bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenovirus type 5 E1A-induced apoptosis in COX-2-overexpressing breast cancer cells
Authors: Sugimoto Takeshi , Bartholomeusz Chandra , Tari Ana M , Ueno Naoto T 
Published: July 2007

Abstract
Introduction
Suppression of Bcl-2 expression can overcome cellular resistance to apoptosis induced by the adenovirus type 5 gene E1A in models of ovarian and breast cancer. Celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, is known to downregulate Bcl-2 expression. We hypothesized that celecoxib would enhance E1A-induced apoptosis by suppressing Bcl-2 through suppressing COX-2 expression. If successful, this strategy could represent a means of overcoming resistance to E1A gene therapy.

Methods
We first established the cytotoxicity of celecoxib in two COX-2-overexpressing E1A-transfected breast cancer cell lines (MDA-MB-231 and MDA-MB-435) and in two low-COX-2-expressing E1A-transfected cell lines (MCF-7 (breast cancer) and SKOV3.ip1 (ovarian cancer)). We next tested whether higher sensitivity to celecoxib among these cell lines resulted from increased apoptosis by flow cytometry and western blotting. We further investigated whether suppression of Bcl-2 by celecoxib was involved in the apoptosis resulting from celecoxib treatment, and we explored whether the celecoxib-induced apoptosis in these cells depends on a COX-2 downstream pathway.

Results
The two COX-2-overexpressing cell lines MDA-MB-231-E1A and MDA-MB-435-E1A were more sensitive to celecoxib than the corresponding control cells, but the two low-COX-2-expressing cell lines MCF-7-E1A and SKOV3.ip1-E1A were no more sensitive than control cells to celecoxib. Therefore, we used the MDA-MB-231-E1A and MDA-MB-435-E1A cells for all further experiments. In both cell lines, sub-G1 fraction was increased, or cleavage of PARP and caspase-9 were increased after 5 days of exposure to 40 μM celecoxib. However, Bcl-2 was suppressed only in the MDA-MB-435-E1A cells and not in the MDA-MB-231-E1A cells. Restoring Bcl-2 expression in the MDA-MB-435-E1A stable transfectants did not affect their sensitivity to celecoxib. However, adding prostaglandin E2 (PGE2) or PGF2α blunted the sensitivity to celecoxib of both E1A stable transfectants.

Conclusion
We speculate that one mechanism by which celecoxib enhances E1A-induced apoptosis in cells that express high levels of COX-2 is through blocking PGE2 or PGF2α.
FlyMine: an integrated database for Drosophila and Anopheles genomics
Authors: Lyne Rachel , Smith Richard , Rutherford Kim , Wakeling Matthew , Varley Andrew , Guillier Francois , Janssens Hilde , Ji Wenyan , Mclaren Peter , North Philip , Rana Debashis , Riley Tom , Sullivan Julie , Watkins Xavier , Woodbridge Mark , Lilley Kathryn , Russell Steve , Ashburner Michael , Mizuguchi Kenji , Micklem Gos 
Published: July 2007

AbstractFlyMine is a data warehouse that addresses one of the important challenges of modern biology: how to integrate and make use of the diversity and volume of current biological data. Its main focus is genomic and proteomics data for Drosophila and other insects. It provides web access to integrated data at a number of different levels, from simple browsing to construction of complex queries, which can be executed on either single items or lists.
Relationships for tensile creep under transient stresses
Authors: Tilly G P 
Published: July 2007

The tensile creep occurring during and immediately after loading has been studied for an 11 per cent chromium steel and a nickel-base alloy at elevated temperatures. It was found that the strains incurred during loading are dependent upon loading rate and can be estimated from consideration of the equations for static creep by using the assumption of strain hardening. The strain incurred during slow loading causes the processes of creep to be at a more advanced stage when the static phase commences so that the resulting strain rates are also dependent upon the rate of loading. Rapid loading tends to produce almost wholly elastic strains so that the subsequent static phase involves a more fundamental shape of creep curve. The approach was extended to consider minimum creep rate and fracture, and it was shown that they could be related to applied stress by use of the creep equation. The shapes of the stress-strain hysteresis loops were also derived from the creep equation and estimates based on static-creep data were shown to correlate with experimental data from repeated-tension cycling with a triangular wave shape.
Comparison of various formulae and experimental stress-concentration factors for symmetrical u-notched plates
Authors: Baratta F I 
Published: July 2007

Formulae of Baratta and Neal, Neuber, and Heywood are compared with available data on experimental stress-concentration factors in the literature for symmetrical U-notched plates. From comparisons of such formulae, guidance is provided to the researcher and designer with regard to accuracy and tendency to under- or over-estimate.
The application of photo-orthotropic elasticity
Authors: Prabhakaran R , Dally J W 
Published: July 2007

A brief review of the recent developments in photo-orthotropic elasticity which covers methods of producing transparent, birefringent orthotropic model materials from glass fibres and plastics is presented. A classical form of the stress-optic law applicable in uniaxial-stress fields is given in which the orthotropic characteristics of the model material are treated by considering the material fringe value fu to be dependent upon fibre orientation. Limitations of the orthotropic model materials are identified and the effects of material non-linearities, fibre debonding and fibre distribution are described. The methods established were used to obtain a solution of the stresses in an orthotropic half-plane loaded with a concentrated force. The experimental results obtained were compared with theoretical results due to Green, and while the agreement was good, errors were considerably larger than those encountered in photo-isotropic elasticity. Finally the methods were applied to the solution of boundary stress on an elliptical hole in a finite-width tension strip.
Computation of post-yield behaviour in notch-bend and tension testpieces
Authors: Turner C E , Cheung J S T 
Published: July 2007

First results of an analysis of notch-bend pieces in plane strain by two-dimensional elastic-plastic finite-element computations are given. Comparisons are given of load-displacement records for three notch depths and a general non-dimensional presentation proposed. Relations between the values of surface and cracktip crack opening displacement are shown and comparison is made with a few results in plane stress, by Dugdale model and in tension. The trend of local stress and strain patterns is shown and stress triaxiality is evaluated approximately. It is concluded that nearly quantitative agreement can be reached for the general behaviour of notched pieces by the use of fairly simple two-dimensional models but many of the results could be improved by the use of better element meshes. For the study of local crack-tip deformations more detailed models or more powerful means of characterizing the crack tip are required.
Precision casting of epoxy-resin photoelastic models
Authors: Fessler H , Perla M 
Published: July 2007

Photoelastic models may be made by four different methods: by machining from fully cured blocks; by machining of oversize simplified castings; by cementing of machined parts; by accurate casting to the same shape as the prototype. A method of casting models to the same proportional accuracy as the prototype and its limitation are described. In this technique a pattern is coated with silicone rubber which is supported by an epoxy-resin casing. Curing shrinkage and differential thermal expansion of the epoxy casing, rubber coating, and Araldite casting are factors which essentially influence the resulting accuracy of the cast models.
Rubber model for adhesive lap joints
Authors: Adams R D , Chambers S H , Del Strother P H A , Peppiatt N A 
Published: July 2007

Models of adhesive joints have been constructed in which hard rubber has been used as the adherends and relatively soft foam rubber as the adhesive. The models were scaled to represent various types of lap joint. Very good agreement was obtained when the experimental results were compared with available theory, showing that the model accurately represented the shear-stress distribution in the adhesive. Two joints are shown in which the adhesive thickness was profiled (one optimally, the other linearly) to reduce or eliminate the shear-stress concentration at the ends.
Contact between a curved viscoelastic beam and a rigid plane
Authors: Granstam I 
Published: July 2007

The following problem has been analysed by the theory of small deflections of bending. A circularly curved beam of Maxwell material is pressed against a rigid horizontal plane by two constant and concentrated forces P, each acting on one end of the beam. Before loading there is contact only at the mid-point of the beam. As load is applied the Maxwellian beam behaves like a Hookean beam. If the load P is below a critical value Pc, there is contact only at the mid-point, but if the load exceeds this value, linear contact is formed along a certain length 2λ° of the beam. At the time t the beam will rise from the support over a distance of 2λ° ( t) if the load P exceeds Pc, while if P is less than Pc there will be a similar deflection only after a critical time tc. The contact pressure is two concentrated forces, acting on each contact point. Expressions for the deflections w(O, t) and w( L, t) of the centre and the ends of the beam are also derived and are compared with corresponding expressions for a Hookean beam. The paper shows that essential differences can exist between contact problems with similar viscoelastic or elastic bodies.
A simple model of uniaxial creep recovery and stress relaxation based on residual-stress redistribution
Authors: Addleman R L , Webster G A 
Published: July 2007

A useful and simple model describing primary creep, creep recovery, and stress relaxation is put forward. The model is based on the concept that creep recovery and stress relaxation occur as a result of the redistribution of internal stresses within materials. These internal stresses result from the inhomogeneity of crystalline materials on a microscopic scale, the stresses being attributed to the constraints between neighbouring grains, to the coherency strains associated with solute atoms and second-phase particles, and to dislocation interactions. It is shown that the model satisfactorily describes the creep-recovery and stress-relaxation properties of commercially pure copper. It also predicts a number of other experimental observations. These are (1) that creep strain recovered will be proportional to the originally applied stress and less, in most circumstances, than the initial elastic loading strain, (2) that creep recovery in single crystals of pure metals will be negligible, and (3) that creep recovery in highly alloyed materials will be greater than in relatively pure metals. The analysis is limited to loading within the elastic range, but this is not an essential feature of the model and the effects of plastic strain on loading are discussed.
Interpretation of tensile and compressive creep behaviour of two nickel alloys
Authors: Tilly G P , Harrison G F 
Published: July 2007

The tensile and compressive creep behaviour of Nimonic 90 and Nimonic 108 have been studied at 700–900°C and the strain-time curves were found to have similar shapes. At the higher temperatures, both alloys exhibited tertiary creep under compression at strains less than 2 per cent. In Nimonic 108 each stage of the curves coincided for tension and compression, and tertiary deformation was exhibited only at 900°C. For Nimonic 90 tertiary deformation in compression occurred above 700°C and was delayed relative to tension at each temperature. In all cases the primary and secondary stages of deformation coincided. It appears that the more rapid development of tertiary creep in tension is due to the development of cracks and their influence on recovery processes. It is suggested that the structural recovery is mainly through development of zones adjacent to grain boundaries that are denuded of γ′ precipitate.
Effect of poisson's ratio strains in adherends on stresses of an idealized lap joint
Authors: Adams R D , Peppiatt N A 
Published: July 2007

Poisson's ratio strains in the adherends of a simple adhesive lap joint induce transverse stresses both in the adhesive and in the adherends. Two simultaneous second-order partial-differential equations were set up to describe the normal stresses along and across an adherend and were solved both by an approximate analytical method and a finite-difference technique: the two solutions agreed closely. The adhesive shear stresses can then be obtained by differentiating these solutions. The transverse shear stress has a maximum value for metals of about one-third of the maximum longitudinal shear stress, and this occurs at the corners of the lap, thus making the corners the most highly stressed parts of the adhesive. Bonding adherends of dissimilar stiffness was shown to produce greater stress concentrations in the adhesive than when similar adherends are used.
Free vibration of initially stressed solids, with particular reference to centrifugal-force effects in rotating machinery
Authors: Bossak M A J , Zienkiewicz O C 
Published: July 2007

Initial stresses due to centrifugal forces or other causes change the stiffness characteristics of a solid in a manner which can be simply formulated. The effect is incorporated in a programme using isoparametric solid elements and it is shown that excellent results can be obtained for a diverse range of problems. Indeed the use of ‘reduced integration’ technique allows the extreme problems of thin plates and shells to be treated by the same element. The proposed formulation is particularly useful for turbine and compressor blades where the geometry changes from thick solid section to thin plate or slab.
Shrinkage stresses in three-dimensional two-phase systems
Authors: Theocaris P S , Paipetis S A 
Published: July 2007

Stress fields, due to polymerization shrinkage of a matrix cast around a three-dimensional array of closely packed inclusions, were studied photoelastically. The composite model consisted of a group of spherical inclusions, made of unplasticized hot-setting epoxy resin and forming a body-centred cubic arrangement, around which a plasticized matrix was cast, so that control over the ratio of matrix modulus to inclusion modulus was possible. A theoretical approximation to the problem of stress distribution around a single inclusion was also attempted and subsequently found to be in fair agreement with experimental results. With closely packed inclusions the stress distribution was studied for different degrees of packing and matrix plastification. From these studies further conclusions can be drawn, confirming the validity of the qualitative results stated for a single inclusion.
Experimental and theoretical fatigue-crack propagation lives of variously notched plates
Authors: Smith R A , Jerram K , Miller K J 
Published: July 2007

The fatigue lives of variously notched plates have been determined theoretically and experimentally. Theoretical predictions of fatigue lives involved the determination of stress-intensity factors from finite-element analyses. By invoking a crack propagation law, fatigue-life predictions were made for four specimens. Fatigue experiments were conducted on four notched plates subjected to end load plus bending. Comparison with theoretical results shows that the experimental lives were greater by factors of 1.30 to 1.54. These results are most satisfactory since (1) a safe prediction of fatigue life has been made for a complex profile subjected to non-simple loading conditions, and (2) a theoretical elastic analysis has sufficed for a situation involving plastic strains.
Prediction of earing in cups drawn from anisotropic sheet using slip-line field theory
Authors: Sowerby R , Johnson W 
Published: July 2007

Anisotropic slip-line fields have been developed in the flanges of drawn cups and used to predict the location of the ears and hollows at the onset of the drawing operation. The analysis is based on Hill's plane-strain theory of anisotropic metals. The material anisotropy is characterized by a lumped anisotropic parameter c. Deep-drawing tests were performed on circular blanks cut from anisotropic sheet and the actual deformation mode of particles in the flange was compared with the theoretical predictions. The correlation was found to be favourable.
Reinforced openings in plastically deforming plates: A finite-difference analysis
Authors: Budney D , Svensson N L 
Published: July 2007

This investigation deals with the stress and strain distribution in a large plate containing a reinforced circular hole when loaded monotonically in uniaxial tension beyond the elastic range. The hole is reinforced with a cylindrical member which is symmetrical with respect to the plate to which it is continuously joined. Consideration is given to various degrees of plastic deformation of plate and reinforcement corresponding to various uniaxial tension loads. Whole-field analyses of the reinforcement in cylindrical co-ordinates and of the plate in plane polar co-ordinates are obtained by the finite-difference method in which the governing equilibrium equations are expressed in terms of displacements and plastic strains. Deformation theory of plasticity is employed. Limitations of the ‘compact’ reinforcement assumption result from the subsequent whole-field investigation. Results are obtained for material of a specific stress-strain curve so that strain-gauge results could be compared with the strains predicted by the finite-difference analysis. It is demonstrated that the compact reinforcement is adequate for analysis of the plate, but for a very significant range of reinforcement geometry it neglects a more serious stress concentration in the reinforcement. For the whole-field analysis, prediction of first yield is made for four critical points: tensile-stress concentration in the plate; tensile-stress concentration in the reinforcement; and shear-stress concentrations in both plate and reinforcement at their joint.
Shear stiffness of a glass-reinforced thermoplastic
Authors: Ogorkiewicz R M , Weidmann G W 
Published: July 2007

Inclusion of glass fibres in plastics has been thought to produce little improvement in their stiffness in shear compared with that in tension but results obtained with polypropylene filled with fibres show that they increase in shear stiffness to a significant extent and in some directions more than its tensile stiffness. The filling of polypropylene with glass spheres instead of fibres results in smaller but still significant increases In shear stiffness, which are comparable to the relative increases in tensile stiffness. In both cases the experimentally determined values of shear stiffness fall within the bounds derived from energy considerations and correlate closely with the results obtained from a simple model of a composite material
Behaviour of brazed pipe flanges with separate clamping rings
Authors: Fessler H , Perry D A 
Published: July 2007

Three pairs of aluminium-brass 100-mm-bore flange models with different surface finishes of the joint faces have been subjected to known bolting forces and internal pressures up to seven times the rated pressure at room temperature. Hard and soft flat gaskets were used and it was found that the joint efficiency was independent of gasket material, surface finish, and initial bolt tension. Surface strains on the outer surfaces of the tubes and flange rings were measured with electrical-resistance strain gauges where these could be fitted. These results are also presented. The flanges did not fail; tests ended when the loose steel rings touched owing to excessive deformation, so that the gaskets were prevented from sealing.
An optical method for direct measurements of strain in a torsional Hopkinson-bar apparatus
Authors: Stevenson M G , Campbell J D 
Published: July 2007

A method has been developed to measure the related rotation of the flanges of a thin-walled tubular specimen during a torsion test. The method, which is based on the Moiré-fringe technique, is capable of use at the high rates of strain encountered during a Hopkinson-bar test, as well as at low rates of strain. In the application described, the specimen gauge length is very short, but the method could be used for specimens of considerably longer gauge length. Direct calibration of the system is easily carried out at low angular velocities. The method can then be used to measure directly the specimen strain during a Hopkinson-bar test, and thus to check the value derived from measuremets of torsional waves in the elastic bars. Results of such comparisons are given, and it is found that the values given by the two method agree well, the differnce being attributable largely to inaccuracies in the torque measurement. The new method permits the determination of specimen deformation during the later stages of the test when multiple wave reflections render the wave analysis iaccurate. In particular, it has been found that the specimen may be subjected to reversed plastic straining, so that the total plastic strain connot be determined from the permenent deformation at the end of the test.
Elastic-plastic fatigue crack growth under load cycling
Authors: Branco C M , Radon J C , Culver L E 
Published: July 2007

An analytical solution based on non-linear beam theory has been derived to compute the variation of total cyclic potential energy in fatigue crack growth under conditions of gross plasticity. It was assumed that the variation in total potential energy with crack length was equal to the cyclic value of J, written as Δ J = Jmax - Jmin where Jmax and Jmin are the maximum and minimum values of the contour integral J in the loading cycle. The solution is applicable to any geometry, providing fully tensile loading and cyclic creep occurs. It was applied to the contoured double-cantilever-beam (d.c.b.) geometry and Δ J was found to be dependent upon load P, crack length a, number of cycles N and the strain hardening and cyclic creep properties of the material. The results obtained may be applied in the study of crack propagation at relatively small deflections. Fatigue crack growth rates were investigated experimentally under tensile cyclic conditions, leading to generalized plasticity. Tests were performed on mild steel d.c.b. specimens at room temperature in laboratory air, 50 per cent r.h. at a loading frequency of 0.1 Hz. Load-deflection loops were monitored during the lifetime and it was found that the experimentally measured variations in potential energy were 5-10 per cent above the theoretical Δ J values. The difference is explained in terms of the shear force effect and also rotation at the crack tip not considered in the theoretical analysis. When the crack growth rate, d a/d N, was plotted against Δ J, a good correlation was obtained. These results offer supporting evidence to the thesis that crack growth rate at high strains is substantially controlled by Δ J.
Shape imperfections in cylinders and spheres: Their importance in design and methods of measurement
Authors: Kendrick S B 
Published: July 2007

Most design codes require stiffened cylinders to be made circular to within ½ per cent on radius, and large penalties are incurred by exceeding the shape tolerance. The methods specified for checking on circularity vary greatly and they are vague in some cases and illogical in others. Two methods of measuring shape are presented, and it is shown that extreme care must be used in analysing the results obtained from chord gauge readings which are often the most convenient to take. The accuracy of the two methods is compared.