, heart, and brain). Total cholesterol, triglyceride, free fatty acid, and phospholipid (LDL‐C and VLDL‐C in plasma only) levels increased in plasma and tissues significantly, whereas plasma HDL‐C significantly decreased in diabetic rats. Treatment with 3‐HMX or glibenclamide reversed the above‐mentioned changes and improved toward normalcy. Histological study of liver also confirmed the biochemical findings. Thus administration of 3‐HMX is able to reduce hyperglycemia and hyperlipidemia related to the risk of diabetes mellitus. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:95–101, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20317
Gas–liquid mass transfer studies for biomass support materials in a bioreactor
Authors: Kılıç Apar Dilek
Published: February 2010

BACKGROUND: Oxygen mass transfer can be described and analyzed by means of the mass transfer coefficient kLa, which is the most important parameter involved in the design and operation of mixing–sparging equipment for bioreactors. In the present study, the effect of biomass support materials on the gas–liquid mass transfer coefficient was studied in a bioreactor under variable process conditions. The biomass support materials used were activated carbon, pumice and loofa sponge.

RESULTS: Compared with the case with distilled water only, the presence of the biomass support materials negatively influenced mass transfer. On the other hand, the mass transfer coefficient increased with increased impeller speed, air flow rate and temperature; and decreased with the increase of liquid viscosity and biomass support material concentration for all cases.

CONCLUSIONS: Evaluation of the experimental data showed that kLa values were affected by process variables. Besides the major exponential correlations used in the literature, satisfactory linear correlations for the relationship between the kLa and process variables were obtained. Copyright © 2010 Society of Chemical Industry
Is prenatal volumetric evaluation of aneurysm of the vein of Galen important in the prediction of adverse fetal outcome?
Authors: Gün İsmet , Müngen Ercüment , Kurdoğlu Mertihan , Babacan Ali , Muhcu Murat , Atay Vedat
Published: February 2010

Aneurysm of the vein of Galen is a rare congenital vascular malformation of the central nervous system. There are controversies in the literature regarding the possible prognostic value of aneurysmal volume estimation with 3‐dimensional US for the prediction of fetal outcome. In this report, we present a case of prenatally diagnosed large aneurysm of the vein of Galen complicated by heart failure in a fetus. The volume of the malformation was calculated as 17.8 cm3 and the fetal outcome was poor. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:443–445, 2010
Leptin‐like immunoreactivity in the muscle of juvenile sea bass (Dicentrarchus labrax)
Authors: Gambardella Chiara , Ferrando Sara , Gallus Lorenzo , Ravera Silvia , Bianchini Paolo , Ramoino Paola , Fasulo Salvatore , Tagliafierro Grazia
Published: February 2010

The mammalian hormone, leptin, is mainly synthesized in adipose tissue along with other tissues. Leptin plays a role in numerous processes such as in the control of food intake, homeostasis, immune function and reproduction. In this study, we detected and localized leptin immunoreactivity to the muscle of early juvenile sea bass (Dicentrarchus labrax) by Western blot analysis and immunohistochemistry. A leptin immunopositive band with a molecular weight of ∼16 kDa, corresponding to mammalian leptin, was identified in trunk skeletal muscle homogenate. Furthermore, leptin immunopositive cells were detected in the endomysium of skeletal muscular fibers. These cells showed immunostained cytoplasmic granules and roundish and oval nuclei. The most intense immunostaining was observed in the endomysial space among the superficial red muscular fibers of the trunk. These findings suggest that in early juvenile sea bass, leptin is mostly produced by skeletal muscles. Therefore, during the developmental stage lacking adipose tissue, skeletal muscles can be considered an important source of leptin. As already suggested in mammals, we can hypothesize the potential roles of leptin not only in energy expenditure for muscle contraction but also during muscle differentiation and growth. Microsc. Res. Tech. 73:797–802, 2010. © 2010 Wiley‐Liss, Inc.
The administration of nonmetabolizable glucose analogues fails to suppress the development of glycogen autophagy in newborn rat hepatocytes
Authors: Kalamidas Stefanos A. , Kondomerkos Dimitrios J.
Published: February 2010

The effects of parenteral administration of glucose, 3‐methylglucose (3MG), or 2‐deoxyglucose (2DG) on the glycogen autophagy were studied in the newborn rat liver using electron microscopy and biochemical methods. The administration of glucose resulted in hyperglycemia and prevented the mobilization of hepatocytic glycogen. It also prevented the development of autophagic vacuoles in general and inhibited the glycogen‐degrading activity of acid α‐1,4‐glucosidase. The nonphosphorylated and not further metabolized glucose analog 3MG also produced hyperglycemia, but increased acid glucosidase. Pretreating the newborns with the β‐adrenergic blocker propranolol inhibited the effects of 3MG. The phosphorylated but not fully metabolized glucose analog 2DG produced similar effects. The administration of xylitol to the newborns already treated with 2DG, suppressed acid glucosidase. The results of this and our previous studies suggest that glucose must be metabolized beyond its phosphorylation step to inhibit acid glucosidase activity. Microsc. Res. Tech. 73:1009–1014, 2010. © 2010 Wiley‐Liss, Inc.
Microhardness and SEM after CO2 laser irradiation or fluoride treatment in human and bovine enamel
Authors: Souza‐Gabriel A.E. , Colucci V. , Turssi C.P. , Serra M.C. , Corona S.A.M.
Published: February 2010

Background: It remains uncertain as to whether or not CO2 laser is able to hinder demineralization of enamel. The possibility to use bovine instead of human teeth on anticariogenic studies with laser has not yet been determined. Purpose: To compare the ability of CO2 laser and fluoride to inhibit caries‐like lesions in human enamel and to test whether a similar pattern of response would hold for bovine enamel. Study Design: Ninety‐six enamel slabs (2 × 2 × 4 mm) (48 from bovine and 48 from human teeth) were randomly distributed according to surface treatment (n = 12): CO2 laser, 5% sodium fluoride varnish (FV), 1.23% acidulated phosphate fluoride (APF) gel, or no treatment (control). Specimens were subjected to a 14‐day in vitro cariogenic challenge. Microhardness (SMH) was measured at 30 μm from the surface. For ultrastructural analysis, additional 20 slabs of each substrate (n = 5) received the same treatment described earlier and were analyzed by SEM. Results: ANOVA and Tukey test ascertained that CO2 laser promoted the least mineral loss (SMH = 252a). Treatment with FV resulted in the second highest values (207b), which was followed by APF (172c). Untreated specimens performed the worst (154d). SEM showed no qualitative difference between human and bovine teeth. APF and control groups exhibited surfaces covered by the smear layer. A granulate precipitate were verified on FV group and fusion of enamel crystals were observed on lased‐specimens. Conclusions: CO2 laser may control caries progression more efficiently than fluoride sources and bovine teeth may be a suitable substitute for human teeth in studies of this nature. Microsc. Res. Tech. 73:1030–1035, 2010. © 2010 Wiley‐Liss, Inc.
Image processing techniques in a preliminary morphometric characterization of corneal epithelium by scanning electron microscopy
Authors: Julio Gemma , Merindano Dolores , Canals Marc , Ralló Miquel
Published: February 2010

Several processing techniques of digital images allowed us to quantify the percentage of cell surface covered by microprojections (microvilli or microplicae) (SCM), the adhesion between epithelial cells by the parameter intercellular junctions (IJ), the size (cell area), shape (cell shape) and shade (cell shade) of cells on the corneal epithelium of nine rabbits. The data were analyzed and the epithelial cells were classified into three groups by cluster analysis. Assuming the representativeness of the sample, our findings suggest that for a normal corneal epithelium, 80% of the cells could show SCM >41%, and IJ >0.98 (being one a cell to cell junction without disruptions). Standard deviations of cell shade lower than 21 gray levels could indicate a tendency to lose the cell shade mosaic. Normal corneas could show a majority of cells (54–69%) included in group 2 with smaller mean size (80% of cells with cell area <242 μm2), higher SCM (80% of cells with SCM >44.83%), polygonal mean shape and brighter shade. Group 1 (15–30% of cells) could show a larger mean size (80% of cells with cell area >494 μm2), lower SCM (although 80% of cells with SCM >32.61%), circular mean shape and darker electron reflex. Group 3 could display a medium mean size, higher SCM (similar to group 2), circular mean shape (similar to group 1), and brighter shade. These analyses could possibly be used to further assess the corneal response to ocular drugs, contact lens, and surgical procedures or to discriminate between pathology stages. Microsc. Res. Tech. 73:1059–1066, 2010. © 2010 Wiley‐Liss, Inc.
Nucleophilic [18F]Fluorination and subsequent decarbonylation of methoxy‐substituted nitro‐ and halogen‐benzenes activated by one or two formyl groups
Authors: Shen Bin , Löffler Dirk , Reischl Gerald , Machulla Hans‐Jürgen , Zeller Klaus‐Peter
Published: February 2010

As model reactions for the introduction of 18F into protected aromatic amino acids, the replacement of NO2, Cl, Br and F by [18F]fluoride in 2‐isophthalaldehyde and 2‐terephthalaldehyde derivatives which model 18F‐DOPA and 18F‐tyrosine was investigated by comparing labelling yields and reaction rates with those of corresponding mono‐aldehyde compounds. All isophthalaldehydes showed maximum radiochemical yields (79 to 86%) at 140°C and in comparison with the corresponding mono‐aldehydes the reaction proceeded faster. At lower temperature the reaction already resulted in high yields, e.g. 2‐nitroisophthalaldehyde was labelled with a yield of 78% at 25°C after 7 min, whereas 2‐nitrobenzaldehyde only reached a yield of 1.7% under the same reaction conditions. The 18F/NO2 exchange in nitroterephthalaldehydes proceeded more slowly and with lower radiochemical yields when compared with corresponding isophthalaldehydes and monoaldehydes. The decarbonylation of 18F‐labelled aromatic dialdehydic compounds with 4 eq. of Wilkinson's catalyst at 150°C in benzonitrile resulted in high yields, e.g. 2‐[18F]fluoro‐5‐methoxyisophthalaldehyde and 4‐[18F]fluoro‐2‐methoxy‐5‐methylisophthalaldehyde were decarbonylated efficiently with yields of 67±3% and 72±2%, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Social and trauma‐related pathways leading to psychological distress and functional limitations four years after the humanitarian emergency in Timor‐Leste
Authors: Silove D. , Brooks R. , Steel Bateman C. , Steel Z. , Fonseca C. Amaral Z. , Rodger J. , Soosay I.
Published: February 2010

There is growing acknowledgment that research in the postconflict field needs to include a focus on social conditions. The authors applied structural equation modeling to epidemiologic data obtained from postconflict Timor‐Leste, to examine for links involving potentially traumatic events and sociodemographic factors (age, gender, educational levels, and unemployment) with psychological symptoms and functioning. Exposure to trauma and lack of education emerged as most relevant with psychological distress impacting on education in the urban area. Age and gender exerted influences at different points in the model consistent with the known history of Timor. Although based on cross‐sectional data, the model supports the relevance of past trauma, posttraumatic distress, and postconflict social conditions to functioning in societies such as Timor‐Leste.
Preparation of cis‐1,4‐Polyisoprene Electrospun Microfibers
Authors: Hao Xiufeng , Bai Chenxi , Huang Yue , Bi Jifu , Zhang Chunyu , Cai Hongguang , Zhang Xuequan , Du Liping
Published: February 2010

cis‐1,4‐Polyisoprene, a significant industrial elastomer, is electrospun into different nanostrucutures. Cis‐1,4‐polyisoprene electrospun fibers are prepared from cis‐1,4‐polyisoprene solutions in dichloromethane or chloroform and characterized by environmental scanning electron microscope and Fourier‐transform infrared spectroscopy. ESEM observation reveals that the cis‐1,4‐polyisoprene fibers show a bamboo‐like morphology with a nearly constant node distance, a diameter of 20–60 µm and a length of about 300 µm. In addition, within the individual nodes parallel grooves are clearly seen, which is very promising for their use in microprinting in the field of microelectronics. Smooth cis‐1,4‐polyisoprene fibers with a diameter of 5–8 µm can be obtained via electrospinning its chloroform solutions. In contrast to most polymers, the jet of cis‐1,4‐polyisoprene does not split during the electrospinning processes, which facilitates the collection of highly aligned fibers by using a rotating mandrel as a ground target.

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AMPK‐mediated phosphorylation of murine p27 at T197 promotes binding of 14‐3‐3 proteins and increases p27 stability
Authors: Short John D. , Dere Ruhee , Houston Kevin D. , Cai Sheng‐Li , Kim Jinhee , Bergeron Judith M. , Shen Jianjun , Liang Jiyong , Bedford Mark T. , Mills Gordon B. , Walker Cheryl Lyn
Published: February 2010

The tuberous sclerosis complex 2 (Tsc2) gene product, tuberin, acts as a negative regulator of mTOR signaling, and loss of tuberin function leads to tumors of the brain, skin, kidney, heart, and lungs. Previous studies have shown that loss of tuberin function affects the stability and subcellular localization of the cyclin‐dependent kinase inhibitor (CKI) p27, although the mechanism(s) by which tuberin modulates p27 stability has/have not been elucidated. Previous studies have also shown that AMP‐activated protein kinase (AMPK), which functions in an energy‐sensing pathway in the cell, becomes activated in the absence of tuberin. Here we show that in Tsc2‐null tumors and cell lines, AMPK activation correlates with an increase in p27 levels, and inhibition of AMPK signaling decreases p27 levels in these cells. In addition, activation of AMPK led to phosphorylation of p27 at the conserved terminal threonine residue of murine p27 (T197) in both in vitro kinase assays and in cells. Phosphorylation of p27 at T197 led to increased interaction between p27 and 14‐3‐3 proteins and increased the protein stability of p27. Furthermore, activation of AMPK signaling promoted the interaction between p27 and 14‐3‐3 proteins and increased the stability of the p27 protein in a manner that was dependent on T197. These data identify a conserved mechanism for the regulation of p27 stability via phosphorylation at the terminal threonine (mT197/hT198) and binding of 14‐3‐3 proteins, which when AMPK is activated results in stabilization of the p27 protein. © 2010 Wiley‐Liss, Inc.
Peroneal artery perforator chimeric flap for reconstruction of composite defects in extremities
Authors: Chai Yi‐Min , Wang Chun‐Yang , Zeng Bing‐Fang , Chen Zeng‐Gan , Cai Pei‐Hua , Kang Qing‐Lin , Ruan Hong‐Jiang
Published: February 2010

Large bone defects of extremities, especially those associated with soft tissue defects, represent difficult reconstructive problems. Chimeric flap is a suitable option for reconstruction of complex bone and soft‐tissue defects. In this report, we present the experience on use of the peroneal artery perforator chimeric flap for the reconstruction of complex bone and soft tissue defects in the extremities in 16 patients. The bone defects were located in the tibia in 8 patients, in both tibia and fibula in 1 patient, in the ulna in 2 patients, in both ulna and radius in 2 patients, and the metatarsal bone in 3 patients. The flap was created with skin paddle and fibula bone segments based on independent perforators. The sizes of flap ranged from 8 × 6 to 20 × 11 cm2, and the length of fibular grafts ranged from 6 to 22 cm. All flaps survived completely. Bone union was ultimately obtained in all cases at 5 to 11 months, while two cases suffered from stress fractures in 12 month and 18 month after operation, respectively, which eventually healed with external fixation treatment. The follow‐up time ranged from 12 to 37 months. The definite bone hypertrophy was observed from X‐ray at 18 months after operation. In conclusion, our results show that the peroneal artery perforator chimeric flap is a good option for reconstruction of complex bone and soft‐tissue defects of extremities, particularly for those with three‐dimensional defects and bone defects exceeding 6 cm in length. © 2010 Wiley‐Liss, Inc. Microsurgery, 2010.
Optimizing the number of multigrid cycles in the full multigrid algorithm
Authors: Thekale A. , Gradl T. , Klamroth K. , Rüde U.
Published: February 2010

Multigrid (MG) methods are among the most efficient and widespread methods for solving large linear systems of equations that arise, for example, from the discretization of partial differential equations. In this paper we introduce a new approach for optimizing the computational cost of the full MG method to achieve a given accuracy by determining the number of MG cycles on each level. To achieve this, a very efficient and flexible Branch and Bound algorithm is developed. The implementation in the parallel finite element solver Hierarchical Hybrid Grids leads to a significant reduction in CPU time. Copyright © 2010 John Wiley & Sons, Ltd.
An evaluation of a problem‐based learning experience in an occupational therapy curriculum in the UK
Authors: Spalding Nicola Jane , Killett Anne
Published: February 2010

The objectives of the study was to evaluate an adapted approach to problem‐based learning (PBL) on a pre‐registration Masters course in Occupational Therapy at the University of East Anglia in the UK. The adaptation, named placement PBL, required students to write and select the material based on their placement experiences, for the cohort's learning. The evaluation purpose was to determine the students' views of the efficacy of placement PBL for facilitating their learning in the final 3 months of their pre‐registration education. Placement PBL was evaluated using both questionnaires and focus groups, with two cohorts of students for data collection. Placement PBL was seen to provide current, relevant and complex learning scenarios that help students to move from a theoretical understanding to application of theory in the complexity of actual service situations. The authors conclude that placement PBL has the potential to prepare students for the transition from student to qualified practitioner. Both researchers were also the PBL tutors which may have affected the students' honesty in their feedback. Further research is indicated for ongoing evaluations of the effectiveness of PBL in helping students to become confident occupational therapy clinicians, and comparative studies with other learning approaches. Copyright © 2010 John Wiley & Sons, Ltd.
Medulloblastoma in young children
Authors: Rutkowski Stefan , Cohen Bruce , Finlay Jonathan , Luksch Roberto , Ridola Vita , Valteau‐Couanet Dominique , Hara Junichi , Garre Maria‐Luisa , Grill Jacques
Published: February 2010

In early childhood medulloblastoma, three distinct treatment strategies are currently used by different national groups to improve survival rates and to delay or avoid craniospinal radiotherapy: (1) systemic chemotherapy and high‐dose chemotherapy, followed by radiotherapy at relapse; (2) systemic and intraventricular chemotherapy; (3) systemic chemotherapy and local conformal radiotherapy. A role for high‐dose chemotherapy to delay or avoid craniospinal radiotherapy as a part of multimodal treatment strategies, especially in young children with metastatic or postoperative residual disease, has been recognized by different co‐operative groups. Clinical and histological factors such as nodular‐desmoplastic variants are considered as important prognostic factors for risk‐adapted treatment recommendations. Pediatr Blood Cancer 2010;54:635–637. © 2009 Wiley‐Liss, Inc.
The role of myeloablative chemotherapy with autologous hematopoietic cell rescue in central nervous system germ cell tumors
Authors: Bouffet Eric
Published: February 2010

This review of the experience of high dose chemotherapy in patients with recurrent or refractory intracranial germ cell tumor confirms that sustained tumor control can be achieved with this modality both in germinoma and non‐germinomatous germ cell tumors. Data from cooperative groups in Europe and North America suggest that the success rate is higher among patients with recurrent germinoma. The role of adjuvant radiation in that context remains unclear. These promising results have led some cooperative groups to incorporate in their protocols a high dose chemotherapy component for newly diagnosed patients with high‐risk features or poor response to initial chemotherapy. Pediatr Blood Cancer 2010;54:644–646. © 2010 Wiley‐Liss, Inc.
Adverse drug reactions induced by cardiovascular drugs in cardiovascular care unit patients
Authors: Mohebbi Niayesh , Shalviri Gloria , Salarifar Mojtaba , Salamzadeh Jamshid , Gholami Kheirollah
Published: February 2010

Purpose

To detect the type, rate, seriousness, and preventability of adverse drug reactions (ADRs) attributable to cardiovascular drugs in cardiovascular care unit; and to determine the relationship between patient factors and detected ADRs.

Methods

Patients admitted to cardiovascular care units in Tehran Heart Center over an eight month period who received at least one cardiovascular drug were eligible to enter the study. ADRs were recorded based on information collected by interviewing patients, reviewing patients' charts, laboratory test monitoring, and confirmation by physicians. The World Health Organization definition for ADR, its seriousness and casualty criteria, was used to evaluate the reactions. The preventability was estimated based on Schumock and Thornton questioning. The relationship between possible risk factors and ADRs occurrence were assessed by statistical analysis.

Results

During the study period, 677 patients entered the study. A total number of 189 ADRs were registered of which 22.2% were serious. The highest ADR rates were observed with Streptokinase (59.3%). The rate of preventable ADRs was 6.9%. Multivariate logistic regression analysis showed that patients with lower weight (OR = 0.95, 95%CI: 0.9–0.99) and patients with smoking history who had concurrent diseases (OR = 8.72, 95%CI: 1.53–49.52) had a higher risk of experiencing ADRs.

Conclusion

The rate of ADRs induced by cardiovascular drugs in this study was 24.2%. This study has shown that anti‐arrhythmic and thrombolytic agents need more attention. Copyright © 2010 John Wiley & Sons, Ltd.
The mechanisms of the homogeneous, unimolecular, elimination kinetics of several β‐substituted diethyl acetals in the gas‐phase
Authors: Mora José R. , Maldonado Alexis , Domínguez Rosa M. , Chuchani Gabriel
Published: February 2010

The rates of gas‐phase elimination of several β‐substituted diethyl acetals have been determined in a static system and seasoned with allyl bromide. The reactions, inhibited with toluene, are homogeneous, unimolecular, and follow first‐order law kinetics. These elimination processes involve two parallel reactions. The first parallel reaction yields ethanol and the corresponding ethyl vinyl ether. The latter product is an unstable intermediate and further decomposes to ethylene and the corresponding substituted aldehyde. The second parallel reaction gives ethane and the corresponding ethyl ester. The kinetics has been measured over the temperature range of 370–441 °C and pressure range of 23–160 torr. The rate coefficients are given by the following Arrhenius equations:

The differences in the rates of ethanol formation may be attributed to electronic transmission of the β‐substituent. The comparative kinetic and thermodynamic parameters of the parallel reactions suggest two different concerted polar four‐membered cyclic transition state types of mechanisms. Copyright © 2010 John Wiley & Sons, Ltd.