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1.
RSC Adv ; 10(56): 33747-33752, 2020 Sep 10.
Article in English | MEDLINE | ID: mdl-35519042

ABSTRACT

Superhydrophobic/superoleophilic materials have shown great potential for applications in oil/water separation. However, practical applications of these materials are restricted due to their toxicity and complicated, expensive, and non-eco-friendly fabrication procedures. Here, we have successfully developed an easy, simple, cost-effective, and environmentally friendly strategy towards the synthesis of superhydrophobic and superoleophilic porous polypyrrole nanotubes. Such wettability has been introduced into polypyrrole by co-doping with sodium dodecylbenzenesulfonate, a surfactant for lowering surface energy and controlling the morphology of the nanotubes. These non toxic and environment friendly polymer nanotubes exhibit oil absorption capability from oil/water mixtures with a reasonable efficiency with good reusability.

2.
Indian Heart J ; 71(4): 360-363, 2019.
Article in English | MEDLINE | ID: mdl-31779867

ABSTRACT

There is a paucity of experience regarding His bundle pacing (HBP) at laboratories initially attempting the procedure, especially in the Indian scenario. Patient who underwent HBP were selected for pacing therapy or in lieu of cardiac resynchronization therapy (CRT) at a single center. Among 22 patients attempted, 19 patients underwent successful implant, achieving selective HBP in 14 patients. There was a significant improvement in left ventricular ejection fraction (LVEF) (49.3 ± 9.3 vs. 36.7 ± 9.2) in the LV dysfunction subgroup (n = 6). Over a follow-up of 15 ± 6.5 months, thresholds were stable in all except one patient, and there was no requirement of lead revision. In summary, we found that HBP is a feasible option for achieving physiological pacing.


Subject(s)
Bundle of His/physiopathology , Cardiac Pacing, Artificial , Aged , Atrial Fibrillation/physiopathology , Atrial Fibrillation/therapy , Bundle-Branch Block/physiopathology , Bundle-Branch Block/therapy , Coronary Disease/physiopathology , Coronary Disease/therapy , Electrocardiography , Feasibility Studies , Female , Humans , India , Male
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 137: 790-803, 2015 Feb 25.
Article in English | MEDLINE | ID: mdl-25277627

ABSTRACT

This study reports about the optimized molecular structures, vibrational wavenumbers, atomic charges, molecular electrostatic potentials, NBO, electronic properties, (1)H NMR and (13)C NMR chemical shifts for the molecules 2-chloro-4-nitropyridine (CNP), 2-chloro-4-methyl-5-nitropyridine (CMNP) and 3-amino-2-chloro-4-methylpyridine (ACMP). Theoretical calculations were performed by density functional theory (DFT)/B3LYP method using 6-311++G (d,p) basis set. The stability and charge delocalization of the title molecules were studied by natural bond orbital (NBO) analysis. Molecular electrostatic potential maps (MEP) were calculated to predict the reactive sites. The reactivity of the title compounds were investigated by HOMO-LUMO energies and global descriptors. The electronic properties of the compounds were also discussed and the transitions were found to be π→π(∗). In addition, the thermodynamic properties were studied for the title compounds and corresponding relations between the properties and temperature were also discussed. The hyperpolarizability values (ßtot) were calculated for the title compounds. Hyperpolarizability value (ßtot) of CMNP was found to be high and nineteen times greater than that of urea.


Subject(s)
Magnetic Resonance Spectroscopy , Pyridines/chemistry , Algorithms , Chemistry, Pharmaceutical , Electrons , Molecular Conformation , Molecular Structure , Normal Distribution , Software , Spectrophotometry , Static Electricity , Urea/chemistry
5.
Indian Heart J ; 66(5): 525-9, 2014.
Article in English | MEDLINE | ID: mdl-25443606

ABSTRACT

BACKGROUND: Second generation bare metal stents made of cobalt chromium alloy are superior to first generation stain less steel stents. The thin struts are shown to reduce clinical and angiographic adverse outcomes. OBJECTIVE: To study the long term clinical and angiographic outcomes in patients who underwent coronary angioplasty with an indigenously made cobalt chromium bare metal stents with thin strut Cobal+C™ (Relisys). METHODS: A total of 268 consecutive patients who underwent coronary angioplasty with Cobal+C stents were studied retrospectively. Clinical follow up was done after a minimum period of nine months through telephonic interview and angiographic follow up was done in 80 patients chosen randomly. The end points analyzed included major adverse cardiac events (MACE) at nine months and the rate of binary restenosis at follow up angiogram done between 9 and 15 months post angioplasty. RESULTS: Thirty four percent were diabetic and 33% had acute myocardial infarction. Females constituted 17%. Mean stent diameter was 2.88 ± 0.28 and mean stent length 18.8 ± 4.2. MACE at nine months was 4.5% with TLR 0.3%. The rate of binary restenosis was 21%. Patients with longer stent lengths and non-compliance with medications had significantly higher rates of binary restenosis. CONCLUSIONS: The use of Relisys Cobal+C stents was associated with good long term clinical and angiographic outcomes as evidenced by low incidence of MACE and binary restenosis rates for a bare metal stent.


Subject(s)
Coronary Disease/surgery , Prosthesis Design , Stents , Adult , Aged , Aged, 80 and over , Angioplasty, Balloon, Coronary , Chromium , Cobalt , Coronary Angiography , Coronary Restenosis/epidemiology , Female , Follow-Up Studies , Humans , India/epidemiology , Male , Middle Aged , Percutaneous Coronary Intervention , Retrospective Studies , Treatment Outcome
6.
Article in English | MEDLINE | ID: mdl-24291430

ABSTRACT

This study represents the conformation, tautomeric stability, protonation and deprotonation effects, vibrational, electronic, NBO and NMR aspects of 2,4-Dioxoimidazolidine-5-acetic acid (DOIAA). Theoretical calculations were performed by ab initio HF and density functional theory (DFT)/B3LYP method using 6-311++G(d,p) basis sets. Tautomerism and the effect of solvent on the tautomeric equilibria in the gas phase and in different solvents were studied. The protonation and deprotonation effects on the reactivity and conformations of DOIAA were investigated. Electronic transitions were also studied and the most prominent transition corresponds to π→π*. Natural bond orbital (NBO) analysis was also carried out to find the intramolecular interactions and their stabilization energy. In DOIAA, the interaction between the lone pair donor orbital (n(LP1N5)) and the acceptor antibonding orbital π*(C6O7) reveals the strong stabilization energy of 224.9 kJ mol(-1). Molecular electrostatic potential (MEP) was calculated to predict the reactive sites of the title compound. The NMR results indicated that the observed chemical shifts for NH, COOH protons of DOIAA not only depend on the structure of the molecule being studied but also on the nature of the solvent, concentration of the sample and the presence of the other exchangeable protons.


Subject(s)
Acetates/chemistry , Acetic Acid/chemistry , Hydantoins/chemistry , Magnetic Resonance Spectroscopy , Models, Molecular , Protons , Quantum Theory , Vibration , Electrons , Molecular Conformation , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Static Electricity , Stereoisomerism , Thermodynamics
7.
Indian Heart J ; 66(6): 612-6, 2014.
Article in English | MEDLINE | ID: mdl-25634394

ABSTRACT

INTRODUCTION: Atrial synchronous left ventricular (LV) only pacing using two leads and VDD pacemaker could be a cost effective alternative to conventional cardiac resynchronization therapy (CRT). METHODS: We implanted right atrial (RA) and LV leads with VDD pulse generator (LV only pacing) in five carefully screened heart failure patients who could not afford conventional CRT. All had NYHA class III/IV symptoms despite maximal guideline directed medical therapy. The sensed atrioventricular delay was programmed to pre-excite the LV and achieve fusion beat. Response to treatment was assessed at 6 months. RESULTS: Four patients were males. The mean age was 58 ± 12 years. At follow up, there was improvement in electrocardiographic, and echocardiographic parameters: Mean QRS duration decreased from 174 ± 17 msec to 128 ± 10.9 msec (p = 0.009), LV end-diastolic diameter decreased from 73.2 ± 12 mm to 65.8 ± 9.6 mm (p = 0.026), LV end-systolic diameter decreased from 65 ± 12 mm to 54 ± 10 mm (p = 0.020). There was a trend towards reduction of LV end-systolic and end-diastolic volumes. LV ejection fraction improved from 25 ± 6% to 34 ± 6% (p = 0.013) and left atrial dimension reduced from 44 ± 4 mm to 39 ± 5 mm (p = 0.045). All patients improved clinically. CONCLUSION: RA-LV pacing using VDD pacemaker is a safe and effective technique of CRT. This may be a cost effective alternative to conventional CRT for patients in developing countries.


Subject(s)
Heart Failure/therapy , Pacemaker, Artificial/economics , Adult , Aged , Cardiac Resynchronization Therapy/economics , Cost-Benefit Analysis , Female , Heart Failure/physiopathology , Heart Ventricles/physiopathology , Humans , Male , Middle Aged , Treatment Outcome
8.
Indian Heart J ; 65(4): 478-81, 2013.
Article in English | MEDLINE | ID: mdl-23993015

ABSTRACT

Focal atrial tachycardias (AT) in the right atrium (RA) tend to cluster around the crista terminalis, coronary sinus (CS) region, tricuspid annulus, and para-hisian region. In most cases, the AT focus can be identified by careful activation mapping, and completely eliminated by radiofrequency (RF) catheter ablation. However, RF ablation near the His bundle (HB) carries a risk of inadvertent damage to the atrioventricular (AV) conduction system. Here we describe a patient with an AT originating in the vicinity of the AV node, which was successfully ablated earlier from non-coronary aortic cusp (NCC), and recurred with an exit from para-hisian location. Respiratory excursions of the catheter were associated with migration to the area of HIs. This was successfully ablated during controlled apnoea, using 3D electroanatomic mapping.


Subject(s)
Bundle of His/physiopathology , Catheter Ablation , Tachycardia, Supraventricular/physiopathology , Tachycardia, Supraventricular/surgery , Electrocardiography , Female , Humans , Middle Aged
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 107: 334-46, 2013 Apr 15.
Article in English | MEDLINE | ID: mdl-23434562

ABSTRACT

This study represents the vibrational, electronic, NMR, NLO, reactivity and structural aspects of (3Z)-3-(2-oxo-2-phenylethylidene)-1,3-dihydro-2H-indol-2-one (OPEDI). A detailed interpretation of the FT-IR, FT-Raman, UV and NMR spectra were reported. Theoretical calculations were performed by ab initio HF and density functional theory (DFT)/B3LYP method using 6-311++G(d,p) basis sets. The most preferred Z isomer (cis-configuration) was confirmed through PES scan studies. The vibrational wavenumbers and potential energy distribution (PED) of various normal modes were calculated. The lower frontier orbital energy gap and high dipole moment of OPEDI illustrates the high reactivity. The stability and charge delocalization of the molecule was studied by natural bond orbital (NBO) analysis. OPEDI exhibited good nonlinear optical activity and was 13 times greater than that of urea. Molecular electrostatic potential (MEP) was carried out for predicting the reactive sites. The NMR results indicated that the observed chemical shifts depend not only on the structure of the molecule being studied, but also on the solvent used.


Subject(s)
Indoles/chemistry , Magnetic Resonance Spectroscopy , Models, Molecular , Quantum Theory , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
10.
Article in English | MEDLINE | ID: mdl-22248456

ABSTRACT

This study represents an integrated approach towards understanding the vibrational, electronic, NMR, reactivity and structural aspects of 2-amino-4H-chromene-3-carbonitrile (ACC). A detailed interpretation of the FT IR, UV and NMR spectra were reported. Theoretical calculations were performed by ab initio HF and density functional theory (DFT)/B3LYP method using 6-311++G(d,p) basis sets. The electronic properties was also studied and the most prominent transition corresponds to π→π*. The lower frontier orbital energy gap and high dipole moment illustrates the high reactivity of the title molecule. The NMR results indicated that the observed chemical shifts depend not only on the structure of the molecule being studied, but also on the solvent used. ACC exhibited good nonlinear optical activity and was much greater than that of urea. Molecular electrostatic potential (MEP) results predicted that the enaminonitrile fragment of ACC to be the most reactive site for both electrophilic and nucleophilic attack. In addition, the thermodynamic properties of the compound were calculated at different temperatures and corresponding relations between the properties and temperature were also studied.


Subject(s)
Benzopyrans/chemistry , Magnetic Resonance Spectroscopy , Nitriles/chemistry , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Models, Molecular , Quantum Theory , Thermodynamics
11.
Indian Pacing Electrophysiol J ; 9(6): 364-9, 2009 Nov 01.
Article in English | MEDLINE | ID: mdl-19898661

ABSTRACT

Ventricular tachycardia (VT) occurring late after myocardial infarction is often due to reentry circuit in the peri-infarct zone. The circuit is usually located in the sub-endocardium, though subepicardial substrates are known. Activation mapping during VT to identify target regions for ablation can be difficult if VT is non inducible or poorly tolerated. In the latter, a substrate based approach of mapping during sinus rhythm in conjunction with pace mapping helps to define the reentry circuit and select target sites for ablation in majority of patients with hemodynamically unstable VT. Percutaneous epicardial catheter ablation has been attempted as an approach where ablation by a conventional endocardial access has been unsuccessful. We report a case of post myocardial infarction scar VT which could be successfully ablated with a substrate based approach from the epicardial aspect.

12.
Pacing Clin Electrophysiol ; 32 Suppl 1: S211-3, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19250098

ABSTRACT

INTRODUCTION: Cardiac resynchronization therapy (CRT) is an established treatment for patients with heart failure. However, one-third of the patients fail to improve with this therapy. Stimulation with different left ventricular stimulation (LVS) configurations has been used to prevent diaphragmatic capture and to decrease the capture thresholds. We evaluated the hemodynamic effects of different LVS configurations using echocardiography. METHODS: Recipients of CRT systems capable of multiple LVS configurations were studied. Biventricular capture was confirmed for each polarity and echocardiographic measurements were made. The atrioventricular and interventricular delays were optimized and kept constant during the study. The cardiac output (CO), myocardial performance index (MPI), and severity of mitral regurgitation (MR) were recorded for all LVS configurations and compared for the best and the worst configurations, determined by CO. RESULTS: We studied 10 men and four women, 55 +/- 13 years of age on average. The CO and MPI changed significantly by changing the LVS configurations. The difference in CO ranged from 0.3 to 1.5 L, and seven patients (50%) showed > or =20% difference in CO between best and worst LVS configurations. Severity of MR decreased by > or =1 grade in nine patients, while in two patients MR worsened despite improvement in CO. CONCLUSIONS: Changing the LVS configuration changes hemodynamic function in some CRT system recipients.


Subject(s)
Cardiac Pacing, Artificial/methods , Heart Failure/diagnosis , Heart Failure/prevention & control , Therapy, Computer-Assisted/methods , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/prevention & control , Female , Heart Failure/complications , Humans , Male , Middle Aged , Treatment Outcome , Ventricular Dysfunction, Left/complications
13.
J Am Soc Echocardiogr ; 17(5): 466-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15122189

ABSTRACT

Demonstration of coronary collaterals has been mostly done by coronary angiographic techniques. Coronary collaterals have been demonstrated by transthoracic echocardiography for patients with anomalous origin of coronary arteries from pulmonary artery. Indirect assessment of collaterals to an infarct-related artery has been done using myocardial contrast echocardiography. We describe in this article 3 patients with coronary artery disease in whom coronary collaterals were demonstrated by transthoracic echocardiography before angiography. To our knowledge, coronary collateral demonstration by transthoracic echocardiography before angiography in patients with coronary artery disease has not been previously reported.


Subject(s)
Angina Pectoris/physiopathology , Coronary Vessels/diagnostic imaging , Echocardiography, Doppler, Color , Angina Pectoris/diagnostic imaging , Angina Pectoris/etiology , Collateral Circulation , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/etiology , Coronary Artery Disease/physiopathology , Coronary Vessels/physiopathology , Humans , Male , Middle Aged
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