A general framework for continuum damage models. II. Integration algorithms, with applications to the numerical simulation of porous metals

In this paper, we develop numerical algorithms for the integration of the continuum plastic damage models formulated in the general framework identified in Part I of this work. More specifically, we focus our attention on a particular plastic damage model of porous metals, involving a classical von Mises yield criterion coupled with a pressure dependent damage surface to model the nucleation and growth of voids in the metallic matrix. Unilateral damage leading to a sudden change of stiffness in the material's response due to the closing/opening of these voids is also incorporated through the imposition of the unilateral constraint of a positive void fraction, thus, illustrating the clear physical significance added by this framework in the resulting constitutive models. The proposed integration algorithms fully use the modularity of the identified framework, leading in this way to independent integration algorithms for the elastoplastic part and each damage mechanism. Remarkably, all these individual integration schemes share the same formal structure as the classical return mapping algorithms employed in the numerical integration of elastoplastic models, namely an operator split structure consisting of a trial state and the return map imposing the plastic and damage consistency, respectively. A Newton iterative scheme imposes the equilibrium (equal stresses) among the different mechanisms of the response of the material. This modular structure allows to obtain the closed-form consistent linearization, involving in a simple form the algorithmic consistent tangents corresponding to each independent mechanism, thus resulting in a very modular and efficient computational implementation. The performance of the proposed algorithms is illustrated in several representative numerical simulations

On the formulation of closest-point projection algorithms in elastoplasticity. Part I: The variational structure.

Report UCB/SEMM 2000-01 - Dept. of Civil Engineering - University of California at Berkeley, USAWe present in this paper the characterization of the variational structure behind the discrete equa- tions defining the closest-point projection approximation in elastoplasticity. Rate-independent and viscoplastic formulations are considered in the infinitesimal and the finite deformation range, the later in the context of isotropic finite strain multiplicative plasticity. Primal variational prin- ciples in terms of the stresses and stress-like hardening variables are presented first, followed by the formulation of dual principles incorporating explicitly the plastic multiplier. Augmented La- grangian extensions are also presented allowing a complete regularization of the problem in the constrained rate-independent limit. The variational structure identified in this paper leads to the proper framework for the development of new improved numerical algorithms for the integration of the local constitutive equations of plasticity as it is undertaken in Part II of this work.Preprin

On the formulation of closest-point projection algorithms in elastoplasticity. Part II: Globally convergent schemes. With applications to deviatoric and pressure-dependent plastic models.

Report UCB/SEMM 2000-02 - Dept. of Civil Engineering - University of California at Berkeley, USAPreprin

Association of the 3467C>T mutation (T1156M) in the von Willebrands factor gene with dominant type 1 von Willebrands disease

[EN] Type I is the most frequent form of von Willebrand's disease, which is characterized by a quantitative partial deficiency of von Willebrand's factor. At present, only two mutations located in the D3 domain (C1149R, C1130F) have been reported to cause the classic type I variant. The 3467C>T transition that predicts the T1156M amino acid change was detected in seven patients from one family and was not found in 110 normal alleles screened. This is a candidate mutation to cause dominant type I variant with complete penetrance. On the other hand, neither of the two mutations mentioned above has been detected in the other 15 families studied with type I or possible type 1 patients.This work was supported in part by grant #99/0633 (FIS, Spain). We wish to thank R. Curats and J.M. Montoro for their technical assistance and Mr. Peter Blair for his linguistic advice.Casaña-Gargallo, MP.; Francisco Martínez; Saturnino Haya; Espinós-Armero, CÁ.; José Antonio Aznar (2001). Association of the 3467C>T mutation (T1156M) in the von Willebrands factor gene with dominant type 1 von Willebrands disease. Annals of Hematology. 80(7):381-383. https://doi.org/10.1007/s00277010030738138380

Significant linkage and non-linkage of type 1 von Willebrand Disease to the von Willebrand factor gene

[EN] Significant linkage of types 2A and 2B von Willebrand disease (VWD) to the von Willebrand factor (VWF) gene have been reported, as well as mutations in the VWF gene. However, data for the partial quantitative variant are less consistent. An inconsistency of association between the type 1 VWD phenotype and genotype has been reported recently. We undertook linkage analysis of 12 families with definite or possible type 1 VWD patients. One family with classic type 1 VWD had a high lod score (Z = 5.28, theta = 0.00). A total lod score of 10.68 was obtained for the four families with fully penetrant disease. In two families linkage was rejected, while three families did not show conclusive evidence of linkage. This study corroborates ABO blood group influence, especially in patients with mild deficiencies and/or incomplete penetrance, Indirect genetic analysis may be an option for diagnosing asymptomatic or presymptomatic type 1 VWD carriers, particularly in families showing higher penetrance. The study indicates defects of the VWF locus are to be expected in more than half of the families studied. However, as defects at different loci may be the cause of this phenotype, the results of the segregation analyses should be interpreted with caution, especially in studies involving small families, or mild expressions of the disorder or incomplete penetrance.This work was partly supported by F1S grant # 99/0633 (Spain). We wish to thank J. M. Montoro for the multimeric structure analyses, R. Curats for his help in the segregation analyses, all the staff of the `Unidad de CoagulopatõÂas CongeÂnitas de la Comunidad 5alenciana' for their technical and clinical assistance, and Mr Peter Blair for the linguistic advice given in writing this paper.Casaña-Gargallo, MP.; Martínez, F.; Haya, S.; Espinós-Armero, CÁ.; Aznar, JA. (2001). Significant linkage and non-linkage of type 1 von Willebrand Disease to the von Willebrand factor gene. British Journal of Haematology. 115(3):692-700. https://doi.org/10.1046/j.1365-2141.2001.03132.x692700115

Bayesian approach to urinary ESBL-producing Escherichia coli

This is a retrospective study about the prevalence of ESBL-producing Escherichia coli (EEC) in urinary specimens from patients from the Comunitat Valenciana from January 2007 to December 2008. Data were retrieved from RedMIVA, and Bayesian generalized linear mixed models were considered to study the prevalence of EEC with regard to demographical and microbiological factors. The total number of infections considered was 164,502, the amount of urinary isolates was 70,827 belonging to 49,304 different patients, and 5,161 (7.3%) of the urinary isolates were EEC. Three out of four E. coli were isolated in women (76.8%), men showed higher rates of EEC (9.7% in men vs. 6.5% in women). EEC patients were, in average, 10.8 years older, and hospitalization was more frequent (9.9% vs. 6.9%). Resistance to non-β-lactams antimicrobials was higher in EEC. The rates of ciprofloxacin and co-trimoxazol resistance in EEC were 75.5% and 52.0%, respectively, whereas it ranged between 1.4-12.4% for the rest of antimicrobials.Prior EEC infection and hospitalization were the most relevant risk factors and increased the expected EEC probability approximately 400% and 50% respectively. Other infections played an important and positive role too, Enterobacteriaceae, P. aeruginosa and other bacteria being the most relevant elements. Female gender was a protective factor and reduced the risk by approximately 25% while age was an additive risk factor. Finally, an open-access web-based software was constructed to compute the probability that an E. coli in a urinary infection be an EEC from a specific combination of risk factors. This pharmacovigilance tool should prove useful to monitor and control antimicrobial resistance spread

Search for Mutations in a Segment of the Exon 28 of the Human Von Willebrand Factor Gene. New Mutations, R1315C and R1341W, Associated with Type 2M and 2B Variants

[EN] von Willebrand Disease (vWD) is the most frequently inherited bleeding disorder in humans, and is caused by a qualitative and/or quantitative abnormality of the von Willebrand factor (vWF), A large number of defects that cause qualitative variants have been located in the Al domain of the vWF, which contains sites for interaction with platelet glycoprotein Ib (GPIb). We have developed a new approach to detect mutations based on Ddel digestion and single-strand conformation polymorphism analysis. A segment of 487 nucleotides, extending from intron 27 to codon 1368 of the pre-pro vWF was amplified from genomic DNA, The cleavage with Ddel yields two fragments of appropriate size for this kind of analysis and confirms that the gene, rather than the pseudogene, is being investigated, Six families with type 2B vWD: one type 2M vWD family, and one another type 2A vWD family were studied. After sequencing the fragments with an altered electrophoretic pattern, we found four mutations previously described-R1308C, V1316M, P1337L, and R1306W-in patients with 2B vWD, The last one arose de novo in the patient. In addition, two new candidate mutations were observed: R1315C and R1341W. The first one was associated to type 2M vWD, whereas the one second cosegregated with type 2B vWD. The fact that these new mutations were not found in 100 normal alleles screened further supports their causal relationship with the disease, These mutations, which induce either a gain or a loss of function, further show an important regulatory role of this region in the binding of vWF to GPIb and its implications in causing disease.We wish to thank J.M. Montoro for performing multimeric assays and R. Curats for his technical assistance.Casaña, P.; Martínez, F.; Espinós-Armero, CÁ.; Haya, S.; Lorenzo, JI.; Aznar, JA. (1998). Search for Mutations in a Segment of the Exon 28 of the Human Von Willebrand Factor Gene. New Mutations, R1315C and R1341W, Associated with Type 2M and 2B Variants. American Journal of Hematology. 59(1):57-63. https://doi.org/10.1002/(sici)1096-8652(199809)59:13.0.co;2-z576359

Changes in radiological protection and quality control in Spanish dental installations : 1996-2003

Introduction: The European Union has established specific directives concerning radiological protection which are obligatory for member States. In addition, all Spanish dental clinics with radiological equipment are required to have an annual quality control check. Objective: To analyze the effect of new European legislation on dental radiological practice in Spain and to determine whether it has resulted in lower doses being administered to patients. Material and Methods: A total of 10,171 official radiological quality control reports on Spanish dental clinics, covering 16 autonomous regions, were studied following the passing of Royal Decree 2071/1995 on quality criteria in radiodiagnostic installations. The reports, compiled by U.T.P.R Asigma S.A., a company authorised by the Nuclear Safety Council, cover the years 1996 to 2003, which has enabled us to monitor the evolution of radiological procedures in dental clinics over a seven year period. Results: According to the reports for 2003, 77.3 % of clinics complied with EU requirements, using equipment of 70 kVp, 8 mA, 1.5 mm Al filters, with a collimator length of 20 cm. However, non-compliance was detected in approximately a third (30.8%) of the equipment inspected: alterations in the kilovoltage used, exposure time, performance of the tubing, dosage, linearity/intensity of current and acoustic-luminous signal 6.86%. The mean skin dose reached 3.11 mGy for patients who received an x-ray of an upper molar, representing a decrease of 18% over the seven years studied. Conclusion: there has obviously been a general improvement in the parameters studied, but only 77.3% of the installations complied fully with official EU regulations concerning dental radiological protection

Q1311X: a novel nonsense mutation of putative ancient origin in the von Willebrand factor gene

[EN] Type 3 von Willebrand disease, a recessive autosomally inherited bleeding disorder, refers to complete deficiency of von Willebrand factor (VWF). The novel Q1311X mutation was detected in the homozygous state in four Spanish patients from two apparently unrelated families of gypsy origin. The lack of specific amplification of platelet VWF cDNA from two of the patients indicates reduced levels of mutated gene expression. The similar haplotype linked to mutated alleles suggests a common origin. On the basis of the two instabilities observed and the estimated mutation rate of the microsatellites of intron 40 of the VWF gene, we can estimate that this mutation could have arisen about 2300 years ago.We wish to thank J.M. Montoro and R. Curats for their technical assistance. This work was supported in part by F1S 99/0633.Casaña, P.; Martínez, F.; Haya, S.; Lorenzo, JI.; Espinós-Armero, CÁ.; Aznar, JA. (2000). Q1311X: a novel nonsense mutation of putative ancient origin in the von Willebrand factor gene. British Journal of Haematology. 111(2):552-555. https://doi.org/10.1046/j.1365-2141.2000.02410.x552555111

Protocolo de valorización de residuos en la fabricación de materiales de base cemento: sedimentos dragados como componente de hormigón autocompactante

[ES] La incorporación de los materiales procedentes del dragado como materia prima en la industria de la construcción es uno de los principales objetivos del sector, dada la creciente demanda de este tipo de materiales y la cada vez mayor escasez de los recursos procedentes del interior. La mayor parte de las investigaciones realizadas se han centrado en la reutilización de residuos industriales y de demolición, sin embargo, el uso de materiales procedentes de dragado no ha sido tan ampliamente estudiado y no se han encontrado protocolos para evaluar de forma sistemática su viabilidad como materia prima en la fabricación de materiales con base cemento. En este sentido, el principal objetivo de esta investigación es el diseño de un protocolo que permita evaluar la idoneidad de un residuo procedente de un puerto español como componente de un hormigón autocompactante (SCC). Para ello se realizará un completo análisis químico, mineralógico y granulométrico del sedimento y, una vez comprobada su idoneidad, el éxito de su inclusión como parte del SCC se estudiará mediante ensayos de durabilidad y de compatibilidad medioambiental. Estos ensayos mostrarán que las propiedades del SCC obtenido están de acuerdo con las esperadas para uno convencional fabricado con filler silíceo normal.Esta investigación formó parte del proyecto CLEAM CENIT patrocinado por el Centro Español de Desarrollo Tecnológico Industrial (CDTI) dentro del programa CENIT y ha sido posible gracias al apoyo económico del CDTI y A.I.E. (Asociación de Interés Económico) CLEAM-CENIT. Mención especial a DRAGADOS, que fue el responsable de la coordinación industrial de la tarea en la que se desarrolló este trabajo. Los autores también agradecen al Ministerio de Economía y Competitividad la financiación aportada por el proyecto BIA 2011-25653 '' TELEPASSCLOR '' otorgado en el marco del Plan Nacional de I + D + iRozas, F.; Castillo Talavera, A.; Martínez Sierra, I.; Castellote Armero, M. (2018). Protocolo de valorización de residuos en la fabricación de materiales de base cemento: sedimentos dragados como componente de hormigón autocompactante. En HAC 2018. V Congreso Iberoamericano de hormigón autocompactable y hormigones especiales. Editorial Universitat Politècnica de València. 291-300. https://doi.org/10.4995/HAC2018.2018.5637OCS29130