62 research outputs found
Synthesis, Spectroscopic and Physicochemical Characterization and Biological Activity of Co(II) and Ni(II) Coordination Compounds with 4-Aminoantipyrine Thiosemicarbazone
We describe the synthesis and characterization of cobalt(II) and nickel(II) coordination compounds of
4[N-(furan-2’-aldimine)amino]antipyrine thiosemicarbazone (FFAAPTS) and 4[N-(4'-nitrobenzalidene)
amino]antipyrine thiosemicarbazone (4'-NO2BAAPTS). All the isolated compounds have the
general composition MX2(L)(H2O) (M = Co2+ or Ni2+; X = Cl, Br, NO3, NCS or CH3COO; L = FFAAPTS or
4'-NO2BAAPTS) and M(ClO4)2(L)2 (M = Co2+ or Ni2+; L = FFAAPTS or 4'-NO2BAAPTS). Infrared spectral
studies indicate that both the thiosemicarbazones coordinate in their neutral form and they act as {N,N,S}
tridentate chelating ligands. Room temperature magnetic measurements and electronic spectral studies
suggest the distorted octahedral geometries of the prepared complexes. Thermogravimetric studies are also
reported and the possible structures of the complexes are proposed. Antibacterial and antifungal properties of
these metal-coordination compounds have also been studied
Management of difficult airway in intratracheal tumor surgery
BACKGROUND: Tracheal malignancies are usual victim of delay in diagnosis by virtue of their symptoms resembling asthma. Sometimes delayed diagnosis may lead to almost total airway obstruction. For difficult airways, not leaving any possibility of manipulation into neck region or endoscopic intervention, femorofemoral cardiopulmonary bypass can be a promising approach. CASE PRESENTATION: We are presenting a case of tracheal adenoid cystic carcinoma (cylindroma) occupying about 90% of the tracheal lumen. It was successfully managed by surgical excision of mass by sternotomy and tracheotomy under femorofemoral cardiopulmonary bypass (CPB). CONCLUSION: Any patient with recurrent respiratory symptoms should be evaluated by radiological and endoscopic means earlier to avoid delay in diagnosis of such conditions. Femorofemoral cardiopulmonary bypass is a relatively safe way of managing certain airway obstructions
Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network
Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
Ultralight vector dark matter search using data from the KAGRA O3GK run
Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM
Studies on the effect of picolines on the stereochemistry of Lanthanide (III) Nitrate coordination compounds of 4[N-Furfural) amino] antipyrine semicarbazone and antibacterial activities
The effect of α-, β- and γ-picolines on the stereochemistry of the coordination compounds of lanthanide(III) nitrates derived from 4[N-(furfural)amino]antipyrine semicarbazone (FFAAPS) has been studied. The general composition of the present coordination compounds is [Ln(FFAAPS)(NO3)3Pic] (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy or Ho and Pic=α-, β- or γ-picolines). All these coordination compounds have been characterized by elemental analyses, molecular weight, molar conductance, magnetic susceptibility, infrared and electronic spectra. The infrared studies suggest that the FFAAPS behaves as a neutral tridentate ligand with N, N, O donor while α-, β- or γ-picoline is coordinated to the lanthanide(III) ions via heterocyclic N-atom. Nitrates are bicovalently bonded in these compounds. From the electronic spectral data, nephelauxetic effect (β), covalence factor (b1/2), Sinha parameter (δ%) and the covalence angular overlap parameter (η) have been calculated. Thermal stabilities of these complexes have been studied by thermogravimetric analysis. The coordination number of lanthanide(III) ions in the present compound is found to be ten. The antibacterial studies screening of the primary ligand FFAAPS and the complexes showed that the present complexes have moderate antibacterial activities
Synthesis, physico-chemical and biological properties of complexes of cobalt(II) derived from hydrazones of isonicotinic acid hydrazide
Hydrazones of isonicotinic acid hydrazide, viz., N-isonicotinamido-furfuralaldimine (INH-FFL), N-isonicotnamido-cinnamalidine (INH-CIN) and N-isonicotnamido-3',4',5'-trimethoxybenzaldimine (INH-TMB) were prepared by reacting isonicotinic acid hydrazide with respective aromatic aldehydes, i.e., furfural, cinnamaldehyde or 3,4,5-trimethoxy-benzaldehyde. A new series of fifteen complexes of cobalt(II) with these new hydrazones, INH-FFL, INH-CIN and INH-TMB, were synthesized by their reaction with cobalt(II) salts. The infrared spectral data reveal that hydrazone ligands behave as a bidentate ligand with N, O donor sequence towards the Co2+ ion. The complexes were characterized on the basis of elemental analysis, magnetic susceptibility, conductivity, infrared and electronic spectral measurements. Analytical data reveal that the complexes have general composition [Co(L)2X2] and [Co(L)3](ClO4)2 where L= INH-FFL, INH-CIN or INH-TMB and X = Cl?,NO3?, NCS? or CH3COO?. The thermal behaviour of the complexes were studied using thermogravimetrictechnique. Electronic spectral results and magnetic susceptibility measurements are consistent with the adoption of a six-coordinate geometry for the cobalt(II) chelates. The antimicrobial properties of cobalt(II) complexes and few standard drugs have revealed that the complexes have very moderate antibacterial activities
Synthesis, spectral and thermal characteristics of some ten coordinated complexes of dioxouranium (VI) derived from semicarbazones as primary ligand and diphenyl sulfoxide as secondary ligand
The reactions of dioxouranium(VI) acetate with several semicarbazones derived from 4-aminoantipyrine in the presence of diphenyl sulfoxide (DPSO) led to the formation of complexes corresponding to the formulae [UO2(CH3COO)2 (L).DPSO], where L = 4[N-(benzalidene)amino]antipyrinesemicarbazone (BAAPS), 4[N-(2'-hydroxybenzalidene)- amino]antipyrinesemicarbazone (HBAAPS) 4[N-(4'-methoxybenzalidene)amino] antipyrine semicarbazone (MBAAPS) 4[N-(4'-dimethylaminobenzalidene)amino]- antipyrinesemicarbazone (DABAAPS) 4[N-(2'-nitrobenzalidene)amino]antipyrine- semicarbazone (2'-NO2 BAAPS) 4[N-(3'-nitrobenzalidene)amino]antipyrine- semicarbazone (3'-NO2BAAPS) 4[N-(4'-nitrobenzalidene)amino]antipyrine- semicarbazone (4'-NO2BAAPS), 4[N-(4'-hydroxy-3'-methoxybenzalidene)amino]- antipyrinesemicarbazone (HMBAAPS) 4[N-(2'-hydroxy-1'-naphthalidene)amino]- antipyrinesemicarbazone (HNAAPS) 4[N-(cinnamalidene)amino]antipyrine- semicarbazone (CAAPS)4[N-(3',4',5'-trimethoxybenzalidene)amino]antipyrine- semicarbazone (TMBAAPS) and 4[N-(furfural)amino]antipyrinesemicarbazone (FFAAPS). The complexes were characterised by means of elemental analyses, conductivity measurements, molecular weight, magnetic moments and infrared studies. The coordination number 10 is proposed for these complexes. Thermal properties of the representative complexes are also reported
Synthesis, spectral and thermal investigations of some mixed ligand complexes of thorium(IV) derived from semicarbazones and diphenyl sulfoxide
In the present work, the authors describe the synthesis of some mixed ligand complexes of thorium(IV) derived from 4[N-(2'-hydroxy-1'-naphthalidene)amino]antipyrine semicarbazone (HNAAPS) or 4[N-(cinnamalidene)amino]antipyrinesemicarbazone (CAAPS) as primary ligand and diphenyl sulfoxide (DPSO) as secondary ligand with the general composition ThX4.n(L).DPSO (n = 1, X = Cl, Br, NCS or NO3; n = 2, X = I or ClO4, L = HNAAPS or CAAPS). All the compounds were characterized through elemental analysis, molar conductance, molecular weight, infrared data and thermogravimetric analysis. The infrared studies reveal that the semicarbazones behave as neutral tridentate (N,N,O) while DPSO coordinates through its oxygen atom. The nitrates are bicovalently bonded, while thiocyanates are N-coordinated in these compounds. In conclusion, the coordination number of the central metal ion displays coordination number 7, 8, 9 or 12 depending on the nature of the anionic ligands
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