bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proliferating cell nuclear antigen but not p53 or human papillomavirus DNA correlates with advanced clinical stage in renal cell carcinoma
Authors: KAMEL D. , TURPEENNIEMI‐HUJANEN T. , VÄHÄKANGAS K. , PÄÄKKÖ P. , SOINI Y. 
Published: April 2007

In this study we investigated 56 renal cell carcinomas immunohistochemically for the expression of proliferating cell nuclear antigen (PCNA) and tumour suppressor protein p53. We also analyzed for the presence of human papilloma virus (HPV) DNA subtypes 6, 11, 16, 18, 31 and 33 by in situ hybridization. In carcinomas which showed more than 10% of PCNA positive nuclei there were significantly more cases with invasion (P= 0.032) or metastatic disease (P= 0.047). Nine out of 22 grade III‐IV tumours (40.9%) but only six out of 30 grade I‐II tumours (20%) showed more than 10% of PCNA positive cells (P= 0.097). Patients with 10% or more PCNA positive cells in kidney tumours had more advanced disease at the time of diagnosis than those showing less PCNA positive cells (P= 0.05).Six p53 positive cases were found among 56 tumours (11%), but only one case had more than 10% positive cell nuclei. The presence of HPV DNA was found in 29 out of 56 cases (52%). Multiple subtypes were found in 19 cases (34%). The most commonly occurring subtypes were 18 and 33. There was no association between PCNA, p53 and the presence of HPV DNA subtypes. Because of the association of PCNA with invasion and metastatic disease, it would be worth while to study PCNA further as a possible marker for aggressiveness of renal carcinomas. Both this study and those concentrated on mutational analysis suggest that p53 is generally not important for the development of renal cell carcinoma. On the other hand, the presence of HPV DNA in these tumours implicates HPV viral infection in the aetiology of renal cancer.
Contribution of cellular infiltration to the progression of IgA nephropathy: A longitudinal, immunocytochemical study on repeated renal biopsy specimens
Authors: OOTAKA Tetsuya , SAITO Takao , YUSA Akira , MUNAKATA Takako , SOMA Jun , ABE Keishi 
Published: April 2007

Summary: A retrospective immunocytochemical study was performed on repeated renal biopsy specimens from 47 patients with IgA nephropathy, 23 of whom received steroid therapy after the initial biopsy. Immune cells in renal tissues were detected by the immunoperoxidase method using monoclonal antibodies against common leukocyte antigens, T cells, B cells and monocytes/macrophages.Overall, glomerular infiltration of total leukocytes and monocytes/macrophages was significantly correlated with proteinuria. Interstitial infiltration of total leukocytes, T cells and monocytes/macrophages was significantly correlated with histological injury and renal dysfunction. In the steroid‐treated group (group S), urinary protein and glomerular infiltration of total leukocytes and macrophages were significantly reduced at the follow‐up biopsy, while these parameters remained unchanged in the nonsteroid‐treated group (group N). In group S, interstitial infiltration of almost all of the various cell types, histological renal damage and renal function remained unchanged at the follow‐up biopsy, while group N showed a significant increase in the number of interstitial total leukocytes, T cells and macrophages and showed a significant progression of histological renal injury.These findings suggest that glomerular immune cells, especially monocytes/macrophages, are involved in inducing proteinuria and interstitial immune cells are involved in renal deterioration. Furthermore, steroid therapy appears to reduce urinary protein and prevent the progression of tissue injury through suppression of renal infiltration of these inflammatory cells.
An education programme promoting organ donation for 13–14 year old schoolchildren
Authors: AGAR John WM , SIMMONDS Rosemary , HEINTZ Rosemary 
Published: April 2007

Summary: Many programmes have attempted community education in organ donation. Too often these ‘preach to the converted’ or concentrate on special interest groups, thus failing to widely influence community perceptions of transplantation and organ donation.As 13–14 year old children appear sufficiently mature to be receptive to challenging ideas yet may not yet have developed fixed biases or opinions to impair concept assimilation, an educational package dealing with dialysis/transplantation and organ donation was tested in two evenly aged, socio‐economic and sex matched student groups at this age level in a single co‐educational school. One group only was exposed to a 3 h comprehensive course in renal structure and function, dialysis and transplantation. the two groups were assessed 1 year later by questionnaire to test the retention of information and, more importantly, to compare attitudes to organ donation.Statistically significant differences characterized the knowledge of and attitudes towards dialysis and transplantation between the two groups. In particular, the tutored group was much more likely to agree to organ donation by self (P<0.009) or by relatives (P<0.03) when compared to the untutored group.This study demonstrates that a short, simple education course for 13–14 year old students can favourably change their perceptions and attitudes towards organ donation. the wider application of similar courses may have a positive impact upon dialysis and transplantation awareness and, ultimately, on national donor rates, becoming a useful addition to national strategies to increase organ donation.
FATIGUE THRESHOLDS AND DUCTILE‐BRITTLE TRANSITIONS IN Ti‐30Mo
Authors: JATAVALLABHULA K. , GERBERICH W. W. 
Published: April 2007

Abstract—Substantial effects of hydrogen are found on the DBTT and cleavage fracture stress in both cathodically and gas phase charged samples of a BCC Ti alloy. Fatigue thresholds when plotted as a function of temperature exhibit a peak and this peak shifts towards higher temperatures when the hydrogen level is increased. An elastic calculation of static threshold stress intensities using experimentally observed fracture stress parameters show a similar trend to fatigue threshold stress intensities.
INTRINSIC MATERIAL SCATTER IN FATIGUE CRACK PROPAGATION
Authors: SHAW W. J. D. , MAY I. LE 
Published: April 2007

AbstractThe statistical nature of fatigue crack growth rate has been examined for G41400 steel exposed to different heat treatments and for different loading and environmental conditions. Techniques for determining the intrinsic value of the crack propagation rate are discussed. The intrinsic scatter due to the material has been evaluated and considered in terms of its effect on fatigue life prediction, both normal and log normal distributions of fatigue crack growth data being considered. It appears that the intrinsic material scatter in crack propagation rate is closely related to the scatter in total life.
INFLUENCE OF AN OVERLOAD ON THE FATIGUE CRACK GROWTH IN STEELS
Authors: ROBIN C. , LOUAH M. , PLUVINAGE G. 
Published: April 2007

Abstract— This study is concerned with the influence of a single‐peak overload and the overload ratio on the subsequent rate of growth of a fatigue crack in steels. Retardation increases with increasing overload ratio.The crack opening load was also measured during all tests. It is shown that the Elber's crack closure concept is not able to explain the effect of overloads. The importance of the material yield stress was evaluated by testing steels of different strength. It seems that the residual stress state induced by the overload is the major factor causing retardation. Two models are analyzed.
ANISOTROPIC YIELD SURFACES IN CYCLIC PLASTICITY
Authors: HARVEY S. J. , ADKIN P. , JEANS P. J. 
Published: April 2007

Abstract— An anisotropic form of the Von Mises yield criteria is presented which includes linear terms and therefore enables Bauschinger effects to be considered when constructing yield or loading surfaces.The coefficients representing the state of anisotropy are expressed in terms of the uni‐axial and shear yield stress of the material. It is suggested that this form of the yield or loading surface can be used to determine the plastic strains for a range of multi‐axial and cyclic plasticity problems and results are presented for the particular case of a tube subjected to cyclic plastic torsion with an axial stress.
THE EFFECT OF CRACK LENGTH ON FATIGUE THRESHOLD
Authors: Taylor D. 
Published: April 2007

This paper puts forward a new method for analysing the behaviour of very short fatigue cracks. A probability function is introduced into the definition of the growth threshold, which rationalises the scatter in experimental data produced using an aluminium bronze alloy. This probability function can be visualised in terms of the microstructure of the material.It is shown that, in this material as in mild steels, fatigue crack initiation is not the critical stage. Initiation occurs relatively easily, but the cracks so formed may grow to only a few grain diameters in length before being arrested; thus it is the behaviour of cracks of this length which is critical in determining the fatigue strength of the material.These observations, when combined with the probability functions, allow estimation of the probability of failure of a component or structure in service with greater confidence than the methods used at present.
SMALL FATIGUE CRACK GROWTH BEHAVIOUR UNDER TWO STRESS LEVEL MULTIPLE LOADING
Authors: Tokaji Keiro , Ando Zenji 
Published: April 2007

AbstractSmall fatigue crack growth behaviour in a low alloy steel was investigated under two stress step multiple loading in which the secondary stress was below the fatigue limit. Crack growth rates were presented in terms of a stress intensity factor and compared with data obtained under constant amplitude loading. In the higher ΔK region, crack growth rates increased monotonously with increasing ΔK even though the stress level was below the fatigue limit, and tended to be lower than those for constant amplitude loading. In the lower ΔK region, cracks showed a complicated behaviour, that is, an initial high growth rate was observed followed by an arrest or a drop to a minimum value and then a gradual increase. The average crack growth rates per cycle at both primary and secondary stresses in each block were approximately consistent with the da/dn‐ΔK relation for constant amplitude loading. A suggestion for the prediction of crack growth life is given.
ANALYSIS OF THE LOW‐CYCLE FATIGUE BEHAVIOUR OF TWO Ni‐Cr‐BASE ALLOYS
Authors: Day M. F. , Thomas G. B. 
Published: April 2007

AbstractThe low‐cycle fatigue performance of the Ni‐Cr‐base alloys IN597 and IN738 has been examined with particular reference to the creep‐fatigue interaction. Results are reported showing a systematic effect on life of IN597 of the level of tensile stress during tests involving cycles with dwell periods. For both alloys the simple life fraction rule correlates the data in a fairly satisfactory manner but some method of stress compensation is necessary for the strain range partitioning (SRP) method. Certain limitations of the SRP method in dealing with results from highly creep resistant alloys are discussed.
ENVIRONMENTAL SENSITIVITY OF SMALL CRACK GROWTH IN 7075 ALUMINIUM ALLOY
Authors: Zeghloul A. , Petit J. 
Published: April 2007

AbstractFatigue propagation tests on artificial short cracks (initial length ˜ 0.15 mm) were performed in vacuum and in nitrogen containing small traces of water vapour (˜ 3 ppm) on a high strength aluminium alloy type 7075 in two aged conditions (T651 and T7351) at a load ratio of 0.1 and a frequency of 35 Hz. A predominant influence of environment was determined for short crack growth. This behaviour has been discussed in terms of crack growth rate versus the effective stress intensity factor range relationship previously determined for long cracks. The results obtained suggest the absence of closure at the early stage of short crack growth with an enhanced environmental influence as compared to long crack behaviour at the same load ratio. As the crack grows the effect of closure increases progressively and the short crack effect disappears after a crack growth of the order of 1 mm.
THE GROWTH OF SMALL FATIGUE CRACKS IN A LOW CARBON STEEL; THE EFFECT OF MICROSTRUCTURE AND LIMITATIONS OF LINEAR ELASTIC FRACTURE MECHANICS
Authors: Tokaji Keiro , Ogawa Takeshi , Harada Yukio 
Published: April 2007

AbstractThe growth characteristics of small fatigue cracks were studied under rotary bending in a low carbon steel prepared with two ferrite grain sizes of 24 and 84 μm, and were compared with the growth characteristics of large through cracks in fracture mechanics type specimens. The effect of microstructure on crack growth rates and the interaction in growth behaviour between two neighboring small cracks were examined experimentally, and also the critical crack lengths above which linear elastic fracture mechanics (LEFM) is applicable were evaluated for small crack growth and for fatigue crack thresholds. It is found that small cracks grow much faster than large ones and also show growth rate perturbations due to grain boundaries. It is indicated that the critical crack lengths for fatigue crack thresholds are significantly shorter than those for small crack growth.
COMPARISON OF SHORT AND LONG FATIGUE CRACK GROWTH IN 7075‐T6 ALUMINUM
Authors: Bu R. , Stephens R. I. 
Published: April 2007

AbstractThe fatigue crack growth rates of physically‐short cracks (0.5 ≤a≤ 1.0 mm), intermediate cracks (1 < a≤ 2 mm) and long cracks (7 < a < 25 mm) were compared using SEN type tensile specimens in 7075‐T6 aluminum alloy with load ratios, R, of 0.05, − 1 and 0.5 under constant amplitude testing at room temperature. It was found that the short cracks grew much faster than long cracks based on applied δK with da/dN≤ 10−7 m/cycle. Even the intermediate cracks grew faster than the long cracks below 10−7 m/cycle. The transition crack lengths where similitude with δK existed was between 1 and 2 mm. Mean stress effects were similar for R= 0.05 and − t, but R= 0.5 caused increased crack growth rates. The above differences are partially attributed to crack closure effects. Based upon plastic zone sizes, LEFM was justifiable with all the experiments.
MICROSTRUCTURAL STUDY OF CYCLIC STRAIN HARDENING BEHAVIOUR IN BIAXIAL STRESS STATES AT ELEVATED TEMPERATURE
Authors: Nishino Seiichi , Hamada Naomi , Sakane Masao , Ohnami Masateru , Matsumura Naomi , Tokizane Masaharu 
Published: April 2007

AbstractThis paper describes the cyclic strain hardening behaviour and dislocation structures of material in biaxial low cycle fatigue at elevated temperatures. In this study, push‐pull, reversed torsion and combined push‐pull/reversed torsion tests were carried out using a type 304 stainless steel in air. While there was no significant difference between the cyclic stress amplitudes in the push‐pull and reversed torsion tests on a von Mises' base, combination tests exhibited a 40% increase in stress amplitude. Most of the dislocations in the first two types of test adopted ladder or maze structures, while in the later case cells were found. Changing the loading mode at a certain cycle, for example, from push‐pull to reversed torsion, revealed that stress amplitude depended mainly on the concurrent applied strain mode and furthermore, that the strain mode before the interchange had little or no effect on the stress amplitude after the interchange. Tests were also performed in order to examine how prestrained material hardened in the three different loading modes, with the following results: prestrained material in push‐pull or in reversed torsion exhibited an anisotropic stress response, while the material in the combined tests exhibited an isotropic response. These cyclic responses are discussed in connection with the dislocation structure.
CRACK PROPAGATION STUDIES ON Al 7475 ON THE BASIS OF CONSTANT AMPLITUDE AND SELECTIVE VARIABLE AMPLITUDE LOADING HISTORIES
Authors: Zhang S. , Marissen R. , Schulte K. , Trautmann K. K. , Nowack H. , Schijve J. 
Published: April 2007

Abstract— Fatigue crack propagation behaviour under variable amplitude loading is significantly influenced by load history induced sequence effects. Because the understanding of the causes of such sequence effects is still rather limited, crack propagation predictions become difficult. In the present investigation an exploratory test program with simple variable amplitude load sequences was performed, which was designed to improve the general understanding of sequence effects and to offer a basis both for an evaluation of existing crack propagation prediction models and for the development of improved methods.The investigations were performed on center cracked 8 mm thick Al 7475‐T7351 specimens. In the first part of the study constant amplitude tests were performed over a wide range of R‐ratios. The test results and the transition of the fracture mode during tests could be represented on the basis of the effective ΔK‐value.In the second part of the paper tests with simple systematically varied sequences of high loads, low loads and underloads were performed and the crack propagation behaviour was measured. In order to obtain detailed information on the crack propagation increments per cycle, fractographic analyses were also performed. It was found that also under variable amplitude loading the crack propagation approximately followed the effective ΔK‐values, except in one case.A linear (non‐interaction) prediction model could not describe the observed crack propagation behaviour. The results of the application of a model assuming a constant crack opening level are also given. Finally, some general viewpoints regarding further developments of models are outlined.
WEIGHTED AVERAGED STRESS INTENSITY FACTORS OF CIRCULAR‐FRONTED CRACKS IN CYLINDRICAL BARS
Authors: CASPERS M. , Mattheck C. 
Published: April 2007

AbstractStress intensity factors are calculated in weighted average at the surface and the deepest point of a circular‐fronted surface crack in a cylindrical bar by use of the weight function method. A wide range of various crack shapes are studied, from a nearly straight‐fronted edge crack to a semi‐circular crack front. Use of the weight function method requires that the crack opening displacement field of a reference load has to be known. It was obtained by 3‐D finite element analysis. Results are presented for the cracked cylinder subjected to a constant stress (tension) and a linear stress distribution acting perpendicular to the crack faces and they are compared with values found by other investigators.
A STATISTICAL MODEL OF INTERMITTENT SHORT FATIGUE CRACK GROWTH
Authors: Cox B. N. , Pardee W. J. , Morris W. L. 
Published: April 2007

AbstractThe stochastic nature of the growth of short surface fatigue cracks under uniform cyclic loading can be attributed to their interaction with a stochastic microstructure. In this paper, a computational scheme is proposed to describe the statistical effects of the temporary arrest of short cracks by grain boundaries, and the modification of rates of propagation across grains by various effects of grain boundary constraint. The fact that a crack tip may be in one of two states, either temporarily arrested at a grain boundary or actively propagating, is treated explicitly by considering probability densities evolving in complementary state spaces corresponding to each case. The evolution of the densities during fatigue is described by conservation equations, which are solved numerically. It is shown how engineering quantities, such as the time to initiation of a macroscopic crack, can be derived from the calculated densities. The explicitness with which the characteristics of short crack growth are treated greatly enhances the potential accuracy of predictions based on this approach.The theory is constructed to allow considerable flexibility in the microstructure‐related mechanisms assumed to control growth rates in any given material. However, as it is stated here, the theory is restricted to Mode I (tensile opening) transgranular crack growth under constant amplitude cyclic loading. Examples are given of the various effects that can be treated, as well as those that would require modification of the structure of the computational procedure. The theory is illustrated by an application to data for Al 2219‐T851.
FATIGUE UNDER OUT‐OF‐PHASE BENDING AND TORSION
Authors: McDiarmid D. L. 
Published: April 2007

AbstractTest data on fatigue under out‐of‐phase bending and torsion has been reanalysed. For the materials tested failure has been found to be consistent with the plane of maximum range of maximum range of maximum principal stress, as for the in‐phase case. The critical shear planes are assumed to be those associated with this principal stress plane. A multiaxial fatigue damage parameter based on the maximum range of shear stress on the critical shear plane allowing for the effect of the range of normal stress occurring on this plane has been used to develop a proposed set of design curves for in‐phase bending and torsion which are conservative for the long life out‐of‐phase case.
A FATIGUE CRACK PROPAGATION MODEL FOR APPLICATION TO SERVICE LOADS
Authors: Ono H. , Tsunenari T. 
Published: April 2007

Abstract— The authors previously proposed a simulation model for fatigue crack propagation for varying load ranges by considering retardation behaviour due to high level loads and showed that the model could estimate crack propagation lives under quasi‐random loading. However as the model was somewhat simplified, it was predicted that some problems would occur when estimating lives under actual random loads.In this study the model was modified by considering the interaction effect of retardation and acceleration processes of crack propagation based on the test results of two and three level load programs. The model was verified by executing random load crack propagation tests.
A THERMOELASTICITY THEORY FOR DAMAGE IN ANISOTROPIC MATERIALS
Authors: Zhang Daqing , Sandor Bela I. 
Published: April 2007

AbstractA thermoelasticity theory for damage in anisotropic materials is developed. This theory can be applied to evaluate the damage parameter D, the normalized effective mess density ρe/ρ, and the effective modulus Ee quantitatively in some metals and composites by incorporating the thermographic stress analysis method (TSA; also, SPATE method). The effective moduli due to fatigue damage and static loads in a glass fiber/epoxy laminate obtained by the TSA method are compared with the values measured by an extensometer. The correlation between the measurements using the two methods is very good.
RETARDATION IN FATIGUE CRACK GROWTH IN Al‐2024 AFTER BLOCKS OF UNDERLOADING
Authors: Zuidema Jan , Shen Wu Yi , Janssen Michael 
Published: April 2007

AbstractIn contrast with overloads, small numbers of underloads lead to acceleration in crack growth rate after application of the underloads. Larger numbers of underloads, however, give rise to retardation effects comparable with the effects of overloads. The retardation effects are attributed to the development of shear lips. Irregular shear lips show a greater effect than regular (smooth) shear lips. Increasing numbers of underloads give rise to greater retardation. For high numbers of underloads at high ΔKeff there is even an increase in the total life of the fatigue specimen with respect to the situation without underloads. High numbers of underload at high ΔKeff cause crack arrest at one side of the centre‐cracked tension specimen. The non‐growing side is often in single shear, the growing side always in double shear.