1,959 research outputs found
Model-Based Cross-Correlation Search for Gravitational Waves from Scorpius X-1
We consider the cross-correlation search for periodic GWs and its potential
application to the LMXB Sco X-1. This method coherently combines data from
different detectors at the same time, as well as different times from the same
or different detectors. By adjusting the maximum time offset between a pair of
data segments to be coherently combined, one can tune the method to trade off
sensitivity and computing costs. In particular, the detectable signal amplitude
scales as the inverse fourth root of this coherence time. The improvement in
amplitude sensitivity for a search with a coherence time of 1hr, compared with
a directed stochastic background search with 0.25Hz wide bins is about a factor
of 5.4. We show that a search of 1yr of data from Advanced LIGO and Advanced
Virgo with a coherence time of 1hr would be able to detect GWs from Sco X-1 at
the level predicted by torque balance over a range of signal frequencies from
30-300Hz; if the coherence time could be increased to 10hr, the range would be
20-500Hz. In addition, we consider several technical aspects of the
cross-correlation method: We quantify the effects of spectral leakage and show
that nearly rectangular windows still lead to the most sensitive search. We
produce an explicit parameter-space metric for the cross-correlation search in
general and as applied to a neutron star in a circular binary system. We
consider the effects of using a signal template averaged over unknown amplitude
parameters: the search is sensitive to a combination of the intrinsic signal
amplitude and the inclination of the neutron star rotation axis, and the peak
of the expected detection statistic is systematically offset from the true
signal parameters. Finally, we describe the potential loss of SNR due to
unmodelled effects such as signal phase acceleration within the Fourier
transform timescale and gradual evolution of the spin frequency.Comment: 27 pages, 12 figures, 4 tables, pdflatex; synchronized to final
version published in Phys Rev
Early recurrent ischemic stroke complicating intravenous thrombolysis for stroke: incidence and association with atrial fibrillation
<p><b>Background and Purpose:</b> Mechanisms of early neurologic deterioration after treatment with intravenous, recombinant, tissue-type plasminogen activator (IV rt-PA) include symptomatic intracerebral hemorrhage (SICH) and early recurrent ischemic stroke. We observed a number of cases of acute deterioration due to recurrent ischemic events.</p>
<p><b>Methods:</b> We undertook a single-center, retrospective analysis of consecutive acute stroke patients treated with IV rt-PA between January 2006 and December 2008 to define the incidence of early neurologic deterioration (>= 4-point drop on the National Institutes of Health Stroke Scale within 72 hours) and its mechanism. Deterioration was attributed to SICH when associated with a PH1 or PH2 hemorrhage on postdeterioration computed tomography scans, to recurrent ischemic stroke when there was clinical and radiologic evidence of a new territorial infarction or new vessel occlusion, and otherwise to evolution of the incident stroke.</p>
<p><b>Results:</b> Of 228 consecutive IV rt-PA-treated patients, 34 (15%) developed early neurologic deterioration, 18 (8%) secondary to incident strokes 10 (4.4%) due to SICH, and 6 (2.6%) due to early recurrent ischemic events, which were significantly associated with atrial fibrillation (present in 5 of 6 patients; 4 paroxysmal, 1 permanent). In 4 patients, sudden clinical deterioration developed during or shortly after IV rt-PA infusion, and in 2, deterioration developed 3 days later. All died 2 days to 2 weeks later. The single case without atrial fibrillation had a recurrent, contralateral, middle cerebral artery stroke during IV rt-PA infusion and multiple high-signal emboli detected by transcranial Doppler. Early recurrent ischemic stroke accounted for 5 of 12 (42%) cases of early neurologic deterioration in patients with atrial fibrillation.</p>
<p><b>Conclusion:</b> In this single-center series, the incidence of early recurrent ischemic stroke after IV rt-PA was 2.6% and was associated with previous atrial fibrillation.</p>
Particle Engineering Techniques: A Boon in Enhancing Dissolution Rate of Poorly Water Soluble Drugs
For any dosage forms enhancing dissolution is the first criteria i.e. it should give increased bioavailability in order to provide onset of action. In market many poorly soluble drugs are available which are having problem of low solubility. Low solubility of these poorly water soluble drugs are the main issue factor in preparing dosage forms of these drugs as with low solubility enhanced or effective dissolution to reach therapeutic effect is difficult. To overcome these problems there are main engineering techniques came in market which helps in enhancing the dissolution of these drugs. Some of the common use techniques are cryogenic, super critical fluid technology, evaporative precipitation into aqueous solution, nano- milling methods were developed based on the drug properties and required nanoparticles character. Making use of these techniques has increases the in vitro dissolution rates and in vivo bioavailability of many poorly water soluble drugs. This review highlights about the materialistic availability of particle engineering processes recently reported in the literature for enhancing the dissolution properties of poorly water soluble drugs.
Keywords: Solubility. Dissolution Rate, Poorly Soluble Drugs, Particle Engineering Technique
Adaptive Load Balancing Using RR and ALB: Resource Provisioning in Cloud
Cloud Computing context, load balancing is an issue. With a rise in the number of cloud-based technology users and their need for a broad range of services utilizing resources successfully or effectively in a cloud environment is referred to as load balancing, has become a significant obstacle. Load balancing is crucial in storage systems to increase network capacity and speed up response times. The main goal is to present a new load-balancing mechanism that can balance incoming requests from users all over globally who are in different regions requesting data from remote data sources. This method will combine effective scheduling and cloud-based techniques. A dynamic load balancing method was developed to ensure that cloud environments have the ability to respond rapidly, in addition to running cloud resources efficiently and speeding up job processing times. Applications' incoming traffic is automatically split up across a number of targets, including Amazon EC2 instances, network addresses, and other entities by elastic load balancing. Elastic load balancing offers three distinct classifications of load balancer, and each one provides high availability, intelligent scalability, and robust security to guarantee the error-free functioning of your applications. Application load balancing and round robin are the two load balancing mechanisms in database cloud that are focus of this research study
Sublingual Drug Delivery Systems- Faster Therapeutic Action Dosage Forms
Sublingual means “under the tongue” refers to administrating substances through mouth such that the substance is absorbed rapidly via blood vessels under the tongue. It outweighs orally ingested tablets in rapid onset of action and better patient compliances. The amount of drug absorbed through sublingual blood vessels bypasses hepatic first pass metabolic process giving more bioavailability. These days people lead short period of action so sublingual is the most suitable form of administration. New sublingual technologies address many pharmaceutical and patient desires and convenient dosing for all age groups.
Keywords: Sublingual route and patient compliance, dysphagia, sublingual technologies
Single Production of Doubly Charged Higgsinos at linear e-e- colliders
Several extended supersymmetric models, motivated by either grand
unification, or by neutrino mass generation, predict light doubly charged
higgsinos. We study the production of a single doubly charged higgsino and its
decay channels at the International Linear Collider (ILC) operating in the e-e-
mode. We analyze the production cross section for e-e- -->
tilde{Delta}^{--}_{L,R} chi^0_1 as a function of different kinematic variables,
followed by the decay, through several channels, of the doubly charged higgsino
into a final state of two leptons plus missing energy. We include the standard
model background and discuss how kinematic cuts could be used effectively to
limit this background. Single production of these exotics could provide a
spectacular signal for a new underlying symmetry and for physics beyond the
minimal supersymmetric standard model.Comment: Typos corrected, Journal Versio
Microemulsions: Transdermal Drug Delivery Systems With Enhanced Bioavailability
Microemulsions are preferred because of its advantages like low cost of preparation and enhanced bioavailability due to increased absorption of drug through skin which is achieved by adding penetration enhancers. Most frequently used permeation enhancers are saturated and unsaturated fatty acids like oleic acid . Microemulsions are the systems which can be used as a carrier to enhance the solubility of the drug and they protect the drug from oxidation, degradation and hydrolysis. As this system is directly applied on the skin, there is lesser risk of side effects like toxicity. Thus, microemulsions can be used as safe and effective dosage form to enhance the bioavailability of drugs in the transdermal drug delivery system. This article summarizes the structure of microemulsions, its components, merits and demerits of microemulsion system.
Keywords: Microemulsion, transdermal drug delivery, bioavailability
SYNTHESIS, CHARACTERIZATION AND EVALUATION OF STARCH XANTHATE AS A SUPERDISINTEGRANT IN THE FORMULATION OF FAST DISSOLVING TABLETS
Objective: To synthesize, characterize and evaluate starch xanthate as a superdisintegrant in the formulation of fast dissolving tablets by employing 23 factorial design.Methods: Starch xanthate was synthesized by gelatinization process. The physical and micromeritic properties were performed to evaluate the synthesized starch xanthate. The fast dissolving tablet of ibuprofen was prepared by employing starch xanthate as a superdisintegrant in different proportions in each case by direct compression method using 23 factorial design. The drug content, hardness, friability, disintegration time and other dissolution characteristics like percent dissolved in 5 min (PD5), dissolution efficiency in 5 min (DE5%) and first order rate constant (K1) were used in the evaluation of prepared fast dissolving tablets.Results: The starch xanthate prepared was found to be fine, free flowing slightly crystalline powder. Starch xanthate exhibited good swelling in water. The study between ibuprofen and starch xanthate was shown the absence of interaction by fourier transform infrared spectra (FTIR) and differential scanning calorimetry (DSC). The drug content (100±5%), hardness (3.6–4 kg/sq. cm), and friability (0.12-0.15%) has been effective with regard to all the formulated fast dissolving tablets employing starch xanthate. The disintegration time of all the formulated tablets was found to be in the range of 12±0.01 to 312±0.02s. The optimized formulation F5 has the least disintegration time i.e., 12±0.01s. The In vitro wetting time of the formulated tablets was found to be in the range of 76±0.21 to 217±0.17s. The In vitro wetting time was less (i.e., 90s) in optimized formulation F5. The water absorption ratio of the formulated tablets was found to be in the range of 16±0.16 to 174±0.21%. The cumulative drug dissolved in the optimized formulation F5 was found to be 99.83±0.56% in 5 min.Conclusion: The dissolution efficiency of ibuprofen was enhanced when starch xanthate was found to be a superdisintegrant when combined with sodium starch glycolate, croscarmellose sodium and, hence it could be used in the formulation of fast dissolving tablets to provide immediate release of the contained drug within 5 min
Quark Propagator and Chiral Symmetry with String Tension
General properties of the light and heavy quark propagators have been
investigated in the context of string tension interaction. Confinement, chiral
symmetry breaking, spectral properties of the propagator are analytically
studied and numerically validated. We show that the propagator is analytic in
the infrared region even for massless quarks with a non zero radius of
convergence. Emergence of more than one mass scale is exemplified. Massless
limit of the quark propagator does exhibit critical behaviour.Comment: 15 pages, 6 eps figures, LaTe
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