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D Mukherjee

Publications and source records attributed to D Mukherjee.

At least 19 recordsLinked to original sources
PubMed2007

Relativistic coupled-cluster calculations of parity nonconservation in Ba+ by the sum-over-states approach.

The authors present the results of their calculation for the parity nonconserving 5p(6)6s(1/2)-->5p(6)5d(3/2) transition in Ba+ using the relativistic coupled-cluster theory in the singles, doubles, and partial triples approximation. The contributions from the leading intermediate states are explicitly considered. It is found that the largest contribution comes from the |5p(6)6p(1/2)> state. Their results are in reasonable agreement with other calculations.

Journal Article↗
PubMed2006

Electric quadrupole moments of the D states of alkaline-earth-metal ions.

The electric quadrupole moment for the 4d(2)D(5/2) state of (88)Sr(+); one of the most important candidates for an optical clock, has been calculated using the relativistic coupled-cluster theory. This is the first application of this theory to determine atomic electric quadrupole moments. The result of the calculation is presented and the important many-body contributions are highlighted. The calculated electric quadrupole moment is (2.94 +/- 0.07)ea(2)(0), where a(o) is the Bohr radius and the electronic charge while the measured value is (2.6 +/- 0.3) ea(2)(0). This is so far the most accurate determination of the electric quadrupole moment for the above mentioned state. We have also calculated the electric quadrupole moments for the metastable 4d(2)D(3/2) state of 88(Sr(+) and for the 3d(2)D(3/2.5/2) and 5d(2)D(3/2.5/2) states of (43)Ca(+) and (138)Ba(+), respectively.

Journal Article↗
PubMed2005

Size-resolved kinetic measurements of aluminum nanoparticle oxidation with single particle mass spectrometry.

Aluminum nanoparticles are being considered as a possible fuel in advanced energetic materials application. Of considerable interest therefore is a knowledge of just how reactive these materials are, and what the effect of size on reactivity is. In this paper we describe results of size resolved oxidation rate using a recently developed quantitative single particle mass spectrometer (SPMS). Aluminum nanoparticles used were either generated by DC Arc discharge or laser ablation, or by use of commercial aluminum nanopowders. These particles were oxidized in an aerosol flow reactor in air for specified various temperatures (25-1100 degrees C), and subsequently sampled by the SPMS. The mass spectra obtained were used to quantitatively determine the elemental composition of individual particles and their size. We found that the reactivity of aluminum nanoparticles is enhanced with decreasing primary particle size. Aluminum nanoparticles produced from the DC Arc, which produced the smallest primary particle size (approximately 19 nm), were found to be the most reactive (approximately 68% aluminum nanoparticles completely oxidized to aluminum oxide at 900 degrees C). In contrast, nanopowders with primary particle size greater than approximately 50 nm were not fully oxidized even at 1100 degrees C (approximately 4%). The absolute rates observed were found to be consistent with an oxide diffusion controlled rate-limiting step. We also determined the size-dependent diffusion-limited rate constants and Arrehenius parameters (activation energy and pre-exponential factor). We found that as the particle size decreases, the rate constant increases and the activation energy decreases. This work provides a quantification of the known pyrophoric nature of fine metal particles.

Journal Article↗
PubMed2005

Extracardiac vascular disease and effectiveness of sustained clopidogrel treatment.

OBJECTIVE: To assess the effectiveness of long term treatment with clopidogrel of patients with extracardiac vascular disease (ECVD) (a history of either peripheral arterial disease or cerebrovascular disease). DESIGN: Subgroup analysis of a prospective randomised clinical trial. SETTING: The CREDO (clopidogrel for the reduction of events during observation) trial was a randomised, double blind, placebo controlled trial conducted at 99 centres in North America from June 1999 through April 2001. PATIENTS: 2116 patients who were to undergo elective coronary intervention or were deemed at high likelihood of undergoing percutaneous coronary intervention were enrolled in the CREDO trial. The current study sample consisted of 272 patients with ECVD. MAIN OUTCOME MEASURE: One year incidence of the composite of death, myocardial infarction, or stroke in the intent to treat population. RESULTS: Patients with ECVD had a more than twofold greater relative risk reduction with clopidogrel for the primary end point compared with patients without ECVD (47.9%, 95% confidence interval (CI) -4.2% to 73.9%, v 18.2%, 95% CI -10.5 % to 39.5%, respectively). CONCLUSIONS: Longer term clopidogrel treatment provides added protection against thrombotic events throughout the arterial vasculature, not limited to the coronary arteries, and may be especially effective for patients with more diffuse atherosclerosis such as ECVD.

Aged↗
PubMed2005

Flucloxacillin alone or combined with benzylpenicillin to treat lower limb cellulitis: a randomised controlled trial.

OBJECTIVE: To determine whether using intravenous benzylpenicillin in addition to intravenous flucloxacillin would result in a more rapid clinical response in patients with lower limb cellulitis. METHODS: This was a randomised controlled trial set in an inner city teaching hospital, comprising 81 patients with lower limb cellulitis requiring intravenous antibiotics. The main outcome measure was the mean number of doses of antibiotic required until clinical response. RESULTS: The mean number of doses required was 8.47 (95% confidence interval (CI) 7.09 to 9.86) in the benzylpenicillin and flucloxacillin combined group. In the flucloxacillin only group it was 8.71 doses (95% CI 6.90 to 10.5), a mean difference of -0.24 doses (95% CI -2.48 to 2.01, p = 0.83). Other markers of treatment efficacy showed no difference between groups at review the following day; temperature decrease (mean difference -0.07 degrees C, 95% CI -0.76 to 0.62, p = 0.84), or diameter decrease of affected area (mean difference -34 mm, 95% CI -99 to 31, p = 0.30). Patient subjective assessments were also similar between the different drug regimen; improvement on a visual analogue scale of pain/discomfort from admission to first review (mean difference 10 mm, 95% CI -12.6 to 14.2, p = 0.91) and on second review (mean difference 15 mm, 95% CI -18.6 to 21.6, p = 0.88). Patient overall subjective feelings of improvement on first review (p = 0.32) and on second review (p = 0.64) were also similar. CONCLUSIONS: This study provides no evidence to support the addition of intravenous benzylpenicillin to intravenous flucloxacillin in the treatment of lower limb cellulitis.

Adult↗
PubMed2005

Lack of clopidogrel-CYP3A4 statin interaction in patients with acute coronary syndrome.

OBJECTIVE: To assess a clinically significant interaction between cytochrome P450 3A4 (CYP3A4) metabolised statin and clopidogrel. DESIGN: Prospective single centre cohort study. SETTING: Academic teaching hospital in the USA. PATIENTS: 1651 patients presenting with acute coronary syndromes between January 1999 and February 2003 were studied. Data on baseline demographics, co-morbidities, and in-hospital management were collected. MAIN OUTCOME MEASURE: Association of CYP3A4 metabolised statin and clopidogrel use with in-hospital and six month mortality. The impact of the combined use of a CYP3A4 statin and clopidogrel on six month mortality and major adverse cardiac events was analysed by a risk adjusted logistic regression model. RESULTS: The odds ratios for six month mortality were: for CYP3A4 statin, 0.43 (95% confidence interval (CI) 0.27 to 0.71, p = 0.0009); for CYP3A4 statin plus clopidogrel, 0.36 (95% CI 0.23 to 0.60, p < 0.001); for non-CYP3A4 statin, 0.22 (95% CI 0.08 to 0.59, p = 0.002); and for non-CYP3A4 statin plus clopidogrel, 0.22 (95% CI 0.06 to 0.75, p = 0.016). CONCLUSIONS: Use of a combination of a CYP3A4 statin plus clopidogrel was associated with lower six month mortality and morbidity in patients with acute coronary syndromes. There was no significant difference in clinical benefit between a CYP3A4 statin and a non-CYP3A4 statin when used in conjunction with clopidogrel. This suggests that the proposed interaction is probably an ex vivo phenomenon and may not be clinically relevant.

Aged↗
PubMed2005

Body mass index in Bengali adolescents.

We describe a mixed longitudinal analysis of body mass index (BMI) in a group of Bengali adolescents (age 11-17 years) from a middle income family background and compare this against existing national and international data. Healthy school children, comprising of 416 boys and 343 girls were consented for annual repeat measurements of weight, height and pubertal staging between the years 1998 and 2001. The LMS method was used to construct smoothed BMI mean and standard deviation (SD) curves. Bengali adolescents have lower BMI than affluent Indian children and are -1 to -2 SD below US children. BMI increases in adolescence (boys: r = 0.49, p < 0.001, girls: r = 0.54, P < 0.001) with age but SMR does not have an independent effect on BMI.

Adolescent↗
PubMed2004

Pseudoaneurysm following lateral wall myocardial infarction.

Pseudoaneursym (PA) formation of left ventricle (LV) following acute myocardial infarction (AMI) is uncommon and is usually believed to be associated with a grave prognosis. We describe a case of 55 year old male patient presented with AMI and heart failure with a systolic murmur later diagnosed to have PA of the lateral wall of LV on echocardiography (transthoracic and transesophageal, TTE andTEE). Cardiac MRI and coronary angiogram (CAG) were performed. CAG showed 60% lesion at origin of major obtuse marginal artery (OM1). The patientwas advised surgical treatment, but he refused and took discharge against medical advice on 27th dayof admission on stable condition.

Aneurysm, False↗
PubMed2002

Platelet glycoprotein IIb/IIIa inhibition in acute coronary syndromes. Gradient of benefit related to the revascularization strategy.

AIMS: To assess the efficacy of platelet glycoprotein IIb/IIIa inhibitors in patients with acute coronary syndromes primarily medically managed. METHODS AND RESULTS: We performed a meta-analysis of the randomized clinical trials of platelet glycoprotein IIb/IIIa inhibitor therapy in the medical management of non-ST-elevation acute coronary syndromes. Among 29570 patients, IIb/IIIa integrin blockade was associated with a reduction in death or non-fatal myocardial infarction at 30 days, from 11.5% to 10.7% (odds ratio 0.91,P =0.02). Patients undergoing percutaneous coronary intervention during index hospitalization sustained a greater reduction in ischaemic events (odds ratio 0.82, P=0.01) than patients medically managed (odds ratio 0.95, P=0.27). Among patients undergoing intervention, the benefit was more pronounced if the procedure was performed during glycoprotein IIb/IIIa inhibitor infusion (odds ratio 0.74; P=0.02), than if revascularization was performed after drug discontinuation (odds ratio 0.87,P =0.17). CONCLUSION: This analysis, including the entire large-scale trial experience of intravenous glycoprotein IIb/IIIa inhibitors in patients with acute coronary syndromes primarily medically managed, demonstrates an overall significant, albeit moderate, reduction in 30-day death or myocardial infarction associated with therapy. Although not based on a prospectively defined hypothesis, the findings suggest a gradient of benefit conferred by these agents depending on the revascularization strategy used.

Acute Disease↗
PubMed2002

Cardiac risk in noncardiac surgery.

Preoperative risk assessment plays an important role in reducing perioperative morbidity and mortality in patients undergoing noncardiac surgery. In general, evaluation should reflect the circumstances of the consultation and the nature of the surgical illness. If emergent surgery is indicated, it may not allow further cardiac assessment or treatment. Perioperative medical management, surveillance and postoperative risk stratification is appropriate in these cases and may be instrumental to improving long-term outcomes. Successful perioperative evaluation is best achieved with an integrated multidisciplinary approach and good communication between the patient, primary care physician, anesthesiologist, consultant, and surgeon. A thorough history and physical examination is the most important component of a comprehensive preoperative evaluation. In general, indications for further cardiac testing and treatments are similar to those in the nonoperative setting. Coronary revascularization before noncardiac surgery is indicated in only a small subgroup of patients at very high cardiac risk. Finally, the goal of appropriate preoperative evaluation and therapy should be to not only improve immediate periprocedural outcomes but should also be geared towards improved long term clinical outcome.

Cardiovascular Diseases↗