1,055 research outputs found
Application of Entropy Techniques in Analyzing Heart Rate Variabilityusing ECG Signals
The variation of the heart rate about a mean value is the Heart Rate Variability (HRV). HRV reflects the functioning of cardio-respiratory control system. It is used as one of the diagnostic measures to detect heart disorders. In the proposed work, HRV analysis using entropy measures is carried out on healthy, Congestive Heart Failure (CHF) and Atrial Fibrillations (AF) subjects using their ECG signals. The entropy methods used in the work are Approximate entropy (ApE), Symbolic entropy (SyE) and Spectral entropy (SpE). ECG signals of 20 healthy subjects in the age group of 21 – 30 years were acquired using dry electrode at a sampling rate of 500 Hz for 10 minutes. Signal processing algorithms for removal of baseline wandering, power line interference and motion artefacts were applied for the raw ECG signal. The ECG signals for CHF and AF subjects in the age group of 30 – 75 years were obtained from the Physionet database. From the analysis it was found that values of ApE and SyE were highest for AF subjects and for SpE, the value was highest for healthy subjects. Further, values of all the three entropies were lowest for CHF subjects. In conclusion, it indicates that the entropy techniques are useful tools in diagnosing patients having heart disorders
A Search for 6.7 GHz Methanol Masers in M33
We report the negative results from a search for 6.7 GHz methanol masers in
the nearby spiral galaxy M33. We observed 14 GMCs in the central 4 kpc of the
Galaxy, and found 3 sigma upper limits to the flux density of ~9 mJy in
spectral channels having a velocity width of 0.069 km/s. By velocity shifting
and combining the spectra from the positions observed, we obtain an effective
3sigma upper limit on the average emission of ~1mJy in a 0.25 km/s channel.
These limits lie significantly below what we would expect based on our
estimates of the methanol maser luminosity function in the Milky Way. The most
likely explanation for the absence of detectable methanol masers appears to be
the metallicity of M33, which is modestly less than that of the Milky Way
SYNTHESIS, CHARACTERIZATION, ANTI-MICROBIAL, ANTI-CANCER, AND ANTI-OXIDANT ACTIVITY OF NOVEL 1-(NAPHTHALEIN 2-YL OXY)(PHENYL)(METHYL) THIOUREA MANNICH BASE AND ITS METAL COMPLEXES
ABSTRACT
Objective: Mannich bases of 2-naphthol are predominantly popular in metal-mediated and ligand-accelerated catalysis of enantioselective carbon-carbon bond formation. Since these compounds have multiple centre for chelation with metal ions, they are likely to be potent inhibitors of metallo-enzymes. A number of pharmaceutical and agricultural agents have a naphthalein frame work. Our present study focuses on the synthesis of Mannich base derived from the condensation of 2-naphthol, benzaldehyde and thiourea and its metal complexes and their biological activities.
Methods: The ligand 1-(naphthalein -2-yloxy )(phenyl)(methyl) thiourea (BNBTU) was synthesized by Mannich condensation reaction between 2- naphthol, benzaldehyde and thiourea in 1:1:1 molar ratio. Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of the new Mannich base BNBTU have been synthesized.
Results: The anti-bacterial activity of the ligand and all the metal complexes leads to the conclusion that most of the complexes were found to have activities against E.coli   and B. subtilis. The cytotoxic effects of the newly synthesized ligand have been found good inhibition activity against the cancer cell line. Further the ligand and the metal complexes have been screened for their fungicidal and anti-oxidant properties and they are found to be significantly active.
Conclusion: The ligand 1-(naphthalein -2-yloxy )(phenyl)(methyl) thiourea (BNBTU) has shown as one of the novel ligand and its coordination with transition metals exhibited enhanced biological activity
The Arecibo Methanol Maser Galactic Plane Survey - II: Statistical and Multi-wavelength Counterpart Analysis
We present an analysis of the properties of the 6.7 GHz methanol maser sample
detected in the Arecibo Methanol Maser Galactic Plane Survey. The distribution
of the masers in the Galaxy, and statistics of their multi-wavelength
counterparts is consistent with the hypothesis of 6.7 GHz maser emission being
associated with massive young stellar objects. Using the detection statistics
of our survey, we estimate the minimum number of methanol masers in the Galaxy
to be 1275. The l-v diagram of the sample shows the tangent point of the
Carina-Sagittarius spiral arm to be around 49.6 degrees, and suggests
occurrence of massive star formation along the extension of the Crux-Scutum
arm. A Gaussian component analysis of the maser spectra shows the mean
line-width to be 0.38 km/s which is more than a factor of two larger than what
has been reported in the literature. We also find no evidence that faint
methanol masers have different properties than those of their bright
counterparts.Comment: Accepted by ApJ; Revised footnote number 3 on page 8 based on private
communicatio
Agricultural bio-waste recycling through efficient microbial consortia
In India and other countries, rice straw, a byproduct of rice production, is burned in enormous amounts, which contributes to environmental pollution and climate change by releasing greenhouse gases viz., CO2, N2O, CH4, into the atmosphere. This study aimed to accelerate the degradation of this enormous amount of agricultural biomass via microbial inoculants. Four treatments—rice straw (RS), rice straw plus water (RSW), rice straw plus water plus Pusa decomposer (RSWF), and rice straw plus water plus Tamil Nadu Agricultural University (TNAU) biomineralizer (RSWB) were used in the current investigation. The study's findings demonstrated that rice straw treated with microorganisms decomposed more quickly than RS and RSW treatments. According to EDAX spectra of elemental composition, the carbon content of rice straw in the RS, RSW, RSWF, and RSWB treatments was 33.66%, 29.75%, 13.33%, and 20.65% w/w, respectively. The RSWF treatment of rice straw was found to have the highest nitrogen concentration (0.64% w/w), followed by RSWB (0.61% w/w), RSW (0.45%) w/w, and RS (0.43% w/w). Treatments RSWF and RSWB had lower C/N ratios 20.83, and 33.85, respectively, than that RSW (66.11) and RS (78.28). The RSWF and RSWB treatments' porous, distorted, and rough surface structures provided further evidence that both microbial consortia could decompose rice straw more quickly than the RSW and RS treatments. Therefore, the results of this study imply that rice straw could be added to the soil to improve soil fertility for sustainable crop production rather than being burned
Heterologous Processing and Export of the Bacteriocins Pediocin PA-1 and Lactococcin A in Lactococcus Lactis:A Study with Leader Exchange
The bacteriocins pediocin PA-1 and lactococcin A are synthesized as precursors carrying N-terminal extensions with a conserved cleavage site preceded by two glycine residues in positions -2 and -1. Each bacteriocin is translocated through the cytoplasmic membrane by an integral membrane protein of the ABC cassette superfamily which, in the case of pediocin PA-1, has been shown to possess peptidase activity responsible for proteolytic cleavage of the pre-bacteriocin. In each case, another integral membrane protein is essential for bacteriocin production. In this study, a two-step PCR approach was used to permutate the leaders of pediocin PA-1 and lactococcin A. Wild-type and chimeric pre-bacteriocins were assayed for maturation by the processing/export machinery of pediocin PA-1 and lactococcin A. The results show that pediocin PA-1 can be efficiently exported by the lactococcin machinery whether it carries the lactococcin or the pediocin leader. It can also compete with wild-type lactococcin A for the lactococcin machinery. Pediocin PA-1 carrying the lactococcin A leader or lactococcin A carrying that of pediocin PA-1 was poorly secreted when complemented with the pediocin PA-1 machinery, showing that the pediocin machinery is more specific for its bacteriocin substrate. Wild-type pre-pediocin and chimeric pre-pediocin were shown to be processed by the lactococcin machinery at or near the double-glycine cleavage site. These results show the potential of the lactococcin LcnC/LcnD machinery as a maturation system for peptides carrying double-glycine-type amino-terminal leaders
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