bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Nanogold‐Labeled Immunoresonance Scattering Spectral Probe for Determination of Trace IgG
Authors: Jiang Zhi‐Liang , Li Yan , Sun Shuang‐Jiao , Chen Bing
Published: September 2007

A kind of 9 nm gold nanoparticles was prepared with the trisodium citrate and used to label goat anti‐human IgG to obtain an IgG immunoresonance scattering spectral probe. In pH 5.8 buffer solution and in the presence of polyethylene glycol (PEG), the immune reaction between gold‐labeled goat anti‐human IgG and IgG took place, and the resonance scattering intensity at 580 nm (I580 nm) was enhanced greatly. The enhanced intensity ΔIRS is proportional to the IgG concentration from 1.3 to 1.5×103 ng·mL−1, with a detection limit of 0.78 ng·mL−1. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum, with satisfactory results.
Extractive Spectrophotometric Determination of Fluconazole by Ion‐pair Complex Formation with Bromocresol Green
Authors: Jalali Fahimeh , Rajabi Mohammad J.
Published: September 2007

An extraction‐spectrophotometric method for the determination of trace amounts of fluconazole was described. Fluconazole was effectively extracted as a 1:1 ion‐pair complex with bromocresole green (BCG) at pH 3.0 into chloroform, followed by spectrophotometric determination at 420 nm. Beer′s law was obeyed over the range of 4–50 µg·mL−1 of fluconazole with a detection limit of 3.7 µg·mL−1. The method is simple, rapid and sensitive. The procedure was applied to the determination of fluconazole in pharmaceutical preparations as well as its recovery from a blood serum sample.
Reaction of Alkanesulfinyl Chloride with Grignard Reagents: a Convenient Synthesis of Alkyl Sulfoxides
Authors: Li Xiao‐Bo , Liu Jin‐Tao
Published: September 2007

Alkyl sulfoxides were synthesized in good yields from the reaction of alkanesulfinyl chloride with Grignard reagents in the presence of zinc chloride.
Ligand Bridged and Bis‐ligand Coordinated Titanium Complexes: Synthesis, Structure and Relevance to Phenylacetylene Hydroanilination Catalysis
Authors: Han Xiao‐Yu , Li Ya‐Hong , Wei Hua , Zhang Yong
Published: September 2007

Two ligand bridged binuclear titanium complexes Ti2(bppda)3(NMe2)2·3THF (1) and Ti2(bppda)3(NEt2)2·3THF (2) and one bis‐ligand coordinated mononuclear complex Ti(bppda)2 (3) (ligand: H2bppdaN,N′‐Bis(2‐pyrrylmeth‐ylidene)‐1,2‐phenylenediamine) were synthesized by adjusting the ratio of the starting materials and the reaction speed. The complexes were fully characterized with NMR, elemental analysis and X‐ray crystal diffraction. The catalytic activity of the complex 1 to phenylacetylene hydroanilination reaction was also investigated.
Organogels Derived from Potassium 8‐Nitroquinolinecarboxylate
Authors: Hu Hai‐Yu , Yang Yong , Xiang Jun‐Feng , Chen Chuan‐Feng
Published: September 2007

A new class of organogels derived from potassium 8‐nitroquinolinecarboxylate was selectively formed inTHF/MeOH (V:V=1:1), and their superstructures were characterized by atomic force microscopy, scanning electron microscopy and transmission electron microscopy.
Characterization of a multiple epigenetic marker panel for lung cancer detection and risk assessment in plasma
Authors: Hsu Han‐Shui , Chen Tsz‐Pei , Hung Chein‐Hui , Wen Chiao‐Kai , Lin Rou‐Kai , Lee Hui‐Chen , Wang Yi‐Ching
Published: September 2007

BACKGROUND.

Methylation patterns may be useful biomarkers of cancer detection and risk assessment.

METHODS.

The methylation status of 6 genes, including a candidate tumor suppressor gene (BLU), the cadherin 13 gene (CDH13), the fragile histidine triad gene (FHIT), the cell cycle control gene p16, the retinoic acid receptor β gene (RARβ), and the Ras association domain family 1 gene (RASSF1A), was examined in plasma samples, corresponding tumor tissues, and normal lung tissues from a group of 63 patients with lung cancer and in plasma samples from 36 cancer‐free individuals. The detection rate of the p16 gene was validated in a test group of 20 patients with lung cancer.

RESULTS.

The concordance of methylation in tumor tissues and plasma samples was 86%, 87%, 80%, 75%, 76%, and 84% for the BLU, CDH13, FHIT, p16, RARβ, and RASSF1A genes, respectively. The test group showed a similar concordance for p16 methylation detection. Multiple logistic regression analysis showed that the odds ratio for having lung cancer was 10.204 for individuals with p16 methylation (P = .013) and 9.952 for individuals with RASSFIA methylation (P = .019). After several trial tests, the authors established that methylation for ≥2 of the 6 markers met the criterion for an elevated risk of cancer. Comparisons yielded a sensitivity of 73%, a specificity of 82%, and a concordance of 75% between the methylation patterns in tumor tissues and in corresponding plasma samples. The detection rate was relatively high in cigarette smokers with advanced squamous cell lung cancer.

CONCLUSIONS.

The current results indicated that multiple epigenetic markers in the plasma, especially the p16 and RASSF1A genes, can be used for lung cancer detection. This methylation marker panel should improve the detection of cancer or the risk assessment for lung cancer in combination with conventional diagnostic tools. Cancer 2007. © 2007 American Cancer Society.
Electromechanical analysis of electrostatic nano‐actuators using the differential quadrature method
Authors: Hsu Ming‐Hung
Published: September 2007

The nonlinear analysis of nanoelectromechanical systems using the differential quadrature model is investigated. The differential quadrature method is applied to overcome the difficulty of determining the nonlinear equation of motion. The characteristics of various combinations of curved electrodes and cantilever beams are considered to optimize the design. Various nano‐actuators, such as the cantilever beam actuator, are derived and simulated to examine the feasibility of applying the differential quadrature method to the nonlinear deflection in solving the nano‐actuator problem. The effects of the electrode shapes, the lengths of the actuators, and the moments of inertia of the actuators on the pull‐in behavior of the cantilever actuators in electrostatic nanoelectromechanical systems are investigated. The differential quadrature approach is used to generate the electrostatic field equations in matrix form. Copyright © 2007 John Wiley & Sons, Ltd.
An efficient graph‐theoretical force method for three‐dimensional finite element analysis
Authors: Kaveh A. , Koohestani K.
Published: September 2007

In this paper an efficient method is developed for the formation of null bases of finite element models (FEMs) composed of tetrahedron elements, corresponding to highly sparse and banded flexibility matrices. This is achieved by associating special graphs with the FEM and selecting appropriate subgraphs and forming the self‐stress systems on these subgraphs. The efficiency of the present method is illustrated through two examples. Copyright © 2007 John Wiley & Sons, Ltd.
Development of New Glass Composite Membranes and their Properties for Low Temperature H2/O2 Fuel Cells
Authors: Uma T. , Nogami M.
Published: September 2007

A new glass electrolyte formed by constant amounts of titanium oxide (TiO2) and various amount of phosphotungstic acid (PWA) doped P2O5–SiO2 is prepared using the sol‐gel process. The structural formation is confirmed by Fourier infrared spectroscopy (FTIR) and from thermogravimetric and differential thermal analysis (TG/DTA) measurements, the glasses display good thermal stability. Further characterisation is undertaken by N2 adsorption/desorption measurements, proton conductivity and hydrogen permeability analyses and a H2/O2 fuel cell test is also performed. The glass materials with large pores and specific surface area are suitable for use as the electrolyte in H2/O2 fuel cells. The effect of TiO2 processing with constant amount of PWA in phosphosilicate glasses, is investigated and discussed. The hydrogen permeability is 1.57×10−11 mol cm−1 s−1 Pa−1 at 110 °C for 0.8 mm thick glass; a power density of 46.3 mW cm−2 at 125 mA cm−2 and a current density of 175 mA cm−2 is obtained (T=28 °C, relative humidity).
First Kinetic Determination of Partition Coefficients for Organic Compounds between the Three Microenvironments of AOT‐Based Microemulsions
Authors: García‐Río Luis , Méndez María
Published: September 2007

Kinetic data for the hydrolysis of N‐picolinoylimidazole (I) and 2,4‐dinitrophenylpicolinate (II) in AOT [bis(2‐ethylhexyl) sodium sulfosuccinate] microemulsions are used to determine for the first time the two partition constants for each substrate (i.e. Kwi and Koi, corresponding to the incorporation of substrate molecules from water microdroplets and the continuous medium, respectively, into the interface). Application of the pseudophase formalism to the partition constants allowed the rate constant in each phase to be determined. The rate of hydrolysis of II increased with decreasing polarity of the medium; as a result, the hydrolysis reaction took place largely at the interface. On the other hand, the rate of hydrolysis of acylimidazole I decreased with decreasing polarity, possibly as a result of changes in the resonance structures of the reagent causing the hydrolysis process to occur preferentially in water microdroplets.
Behavior of phosphorus impurities during Czochralski growth of high‐purity germanium single crystals
Authors: Gusev A. V. , Gavva V. A.
Published: September 2007

The effect of evaporation of phosphorus impurities from the melt is investigated as well as the contaminating effect of quartz glass crucibles on residual content and distribution of this impurities by length of high‐purity germanium single crystals. The residual content of phosphorus impurities is mainly influenced by the contaminating effect of crucible material and its distribution by length of crystals is described by the model accounting for the impurities income from crucible material. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nucleation kinetics, growth, solubility and dielectric studies of L‐proline cadmium chloride monohydrate semi organic nonlinear optical single crystal
Authors: Kandasamy A. , Mohan R. , Lydia Caroline M. , Vasudevan S.
Published: September 2007

Nucleation parameters such as solubility, induction period, interfacial energy and metastable zone width have been investigated for the aqueous solution growth of a semi‐organic nonlinear optical (NLO) material of L‐Proline cadmium chloride monohydrate (L‐PCCM) single crystal. Metastable zone width and induction period values were determined experimentally in order to optimize the growth parameters. The grown crystals are transparent (dimensions: 16 x 8 x 5 mm3) and characterized by powder X‐Ray Diffraction and dielectric studies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Repeating cytological preparations on liquid‐based cytology samples: A methodological advantage?
Authors: Pinto Álvaro P. , Maia Henrique Felde , di Loretto Celso , Krunn Patrícia , Túlio Siumara , Collaço Luis Martins
Published: September 2007

This study investigates the rule that repeating cytological preparations on liquid‐based cytology improves sample adequacy, diagnosis, microbiological, and hormonal evaluations. We reviewed 156 cases of pap‐stained preparations of exfoliated cervical cells in two slides processed by DNA‐Cytoliq System®. After sample repeat/dilution, limiting factors affecting sample adequacy were removed in nine cases and three unsatisfactory cases were reclassified as satisfactory. Diagnosis was altered in 24 cases. Of these, the original diagnosis in 15 was atypical squamous cells of undetermined significance; after the second slide examination, diagnosis in 5 of the 15 cases changed to low‐grade squamous intraepithelial lesion, 3 to high‐grade squamous intraepithelial lesion, and 7 to absence of lesion. Microbiological evaluation was altered, with Candida sp. detected in two repeated slides. Repeat slide preparation or dilution of residual samples enhances cytological diagnosis and decreases effects of limiting factors in manually processed DIGENE DCS LBC. Diagn. Cytopathol. 2007;35:663–669. © 2007 Wiley‐Liss, Inc.
Non‐gynecologic cytology on liquid‐based preparations: A morphologic review of facts and artifacts
Authors: Hoda Rana S.
Published: September 2007

Liquid‐based preparations (LBP) are increasingly being used both for gynecologic (gyn) and non‐gynecologic (non‐gyn) cytology including fine needle aspirations (FNA). The two FDA‐approved LBP currently in use include ThinPrep (TP), (Cytyc Corp, Marlborough, MA) and SurePath (SP), (TriPath Imaging Inc., Burlington, NC). TP was approved for cervico‐vaginal (Pap test) cytology in 1996 and SP in 1999 and both have since also been used for non‐gyn cytology. In the LBP, instead of being smeared, cells are rinsed into a liquid preservative collection medium and processed on automated devices. Even after a decade of use, the morphological interpretation of LBP remains a diagnostic challenge because of somewhat altered morphology and artifacts or facts resulting from the fixation and processing techniques. These changes include cleaner background with altered or reduced background and extracellular elements; architectural changes such as smaller cell clusters and sheets, breakage of papillae; altered cell distribution with more dyscohesion and changes in cellular morphology with enhanced nuclear features, smaller cell size and slightly more three‐dimensional (3‐D) clusters. Herein, we review the published literature on morphological aspects of LBP for non‐gyn cytology. Diagn. Cytopathol. 2007;35:621–634. © 2007 Wiley‐Liss, Inc.
Use of imprint cytology for assessment of surgical margins in lumpectomy specimens of breast cancer patients
Authors: Bakhshandeh Maryam , Tutuncuoglu S. Osman , Fischer Gabor , Masood Shahla
Published: September 2007

In the past several years, breast‐conservation therapy has provided an alternative to mastectomy. In order to reduce the subsequent local tumor recurrence, it is critical that all the measures are in place to find the residual foci of occult microscopic tumor at the time of the initial lumpectomy procedure. An accepted method to evaluate the lumpectomy margins for presence of residual tumor is the use of imprint cytology (also called touch‐prep), which is assessment of the presence or absence of the tumor cells by cytological preparation. This is a rapid, cost effective, and easy to use procedure with added advantage of saving tissue for permanent sectioning and rendering a definitive diagnosis. In this report, we present our experience using intraoperative imprint cytology for evaluation of the status of lumpectomy specimens in breast cancer patients. The objective of this study was to evaluate the diagnostic accuracy of intraoperative imprint cytology for assessment of surgical resection margins in lumpectomy margins of patients with breast carcinoma. This is a retrospective study of 100 cases of breast lumpectomy specimens, which had undergone intraoperative imprint cytology. The cases were retrieved from the archived files of the University of Florida, Department of Pathology at Shands Jacksonville. The results of intraoperative imprint cytology were compared with the histological findings of the corresponding permanent sections of the same cases as the gold standard. Overall, we reviewed 510 cytology imprint slides, which were obtained from 100 lumpectomy specimens. Among these cases, 37 slides from 22 cases were reported positive and the remaining were negative. Only eight slides from six cases of lumpectomy showed discrepancy between the result of intraoperative imprint cytology and the permanent sections of the same cases. In our study, intraoperative imprint cytology showed a sensitivity of 97%, specificity of 99%, with positive predictive value of 84%, and negative predictive value of 99%. This study demonstrates that intraoperative imprint cytology can be used as a reliable diagnostic procedure for the evaluation of the status of lumpectomy margins in breast cancer patients. Diagn. Cytopathol. 2007;35:656–659. © 2007 Wiley‐Liss, Inc.
Leptomeningeal metastasis in a patient with squamous cell carcinoma of the uterine cervix: Report of a case and review of the literature
Authors: Han Liying , Bhan Raj , Johnson Samuel , Zak Imad , Husain Mujtaba , Al‐Abbadi Mousa A.
Published: September 2007

Leptomeningeal spread of advanced squamous cell carcinoma (SCC) of the uterine cervix is unusual. To our knowledge, very few cases were reported in the English literature. We report a case of a 39‐yr‐old woman who presented with leptomeningeal metastasis from a stage IIb SCC of uterine cervix. The diagnosis was made by cytomorphological examination of smears obtained from cerebrospinal fluid. The cytomorphological features are demonstrated. Diagn. Cytopathol. 2007;35:660‐662. © 2007 Wiley‐Liss, Inc.
Symptomatic candidiasis: Using self sampled vaginal smears to establish the presence of Candida, lactobacilli, and Gardnerella vaginalis
Authors: Engberts M. K. , Boon M. E. , van Haaften M. , Heintz A. P. M.
Published: September 2007

In a prospective cohort study, 10 symptomatic women with recurrent vulvovaginal candidiasis were taught how to prepare vaginal smears of their own vaginal fluids on days 7, 14, 21, and 28. The 40 smears were stained with the PAS‐method and examined by three different cytopathologists for presence of Candida. Thereafter, the smears were restained with Giemsa‐stain to determine presence of lactobacilli, Gardnerella vaginalis (“clue cells”) and neutrophils.

All three cytopathologists unequivocally established Candida blastospores and (pseudo)hyphae in 27 out of the 40 PAS‐stained vaginal smears, whereas in the remaining 13 smears Candida was not found. All 10 patients had Candida in their smears during the second half of their menstrual cycle.

Self sampled smears prove to be reliable for establishing the presence of Candida in symptomatic patients with candidiasis. Candida is associated with a lactobacillus‐predominated vaginal flora, but with the absence of Gardnerella vaginalis. Further studies may be directed towards the interaction between the various members of the vaginal flora. This study should open molecular methodology for determining the possible interactions of lactobacilli and Candida. Diagn. Cytopathol. 2007;35:635–639. © 2007 Wiley‐Liss, Inc.
Comparison of cell block preparation methods for nongynecologic ThinPrep specimens
Authors: Nigro Kelly , Tynski Zofia , Wasman Jay , Abdul‐Karim Fadi , Wang Nancy
Published: September 2007

The purpose of this study was to compare four cell block (CB) methods in the setting of nongynecologic ThinPrep (TP) specimens. 48 CBs were prepared from 12 nongynecologic TP specimens using the following CB methods: (1) Inverted filter sedimentation (IFS); (2) Thrombin method; (3) Albumin method; (4) Simple sedimentation. Each CB was assigned a cellularity score: 0 no cells, 1+ hypocellular, 2+ hypocellular with tissue fragments, 3+ cellular. A score of 2+ or 3+ was given for 11/12 of thrombin, 7/12 IFS, 5/12 albumin, and 2/12 simple sedimentation CBs. Thrombin CBs demonstrated a pale background clot with evenly distributed cells. Albumin CBs had a cracked uneven background. IFS CBs had a clear background, but were technically difficult and cells appeared artifactually crowded. In the setting of nongynecologic TP specimens, the thrombin CB was easily prepared and produced the best CB in regards to cellularity, cell distribution, and background quality. Diagn. Cytopathol. 2007;35:640–643. © 2007 Wiley‐Liss, Inc.
Apical and lateral cell protrusions interconnect epithelial cells in live Drosophila wing imaginal discs
Authors: Demontis Fabio , Dahmann Christian
Published: September 2007

Communication among cells by means of the exchange of signaling cues is important for tissue and organ development. Recent reports indicate that one way that signaling cues can be delivered is by movement along cellular protrusions interconnecting cells. Here, by using confocal laser scanning microscopy and three‐dimensional rendering, we describe in Drosophila melanogaster wing imaginal discs lateral protrusions interconnecting cells of the columnar epithelium. Moreover, we identified protrusions of the apical surface of columnar cells that reached and apparently contacted cells of the overlying squamous epithelium. Both apical and lateral protrusions could be visualized by expression of Tkv‐GFP, a green fluorescent protein (GFP) ‐tagged version of a receptor of the Dpp/BMP4 signaling molecule, and the endosome marker GFP‐Rab5. Our results demonstrate a previously unexpected richness of cellular protrusions within wing imaginal discs and support the view that cellular protrusions may provide a means for exchanging signaling cues between cells. Developmental Dynamics 236:3408–3418, 2007. © 2007 Wiley‐Liss, Inc.
A rapid CZE method for the analysis of benzodiazepines in spiked beverages
Authors: Webb Rebecca , Doble Philip , Dawson Michael
Published: September 2007

A rapid CZE method was developed for the simultaneous determination of nine benzodiazepines in spiked beverages (nitrazepam oxazepam, alprazolam, flunitrazepam, temazepam, diazepam, 7‐aminoflunitrazepam, 7‐aminonitrazepam and 7‐aminoclonazepam). The method employed a double‐coated capillary coated with poly(diallyldimethylammonium chloride) and then dextran sulphate. The BGE conditions were 100 mM ammonium phosphate buffer, pH 2.5, which gave baseline resolution between consecutive peaks and a run time of less than 6.5 min. This method offers improvements in both resolution and run time, compared to those attained under analogous conditions with an uncoated capillary. The validated method was successfully applied to beverages that had been spiked with benzodiazepines at concentrations simulating prescription tablets. No sample pretreatment was required to quantify five benzodiazepines in Coca‐Cola, orange juice, beer, bourbon and Bacardi. The exception was white wine, where the complex sample matrix did not enable the accurate quantification of nitrazepam.
Persistence of the surface texture of a gravel‐bed river during a large flood
Authors: Clayton Jordan A. , Pitlick John
Published: September 2007

We present herein clear field evidence for the persistence of a coarse surface layer in a gravel‐bed river during flows capable of transporting all grain sizes present on the channel bed. Detailed field measurements of channel topography and bed surface grain size were made in a gravel‐bed reach of the Colorado River prior to a flood in 2003. Runoff produced during the 2003 snowmelt was far above average, resulting in a sustained period of high flow with a peak discharge of 27 m3/s (170% of normal peak flow); all available grain sizes within the study reach were mobilized in this period of time. During the 2003 peak flow, the river avulsed immediately upstream of the study reach, thereby abandoning approximately one half kilometer of the former channel. The abandonment was rapid (probably within a few hours), leaving the bed texture essentially frozen in place at the peak of the flood. All locations sampled prior to the flood were resampled following the stream abandonment. In response to the high flow, the surface median grain size (D50s) coarsened slightly in the outer part of the bend while remaining nearly constant along the inner part of the bend, resulting in an overall increase from 18 to 21 mm for the study reach. Thus, the coarse bed surface texture persisted despite shear stresses throughout the bend that were well above the critical entrainment value. This may be explained because the response of the bed texture to increases in flow strength depends primarily upon the continued availability of the various grain size percentiles in the supply, which in this case was essentially unlimited for all sizes present in the channel. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing the ability of airborne LiDAR to map river bathymetry
Authors: Hilldale Robert C. , Raff David
Published: September 2007

Airborne bathymetric LiDAR was collected for 220 river kilometres in the Yakima and Trinity River Basins in the USA. Concomitant with the aerial data collection, ground surveys of the river bed were performed in both basins. We assess the quality of the bathymetric LiDAR survey from the perspective of its application toward creating accurate, precise and complete streambed topography for numerical modelling and geomorphological assessment. Measurement error is evaluated with respect to ground surveys for magnitude and spatial variation. Analysis of variance statistics indicate that residuals from two independent ground surveys in similar locations do not come from the same population and that mean errors at different study locations also come from different populations. Systematic error indicates a consistent bias in the data and random error falls within values of expected precision. Published in 2007 by John Wiley & Sons, Ltd.
Field observations of nearshore bar formation
Authors: Aagaard Troels , Kroon Aart , Hughes Michael G. , Greenwood Brian
Published: September 2007

The formation of an inner nearshore bar was observed during a high‐energy event at the sandy beach of Vejers, Denmark. The bar accreted in situ during surf zone conditions and the growth of the bar was associated with the development of a trough landward of the bar. Measurements of hydrodynamics and sediment fluxes were obtained from electromagnetic current meters and optical backscatter sensors. These process measurements showed that a divergence in sediment transport occurred at the location of the developing trough, and observed gradients in cross‐shore net sediment flux were consistent with the morphological development. The main cause for the flux gradients were cross‐shore gradients in offshore‐directed mean current (undertow) speed which depended upon local relative wave height and local bed slope. Copyright © 2007 John Wiley & Sons, Ltd.
Steady heat release rate by the moment–area method
Authors: Lyon Richard E. , Crowley Sean , Walters Richard N.
Published: September 2007

A simple mathematical procedure is described for computing temporal averages of heat release rate (HRR) data from the moments and area of the history. The moment–area method was used to calculate average HRRs for over 200 specimens having a wide range of chemical composition and sample thickness tested on a bench‐scale fire calorimeter at various external heat fluxes. The average values of HRR obtained by the moment–area method are essentially independent of sample thickness and are potentially useful for ranking material flammability and determining material combustion properties. Published in 2007 by John Wiley & Sons, Ltd.
A hybrid vortex method for the simulation of three‐dimensional flows
Authors: Li Wei , Vezza Marco
Published: September 2007

This paper presents an integral vorticity method for solving three‐dimensional Navier–Stokes equations. A finite volume scheme is implemented to solve the vorticity transport equation, which is discretized on a structured hexahedral mesh. A vortex sheet algorithm is used to enforce the no‐slip boundary condition through a vorticity flux at the boundary. The Biot–Savart integral is evaluated to compute the velocity field, in conjunction with a fast algorithm based on multipole expansion. This method is applied to the simulation of uniform flow past a sphere. Copyright © 2007 John Wiley & Sons, Ltd.
Fluid flow simulation at open–porous medium interface using the lattice Boltzmann method
Authors: Nabovati A. , Sousa A. C. M.
Published: September 2007

The present study investigates, using the lattice Boltzmann method, the influence on the flow of the boundary condition at the open and porous medium interface for a two‐dimensional channel with half of the channel filled with a random porous medium. By simulating the fluid flow at pore level, the proposed macroscopic hydrodynamic boundary conditions are evaluated; correlations for the empirical constant in one of the most widely used models are also presented. The predicted values for the flow rate are in overall agreement with the previously published values. Copyright © 2007 John Wiley & Sons, Ltd.
Cost inefficiency and hospital health outcomes
Authors: McKay Niccie L. , Deily Mary E.
Published: September 2007

This study explores the association between cost inefficiency and health outcomes in a national sample of acute‐care hospitals in the US over the period 1999–2001, with health outcomes being measured by both mortality and complications rates. The empirical analysis examines health outcomes as a function of cost inefficiency and other determinants of outcomes, using stochastic frontier analysis to obtain hospital cost inefficiency scores. The results showed no systematic pattern of association between cost inefficiency and hospital health outcomes; the basic results were unchanged regardless of whether cost inefficiency was measured with or without using instrumental variables. The analysis also indicated, however, that the association between cost inefficiency and health outcomes may vary substantially across geographical regions. The study highlights the importance of distinguishing between ‘good’ costs that reflect the efficient use of resources and ‘bad’ costs that stem from waste and other forms of inefficiency. In particular, the study's results suggest that hospital programs focused on reducing cost inefficiency are unlikely to be associated with worsened hospital‐level mortality or complications rates, while, on the other hand, across‐the‐board reductions in cost could well have adverse consequences on health outcomes by reducing efficient as well as inefficient costs. Copyright © 2007 John Wiley & Sons, Ltd.
Drug price reform in the UK: debunking the myths
Authors: Thornton Simeon
Published: September 2007

The OFT report into the Pharmaceutical Price Regulation Scheme (PPRS) called for reform of the scheme, replacing existing profit and price controls with a system of value‐based pricing (VBP). The report argued that VBP would be much more effective than the current PPRS both at providing value for money for the NHS and giving pharmaceutical companies the right incentives to invest in drugs in the future.

The report has sparked a widespread debate about drug pricing in the UK and has been controversial in some quarters. Some of the more negative responses are, however, based on fundamental misconceptions about the OFT recommendations. In particular, contrary to some claims, the recommended system would provide strong incentives for incremental innovation and the right balance of rewards for first in class and follow‐on products. Nor, as is sometimes argued, would VBP have an adverse effect on investment in the UK.

Certainly, real challenges lie ahead if VBP is to be implemented. These concern the definition of value, particularly where patient benefits differ significantly by subgroup or indication, and the level of resource required to implement VBP. The OFT report contains proposals for addressing each of these areas. Perhaps the most difficult challenge is the political one: securing acceptance for a reform package that would create winners and losers among pharmaceutical companies according to their success in producing valuable drugs. Ultimately, however, only a scheme that does precisely this can hope to meet the needs of patients, the NHS and innovative companies in the long run. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of an oral iron chelator or iron-deficient diets on uroporphyria in a murine model of porphyria cutanea tarda
Authors: Gorman Nadia , Zaharia Adrian , Trask Heidi S. , Szakacs Juliana G. , Jacobs Nicholas J. , Jacobs Judith M. , Balestra Dominic , Sinclair Jacqueline F. , Sinclair Peter R.
Published: September 2007

Porphyria cutanea tarda is a liver disease characterized by elevated hepatic iron and excessive production of uroporphyrin (URO). Phlebotomy is an effective treatment that probably acts by reducing hepatic iron. Here we used

Hfe

(−/−) mice to compare the effects on hepatic URO accumulation of two different methods of hepatic iron depletion: iron chelation using deferiprone (L1) versus iron-deficient diets.

Hfe

(−/−) mice in a 129S6/SvEvTac background were fed 5-aminolevulinic acid (ALA), which results in hepatic URO accumulation, and increasing doses of L1 in the drinking water. Hepatic URO accumulation was completely prevented at low L1 doses, which partially depleted hepatic nonheme iron. By histological assessment, the decrease in hepatic URO accumulation was associated with greater depletion of iron from hepatocytes than from Kupffer cells. The L1 treatment had no effect on levels of hepatic cytochrome P4501A2 (CYP1A2). L1 also effectively decreased hepatic URO accumulation in C57BL/6

Hfe

(−/−) mice treated with ALA and a CYP1A2 inducer. ALA-treated mice maintained on defined iron-deficient diets, rather than chow diets, did not develop uroporphyria, even when the animals were iron-supplemented either directly in the diet or by iron dextran injection.

Conclusion:

The results suggest that dietary factors other than iron are involved in the development of uroporphyria and that a modest depletion of hepatocyte iron by L1 is sufficient to prevent URO accumulation. (Hepatology 2007.)
A simple primary care information system featuring feedback to clinicians
Authors: Gaumer Gary , Hassan Nefesa , Murphy Michael
Published: September 2007

A simple information system for primary care clinics was designed to support the USAID funded health system strengthening project in the Suez Governorate in Egypt. This system (FACT—Feedback and Analytic Comparison Tool) was implemented in December 2003 in 14 primary care clinics. The MS Access‐based system was designed and prototyped in several months, and was easily and cheaply modified several times after implementation. A total of 128 562 persons have been registered in the system (as of June 2005) and 36 083 visits have been documented. A key feature of FACT is the ease with which clinicians can conduct exploratory research about practice patterns, and variations in them across doctors and the other clinics. This analytic feature enables the clinicians to self‐diagnose quality problems and take action accordingly. Several of the clinics have used this feature of FACT to identify important gaps in service use among patients, and have taken steps to remove barriers to promote more appropriate patterns of utilization. The paper reviews the design and implementation issues and early evidence of the system's utility in helping support quality improvement (QI) work in the clinics. Copyright © 2007 John Wiley & Sons, Ltd.
Bone growth in rapid prototyped porous titanium implants
Authors: Lopez‐Heredia M. A. , Goyenvalle E. , Aguado E. , Pilet P. , Leroux C. , Dorget M. , Weiss P. , Layrolle P.
Published: September 2007

Two porous titanium implants with a pore size diameter of 800 and 1200 μm (Ti800 and Ti1200) and an interconnected network were manufactured using rapid prototyping. Their dimensions and structure matched those of the computer assisted design. The porosity of the implants was around 60%. Their compressive strength and Young's modulus were around 80 MPa and 2.7 GPa, respectively. These values are comparable to those of cortical bone. The implants were implanted bilaterally in the femoral epiphysis of 15 New Zealand White rabbits. After 3 and 8 weeks, abundant bone formation was found inside the rapid prototyped porous titanium implants. For the Ti1200 implants, bone ingrowth was (23.9 ± 3.5)% and (10.3 ± 2.8)%, respectively. A significant statistical difference (p < 0.05) was found for bone ingrowth in the Ti1200 between the two delays. The percentage of bone directly apposited on titanium was (35.8 ± 5.4)% and (30.5 ± 5.0)%. No significant difference was found for bone‐implant contact between the different time periods and pore sizes. This work demonstrates that manufacturing macroporous titanium implants with controlled shape and porosity using a rapid prototyping method is possible and that this technique is a good candidate for orthopedic and maxillofacial applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Degradation of PCL‐MPEG diblock copolymer in rat plasma
Authors: Lin Wen‐Jen , Chang Kai‐Ling
Published: September 2007

The poly(ε‐caprolactone)‐co‐poly(ethylene glycol) (PCL‐MPEG) amphiphilic diblock copolymer with molar ratio of ε‐CL to MPEG 81:1 is synthesized via a ring‐opening polymerization without a catalyst. The Mw and Mn molecular weights and the polydispersities are 18,000, 11,000 g/mole and 1.55, respectively. The pegylated amphiphilic copolymer forms micelles with a low critical micelle concentration 6.71 × 10−8 mole/L, and the average particle size of copolymeric micelles is 62.3 ± 12.9 nm. The degradation behavior of diblock copolymer was studied in rat plasma at 37°C for 90 days. The changes of mass, composition, morphology, molecular weight, and thermal property of PCL‐MPEG copolymer were investigated. The decrease of copolymer mass shows two phases with rate constants of 1.91 × 10−1 day−1 in the first‐phase (1–24 h) and 1.77 × 10−3 day−1 in the second‐phase (1–90 days). The degradation of labile ester linkage between PCL block and MPEG block accounts for continuous decrease of copolymer mass in plasma. The decrease of EG molar ratio from 1.30 to 0.67 and prominent reduction of enthalpy of fusion of remained copolymer from 116.5 to 85.2 J/g provide evidences of PCL‐MPEG chain scission. On the other hand, the presence of partially degraded copolymers in the residuals results in its polydispersity increased from 1.55 to 2.24 at the end of 90 days. Nevertheless, the surface erosion of copolymer makes the molecular weight not quite different from its original value. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Copolymerization of D,L‐lactide and glycolide in supercritical carbon dioxide with zinc octoate as catalyst
Authors: Mazarro Rosario , de Lucas Antonio , Gracia Ignacio , Rodríguez Juan F.
Published: September 2007

The objective of the study is the development of a new technique based on supercritical technology for the production of bioabsorbable polymeric microparticles containing pharmaceutical principles, for their use in the controlled release of medicines. For this purpose, the ring‐opening copolymerization of D,L‐lactide and glycolide in supercritical carbon dioxide, using zinc(II) 2‐ethylhexanoate (ZnOct2) as catalyst, was studied. The polymer obtained with ZnOct2 has similar characteristics to that obtained with stannous octoate (SnOct2), the conventional catalyst used up to now for this kind of polymerization process. Experiments were performed at various reaction times, pressures, and stirring rates. The most outstanding result was found by varying the stirring rate, where particles forming agglomerates seem to be obtained at the greater agitation levels. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Transfer of metallic debris from the metal surface of an acetabular cup to artificial femoral heads by scraping: Comparison between alumina and cobalt–chrome heads
Authors: Chang Chong Bum , Yoo Jeong Joon , Song Won Seok , Kim Deug Joong , Koo Kyung‐Hoi , Kim Hee Joong
Published: September 2007

We aimed to investigate the transfer of metal to both ceramic (alumina) and metal (cobalt–chrome) heads that were scraped by a titanium alloy surface under different load conditions. The ceramic and metal heads for total hip arthroplasties were scraped by an acetabular metal shell under various loads using a creep tester. Microstructural changes in the scraped area were visualized with a scanning electron microscope, and chemical element changes were assessed using an energy dispersive X‐ray spectrometry. Changes in the roughness of the scraped surface were evaluated by a three‐dimensional surface profiling system. Metal transfer to the ceramic and metal heads began to be detectable at a 10 kg load, which could be exerted by one‐handed force. The surface roughness values significantly increased with increasing test loads in both heads. When the contact force increased, scratching of the head surface occurred in addition to the transfer of metal. The results documented that metallic debris was transferred from the titanium alloy acetabular shell to both ceramic and metal heads by minor scraping. This study suggests that the greatest possible effort should be made to protect femoral heads, regardless of material, from contact with metallic surfaces during total hip arthroplasty. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Hydrophilic biodegradable microspheres of interferon‐alpha and its pharmacokinetics in mice
Authors: Zheng Cai‐Hong , Yu He‐Yong , Gao Jian‐Qing , Sun Xiao‐Yi , Liang Wen‐Quan
Published: September 2007

The goal of this research was to prepare a kind of hydrophilic sustained release microspheres of interferon‐alpha (IFN‐α), alginate‐chitosan microspheres (ACM) of IFN, and investigate its pharmacokinetics in mice. Alginate microspheres of IFN‐α were first prepared by an emulsion method and further incubated in chitosan to form IFN‐ACM. The influences of isopropanol, bovine serum albumin (BSA), and pH adjustment by isoelectric point of IFN were studied. The optimized IFN‐ACM was obtained with smooth and round morphology, size of 2.18 ± 0.43 μm and entrapment efficiency of 40%. All the concentrations of IFN‐α were determined by IFN assay kits. Finally the pharmacokinetics of IFN‐ACM suspension was studied in ICR mice by intramuscular (I.M.) routes. Compared with IFN solution, Cmax of IFN‐ACM reduced 2.3‐fold, and time to achievement of maximum serum concentrations (Tmax) increased 4‐fold. Meanwhile the area under the concentration‐time curve (AUC) was the same as that of solution. The concentration‐time profiles presented the prolonged serum levels of IFN from IFN‐ACM. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Asynchronous replica exchange for molecular simulations
Authors: Gallicchio Emilio , Levy Ronald M. , Parashar Manish
Published: September 2007

An asynchronous implementation of the replica exchange method that addresses some of the limitations of conventional synchronous replica exchange implementations is presented. In asynchronous replica exchange pairs of processors initiate and perform temperature replica exchanges independently from the other processors, thereby removing the need for processor synchronization found in conventional synchronous implementations. Illustrative calculations on a molecular system are presented that show that asynchronous replica exchange, contrary to the synchronous implementation, is able to utilize at nearly top efficiency loosely coupled pools of processors with heterogeneous speeds, such as those found in computational grids and CPU scavenging environments. It is also shown that employing non‐nearest‐neighbor temperature exchanges, which are straightforward to implement within the asynchronous algorithm, can lead to faster temperature equilibration across processors. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Encapsulated human primary myoblasts deliver functional hFIX in hemophilic mice
Authors: Wen Jianping , Xu Nong , Li Anna , Bourgeois Jacqueline , Ofosu Frederick A. , Hortelano Gonzalo
Published: September 2007

Background

Hemophilia B is a bleeding disorder caused by defective factor IX (FIX), currently treated by regular infusions of plasma‐derived or recombinant FIX. We propose a gene therapy strategy based on the implantation of cells secreting FIX enclosed in alginate microcapsules as a highly desirable alternative treatment. We have reported sustained delivery of human factor IX (hFIX) in immunocompetent mice implanted with encapsulated primary mouse myoblasts engineered to secrete hFIX. As a step towards the treatment of human patients, in this study we report the implantation of encapsulated human primary myoblasts secreting hFIX in hemophilia B mice.

Methods

Human primary myoblasts were transfected with plasmids pKL4M‐hFIX, pLNM‐βIXL, pMFG‐hFIX, and transduced with retrovirus MFG‐hFIX. Two human primary myoblast clones secreting ∼1 µg hFIX/106 cells/day were enclosed in biocompatible alginate microcapsules and implanted intraperitoneally into SCID and hemophilic mice.

Results

Circulating hFIX (peak of ∼120 ng/ml) was detected in hemophilia B mice on day 1 after implantation. Human FIX delivery was transient, however, becoming undetectable on day 14. Concurrently, anti‐hFIX antibodies were detected. At the same time, activated partial thromboplastin time (APTT) was reduced from 94 s before treatment to 78–80 s. Tail bleeding time decreased from 15 min to 1.5–7 min after treatment, some mice being normalised. These findings indicate that the delivered hFIX is biologically active. Similarly treated NOD/SCID mice had circulating hFIX levels of 170 ng/ml on day 1 that remained detectable for 1 month, albeit at low levels. Cell viability of microcapsules retrieved on day 60 was below 5%.

Conclusions

Our findings indicate that encapsulated human primary myoblasts secrete functional hFIX. Furthermore, implantation of encapsulated human primary myoblasts can partially correct the phenotype of hemophilia B mice, supporting the feasibility of this gene therapy approach for hemophilia B. However, the long‐term viability of the encapsulated human myoblasts must first be improved. Copyright © 2007 John Wiley & Sons, Ltd.
Soochong virus and amur virus might be the same entities of hantavirus
Authors: Jiang Jia‐Fu , Zhang Wen‐Yi , Wu Xiao‐Ming , Zhang Pan‐He , Cao Wu‐Chun
Published: September 2007

Amur virus (AMRV) and Soochong virus (SOOV) were reported to be carried by Korean field mice (Apodemus peninsulae) in the Far East of Russia, China, and Korea. The distinction and demarcation between these two viruses have been a matter of debate. In order to clarify this issue and to confirm taxonomic position of AMRV and SOOV, the extensive phylogenetic analyses based on entire S segment and entire M segment sequences of AMRV, SOOV and other reference virus strains deposited in GenBank, were carried out using maximum likelihood and distant matrix methods. All inferred phylogenies revealed that all AMRV strains from China and Far East and SOOV (especially SOO‐1/2 strains from Northeastern Korea) shared high identities of nucleotide sequences and were monophyletic distinct from Apodemus agrarius HTNV. Although two genetic sublineages of SOOV exist, these findings revealed that AMRV and SOOV might belong to the same entities of hantavirus. J. Med. Virol. 79:1792–1795, 2007. © 2007 Wiley‐Liss, Inc.