182 research outputs found
Lower order and higher order entanglement in hyperfine manifold modeled as a four-wave mixing process
Possibilities of generation of lower order and higher order intermodal
entanglement in 87Rb 5S-5P-5D hyperfine manifold are rigorously investigated
using Sen-Mandal perturbative technique by showing the equivalence of the
system with the four-wave mixing (FWM) process. The investigation has revealed
that for a set of experimentally realizable/relevant parameters we can observe
lower order and higher order intermodal entanglement between pump and signal
modes, signal and idler modes, and idler and pump modes in a FWM process
associated with the 87Rb 5S-5P-5D hyperfine manifold. In addition, trimodal
entanglement involving pump, signal and idler modes is also reported.Comment: 12 pages, 5 figure
Development and Use of a Tablet-Based Resuscitation Sheet for Improving Outcomes During Intensive Patient Care
Data documentation from resuscitation events in hospitals, termed code blue events, utilizes a paper form, which is institution-specific. Problems with data capture and transcription exists, due to the challenges of dynamic documentation of patient, event and outcome variables as the code blue event unfolds. We hypothesize that an electronic version of code blue real-time data capture would lead to improved resuscitation data transcription, and enable clinicians to address deficiencies in quality of care. To this effect, we present the design of a tablet-based application and its use by 20 nurses at the Mayo Clinic hospital. The results showed that the nurses preferred the tablet application over the paper based form. Furthermore, a qualitative survey showed the clinicians perceived the electronic version to be more accurate and efficient than paper-based documentation, both of which are essential for an emergency code blue resuscitation procedure
Dimensional advantage in secure information trading via the noisy dense coding protocol
The quantum dense coding (DC) protocol, which has no security feature, deals
with the transmission of classical information encoded in a quantum state by
using shared entanglement between a single sender and a single receiver. Its
appropriate variant has been established as a quantum key distribution (QKD)
scheme for shared two-qubit maximally entangled states, with the security proof
utilizing the uncertainty relation of complementary observables and the
Shor-Preskill entanglement purification scheme. We present the DC-based QKD
protocol for higher dimensional systems and report the lower bounds on secret
key rate, when the shared state is a two-qudit maximally entangled state, and
mixtures of maximally entangled states with different ranks. The analysis also
includes the impact of noisy channels on the secure key rates, before and after
encoding. In both the noiseless and the noisy scenarios, we demonstrate that
the key rate as well as the robustness of the protocol against noise increases
with the dimension. Further, we prove that the set of useless states in the
DC-based QKD protocol is convex and compact.Comment: 11 pages, 3 figure
Perfect transfer of arbitrary continuous variable states across optical waveguide lattices
We demonstrate that perfect state transfer can be achieved in an optical
waveguide lattice governed by a Hamiltonian with modulated nearest-neighbor
couplings. In particular, we report the condition that the evolution
Hamiltonian should satisfy in order to achieve perfect transfer of any
continuous variable input state. The states that can be transmitted need not
have any specific properties - they may be pure or mixed, Gaussian or
non-Gaussian in character, and comprise an arbitrary number of modes. We
illustrate that the proposed protocol is scalable to two- and three-dimensional
waveguide geometries. With the help of local phase gates on all the modes, our
results can also be applied to realize a SWAP gate between mirror-symmetric
modes about the centre of the waveguide setup.Comment: 13 pages, 3 figure
Information theoretic resource-breaking channels
We present a framework of channels that break the resource associated with a
given quantum information processing task, in which entanglement is not
adequate. In particular, we illustrate our proposed notion, referred to as
process resource-breaking channels, by examining two important communication
protocols, quantum dense coding, and teleportation. We prove that the sets of
dense coding (DBT) and teleportation resource-breaking channels (TBT) are
convex and compact, and identify a specific class of classical-quantum channels
as the extreme points of those sets. We provide sufficient conditions for a
channel to be in TBT or DBT, when they are group-covariant along with having
the ability to transform a maximally entangled state into a useless one. We
also establish sufficient requirements on unital qubit channels to break the
dense codeability of any resource shared by one or more senders and a single
receiver. Regarding teleportation, we prove that the set TBT in the qubit
regime is equivalent to that of qubit entanglement-breaking channels provided
pre-processing is allowed. Furthermore, we construct witness operators capable
of identifying non-TBT(non-DBT) maps.Comment: 15 pages, 2 figure
Production of genuine multimode entanglement in circular waveguides with long-range interactions
Starting with a product initial state, squeezed (coherent squeezed) state in
one of the modes, and vacuum in the rest, we report that a circular waveguide
comprising modes coupled with varying interaction strength is capable of
producing genuine multimode entanglement (GME), quantified via the generalized
geometric measure (GGM). We demonstrate that for a fixed interaction and
squeezing strength, the GME content of the resulting state increases as the
range of interactions between the waveguides increases, although the GGM
collapses and revives with the variation of interaction strength and time. To
illustrate the advantage of long-range interactions, we propose a quantity,
called accumulated GGM, measuring the area under the GGM curve, which clearly
illustrates the growing trends with the increasing range of interactions. We
analytically determine the exact expression of GGM for systems involving an
arbitrary number of modes, when all the modes interact with each other equally.
The entire analysis is performed in phase-space formalism. We manifest the
constructive effect of disorder in the coupling parameter, which promises a
steady production of GME, independent of the interaction strength.Comment: 13 pages, 6 figure
Study the impact of ketamine, clonidine and combination of ketamine-clonidine on cardiovascular system during pre and postoperatively: A double blind, placebo controlled study
Background: The use of ketamine as a sole anesthetic induces marked central sympathetic stimulation, causing increased heart rate, blood pressure (BP), and oxygen consumption (VO2). Both alpha 2-agonists and benzodiazepines have been used to attenuate these potentially harmful ketamine-induced responses. Materials and Methods: After approval from institutional ethical committee and written informed consent, 120 adult patients, ASA physical status I and II, undergoing elective surgeries e.g. Open abdominal surgery, laparoscopic surgery, open urological surgery were included in this controlled, prospective, randomized, double-blind study. Patients were randomly (envelop randomization) allocated in 4 groups (n=30): Group K received IV ketamine (0.5mg/kg), Group C received IV clonidine (1.5μg/kg), Group KC received combination of IV ketamine (0.25mg/kg) and IV clonidine (0.75μg/kg) and Group P received IV normal saline (placebo). One envelop at a time was chosen by an anaesthesiologist, who was blinded to the preparation of study agents and administered the study drugs in the envelope one after the other, intravenously approximately 20 minutes before extubation. Results: Pre operative haemodynamic parameters like mean arterial pressure (MAP) and heart rate are comparable across the groups. There was statistically significant (two tailed p value < 0.001) rise in intra operative heart rate following intubation in groups K, KC and P. There was statistically significant increase in systolic blood pressure (SBP) in groups K and P (two tailed p value < 0.001). In group C and KC, there were significant fall in SBP, from the baseline values, following induction. Conclusion: The unwanted effects of the individual drugs like, haemodynamic alteration, hallucination or lower incidences of nausea and vomiting could be achieved by using half of the dose of each of the drugs in combination
Mitochondria as Target for Tumor Management of Hemangioendothelioma
Aims: Hemangioendothelioma (HE) may be benign or malignant. Mouse hemangioendothelioma endothelial (EOMA) cells are validated to study mechanisms in HE. This work demonstrates that EOMA cells heavily rely on mitochondria to thrive. Thus, a combination therapy, including weak X-ray therapy (XRT, 0.5 Gy) and a standardized natural berry extract (NBE) was tested. This NBE is known to be effective in managing experimental HE and has been awarded with the Food and Drug Administration Investigational New Drug (FDA-IND) number 140318 for clinical studies on infantile hemangioma.
Results: NBE treatment alone selectively attenuated basal oxygen consumption rate of EOMA cells. NBE specifically sensitized EOMA, but not murine aortic endothelial cells to XRT-dependent attenuation of mitochondrial respiration and adenosine triphosphate (ATP) production. Combination treatment, selectively and potently, influenced mitochondrial dynamics in EOMA cells such that fission was augmented. This was achieved by lowering of mitochondrial sirtuin 3 (SIRT3) causing increased phosphorylation of AMP-activated protein kinase (AMPK). A key role of SIRT3 in loss of EOMA cell viability caused by the combination therapy was evident when pyrroloquinoline quinone, an inducer of SIRT3, pretreatment rescued these cells.
Innovation and Conclusion: Mitochondria-targeting NBE significantly extended survival of HE-affected mice. The beneficial effect of NBE in combination with weak X-ray therapy was, however, far more potent with threefold increase in murine survival. The observation that safe natural products may target tumor cell mitochondria and sharply lower radiation dosage required for tumor management warrants clinical testing
Risk Factors for and Prediction of Post-Intubation Hypotension in Critically Ill Adults: A Multicenter Prospective Cohort Study
OBJECTIVE: Hypotension following endotracheal intubation in the ICU is associated with poor outcomes. There is no formal prediction tool to help estimate the onset of this hemodynamic compromise. Our objective was to derive and validate a prediction model for immediate hypotension following endotracheal intubation.
METHODS: A multicenter, prospective, cohort study enrolling 934 adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 was conducted to derive and validate a prediction model for immediate hypotension following endotracheal intubation. We defined hypotension as: 1) mean arterial pressure \u3c 65 mmHg; 2) systolic blood pressure \u3c 80 mmHg and/or decrease in systolic blood pressure of 40% from baseline; 3) or the initiation or increase in any vasopressor in the 30 minutes following endotracheal intubation.
RESULTS: Post-intubation hypotension developed in 344 (36.8%) patients. In the full cohort, 11 variables were independently associated with hypotension: increasing illness severity; increasing age; sepsis diagnosis; endotracheal intubation in the setting of cardiac arrest, mean arterial pressure \u3c 65 mmHg, and acute respiratory failure; diuretic use 24 hours preceding endotracheal intubation; decreasing systolic blood pressure from 130 mmHg; catecholamine and phenylephrine use immediately prior to endotracheal intubation; and use of etomidate during endotracheal intubation. A model excluding unstable patients’ pre-intubation (those receiving catecholamine vasopressors and/or who were intubated in the setting of cardiac arrest) was also developed and included the above variables with the exception of sepsis and etomidate. In the full cohort, the 11 variable model had a C-statistic of 0.75 (95% CI 0.72, 0.78). In the stable cohort, the 7 variable model C-statistic was 0.71 (95% CI 0.67, 0.75). In both cohorts, a clinical risk score was developed stratifying patients’ risk of hypotension.
CONCLUSIONS: A novel multivariable risk score predicted post-intubation hypotension with accuracy in both unstable and stable critically ill patients.
STUDY REGISTRATION: Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101
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