An immunocompromised dialysis patient with skin and bone lesions

Patients with chronic kidney failure have disturbances of immune function involving both innate and adaptive systems. These result in both immunodepression which increases susceptibility to infection and immunoactivation leading to a chronic inflammatory state [1]. Dialysis treatment may further aggravate aspects of this, especially the induction of inflammation. In addition, there is a growing number of patients who have returned to dialysis programmes following transplant failure. Many of these will have been intensively immunosuppressed, often over years or decades. These patients are at particular risk.Non peer reviewedFinal Published versio

Multiphonon Raman Scattering in Graphene

We report multiphonon Raman scattering in graphene samples. Higher order combination modes involving 3 phonons and 4 phonons are observed in single-layer (SLG), bi-layer (BLG), and few layer (FLG) graphene samples prepared by mechanical exfoliation. The intensity of the higher order phonon modes (relative to the G peak) is highest in SLG and decreases with increasing layers. In addition, all higher order modes are observed to upshift in frequency almost linearly with increasing graphene layers, betraying the underlying interlayer van der Waals interactions.Comment: Accepted for publication in Phys. Rev.

AstroSat view of MAXI J1535-571: broadband spectro-temporal features

We present the results of Target of Opportunity (ToO) observations made with AstroSat of the newly discovered black hole binary MAXI J1535-571. We detect prominent C-type Quasi-periodic Oscillations (QPOs) of frequencies varying from 1.85 Hz to 2.88 Hz, along with distinct harmonics in all the AstroSat observations. We note that while the fundamental QPO is seen in the 3 - 50 keV energy band, the harmonic is not significant above ~ 35 keV. The AstroSat observations were made in the hard intermediate state, as seen from state transitions observed by MAXI and Swift. We attempt spectral modelling of the broadband data (0.7-80 keV) provided by AstroSat using phenomenological and physical models. The spectral modelling using nthComp gives a photon index in the range between 2.18-2.37 and electron temperature ranging from 21 to 63 keV. The seed photon temperature is within 0.19 to 0.29 keV. The high flux in 0.3 - 80 keV band corresponds to a luminosity varying from 0.7 to 1.07 L_Edd assuming the source to be at a distance of 8 kpc and hosting a black hole with a mass of 6 M$_{\odot}$. The physical model based on the two-component accretion flow gives disc accretion rates as high as ~ 1 $\dot{m}_{Edd}$ and halo rate ~ 0.2 $\dot{m}_{Edd}$ respectively. The near Eddington accretion rate seems to be the main reason for the unprecedented high flux observed from this source. The two-component spectral fitting of AstroSat data also provides an estimate of a black hole mass between 5.14 to 7.83 M$_{\odot}$.Comment: 15 pages, 9 figures, MNRAS (Accepted on 2019 May 10

Cabibbo-suppressed non-leptonic B- and D-decays involving tensor mesons

The Cabibbo-suppressed non-leptonic decays of B (and D) mesons to final states involving tensor mesons are computed using the non-relativistic quark model of Isgur-Scora-Grinstein-Wise with the factorization hypothesis. We find that some of these B decay modes, as B --> (K^*, D^*)D^*_2, can have branching ratios as large as 6 x 10^{-5} which seems to be at the reach of future B factories.Comment: Latex, 11 pages, to appear in Phys. Rev.

Mutations in RpoB Gene and Their Association with Rifampicin-resistance Levels in Clinical Isolates of Mycobacterium Tuberculosis

Present study was aimed to identify most frequent mutations in rpoB gene region and to evaluate the association between mutations in rpoB gene and resistance levels to Rifampicin in clinical isolates of Mycobacterium tuberculosis of different geographical regions of India. A total of 100 clinical isolates of Mycobacterium tuberculosis were included in this study. Drug susceptibility testing against first line anti-tuberculosis drugs was performed on LJ medium by conventional minimal inhibitory concentration (MIC) method and the mutation(s) in rpoB gene of M. tuberculosis isolates were analyzed by sequencing method. Of the 100 M. tuberculosis isolates, 31 (31.0%) and 18 (18.0%) were found resistant and susceptible for all four first-line anti-tuberculosis drugs. The genetic mutations were observed in 96% (72/75) rifampicin-resistant M. tuberculosis isolates, while 4% (3/75) of rifampicin-resistant isolates did not have any mutation in rpoB gene. The mutation TCG531TTG (Ser531Leu) was found as most common and frequent mutation in 69.3% (52/75) of rifampicin-resistant isolates of M. tuberculosis with MIC level (≥ 512mg/l). The mutation at codon 511 was associated with low degree (128mg/l) of rifampicin-resistance, deletions at codons 514-516 or substitution at codon 516 were found to be associated with moderate degree (256mg/l) of rifampicin-resistance and mutations at codon 526, 531 were associated with the high degree (512mg/l) of rifampicin-resistance in M. tuberculosis isolates of Indian origin. The findings of this study will be useful for the development of raid and more specific indigenous molecular tools for the early diagnosis of multidrug-resistant tuberculosis in the country

Hadronic Charmed Meson Decays Involving Tensor Mesons

Charmed meson decays into a pseudoscalar meson P and a tensor meson T are studied. The charm to tensor meson transition form factors are evaluated in the Isgur-Scora-Grinstein-Wise (ISGW) quark model. It is shown that the Cabibbo-allowed decay $D_s^+\to f_2(1270)\pi^+$ is dominated by the W-annihilation contribution and has the largest branching ratio in $D\to TP$ decays. We argue that the Cabibbo-suppressed mode $D^+\to f_2(1270)\pi^+$ should be suppressed by one order of magnitude relative to $D_s^+\to f_2(1270)\pi^+$. When the finite width effect of the tensor resonances is taken into account, the decay rate of $D\to TP$ is generally enhanced by a factor of $2\sim 3$. Except for $D_s^+\to f_2(1270)\pi^+$, the predicted branching ratios of $D\to TP$ decays are in general too small by one to two orders of magnitude compared to experiment. However, it is very unlikely that the $D\to T$ transition form factors can be enhanced by a factor of $3\sim 5$ within the ISGW quark model to account for the discrepancy between theory and experiment. As many of the current data are still preliminary and lack sufficient statistic significance, more accurate measurements are needed to pin down the issue.Comment: 11 page

Giant spin-splitting and gap renormalization driven by trions in single-layer WS2_2/h-BN heterostructures

In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable band gaps and strongly bound excitons and trions emerge from strong many-body effects, beyond spin-orbit coupling- and lattice symmetry-induced spin and valley degrees of freedom. Combining single-layer (SL) TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects via engineered interlayer interactions. Here, we employ micro-focused angle-resolved photoemission spectroscopy (microARPES) and in-situ surface doping to manipulate the electronic structure of SL WS$_2$ on hexagonal boron nitride (WS$_2$/h-BN). Upon electron doping, we observe an unexpected giant renormalization of the SL WS$_2$ valence band (VB) spin-orbit splitting from 430~meV to 660~meV, together with a band gap reduction of at least 325~meV, attributed to the formation of trionic quasiparticles. These findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials.Comment: 14 pages, 4 figures. Address correspondence to [email protected] or [email protected]