Phase transition of a Bose gas in a harmonic potential

We consider a dilute Bose gas confined by a harmonic potential. We define an appropriate thermodynamic limit and analyze the properties of the phases and phase transition in this limit. Critical properties in the presence of the potential are found to be different from, though simply related, to those in the usual translationally invariant case. We argue that the properties of magnetically trapped rubidium\cite{Wieman} and sodium\cite{ketterle} gases (in which Bose-Einstein condensation has been recently observed) are well approximated by our thermodynamic limit except in a narrow window of temperature around the critical temperature. We also consider the effect of the confining potential on the non-equilibrium dynamics following a rapid quench to the ordered side and give a scaling description of the late time universal dynamics.Comment: 10 page

AN IN VITRO STUDY OF ANTIOXIDANT CAPACITY AND RADICAL SCAVENGING EFFECT OF SPINACIA OLERACEA LEAF EXTRACT

Objective: The study was carried out to evaluate the preliminary phytochemical screening and antioxidant activity of ethanolic extract of Spinacia oleracea (SO).Methods: The leaves of SO were shade dried, and the extract was prepared using solvent ethanol by Soxhlet extraction method. The preliminary phytochemical screening was carried out on the leaf extract of the plant. The total phenolic content and total flavonoids were estimated using Folin- Ciocalteu's and aluminum chloride reagents, respectively. Antioxidant activities were studied using 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, hydrogen radical, lipid peroxidation, and phosphomolybdenum radical scavenging assays.Results: The preliminary phytochemical analysis revealed the presence of bioactive constituents such as phenols, alkaloids, flavonoids, saponins, and glycosides. As SO is a rich source of different bioactive component, it contains a considerable amount of flavonoids and phenols. The different antioxidant assays proved that spinach is one of the best antioxidants with its ability to scavenge different radicals that generate oxidative stress.Conclusion: The observed activity may be associated with bioactive components such as phenols and flavonoids present in the leaf extracts and could have greater importance as nootropic plant in oxidative stress-related degenerative diseases such as Alzheimer and dementia

Comment on "Spin Transport properties of the quantum one-dimensional non-linear sigma model"

In a recent preprint (cond-mat/9905415), Fujimoto has used the Bethe ansatz to compute the finite temperature, zero frequency Drude weight of spin transport in the quantum O(3) non-linear sigma model in a magnetic field $H \neq 0$. We show here that, contrary to his claims, the results are in accord with earlier semiclassical results (Sachdev and Damle, cond-mat/9610115). We also comment on his 1/N expansion, and show that it does not properly describe the long-time correlations.Comment: 4 page

Intrauterine fetal demise: a retrospective study in tertiary care center in India

Background: An Intrauterine Fetal Demise (IUFD) is a major obstetrical catastrophe at any gestational age but the emotional pain and distress caused by this event increases in direct relation to the duration of pregnancy. The objective of the present study was to determine the incidence and possible causes of Intrauterine Fetal Demise (IUFD), and to determine preventive measures.Methods: Retrospective observational study was done from Jan 2015 to Dec 2017 at Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune. Inclusion criteria were all the pregnant women with IUFD delivered at the centre, at or above 24 weeks of gestation. The methodology followed were parameters of assessment for analysis were maternal age, parity, probable causes for IUFD, booked or unbooked cases, mode of delivery, maternal complications, and placental histopathology. Statistical data were analyzed using SPSS version 25.Results: The incidence of IUFD at authors’ hospital was 27/1000 live births. The IUFD rate was similar in maternal age 30years (p value 0.26). The incidence of IUFD increased with decreasing gestational age which was statistically significant (p value 0.001). IUFD incidence was higher in multiparous women compared to primiparous women (p value 0.036 with OR of 1.6 and 95% CI 1.02 to 2.54). The rate of IUFD was similar when sex of the baby was analyzed. 49.4% of fetuses had signs of maceration. The major cause of IUFD was severe preeclampsia (48.1%) which included HELLP syndrome, IUGR, Abruption. Maternal anemia (20.4%), GDM (3.8%), SLE (2.5%), APLA positive (2.5%), anhydramnios (6.3%) were some of the other important causes of IUFD.Conclusions: This study was conducted to determine the incidence of IUFD and associated maternal risk factors. By understanding the contributing factors, we can seek ways of avoiding recurrence of IUFD by proper antenatal care and early diagnosis of obstetric complications and its appropriate management

A study of obstetric acute renal injury

Background: Acute renal or kidney injury (AKI) is a clinical syndrome characterized by a sudden decline in glomerular filtration rate leading to decreased excretion of nitrogenous waste products. It continues to be a common problem in developing countries. The aim of this study was to understand AKI characteristics in pregnancy and identify the factors related to its unfavorable outcome.Methods: This prospective study was conducted between January 2014 to December 2017. Out of 1057 patients delivered in our institute during this period, out of which 26 patients with Obstetric AKI were included in this study.Results: Incidence of obstetric AKI was 2.64 %. Their age varied from 19 to 34 years, with an average of 26.2 years. About 21(80.8%) patients had not received antenatal care. The main causes of AKI were obstetric hemorrhage (38.46%) and puerperal sepsis (15.38%). The outcome was favorable with complete renal function recovery in 55.76% patients. Two (7.69 %) patients became dialysis dependent. Maternal mortality was one (3.84%).Conclusions: Obstetric AKI is a critical situation in developing countries. Lack of antenatal care (80.8%) is a major contributing factor for obstetric-related complications leading to renal failure. Obstetric hemorrhage (38.46 %) is the most common cause of obstetric AKI. Late referral in 9 (34.61%), puerperal sepsis in three (33.33%), obstetric hemorrhage in three (33.33%) and combined sepsis and hemorrhage in two (27.77%) are the common contributing factors leading to its unfavorable outcomes as maternal morbidity and mortality. Hence, a multidisciplinary approach is warranted to prevent such an avoidable complication

Griffiths Effects in Random Heisenberg Antiferromagnetic S=1 Chains

I consider the effects of enforced dimerization on random Heisenberg antiferromagnetic S=1 chains. I argue for the existence of novel Griffiths phases characterized by {\em two independent dynamical exponents} that vary continuously in these phases; one of the exponents controls the density of spin-1/2 degrees of freedom in the low-energy effective Hamiltonian, while the other controls the corresponding density of spin-1 degrees of freedom. Moreover, in one of these Griffiths phases, the system has very different low temperature behavior in two different parts of the phase which are separated from each other by a sharply defined crossover line; on one side of this crossover line, the system `looks' like a S=1 chain at low energies, while on the other side, it is best thought of as a $S=1/2$ chain. A strong-disorder RG analysis makes it possible to analytically obtain detailed information about the low temperature behavior of physical observables such as the susceptibility and the specific heat, as well as identify an experimentally accessible signature of this novel crossover.Comment: 16 pages, two-column PRB format; 5 figure

Spin and energy correlations in the one dimensional spin 1/2 Heisenberg model

In this paper, we study the spin and energy dynamic correlations of the one dimensional spin 1/2 Heisenberg model, using mostly exact diagonalization numerical techniques. In particular, observing that the uniform spin and energy currents decay to finite values at long times, we argue for the absence of spin and energy diffusion in the easy plane anisotropic Heisenberg model.Comment: 10 pages, 3 figures, gzipped postscrip