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1.
J Cogn Neurosci ; 36(5): 836-853, 2024 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-38357989

RESUMO

Experience in bilingual language control is often accompanied by changes in the structure and function of the brain. Brain structural changes are also often closely related to changes in functions. Previous studies, however, have not directly explored the relationship between structural connectivity and effective functional connectivity of the brain during bilingual language control, and whether the two types of connectivity are associated with behavioral performance of language control. Using behavioral performance, functional, and diffusion imaging techniques, we found that: (1) during language control, the left dorsal lateral prefrontal cortex (dlPFC), left caudate nucleus (CN), inferior parietal lobe, precuneus, and dorsal anterior cingulate cortex (dACC)/pre-SMA were significantly activated. (2) In the language control model with left dlPFC, dACC/pre-SMA, and left CN as ROIs (selected based on activation results and language control models from previous studies), stimuli first enter dACC/pre-SMA and then to left CN. At the left CN, a bidirectional effective connectivity is formed with left dlPFC. (3) There is a nonlinear relationship between effective connectivity during language control and the structural connectivity of the second language learners' brains. Specifically, the fiber density between dACC/pre-SMA and left dlPFC has a positive influence on the bidirectional effective connectivity between left dlPFC and left CN. Findings of the present study contribute evidence toward functional effective connectivity during bilingual language control; toward structural connectivity in the brains of second language learners; as well as toward nonlinear relationships between functional effective connectivity, structural connectivity, and behavioral performance in relation to bilingual language control.


Assuntos
Encéfalo , Córtex Pré-Frontal , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Córtex Pré-Frontal/fisiologia , Giro do Cíngulo/fisiologia , Mapeamento Encefálico/métodos , Idioma , Imageamento por Ressonância Magnética
2.
Environ Sci Technol ; 57(22): 8355-8364, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37220884

RESUMO

The ban/elimination of legacy per- and polyfluoroalkyl substances (PFASs) has led to a dramatic increase in the production and use of various emerging PFASs over the past decade. However, trophodynamics of many emerging PFASs in aquatic food webs remain poorly understood. In this study, samples of seawaters and marine organisms including 15 fish species, 21 crustacean species, and two cetacean species were collected from the northern South China Sea (SCS) to investigate the trophic biomagnification potential of legacy and emerging PFASs. Bis(trifluoromethylsulfonyl)imide was found in seawater via suspect screening (concentration up to 1.50 ng/L) but not in the biota, indicating its negligible bioaccumulation potential. A chlorinated perfluorooctane sulfonate (PFOS) analytical interfering compound was identified with a predicted formula of C14H23O5SCl6- (most abundant at m/z = 514.9373). Significant trophic magnification was observed for 22 PFASs, and the trophic magnification factors of cis- and trans-perfluoroethylcyclohexane sulfonate isomers (1.92 and 2.25, respectively) were reported for the first time. Perfluorohexanoic acid was trophic-magnified, possibly attributed to the PFAS precursor degradation. The hazard index of PFOS was close to 1, implying a potential human health risk via dietary exposure to PFASs in seafood on the premise of continuous PFAS discharge to the SCS.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Animais , Humanos , Cadeia Alimentar , Ácidos Alcanossulfônicos/análise , Água do Mar , China , Fluorocarbonos/análise
3.
Front Psychol ; 14: 1092051, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36844277

RESUMO

Introduction: The neural basis for the processing of musical syntax has previously been examined almost exclusively in classical tonal music, which is characterized by a strictly organized hierarchical structure. Musical syntax may differ in different music genres caused by tonality varieties. Methods: The present study investigated the neural mechanisms for processing musical syntax across genres varying in tonality - classical, impressionist, and atonal music - and, in addition, examined how musicianship modulates such processing. Results: Results showed that, first, the dorsal stream, including the bilateral inferior frontal gyrus and superior temporal gyrus, plays a key role in the perception of tonality. Second, right frontotemporal regions were crucial in allowing musicians to outperform non-musicians in musical syntactic processing; musicians also benefit from a cortical-subcortical network including pallidum and cerebellum, suggesting more auditory-motor interaction in musicians than in non-musicians. Third, left pars triangularis carries out online computations independently of tonality and musicianship, whereas right pars triangularis is sensitive to tonality and partly dependent on musicianship. Finally, unlike tonal music, the processing of atonal music could not be differentiated from that of scrambled notes, both behaviorally and neurally, even among musicians. Discussion: The present study highlights the importance of studying varying music genres and experience levels and provides a better understanding of musical syntax and tonality processing and how such processing is modulated by music experience.

4.
BMC Psychiatry ; 21(1): 232, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947370

RESUMO

BACKGROUND: This study investigated cognitive and emotional functioning in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) and disruptive, impulse-control, and conduct disorders (DICCD). METHODS: Thirty patients with ADHD, 26 with DICCD, 22 with ADHD+DICCD were recruited from the outpatient department of Shanghai Changning Mental Health Center, plus 20 healthy controls (HC). Differences between the groups in cognitive and emotional functioning were examined using Golden's Stroop and Emotional Stroop tests. For Emotional Stroop Mean reaction time (RT) of positive word (POS) and negative word (NEG) with color congruence (C) or incongruence (I) were recorded as POS-C, POS-I, NEG-C and NEG-I, respectively. RESULTS: For Golden's interference scores (IGs), both errors and RTs in the ADHD group were higher than in the other groups. Longer mean RTs of POS-C, POS-I, NEG-C and neural word (NEU) of the ADHD group, and NEG-I of ADHD+DICCD and DICCD groups were observed compared to HC. After 12 weeks of methylphenidate treatment, differences between ADHD subgroups and HC on Golden's Stroop RT disappeared, but differences in Golden's Stroop errors and Emotional Stroop mean RTs remained. The ADHD+DICCD group showed longer mean RTs in NEG-C, NEG-I and NEU of the Emotional Stroop test than the ADHD group. CONCLUSIONS: Our study shows that regardless of emotional responding, deficit in cognitive control is the core symptom of ADHD. However, emotionally biased stimuli may cause response inhibitory dysfunction among DICCD with callous-unemotional traits, and the comorbidity of ADHD and DICCD tends to account for the negative emotional response characteristic of DICCD. These deficits may be eliminated by medication treatment in ADHD, but not the ADHD with comorbid DICCD. Our results support the notion that ADHD with comorbid DICCD is more closely related to DICCD than to ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno da Conduta , Adolescente , Atenção , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Criança , China/epidemiologia , Cognição , Comorbidade , Transtorno da Conduta/complicações , Transtorno da Conduta/epidemiologia , Emoções , Humanos , Testes Neuropsicológicos
5.
Neurosci Biobehav Rev ; 125: 264-295, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33631315

RESUMO

A large body of research has indicated that bilingualism - through continual practice in language control - may impact cognitive functions, as well as relevant aspects of brain function and structure. The present review aimed to bring together findings on the relationship between bilingualism and domain-general cognitive functions from a neural perspective. The final sample included 210 studies, covering findings regarding neural responses to bilingual language control and/or domain-general cognitive tasks, as well as findings regarding effects of bilingualism on non-task-related brain function and brain structure. The evidence indicates that a) bilingual language control likely entails neural mechanisms responsible for domain-general cognitive functions; b) bilingual experiences impact neural responses to domain-general cognitive functions; and c) bilingual experiences impact non-task-related brain function (both resting-state and metabolic function) as well as aspects of brain structure (both macrostructure and microstructure), each of which may in turn impact mental processes, including domain-general cognitive functions. Such functional and structural neuroplasticity associated with bilingualism may contribute to both cognitive and neural reserves, producing benefits across the lifespan.


Assuntos
Multilinguismo , Encéfalo , Cognição , Humanos , Idioma , Plasticidade Neuronal
6.
Front Psychiatry ; 11: 65, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32174848

RESUMO

OBJECTIVE: Neuroendocrine dysfunction is related to the pathogenesis of mental disorders, but conclusions from clinical research lack consistency. We aimed to investigate the neuroendocrinal pathophysiology and its correlation with clinical symptoms in patients with schizophrenia. METHODS: The present cross-sectional study included 486 inpatients with schizophrenia admitted at a psychiatric hospital in Shanghai within one year, and 154 healthy controls (HC) matched on age and gender. The serum hemoconcentrations of thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), free thyroxine (FT4), adrenocorticotrophic hormone (ACTH), and cortisol (COR) were measured via electrochemical luminescence immunoassay. Pathophysiological conversions of neuroendocrine were then associated with gender, age, age at onset, antipsychotic treatment using hierarchical multiple linear regression. RESULTS: When compared to HC, the schizophrenia group showed elevated ACTH and COR levels and decreased TT3 and TT4 levels (p's < 0.05). First-episode patients showed lower TSH and higher FT3 and FT4 (p's < 0.05) compared to recurrent patients. Female patients showed higher TSH and lower TT3, FT3, and ACTH levels (p's < 0.05) compared to males. We observed the area under the curve (AUC) of the predictive model to distinguish between schizophrenia and HC to be 0.737 among total samples and between first-episode and recurrent schizophrenia to be 0.890 among subgroups. CONCLUSIONS: Decreased TT3 and TT4 and elevated ACTH and COR levels appear to be associated with schizophrenia symptoms. The chronic recurrent trait of schizophrenia may cause long-term effects on FT3 and FT4 while changes in thyroid, and adrenal function as a result of mental disorder varied with gender. The pathophysiological parameters provide fair to good accuracy of these models.

7.
Psychiatry Res ; 286: 112903, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32146245

RESUMO

Since the middle of December 2019, human-to-human transmission of novel coronavirus pneumonia (NCP) has occurred among close contacts. At the same time, greater attention should be paid to psychological crisis intervention (PCI) among affected populations, for the timely prevention of inestimable damage from a secondary psychological crisis. PCI has been initiated via remote (telephone and internet) and onsite medical services to help medical workers, patients, and others affected to overcome any psychological difficulties. This paper outlines experiences based on the work of the Shanghai Medical Team.

8.
Environ Int ; 137: 105567, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32087482

RESUMO

The occurrence of triphenyltin (TPT) compounds, a highly toxic antifouling biocide, has been documented in marine environments and organisms all over the world. While some studies showed that marine mammals can be used as sentinel organisms to evaluate the pollution status of emerging contaminants in the environment because of their long lifespans and high trophic levels, information regarding the contamination status of TPT in marine mammal species has been limited over the past decade. More importantly, the primary bioaccumulation pathway of TPT in these long-lived apex predators and the corresponding marine food web is still uncertain. Therefore, this study aimed to evaluate the contamination statuses of TPT in two marine mammal species, namely the finless porpoise and the Indo-Pacific humpback dolphin, and assess the trophic magnification potential of TPT along the food webs of these two species, using stable isotope analysis, and chemical analysis with gas chromatography-mass spectrometry. The results showed that TPT is the predominant residue in majority of the analyzed individuals of two marine mammals, with concentrations ranging from 426.2 to 3476.6 ng/g wet weight in their muscle tissues. Our results also demonstrated an exponential increase in the concentration of TPT along the marine food web, indicating that trophic magnification occurs in the respective food webs of the two marine mammals. The range of trophic magnification factors of TPT in the food webs of finless porpoise and Indo-Pacific humpback dolphin was 2.51-3.47 and 2.45-3.39, respectively. These results suggest that high trophic organisms may be more vulnerable to the exposure of TPT-contaminated environments due to the high trophic magnification potential, and thus ecological risk of these compounds ought to be assessed with the consideration of their bioaccumulation potentials in these marine mammals.


Assuntos
Cadeia Alimentar , Compostos Orgânicos de Estanho , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Peixes , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos de Estanho/farmacocinética , Compostos Orgânicos de Estanho/toxicidade
9.
Neuropsychologia ; 138: 107354, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31972230

RESUMO

Verbal fluency test, a type of word generation task, is a commonly used neuropsychological assessment. Among the healthy population, it has been used to assess verbal ability, but also executive functions. In the clinical field, verbal fluency has been used to support the diagnoses of a number of neuropsychological disorders. However, existing evidence do not allow for clear conclusions on whether such nonlinguistic uses of verbal fluency test are justified. The present study therefore investigated the involvement of domain-general cognitive functions in word production using functional magnetic resonance imaging, assessing verbal fluency, response inhibition, and working memory updating brain activations in the same set of participants. Results showed that response inhibition and working memory updating do play a role in verbal-fluency-type word production tasks, although language-specific regions are also required. Furthermore, domain-general and language-specific areas are closely neighboring subregions within the same broad brain regions. Additionally, a neural network for Chinese lexical production was observed, which corroborate neural bases for production in alphabetic languages, indicating that there is a core network for lexical production, regardless of language, production mode, or cue stimulus type, with other additional areas involved under some production conditions. Given that most previous research only investigated alphabetic languages, these results help gain a better understanding of language production mechanisms across languages.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Função Executiva/fisiologia , Inibição Psicológica , Idioma , Memória de Curto Prazo/fisiologia , Rede Nervosa/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , China , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Testes Neuropsicológicos , Psicolinguística , Fala/fisiologia , Adulto Jovem
10.
Cereb Cortex ; 29(10): 4312-4320, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-30561523

RESUMO

Although it is well-established that human language functions are mostly lateralized to the left hemisphere of the brain, little is known about the functional mechanisms underlying such hemispheric dominance. The present study investigated intrinsic organization of the whole brain at rest, by means of functional connectivity and graph theoretical analysis, with the aim to characterize brain functional organization underlying typical and atypical language dominance. We included healthy left-handers, both those with typical left-lateralized language and those with atypical right-lateralized language. Results show that 1) differences between typical and atypical language lateralization are associated with functional connectivity within the language system, particularly with weakened connectivity between left inferior frontal gyrus and several other language-related areas; and 2) for participants with atypical language dominance, the degree of lateralization is linked with multiple functional connectivities and graph theoretical metrics of whole brain organization, including local efficiency and small-worldness. This is the first study, to our knowledge, that linked the degree of language lateralization to global topology of brain networks. These results reveal that typical and atypical language dominance mainly differ in functional connectivity within the language system, and that atypical language dominance is associated with whole-brain organization.


Assuntos
Encéfalo/fisiologia , Lateralidade Funcional , Idioma , Adolescente , Adulto , Mapeamento Encefálico , Feminino , Humanos , Masculino , Vias Neurais/fisiologia , Adulto Jovem
11.
Sci Rep ; 8(1): 17876, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552339

RESUMO

Intensive trawling activities in Hong Kong waters have seriously depleted fishery resources and damaged marine benthic habitats over the last four decades. To minimize further destruction and rehabilitate fishery resources, the Hong Kong Government implemented a permanent territory-wide trawling closure on 31 December 2012. Such a trawl ban creates a unique opportunity to investigate recoveries in ecosystem structure and function following a major shift in disturbance regime by removing impacts from a major gear. This study was designed to test the hypothesis that dominant predatory mantis shrimps, including Harpiosquilla harpax, Miyakella nepa, Oratosquillina interrupta, and Oratosquilla oratoria would show signs of recovery following the trawl ban. Their population dynamics were investigated before and after the trawl ban. The results showed that their mean weight, mean carapace length and proportion of large-sized individuals increased significantly 3.5 years after the trawl ban, whilst their abundance, biomass and maximum length remained unchanged. This study suggests that the stomatopod assemblage in the human-dominated Hong Kong waters shows some initial signs of possible recovery following the trawl ban but also highlights the complexity of implementing fishery management and detecting changes resulted from management measures in a heavily urbanized seascape where many biotic and abiotic factors can influence their population dynamics.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Crustáceos/crescimento & desenvolvimento , Ecossistema , Atividades Humanas , Dinâmica Populacional , Animais , Biomassa , Biometria , Tamanho Corporal , Peso Corporal , Conservação dos Recursos Naturais , Crustáceos/anatomia & histologia , Hong Kong , Água do Mar
12.
PLoS One ; 13(7): e0199680, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30020988

RESUMO

Measures (e.g. δ15N, δ13C, %C, %N and C:N) derived from animal tissues are commonly used to estimate diets and trophic interactions. Since tissue samples are often exposed to air or kept chilled in ice over a short-term during sample preparation, they may degrade. Herein, we hypothesize that tissue decomposition will cause changes in these measures. In this study, we kept marine fish, crustacean and mollusc tissues in air or ice over 120 h (5 days). We found that tissue decomposition in air enriched δ15N (range 0.6‰ to 1.3‰) and δ13C (0.2‰ to 0.4‰), decreased %N (0.47 to 3.43 percentage points from staring values of ~13%) and %C (4.53 to 8.29 percentage points from starting values of ~43%), and subsequently increased C:N ratio (0.14 to 0.75). In air, while such changes to δ13C were relatively minor and therefore likely tolerable, changes in δ15N, %N, %C and C:N ratio should be interpreted with caution. Ice effectively reduced the extent to which decomposition enriched δ15N (≤ 0.4‰) and δ13C (≤ 0.2‰), and eliminated decomposition in C:N ratio, %N and %C. In our second experiment, for fish tissues in either air or ice over 120 h, we observed no effects of decomposition on relationships between lipid content, C:N ratio, and Δδ13C (change in δ13C after lipid removal), which are employed to correct δ13C for samples containing lipid. We also confirmed that lipid in tissues caused large errors when estimating δ13C (mean ± standard error = -1.8‰ ± 0.1‰, range -0.6‰ to -3.8‰), and showed both lipid extraction and mathematical correction performed equally well to correct for lipids when estimating δ13C. We, therefore, recommend that specimens of marine animals should be kept in ice during sample preparation for a short-term, as it is an effective means for minimizing changes of the stable isotope measures in their tissue.


Assuntos
Organismos Aquáticos/química , Carbono/química , Lipídeos/química , Nitrogênio/química , Animais , Carbono/análise , Isótopos de Carbono/análise , Isótopos de Carbono/química , Lipídeos/análise , Nitrogênio/análise , Isótopos de Nitrogênio/análise , Isótopos de Nitrogênio/química
13.
Front Psychol ; 8: 266, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28286491

RESUMO

Foreign accent in speech often presents listeners with challenging listening conditions. Consequently, listeners may need to draw on additional cognitive resources in order to perceive and comprehend such speech. Previous research has shown that, for older adults, executive functions predicted perception of speech material spoken in a novel, artificially created (and therefore unfamiliar) accent. The present study investigates the influences of executive functions, information processing speed, and working memory on perception of unfamiliar foreign accented speech, in healthy young adults. The results showed that the executive processes of inhibition and switching, as well as information processing speed predict response times to both accented and standard sentence stimuli, while inhibition and information processing speed predict speed of responding to accented word stimuli. Inhibition and switching further predict accuracy in responding to accented word and standard sentence stimuli that has increased processing demand (i.e., nonwords and sentences with unexpected semantic content). These findings suggest that stronger abilities in aspects of cognitive functioning may be helpful for matching variable pronunciations of speech sounds to stored representations, for example by being able to manage the activation of incorrect competing representations and shifting to other possible matches.

14.
J Int Neuropsychol Soc ; 21(7): 531-44, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26527242

RESUMO

This study investigated the relationship between bilingualism and task switching ability using a standardized measure of switching and an objective measure of bilingual language proficiency. Heritage Language (HL) speaking Spanish-English and Mandarin-English bilinguals and English speaking monolinguals completed all four subtests of the Color-Word Interference Test (CWIT), an English verbal fluency task, and a picture naming test (the Multilingual Naming Test) in English. Bilinguals also named pictures in their HL to assess HL proficiency. Spanish-English bilinguals were advantaged in task switching, exhibiting significantly smaller switching cost than monolinguals, but were disadvantaged in verbal fluency and picture naming. Additionally, performance on these cognitive and linguistic tasks was related to degree of HL proficiency, so that increased ability to name pictures in Spanish was associated with greater switching advantage, and greater disadvantage in both verbal fluency and picture naming. Mandarin-English bilinguals, who differed from the Spanish-English bilinguals on several demographic and language-use characteristics, exhibited a smaller but statistically significant switching advantage, but no linguistic disadvantage, and no clear relationship between HL proficiency and the switching advantage. Together these findings demonstrate an explicit link between objectively measured bilingual language proficiency and both bilingual advantages and disadvantages, while also showing that consequences of bilingualism for cognitive and linguistic task performance can vary across different language combinations.


Assuntos
Aptidão , Multilinguismo , Análise e Desempenho de Tarefas , Adolescente , Adulto , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Psicolinguística , Adulto Jovem
15.
Front Psychol ; 2: 123, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21713011

RESUMO

Previous studies have demonstrated a bilingual advantage in the efficiency of executive attention. A question remains, however, about the impact of the age of L2 acquisition and relative balance of the two languages on the enhancement of executive functions in bilinguals, and whether this is modulated by the similarity of the bilingual's two languages. The present study explores these issues by comparing the efficiency of attentional networks amongst three groups of young adults living in Australia: English monolinguals and early and late Chinese-English bilinguals. We also address the impact of bilingualism on hemispheric lateralization of cognitive functions, which is of interest since a recent study on early bilinguals revealed reduced hemispheric asymmetry in attentional functioning. In the present study, participants performed a modified version of the lateralized attention network test. Both early and late bilinguals were found to have more efficient executive network than monolinguals. The late bilinguals, who were also reported to be more balanced in the proficiency and usage of their two languages, showed the greatest advantage in conflict resolution, whereas early bilinguals seemed to show enhanced monitoring processes. These group differences were observed when controlling for non-verbal intelligence and socioeconomic status. Such results suggest that specific factors of language experience may differentially influence the mechanisms of cognitive control. Since the bilinguals had distinct language sets, it seems that the influence of bilingualism on executive functions is present regardless of the similarity between the two languages. As for hemispheric lateralization, although the results were not clear-cut, they suggest the reduced lateralization in early bilinguals.

16.
Talanta ; 76(4): 865-71, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18656671

RESUMO

We developed a method using on-line solid phase extraction (SPE) coupled to high performance liquid chromatography-isotope dilution tandem mass spectrometry (HPLC-MS/MS) to measure the serum concentrations of seven environmental phenols and five parabens: bisphenol A; ortho-phenylphenol; 2,4-dichlorophenol; 2,5-dichlorophenol; 2,4,5-trichlorophenol; benzophenone-3; triclosan; and methyl-, ethyl-, propyl-, butyl-, and benzyl-parabens. The phenols and parabens present in serum were retained and concentrated on a C18 reversed-phase size-exclusion SPE column, back-eluted from the SPE column while the eluate was diluted through a mixing Tee (analyte peak focusing), separated using a pair of monolithic HPLC columns, and detected by isotope dilution-MS/MS. Sample preparation did not require protein precipitation, only dilution of the serum with 0.1M formic acid. This method, which combines an on-line SPE with analyte peak focusing feature and the selective atmospheric pressure photoionization MS detection, resulted in limits of detection ranging from 0.1 to 0.5 ng/mL for most of the analytes. The high throughput and adequate sensitivity with yet a relative low serum volume used (100 microL) confirm that analytically it is possible to measure simultaneously these phenols and parabens with the precision and accuracy at sub-parts-per-billion levels required for biomonitoring. However, important additional factors, including validated sample collecting, handling, and storing protocols, as well as toxicokinetic data, are required if these measures are used for exposure assessment.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Parabenos/análise , Espectrometria de Massas em Tandem/instrumentação , Espectrometria de Massas em Tandem/métodos , Automação , Calibragem , Técnicas de Química Analítica/métodos , Meio Ambiente , Formiatos/análise , Íons , Fenol/química , Fenóis/química , Pressão , Controle de Qualidade , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Fatores de Tempo
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