Extended Gaussian ensemble or q-statistics in hadronic production processes?

The extended Gaussian ensemble introduced recently as a generalization of the canonical ensemble, which allows to treat energy fluctuations present in the system, is used to analyze the inelasticity distributions in high energy multiparticle production processes.Comment: Presented at NEXT2005 (News, Expectations and Trends in Statistical Physics, NEXT-SigmaPhi 3rd International Conference) 13-18 August 2005, Kolymbari CRETE, minor corrections, to be published in Europ. Phys. J. B (2006

Enhanced Platinum (II) Drug Delivery for Anti-cancer Therapy

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism of action is based on inhibition of cancer cell replication via binding to nuclear DNA. However, circulating cisplatin binds to glutathione and other proteins in the blood compartment, diminishing the concentration of the free drug available for therapy. Also, highly potent cisplatin is associated with severe side effects, limiting the dosage of Pt(II) that can be administered in the clinic. The next generation Pt(II) drugs aim at sustaining the same effectiveness while improving systemic toxicity. Carboplatin is a second-generation Pt-based agent approved by the Food and Drug Administration (FDA). Slower hydrolysis times for carboxylate ligands in carboplatin, compared to rather fast times for chlorine ligands in cisplatin, lead to longer blood circulation times and lesser side effects. The therapeutic effect of carboplatin is comparable with cisplatin in some tumors, but it requires higher drug dosages, and the survival rate did not improve. The problems above associated with free Pt(II)-based therapy created a need for the development of more efficient drug delivery systems. These include targeted drug delivery such as an antibody or protein conjugates or nanoparticle (NP)-mediated drug delivery, e.g., by using liposomes, polymeric or oil-based NPs, among other approaches. This dissertation presents two alternative drug delivery systems for Pt(II)-based agents: peptide conjugate and a NP. These systems are tested in OC models, where Pt (II) therapy is a golden standard. Chapter II focuses on a peptide-drug conjugate of nuclear localization sequence (NLS) peptide-carboplatin-like complex. Nuclear localization sequence peptides target nuclear transport protein, delivering the therapeutic payload into a cancer cell\u27s nucleus. NLS-Pt(II) conjugate demonstrated enhanced therapeutic effect in vitro in OC cell lines when compared to carboplatin. Conjugation of carboplatin-like complexes with NLS peptide also drastically increased the solubility of Pt(II) drug in an aqueous media. Chapter III focuses on targeted and pH-sensitive polymeric NP to deliver Pt(II). Poly lactic-co-glycolic acid (PLGA)-based NPs are explored, as the PLGA is biodegradable, biocompatible, and, most importantly, approved by the FDA. The NP\u27s corona contains phospholipids and custom-synthesized pH-sensitive polyethylene glycol (PEG)-phospholipid coating. A DNA-aptamer against mucin 1 (MUC1), which is overexpressed in OC cells, is added as an active targeting ligand. The NP design takes advantage of a slightly acidic environment around cancer cells (pH~6.8) to disintegrate PEG-based NP\u27s coating and to expose the aptamer targeting ligands facilitating a fast NP uptake through receptor-mediated endocytosis. Slow intracellular degradation of the NP leads to sustained release of Pt(II). The NPs showed higher cytotoxicity in vitro when compared to free carboplatin, and the NPs effectively accumulated in the tumor tissue in vivo. Importantly, the NP platform can be easily modified. The ease of functionalization of PLGA with other drugs, as well as the choice of different targeting aptamers, can extend the applications of the proposed NP platform to other disease types

Multivalued SK-contractions with respect to b-generalized pseudodistances

A new class of multivalued non-self-mappings, called SK-contractions with respect to b-generalized pseudodistances, is introduced and used to investigate the existence of best proximity points by using an appropriate geometric property. Some new fixed point results in b-metric spaces are also obtained. Examples are given to support the usability of our main result

Entrepreneurial training curriculum assessment: The case of new venture creation learnerships

This paper joins the debate about how best to assess entrepreneurial training interventions, using a case-study. Contextual secondary literature about the structure and content of such interventions is briefly reviewed. Based on this review, a framework is developed and applied to the Provincial Skills Development Pilot Project’s current New Venture Creation Learnership programme. This in-depth case study uses an evaluation instrument based on the entrepreneurial assessment model proposed by Pretorius (2001: 264). Results show that the chosen programme exhibits certain limitations, which restricts its success in developing entrepreneurs in line with the National Skills Development Strategy. However, the programme possesses many strengths and its limitations are easily remedied. The proposed assessment method successfully identifies the strengths and weaknesses of the programme

The Fractal Properties of the Source and BEC

Using simple space-time implementation of the random cascade model we investigate numerically influence of the possible fractal structure of the emitting source on Bose-Einstein correlations between identical particles. The results are then discussed in terms of the non-extensive Tsallis statistics.Comment: LaTeX file and 2 PS files with figures, 8 pages altogether. Talk presented at the 12th Indian Summer School "Relativistic Heavy Ion Physics, Prague, Czech Republic, 30 August-3 Sept. 1999; to be published in Czech J. Phys. (1999). Some typos correcte

Non equilibrium anisotropic excitons in atomically thin ReS2_2

We present a systematic investigation of the electronic properties of bulk and few layer ReS$_2$ van der Waals crystals using low temperature optical spectroscopy. Weak photoluminescence emission is observed from two non-degenerate band edge excitonic transitions separated by $\sim$ 20 meV. The comparable emission intensity of both excitonic transitions is incompatible with a fully thermalized (Boltzmann) distribution of excitons, indicating the hot nature of the emission. While DFT calculations predict bilayer ReS$_2$ to have a direct fundamental band gap, our optical data suggests that the fundamental gap is indirect in all cases

Transverse Momentum Spectra of Pions in Particle and Nuclear Collisions and Some Ratio-Behaviours: Towards A Combinational Approach

The nature of transverse momentum dependence of the inclusive cross-sections for secondary pions produced in high energy hadronic($PP$), hadronuclear($PA$) and nuclear($AA$) collisions has here been exhaustively investigated for a varied range of interactions in a unified way with the help of a master formula. This formula evolved from a new combination of the basic Hagedorn's model for particle(pion) production in PP scattering at ISR range of energies, a phenomenological approach proposed by Peitzmann for converting the results of $NN(PP)$ reactions to those for either $PA$ or $AA$ collisions, and a specific form of parametrization for mass number-dependence of the nuclear cross sections. This grand combination of models(GCM) is then applied to analyse the assorted extensive data on various high energy collisions. The nature of qualitative agreement between measurements and calculations on both the inclusive cross-sections for production of pions, and some ratios of them as well, is quite satisfactory. The modest successes that we achieve here in dealing with the massive data-sets are somewhat encouraging in view of the diversity of the reactions and the very wide range of interaction energies.Comment: 19 pages, 19 figure

CASTOR: Centauro and Strange Object Research in nucleus-nucleus collisions at LHC

We describe the CASTOR detector designed to probe the very forward, baryon-rich rapidity region in nucleus-nucleus collisions at the LHC. We present a phenomenological model describing the formation of a QGP fireball in a high baryochemical potential environment, and its subsequent decay into baryons and strangelets. The model explains Centauros and the long-penetrating component and makes predictions for the LHC. Simulations of Centauro-type events were done. To study the response of the apparatus to new effects different exotic species (DCC, Centauros, strangelets etc.) were passed through the deep calorimeter. The energy deposition pattern in the calorimeter appears to be a new clear signature of the QGP.Comment: Talk given by E. Gladysz-Dziadus for the CASTOR group, Intern. Workshop on Nuclear Theory, 10-15 June, 2002, Bulgaria, Rila Mountains, 15 pages, 14 figure

Total Cross Section, Inelasticity and Multiplicity Distributions in Proton -- Proton Collisions

Multiparticle production in high energy proton -- proton collisions has been analysed in the frame of Strongly Correlated Quark Model (SCQM) of the hadron structure elaborated by the author. It is shown that inelasticity decreases at high energies and this effect together with the total cross section growth and the increasing with collision energy the masses of intermediate clusters result in the violation of KNO -- scaling.Comment: 21 pages, 11 figures, submitted to Yad. Fisik