Photophysical properties and fluorosolvatochromism of D-π-A thiophene based derivatives.

Solvation-dependent photophysical properties of two push-pull thiophene-based compounds with donor-π-acceptor (D-π-A) structures were investigated using absorption, fluorescence emission and time resolved spectroscopy, and supported by different solvation models. Intramolecular charge transfer characteristics of the structurally similar 2-fluoro-4-(5-(4-methoxyphenyl)thiophen-2-yl)benzonitrile (MOT) and 4-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-fluorobenzonitrile (DMAT) were investigated. Significant enhancement of intramolecular charge transfer strength has been observed through molecular structure modification of the electron donating group from a methoxy to dimethylamine group. Ground state absorption spectra show a small red shift of about 10 nm and 18 nm while the fluorescence emission spectra show a large red shift of about 66 nm and 162 nm on changing from the nonpolar cyclohexane to the aprotic polar DMSO for MOT and DMAT, respectively. Dipole moment change from the ground state to the charge transfer excited state is calculated to be 6.6 D in MOT and 9.0 D in DMAT. The fluorescence quantum yield, fluorescence lifetime and the derived radiative and non-radiative rate constants were found to be better correlated to the emission energy rather than any of the solvent properties. Three multi-parametric relationships were used in the interpretation of the specific versus non-specific solute-solvent interactions, namely, Kamlet-Taft, Catalán and Laurence et al. models. The findings of these approaches are used to extract useful information about different aspects of solvent effects on the photophysical properties of the two studied compounds. Kamlet-Taft solvatochromic model indicates that non-specific interactions are dominant in controlling the photophysical properties. Catalán's solvent dipolarity/polarizability parameter is found to play a significant role in solvatochromic behaviour which is also designated by the Laurence model.

Development of community based curriculum on ophthalmology for under graduate medical course in Bangladesh.

The curriculum represents the expression of educational ideas in practice. Ophthalmic education is the corner stone to improve eye care globally. Curriculum needs continuous modification varying in different geographic locations. Though 90% of common conditions are either preventable or curable but emphasis on the common conditions is inadequate. This is a stepwise descriptive study aiming to develop a community based ophthalmology curriculum for undergraduate medical course in Bangladesh conducted during March 2007 to February 2008 at UniSA School of Public Health and Life Sciences, University of South Asia, Banani, Dhaka. Delphi technique, a modified qualitative method was used to accumulate data and reaching a consensus opinion for developing the curriculum. Study approach includes two iterative rounds and finally a workshop. Iteration of round-I was "What are the eye diseases with overall knowledge of their management one MBBS physician should acquire"; followed by a list of eye diseases and topics for expert opinion. The response was collated. Iteration round-II was "How much a MBBS student should have percentage of knowledge, attitude and skills on each topic while being taught". The response was collated and presented to panel of expert ophthalmologists for discussion and validation. In the round-I Delphi, 400 (62%) out to total 641 ophthalmologist were randomly selected dividing in categories (62% in each) of Professor-22, Associate Professor-12, Assistant Professor-26, Consultant-27, ophthalmologists working in NGO-56 and ophthalmologists in private sector-257. Sixty (15%) responded with opinion. In the round-II, 200 (31%) including 60 of round-I, selected randomly but proportionately as before. Forty five (22.5%) responded with opinion. Result collated. The results and opinion of respondents were presented at a workshop attended by 24 (80%), out of 30 invited expert ophthalmic specialists for discussion, criticism, opinion, addition, modification and finally for validation. On the basis of the opinion of the respondents, reviewing literature, analyzing the ocular disease pattern in Bangladesh and also analyzing the present ophthalmology curriculum, a community and need based ophthalmology curriculum for undergraduate medical course in Bangladesh was developed. This research would help developing community and need based ophthalmology curriculum for undergraduate medical course in Bangladesh.

Steroid-responsive large vessel vasculitis: application of whole-brain 320-detector row dynamic volume CT angiography and perfusion.

SUMMARY: A patient with suspected giant cell arteritis and prior negative findings on superficial temporal artery biopsy was evaluated with 320-detector row CT angiography (CTA) and whole-brain perfusion. Corticosteroid treatment was initiated on the basis of CT angiography findings of arteritis and a cortical perfusion deficit. The patient's symptoms and perfusion imaging findings resolved following therapy. Whole-brain CTA and imaging was helpful in the diagnosis and monitoring this patient with suspected vasculitis.

Reduction in urinary arsenic levels in response to arsenic mitigation efforts in Araihazar, Bangladesh.

BACKGROUND: There is a need to identify and evaluate an effective mitigation program for arsenic exposure from drinking water in Bangladesh. OBJECTIVE: We evaluated the effectiveness of a multifaceted mitigation program to reduce As exposure among 11,746 individuals in a prospective cohort study initiated in 2000 in Araihazar, Bangladesh, by interviewing participants and measuring changes in urinary As levels. METHODS: The interventions included a) person-to-person reporting of well test results and health education; b) well labeling and village-level health education; and c) installations of 50 deep, low-As community wells in villages with the highest As exposure. RESULTS: Two years after these interventions, 58% of the 6,512 participants with unsafe wells (As >/=50 microg) at baseline had responded by switching to other wells. Well labeling and village-level health education was positively related to switching to safe wells (As < 50 mug/L) among participants with unsafe wells [rate ratio (RR) = 1.84; 95% confidence interval (CI), 1.60-2.11] and inversely related to any well switching among those with safe wells (RR = 0.80; 95% CI, 0.66-0.98). The urinary As level in participants who switched to a well identified as safe (< 50 microg As/L) dropped from an average of 375 microg As/g creatinine to 200 microg As/g creatinine, a 46% reduction toward the average urinary As content of 136 microg As/g creatinine for participants that used safe wells throughout. Urinary As reduction was positively related to educational attainment, body mass index, never-smoking, absence of skin lesions, and time since switching (p for trend < 0.05). CONCLUSIONS: Our study shows that testing of wells and informing households of the consequences of As exposure, combined with installation of deep community wells where most needed, can effectively address the continuing public health emergency from arsenic in drinking water in Bangladesh.

Socioeconomic status and risk for arsenic-related skin lesions in Bangladesh.

OBJECTIVES: Arsenic contamination of groundwater is a severe public health crisis in Bangladesh, where the population is exposed to arsenic in drinking water through tube wells used for groundwater collection. In this study, we explored the association between socioeconomic status and arsenic toxicity. METHODS: We used baseline data from 11438 men and women who were recruited into the Health Effects of Arsenic Longitudinal Study (HEALS), a prospective cohort study on the health effects of arsenic exposure in Bangladesh. We conducted analyses with logistic regression and generalized estimating equations. RESULTS: We found a strong dose-response association with all measures of arsenic exposure and skin lesions. We also found that the effect of arsenic was modified by land ownership on a multiplicative scale, with an increased risk among non-land owners associated with well water arsenic (P=.04) and urinary total arsenic concentrations (P=.03). CONCLUSIONS: Our study provides insight into potentially modifiable host characteristics and identifies factors that may effectively target susceptible population subgroups for appropriate interventions.

Prevalence of arsenic exposure from drinking water and awareness of its health risks in a Bangladeshi population: results from a large population-based study.

We conducted a population-based prevalence survey in Araihazar, Bangladesh, to describe the distribution of arsenic exposure in a rural Bangladeshi population and to assess the population's awareness to this problem as well as to possible remediation options. Water samples from 5,967 contiguous tube wells in a defined geographic area were tested using laboratory-based methods. Additionally, for each well, the owner/caretaker (or a close relative) was interviewed regarding his or her awareness of the health consequences of As exposure. Arsenic exposure data and demographic characteristics for the 65,876 users of these wells were also collected from the 5,967 respondents. Among the 65,876 residents, more than half (54%) regularly consumed well water with an As concentration > or = 50 microg/L--above the acceptable government standard in Bangladesh. Respondents were 15-92 years of age, with an average age of 42 years, and 43% were male. Presence of awareness was significantly related to male sex, nonlabor head of household occupation, better housing, and having had the well tested for As concentration. Most respondents (92%) expressed a willingness to take steps to reduce their exposure, with switching to a safe well the most favored option (46.2%). Willingness to reduce exposure was positively related to awareness of the health risks of As. However, the association between awareness and switching to a safe well [odds ratio (OR) = 1.25; 95% confidence interval (CI), 1.01-1.54] was no stronger than the associations between awareness and using surface water (with or without treatments) (OR = 1.54; 95% CI, 1.22-1.95) or using an existing well after treatment or increasing the depth (OR = 1.34; 95% CI, 1.08-1.67). These findings suggest that health education programs may need to target individuals with lower socioeconomic status and that well switching should be encouraged with more appropriate health education. Increasing knowledge of the health consequences of As may be an important element in facilitating remediation.

Magnesium sulphate versus diazepam in the management of eclampsia.

This clinical trial was conducted to compare the anticonvulsant response of magnesium sulphate and diazepam in the management of eclampsia. The study was carried out at the eclampsia unit of Dhaka Medical College Hospital during the period from October, 1995 to January, 1996. Two hundred consecutive admitted patients were recruited for the study and randomly assigned to two treatment groups: magnesium sulphate and diazepam. One hundred patients received injection magnesium sulphate and another one hundred received injection diazepam. All patients of both the group were matched for baseline characteristics. Convulsion was controlled in 95% of the patients of magnesium sulphate group and 74% of the patients of diazepam group (p < .0005). The mean controlling time is also significantly lower in magnesium sulphate group than diazepam group (8.50 hours vs 9.39 hours). Patients of magnesium sulphate group regain consciousness much earlier (mean time 20.62 hrs.) than the patients of diazepam group (mean time 40.62 hrs.). No significant difference was observed in controlling blood pressure and foetal outcome. The study finding shows that magnesium sulphate has some advantage over diazepam in controlling convulsion and regaining consciousness. If magnesium sulphate can be made available in the market by local production it may be recommended to use this drug in the primary health care without any hazzard before referring to other hospital.