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1.
Diabet Med ; 32(2): 206-12, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25186500

RESUMEN

AIMS: To evaluate thyroid dysfunction and autoimmunity in women with gestational diabetes and to investigate the frequency of postpartum thyroiditis in women with gestational diabetes. MATERIALS AND METHODS: A total of 350 women with gestational diabetes and 350 healthy pregnant women were enrolled in the study. We studied the thyroid hormone profiles of the women in each group during pregnancy (at 24-28 weeks' gestation) and after delivery (at 6 weeks, 3, 6 and 9 months, and 1 year postpartum). RESULTS: A total of 342 women with gestational diabetes and 313 healthy pregnant women completed the follow-up during pregnancy and 1 year after delivery. Of the women with gestational diabetes, 16.6% had thyroid dysfunction, while of the healthy pregnant women, 6.1% had thyroid dysfunction. The prevalence of postpartum thyroiditis was higher in the women with a history of gestational diabetes (19.6%) than in the healthy pregnant women (10.2%), and this difference was statistically significant. CONCLUSION: According to the results of the present study, the prevalence of postpartum thyroiditis was higher in women with a history of gestational diabetes than in healthy women. We recommend that all women with gestational diabetes and women who have previous thyroid dysfunction should be screened for thyroid hormonal abnormalities during pregnancy and for 1 year after pregnancy.


Asunto(s)
Autoinmunidad , Diabetes Gestacional/fisiopatología , Glándula Tiroides/fisiopatología , Tiroiditis Autoinmune/diagnóstico , Tiroiditis/diagnóstico , Adulto , Autoanticuerpos/análisis , Estudios Transversales , Diabetes Gestacional/sangre , Diabetes Gestacional/inmunología , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Hospitales Públicos , Hospitales Universitarios , Hospitales Urbanos , Humanos , Irán/epidemiología , Periodo Posparto , Embarazo , Prevalencia , Estudios Prospectivos , Riesgo , Glándula Tiroides/inmunología , Tiroiditis/epidemiología , Tiroiditis/etiología , Tiroiditis/inmunología , Tiroiditis Autoinmune/epidemiología , Tiroiditis Autoinmune/etiología , Tiroiditis Autoinmune/inmunología , Adulto Joven
2.
Intern Med J ; 44(11): 1128-33, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24989840

RESUMEN

BACKGROUND AND AIM: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent episodes of painful inflammation in the abdomen, chest or joints. The association between FMF and non-amyloid glomerulopathies are unusual. In this study, we describe our experiences and observations about renal involvement in patients with FMF. METHODS: A total of 108 patients with FMF was enrolled in the study. Twelve patients with FMF were referred to the Nephrology Service, for evaluation and assessment of the degree of renal involvement. All the 12 patients underwent percutaneous ultrasound-guided renal biopsies and genetic analysis. RESULTS: On microscopic examination of the kidney specimens, six patients were found to have amyloidosis, five focal segmental glomerulosclerosis and one patient membranoproliferative glomerulonephritis. It seems that in patients with FMF and renal amyloidosis, the response to treatment with colchicine is excellent, but in patients with FMF and focal segmental glomerulosclerosis, the response to treatment with colchicine is poor. We present an evidence-based algorithm, constructed based on literature review, to aid decision making in management of renal involvement in patients with FMF. CONCLUSION: The results of our study suggest that in patients with FMF and renal involvement, non-amyloid renal lesions should be considered in the differential diagnosis in addition to amyloidosis.


Asunto(s)
Fiebre Mediterránea Familiar/diagnóstico , Fiebre Mediterránea Familiar/epidemiología , Enfermedades Renales/diagnóstico , Enfermedades Renales/epidemiología , Adolescente , Adulto , Estudios Transversales , Diagnóstico Diferencial , Fiebre Mediterránea Familiar/genética , Femenino , Estudios de Seguimiento , Humanos , Irán/epidemiología , Enfermedades Renales/genética , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
3.
Int J Clin Health Psychol ; 24(2): 100458, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38623146

RESUMEN

Background/Objective. Enlarged lateral ventricle (LV) volume and decreased volume in the corpus callosum (CC) are hallmarks of schizophrenia (SZ). We previously showed an inverse correlation between LV and CC volumes in SZ, with global functioning decreasing with increased LV volume. This study investigates the relationship between LV volume, CC abnormalities, and the microRNA MIR137 and its regulated genes in SZ, because of MIR137's essential role in neurodevelopment. Methods. Participants were 1224 SZ probands and 1466 unaffected controls from the GENUS Consortium. Brain MRI scans, genotype, and clinical data were harmonized across cohorts and employed in the analyses. Results. Increased LV volumes and decreased CC central, mid-anterior, and mid-posterior volumes were observed in SZ probands. The MIR137-regulated ephrin pathway was significantly associated with CC:LV ratio, explaining a significant proportion (3.42 %) of CC:LV variance, and more than for LV and CC separately. Other pathways explained variance in either CC or LV, but not both. CC:LV ratio was also positively correlated with Global Assessment of Functioning, supporting previous subsample findings. SNP-based heritability estimates were higher for CC central:LV ratio (0.79) compared to CC or LV separately. Discussion. Our results indicate that the CC:LV ratio is highly heritable, influenced in part by variation in the MIR137-regulated ephrin pathway. Findings suggest that the CC:LV ratio may be a risk indicator in SZ that correlates with global functioning.

4.
J Neurophysiol ; 107(10): 2633-48, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22323632

RESUMEN

The habenula, located in the posterior thalamus, is implicated in a wide array of functions. Animal anatomical studies have indicated that the structure receives inputs from a number of brain regions (e.g., frontal areas, hypothalamic, basal ganglia) and sends efferent connections predominantly to the brain stem (e.g., periaqueductal gray, raphe, interpeduncular nucleus). The role of the habenula in pain and its anatomical connectivity are well-documented in animals but not in humans. In this study, for the first time, we show how high-field magnetic resonance imaging can be used to detect habenula activation to noxious heat. Functional maps revealed significant, localized, and bilateral habenula responses. During pain processing, functional connectivity analysis demonstrated significant functional correlations between the habenula and the periaqueductal gray and putamen. Probabilistic tractography was used to assess connectivity of afferent (e.g., putamen) and efferent (e.g., periaqueductal gray) pathways previously reported in animals. We believe that this study is the first report of habenula activation by experimental pain in humans. Since the habenula connects forebrain structures with brain stem structures, we suggest that the findings have important implications for understanding sensory and emotional processing in the brain during both acute and chronic pain.


Asunto(s)
Habénula/fisiopatología , Red Nerviosa/fisiopatología , Dolor/fisiopatología , Adulto , Vías Aferentes/fisiología , Mapeo Encefálico , Imagen de Difusión Tensora , Calor , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Dimensión del Dolor
5.
Cereb Cortex ; 21(2): 435-48, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20562317

RESUMEN

During migraine attacks, alterations in sensation accompanying headache may manifest as allodynia and enhanced sensitivity to light, sound, and odors. Our objective was to identify physiological changes in cortical regions in migraine patients using painful heat and functional magnetic resonance imaging (fMRI) and the structural basis for such changes using diffusion tensor imaging (DTI). In 11 interictal patients, painful heat threshold + 1°C was applied unilaterally to the forehead during fMRI scanning. Significantly greater activation was identified in the medial temporal lobe in patients relative to healthy subjects, specifically in the anterior temporal pole (TP). In patients, TP showed significantly increased functional connectivity in several brain regions relative to controls, suggesting that TP hyperexcitability may contribute to functional abnormalities in migraine. In 9 healthy subjects, DTI identified white matter connectivity between TP and pulvinar nucleus, which has been related to migraine. In 8 patients, fMRI activation in TP with painful heat was exacerbated during migraine, suggesting that repeated migraines may sensitize TP. This article investigates a nonclassical role of TP in migraineurs. Observed temporal lobe abnormalities may provide a basis for many of the perceptual changes in migraineurs and may serve as a potential interictal biomarker for drug efficacy.


Asunto(s)
Calor/efectos adversos , Hiperalgesia/fisiopatología , Trastornos Migrañosos/patología , Umbral del Dolor/fisiología , Lóbulo Temporal/fisiopatología , Adulto , Mapeo Encefálico , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Hiperalgesia/patología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Lóbulo Temporal/irrigación sanguínea
7.
Klin Onkol ; 34(4): 300-305, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34649440

RESUMEN

BACKGROUND: Breast cancer is recognized as a major clinical challenge in gynecological diseases worldwide. Exosomes are small vesicles derived from multicellular bodies that are secreted by many cells into the extracellular environment and thus participate in intercellular communication through the transfer of genetic information such as encoded and non-encoded RNAs to target cells. Tumor-derived exosomes are thought to be a rich source of microRNAs (miRs) that can regulate the function of other cancer cells in the tumor microenvironment. However, the exact mechanisms by which tumor cell-derived exosomes affect their neighboring cells, as well as the bio-logical function of exosomal miRs in receptor cells, are not well understood. MATERIALS AND METHODS: In this study, after the overexpression of MiR-205 in breast cancer cells (MDA-MB-231 class), cell-derived exosomes were successfully isolated and characterized by electron microscopy and dynamic light scattering. RESULTS: The determination of MiR-205 expression levels in exosomes secreted from engineered cells confirmed the high expression of this miR in exosomes. It was also found that the treatment of tumor exosomes carrying this miR had an apoptotic induction effect and also had a significant effect on reducing the expression of Bcl-2 gene transcript in a time-dependent manner in breast cancer cells (P < 0.001). CONCLUSION: Overall, this study suggests that exosomal transfer of tumor suppressor miRs to cancer cells could be a suitable platform for nucleic acid transfer to these cells and be highly effective in cancer treatment.


Asunto(s)
Neoplasias de la Mama/terapia , Exosomas/genética , Terapia Genética/métodos , Apoptosis/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Dispersión Dinámica de Luz , Exosomas/química , Femenino , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Genes bcl-2 , Humanos , MicroARNs/genética
8.
Malays Orthop J ; 14(2): 94-100, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32983383

RESUMEN

INTRODUCTION: Meniscus injuries are the most frequent problem of the knee. The aim of this study was to investigate the accuracy of the Thessaly test and comparing it with those of McMurray and Joint-line tenderness tests for diagnosing meniscal tears.Materials and methods: This study was designed as a prospective observational one done in an outpatient clinic at a university hospital. 106 patients with knee pain and 82 age-matched control were included during study period (from February 2014 to January 2015). Each patient was clinically examined with McMurray, Thessaly, and joint line tenderness tests. Then, the findings were matched by MRI and arthroscopic findings. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated as main outcomes. RESULTS: Based on MRI, Thessaly was the most sensitive for medial meniscus tears (56.2%), while McMurray and joint-line tenderness were more specific (89.1% and 88.0%, respectively). For lateral meniscus tears, McMurray was the most sensitive (56.2%) and all were specific (McMurray 89.6%, Thessaly 88.4%, joint-line tenderness 90.2%). With arthroscopy, Thessaly was the most sensitive for medial meniscus (76.6%), while McMurray and joint-line tenderness were more specific (81.0%, and 81.0%). Agreement with arthroscopy was the highest with McMurray (for medial meniscus kappa=0.40, p<0.001, and for lateral meniscus kappa=0.38, p=0.002). CONCLUSION: The Thessaly can be used to screen for medial meniscus tears. McMurray and joint-line tenderness should be used for suspected medial meniscus tears. For lateral meniscus, McMurray is appropriate for screening and all the tests are useful in clinic.

9.
East Mediterr Health J ; 15(4): 934-43, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20187545

RESUMEN

A prospective survey of pharmacists' tasks and patients' knowledge and satisfaction was conducted in 35 randomly selected community pharmacies in Tabriz, Islamic Republic of Iran. The total pharmacist interaction received a mean score of 3.05 out of 5. Providing written directions for use attained the highest score of 0.98 out of 1. Patients scored 3.18 out of 5 for knowledge about their medicines. There was a close correlation between patients' knowledge of dispensed drugs and pharmacist interaction (r = 0.95). Mean total prescription filling time was 7.6 min, but only 1.4 min was spent on pharmacist-patient counselling. The interaction between pharmacist and patient increases patients' knowledge about dispensed medicines and their satisfaction with the pharmacist's activities.


Asunto(s)
Servicios Comunitarios de Farmacia/organización & administración , Educación del Paciente como Asunto/organización & administración , Satisfacción del Paciente , Farmacéuticos , Rol Profesional , Relaciones Profesional-Paciente , Comunicación , Etiquetado de Medicamentos , Prescripciones de Medicamentos , Evaluación Educacional , Humanos , Irán , Modelos Lineales , Anamnesis , Satisfacción del Paciente/estadística & datos numéricos , Farmacéuticos/organización & administración , Farmacéuticos/psicología , Rol Profesional/psicología , Estudios Prospectivos , Calidad de la Atención de Salud , Estudios de Tiempo y Movimiento
10.
J Colloid Interface Sci ; 322(1): 274-80, 2008 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-18406416

RESUMEN

The interactions of an imidazolium based ionic liquid (IL), namely 1-dodecyl-3-methylimidazolium chloride [C12 mim][Cl] with two sulfonated anionic dyes, azocarmine G and methyl orange, are studied spectrophotometrically in both acidic and basic media. ILs (with some surface active character) can interact with the above dyes and cause considerable shifts in their spectra. These interactions are then compared with some surfactant-dye interactions. Evolving factor analysis (EFA) and multivariate curve resolution-alternating least squares (MCR-ALS) are used for complete resolution of the measured spectrophotometric data. The concentration and spectral profiles of all species were calculated without any assumption of the chemical models. The spectral variation of dye solutions as a function of IL concentrations below and above the critical aggregation concentration (CAC) is analyzed using MCR-ALS as a soft-modeling technique. The ion pair formation constants between ILs and dyes were calculated using the obtained concentration profiles.

11.
Int J Radiat Oncol Biol Phys ; 14(2): 373-81, 1988 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3276655

RESUMEN

A small field irradiation technique to deliver high doses of single fraction photon radiation to small, precisely located volumes (0.5 to 8 cm3) within the brain has been developed. Our method uses a modified Brown-Roberts-Wells (BRS), CT-guided, stereotactic system and a 6 MV linear accelerator equipped with a special collimator (diameters of 12.5 mm to 30.0 mm projected to isocenter) located 23 cm from isocenter. Target localization via planar angiography has been added. Treatment consists of a series of arcing beams using both gantry and couch rotations. During treatment, the patient's head is immobilized independently of the radiotherapy couch and is precisely positioned without reference to room lasers or light field. A precise verification of alignment precedes each treatment. Extensive performance tests have shown that a target, localized by CT, can be irradiated with a positional accuracy of 2.4 mm in any direction with 95% confidence. If angiography is used for localization, the results are better. The dose 1.0 cm outside the target volume is less than 20% of the prescribed dose for a medium sized collimator.


Asunto(s)
Neoplasias Encefálicas/radioterapia , Aceleradores de Partículas , Radioterapia/instrumentación , Neoplasias Encefálicas/cirugía , Humanos , Dosis de Radiación , Radioterapia/métodos , Radioterapia Asistida por Computador , Técnicas Estereotáxicas
12.
Med Phys ; 12(4): 480-1, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-4033594

RESUMEN

We have evaluated a simple microdensitometer concept by Stanton et al. for measurements of dose distributions with high spatial resolution. A magnified image of the film is created by a slide projector and its light intensity measured with a photomultiplier with a small aperture. The projector is placed on a movable stage to allow scanning of the film. A resolution of 17 micron (full width at half maximum of the line spread function) was achieved in the film plane.


Asunto(s)
Absorciometría de Fotón/instrumentación , Óptica y Fotónica/instrumentación , Fenómenos Biofísicos , Biofisica , Humanos , Dosificación Radioterapéutica
13.
Med Phys ; 15(4): 614-7, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3145391

RESUMEN

A beam-spot camera for measurements of x-ray focal spots of accelerators has been evaluated. The device consists of closely packed 0.25-mm-thick lead and 0.25-mm-thick cardboard strips. It is placed on radiographic film with the lamellae parallel to the beam axis and an exposure made. The images were scanned with a microdensitometer. The results indicate that the broadening of the source intensity profile at half maximum is of the order 1 mm, which permits the use of the beam-spot camera for acceptance testing and quality control. Longer tails in the density profile limit the quantitative information that can be extracted from the images.


Asunto(s)
Radioterapia de Alta Energía/instrumentación , Radioisótopos de Cobalto/uso terapéutico , Diseño de Equipo , Humanos , Aceleradores de Partículas , Fotograbar , Radioterapia de Alta Energía/métodos
14.
Talanta ; 39(3): 281-4, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18965375

RESUMEN

Determination of vanadium at low concentrations is easily performed with pyrogallol as a ligand which forms a bluish-violet complex with vanadium(III), (IV) or (V). The colour of the bluish-violet complex (lambda(max) = 580 nm) contrasts well with the colour of both pyrogallol and vanadium. The complexes are stable for several hours. Beer's law is obeyed over the range 0-14 mug/ml vanadium at pH 6. The apparent molar absorptivity at 580 nm is (7.75 +/- 0.25) x 10(3)1.mole(-1).cm(-1). The effects of diverse ions on the determination of vanadium have been fully studied. Only Mo(VI) and W(VI) interfere seriously. The method is selective, sensitive and can be applied to the determination of total vanadium in a variety of samples.

15.
J Ethnopharmacol ; 75(2-3): 213-8, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11297854

RESUMEN

Extracts obtained from aerial parts of Stachys inflata have been used in Iranian folk medicine in infective, rheumatic and other inflammatory disorders. In the present study, the anti-inflammatory properties of total methanol extract isolated from aerial parts of Stachys inflata were investigated in two well-characterised inflammatory models in rats, carrageenan-induced paw oedema and formalin-induced paw licking. Intraperitoneal injection of the extract, 60 min before induction of inflammation, revealed a dose-related inhibition of carrageenan-induced rat paw oedema over the dose range 50-200 mg/kg. In the formalin test, the extract (50, 100 and 200 mg/kg) had no effect against the first phase (0-5 min) of the formalin-induced pain, but all three doses produced a significant blockade of the second phase (P < 0.001). Myeloperoxidase (MPO) activity was determined, and a histopathological study was carried out in paw tissue 4 h after induction of inflammation. The hydroalcoholic extract (200 mg/kg) substantially reduced MPO activity (P < 0.05), which was increased in the control group. Histological examination showed a marked reduction in tissue injury and inhibition in neutrophil infiltration in rats treated with the extract (200 mg/kg).


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Lamiaceae/química , Extractos Vegetales/farmacología , Animales , Carragenina/toxicidad , Relación Dosis-Respuesta a Droga , Edema/inducido químicamente , Edema/prevención & control , Formaldehído/toxicidad , Masculino , Metanol/química , Dolor/inducido químicamente , Dolor/prevención & control , Peroxidasa/metabolismo , Ratas , Ratas Wistar
16.
Transplant Proc ; 41(7): 2775-6, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19765432

RESUMEN

INTRODUCTION: Renal transplantation remains the treatment of choice for end-stage renal disease (ESRD) in regard to patient survival. Iran was one of the first countries in the Middle East that began renal transplantation. METHODS: In a follow-up study, we enrolled all of our cadaveric renal transplant recipients from 2001 to 2007, namely, 39 cases. Related variables collected through checklists were entered into SPSS software version 16 and analyzed using the Kaplan-Meier method and by descriptive statistics. RESULTS: The mean age of the recipients was 35.18 +/- 14.27 years. Twenty-one patients (53.8%) were men. The underlying disease for development of ESRD was diabetes (7 cases, 21.2%), hypertension (24.2%), glomerulopathies (36.4%), polycystic disease (PKD; 2.6%), and 5 (15.2%) were unknown. Four recipients (10.3%) were hospitalized again because of acute tubular necrosis after transplantation. An acute rejection episode was diagnosed in 7 (17.9%) graft recipients. Surgical complications after transplantation were as follows: urinoma, lymphocele, and surgical site leakage (each 1 case). One-year patient survival rate was 89.7% in this study; 4 recipients died within 1-9 months after transplantation. Death-censored 1-year graft survival rate was 100%. DISCUSSION: The survival rate of cadaveric transplant was in an acceptable range.


Asunto(s)
Cadáver , Fallo Renal Crónico/cirugía , Trasplante de Riñón/fisiología , Donantes de Tejidos/estadística & datos numéricos , Adulto , Femenino , Humanos , Fallo Renal Crónico/etiología , Trasplante de Riñón/mortalidad , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Programas Informáticos , Tasa de Supervivencia , Resultado del Tratamiento , Adulto Joven
17.
Bull Exp Biol Med ; 146(2): 210-3, 2008 Aug.
Artículo en Inglés, Ruso | MEDLINE | ID: mdl-19145320

RESUMEN

Isolated rat hearts were subjected to 30-min coronary artery occlusion followed by 120-min reperfusion. The hearts (n=8-12) were perfused with Krebs-Henseleit solution enriched with L-carnitine (0.5, 2.5 and 5 mM) for 10 min before and after ischemia or reperfusion and for the whole period of ischemia and reperfusion. Two-hour perfusion with L-carnitine during ischemia/reperfusion markedly (p<0.05) and dose-dependently decreased the incidence of ventricular tachycardia (VT, maximum 65%). The incidence of reperfusion ventricular fibrillation (VF) also decreased from 63% (control) to 17% in hearts perfused with 5 mM L-carnitine, as reflected by a significant (p<0.05) decline in VF duration from 218+/-99 sec in control to 19+/-19 sec. Perfusion of etomoxir (palmitoylcarnitinetransferase-1 inhibitor) along with L-carnitine reversed the antiarrhythmogenic action of L-carnitine. Interestingly, short time preischemic administration of L-carnitine produced a concentration-dependent arrhythmogenic effects on both ischemia and reperfusion-induced arrhythmias. These results show that L-carnitine produced a protective effect against reperfusion arrhythmias only when it was perfused for the whole period of the experiment. This protective action was reversed by concomitant use of etomoxir, suggesting that the efficacy of L-carnitine is due to its mitochondrial action but cannot be solely attributed to increased fatty acid oxidation.


Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Carnitina/uso terapéutico , Oclusión Coronaria/tratamiento farmacológico , Corazón/efectos de los fármacos , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Animales , Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/fisiopatología , Carnitina/administración & dosificación , Compuestos Epoxi/uso terapéutico , Glucosa , Masculino , Contracción Miocárdica/efectos de los fármacos , Daño por Reperfusión Miocárdica/fisiopatología , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Taquicardia Ventricular/tratamiento farmacológico , Trometamina , Fibrilación Ventricular/tratamiento farmacológico , Complejos Prematuros Ventriculares/tratamiento farmacológico
18.
Anal Biochem ; 369(2): 149-53, 2007 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-17716615

RESUMEN

The electrochemistry of L-cysteine (CySH) in neutral aqueous media was investigated using carbon ionic liquid electrode (CILE). Comparative experiments were carried out using glassy carbon electrodes. At CILE, highly reproducible and well-defined cyclic voltammograms were obtained for l-cysteine with a peak potential of 0.49V vs Ag/AgCl, showing that CILE manifests a good electrocatalytic activity toward oxidation of l-cysteine. A linear dynamic range of 2-210microM with an experimental detection limit of 2microM was obtained. The method was successfully applied to the determination of l-cysteine in a sample of soya milk. Cysteine oxidation at CILE does not result in deactivation of the electrode surface. Mechanistic studies showed that, at CILE, the overall CySH oxidation is controlled by the oxidation of the CyS(-) electroactive species.


Asunto(s)
Técnicas Biosensibles/métodos , Carbono/química , Cisteína/análisis , Glycine max/química , Líquidos Iónicos/química , Técnicas Biosensibles/instrumentación , Catálisis , Electrodos , Proteínas de la Leche/química , Oxidación-Reducción , Potenciometría , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
19.
Talanta ; 71(1): 498-501, 2007 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-19071333

RESUMEN

Changes in colors of an array of optical sensors that responds in full pH range were recorded using a CCD camera. The data of the camera were transferred to the computer through a capture card. Simple software was written to read the specific color of each sensor. In order to associate sensor array responses with pH values, a number of different mathematics and chemometrics methods were investigated and compared. The results show that the use of "Microsoft Excel's Solver" provides results which are in very good agreement with those obtained with chemometric methods such as artificial neural network (ANN) and partial least square (PLS) methods.

20.
Anal Chim Acta ; 581(1): 37-41, 2007 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-17386423

RESUMEN

In situ mercury film electrode produced in the presence of thiocyanate has been shown extremely useful for highly sensitive adsorptive stripping voltammetric measurements of atrazine down to sub-microg L(-1) level. Operational parameters have been optimized and the stripping voltammetric performance has been investigated using square wave scans. The adsorptive stripping response is linear over the range of 0.5-60 microg L(-1) atrazine, with a detection limit of 0.024 microg L(-1). The method has been applied to the determination of atrazine in soil and water samples.


Asunto(s)
Atrazina/análisis , Mercurio/análisis , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Electroquímica , Electrodos
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