bluuebunny/crossref_metadata_2025_split huggingface dataset:
A coupled BEM‐flexibility force method for bending analysis of internally supported plates
Authors: Rashed Youssef F. 
Published: October 2002

AbstractThis paper presents a new method for the analysis of plates in bending with internal supports. The proposed method can be regarded as an extension of the well‐known force method (the flexibility matrix method) in the matrix analysis of structures. The solution is performed through two phases: the released plate phase, in which the plate is released from all internal supports and solved using the Boundary Element Method (BEM). The effect of internal supports is considered in the second phase, where a series of unit virtual loads is placed instead of the unknown redundant reactions at internal supports. The flexibility matrix is formed and compatibility of deformations at the locations of internal supports is satisfied. Hence, the corresponding system of equations is solved for the unknown redundant forces at internal supports. The final solution of the problem consists of the summation of two phases: the released plate phase and the cases of virtual unit loads phase. An efficient solution algorithm is developed to solve both phases simultaneously. The main advantages of the present formulation are: (1) the present formulation increases the versatility of the BEM as it allows the re‐usability of standard BEM codes for solution of plates in bending to be used in solving problems having internal supports, with even no modifications; and (2) the two solution phases are completely uncoupled; therefore it is easy to trace behaviour of the plate due to failure of one or more of the internal supports without re‐analysis.Several numerical examples are analysed. The results are compared to those of analytical and finite element models to demonstrate the accuracy and the validity of the present formulation. The present formulation is used also to study the differences between the finite element and boundary element modelling for building slabs. Copyright © 2002 John Wiley & Sons, Ltd.
Finite element analyses of wave propagations due to a high‐speed train across bridges
Authors: Ju S. H. 
Published: October 2002

AbstractThe finite element mesh of the unbounded wave problem often contains a large number of degrees of freedom. Moreover, the wave reflection along the mesh boundary cannot be avoided if only the traditional time‐domain finite element method (FEM) is used. Thus, the main purpose of this study is to overcome those drawbacks and discuss how to use the three‐dimensional FEM to simulate the soil vibration due to a moving high‐speed train across bridges. A number of finite element analyses (FEA) including the isolation schemes of in‐filled and open trenches were performed. The appropriate mesh dimension in the direction of the railroad is suggested and validated. Moreover, the 3‐node wheel element for simulating the moving train and the least‐squares method for finding foundation properties are proposed. Since the finite element mesh contains a large number of degrees of freedom, the conjugated gradient method with the SSOR preconditioning scheme is recommended. In conclusion, this study indicates that the difficulty of the FEA for unbounded problems can be overcome efficiently even by using a personal computer. Copyright © 2002 John Wiley & Sons, Ltd.
Modelling of short wave diffraction problems using approximating systems of plane waves
Authors: Laghrouche O. , Bettess P. , Astley R. J. 
Published: October 2002

AbstractThis paper describes a finite element model for the solution of Helmholtz problems at higher frequencies that offers the possibility of computing many wavelengths in a single finite element. The approach is based on partition of unity isoparametric elements. At each finite element node the potential is expanded in a discrete series of planar waves, each propagating at a specified angle. These angles can be uniformly distributed or may be carefully chosen. They can also be the same for all nodes of the studied mesh or may vary from one node to another. The implemented approach is used to solve a few practical problems such as the diffraction of plane waves by cylinders and spheres. The wave number is increased and the mesh remains unchanged until a single finite element contains many wavelengths in each spatial direction and therefore the dimension of the whole problem is greatly reduced. Issues related to the integration and the conditioning are also discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Micromechanics of fibre glass composites at elevated temperatures
Authors: Tesar Alexander , Sotakova Darina , Minar Michal 
Published: October 2002

AbstractThe micromechanical assessment of ultimate response of moulded fibre glass (MFG) composites used in structural engineering and acting at elevated temperatures is treated in the present paper. The advanced crystal simulation model of the MFG‐material at elevated temperatures, based on Washizu's variational principle, is presented. The numerical treatment of non‐linear problems possibly appearing is made using the updated Lagrangian formulation of motion. Each step of iteration approaches the solution of the linear problem and the feasibility of the parallel processing FETM‐simulation approach is established. Some numerical and experimental results are presented in order to demonstrate the efficiency of procedures suggested. Copyright © 2002 John Wiley & Sons, Ltd.
Meshless formulations for simply supported and clamped plate problems
Authors: Sladek J. , Sladek V. , Mang H. A. 
Published: October 2002

AbstractIn this paper, simply supported and clamped thin elastic plates are analysed. The biharmonic differential equation, representing the basis of the Kirchhoff theory, is decomposed into two Poisson equations. Local boundary integral equations are derived for this system of equations. The meshless approximation based on the moving least‐squares method is employed for the implementation. In the case of simply supported plates, it is sufficient to use the local boundary integral equations. For the case of clamped plates we propose to use a combination of the local boundary integral equations and the global ones. Then, two groups of nodal unknowns are computed separately. This leads to a reduced system of algebraic equations. Copyright © 2002 John Wiley & Sons, Ltd.
A computer‐based training system for breast fine needle aspiration cytology
Authors: Diamond James , Anderson Neil H. , Thompson Deborah , Bartels Peter H. , Hamilton Peter W. 
Published: October 2002

AbstractFine‐needle aspiration (FNA) cytology is a rapid and inexpensive technique used extensively in the diagnosis of breast disease. To remove diagnostic subjectivity, a diagnostic decision support system (DDSS) called CytoInform© has been developed, based on a Bayesian belief network (BBN) for the diagnosis of breast FNAs. In addition to acting as a DDSS, the system implements a computer‐based training (CBT) system, providing a novel approach to breast cytology training. The system guides the trainee cytopathologist through the diagnostic process, allowing the user to grade each diagnostic feature using a set of on‐screen reference images as visual clues. The trainee positions a slider on a spectrum relative to these images, reflecting the similarity between the reference image and the microscope image. From this, an evidence vector is generated, allowing the current diagnostic probability to be updated by the BBN. As the trainee assesses each clue, the evidence entered is compared with that of the expert through the use of a defined teaching file. This file records the relative severity of each clue and a tolerance band within which the trainee must position the slider. When all clues in the teaching case have been completed, the system informs the user of inaccuracies and offers the ability to reassess problematic features. In trials with two pathologists of different experience and a series of ten cases, the system provided an effective tool in conveying diagnostic evidence and protocols to trainees. This is evident from the fact that each pathologist only misinterpreted one case and a total of 86%/88% (experienced/inexperienced) of all clues assessed were interpreted correctly. Significantly, in all cases that produced the correct final diagnostic probability, the route taken to that solution was consistent with the expert's solution. Copyright © 2001 John Wiley & Sons, Ltd.
Granulocyte macrophage‐colony stimulating factor (GM‐CSF) recruits immune cells to the pancreas and delays STZ‐induced diabetes
Authors: Krakowski Michelle , Abdelmalik Robin , Mocnik Lorraine , Krahl Troy , Sarvetnick Nora 
Published: October 2002

AbstractGranulocyte macrophage‐colony stimulating factor (GM‐CSF) is one of the most widely used growth factors for enhancing immune responses and is known to recruit and activate antigen‐presenting cells (APCs). This study hypothesized that overexpression of this cytokine within the pancreatic β‐cells would recruit, expand, and activate APCs. The question was whether this would lead to tolerance or autoimmunity to pancreatic antigens. This possibility was tested by preparing transgenic mice (ins‐GM‐CSF) whose islets expressed murine GM‐CSF. By 6–8 weeks of age, these mice developed a profound mononuclear cell infiltration that often overwhelmed the exocrine pancreas, although no changes in enzyme or hormone function were apparent. The majority of the mononuclear infiltrate within the pancreas was identified as F4/80+ macrophages. Transgenic ins‐GM‐CSF mice had splenomegaly due to a massive increase in the macrophage population. Additionally, mononuclear cells were found within the livers of transgenic mice, with F4/80+ cells also identified within the infiltrate, indicating that GM‐CSF‐activated mononuclear cells circulated to organs other than the pancreas. To assess the disease potential, this study tested whether macrophage recruitment to the pancreas might accelerate or protect the islets from diabetes. It was found that the induction of diabetes by low‐dose streptozotocin (STZ) was delayed and reduced within ins‐GM‐CSF transgenic mice, in comparison with negative littermates. Together, these data highlight the role of GM‐CSF in recruiting APCs such as macrophages. Advanced cellular infiltration does not overtly harm, and may even protect, pancreatic function, as seen with the delay in chemically induced diabetes. Copyright © 2001 John Wiley & Sons, Ltd.
Gene expression patterns in melanocytic cells: candidate markers for early stage and malignant transformation†
Authors: Meije Clifton B. , Hakvoort Theodorus B. M. , Swart Guido W. M. , Westerhof Wiete , Lamers Wouter H. , Das Pranab K. 
Published: October 2002

AbstractDifferent stages of differentiation of human melanocytic cells, such as normal melanocytes, naevus and melanoma cells, reflect distinct gene expression patterns. A PCR‐based subtractive hybridization and display method was applied to identify genes that are differentially expressed in melanocytic cells in relation to early stage and malignant transformation. This resulted in the identification of a number of candidate cDNAs differentially expressed among melanocytes, naevus cells, and (non)‐metastatic melanoma cells. Out of this collection of cDNAs, 16 clones were screened that comprised 12 novel genes, one previously identified expressed sequence tag related to vesicular trafficking (Ras‐related protein Rab5b). The other three were also known genes that were either related to cell motility (β‐tubulin), pre‐mRNA splicing (small nuclear protein U1A), or of unknown function (the human TI227‐H gene). The differential expression patterns of Rab5b and two novel gene fragments (pCMa1, pCMn2) were further assessed in melanocytic cells. pCMa1 was expressed more in metastatic melanoma than in primary melanoma cells. In contrast, pCMn2 was expressed in both non‐metastatic and metastatic melanoma cells, but was not detectable in either normal melanocytes or naevus cells. The Ras‐related protein Rab5b showed lower levels of expression in highly metastatic than in other melanoma cells. These three cDNAs may therefore be involved in the early stage and malignant transformation of melanocytes. Copyright © 2001 John Wiley & Sons, Ltd.
Fas receptor‐mediated apoptosis: a clinical application?
Authors: Timmer Tineke , de Vries Elisabeth G. E. , de Jong Steven 
Published: October 2002

AbstractFas is a membrane protein belonging to the death receptor family. Cross‐linking of Fas by its ligand, FasL, or agonistic anti‐Fas antibodies, induces apoptosis of cells expressing Fas on the membrane by triggering a cascade of caspases. Since many different tumours express Fas on their membrane, targeting Fas‐mediated apoptosis by anti‐Fas antibodies may be a promising anticancer therapy. Unfortunately, not all Fas‐expressing cells are sensitive to Fas‐mediated apoptosis. This has resulted in the discovery of many different inhibition mechanisms of Fas‐mediated apoptosis. In addition, mutations in the Fas or p53 gene can also influence the sensitivity for Fas‐mediated apoptosis. However, the role of wild‐type p53 in Fas expression is still controversial. Because several different cytotoxic drugs are able to induce Fas membrane expression, combination therapy of anticancer drugs with anti‐Fas antibodies or FasL is conceivable as an anticancer strategy. The efficiency of the induction of Fas‐mediated apoptosis by anti‐Fas antibodies, FasL‐expressing cells or recombinant FasL (rFasL) in tumours has been demonstrated in vivo in solid tumours implanted in mice. Unfortunately, systemic treatment with anti‐Fas antibodies or rFasL causes severe damage to the liver, so most preclinical studies are now focusing on circumvention of this problem by local administration of FasL, or on the use of inducible FasL‐expressing vectors as gene therapy. Copyright © 2001 John Wiley & Sons, Ltd.
Screening for prostatic cancer and its evolution within Britain
Authors: Parkinson M. C. , Bott S. R. J. , Montironi R. , Melia J. 
Published: October 2002

AbstractThe arguments for and against screening for prostatic cancer are frequently discussed (Albertsen PC. Screening for prostate cancer is neither appropriate nor cost‐effective. Urol Clin North Am 1996; 23: 521–530; Schroder FH, Alexander FE, Bangma CH, Hugosson J, Smith DS. Screening and early detection of prostate cancer. Prostate 2000; 44: 255–263). In contrast, this paper outlines how screening became possible, why the decision was made not to initiate a national screening programme in Britain, the other pathways being pursued, and the current problems, in particular the issue of histopathology workload. Copyright © 2002 John Wiley & Sons, Ltd.
Short‐term preoperative radiotherapy interferes with the determination of pathological parameters in rectal cancer
Authors: Nagtegaal Iris D. , Marijnen Corrie A. M. , Klein Kranenbarg Elma , Mulder‐Stapel Adri , Hermans Jo , van de Velde Cornelis J. H. , Han J. M. van Krieken J. ,   The Pathology Review Committee
Published: October 2002

AbstractShort‐term preoperative radiotherapy in combination with surgery has been shown to decrease the rate of local recurrence in rectal cancer patients. The effects of this type of radiotherapy on the histopathology of rectal carcinoma has been hitherto unknown. Since various histopathological factors are associated with prognosis, the study of alterations induced by irradiation is an important issue. This paper examines the histopathology of resection specimens from 1306 patients who were treated in a randomized trial that evaluated the benefits of preoperative radiotherapy. In this trial, patients were treated with short‐term radiotherapy (5×5 Gy) and operated on within 5 days after radiation. Histopathological parameters were determined by the Pathology Review Committee of the trial and we compared tumours of patients with and without preoperative radiotherapy. Tumours of patients who were treated with preoperative radiotherapy were smaller, more often mucinous carcinomas (13% versus 7%, p<0.001) and more often poorly differentiated (35% versus 24%, p<0.001). After radiotherapy, there was less inflammatory reaction around the tumour (extensive in 7% versus 18%, p<0.001), which was mainly caused by a decrease in T lymphocytes and neutrophil granulocytes. The fibroblastic reaction was more pronounced in the radiotherapy group (extensive in 22% versus 10%, p<0.001). Remarkable histological alterations occurred within a week after 5 days of irradiation of rectal carcinomas. The prognostic value of these factors therefore needs to be re‐evaluated for irradiated patients. Copyright © 2002 John Wiley & Sons, Ltd.
Reduction of hypoxia‐inducible heme oxygenase‐1 in the myocardium after left ventricular mechanical support
Authors: Grabellus Florian , Schmid Christof , Levkau Bodo , Breukelmann Dirk , Halloran Philip F. , August Christian , Takeda Nobuakira , Takeda Atsushi , Wilhelm Markus , Deng Mario C. , Baba Hideo A. 
Published: October 2002

AbstractLeft ventricular assist devices (LVAD) may improve cardiac function. The pathogenesis of this phenomenon, called ‘reverse remodelling’, is not completely elucidated. To examine the hypothesis that LVAD support eliminates tissue stress by reducing local hypoxia, the distribution of heme oxygenase‐1 (HO‐1), a stress protein inducible by hypoxia, was examined in vivo and in vitro. The immunoreactivity for HO‐1 was semi‐quantitatively analysed in left ventricular tissue of 23patients (14 dilated cardiomyopathy (DCM), six ischaemic heart disease (IHD), three myocarditis/congenital heart disease) with end‐stage heart failure before and after LVAD support, while two unused donor hearts served as controls. Control hearts stained almost negative for HO‐1, while failing hearts showed immunoreactivity mainly in cardiomyocytes, but also in endothelial cells, some smooth muscle cells and fibroblasts. Hearts with IHD showed significantly higher HO‐1 immunoreactivity than hearts with DCM or myocarditis/congenital heart disease. After LVAD support, the HO‐1 content decreased significantly in the DCM and IHD group and was significantly higher in the subendocardium than in the subepicardium. In vitro, under hypoxic conditions, neonatal rat cardiomyocytes showed an increase of HO‐1 protein content up to sixfold above the normal level, which returned to normal values after normoxic cultivation. Mechanical support reduces the HO‐1 content of the failing heart and HO‐1 is inducible in vitro under hypoxia and is reversible under normoxia. This supports the concept that restoration of cardiac normoxia by mechanical unloading, particularly in the subendocardium, may be in part responsible for the phenomenon of ‘reverse remodelling’. Copyright © 2002 John Wiley & Sons, Ltd.
New classification of pancreatic intraductal papillary–mucinous tumour by mucin expression: its relationship with potential for malignancy
Authors: Nakamura Akiko , Horinouchi Michiko , Goto Masamichi , Nagata Kohji , Sakoda Koro , Takao Sonshin , Imai Kohzoh , Kim Young S. , Sato Eiichi , Yonezawa Suguru 
Published: October 2002

AbstractIn previous studies of the expression of MUC1 (membrane‐bound type mucin) and MUC2 (intestinal type secretory mucin) in pancreatic tumours, invasive ductal carcinoma (IDC) usually showed MUC1+ and MUC2− expression, whereas intraductal papillary–mucinous tumour (IPMT) showed MUC1− and MUC2+ expression. Recently, however, many IPMTs have been collected, a considerable number of which have shown MUC1− and MUC2− expression. In the present study, the clinicopathological features were examined of 18 IPMTs with MUC2+ and 32 IPMTs with MUC2−, and their potential for malignancy was compared. Most of the IPMTs with MUC2+ were composed of dark columnar cells, whereas most of the IPMTs with MUC2− were composed of clear columnar cells. The incidence of carcinomatous change and invasive proliferation of the carcinoma in the MUC2+ tumours was significantly higher than in the MUC2− tumours. The clinical outcome for the patients with IPMT showing the MUC2+ pattern tended to be worse than for those with IPMT showing the MUC2− pattern, although the overall outcome for the two types of IPMT was significantly better than for those with IDC. Because of the differences in mucin expression pattern, morphological appearance and potential for malignancy between the two types of IPMT, we believe that they belong to different neoplastic lineages and that it may be reasonable to classify them as different entities, although the WHO classification contains a single clinicopathological entity of IPMT forming an adenoma–carcinoma sequence. In conclusion, our classification of IPMTs by MUC2 expression pattern may be of value in the better assessment of the biological behaviour of IPMTs and their potential for malignancy. Copyright © 2002 John Wiley & Sons, Ltd.
Progressive loss of PAX9 expression correlates with increasing malignancy of dysplastic and cancerous epithelium of the human oesophagus
Authors: Gerber Josef‐Karl , Richter Thomas , Kremmer Elisabeth , Adamski Jerzy , Höfler Heinz , Balling Rudi , Peters Heiko 
Published: October 2002

AbstractPax genes encode a family of transcription factors that play key roles in embryonic development. Whereas the functions of Pax genes in the adult organism are largely unknown, upregulated Pax gene expression has been implicated in tumourigenesis. In this study, PAX9‐specific monoclonal antibodies have been generated and it has been shown that PAX9 protein is expressed in the normal epithelium of the adult human oesophagus. PAX9 expression was either lost or significantly reduced in the majority of invasive carcinomas and epithelial dysplasias, the latter representing precancerous lesions. Notably, the percentage of PAX9‐positive cells within the epithelium decreased with increasing malignancy of the epithelial lesion. These results identify PAX9 as a sensitive marker for deregulated differentiation of oesophageal keratinocytes and indicate a role for PAX9 in the normal differentiation process of internal stratified squamous epithelia. These data suggest that upregulated PAX9 expression is not required for the formation of the majority of squamous cell carcinomas of the human oesophagus. Copyright © 2002 John Wiley & Sons, Ltd.
Vascularization of cutaneous melanoma involves vessel co‐option and has clinical significance
Authors: Döme Balázs , Paku Sándor , Somlai Beáta , Tímár József 
Published: October 2002

AbstractThis study was undertaken to determine the role and the fate of the peritumoural vascular plexus during the vascularization of human malignant melanoma (hMM) and in an appropriate murine melanoma model system. The prognostic significance of the vascularity of different tumour areas was also evaluated. Despite morphometry revealing several‐fold higher microvessel densities (MVDs) in the peritumoural tissue than at the centre of the tumour, the development of visceral metastases of hMM was exclusively correlated with the MVD of the tumour centre. Furthermore, the 5‐year survival of the patient group with low tumour centre MVD (<30/mm2, n=29) was 100%, compared to 1/16 patients alive with high tumour centre MVD (>30/mm2, n=16). Morphometric analysis and three‐dimensional reconstruction of vessel networks of both human and murine melanomas showed clearly that the peritumoural vascular plexus present at the melanoma base is continuously being incorporated into the growing tumour mass. Once vessels become incorporated, sprouting ceases and the proliferating endothelial cells (EC) take part only in vessel dilatation. Moreover, the immunohistochemical and ultrastructural characterization of microvessels demonstrated that the pericyte coverage of endothelial tubes was complete in all of the investigated areas, in both human and murine melanomas. Copyright © 2002 John Wiley & Sons, Ltd.