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2.
Bull Environ Contam Toxicol ; 110(3): 60, 2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36892662

RESUMEN

In this study we have analysed the elemental composition of fine particulate matter (PM2.5) to examine the seasonal changes and sources of the elements in Delhi, India from January, 2017 to December, 2021. During the entire sampling period, 19 elements (Al, Fe, Ti, Cu, Zn, Cr, Ni, As, Mo, Cl, P, S, K, Pb, Na, Mg, Ca, Mn, and Br) of PM2.5 were identified by Wavelength Dispersive X-ray Fluorescence Spectrometer. The higher annual mean concentrations of S (2.29 µg m-3), Cl (2.26 µg m-3), K (2.05 µg m-3), Ca (0.96 µg m-3) and Fe (0.93 µg m-3) were recorded during post-monsoon season followed by Zn > Pb > Al > Na > Cu > Ti > As > Cr > Mo > Br > Mg > Ni > Mn > and P. The annual mean concentrations of elemental composition of PM2.5 accounted for 10% of PM2.5 (pooled estimate of 5 year). Principal Component Analysis (PCA) identified the five main sources [crustal/soil/road dust, combustion (BB + FFC), vehicular emissions (VE), industrial emissions (IE) and mixed source (Ti, Cr and Mo rich-source)] of PM2.5 in Delhi, India.


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Plomo/análisis , Monitoreo del Ambiente , India , Estaciones del Año , Iones/análisis
3.
Bull Environ Contam Toxicol ; 109(3): 502-510, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35322279

RESUMEN

Carbonaceous species [organic carbon (OC), elemental carbon (EC), elemental matter (EM), primary organic carbon (POC), secondary organic carbon (SOC), total carbon (TC), and total carbonaceous matter (TCM)] of PM2.5 were analyzed to study the seasonal variability and long-term trend of carbonaceous aerosols (CAs) in megacity Delhi, India from January, 2012 to April, 2021. The average concentrations (± standard deviation) of PM2.5, OC, EC, TC, EM, TCM, POC and SOC were 127 ± 77, 15.7 ± 11.6, 7.4 ± 5.1, 23.1 ± 16.5, 8.2 ± 5.6, 33.3 ± 23.9, 9.3 ± 6.3 and 6.5 ± 5.3 µg m-3, respectively during the sampling period (10-year average). The average CAs accounted for 26% of PM2.5 concentration during the entire sampling period. In addition, the seasonal variations in PM2.5, OC, EC, POC, SOC, and TCM levels were recorded with maxima in post-monsoon and minima in monsoon seasons. The linear relationship of OC and EC, OC/EC and EC/TC ratios suggested that the vehicular emissions (VE), fossil fuel combustion (FFC) and biomass burning (BB) are the major sources of CAs at megacity Delhi, India.


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Carbono/análisis , China , Monitoreo del Ambiente , India , Tamaño de la Partícula , Material Particulado/análisis , Estaciones del Año
4.
J Environ Manage ; 298: 113484, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34391101

RESUMEN

Fabrication of novel metal oxide nanostructured composites is a proficient approach to develop efficient energy storage devices and development of cost-free and eco-friendly metal oxide nanostructures for supercapacitor applications received considerable attention in recent years. The Co3O4 nanocubes-NiO octahedral structured composite was constructed using facile and one-step calcination process. Cyclic voltammetry, charge-discharge, and electrochemical impedance spectral techniques have been employed to analyze the specific capacitance of the synthesized nanostructures and the composites. Specific capacitance and cycling stability of the composites were evaluated with the pristine Co3O4 and NiO nanostructures. The composite showed a specific capacitance of 832 F g-1 at a current density of 0.25 A g-1, which was ~1.5 and ~1.9-times higher than pristine Co3O4 nanocubes and NiO octahedral structure, respectively. On the other hand, electrode showed approximately 50 % capacity retention at a higher current density (5 Ag-1) because of the uniform morphology of Co3O4 and NiO. The charge-discharge stability measurements of the composite showed an admirable specific capacitance retention capability, which was 94.5 % after 2000 continuous charge-discharge cycles at a current density of 5 A g-1. The superior electrochemical performance of the nano-composite was ascribed to synergistic effects and uniform morphology. Efficient nanostructure development using facile and one-step calcination process and electrochemical performance make the synthesized composite a promising device for supercapacitor applications.


Asunto(s)
Nanocompuestos , Óxidos , Técnicas Electroquímicas , Electrodos
5.
Environ Pollut ; 262: 114337, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32193082

RESUMEN

The present study attempts to explore and compare the seasonal variability in chemical composition and contributions of different sources of fine and coarse fractions of aerosols (PM2.5 and PM10) in Delhi, India from January 2013 to December 2016. The annual average concentrations of PM2.5 and PM10 were 131 ± 79 µg m-3 (range: 17-417 µg m-3) and 238 ± 106 µg m-3 (range: 34-537 µg m-3), respectively. PM2.5 and PM10 samples were chemically characterized to assess their chemical components [i.e. organic carbon (OC), elemental carbon (EC), water soluble inorganic ionic components (WSICs) and heavy and trace elements] and then used for estimation of enrichment factors (EFs) and applied positive matrix factorization (PMF5) model to evaluate their prominent sources on seasonal basis in Delhi. PMF identified eight major sources i.e. Secondary nitrate (SN), secondary sulphate (SS), vehicular emissions (VE), biomass burning (BB), soil dust (SD), fossil fuel combustion (FFC), sodium and magnesium salts (SMS) and industrial emissions (IE). Total carbon contributes ∼28% to the total PM2.5 concentration and 24% to the total PM10 concentration and followed the similar seasonality pattern. SN and SS followed opposite seasonal pattern, where SN was higher during colder seasons while SS was greater during warm seasons. The seasonal differences in VE contributions were not very striking as it prevails evidently most of year. Emissions from BB is one of the major sources in Delhi with larger contribution during winter and post monsoon seasons due to stable meteorological conditions and aggrandized biomass burning (agriculture residue burning in and around the regions; mainly Punjab and Haryana) and domestic heating during the season. Conditional Bivariate Probability Function (CBPF) plots revealed that the maximum concentrations of PM2.5 and PM10 were carried by north westerly winds (north-western Indo Gangetic Plains of India).


Asunto(s)
Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Aerosoles/análisis , Carbono/análisis , Polvo/análisis , Monitoreo del Ambiente , India , Estaciones del Año , Emisiones de Vehículos/análisis
6.
J Diabetes Metab Disord ; 19(2): 1367-1379, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33520840

RESUMEN

PURPOSE: Hypertriglyceridemia (HG) is an independent risk factor with more prevalence than hypercholesterolemia and its attributes to cardiovascular disease (CVD) and pancreatitis. Hence, it becomes imperative to search for new triglyceride (TG) lowering agents. Tinospora cordifolia (TC) is a well-known Ayurvedic drug and a rich source of protoberberine alkaloids hence can contribute to TG lowering without side effects. Hence, to explore the therapeutic efficacy of T. cordifolia and its effects on biochemistry and metabolome in the patients of hyper-triglyceridemia, clinical trials were conducted. METHODS: Patients (n = 24) with hypertriglyceridemia were randomized into two groups to receive T. cordifolia extract (TCE) (3.0 g/per day) and metformin (850 mg/day) for 14 days having >300 mg/dl triglyceride level and cholesterol in the range of 130-230 mg/dl. Lipid profiles of blood samples were analyzed. Urine samples were subjected to HPLC-QTOF-MS to quantify oxidative damage and abnormal metabolic regulation. RESULTS: Intervention with TCE reduced the triglyceride, LDL, and VLDL levels to 380.45 ± 17.44, 133.25 ± 3.18, and 31.85 ± 5.88 mg/dL and increased the HDL to 47.50 ± 9.05 mg/dL significantly (p < 0.05) in the HG patients after 14 days treatment. TCE dosage potently suppressed the inflammatory and oxidative stress marker's i.e. levels of isoprostanes significantly (p < 0.01). Qualitative metabolomics approach i.e. PCA and PLS-DA showed significant alterations (p < 0.05) in the levels of 40 metabolites in the urine samples from different groups. CONCLUSION: TCE administration depleted the levels of markers of HG i.e. VLDL, TG, and LDL significantly. Metabolomics studies established that the anti-HG activity of TCE was due to its antioxidative potential and modulation of the biopterin, butanoate, amino acid, and vitamin metabolism. CLINICAL TRIALS REGISTRY: India (CTRI) registration no. CTRI- 2016-08-007187.

7.
Arch Environ Contam Toxicol ; 78(1): 79-85, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31832738

RESUMEN

Mixing ratios of atmospheric ammonia (NH3), nitric oxide (NO), carbon monoxide (CO), nonmethane hydrocarbons (NMHCs), and methane (CH4) were measured to investigate the vehicular emissions, which are a dominant source of atmospheric NH3 in urban sites of Delhi, India from January 2013 to December 2014. The annual average mixing ratios of NH3, NO, CO, NMHCs, and CH4 were 21.2 ± 2.1 ppb, 21.2 ± 6.1 ppb, 1.89 ± 0.18 ppm, 0.67 ± 0.21 ppm and 3.11 ± 0.53 ppm, respectively. Considering NO as a tracer of vehicular plume, ambient NH3 was correlated with NO during peak traffic hour in the morning (7:00-10:00 h) and evening (17:00-19:00 h) and observed significant positive correlation between them. Result reveals that the mixing ratio of atmospheric NH3 significantly positive correlated with traffic related pollutants (NO, CO, and NHHCs) during all the seasons (winter, summer, and monsoon). During winter, the average mixing ratio of atmospheric NH3 was increased by 1.2-3.5 ppb in the morning peak hour, whereas increased by 0.3-1.6 ppb in the evening peak hour. Similarly, an increase in NH3 mixing ratio was observed during summer (morning: 1.2-2.7 ppb and evening: 1.5-1.6 ppb) and monsoon (morning: 0.4-3.6 ppb and evening: 0.9-1.4 ppb) seasons. The results emphasized that the traffic could be one of the dominant source of ambient NH3 at the urban site of Delhi, as illustrated by positive relationships of NH3 with traffic related co-pollutants (NO, CO and NMHCs).


Asunto(s)
Contaminantes Atmosféricos/análisis , Amoníaco/análisis , Monóxido de Carbono/análisis , Monitoreo del Ambiente/métodos , Hidrocarburos/análisis , Óxidos de Nitrógeno/análisis , Emisiones de Vehículos/análisis , Ciudades , India , Óxido Nítrico/análisis , Dióxido de Nitrógeno/análisis , Estaciones del Año
8.
Bull Environ Contam Toxicol ; 100(5): 695-701, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29516139

RESUMEN

Organic carbon (OC) and elemental carbon (EC) in PM2.5 were estimated to study the seasonal and inter-annual variability of atmospheric total carbonaceous aerosols (TCA) at an urban site of megacity Delhi, India for 5 years from January, 2012 to December, 2016. The annual average (± standard deviation) concentrations of PM2.5, OC, EC and TCA were 128 ± 81, 16.6 ± 12.2, 8.4 ± 5.8 and 34.5 ± 25.2 µg m-3, respectively. During the study, significant seasonal variations in mass concentrations of PM2.5, OC, EC and TCA were observed with maxima in winter and minima in monsoon seasons. Significant correlations between OC and EC, and OC/EC ratio suggested that vehicular emissions, fossil fuel combustion and biomass burning could be major sources of carbonaceous aerosols of PM2.5 at the sampling site of Delhi, India.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Material Particulado/análisis , Aerosoles/análisis , Biomasa , Carbono/análisis , China , India , Estaciones del Año , Emisiones de Vehículos/análisis
9.
Bull Environ Contam Toxicol ; 99(2): 281-285, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28321469

RESUMEN

In this study, ambient NH3, NO, NO2, CO and SO2 were measured continuously from February, 2008, to December, 2016. The annual average mixing ratios (mole/mole) of NH3, NO, NO2, CO and SO2 were 17.8 ± 3.4 ppb; 21.2 ± 2.3 ppb, 18.1 ± 3.2 ppb; 1.7 ± 0.3 ppm and 2.0 ± 0.3 ppb, respectively. All the trace gases (NH3, NO, NO2, CO and SO2) showed significant annual variation during the study. A significant increasing trend in mixing ratios of ambient NH3 and NO2 were observed at the observational site of Delhi, whereas, increasing trend were recorded in case of NO, CO and NO2 mixing ratios. The results emphasized that traffic could be one of the significant sources of ambient NH3 at the urban site of Delhi, as illustrated by positive correlations of NH3 with traffic related co-pollutants (NO and CO).


Asunto(s)
Contaminación del Aire/estadística & datos numéricos , Amoníaco/análisis , Monitoreo del Ambiente , Oligoelementos/análisis , Contaminantes Atmosféricos/análisis , Gases/análisis , Humanos , India
10.
Environ Monit Assess ; 189(1): 43, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28039660

RESUMEN

Delhi is one of the most polluted cities in the world. The generation of aerosols in the lower atmosphere of the city is mainly due to a large amount of natural dust advection and sizable anthropogenic activities. The compositions of organic compounds in aerosols are highly variable in this region and need to be investigated thoroughly. Twenty-four-hour sampling to assess concentrations of n-alkanes (ng/m3) in PM10 was carried out during January 2015 to June 2015 at Indira Gandhi Delhi Technical University for Women (IGDTUW) Campus, Delhi, India. The total average concentration of n-alkanes, 243.7 ± 5.5 ng/m3, along with the diagnostic tools has been calculated. The values of CPI1, CPI2, and CPI3 for the whole range of n-alkanes series, petrogenic n-alkanes, and biogenic n-alkanes were 1.00, 1.02, and 1.04, respectively, and C max were at C25 and C27. Diagnostic indices and curves indicated that the dominant inputs of n-alkanes are from petrogenic emissions, with lower contribution from biogenic emissions. Significant seasonal variations were observed in average concentrations of n-alkanes, which is comparatively higher in winter (187.4 ± 4.3 ng/m3) than during the summer season (56.3 ± 1.1 ng/m3).


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año , Emisiones de Vehículos/análisis , Alcanos/análisis , Atmósfera , Ciudades , India , Compuestos Orgánicos/análisis
11.
Environ Sci Pollut Res Int ; 24(2): 1719-1734, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27796981

RESUMEN

To better understand the sources as well as characterization of regional aerosols at a rural semi-arid region Kadapa (India), size-resolved composition of atmospheric particulate matter (PM) mass concentrations was sampled and analysed. This was carried out by using the Anderson low-pressure impactor for a period of 2 years during March 2013-February 2015. Also, the variations of organic carbon (OC), elemental carbon (EC) and water-soluble inorganic ion components (WSICs) present in total suspended particulate matter (TSPM) were studied over the measurement site. From the statistical analysis, the PM mass concentration showed a higher abundance of coarse mode particles than the fine mode during pre-monsoon season. In contrast, fine mode particles in the PM concentration showed dominance over coarse mode particle contribution during the winter. During the post-monsoon season, the percentage contributions of coarse and fine fractions were equal, whereas during the monsoon, coarse mode fraction was approximately 26 % higher than the fine mode. This distinct feature in the case of fine mode particles during the studied period is mainly attributed to large-scale anthropogenic activities and regional prevailing meteorological conditions. Further, the potential sources of PM have been identified qualitatively by using the ratios of certain ions. A high sulphate (SO4) concentration at the measurement site was observed during the studied period which is caused by the nearby/surrounding mining activity. Carbon fractions (OC and EC) were also analysed from the TSPM, and the results indicated (OC/EC ratio of ~4.2) the formation of a secondary organic aerosol. At last, the cluster backward trajectory analyses were also performed at Kadapa for different seasons to reveal the origin of sources from long-range transport during the study period.


Asunto(s)
Contaminantes Atmosféricos/análisis , Carbono/análisis , Material Particulado/análisis , Aerosoles , Monitoreo del Ambiente , Humanos , India , Iones/análisis , Tamaño de la Partícula , Población Rural , Estaciones del Año , Solubilidad
12.
Environ Sci Pollut Res Int ; 23(18): 18809-22, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27316652

RESUMEN

The paper presents the spatio-temporal variation of chemical compositions (organic carbon (OC), elemental carbon (EC), and water-soluble inorganic ionic components (WSIC)) of particulate matter (PM10) over three locations (Delhi, Varanasi, and Kolkata) of Indo Gangetic Plain (IGP) of India for the year 2011. The observational sites are chosen to represent the characteristics of upper (Delhi), middle (Varanasi), and lower (Kolkata) IGP regions as converse to earlier single-station observation. Average mass concentration of PM10 was observed higher in the middle IGP (Varanasi 206.2 ± 77.4 µg m(-3)) as compared to upper IGP (Delhi 202.3 ± 74.3 µg m(-3)) and lower IGP (Kolkata 171.5 ± 38.5 µg m(-3)). Large variation in OC values from 23.57 µg m(-3) (Delhi) to 12.74 µg m(-3) (Kolkata) indicating role of formation of secondary aerosols, whereas EC have not shown much variation with maximum concentration over Delhi (10.07 µg m(-3)) and minimum over Varanasi (7.72 µg m(-3)). As expected, a strong seasonal variation was observed in the mass concentration of PM10 as well as in its chemical composition over the three locations. Principal component analysis (PCA) identifies the contribution of secondary aerosol, biomass burning, fossil fuel combustion, vehicular emission, and sea salt to PM10 mass concentration at the observational sites of IGP, India. Backward trajectory analysis indicated the influence of continental type aerosols being transported from the Bay of Bengal, Pakistan, Afghanistan, Rajasthan, Gujarat, and surrounding areas to IGP region.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Material Particulado/análisis , Aerosoles/análisis , Biomasa , Carbono/análisis , Clima , India , Pakistán , Estaciones del Año , Emisiones de Vehículos/análisis
13.
Bull Environ Contam Toxicol ; 97(2): 286-93, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27209541

RESUMEN

Chemical characterization of PM2.5 [organic carbon, elemental carbon, water soluble inorganic ionic components, and major and trace elements] was carried out for a source apportionment study of PM2.5 at an urban site of Delhi, India from January, 2013, to December, 2014. The annual average mass concentration of PM2.5 was 122 ± 94.1 µg m(-3). Strong seasonal variation was observed in PM2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon. A receptor model, positive matrix factorization (PMF) was applied for source apportionment of PM2.5 mass concentration. The PMF model resolved the major sources of PM2.5 as secondary aerosols (21.3 %), followed by soil dust (20.5 %), vehicle emissions (19.7 %), biomass burning (14.3 %), fossil fuel combustion (13.7 %), industrial emissions (6.2 %) and sea salt (4.3 %).


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Modelos Químicos , Material Particulado/análisis , Aerosoles/análisis , Carbono/análisis , Polvo , India , Industrias , Estaciones del Año , Suelo , Emisiones de Vehículos/análisis
14.
Bull Environ Contam Toxicol ; 95(5): 661-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26438175

RESUMEN

This paper presents the variation of elemental concentrations of total carbon (TC), total nitrogen (TN) and isotopic ratios of δ13C and δ15N along with δ13OC and OC of PM10 mass over Delhi, Varanasi and Kolkata of the Indo Gangetic Plain (IGP), India. For Delhi, the average concentrations of TC and TN of PM10 were 53.0±33.6 and 14.9±10.8 µg m(-3), whereas δ13C and δ15N of PM10 were -25.5±0.5 and 9.6±2.8‰, respectively. For Varanasi, the average values of δ13C and δ15N of PM10 were -25.4±0.8 and 6.8±2.4‰, respectively. For Kolkata, TC and TN values for PM10 ranged from 9.1-98.2 to 1.4-25.9 µg m(-3), respectively with average values of 32.6±24.9 and 9.3±8.2 µg m(-3), respectively. The average concentrations of δ13C and δ15N were -26.0±0.4 and 7.4±2.7‰, respectively over Kolkata with ranges of -26.6 to -24.9‰ and 2.8±11.5‰, respectively. The isotopic analysis revealed that biomass burning, vehicular emission and secondary inorganic aerosols were likely sources of PM10 mass over IGP, India.


Asunto(s)
Contaminantes Atmosféricos/análisis , Isótopos de Carbono/análisis , Monitoreo del Ambiente/métodos , Isótopos de Nitrógeno/análisis , Material Particulado/análisis , Aerosoles/análisis , India , Tamaño de la Partícula , Urbanización , Emisiones de Vehículos/análisis
15.
J Environ Sci Eng ; 56(3): 357-62, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26563090

RESUMEN

Air quality indices are commonly used to indicate the level of severity of air pollution to the public. It is infeasible and perhaps impossible to formulate a universal technique for determining air quality index, one that considers all pollutants and that is appropriate for all situations. The intended use of the air quality index is to identify the vulnerable zone. There are mainly two approaches viz. single pollutant index and multi-pollutant index to determine the air quality index. Every index has its own characteristic strengths and weaknesses that affect its suitability for particular applications. This paper attempts to present a review of all the major air quality indices developed worldwide.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente/normas
16.
Andrologia ; 44(2): 102-15, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21848871

RESUMEN

The present works examined an adverse effect of chlorpyrifos insecticide on testes and lipid peroxidation at low doses (5 mg-10 mg kg(-1) body weight) and the role of antioxidant enzymes systems at higher doses (20-30 mg kg(-1) body weight) in albino rats. At low doses, reduction in plasma levels of testosterone and FSH and LH hormones along with the significant shrinkage of seminiferous tubules and gametogenic changes in germ cells were noticed. But these changes were restored with the revival of serum testosterone, FSH and LH along with regression of testis at higher doses. Similarly, level of testicular lipid peroxidation was elevated, whereas levels of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and steroidogenic enzymes activities (Δ(5) , 3ß-hydroxysteroid dehydrogenase and 17ß-hydroxysteroid dehydrogenase) were reduced significantly at low doses. But, rat testes showed a significant decrease in lipid peroxidation and concomitant increase in antioxidant enzymes and steroidogenic enzymes activities at higher doses. Results showed that at higher doses of chlorpyrifos treatments, rat testes were shown to trigger their natural defence mechanism which became operative possibly through corrective measure of synthesis of antioxidant defence enzymes and steroidogenic enzymes and pituitary gonadotrophins hormone feedback mechanisms.


Asunto(s)
Antioxidantes/metabolismo , Cloropirifos/toxicidad , Insecticidas/toxicidad , Estrés Oxidativo/efectos de los fármacos , Testículo/efectos de los fármacos , 17-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Peroxidación de Lípido/efectos de los fármacos , Masculino , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Túbulos Seminíferos/efectos de los fármacos , Testículo/metabolismo , Testículo/patología , Testosterona/sangre
17.
J Environ Sci (China) ; 22(7): 1023-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21174992

RESUMEN

We present the diurnal and seasonal variability of ambient NH3, NO, NO2 and SO2 over Delhi, India. Ambient NH3, NO and NO2 were measured continuously during winter, summer and autumn seasons using NH3- and NOx-analyzer, which operates by chemiluminescence method with a higher estimation efficiency (> 90%) than the chemical trap method (reproducibility 4.7%). Prominent diurnal, day-to-day and seasonal variations of ambient mixing ratio of NH3, NO, NO2 and SO2 were observed during the study period. Seasonal variation with higher mixing ratio in winter was observed for all measured trace gases except NO. Day-night variation of all measured trace gases observed was higher in winter in comparison with summer. Late morning increase in NO2 mixing ratio might be attributed to conversion of NO to NO2 with the interaction of O3.


Asunto(s)
Amoníaco/análisis , Monitoreo del Ambiente , Óxido Nítrico/análisis , Dióxido de Nitrógeno/análisis , Estaciones del Año , Dióxido de Azufre/análisis , India , Luminiscencia
18.
Environ Monit Assess ; 162(1-4): 225-35, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19234750

RESUMEN

We present diurnal variation of ambient ammonia (NH(3)) in relation with other trace gases (O(3), CO, NO, NO(2), and SO(2)) and meteorological parameters at an urban site of Delhi during winter period. For the first time, ambient ammonia (NH(3)) was monitored very precisely and continuously using ammonia analyzer, which operates on chemiluminescence method. NH(3) estimation efficiency of the chemiluminescence method (>90%) is much higher than the conventional chemical trapping method (reproducibility 4.5%). Ambient NH(3) concentration reaches its maxima (46.17 ppb) at night and minimum during midday. Result reveals that the ambient ammonia (NH(3)) concentration is positively correlated with ambient NO (r(2) = 0.79) and NO(2) (r (2) = 0.91) mixing ratio and negatively correlated with ambient temperature (r(2) = - 0.32). Wind direction and wind speed indicates that the nearby (approximately 500 m NW) agricultural fields may be major source of ambient NH(3) at the observational site.


Asunto(s)
Amoníaco/análisis , Gases/química , Luminiscencia , Espectrofotometría Ultravioleta
19.
Environ Monit Assess ; 169(1-4): 1-13, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19757121

RESUMEN

The variation in air quality was assessed from the ambient concentrations of various air pollutants [total suspended particle (TSP), particulate matter < or =10 microm (PM(10)), SO(2), and NO(2)] for pre-Diwali, Diwali festival, post-Diwali, and foggy day (October, November, and December), Delhi (India), from 2002 to 2007. The extensive use of fireworks was found to be related to short-term variation in air quality. During the festival, TSP is almost of the same order as compared to the concentration at an industrial site in Delhi in all the years. However, the concentrations of PM(10), SO(2), and NO(2) increased two to six times during the Diwali period when compared to the data reported for an industrial site. Similar trend was observed when the concentrations of pollutants were compared with values obtained for a typical foggy day each year in December. The levels of these pollutants observed during Diwali were found to be higher due to adverse meteorological conditions, i.e., decrease in 24 h average mixing height, temperature, and wind speed. The trend analysis shows that TSP, PM(10), NO(2), and SO(2) concentration increased just before Diwali and reached to a maximum concentration on the day of the festival. The values gradually decreased after the festival. On Diwali day, 24-h values for TSP and PM(10) in all the years from 2002 to 2007 and for NO(2) in 2004 and 2007 were found to be higher than prescribed limits of National Ambient Air Quality Standards and exceptionally high (3.6 times) for PM(10) in 2007. These results indicate that fireworks during the Diwali festival affected the ambient air quality adversely due to emission and accumulation of TSP, PM(10), SO(2), and NO(2).


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Dióxido de Nitrógeno/análisis , Material Particulado/análisis , Dióxido de Azufre/análisis , Contaminación del Aire/estadística & datos numéricos , Atmósfera/química , Vacaciones y Feriados , Humanos , India , Exposición por Inhalación/análisis , Exposición por Inhalación/estadística & datos numéricos , Tiempo , Tiempo (Meteorología)
20.
J Ethnopharmacol ; 123(1): 177-80, 2009 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-19429358

RESUMEN

AIM OF THE STUDY: Caesalpinia bonduc (Lin.) Roxb. is a known drug in Ayurveda to treat various diseases specifically tumors, cysts and cystic fibrosis (CF). The aim of this study was to assess in vitro as well as in vivo antimicrobial activity of Caesalpinia bonduc seeds. MATERIALS AND METHODS: The in vitro antimicrobial activities of seed coat and seed kernel extracts were investigated by microbroth dilution assay. In vivo activities of hydro-alcoholic extracts were investigated in rat models of chronic Pseudomonas aeruginosa pneumonia mimicking that in patients with cystic fibrosis. RESULTS: Various extracts of plant seeds exhibited in vitro antimicrobial activities in a range of 22-350 microg/ml. The extracts also showed activity against methicillin resistant (MR) Staphylococcus aureus and ampicillin resistant (AR) Pseudomonas aeruginosa as in the sensitive strains. In rat model of chronic Pseudomonas aeruginosa pneumonia, hydro-alcoholic extracts of Caesalpinia bonduc seed kernel (CBSK) and Caesalpinia bonduc seed coat (CBSC) were injected subcutaneously in the test groups of animals. The control groups were treated with cortisone and saline. Two weeks after challenge with Pseudomonas aeruginosa, the CBSK treated animals showed a significant bacterial clearance from the lungs (P<0.04) and less severe incidence of lung abscess (P<0.05). CONCLUSION: Results showed that Caesalpinia bonduc may have the potential to be promising natural medicine, with other forms of treatments, for CF patients with chronic Pseudomonas aeruginosa lung infections.


Asunto(s)
Antibacterianos/farmacología , Caesalpinia/química , Extractos Vegetales/farmacología , Semillas/química , Caesalpinia/embriología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos
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