A novel approach for vibration analysis of fractional viscoelastic beams with attached masses and base excitation

The Galerkin method is widely applied for finding approximate solutions to vibration problems of beam and plate structures and for estimating their dynamic behavior. Most studies employ the Galerkin method in the analysis of the undamped systems, or for simple structure models with viscous damping. In this paper, a novel approach of using the Galerkin method and Fourier transform to find the solution to the problem of vibration of fractionally damped beams with an arbitrary number of attached concentrated masses and base excitation is presented. The considered approach is novel and it lends itself to determination of the impulse response of the beam and leads to the solution of the system of coupled fractional order differential equations. The proposed approximate solution is validated against the exact solution for a special case with only one tip mass attached, as well as against the Finite Element Method Solution for a special case with classical viscous damping model. Numerical analysis is also given, including the examples of vibration analysis of viscoelastic beams with different fractional derivative orders, retardation times, and the number, weight and position of the attached masses

Assessing the symptoms of Internet Gaming Disorder among college/university students: An international validation study of a self-report

The present study evaluated the psychometric properties of a self-report scale for assessing Internet Gaming Disorder (IGD) symptoms according to the DSM-5 and ICD-11 among 3270 college/university students (2095 [64.1%] females; age mean 21.6 [3.1] years) from different countries worldwide. Croatian, English, Polish, Portuguese, Serbian, Turkish, and Vietnamese versions of the scale were tested. The study showed that symptoms of IGD could be measured as a single underlying factor among college/university students. A nine item-symptom scale following DSM-5, and a short four-item scale representing the main ICD-11 symptoms, had sound internal consistency and construct validity. Three symptom-items were found non-invariant across the language samples (i.e., preoccupation with on-line gaming, loss of interests in previous hobbies and entertainment, and the use of gaming to relieve negative moods). This study provides initial evidence for assessing IGD symptoms among college/university students and will hopefully foster further research into gaming addiction in this population worldwide especially with taking into account language/cultural differences

Original paper GENE EXPRESSION ANALYSIS BY NON-RADIOACTIVE RNA-RNA IN SITU HYBRIDIZATION TECHNIQUES

Summary: RNA-RNA in situ hybridization is a reliable method for studying tissue and cell specific gene expression, which enables visualization of labeled antisense RNA probe hybridized to specific mRNA. In this study we employed non-radioactive RNA-RNA in situ hybridization using biotin- or digoxigenin-labeled RNA probes in order to detect SOX gene expression in carcinoma cell lines. By this approach we confirmed results obtained by Northern blot analysis, where the presence of SOX2 mRNA in NT2/D1 and SOX14 mRNA in HepG2 cells has been established. Our aim was to set up RNA-RNA in situ hybridization method in in vitro cultured cells in order to perform further analyses of SOX gene expression on various normal and cancer tissues. Key words: in situ hybridization, non-radioactively labeled RNA probes, human SOX genes, carcinoma cell line

NUMERICAL SIMULATION OF FIRE SPREAD IN TERMINAL 2 OF BELGRADE AIRPORT

This pa per con cern the re sults of soft ware fire spread pro cess pro to type in ter mi nal 2 of Bel grade air port us ing com pu ta tional fluid dy nam ics. Nu mer-i cal sim u la tion of fire for the most crit i cal fire sce nario has been per formed, pri mar ily ob tain ing the space and time dis tri bu tion of: ve loc ity, pres sure, tem per a ture, and smoke con cen tra tion, as sum ing that HVAC sys tems have been switched off and all doors on the evac u a tion ways have been opened, just as the fire started. Also, two sim u la tions have been com pared of the smoke ven ti la tion and not ven ti la tion for the same sce nario. Within the frame work of the re sults pre sen ta tion, isosurfaces of con stant tem per a ture (100 ºC) and smoke con cen tra tion (4000 ppm) are pre sented, based on the nu mer i cal sim u la tion. Pro gres sion of these sur faces along the ter mi nal 2 co in cides to the ex per i men tal and ex pe ri ence ev i dence, form ing the plume zone just above the fire place, and spread ing in the zone of un der ground ceil ing and stair well open ings. Key words: fire spreading simulation, computational fluid dynamic

SHORT COMMUNICATION

Abstract: The vitamin B12-catalyzed glycosylation reaction of brominated �-D-xylose peracetate with alkanols ROH (C1-C8) has been studied. The catalytically active species in this reaction was cob(I)alamin, obtained by chemical reduction of Vitamin B12 with NaBH4 (Co(III) to Co(I)). The reaction was carried out with 2 mol % of vitamin B12, with respect to xylosyl bromide 1, under argon at room temperature. Under these conditions, peracetylated C1-C8-alkyl �-D-xylopyranosides (3a–3f) were obtained in moderate yield (55–70 %). In all cases 3,4-di-O-acetyl-D-xylal (4) was obtained, as the product of reductive elimination of peracetylated xylosyl bromide (15–25 %)

JSCS–3552 Original scientific paper

Isolation of thymus gland fractions and the determination of their biological activit

TRANS-ACTIVATION OF THE HUMAN SOX3 PROMOTER BY MAZ IN NT2/D1 CELLS

Abstract — In this study, we examine the role of three highly conserved putative binding sites for Myc-associated zinc finger protein (MAZ) in regulation of the human SOX3 gene expression. Electrophoretic mobility shift and supershift assays indicate that complexes formed at two out of three MAZ sites of the human SOX3 promoter involve ubiquitously expressed MAZ protein. Furthermore, in cotransfection experiments we demonstrate that MAZ acts as a positive regulator of SOX3 gene transcription in both undifferentiated and RA-differentiated NT2/D1 cells. Although MAZ increased both basal and RA-induced promoter activity, our results suggest that MAZ does not contribute to RA inducibility of the SOX3 promoter during neuronal differentiation of NT2/D1 cells