A Design of New Brands of Martenzite Steels by Artificial Neural Networks

The paper proposes a model-based approach for the design of martenzite structure steels with improved mechanical and plastic characteristics using proper composition and thermal treatment. For that purpose, artificial neural models approximating the dependence of steels strength characteristics on the percentage content of alloying components were trained. These non-linear models are further used within an optimization gradient procedure based on backpropagation of utility function through neural network structure. In order to optimizing the steel characteristics via its chemical composition, several steel brands with high values of tensile strenght, yield strenght and relative elongation were designed. A steel composition having economical alloying and proper for practical application was determined comparing several obtained decisions. The usage of that steel will lead to lightening of the hardware for automobile industry

The Euler-Poisson equations: An elementary approach to integrability conditions

International audienc

On rational integrability of Euler equations on Lie algebra so(4,C)

We consider the Euler equations on the Lie algebra so(4,C) with a diagonal quadratic Hamiltonian. It is known that this system always admits three functionally independent polynomial first integrals. We prove that if the system has a rational first integral functionally independent of the known three ones then it has a polynomial first integral that is also functionally independent of them (so called fourth integral). This is a consequence of more general fact that for these systems the existence of Darboux polynomial with no vanishing cofactor implies the existence of polynomial fourth integral

On rational integrability of Euler equations on Lie algebra so(4, C), revisited

Abstract. We consider the Euler equations on the Lie algebra so(4, C) with a diagonal quadratic Hamiltonian. It is known that this system always admits three functionally independent polynomial first integrals. We prove that if the system has a rational first integral functionally independent of the known three ones (so called fourth integral), then it has a polynomial fourth first integral. This is a consequence of a more general fact that for these systems the existence of a Darboux polynomial with non vanishing cofactor implies the existence of a polynomial fourth integral

Overexpression of UHRF1 gene correlates with the major clinicopathological parameters in urinary bladder cancer

ABSTRACT Introduction Recently, expression of the UHRF1 gene was found to be up-regulated in numerous neoplasms, including the urinary bladder transitional cell carcinoma (TCC). Objective The aim of our study was to determine if the expression levels of UHRF1 gene correlates with the major pathological characteristics of the tumor and patients’ clinical outcome. Materials and Methods In our study, we have analyzed the tissue samples derived from group of 70 patients with histologically confirmed TCC of the urinary bladder, while normal urinary bladder mucosa obtained from 40 patients with nonmalignant diseases was used as a negative control group. Expression of UHRF1 gene in each patient sample was determined using reverse transcriptase-polymerase chain reaction. Results UHRF1 gene expression was found to be app. 2.5 times higher in samples from patients with TCC in comparison with normal epithelium derived from control group patients. Analysis show that gene expression correlates with the malignancy of the tumor. A highly significant differences were found between the expression values of samples from low and high grade TCC, as well as between the high grade and control group. UHRF1 expression was higher in patients with non-muscle invasive disease than in those with muscle invasive disease. Conclusions The result of this study indicates that UHRF1 gene expression levels correlates with the major pathological characteristics of TCC samples and with the clinical outcome of those patients. Determination of UHRF1 gene expression could have a potential to be used as a sensitive molecular marker in patients with urinary bladder cancer

High frequency of the HRAS oncogene codon 12 mutation in Macedonian patients with urinary bladder cancer

Point mutations at codon 12 of the HRAS (v-Ha-ras Harvey rat sarcoma viral oncogene homolog) oncogene are one of the best defined and widely studied molecular genetic events in transitional cell carcinoma (TCC) of the urinary bladder. The aim of this study was to use the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of paraffin-embedded tissue-derived DNA to determine the frequency of the HRAS oncogene G ->T codon 12 mutation in TCC patients being treated at the University Urology Clinic in Skopje, Republic of Macedonia. DNA isolated from paraffin-embedded tissue (PET) surgically removed TCC specimens of 62 (81.58%) out of 76 patients were successfully amplified, the remaining 14 (18.42%) showing compromised DNA integrity. The codon 12 mutation of the HRAS oncogene was found in 24 (38.71%) out of 62 successfully tested TCC urinary bladder samples. No significant relationship between the mutation frequency and the histopathological grade of tumor differentiation was detected (chi² = 0.044; p = 0.978). The relatively high frequency of mutations found in our study was comparable with some of the previously reported data obtained by this and/or other PCR-based methods. This highly sensitive and specific PCR-RFLP analysis was demonstrated to be a suitable method for the detection of mutations at codon 12 of the HRAS oncogene in PET samples of urinary bladder TCC