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1.
Artículo en Inglés | MEDLINE | ID: mdl-38083433

RESUMEN

The noise-assisted multivariate Empirical mode decomposition (NA-MEMD) is applied to multi-channel EEG signals to obtain narrow-band scale-aligned intrinsic mode functions (IMFs) upon which functional connectivity analysis is performed. The connectivity pattern in relation to inherent functional activity of brain is estimated with the phase locking value (PLV). Instantaneous phase difference among different EEG channels gives PLV that is used to build the functional connectivity map. The connectivity map yields spatial-temporal feature representation which is taken as input of the proposed emotion detection system. The spatial-temporal features can be learned with a 3D convolutional neural network for classifying emotion states. The proposed system is evaluated on two publicly available DEAP and SEED dataset for binary and multi-class emotion classification. On detecting low versus high level in the valence and arousal dimensions, the attained accuracy values are 97.37% and 96.26% respectively. Meanwhile, this system yields 94.78% and 99.54% accuracy on multi-class task on DEAP and SEED, which outperform previously reported systems with other deep learning models and conventional EEG features.


Asunto(s)
Electroencefalografía , Emociones , Electroencefalografía/métodos , Encéfalo , Redes Neurales de la Computación , Nivel de Alerta
2.
J Couns Psychol ; 70(5): 562-570, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37439739

RESUMEN

This study investigates the relationships between therapists' use of discourse particles and therapist empathy. Discourse particles, commonly found in non-English languages, are verbal elements that constitute metacommunication by encoding speakers' emotions and attitudes, which are typically expressed by nonverbal behaviors (e.g., intonation, tone, facial expression, nodding). We hypothesize an inverted U-shaped curvilinear relationship between therapists' use of discourse particles and therapist empathy, given the notion that an optimal level of therapists' emotion in psychotherapy can facilitate clients' inner experiencing and self-expression. Four psychotherapy sessions each from 39 therapist-client dyads were analyzed. After each session, therapist empathy was rated by trained observers using the Therapist Empathy Scale (TES) and by clients using the Barrett-Lennard Relationship Inventory (BLRI). Multilevel modeling shows that both the person-level negative quadratic term and positive linear term for therapists' usage of discourse particles are significant in predicting mean TES with large effect sizes. The same predictors do not yield significant results in predicting mean BLRI but they trend in similar directions of associations with medium effect sizes. Our results suggest the optimal usage of discourse particles by therapists is around 20.3% (out of all utterances). The nonsignificant results in BLRI may be attributed to the relatively small sample size of our data and the noncommunication orientation of the client-rated measure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Asunto(s)
Empatía , Relaciones Profesional-Paciente , Humanos , Psicoterapia/métodos , Emociones
3.
Sci Rep ; 13(1): 437, 2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36624146

RESUMEN

Eggshells offer many advantages as adsorbents, such as affordability without special preparations other than pulverization and calcination. However, the manufacturing industry generally has a severe problem with high concentrations of heavy metals in wastewater. The purpose of this study was to use eggshell byproducts and calcined eggshell treatment for the adsorption of copper in an aqueous solution. The reaction time, metal concentration, adsorbent dose, temperature, and pH were evaluated using primary factors followed by the response surface method (RSM) to investigate the optimum conditions for eggshell byproducts and calcined eggshell adsorption treatment. The results of the one-factor-at-a-time experiment showed that the optimal adsorption rate was obtained from treatment at 24 h, 25 mg/L, 10 mg, and 25 °C. In addition, the effect of pH on the adsorption rates of eggshells and eggshells with membrane were detected at pH values of 5 and 5.9 and found to be 95.2, 90.5, and 73.3%. The reaction surface experiment showed that the best adsorption rate reached 99.3% after calcination at 900 °C for 2 h and a 20 min reaction. The results showed that eggshells, eggshell membranes, eggshells with membrane, and calcined eggshells could be applied to remove copper ions from industrial wastewater. The adsorption capacity of the calcined eggshell is better than that of the non-calcined eggshell and has good neutrality in acidic industrial wastewater. Therefore, it is convenient and practical for practical production and application. Likewise, this study conveys promising findings in the context of improving wastewater treatment based on a circular economy approach to waste reuse in the food industry and represents a valuable direction for future research.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Animales , Aguas Residuales , Cobre , Cáscara de Huevo/química , Agua , Adsorción , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/análisis , Cinética , Iones
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 3694-3697, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36086642

RESUMEN

In this study, the Multivariate Empirical Mode Decomposition (MEMD) approach is applied to extract features from multi-channel EEG signals for mental state classification. MEMD is a data-adaptive analysis approach which is suitable particularly for multi-dimensional non-linear signals like EEG. Applying MEMD results in a set of oscillatory modes called intrinsic mode functions (IMFs). As the decomposition process is data-dependent, the IMFs vary in accordance with signal variation caused by functional brain activity. Among the extracted IMFs, it is found that those corresponding to high-oscillation modes are most useful for detecting different mental states. Non-linear features are computed from the IMFs that contribute most to mental state detection. These MEMD features show a significant performance gain over the conventional tempo-spectral features obtained by Fourier transform and Wavelet transform. The dominance of specific brain region is observed by analysing the MEMD features extracted from associated EEG channels. The frontal region is found to be most significant with a classification accuracy of 98.06%. This multi-dimensional decomposition approach upholds joint channel properties and produces most discriminative features for EEG based mental state detection.


Asunto(s)
Algoritmos , Electroencefalografía , Encéfalo , Electroencefalografía/métodos , Análisis de Ondículas
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 284-287, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36085624

RESUMEN

In this study, the Multivariate Empirical Mode Decomposition (MEMD) is applied to multichannel EEG to obtain scale-aligned intrinsic mode functions (IMFs) as input features for emotion detection. The IMFs capture local signal variation related to emotion changes. Among the extracted IMFs, the high oscillatory ones are found to be significant for the intended task. The Marginal Hilbert spectrum (MHS) is computed from the selected IMFs. A 3D convolutional neural network (CNN) is adopted to perform emotion detection with spatial-temporal-spectral feature representations that are constructed by stacking the multi-channel MHS over consecutive signal segments. The proposed approach is evaluated on the publicly available DEAP database. On binary classification of valence and arousal level (high versus low), the attained accuracies are 89.25% and 86.23% respectively, which significantly outperform previously reported systems with 2D CNN and/or conventional temporal and spectral features.


Asunto(s)
Emociones , Redes Neurales de la Computación , Nivel de Alerta , Bases de Datos Factuales , Electroencefalografía
6.
Molecules ; 27(15)2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35956940

RESUMEN

Mayonnaise is a semisolid oil-in-water emulsion comprised of egg yolk, oil, and vinegar. One main problem with mayonnaise is its high fat content, so efforts have been made to develop low-fat sauces with similar characteristics to real mayonnaise. The purpose of this study was to evaluate the effect of medium-chain triglycerides (MCTs) blended with edible oil (soybean and olive oil) on the rheological, physicochemical, and sensory properties of low-fat mayonnaise. The results revealed that the shear viscosity decreased with the increase in medium-chain fatty acid (MCFA) contents and decreased with an increasing shear rate. Tan δ was <1, and a semisolid fluid with shear-thinning behavior was formed. The oscillation frequency test showed that the MCFA-containing mayonnaise was viscoelastic. The particle size and oil droplet analyses revealed that the emulsion droplet size and distribution were not significantly different in the MCT group compared to the control. The sensory evaluation demonstrated that the MCFA-containing mayonnaise was acceptable. This study illustrates that MCTs are a good substitute to produce the proper physicochemical properties of mayonnaise.


Asunto(s)
Condimentos , Yema de Huevo , Yema de Huevo/química , Emulsiones/química , Ácidos Grasos/análisis , Alimentos , Triglicéridos/análisis
7.
Artículo en Inglés | MEDLINE | ID: mdl-35742295

RESUMEN

This study developed a speech database for assessing one of the elements of physical literacy-physical competence. Thirty-one healthy and native Cantonese speakers were instructed to read a material aloud after various exercises. The speech database contained four types of speech, which were collected at rest and after three exercises of the Canadian Assessment of Physical Literacy 2nd Edition. To show the possibility of detecting each exercise state, a support vector machine (SVM) was trained on the acoustic features. Two speech feature sets, the extended Geneva Minimalistic Acoustic Parameter Set (eGeMAPS) and Computational Paralinguistics Challenge (ComParE), were utilized to perform speech signal processing. The results showed that the two stage four-class SVM were better than the stage one. The performances of both feature sets could achieve 70% accuracy (unweighted average recall (UAR)) in the three-class model after five-fold cross-validation. The UAR result of the resting and vigorous state on the two-class model running with the ComParE feature set was 97%, and the UAR of the resting and moderate state was 74%. This study introduced the process of constructing a speech database and a method that can achieve the short-time automatic classification of physical states. Future work on this corpus, including the prediction of the physical competence of young people, comparison of speech features with other age groups and further spectral analysis, are suggested.


Asunto(s)
Alfabetización , Habla , Adolescente , Canadá , Humanos , Estudiantes , Máquina de Vectores de Soporte
8.
Foods ; 11(10)2022 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-35626996

RESUMEN

In this study, the effect of various heating temperatures (61−70 °C) and times (1−10 min) on physical and chemical properties of liquid egg yolk (LEY) and mayonnaise were investigated. Initially, we found that the increase of LEY protein denaturation was highly correlated with the increase of temperature and time, without causing either protein degradation or aggregation. In addition, the viscosity and particle size of LEY were significantly increased with greater heating temperature and time. Furthermore, the emulsification stability of mayonnaise prepared from thermally processed LEY were significantly better than that of the unheated control group, in particular, the emulsion stability of mayonnaise was higher at a temperature ranging from 62 °C to 68 °C, whereas the emulsion stability decreased above 69 °C. A rheological analysis showed that mayonnaise prepared from thermally processed LEY has higher shear stress when compared with the control group. Indeed, a sharp increase in the shear stress was observed when LEY was heated above 67 °C. Results from storage behavior analysis suggest that mayonnaise prepared from thermally processed LEY failed to affect the chemical qualities of mayonnaise, as evidenced by the fact that acid values and TBA values were not statistically significant with the unheated control group. Microscopic observation indicates that the number of complete oil droplets were significantly reduced at higher heating (70 °C/5 and 10 min) conditions. Finally, the sensory evaluation results suggest that mayonnaise prepared from thermally processed LEY does not influence the appearance, aroma, taste, greasy feeling, and overall acceptance of mayonnaise, as indicated by there being no significant differences between the experimental group and the control group (p > 0.05). We conclude from our study that a combination of heating conditions over 67 °C/5 min can allow the mayonnaise to retain better quality in terms of stability.

9.
Front Psychiatry ; 13: 1018170, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36620681

RESUMEN

Introduction: Previous studies explored the preferences for therapists' attire and office setting based on initial impressions as a reference for the formality in psychotherapy. This study examines the formality of psychotherapy by investigating therapists' and clients' use of discourse particles, the linguistic marker and quantifier of the formality in speech, in relation to therapist empathy in different stages of psychotherapy. Methods: Four psychotherapy sessions (representing early, mid, and late stages) each from 39 therapist-client dyads were analyzed. Trained observers rated therapist empathy in each session using the Therapist Empathy Scale. Results: Results of multilevel modeling show that synchrony in particle usage, hence synchrony in formality, between clients and therapists is not associated with therapist empathy. Therapists' use of particles (i.e., absolute formality of therapists) was also not associated with therapist empathy. In contrast, the relative formality of therapists plays significant roles: therapist empathy is generally observed when therapists are relatively more formal than the clients (i.e., lower relative usage of particles by the therapists when compared to the clients). However, for clients who speak formally with few particles, therapist casualness (i.e., higher relative usage of particles than the clients) at the beginning of therapy may be interpreted as therapist empathy as therapists help these clients ease into the therapeutic relationships. Discussion: Our results suggest that the examination of therapists' and clients' use of particles across different stages of treatment may illuminate dynamic interactional styles that facilitate or hinder the psychotherapy process.

10.
IEEE J Sel Top Signal Process ; 14(2): 331-345, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32499841

RESUMEN

Aphasia is a common type of acquired language impairment resulting from dysfunction in specific brain regions. Analysis of narrative spontaneous speech, e.g., story-telling, is an essential component of standardized clinical assessment on people with aphasia (PWA). Subjective assessment by trained speech-language pathologists (SLP) have many limitations in efficiency, effectiveness and practicality. This paper describes a fully automated system for speech assessment of Cantonese-speaking PWA. A deep neural network (DNN) based automatic speech recognition (ASR) system is developed for aphasic speech by multi-task training with both in-domain and out-of-domain speech data. Story-level embedding and Siamese network are applied to derive robust text features, which can be used to quantify the difference between aphasic speech and unimpaired one. The proposed text features are combined with conventional acoustic features to cover different aspects of speech and language impairment in PWA. Experimental results show a high correlation between predicted scores and subject assessment scores. The best correlation value achieved with ASR-generated transcription is .827, as compared with .844 achieved with manual transcription. The Siamese network significantly outperforms story-level embedding in generating text features for automatic assessment.

11.
Int J Surg Case Rep ; 33: 119-123, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28314224

RESUMEN

INTRODUCTION: The management of orbital abscesses in neonates and infants is very challenging. Surgical drainage of the abscess is aimed at removing the pus and preventing blindness. We describe a case of orbital abscess in an infant that was caused by methicillin-resistant Staphylococcus aureus and that was successfully drained with image-guided endoscopic surgery. PRESENTATION OF CASE: A 39-day-old infant presented with progressive right maxillary swelling complicated by methicillin-resistant Staphylococcus aureus orbital abscess. Tooth bud abscess was the most likely primary cause and a combination of intravenous antibiotics was initially prescribed. The collection of intra-orbital pus was removed using image-guided system-aided endoscopic surgical drainage. DISCUSSION: Prompt diagnosis and management are very crucial. Endoscopic drainage of these abscesses in children has been described. Image-guided drainage of the orbital abscess is a newer technique that has been reported in a teenager and in adult patients. This is the first reported case of endoscopic orbital drainage surgery in an infant. The procedure was performed successfully. This approach provides for better identification of the anatomical structures in a very young patient. Injuries to the medial rectus, globe and optic nerve can be avoided with this technique. CONCLUSION: Aggressive management of orbital abscesses in infants is mandatory. Image-guided endoscopic orbital drainage offers precise visualization and a safer technique in a relatively smaller orbit.

12.
Ear Hear ; 38(2): e85-e92, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28225737

RESUMEN

PURPOSE: In this study, the authors evaluated the effect of personalized amplification on mobile phone speech recognition in people with and without hearing loss. METHODS: This prospective study used double-blind, within-subjects, repeated measures, controlled trials to evaluate the effectiveness of applying personalized amplification based on the hearing level captured on the mobile device. The personalized amplification settings were created using modified one-third gain targets. The participants in this study included 100 adults of age between 20 and 78 years (60 with age-adjusted normal hearing and 40 with hearing loss). The performance of the participants with personalized amplification and standard settings was compared using both subjective and speech-perception measures. Speech recognition was measured in quiet and in noise using Cantonese disyllabic words. Subjective ratings on the quality, clarity, and comfortableness of the mobile signals were measured with an 11-point visual analog scale. Subjective preferences of the settings were also obtained by a paired-comparison procedure. RESULTS: The personalized amplification application provided better speech recognition via the mobile phone both in quiet and in noise for people with hearing impairment (improved 8 to 10%) and people with normal hearing (improved 1 to 4%). The improvement in speech recognition was significantly better for people with hearing impairment. When the average device output level was matched, more participants preferred to have the individualized gain than not to have it. CONCLUSIONS: The personalized amplification application has the potential to improve speech recognition for people with mild-to-moderate hearing loss, as well as people with normal hearing, in particular when listening in noisy environments.


Asunto(s)
Teléfono Celular , Pérdida Auditiva/rehabilitación , Aplicaciones Móviles , Percepción del Habla , Adulto , Anciano , Estudios de Casos y Controles , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ruido , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Adulto Joven
13.
NPJ Prim Care Respir Med ; 27: 16089, 2017 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-28055000

RESUMEN

REALISE Asia-an online questionnaire-based study of Asian asthma patients-identified five patient clusters defined in terms of their control status and attitude towards their asthma (categorised as: 'Well-adjusted and at least partly controlled'; 'In denial about symptoms'; 'Tolerating with poor control'; 'Adrift and poorly controlled'; 'Worried with multiple symptoms'). We developed consensus recommendations for tailoring management of these attitudinal-control clusters. An expert panel undertook a three-round electronic Delphi (e-Delphi): Round 1: panellists received descriptions of the attitudinal-control clusters and provided free text recommendations for their assessment and management. Round 2: panellists prioritised Round 1 recommendations and met (or joined a teleconference) to consolidate the recommendations. Round 3: panellists voted and prioritised the remaining recommendations. Consensus was defined as Round 3 recommendations endorsed by >50% of panellists. Highest priority recommendations were those receiving the highest score. The multidisciplinary panellists (9 clinicians, 1 pharmacist and 1 health social scientist; 7 from Asia) identified consensus recommendations for all clusters. Recommended pharmacological (e.g., step-up/down; self-management; simplified regimen) and non-pharmacological approaches (e.g., trigger management, education, social support; inhaler technique) varied substantially according to each cluster's attitude to asthma and associated psychosocial drivers of behaviour. The attitudinal-control clusters defined by REALISE Asia resonated with the international panel. Consensus was reached on appropriate tailored management approaches for all clusters. Summarised and incorporated into a structured management pathway, these recommendations could facilitate personalised care. Generalisability of these patient clusters should be assessed in other socio-economic, cultural and literacy groups and nationalities in Asia.


Asunto(s)
Asma/terapia , Actitud Frente a la Salud , Educación del Paciente como Asunto , Asia , Análisis por Conglomerados , Consenso , Técnica Delphi , Manejo de la Enfermedad , Hong Kong , Humanos , Malasia , Países Bajos , Filipinas , Guías de Práctica Clínica como Asunto , República de Corea , Singapur , Reino Unido
14.
Speech Commun ; 67: 102-112, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26150679

RESUMEN

Periodicity is an important property of speech signals. It is the basis of the signal's fundamental frequency and the pitch of voice, which is crucial to speech communication. This paper presents a novel framework of periodicity enhancement for noisy speech. The enhancement is applied to the linear prediction residual of speech. The residual signal goes through a constant-pitch time warping process and two sequential lapped-frequency transforms, by which the periodic component is concentrated in certain transform coefficients. By emphasizing the respective transform coefficients, periodicity enhancement of noisy residual signal is achieved. The enhanced residual signal and estimated linear prediction filter parameters are used to synthesize the output speech. An adaptive algorithm is proposed for adjusting the weights for the periodic and aperiodic components. Effectiveness of the proposed approach is demonstrated via experimental evaluation. It is observed that harmonic structure of the original speech could be properly restored to improve the perceptual quality of enhanced speech.

15.
Int Conf Speech Database Assess ; 2015: 86-89, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28361009

RESUMEN

This paper presents a study on intonation patterns in Cantonese aphasia speech. The speech materials were spontaneous discourse recorded from seven pairs of aphasic and unimpaired speakers. Hidden Markov model based forced alignment was applied to obtain syllable-level time alignments. The pitch level of each syllable was determined and normalized according to the given tone identity of the syllable. Linear regression of the normalized pitch levels was performed to describe the intonation patterns of sentences. It was found that aphasic speech has a higher percentage of sentences with increasing pitch. This trend was found to be more prominent in story-telling than descriptive discourses.

16.
Int J Audiol ; 53(8): 546-57, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24694089

RESUMEN

OBJECTIVES: This study investigates the efficacy of a cochlear implant (CI) processing method that enhances temporal periodicity cues of speech. DESIGN: Subjects participated in word and tone identification tasks. Two processing conditions - the conventional advanced combination encoder (ACE) and tone-enhanced ACE were tested. Test materials were Cantonese disyllabic words recorded from one male and one female speaker. Speech-shaped noise was added to clean speech. The fundamental frequency information for periodicity enhancement was extracted from the clean speech. Electrical stimuli generated from the noisy speech with and without periodicity enhancement were presented via direct stimulation using a Laura 34 research processor. Subjects were asked to identify the presented word. STUDY SAMPLE: Seven post-lingually deafened native Cantonese-speaking CI users. RESULTS: Percent correct word, segmental structure, and tone identification scores were calculated. While word and segmental structure identification accuracy remained similar between the two processing conditions, tone identification in noise was better with tone-enhanced ACE than with conventional ACE. Significant improvement on tone perception was found only for the female voice. CONCLUSIONS: Temporal periodicity cues are important to tone perception in noise. Pitch and tone perception by CI users could be improved when listeners received enhanced temporal periodicity cues.


Asunto(s)
Implantes Cocleares , Percepción del Habla , Adulto , Anciano , China , Femenino , Humanos , Lenguaje , Masculino , Persona de Mediana Edad
17.
Artículo en Inglés | MEDLINE | ID: mdl-24110118

RESUMEN

This paper discusses a single-channel speech enhancement method for cochlear implant listeners. It is assumed that the Fourier Transform coefficients of speech and background noise have different statistical distributions. A statistical-model-based method is adopted to update the signal-to-noise ratio and estimate the background noise so that the musical noise and speech distortion induced by traditional spectral subtraction method can be effectively reduced. This enhancement method was evaluated on seven postlingually deaf Chinese cochlear implant listeners in comparison with other two speech enhancement methods. Test materials were Mandarin sentences corrupted by three different types of background noise. Experimental results showed that the proposed speech enhancement method could benefit the speech intelligibility of Chinese cochlear implant listeners. The results suggest that different noise types may affect the performance of different speech enhancement algorithms.


Asunto(s)
Percepción Auditiva/fisiología , Implantes Cocleares , Percepción del Habla/fisiología , Algoritmos , Pueblo Asiatico , Humanos , Modelos Teóricos , Ruido , Personas con Deficiencia Auditiva , Relación Señal-Ruido , Inteligibilidad del Habla/fisiología
19.
Int J Audiol ; 51(8): 606-10, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22676699

RESUMEN

OBJECTIVE: To establish the reliability and validity of a computerized self-administered hearing test. DESIGN: Cross-sectional within a comparative study of subjects. STUDY SAMPLE: Subjects were 100 Chinese adults who attended the audiology clinic in a hospital for a hearing test. RESULTS: There was no significant difference in the thresholds of unmasked air-conduction hearing obtained with the computerized self-administered hearing test via a smartphone and those obtained with standard pure-tone audiometry. High test-retest reliability was observed with the self-administered hearing test (intraclass correlation coefficient = 0.95), and was comparable with that observed in standard pure-tone audiometry (intraclass correlation coefficient = 0.97). The thresholds of the self-administered hearing test measured in a sound-proof booth were not significantly different from those measured in a quiet office room. CONCLUSIONS: The results suggest that the computerized self-administered hearing test is a reliable and valid measure of unmasked air-conduction hearing thresholds.


Asunto(s)
Audiometría de Tonos Puros , Autoevaluación Diagnóstica , Pérdida Auditiva/diagnóstico , Adolescente , Adulto , Anciano , Umbral Auditivo , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto Joven
20.
Mar Drugs ; 8(6): 1743-9, 2010 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-20631866

RESUMEN

In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1), and four other known metabolites, aplysidiol (2), cupalaurenol (3), 1-methyl-2,3,5-tribromoindole (4), and chamigrane epoxide (5), were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae.


Asunto(s)
Antibacterianos/farmacología , Diterpenos/farmacología , Descubrimiento de Drogas , Hidrocarburos Bromados/farmacología , Laurencia/química , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Borneo , Diterpenos/química , Diterpenos/aislamiento & purificación , Cocos Grampositivos/efectos de los fármacos , Hidrocarburos Bromados/química , Hidrocarburos Bromados/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Océano Pacífico , Salmonella/efectos de los fármacos , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Vibrio cholerae/efectos de los fármacos
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