Dynamics of Hot QCD Matter -- Current Status and Developments

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results.Comment: Compilation of the contributions (148 pages) as presented in the `Hot QCD Matter 2022 conference', held from May 12 to 14, 2022, jointly organized by IIT Goa & Goa University, Goa, Indi

Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016

Effect of Two Interacting Rings in Metalloporphyrin Dimers upon Stepwise Oxidations

The interaction between two porphyrin macrocycles, connected covalently through either a rigid ethylene or a flexible ethane bridge, in the metalloporphyrin dimers (M: 2H, Zn²⁺) have been investigated upon stepwise oxidations. Upon 1e-oxidation, two porphyrin macrocycles come closer and cofacial to each other while 2e-oxidation forces them to be separated as far as possible. This has resulted in the conversion of the <i>cis</i> isomer to <i>trans</i> for the ethylene bridged porphyrin dimer with the stabilization of an unusual “<i>U</i>” form, which has unique spectral and geometrical features. Detailed ultraviolet–visible–near-infrared (UV-vis-NIR), infrared (IR), electron paramagnetic resonance (EPR), and nuclear magnetic resonance (NMR) spectroscopic investigations, along with X-ray structure determination of the 2e-oxidized complexes, have demonstrated strong electronic communications between two porphyrin π-cation radicals through the bridging ethylene group. Such extensive π-conjugation also results in strong antiferromagnetic coupling between the radical spins of both of the macrocycles, which generates a diamagnetic compound. The experimental observations are also strongly supported by density functional theory (DFT) calculations

Switching Orientation of Two Axial Imidazole Ligands between Parallel and Perpendicular in Low-Spin Fe(III) and Fe(II) Nonplanar Porphyrinates

We have reported here the synthesis, structure, and properties of low-spin bis-imidazole-coordinated Fe­(III) and Fe­(II) complexes of 5,10,15,20-tetrakis­(pentafluorophenyl)-2,3,7,8,12,13,17,18-octachloroporphyrin, [Fe^III(TFPPCl₈)­(L)₂]­ClO₄ and Fe^II(TFPPCl₈)­(L)₂ (L = 1-methylimidazole, 4-methylimidazole, imidazole). The X-ray structure of Fe^II(TFPPCl₈)­(1-MeIm)₂ is reported here, which demonstrated the near-perpendicular axial ligand orientation (dihedral angle between two 1-methylimidazoles is 80.7°) for Fe­(II) porphyrins in a highly saddle-distorted macrocyclic environment. Oxidation of Fe^II(TFPPCl₈)­(L)₂ using thianthrenium perchlorate produces [Fe^III(TFPPCl₈)­(L)₂]­ClO₄, which was also isolated in the solid state and characterized spectroscopically. The complex gives rhombic EPR spectra in both solid and solution phases at 77 K and thus represents a rare example of nearly parallel axial ligand orientations for the unhindered imidazoles in a saddle-distorted porphyrin macrocycle. Geometry optimization using DFT also converged to the parallel axial alignment when 1-methylimidazole was used as the axial ligand (the dihedral angle between two axial ligands is 8.6°). The potential energy surface (PES) scan results also show that the relatively parallel axial orientations are energetically preferred for Fe­(III), while perpendicular orientations are preferred for the Fe­(II) complexes reported here. Bulk oxidation of Fe^II(TFPPCl₈)­(L)₂ in dichloromethane at a constant potential under nitrogen converts it to [Fe^III(TFPPCl₈)­(L)₂]­ClO₄, which gives identical EPR spectra at 77 K and which upon reduction regenerates Fe^II(TFPPCl₈)­(L)₂ again. Thus, we have demonstrated here very rare examples of Fe porphyrins in which the relative axial imidazole orientations switch between parallel and perpendicular just upon changing the oxidation states of iron from +3 to +2, respectively, in a nonplanar porphyrinic environment. These observations could be immensely important for understanding the possible effects of axial histidine orientations on similar macrocyclic deformations observed in various heme proteins