313 research outputs found
ARBEKACIN – A RAY OF HOPE TO FIGHT AGAINST MDR AND XDR GRAM-NEGATIVE BACTERIA IN A SCIENTIFIC AND COST-EFFECTIVE WAY IN INDIAN SCENARIO
Objective: The objective of the study was to see the in vitro activity of arbekacin, a novel aminoglycoside, against multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacilli (GNB) so that it can become a good alternative as empirical treatment for severe sepsis.
Methods: Identification and antibiotic sensitivity testing of the GNB isolated from the clinical samples were done using the VITEK-II system in a tertiary care hospital, Kolkata. MDR and XDR strains were selected by their definitions and molecular characterization was done by multiplex polymerase chain reaction. The minimum inhibitory concentration (MIC) value of arbekacin was detected by the E-test strip and compared with other aminoglycosides.
Results: A total of 140 drug-resistant strains including ESBL- and carbapenemase-producing GNB were selected for the study. Arbekacin showed reduced values of MIC50 and MIC90 compared to other aminoglycosides for most of the drug-resistant GNB.
Conclusion: Hence, in this drug-resistant era, arbekacin with the advantage of a single daily dose can be used as an empirical choice in severe sepsis as monotherapy or in combination with other antibiotics such as colistin or polymyxin to fight against MDR and XDR bugs
Cutaneous Nocardia Brasiliensis
Nocardia brasiliensis is a rare human pathogen that is usually associated with localised cutaneous infections. We report a case of primary cutaneous Nocardia brasiliensis infection causing delayed wound healing that developed after ovarian cystectomy in an otherwise healthy 32-year-old woman. The patient was initially treated with cotrimoxazole, however due to intolerance intravenous amikacin was given and gradually the wound healed. The diagnosis was confirmed by demonstrating the causative organism in exudates, and cultures. Early diagnosis as well as early institution of chemotherapy is effective in most patients, and antimicrobial susceptibility testing of the isolate should be performed to identify the best treatment options
Gall bladder perforation: A rare complication of a common disease
Perforation of the gall bladder is rare in acalculous cholecystitis, more so following infection with Salmonella typhi. This is a case report of a 55 year old lady who presented with fever for 3 weeks duration with sudden severe generalized pain abdomen associated with bilious vomiting for 2days. The patient was investigated and in view of signs of generalized peritonitis, exploratory laparotomy was done. Operative finding was gallbladder perforation and she underwent cholecystectomy. Post operative period was uneventful and the patient was discharged on 10th post operative day
Combination of Fascia Iliaca Compartment Block on the Surgical Side with Sacral Spinal Anesthesia for Hip to Knee Surgery
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
Search for gravitational wave bursts in LIGO's third science run
We report on a search for gravitational wave bursts in data from the three
LIGO interferometric detectors during their third science run. The search
targets subsecond bursts in the frequency range 100-1100 Hz for which no
waveform model is assumed, and has a sensitivity in terms of the
root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No
gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published
in Classical and Quantum Gravit
Quantum state preparation and macroscopic entanglement in gravitational-wave detectors
Long-baseline laser-interferometer gravitational-wave detectors are operating
at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within
a broad frequency band. Such a low classical noise budget has already allowed
the creation of a controlled 2.7 kg macroscopic oscillator with an effective
eigenfrequency of 150 Hz and an occupation number of 200. This result, along
with the prospect for further improvements, heralds the new possibility of
experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical
behavior of objects in the realm of everyday experience - using
gravitational-wave detectors. In this paper, we provide the mathematical
foundation for the first step of a MQM experiment: the preparation of a
macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum
state, which is possible if the interferometer's classical noise beats the SQL
in a broad frequency band. Our formalism, based on Wiener filtering, allows a
straightforward conversion from the classical noise budget of a laser
interferometer, in terms of noise spectra, into the strategy for quantum state
preparation, and the quality of the prepared state. Using this formalism, we
consider how Gaussian entanglement can be built among two macroscopic test
masses, and the performance of the planned Advanced LIGO interferometers in
quantum-state preparation
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
Medulloblastoma Exome Sequencing Uncovers Subtype-Specific Somatic Mutations
Medulloblastomas are the most common malignant brain tumors in children1. Identifying and understanding the genetic events that drive these tumors is critical for the development of more effective diagnostic, prognostic and therapeutic strategies. Recently, our group and others described distinct molecular subtypes of medulloblastoma based on transcriptional and copy number profiles2–5. Here, we utilized whole exome hybrid capture and deep sequencing to identify somatic mutations across the coding regions of 92 primary medulloblastoma/normal pairs. Overall, medulloblastomas exhibit low mutation rates consistent with other pediatric tumors, with a median of 0.35 non-silent mutations per megabase. We identified twelve genes mutated at statistically significant frequencies, including previously known mutated genes in medulloblastoma such as CTNNB1, PTCH1, MLL2, SMARCA4 and TP53. Recurrent somatic mutations were identified in an RNA helicase gene, DDX3X, often concurrent with CTNNB1 mutations, and in the nuclear co-repressor (N-CoR) complex genes GPS2, BCOR, and LDB1, novel findings in medulloblastoma. We show that mutant DDX3X potentiates transactivation of a TCF promoter and enhances cell viability in combination with mutant but not wild type beta-catenin. Together, our study reveals the alteration of Wnt, Hedgehog, histone methyltransferase and now N-CoR pathways across medulloblastomas and within specific subtypes of this disease, and nominates the RNA helicase DDX3X as a component of pathogenic beta-catenin signaling in medulloblastoma
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