bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Expression Levels of MRP1, MRP4, and MRP5 in Response to Human Immunodeficiency Virus Infection in Human Macrophages
Authors: Jorajuria Sylvie , Dereuddre-Bosquet Nathalie , Naissant-Storck Karen , Dormont Dominique , Clayette Pascal 
Published: April 2004

ABSTRACT
Multidrug resistance proteins (MRPs) have been reported to be involved in the efflux of some anti-human immunodeficiency virus (HIV) drugs. We show here that MRP1, MRP4, and MRP5 are expressed at the mRNA level in human monocyte-derived macrophages. HIV infection caused increased transcription of these MRPs; however, temporal differences in stimulation are reported.
Iron Blocks the Accumulation and Activity of Tetracyclines in Bacteria
Authors: Avery Angela M. , Goddard Helen J. , Sumner Edward R. , Avery Simon V. 
Published: April 2004

ABSTRACT
The apparent sensitivities of several bacterial pathogens to tetracyclines varied by up to 128-fold with the medium content of Fe, but not of other metals. The effect of Fe was independent of superoxide dismutase activity and of intracellular Fe, but accumulation of tetracyclines was blocked in high-Fe medium. Thus, synergistic suppression of bacterial growth in the presence of a low Fe concentration and tetracyclines arises because of elevated antibiotic accumulation.
Effects of Maribavir and Selected Indolocarbazoles on Epstein-Barr Virus Protein Kinase BGLF4 and on Viral Lytic Replication
Authors: Gershburg Edward , Hong Ke , Pagano Joseph S. 
Published: April 2004

ABSTRACT
The human cytomegalovirus (HCMV) homolog of the Epstein-Barr virus (EBV) protein kinase (PK), UL97, is inhibited by maribavir (1263W94) and selected indolocarbazoles. Here we show that only one of these indolocarbazoles (K252a), but not maribavir, inhibits autophosphorylation of the EBV PK, BGLF4. However, maribavir and another indolocarbazole, NGIC-I, do inhibit EBV DNA synthesis, suggesting that although these last compounds inhibit both HCMV and EBV, they seem to operate through differ-ent pathways.
Pharmacokinetics of Indinavir Combined with Low-Dose Ritonavir in Human Immunodeficiency Virus Type 1-Infected Children
Authors: Bergshoeff A. S. , Fraaij P. L. A. , van Rossum A. M. C. , Verweel G. , Wynne L. H. , Winchell G. A. , Leavitt R. Y. , Nguyen B.-Y. T. , de Groot R. , Burger D. M. 
Published: April 2004

ABSTRACTSo far, no pediatric doses for indinavir combined with ritonavir have been defined. This study evaluated the pharmacokinetics of 400 mg of indinavir/m2combined with 125 mg of ritonavir/m2every 12 h (q12h) in 14 human immunodeficiency virus type 1-infected children. The area under the concentration-time curve from 0 to 24 h and the minimum concentration of drug in serum for indinavir were similar to those for 800 mg of indinavir-100 mg of ritonavir q12h in adults, while the maximum concentration of drug in serum was slightly decreased, with geometric mean ratios (90% confidence intervals in parentheses) of 1.1 (0.87 to 1.3), 0.96 (0.60 to 1.5), and 0.80 (0.68 to 0.94), respectively.
In Vitro Activity of Anidulafungin against Selected Clinically Important Mold Isolates
Authors: Odabasi Zekaver , Paetznick Victor L. , Rodriguez Jose R. , Chen Enuo , Ostrosky-Zeichner Luis 
Published: April 2004

ABSTRACT

In this study, we evaluated the in vitro activity of anidulafungin against selected mold isolates. Anidulafungin showed promising activity against
Bipolaris spicifera
,
Exophiala jeanselmei
,
Fonsecaea pedrosoi
,
Madurella mycetomatis
,
Penicillium marneffei
,
Phialophora verrucosa
,
Pseudallescheria boydii
,
Sporothrix schenckii
, and
Wangiella dermatitidis.
DBTDL Replacement in High Resilience Slabstock Foams
Authors: Gerard E. -J. , Verstraete H. , Maas W. , Schlenter B. 
Published: April 2004

Over the last two years, serious concerns have been expressed in the press about human exposures to trace amounts of alkyl tin moieties such as tributyltin (TBT). Organostannic compounds are commonly used as catalysts in polyurethane chemistry. Whereas stannous octoate (SNOCT) exhibits a TBT content below the detection limit of most analysis equipment (< 0.01%), TBT levels as high as 0.6% have been measured in dibutyltin dilaurate (DBTDL). Although DBTDL manufacturers are currentlyoptimising their process to lower the TBT content in DBTDL, the (chemo) pressure exerted on polyurethane foamers is such that DBTDL-free formulations are being activelylooked for. High resilience (HR) foams based on various polymer polyols–particularly polyols made with pure polystyrene (POSTech*) or poly(styrene–acrylonitrile)–have been developed using DBTDL as the gel catalyst. The direct replacement of DBTDL is not straightforward, as foam block dimensional stabilityissues (often referred to as “cold flow”) are encountered when other catalyst (i.e., SNOCT) are used. This “cold flow” phenomenon is verymuch dependent on the size and the weight of the foam block produced, making all small scale laboratory experiments unsuitable for developing novel stable HR foam formulations. The present research has shown that properties derived from small scale experiments can nevertheless be related to the “cold flowability” of HR formulations. Amongst the various tests investigated, the variation in sag factor from top to bottom of the foam block was found to be the most relevant test method to assess the dimensional stability. Sag factor is here defined as the force exerted bythe foam compressed to 65% of the original thickness divided by that exerted at 25% compression during the compression load deflection (CLD) test. The test method based on this variation in sag factor through the foam block (vSag) made possible the laboratoryexamination of formulation parameters for their impact on foam block stability. It also allowed us to develop a wide density range of POSTech-based DBTDL-free HR slabstock foams that are dimensionallystable.
Diffusion of Cyclopentane in Polyurethane Foam at Different Temperatures and Implications for District Heating Pipes
Authors: Olsson Maria E. , Jarfelt Ulf , Fröling Morgan , Mangs Sara , RamnäS Olle 
Published: April 2004

District heating pipes are usually polyurethane-(PUR)-insulated and the outside is protected by a polyethylene (HDPE) casing. The permeability of the cell gases (oxygen, nitrogen, carbon dioxide and cyclopentane) in the PUR foam and in the HDPE casing was determined for a temperature range of 20–60 C (PUR) and 5–40 C (HDPE). From the results, it was concluded that the casing acts as the main diffusion barrier for carbon dioxide, oxygen and nitrogen, whereas the main diffusion barrier for diffusion of cyclopentane is due to the PUR foam. This conclusion is valid for district heating pipes of small to medium dimensions.
Deformation of Polypropylene Foam Neopolen® P in Compression
Authors: Beverte Ilze 
Published: April 2004

Neopolen® P is a two-phase cellular composite foam material produced by BASF AG, Germany. In most of the practical applications, Neopolen® P works under a range of small and compressive deformations. Therefore it is necessary to determine the moduli in compression and compressive strength in the most effective way for a wide range of foam densities: 22≤ρ84≤kg/m3. Several experimental methods of different precision for deformation properties of Neopolen® P were compared. The direct measurements performed by a universal testing machine were used for the main part of the experiments. They were compared with results obtained by a more precise and time-consuming method, using an inductive extensiometer HBW5K. Experimental data were obtained for structural, elastic, and strength properties. It was proved that the foam exhibited a slight monotropy for the highest density of the investigated range. The observed anisotropy of mechanical properties was correlated to the structure and the manufacturing technology of the foam. Influence of the interaction of the two main factors: the electrostatic forces and the Earth gravity on the final anisotropy mode of the foam was analyzed.
S2-Glass/Epoxy Polymer Nanocomposites: Manufacturing, Structures, Thermal and Mechanical Properties
Authors: Haque A. , Shamsuzzoha M. , Hussain F. , Dean D. 
Published: April 2004

This paper is primarily focused in studying the effects of nanoclay particles such as montmorillonite on improving mechanical and thermal properties of fiber reinforced polymer matrix composite materials. Basic correlations between polymer morphology, strength, modulus, toughness, and thermal stability of thermoset nanocomposites were investigated as a function of layered silicate content. S2-glass/epoxy-clay nanocomposites were manufactured through an affordable vacuum assisted resin infusion method (VARIM). The nanocomposites are formed during polymerization when the adsorbing monomer separates the clay particles into nanometer scales. Transmission electron microscopy (TEM) and wide angle X-ray diffraction(WAXD) were used to characterize the morphology of the dispersed clay particles. The thermal properties such as onset of decomposition and glass transition temperatures were determined by Thermo Gravimetric Analysis (TGA) and Dynamic Modulus Analyzer (DMA). Mechanical properties such as interlaminar shear strength, flexural properties and fracture toughness are also determined for both conventional S2-glass/epoxy composites and S2-glass fiber reinforced nanocomposites. The results show significant improvements in mechanical and thermal properties of conventional fiber reinforced composites with low loading of organo silicate nanoparticles. By dispersing 1% by weight nanosilicates, S2-glass/epoxy-clay nanocomposites attributed to almost 44, 24 and 23% improvement in interlaminar shear strength, flexural strength and fracture toughness in comparison to conventional S2-glass/epoxy composites. Similarly, the nanocomposites exhibit approximately 26 C higher decomposition temperatures than that of conventional composites. This improved properties of fiber reinforced polymer nanocomposites are achieved mostly due to increased interfacial surface areas, improved bond characteristics and intercalated/exfoliated morphology of the epoxy-clay nanocomposites. The TEM observations provide evidence of detailed morphology of the polymer layered-clay nanocomposites.
Rigorous Dynamic Model-Based Economic Design of the Injected Pultrusion Process with Controllability Considerations
Authors: Srinivasagupta Deepak , Kardos John L. , Joseph Babu 
Published: April 2004

The current industrial practice in design of the injected pultrusion (IP) process involves costly trial and error procedures, hitherto unavoidable in the absence of established process models. Even for well understood processes, economic design has traditionally used steady-state physical models, separately followed by control system synthesis using simpler dynamic models. This work describes the development of a rigorous model-based design algorithm for the IP process by integration of economics, operability, and environmental considerations. In our previous work, a 3D dynamic physical model of the IP process was experimentally validated on a bench-scale setup. Using this validated model, we can now reduce the time and expenses associated with a purely experimental approach. An understanding of processing economics leads to throughput rate maximization as the desired economic objective. We develop a multiobjective optimization algorithm that maximizes this objective function, using a response surface methodology with iterative meshing to determine optimal equipment specifications (die dimensions, puller ratings) and processing condition parameters (heating zone temperatures, resin injection pressure). Retrofit design of the bench-scale setup promised a tenfold increase in throughput rate. Calculation of theoretical limit on throughput rates from intrinsic resin cure kinetics supported this finding. Various metrics were proposed to evaluate quality of design in a distributed-parameter sense. Sensitivity studies verified that the economic optimum is also robust to a wide range of expected process disturbances. An analysis of process instrumentation revealed the need for additional measurements. We propose resin flow-rate and cutting force measurements for void and cure sensing respectively. This research is a first step to the integration of design and control for a complex multiphase process using a single dynamic physical model. The integration offers several benefits over current design practices, and highlights the potential for increased productivity in polymer composites manufacturing.
Hygrothermal Modeling of Thick Thermoset Resin during Electron-Beam-Cure – Part I: Methodology and Modeling Cure Kinetics
Authors: Moon Sung-Won , Morgan Roger J. , Lau Sai C. 
Published: April 2004

The hygrothermal model has been developed to predict the temperature evolution, epoxy conversion ratio, the glass transition temperature increase and associated resin yield stress rise, and absorbed moisture vapor pressure in ISbF 6 -catalyzed DGEBA epoxy resin systems during e-beam-induced polymerization on the effects of four different initiator concentrations: 0.1,1,3, and 10 phr. This paper summarizes the modeling procedure of e-beam-induced cure kinetics, and the results of local temperature and degree of cure rise within the sample as a function of dose. Dynamic characteristics of Tg y Pv rise and their modeling procedures together with an attempt at optimizing e-beam cure process will be presented in a subsequent paper. These papers provide a methodology to generate the overall integrated model for the e-beam, fast cure process of composites and the consequences upon process control in terms of thermal control, moisture-induced void elimination, and minimization of inherent composite processing stresses that had not been previously addressed by composite process model studies. An autocatalytic model was chosen to describe the cure kinetics for this study and provided excellent agreement with experimental results. The numerical results showed that the cure reaction of ISbF 6 –DGEBA epoxy resin is diffusion controlled, but long lived reactive species allowed for measurable increase in conversion after e-beam irradiation (postcure effects). Higher initiator concentration results in higher degree of cure at a specific dose, causing higher temperature rise and larger temperature and conversion ratio gradients within the sample under given experimental conditions.
Compressive Failure of Impacted NCF Composite Sandwich Panels - Characterisation of the Failure Process
Authors: Edgren Fredrik , Asp Leif E. , Bull Peter H. 
Published: April 2004

In the present study, non-crimp fabric (NCF) composite face sheet sandwich panels have been tested in compression after impact (CAI). Damage in the face sheets was characterised by fractography. Compression after impact loaded panels were found to fail by plastic fibre microbuckling (kinking) in the damaged face sheet. Studies of panels for which loading was interrupted prior to failure revealed extensive stable kink band formation at several positions and in numerous plies. Kink bands initiated and propagated within a wide region close to the point of impact. In addition, kink bands initiated in zones with high shear stresses, away from the impact centre line. Consequently, the fractographic results from this investigation do not support the assumption of modelling the impact damage as an equivalent hole. To achieve accurate predictions of kink band initiation, the stress field must be known. The results from this study imply that bending effects caused by remaining dent or material eccentricities in the damaged region must be considered.
Mathematical Model of Smoldering Combustion in a Carbonaceous Porous Medium Part 2 – Sensitivity Analysis of Model Parameters
Authors: Yi Sung-Chul , Song Eun-Seok , Joung Whi-Dong , Oh Seong-Geun , Moon Sei Ki , Hajaligol Mohammad R. 
Published: April 2004

In this paper, we systematically evaluated the effects of model parameters on the linear burn rate (LBR) and temperature to control smoldering of a cigarette. Fifteen model parameters were identified as smoldering factors. Among them, the theoretical findings of the effects of the cigarette radius, packing density, and water content on LBR and the peak temperature agree well with the experimental results in the literature. The method presented in this paper is adequate, and the basic mechanism of the natural smoldering process of tobacco can be explained. We evaluated the effects of smoldering factors on the LBR and the peak temperature ( Tmax), and obtained the basic data for establishing a scientific means of limiting the smoldering process, that can replace conventional experience and the trial and error approach.
Analysis of Key Equations in a Two-Layer Zone Model and Application with Symbolic Mathematics in Fire Safety Engineering
Authors: Chow W. K. , Meng L. 
Published: April 2004

There are two objectives in this paper on applying fire modelling techniques for designing fire safety provisions with symbolic mathematics. The first is to review key equations for a two-layer zone model and simplification to a simpler model. There are eleven equations on the mass, volume, temperature, density and internal energy for the upper hot layer and lower cool layer; and the pressure of the compartment. In addition, there are seven constraints and so only four equations are required to be solved. By following the assumptions made in the ASET type of two-layer zone model, these four equations can be further reduced to only two ordinary differential equations. Both the ASET model itself and its modification to FIRM in a compartment with a vertical vent were considered. The second objective is to solve the two ordinary differential equations in the simplified model by symbolic mathematics. The advantages of using symbolic mathematics are discussed. It is proposed that symbolic mathematics is suitable for use by the Authority on assessing fire safety design based on performancebased fire codes where fire modelling technique has to be used.
Development of a Food Packaging Coating Material with Antimicrobial Properties
Authors: Limjaroen Paweena , Ryser Elliot , Lockhart Hugh , Harte Bruce 
Published: April 2004

Antimicrobial films may provide an effective way to control food-borne pathogens and spoilage microorganisms to thus enhance food safety and decrease product spoilage. Antimicrobial films can be produced by incorporation of chemical preservatives or antimicrobial agents into a plastic film. The agents can then diffuse into the food to control target microorganisms. In this work, antimicrobial coatings were developed by incorporation of nisin, lactoferrin (an antimicrobial peptide derived from bovine lactoferrin in cow’s milk), sodium diacetate, sorbic acid, and potassium sorbate into a coating material. Saran® F-310 resin, a copolymer of vinylidene chloride, was used to produce the base coating using a solvent casting method. The antimicrobial activity of these films was verified on laboratory media against the food-borne pathogen Listeria monocytogenes. Films containing nisin, sorbic acid, and potassium sorbate inhibited L. monocytogenes strain CWD 95. The lowest level of nisin, sorbic acid, and potassium sorbate that had antimicrobial activity was 1, 1.5, and 2% w/v respectively. Films containing sorbic acid were the most compatible with the resin solution and had the best physical appearance. The water vapor barrier of films containing sorbic acid was almost unchanged compared to the control film (no antimicrobial agent). The three-dimensional structure of the films was observed using Scanning Electron Microscope (SEM). The results show that films containing sorbic acid were the most homogenous of the sample films.
Otx2 regulates the extent, identity and fate of neuronal progenitor domains in the ventral midbrain
Authors: Puelles Eduardo , Annino Alessandro , Tuorto Francesca , Usiello Alessandro , Acampora Dario , Czerny Thomas , Brodski Claude , Ang Siew-Lan , Wurst Wolfgang , Simeone Antonio 
Published: April 2004

The specification of distinct neuronal cell-types is controlled by inducing signals whose interpretation in distinct areas along the central nervous system provides neuronal progenitors with a precise and typical expression code of transcription factors.To gain insights into this process, we investigated the role of Otx2 in the specification of identity and fate of neuronal progenitors in the ventral midbrain. To achieve this, Otx2 was inactivated by Cre recombinase under the transcriptional control of En1. Lack of Otx2 in the ventrolateral and posterior midbrain results in a dorsal expansion of Shh expression and in a dorsal and anterior rotation of the midbrain-hindbrain boundary and Fgf8 expression. Indeed, in this mutant correct positioning of the ventral site of midbrain-hindbrain boundary and Fgf8 expression are efficiently controlled by Otx1 function, thus allowing the study of the identity and fate of neuronal progenitors of the ventral midbrain in the absence of Otx2. Our results suggest that Otx2 acts in two ways: by repressing Nkx2.2 in the ventral midbrain and maintaining the Nkx6.1-expressing domain through dorsal antagonism on Shh. Failure of this control affects the identity code and fate of midbrain progenitors, which exhibit features in common with neuronal precursors of the rostral hindbrain even though the midbrain retains its regional identity and these neuronal precursors are rostral to Fgf8 expression. Dopaminergic neurons are greatly reduced in number, red nucleus precursors disappear from the ventral midbrain where a relevant number of serotonergic neurons are generated. These results indicate that Otx2 is an essential regulator of the identity, extent and fate of neuronal progenitor domains in the ventral midbrain and provide novel insights into the mechanisms by which neuronal diversity is generated in the central nervous system.
Reduction rate of neptunium(V) in heterogeneous solution with magnetite
Authors: Nakata K. , Nagasaki S. , Tanaka S. , Sakamoto Y. , Tanaka T. , Ogawa H. 
Published: April 2004

SummaryThe sorption kinetics of neptunium on magnetite was investigated under both aerobic and anaerobic conditions in 0.1mol L-1NaNO3at pH=5.7 to 5.9. It was found that the sorption of neptunium on magnetite reaches an equilibrium in 1h under aerobic conditions, while it takes 10h or more to reach the equilibrium under anaerobic conditions. The difference in sorption kinetics between aerobic and anaerobic conditions took place because sorption kinetics under the anaerobic condition involved the reduction of Np(V) to Np(IV), confirmed by an extraction technique using 0.5mol L-1TTA in xylene and 2.0mol L-1HNO3solution. The reduction rate of Np(V) by Fe(II) in magnetite was calculated in solution with magnetite. It was found that Np(V) was reduced 1000 or more times faster in solution with magnetite than the Np(V) reduction by Fe(II) ions in homogeneous solution. It was revealed that the reduction of Np(V) in solution with magnetite took place on the surface of magnetite.