Holocord low grade astrocytoma – Role of radical irradiation and chemotherapy

AbstractSpinal intradural tumors, especially those extending along the entire length of the spinal cord, termed as ‘holocord’ tumors are uncommon. Most of these are gliomas, with astrocytomas (low grade) predominating in children and ependymomas in adults. Other histologies, though reported, are even rarer. Management is debatable, with both surgery and radiotherapy of such extensive tumors posing challenges. We describe a case of a 14-year-old girl with holocord astrocytoma extending from cervicomedullary junction till lumbar spine, who recovered full neurological function following radical irradiation of entire spine followed by temozolomide-based chemotherapy. No grade 3/4 bone marrow morbidity was seen. Five years following treatment, she maintained normal neurological function and apparently normal pubertal and skeletal growth despite residual disease visible on imaging. Literature review of existing reports of holocord astrocytomas highlighting management and outcome is presented

Protective Effect of Phyllanthus niruri on DMBA/Croton Oil Mediated Carcinogenic Response and Oxidative Damage in Accordance to Histopathological Studies in Skin of Mice

The current study has been designed to unveil the preventive effect of Phyllanthus niruri extract (PNE) on two stage skin carcinogenesis and oxidative damage in Swiss albino mice. Single topical application of 7, 12-dimethylbenz (a) anthracene (DMBA), followed by croton oil thrice weekly produced 100% incidence of tumors in carcinogen control animals (Gr. III) by 16 weeks. On the other hand, oral administration of animals with PNE (1 week before of DMBA application & continued until the end of experiment, Gr. IV), significantly reduced the tumor incidence, tumor burden, tumor volume and weight and the number of tumors but  prolong the latent period of tumor occurrence, as compared with carcinogen control animals. Furthermore, administration of PNE protected against the losses provoked in levels of glutathione, Vit.C, total proteins and activity of catalase and superoxide dismutase in skin and liver of animals by the application of DMBA/croton oil, concomitantly, the levels of lipid peroxidation were also reduced significantly. P. niruri administration profoundly reverted back the pathological changes observed in skin and liver of cancerous animals. From the results, P. niruri extract proves to scavenge free radical and found to be a potent chemopreventive agent against chemical induced skin carcinogenesis. Keywords: carcinogenesis, Phyllanthus niruri, cancer chemoprevention, tumor incidence, reactive oxygen species (ROS), antioxidant enzyme

Crystal growth and magneto-transport of Bi2Se3 single crystals

In this letter, we report on the growth and characterization of bulk Bi2Se3 single crystals. The studied Bi2Se3 crystals are grown by the self-flux method through the solid-state reaction from high-temperature (950 °C) melt of constituent elements and slow cooling (2 °C/h). The resultant crystals are shiny and grown in the [00l] direction, as evidenced from surface XRD. Detailed Reitveld analysis of powder X-ray diffraction (PXRD) of the crystals showed that these are crystallized in the rhombohedral crystal structure with a space group of R3m (D5), and the lattice parameters are a = 4.14 (2), b = 4.14 (2), and c = 28.7010 (7) A° . Temperature versus resistivity (ρ − T ) plots revealed metallic conduction down to 2 K, with typical room temperature resistivity (ρ300 K) of around 0.53 mΩ- cm and residual resistivity (ρ0 K) of 0.12 mΩ-cm. Resistivity under magnetic field [ρ(T )H] measurements exhibited large+ve magneto-resistance right from 2 to 200 K. Isothermal magneto-resistance [ρH] measurements at 2, 100, and 200 K exhibited magneto-resistance (MR) of up to 240 %, 130 %, and 60 %, respectively, at 14 T. Further, the MR plots are nonsaturating and linear with the field at all temperatures. At 2 K, the MR plots showed clear quantum oscillations at above say 10 T applied field. Also, the Kohler plots, i.e., Δρ/ρo versus B/ρ, were seen consolidating on one plot. Interestingly, the studied Bi2Se3 single crystal exhibited the Shubnikov-de Haas (SdH) oscillations at 2 K under different applied magnetic fields ranging from 4 to 14 T

Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Search for gravitational-wave transients associated with magnetar bursts in advanced LIGO and advanced Virgo data from the third observing run

Gravitational waves are expected to be produced from neutron star oscillations associated with magnetar giant f lares and short bursts. We present the results of a search for short-duration (milliseconds to seconds) and longduration (∼100 s) transient gravitational waves from 13 magnetar short bursts observed during Advanced LIGO, Advanced Virgo, and KAGRA’s third observation run. These 13 bursts come from two magnetars, SGR1935 +2154 and SwiftJ1818.0−1607. We also include three other electromagnetic burst events detected by FermiGBM which were identified as likely coming from one or more magnetars, but they have no association with a known magnetar. No magnetar giant flares were detected during the analysis period. We find no evidence of gravitational waves associated with any of these 16 bursts. We place upper limits on the rms of the integrated incident gravitational-wave strain that reach 3.6 × 10−²³ Hz at 100 Hz for the short-duration search and 1.1 ×10−²² Hz at 450 Hz for the long-duration search. For a ringdown signal at 1590 Hz targeted by the short-duration search the limit is set to 2.3 × 10−²² Hz. Using the estimated distance to each magnetar, we derive upper limits upper limits on the emitted gravitational-wave energy of 1.5 × 1044 erg (1.0 × 1044 erg) for SGR 1935+2154 and 9.4 × 10^43 erg (1.3 × 1044 erg) for Swift J1818.0−1607, for the short-duration (long-duration) search. Assuming isotropic emission of electromagnetic radiation of the burst fluences, we constrain the ratio of gravitational-wave energy to electromagnetic energy for bursts from SGR 1935+2154 with the available fluence information. The lowest of these ratios is 4.5 × 103

A joint Fermi-GBM and Swift-BAT analysis of gravitational-wave candidates from the third gravitational-wave observing run

We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers

Constraints on the cosmic expansion history from GWTC–3

We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34 M⊙, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding ${H}_{0}={68}_{-8}^{+12}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ (68% credible interval) when combined with the H0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event's potential hosts. Assuming a fixed BBH population, we estimate a value of ${H}_{0}={68}_{-6}^{+8}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H0) is the well-localized event GW190814

Riccati generalization of self-similar solutions of nonautonomous Gross-Pitaevskii equation

We present a systematic analytical approach to construct a family of self-similar waves, related through a free parameter, in quasi one-dimension Gross-Pitaevskii equation with time-varying parameters. This approach enables us to control the dynamics of dark and bright similaritons, and first- and second- order self-similar rogue waves in Bose-Einstein condensate through the modulation of time dependent trapping potential. The analysis is done for the sech2− type time-varying quadratic trapping potential for two different choices of linear potential