Hybrid computer system for the identification of metallic material models on the basis of laboratory experiments

The identification of the proper parameters of material models plays a crucial role in the design of production technologies, especially in the case of modern materials with diversified properties under different boundary conditions. The procedure of identification is usually based on an optimization algorithm that uses sophisticated numerical simulations as a part of the goal function and compares the obtained results with experimental tests. Despite its reliability, such an approach is numerically inefficient. This paper presents the concept of how to replace the most numerically-demanding part of the identification procedure with metamodels, allowing us to maintain uniform result quality. The computer system, which allows us to manage input data, metamodels, and calculations, is proposed and described in detail in this paper. Finally, the proposed approach is validated on the basis of tests performed in the laboratory

On mathematical aspects of evolution of dislocation density in metallic materials

This paper deals with the solution of delay differential equations describing evolution of dislocation density in metallic materials. Hardening, restoration, and recrystallization characterizing the evolution of dislocation populations provide the essential equation of the model. The last term transforms ordinary differential equation (ODE) into delay differential equation (DDE) with strong (in general, H\"older) nonlinearity. We prove upper error bounds for the explicit Euler method, under the assumption that the right-hand side function is H\"older continuous and monotone which allows us to compare accuracy of other numerical methods in our model (e.g. Runge-Kutta), in particular when explicit formulas for solutions are not known. Finally, we test the above results in simulations of real industrial process

Structural analysis and molecular substrate recognition properties of Arabidopsis thaliana ornithine transcarbamylase, the molecular target of phaseolotoxin produced by Pseudomonas syringae

Halo blight is a plant disease that leads to a significant decrease in the yield of common bean crops and kiwi fruits. The infection is caused by Pseudomonas syringae pathovars that produce phaseolotoxin, an antimetabolite which targets arginine metabolism, particularly by inhibition of ornithine transcarbamylase (OTC). OTC is responsible for production of citrulline from ornithine and carbamoyl phosphate. Here we present the first crystal structures of the plant OTC from Arabidopsis thaliana (AtOTC). Structural analysis of AtOTC complexed with ornithine and carbamoyl phosphate reveals that OTC undergoes a significant structural transition when ornithine enters the active site, from the opened to the closed state. In this study we discuss the mode of OTC inhibition by phaseolotoxin, which seems to be able to act only on the fully opened active site. Once the toxin is proteolytically cleaved, it mimics the reaction transition state analogue to fit inside the fully closed active site of OTC. Additionally, we indicate the differences around the gate loop region which rationally explain the resistance of some bacterial OTCs to phaseolotoxin

Genetic background of immune complications after allogeneic hematopoietic stem cell transplantation in children

Immune reactions are among the most serious complications observed after hematopoietic stem cell transplantation (HSCT) in children. Microarray technique allows for simultaneous assessment of expression of nearly all human genes. The objective of the study was to compare the whole genome expression in children before and after HSCT. A total of 33 children referred for HSCT were enrolled in the study. In 70% of the patients HSCT was performed for the treatment of neoplasms. Blood samples were obtained before HSCT and six months after the procedure. Subsequently, the whole genome expression was assessed in leukocytes using GeneChip Human Gene 1.0 ST microarray. The analysis of genomic profiles before and after HSCT revealed altered expression of 124 genes. Pathway enrichment analysis revealed upregulation of five pathways after HSCT: allograft rejection, graft-versus-host disease, type I diabetes mellitus, autoimmune thyroid disease, and viral myocarditis. The activation of those pathways seems to be related to immune reactions commonly observed after HSCT. Our results contribute to better understanding of the genomic background of the immunologic complications of HSCT

Post-traumatic isolated aneurysm of aortic arch surgically repaired

An aneurysm is a permanent localized dilatation of an artery. A trauma is a rare cause of aortic aneurysm. The prognosis of untreated thoracic aneurysm is poor, with 3-year survival rates as low as 25%. Factors that seem to worsen the prognosis are female gender, size greater than 6cm, and traumatic origin. Because of the poor prognosis for the untreated patient and inability to predict rupture, surgical treatment of thoracic aortic aneurysms that result from trauma, even when asymptomatic is justified. The case of a 29 year-old patient, with post-traumatic aortic arch aneurysm qualified for delayed surgery treatment, is presented

The antimicrobial effect of thyme and rosemary essential oils against Listeria monocytogenes in sous vide turkey meat during storage

The research was aimed to study the impact of sous vide thermal treatment on the microbiological quality of fresh turkey breast meat after treatment with thyme and rosemary EOs and the survival of Listeria monocytogenes on the turkey meat samples. The samples were vacuum-packed and cooked at 55 °C, 60 °C, and 65 °C for 5, 15, 30 and, 60 min. There was an amount of 5 g (5 ±0.2 g) of the sample placed in PA/PE film bags and inoculated with 100 μL of L. monocytogenes inoculum. The sample was incubated at 37 °C for 18 h after bag sealing. The samples were tested on the 1st and 3rd days of experiments. The microbiological quality of fresh turkey breast meat was assessed by the detection of total microbial counts and meat microbiota was identified by mass spectrometry using MALDI-TOF MS Biotyper (Bruker Daltonics, Germany). Microbial counts differed significantly depending on temperature and time and the microbial counts ranged from 2.21 log cfu.g-1 to 8.26 log cfu.g-1 on the 1st and 3rd day of the experiment. The study shows that the sous vide method with essential oils combination is an effective method and it can be used to protect the microbiota of turkey meat and L. monocytogens survival, however, the quality of raw material is crucial

Health-related quality of life in Polish adolescents with "Hymenoptera" venom allergy treated with venom immunotherapy

Introduction: Venom allergy, though rare, may seriously influence health-related quality of life (HRQoL). There is a paucity of research on HRQoL of adolescents and young adults with Hymenoptera venom allergy. The aim was to assess the level of HRQoL and to evaluate its independent predictors in Polish adolescents and young adults treated with venom immunotherapy. Material and methods: A multicenter cross-sectional study based on the Vespid Allergy Quality of Life Questionnaire (VQLQ) adapted for Polish adolescents was used. The study sample included 87 patients (14-21 years) studied at different stages of venom immunotherapy (VIT). Statistical analysis was done with multivariate linear regression. Results: Anxiety level was higher in patients with 4th grade of Mueller’s classification (anaphylactic shock) than in those with 3rd grade (B = 0.84, 95% CI = 0.07-1.61, p = 0.03). Caution increased along with an increase of anxiety of adolescents treated with VIT (B = 0.54, 95% CI = 0.39-0.68, p < 0.01). Level of limitations increased with increasing caution of adolescents (B = 0.63, 95% CI = 0.35-0.91, p < 0.01). Discomfort increased along with a rise of caution of patients (B = 0.38, 95% CI = 0.22-0.55, p < 0.01). Similarly, it increased with an increase of their feeling of limitations (B = 0.37, 95% CI = 0.23-0.51, p < 0.01). The level of discomfort in adolescents treated with VIT was lower in those who were treated with conventional protocol in comparison to those treated with rush or ultrarush ones (B = –0.47, 95% CI = –0.90 - –0.03, p = 0.04). Conclusions: Severity of anaphylactic reaction is an independent determinant of anxiety level in adolescents treated with VIT. The VIT protocol affects HRQoL of treated patients

Theoretical validity and reliability of Vespide Quality of Life Questionnaire in Polish adolescents with Hymenoptera venom allergy

Measurement of health-related quality of life is mostly used with advanced measurement tools, such as scales. The use of a certain scale in different cultural settings or in age groups other than those it was designed for needs conducting the adaptation process and assessment of psychometric properties of the adapted scale. This paper presents the results of theoretical validity and reliability analysis of the Polish adaptation of the VQLQ scale for adolescents with Hymenoptera venom allergy. The study sample consisted of 78 adolescents aged 14-19 years, who were treated with venom immunotherapy in Polish allergological centers in 2008 year. Theoretical validity of the scale was analyzed with exploratory factor analysis using the principal components method. Reliability analysis was assessed in terms of internal consistency with Cronbach's α coefficient and by testing Kline's criterion. The results showed satisfactory validity of the scale: factor analysis revealed a 3-factor structure of the scale - extracted factors were described as anxiety, caution and discomfort. All the scale items contributed to unique factors, except for one item concerning limitation in summer due to allergy, which was identified as a separate dimension of health-related quality of life of Polish adolescents with Hymenoptera venom allergy. All the extracted subscales were characterized by values of α coefficient equal or higher than 0.8, what is usually considered as a high-level reliability coefficient. The adapted scale is a valid and reliable tool measuring health-related quality of life in Polish adolescents treated with venom-specific immunotherapy