Laminar heat transfer and friction factor characteristics of carbon nano tube/water nanofluids.

This paper presents an experimental investigation on the convective heat transfer and friction factor characteristics of CNT/water nanofluid through a circular tube fitted with helical screw tape inserts with constant heat flux under laminar flow condition. Nanofluids of 0.1% and 0.2% volume fractions are prepared by two step method. Thermo-physical properties like thermal conductivity and viscosity are measured by using KD2 thermal property analyzer and Brooke field cone and plate viscometer respectively. From the measurements, it is found that the viscosity increase is substantially higher than the increase in the thermal conductivity. The helical screw tape insets with twist ratios Y = 3, 2.44 and 1.78 are used to study the convective heat transfer and friction factor characteristics under laminar flow in the Reynolds number range of 520-2500. It is observed that, in a plain tube, maximum enhancement in Nusselt number for 0.1% and 0.2% volume fractions of nanofluids compared to pure water is 15% and 32% respectively. With the use of inserts, maximum enhancement in Nusselt number corresponding to twist ratios of 1.78, 2.44 and 3 are obtained as 8%, 16% and 4.6% for 0.1% volume fraction of nanofluid and 5%, 4% and 12% for 0.2% volume fraction of nanofluid when compared with water in plain tube. Thermal performance factor evaluation revealed that the values at all Reynolds number for all twist ratios and both concentration of CNT nanofluid are greater than unity which indicates that helical screw tape inserts with twist ratios considered are feasible in terms of energy saving in laminar flow.

Paget's disease of the mandible.

Paget's disease (PD) is a chronic progressive disease of the bone characterized by abnormal bone resorption and deposition affecting either single bone (monostotic) or many bones (polyostotic) with uncertain etiology. We report a case of isolated mandibular involvement in a 65-year-old female patient, clinically asymptomatic with abnormally increased alkaline phosphatase level (1 368.1 U/l). Although prevalence of PD is common in western countries, but rare in Asian chapter, that too isolated mandibular involvement, considering this fact, we report this case of PD for documentation.

Distribution of enteric bacteria in the sediments of Parangipettai and Cuddalore coast of India.

Distribution of major groups of enteric bacteria viz., Escherichia coli, Shigella spp., Salmonella spp., Vibrio parahaemolyticus and Vibrio cholerae was studied in the sediment samples collected from different depths of 5, 15, 25 and 35 m in Parangipettai and Cuddalore coast during March, 2009 to February, 2010. Among the bacterial population in Parangipettai, V parahaemolyticus was found to be maximum with an occurrence of 55% followed by Shigella spp. (15%), V cholerae (12%), Salmonella spp. (12%) and E. coli (6%). In Cuddalore, as an oddity, Vibrio cholerae emerged as dominant species with an incidence of 60% of the total. V parahaemolyticus came next in the order with an incidence of 14%, followed by E. coli (11%), Shigella spp. (8%) and Salmonella spp. (7%). Similarly, monsoon and premonsoon seasons registered higher bacterial populations in both the regions. When the depth wise results were viewed, 5 and 15 m depths showed maximum (V parahaemolyticus 3.7 x 10 CFU g(-1) in Parangipettai; V cholera--8.6 x 10 CFU g(-1) in Cuddalore) bacterial population compared to subsequent depths. Cluster and MDS also showed distinct spatial and seasonal variations of bacterial populations in both the regions. Biota-Environment (BIO-ENV) method revealed the combinations of temperature, salinity and TOC as the best match influencing bacterial population.

Assessment of soft bottom polychaete diversity in Thondi, Palk Bay, India.

Polychaete assemblages are relatively poorly known in comparison to other components from Indian waters. In the present study, the spatial and seasonal distributions of polychaetes were investigated in the Thondi coastal area. Polychaete assemblage structure seems to be influenced by environmental parameters, such as temperature, salinity, pH, dissolved oxygen and total organic carbon. A total of 34 polychaete species were found, of which 26 species were in station I while 22 species in station II. There was a pronounced variation in diversity of polychaetes between the studied sites. Among the families maximum percentage of species constituted by Glyceridae (12%) and minimum Owenidae (4%) at station I and in station II, the Eunicidae (14%) was maximum and Pisinidae as (4%) minimum. The population density varied from 1456 to 2456 no m(-2) in station I; 2120 to 4424 in station II and diversity index varied from 1.96 to 2.48 in station I; 2.01 to 2.53 in station II. Species richness varied from 1.21 to 1.65 in station I; 1.36 to 1.69 in station II and evenness index varied from 0.9 to 0.97 in station I; 0.91 to 0.98 in station II. BIO-ENV analysis showed that salinity, TOC and temperature as the key variables in influencing the faunal distribution.

Alcohol use disorders (AUD) among tuberculosis patients: a study from Chennai, South India.

BACKGROUND: Alcohol Use Disorders (AUDs) among tuberculosis (TB) patients are associated with nonadherence and poor treatment outcomes. Studies from Tuberculosis Research Centre (TRC), Chennai have reported that alcoholism has been one of the major reasons for default and mortality in under the DOTS programme in South India. Hence, it is planned to conduct a study to estimate prevalence of alcohol use and AUDs among TB patients attending the corporation health centres in Chennai, India. METHODOLOGY: This is a cross-sectional cohort study covering 10 corporation zones at Chennai and it included situational assessment followed by screening of TB patients by a WHO developed Alcohol Use Disorders Identification Test AUDIT scale. Four zones were randomly selected and all TB patients treated during July to September 2009 were screened with AUDIT scale for alcohol consumption. RESULTS: Out of 490 patients, 66% were males, 66% were 35 years and above, 57% were married, 58% were from the low monthly income group of 8. Age (>35 years), education (less educated), income (

HIV prevention interventions in Chennai, India: are men who have sex with men being reached?

India has the greatest number of HIV infections in Asia and the third highest total number of infected persons globally. Men who have sex with men (MSM) are considered by the Government of India's National AIDS Control Organization (NACO) a "core risk group" for HIV in need of HIV prevention efforts. However there is a dearth of information on the frequency of participation in HIV prevention interventions and subsequent HIV risk and other correlates among MSM in India. Recruited through peer outreach workers, word of mouth and snowball sampling techniques, 210 MSM in Chennai completed an interviewer-administered assessment, including questions about participating in any HIV prevention interventions in the past year, sexual risk taking, demographics, MSM identities, and other psychosocial variables. Bivariate and multivariable logistic regression procedures were used to examine behavioral and demographic correlates with HIV prevention intervention participation. More than a quarter (26%) of the sample reported participating in an HIV prevention intervention in the year prior to study participation. Participants who reported engaging in unprotected anal sex (UAS; odds ratio [OR] = 0.28; p = 0.01) in the 3 months prior to study enrollment were less likely to have participated in an HIV prevention program in the past year. MSM who were older (OR = 1.04; p = 0.05), kothis (feminine acting/appearing and predominantly receptive partners in anal sex) compared to panthis (masculine appearing, predominantly insertive partners; OR = 5.52, p = 0.0004), those with higher educational attainment (OR = 1.48, p = 0.01), being "out" about having sex with other men (OR = 4.03, p = 0.0001), and MSM who reported ever having been paid in exchange for sex (OR = 2.92, p = 0.001) were more likely to have reported participation in an HIV prevention intervention in the preceding year. In a multivariable model, MSM reporting UAS in the prior 3 months were less likely to have participated in an HIV prevention intervention (AOR = 0.34, p = 0.04). MSM who were older (AOR = 1.05, p = 0.05), those with higher educational attainment (AOR = 1.92, p = 0.0009), and MSM who were "out" about having sex with other men (AOR = 2.71, p = 0.04) were more likely to have reported participating in an HIV prevention program. Findings suggest that exposure to HIV prevention interventions may be protective against engaging in UAS for some MSM in India. Understanding predictors of participation in an HIV prevention intervention is helpful for identifying Indian MSM who might have had no exposure to HIV prevention information and skills building, hence allowing researchers and prevention workers to focus efforts on individuals at greatest need.

Unseen and unheard: predictors of sexual risk behavior and HIV infection among men who have sex with men in Chennai, India.

In India men who have sex with men (MSM) are stigmatized, understudied, and at high risk for HIV. Understanding the impact of psychosocial issues on HIV risk behavior and HIV infection can help shape culturally relevant HIV prevention interventions. Peer outreach workers recruited 210 MSM in Chennai who completed an interviewer-administered psychosocial assessment battery and underwent HIV testing and counseling. More than one fifth (46/210) reported unprotected anal intercourse in the past 3 months, 8% tested positive for HIV, and 26% had previously participated in an HIV prevention intervention. In a multivariable logistic-regression model controlling for age, MSM subpopulation (kothi, panthi, or double-decker), marital status, and religion, significant predictors of any unprotected anal intercourse were being less educated (adjusted odds ratio [AOR] = .54; p = .009), not having previously participated in an HIV prevention program (AOR = 3.75; p = .05), having clinically significant depression symptoms (AOR = 2.8; p = .02), and lower self-efficacy (AOR = .40; p < .0001). Significant predictors of testing positive for HIV infection were: being less educated (AOR = .53; .05) and not currently living with parent(s) (AOR = 3.71; p = .05). Given the prevalence of HIV among MSM, efforts to reach hidden subpopulations of MSM in India are still needed. Such programs for MSM in India may need to address culturally-relevant commonly cooccurring psychosocial problems to maximize chances of reducing risk for infection.

Assessment of long term status of sputum positive pulmonary TB patients successfully treated with short course chemotherapy.

BACKGROUND: Long term status of pulmonary tuberculosis (PTB) patients treated with short course chemotherapy (SCC) regimens remains unknown. OBJECTIVE: To assess the clinical, bacteriological, radiological status and health related quality of life (HRQoL) of PTB patients 14-18 years after successful treatment with SCC. METHODOLOGY: In a cross-sectional study, cured PTB patients treated during 1986-1990 at the Tuberculosis Research Centre (TRC) were investigated for their current health status including pulmonary function tests (PFT). The St Georges respiratory questionnaire (SGRQ) was used to assess the HRQoL. RESULTS: The mean period after treatment completion for the 363 eligible participants was 16.5 yrs (range 14-18 yrs., 84% coverage); 25 (7%) had been re-treated and 52 (14%) died. Among the investigated, 58 (29%) had persistent respiratory symptoms; 170 (86%) had radiological sequelae but none had active disease. Abnormal PFT was observed in 96 (65%) with predominantly restrictive type of disease in 66 (45%). The SGRQ scores for activity and impact were high implying impairment in HRQoL. CONCLUSION: Assessment of long term status of cured PTB patients showed an impairment of lung functions and HRQoL highlighting the need to address these issues in the management of TB that may provide added value to patient care.

Use of benthic biodiversity for assessing the impact of shrimp farming on environment.

An attempt was made to find out the impact of shrimp farm discharges on benthic diversity in the discharge point of a shrimp farm. The duration of the study was one culture period right from stocking to harvest. The results revealed that the values of environmental entities were in the safe levels. As regards nutrients, maximum value of TOC and phosphorus were recorded in the sample collected after harvest and minimum in the sample collected during culture. BIO-ENV method revealed that nitrogen, sediment salinity and TOC were manifested as best variable combination explaining faunal distribution. Polychaetes are the dominant group (50%) with 13 species followed by crustaceans (32%) with 10 species, gastropods (10%) with 2 species and bivalves (8%) with 3 species. The faunal density was found to vary in relation to months as observed in the samples which were collected during various seasons in the other areas of estuary. In line with this, diversity values were also paralleled to the faunal density. In a nut shell, the study revealed no negative impact of shrimp farming to the estuarine benthic biota.

Fourier transform infrared and Raman spectral assignments and analysis of 7-amino-4-trifluoromethylcoumarin.

FTIR and FT-Raman spectra of 7-amino-4-trifluoromethylcoumarin (ATMC) have been recorded in the range 4000-400 and 3500-100 cm(-1), respectively, using Bruker IFS 66 V spectrometer. A detailed vibrational analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions, relative intensities, fundamentals, overtones and combination bands. With hope of providing more and effective information on the fundamental vibrations, a normal co-ordinate analysis has been performed by assuming C(S) point group symmetry. The simple valance force field (SVFF) has been employed in normal co-ordinate analysis and to calculate the potential energy distribution (PED) for each fundamental vibration are reported. The PED contribution to each of the observed frequencies shows the reliability and precision of the spectral analysis.

A novel rapid method for preparation of sample solution for chemical characterisation of titanium minerals by atomic spectrometry.

A new rapid decomposition and dissolution method with a mixture of sodium di-hydrogen orthophosphate and di-sodium hydrogen orthophosphate as a novel flux is described. The minerals are fused with (1:1) mixture of the above salts (flux) and the melt is dissolved in distilled water. The solution is diluted to desired volume depending on the instrumental technique used for determination. ICP-OES is used for the determination of Al, Ca, Mg, Cr, V, Si, Fe and Ti without interference from titanium, iron and sodium phosphate (introduced as flux). All the elements except Si and V are also determined by AAS. The use of nitrous oxide-acetylene flame eliminates the depression due to titanium in the measurement of Mg, Mn, Cr and Fe in air-acetylene flame. Synthetic mixture conforming to ilmenite and rutile composition are analyzed by ICP-OES and AAS to check the validity of the method. The results are in good agreement. The proposed method has been applied to natural samples and the results are evaluated against the established decomposition method using potassium bisulphate. Both ICP-OES and AAS yielded comparable results. The R.S.D. of the proposed method in case of ICP-OES varies from 0.5 to 2%, whereas for AAS it varies from 1.5 to 3% for different elements (n=5). The novelty of the proposed sample decomposition lies in its simplicity, ease and speed of fusion with minimal skills besides being eco-friendly unlike the reported tedious complicated decomposition procedures involving variety of fluxes and lot of hazardous chemicals.

Effect of Aroclor 1254 on Sertoli cellular antioxidant system, androgen binding protein and lactate in adult rat in vitro.

Polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental toxicants. Previous studies suggested that PCBs (Aroclor 1254) induce toxic effects including reproductive toxicity. The present study was designed to investigate the impact of Aroclor 1254 on Sertoli cellular function and antioxidant system of adult rat in vitro. Sertoli cells were isolated from adult rat testes and treated with various concentrations (10(-10) to 10(-7) M) of Aroclor 1254 for 6, 12 and 24 h. After the treatment period, cell viability was assessed and the Sertoli cellular antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), gamma-glutamyl transpeptidase (gamma-GT) and glutathione reductase (GR) and lipid peroxidation (LPO) were assayed. In addition, androgen binding protein (ABP) and lactate secretions were also quantified in Sertoli cell culture medium. Sertoli cellular viability and activity of antioxidant enzymes were significantly reduced in Aroclor 1254 (10(-10) to 10(-7) M) treatment for 6, 12 and 24 h whereas, the Sertoli cellular lipid peroxidation was significantly increased in a dose and duration dependent manner. In addition, ABP secretion diminished and lactate secretion was significantly elevated in the same manner. To conclude, the present study suggested that Aroclor 1254 disrupts Sertoli cellular metabolic functions such as ABP, lactate secretions and activity of antioxidant enzymes.

Impact of polychlorinated biphenyl Aroclor 1254 on testicular antioxidant system in adult rats.

To clarify the reproductive toxicity of polychlorinated biphenyl compounds through determination of testicular lipid peroxidation, reactive oxygen species and enzymatic and non-enzymatic antioxidants in rats exposed to Aroclor 1254. Adult male rats were administered Aroclor 1254 at a dose of 2 mg/kg per day ip for 30 days. The rats were sacrificed 24 hours after last dosing and the serum and other tissues collected and processed for relevant determinations. The body weight and the weights of the testis, epididymis, ventral prostate and seminal vesicle and the serum testosterone and estradiol were significantly decreased in Aroclor 1254 treated rats. The testicular lipid peroxidation, hydrogen peroxide and hydroxyl radical were significantly elevated whereas, testicular antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and glutathione reductase (GR) were significantly decreased. The non-enzymatic antioxidants, vitamin C and vitamin E, were also decreased. These results suggest that Aroclor 1254 induces an increase in the lipid peroxidation, hydrogen peroxide and hydroxyl radical and diminish in the antioxidant defense system in rats, indicating that the free radical-dependent mechanism may play an important role in the testicular toxicity of polychlorinated biphenyls.

Effects of Vitamin C and E on PCB (Aroclor 1254) induced oxidative stress, androgen binding protein and lactate in rat Sertoli cells.

The effect of Aroclor 1254 and the ameliorative effect of Vitamin C and E on Sertoli cell function were studied in adult male rats. The rats were administered Aroclor 1254 at a dose of 2 mg/kg bw/day intraperitoneally for 30 days. One group of rats received Vitamin C (100 mg/kg bw/day) while the other group received Vitamin E (50 mg/kg bw/day) orally simultaneously with Aroclor 1254 for 30 days. Necropsy was performed at 24 h after the last injection. Sertoli cells were isolated for the estimation of enzymatic antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GST), and gamma-glutamyl transpeptidase (gamma-GT). Lipid peroxidation (LPO), hydrogen peroxide and hydroxyl radical were estimated. Sertoli cellular androgen binding protein (ABP) and lactate were also quantified. Whereas body weight, testis weight, relative weight of testis, ABP, lactate and specific activities of SOD, CAT, GPx, GR, GST, gamma-GT were all decreased, the levels of hydrogen peroxide, hydroxyl radical and LPO were significantly increased in the Sertoli cells of Aroclor 1254 treated rats. Simultaneous administration of Vitamin C or E restored these parameters to a normal range. Thus, the present study suggests that Aroclor 1254 exposure induces oxidative stress in rat Sertoli cells and furthermore that simultaneous administration of Vitamin C or E ameliorated these effects.

A modified catalytic-photometric method for the determination of vanadium in chloride rich hydro-geochemical samples.

The vanadium content in chloride rich hydrogeochemical samples has been determined through a modification in the existing standard gallic acid oxidation method which has severe interference problem from halides. The modification incorporates a preliminary fume-drying of the sample aliquot with a mixture of perchloric and sulphuric acids. This ensures total removal of halides and hence their interference. The estimation is completed as per the standard method after taking the sample in 10 ml of 1% nitric acid. Also mercuric nitrate addition which forms a part of the standard procedure to prevent halide interference, is also dispensed with keeping in view the toxic nature of mercury. The method has been tried on a number of samples having varying chloride content. The results obtained compare well with the standard PAR method. The method can be used to determine vanadium down to 1 ppb. The relative standard deviation obtained for vanadium contents in the range 400-10 ppb is in the range 4-8.2%.