2,489 research outputs found
Coordination properties of vic-isonitrosoimines in their copper (II) and palladium (II) complexes
Preparation and structural characterization of palladium (II) complexes of ligands III-V and copper (II) complexes of III are reported. The elemental analyses of the complexes show that the metal: ligand ratio is 1:2. The electrical conductance in acetone shows the non-electrolytic nature of the complexes. The diamagnetic character suggests a gross square-planar geometry for the palladium (II) complexes. Copper (II) complexes are paramagnetic with μeff.~1·90 B.M. Spectral data suggest that in all the complexes the ligand coordinates to the metal (II) symmetrically through isonitroso-nitrogen and imine-nitrogen, forming a five membered chelate ring. Amine-exchange reactions of the complexes are discussed and compared on the basis of their structures
Broadband Passive Sonar Signal Simulation in Shallow Ocean
The broadband plane wave model is valid only in the far-field of a point source under free-field propagating conditions. However the acoustics in ocean is characterized by multi-modal acoustic propagation due to its top-bottom limited boundary conditions. The effect of multi-modal field is to alter the source spectrum while the effect of dispersion is to modify the pulse shape. Moreover the use of a plane wave beamformer in a multi-modal field leads to a bias in the bearing estimates. These effects are highly dependant on the environment parameters and have important ramifications for target localization and classification in an ocean waveguide. We propose a more realistic simulator which essentially models these effects and therefore serves to provide test signals for first hand verification of signal processing algorithms to be developed for such scenarios. This model is to be understood as a better model than the naïve plane wave model which is entirely oblivious of even the gross features such as wave propagation in an oceanic waveguide. The channel parameter so estimated from the present simulation can be convolved with the radiated noise spectra of the source to generate the passive sonar signal.Defence Science Journal, 2011, 61(4), pp.370-376, DOI:http://dx.doi.org/10.14429/dsj.61.8
Microalbuminuria and spot protein creatinine ratio in early pregnancy as a predictor of preeclampsia
Background: Hypertensive disorders complicate 5-10% of all the pregnancies and preeclampsia is identified in 3.9%.Preeclampsia is a pregnancy specific syndrome characterized by the development of hypertension and proteinuria in the second trimester of the pregnancy. Microalbuminuria and elevated spot protein creatinine ratio are commonly found in preeclampsia. The aim of this study was to determine microalbuminuria and spot creatinine ratio in early pregnancy as predictors of pre-eclampsia.Methods: The study was conducted among 102 pregnant women by detecting the levels of albuminuria and spot protein creatinine ratio at 10-14 weeks period of gestation. Random urine sample of about 5 ml was taken to analyse the samples for microalbuminuria and spot protein creatinine ratio. All the women included in the study were followed up till delivery to rule out the possibility of developing preeclampsia depending on their microalbumin and spot protein creatinine ratio values.Results: Pregnant women who developed preeclampsia or eclampsia had significantly higher levels of microalbumin and spot protein creatinine ratio.Conclusions: A detailed study among a larger group of population is required to determine that microalbuminuria and spot protein creatinine ratio in early pregnancy are definitive predictors of preeclampsia
Genetic correlates of longevity and selected age-related phenotypes: a genome-wide association study in the Framingham Study
BACKGROUND: Family studies and heritability estimates provide evidence for a genetic contribution to variation in the human life span. METHODS:We conducted a genome wide association study (Affymetrix 100K SNP GeneChip) for longevity-related traits in a community-based sample. We report on 5 longevity and aging traits in up to 1345 Framingham Study participants from 330 families. Multivariable-adjusted residuals were computed using appropriate models (Cox proportional hazards, logistic, or linear regression) and the residuals from these models were used to test for association with qualifying SNPs (70, 987 autosomal SNPs with genotypic call rate [greater than or equal to]80%, minor allele frequency [greater than or equal to]10%, Hardy-Weinberg test p [greater than or equal to] 0.001).RESULTS:In family-based association test (FBAT) models, 8 SNPs in two regions approximately 500 kb apart on chromosome 1 (physical positions 73,091,610 and 73, 527,652) were associated with age at death (p-value < 10-5). The two sets of SNPs were in high linkage disequilibrium (minimum r2 = 0.58). The top 30 SNPs for generalized estimating equation (GEE) tests of association with age at death included rs10507486 (p = 0.0001) and rs4943794 (p = 0.0002), SNPs intronic to FOXO1A, a gene implicated in lifespan extension in animal models. FBAT models identified 7 SNPs and GEE models identified 9 SNPs associated with both age at death and morbidity-free survival at age 65 including rs2374983 near PON1.
In the analysis of selected candidate genes, SNP associations (FBAT or GEE p-value < 0.01) were identified for age at death in or near the following genes: FOXO1A, GAPDH, KL, LEPR, PON1, PSEN1, SOD2, and WRN. Top ranked SNP associations in the GEE model for age at natural menopause included rs6910534 (p = 0.00003) near FOXO3a and rs3751591 (p = 0.00006) in CYP19A1. Results of all longevity phenotype-genotype associations for all autosomal SNPs are web posted at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007. CONCLUSION: Longevity and aging traits are associated with SNPs on the Affymetrix 100K GeneChip. None of the associations achieved genome-wide significance. These data generate hypotheses and serve as a resource for replication as more genes and biologic pathways are proposed as contributing to longevity and healthy aging
Thermodynamics of target peptide recognition by calmodulin and a calmodulin analogue: implications for the role of the central linker
The thermodynamics of interaction of two model peptides melittin and mastoparan with bovine brain calmodulin (CAM) and a smaller CAM analogue, a calcium binding protein from Entamoeba histolytica (CaBP) in 10 mM MOPS buffer (pH 7.0) was examined using isothermal titration calorimetry (ITC). These data show that CAM binds to both the peptides and the enthalpy of binding is endothermic for melittin and exothermic for mastoparan at 25°C. CaBP binds to the longer peptide melittin, but does not bind to mastoparan, the binding enthalpy being endothermic in nature. Concurrently, we also observe a larger increase in α-helicity upon the binding of melittin to CAM when compared to CaBP. The role of hydrophobic interactions in the binding process has also been examined using 8-anilino-1-naphthalene-sulphonic acid (ANS) binding monitored by ITC. These results have been employed to rationalize the energetic consequences of the binding reaction
Structure of CARDS toxin, a unique ADP-ribosylating and vacuolating Cytotoxin from Mycoplasma Pneumoniae
Mycoplasma pneumoniae (Mp) infections cause tracheobronchitis and walking pneumonia, and are linked to asthma and other reactive airway diseases. As part of the infectious process, the bacterium expresses a 591-aa virulence factor with both mono-ADP ribosyltransferase (mART) and vacuolating activities known as Community-Acquired Respiratory Distress Syndrome Toxin (CARDS TX). CARDS TX binds to human surfactant protein A and annexin A2 on airway epithelial cells and is internalized, leading to a range of pathogenetic events. Here we present the structure of CARDS TX, a triangular molecule in which N-terminal mART and C-terminal tandem beta-trefoil domains associate to form an overall architecture distinct from other well-recognized ADP-ribosylating bacterial toxins. We demonstrate that CARDS TX binds phosphatidylcholine and sphingomyelin specifically over other membrane lipids, and that cell surface binding and internalization activities are housed within the C-terminal beta-trefoil domain. The results enhance our understanding of Mp pathogenicity and suggest a novel avenue for the development of therapies to treat Mp-associated asthma and other acute and chronic airway diseases
2,5-Dimethylphenyl quinoline-2-carboxylate
In the title compound, C18H15NO2, the dihedral angle between the mean planes of the quinoline ring system and the phenyl ring is 78.8 (1)°. The mean plane of the carboxylate group is twisted from the mean planes of the quinoline ring system and phenyl ring by 1.5 (9) and 77.6 (4)°, respectively. In the crystal, molecules are linked by weak C-H...O interactions, generating C(8) chains along [001]. Weak [pi]-[pi] stacking interactions are also observed [centroid-centroid separation = 3.6238 (12) Å]
Sorption studies of divalent ions onto ternary beads of alginate, chitosan and carboxymethyl cellulose
The potential of sodium alginate (AL)/ chitosan (CS)/ carboxymethyl cellulose (CMC) beads as an adsorbent for removing the divalent metal ions such as Cu (II) and Ni (II) ions from aqueous solution was assessed in the current work using a batch adsorption technique. FT-IR and XRD measurements were used to investigate the formation of the ternary beads. The percentage removal of metal ions was investigated in batch mode as a function of metal ion solution pH, initial metal ion concentration, adsorbent dosage, and contact time. The observed outcome shows that the best pH for removing both metal ions was reported to be 5.0. The incorporation of experimental data in theoretical modelling exhibits that the adsorption would be multilayer through pseudo-second order (R2 > 0.9) kinetics. The removal efficiency of ternary beads reveals that copper ions (Cmax = 203.69 mg/g) were removed better than nickel ions (Cmax = 194.05 mg/g)
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