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Herrera W, Vera J, Hermosilla E, Diaz M, Tortella GR, Dos Reis RA, Seabra AB, Diez MC, Rubilar O. The Catalytic Role of Superparamagnetic Iron Oxide Nanoparticles as a Support Material for TiO 2 and ZnO on Chlorpyrifos Photodegradation in an Aqueous Solution. Nanomaterials (Basel) 2024; 14:299. [PMID: 38334570 PMCID: PMC10856829 DOI: 10.3390/nano14030299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/10/2024]
Abstract
Chlorpyrifos (CP) is a globally used pesticide with acute toxicity. This work studied the photocatalytic degradation of CP using TiO2, ZnO nanoparticles, and nanocomposites of TiO2 and ZnO supported on SPIONs (SPION@SiO2@TiO2 and SPION@SiO2@ZnO). The nanocomposites were synthesized by multi-step incipient wetness impregnation. The effects of the initial pH, catalyst type, and dose were evaluated. The nanocomposites of SPION@SiO2@TiO2 and SPION@SiO2@ZnO showed higher CP photodegradation levels than free nanoparticles, reaching 95.6% and 82.3%, respectively, at pH 7. The findings indicate that iron oxide, as a support material for TiO2 and ZnO, extended absorption edges and delayed the electron-hole recombination of the nanocomposites, improving their photocatalytic efficiency. At the same time, these nanocomposites, especially SPION@SiO2@TiO2, showed efficient degradation of 3,5,6-trichloropyridinol (TCP), one of the final metabolites of CP. The stability and reuse of this nanocomposite were also evaluated, with 74.6% efficiency found after six cycles. Therefore, this nanomaterial represents an eco-friendly, reusable, and effective alternative for the degradation of chlorpyrifos in wastewater treatment.
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Affiliation(s)
- Wence Herrera
- Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Temuco 4780000, Chile
| | - Joelis Vera
- Programa de Doctorado en Ciencias de la Ingeniería Mención Bioprocesos, Universidad de la Frontera, Temuco 4780000, Chile;
| | - Edward Hermosilla
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco 4780000, Chile; (E.H.); (M.D.); (G.R.T.); (M.C.D.)
| | - Marcela Diaz
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco 4780000, Chile; (E.H.); (M.D.); (G.R.T.); (M.C.D.)
| | - Gonzalo R. Tortella
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco 4780000, Chile; (E.H.); (M.D.); (G.R.T.); (M.C.D.)
| | - Roberta Albino Dos Reis
- Center for Natural and Human Sciences, Universidade Federal do ABC, Santo André 09210-580, SP, Brazil; (R.A.D.R.); (A.B.S.)
| | - Amedea B. Seabra
- Center for Natural and Human Sciences, Universidade Federal do ABC, Santo André 09210-580, SP, Brazil; (R.A.D.R.); (A.B.S.)
| | - María Cristina Diez
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco 4780000, Chile; (E.H.); (M.D.); (G.R.T.); (M.C.D.)
- Departamento de Ingeniería Química, Universidad de La Frontera, Temuco 4780000, Chile
| | - Olga Rubilar
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco 4780000, Chile; (E.H.); (M.D.); (G.R.T.); (M.C.D.)
- Departamento de Ingeniería Química, Universidad de La Frontera, Temuco 4780000, Chile
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Herrera W, Vera J, Aponte H, Hermosilla E, Fincheira P, Parada J, Tortella G, Seabra AB, Diez MC, Rubilar O. Meta-analysis of metal nanoparticles degrading pesticides: what parameters are relevant? Environ Sci Pollut Res Int 2023; 30:60168-60179. [PMID: 37017842 DOI: 10.1007/s11356-023-26756-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/27/2023] [Indexed: 05/10/2023]
Abstract
The rise in the global population demands an increasing food supply and methods to boost agricultural production. Pesticides are necessary for agricultural production models, avoiding losses of close to 40%. Nevertheless, the extensive use of pesticides can cause their accumulation in the environment, causing problems for human health, biota, and ecosystems. Thus, new technologies have emerged to remove these wastes efficiently. In recent years, metal and metal oxide nanoparticles (MNPs) have been reported as promising catalysts to degrade pesticides; however, a systematic understanding of their effect on pesticide degradation is still required. Therefore, this study focused on a meta-analysis of articles available in Elsevier's Scopus and Thomas Reuters Web of Science, found by searching for "nanoparticle pesticide" and "pesticide contamination." After passing different filters, the meta-analysis was performed with 408 observations from 94 reviews, which comprise insecticides, herbicides, and fungicides, including organophosphates, organochlorines, carbamates, triazines, and neonicotinoids. Herein, 14 different MNPs (Ag, Ni, Pd, Co3O4, BiOBr, Au, ZnO, Fe, TiO2, Cu, WO3, ZnS, SnO2, and Fe0), improved pesticide degradation, with the highest degradation rates achieved by Ag (85%) and Ni (82.5%). Additionally, the impact of the MNP functionalization, size, and concentration on pesticide degradation was quantified and compared. In general, the degradation rate increased when the MNPs were functionalized (~ 70%) compared to naked (~ 49%). Also, the particle size significantly affected the degradation of pesticides. To our knowledge, this study is the first meta-analysis performed about the impact of MNPs on pesticide degradation, providing an essential scientific basis for future studies.
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Affiliation(s)
- Wence Herrera
- Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Temuco, Chile
| | - Joelis Vera
- Programa de Doctorado en Ciencias de la Ingeniería mención Bioprocesos, Universidad de la Frontera, Temuco, Chile
| | - Humberto Aponte
- Instituto de Ciencias Agroalimentarias, Animales y Ambientales, Laboratorio de Ecología Microbiana Y Biogeoquímica de Suelos, Universidad de O'Higgins, San Fernando, Chile
| | - Edward Hermosilla
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile
| | - Paola Fincheira
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile
| | - Javiera Parada
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile
- Departamento de ingeniería Química, Universidad de La Frontera, Temuco, Chile
| | - Gonzalo Tortella
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile
- Departamento de ingeniería Química, Universidad de La Frontera, Temuco, Chile
| | - Amedea B Seabra
- Center for Natural and Human Sciences, Universidade Federal do ABC, SP, Santo André, Brazil
| | - Maria Cristina Diez
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile
- Departamento de ingeniería Química, Universidad de La Frontera, Temuco, Chile
| | - Olga Rubilar
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente CIBAMA-BIOREN, Universidad de La Frontera, Temuco, Chile.
- Departamento de ingeniería Química, Universidad de La Frontera, Temuco, Chile.
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Vera J, Herrera W, Hermosilla E, Díaz M, Parada J, Seabra AB, Tortella G, Pesenti H, Ciudad G, Rubilar O. Antioxidant Activity as an Indicator of the Efficiency of Plant Extract-Mediated Synthesis of Zinc Oxide Nanoparticles. Antioxidants (Basel) 2023; 12:784. [PMID: 37107159 PMCID: PMC10135172 DOI: 10.3390/antiox12040784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 04/29/2023] Open
Abstract
The green synthesis of zinc oxide nanoparticles (ZnO NPs) using a diverse range of plant species has been extensively reported. Despite the success achieved by biogenic synthesis, there are problems with the control and prediction of the properties of ZnO NPs, due to phytochemical diversity between plant species. In this sense, the main objective of our work was to investigate the effect of the antioxidant activity (AA) of plant extracts on the physicochemical characteristics of ZnO NPs (production yield, chemical composition, polydispersity index (PDI), surface charge (ζ-potential) and average particle size). In order to accomplish this objective, four plant extract with different antioxidant activities were used: Galega officinalis, Buddleja globosa, Eucalyptus globulus, and Aristotelia chilensis. Phytochemical screening, quantitative analysis of phenolic compounds and antioxidant activity determination of the different extracts were carried out. Chemical species such as catechin, malvidin, quercetin, caffeic acid, and ellagic acid were the dominant components, found in the extracts studied. The A. chilensis extract showed the highest value of total phenolic compounds (TPC) and AA, followed by E. globulus, B. globosa and G. officinalis. Zetasizer, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) data show that plant extracts with lower AA leads to a decrease in the yield of ZnO NPs and an increase in the amount of residual organic extract that remains on the particles. The latter caused an increase in the average particle size, PDI and ζ-potential as a consequence of agglomeration and particle coarsening. Our result suggest that it is possible to use the AA as an indicator of the potential reducing capacity of plant extracts. In this way it is possible to guarantee the reproducibility of the synthesis process as well as ensure the formation of ZnO NPs with desired characteristics.
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Affiliation(s)
- Joelis Vera
- Doctorate in Sciences Engineering with Specialization in Bioprocess, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Wence Herrera
- Doctoral Program in Sciences of Natural Resources, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Edward Hermosilla
- Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile; (E.H.); (M.D.); (J.P.); (G.T.)
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Marcela Díaz
- Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile; (E.H.); (M.D.); (J.P.); (G.T.)
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Javiera Parada
- Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile; (E.H.); (M.D.); (J.P.); (G.T.)
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Amedea B. Seabra
- Center for Natural and Human Sciences, Universidade Federal do ABC, Santo André 09210-580, Brazil;
| | - Gonzalo Tortella
- Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile; (E.H.); (M.D.); (J.P.); (G.T.)
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Héctor Pesenti
- Núcleo de Investigación en Bioprocesos y Materiales Avanzados, Facultad de Ingeniería, Universidad Católica de Temuco, Temuco 4810302, Chile;
| | - Gustavo Ciudad
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
- Instituto del Medio Ambiente (IMA), Universidad de La Frontera, Temuco 4811230, Chile
| | - Olga Rubilar
- Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile; (E.H.); (M.D.); (J.P.); (G.T.)
- Chemical Engineering Department, Faculty of Engendering and Science, Universidad de La Frontera, Temuco 4811230, Chile;
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Muñoz MT, Maldonado V, Herrera W, Mutis A, Bardehle L, Medina C, Hormazábal E, Ortega F, Quiroz A. Optimization of enzymatic parameters for the production of formononetin from red clover ( Trifolium pratense L.) through a response surface methodology. Nat Prod Res 2021; 36:4719-4724. [PMID: 34775894 DOI: 10.1080/14786419.2021.2002324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Trifolium pratense, is a forage found worldwide, but it is negatively impacted by the clover root borer, Hylastinus obscurus. Methanolic extraction has been reported for isolating formononetin from vegetal tissues, with an antifeeding effect on H. obscurus. However, this methodology is time-consuming and also extracts other secondary metabolites, whereas enzymatic assays can provide higher specificity. Hence, the objective of this work was to determine the optimal conditions in pH, temperature, and incubation time for the activity of isoflavone synthase via a response surface model. Once these parameters were optimized, the concentration of formononetin in cultivars and experimental lines of T. pratense was evaluated enzymatically. The results showed that the best condition for developing the enzymatic assay was pH 9.1 with an incubation at 34.5 °C for 155 min. The formononetin content fluctuated between 0.74 and 1.96 mg/g of fresh weight, where Precoz-3, Precoz-1, and Superqueli-INIA presented the highest production.
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Affiliation(s)
- María Teresa Muñoz
- Carrera Bioquímica, Facultad de Ingeniería y Ciencias, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile.,Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile
| | - Vanessa Maldonado
- Carrera Bioquímica, Facultad de Ingeniería y Ciencias, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile.,Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile
| | - Wence Herrera
- Centre for Biotechnological Research Applied to the Environment (CIBAMA), Universidad de La Frontera, Temuco, Chile
| | - Ana Mutis
- Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile.,Centre for Biotechnological Research Applied to the Environment (CIBAMA), Universidad de La Frontera, Temuco, Chile
| | - Leonardo Bardehle
- Centre for Biotechnological Research Applied to the Environment (CIBAMA), Universidad de La Frontera, Temuco, Chile.,Departamento de Producción Agropecuaria, Facultad de Ciencias Agropecuarias y Forestales, Universidad de La Frontera, Temuco, Chile
| | - Cristian Medina
- Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile
| | - Emilio Hormazábal
- Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile.,Centre for Biotechnological Research Applied to the Environment (CIBAMA), Universidad de La Frontera, Temuco, Chile
| | - Fernando Ortega
- Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación Carillanca, Temuco, Chile
| | - Andrés Quiroz
- Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile.,Centre for Biotechnological Research Applied to the Environment (CIBAMA), Universidad de La Frontera, Temuco, Chile
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Aponte H, Herrera W, Cameron C, Black H, Meier S, Paolini J, Tapia Y, Cornejo P. Alteration of enzyme activities and functional diversity of a soil contaminated with copper and arsenic. Ecotoxicol Environ Saf 2020; 192:110264. [PMID: 32035397 DOI: 10.1016/j.ecoenv.2020.110264] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/22/2020] [Accepted: 01/29/2020] [Indexed: 05/27/2023]
Abstract
Copper (Cu) mining has to address a critical environmental issue related to the disposal of heavy metals and metalloids (HMs). Due to their deleterious effects on living organisms, Cu and arsenic (As) have gained global attention, and thus their monitoring in the environment is an important task. The aims of this study were: 1) to evaluate the alteration of soil enzyme activities (EAs) and soil microbial functional diversity with Cu/As contamination, and 2) to select the most reliable biochemical indicators of Cu/As contamination. A twelve-week soil experiment was performed with four increasing levels of Cu, As, and Cu/As from 150/15 to 1000/100 mg Cu/As kg-1. Soil enzyme activities and soil community-level physiological profile (CLPP) using MicroResp™ were measured during the experiment. Results showed reduced EAs over time with increasing Cu and Cu/As levels. The most Cu-sensitive EAs were dehydrogenase, acid phosphatase, and arylsulfatase, while arginine ammonification might be related to the resilience of soil microbial communities due to its increased activity in the last experimental times. There was no consistent response to As contamination with reduced individual EAs at specific sampling times, being urease the only EA negatively affected by As. MicroResp™ showed reduced carbon (C) substrate utilization with increasing Cu levels indicating a community shift in C acquisition. These results support the use of specific EAs to assess the environmental impact of specific HMs, being also the first assessment of EAs and the use of CLPP (MicroResp™) to study the environmental impact in Cu/As contaminated soils.
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Affiliation(s)
- Humberto Aponte
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Temuco, Chile; Doctoral Program in Sciences of Natural Resources, Universidad de La Frontera, Temuco, Chile
| | - Wence Herrera
- Doctoral Program in Sciences of Natural Resources, Universidad de La Frontera, Temuco, Chile
| | - Clare Cameron
- Ecological Sciences, The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Helaina Black
- Ecological Sciences, The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Sebastian Meier
- Instituto de Investigaciones Agropecuarias (INIA), Centro de Investigación Regional de Investigación Carillanca, P.O. Box 58-D, Temuco, Chile
| | - Jorge Paolini
- Instituto Venezolano de Investigaciones Científicas (IVIC), Centro de Ecología, Altos de Pipe, Apdo. 21827, Caracas 1020-A, Venezuela
| | - Yasna Tapia
- Departamento de Ingeniería y Suelos, Universidad de Chile, La Pintana, Santiago, Chile
| | - Pablo Cornejo
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Temuco, Chile.
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Domuez L, Herrera W, Rivera A, Bermdez C. Laparoscopic Cholecystectomy For Acute Cholecystitis In The Elderly: A Discriminative Analysis In Populations Over 65 Years. J Surg Res 2011. [DOI: 10.1016/j.jss.2010.11.800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Herrera W, de Jesús Mari J, Ferraz MPT. Mental disorders and the internal armed conflict in Guatemala. Actas Esp Psiquiatr 2005; 33:238-43. [PMID: 15999300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
INTRODUCTION The Guatemalan society was exposed to an internal armed conflict during the period from 1962 to 1996. During these years, the civil society suffered multiple traumatic events. The objective of this study is to understand the psychological impact that the conflict had on the mental health of the Guatemalans. METHODS A review of articles published between 1962 and 2004, in the databases Medline, Lilacs, Embase, Psiclit-Infon, Cochrane Library and Pilots was conducted. The articles that were selected found mental disorder prevalences in Guatemalans through standardized instruments. RESULTS Eight studies were found to demonstrate, in general, elevated prevalences for mental disorders in different population groups affected by the violence. For the depression ranges, the prevalence was between 38.8% and 41.8%; for anxiety symptoms intervals between 27.7% and 54.4 %; for sleep problems, 75 %, and for posttraumatic stress disorder (PTSD) studies with low frequencies from 2% to 11.8 % and other studies that demonstrated higher prevalences from 32% to 52%. CONCLUSIONS These mental disorders prevalences can be interpreted as elevated when compared with population studies of persons not exposed to armed conflicts where the PTSD ranges generally go from 0.5% to 11.7%. This permits the inference that these high frequencies are probably related to traumatic experiences of the war in Guatemala and in exile.
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Affiliation(s)
- W Herrera
- Escuela Paulista de Medicina, Universidad Federal de São Paulo, Brazil.
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Fernández T, Herrera W, Harmony T, Díaz-Comas L, Santiago E, Sánchez L, Bosch J, Fernández-Bouzas A, Otero G, Ricardo-Garcell J, Barraza C, Aubert E, Galán L, Valdés R. EEG and behavioral changes following neurofeedback treatment in learning disabled children. ACTA ACUST UNITED AC 2004; 34:145-52. [PMID: 14521276 DOI: 10.1177/155005940303400308] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neurofeedback (NFB) is an operant conditioning procedure, by which the subject learns to control his/her EEG activity. On one hand, Learning Disabled (LD) children have higher values of theta EEG absolute and relative power than normal children, and on the other hand, it has been shown that minimum alpha absolute power is necessary for adequate performance. Ten LD children were selected with higher than normal ratios of theta to alpha absolute power (theta/alpha). The Test Of Variables of Attention (TOVA) was applied. Children were divided into two groups in order to maintain similar IQ values, TOVA values, socioeconomical status, and gender for each group. In the experimental group, NFB was applied in the region with highest ratio, triggering a sound each time the ratio fell below a threshold value. Noncontingent reinforcement was given to the other group. Twenty half-hour sessions were applied, at a rate of 2 per week. At the end of the 20 sessions, TOVA, WISC and EEG were obtained. There was significant improvement in WISC performance in the experimental group that was not observed in the control group. EEG absolute power decreased in delta, theta, alpha and beta bands in the experimental group. Control children only showed a decrease in relative power in the delta band. All changes observed in the experimental group and not observed in the control group indicate better cognitive performance and the presence of greater EEG maturation in the experimental group, which suggests that changes were due not only to development but also to NFB treatment.
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Affiliation(s)
- T Fernández
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, QRO. 76230, México
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Abstract
An epidemiologic survey (n = 466) was conducted in an area of subtropical rainforest in north-west Ecuador with the following objectives: (1) to determine the prevalence of cutaneous leishmaniasis (CL), (2) to identify the Leishmania species causing human disease, (3) to investigate the major clinical manifestations of leishmaniasis, (4) to study cellular and humoral immune response indicators associated with disease status and (5) to identify risk factors for CL. Fourteen percent of subjects had parasitologically confirmed CL; 33% had evidence of prior disease. However, 17.2% of subjects with a negative CL clinical history presented with a positive Montenegro skin test (MST), indicating the possibility of subclinical infection. The species isolated from subject lesions were L. guyanensis (63%), L. panamensis (33%), and L. brazilensis (4%). Mean specific anti-Leishmania IgG and IgM OD serum levels were highest in subjects diagnosed with current CL, followed by those with prior CL, and were lowest in healthy subjects, respectively (0.56 +/- 0.27 vs 0.33 +/- 0.2 vs 0.22 +/- 0.14; F-ratio = 74; P < 0.00001) and (665 +/- 270 vs 481 +/- 220 vs 301 +/- 128.5; F-ratio = 37; P < 0.00001). Likewise, subjects with present CL had measurably higher MST reactions (13 +/- 6.7 mm) than those with prior CL (10.9 +/- 7.8 mm) or healthy individuals (2.4 +/- 2.5 mm; F-ratio = 106; P < 0.00001). Serum concentrations of IgG were predicted by lesion number (t = 2.5; P = 0.018), size (t = 3.7; P = 0.0006), and duration (t = 3.5; P = 0.0013). Furthermore, the MST induration size increased as a function of lesion number (t = 3.0; P = 0.005) and size (t = 3.4; P = 0.022). Subject age and sex did not predict serum IgG or IgM concentrations or MST reactions in the 3 disease groups. Although no sex differences were found with respect to clinical characteristics, children < or = 12 years of age were almost 3 times more likely to have CL lesions or scars located on the face and head area compared to adults (OR = 2.75; 95% CI = 1.4-5.6, P = 0.004). The risk factors associated with disease included age under 5 years (AOR = 1.5; 95% CI = 0.48-2.35), male gender in adults (AOR = 2.8; 95% CI = 1.1-7.8), and wood and/or cane exterior house walls (AOR = 1.8; 95% CI = 1.4-2.5). In contrast, electric home lighting was associated with decreased risk (AOR = 0.7; 95% CI = 0.4-2.3). The results suggest that it may be possible to modify a portion of the risk of CL by making changes in the housing environment which may help to reduce the amount of human-vector contact.
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Affiliation(s)
- R X Armijos
- Laboratorio de Inmunología, Facultad de Ciencias Médicas, Universidad Central del Ecuador, Quito, Ecuador
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Lamon JM, Frykholm BC, Herrera W, Tschudy DP. Danazol administration to females with menses-associated exacerbations of acute intermittent porphyria. J Clin Endocrinol Metab 1979; 48:123-6. [PMID: 422693 DOI: 10.1210/jcem-48-1-123] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Acute intermittent porphyria (AIP) is a disorder of porphyrin metabolism in which the basic defect is a partial deficiency of uroporphyrinogen I synthase. The clinical disorder is more common in women, and some experience acute attacks before menstrual periods. Oral contraceptives have prevented menstrual-associated attacks in some cases, but exogenous estrogens and progestins are otherwise contraindicated in this disease. Danazol, a new synthetic steroid with weak androgenic activity, was thought to be of potential therapeutic benefit in AIP because of its effect of decreasing gonadotropin secretion without exposure to estrogen or progesterone. The drug was administered at a dosage of 200 mg t.i.d. to two adult females with AIP who were experiencing frequent exacerbations of their disease in association with their menstrual periods. Symptomatic and chemical evidence for exacerbation of porphyria occurred within 10 days of commencing danazol treatment in both patients.
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