884 research outputs found
Is screening for diabetes among tuberculosis patients feasible at the field level?
Supported by the TB Union/MSF Course on Operational Researc
Preparation, Characterization and In Vitro Drug Release Studies of 6-mercaptopurine Thin Film
Oral thin films of 6-mercaptopurine were fabricated from mucoadhesive polymer, chitosan and polyvinylpyrrolidone for the purpose of prolonging drug release and improving its bioavailability. All fabricated film formulations prepared were smooth and translucent, with good flexibility. The weight and thickness of all the formulations were found to be uniform. These films were also evaluated for surface pH, folding endurance, swelling percentage (% S) and in vitro disintegration time. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) were used to evaluate the physico-chemical nature of the films. In-vitro drug release have shown enhanced release profiles for thin films compared to pure drug and the release patterns have been found to be pH dependant. The results of the study reveals that fabrication of 6-MP oral thin film by using solvent cast technology is a simple and an efficient method for drug delivery to achieve desired therapeutic compliance.Keywords: 6-mercaptopurine; In Vitro Drug Release; SEM; FTI
Discovering Polarized Communities in Signed Networks
Signed networks contain edge annotations to indicate whether each interaction
is friendly (positive edge) or antagonistic (negative edge). The model is
simple but powerful and it can capture novel and interesting structural
properties of real-world phenomena. The analysis of signed networks has many
applications from modeling discussions in social media, to mining user reviews,
and to recommending products in e-commerce sites. In this paper we consider the
problem of discovering polarized communities in signed networks. In particular,
we search for two communities (subsets of the network vertices) where within
communities there are mostly positive edges while across communities there are
mostly negative edges. We formulate this novel problem as a "discrete
eigenvector" problem, which we show to be NP-hard. We then develop two
intuitive spectral algorithms: one deterministic, and one randomized with
quality guarantee (where is the number of vertices in the
graph), tight up to constant factors. We validate our algorithms against
non-trivial baselines on real-world signed networks. Our experiments confirm
that our algorithms produce higher quality solutions, are much faster and can
scale to much larger networks than the baselines, and are able to detect
ground-truth polarized communities
Therapeutic hypothermia initiated within 6 hours of birth is associated with reduced brain injury on MR biomarkers in mild hypoxic ischemic encephalopathy: a non-randomised cohort study
Objective To examine the effect of therapeutic hypothermia on MR biomarkers and neurodevelopmental outcomes in babies with mild hypoxic-ischaemic encephalopathy (HIE). Design Non-randomised cohort study. Setting Eight tertiary neonatal units in the UK and the USA. Patients 47 babies with mild HIE on NICHD neurological examination performed within 6 hours after birth. Interventions Whole-body cooling for 72 hours (n=32) or usual care (n=15; of these 5 were cooled for <12 hours). Main outcome measures MRI and MR spectroscopy (MRS) within 2 weeks after birth, and a neurodevelopmental outcome assessment at 2 years. Results The baseline characteristics in both groups were similar except for lower 10 min Apgar scores (p=0.02) in the cooled babies. Despite this, the mean (SD) thalamic NAA/Cr (1.4 (0.1) vs 1.6 (0.2); p<0.001) and NAA/Cho (0.67 (0.08) vs 0.89 (0.11); p<0.001) ratios from MRS were significantly higher in the cooled group. Cooled babies had lower white matter injury scores than non-cooled babies (p=0.02). Four (27%) non-cooled babies with mild HIE developed seizures after 6 hours of age, while none of the cooled babies developed seizures (p=0.008). Neurodevelopmental outcomes at 2 years were available in 40 (85%) of the babies. Adverse outcomes were seen in 2 (14.3%) non-cooled babies, and none of the cooled babies (p=0.09). Conclusions Therapeutic hypothermia may have a neuroprotective effect in babies with mild HIE, as demonstrated by improved MRS biomarkers and reduced white matter injury on MRI. This may warrant further evaluation in adequately powered randomised controlled trials
Optimization of Vanadium Content for Achieving Higher Wear Resistance and Hardness in High Cr-V White Cast Irons for Ball Tube Mill Liner Application
The liner materials, being used, at present from high Cr cast iron grades in coal fired tube mills are less promising due to lower combination of abrasion wear resistance, hardness and impact toughness properties, thus giving life of only 25,000 to 35,000 hours. In this study, focus was given to develop a high Cr-V cast iron of high abrasion wear resistance with higher hardness and impact strength for ball tube mill liner application. The developed liner possesses high abrasive wear resistance and impact resistance simultaneously for having life of 40,000 to 50,000 hours. This grade was made using induction melting and sand casting method. The casting was heat treated in two stages to achieve higher abrasion wear resistance and mechanical properties. Various tests like chemical analysis, abrasion wear, hardness and impact tests were conducted on the above developed material. Abrasion wear test results show a low wear loss value (2.7 to 4.4 mg/min). Hardness and impact tests show a high combination of hardness (57 to 64 HRC) and impact strength (44 to 57 J/cm2). Prototype tube mill liners were manufactured and tested in a tube mill at 250MW site. Results obtained from site testing are also discussed in this study
Specific-Heat Exponent of Random-Field Systems via Ground-State Calculations
Exact ground states of three-dimensional random field Ising magnets (RFIM)
with Gaussian distribution of the disorder are calculated using
graph-theoretical algorithms. Systems for different strengths h of the random
fields and sizes up to N=96^3 are considered. By numerically differentiating
the bond-energy with respect to h a specific-heat like quantity is obtained,
which does not appear to diverge at the critical point but rather exhibits a
cusp. We also consider the effect of a small uniform magnetic field, which
allows us to calculate the T=0 susceptibility. From a finite-size scaling
analysis, we obtain the critical exponents \nu=1.32(7), \alpha=-0.63(7),
\eta=0.50(3) and find that the critical strength of the random field is
h_c=2.28(1). We discuss the significance of the result that \alpha appears to
be strongly negative.Comment: 9 pages, 9 figures, 1 table, revtex revised version, slightly
extende
Exploring the Anti-inflammatory and Anti-cancer compounds from the leaves of Acalypha indica
Abstract: Acalypha indica (Euphorbiaceae) is commonly known as Indian Copperleaf and India
Kurt Symanzik - a stable fixed point beyond triviality
In 1970 Kurt Symanzik proposed a "precarious" phi**4-theory with a negative
quartic coupling constant as a valid candidate for an asymptotically free
theory of strong interactions. Symanzik's deep insight in the non-trivial
properties of this theory has been overruled since then by the Hermitian
intuition of generations of scientists, who considered or consider this
actually non-Hermitian highly important theory to be unstable. This short -
certainly controversial - communication tries to shed some light on the
historical and formalistic context of Symanzik's theory in order to sharpen our
(quantum) intuition about non-perturbative theoretical physics between
(non)triviality and asymptotic freedom.Comment: 6 pages, no figures, new style files, revised for typos, improved
discussion, new references adde
Maximum gradient embeddings and monotone clustering
Let (X,d_X) be an n-point metric space. We show that there exists a
distribution D over non-contractive embeddings into trees f:X-->T such that for
every x in X, the expectation with respect to D of the maximum over y in X of
the ratio d_T(f(x),f(y)) / d_X(x,y) is at most C (log n)^2, where C is a
universal constant. Conversely we show that the above quadratic dependence on
log n cannot be improved in general. Such embeddings, which we call maximum
gradient embeddings, yield a framework for the design of approximation
algorithms for a wide range of clustering problems with monotone costs,
including fault-tolerant versions of k-median and facility location.Comment: 25 pages, 2 figures. Final version, minor revision of the previous
one. To appear in "Combinatorica
Stress perfusion cardiovascular magnetic resonance and serial fractional flow reserve assessment of the left anterior descending artery in patients undergoing right coronary artery chronic total occlusion revascularization
Background: Fractional flow reserve (FFR) assessment of remote arteries, in the context of a bystander chronic total occlusion (CTO), can lead to false positive results. Adenosine stress cardiovascular magnetic resonance (CMR) evaluates perfusion defects across the entire myocardium and may therefore be a reliable tool in the work-up of remote lesions in CTO patients. The IMPACT-CTO study investigated donor artery invasive physiology before, immediately post, and at 4 months following right coronary artery (RCA) CTO percutaneous coronary intervention (PCI). The aim of this subanalysis was to assess the concordance between baseline perfusion CMR and serial FFR evaluation of left anterior descending artery (LAD) ischemia in patients from the IMPACT-CTO study.Methods: Baseline adenosine stress CMR examinations from 26 patients were analyzed for qualitative evidence of LAD ischemia. The results were correlated with the serial LAD FFR measurements.Results: The present findings demonstrated that before RCA CTO PCI, there was 62% agreement between perfusion CMR and FFR (ischemic threshold ÂŁ 0.8) in the assessment of LAD ischemia (k = 0.29; fair concordance). At 4 months after revascularization, there was 77% agreement (k = 0.52; moderate concordance) between the index CMR assessment of LAD ischemia and the follow-up LAD FFR. Concordance was improved at a LAD FFR ischemic threshold of ÂŁ 0.75.Conclusions: In this hypothesis generating study, baseline CMR assessment of LAD ischemia correlated better with the 4 months LAD FFR data (threshold ÂŁ 0.8) as compared to the FFR measurements taken prior to RCA CTO revascularization
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