Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Unsteady Pressure Analysis of a Swirling Flow With Vortex Rope and Axial Water Injection in a Discharge Cone

Abstract: The variable demand of the energy market requires that hydraulic turbines operate atvariable conditions, which includes regimes far from the best efficiency point. The vortexrope developed at partial discharges in the conical diffuser is responsible for large pres-sure pulsations, runner blades breakdowns and may lead to power swing phenomena. Anovel method introduced by Resiga et al. (2006, “Jet Control of the Draft Tube in FrancisTurbines at Partial Discharge,” Proceedings of the 23rd IAHR Symposium on HydraulicMachinery and Systems, Yokohama, Japan, Paper No. F192) injects an axial water jetfrom the runner crown downstream in the draft tube cone to mitigate the vortex rope andits consequences. A special test rig was developed at “Politehnica” University of Timi-soara in order to investigate different flow control techniques. Consequently, a vortexrope similar to the one developed in a Francis turbine cone at 70% partial discharge isgenerated in the rig’s test section. In order to investigate the new jet control method anauxiliary hydraulic circuit was designed in order to supply the jet. The experimentalinvestigations presented in this paper are concerned with pressure measurements at thewall of the conical diffuser. The pressure fluctuations’ Fourier spectra are analyzed inorder to assess how the amplitude and dominating frequency are modified by the waterinjection. It is shown that the water jet injection significantly reduces both the amplitudeand the frequency of pressure fluctuations, while improving the pressure recovery in theconical diffuser. [DOI: 10.1115/1.4007074]Keywords: decelerated swirling flow, vortex rope, water injection method, unsteadypressure, experimental investigation

The Selective Estrogen Receptor Modulator Bazedoxifene Inhibits Hormone-Independent Breast Cancer Cell Growth and Down-Regulates Estrogen Receptor α and Cyclin D1

Abstract: Bazedoxifene (BZA) is a third-generation selective estrogen receptor modulator (SERM) that has been approved for the prevention and treatment of postmenopausal osteoporosis. It has antitumor activity; however, its mechanism of action remains unclear. In the present study, we characterized the effects of BZA and several other SERMs on the proliferation of hormone-dependent MCF-7 and T47D breast cancer cells and hormone-independent MCF-7:5C and MCF-7:2A cells and examined its mechanism of action in these cells. We found that all of the SERMs inhibited the growth of MCF-7, T47D, and MCF-7:2A cells; however, only BZA and fulvestrant (FUL) inhibited the growth of hormone-independent MCF-7:5C cells. Cell cycle analysis revealed that BZA and FUL induced G1 blockade in MCF-7:5C cells; however, BZA down-regulated cyclin D1, which was constitutively overexpressed in these cells, whereas FUL suppressed cyclin A. Further analysis revealed that small interfering RNA knockdown of cyclin D1 reduced the basal growth of MCF-7:5C cells, and it blocked the ability of BZA to induce G1 arrest in these cells. BZA also down-regulated estrogen receptor-α (ERα) protein by increasing its degradation and suppressing cyclin D1 promoter activity in MCF-7:5C cells. Finally, molecular modeling studies demonstrated that BZA bound to ERα in an orientation similar to raloxifene; however, a number of residues adopted different conformations in the induced-fit docking poses compared with the experimental structure of ERα-raloxifene. Together, these findings indicate that BZA is distinct from other SERMs in its ability to inhibit hormone-independent breast cancer cell growth and to regulate ERα and cyclin D1 expression in resistant cells.

DNA computing, sticker systems, and universality ?

Abstract: We introduce the sticker systems, a computability model, which is an abstraction of the computations using the Watson-Crick complementarity as in Adleman's DNA computing experiment, [1]. Several types of sticker systems are shown to characterize (modulo a weak coding) the regular languages, hence the power of finite automata. One variant is proven to be equivalent to Turing machines. Another one is found to have a strictly intermediate power.