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1.
Environ Pollut ; 311: 119901, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35963388

ABSTRACT

Harmful algal blooms (HABs) are recurrent in the NW Patagonia fjords system and their frequency has increased over the last few decades. Outbreaks of HAB species such as Alexandrium catenella, a causal agent of paralytic shellfish poisoning, and Protoceratium reticulatum, a yessotoxins producer, have raised considerable concern due to their adverse socioeconomic consequences. Monitoring programs have mainly focused on their planktonic stages, but since these species produce benthic resting cysts, the factors influencing cyst distributions are increasingly gaining recognition as potentially important to HAB recurrence in some regions. Still, a holistic understanding of the physico-chemical conditions influencing cyst distribution in this region is lacking, especially as it relates to seasonal changes in drivers of cyst distributions, as the characteristics that favor cyst preservation in the sediment may change through the seasons. In this study, we analyzed the physico-chemical properties of the sediment (temperature, pH, redox potential) and measured the bottom dissolved oxygen levels in a "hotspot" area of southern Chile, sampling during the spring and summer as well as the fall and winter, to determine the role these factors may play as modulators of dinoflagellate cyst distribution, and specifically for the cysts of A. catenella and P. reticulatum. A permutational analysis of variance (PERMANOVA) showed the significant effect of sediment redox conditions in explaining the differences in the cyst assemblages between spring-summer and fall-winter periods (seasonality). In a generalized linear model (GLM), sediment redox potential and pH were associated with the highest abundances of A. catenella resting cysts in the spring-summer, however it was sediment temperature that most explained the distribution of A. catenella in the fall-winter. For P. reticulatum, only spring-summer sediment redox potential and temperature explained the variation in cyst abundances. The implications of environmental (physico-chemical) seasonality for the resting cysts dynamics of both species are discussed.


Subject(s)
Cysts , Dinoflagellida , Shellfish Poisoning , Estuaries , Harmful Algal Bloom , Humans , Seasons
2.
Mar Pollut Bull ; 97(1-2): 85-94, 2015 Aug 15.
Article in English | MEDLINE | ID: mdl-26099789

ABSTRACT

Although a plethora of benthic indices exist, there is no agreement on what index or indices should be used by environmental managers to establish benthic quality. The objective of this investigation was to rank 35 benthic quality assessment indices used in different countries to evaluate the impact produced by 15 different human pressures (including multipressure, aquaculture, sewage discharges, eutrophication, physical alteration, chemical pollution, climate change, etc.). The ranking was determined by taking into account the coverage area of biogeographical provinces, number of citations testing a pressure and number of citations with significant correlation with pressure. We analysed 363 references, of which 169 showed quantitative data. Over a potential total score of 100, the highest values were obtained by the following indices: (i) AZTI's Marine Biotic Index (AMBI), which scored 77, tested by using 14 pressures in 14 provinces from the Arctic to tropical seas; (ii) multivariate AMBI (M-AMBI), which scored 74, tested with 12 pressures in 13 provinces; (iii) Bentix (BENTIX), which scored 68, tested with nine pressures in six provinces; (iv) Benthic Quality Index (BQI), which scored 66, tested with five pressures in seven provinces; and (v) Benthic Opportunistic Polychaetes Amphipods (BOPA) index, which scored 62, tested with eight pressures in six provinces.


Subject(s)
Aquatic Organisms , Environmental Monitoring/methods , Environmental Monitoring/standards , Invertebrates , Animals , Aquaculture , Climate Change , Ecosystem , Eutrophication , Sewage
3.
J Sep Sci ; 31(1): 201-6, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18080244

ABSTRACT

The chemical stability of haloperidol lactate injection was studied under different storage conditions by high performance thin-layer chromatography (HPTLC). The study was performed at 25 +/- 2 degrees C and at refrigeration temperature (8 +/- 1 degrees C) in original glass ampoules over 15 days after being opened. The samples tested at 25 +/- 2 degrees C were stored with exposure to and protection from light. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone/chloroform/n-butanol/glacial acetic acid/water (5:10:10:2.5:2.5, v/v/v/v/v) as a mobile phase. Quantitative analyses were carried out at a wavelength of 254 nm. The method exhibited adequate linearity (r = 0.999), selectivity, precision (RSD = 1.92%), and accuracy (recoveries from 98.59 to 101.90%). The concentrations of all samples remained greater than or 90% of the original concentration. Haloperidol lactate injection was chemically stable under all conditions studied over 15 days.


Subject(s)
Chromatography, Thin Layer/methods , Haloperidol/analysis , Haloperidol/chemistry , Chromatography, High Pressure Liquid , Molecular Structure , Reproducibility of Results
4.
J Sep Sci ; 30(5): 772-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17461119

ABSTRACT

A densitometric high performance thin-layer chromatography (HPTLC) method was developed and validated for the quantitative analysis of haloperidol in tablets. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone/chloroform/n-butanol/acetic acid glacial/water (5:10:10:2.5:2.5 v/v/v/v/v) as the mobile phase. Quantitative analysis was carried out at a wavelength of 254 nm. The method was linear in the 10-100 ng/microL range, with a determination coefficient of 0.999. The coefficients of variation for precision were not higher than 2.35%. The detection limit was 0.89 ng/microL, and the quantification limit was 2.71 ng/microL. The accuracy ranged from 97.76 to 100.33%, with a CV not higher than 4.50%. This method was successfully applied to quantify haloperidol in real pharmaceutical samples, including the comparison with HPLC measurements. The method was fast, specific, with a good precision and accuracy for the quantitative determination of haloperidol in tablets.


Subject(s)
Chromatography, Thin Layer/methods , Haloperidol/analysis , Tablets/chemistry , Chromatography, High Pressure Liquid , Haloperidol/chemistry , Molecular Structure
5.
Santiago de Chile; s.n; 1999. 69 p. tab, graf.
Thesis in Spanish | LILACS | ID: lil-261200

ABSTRACT

El creciente aumento de la obesidad en la población infantil ha alcanzado en Chile cifras de un 23 por ciento para el sobrepeso y un 7 por ciento para la obesidad, resultando inquietante por sus efectos en la calidad de vida del niño, lo cual tiende a extenderse a la vida adulta por las dificultades para mejorar esta condición, generando una fuerte carga y costo para el país por las complicaciones médicas que se pueden presentar. La importancia para la enfermera pediátrica radica en el rol preventivo que ésta puede desempeñar a través de la actividad de control de salud infantil. Este estudio es de tipo descriptivo transversal, está dirigido a determinar la evolución de estado nutricional de los niños y adolescentes con mal nutrición en exceso atendidos en el Servicio de Pediatría del Centro Médico San Joaquín en los años 1996 a 1997, N=112. la información se obtuvo de las fichas clínicas de cada año. Los resultados obtenidos revelan que esta población es obesa en un 96.4 por ciento, determinado por la relación de Peso/Talla. El rango de edad predominante es de los 5 a 9 años con un 32.1 por ciento. Hay similar distribución para ambos sexo


Subject(s)
Child , Adolescent , Adolescent Nutrition , Child Nutrition , Protein-Energy Malnutrition , Obesity
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