Transverse momentum dependence of directed particle flow at 160 AGeV

The transverse momentum ($p_t$) dependence of hadron flow at SPS energies is studied. In particular, the nucleon and pion flow in S+S and Pb+Pb collisions at 160 AGeV is investigated. For simulations the microscopic quark-gluon string model (QGSM) is applied. It is found that the directed flow of pions $v_1(y, \Delta p_t)$ changes sign from a negative slope in the low-$p_t$ region to a positive slope at $p_t \geq 0.6$ GeV/c as recently also observed experimentally. The change of the flow behaviour can be explained by early emission times for high-$p_t$ pions. We further found that a substantial amount of high-$p_t$ pions are produced in the very first primary NN collisions at the surface region of the touching nuclei. Thus, at SPS energies high-$p_t$ nucleons seem to be a better probe for the hot and dense early phase of nuclear collisions than high-$p_t$ pions. Both, in the light and in the heavy system the pion directed flow $v_1(p_t, \Delta y)$ exhibits large negative values when the transverse momentum approaches zero, as also seen experimentally in Pb+Pb collisions. It is found that this effect is caused by nuclear shadowing. The proton flow, in contrary, shows the typical linear increase with rising $p_t$.Comment: REVTEX, 20 pages incl. 6 figures, revised and extended versio

Pair-Hopping Mechanism for Layered Superconductors

We propose a possible charge fluctuation effect expected in layered superconducting materials. In the multireference density functional theory, relevant fluctuation channels for the Josephson coupling between superconducting layers include the interlayer pair hopping derived from the Coulomb repulsion. When interlayer single-electron tunneling processes are irrelevant in the Kohn-Sham electronic band structure calculation, the two-body effective interactions stabilize a superconducting phase. This state is also regarded as a valence-bond solid in a bulk electronic state. The hidden order parameters coexist with the superconducting order parameter when the charging effect of a layer is comparable to the pair hopping. Relevant materials structures favorable for the pair-hopping mechanism are discussed.Comment: 24 pages, 2 figures, to be published in J. Phys. Soc. Jpn. (2009

Dilepton production in heavy ion collisions at intermediate energies

We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The theoretical framework is an extended vector meson dominance model (eVMD). The treatment of the resonance decays $R\longmapsto NV$ with arbitrary spin is covariant and kinematically complete. The eVMD includes thereby excited vector meson states in the transition form factors. This ensures correct asymptotics and provides a unified description of photonic and mesonic decays. The resonance model is successfully applied to the $\omega$ production in $p+p$ reactions. The same model is applied to the dilepton production in elementary reactions ($p+p, p+d$). Corresponding data are well reproduced. However, when the model is applied to heavy ion reactions in the BEVALAC/SIS energy range the experimental dilepton spectra measured by the DLS Collaboration are significantly underestimated at small invariant masses. As a possible solution of this problem the destruction of quantum interference in a dense medium is discussed. A decoherent emission through vector mesons decays enhances the corresponding dilepton yield in heavy ion reactions. In the vicinity of the $\rho/\omega$-peak the reproduction of the data requires further a substantial collisional broadening of the $\rho$ and in particular of the $\omega$ meson.Comment: 32 pages revtex, 19 figures, to appear in PR

Isospin Physics in Heavy-Ion Collisions at Intermediate Energies

In nuclear collisions induced by stable or radioactive neutron-rich nuclei a transient state of nuclear matter with an appreciable isospin asymmetry as well as thermal and compressional excitation can be created. This offers the possibility to study the properties of nuclear matter in the region between symmetric nuclear matter and pure neutron matter. In this review, we discuss recent theoretical studies of the equation of state of isospin-asymmetric nuclear matter and its relations to the properties of neutron stars and radioactive nuclei. Chemical and mechanical instabilities as well as the liquid-gas phase transition in asymmetric nuclear matter are investigated. The in-medium nucleon-nucleon cross sections at different isospin states are reviewed as they affect significantly the dynamics of heavy ion collisions induced by radioactive beams. We then discuss an isospin-dependent transport model, which includes different mean-field potentials and cross sections for the proton and neutron, and its application to these reactions. Furthermore, we review the comparisons between theoretical predictions and available experimental data. In particular, we discuss the study of nuclear stopping in terms of isospin equilibration, the dependence of nuclear collective flow and balance energy on the isospin-dependent nuclear equation of state and cross sections, the isospin dependence of total nuclear reaction cross sections, and the role of isospin in preequilibrium nucleon emissions and subthreshold pion production.Comment: 101 pages with embedded epsf figures, review article for "International Journal of Modern Physics E: Nuclear Physics". Send request for a hard copy to 1/author

Curcumin-induced inhibition of cellular reactive oxygen species generation: novel therapeutic implications

There is evidence for increased levels of circulating reactive oxygen species (ROS) in diabetics, as indirectly inferred by the findings of increased lipid peroxidation and decreased antioxidant status. Direct measurements of intracellular generation of ROS using fluorescent dyes also demonstrate an association of oxidative stress with diabetes. Although phenolic compounds attenuate oxidative stress-related tissue damage, there are concerns over toxicity of synthetic phenolic antioxidants and this has considerably stimulated interest in investigating the role of natural phenolics in medicinal applications. Curcumin (the primary active principle in turmeric, Curcuma longa Linn.) has been claimed to represent a potential antioxidant and antiinflammatory agent with phytonutrient and bioprotective properties. However there are lack of molecular studies to demonstrate its cellular action and potential molecular targets. In this study the antioxidant effect of curcumin as a function of changes in cellular ROS generation was tested. Our results clearly demonstrate that curcumin abolished both phorbol-12 myristate-13 acetate (PMA) and thapsigargin-induced ROS generation in cells from control and diabetic subjects. The pattern of these ROS inhibitory effects as a function of dose-dependency suggests that curcumin mechanistically interferes with protein kinase C (PKC) and calcium regulation. Simultaneous measurements of ROS and Ca2+ influx suggest that a rise in cytosolic Ca2+ may be a trigger for increased ROS generation. We suggest that the antioxidant and antiangeogenic actions of curcumin, as a mechanism of inhibition of Ca2+ entry and PKC activity, should be further exploited to develop suitable and novel drugs for the treatment of diabetic retinopathy and other diabetic complications

Maxillary Tumor in the Base of the Skull

A large bony swelling in the region of body of maxilla with extension to nasal, zygomatic and palatal region suspected to be a malignant tumor or aggressive benign tumor is clinically recorded and investigated. Conventional radiograph of skull reveals that a radiopacity in the region of body of maxilla obliterating the maxillary antrum with areas of radiolucency. The radiopacity extends to nasal, zygomatic, palatal and lateral wall of the nose. Computerized Tomography image revealed in both coronal and axial view, a well-defined soft tissue mass with areas of calcifications. The mass extended to the base of the skull towards the lateral part of the sphenoid sinus. The margins are well defined and not infiltrative in nature. Biopsy revealed that it was a cemento-ossifying fibroma. Thus a swelling clinically appeared as malignant tumor was diagnosed as benign tumor with extension to the base of the skull without any complications. The case is presented and discussed

Knowledge, attitude and perception on OPMD among oral medicine specialists

BACKGROUND: Oral potentially malignant disorders are common oral mucosal lesions associated with tobacco habit mainly and few congenital, immunologically mediated mucocutaneous disorders with increased risk for malignant transformation diseases. Aim: The aim of this questionnaire study is to assess the awareness of evidence based medical management of OPMDs among oral medicine specialists in a university setting. The questionnaire based study was conducted among 100 participants. A self-administered questionnaire was used. Sampling was done by convenient sampling. The study was done in a university setting. The questionnaires were distributed to the post graduates and teaching faculties with varied teaching experience in Oral medicine speciality. It was circulated using an online search software, google form and the response was collected through it. CONCLUSION: The collected data was ranked as good, average and below average and the data collected were stored and results were analysed by SPSS software. Out of 100, the need of educational programs exclusively on topical therapeutics in management of oral mucosal lesions to be initiated from the beginning of post-graduation course and educational programs on current updates of topical therapeutics is essential for Oral Medicine Specialist to ensure proper treatment protocol in dental practice

Tuberculous Granuloma

Tuberculosis is a chronic granulomatous disease caused by Mycobacterium tuberculosis. There are two forms namely primary and secondary tuberculosis. Pulmonary tuberculosis is the most common form of primary tuberculosis. Primary tuberculosis in extrapulmonary site, though very uncommon, can occur in any site such as skin, brain, bone, eye, genitourinary tract and oral cavity. A 50-year-old male reported with complaint of swelling in the left maxillary region for 3 months duration. Intraorally diffuse firm swelling in the buccal mucosa with mild tenderness, free of secondary changes was present. Histhopathological report revealed Langhans′ giant cell suggestive of tuberculous granuloma. This article emphasis the fact that primary oral tuberculosis should be considered as differential diagnosis of soft tissue swellings, as the communicable nature of the disease demands early diagnosis and treatment

Preparation of oregano, coffee and black cumin aqueous formulation and its anti inflammatory activity

Background: Origanum vulgare (referred to as Spanish thyme and wild marjoram),is a member of the plant family Lamiaceae. Oregano contains potent components which contributes towards the cardiovascular and nervous systems, relieves symptoms of inflammation, and modulates blood sugar and lipids. Coffee which contains polyphenols attributes to a number of pharmacological activities that include antioxidant, antiinflammatory, immunomodulatory, anti-microbial, anti-cancer, cardioprotective and neuroprotective effects. Nigella sativa, black caraway is also called kalonji or nigella, and more common in the Far East, Mideast, Bangladesh, India and Africa. Nigella sativa contains active ingredients, in particular, thymoquinone, the main active constituent known for anti-inflammatory effect. Aim: To evaluate the antiinflammatory effect of oregano, coffee and black cumin formulation. Materials and methods: This study includes the usage of about 1g of oregano, coffee and black cumin extracts mixed with 100 mL of distilled water and boiled for 15 minutes, filtered and again concentrated till 10mL.The antiinflammatory activity of this formulation is assessed by using Bovine Serum Albumin assay. Results: The anti-inflammatory activity of oregano, coffee and black cumin aqueous formulation shows about 65% of inhibition when compared with standard