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1.
Transl Psychiatry ; 12(1): 473, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351888

RESUMO

Effective strategies for early detection of cognitive decline, if deployed on a large scale, would have individual and societal benefits. However, current detection methods are invasive or time-consuming and therefore not suitable for longitudinal monitoring of asymptomatic individuals. For example, biological markers of neuropathology associated with cognitive decline are typically collected via cerebral spinal fluid, cognitive functioning is evaluated from face-to-face assessments by experts and brain measures are obtained using expensive, non-portable equipment. Here, we describe scalable, repeatable, relatively non-invasive and comparatively inexpensive strategies for detecting the earliest markers of cognitive decline. These approaches are characterized by simple data collection protocols conducted in locations outside the laboratory: measurements are collected passively, by the participants themselves or by non-experts. The analysis of these data is, in contrast, often performed in a centralized location using sophisticated techniques. Recent developments allow neuropathology associated with potential cognitive decline to be accurately detected from peripheral blood samples. Advances in smartphone technology facilitate unobtrusive passive measurements of speech, fine motor movement and gait, that can be used to predict cognitive decline. Specific cognitive processes can be assayed using 'gamified' versions of standard laboratory cognitive tasks, which keep users engaged across multiple test sessions. High quality brain data can be regularly obtained, collected at-home by users themselves, using portable electroencephalography. Although these methods have great potential for addressing an important health challenge, there are barriers to be overcome. Technical obstacles include the need for standardization and interoperability across hardware and software. Societal challenges involve ensuring equity in access to new technologies, the cost of implementation and of any follow-up care, plus ethical issues.


Assuntos
Disfunção Cognitiva , Humanos , Disfunção Cognitiva/diagnóstico , Cognição , Biomarcadores , Eletroencefalografia , Encéfalo
2.
Front Digit Health ; 4: 944753, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35966140

RESUMO

Recent advances have enabled the creation of wireless, "dry" electroencephalography (EEG) recording systems, and easy-to-use engaging tasks, that can be operated repeatedly by naïve users, unsupervised in the home. Here, we evaluated the validity of dry-EEG, cognitive task gamification, and unsupervised home-based recordings used in combination. Two separate cohorts of participants-older and younger adults-collected data at home over several weeks using a wireless dry EEG system interfaced with a tablet for task presentation. Older adults (n = 50; 25 females; mean age = 67.8 years) collected data over a 6-week period. Younger male adults (n = 30; mean age = 25.6 years) collected data over a 4-week period. All participants were asked to complete gamified versions of a visual Oddball task and Flanker task 5-7 days per week. Usability of the EEG system was evaluated via participant adherence, percentage of sessions successfully completed, and quantitative feedback using the System Usability Scale. In total, 1,449 EEG sessions from older adults (mean = 28.9; SD = 6.64) and 684 sessions from younger adults (mean = 22.87; SD = 1.92) were collected. Older adults successfully completed 93% of sessions requested and reported a mean usability score of 84.5. Younger adults successfully completed 96% of sessions and reported a mean usability score of 88.3. Characteristic event-related potential (ERP) components-the P300 and error-related negativity-were observed in the Oddball and Flanker tasks, respectively. Using a conservative threshold for inclusion of artifact-free data, 50% of trials were rejected per at-home session. Aggregation of ERPs across sessions (2-4, depending on task) resulted in grand average signal quality with similar Standard Measurement Error values to those of single-session wet EEG data collected by experts in a laboratory setting from a young adult sample. Our results indicate that easy-to-use task-driven EEG can enable large-scale investigations in cognitive neuroscience. In future, this approach may be useful in clinical applications such as screening and tracking of treatment response.

3.
Materials (Basel) ; 15(6)2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35329607

RESUMO

Essential oils have been used in diverse areas such as packaging, agriculture and cosmetics, for their antimicrobial and pesticide activity. The organic volatile compounds of the essential oils are involved in its activity. Controlling their release helps to prolong their functionality. In this study, a functionalized calcium carbonate porous coating was employed to control the release of thyme and rosemary oil in a confined space. The release rate was evaluated at 7 °C and 23 °C, gravimetrically. It was shown that the capillary effect of the porous coating slowed down the release of the volatiles into the headspace compared to the bulk essential oil. A linear drive force model was used to fit the obtained data from both essential oils. The model showed that rosemary reached the asymptotic mass loss equilibrium faster than thyme. This result can be explained by the diverse composition and concentration of monoterpenoids between the two essential oils. Temperature and degree of loading also played important roles in the desorption of the essential oils. It was observed that at high degrees of loading and temperatures the desorption of essential oils was higher. The above-described technology could be used for applications related to food preservation, pest control among others.

4.
Front Psychiatry ; 12: 574482, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276428

RESUMO

Access to affordable, objective and scalable biomarkers of brain function is needed to transform the healthcare burden of neuropsychiatric and neurodegenerative disease. Electroencephalography (EEG) recordings, both resting and in combination with targeted cognitive tasks, have demonstrated utility in tracking disease state and therapy response in a range of conditions from schizophrenia to Alzheimer's disease. But conventional methods of recording this data involve burdensome clinic visits, and behavioural tasks that are not effective in frequent repeated use. This paper aims to evaluate the technical and human-factors feasibility of gathering large-scale EEG using novel technology in the home environment with healthy adult users. In a large field study, 89 healthy adults aged 40-79 years volunteered to use the system at home for 12 weeks, 5 times/week, for 30 min/session. A 16-channel, dry-sensor, portable wireless headset recorded EEG while users played gamified cognitive and passive tasks through a tablet application, including tests of decision making, executive function and memory. Data was uploaded to cloud servers and remotely monitored via web-based dashboards. Seventy-eight participants completed the study, and high levels of adherence were maintained throughout across all age groups, with mean compliance over the 12-week period of 82% (4.1 sessions per week). Reported ease of use was also high with mean System Usability Scale scores of 78.7. Behavioural response measures (reaction time and accuracy) and EEG components elicited by gamified stimuli (P300, ERN, Pe and changes in power spectral density) were extracted from the data collected in home, across a wide range of ages, including older adult participants. Findings replicated well-known patterns of age-related change and demonstrated the feasibility of using low-burden, large-scale, longitudinal EEG measurement in community-based cohorts. This technology enables clinically relevant data to be recorded outside the lab/clinic, from which metrics underlying cognitive ageing could be extracted, opening the door to potential new ways of developing digital cognitive biomarkers for disorders affecting the brain.

5.
Int J Nurs Stud Adv ; 3: 100015, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38746730

RESUMO

Background: The impact of health problems on daily life and consequent treatment goals differ from person to person, particularly for older people with multiple health problems. Personalized care in general practice can help address these health problems, but evaluation of its effects remains difficult. In rehabilitation, a common approach to the evaluation of personalized care is Goal Attainment Scaling. This feasibility study assesses whether goal attainment scaling can also be applied to the evaluation of personal care for community-dwelling older people in general practice. Methods: General practices were invited to participate in this longitudinal, observational feasibility study. Practice nurses and general practitioners received training in care plans and goal attainment scaling. They were each asked to create care plans and goal attainment scales for patients (aged ≥75 years) and to carry out evaluations at three and six months. Professionals and patients both completed a short questionnaire to evaluate their experiences regarding the (dis)advantages of goal attainment scaling. Results: Professionals (n=10) and patients (n=23) were able to set goals and scales (n=57) for problems across five health domains (somatic, functional, social, psychological and communicative), but experienced difficulties formulating goals and corresponding goal attainment scaling levels. Reported benefits of goal attainment scaling were 1) important problems were addressed, 2) patients were involved and motivated to attain goals, and 3) evaluation was straightforward once a scale was created. Disadvantages were 1) difficult for older people, 2) time-consuming and complex for clinical practice. Conclusions: Goal attainment scaling shows potential benefit for clinical practice and general practice research in terms of the setting and evaluation of goals for community-dwelling older persons. Further research is needed to develop more standardized and less time-consuming goal attainment scaling methods.

6.
Mov Disord ; 33(12): 1857-1870, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30357936

RESUMO

This comprehensive MDSGene review is devoted to the three autosomal-dominant PD forms: PARK-SNCA, PARK-LRRK2, and PARK-VPS35. It follows MDSGene's standardized data extraction protocol, screened a total of 2,972 citations, and is based on fully curated phenotypic and genotypic data on 937 patients with dominantly inherited PD attributed to 44 different mutations in SNCA, LRRK2, or VPS35. All of these data are also available in an easily searchable online database (www.mdsgene.org), which additionally provides descriptive summary statistics on phenotypic and genetic data. Despite the high degree of missingness of phenotypic features and unsystematic reporting of genotype data in the original literature, the present review recapitulates many of the previously described findings including later onset of disease (median age at onset: ∼49 years) compared to recessive forms of PD of an overall excellent treatment response. Our systematic review validates previous reports showing that SNCA mutation carriers have a younger age at onset compared to LRRK2 and VPS35 (P < 0.001). SNCA mutation carriers often have additional psychiatric symptoms, and although not exclusive to only LRRK2 or VPS35 mutation carriers, LRRK2 mutation carriers have a typical form of PD, and, lastly, VPS35 mutation carriers have good response to l-dopa. © 2018 International Parkinson and Movement Disorder Society.


Assuntos
Genótipo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Fenótipo , Proteínas de Transporte Vesicular/genética , alfa-Sinucleína/genética , Humanos , Doença de Parkinson/genética
7.
Nanotoxicology ; 11(4): 496-506, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28368214

RESUMO

Nanotechnology offers new opportunities for providing health benefits in foods. Food fortification with iron phosphate nanoparticles (FePO4 NPs) is a promising new approach to reducing iron deficiency because FePO4 NPs combine high bioavailability with superior sensory performance in difficult to fortify foods. However, their safety remains largely untested. We fed rats for 90 days diets containing FePO4 NPs at doses at which iron sulfate (FeSO4), a commonly used food fortificant, has been shown to induce adverse effects. Feeding did not result in signs of toxicity, including oxidative stress, organ damage, excess iron accumulation in organs or histological changes. These safety data were corroborated by evidence that NPs were taken up by human gastrointestinal cell lines without reducing cell viability or inducing oxidative stress. Our findings suggest FePO4 NPs appear to be as safe for ingestion as FeSO4.


Assuntos
Compostos Férricos , Alimentos Fortificados , Nanopartículas , Estresse Oxidativo/efeitos dos fármacos , Animais , Disponibilidade Biológica , Sobrevivência Celular/efeitos dos fármacos , Dieta , Relação Dose-Resposta a Droga , Compostos Férricos/administração & dosagem , Compostos Férricos/efeitos adversos , Compostos Férricos/metabolismo , Glutationa/metabolismo , Células HT29 , Humanos , Sobrecarga de Ferro , Masculino , Nanopartículas/administração & dosagem , Nanopartículas/efeitos adversos , Nanopartículas/metabolismo , Ratos , Ratos Sprague-Dawley
8.
Nat Nanotechnol ; 12(7): 642-647, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28436960

RESUMO

Iron-deficiency anaemia (IDA) is a major global public health problem. A sustainable and cost-effective strategy to reduce IDA is iron fortification of foods, but the most bioavailable fortificants cause adverse organoleptic changes in foods. Iron nanoparticles are a promising solution in food matrices, although their tendency to oxidize and rapidly aggregate in solution severely limits their use in fortification. Amyloid fibrils are protein aggregates initially known for their association with neurodegenerative disorders, but recently described in the context of biological functions in living organisms and emerging as unique biomaterial building blocks. Here, we show an original application for these protein fibrils as efficient carriers for iron fortification. We use biodegradable amyloid fibrils from ß-lactoglobulin, an inexpensive milk protein with natural reducing effects, as anti-oxidizing nanocarriers and colloidal stabilizers for iron nanoparticles. The resulting hybrid material forms a stable protein-iron colloidal dispersion that undergoes rapid dissolution and releases iron ions during acidic and enzymatic in vitro digestion. Importantly, this hybrid shows high in vivo iron bioavailability, equivalent to ferrous sulfate in haemoglobin-repletion and stable-isotope studies in rats, but with reduced organoleptic changes in foods. Feeding the rats with these hybrid materials did not result in abnormal iron accumulation in any organs, or changes in whole blood glutathione concentrations, inferring their primary safety. Therefore, these iron-amyloid fibril hybrids emerge as novel, highly effective delivery systems for iron in both solid and liquid matrices.


Assuntos
Amiloide , Sistemas de Liberação de Medicamentos , Ferro , Lactoglobulinas , Nanopartículas Metálicas , Amiloide/química , Amiloide/farmacocinética , Amiloide/farmacologia , Anemia Ferropriva/tratamento farmacológico , Animais , Coloides , Alimentos Fortificados , Humanos , Ferro/química , Ferro/farmacocinética , Ferro/farmacologia , Lactoglobulinas/química , Lactoglobulinas/farmacocinética , Lactoglobulinas/farmacologia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Ratos
9.
J Nutr ; 147(3): 353-360, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28148687

RESUMO

Background: Low dietary calcium intake and bioavailability may adversely affect bone health. Reducing the size of calcium compounds increases their specific surface area (SSA, expressed as m2/g) and may increase calcium dissolution and bioavailability.Objective: We investigated the influence of SSA and chemical composition on the bioavailability of calcium and compared in vitro calcium dissolution with in vivo absorption.Methods: Calcium dissolution was measured in 0.1 M phosphoric acid, whereas color and pH changes of foods were assessed as indicators for potential sensory performance. Calcium absorption, retention, and fractional retention were measured over a 5-d balance study in growing Sprague-Dawley male rats after 21 d of feeding. Femoral and vertebral bone mineral density (BMD) and extensive tissue histology were assessed at study end. The influence of SSA on calcium bioavailability was assessed by comparing the groups fed pure calcium carbonate (CaCO3) with increasing SSAs of 3, 36, and 64 m2/g (CaCO3_3, CaCO3_36 and CaCO3_64), whereas chemical composition was assessed by comparing the smallest CaCO3_64, a 50:50 wt:wt percent solution mixture of CaCO3 and hydroxyapatite_94, and pure hydroxyapatite_100.Results: In vivo, fractional calcium retention from hydroxyapatite_100 (mean ± SEM: 54.86% ± 0.95%/5 d) was significantly greater than from CaCO3_64 (49.66% ± 1.15%/5 d) (P = 0.044). Increasing SSA of the pure CaCO3 did not significantly improve calcium retention. Across all 5 groups, there were no significant differences in BMD or tissue calcification by histology. In vitro calcium dissolution did not correlate with SSA or calcium absorption. In selected food matrixes, hydroxyapatite_100 caused less color change and/or smaller pH increase than did the other calcium compounds.Conclusions: Our findings suggest that chemical composition rather than SSA is a predictor of nanostructured calcium bioavailability and that in vitro dissolution of nanostructured calcium does not predict in vivo absorption. Although its phosphorus content may limit use in some populations, nanostructured hydroxyapatite may be a promising calcium compound for food fortification.


Assuntos
Cálcio/química , Cálcio/farmacocinética , Nanoestruturas , Adsorção , Ração Animal/análise , Animais , Densidade Óssea , Osso e Ossos/química , Dieta/veterinária , Alimentos , Concentração de Íons de Hidrogênio , Masculino , Ratos , Ratos Sprague-Dawley , Leite de Soja/química
10.
Psychoneuroendocrinology ; 73: 63-66, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27472166

RESUMO

The hormone oxytocin is known to facilitate positive communication behaviors. In the current study, we aimed to examine how it affects the interpretation of verbal information during communication. We predicted oxytocin to promote the understanding of the socially most effortful dimension of appeal. After intranasal administration of oxytocin or a placebo, participants responded to a "four-ear communication" questionnaire. Results revealed that participants under oxytocin not only chose the dimension of appeal as first choice significantly more often than participants under placebo but also preferred it over most of the other dimensions of interpretation. The findings add to our knowledge of oxytocin as a facilitator of social approach and indicate how oxytocin might work in communicative settings.


Assuntos
Comunicação , Neurotransmissores/farmacologia , Ocitocina/farmacologia , Percepção Social , Adulto , Humanos , Masculino , Neurotransmissores/administração & dosagem , Ocitocina/administração & dosagem , Adulto Jovem
11.
J Nutr ; 142(2): 271-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22190022

RESUMO

Iron (Fe) deficiency anemia is a global health concern and Fe fortification and supplementation are common corrective strategies. Fe is essential not only for the human host but also for nearly all gut bacteria. We studied the impact of Fe deficiency and Fe repletion on the gut microbiota in rats. Weanling rats were fed an Fe-deficient diet for 24 d and then repleted for 13 d with FeSO4 (n = 15) or electrolytic Fe (n = 14) at 10 and 20 mg Fe · kg diet⁻¹. In addition, one group of rats (n = 8) received the Fe-deficient diet and one group (n = 3) received a Fe-sufficient control diet for all 37 d. Fecal samples were collected at baseline and after the depletion and repletion periods, and colonic tissues were examined histologically. Microbial metabolite composition in cecal water was measured and fecal samples were analyzed for microbial composition with temporal temperature gradient gel electrophoresis and qPCR. Compared to Fe-sufficient rats, Fe-deficient rats had significantly lower concentrations of cecal butyrate (-87%) and propionate (-72%) and the abundance of dominant species was strongly modified, including greater numbers of lactobacilli and Enterobacteriaceae and a large significant decrease of the Roseburia spp./E. rectale group, a major butyrate producer. Repletion with 20 mg FeSO4 · kg diet⁻¹ significantly increased cecal butyrate concentrations and partially restored bacterial populations compared to Fe-deficient rats at endpoint. The effects on the gut microbiota were stronger in rats repleted with FeSO4 than in rats repleted with electrolytic Fe, suggesting ferrous Fe may be more available for utilization by the gut microbiota than elemental Fe. Repletion with FeSO4 significantly increased neutrophilic infiltration of the colonic mucosa compared to Fe-deficient rats. In conclusion, Fe depletion and repletion strongly affect the composition and metabolic activity of rat gut microbiota.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Bactérias/metabolismo , Ceco/microbiologia , Colo/microbiologia , Compostos Ferrosos/uso terapêutico , Ferro/uso terapêutico , Ração Animal , Animais , Peso Corporal , Cromatografia Líquida de Alta Pressão , Dieta , Fezes/microbiologia , Hemoglobinas , Ferro/química , Ferro da Dieta/análise , Ferro da Dieta/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley
12.
J Food Sci ; 76(1): N2-10, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21535701

RESUMO

Iron deficiency is one of the most common micronutrient deficiencies worldwide. Food fortification can be an effective and sustainable strategy to reduce Fe deficiency but selection of iron fortificants remains a challenge. Water-soluble compounds, for example, FeSO(4), usually demonstrate high bioavailability but they often cause unacceptable sensory changes in foods. On the other hand, poorly acid-soluble Fe compounds, for example FePO(4), may cause fewer adverse sensory changes in foods but are usually not well bioavailable since they need to be dissolved in the stomach prior to absorption. The solubility and the bioavailability of poorly acid-soluble Fe compounds can be improved by decreasing their primary particle size and thereby increasing their specific surface area. Here, Fe oxide-based nanostructured compounds with added Mg or Ca were produced by scalable flame aerosol technology. The compounds were characterized by nitrogen adsorption, X-ray diffraction, transmission electron microscopy, and Fe solubility in dilute acid. Sensory properties of the Fe-based compounds were tested in 2 highly reactive, polyphenol-rich food matrices: chocolate milk and fruit yoghurt. The Fe solubility of nanostructured Fe(2)O(3) doped with Mg or Ca was higher than that of pure Fe(2)O(3). Since good solubility in dilute acid was obtained despite the inhomogeneity of the powders, inexpensive precursors, for example Fe- and Ca-nitrates, can be used for their manufacture. Adding Mg or Ca lightened powder color, while sensory changes when added to foods were less pronounced than for FeSO(4). The combination of high Fe solubility and low reactivity in foods makes these flame-made nanostructured compounds promising for food fortification. Practical Application: The nanostructured iron-containing compounds presented here may prove useful for iron fortification of certain foods; they are highly soluble in dilute acid and likely to be well absorbed in the gut but cause less severe color changes than FeSO(4) when added to difficult-to-fortify foods.


Assuntos
Cálcio/química , Compostos Férricos/química , Tecnologia de Alimentos , Alimentos Fortificados/análise , Magnésio/química , Nanoestruturas/química , Nanotecnologia , Anemia Ferropriva/prevenção & controle , Animais , Cor , Concentração de Íons de Hidrogênio , Ferro da Dieta/administração & dosagem , Microscopia Eletrônica de Transmissão e Varredura , Microscopia Eletrônica de Transmissão , Leite/química , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Solubilidade , Propriedades de Superfície , Difração de Raios X , Iogurte/análise
13.
Nanoscale ; 3(6): 2390-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21483965

RESUMO

Recent studies suggest nanostructured oxides and phosphates of Fe and atomically mixed Fe/Zn may be useful for nutritional applications. These compounds may have several advantages over existing fortificants, such as ferrous sulfate (FeSO(4)), NaFeEDTA and electrolytic iron. Because of their very low solubility and formation of soft agglomerates of micron size at neutral pH as well as their light native color, they tend to be less reactive in difficult-to-fortify foods and thus have superior sensory performance. At gastric pH the soft agglomerates break up and the Fe compounds rapidly and completely dissolve due to their very high surface area. This results in in vitro solubility and in vivo bioavailability comparable to FeSO(4). Doping with Mg and/or Ca may increase solubility and improve sensory characteristics by lightening color. Feeding the nanostructured compounds at 150-400 µg Fe day(-1) for 15 days to weanling rats in two studies did not induce measurable histological or biochemical adverse effects. No significant Fe was detected in the submucosa of the gastrointestinal tract or lymphatic tissues, suggesting that the nanosized Fe is absorbed through usual non-heme Fe absorption pathways. Thus, these novel compounds show promise as food fortificants or supplements.


Assuntos
Suplementos Nutricionais , Compostos de Ferro/química , Nanoestruturas/química , Compostos de Zinco/química , Animais , Humanos , Compostos de Ferro/administração & dosagem , Microscopia Eletrônica de Transmissão , Nanoestruturas/administração & dosagem , Ratos , Compostos de Zinco/administração & dosagem
14.
Public Health Nutr ; 14(7): 1312-4, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21205406

RESUMO

OBJECTIVE: To investigate the iodine status of schoolchildren in the Principality of Liechtenstein. DESIGN: A representative, cross-sectional principality-wide screening of iodine level in household salt and urinary iodine concentrations (UIC) in primary-school children. Data were compared with the WHO criteria and with 2009 iodine survey data from Switzerland, a neighbouring country that supplies most of the salt used in Liechtenstein. SETTINGS: Principality of Liechtenstein. SUBJECTS: Schoolchildren (n 228) aged 6-12 years from five different primary schools representing 11·4 % of the children at this age. RESULTS: The median UIC was 96 (range: 10-446) µg/l; 11 %, 56 % and 1 % of children had a UIC <50, <100 and >300 µg/l, respectively. In all, 79 % of households were using adequately iodised salt (≥15 ppm). The median UIC was 20 % lower than that in children at comparable age in Switzerland (120 µg/l; P < 0·05). CONCLUSIONS: According to the WHO criteria, schoolchildren in Liechtenstein are mildly iodine deficient and household iodised salt coverage is inadequate. Public health measures to increase iodine intakes in the Principality should be considered.


Assuntos
Iodo/deficiência , Iodo/urina , Saúde Pública , Cloreto de Sódio na Dieta/administração & dosagem , Criança , Estudos Transversais , Feminino , Bócio/epidemiologia , Bócio/prevenção & controle , Humanos , Iodo/administração & dosagem , Liechtenstein/epidemiologia , Masculino , Instituições Acadêmicas
15.
Nat Nanotechnol ; 5(5): 374-80, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20418865

RESUMO

Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO(4)), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area approximately 190 m(2) g(-1)) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO(4) and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO(4) and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value.


Assuntos
Ferro/metabolismo , Nanopartículas/química , Zinco/metabolismo , Animais , Disponibilidade Biológica , Cor , Eletrólise , Comportamento Alimentar , Alimentos Fortificados , Hemoglobinas/metabolismo , Masculino , Nanopartículas/ultraestrutura , Especificidade de Órgãos , Ratos , Ratos Sprague-Dawley , Solubilidade , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Aumento de Peso
17.
J Am Acad Audiol ; 12(3): 113-20, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11316048

RESUMO

A maximum-likelihood yes-no procedure was used to measure minimum detectable gaps (MDGs) at 1 and 4 kHz using two track lengths (15 and 30 trials). Results from 11 normal listeners show no difference between MDGs for the two track lengths, and variability of the MDGs did not differ significantly for the track lengths. Results from simulations indicate that the variability of MDGs from real listeners is considerably larger than that imposed by the psychophysical procedure. Additional simulations show that random variability of listeners' response criterion is a compelling explanation for the excess variability. These findings indicate that changes in a listener's threshold over time impose a lower bound on the variability obtainable with a yes-no procedure. They imply that increasing the number of trials in a track, beyond the minimum number required to obtain a stable threshold estimate, offers little or no advantage for the test-retest reliability of a clinical threshold measurement.


Assuntos
Detecção de Sinal Psicológico/fisiologia , Percepção da Fala/fisiologia , Adulto , Limiar Auditivo/fisiologia , Feminino , Humanos , Masculino , Psicometria/estatística & dados numéricos , Psicofísica , Fatores de Tempo
18.
Audiology ; 39(3): 161-7, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10905402

RESUMO

This paper examines a possible procedure for a clinical gap-detection test that is simple, frequency specific, and reliable. A cued yes-no method of maximum likelihood (MML) procedure was compared to an up-down three-interval, two-alternative, forced-choice procedure. Results from five trained and seven naive listeners indicate that the yes-no MML procedure yields valid and efficient estimates of narrowband gap-detection thresholds. Preliminary tests yield encouraging results.


Assuntos
Percepção Auditiva/fisiologia , Adulto , Sinais (Psicologia) , Humanos , Psicofísica , Fatores de Tempo
20.
J Acoust Soc Am ; 105(6): 3464-80, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10380670

RESUMO

To investigate how hearing loss of primarily cochlear origin affects the loudness of brief tones, loudness matches between 5- and 200-ms tones were obtained as a function of level for 15 listeners with cochlear impairments and for seven age-matched controls. Three frequencies, usually 0.5, 1, and 4 kHz, were tested in each listener using a two-interval, two--alternative forced--choice (2I, 2AFC) paradigm with a roving-level, up-down adaptive procedure. Results for the normal listeners generally were consistent with published data [e.g., Florentine et al., J. Acoust Soc. Am. 99, 1633-1644 (1996)]. The amount of temporal integration--defined as the level difference between equally loud short and long tones--varied nonmonotonically with level and was largest at moderate levels. No consistent effect of frequency was apparent. The impaired listeners varied widely, but most showed a clear effect of level on the amount of temporal integration. Overall, their results appear consistent with expectations based on knowledge of the general properties of their loudness-growth functions and the equal-loudness-ratio hypothesis, which states that the loudness ratio between equal-SPL long and brief tones is the same at all SPLs. The impaired listeners' amounts of temporal integration at high SPLs often were larger than normal, although it was reduced near threshold. When evaluated at equal SLs, the amount of temporal integration well above threshold usually was in the low end of the normal range. Two listeners with abrupt high-frequency hearing losses (slopes > 50 dB/octave) showed larger-than-normal maximal amounts of temporal integration (40 to 50 dB). This finding is consistent with the shallow loudness functions predicted by our excitation-pattern model for impaired listeners [Florentine et al., in Modeling Sensorineural Hearing Loss, edited by W. Jesteadt (Erlbaum, Mahwah, NJ, 1997), pp. 187-198]. Loudness functions derived from impaired listeners' temporal-integration functions indicate that restoration of loudness in listeners with cochlear hearing loss usually will require the same gain whether the sound is short or long.


Assuntos
Cóclea/fisiopatologia , Perda Auditiva Neurossensorial/fisiopatologia , Percepção Sonora/fisiologia , Adulto , Idoso , Audiometria de Tons Puros , Feminino , Auxiliares de Audição , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo
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