bluuebunny/crossref_metadata_2025_split huggingface dataset:
The novel inflammatory cytokine high mobility group box protein 1 (HMGB1) is expressed by human term placenta
Authors: Holmlund Ulrika , Wähämaa Heidi , Bachmayer Nora , Bremme Katarina , Sverremark‐Ekström Eva , Palmblad Karin 
Published: July 2007

SummaryHigh mobility group box protein 1 (HMGB1) was previously considered a strict nuclear protein, but lately data are accumulating on its extranuclear functions. In addition to its potent proinflammatory capacities, HMGB1 has a prominent role in a number of processes of specific interest for the placenta. Our overall aim was to investigate the expression of HMGB1 in human term placenta and elucidate a potential difference in HMGB1 expression comparing vaginal deliveries with elective Caesarean sections. In addition, placentas from normal pregnancies were compared with placentas from pregnancies complicated by pre‐eclampsia. Twenty‐five placentas, 12 from normal term pregnancies and 13 from pregnancies complicated by pre‐eclampsia were analysed with immunohistochemistry for HMGB1 and its putative receptors; receptor for advanced glycation end‐products (RAGE), Toll‐like receptor 2 (TLR2) and TLR4. We present the novel finding that in addition to a strong nuclear HMGB1 expression in almost all cells in investigated placentas, an individual variation of cytoplasmic HMGB1 expression was detected in the syncytiotrophoblast covering the peripheral chorionic villi, by cells in the decidua and in amnion. Production of HMGB1 was confirmed byin situhybridization. Although labour can be described as a controlled inflammatory‐like process no differences in HMGB1 expression could be observed comparing active labour and elective Caesarean sections. However, a tendency towards a higher expression of cytoplasmic HMGB1 in the decidua from women with pre‐eclampsia was demonstrated. The abundant expression of the receptors RAGE, TLR2 and TLR4 implicates a local capability to respond to HMGB1, although the precise role in the placenta remains to be elucidated.
Evaluation of changes during storage of probiotic dahi at 7°C
Authors: YADAV HARIOM , JAIN SHALINI , SINHA P R 
Published: July 2007

Low‐fat probiotic dahi (an Indian traditional fermented milk product like yogurt) prepared with lactococci starter and two adjunct probiotic cultures of Lactobacillus acidophilus and Lactobacillus casei was stored at 7°C. The survival of bacterial species was affected during storage of dahi, in which viable counts increased up to 2 days and gradually decreased from 2 days, up to 8 days. The quality of refrigerated dahi was assessed by a panel of trained judges. On storage, pH significantly decreased over storage time, indicating that the dahi samples did not develop much acidity under the storage conditions of the study. However, after 8 days of storage, the samples were disliked by the panel, which reported slight bitterness, which may have been due to proteolysis. Proteolysis increased during storage. More αs1‐casein was degraded than β‐casein. On the basis of the results of this study we can conclude that dahi stored up to 8 days may be acceptable to consumers.
Prevalence of Campylobacter and four endoparasites in dog populations associated with Hearing Dogs
Authors: Guest C. M. , Stephen J. M. , Price C. J. 
Published: July 2007

Objectives: This study established the prevalence of four gastrointestinal parasites (Isopora species, Giardia species, Uncinaria stenocephala, Toxocara canis) and one bacterial infection (Campylobacter jejuni/coli) in dogs associated with the charity Hearing Dogs for Deaf People. Methods: Dogs’ faeces were routinely sampled from dogs according to whether they were in Socialising, Kennelling or Visiting the Hearing Dogs site. A further group consisted of dogs with diarrhoea. Results: Prevalence rates for dogs in Socialising (n=326), Kennelling (n=117), Visiting (n=106) and Diarrhoea (n=59) groups, respectively, were as follows: Campylobacter– 26, 21, 15 and 31 per cent; Coccidia – 3, 0, 0 and 2 per cent; Giardia– 13, 3, 2 and 10 per cent; hookworm – 1, 1, 4 and 5 per cent; and Toxocara– 4, 2, 3 and 2 per cent. There were significant differences in the levels of Giardia and hookworm found between the four different groups of dogs. No significant gender differences were found, and dogs that were positive for Campylobacter in the Visiting group were significantly younger. Clinical Significance: This study provides current information on the infection rates in specific dog populations in the UK. This is relevant to the veterinary health of dogs and the possible risk of zoonotic infection to humans.
Genetic Code Ambiguity Confers a Selective Advantage on
Acinetobacter baylyi
Authors: Bacher Jamie M. , Waas William F. , Metzgar David , de Crécy-Lagard Valérie , Schimmel Paul 
Published: July 2007

ABSTRACT

A primitive genetic code, composed of a smaller set of amino acids, may have expanded via recursive periods of genetic code ambiguity that were followed by specificity. Here we model a step in this process by showing how genetic code ambiguity could result in an enhanced growth rate in
Acinetobacter baylyi
.
Prediction of human pharmacokinetics —gastrointestinal absorption
Authors: Fagerholm Urban 
Published: July 2007

AbstractPermeability (Pe) and solubility/dissolution are two major determinants of gastrointestinal (GI) drug absorption. Good prediction of these is crucial for predicting doses, exposures and potential interactions, and for selecting appropriate candidate drugs. The main objective was to evaluate screening methods for prediction of GI Pe, solubility/dissolution and fraction absorbed (fa) in humans. The most accurate Pe models for prediction of fa of passively transported and highly soluble compounds appear to be the 2/4/A1 rat small intestinal cell model (in-vitro and in-silico), a newly developed artificial-membrane method, and a semi-empirical approach based on in-vitro membrane affinity to immobilized lipid bilayers, effective molecular weight and physiological GI variables. The predictability of in-vitro Caco-2, in-situ perfusion and other artificial membrane methods seems comparably low. The Pe and fa in humans for compounds that undergo mainly active transport were predicted poorly by all models investigated. However, the rat in-situ perfusion model appears useful for prediction of active uptake potential (complete active uptake is generally well predicted), and Caco-2 cells are useful for studying bidirectional active transport, respectively. Human intestinal in-vitro Pe, which correlates well with fa for passively transported compounds, could possibly also have potential to improve/enable predictions of fa for actively transported substances. Molecular descriptor data could give an indication of the passive absorption potential. The ‘maximum absorbable dose’ and ‘dose number’ approaches, and solubility/dissolution data obtained in aqueous media, appear to underestimate in-vivo dissolution to a considerable extent. Predictions of in-vivo dissolution should preferably be done from in-vitro dissolution data obtained using either real or validated simulated GI fluids.
Physical characteristics and aerosolization performance of insulin dry powders for inhalation prepared by a spray drying method
Authors: You Yu , Zhao Min , Liu Guangli , Tang Xing 
Published: July 2007

AbstractThe objective of this study was to investigate the influence of formulation excipients on the physical characteristics and aerosolization performance of insulin dry powders for inhalation. Insulin dry powders were prepared by a spray drying technique using excipients such as sugars (trehalose, lactose and dextran), mannitol and amino acids (L-leucine, glycine and threonine). High performance liquid chromatography and the mouse blood glucose method were used for determination of the insulin content. The powder properties were determined and compared by scanning electron microscopy, thermo-gravimetric analysis and size distribution analysis by a time-of-flight technique. The in-vitro aerosolization behaviour of the powders was assessed with an Aerolizer inhaler using a twin-stage impinger. Powder yield and moisture absorption were also determined. Results showed that there was no noticeable change in insulin content in any of the formulations by both assay methods. All powders were highly wrinkled, with median aerodynamic diameters of 2–4 μm, and consequently suitable for pulmonary administration. The tapped density was reduced dramatically when glycine was added. The powders containing mannitol, with or without L-Ieucine, were less sensitive to moisture. The highest respirable fraction of 67.3 ± 1.3% was obtained with the formulation containing L-leucine, in contrast to formulations containing glycine and threonine, which had a respirable fraction of 11.2 ± 3.9% and 23.5 ± 2.5%, respectively. In addition, powders with good physical properties were achieved by the combination of insulin and trehalose. This study suggests that L-leucine could be used to enhance the aerosolization behaviour of the insulin dry powders for inhalation, and trehalose could potentially be used as an excipient in the formulations.
Inhibition of P-glycoprotein function by tannic acid and pentagalloylglucose
Authors: Kitagawa Shuji , Nabekura Tomohiro , Nakamura Yutaka , Takahashi Tomoharu , Kashiwada Yoshiki 
Published: July 2007

Abstract
We studied the effects of tannic acid and 1(β),2,3,4,6-penta-O-galloyl-D-glucose (pentagalloylglucose), one of the components of tannic acid, on the P-glycoprotein (P-gp) function in multidrug-resistant P-gp over-expressing KB-C2 cells. Both tannic acid and pentagalloylglucose markedly elevated the accumulation of P-gp substrates, rhodamine 123 and daunorubicin, by inhibiting their efflux. A 19-fold increase in cellular rhodamine 123 was observed for tannic acid at 60 μM (85 μg mL−1) and a 21-fold increase was observed for pentagalloylglucose at 100 μM (94 μg mL−1). The increasing effects of these compounds in the accumulation were much larger than that of (-)epigallocatechin-3-O-gallate (EGCG), which has been revealed to have a prominent inhibitory effect on P-gp compared with other flavonoids. Analysis of verapamil-stimulated ATPase activity in membrane vesicles expressing human P-gp suggested that inhibition of P-gp function by tannic acid and pentagalloylglucose was at least partly due to ATPase inhibition of P-gp. The findings also suggested that the presence of a large number of galloyl groups in polyphenols strengthens the interaction with regulatory regions in P-gp.
In-vitro and in-vivo correlation for two gliclazide extended-release tablets
Authors: Mandal U , Ray K K , Gowda Veeran , Ghosh A , Pal T K 
Published: July 2007

Abstract
The aim of this study was to perform an in-vitro-in-vivo correlation (IVIVC) for two 60-mg gliclazide extended-release formulations (Fast and Slow release) given once a day and to compare their plasma concentrations over time. In-vitro release rate data were obtained for each formulation using the USP apparatus II, paddle stirrer at 50 and 100 rev min−1 in 0.1 M HCl and pH 7.4 phosphate buffer. The similarity factor (f2) was used to analyse the dissolution data. Eighteen healthy subjects participated in the study, conducted according to a completely randomized, two-way crossover design. The formulations were compared using area under the plasma concentration-time curve, AUC0-∞′, time to reach peak plasma concentration, Tmax', and peak plasma concentration Cmax', while correlation was determined between in-vitro release and in-vivo absorption. A linear correlation model was developed using percent absorbed data versus percent dissolved data from the two formulations. Predicted gliclazide concentrations were obtained by use of a curve fitting equation. Prediction errors were estimated for Cmax and area under the curve AUC0-∞ to determine the validity of the correlation. 0.1 M HCl at 50 rev min−1 was found to be the most discriminating dissolution method. Linear regression analysis of the mean percentage of dose absorbed versus the mean percentage of in-vitro release resulted in a significant correlation (r2 &gt; 0.98) for the two formulations. An average percent prediction error for Cmax was 4.15% for Fast release and 3.99% for Slow release formulation whereas for AUC0-∞ it was 6.36% and 4.66% for Fast release and Slow release formulation, respectively.
Effect of hydrostatic pressure on strand behaviour
Authors: Raoof M 
Published: July 2007

High density, supposedly impermeable, polythene sheaths have been offered by cable manufacturers for corrosion protection of large diameter spiral strands used in deep water floating production systems. Using previously reported orthotropic sheet theory, an insight is given into the effect of high external pressure on various sheathed cable characteristics, which include: 1 axial stiffness and hysteresis; 2 torsional stiffness and hysteresis; 3 free bending fatigue behaviour in the vicinity of end terminations. It is shown that such high pressures can significantly alter the pattern of interwire/interlayer contact forces. Recent published research has clearly demonstrated the central role such interwire contact pressures play as regards cables’ fatigue life under various modes of loading. The present theory shows that increases in contact forces in deep water sheathed cable applications lead to significant reductions in cable fatigue life. Moreover, such high external forces are shown to affect cables’ axial and torsional characteristics by suppressing the relative slippage of wires in the strand and increasing frictional forces between them. A higher cable stiffness will then follow. This then leads to significant variations in strands’ axial and/or torsional hysteresis which may have a considerable bearing on the overall dynamics of, for example, a guyed tower platform using sheathed strands. The significant influence of high external pressures on various cable characteristics have been demonstrated by numerical examples on a realistic 39 mm outside diameter (OD) multi-layered structural strand. Results are also presented for the case of zero external pressure relevant to unsealed mooring cables in deep water applications, in which case the absence of the sheath will permit water migration inside the strand and the cable behaviour is independent of the level of water depth.
Estimating the creep-fracture mechanics parameter C [t] from uniaxial creep strain and rupture data
Authors: Smith D J 
Published: July 2007

The methods of estimating the creep-fracture mechanics parameter C[ t] proposed by Riedel, Webster, Ainsworth, and their respective co-workers have been reviewed and extended. Quantitative estimates for C[ t] have been obtained for the infinite centre cracked plate (CCP) and compact tension (CT) specimens using uniaxial creep strain and rupture data for 1 CrMoV steel at 565°C. It has been shown that the estimates substantially differ for each method and on the assumed state of stress. The creep material parameters for 1CrMoV at 565°C are shown to be different for stresses above and below 200 MPa. In selecting the appropriate material parameters for estimating C[ t] the reference stress technique is used. At high stresses the greatest estimate of C[ t] is obtained from Webster's method, the lowest obtained from Ainsworth's approach and an intermediate estimate obtained using methods proposed by Riedel. At low stresses, where stress redistribution from an initial elastic condition dominates, it has shown that Ainsworth's method is the largest estimate. For industrial components, containing small cracks and subjected to predominantly tension loading, simple estimates of C[ t] can be obtained from the results given in this paper.
An expert system for the determination of creep constitutive equations based on continuum damage mechanics
Authors: Dunne F. P. E. , Hayhurst D. R. 
Published: July 2007

Methods have been developed for the determination of a suitable stress range over which uniaxial creep tests should be carried out in order to find the best constitutive equations for the material. The method is based on a proposed empirical relation and Ashby deformation mechanism maps. An automatic data logging system has been developed for the capture of uniaxial creep test data and a robust and reliable optimization scheme has been devised for the determination of the creep constitutive equations for a material. The above methods have been combined in an expert system that enables the user without specialist knowledge to carry out uniaxial creep tests to determine the best creep constitutive equations for a material. The system is stored on two floppy disks and is run from any IBM compatible microcomputer. The expert system has been used to determine the creep constitutive equations for copper.
Constitutive equations for creep
Authors: White P S , Goodman A M 
Published: July 2007

Creep constitutive equations are discussed in their role as material descriptions forming one of the governing conditions of an inelastic stress analysis. The view taken is that they must not only give an adequate picture of the material behaviour itself, but must also be suitable from the numerical point of view. Furthermore, in practical engineering contexts, constitutive equations must be principally aimed at giving information for structural assessment under realistic loading conditions and subject to various uncertainties. The choice of model is, therefore, not aimed at an exact material description, and the practial choice may be problem-dependent for a given material. Both the classical formulation and the more recent unified formulation are outlined, with discussion of advantages and disadvantages. Some unified formulations are regarded as practically useful but great use is still to be expected of classical forms in which creep and plasticity are regarded as separate. In the latter class descriptions are given of the widely-employed time- and strain-hardening descriptions, of back-stress models, and of certain tertiary creep models including damage variables. The difficulties of anisotropy are also noted. Finally the paper discusses the process of fitting material data to the classical time- and strain-hardening models, and some hints are given for the analyst who may be faced with performing this task for materials of interest.
Mechanisms-based creep constitutive equations for an aluminium alloy
Authors: Kowalewski Z L , Hayhurst D R , Dyson B F 
Published: July 2007

A number of mechanisms-based constitutive equations were assessed in an effort to describe the creep behaviour of an aluminium alloy at 150°C. It was found that a sinh function of stress, rather than the usually used power law, is best able to describe the strain rate and rupture behaviour over the narrow stress range analysed. A single state variable theory which represents a dominant damage mechanism is not capable of predicting the shape of the tertiary curve; however, a two state variable theory which represents two mechanisms provides a good description. The two relevant mechanisms identified are creep-constrained cavitation and ageing of the particulate microstructure. The non-linear equations which describe both these physical mechanisms are complex and strongly coupled. This makes it difficult to determine the constants in the constitutive equations from experimental data. The paper reports the development of automated numerical optimization techniques which overcome these difficulties.
Three-dimensional embedded strain gauge analysis of the effect of collared versus collarless prostheses on cement mantle stresses in a femoral model of a total hip replacement
Authors: Colgan D , McTague D , O'Donnell P , Little E G 
Published: July 2007

Experimental and finite element analyses have attributed considerable significance to the role of the prosthetic collar in load transfer to the proximal femur; however, some clinical evidence suggests that collar/calcar contact is unnecessary and detrimental. This study investigates the effects of collared versus collarless prostheses on cement mantle stresses in a model analysis of the proximal femur. Three-dimensional embedded strain gauging is used in a three-times full-size model of an implanted left femur. Tensor stresses in the cement mantle are derived for a collarless Exeter™ stem, a small and a large medial-collared stem and a full-collared prosthesis. Results show that the collar causes an increase in proximal-medial compressive longitudinal stresses, with other proximal stresses significantly reduced. Subsidence of the stem in the cement mantle is prevented, inducing unfavourable pivoting of the prosthesis about the calcar into varus. The collar type produces only minor additional effects in the mechanism of load transfer. The analysis suggests that collars may inhibit the prosthesis from attaining long-term secondary stability, by preventing the stem subsidence evident with cemented collarless implants. Derived stresses also illustrate the considerable variation in the mechanism of load transfer between collared and collarless prostheses in both the proximal and distal regions.
Prediction of axial hysteresis in locked coil ropes
Authors: Raoof M , Kraincanic I 
Published: July 2007

In published literature, the strand constructions dealt with have almost invariably involved only wires which are circular in cross-section. There are, however, instances when shaped wires are used in, for example, half-lock and full-lock coil constructions. The paper reports details of a theoretical model which enables an insight to be gained into various characteristics of axially loaded lock coil ropes. The model is based on an extension of a previously reported orthotropic sheet concept and provides a fairly simple means of estimating wire kinematics, interwire/interlayer contact forces, effective axial stiffnesses and axial hysteresis in axially preloaded locked coil ropes experiencing uniform cyclic axial load perturbations. The theory takes interwire contact deformations and friction into account. Final numerical results based on theoretical parametric studies on some substantial cables highlight the substantial role that the outermost layer(s) with shaped wires play as regards the overall axial damping capacity of fully bedded-in (old) locked coil ropes, and it is found that (for the same lay angles and outer diameters) axial hysteresis in locked coil ropes is generally higher than spiral strands which are composed of only round wires. This finding may have significant practical implications in terms of the design against dynamic instability of structures supported by such cables.