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1.
J Econ Entomol ; 113(4): 1872-1880, 2020 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-32333602

RESUMEN

Drosophila suzukii Matsumura is an economically important pest of small and stone fruits. Its establishment in the Americas and Europe marked an important turning point in crop management programs. Ten years after its first detection, an effective integrated pest management program has yet to be developed and pesticides are mainly used to control this pest. Here we test a new behavioral control tool, with the aim to develop an alternative pest control strategy. A food-grade gum matrix, was evaluated under controlled and open field conditions for its ability to attract the pest and protect the ripening fruit. Here, we report that the gum effectively reduces fruit infestation when used under managed conditions. We show that a single point source can affect D. suzukii behavior over a 3.6 m radius and last for up to 21 d. Open field data reveal that the efficacy of the gum is significantly impacted by water content. We discuss these results in respect to the future implications for D. suzukii management, along with important considerations on gum mechanism of action, possible application strategies and economic suitability for growers.


Asunto(s)
Drosophila , Control de Insectos , Animales , Europa (Continente) , Frutas
2.
Skin Res Technol ; 24(4): 551-556, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29479745

RESUMEN

BACKGROUND: A woman's skin is dramatically affected by pregnancy. Its biomechanical properties are critical for resisting highly stressed areas. The aim of this work was to evaluate the impact of pregnancy on the mechanical properties of skin, as well as to evaluate the imprint that pregnancy leaves on the skin after delivery. MATERIALS AND METHODS: Suction tests using a cutometer were performed on 15 non-pregnant women and 26 pregnant women at 8 months of pregnancy and 4 months after delivery. Areas of abdomen and thighs were studied. RESULTS: Significant differences between the non-pregnant and 8-month pregnant groups were observed. Our data demonstrate that skin becomes less elastic and less deformable on the abdomen during pregnancy. On the thighs, a loss of elasticity and firmness was also observed. At 4 months after delivery, the skin did not return to its initial state. CONCLUSION: This study showed that the mechanical properties of skin changed drastically during pregnancy compared to the non-pregnant condition and that these properties remain altered 4 months after delivery. In addition to alterations in abdominal skin during pregnancy, we also observed mechanical changes on the thighs, which are less subject to stretching.


Asunto(s)
Embarazo/fisiología , Fenómenos Fisiológicos de la Piel , Abdomen/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Muslo/fisiología , Adulto Joven
3.
J Mech Behav Biomed Mater ; 27: 273-82, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23867292

RESUMEN

Human skin is one of the most important organ of the body. The assessment and knowledge of its properties are very useful for clinical or cosmetic research. Many techniques are used to measure the mechanical properties of this organ, like suction, indentation, torsion or tension tests. The aim of this paper is to present a new device based on tension technique and combining mechanical and optical measurements. The whole procedure used to assess the displacement field as described, and first results of tests performed in vivo are shown.


Asunto(s)
Análisis de Elementos Finitos , Ensayo de Materiales/instrumentación , Fenómenos Mecánicos , Fenómenos Ópticos , Piel , Resistencia a la Tracción , Algoritmos , Fenómenos Biomecánicos , Femenino , Humanos , Persona de Mediana Edad , Modelos Biológicos , Reproducibilidad de los Resultados , Adulto Joven
4.
Med Eng Phys ; 34(2): 172-8, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21807547

RESUMEN

The assessment of human tissue properties by objective and quantitative devices is very important to improve the understanding of its mechanical behaviour. The aim of this paper is to present a non contact method to measure the mechanical properties of human skin in vivo. A complete non contact device using an air flow system has been developed. Validation and assessment of the method have been performed on inert visco-elastic material. An in vivo study on the forearm of two groups of healthy women aged of 23.2±1.6 and 60.4±2.4 has been performed. Main parameters assessed are presented and a first interpretation to evaluate the reduced Young's modulus is proposed. Significant differences between the main parameters of the curve are shown with ageing. As tests were performed with different loads, the influence of the stress is also observed. We found a reduced Young's modulus with an air flow force of 10 mN of 14.38±3.61 kPa for the youngest group and 6.20±1.45 kPa for the oldest group. These values agree with other studies using classical or dynamic indentation. Non contact test using the developed device gives convincing results.


Asunto(s)
Envejecimiento , Ensayo de Materiales/métodos , Fenómenos Mecánicos , Piel , Fenómenos Biomecánicos , Módulo de Elasticidad , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven
5.
Magn Reson Chem ; 47(8): 706-10, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19459182

RESUMEN

The complete 1H and 13C NMR signal assignments of 23 new N,N'-diacyl proflavine derivatives were achieved using one- and two-dimensional experiments (DEPT, HMQC and HMBC).


Asunto(s)
Proflavina/química , Antiinfecciosos Locales/química , Isótopos de Carbono , Hidrógeno , Espectroscopía de Resonancia Magnética , Estructura Molecular , Proflavina/análogos & derivados
6.
Skin Res Technol ; 15(1): 55-67, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19152580

RESUMEN

BACKGROUND/PURPOSE: Knowledge of the mechanical properties of the human skin is very important for cosmetic and clinical research. Objective and quantitative measurements are essential to compare studies performed by different experimenters in different centres. The aim of this paper is to present a method to measure the viscoelastic properties of human skin in vivo using dynamic indentation. METHODS: A complete device to assess the stiffness and damping of skin has been developed. The frequency and strain amplitude range from 10 to 60 Hz and from 1 to 10 mum. Tests on pure elastic inert materials have been performed to validate the device. An in vivo study including dynamic indentation, suction test, hydration measurement and topographic analysis has been performed on 46 subjects aged from 18 to 70 years, divided into three groups. RESULTS: Results on inert materials show the validity of the device developed. The mechanical behaviour of the skin can be described by a Kelvin-Voight model under dynamic indentation. A comparison with a suction test, hydration and topographic measurements shows that the stiffness and the damping measured by dynamic indentation correspond mainly to the natural tense state of the skin on the body due to the dermis. A weak correlation has been found between dynamic indentation and suction parameters. The complex modulus measured by dynamic indentation at 10 Hz frequency stress ranges from 7.2 +/- 2.1 kPa for the oldest group to 10.7 +/- 2.6 kPa for the youngest group. CONCLUSION: The device presented gives convincing results. The measurement of stiffness and damping complements the viscoelastic phenomenological parameters of the suction test.


Asunto(s)
Envejecimiento/fisiología , Modelos Biológicos , Fenómenos Fisiológicos de la Piel , Pruebas Cutáneas/instrumentación , Adolescente , Adulto , Anciano , Simulación por Computador , Módulo de Elasticidad/fisiología , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Dureza , Pruebas de Dureza/instrumentación , Pruebas de Dureza/métodos , Humanos , Persona de Mediana Edad , Pruebas Cutáneas/métodos , Viscosidad , Adulto Joven
7.
Artículo en Inglés | MEDLINE | ID: mdl-18003026

RESUMEN

The human skin, the interface between the body and the outside environment, has a very complex mechanical behaviour. Knowledge of its in vivo mechanical characteristics is essential to characterize the effects of medical or cosmetic products. The aim of this work is to present a non-invasive device using dynamic indentation to quantify the viscoelastic properties of human skin in vivo. The frequency and strain amplitude are in the range of 10 to 60 Hz and 1 to 10 microm. The results on 4 subjects show that a Kelvin Voigt model describes the mechanical behaviour of in vivo human skin with dynamic indentation well. The frequency average values of stiffness and damping have also been used to compare skin properties. We found a stiffness value of 47.3 to 128.3 N/m, and damping of 0.08 to 0.121 N.s/m, corresponding to a complex modulus of 13.2 to 33.4 kPa. These results show the ability of this device to characterize viscoelastic properties of human skin.


Asunto(s)
Elasticidad , Modelos Biológicos , Fenómenos Fisiológicos de la Piel , Piel , Cosméticos , Evaluación de Medicamentos/métodos
8.
Appl Environ Microbiol ; 73(14): 4570-8, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17526791

RESUMEN

The distribution and genotypic variation of potential microcystin (MC) producers along the southern and eastern shores of Lake Ontario in 2001 and 2003 were examined using a suite of PCR primers. Cyanobacterial, Microcystis sp., and Microcystis-specific toxin primer sets identified shoreline distribution of cyanobacterial DNA (in 97% of the stations) and MC synthetase genes (in 50% of the stations). Sequence analysis of a partial mcyA amplicon targeting Microcystis, Anabaena, and Planktothrix species indicated that the Microcystis sp. genotype was the dominant MC genotype present and revealed a novel Microcystis-like sequence containing a 6-bp insert. Analysis of the same samples with genus-specific mcyE primers confirmed that the Microcystis sp. genotype was the dominant potential MC producer. Genotype compositions within embayments were relatively homogenous compared to those for shoreline and tributary samples. MC concentrations along the shoreline exhibited both temporal and spatial differences as evidenced by the protein phosphatase inhibition assay, at times exceeding the World Health Organization guideline value for drinking water of 1.0 microg MC-LReq liter(-1). MC genotypes are widespread along the New York State shoreline of Lake Ontario, appear to originate nearshore, and can be carried through the lake via wind and surface water current patterns.


Asunto(s)
Agua Dulce/microbiología , Microcistinas/genética , Microcystis/genética , Anabaena/clasificación , Anabaena/genética , Anabaena/aislamiento & purificación , Proteínas Bacterianas/genética , Biomasa , ADN Bacteriano/química , ADN Bacteriano/genética , Geografía , Microcistinas/metabolismo , Microcystis/clasificación , Microcystis/aislamiento & purificación , Microcystis/metabolismo , Datos de Secuencia Molecular , New York , Péptido Sintasas/genética , Filogenia , Reacción en Cadena de la Polimerasa , Recombinación Genética , Análisis de Secuencia de ADN , Factores de Tiempo
9.
Magn Reson Chem ; 43(12): 1077-9, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16142837

RESUMEN

The 1H and 13C NMR resonances of 15 N,N'-diacylproflavines were assigned completely and unequivocally using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).

10.
Environ Sci Technol ; 39(11): 4198-205, 2005 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-15984800

RESUMEN

In August of 2003 and August of 2004, blooms of potentially toxic cyanobacteria Microcystis spp. persisted in western Lake Erie. Samples collected from the bloom were analyzed for the cyanobacterial toxin microcystin and the presence of Microcystis spp. cells. Estimates of microcystin toxicity exceeding 1 microg L(-1) (microcystin-LR activity equivalents), the safety limit set by the World Health Organization, were found from the samples in both 2003 and 2004. The presence of Microcystis spp. in water samples was confirmed through standard polymerase chain reaction (PCR) using a combination of four primer sets. Quantification of Microcystis was accomplished by a real-time PCR assay utilizing specific primer-Taq-man probe sets targeted on a conserved, Microcystis-specific 16S rDNA fragment and a microcystin toxin synthetase gene mcyD. This approach allowed us to specifically study the distribution and abundance of toxic Microcystis in the lake in contrast to previous studies that have assessed Microcystis populations with less refined methods. On the basis of quantification by quantitative real-time PCR analysis, the total abundance of Microcystis cells in the bloom area varied from 4 x 10(8) to 2 x 10(3) cells L(-1). The results of this study provide novel insight regarding the distribution and abundance of Microcystis spp. in the western basin of Lake Erie, a region plagued in recent years by large-scale (>20 km2) blooms. Our results suggest that the Maumee River and Bay may serve as a source for Microcystis to western and central Lake Erie.


Asunto(s)
Toxinas Bacterianas/aislamiento & purificación , Agua Dulce/microbiología , Microcystis/fisiología , Reacción en Cadena de la Polimerasa/métodos , Microbiología del Agua , Toxinas Bacterianas/clasificación , Secuencia de Bases , ADN Ribosómico/genética , Microcystis/aislamiento & purificación , Péptido Sintasas/genética , Especificidad de la Especie , Factores de Tiempo
11.
Micron ; 34(6-7): 275-82, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12932770

RESUMEN

The three-dimensional (3D) focal behaviour of the super-resolving Frieden filters is investigated numerically. It is shown that, as the central bright spot is sharpened, super-giant secondary maximums are formed on the optic axis. These lobes are much higher that the well-known side-lobes inherent to spatial filtering that surround the restricted, utilisable field, whose characteristics in the meridional plane are depicted for various values of the space-bandwidth parameter and for various numbers of terms that compose the window function. The two-terms filter is found to present, for the first time to my knowledge, some axial apodizing properties. To be compatible with practical realisation, the use of this class of filters in a single- and two-photon confocally scanned system is discussed in terms of 3D super-resolution with an intentionally limited light-power loss. It is shown that these filters match particularly well with recently designed axial apodizers for the transmission-mode confocal scanning microscope and provide a 3D intensity point-spread volume reduction of variable amount as high as 37 percent. The filtering process is shown to vary significantly with the mode of operation.


Asunto(s)
Filtración/instrumentación , Imagenología Tridimensional/instrumentación , Microscopía Confocal/instrumentación , Imagenología Tridimensional/métodos , Microscopía Confocal/métodos , Modelos Teóricos
12.
Phytochemistry ; 57(5): 787-9, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11397449

RESUMEN

Aureoumbra lagunensis, the alga responsible for the "Texas brown tide", contains (E)-24-propylidenecholesterol (35.7% of total sterols) as its dominant sterol, in common with other members of the Pelagophyceae. Other major sterols are stigmasterol (22.2%), sitosterol (19.2%), cholesterol (14.1%), and (24R)-24-propylcholesterol (5.2%). Trace amounts of 24-methylenecholesterol, crinosterol, clerosterol, campesterol, dihydrobrassicasterol, and 24-isopropylcholesterol were also detected.


Asunto(s)
Phaeophyceae/química , Esteroles/química , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética
13.
Can J Occup Ther ; 68(2): 112-20, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11355616

RESUMEN

The purpose of this article is to convey the findings of two studies related to the perception of past, present and future roles, the value attributed to these roles as well as the role patterns. Both studies were conducted with adults who have schizophrenia and are involved in a rehabilitation or work program. Data were collected from two sources: 1) secondary analysis of a study related to the methodology for validating the French translation (Hachey, Jumoorty, & Mercier, 1995) of the "Role Checklist", (Barris, Oakley, & Kielhofner, 1988) and 2) a research project on the perception of roles and quality of life. Results showed that the dominant roles assumed by participants regardless of time were family member, friend, home maintainer and hobbyist. The most valued roles were those of friend, worker, and family member. The discussion will address the questions asked and elucidate the role patterns. The conclusion underlines the importance, for occupational therapists and health professionals, of including roles in the daily lives of their clients, taking into consideration the ones they value most highly.


Asunto(s)
Terapia Ocupacional , Ocupaciones , Calidad de Vida , Esquizofrenia/rehabilitación , Autoimagen , Actividades Cotidianas , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Percepción , Relaciones Profesional-Paciente
14.
Can J Public Health ; 91(1): 60-3, 2000.
Artículo en Francés | MEDLINE | ID: mdl-10765588

RESUMEN

Studies show that it is difficult to recruit women of low socioeconomic status as clinical research participants. Such an objective was attained though as our results demonstrate in an evaluative study of a program implemented to lower the percentage of low birthweight in four CLSCs of the Island of Montreal between 1994 and 1996. The global recruitment strategy enabled us to reach 56.2% of our goal in 1994 and 77.4% in 1996. Two conclusions can be drawn from this result: the effectiveness of the three methods of recruitment varied according to each participating CLSC, and the global strategy, combined with the mobilization of community resources, was successful in enrolling women of low socioeconomic status.


Asunto(s)
Madres/psicología , Selección de Paciente , Pobreza/psicología , Embarazo/psicología , Ensayos Clínicos Controlados Aleatorios como Asunto , Adolescente , Adulto , Servicios de Salud Comunitaria , Participación de la Comunidad , Femenino , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Madres/estadística & datos numéricos , Motivación , Pobreza/estadística & datos numéricos , Evaluación de Programas y Proyectos de Salud , Quebec , Población Urbana
15.
J Rheumatol ; 27(1): 170-6, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10648035

RESUMEN

OBJECTIVES: To determine the relative severity and compare the clinical expression of spondyloarthropathy (SpA) in men and women. METHODS: A clinical study was conducted in 43 women and 40 men who made up 80% of all individuals identified as having SpA in a community-wide epidemiologic study of Alaskan Eskimos. The study included interviews, physical, laboratory, radiographic and electrocardiographic examinations, record reviews, and functional assessments. A measure of relative severity was developed to evaluate disease impact in individual patients. The results in men and women were compared. RESULTS: No significant differences between men and women were found in many features, including the age of onset, frequency of inflammatory joint swelling or inflammatory back pain, physical signs of sacroiliitis, presence of skin changes, or positive family history of SpA. Women were less likely to have sacroiliac joint fusion, advanced spinal changes, uveitis, severe cardiac conduction and valvular abnormalities, and elevated erythrocyte sedimentation rates. According to our relative severity measure, a smaller proportion of women had severe disease than men. CONCLUSION: Although as many women as men were affected by SpA in the communities studied, severe disease was seen more often in men and a number of disease manifestations were more frequent or more marked in men. These discrepancies in disease severity and expression may contribute to the underdiagnosis of SpA in women and the long standing impression that SpA is a disease predominantly of men.


Asunto(s)
Inuk , Espondilitis/complicaciones , Espondilitis/diagnóstico , Adulto , Alaska , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad , Espondilitis/epidemiología
16.
Can J Commun Ment Health ; 19(1): 201-14, 2000.
Artículo en Francés | MEDLINE | ID: mdl-12152176

RESUMEN

This paper investigates the construct validity and reliability of a Quebec version of the Edinburgh Postnatal Depression Scale (EPDS) for a population of low-socioeconomic-status mothers. This scale was constructed for the specific purpose of measuring mothers' symptoms of depression during the postnatal period in an effort to alleviate the validity problems that could arise from depression scales intended for the general population. Two hundred and twenty-four mothers participating in a Quebec prevention program, "Naître égaux, grandir en santé" (Martin & Boyer, 1995) filled out the EPDS between the 22nd and the 35th day postpartum. A confirmatory factor analysis, conducted with LISREL, gives a 2-factor structure for the EPDS, the first representing symptoms of depression and the second symptoms of anxiety. This structure differs from the one presented by Cox, Holden, and Sagovsky (1987), authors of the EPDS. It corresponds, however to the results of other authors who looked at the EPDS with confirmatory factor analysis (Pop, Komproe, & van Son, 1992) and indicates a good construct validity. The reliability of the scale also appears satisfactory, with a Cronbach alpha co-efficient of 0.82.


Asunto(s)
Depresión Posparto/diagnóstico , Encuestas y Cuestionarios , Adolescente , Adulto , Depresión Posparto/epidemiología , Depresión Posparto/psicología , Femenino , Humanos , Embarazo , Evaluación de Programas y Proyectos de Salud , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Factores Socioeconómicos
17.
Opt Lett ; 25(9): 601-3, 2000 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-18064123

RESUMEN

It is predicted numerically that soliton generation by four-wave mixing when the central wavelength of the initial pulse is below the zero-dispersion point of a nonlinear waveguide can be significantly boosted by shock-wave formation that reduces the launching power and extends the efficiency of that process deep inside the normal-dispersion region. Experimental evidence of the validity of this prediction is provided by spectral phase and intensity measurement of the propagated bound-state pulse.

18.
Qual Life Res ; 8(6): 509-14, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10548866

RESUMEN

Psychometric properties of Client's questionnaire from the Canadian version of the Wisconsin Quality of Life-Index (CaW-QLI) were assessed with two groups, 89 English (E) and 94 French (F) individuals with schizophrenia or schizoaffective disorder. Sub-samples of 40 E and 36 F were re-interviewed within a 2-week period. Spearman correlations-SC between each domain and CaW-QLI global Score ranged from 0.39 to 0.76, while interdomain correlations were low, confirming the multi-dimensional properties of the scale. Cronbach's alpha (internal consistency) were 0.78 (E) and 0.70 (F) for the CaW-QLI global scores and, from 0.45 to 0.88 among seven of eight domains. Test-retest (Concordance Correlation Coefficient--CCC) ranged from 0.36 to 0.80 among the domains, and from 0.80 (E) and 0.85 (F) between CaW-QLI global scores. Regarding convergent validity, SC between CaW-QLI global score and Spitzer's QOL-Index were 0.72 (E) and 0.58 (F). As hypothesized, there were higher correlations between CaW-QLI global scores (E and F) and SF-36 scales related to mental health than those related to physical health. Minor changes in the scoring are proposed to enhance face and content validity.


Asunto(s)
Trastornos Psicóticos , Calidad de Vida , Esquizofrenia , Adolescente , Adulto , Canadá , Femenino , Indicadores de Salud , Humanos , Masculino , Persona de Mediana Edad , Psicometría , Reproducibilidad de los Resultados , Wisconsin
19.
J Rheumatol ; 26(7): 1537-44, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10405942

RESUMEN

OBJECTIVE: To define the clinical spectrum and disease manifestations of spondyloarthropathy (SpA) as seen in a community, rather than a referral setting. METHODS: Eighty percent (83/104) of all individuals identified as having SpA in a community wide epidemiologic study of Alaskan Eskimos and 83 age and sex matched controls from the same regions participated in a 5 year clinical study. The study included baseline and followup interviews, physical, radiographic, and electrocardiographic examinations, record reviews, and functional assessment. The medical records of an additional 83 age and sex matched controls were reviewed and followed over the same 5 year period. RESULTS: The spectrum of disease varied from very mild undifferentiated SpA (USpA) to incapacitating ankylosing spondylitis (AS). Most cases were mild. Overlapping clinical features were common in the different syndromes; 10% of the cases met more than 1 set of disease criteria. Axial signs and symptoms were more frequent in patients with AS, but occurred in over half of the patients with USpA and reactive arthritis (ReA) also. Peripheral joint involvement was noted in 85% of the AS cases, usually early in the course of disease. The patterns of joint involvement and enthesopathy were similar in SpA subjects with different syndromes and significantly different from those in control subjects. Patients with AS had a higher frequency of uveitis and of aortic root disease than patients with other syndromes. CONCLUSION: The results illustrate the extent of shared clinical features in the different SpA syndromes, and describe the frequency of different features associated with SpA in patients and matched controls in a community setting. ReA and USpA were more prevalent and less severe than AS in these populations.


Asunto(s)
Inuk , Artropatías/fisiopatología , Enfermedades de la Columna Vertebral/fisiopatología , Adolescente , Adulto , Anciano , Alaska , Niño , Femenino , Humanos , Artropatías/complicaciones , Masculino , Persona de Mediana Edad , Prohibitinas , Enfermedades de la Columna Vertebral/complicaciones , Enfermedades de la Columna Vertebral/etnología , Espondilitis Anquilosante/etnología , Espondilitis Anquilosante/fisiopatología , Síndrome
20.
Nat Toxins ; 7(6): 353-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-11122529

RESUMEN

High Performance Liquid Chromatography (HPLC) is an important tool for the study of PSP toxins. It provides an alternative to bioassays and gives the concentration of individual toxin isomers. The current HPLC protocol uses a post-column chemical reaction system (PCRS) to oxidize the saxitoxin ring system to form a fluorescent chromophore. This oxidation is sensitive to changes in the flow rate, temperature, pH and age of the reagents. We have previously shown that this oxidation can be accomplished using electrochemical techniques. Termed the electrochemical oxidation system (ECOS), this approach provides a simpler alternative to the traditional PCRS-based HPLC system. A detailed description of the construction and maintenance of an HPLC-ECOS system for the analysis of PSP toxins is presented. Comparisons of the mouse bioassay, HPLC-PCRS and HPLC-ECOS system are presented for three different sample matrices: toxic dinoflagellates (Alexandrium tamarense), geoduck (Panopea generosa) and scallops (Placopectin magellanicus). In all three cases, the correlation of the HPLC-ECOS system to the mouse bioassay is similar to that obtained using the HPLC-PCRS system for the analysis of PSP toxins.


Asunto(s)
Cromatografía Líquida de Alta Presión/instrumentación , Electroquímica/instrumentación , Toxinas Marinas/análisis , Animales , Bioensayo , Bivalvos/química , Cromatografía Líquida de Alta Presión/métodos , Dinoflagelados/química , Electroquímica/métodos , Ratones , Moluscos/química , Oxidación-Reducción , Reproducibilidad de los Resultados
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