Global hyperon polarization, $\bar{P}_H$, in Au+Au collisions over a large range of collision energy, $\sqrt{s_{NN}}$, has recently been measured and successfully reproduced by hydrodynamic and ...transport models with intense fluid vorticity of the Quark-Gluon Plasma (QGP). While naïve extrapolation of data trends suggests a large $\bar{P}_H$ as the collision energy is reduced, the behavior of $\bar{P}_H$ at small $\sqrt{s_{NN}}$ < 7.7 GeV is unknown. Operating the STAR experiment in fixed-target mode, we have measured the polarization of Λ hyperons along the direction of global angular momentum in Au+Au collisions at $\sqrt{s_{NN}}$ = 3 GeV. The observation of substantial polarization of 4.91±0.81(stat.)±0.15(syst.)% in these collisions may require a reexamination of the viscosity of any fluid created in the collision, the thermalization timescale of rotational modes, and of hadronic mechanisms to produce global polarization.
New measurements of directed flow for charged hadrons, characterized by the Fourier coefficient v1, are presented for transverse momenta pT, and centrality intervals in Au+Au collisions recorded by ...the STAR experiment for the center-of-mass energy range sNN=7.7–200 GeV. The measurements underscore the importance of momentum conservation, and the characteristic dependencies on sNN, centrality and pT are consistent with the expectations of geometric fluctuations generated in the initial stages of the collision, acting in concert with a hydrodynamic-like expansion. The centrality and pT dependencies of v1even, as well as an observed similarity between its excitation function and that for v3, could serve as constraints for initial-state models. The v1even excitation function could also provide an important supplement to the flow measurements employed for precision extraction of the temperature dependence of the specific shear viscosity.
Central venous catheterization is one of the very essential tool of modern intensive care. Apart from monitoring the critically ill patient, it helps in administration of antibiotics, parenteral ...nutrition, chemotherapy, fluids and drug delivery. Peripheral inserted central catheter (PICC) by surgically isolating basilic vein or venous cut down, is considered one of the safe technique to access central veins. The advantage of this procedure is that traumatic complications like pneumothorax, hemothorax and arterial puncture are less as compared to directly placing central catheters. Malposition (intracaval or extracaval) is one of the commonly encountered complication associated with central venous catheterization. Extracaval is rarely encountered and there are isolated case reports in the literature where catheter tip is found outside the central vein into the surrounding structures. Knowledge of such complications is important else these remain unrecognized resulting in delayed treatment and poor outcome. Here, we report a unique case, wherein tip of infant feeding tube inserted from basilic vein was found in anterior mediastinum resulting bilateral hemothorax and pleural effusion.
The beam energy scan (BES) program at the Relativistic Heavy Ion Collider (RHIC) was extended to energies below √ sNN = 7.7 GeV in 2015 by successful implementation of the fixed-target mode 3 of ...operation in the STAR (Solenoidal Tracker At RHIC) experiment. In this mode, ions circulate in one ring of the collider and interact with a stationary target at the entrance of the STAR Time Projection Chamber. The first results for Au+Au collisions at √ sNN = 4.5 GeV are presented, demonstrating good performance of all the relevant detector subsystems in fixed-target mode. Results presented here include directed and elliptic flow of identified hadrons, and radii from pion femtoscopy. The latter, together with recent HADES results, reveal a long-sought peak structure that may be caused by the system evolving through a first-order phase transition from quark-gluon plasma to the hadronic phase. Directed and elliptic flow for pions are presented for the first time at this beam energy. Pion and proton elliptic flow show behavior which hints at constituent quark scaling, and demonstrate that a definitive conclusion will be achievable using the full statistics of the on-going second phase of BES (BES-II). In particular, BES-II to date has recorded fixed-target data sets with two orders of magnitude more events at each of nine energies between √ sNN = 3.0 and 7.7 GeV.
Laparoscopic cholecystectomy (LC) is a well-established procedure for symptomatic cholelithiasis in India, but there are few data available regarding the procedure and its related complications.
This ...paper represents a retrospective review of 1233 patients who underwent LC at Government Medical College and Hospital, Chandigarh, India, over 4 years (1997-2000). The case files of all these patients were analyzed for patient particulars, intraoperative findings, reason for any open conversion, postoperative stay, and mortality.
The overall conversion rate was 7.06% (87 patients). The commonest cause of conversion was a frozen Calot's triangle (52 patients), followed by injury to the common bile duct (8 patients). The average postoperative stay in successful LC was 1.32 days. The overall mortality rate was 0.16% (2 deaths). The quality of life after LC was good to excellent in more than 90% of patients.
Despite multiple hands in training, the complication rates of LC are within acceptable limits. The overall conversion rate has risen because of the increase in elective conversions, but the incidence of complications has come down because of a "no hesitation" policy in converting. In spite of multiple operators, LC is the procedure of choice for symptomatic cholelithiasis at our hospital.
We present STAR measurements of strange hadron ( K S0, Λ , Λ ¯, Ξ -, Ξ ¯+, Ω -, Ω ¯+ , and Φ ) production at midrapidity ( |y|<0.5 ) in Au+Au collisions at sNN = 7.7–39 GeV from the Beam Energy Scan ...Program at the Relativistic Heavy Ion Collider (RHIC). Transverse-momentum spectra, averaged transverse mass, and the overall integrated yields of these strange hadrons are presented versus the centrality and collision energy. Antibaryon-to-baryon ratios ( Λ ¯/ Λ , Ξ ¯+/ Ξ -, Ω ¯+/ Ω - ) are presented as well and used to test a thermal statistical model and to extract the temperature normalized strangeness and baryon chemical potentials at hadronic freeze-out ( μB/Tch and μS/Tch ) in central collisions. Strange baryon-to-pion ratios are compared to various model predictions in central collisions for all energies. The nuclear modification factors ( RCP ) and antibaryon-to-meson ratios as a function of transverse momentum are presented for all collision energies. The K S0 RCP shows no suppression for pT up to 3.5 GeV/c at energies of 7.7 and 11.5 GeV. The Λ ¯/ K S0 ratio also shows baryon-to-meson enhancement at intermediate pT ( ≈2.5 GeV/c ) in central collisions at energies above 19.6 GeV. Lastly, both observations suggest that there is likely a change of the underlying strange quark dynamics at collision energies below 19.6 GeV.
Ambient visibility is a complex manifestation arising out of interactions among many atmospheric variables, including ambient aerosol load, and region specific geophysical characteristics. To ...functionally relate visibility impairment in Delhi region during winter months-months marred with poor visibility conditions–a novel experiment was designed to relate visibility with ambient aerosol load (PM2.5), and relevant meteorological variables: dew point temperature (Dp), height of planetary boundary layer (PBL), ambient temperature (T), relative humidity (RH), wind speed (WS) and wind direction (WD). Time series data sets of Visibility(t) and other variables were subjected to non–linear decomposition using Empirical Mode Decomposition Method (EMD), enabling to obtain total cyclic and acyclic–trend components embedded in all data–sets. Extracted total cyclic visibility components were functionally related with the corresponding components associated with PM2.5 load and meteorological variables. Decomposed acyclic–trend component of the visibility, representing time dependent acyclic trend (AT), was separately related with the corresponding AT components of the considered meteorological variables. The decomposed components of the visibility (total cyclic and AT) were subjected to multiple linear regression to establish a functional relationship between them and a set of variables among the considered variables. The analysis suggests that acyclic–trend associated with Visibility(t) can be predicted better as opposed to the Visibility(t)cyclic component.
We present three-particle mixed-harmonic correlations 〈cos(mϕa+nϕb−(m+n)ϕc)〉 for harmonics m,n=1−3 for charged particles in sNN=200 GeV Au+Au collisions at RHIC. These measurements provide ...information on the three-dimensional structure of the initial collision zone and are important for constraining models of a subsequent low-viscosity quark–gluon plasma expansion phase. We investigate correlations between the first, second and third harmonics predicted as a consequence of fluctuations in the initial state. The dependence of the correlations on the pseudorapidity separation between particles show hints of a breaking of longitudinal invariance. We compare our results to a number of state-of-the art hydrodynamic calculations with different initial states and temperature dependent viscosities. These measurements provide important steps towards constraining the temperature dependent viscosity and longitudinal structure of the initial state at RHIC.
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