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1.
Dig Dis Sci ; 65(8): 2412-2418, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31745688

RESUMO

BACKGROUND/AIMS: The black population in the USA is a heterogeneous group composed of smaller subgroups from different origins. The definition of black in many colorectal cancer (CRC) risk studies is vague, and differences in CRC risk comparing black subpopulations have not been evaluated. The aim of the study is to compare advanced colorectal neoplasia (ACN) between two subgroups of black populations: African-American (AA) and Afro-Caribbean (AC). A secondary aim was to determine whether there are differences in prevalence of adenomas. METHODS: This was a retrospective study of 3797 AA and AC patients undergoing first time screening colonoscopy in two different institutions in the USA. RESULTS: Overall adenoma prevalence was 29.3% for the entire population with 29.5% in AAs and 29.0% in AC with no statistically significant difference between the study groups (AOR: 1.02; 95% CI 0.88-1.18, P = 0.751). However, ACN was significantly higher in the AA group (11.8%) compared to AC (9.0%) (AOR: 1.30, 95% CI 1.02-1.66, P = 0.034). It was observed that AAs had ACN at a higher BMI than AC. After adjusting for BMI/ethnicity interactions, the difference in ACN between both groups became more significant (AOR: 1.93, 95% CI 1.16-3.23, P = 0.012). CONCLUSIONS: AAs have a higher risk of ACN than AC. Current recommendations to start screening in average-risk AAs at an earlier age may not apply to other black subgroups.


Assuntos
Adenoma/etnologia , Negro ou Afro-Americano/estatística & dados numéricos , Neoplasias do Colo/etnologia , Idoso , Região do Caribe/etnologia , Feminino , Florida/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Ohio/epidemiologia , Prevalência , Estudos Retrospectivos
2.
J Food Sci Technol ; 55(12): 4792-4801, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30482974

RESUMO

The effects of different drying temperatures between 40 and 80 °C on bioactive constituents and antioxidant activity of edible sub Antarctic brown seaweed, Durvillaea antarctica were studied. Dietary fibre, amino acids profile, pigments (chlorophyll and carotenoids), vitamin E, total phenolics and total flavonoids as well as antioxidant activity were determined, beside a measurement of the chromatic coordinates. The brown seaweed D. antarctica had a high content of dietary fibre and was rich in essential amino acids and drying between 40 and 80 °C did not influence significantly dietary fibre content nor the level of essential amino acids that remained around 44%. However, a significant degradation of the chlorophyll pigments was observed with the lowest level of the initial chlorophyll content occurring at 60 °C (59%). Total carotenoids content was stable during drying between 50 and 70 °C. Vitamin E showed no significant loss during drying at any of the assayed temperatures, which could be due to its occurrence within the lipid fraction. Drying at 40 °C imparted a darker brown colour to the seaweed, while a lighter brown colour was acquired as drying temperature increased. The greatest loss in total phenolics content occurred at 60 °C, while total flavonoids content showed a significant reduction, which declined as drying temperature increased. According to the experimental results, phenolics and flavonoids could be considered as an important source of bioactive compounds with relatively high antioxidant activity. Thus D. antarctica may satisfy the requirements for development of functional foods.

3.
Analyst ; 140(16): 5640-9, 2015 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-26133311

RESUMO

Nanocellulose is of research interest due to its extraordinary optical, thermal, and mechanical properties. The incorporation of guest nanoparticles into nanocellulose substrates enables production of novel nanocomposites with a broad range of applications. In this study, gold nanoparticle/bacterial cellulose (AuNP/BC) nanocomposites were prepared and evaluated for their applicability as surface-enhanced Raman scattering (SERS) substrates. The nanocomposites were prepared by citrate mediated in situ reduction of Au(3+) in the presence of a BC hydrogel at 303 K. Both the size and morphology of the AuNPs were functions of the HAuCl4 and citrate concentrations. At high HAuCl4 concentrations, Au nanoplates form within the nanocomposites and are responsible for high SERS enhancements. At lower HAuCl4 concentrations, uniform nanospheres form and the SERS enhancement is dependent on the nanosphere size. The time-resolved increase in the SERS signal was probed as a function of drying time with SERS 'hot-spots' primarily forming in the final minutes of nanocomposite drying. The application of the AuNP/BC nanocomposites for detection of the SERS active dyes MGITC and R6G as well as the environmental contaminant atrazine is illustrated as is its use under low and high pH conditions. The results indicate the broad applicability of this nanocomposite for analyte detection.


Assuntos
Celulose/química , Ouro/química , Nanopartículas Metálicas/química , Nanocompostos/química , Análise Espectral Raman/métodos , Tamanho da Partícula
4.
J Intell ; 12(8)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39195123

RESUMO

Intellectual precocity in children poses unique challenges and opportunities for educational systems. This systematic review aims to comprehensively analyze intellectual precocity in children until 6 years old, including its definition, manifestations, and various educational programs for intellectually precocious learners. Following PRISMA guidelines, a comprehensive search of electronic databases was conducted. The study included 26 articles published between 2013 and 2023 that provided a conceptualization of precocity or giftedness, and/or focused on characteristics of precocity, and/or investigated educational programs for intellectually precocious children. The authors' conceptualizations of precocity varied, with some providing clear definitions based on a developmental view of precocity, while others merely mentioned the concept. Early indicators of superior traits have been observed in areas such as reading, math, problem-solving, and even in fields that have been traditionally disregarded, such as visual arts. Educational provisions varied widely, including approaches based on enrichment and project-based learning; however, interventions based on socioemotional elements are also highlighted. The findings emphasize the importance of early identification and targeted educational strategies to support the unique needs of intellectually precocious individuals. Future research should focus on longitudinal studies and the development of evidence-based interventions.

6.
BMJ Open ; 10(3): e034749, 2020 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-32152172

RESUMO

OBJECTIVES: There is emerging interest and data supporting the effectiveness of community health workers (CHWs) in non-communicable diseases (NCDs) in low/middle-income countries (LMICs). This study aimed to determine whether a CHW-led intervention targeting diabetes and hypertension could improve markers of clinical disease control in rural Mexico. DESIGN AND SETTING: A prospective observational stepped-wedge study was conducted across seven communities in rural Chiapas, Mexico from March 2014 to April 2018. PARTICIPANTS: 149 adults with hypertension and/or diabetes. INTERVENTION: This study was conducted in the context of the programmatic roll-out of an accompaniment-based CHW-led intervention designed to complement comprehensive primary care for adults with diabetes and/or hypertension. Implementation occurred sequentially at 3-month intervals with point-of-care data collected at baseline and every 3 months thereafter for 12 months following roll-out in all communities. OUTCOME MEASURES: Primary outcomes were glycated haemoglobin (HbA1c) and systolic blood pressure (SBP), overall and stratified by baseline disease control. We conducted an individual-level analysis using mixed effects regression, adjusting for time, cohort and clustering at the individual and community levels. RESULTS: Among patients with diabetes, the CHW-led intervention was associated with a decrease in HbA1c of 0.35%; however, CIs were wide (95% CI -0.90% to 0.20%). In patients with hypertension, there was a 4.7 mm Hg decrease in SBP (95% CI -8.9 to -0.6). In diabetic patients with HbA1c ≥9%, HbA1c decreased by 0.96% (95% CI -1.69% to -0.23%), and in patients with uncontrolled hypertension, SBP decreased by 10.2 mm Hg (95% CI -17.7 to -2.8). CONCLUSIONS: We found that a CHW-led intervention resulted in clinically meaningful improvement in disease markers for patients with diabetes and hypertension, most apparent among patients with hypertension and patients with uncontrolled disease at baseline. These findings suggest that CHWs can play a valuable role in supporting NCD management in LMICs. TRIAL REGISTRATION NUMBER: NCT02549495.


Assuntos
Agentes Comunitários de Saúde/organização & administração , Diabetes Mellitus/terapia , Hipertensão/terapia , Atenção Primária à Saúde/organização & administração , População Rural , Idoso , Pressão Sanguínea , Países em Desenvolvimento , Diabetes Mellitus/epidemiologia , Feminino , Hemoglobinas Glicadas , Humanos , Hipertensão/epidemiologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores Socioeconômicos
7.
Artigo em Inglês | MEDLINE | ID: mdl-31509963

RESUMO

Sugarcane is one of the main crops worldwide, and it has an important impact on environmental issues. A bibliometric mapping analysis of the research on sugarcane was carried out, using data on the titles, abstracts, and keywords of articles published in leading journals and other peer-reviewed documents available in the SCOPUS database from 1858 to 2019 (27 August), and this was subsequently analyzed with the software VOSviewer. The three most important countries that publish research and were most-cited regarding sugarcane were Brazil, the USA, and India. The analysis of the co-occurrence of terms shows that the main research areas were sugarcane bagasse and terms related to bioenergy, and on a second level of relevance agronomy topics related to increasing crop yields. This first attempt to visualize the abundance of publications regarding sugarcane in their totality is in itself a good starting point for further scientific discussion.


Assuntos
Bibliometria , Publicações Periódicas como Assunto , Saccharum , Celulose , Produtos Agrícolas , Bases de Dados Factuais , Humanos
8.
Plants (Basel) ; 7(4)2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30558108

RESUMO

Phania matricarioides (Spreng.) Griseb. is a traditionally used plant with various pharmacological properties. However, there are only scarce reports about the phytochemistry and biological activity of this plant. In this work, P. matricarioides was collected from three different localities of Cuba: PmB (collected in Bauta, Artemisa), PmC (collected in Cangrejeras, Artemisa), and PmI (collected in La Lisa, Havana), extracted with aqueous ethanol, and analyzed macroscopically and microscopically. The extracts were screened for phytochemical contents, analyzed by TLC and HPLC, and screened for antioxidant activity using the FRAP and DPPH assays. Macroscopic analysis showed similar results for all samples; however, microscopic, physicochemical and phytochemical studies showed appreciable differences. In particular, the total solid of PmC extract was higher (1.94 ± 0.03%) than the other samples. In HPLC profiles, quercetin was identified in the three samples and a greater similarity between samples PmB and PmI was observed. All samples demonstrated radical-scavenging antioxidant activity by the DPPH assay, which PmC also demonstrated the smaller (p < 0.05) value (IC50 = 27.4 ± 0.1 µg/mL), but was statistically superior (p < 0.05) to vitamin C (IC50 = 23.7 ± 0 µg/mL). Also, in the FRAP assay, a higher vitamin C equivalent of PmC was significantly superior (p < 0.05) to the other extracts at the evaluated concentrations, which is likely due to a higher concentration of quercetin. In conclusion, P. matricarioides could constitute a potential resource in the field of phytotherapeutic products, and the results obtained can contribute to the development of the quality control norms for this species.

9.
Meat Sci ; 118: 122-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27093350

RESUMO

Longissimus dorci (LD) samples of different origin (imported and domestic) with pre-treatments (imported meat stored at -18°C for 6months, domestic meat stored at -18°C for 10days, and domestic meat stored at 4°C for 24h) were cooked as barbacoa and frozen using two treatments (air blast and liquid immersion) and then evaluated after 30days of storage. The results showed that the origin and pre-treatment of meat affected L*, a*, instrumental texture and microstructure; that the storage time affected pH, aw, b* and microstructure; and that the freezing treatments did not affect the meat. Overall, the frozen cooked lamb dish barbacoa could present some problems at the conservation stage due to an increase in pH, aw and changes in microstructure; however, the physical traits (color and texture) remained mostly unchanged and depended more on the quality of the raw meat.


Assuntos
Armazenamento de Alimentos , Carne Vermelha/análise , Animais , Cor , Culinária , Congelamento , Concentração de Íons de Hidrogênio , Masculino , Refrigeração , Ovinos
10.
Int J Biol Macromol ; 81: 591-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26299710

RESUMO

The effects of the incorporation of PLA-ß-cyclodextrin-inclusion complex (IC) and ß-cyclodextrin (ß-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and ß-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing ß-CD (ß-CD-PLA-CFs) showed high agglomeration of ß-CD due to poor interfacial interaction between ß-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or ß-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or ß-CD content. Both composite films had higher oxygen and water vapor permeability as IC or ß-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films.


Assuntos
Ácido Láctico/química , Nanocompostos/química , Polímeros/química , beta-Ciclodextrinas/química , Varredura Diferencial de Calorimetria , Nanocompostos/ultraestrutura , Poliésteres , Propriedades de Superfície , Temperatura , Resistência à Tração , Termodinâmica , Termogravimetria
11.
Carbohydr Polym ; 100: 143-9, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24188848

RESUMO

Introducing porosity in electrospun scaffolds is critical to improve cell penetration and nutrient diffusion for tissue engineering. Nanofibrous cellulose scaffolds were prepared by electrospinning cellulose acetate (CA) followed by saponification to regenerate cellulose. Using a computer-assisted design approach, scaffolds underwent laser ablation resulting in pores with diameters between 50 and 300 µm without damaging or modifying the surrounding scaffold area. A new mineralization method was employed in conjunction with microablation using commercial phosphate buffered saline (PBS) to soak carboxymethylcellulose surface-modified electrospun scaffolds. The resulting crystals within the scaffold on the interior of the pore had a calcium to phosphate ratio of 1.56, similar to hydroxyapatite. It was observed that porosity of the cellulose scaffolds enhanced osteoblast cell attachment at the edge of the pores, while mineralization enhanced overall cell density.


Assuntos
Celulose/química , Nanofibras/química , Nanotecnologia/métodos , Alicerces Teciduais/química , Células 3T3 , Animais , Cálcio/metabolismo , Celulose/metabolismo , Celulose/farmacologia , Camundongos , Minerais/metabolismo , Fósforo/metabolismo , Porosidade , Propriedades de Superfície , Engenharia Tecidual
12.
Nucleus (La Habana) ; (66): 58-65, jul.-dic. 2019. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1091402

RESUMO

RESUMEN Se resumen las diferentes experiencias en la aplicación de las técnicas nucleares y conexas en el estudio de diversos problemas ambientales de la Ciudad de La Habana. El análisis medioambiental mediante las técnicas de Análisis por Activación Neutrónica (AAN) y Gamma (AAG), Fluorescencia de Rayos X (FRX), Espectrometría por Absorción Atómica (EAA) y por Inducción de plasma acoplado (ICP), así como la Espectrometría Gamma de Bajo Fondo (EGBF), han permitido obtener información muy relevante sobre el comportamiento de los metales pesados, antibióticos y radionúclidos en los sedimentos marinos y fluviales, suelos urbanos y agrícolas, aguas, arenas de balnearios, polvos urbanos y productos de la agricultura urbana de la ciudad de La Habana.


ABSTRACT Various nuclear and related analytical techniques applied to study different environmental problems in Havana city are presented. The environmental analysis by means of Neutron and Gamma Activation analyses, X-ray Fluorescence Atomic Abortion and Induced Coupled Plasma spectroscopies and Low Background , Gamma Spectrometry, have allowed to obtain important information about the behavior of heavy metals, antibiotics and radionuclides in sediments, urban and agricultural soils, waters, beach sands, urban dusts and agricultural products farmed in the Havana city.

14.
Nucleus (La Habana) ; (61): 1-5, Jan.-June 2017.
Artigo em Inglês | LILACS | ID: biblio-841901

RESUMO

Heavy metal (Co, Ni, Cu, Zn and Pb) content in muds from some Cuban spas (San Diego, Elguea, Santa Lucía and Cajío) have been studied using X-ray fluorescence. The measured metal contents are in the same order of magnitude as those reported for average Earth’s upper crust average shales and muds as well as with worldwide reported peloids. The comparison with sediment quality guidelines (SQGs) shows a different degree of pollution for peloids from each studied spa. Nevertheless, the estimated sum of metal/probable effect level value ratios (0.9 - 2.4) correspond to a low potential acute toxicity of contaminants. Therefore, the heavy metal content present in peloids from the studied Cuban spas is not an obstacle for its use with therapeutic purposes


Se estudia mediante la técnica de Fluorescencia de rayos X, el contenido de metales pesados (Co, Ni, Cu, Zn y Pb) en lodos terapéuticos provenientes de varios balnearios cubanos (San Diego, Elguea, Santa Lucía y Cajío). Los contenidos de metales pesados determinados en los lodos terapéuticos se encuentran en el mismo orden que los reportados para lodos y esquistos representativos de la corteza terrestre, así como para lodos utilizados en balnearios internacionalmente. La comparación con las Guías de Calidad de sedimentos muestran diferentes grados de polución para los lodos de cada balneario. Independientemente de ello, los valores de las razones suma de metales/nivel de efecto probable (0,9-2,4) corresponden a un bajo potencial agudo de toxicidad por contaminantes. De esta manera, el contenido de metales pesados presentes en los lodos de los balnearios estudiados no representa impedimento alguno para su uso con fines terapéuticos.

15.
ACS Appl Mater Interfaces ; 3(3): 681-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21355545

RESUMO

Novel cellulose based-scaffolds were studied for their ability to nucleate bioactive calcium phosphate crystals for future bone healing applications. Cellulose-based scaffolds were produced by electrospinning cellulose acetate (CA) dissolved in a mixture of acetone/dimethylacetamide (DMAc). The resulting nonwoven CA mats containing fibrils with diameters in the range of 200 nm to 1.5 µm were saponified by NaOH/ethanol for varying times to produce regenerated cellulose scaffolds. Biomimetic crystal growth nucleated from the fiber surface was studied as a function of surface chemistry. Regenerated cellulose scaffolds of varying treatments were soaked in simulated body fluid (SBF) solution. Scaffolds that were treated with CaCl(2), a mixture of carboxymethyl cellulose (CMC) and CaCl(2), and NaOH and CaCl(2), were analyzed using X-ray photoelectron spectroscopy, X-ray powder diffraction, and scanning electron microscopy to understand the growth of bioactive calcium phosphate (Ca-P) crystals as a function of surface treatment. The crystal structure of the nucleated Ca-P crystals had a diffraction pattern similar to that of hydroxyapatite, the mineralized component of bone. The study shows that the scaffold surface chemistry can be manipulated, providing numerous routes to engineer cellulosic substrates for the requirements of scaffolding.


Assuntos
Materiais Biomiméticos/síntese química , Substitutos Ósseos/síntese química , Fosfatos de Cálcio/química , Celulose/química , Cristalização/métodos , Alicerces Teciduais , Animais , Calcificação Fisiológica , Eletroquímica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Teste de Materiais , Rotação , Propriedades de Superfície
16.
Physiol Behav ; 104(4): 555-61, 2011 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-21565213

RESUMO

Food is a potent time signal for the circadian system and has shown to entrain and override temporal signals transmitted by the biological clock, the suprachiasmatic nucleus, which adjusts mainly to the daily light/dark (LD) alternation. Organisms mostly ingest food in their active period and this permits a correct coordination between the LD and the food elicited time signals with the circadian system. Under conditions when feeding opportunities are shifted to the usual resting/sleep phase, the potent entraining force of food, shifts circadian fluctuations in several tissues, organs, and brain structures toward meal time, resulting a desynchrony within the body and between the organism and the external LD cycle. The daily scheduled access to a palatable snack exerts similar changes specifically to brain areas involved in motivation and reward responses. This review describes the phenomenology of food entrainment and entrainment by a palatable snack. It suggests how scheduled feeding can lead to food addiction and how shifted feeding schedules toward the sleep phase can result in altered ingestive behavior, obesity and disturbed metabolic responses.


Assuntos
Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Animais , Comportamento Aditivo/fisiopatologia , Encéfalo/fisiologia , Humanos , Obesidade/etiologia , Fotoperíodo , Fatores de Tempo
17.
Bioresour Technol ; 101(19): 7265-70, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20452204

RESUMO

Olive cake is an important agro industrial by-product with the dried cake being the input material of many applications areas. In this research, the drying kinetics of olive cake during convective dehydration at five temperatures (50, 60, 70, 80 and 90 degrees C) was investigated. Several empirical mathematical models were selected to describe experimental drying kinetics data, namely, Page, Modified Page, Henderson and Pabis, Modified Henderson and Pabis, Two-Terms, Logarithmic and Weibull. Air temperature showed a significant effect on drying rates. Based on the statistical tests results (sum squared errors, chi-square and correlation coefficients), the Modified Henderson and Pabis equation is the most suitable model to describe the experimental drying curves. Effective moisture diffusivity of olive cake was in the range of 2.03x10(-9)-1.71x10(-9) m(2) s(-1). An activation energy value of 12.43 kJ mol(-1) was determined. The findings allow the successful simulation of olive cake drying between 50 and 90 degrees C.


Assuntos
Dessecação/métodos , Modelos Estatísticos , Olea/química , Eliminação de Resíduos , Água/química , Difusão , Cinética , Padrões de Referência , Temperatura
18.
Nucleus (La Habana) ; (58): 34-38, jul.-dic. 2015.
Artigo em Espanhol | LILACS | ID: lil-775531

RESUMO

Concentrations of Cr, Co, Ni, Cu, Zn, Pb and Fe in the street dust from Camagüey city were studied by X-ray .uorescence analysis. The mean Cr, Co, Ni, Cu, Zn and Pb contents in the urban dust samples (97 ± 30, 14 ± 2, 35 ± 36, 94 ± 26, 199 ± 87 and 42 ± 29 mg.kg-1 dry weight, respectively) were compared with mean concentrations in other cities around the world. Spatial distribution maps indicated the same behaviour for Cr-Ni and Pb-Zn-Cu, respectively, whereas the spatial distribution of Co differs from other heavy metals. The metal-to-iron normalization, using Cuban average metal soil contents as background, showed that street dusts from Camagüey city are moderately or significantly Zn-Pb enriched in those areas associated with heavy traffic density and metallurgic plant location. However, the calculation of the potential ecological risk index shows that metal content in Camagüey street dust does not represent any risk for the city population.


Se determinan por fluorescencia de rayos X las concentraciones de Cr, Co, Ni, Cu, Zn y Pb en los polvos urbanos de la ciudad de Camagüey. Los contenidos medios de metales pesados en las muestras de polvos urbanos (97 ± 30, 14 ± 2, 35 ± 36, 94 ± 26, 199 ± 87 y 42 ± 29 mg.kg-1 en peso seco respectivamente) son comparados con las concentraciones medias determinadas en otras ciudades del mundo. Los mapas de distribución espacial indican comportamientos similares para Cr-Ni y Pb-Zn-Cu respectivamente, en tanto la distribución espacial de Co difiere del resto de los metales. La normalización a un metal de referencia, empleando como fondo los valores medios de concentraciones de metales pesados cubanos, mostró que los polvos urbanos de la ciudad de Camagüey tienen un enriquecimiento moderado o significativo de Zn y Pb en aquellas áreas que están asociadas a una elevada densidad del tráfico automotor y a la ubicación de plantas metalúrgicas. El cálculo del índice de riesgo ecológico potencial mostró que el contenido de metales pesados en los polvos urbanos de Camagüey no representa riesgo alguno para su población.

19.
Nucleus (La Habana) ; (58): 13-19, jul.-dic. 2015.
Artigo em Espanhol | LILACS | ID: lil-775528

RESUMO

Se resumen los principales resultados obtenidos en los últimos 25 años por el Grupo de Aplicaciones Nucleares del InSTEC, en el desarrollo de técnicas nucleares y su aplicación en diferentes sectores de la sociedad. Se presenta el impacto que han tenido las investigaciones aplicadas en la formación de pregrado y posgrado en carreras nucleares y en el reconocimiento social de la comunidad universitaria.


The paper includes the most relevant results obtained by InSTEC´s Group of Nuclear Applications in the last 25 years, in the development of nuclear techniques and its application in different social areas. The impact of applied research on graduated and post graduated education in nuclear careers as well as the social recognition of the university community are presented.

20.
Nucleus (La Habana) ; (57): 38-43, Jan.-June 2015.
Artigo em Inglês | LILACS | ID: lil-754877

RESUMO

Concentrations of Cr, Co, Ni, Cu, Zn and Pb in the topsoils (0-10 cm) from ten farms located in the vicinity of a steel-smelter plant at Cotorro (Havana, Cuba) were measured by X-ray fluorescence analysis. The concentration ranges of Cr, Co, Ni, Cu, Zn and Pb were 54-186, 15-39, 19-137, 50-945, 91-7739 and 21-731 dry weight respectively. The metal mean contents in the farm topsoil samples were compared with metal contents reported for soils from the vicinity of other smelters worldwide. The Metal-to-Iron normalisation and estimation of the integral pollution indexes allowed observing that most metal polluted soils are from those farms, and that their location coincide with the prevalent wind direction in the studied area. The enrichment index values show that metal concentrations in soils from these farms are above the permissible levels for urban agriculture.


Se determinan por fluorescencia de rayos X las concentraciones de Cr, Co, Ni, Cu, Zn y Pb en los suelos superficiales (0-10 cm) de 10 granjas agrícolas, localizadas en la vecindad de la planta de acero del Cotorro (La Habana, Cuba). Los rangos de concentraciones de Cr, Co, Ni, Cu, Zn y Pb fueron de 54-186, 15-39, 19-137, 50-945, 91-7739 y 21-731 de peso seco respectivamente. Los contenidos medios de metales pesados en los suelos superficiales de las granjas se comparan con los niveles de metales pesados reportados en la literatura para suelos adyacentes a plantas de acero. La normalización de los metales al hierro y la estimación del los índices de polución integral, permitió determinar que los suelos contaminados por metales pesados fueron aquellos, cuya ubicación coincide con la dirección predominante de los vientos en la zona estudiada. Los valores delíndice de enriquecimiento mostraron que las concentraciones de metales pesados en los suelos de esas granjas, superan los niveles permisibles para la agricultura urbana.

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