Sofia University

About: Sofia University is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Large Hadron Collider & Standard Model. The organization has 8533 authors who have published 15730 publications receiving 306320 citations. The organization is also known as: University of Sofia & BFUS.

Prognostic factors in survival of patients with stage Ta and T1 bladder urothelial tumors: the role of G1-S modulators (p53, p21Waf1, p27Kip1, cyclin D1, and cyclin D3), proliferation index, and clinicopathologic parameters.

Abstract: We studied 159 cases of superficial (stage Ta or T1) bladder tumors to determine the significance on survival of a subset of regulators of transition from G 1 to S phase of the cell cycle (p53, p21 Waf1, p27Kip1, cyclin Dl, cyclin D3) and tumor proliferation (Ki-67 [MIB-1]). Clinical findings (patient age, sex, tumor size, grade, stage [Ta or T1]) were included in the analysis. Univariate analysis revealed association of tumor size (P = .0353), grade in stage Ta tumors (P = .0074), cyclin D1 expression (P = .0182), and Ki-67 index (P = .0033) with disease-free survival and of tumor size (P = .0005), stage (P = .0494), cyclin D3 expression (P = .0105), and Ki-67 index (P = .0272) with overall survival. Cox multivariate analysis revealed cyclin D1 expression and high proliferation index (disease-free) and tumor size, cyclin D3 expression, and high proliferation index (overall survival) as independent predictors. Results suggest that alterations of the progression from the G 1 to S phase of the cell cycle are common in papillary urothelial bladder tumors. High tumor proliferation, expression of cyclins Dl and D3, and tumor size at diagnosis might be relevant predictors of survival in patients with stage Ta and Tl bladder urothelial tumors.

Diffusion of charged colloidal particles at low volume fraction: Theoretical model and light scattering experiments

Abstract: An appropriate mean force potential was utilized in Felderhof's Theory to derive simple analytical expressions for the concentration dependence of the collective and short time self diffusion coefficients, as well as for the sedimentation velocity of charged spherical particles. It is demonstrated theoretically that the osmotic viriat and the Oseen hydrodynamic terms play a dominant role. To check the theoretical model, the dependence of the collective diffusion coefficient on the volume fraction of latex particles was experimentally studied. Dynamic light scattering was used at several different concentrations of electrolyte. It turns out that our experimental results, as well as the results of other authors, are in very good agreement with the proposed theoretical model. The results show that the increase of the electrolyte concentration leads to increase of the particle charge, but almost does not change the particle surface potential. A minimum in the dependence of the diffusion coefficient of a single particle on the ionic strength was also obtained. © 1992 Academic Press, Inc.

Search for top squarks and dark matter particles in opposite-charge dilepton final states at s = 13 TeV

Abstract: A search for new physics is presented in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from b quarks, and missing transverse momentum (pTmiss). The search uses proton-proton collision data at s=13 TeV amounting to 35.9 fb-1 of integrated luminosity collected using the CMS detector in 2016. Hypothetical signal events are efficiently separated from the dominant tt¯ background with requirements on pTmiss and transverse-mass variables. No significant deviation is observed from the expected background. Exclusion limits are set in the context of simplified supersymmetric models with pair-produced top squarks. For top squarks, decaying exclusively to a top quark and a neutralino, exclusion limits are placed at 95% confidence level on the mass of the lightest top squark up to 800 GeV and on the lightest neutralino up to 360 GeV. These results, combined with searches in the single-lepton and all-jet final states, raise the exclusion limits up to 1050 GeV for the lightest top squark and up to 500 GeV for the lightest neutralino. For top squarks undergoing a cascade decay through charginos and sleptons, the mass limits reach up to 1300 GeV for top squarks and up to 800 GeV for the lightest neutralino. The results are also interpreted in a simplified model with a dark matter (DM) particle coupled to the top quark through a scalar or pseudoscalar mediator. For light DM, mediator masses up to 100 (50) GeV are excluded for scalar (pseudoscalar) mediators. The result for the scalar mediator achieves some of the most stringent limits to date in this model.

Dietary fat modifies the postprandial inflammatory state in subjects with metabolic syndrome: the LIPGENE study

Abstract: Scope Our aim was to investigate whether the inflammatory state associated to metabolic syndrome (MetS) patients is affected by diets with different fat quality and quantity. Methods and results Seventy-five subjects from LIPGENE cohort were included in this feeding trial and randomly assigned to one of four diets: high saturated fatty acids (HSFA); high monounsaturated fatty acids (HMUFA) and two low-fat, high complex carbohydrate (LFHCC) diets, supplemented with long-chain n-3 polyunsaturated fatty acids (LFHCC n-3) or placebo (LFHCC), for 12 weeks each. A postprandial fat challenge, reflecting the intervention dietary fat composition, was conducted post-intervention. The HMUFA diet significantly reduced postprandial nuclear transcription factor-kappaB (NF-kB) activity and the nuclear p65 protein levels relative to fasting values (p < 0.05). Furthermore, we observed a postprandial decrease in this protein with the HMUFA diet compared with the HSFA and LFHCC diets (p < 0.05). The postprandial response of inhibitory molecule from NF-kB mRNA levels increased with the HMUFA diet compared with the HSFA and LFHCC n-3 diets (p < 0.05). Postprandial tumor necrosis factor-α and Metalloproteinase 9 mRNA levels were also reduced after the HMUFA diet compared with the HSFA diet (p < 0.05). Conclusion Our results indicate that the long-term consumption of a healthy diet model with HMUFA attenuates the postprandial inflammatory state associated with MetS.