Randall-Sundrum limit of f(R) brane-world models

By setting some special boundary conditions in the variational principle we obtain junction conditions for the five-dimensional $f(R)$ gravity which in the Einstein limit $f(R)\rightarrow R$ transform into the standard Randall-Sundrum junction conditions. We apply these junction conditions to a particular model of a Friedmann universe on the brane and show explicitly that the limit gives the standard Randall-Sundrum model Friedmann equation.Comment: 6 pages, no figures, REVTEX4, minor change

Phase II Trial of Dolastatin-10, a Novel Anti-Tubulin Agent, in Metastatic Soft Tissue Sarcomas

Patients:Soft tissue sarcomas are uncommon malignancies with few therapeutic options for recurrent or metastatic disease. Dolastatin-10 (Dol-10) is a pentapeptide anti-microtubule agent that binds to tubulin sites distinct from vinca alkaloids. Based on the novel mechanism of action, limited activity of other anti-microtubular agents, and anti-neoplastic activity in pre-clinical screening of Dol-10, this multi-institutional phase II study was conducted to determine the objective response rate of Dol-10 in recurrent or metastatic soft tissue sarcomas that had not been treated with chemotherapy outside of the adjuvant setting

Gibbons-Hawking Boundary Terms and Junction Conditions for Higher-Order Brane Gravity Models

We derive the most general junction conditions for the fourth-order brane gravity constructed of arbitrary functions of curvature invariants. We reduce these fourth-order theories to second order theories at the expense of introducing new scalar and tensor fields - the scalaron and the tensoron. In order to obtain junction conditions we apply the method of generalized Gibbons-Hawking boundary terms which are appended to the appropriate actions. After assuming the continuity of the scalaron and the tensoron on the brane, we recover junction conditions for such general brane universe models previously obtained by different methods. The derived junction conditions can serve studying the cosmological implications of the higher-order brane gravity models.Comment: REVTEX4, 6 pages, no figures, version to match a JCAP accepted pape

Selektivno određivanje Fe(III) u uzorcima Fe(II) UV-spektrofotometrijom pomoću kvercetina i morina

Selective UV-spectrophotometric methods for determination of iron(III) in iron(II) samples have been developed. The methods are based on the interaction of Fe(III) with quercetin and morin, compounds of the flavonoid group. Redox reactions occurring between Fe(III) ions and the reagents used make the basis for the detection. Iron(II) does not react with quercetin and morin under the conditions applied [aqueous-methanolic (3 : 2) solutions, 0.3 mol L1 HCl, and 1.2 × 10-4 mol L1 quercetin (morin)] and does not interfere with the determination of Fe(III). Iron(III) can be determined up to 15 μg mL1 using both the examined systems. The detection limits are 0.06 and 0.38 μg mL1 when using quercetin or morin, respectively. The method with quercetin was applied to the determination of Fe(III) (ca. 0.2%) in a Fe(II) pharmaceutical product.U radu je opisan razvoj selektivnih UV-spektrofotometrijskih metoda za određivanje željeza(III) u uzorku željeza(II). Metode se temelje na redoks reakciji Fe(III) sa spojevima iz skupine flavonoida kvercetinom i morinom u reakcijskim uvjetima u kojima željezo(II) ne reagira (vodeno/metanolna otopina 3:2, 0,3 mol L1 HCl, 1,2 x 104 mol L1 kvercetin ili morin). Najniža koncentracija željeza(III) koja se može odrediti je 15 μg mL1 u oba ispitivana sustava. Granice detekcije su 0,06 i 0,38 μg mL1 ako se koristi kvercetin, odnosno morfin. Metoda s kvercetinom primijenjena je za određivanje Fe(III (približno 0,2%) u farmaceutskom produktu Fe(II)

Quantum driven Bounce of the future Universe

It is demonstrated that due to back-reaction of quantum effects, expansion of the universe stops at its maximum and takes a turnaround. Later on, it contracts to a very small size in finite future time. This phenomenon is followed by a " bounce" with re-birth of an exponentially expanding non-singular universe

Oxide nanoparticle exsolution in Lu-doped (Ba,La)CoO3

This study investigated Lu doping of BaLaCoO and its influence on the exsolution of oxide nanoparticles (NPs). As a result of Lu doping, we observed the phase segregation into the main BaLaCoLuO (BLCO-Lu) phase and the secondary BaLaCoLuO (BCO-Lu) phase. We noticed the exsolution of BCO-Lu nanoparticles on the main BLCO-Lu phase. Moreover, the BLCO-Lu phase exsolved in the form of nanoparticles on the adjacent BCO-Lu grains. That shows that the phases are covered with mutually exsolved oxide NPs. In addition, trace amounts of the BaLuCoO phase are detected. We noticed that the exsolved oxides even in the as-prepared sample were fine (average size of 18 nm), and well distributed with a dense population of NPs above 280 per 1 μm. Furthermore, we showed that the size and shape of the exsolved oxide NPs can be controlled by varying the annealing temperature. For example, at 800 °C the exsolved oxides segregate and form two different shapes; spherical and cuboidal, with an average size of 31 nm and NP population of about 23 NPs per μm. Meanwhile, with lowering the temperature to 400 °C the oxides form only spherical and quite evenly distributed NPs with the occurrence of 137 NPs per 1 μm. The obtained results open the possibility of tailoring a novel, more catalytically active material for future applications in electrochemical devices.Project FunKeyCat is supported by the National Science Centre, Poland under the M-ERA.NET 2, which has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no 685451. The Research Council of Norway is also acknowledged for support to the Norwegian Center for Transmission Electron Microscopy (NORTEM) (no. 197405/F50)

Screening of cosmological constant for De Sitter Universe in non-local gravity, phantom-divide crossing and finite-time future singularities

We investigate de Sitter solutions in non-local gravity as well as in non-local gravity with Lagrange constraint multiplier. We examine a condition to avoid a ghost and discuss a screening scenario for a cosmological constant in de Sitter solutions. Furthermore, we explicitly demonstrate that three types of the finite-time future singularities can occur in non-local gravity and explore their properties. In addition, we evaluate the effective equation of state for the universe and show that the late-time accelerating universe may be effectively the quintessence, cosmological constant or phantom-like phases. In particular, it is found that there is a case in which a crossing of the phantom divide from the non-phantom (quintessence) phase to the phantom one can be realized when a finite-time future singularity occurs. Moreover, it is demonstrated that the addition of an $R^2$ term can cure the finite-time future singularities in non-local gravity. It is also suggested that in the framework of non-local gravity, adding an $R^2$ term leads to possible unification of the early-time inflation with the late-time cosmic acceleration.Comment: 42 pages, no figure, version accepted for publication in General Relativity and Gravitatio

Reconstruction of the equation of state for the cyclic universes in homogeneous and isotropic cosmology

We study the cosmological evolutions of the equation of state (EoS) for the universe in the homogeneous and isotropic Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) space-time. In particular, we reconstruct the cyclic universes by using the Weierstrass and Jacobian elliptic functions. It is explicitly illustrated that in several models the universe always stays in the non-phantom (quintessence) phase, whereas there also exist models in which the crossing of the phantom divide can be realized in the reconstructed cyclic universes.Comment: 29 pages, 8 figures, version accepted for publication in Central European Journal of Physic

f(R) theories

Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom