Thick gas discs in faint dwarf galaxies

We determine the intrinsic axial ratio distribution of the 'gas' disks of extremely faint M_B > -14.5 dwarf irregular galaxies. We start with the measured (beam corrected) distribution of apparent axial ratios in the HI 21cm images of dwarf irregular galaxies observed as part of the Faint Irregular Galaxy GMRT Survey (FIGGS). Assuming that the disks can be approximated as oblate spheroids, the intrinsic axial ratio distribution can be obtained from the observed apparent axial ratio distribution. We use a couple of methods to do this, and our final results are based on using Lucy's deconvolution algorithm. This method is constrained to produce physically plausible distributions, and also has the added advantage of allowing for observational errors to be accounted for. While one might a priori expect that gas disks would be thin (because collisions between gas clouds would cause them to quickly settle down to a thin disk), we find that the HI disks of faint dwarf irregulars are quite thick, with mean axial ratio ~ 0.6. While this is substantially larger than the typical value of ~ 0.2 for the 'stellar' disks of large spiral galaxies, it is consistent with the much larger ratio of velocity dispersion to rotational velocity (sigma/v_c) in dwarf galaxy HI disks as compared to that in spiral galaxies. Our findings have implications for studies of the mass distribution in and the Tully - Fisher relation for faint dwarf irregular galaxies, where it is often assumed that the gas is in a thin disk.Comment: 5 pages, 4 figures. Minor changes in revised version. The definitive version is available at http://www.blackwell-synergy.com

Baryonic Tully-Fisher Relation for Extremely Low Mass Galaxies

We study Tully-Fisher relations for a sample that combines extremely faint (M_B > -14.0) galaxies along with bright (i.e. L_*) galaxies. Accurate (~ 10%) distances, I band photometry, and B-V colors are known for the majority of the galaxies in our sample. The faint galaxies are drawn from the Faint Irregular Galaxy GMRT survey (FIGGS), and we have HI rotation velocities derived from aperture synthesis observations for all of them. For the faint galaxies, we find that even though the median HI and stellar masses are comparable, the HI mass correlates significantly better with the circular velocity indicators than the stellar mass. We also find that W$_{20}$ correlates better with mass than the rotation velocity, although the difference is not statistically significant. The faint galaxies lie systematically below the I band TF relation defined by bright galaxies, and also show significantly more intrinsic scatter. This implies that the integrated star formation in these galaxies has been both less efficient and also less regulated than in large galaxies. We find that while the faint end deviation is greatly reduced in Baryonic Tully-Fisher (BTF) relations, the existence of a break at the faint end of the BTF is subject to systematics such as the assumed stellar mass to light ratio. If we assume that there is an intrinsic BTF and try to determine the baryonic mass by searching for prescriptions that lead to the tightest BTF, we find that scaling the HI mass leads to a much more significant tightening than scaling the stellar mass to light ratio. The most significant tightening that we find however, is if we scale the entire baryonic mass of the faint (but not the bright) galaxies. Such a scenario would be consistent with models where dwarf (but not large) galaxies have a large fraction of dark or ``missing'' baryons (Slightly abridged)Comment: 7 pages, 7 figures. Accepted for publication in MNRA

Small Bites: Star formation recipes in extreme dwarfs

We study the relationship between the gas column density (Sigma_HI) and the star formation rate surface density (Sigma_SFR) for a sample of extremely small (M_B ~ -13, Delta V_50 ~ 30 km/s) dwarf irregular galaxies. We find a clear stochasticity in the relation between the gas column density and star formation. All gas with Sigma_HI >~ 10 M_sun/pc^2 has some ongoing star formation, but the fraction of gas with ongoing star formation decreases as the gas column density decreases, and falls to about 50% at Sigma_HI ~ 3 M_sun/pc^2. Further, even for the most dense gas, the star formation efficiency is at least a factor of ~ 2 smaller than typical of star forming regions in spirals. We also find that the ratio of H-alpha emission to FUV emission increases with increasing gas column density. This is unlikely to be due to increasing dust extinction because the required dust to gas ratios are too high. We suggest instead that this correlation arises because massive (i.e. H-alpha producing) stars are formed preferentially in regions with high gas density.Comment: 5 pages, 5 figures, 1 table. Accepted for publication in MNRAS Letters. The definitive version is available at www.blackwell- synergy.co

In-vitro and in-vivo evaluation of Cimetidine loaded mucoadhesive microspheres

In the present research work mucoadhesive microspheres of cimetidine was prepared using ionotropic gelation technique. All the microspheres were characterized for particle size, scanning electron microscopy, FT-IR study, DSC, percentage yield, drug entrapment, stability studies and for in vitro release kinetics and found to be within the limits. Among all the formulations M12 was selected as optimized formulation based on the physicochemical and release studies.In vitro drug release study of optimized formulation M12 showed 99.12% after 12 h in a controlled manner, which is essential for anti ulcer therapy. The innovator cimetine conventional tablet showed the drug release of 96.15% within 1 h. The drug release of cimetidine optimized formulation M12 followed zero order and Higuchi kinetics indicating diffusion controlled drug release. In vivo studies revealed that the optimized formulation M12 gave the highest AUC and Tmax. The results are indicative of cimetidine as mucoadhesive microspheres for improving the oral bioavailability with controlled drug release

Adverse drug reaction profiles of commonly used platinum compounds in cancer chemotherapy

Background: The aim of the present study was to monitor and analyze the pattern of occurrence of adverse drug reactions (ADRs) to commonly used platinum compounds in MNJ Cancer Hospital, Hyderabad.Methods: Cancer patients, who received platinum compounds as chemotherapy regimen, were monitored for adverse reactions. Cancer patients belonging to either gender and of all ages, who were receiving platinum compounds under any standard regimen, were included for the study. Cases that were unlikely, conditional or unaccessible under World Health Organization (WHO)-Uppsala Monitoring Centre causality criteria were excluded from the study. The ADRs were recorded in Central Drugs Standard Control Organization forms. Causality was assessed by the WHO Causality Assessment Scale and Naranjo’s Algorithm. Preventability and severity of ADRs were assessed by modified Schumock and Thornton scale, modified Hartwig and Siegel scale, respectively.Results: Among 100 patients, 78 developed ADRs to platinum compounds. The reactions observed were vomiting, diarrhea, abnormal renal function tests, myelosuppression, anemia, thrombocytopenia, alopecia, and constipation. The WHO Causality Assessment Scale indicated 64.6% “possible” and 35.4% “probably,” but no “certain” reactions. Naranjo’s Algorithm showed 59.4% “possible” 40.6% “probable” reactions. 48% reactions were “definitely preventable” 16% were “probably preventable” and 36% were “not preventable.” Modified Hartwig and Siegel Scale of severity assessment showed that 12% reactions were “mild” 69% were “moderate” and 19% were severe.Conclusion: Platinum compounds have high potential for adverse effects. There is a need to improve the management of adverse effects. This study also emphasizes the need to improve pharmacovigilance awareness among physicians in order to improve the pharmacovigilance in India

Acute Administration of Bioavailable Curcumin Alongside Ferrous Sulphate Supplements Does Not Impair Iron Absorption in Healthy Adults in a Randomised Trial.

Ferrous sulphate (FS) is a cost effective, readily available iron supplement for iron deficiency (ID). The pro-oxidant effect of oral ferrous iron is known to induce inflammation, causing gastric side-effects and resulting in poor compliance. Curcumin is a potent antioxidant and has also been shown to exhibit iron chelation in-vitro, although it is not established whether these effects are retained in-vivo. The aim of this study was therefore to assess the influence of a formulated bioavailable form of curcumin (HydroCurc ; 500 mg) on acute iron absorption and status in a double blind, placebo-controlled randomized trial recruiting 155 healthy participants (79 males; 26.42 years ± 0.55 and 76 females; 25.82 years ± 0.54). Participants were randomly allocated to five different treatment groups: iron and curcumin placebo (FS0_Plac), low dose (18 mg) iron and curcumin placebo (FS18_Plac), low dose iron and curcumin (FS18_Curc), high dose (65 mg) iron and curcumin placebo (FS65_Plac), and high dose iron and curcumin (FS65_Curc). Participants were provided with the supplements according to their relevant treatment groups at baseline (0 min), and blood collection was carried out at 0 min and at 180 min following supplementation. In the treatment groups, significant difference was observed in mean serum iron between baseline (0 min) and at end-point (180 min) (F (1, 144) = 331.9, < 0.0001) with statistically significant intra-group increases after 180 min ( < 0.0001) in the FS18_Plac (8.79 µmol/L), FS18_Curc (11.41 µmol/L), FS65_Plac (19.09 µmol/L), and FS65_Curc (16.39 µmol/L) groups. A significant difference was also observed between the two time points in serum TIBC levels and in whole blood haemoglobin (HGB) in the treatment groups, with a significant increase (1.55%/2.04 g/L) in HGB levels from baseline to end-point observed in the FS65_Curc group ( < 0.05). All groups receiving iron demonstrated an increase in transferrin saturation (TS%) in a dose-related manner, demonstrating that increases in serum iron are translated into increases in physiological iron transportation. This study demonstrates, for the first time, that regardless of ferrous dose, formulated curcumin in the form of HydroCurc™ does not negatively influence acute iron absorption in healthy humans

DECOLOURIZATION OF TRIPHENYLMETHANE DYES AND DYE INDUSTRY EFFLUENT BY STAPHYLOCOCCUS AUREUS ISOLATED FROM DYE CONTAMINATED SITE

Objective: The objectives of the present study were a) to isolate and screen bacteria for dye removal from synthetic solution b) to optimize various variables such as pH, static/shaking and initial dye concentration on degradation of triphenyl methane dyes namely basic violet 3 and basic green 4 by isolated Staphylococcus aureus c) to analyse enzymes involved in the biodegradation of triphenylmethane dyes d) to treat real leather dyeing wastewater with newly isolated strain of Staphylococcus aureus e) to characterize untreated and treated leather dyeing wastewater f) to study the effects of real and treated effluent on plants and Rhizobium.Methods: Isolation of bacteria from sludge was carried out by spread plate method and the bacteria was identified by morphological and biochemical characterization. The isolated bacterium was screened for dye decolorization potential of triphenylmethane dyes basic violet 3 and basic green 4 The effects of parameters were studied by varying pH (from 3 to 9), temperature (from 15-45 °C), and initial dye concentration (from 10-500 mg/l). The enzyme involved in biodegradation was studied in intracellular extract. Real leather dyeing wastewater was treated with the bacteria and characterized. The treated wastewater was tested on plants and Rhizobium for toxicity. Results: Dye decolorization potential of bacteria Staphylococcus aureus isolated from wastewater for leather dyes basic violet 3 and basic green 4 were evaluated. Dye decolorization using bacteria was found to be dependent on physicochemical parameters (shaking, pH and initial dye concentration). Enzymes NADH-DCIP reductase and MG reductase were found to play dominant role during biodegradation of synthetic dyes. Application oriented studies using growing bacteria in pure cultures were carried out with leather dyeing wastewater collected from DKS prime tanners. Analysis of raw leather dyeing wastewater showed high pollution load in terms of color, Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand whereas the leather dyeing wastewater treated with pure culture of Staphylococcus aureus showed considerable decrease in Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand values which were within the permissible limits. Phytotoxicity and microbial toxicity studies confirmed the non-toxic nature of treated leather dyeing wastewater. Conclusion: Our study proved that Staphylococcus aureus can serve as a potential remediation agent for the treatment of leather dyeing wastewater