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

Serum ROBO4 and CLEC14A: preliminary evaluation as diagnostic and progression biomarkers in colorectal cancer patients

Introduction. Colorectal cancer (CRC) is an important global burden, and the discovery of biomarkers for screening and monitoring is a current challenge. The present study aimed to determine the serum concentration of ROBO4 and CLEC14A in CRC patients and assess the diagnostic and progression value of these biomarkers in CRC. Material and methods. Serum samples were collected from 32 patients with CRC and from 16 healthy individuals. Blood serum of CRC patients were tested before and after surgery. Serum concentration of ROBO4 and CLEC14A were measured using ELISA tests. Results. The serum concentrations of ROBO4 and CLEC14A were significantly higher in CRC patients than non-cancer controls. The sensitivitiy and specificity of ROBO4 and CLEC14A in distiguishing cancer patients from controls ranged from 71.9% to 100% and from 84.5% to 100%, respectively. The serum ROBO4 concentration was associated with the TNM stage, depth of invasion, and lymph node and distant metastases. The level of ROBO4 was statistically lower 3 months after the surgery, compared to the level noted prior to the operation. Conclusions. Our preliminary study has provided evidence that ROOB4 and CLEC14A seem to be suitable biomarkers for clinical diagnostic purposes in colorectal cancer

Evaluation of peritoneal tissue by means of differential scanning calorimetry (DSC)

Abdominal surgeries alter the integrity of the peritoneal layer and cause imbalances among immunological, inflammatory and angiogenic mechanisms within the tissue. During laparoscopic procedures a protective function of the peritoneal layer can be disturbed by the gas used to create a pneumoperitoneum. The aim of this study was to characterize peritoneal tissue by means of differential scanning calorimetry (DSC) as a reference for future investigations on the influence of surgical procedures on the physicochemical state of the peritoneum. Thirty-seven patients participated in the study. Patients were divided into three groups according to the type of surgery: group H — patients who underwent hernia repair; group Ch — patients who underwent laparoscopic cholecystectomy; and group C — patients operated due to rectal cancer. It was observed that onset temperature (To), denaturation temperature (Tm) and change of enthalpy (ΔH) during thermal denaturation of peritoneal collagen in were significantly different for these three groups of patients. The mean values of onset temperature (To) and denaturation temperature (Tm) in group H were significantly lower, while DH in this group was significantly higher than in the two other groups (Ch and C). This preliminary study does not answer whether the differences in collagen denaturation found in peritoneal tissue from different groups of patients resulted from a different inherent state of the tissue, or from surgical procedures. However, the results suggest that DSC is an appropriate method to study subtle changes in the physicochemical condition of the peritoneum using small samples obtained during surgical procedures. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 700–705

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

Samotność idei? : społeczeństwo obywatelskie we współczesnym świecie

Publikacja recenzowana / Peer-reviewed publicationCelem niniejszej pracy jest próba przedstawienia kształtu obecnych relacji i stosunków między społeczeństwem obywatelskim a wspomnianymi ideami czy procesami społecznymi.Książka, którą oddajemy do rąk Czytelników jest zbiorem prac studialnych o zróżnicowanym poziomie analizy. Dla części autorów jest to próba pierwszej, samodzielnej pracy naukowo-badawczej, dla innych - kolejna okazja do podzielenia się przemyśleniami, ugruntowanymi wieloletnim doświadczeniem badawczym i studiami.Wszystkich połączyło i skłoniło do współpracy zainteresowanie tym samym - losem społeczeństwa obywatelskiego w zderzeniu z problemami współczesności