A Case of Vanishing Metastatic Mass: Right Atrial Mass in the Setting of Primary Epithelioid Hemangioendothelioma of the Spine

Epithelioid hemangioendothelioma (EHE) is a rare low-grade vascular neoplasm that is characterized as intermediate between benign hemangioma and high-grade angiosarcoma affecting 1 in 1,000,000 people worldwide. It has been described throughout the body with lung, liver, skin, and bone being the most frequent sites. Primary EHE of the spine has been reported in 56 cases so far with no correlation of age and sex. Our case highlights a rare clinical presentation, etiopathogenesis, diagnosis, and treatment of EHE of the spine with metastasis to the right atrium. This is the first documented case of EHE of the spine with metastatic spread to the heart treated with bevacizumab leading to resolution of the heart metastatic mass. Further studies are warranted to develop a treatment formula for this rare tumor, to consider combination chemotherapy and new adjuvant targeted immunotherapies to prevent progression of disease

Material-Specific Investigations of Correlated Electron Systems

We present the results of numerical studies for selected materials with strongly correlated electrons using a combination of the local-density approximation and dynamical mean-field theory (DMFT). For the solution of the DMFT equations a continuous-time quantum Monte-Carlo algorithm was employed. All simulations were performed on the supercomputer HLRB II at the Leibniz Rechenzentrum in Munich. Specifically we have analyzed the pressure induced metal-insulator transitions in Fe2O3 and NiS2, the charge susceptibility of the fluctuating-valence elemental metal Yb, and the spectral properties of a covalent band-insulator model which includes local electronic correlations.Comment: 14 pages, 7 figures, to appear in "High Performance Computing in Science and Engineering, Garching 2009" (Springer

Two-dimensional superconductivity at a Mott-Insulator/Band-Insulator interface: LaTiO3/SrTiO3

Transition metal oxides display a great variety of quantum electronic behaviours where correlations often play an important role. The achievement of high quality epitaxial interfaces involving such materials gives a unique opportunity to engineer artificial structures where new electronic orders take place. One of the most striking result in this area is the recent observation of a two-dimensional electron gas at the interface between a strongly correlated Mott insulator LaTiO3 and a band insulator SrTiO3. The mechanism responsible for such a behaviour is still under debate. In particular, the influence of the nature of the insulator has to be clarified. Here we show that despite the expected electronic correlations, LaTiO3/SrTiO3 heterostructures undergo a superconducting transition at a critical temperature Tc=300 mK. We have found that the superconducting electron gas is confined over a typical thickness of 12 nm. We discuss the electronic properties of this system and review the possible scenarios

Strong electronic correlations in superconducting organic charge transfer salts

We review the role of strong electronic correlations in quasi--two-dimensional organic charge transfer salts such as (BEDT-TTF)$_2X$, (BETS)$_2Y$ and $\beta'$-[Pd(dmit)$_2$]$_2Z$. We begin by defining minimal models for these materials. It is necessary to identify two classes of material: the first class is strongly dimerised and is described by a half-filled Hubbard model; the second class is not strongly dimerised and is described by a quarter filled extended Hubbard model. We argue that these models capture the essential physics of these materials. We explore the phase diagram of the half-filled quasi--two-dimensional organic charge transfer salts, focusing on the metallic and superconducting phases. We review work showing that the metallic phase, which has both Fermi liquid and `bad metal' regimes, is described both quantitatively and qualitatively by dynamical mean field theory (DMFT). The phenomenology of the superconducting state is still a matter of contention. We critically review the experimental situation, focusing on the key experimental results that may distinguish between rival theories of superconductivity, particularly probes of the pairing symmetry and measurements of the superfluid stiffness. We then discuss some strongly correlated theories of superconductivity, in particular, the resonating valence bond (RVB) theory of superconductivity. We conclude by discussing some of the major challenges currently facing the field.Comment: A review: 52 pages; 10 fig

Two-Particle-Self-Consistent Approach for the Hubbard Model

Even at weak to intermediate coupling, the Hubbard model poses a formidable challenge. In two dimensions in particular, standard methods such as the Random Phase Approximation are no longer valid since they predict a finite temperature antiferromagnetic phase transition prohibited by the Mermin-Wagner theorem. The Two-Particle-Self-Consistent (TPSC) approach satisfies that theorem as well as particle conservation, the Pauli principle, the local moment and local charge sum rules. The self-energy formula does not assume a Migdal theorem. There is consistency between one- and two-particle quantities. Internal accuracy checks allow one to test the limits of validity of TPSC. Here I present a pedagogical review of TPSC along with a short summary of existing results and two case studies: a) the opening of a pseudogap in two dimensions when the correlation length is larger than the thermal de Broglie wavelength, and b) the conditions for the appearance of d-wave superconductivity in the two-dimensional Hubbard model.Comment: Chapter in "Theoretical methods for Strongly Correlated Systems", Edited by A. Avella and F. Mancini, Springer Verlag, (2011) 55 pages. Misprint in Eq.(23) corrected (thanks D. Bergeron

Structural matters in HTSC; the origin and form of stripe organization and checker boarding

The paper deals with the controversial charge and spin self-organization phenomena in the HTSC cuprates, of which neutron, X-ray, STM and ARPES experiments give complementary, sometimes apparently contradictory glimpses. The examination has been set in the context of the boson-fermion, negative-U understanding of HTSC advocated over many years by the author. Stripe models are developed which are 2q in nature and diagonal in form. For such a geometry to be compatible with the data rests upon both the spin and charge arrays being face-centred. Various special doping concentrations are closely looked at, in particular p = 0.1836 or 9/49, which is associated with the maximization of the superconducting condensation energy and the termination of the pseudogap regime. The stripe models are dictated by real space organization of the holes, whereas the dispersionless checkerboarding is interpreted in terms of correlation driven collapse of normal Fermi surface behaviour and response functions. The incommensurate spin diffraction below the resonance energy is seen as in no way expressing spin-wave physics or Fermi surface nesting, but is driven by charge and strain (Jahn-Teller) considerations, and it stands virtually without dispersion. The apparent dispersion comes from the downward dispersion of the resonance peak, and the growth of a further incoherent commensurate peak ensuing from the falling level of charge stripe organization under excitation.Comment: 49 pages with 8 figure

Oxidative cyclization of prodigiosin by an alkylglycerol monooxygenase-like enzyme

Prodiginines, which are tripyrrole alkaloids displaying a wide array of bioactivities, occur as linear and cyclic congeners. Identification of an unclustered biosynthetic gene led to the discovery of the enzyme responsible for catalyzing the regiospecific C-H activation and cyclization of prodigiosin to cycloprodigiosin in Pseudoalteromonas rubra. This enzyme is related to alkylglycerol monooxygenase and unrelated to RedG, the Rieske oxygenase that produces cyclized prodiginines in Streptomyces, implying convergent evolution

Osmotic Release Tablets Formulation and Evaluationof Ace Inhibitor Molecule

In the present study the Suitable analytical methods were developed for the drug using UV – visible spectrophotometer. From the Preformulation study and thermal analysis (DSC), the interference was verified and found that the drug did not interfere with the excipient use.Core tablet was successfully prepared by wet granulation using Polyethylene oxide WSR N80, Mannitol 25C, silicon dioxide, magnesium stearate, Polyethylene WSR 303, sodium chloride, hydroxypropyl methylcellulose (HPMC E5), Iron oxide red. Isopropyl cellulose was found to be suitable granulating fluid for binder.Formulation of the drug coating was optimized by using 22 factorial design of experiment.The coated tablets were evaluated for various physicochemical parameter. About  79 to 95% of drug was released from the formulation A-E in 24 hr in 6.8 phosphate buffer.The in vitro drug release data were plotted in zero order kinetics and optimized batch were evaluated on the basis of regression coefficient.The in-vitro drug release from the optimized formulation in the dissertation was directly proportional to the concentration of plasticizer and concentration of cellulose acetate.The manufacturing procedure was standardized and reproducibl

Formulation and Evaulation of Triazolam Odts by Direct Compression Forselection & Optimization of Super Disintegrates

Oral Disintegrating Tablets of Triazolam were formulated with an aim to improve the versatility, patient compliance, and accurate dosing. The formulations ere developed with an objective to use by the pediatric and geriatric patients. Triazolam Oral Disintegrating Tablets were prepared by direct compression method using cross povidone, croscarmellose sodium, sodium starch  glycolate and combinations of CP+CCS, and CP + SSG as super disintegrates exhibited good pre-formulation and tableting properties of three super disintegrates, the formulation contained combination of CP + CCS showed better performance in terms of disintegration time when compared to other formulations. Order of the super disintegrates activity is as follows. (CP + CCS) > (CP + SSG) > CP > CCS >SSG The formulation F15 was found to be the best among all twenty Triazolam ODT formulations because it has exhibited Faster disintegration time (17.66 sec) when compared to the other formulations and it showed 99.87±0.18% drug release at the end of 25 min. Triazolam Oral Disintegrating Films were prepared by solvent casting method using different grades of Hydroxypropyl Methyl Cellulose like HPMC – E15, HPMC – 5cps, HPMC – 50cps. Based on disintegration and dissolution results it was concluded that the formulation F15 contained CP 5% + CCS 5% was the best formulation among all otherformulations

Selection of M. Tuberculosis Clinically Isolated Sensitive & Resistant to Fluoroquinolones

In the present study we observed on performing docking analysis that OFX interacted with conserved residues of Usp, SDR, PspA and CoA transferease domain of Rv2140c, Rv0148, Rv2744c and Rv3551, respectively, which might alter this function. It is predicted that these proteins might be exhibiting increased intensities to inhibit/modulate/compensate the effect of drugs. Further, detailed study in this direction might help to search new targets for drug development. Besides known proteins, upregulation of hypothetical proteins strengthen the possibility of some unknown underlying mechanism responsible for resistance to OFX. This could be crucial for the initial survival of the cells before gene level changes could come into play to ensure survival under prolonged adverse conditions. These findings may be further exploited to develop newer therapeutic agents derived from OFX. Further detailed and in-depth investigations to explore these leads will give an insight into probable sites of drug action, other than established primary sites and hence may help in the search of novel chemotherapeutic agents at these new sites as inhibitors and could provide the mankind with some ultimate treatmentstrategies