Influence of momentum-dependent interactions on balance energy and mass dependence

We aim to study the role of momentum-dependent interactions in transverse flow as well as in its disappearance. For the present study, central collisions involving mass between 24 and 394 are considered. We find that momentum-dependent interactions have different impact in lighter colliding nuclei compared to heavier colliding nuclei. In lighter nuclei, the contribution of mean field towards the flow is smaller compared to heavier nuclei where binary nucleon-nucleon collisions dominate the scene. The inclusion of momentum-dependent interactions also explains the energy of vanishing flow in $^{12}C+^{12}C$ reaction which was not possible with the static equation of state. An excellent agreement of our theoretical attempt is found for balance energy with experimental data throughout the periodic table

Disappearance of Transverse Flow in Central Collisions for Heavier Nuclei

For the first time, mass dependence of balance energy only for heavier systems has been studied. Our results are in excellent agreement with the data which allow us to predict the balance energy of U+U, for the first time, around 37-39 MeV/nucleon. Also our results indicate a hard equation of state along with nucleon-nucleon cross-section around 40 mb.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

Delivery of siHIF-1α to reconstruct tumor normoxic microenvironment for effective chemotherapeutic and photodynamic anticancer treatments

The tumor hypoxic microenvironment not only induces genetic and epigenetic changes in tumor cells, immature vessels formation for oxygen demand, but also compromises the efficiency of therapeutic interventions. On the other hand, conventional therapeutic approaches which kill tumor cells or destroy tumor blood vessels to block nutrition and oxygen supply usually facilitate even harsher microenvironment. Thus, simultaneously relieving the strained response of tumor cells and blood vessels represents a promising strategy to reverse the adverse tumor hypoxic microenvironment. In the present study, an integrated amphiphilic system (RSCD) is designed based on Angiotensin II receptor blocker candesartan for siRNA delivery against the hypoxia-inducible factor-1 alpha (HIF-1α), aiming at both vascular and cellular "relaxation" to reconstruct a tumor normoxic microenvironment. Both in vitro and in vivo studies have confirmed that the hypoxia-inducible HIF-1α expression is down-regulated by 70% and vascular growth is inhibited by 60%. The "relaxation" therapy enables neovascularization with more complete and organized structures to obviously increase the oxygen level inside tumor, which results in a 50% growth inhibition. Moreover, reconstruction of tumor microenvironment enhances tumor-targeted drug delivery, and significantly improves the chemotherapeutic and photodynamic anticancer treatments.Drug Delivery Technolog

Cold Strangelets Formation with Finite Size Effects in High Energy Heavy-Ion Collisions

We have studied the phase diagram and evolution of a strangelet in equilibrium with a finite hadronic gas. Significant finite size modifications of the phase diagram are found and their parameter dependences are studied. With the inclusion of finite size effects we have also been able to obtain the detailed properties of the cold strangelet emerging in the final stage of the isentropic expansion of a finite strange fireball in high energy heavy-ion collisions.Comment: 19 pages(RevTex), 11 Postscript figures; To appear in Phys. Rev.

ππ\pi\pi scattering in the ρ\rho-meson channel at finite temperature

We study $\pi\pi$ scattering in the I=1, $J^P=1^-$ channel at finite temperature in the framework of the extended Nambu-Jona-Lasinio model that explicitly includes vector and axial-vector degrees of freedom in addition to the usual scalar and pseudoscalar sector. The S-matrix in the coupled channels $q\bar q$ and $\pi \pi$ is constructed via $\rho$-exchange in the $s$-channel. The self-energy of the $\rho$-meson contains both quark and pion loop contributions. The analytic structure of the S-matrix for $T\geq 0$ is investigated and the motion of the $\rho$-pole as a function of coupling constant and temperature is followed in the complex $\sqrt{s}$-plane. For numerical calculations, parameters are chosen in order that $m_\pi$, $f_\pi$ and the experimental $\pi\pi$ phase shifts $\delta_1^1$ at zero temperature are reproduced, and then the behavior of the $\rho$-pole as well as the $\pi\pi$ cross section is investigated as a function of the temperature. We find that the position of the $\rho$ mass stays practically constant for $0\leq T\leq 130$ MeV, and then moves down in energy by about 200 MeV for 130 MeV$\leq T\leq 230$ MeV.Comment: 25 pages, 12 figures, to appear in Nucl. Phys.

Physics and Astrophysics of Strange Quark Matter

3-flavor quark matter (strange quark matter; SQM) can be stable or metastable for a wide range of strong interaction parameters. If so, SQM can play an important role in cosmology, neutron stars, cosmic ray physics, and relativistic heavy-ion collisions. As an example of the intimate connections between astrophysics and heavy-ion collision physics, this Chapter gives an overview of the physical properties of SQM in bulk and of small-baryon number strangelets; discusses the possible formation, destruction, and implications of lumps of SQM (quark nuggets) in the early Universe; and describes the structure and signature of strange stars, as well as formation and detection of strangelets in cosmic rays. It is concluded, that astrophysical and laboratory searches are complementary in many respects, and that both should be pursued to test the intriguing possibility of a strange ground state for hadronic matter, and (more generally) to improve our knowledge of the strong interactions.Comment: 45 pages incl. figures. To appear in "Hadrons in Dense Matter and Hadrosynthesis", Lecture Notes in Physics, Springer Verlag (ed. J.Cleymans

aHUS caused by complement dysregulation: new therapies on the horizon

Atypical hemolytic uremic syndrome (aHUS) is a heterogeneous disease that is caused by defective complement regulation in over 50% of cases. Mutations have been identified in genes encoding both complement regulators [complement factor H (CFH), complement factor I (CFI), complement factor H-related proteins (CFHR), and membrane cofactor protein (MCP)], as well as complement activators [complement factor B (CFB) and C3]. More recently, mutations have also been identified in thrombomodulin (THBD), an anticoagulant glycoprotein that plays a role in the inactivation of C3a and C5a. Inhibitory autoantibodies to CFH account for an additional 5–10% of cases and can occur in isolation or in association with mutations in CFH, CFI, CFHR 1, 3, 4, and MCP. Plasma therapies are considered the mainstay of therapy in aHUS secondary to defective complement regulation and may be administered as plasma infusions or plasma exchange. However, in certain cases, despite initiation of plasma therapy, renal function continues to deteriorate with progression to end-stage renal disease and renal transplantation. Recently, eculizumab, a humanized monoclonal antibody against C5, has been described as an effective therapeutic strategy in the management of refractory aHUS that has failed to respond to plasma therapy. Clinical trials are now underway to further evaluate the efficacy of eculizumab in the management of both plasma-sensitive and plasma-resistant aHUS