Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Analyst ; 2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-32386286

RESUMO

With the expansion of the aquatic market and the large quantity of seafood consumption, the issues on safety, traceability and authenticity of seafood are becoming more and more important. Herein, a mass spectrometric method by direct analysis of fish samples was developed for fish authentication. A high-throughput matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) technique was applied to analyze the substances on the fish skin, or the surface molecularly imprinted substances on the surface of muscle tissues using a MALDI-target plate. A multivariate analysis was executed on the obtained mass spectra, and plots of principal component analysis (PCA) for different fish samples were differently clustered in a 95% confidence level. The developed strategy was capable of classifying and identifying fish species. The molecular imprinting method was found with good analytical reproducibility. The strategy enables the distinguishment of fish samples in a quick, efficient and easy mode. It is promising to apply the presently developed strategy for the authentication of seafood and extend the protocol for the detection of other protein food products.

2.
Hum Brain Mapp ; 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32090433

RESUMO

There is an ongoing debate about whether, and to what extent, males differ from females in their language skills. In the case of handwriting, a composite language skill involving language and motor processes, behavioral observations consistently show robust sex differences but the mechanisms underlying the effect are unclear. Using functional magnetic resonance imaging (fMRI) in a copying task, the present study examined the neural basis of sex differences in handwriting in 53 healthy adults (ages 19-28, 27 males). Compared to females, males showed increased activation in the left posterior middle frontal gyrus (Exner's area), a region thought to support the conversion between orthographic and graphomotor codes. Functional connectivity between Exner's area and the right cerebellum was greater in males than in females. Furthermore, sex differences in brain activity related to handwriting were independent of language material. This study identifies a novel neural signature of sex differences in a hallmark of human behavior, and highlights the importance of considering sex as a factor in scientific research and clinical applications involving handwriting.

3.
Neurology ; 93(20): e1873-e1880, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31624089

RESUMO

OBJECTIVE: To define the clinicopathologic features of amphiphysin-immunoglobulin G (IgG)-mediated neuropathy. METHODS: Patients examined at our institution from January 1, 1995, to September 30, 2018, with amphiphysin-IgG by indirect immunofluorescence and Western blot, were reviewed. Their phenotypes were compared to cases of coexisting collapsin response-mediator protein-5 (CRMP5)-IgG or anti-neuronal nuclear antibody type 1 (ANNA1-IgG) and CRMP5-IgG autoimmunity. Improvement in modified Rankin Scale (mRS) (≥1) on follow-up was considered a favorable outcome. Amphiphysin RNA expression was assessed in healthy nerves. RESULTS: Fifty-three amphiphysin-IgG-positive cases were identified. Of 33 (60%) patients with neuropathy, 21 had amphiphysin-IgG alone, and 12 had coexisting autoantibodies (ANNA1-IgG, n = 8; CRMP5-IgG, n = 2; ANNA1-IgG and CRMP5-IgG, n = 2). The neuropathies in isolated amphiphysin-IgG autoimmunity included polyradiculoneuropathy (62%), diffuse sensory neuronopathy (35%), and facial neuropathy with gastroparesis (3%). Among these, pain (80%), breast cancer (63%), and CNS (57%) involvements commonly coexisted, and neuropathy frequently prompted breast cancer diagnosis (76%). Stiff-person spectrum disorder was the most common CNS accompaniment (45%). Nerve biopsies showed axonal loss (n = 6/6), subperineurial edema (n = 4/6), and CD4 predominant inflammation (n = 2/6). Median mRS score at last follow-up was 3.5; 58% of patients were immunotherapy-responsive. Patients with amphiphysin-IgG alone had more favorable immunotherapy response than patients with CRMP5-IgG polyneuropathy (n = 45) (44% vs 16%, p = 0.028, odds ratio 4.2, 95% confidence interval 1.1 to 15.5). Only 1/9 (11%) patients with amphiphysin-IgG with coexisting CRMP5-IgG or ANNA1-IgG had immunotherapy response. RNA amphiphysin expression occurred at low levels in nerve. CONCLUSION: Amphiphysin-IgG autoimmune neuropathy has a recognizable phenotype, is frequently immune responsive, and can prompt early diagnosis of breast cancer.


Assuntos
Autoanticorpos/imunologia , Doenças Autoimunes do Sistema Nervoso/imunologia , Proteínas do Tecido Nervoso/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antinucleares/imunologia , Doenças Autoimunes do Sistema Nervoso/epidemiologia , Doenças Autoimunes do Sistema Nervoso/patologia , Doenças Autoimunes do Sistema Nervoso/fisiopatologia , Biópsia , Neoplasias da Mama/epidemiologia , Comorbidade , Doenças do Nervo Facial/epidemiologia , Doenças do Nervo Facial/imunologia , Doenças do Nervo Facial/patologia , Doenças do Nervo Facial/fisiopatologia , Feminino , Humanos , Hidrolases/imunologia , Imunoglobulina G/imunologia , Masculino , Proteínas Associadas aos Microtúbulos/imunologia , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/genética , Dor , Nervos Periféricos/imunologia , Nervos Periféricos/metabolismo , Nervos Periféricos/patologia , Polirradiculoneuropatia/epidemiologia , Polirradiculoneuropatia/imunologia , Polirradiculoneuropatia/patologia , Polirradiculoneuropatia/fisiopatologia , Rigidez Muscular Espasmódica/epidemiologia , Síndrome
5.
Food Chem ; 301: 125261, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31377618

RESUMO

Some Eastern Asian countries deem pufferfish - especially its muscle - a culinary delight. Herein, molecular mass fingerprinting of soups prepared by Takifugu flavidus, Takifugu obscurus and Takifugu rubripes was established via matrix-assisted laser desorption/ionization - mass spectrometry (MALDI MS). Soup samples were directly analyzed by MALDI MS to collect mass spectra within 0-700 Da in a quick way, followed by principal component analysis to distinguish the different soups and to find out the distinctive compounds among the soups. High performance liquid chromatography - tandem MS (HPLC-MS/MS) was applied to identify the compounds. Nineteen compounds were identified from the HPLC-MS/MS data by using METLIN database. Through literature mining, we found that these compounds are closely related to the flavor, nutrition, and safety of pufferfish soups. This method can also be used as a facile way to distinguish between different pufferfish fillets when morphological characters have been damaged or destroyed.


Assuntos
Análise de Alimentos/métodos , Inocuidade dos Alimentos , Metabolômica , Valor Nutritivo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Paladar , Tetraodontiformes/metabolismo , Animais , Culinária , Análise de Componente Principal
6.
J Org Chem ; 84(16): 9859-9868, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31347845

RESUMO

An atom-economical and practical method for the efficient synthesis of various pyrazino[1,2-a]indole-2-oxides was developed through a nickel(II)-catalyzed [5 + 1] annulation of 2-carbonyl-1-propargylindoles with hydroxylamine in water without using an organic solvent. The reaction involved an initial condensation of 2-carbonyl-1-propargylindoles with hydroxylamine to afford oxime intermediates, which then underwent a nickel(II)-catalyzed 6-exo-dig cyclization. Preliminary studies showed that (n-Bu)4NI served as a phase transfer catalyst and promoted the formation of active nickel(II) species. More importantly, the nickel(II) salt and phase transfer catalyst-in-water could be recycled seven times, and a gram scalable product was easily obtained in good yields through a filtration and washing protocol.

7.
Rapid Commun Mass Spectrom ; 33(16): 1336-1343, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31034697

RESUMO

RATIONALE: Authentication of fish is of importance in the view of toxins, allergen warnings and economic fraud control. Traditional methods in the authentication of fish, e.g. morphological, genetic and proteomic analysis, are either at low throughput or at high-cost. METHODS: A high-throughput matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS)-based approach was developed to analyze biomaterials from fish skin, and mass spectra from different fish species were compared by chemometric methods to differentiate fish species. RESULTS: A total of 51 fish samples were used to generate more than 150 fingerprinting mass spectra. The fish belonging to the same genus can be identified at species level. A mass spectral database of different fishes can be built as reference for authentication. The analysis can be performed based on micrograms of fish-skin sample and accomplished in 1-3 hours. CONCLUSIONS: The developed strategy holds potential to be applied to fish authentication in the fishing industry and as a scientific method to avoid mislabeling. It has promise to be practically used for fast and effective identification of closely related fish species to guarantee the quality of fishery products to consumers.


Assuntos
Proteínas de Peixes , Peixes/classificação , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Proteínas de Peixes/análise , Proteínas de Peixes/química , Análise de Componente Principal , Pele/química
8.
Neural Regen Res ; 14(5): 775-782, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30688263

RESUMO

Constraint-induced movement therapy is an effective rehabilitative training technique used to improve the restoration of impaired upper extremity movement after stroke. However, whether constraint-induced movement therapy is more effective than conventional rehabilitation in acute or sub-acute stroke remains controversial. The aim of the present study was to identify the optimal time to start constraint-induced movement therapy after ischemic stroke and to explore the mechanisms by which constraint-induced movement therapy leads to post-stroke recovery. Sixty-four adult male Sprague-Dawley rats were randomly divided into four groups: sham-surgery group, cerebral ischemia/reperfusion group, early constraint-induced movement therapy group, and late constraint-induced movement therapy group. Rat models of left middle cerebral artery occlusion were established according to the Zea Longa line embolism method. Constraint-induced movement therapy was conducted starting on day 1 or day 14 in the early constraint-induced movement therapy and late constraint-induced movement therapy groups, respectively. To explore the effect of each intervention time on neuromotor function, behavioral function was assessed using a balance beam walking test before surgery and at 8 and 21 days after surgery. The expression levels of brain-derived neurotrophic factor, nerve growth factor and Nogo receptor were evaluated using real time-polymerase chain reaction and western blot assay to assess the effect of each intervention time. The results showed that the behavioral score was significantly lower in the early constraint-induced movement therapy group than in the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. At 21 days, the scores had significantly decreased in the early constraint-induced movement therapy and late constraint-induced movement therapy groups. At 8 days, only mild pyknosis appeared in neurons of the ischemic penumbra in the early constraint-induced movement therapy group, which was distinctly better than in the cerebral ischemia/reperfusion group. At 21 days, only a few vacuolated cells were observed and no obvious inflammatory cells were visible in late constraint-induced movement therapy group, which was much better than at 8 days. The mRNA and protein expression levels of brain-derived neurotrophic factor and nerve growth factor were significantly higher, but expression levels of Nogo receptor were significantly lower in the early constraint-induced movement therapy group compared with the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. The changes in expression levels at 21 days were larger but similar in both the early constraint-induced movement therapy and late constraint-induced movement therapy groups. Besides, the protein nerve growth factor level was higher in the late constraint-induced movement therapy group than in the early constraint-induced movement therapy group at 21 days. These results suggest that both early (1 day) and late (14 days) constraint-induced movement therapy induces molecular plasticity and facilitates functional recovery after ischemic stroke, as illustrated by the histology. The mechanism may be associated with downregulation of Nogo receptor expression and upregulation of brain-derived neurotrophic factor and nerve growth factor expression.

9.
Colloids Surf B Biointerfaces ; 173: 171-177, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30292025

RESUMO

The composite fiber membrane of polyvinyl alcohol (PVA)/sodium alginate (SA)/nano-hydroxyapatite (nHAP) was fabricated by electrospinning method. In order to prevent the agglomeration and precipitation of nHAP in aqueous spinning solution, nHAP was ultrasonically suspended in aqueous solution using SA (the component of composite membrane) as stabilizer. The effect of nHAP on the morphology and mechanical property of composite fiber membrane was investigated. The in vitro biological properties including hemolysis, cytotoxicity, cell adhereing and proliferation of composite fiber membrane were evaluated. Results show that SA stabilized nHAP (SA-nHAP) suspension (1.67-10.02 mg/mL) can be obtained with SA/nHAP mass ratio of 1:33.4 for preparing homogeneous spinning solution. The electrospun membranes with PVA/SA/nHAP mass ratio of 9.33:(0.67-0.69):(0-0.668) show good fiber morphology, homogeneous incorporation and distribution of nHAP in fibers, and the content of SA-nHAP (6.25 wt%) in membrane is significantly increased compared to that of untreated nHAP (3.23 wt%). The incorporation of SA-nHAP of 1.64 wt.% significantly improves the tensile strength of PVA/SA/nHAP fiber membrane with about 45% enhancement. The hemolysis and cytotoxicity tests show that the composite fiber membrane has good biocompatibility. Moreover, cells can be seeded and proliferate well on composite fiber membrane. Therefore, the obtained PVA/SA/nHAP composite fiber membrane has the potential use as a tissue regeneration material.


Assuntos
Alginatos/química , Durapatita/química , Nanocompostos/química , Álcool de Polivinil/química , Tecidos Suporte , Alginatos/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Durapatita/farmacologia , Técnicas Eletroquímicas , Eritrócitos/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Camundongos , Nanocompostos/ultraestrutura , Álcool de Polivinil/farmacologia , Coelhos , Resistência à Tração
10.
Sleep Med ; 53: 81-87, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30458382

RESUMO

BACKGROUND: Recent studies have suggested that cerebral ischemic infarction may contribute to the development of restless legs syndrome (RLS). This study analyzed the clinical and radiological profiles of RLS with onset after acute lacunar infarction. METHODS: In this retrospective study we enrolled 244 consecutive patients with acute lacunar infarction between January 2012 and June 2014. RLS was identified and evaluated based on the International RLS Rating Scale (IRLS-RS). Individual sleep quality was assessed using the Epworth Sleepiness Scale (ESS). Psychological state was also assessed using the Hamilton Depression Scale (HDS) and the Hamilton Anxiety Scale (HAS). RESULTS: The incidence of RLS in patients with lacunar infarction was 5.33%. Our participant group consisted of nine males and four females. Three patients had symptoms in bilateral limbs, and 10 patients had symptoms only contralateral to the cerebral infarction. The infarctions were localized to the pons, centrum semiovale, thalamus, putamen, medulla, and occipital lobe. Contralateral paralysis was found in 13 patients, and contralateral sensory deficit in seven patients. The average IRLS-RS, ESS, HDS, HAS scores were 19.07 ± 8.70, 4.69 ± 5.82, 4.38 ± 4.68, and 3.85 ± 4.76, respectively. Nine patients had diabetes mellitus. After administration of dopaminergic drugs, patients' RLS significantly improved. CONCLUSIONS: The incidence of RLS after acute lacunar infarction was 5.33%. Pons, centrum semiovale, and basal ganglia were the common locations of responsible lesions. Compared to idiopathic RLS, symptoms of RLS after acute lacunar infarction appeared more unilateral and more likely involved the arm. Moreover, diabetes mellitus may be a risk factor for RLS in stroke patients.

11.
Front Behav Neurosci ; 12: 288, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30555308

RESUMO

Writing is an essential tool for human communication and involves multiple linguistic, cognitive, and motor processes. Chinese, a logographic writing system, differs remarkably from the writing systems of alphabetic languages. The neural substrates of Chinese writing are largely unknown. Using functional magnetic resonance imaging (fMRI) in a copying task, this study probed the neural underpinnings of orthographic access during Mandarin Chinese writing by employing the word-frequency effect. The results showed that writing low-frequency characters evoked greater activation in the bilateral superior/middle/inferior frontal gyrus, superior/inferior parietal lobule, and fusiform gyrus than writing high-frequency characters. Moreover, psychophysiological interaction (PPI) analysis demonstrated that the word-frequency effect modulated functional connectivity within the frontal-occipital networks and the parietal-occipital networks. Together, these findings illustrate the neural correlates of orthographic access for Mandarin Chinese writing, shedding new light on the cognitive architecture of writing across various writing systems.

12.
Mikrochim Acta ; 185(12): 542, 2018 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-30415312

RESUMO

A method is described for fast identification of bacteria by combining (a) the enrichment of bacterial cells by using magnetite (Fe3O4) magnetic beads modified with human IgG (IgG@Fe3O4) and (b) MALDI-TOF MS analysis. IgG has affinity to protein A, protein G, protein L and glycans on the surface of bacterial cells, and IgG@Fe3O4. It therefore is applicable to the preconcentration of a range of bacterial species. The feasibility of the method has been demonstrated by collecting six species of pathogenic bacteria (Gram-positives: Staphylococcus aureus and Kocuria rosea; Gram-negatives: Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae and Pseudomonas aeruginosa). Bacteria with concentrations as low as 10 CFU·mL-1 in spiked water samples were extracted by this sorbent with recovery rates of >50%. After enrichment, bacteria on the IgG@Fe3O4 sorbent were further identified by MALDI-TOF MS. Bacteria in concentrations as low as 105 CFU in 100 µL of human whole blood can be identified by the method. Compared to other blood culture based tests, the culture time is shortened by 40% (from ~10 h to ~6 h), and the plate culture procedure (overnight) is avoided. After short blood culture, the enrichment and identification can be finished in one hour. The IgG@Fe3O4 is of practical value in clinical diagnosis and may be combined with other identification methods, e.g. PCR, Raman spectroscopy, infrared spectroscopy, etc. Graphical abstract A non-targeted, fast and sensitive assay for bacterial identification from human blood has been developed based on the enrichment of bacteria by IgG@Fe3O4 and identification by MALDI-TOF MS.


Assuntos
Bactérias/isolamento & purificação , Técnicas Biossensoriais/métodos , Sangue/microbiologia , Óxido Ferroso-Férrico/química , Imunoglobulina G/química , Microesferas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Bacteriemia/sangue , Bacteriemia/diagnóstico , Humanos , Microbiologia da Água
13.
Anal Chem ; 90(9): 5512-5520, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29595252

RESUMO

Microfluidics based biochemical analysis shows distinctive advantages for fast detection of pathogenic microorganisms. This Feature summarizes the progress in the past decade on microfluidic methods for purification and detection of pathogenic bacteria and viruses as well as their applications in food safety control, environmental monitoring, and clinical diagnosis.


Assuntos
Bactérias/isolamento & purificação , Técnicas Biossensoriais , Técnicas Analíticas Microfluídicas , Vírus/isolamento & purificação , Animais , Humanos
14.
ACS Omega ; 3(12): 17881-17887, 2018 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458381

RESUMO

Due to the globally existed and economically motivated adulteration including mislabeling and/or blending, fast wine characterization is important in wine industry. Herein, we developed an electrostatic spray ionization-mass spectrometry (ESTASI-MS)-based method to distinguish wines. Wine samples were directly analyzed by ESTASI-MS without any pretreatment. Microdroplets of wine were deposited on a plastic plate for analysis. The collection of each mass spectrometric datum can be accomplished in 1-2 min without any need of pretreatment to the sample, followed by principle component analysis to discriminate wines with different labels and vintages. Long-term storage of wine was simulated and characterized by utilizing the method. High-performance liquid chromatography-MS was further applied to identify the distinctive compounds in wines to indicate their difference. We found that the method can offer a strategy for quick wine analysis, which is of practical value in wine industry for wine classification and aging control.

15.
Chronic Dis Transl Med ; 3(3): 186-190, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29063076

RESUMO

OBJECTIVE: Pontine infarction is a common type of stroke in the cerebral deep structures, resulting from occlusion of small penetrating arteries, may manifest as hemi-paralysis, hemi-sensory deficit, ataxia, vertigo, and bulbar dysfunction, but patients presenting with restless legs syndrome (RLS) are extremely rare. Herein, we reported five cases with RLS as a major manifestation of pontine infarction. METHODS: Five cases of pontine infarction related RLS were collected from July 2013 to February 2016. The diagnosis of RLS was made according to criteria established by the International RLS Study Group (IRLSSG) in 2003. Neurological functions were assessed according to the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Severity of RLS was based on the International RLS Rating Scale (IRLS-RS). Sleep quality was assessed by Epworth Rating Scale (ERS), and individual emotional and psychological states were assessed by Hamilton Depression Scale (HDS) and Hamilton Anxiety Scale (HAS). RESULTS: The laboratory data at the onset including hemoglobin, serum concentration of homocysteine, blood urea nitrogen (BUN), creatinine, electrolytes, and thyroid hormones were normal. The electroencephalogram (EEG), lower-extremity somatosensory evoked potential (SEP), and nerve conduction velocity (NCV) in four limbs were normal. The average period of follow-up was 34.60 ± 12.76 months. The MRI examination showed acute or subacute pontine infarction lesions, 3 cases in the rostral inner side, 1 case in the rostral lateral and inner side, and 1 case in rostral lateral side. The neurological deficits included weakness in 4 cases, contralateral sensory deficit in 1 case, and ataxia in 2 cases. All 5 patients presented with symptom of RLS at or soon after the onset of infarction and 4 patients experienced uncomfortable sensations in the paralyzed limbs contralateral to the ischemic lesion. Their neurological deficits improved significantly 2 weeks later, but the symptoms of RLS did not resolve. Among them, 3/5 patients were treated with dopaminergic drugs. At the end of the follow-up, RLS symptom eventually resolved in 3 patients but persisted in two. The IRLS-RS, NIHSS and mRS scores were significantly lower at the onset than those at the last follow-up (P = 0.035, 0.024 and 0.049, respectively). However, there was no significant difference in the ERS, HDS and HAS scores (P = 0.477, 0.226 and 0.778, respectively). CONCLUSION: RLS can be an onset manifestation of pontine infarction, clinicians should be aware of this potential symptom. RLS usually occurs in the paralyzed limbs contralateral to the infarction lesion. The pathogenesis still needs further investigation.

16.
PLoS One ; 12(7): e0179712, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28704422

RESUMO

Previous studies have indicated that the relationship between magnocellular-dorsal (M-D) function and reading-related skills may vary with reading development in readers of alphabetic languages. Since this relationship could be affected by the orthographic depth of writing systems, the present study explored the relationship between M-D function and reading-related skills in Chinese, a writing system with a deeper orthography than alphabetic languages. Thirty-seven primary school students and fifty-one undergraduate students participated. Orthographic and phonological awareness tests were adopted as reading-related skill measurements. A steady-pedestal paradigm was used to assess the low-spatial-frequency contrast thresholds of M-D function. Results showed that M-D function was only correlated with orthographic awareness for adults, revealing an enhancement with reading development; while being related to phonological awareness only for children revealing a developmental decrement. It suggested that the mechanism responsible for the relationship between M-D activity and reading-related skills was affected by the characteristics of literacy development in Chinese.


Assuntos
Encéfalo/fisiologia , Alfabetização/psicologia , Leitura , Criança , China , Feminino , Humanos , Testes de Linguagem , Masculino , Fonética , Psicometria , Redação , Adulto Jovem
18.
J Org Chem ; 81(17): 8014-21, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27500856

RESUMO

A metal-free method for synthesis of N-(2-hydroxyaryl)benzotriazoles via O-arylation of N-hydroxybenzotriazoles with readily available diaryliodonium salts and sequential N-O bond cleavage under mild conditions has been developed. The [3,3]-rearrangement of N-O bond cleavage could take place on the N instead of C atom. The reaction was compatible with diverse functional groups and a new type of P,N-ligand was synthesized in three steps.

19.
Brain Lang ; 160: 42-9, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27474853

RESUMO

The present study explored the relationship between visual dorsal stream and Chinese reading by resting-state fMRI technique. We collected the resting-state brain activities and reading skills of Chinese-speaking adult readers. The results showed that the values of amplitude of low frequency fluctuation (ALFF) in right posterior parietal cortex (PPC) and left visual middle temporal area (MT) (two regions of dorsal stream) were significantly correlated with rapid naming (RAN) speed, and the ALFF values of right PPC were correlated with orthographic awareness (OA). Further resting-state functional connectivity (RSFC) analysis revealed that RAN speed was related to RSFCs between dorsal stream areas and reading areas (e.g., left fusiform gyrus, bilateral middle occipital gyrus). OA was correlated with RSFCs between right PPC and left middle occipital gyrus. It suggested that spontaneous activities of visual dorsal stream, as well as connection between it and reading-related areas, were highly associated with Chinese reading skills.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Imagem por Ressonância Magnética , Leitura , China/etnologia , Feminino , Humanos , Masculino , Lobo Occipital/fisiologia , Lobo Parietal/fisiologia , Lobo Temporal/fisiologia , Adulto Jovem
20.
Biosens Bioelectron ; 85: 568-572, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27236140

RESUMO

Quantitative analysis of antioxidants in a fast, simple and accurate manner is of great importance in the view of real-time monitoring the health of individuals. Recently, we have developed a UV/vis spectroscopic microfluidic sensor to specifically quantify ascorbic acid based on the immobilization of ascorbate oxidase, a relatively unstable enzyme. In this work, three different strategies for the immobilization of the unstable enzyme, including alumina sol-gel encapsulation, physisorption to PDMS channels with, and without alumina xerogel modification, were compared to build a microsensor. We found that the loading amount of the enzyme is not the determinative factor for the performance of the microfluidic biosensor but the retained activity of the enzyme and diffusion in the microfluidic channel. Taking into account of the two factors, the protocol of adsorbing enzymes to alumina (Al2O3) xerogel modified PDMS surface was demonstrated to be the best for preparing the microfluidic sensor among the utilized protocols. The microsensor prepared under the optimized protocol was further used to quantify ascorbic acid in human blood, where only dozens of microliters of blood (few drops) was required, demonstrating its potential application in clinical diagnosis. The developed strategy is featured with optimized enzymatic activity, simple process of microfluidic platform, low sample consumption, and straightforward spectrophotometry based detection.


Assuntos
Ácido Ascórbico/sangue , Técnicas Biossensoriais/métodos , Técnicas Analíticas Microfluídicas/métodos , Espectrofotometria Ultravioleta/métodos , Adsorção , Óxido de Alumínio/química , Ascorbato Oxidase/química , Ascorbato Oxidase/metabolismo , Ácido Ascórbico/metabolismo , Dimetilpolisiloxanos/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Humanos , Limite de Detecção , Transição de Fase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA