bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybridization of aqueous PU/epoxy resin via a dual self‐curing process
Authors: Chen Wei‐Jen , Wang Shih‐Chieh , Chen Po‐Cheng , Chen Tsorng‐Wen , Chen Kan‐Nan
Published: June 2008

Amino‐terminated and carboxyl‐containing polyurethane (PU) is prepared by an isocyanate‐terminated PU prepolymer process. Carboxyl‐containing epoxy resin is obtained from a half‐esterification of epoxy resin with maleic anhydride. These two aqueous resins are obtained after neutralization with triethylamine and dispersion into water phase, respectively. A latent curing agent (TMPTA‐AZ) is prepared by a Michael addition of aziridine with trimethylolpropane triacrylate (TMPTA). A self‐curing system of PU/epoxy hybrid is obtained from a blending of these two aqueous resins with latent curing agent. PU/epoxy hybrid is derived from two self‐curing reactions on drying. The first curing for hybridization between PU amino groups with oxirane groups of epoxy resin is via a ring‐opening reaction and the secondary curing takes place on carboxyl groups of PU/epoxy hybrid with aziridine of TMPTA‐AZ. The final properties of these dual self‐cured PU/epoxy hybrids are reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanism involved in the dyeing of wool with an oil‐in‐water microemulsion system
Authors: Paul Roshan , Solans Conxita , Erra Pilar
Published: June 2008

This article investigates the influence of oil‐in‐water (o/w) microemulsions, used as media for both dye solubilization and dye baths, on the dye uptake on fiber surfaces. An acetic acid solution/Synperonic L7/benzyl alcohol microemulsion system was used to solubilize a water‐insoluble antimicrobial natural dye (C.I. Natural Orange 2) and to dye wool fabric at an acidic pH. The results clearly show that the dye exhaustion on the fabric took place mainly when the temperature of the dye bath promoted a change in the molecular organization of the microemulsions with the liberation of the dye solubilized in the oil droplets of the microemulsions. Although uniformly and evenly dyed fabrics were obtained, they showed very low wash fastness. To confirm the mechanism involved and to achieve dyed fabrics with good wash‐fastness properties, two different dyeing methods were also studied. The first method was dyeing at a constant low temperature, at which the o/w microemulsion remained a monophase system; the second one was dyeing at a high temperature, at which it was transformed into a multiphase system. Both the dye exhaustion and wash fastness improved considerably for the fabrics dyed at a high temperature. Moreover, uniform and even dyeing was achieved. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Surface functionalization of poly(lactic acid) film by UV‐photografting of N‐vinylpyrrolidone
Authors: Gutierrez‐Villarreal Mario H. , Ulloa‐Hinojosa Mayra G. , Gaona‐Lozano Jose G.
Published: June 2008

The photoinitiated grafting of N‐vinylpyrrolidone (NVP) onto poly(lactic acid) (PLA) film with the use of benzophenone (BP) as the initiator, modified the natural hydrophobic PLA behavior to an hydrophilic film with desirable wettability. The surface photografting parameters‐percent conversion of monomer to overall photopolymerization (Cp), percent conversion of monomer to the photograft polymerization (Cg), and grafting efficiency (Eg) were calculated. The resulting film surface was analyzed using ATR‐FTIR and UV spectroscopy, derivative spectroscopy and water contact angle. Besides, we demonstrated that the grafted polyvinylpyrrolidone chains could easily react with iodine to form a complex as the homopolymer does with antibacterial activity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on phase separation of PET/PEN blends by dynamic rheology
Authors: Wagner M. H. , Wu W. , Liu Y. , Qian Q. , Zhang Y. , Mielke W.
Published: June 2008

Blends of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) were processed into biaxially drawn films, and samples taken from the bi‐oriented films were then investigated by dynamic rheology experiments in the melt state. Storage modulus G′ and loss modulus G″ were determined in the frequency range of 10−2–102 rad/s at temperatures between 260 and 300°C. Although the time–temperature superposition (TTS) principle was found to hold in the high frequency regime, a breakdown of TTS was observed at low frequencies, and the terminal behavior of the storage modulus G′ of the blends departs drastically from the terminal behavior observed for the blend components. This is caused by interfacial surface tension effects. The results indicate that despite the effect of transesterification reactions, the PET/PEN blend systems investigated consist of a microseparate phase of PEN platelets in a matrix of PET. This morphology is produced when the blends are processed into biaxially oriented PET/PEN films, and droplets of PEN are deformed into a lamellar structure consisting of parallel and extended, separate layers. The large interfacial surface area of the bi‐oriented PET/PEN blends leads to remarkably strong interfacial tension effects in dynamic rheology measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Modification of the mechanical and thermal properties of PVC by semi IPN formation with poly(butyl acrylate)
Authors: Chakrabarti Rupa , Chakraborty Debabrata
Published: June 2008

Semi1 and semi2 interpenetrating polymer networks of poly(vinyl chloride) PVC and in situ formed poly(butyl acrylate) (PBA) have been synthesized and characterized using diallyl phthalate (DAP) and ethylene glycol dimethacrylate (EGDM) as the crosslinkers of PVC and PBA, respectively. These two types of IPNs have been compared with respect to their mechanical and thermal properties. The semi1 IPNs displayed a decrease in their mechanical parameters and the physical properties as well, while in contrast, the semi2 IPNs exhibited a marginal increase in the corresponding values when compared to the crosslinked PVC in the case of semi1 IPN and linear PVC in case of semi2 IPN. The representative samples of semi1 and semi2 IPNs revealed a two‐stage‐degradation typical of PVC while confirming the increased stability of the samples with higher onset temperature of degradation. The softening characteristics as detected by thermomechanical analysis are in conformity with their mechanicals. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Development of a benzaldehyde sensor utilizing chemiluminescence on nanosized Y2O3
Authors: Wu Yayan , Zhang Sichun , Wang Xin , Na Na , Zhang Zhenxi
Published: June 2008

A chemiluminescence sensor has been proposed for sensitive determination of benzaldehyde, with nanosized Y2O3 as the sensing material. Under optimized conditions, the linear range of the CL intensity vs. the concentration of benzaldehyde vapour is 1.8 ng/mL–10.8 µg/mL (r2 = 0.9996), with a detection limit of 0.90 ng/mL (signal:noise ratio = 3:1). The sensor also exhibits high selectivity to benzaldehyde because no or weak CL signals have been detected when foreign substances are introduced into the sensor. In addition, the sensor also shows good stability and longer lifetime within 100 h. The results indicate that the proposed sensor, which has high sensitivity and selectivity, shows great potential for the detection of benzaldehyde. Copyright © 2008 John Wiley & Sons, Ltd.
Extracellular recombinant protein production from an Escherichia coli lpp deletion mutant
Authors: Shin Hyun‐Dong , Chen Rachel R.
Published: June 2008

E. coli is one of the most commonly used host strains for recombinant protein production. However, recombinant proteins are usually found intracellularly, in either cytoplasm or periplasmic space. Inadequate secretion to the extracellular environment is one of its limitations. This study addresses the outer membrane barrier for the translocation of recombinant protein directed to the periplasmic space. Specifically, using recombinant maltose binding protein (MalE), xylanase, and cellulase as model proteins, we investigated whether the lpp deletion could render the outer membrane permeable enough to allow extracellular protein production. In each case, significantly higher excretion of recombinant protein was observed with the lpp deletion mutant. Up to 90% of the recombinant xylanase activity and 70% of recombinant cellulase activity were found in the culture medium with the deletion mutant, whereas only 40–50% of the xylanase and cellulase activities were extracellular for the control strain. Despite the weakened outer membrane in the mutant strain, cell lysis did not occur, and increased excretion of periplasmic protein was not due to cell lysis. The lpp deletion is a simple method to generate an E. coli strain to effect significant extracellular protein production. The phenotype of extracellular protein production without cell lysis is useful in many biotechnological applications, such as bioremediation and plant biomass conversion. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Determination of protein aggregation with differential mobility analysis: Application to IgG antibody
Authors: Pease Leonard F. , Elliott John T. , Tsai De‐Hao , Zachariah Michael R. , Tarlov Michael J.
Published: June 2008

Here we describe the use of electrospray differential mobility analysis (ES‐DMA), also known as gas‐phase electrophoretic mobility molecular analysis (GEMMA), as a method for measuring low‐order soluble aggregates of proteins in solution. We demonstrate proof of concept with IgG antibodies. In ES‐DMA, aqueous solutions of the antibody protein are electrosprayed and the various aerosolized species are separated according to their electrophoretic mobility using a differential mobility analyzer. In this way, complete size distributions of protein species present from 3 to 250 nm can be obtained with the current set up, including distinct peaks for IgG monomers to pentamers. The sizes of the IgG and IgG aggregates measured by DMA were found to be in good agreement with those calculated from simple models, which take the structural dimensions of IgG from protein crystallographic data. The dependence of IgG aggregation on the solution concentration and ionic strength was also examined, and the portion of aggregates containing chemically crosslinked antibodies was quantified. These results indicate that ES‐DMA holds potential as a measurement tool to study protein aggregation phenomena such as those associated with antibody reagent manufacturing and protein therapeutics. Biotechnol. Bioeng. 2008;101: 1214–1222. © 2008 Wiley Periodicals, Inc.
Biologically mediated mobilization of arsenic from granular ferric hydroxide in anaerobic columns fed landfill leachate
Authors: Cortinas Irail , Sierra‐Alvarez Reyes , Field Jim A.
Published: June 2008

To gain insight on the fate of arsenic (As) from drinking water treatment residuals in landfills, the mobilization of arsenate adsorbed onto granular ferric hydroxide (GFH) was studied in continuous anaerobic columns fed with a synthetic landfill leachate. The release of As was compared in biologically active and abiotic columns. More than 150 days of incubation were required before noteworthy As release occurred. After 400 days of operation, 19% of the As was mobilized as identified species in the biologically active column, which was 25.5‐fold greater than that of the abiotic column. Fine colloids accounted for up to 81% of the As released. Arsenite was the predominant species identified in filtered (0.45 µm) effluent samples. Dimethylarsinic acid and monomethylarsonic acid were also observed as metabolites. During column operation, approximately 30% of the iron (hydr)oxide mass was lost and most of the mass loss was attributed to changes in iron mineralogy that could be demonstrated in a batch bioassay. The results indicate that As‐laden GFH residuals from drinking water treatment are subject to mobilization in municipal landfills and that biologically mediated changes in the iron mineralogy may play an important role in the mobilization mechanism. Biotechnol. Bioeng. 2008;101: 1205–1213. © 2008 Wiley Periodicals, Inc.
Cell‐free synthesis of functional proteins using transcription/translation machinery entrapped in silica sol–gel matrix
Authors: Kim Kyeong‐Ohn , Lim Seong Yoon , Hahn Geun‐Hee , Lee Sahng Ha , Park Chan Beum , Kim Dong‐Myung
Published: June 2008

Herewith we report the encapsulation of functional protein synthesis machinery in a silica sol–gel matrix. When the sol–gel reaction using alkoxysilane monomers was carried out in the presence of Escherichia coli cell extract, macromolecular protein synthesis machinery in the cell extract was successfully immobilized within a silica gel matrix, catalyzing the translation of co‐immobilized DNA when supplied with small‐molecular‐weight substrates for protein synthesis. The efficiency of protein synthesis was affected by the pore size of the gel structure, which was controlled through the use of appropriate additives during the sol–gel reactions. To the best of our knowledge, this is the first report describing the reproduction of the entire set of complicated biological process within an inorganic gel matrix, and we expect that the developed technology will find many applications in numerous fields such as high‐throughput gene expression and the development of multifunctional biosensors. Biotechnol. Bioeng. 2009;102: 303–307. © 2008 Wiley Periodicals, Inc.
Transient gene delivery for functional enrichment of differentiating embryonic stem cells
Authors: Wallenstein Eric J. , Barminko Jeffrey , Schloss Rene S. , Yarmush Martin L.
Published: June 2008

There is a critical need for new sources of hepatocytes, both clinically to provide support for patients with liver failure and in drug discovery for toxicity, metabolic and pharmacokinetic screening of new drug entities. We have reported previously a variety of methods for differentiating murine embryonic stem (ES) cells into hepatocyte‐like cells. One major challenge of our work and others in the field has been the ability to selectively purify and enrich these cells from a heterogeneous population. Traditional approaches for inserting new genes (e.g., stable transfection, knock‐in, retroviral transduction) involve permanent alterations in the genome. These approaches can lead to mutations and involve the extra costs and time of developing, validating and maintaining new cell lines. We have developed a transient gene delivery system that uses fluorescent gene reporters for purification of the cells. Following a transient transfection, the cells are purified through a fluorescence‐activated cell sorter (FACS), re‐plated in secondary culture and subsequent phenotypic analysis is performed. In an effort to test the ability of the reporters to work in a transient environment for our differentiation system, we engineered two non‐viral plasmid reporters, the first driven by the mouse albumin enhancer/promoter and the second by the mouse cytochrome P450 7A1 (Cyp7A1) promoter. We optimized the transfection efficiency of delivering these genes into spontaneously differentiated ES cells and sorted independent fractions positive for each reporter 17 days after inducing differentiation. We found that cells sorted based on the Cyp7A1 promoter showed significant enrichment in terms of albumin secretion, urea secretion and cytochrome P450 1A2 detoxification activity as compared to enrichment garnered by the albumin promoter‐based cell sort. Development of gene reporter systems that allow us to identify, purify and assess homogeneous populations of cells is important in better understanding stem cell differentiation pathways. And engineering cellular systems without making permanent gene changes will be critical for the generation of clinically acceptable cellular material in the future. Biotechnol. Bioeng. 2008;101: 859–872. © 2008 Wiley Periodicals, Inc.
Histo‐Topographic study of the longitudinal anal muscle
Authors: Macchi Veronica , Porzionato Andrea , Stecco Carla , Vigato Enrico , Parenti Anna , Caro Raffaele De
Published: June 2008

The longitudinal anal muscle (LAM) has been described as a vertical layer of muscular tissue interposed between the circular layers of the internal (IAS) and external (EAS) anal sphincters. There is, however, no general agreement in the literature on its composition and attachments. The aim of this study was to investigate the histological structure, attachments, and topography of the LAM in order to evaluate its role in continence and defecation, thus enhancing knowledge of the surgical anatomy of this region. After in situ formalin fixation, the pelvic viscera were removed from eight male and eight female cadavers (age range: 52–72 years). Serial macrosections of the bladder base, lower rectum and anal canal, cervix and pelvic floor complex, cut in the transverse (six specimens) and coronal (six specimens) planes, underwent histological and immunohistochemical studies. Four specimens were studied using the E12 sheet plastination technique. The LAM was identified in 10/12 specimens (83%). Transverse and coronal sections made clear that it is a longitudinal layer of muscular tissue, marking the boundary between the internal and external anal sphincters. From the anorectal junction it extends along the anal canal, receives fibers from the innermost part of the puborectalis and the puboanalis muscles, and terminates with seven to nine fibro‐elastic septa, which traverse the subcutaneous part of the external anal sphincter, reaching the perianal dermis. In the transverse plane, the mean thickness of the LAM was 1.68 ± 0.27 mm. Immunohistochemical staining showed that the LAM consists of predominantly outer striated muscle fibers and smaller numbers of inner smooth muscle fibers, respectively coming from the levator ani muscle and from the longitudinal muscular layer of the rectum. The oblique fibers suggest that the LAM may represent the intermediate longitudinal course of small bridging muscle bundles going reciprocally from the striated EAS to the smooth IAS and vice versa. The spatial result is the helical course of striated and smooth muscle fibers between the EAS and IAS, which contribute not only to the narrowing but also to some shortening of the anal canal during sphincter contraction. Thus, rather than being a boundary, the LAM gives anatomical evidence of a functional connection between two muscle systems with different structures and topography. Clin. Anat. 21:447–452, 2008. © 2008 Wiley‐Liss, Inc.
Linearity analysis in pipeline A/D converters
Authors: Sedighi Behnam , Sharif Bakhtiar Mehrdad
Published: June 2008

A method for estimating integral nonlinearity (INL) in pipeline analog‐to‐digital converters is presented. In this method, errors in each stage are modeled by an equivalent input‐referred gain error and an input‐referred nonlinearity. For a switched capacitor implementation, the proposed model predicts the maximum statistical INL in terms of capacitor mismatch and also provides an exact formula for INL in terms of finite gain of operational amplifiers. Using this model, it is proved that a high per‐stage resolution reduces the power consumption in low‐speed converters, whereas in high‐speed circuits 1.5‐bit or 2.5‐bit stage is more advantageous. It is also shown that when voltage swing is below 1 V, the lower limit for the size of the capacitors is mainly determined by thermal noise rather than by INL. Copyright © 2008 John Wiley & Sons, Ltd.
Regulation of hepatic glucose production and the role of gluconeogenesis in humans: is the rate of gluconeogenesis constant?
Authors: Nuttall Frank Q. , Ngo Angela , Gannon Mary C.
Published: June 2008

We have been interested in the metabolic effects of ingested fuels, both in normal subjects and in people with type 2 diabetes. Recently, we have become interested in the regulation of glucose production and the regulation of gluconeogenesis in particular. We are not aware of a recent comprehensive review of these topics. Therefore, we have reviewed the currently available literature.

The pertinent papers obtained from a Medline search of the words gluconeogenesis, glycogenolysis, hepatic glucose output, as well as papers from our personal files, form the basis of this review.

In order to analyse the data, it also was necessary to review the relevant methodology used in determining gluconeogenesis. Pathway diagrams have been included with this review in order to illustrate and highlight key aspects of the methodologies.

Current data support the hypothesis that the rate of glucose appearance changes but the rate of gluconeogenesis remains remarkably stable in widely varying metabolic conditions in people without diabetes. In people with diabetes, whether gluconeogenesis remains unchanged is at present uncertain. Available data are very limited. The mechanism by which gluconeogenesis remains relatively constant, even in the setting of excess substrates, is not known. One interesting speculation is that gluconeogenic substrates substitute for each other depending on availability. Thus, the overall rate is either unaffected or only modestly changed. This requires further confirmation. Published in 2008 by John Wiley & Sons, Ltd.
Heparanase prevents the development of type 1 diabetes in non‐obese diabetic mice by regulating T‐cell activation and cytokines production
Authors: Bitan Menachem , Weiss Lola , Zeira Michael , Reich Shoshana , Pappo Orit , Vlodavsky Israel , Slavin Shimon
Published: June 2008

Background

Heparanase is an endo‐β‐D‐glucuronidase that cleaves heparan sulfate saccharide chains. The enzyme promotes cell adhesion, migration and invasion, and was shown to play a significant role in cancer metastasis and angiogenesis.

Methods

The present study focuses on the involvement of heparanase in autoimmunity, applying the murine non‐obese diabetic (NOD) model, a T‐cell‐dependent disease often used to investigate the pathophysiology of type 1 diabetes.

Results

It was found that intra‐peritoneal administration of heparanase ameliorated the clinical signs of the disease. In vitro studies revealed that heparanase has an inhibitory effect on the activation of T‐cells through modulation of their repertoire of cytokines indicated by a marked increase in the levels of IL‐4 and IL‐10, and a parallel decrease in IL‐12, tumour necrosis factor‐alpha (TNF‐α) and interferon‐gamma (IFN‐γ).

Conclusions

We suggest that heparanase induces a shift from a Th1‐ to Th2‐phenotype, resulting in inhibition of diabetes in NOD mice and possibly other autoimmune disorders. Copyright © 2008 John Wiley & Sons, Ltd.
An improvement of classical slope limiters for high‐order discontinuous Galerkin method
Authors: Ghostine R. , Kesserwani G. , Mosé R. , Vazquez J. , Ghenaim A.
Published: June 2008

In this paper, we describe some existing slope limiters (Cockburn and Shu's slope limiter and Hoteit's slope limiter) for the two‐dimensional Runge–Kutta discontinuous Galerkin (RKDG) method on arbitrary unstructured triangular grids. We describe the strategies for detecting discontinuities and for limiting spurious oscillations near such discontinuities, when solving hyperbolic systems of conservation laws by high‐order discontinuous Galerkin methods. The disadvantage of these slope limiters is that they depend on a positive constant, which is, for specific hydraulic problems, difficult to estimate in order to eliminate oscillations near discontinuities without decreasing the high‐order accuracy of the scheme in the smooth regions. We introduce the idea of a simple modification of Cockburn and Shu's slope limiter to avoid the use of this constant number. This modification consists in: slopes are limited so that the solution at the integration points is in the range spanned by the neighboring solution averages. Numerical results are presented for a nonlinear system: the shallow water equations. Four hydraulic problems of discontinuous solutions of two‐dimensional shallow water are presented. The idealized dam break problem, the oblique hydraulic jump problem, flow in a channel with concave bed and the dam break problem in a converging–diverging channel are solved by using the different slope limiters. Numerical comparisons on unstructured meshes show a superior accuracy with the modified slope limiter. Moreover, it does not require the choice of any constant number for the limiter condition. Copyright © 2008 John Wiley & Sons, Ltd.
Viscoelastic effects in double‐pipe single‐pass counterflow heat exchangers
Authors: Chinyoka T.
Published: June 2008

The conducto‐convective heat loss from a viscoelastic liquid, in the core of a double‐pipe heat exchanger arrangement, to a cooler Newtonian fluid flowing in the outer annulus is investigated with direct numerical simulations. A numerical algorithm based on the finite difference method is implemented in time and space with the Giesekus constitutive model for the viscoelastic liquids. The flow of both the annulus and core‐fluids is considered to be Poiseuille flow, driven by respective pressure gradients. In general, the results show that a viscoelastic core‐fluid leads to slightly lower (albeit comparable) attainable temperatures in the core‐fluid stream as compared with a corresponding Newtonian fluid. Copyright © 2008 John Wiley & Sons, Ltd.
Late and very‐late first‐contact schizophrenia and the risk of dementia–a nationwide register based study
Authors: Kørner Alex , Lopez Ana Garcia , Lauritzen Lise , Andersen Per Kragh , Kessing Lars Vedel
Published: June 2008

Objective

To examine whether late and very‐late first‐contact schizophrenia carry a risk for later development of dementia.

Methods

By linkage of the psychiatric and the somatic nation‐wide registers of all out‐ and in‐patients with hospital contact in Denmark, we identified all patients with first ever contact during the period from January 1994 to December 2001 with one of the index main diagnoses: late (age ≥40) and very‐late first‐contact (age ≥60) schizophrenia. First contact osteoarthritis patients as well as data on the general population were used as controls. The first diagnosis of dementia for each individual at discharge or at out‐patient contact was established. The probability of getting a dementia diagnosis is estimated using Poisson regression models with dementia as the outcome of interest.

Results

Twelve thousand six hundred and sixteen and 7,712 individuals were included in the late and very‐late sample, respectively. Follow‐up time was between 3.00 and 4.58 years. The rate ratio (RR) of developing dementia in late and very‐late first‐contact schizophrenia compared to osteoarthritis patients were 3.47 (95%CI: 2.19–5.50) and 3.15 (95%CI: 1.93–5.14), respectively. Compared to the general population the RR were 2.36 (95%CI: 1.54–3.62) and 2.21 (95%CI: 1.39–3.50), respectively.

Conclusion

schizophrenic patients with late‐ and very‐late first‐contact with the psychiatric hospital system are at two to three times higher risk of subsequently getting a diagnosis of dementia compared to patients with osteoarthritis and compared to the general population. Copyright © 2008 John Wiley & Sons, Ltd.
Winter rain on snow and its association with air temperature in northern Eurasia
Authors: Ye Hengchun , Yang Daqing , Robinson David
Published: June 2008

This study examines the characteristics of winter (Dec–Feb) rain‐on‐snow events and their relationship to surface air temperatures to reveal potential changes in rain‐on‐snow days under a warming climate over northern Eurasia. We found that rain‐on‐snow events mostly occur over European Russia during winter. Rain‐on‐snow days increase as air temperature increases and are primarily attributable to the increase in rainfall days. Air temperature is the primary cause for these changes, while the North Atlantic Oscillation has some influence on the rain on snow and rainfall over the northern part of European Russia. The magnitude of rain‐on‐snow increase ranges from 0·5 day to 2·5 days per degree Celsius increase in air temperature. Higher rates of increase in rain‐on‐snow days occur in the northern and eastern parts of European Russia where the air temperature is lower, in contrast to rainfall days which have higher rates at locations with higher air temperatures. This suggests that a decrease in snowfall days might be limiting the rate of increase in rain‐on‐snow events over warmer regions where the temperature is about − 8 °C or higher. This study also implies that rain‐on‐snow days will become more common over regions in which it is currently a rare event as air temperatures increase. Copyright © 2008 John Wiley & Sons, Ltd.
The art of combining statistics with the law
Authors: Luna Andrew L.
Published: June 2008

Although the practice of law and the science of statistics are often incongruent, they can and should be used together.
The use of data in affirmative action litigation
Authors: Harris Michael S. , Roth John H.
Published: June 2008

The courts have ruled as to what types of institutional data and decision making meet constitutional and legal thresholds to avoid legal action.
Statistical evidence and compliance with Title IX
Authors: Cheslock John J. , Eckes Suzanne E.
Published: June 2008

This chapter examines the statistical evidence used to determine whether an institution's athletic program is in compliance with Title IX.
Organization and maintenance of data in employment discrimination litigation
Authors: Christenson Bruce A. , Maher Kathleen M. , Mueller Lorin M.
Published: June 2008

This chapter addresses the role of personnel data systems in addressing allegations of employment discrimination.
Analyzing personnel selection decisions in employment discrimination litigation settings
Authors: Mueller Lorin M. , Dunleavy Eric M. , Buonasera Ash K.
Published: June 2008

Employment decisions like selection, promotion, and termination should be analyzed to prevent litigation or to refute a prima facie case.
Regression analysis: Legal applications in institutional research
Authors: Frizell Julie A. , Shippen Benjamin S. , Luna Andrew L.
Published: June 2008

Through a history of decisions, the courts have outlined how regression models should be used in discrimination cases.
Preparation, characterization, andin vitrocytotoxicity study of cationic PCL‐Pluronic‐PCL (PCFC) nanoparticles for gene delivery
Authors: Zhao Jian , Gou MaLing , Dai Mei , Li XingYi , Cao Mei , Huang MeiJuan , Wen YanJun , Kan Bing , Qian ZhiYong , Wei YuQuan
Published: June 2008

In this article, poly(ε‐caprolactone)‐Pluronic‐poly(ε‐caprolactone) (PCFC) copolymer was synthesized by ring‐opening polymerization and characterized by1H‐NMR and GPC. Cationic PCFC nanoparticles were prepared at one‐step by modified emulsion solvent evaporation method using cetyltrimethylammonium bromide as the stabilizer. The cytotoxicity of PCFC nanoparticles was studied here with and without serum. The obtained cationic PCFC nanoparticles were employed to condense and adsorb DNA onto its surface. And it could protect plasmid GFP (pGFP) from enzymatic degradation and acidic degradation in a certain period. Release behavior of pGFP from the pGFP/PCFC nanoparticles complex was also studiedin vitro. The obtained cationic PCEC nanoparticles might have great potential application in DNA delivery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Human mesenchymal stem cell adhesion and proliferation in response to ceramic chemistry and nanoscale topography
Authors: Dulgar‐Tulloch A. J. , Bizios R. , Siegel R. W.
Published: June 2008

Modification of the chemistry and surface topography of nanophase ceramics was used to provide biomaterial formulations designed to direct the adhesion and proliferation of human mesenchymal stem cells (HMSCs). HMSC adhesion was dependent upon both the substrate chemistry and grain size, but not on surface roughness or crystal phase. Specifically, cell adhesion on alumina and hydroxyapatite was significantly reduced on the 50 and 24 nm surfaces, as compared with the 1500 and 200 nm surfaces, but adhesion on titania substrates was independent of grain size. HMSC proliferation was minimal on the 50 and 24 nm substrates of any chemistry tested, and thus significantly lower than the densities observed on either the 1500 or 200 nm surfaces after 3 or more consecutive days of culture. Furthermore, HMSC proliferation was enhanced on the 200 nm substrates, compared with results obtained on the 1500 nm substrates after 7 or more days of culture. HMSC proliferation was independent of both substrate surface roughness and crystal phase. Rat osteoblast and fibroblast adhesion and proliferation exhibited similar trends to that of HMSCs on all substrates tested. These results demonstrated the potential of nanophase ceramic surfaces to modulate functions of HMSCs, which are pertinent to biomedical applications such as implant materials and devices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Zirconia: Established facts and perspectives for a biomaterial in dental implantology
Authors: Hisbergues Michael , Vendeville Sophie , Vendeville Philippe
Published: June 2008

Currently, zirconia is widely used in biomedical area as a material for prosthetic devices because of its good mechanical and chemical properties. Largely employed in clinical area for total hip replacement, zirconia ceramics (ZrO2) are becoming a prevalent biomaterial in dentistry and dental implantology. Although titanium is used in dental implantology currently, there is a trend to develop new ceramic‐based implants as an alternative to monolithic titanium. This article reviews the evolution and development of zirconia through data published between 1963 and January 2008 in English language. Articles were identified via a MEDLINE search using the following keywords: zirconia, zirconia/biocompatibility, zirconia/osseointegration, zirconia/periointegration, zirconia/review, and zirconia/bacterial adhesion or colonization. This review of the literature aims at highlighting and discussing zirconia properties in biological systems for their future use in dental implantology. In conclusion, zirconia with its interesting microstructural properties has been confirmed to be a material of choice for the “new generation” of implants, thanks to its biocompatibility, osseoconductivity, tendency to reduce plaque accumulation, and interaction with soft tissues, which leads to periointegration. However, scientific studies are promptly needed to fulfill gaps like long‐term clinical evaluations of “all zirconia implants,” currently leading to propose an alternative use of “hybrid systems” (i.e., titanium screw with zirconia collar) and also bacterial colonization of zirconia. Moreover, there is a permanent need for consistent information about topography and chemistry of zirconia allowing easier cross‐product comparisons of clinical devices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Corrosion of machined titanium dental implants under inflammatory conditions
Authors: Messer Regina L. W. , Tackas Gyula , Mickalonis John , Brown Yolanda , Lewis Jill B. , Wataha John C.
Published: June 2008

The effects of hyperglycemia, altered cell function, or inflammatory mediators on implant corrosion are not well studied; yet, these effects are critical to implant biocompatibility and osseointegration. Because implant placement is burgeoning, patients with medically compromising systemic conditions such as diabetes are increasingly receiving implants, and the role of other inflammatory diseases on implant corrosion also needs investigation. In the current study, the corrosion properties of commercially available, machined titanium implants were studied in blood, cultures of monocytic cells, and solutions containing elevated dextrose concentrations. Implant corrosion was estimated by open circuit potentials, linear polarization resistance, and electrical impedance spectroscopy (EIS) for 26 h. In selected samples, THP1 monocytic cells were activated for 2 h with Lipopolysaccharide prior to implant exposure, and IL‐1β secretion was measured to assess the affect of the implants on monocyte activation. Implants under conditions of inflammatory stress exhibited more negative Ecorr values, suggesting an increased potential for corrosion. Linear polarization measurements detected increased corrosion rates in the presence of elevated dextrose conditions over PBS conditions. EIS measurements suggested that implants underwent surface passivation reactions that may have limited corrosion over the short term of this test. This result was supported by cyclic polarization tests. IL‐1β secretion was not altered under conditions of corrosion or implant exposure. The results suggest that inflammatory stress and hyperglycemia may increase the corrosion of dental endosseous titanium‐based implants, but that longer, more aggressive electrochemical conditions may be necessary to fully assess these effects. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Effects of restoration and substrate on polymerization contraction stress of dental composites
Authors: Feng L. , Nunez R. , Carvalho R. , Suh B. I.
Published: June 2008

The aim of this study was to treat both restoration and substrate as a combined factor (RS‐factor) to complement the popular C‐factor in prediction of polymerization contraction stress (PCS). A simple model consists of a uniaxial restoration with a curing composite sandwiched between two solid mountings (substrates). By using the equal stress principle and taking into account substrate deformation, a set of equations were developed and solved, resulting in a mathematical relationship between PCS and the size and stiffness of the substrate and the restoration. The strain gage method was used to experimentally assess the PCS of a light‐cured composite encircled in an aluminum ring. Differently sized inserts made of cured composites and glass were placed in the center of the ring to control the thickness of the composite to be cured and created different RS factors as well as C‐factors. According to the model, a restoration with a small RS‐factor will produce a high PCS. The model also predicts that a restoration with a small C‐factor will have a high PCS because of the compliance of substrates. These predictions were tentatively confirmed by the strain gage measurements. A higher PCS was detected when a smaller insert was used, which created a smaller RS‐factor or C‐factor, or when a glass insert was used instead of a less stiff composite insert, in which the former created a smaller RS‐factor. The RS‐factor may be a dominant factor in determining the PCS outcome in some special cases. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Novel surface expression of reticulocalbin 1 on bone endothelial cells and human prostate cancer cells is regulated by TNF‐α
Authors: Cooper Carlton R. , Graves Bianca , Pruitt Freddie , Chaib Hassan , Lynch Jill E. , Cox Andrew Koemeter , Sequeria Linda , van Golen Kenneth L. , Evans Angelo , Czymmek Kirk , Bullard Rebecca S. , Donald Carlton D. , Sol‐Church Katia , Gendernalik James D. , Weksler Babette , Farach‐Carson Mary C. , Macoska Jill A. , Sikes Robert A. , Pienta Kenneth J.
Published: June 2008

An unbiased cDNA expression phage library derived from bone‐marrow endothelial cells was used to identify novel surface adhesion molecules that might participate in metastasis. Herein we report that reticulocalbin 1 (RCN1) is a cell surface‐associated protein on both endothelial (EC) and prostate cancer (PCa) cell lines. RCN1 is an H/KDEL protein with six EF‐hand, calcium‐binding motifs, found in the endoplasmic reticulum. Our data indicate that RCN1 also is expressed on the cell surface of several endothelial cell lines, including human dermal microvascular endothelial cells (HDMVECs), bone marrow endothelial cells (BMEC), and transformed human bone marrow endothelial cells (TrHBMEC). While RCN1 protein levels were highest in lysates from HDMVEC, this difference was not statistically significant compared BMEC and TrHBMEC. Given preferential adhesion of PCa to bone‐marrow EC, these data suggest that RCN1 is unlikely to account for the preferential metastasis of PCa to bone. In addition, there was not a statistically significant difference in total RCN1 protein expression among the PCa cell lines. RCN1 also was expressed on the surface of several PCa cell lines, including those of the LNCaP human PCa progression model and the highly metastatic PC‐3 cell line. Interestingly, RCN1 expression on the cell surface was upregulated by tumor necrosis factor alpha treatment of bone‐marrow endothelial cells. Taken together, we show cell surface localization of RCN1 that has not been described previously for either PCa or BMEC and that the surface expression on BMEC is regulated by pro‐inflammatory TNF‐α. J. Cell. Biochem. 104: 2298–2309, 2008. © 2008 Wiley‐Liss, Inc.
Membrane fouling caused by amino acid and calcium during bipolar membrane electrodialysis
Authors: Ren Hongyan , Wang Qian , Zhang Xiaoyan , Kang Ruijuan , Shi Shaoyuan , Cong Wei
Published: June 2008

BACKGROUND: Bipolar membrane electrodialysis (BMED) has been widely applied in the recovery/production of organic acids and in the treatment of wastewater containing ammonium sulfate, sodium nitrate, sodium acetate and ammonium nitrate. However, membrane fouling is still one of the major problems in the electrodialysis process. Since calcium and amino acid are present naturally in fermentation wastewater, this study was carried out to determine the effects of calcium and amino acid on membrane fouling when simulated fermentation wastewater containing ammonium sulfate was treated by BMED.

RESULTS: Calcium formed a scale on the cation exchange membrane (CEM) surface in contact with the base cell, but this had no significant adverse effect on the BMED performance. Amino acid, however, caused CEM fouling of the inner membrane, which hampered the BMED process. The coexistence of calcium and amino acid aggravated the membrane fouling, as observed morphologically on the CEM surface on the base cell side. Elemental mapping analysis showed that the membrane foulant was composed of calcium hydroxide and amino acid.

CONCLUSION: The CEM fouling caused by calcium and that due to amino acid, which were distributed differently on the membrane, had different effects on the BMED performance. The coexistence of amino acid and calcium deteriorated the CEM fouling during BMED. Copyright © 2008 Society of Chemical Industry
Modeling of supercritical drying of ethanol‐soaked silica aerogels with carbon dioxide
Authors: Mukhopadhyay Mamata , Rao Bhatta Sankara
Published: June 2008

BACKGROUND: Supercritical drying (SCD) of aerogels entails replacement of the primary solvent ethanol in the porous solid network with supercritical carbon dioxide (SCCO2) without a vapor–liquid interface to avoid collapse of the pores by capillary forces. The present paper proposes a mechanistic SCD model for producing crack‐free aerogels and elucidates the requirement of such a process by focusing on mass transfer modeling for silica aerogel with parallel cylindrical mesopores having a known pore size distribution.

RESULTS: The model incorporates extraction of ethanol by two‐way mass transfer of SCCO2 and ethanol to and from the wet gel until it attains 99.995 mole% CO2. Initially the pores are filled with pure ethanol and the liquid volume swells due to dissolution of CO2, rendering spillage of the excess liquid volume. Thus ethanol is removed by spillage as well as by evaporation from the open end of the pores, followed by convective mass transfer. The convective velocity of SCCO2 needs to be kept less than a critical value to obviate vapor–liquid interface within the pores at any time. Simulation results indicate that initially the ratio of spillage to convective transport is very high (16–20) which asymptotically decreases to zero with time as the mixture in the pores attains critical mole fraction (MCM). This indicates that the bulk of the ethanol is removed by spillage caused by diffusion of SCCO2 into the pores, rather than by convective evaporation. Their ratio is higher at lower temperature, higher pressure, lower flow rate and thicker gel, similar to the drying time.

CONCLUSIONS: The mechanistic model for SCD of a silica aerogel with SCCO2 illustrates that a vapor–liquid interface within the pores at any time can be avoided by keeping the convective velocity of SCCO2 less than a critical value. Most of the ethanol is removed by spillage as a result of SCCO2 dissolution in the pore liquid, rather than by convective evaporation. Higher pressure, lower temperature, lower SCCO2 velocity and thicker gel slow down the SCD process and are conducive to producing crack‐free transparent aerogels. Copyright © 2008 Society of Chemical Industry
Pancreatic arteriovenous malformation: A rare manifestation of hereditary hemorrhagic telangiectasia
Authors: Demirpolat Gulen , Oran Ismail , Demirpolat Gulgun , Tamsel Sadik , Parildar Mustafa
Published: June 2008

We present Doppler ultrasound, computed tomography and angiography findings of a rare pancreatic arteriovenous malformation associated with hereditary hemorrhagic telangiectasia. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Normal reference values of ratios of blood flow velocities in internal carotid artery to those in common carotid artery using Doppler sonography
Authors: Kochanowicz Jan , Turek Grzegorz , Rutkowski Robert , Mariak Zenon , Szydlik Piotr , Lyson Tomasz , Krejza Jaroslaw
Published: June 2008

Purpose.

The ratios of of blood flow velocities in the internal carotid artery (ICA) to those in the common carotid artery (CCA) (VICA/VCCA) are used to identify patients with critical ICA narrowing, but their normal reference values have not been established. We provide reference data for the VICA/VCCA ratios for the peak systolic velocity (PSV), mean velocity (MV), and end‐diastolic velocity (EDV) measured in a large group of healthy subjects.

Methods.

We examined 343 healthy subjects with color duplex sonography. They were divided into 3 age groups: group I, <40 years; group II, 40–60 years; group III, >60 years.

Results.

The values of VICA/VCCA ratio for the PSV were as follows [mean (upper and lower reference values)]. In women, group I: 0.81 (0.48–1.14), group II: 0.88 (0.36–1.40), group III: 0.9 (0.36–1.40). In men, group I: 0.65 (0.32–0.98), group II: 0.72 (0.39–1.05), group III: 0.91 (0.27–1.56). The VICA/VCCA ratio for PSV increased with age only in men and its values were significantly higher in women than in men in the group I and group II age groups.

Conclusion.

This study provides normal reference values for the VICA/VCCA ratios for PSV and shows that the ratio varies with age and sex. The upper reference limit for the ratio can serve as an aid in the more specific identification of patients with minor or mild ICA narrowing. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Pulsatile tinnitus in a case of traumatic temporal extradural arteriovenous fistula: Carotid duplex sonography findings before and after embolization
Authors: Tan Teng‐Yeow , Lin Yun‐Yu , Schminke Ulf , Chen Ting‐Yao
Published: June 2008

Carotid duplex sonography (CDS) is regarded as a screening tool for lateral dural arteriovenous fistulae (AVF). However, data on evaluating long‐term effects of endovascular treatment are limited. We report the CDS findings in the feeding arteries of a traumatic temporal extradural AVF before and after transarterial embolization. Volume flow of the left common carotid artery was greater than the right (433 ml/minute versus 294 ml/minute right) and the resistance index of the left external carotid artery was lower than the right (0.69 left versus 0.84 right). Both parameters returned to normal 4 months after embolization, thus confirming successful endovascular treatment. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Hadwiger's conjecture for quasi‐line graphs
Authors: Chudnovsky Maria , Fradkin Alexandra Ovetsky
Published: June 2008

A graph G is a quasi‐line graph if for every vertex v ∈ V(G), the set of neighbors of v in G can be expressed as the union of two cliques. The class of quasi‐line graphs is a proper superset of the class of line graphs. Hadwiger's conjecture states that if a graph G is not t‐colorable then it contains Kt + 1 as a minor. This conjecture has been proved for line graphs by Reed and Seymour. We extend their result to all quasi‐line graphs. © 2008 Wiley Periodicals, Inc. J Graph Theory 59: 17–33, 2008