A REVIEW ON VARIATION OF NATURAL RADIOACTIVITY ALONG THE SOUTHEAST COAST OF TAMIL NADU FOR THE PAST 4 DECADES (1974-2016)

This review deals with natural radioactivity variation along the southeast coast of Tamil Nadu for the past four decades (1974-2016). About 40 research works have been conducted along the coast since 1974 in various environmental matrices using a variety of experimental methods. For these measurements researchers are adopted different experimental methods. The measured gamma dose rate ranged from 30 to 8700 nGy/h. The mean specific activity of 238U, 232Th and 40K was found to be 58.8 ± 28.7, 465.2 ± 147.3 and 311.2 ± 27.8 Bq/kg, respectively. The calculated annual exposure rate ranged from 0.29 to 12.8 mSv/y with the mean value of 3.7 mSv/y which is above the global average of 2.4 mSv/y as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (Report to General Assembly, Annex B Exposures of the public and workers from various sources of radiation. United Nations, New York (2008)). Plant food items recorded low 210Po activities as compared to seafood organisms. Grain size, season and place of sampling have a decisive bearing on coastal radioactivity. Therefore, it is concluded from the review data that there is an appreciable elevation in background radiation level in the coastal region. This review suggests that new radiological surveys using improved methodology that cover the entire coastal stretch are needed.

Evaluation of Oxacillin and Cefoxitin Disk Diffusion and MIC Breakpoints Established by the Clinical and Laboratory Standards Institute for Detection of mecA-Mediated Oxacillin Resistance in Staphylococcus schleiferi

Staphylococcus schleiferi is a beta-hemolytic, coagulase-variable colonizer of small animals that can cause opportunistic infections in humans. In veterinary isolates, the rate of mecA-mediated oxacillin resistance is significant, with reported resistance rates of >39%. The goal of this study was to evaluate oxacillin and cefoxitin disk diffusion (DD) and MIC breakpoints for detection of mecA-mediated oxacillin resistance in 52 human and 38 veterinary isolates of S. schleiferi Isolates were tested on multiple brands of commercial media and according to Clinical and Laboratory Standards Institute (CLSI) methods. Zone diameters and MIC values were interpreted using CLSI breakpoints (CLSI, Performance Standards for Antimicrobial Susceptibility Testing. M100-S27, 2017) for Staphylococcus aureus/Staphylococcus lugdunensis, coagulase-negative staphylococci (CoNS), and Staphylococcus pseudintermedius Results were compared to those of mecA PCR. Twenty-nine of 90 (32%) isolates were mecA positive. Oxacillin inhibition zone sizes and MICs interpreted by S. pseudintermedius breakpoints reliably differentiated mecA-positive and mecA-negative isolates, with a categorical agreement (CA) of 100% and no very major errors (VMEs) or major errors (MEs) for all media. For cefoxitin DD results interpreted using S. aureus/S. lugdunensis and CoNS breakpoints, CA values were 85% and 75%, respectively, and there were 72% and 64% VMEs, respectively, and 0 MEs. For cefoxitin MICs interpreted using S. aureus/S. lugdunensis breakpoints, CA was 81%, and there were 60% VMEs and no MEs. Our data demonstrate that oxacillin DD or MIC testing methods using the current S. pseudintermedius breakpoints reliably identify mecA-mediated oxacillin resistance in S. schleiferi, while cefoxitin DD and MIC testing methods perform poorly.

Altered pharmacokinetics of rosiglitazone in a mouse model of non-alcoholic fatty liver disease

BACKGROUND

Severe forms of non-alcoholic fatty liver disease (NAFLD) adversely affect the liver physiology and hence the pharmacokinetics of drugs. Here, we investigated the effect of NAFLD on the pharmacokinetics of rosiglitazone, an insulin sensitizer used in the treatment of type 2 diabetes.

METHODS

Male C57BL/6 mice were divided into two groups. The first group (n=14) was fed with normal chow feed and the second group (n=14) was fed with 60% high-fat diet (HFD) and 40% high fructose liquid (HFL) for 60 days to induce NAFLD. The development of NAFLD was confirmed by histopathology, liver triglyceride levels and biochemical estimations, and used for pharmacokinetic investigations. Rosiglitazone was administered orally at 30 mg/kg dose. At predetermined time points, blood was collected and rosiglitazone concentrations were determined using LC/MS/MS. Plasma concentrations were subjected to non-compartmental analysis using Phoenix WinNonlin (6.3), and the area under the plasma concentration-time curve (AUC) was calculated by the linear-up log-down method.

RESULTS

HFD and HFL diet successfully induced NAFLD in mice. Rosiglitazone pharmacokinetics in NAFLD animals were altered significantly as compared to healthy mice. Rosiglitazone exposure increased significantly in NAFLD mice (2.5-fold higher AUC than healthy mice). The rosiglitazone oral clearance was significantly lower and the mean plasma half-life was significantly longer in NAFLD mice as compared to healthy mice.

CONCLUSIONS

The NAFLD mouse model showed profound effects on rosiglitazone pharmacokinetics. The magnitude of change in rosiglitazone pharmacokinetics is similar to that observed in humans with moderate to severe liver disease. The present animal model can be utilized to study the NAFLD-induced changes in the pharmacokinetics of different drugs.

Dissipation kinetics of beta-cyfluthrin and imidacloprid in tea and their transfer from processed tea to infusion

Dissipation kinetics of mixed formulation consisting beta-cyfluthrin and imidacloprid in tea crop under an open field ecosystem was investigated. The mixed formulation was applied on tea plant at recommended (27 + 63) and double the recommended (54 + 126g a.i./ha) dose and residues were determined using gas chromatography-electron capture detector and high performance liquid chromatography-photodiode array detector for beta-cyfluthrin and imidacloprid, respectively. The limit of quantification of analytical method was 0.05µg/g and the average recoveries were ranged from 88.36% to 103.49% with relative standard deviations of less than 6% at three spiked levels. The experimental results showed that in the green tea leaves imidacloprid dissipated faster than beta-cyfluthrin with the half-life ranging between 1.20-1.39 and 2.89-3.15days, respectively. The beta-cyfluthrin residues present in the processed tea not transferred into the tea infusion during the infusion process and imidacloprid transferred in the range 43.12-49.7%. On the basis of the transfer of residues from processed tea to infusion, a waiting period of 17 days for tea plucking after pesticide application at recommended dose may be suggested.

Enrolment and retention of people who inject drugs in the Needle & Syringe Exchange Programme in Malaysia

Setting: Needle and Syringe Exchange Programme (NSEP) implemented by non-governmental organisations in Malaysia. Objectives: To determine enrolment, characteristics and retention in the NSEP of people who inject drugs (PWID) between 2013 and 2015. Design: Retrospective cohort study. Results: There were 20 946 PWID, with a mean age of 38 years. The majority were male (98%) and of Malay ethnicity (92%). Follow-up data were available for 20 761 PWID. Annual retention of newly enrolled PWID for each year was respectively 85%, 87% and 78% for 2013, 2014 and 2015, although annual enrolment over these years declined from 10 724 to 6288 to 3749. Total person-years (py) of follow-up were 27 806, with loss to follow-up of 40 per 100 py. Cumulative probability of retention in NSEP was 66% at 12 months, 45% at 24 months and 26% at 36 months. Significantly higher loss to follow-up rates were observed in those aged 15-24 years or ⩾50 years, females, transgender people and non-Malay ethnic groups. Conclusion: Annual retention of new PWID on NSEP was impressive, although enrolment declined over the 3 years of the study and cumulative loss to follow-up was high. A better understanding of these programmatic outcomes is required.

Multifocal Tuberculosis

Multifocal Tuberculosis represents the many faces of an age old disease. It is characterized by the presence of large multifocal tuberculous areas in same or different organs. A 50 year old male patient, presented with features suggestive of renal failure, low grade fever and cough with mucoid expectoration. He was found to have pulmonary TB, genitourinary TB and tuberculous lymphadenitis. He was started on antituberculous treatment to which he showed good response.

Biomass yielding potential of naturally regenerated Prosopis juliflora tree stands at three varied ecosystems in southern districts of Tamil Nadu, India

Fuel energy demand is of great concern in recent times due to the depletion of fossil fuel resources. Biomass serves as widely available primary renewable energy source. Hence, a study was performed to assess the above-ground biomass yielding capability of fuel wood tree Prosopis juliflora in three varied ecosystems viz., coastal, fallow land and riparian ecosystems in southern districts of Tamil Nadu. The results showed that the biomass production potential and above-ground net primary productivity of P. juliflora depend on the age of the tree stands and the nature of ecosystem. A higher biomass yield was observed for P. juliflora trees with 5 to 10 years old when compared to less than 5 years of their age. Among the three ecosystems, the maximum biomass production was recorded in riparian ecosystem. The stands with less than 5-year-old P. juliflora trees gave 1.40 t/ha, and 5- to 10-year-old tree stands produced 27.69 t/ha in riparian ecosystem. Above-ground net primary productivity of both the age groups was high in fallow land ecosystem. In riparian ecosystem, the wood showed high density and low sulphur content than the other two ecosystems. Hence, P. juliflora biomass can serve as an environmentally and economically feasible fuel as well as their utilization proffers an effective means to control its invasiveness.

Early Changes in Brain Oxygen Tension May Predict Outcome Following Severe Traumatic Brain Injury

We report on the change in brain oxygen tension (PbtO2) over the first 24 h of monitoring in a series of 25 patients with severe traumatic brain injury (TBI) and relate this to outcome. The trend in PbtO2 for the whole group was to increase with time (mean PbtO2 17.4 [1.75] vs 24.7 [1.60] mmHg, first- vs last-hour data, respectively; p = 0.002). However, a significant increase in PbtO2 occurred in only 17 patients (68 %), all surviving to intensive care unit discharge (p = 0.006). Similarly, a consistent increase in PbtO2 with time occurred in only 13 patients, the correlation coefficient for PbtO2 versus time being ≥0.5 for all survivors. There were eight survivors and four non-survivors, with low correlation coefficients (<0.5). Significantly more patients with a correlation coefficient ≥0.5 for PbtO2 versus time survived in intensive care (p = 0.039). The cumulative length of time that PbtO2 was <20 mmHg was not significantly different among these three groups. In conclusion, although for the cohort as a whole PbtO2 increased over the first 24 h, the individual trends of PbtO2 were related to outcome. There was a significant association between improving PbtO2 and survival, despite these patients having cumulative durations of hypoxia similar to those of non-survivors.

Soil radioactivity measurements and estimation of radon/thoron exhalation rate in soil samples from Kalpakkam residential complex

The objective of this study is to compute the primordial radionuclides activity in soil samples and estimate the radon/thoron exhalation rates. A total of 25 locations were chosen for the study at Kalpakkam. Ambient radiation levels were monitored prior to collection of samples, which were subjected to gamma spectrometry. While (238)U concentration was found to be below detectable limit, the activities of (232)Th and (40)K were varying from 34.53 to 1093.11 Bq kg(-1) and 36.6 to 570.08 Bq kg(-1), respectively. The radium equivalent activities (Raeq) were in the range of 83-1574 Bq kg(-1). There was no appreciable radon exhalation, and the thoron surface exhalation rate varied from 942 to 7720 Bq m(-2) h(-1). The annual effective dose was ranging from 0.05 to 0.81 mSv y(-1). Good correlation was observed between (232)Th content and thoron exhalation rate. The details of the study are presented in this article.

Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V2O5 for the degradation of phenols

Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V2O5 in natural sunlight exposure. V2O5 was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼ 5% per 100ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V2O5 in the photocatalytic process. In sunlight exposure, V2O5 powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V2O5 followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive oxygen species (ROS) was also explored.

Aggression is associated with aerobic glycolysis in the honey bee brain(1)

Aerobic glycolysis involves increased glycolysis and decreased oxidative catabolism of glucose even in the presence of an ample oxygen supply. Aerobic glycolysis, a common metabolic pattern in cancer cells, was recently discovered in both the healthy and diseased human brain, but its functional significance is not understood. This metabolic pattern in the brain is surprising because it results in decreased efficiency of adenosine triphosphate (ATP) production in a tissue with high energetic demands. We report that highly aggressive honey bees (Apis mellifera) show a brain transcriptomic and metabolic state consistent with aerobic glycolysis, i.e. increased glycolysis in combination with decreased oxidative phosphorylation. Furthermore, exposure to alarm pheromone, which provokes aggression, causes a metabolic shift to aerobic glycolysis in the bee brain. We hypothesize that this metabolic state, which is associated with altered neurotransmitter levels, increased glycolytically derived ATP and a reduced cellular redox state, may lead to increased neuronal excitability and oxidative stress in the brain. Our analysis provides evidence for a robust, distinct and persistent brain metabolic response to aggression-inducing social cues. This finding for the first time associates aerobic glycolysis with naturally occurring behavioral plasticity, which has important implications for understanding both healthy and diseased brain function.

Comparative supercapacitance performance of CuO nanostructures for energy storage device applications

(a)–(c) FE-SEM images of CuO nanoplates on Ni foam, flower-shaped CuO and bud-shaped CuO. (d) Specific capacitance and (d) and (e) Ragone plots of power density vs. energy density according to CuO electrodes in an asymmetrical device.

Enhanced photocatalytic activity of V₂O₅-ZnO composites for the mineralization of nitrophenols

In an effort to enhance the photocatalytic activity of ZnO in natural sunlight, V2O5-ZnO nanocomposites were synthesized by co-precipitation technique. The characterization of the synthesized powders by FESEM, XRD and UV-visible diffuse reflectance spectroscopy (DRS) revealed that the both V2O5 and ZnO retain their individual identity in the composites but the increasing concentration of V2O5 affect the particle size of ZnO. As estimated by photoluminescence spectroscopy, in comparison to pure ZnO, the presence of V2O5 significantly suppressed the charge carrier's recombination process. The photocatalytic activity of the synthesized powders was evaluated for the degradation/mineralization of three potential nitrophenol pollutants (2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol). The synthesized composites showed significantly higher activity for both degradation and mineralization of nitrophenols compared to pure ZnO. The progress of the degradation process was evaluated by HPLC while mineralization was monitored by TOC analysis. The degradation/mineralization route was estimated by identifying the intermediates using GC-MS. The correlation of the experimental data revealed that the position of NO2 group in 2- and 4-nitrophenol significantly affect the rate of degradation. The identification of hydroxyl group containing intermediates in the degradation of 4-NP confirmed the formation and vital role of hydroxyl radicals in degradation process. The rapid mineralization of nitrophenol substrates pointed out superoxide anions as major contributors in degradation and mineralization process. The assessment of the release of relevant ions (NO2(-), NO3(-), ONOO(-) and NH4(+)) during the degradation process assisted in identifying the plausible interaction sites.