78 research outputs found
Atypical presentation of scrub typhus encephalitis with cerebral hemorrhage
Scrub typhus, an arthropod borne infection caused by the rickettsial organism Orientia tsutsugamushi, is a fairly common disease in north-eastern sub-Himalayan India, particularly the forest areas, and is known to manifest with varied presentations ranging from non-specific fever to severe multi-organ complications. Hemorrhagic manifestations described in the literature are mostly gastrointestinal and genitourinary, secondary to vasculitis and/or thrombocytopenia, but reports of cerebral hemorrhage have been extremely rare. We report a case from sub-Himalayan eastern India where a 23 years old male tea plantation worker presented with recurrent convulsions with magnetic resonance imaging (MRI) brain showing multiple parenchymal hemorrhages with encephalitis involving both the cerebral hemispheres. Although patient developed fever and acute kidney injury later in the course, these were not the presenting complaints despite fever being the most consistent sign of a scrub typhus infection. We suggest consideration of scrub typhus as a differential diagnosis of a cerebral hemorrhage in endemic regions
Reducing Computational Complexity of Quantum Correlations
We address the issue of reducing the resource required to compute
information-theoretic quantum correlation measures like quantum discord and
quantum work deficit in two qubits and higher dimensional systems. We show that
determination of the quantum correlation measure is possible even if we utilize
a restricted set of local measurements. We find that the determination allows
us to obtain a closed form of quantum discord and quantum work deficit for
several classes of states, with a low error. We show that the computational
error caused by the constraint over the complete set of local measurements
reduces fast with an increase in the size of the restricted set, implying
usefulness of constrained optimization, especially with the increase of
dimensions. We perform quantitative analysis to investigate how the error
scales with the system size, taking into account a set of plausible
constructions of the constrained set. Carrying out a comparative study, we show
that the resource required to optimize quantum work deficit is usually higher
than that required for quantum discord. We also demonstrate that minimization
of quantum discord and quantum work deficit is easier in the case of two-qubit
mixed states of fixed ranks and with positive partial transpose in comparison
to the corresponding states having non-positive partial transpose. Applying the
methodology to quantum spin models, we show that the constrained optimization
can be used with advantage in analyzing such systems in quantum
information-theoretic language. For bound entangled states, we show that the
error is significantly low when the measurements correspond to the spin
observables along the three Cartesian coordinates, and thereby we obtain
expressions of quantum discord and quantum work deficit for these bound
entangled states.Comment: 19 pages, 14 figures, 3 table
Static and dynamical quantum correlations in phases of an alternating field XY model
We investigate the static and dynamical patterns of entanglement in an
anisotropic XY model with an alternating transverse magnetic field, which is
equivalent to a two-component one-dimensional Fermi gas on a lattice, a system
realizable with current technology. Apart from the antiferromagnetic and
paramagnetic phases, the model possesses a dimer phase which is not present in
the transverse XY model. At zero temperature, we find that the first derivative
of bipartite entanglement can detect all the three phases. We analytically show
that the model has a "factorization line" on the plane of system parameters, in
which the zero temperature state is separable. Along with investigating the
effect of temperature on entanglement in a phase plane, we also report a
non-monotonic behavior of entanglement with respect to temperature in the
anti-ferromagnetic and paramagnetic phases, which is surprisingly absent in the
dimer phase. Since the time dynamics of entanglement in a realizable physical
system plays an important role in quantum information processing tasks, the
evolutions of entanglement at small as well as large time are examined.
Consideration of large time behavior of entanglement helps us to prove that in
this model, entanglement is always ergodic. We observe that other quantum
correlation measures can qualitatively show similar features in zero and finite
temperatures. However, unlike nearest-neighbor entanglement, the
nearest-neighbor information theoretic measures can be both ergodic as well as
non-ergodic, depending on the system parameters.Comment: 20 Pages, 13 Figures, 2 Tables, Published versio
Thermostable Direct Hemolysin Downregulates Human Colon Carcinoma Cell Proliferation with the Involvement of E-Cadherin, and β-Catenin/Tcf-4 Signaling
BACKGROUND: Colon cancers are the frequent causes of cancer mortality worldwide. Recently bacterial toxins have received marked attention as promising approaches in the treatment of colon cancer. Thermostable direct hemolysin (TDH) secreted by Vibrio parahaemolyticus causes influx of extracellular calcium with the subsequent rise in intracellular calcium level in intestinal epithelial cells and it is known that calcium has antiproliferative activity against colon cancer. KEY RESULTS: In the present study it has been shown that TDH, a well-known traditional virulent factor inhibits proliferation of human colon carcinoma cells through the involvement of CaSR in its mechanism. TDH treatment does not induce DNA fragmentation, nor causes the release of lactate dehydrogenase. Therefore, apoptosis and cytotoxicity are not contributing to the TDH-mediated reduction of proliferation rate, and hence the reduction appears to be caused by decrease in cell proliferation. The elevation of E-cadherin, a cell adhesion molecule and suppression of β-catenin, a proto-oncogene have been observed in presence of CaSR agonists whereas reverse effect has been seen in presence of CaSR antagonist as well as si-RNA in TDH treated cells. TDH also triggers a significant reduction of Cyclin-D and cdk2, two important cell cycle regulatory proteins along with an up regulation of cell cycle inhibitory protein p27(Kip1) in presence of CaSR agonists. CONCLUSION: Therefore TDH can downregulate colonic carcinoma cell proliferation and involves CaSR in its mechanism of action. The downregulation occurs mainly through the involvement of E-cadherin-β-catenin mediated pathway and the inhibition of cell cycle regulators as well as upregulation of cell cycle inhibitors
Public library services for refugees and asylum-seekers The results of the 'Words without frontiers' survey
Available from British Library Document Supply Centre- DSC:m03/24255 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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