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1.
Chem Asian J ; 14(20): 3675-3681, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31328421

RESUMO

Aluminium-based metal-organic framework (MOF) coatings on polystyrene bead surfaces were easily synthesized by reacting an intermediate metal hydroxide coating with an organic linker. Several different sizes of polystyrene beads were coated with aluminium metal hydroxide to construct Al@PS core-shell bead materials. The activated Al@PS core-shell beads were involved to make a homogenous MOF-based layer in the presence of the organic linker. By using different sizes of the PS support the size of MOFs on the PS composites could be fine-tuned under specific reaction conditions. MOF-coated core-shell bead materials (Al-1,4-NDC@PS and MIL-53(Al)@PS) were characterized using various analytical techniques. Al-1,4-NDC@PS and MIL-53(Al)@PS were evaluated for solid-phase microextraction (SPME) of hydrophobic polycyclic aromatic hydrocarbons (PAHs) and hydrophilic non-steroidal anti-inflammatory drugs (NSAIDs), respectively. Al-1,4-NDC@PS-1000 displayed high extraction recoveries ranging from 79.2 % to 99.8 % in the SPME of PAHs. Meanwhile, MIL-53(Al)@PS-1000 showed 85.9-99.0 % extraction recoveries in the SPME of NSAIDs. These results show that the proposed approach holds potential to extract organic analytes on an industrial scale.

2.
J Phys Chem B ; 122(44): 10179-10189, 2018 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-30290115

RESUMO

Increasing atmospheric CO2 concentration and dwindling fossil fuel supply necessitate the search for efficient methods for CO2 conversion to fuels. Assorted studies have shown pyridine and its derivatives capable of (photo)electrochemically reducing CO2 to methanol, and some mechanistic interpretations have been proposed. Here, we analyze the thermodynamic and kinetic aspects of the efficacy of pyridines as hydride-donating catalytic reagents that transfer hydrides via their dihydropyridinic form. We investigate both the effects of functionalizing pyridinic derivatives with electron-donating and electron-withdrawing groups on hydride-transfer catalyst strength, assessed via their hydricity (thermodynamic ability) and nucleophilicity (kinetic ability), and catalyst recyclability, assessed via their reduction potential. We find that pyridines substituted with electron-donating groups have stronger hydride-donating ability (having lower hydricity and larger nucleophilicity values), but are less efficiently recycled (having more negative reduction potentials). In contrast, pyridines substituted with electron-withdrawing groups are more efficiently recycled, but are weaker hydride donors. Functional group modification favorably tunes hydride strength or efficiency, but not both. We attribute this problematic coupling between the strength and recyclability of pyridinic hydrides to their aromatic nature and suggest several avenues for overcoming this difficulty.

3.
J Chromatogr A ; 1539: 12-18, 2018 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-29402430

RESUMO

In this study, activated carbon-organic polymer (AC-polymer) extraction columns were prepared via microwave-assisted polymerization. The AC-polymer was applied in polymer monolith microextraction (PMME) of phenolic acids (PAs) in food samples. Structural characterization using Raman and Fourier transform infrared (FTIR) spectroscopy revealed the successful incorporation of AC into polymer monolith. In contrast to neat polymer in which low extraction efficiency (17.0-57.7%) was observed, the AC-polymer (8 mg AC, 4 cm column length) afforded better extraction efficiency for PAs ranging from 75.8 to 99.8% for intra-day with less than 1.4% relative standard deviations (RSDs) and inter-day precision ranging from 74.3 to 100.1% (<2.7% RSDs). The extraction efficiency for column-to-column were found to be in the range of 72.8-100.5% (<2.0% RSDs) (n = 3). Under the optimized conditions, the AC-polymer monolithic column was successfully applied in PMME of PAs in fruit wine and cranberry juice samples at concentrations of <4.8 mg L-1 and 26.54 mg L-1, respectively.


Assuntos
Carbono/química , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Hidroxibenzoatos/isolamento & purificação , Polímeros/química , Vinho/análise , Sucos de Frutas e Vegetais/análise , Micro-Ondas , Polimerização , Vaccinium macrocarpon/química
4.
Chemistry ; 23(1): 42-46, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27796059

RESUMO

A facile method to improve the feasibility of water-unstable metal-organic frameworks in an aqueous environment has been developed that involves imbedding in a polymer monolith. The effect of compartment type during polymerization plays a significant role in maintaining the crystalline structure and thermal stability of the MOFs, which was confirmed by powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA), respectively. The MOF-polymer composite prepared in a narrow compartment (column, ID 0.8 mm) has better thermal and chemical stability than that prepared in a broad compartment (vial, ID 7 mm). The developed MOF-polymer composite was applied as an adsorbent in solid-phase microextraction of nine non-steroidal anti-inflammatory drugs (NSAIDs) and could be used for extraction more than 30 times, demonstrating that the proposed approach has potential for industrial applications.


Assuntos
Compostos Organometálicos/química , Microextração em Fase Sólida/métodos , Água/química , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Polímeros/química , Termogravimetria , Difração de Raios X
5.
J Voice ; 30(4): 460-5, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26096986

RESUMO

OBJECTIVE: Many studies focused on teachers' voice problems and most of them were conducted using questionnaires, whereas little research has investigated the relationship between self-reported voice disorders and objective quantification of voice. This study intends to explore the relationship of acoustic measurements according to self-reported symptoms and its predictive value of future dysphonia. STUDY DESIGN: This is a case-control study. METHODS: Voice samples of 80 female teachers were analyzed, including 40 self-reported voice disorders (VD) and 40 self-reported normal voice (NVD) subjects. The acoustic measurements included jitter, shimmer, and noise-to-harmonics ratio (NHR). Levene's t test and logistic regression were used to analyze the differences between VD and NVD and the relationship between self-reported voice conditions and the acoustic measurements. To examine whether acoustic measurements can be used to predict further voice disorders, we applied a receiver operating characteristic (ROC) curve to determine the cutoff values and the associated sensitivity and specificity. RESULTS: The results showed that jitter, shimmer, and the NHR of VD were significantly higher than those of NVD. Among the parameters, the NHR and shimmer demonstrated the highest correlation with self-reported voice disorders. By using the NHR ≥0.138 and shimmer ≥0.470 dB as the cutoff values, the ROC curve displayed 72.5% of sensitivity and 75% of specificity, and the overall positive predictive value for subsequent dysphonia achieved 60%. CONCLUSIONS: This study demonstrated a significant correlation between acoustic measurements and self-reported dysphonic symptoms. NHR and ShdB are two acoustic parameters that are more able to reflect vocal abnormalities and, probably, to predict subsequent subjective voice disorder. Future research recruiting more subjects in other occupations and genders shall validate the preliminary results revealed in this study.


Assuntos
Acústica , Percepção Auditiva , Doenças Profissionais/diagnóstico , Saúde Ocupacional , Professores Escolares , Autorrelato , Medida da Produção da Fala , Distúrbios da Voz/diagnóstico , Qualidade da Voz , Adulto , Área Sob a Curva , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Profissionais/fisiopatologia , Doenças Profissionais/psicologia , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes , Fatores Sexuais , Distúrbios da Voz/fisiopatologia , Distúrbios da Voz/psicologia , Adulto Jovem
6.
BMJ Open ; 5(1): e006777, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25628048

RESUMO

OBJECTIVE: The impact of schizophrenia on vital diseases, such as chronic kidney disease (CKD), has not as yet been verified. This study aims to establish whether there is an association between schizophrenia and CKD. DESIGN: A nationwide matched cohort study. SETTING: Taiwan's National Health Insurance Research Database. PARTICIPANTS: A total of 2338 patients with schizophrenia, and 7014 controls without schizophrenia (1:3), matched cohort for sex, age group, geography, urbanisation and monthly income, between 1 January 2003 and 31 December 2007, based on the International Classifications of Disease Ninth Edition (ICD-9), Clinical Modification codes. PRIMARY AND SECONDARY OUTCOME MEASURES: After making adjustments for confounding risk factors, a Cox proportional hazards model was used to compare the risk of developing CKD during a 3-year follow-up period from the index date. RESULTS: Of the 2338-subject case cohort, 163 (6.97%) developed a CKD, as did 365 (5.20%) of the 7014 control participants. Cox proportional hazards regression analysis revealed that patients with schizophrenia were more likely to develop CKD (HR=1.36, 95% CI 1.13 to 1.63; p<0.001). After adjusting for gender, age group, hypertension, diabetes mellitus, hyperlipidaemia, heart disease and non-steroid anti-inflammatory drugs (NSAIDs) usage, the HR for patients with schizophrenia was 1.25 (95% CI 1.04 to 1.50; p<0.05). Neither typical nor atypical antipsychotics was associated an increased risk of CKD in patients with schizophrenia. CONCLUSIONS: The findings from this population-based retrospective cohort study suggest that schizophrenia is associated with a 25% increase in the risk of developing CKD within only a 3-year follow-up period.


Assuntos
Insuficiência Renal Crônica/etiologia , Esquizofrenia/complicações , Adolescente , Adulto , Idoso , Feminino , Humanos , Classificação Internacional de Doenças , Masculino , Pessoa de Meia-Idade , Prevalência , Modelos de Riscos Proporcionais , Análise de Regressão , Insuficiência Renal Crônica/epidemiologia , Estudos Retrospectivos , Risco , Fatores de Risco , Taiwan , Adulto Jovem
7.
Clin Neurophysiol ; 125(8): 1568-75, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24388404

RESUMO

OBJECTIVE: This study examined the impact of spectral resolution on the processing of lexical tones and the number of frequency channels required for a cochlear implant (CI) to transmit Chinese tonal information to the brain. METHODS: ERPs were recorded in an auditory oddball task. Normal-hearing participants listened to speech sounds of two tones and their CI simulations in 1, 4, 8, or 32 channels. The mismatch response elicited by speech sounds and CI simulations in different numbers of channels were compared. RESULTS: The mismatch negativity (MMN) was observed for speech sounds. For the 1-channel CI simulations, deviants elicited a more positive waveform than standard stimuli. No MMN response was observed with the 4-channel simulations. A reliable MMN response was observed for the 8- and 32-channel simulations. The MMN responses elicited by the 8- and 32-channel simulations were equivalent in magnitudes and smaller than that elicited by speech sounds. CONCLUSIONS: More than eight frequency channels are required for a CI to transmit Chinese tonal information. The presence of both positive and negative mismatch responses suggests multiple mechanisms underlying auditory mismatch responses. SIGNIFICANCE: The current findings of spectral resolution constraints on the transmission of tonal information should be taken into account in the design of the CI devices.


Assuntos
Povo Asiático/classificação , Implantes Cocleares , Potenciais Evocados , Idioma , Modelos Neurológicos , Fonética , Discriminação da Altura Tonal , Adolescente , Comunicação , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Percepção da Fala , Adulto Jovem
8.
Psychophysiology ; 50(11): 1120-32, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23909649

RESUMO

In two ERP experiments, we examined whether active inhibition is involved in intentional forgetting. Both experiments consisted of a nondirected-forgetting (nDF) and a directed-forgetting (DF) block. Participants were sequentially presented with a prime, an R/F (remember/forget) cue, and a target. Participants made lexical decisions to both the primes and targets (Experiment 1) or only to the targets (Experiment 2). They were also instructed to remember or to forget the primes in response to the R/F cues in the DF block but to ignore these cues in the nDF block. The N400 semantic priming effect was observed when comparing the ERPs elicited by semantically unrelated and related targets in the DF block. In comparison to the nDF block, the N400 effect was greatly reduced for targets preceded by F cues in the DF block. These findings suggest that semantic processing is reduced by the instruction to forget and active inhibition is involved in intentional forgetting.


Assuntos
Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Inibição Psicológica , Intenção , Memória/fisiologia , Adolescente , Sinais (Psicologia) , Eletroencefalografia , Feminino , Humanos , Masculino , Rememoração Mental , Tempo de Reação , Priming de Repetição , Semântica , Adulto Jovem
9.
Mol Nutr Food Res ; 56(8): 1324-32, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22641311

RESUMO

SCOPE: Chemoprevention is one of the most feasible approaches to reduce the risk of cancer. Over the past decades, scientists have realized that chronic inflammation is a critical component of cancer development. Inotilone, existing in Inonotus mushroom has been reported to exhibit anti-inflammatory properties in vitro. Hence, we investigated the effects of inotilone on 12-O-tetradecanoylphorbol-13-acetate (TPA)-mediated acute inflammation and tumor promotion in mouse skin and the underlying molecular mechanisms. METHODS AND RESULTS: Inotilone was topically applied to mouse skin 30 min prior to TPA treatment. The results have shown that inotilone inhibited the production of inflammatory mediators by attenuating the activation of nuclear factor-κB (NF-κB) and the expression of CCAAT/enhancer binding protein ß (C/EBPß). Furthermore, the ability of inotilone to prevent tumorigenesis at promotion stage was evaluated using a classical two-stage mouse skin carcinogenesis model. After initiation of 7,12-dimethylbenz[a]anthracene (DMBA), applying inotilone topically before each TPA treatment was found to reduce the tumor incidence and tumor multiplicity of papillomas. CONCLUSION: Based on the results, we concluded that inotilone has potential to be developed into an effective chemopreventive agent for the treatment of a variety of inflammatory diseases, especially the prevention and treatment of epithelial skin cancer.


Assuntos
Anti-Inflamatórios/farmacologia , Dermatite/tratamento farmacológico , Furanos/farmacologia , Macrolídeos/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Carcinógenos/toxicidade , Ciclo-Oxigenase 2/metabolismo , Ativação Enzimática/efeitos dos fármacos , Feminino , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos ICR , NF-kappa B/metabolismo , Pele/efeitos dos fármacos , Pele/metabolismo , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol/toxicidade
11.
Otol Neurotol ; 32(6): 937-42, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21593702

RESUMO

OBJECTIVE: The objectives of this investigation were to analyze auditory performance among Mandarin-speaking school-aged children with cochlear implants from their parents' perspective and to derive predictive factors of the performance. STUDY DESIGN: Parental perspective survey of cochlear implant outcome was developed, and factor analysis of auditory performance was performed by analysis of variance. Categorical regression and Pratt measure of relative importance were approached to derive predictive factors of the performance. SETTING: Chung Shan Medical University, School of Speech Language Pathology and Audiology, and 7 major cochlear implant hospitals in Taiwan. PATIENTS: A total of 177 parents of school-aged children with cochlear implants, with a mean age of 11.36 years (range, 6.75-18.75 yr), were included as participants from 7 major cochlear implant centers nationally. INTERVENTION: All children received unilateral multichannel cochlear implants for a 1-year experience. MAIN OUTCOME MEASURES: The CAPR was the measure of auditory performance, and 31 variables from 5 parts of the recipients' information were explored as independent variables. RESULTS: Of all children with implants, 63.8% reached the level of telephone use. Analysis of variance showed that 9 variables correlated significantly with auditory performance (F = 14.04, p < 0.001; multiple R = 0.79, R = 0.63). Categorical regression demonstrated that 5 factors, namely, "no additional disabilities," "oral/aural communication mode at home" and "at school," "educational placement," and "perception of implantation decision" predicted auditory performance. CONCLUSION: Parental perspective survey demonstrated the level of auditory performance among 177 school-aged children with implant. Five factors were found to predict the auditory performance of these children, suggesting the recipient's participation in the environments, oral/aural communication mode, and without additional disabilities significantly contributing auditory performance. The parent's view of cochlear implantation provides not only an important value of children's function in real life but also as another outcome measure.


Assuntos
Implantes Cocleares , Perda Auditiva Neurossensorial/fisiopatologia , Percepção da Fala/fisiologia , Adolescente , Povo Asiático , Criança , Feminino , Humanos , Masculino , Pais , Valor Preditivo dos Testes
12.
Mol Nutr Food Res ; 53(11): 1386-95, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19743406

RESUMO

The inhibitory effects of inotilone and methylinotilone on the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in murine RAW 264.7 cells activated with LPS were investigated. The results show that both hydroxyl groups on the benzene ring of the inotilone molecule are required for better anti-inflammatory effect. Western blotting and RT-PCR analyses demonstrated that inotilone blocked protein and mRNA expression of iNOS but not COX-2. Instead, inotilone inhibited prostaglandin E(2) production through decreasing the enzyme activity of COX-2. The repression of iNOS but not COX-2 expression may come from the differential effect of inotilone on nuclear factor-kappaB (NFkappaB) and CCAAT/enhancer-binding protein beta Treatment with inotilone resulted in the reduction of LPS-induced nuclear translocation of NFkappaB subunit and the NFkappaB-dependent transcriptional activity by blocking phosphorylation of inhibitor kappaB(IkappaB)alpha and p65 and subsequent degradation of inhibitor kappaBalpha. Inotilone also inhibited LPS-induced activation of PI3K/Akt and extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase. Our results suggest that inotilone may have potential to be developed into an effective anti-inflammatory agent.


Assuntos
Anti-Inflamatórios/farmacologia , Ciclo-Oxigenase 2/biossíntese , Furanos/farmacologia , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Macrolídeos/farmacologia , Macrófagos/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/biossíntese , Animais , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Células Cultivadas , Dinoprostona/biossíntese , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas I-kappa B/metabolismo , Macrófagos/metabolismo , Camundongos , Inibidor de NF-kappaB alfa , NF-kappa B/metabolismo , Nitritos/metabolismo , Fosforilação , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
J Acoust Soc Am ; 123(5): 2815, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18529197

RESUMO

The present study systematically manipulated three acoustic cues--fundamental frequency (f0), amplitude envelope, and duration--to investigate their contributions to tonal contrasts in Mandarin. Simplified stimuli with all possible combinations of these three cues were presented for identification to eight normal-hearing listeners, all native speakers of Mandarin from Taiwan. The f0 information was conveyed either by an f0-controlled sawtooth carrier or a modulated noise so as to compare the performance achievable by a clear indication of voice f0 and what is possible with purely temporal coding of f0. Tone recognition performance with explicit f0 was much better than that with any combination of other acoustic cues (consistently greater than 90% correct compared to 33%-65%; chance is 25%). In the absence of explicit f0, the temporal coding of f0 and amplitude envelope both contributed somewhat to tone recognition, while duration had only a marginal effect. Performance based on these secondary cues varied greatly across listeners. These results explain the relatively poor perception of tone in cochlear implant users, given that cochlear implants currently provide only weak cues to f0, so that users must rely upon the purely temporal (and secondary) features for the perception of tone.


Assuntos
Acústica , Implantes Cocleares , Sinais (Psicologia) , Idioma , Adulto , Comportamento de Escolha , Feminino , Humanos , Masculino , Reconhecimento Psicológico , Taiwan
14.
J Nanosci Nanotechnol ; 6(1): 95-100, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16573077

RESUMO

The alloy-based hybrid materials with macroscopic network arrays were developed by AuAg/Au and AuAgPd/Au nanoparticle composites through oligonucleotides hybridization. AuAg/Au and AuAgPd/Au exhibited distinct organization. The morphology of AuAg/Au conjugation assembled mainly as compact aggregates while AuAgPd/Au hybrid conjugated into the loosen network assemblies. The dehybridization temperatures were studied as a function of molar ratio of alloy/Au. It was found that higher alloy/gold molar ratio led to stronger hybridization for alloy/gold composite, accompanied with increased melting temperature. These results could be interpreted in terms of more alloy nanoparticles bound to a Au particle when the molar ratio of alloy/gold increased. The thermal analysis also showed that AuAg/Au exhibited higher dehybridization temperature. A modified model describing the dehybridization probability of an intact Au/alloy aggregate was performed to support the dehybridization temperature increased with increasing alloy/Au molar ratio. As to more oligonucleotides carried by AuAg (4.9 +/- 1.9 nm) than by AuAgPd (4.4 +/- 1.5 nm) due to larger size in AuAg, the efficient hybridization could result in higher dehybridization temperature in AuAg/Au.


Assuntos
Ligas/química , Ouro/química , Oligonucleotídeos/química , Cinética , Microscopia Eletrônica , Nanoestruturas/química , Prata/química , Espectrofotometria
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