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INTRODUCTION: The perceptions of medical futility and decisions about termination of resuscitation (TOR) for out-of-hospital cardiac arrest (OHCA) are highly heterogeneous and dependent on the practice of the attending emergency physicians. The objective of this study was to report and investigate the knowledge, attitudes, and practices regarding medical futility and TOR during management of OHCA in Hong Kong. METHODS: A cross-sectional survey was conducted among emergency medicine physicians in Hong Kong. The questionnaire assessed participants' background, knowledge, attitudes, and behaviours concerning medical futility and TOR in management of OHCA. Composite scores were calculated to reflect knowledge, attitudes, and practices of OHCA treatment. Subgroup analysis and multiple regression analysis were used to explore the relationship between participants' background, knowledge, attitudes, and behaviours. RESULTS: The response rate to this survey was 57% (140/247). Independent predictors of less aggressive resuscitation in OHCA patients included status as a Fellow of the Hong Kong College of Emergency Medicine (ß= -0.314, P=0.028) and being an Advanced Cardiac Life Support instructor (ß= -0.217, P=0.032). There was no difference in aggressiveness of resuscitation in terms of years of clinical experience (ß=0.015, P=0.921), knowledge of TOR (ß=0.057, P=0.509), or attitudes about TOR (ß= -0.103, P=0.214). The correlation between knowledge and attitudes was low (Spearman's coefficient=0.02, P=0.795). CONCLUSION: Clinical practice and behaviour of TOR was not demonstrated to have associations with knowledge or attitude. Status as a Fellow of the Hong Kong College of Emergency Medicine or Advanced Cardiac Life Support instructor were the only two parameters identified that had significant relationships with earlier TOR in medically futile patients with OHCA.
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Reanimación Cardiopulmonar , Servicios Médicos de Urgencia , Conocimientos, Actitudes y Práctica en Salud , Inutilidad Médica , Paro Cardíaco Extrahospitalario/terapia , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Médicos , Análisis de Regresión , Encuestas y CuestionariosRESUMEN
INTRODUCTION: There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. METHODS: This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. RESULTS: The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. CONCLUSIONS: Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.
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Antivenenos/farmacología , Coagulación Sanguínea/efectos de los fármacos , Venenos de Crotálidos/antagonistas & inhibidores , Adulto , Pruebas de Coagulación Sanguínea , China , Venenos de Crotálidos/envenenamiento , Voluntarios Sanos , Hong Kong , Humanos , Mordeduras de Serpientes/terapia , Tailandia , Factores de TiempoRESUMEN
OBJECTIVE: The objective was to determine the accuracy of the outcome predictive scores (Modified Early Warning Score [MEWS]; Hypotension, Low Oxygen Saturation, Low Temperature, Abnormal ECG, Loss of Independence [HOTEL] score; and Simple Clinical Score [SCS]) in predicting en-route complications during interfacility transport (IFT) in emergency department. DESIGN: This was a retrospective cohort study. METHODS: All IFT cases by ambulances with either nurse-led or physician-led escort, occurring between 1 January 2011 and 31 December 2012, were included. Obstetric and pediatric cases (age < 18 years) were excluded. The condition of patients was quantified by using the predictive scores (MEWS, HOTEL, and SCS) at triage station and on ambulance departure. The accuracy of predictive scores was compared by the receiver operating characteristic (ROC) curves. RESULTS: A total of 659 cases were included. Seventeen cases had en-route complications (2.6%). The complication rate in physician-escorted transport (2.2%) was similar to that in nurse-escorted transport (2.6%). None of the 57 intubated cases had en-route complications. The area under the ROC curve for MEWS was 0.662 (triage) and 0.479 (departure). The accuracy of MEWS at triage was better than that at departure (P = .049). The area under the ROC curve for HOTEL was 0.613 (triage) and 0.597 (departure), and that for SCS was 0.6 (triage) and 0.568 (departure). In general, the predictive scores at triage were better than those on departure. CONCLUSION: None of the scores had good accuracy in prediction of en-route complications during IFT. MEWS at triage was among the best one already but was not ideal.
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Técnicas de Apoyo para la Decisión , Servicio de Urgencia en Hospital , Transferencia de Pacientes , Índice de Severidad de la Enfermedad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Medición de Riesgo , Triaje , Adulto JovenRESUMEN
Microalgae have been used as energy resources in recent decades to mitigate the global energy crisis. As the demand for pure microalgae strains for commercial use increases, designing an effective photobioreactor (PBR) for mass cultivation is important. Chlorella vulgaris, a local freshwater microalga, was used to study the algal biomass cultivation and lipid production using various PBR configurations (bubbling, air-lift, porous air-lift). The results show that a bubbling column design is a better choice for the cultivation of Chlorella vulgaris than an air-lift one. The highest biomass concentration in the bubbling PBR was 0.78 g/L while the air-lift PBR had a value of 0.09 g/L. Key operating parameters, including draft-tube length and bubbling flowrate, were then optimized based on biomass production and lipid yield. The highest lipid content was in the porous air-lift PBR and the air-lift PBR with shorter draft tube (35 cm) was also better than a longer one (50 cm) for algal cultivation, but the microalgae attachment on the inner tube of PBR always occurred. The highest biomass concentration could be produced under the highest gas flowrate of 2.7 L/min, whereas the lowest dry cell mass was under the lowest gas flowrate of 0.2 L/min.
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Chlorella vulgaris/metabolismo , Fotobiorreactores/microbiología , Biomasa , Metabolismo de los Lípidos , Microalgas/metabolismoRESUMEN
Scenedesmus quadricauda, a local freshwater microalga, was used to treat primary settled and filtrate wastewater and to produce algal lipid. For the primary settled wastewater, the maximum biomass concentrations of acclimated and unacclimated microalgae were 0.995 g/L and 0.940 g/L, respectively. Over 90% orthophosphate and 95% ammonia nitrogen in the acclimated and unacclimated cultures, respectively, were removed after five days. The lipid contents of the microalgae were higher than 13% in all cultures. The highest growth rate occurred in the 25% filtrate culture. Over 80% phosphate was removed under the 25% and 50% filtrate cultures within six days, while over 90% ammonia nitrogen was removed within five days under both conditions. The lipid content was the highest (18.1%) under the 50% filtrate condition. C16:0, C18:2n6, and C18:3n3 were dominant fatty acids. In conclusion, S. quadricauda is a viable candidate for wastewater treatment and lipid production.
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Lípidos/biosíntesis , Scenedesmus/fisiología , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Clorofila/metabolismo , Clorofila A , Concentración de Iones de Hidrógeno , Metabolismo de los Lípidos , Microalgas/fisiología , Nitratos/química , Nitratos/metabolismo , Nitritos/química , Nitritos/metabolismo , Factores de Tiempo , Purificación del AguaRESUMEN
BACKGROUND AND PURPOSE: Both blood pressure (BP) and its variability (BPV) are established risk factors for development of atherosclerotic disease and are associated with an increased risk for cardiovascular and all-cause mortality. The prognostic implications of outpatient clinic visit-to-visit BPV amongst patients with lacunar infarction are nevertheless unknown. METHODS: The clinical outcome of 281 patients with lacunar infarction was prospectively followed up. The average BP and BPV, as determined by the standard deviation of the systolic and diastolic BP, were recorded during a mean 13 ± 6 outpatient clinic visits. RESULTS: The mean age of the population was 70 ± 10 years. After a mean 78 ± 18 months follow-up, 65 patients died (23%), 31% (20/65) due to cardiovascular causes; 14% and 7% developed recurrent stroke and acute coronary syndrome. After adjusting for age, sex, mean systolic and diastolic BP, cardiovascular risk factors and comorbidities, patients with a systolic BPV of the third tertile had significantly higher risk of all-cause mortality [hazard ratio (HR) 1.97, 95% confidence interval (CI) 1.02-3.80, P = 0.04) and cardiovascular mortality (HR 7.64, 95% CI 1.65-35.41, P < 0.01) than those with systolic BPV of the first tertile. Nevertheless, systolic BPV did not predict recurrent stroke or acute coronary syndrome. Diastolic BPV did not predict various adverse clinical outcomes. CONCLUSIONS: Visit-to-visit systolic BPV predicts long-term all-cause and cardiovascular mortality after lacunar infarct, independent of conventional risk factors including average BP control.
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Presión Sanguínea/fisiología , Enfermedades Cardiovasculares/mortalidad , Accidente Vascular Cerebral Lacunar/mortalidad , Anciano , Anciano de 80 o más Años , Determinación de la Presión Sanguínea , Enfermedades Cardiovasculares/fisiopatología , Causas de Muerte , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Accidente Vascular Cerebral Lacunar/fisiopatologíaRESUMEN
UNLABELLED: Treatment of vitamin D deficiency for 3 months with oral cholecalciferol 5,000 IU daily was more effective than 2,000 IU daily in achieving optimal serum 25-hydroxyvitamin D (25OHD) concentrations. Optimal 25OHD serum level calculated to be 63.8 nmol/L. All parameters of muscle strength improved following administration of cholecalciferol for 3 months. INTRODUCTION: The aim of this study was to determine the optimal dose of cholecalciferol required to achieve target serum 25OHD level ≥ 75 nmol/L and its relationship to both bone turnover and muscle strength. METHODS: Thirty deficient patients (serum 25OHD ≤ 50 nmol/L) were randomly assigned into two groups-i.e. 2,000 and 5,000 IU/day. Data were collected at baseline, at 2 and 3 months post-therapy: (a) clinical demographics, (b) dietary calcium recall, (c) physical tests of muscle function and (d) biochemistry. Statistical analysis used paired student t test and analysis of variance. Regression analysis was used to determine relationship between serum 25OHD and parathyroid hormone (PTH). RESULTS: Twenty-six (87%) patients completed 3 months of therapy. The percent increase in serum 25OHD (compared to baseline) was 82.7% in 2,000-IU group and 219.5% in 5,000-IU group. All participants (100%) achieved a serum 25OHD concentration >50 nmol/L; only 5 subjects (45.4%) in 2,000-IU group compared to 14 subjects (93.3%) in 5,000-IU group achieved final 25OHD concentration ≥ 75 nmol/L (p < 0.01). In the regression analysis, the reflexion point at which the PTH level increased above the normal range was calculated to be 63.8 nmol/L 25OHD. All parameters of muscle strength showed trends in improvements following the administration of both the 2,000 and 5,000 IU doses. No patient reported untoward side effects and no patient developed hypercalcaemia. CONCLUSION: Treatment for 3 months with oral cholecalciferol 5,000 IU daily may be more effective than 2,000 IU daily in achieving optimal serum 25OHD concentrations in vitamin D-deficient patients.
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Conservadores de la Densidad Ósea/administración & dosificación , Remodelación Ósea/efectos de los fármacos , Colecalciferol/administración & dosificación , Fuerza Muscular/efectos de los fármacos , Deficiencia de Vitamina D/tratamiento farmacológico , Administración Oral , Adulto , Conservadores de la Densidad Ósea/uso terapéutico , Colecalciferol/uso terapéutico , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiopatología , Hormona Paratiroidea/sangre , Resultado del Tratamiento , Vitamina D/análogos & derivados , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/fisiopatologíaRESUMEN
We investigate the chaotic phase synchronization in a system of coupled bursting neurons in small-world networks. A transition to mutual phase synchronization takes place on the bursting time scale of coupled oscillators, while on the spiking time scale, they behave asynchronously. It is shown that phase synchronization is largely facilitated by a large fraction of shortcuts, but saturates when it exceeds a critical value. We also study the external chaotic phase synchronization of bursting oscillators in the small-world network by a periodic driving signal applied to a single neuron. It is demonstrated that there exists an optimal small-world topology, resulting in the largest peak value of frequency locking interval in the parameter plane, where bursting synchronization is maintained, even with the external driving. The width of this interval increases with the driving amplitude, but decrease rapidly with the network size. We infer that the externally applied driving parameters outside the frequency locking region can effectively suppress pathologically synchronized rhythms of bursting neurons in the brain.
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Potenciales de Acción/fisiología , Sincronización de Fase en Electroencefalografía , Red Nerviosa/fisiología , Neuronas/fisiología , Dinámicas no Lineales , Factores de TiempoRESUMEN
OBJECTIVE: To evaluate psychometric properties of the Chinese version of Dementia Quality of Life Measure - Proxy (C-DEMQoL-Proxy). METHODS: Care home residents aged ≥60 years who were diagnosed with dementia or demonstrated impairment in cognition were recruited from four care facilities in Hong Kong. Caregivers of these participants were also invited to participate. The original DEMQoL-Proxy was translated into Chinese (Cantonese) by a trained translator. The forward-translated version was reviewed by an expert panel of six experienced healthcare professionals. Revisions were made based on comments. The instrument was back-translated to English to check whether further changes were necessary. Demographic data (age, sex, type and severity of dementia, and Mini-Mental State Examination [MMSE] score) were collected from medical records of participants with dementia. Caregivers were interviewed by an occupational therapist or personnel supervised by the occupational therapist using the C-DEMQoL-Proxy and the Chinese version of Quality of Life-Alzheimer's Disease-Proxy (C-QoL-AD-Proxy). Acceptability, reliability, and validity of the C-DEMQoL-Proxy were evaluated using standard psychometric methods. RESULTS: 90 individuals (82.2% women) with dementia aged 72 to 102 years were included. Their diagnosis included Alzheimer's disease (23.3%), vascular dementia (15.6%), mixed and other types of dementias (51.1%), and missing (10%). Severity was mild in 12.2%, moderate in 62.2%, and severe in 25.6%. The mean MMSE score was 12.0 ± 4.9. 20% of the caregivers were family members and the rest were professional carers. The C-DEMQoL-Proxy had good acceptability, with no floor or ceiling effects or missing data. It had good internal consistency (Cronbach alpha = 0.91) and test-retest reliability (intraclass correlation coefficients = 0.83). It was mildly correlated with C-QoL-AD-Proxy (r = 0.29, p < 0.01). Age and sex were not correlated with C-DEMQoL-Proxy scores. C-DEMQoL-Proxy scores were not significantly different between dementia types, severity levels, or between those with higher or lower MMSE scores. CONCLUSION: The C-DEMQoL-Proxy is a valid and reliable instrument to assess health-related quality of life in individuals with dementia.
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Demencia , Calidad de Vida , Encuestas y Cuestionarios , Anciano , Anciano de 80 o más Años , Femenino , Hong Kong , Humanos , Masculino , Apoderado , Psicometría , Reproducibilidad de los Resultados , Instituciones Residenciales , TraduccionesRESUMEN
Sagittal split ramus osteotomy (SSRO) of the mandible is one of the most common surgical techniques to correct mandibular deformities. Measurement of nerve position using conventional methods has been reported in the literature, but surgeons have found that further investigation of the anatomical relationship is needed. The aim of this study was to attempt to increase the accuracy of treatment by using 3-dimensional computed tomography scan measurements. From the normal population, 20 females and 20 males were enrolled during planning of denture implants in Taiwan. The mean age was 28+/-6, ranging from 20 to 39 years old. Using 3D tomography data, nerve position at osteotomy sites was measured and the geometric relationship examined between the antilingula and mandibular foramen. The results gave the mean distance from buccal plate to mandibular canal at the second molar, from mandibular canal to inferior border of the mandibular body, from the mandibular foramen to the highest tip of the lingula, and from the mandibular foramen to the anterior margin of the oblique ridge. When applied to SSRO operations, the anatomic data provided by this study may help surgeons gain more understanding of nerve position during surgery.
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Imagenología Tridimensional/métodos , Mandíbula/anatomía & histología , Osteotomía/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Proceso Alveolar/anatomía & histología , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/inervación , Cefalometría/métodos , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Arco Dental/inervación , Implantes Dentales , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Mandíbula/inervación , Mandíbula/cirugía , Nervio Mandibular/anatomía & histología , Nervio Mandibular/diagnóstico por imagen , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Diente Molar/inervación , Planificación de Atención al PacienteRESUMEN
Adaptive fuzzy control is proposed for a class of affine nonlinear systems in strict-feedback form with unknown nonlinearities. The unknown nonlinearities include two types of nonlinear functions: one satisfies the "triangularity condition" and can be directly approximated by fuzzy logic system, while the other is assumed to be partially known and consists of parametric uncertainties. Takagi-Sugeno type fuzzy approximators are used to approximate unknown system nonlinearities and the design procedure is a combination of adaptive backstepping and generalized small gain design techniques. It is proved that the proposed adaptive control scheme can guarantee the uniformly ultimately bounded (UBB) stability of the closed-loop systems. Simulation studies are shown to illustrate the effectiveness of the proposed approach.
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Algoritmos , Retroalimentación , Lógica Difusa , Modelos Estadísticos , Dinámicas no Lineales , Simulación por ComputadorRESUMEN
The aim of this study was to investigate potential biomarkers in human saliva and plasma to aid in the early diagnosis of oral squamous cell carcinoma (OSCC). Saliva and plasma samples obtained from OSCC patients (n=41) and non-oral cancer patients (n=24) were analyzed by Luminex Bead-based Multiplex Assay. Data were analyzed using the non-parametric Mann-Whitney U-test, Kruskal-Wallis test, and receiver operating characteristics curve (ROC) to evaluate the predictive power of 14 biomarkers individually for OSCC diagnosis. The plasma level of IP-10 in early OSCC differed significantly from that in controls. Among the salivary biomarkers, IL-1ß, IL-6, IL-8, MIP-1ß, eotaxin and IFN-γ and TNF-α showed significant differences between OSCC patients and controls. With respect to carcinogenesis, significant differences in plasma levels of eotaxin, G-CSF, and IL-6 were found between OSCC stages III/IV and OSCC stages I/II. The area under the curve (AUC) for OSCC vs. control was greater than 0.7 for plasma IP-10 and saliva IL-1ß, IL-6, IL-8, and TNF-α. The study findings indicate that salivary biomarkers may serve a useful role as a complementary adjunct for the early detection of oral OSCC. With regard to the evaluation of tumour progression, plasma eotaxin, G-CSF, and IL-6 may help in the detection of advanced OSCC. However, the correlation between saliva and plasma biomarkers in OSCC was weak.
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Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/metabolismo , Citocinas/metabolismo , Neoplasias de la Boca/metabolismo , Saliva/química , Adulto , Anciano , Biomarcadores de Tumor/sangre , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/patología , Citocinas/sangre , Progresión de la Enfermedad , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/sangre , Neoplasias de la Boca/patología , Estadificación de Neoplasias , Factores de RiesgoRESUMEN
Chlorella vulgaris was cultivated under limitation and starvation and under controlled conditions using different concentrations of nitrate (NaNO3) and phosphate (K2HPO4 and KH2PO4) chemicals in modified Bold basal medium (BBM). The biomass and lipid production responses to different media were examined in terms of optical density, cell density, dry biomass, and lipid productivity. In the 12-day batch culture period, the highest biomass productivity obtained was 72.083 mg L-1 day-1 under BBM - NcontrolPlimited condition. The highest lipid content, lipid concentration, and lipid productivity obtained were 53.202 %, 287.291 mg/L, and 23.449 mg L-1 day-1 under BBM - NControlPDeprivation condition, respectively. Nitrogen had a major effect in the biomass concentration of C. vulgaris, while no significant effect was found for phosphorus. Nitrogen and phosphorus starvation was found to be the strategy affecting the lipid accumulation and affected the lipid composition of C. vulgaris cultures.
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Biocombustibles , Chlorella vulgaris , Biomasa , Chlorella , Agua Dulce , Lípidos/química , MicroalgasRESUMEN
Identifying the cellular binding targets of drugs and other bioactive small molecules is a crucial step for understanding their molecular mechanisms of action as well as potential off-target effects. The field of chemical proteomics is an emerging discipline in chemical biology using synthetic chemistry and high-throughput detection techniques to study small molecule-protein interactions. In this chapter, we describe a quantitative chemical proteomics protocol combining bioorthogonal click chemistry and quantitation by isobaric tags for relative and absolute quantification (iTRAQ) to identify the specific binding targets of drugs and bioactive small molecules such as natural products. A modified drug probe with a click chemistry-enabling addition is synthesized and used in live cell treatments where it undergoes covalent interactions with its cognate cellular targets. The probes are then ligated to biotin through click chemistry and enriched with avidin beads, followed by iTRAQ labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for protein identification and relative quantitation discriminating specific targets from nonspecific binding proteins. The presented protocol has been used to successfully profile prominent drugs and natural products including andrographolide, aspirin, curcumin, etc., and can be a powerful tool to study the molecular mechanisms of bioactive small molecules.
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Alquinos/química , Diterpenos/química , Proteoma/aislamiento & purificación , Cromatografía Liquida , Química Clic , Células HCT116 , Humanos , Unión Proteica , Proteoma/química , Proteómica , Coloración y Etiquetado , Espectrometría de Masas en TándemRESUMEN
The up-to-date concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment materials of Victoria Harbour was investigated so as to evaluate the pollution potential associated with the reclamation projects in Hong Kong. A total of 100 sediment samples were collected at 20 locations. Except the control point in reservoir, the PAHs concentrations were detectable levels all sites (131-628.3ng/g, dw) and such values were higher than Dutch Target and Intervention Values (the New Dutch standard in 2016). The PAHs concentration indicating that construction waste and wastewater discharges were the main pollutant sources. Results of correlation in single cell gel electrophoresis assay (comet assay) studies also revealed that the PAHs concentration was highly correlated (<0.01) with DNA migration (i.e. the length of tail moment of fish cells) in 5mg/ml of PAHs. The above observation indicates that the PAHs present in the sediment may substantially effect the marine ecosystem. Although the dredged sediment can be a useful sea-filling material for land reclamation; however, the continuing leaching of PAHs and its impact on the aquatic environment need to be studied further.
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Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Disponibilidad Biológica , Ensayo Cometa , Industria de la Construcción , Daño del ADN , Peces/genética , Sedimentos Geológicos/análisis , Hong Kong , Hidrocarburos Policíclicos Aromáticos/toxicidad , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidadRESUMEN
This article explores the potential of using an electro-coagulation-flotation (ECF) harvester to allow flotation of microalgae cells for surface harvesting. A response surface methodology (RSM) model was used to optimize ECF harvesting by adjusting electrode plate material, electrode plate number, charge of the electrodes, electrolyte concentration, and pH value of the culture solution. The result revealed that three aluminum electrode plates (one anode and two cathodes), brine solution (8 g/L), and acidity (pH = 4) of culture solution (optimized ECF harvester) The highest flocculant concentration was measured at 2966 mg/L after 60 min and showed a 79.8 % increase of flocculation concentration. Such results can provide a basis for designing a large-scale microalgae harvester for commercial use in the future.
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Chlorella vulgaris , Microalgas , Aluminio , Chlorella , FloculaciónRESUMEN
The objective of this study is to evaluate the current status of heavy metal concentrations in constructed wetland, Shaoguan (Guangdong, China). Sediments, three wetland plants (Typha latifolia, Phragmites australis, and Cyperus malaccensis), and six freshwater fish species [Carassius auratus (Goldfish), Cirrhinus molitorella (Mud carp), Ctenopharyngodon idellus (Grass carp), Cyprinus carpio (Wild common carp), Nicholsicypris normalis (Mandarin fish), Sarcocheilichthys kiangsiensis (Minnows)] in a constructed wetland in Shaoguan were collected and analyzed for their heavy metal compositions. Levels of Pb, Zn, Cu, and Cd in sediments exceeded approximately 532, 285, 11, and 66 times of the Dutch Intervention value. From the current study, the concentrations of Pb and Zn in three plants were generally high, especially in root tissues. For fish, concentrations of all studied metals in whole body of N. mormalis were the highest among all the fishes investigated (Pb 113.4 mg/kg, dw; Zn 183.1 mg/kg, dw; Cu 19.41 mg/kg, dw; 0.846 mg/kg, dw). Heavy metal accumulation in different ecological compartments was analyzed by principle component analysis (PCA), and there is one majority of grouped heavy metals concentration as similar in composition of ecological compartment, with the Cd concentration quite dissimilar. In relation to future prospect, phytoremediation technology for enhanced heavy metal accumulation by constructed wetland is still in early stage and needs more attention in gene manipulation area.
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Humedales , Zinc , Animales , Carpas , China , Monitoreo del Ambiente , Plomo , Metales Pesados , Contaminantes Químicos del AguaRESUMEN
The overall goal of our research is to develop effective new photosensitizers for tumor-selective photodynamic therapy. Phenoxazine dyes, including several Nile blue analogues, are known to localize selectively in animal tumors. Structural modifications yielded several series of analogues with substantially higher 1O2 yields and different photochemical and physicochemical properties. This study examined the photosensitization potency, cellular uptake, and retention of these derivatives in human bladder carcinoma cells (MGH-U1) in culture. Nile blue derivatives containing halogens and/or sulfur substitutes were selected to exhibit different 1O2 yields, pKa values, and hydrophobicities. The effectiveness of these derivatives in mediating photokilling of tumor cells in vitro corresponded well with the 1O2 yields of these compounds, indicating that structural modifications which resulted in increased 1O2 yields enhanced potency in mediating photocytotoxicity in vitro. Using derivatives (sat-NBS and sat-NBS-61) with the highest 1O2 quantum yield (0.35 and 0.821), over 90% cell kill was achieved at a sensitizer concentration of 5 x 10(-8) M, about 3 orders of magnitude more effective than hematoporphyrin derivative, the only sensitizer currently available clinically. This result suggests that some of the oxazine derivatives could potentially be effective photosensitizers. The correspondence between 1O2 yield and photosensitizing potency, together with results showing enhanced photocytotoxicity in the presence of D2O and reduced photocytotoxicity under hypoxic conditions, strongly suggests that the generation of 1O2 is a major mechanism mediating the photocytotoxic effect. The uptake of Nile blue derivatives by cells in culture exhibited a pattern of rapid initial uptake followed by a gradual increase in cellular dye contents. The uptake does not correlate directly with the individual pKa values or hydrophobicities of the derivatives, indicating that the structural modifications that increased 1O2 yields did not significantly alter the uptake and retention of Nile blue derivatives. The highly concentrative uptake by and slow efflux from dye-loaded cells were consistent with an active mechanism for the cellular accumulation of these dyes. On the other hand, the retention of the compounds was directly proportional to dye concentration in the medium over a 1000-fold range of concentrations, and the uptake could proceed at temperatures below 2 degrees C; these observations excluded endocytosis or a carrier-mediated mechanism for the uptake. The uptake was also unaffected by the presence of serum in the medium. Based on these results, we hypothesize that Nile blue derivatives transport across the cell membrane possibly as deprotonated forms and, upon entering the cell, either partition into lipophilic areas of the cell membranes and/or become sequestered in certain intracellular organelles.
Asunto(s)
Oxazinas/farmacocinética , Fotoquimioterapia , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Hipoxia de la Célula , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Fenómenos Químicos , Química , Deuterio/farmacología , Óxido de Deuterio , Relación Dosis-Respuesta a Droga , Humanos , Técnicas In Vitro , Oxazinas/farmacología , Oxazinas/toxicidad , Oxígeno/metabolismo , Temperatura , Agua/farmacologíaRESUMEN
OBJECTIVE: To determine whether current vascular Chlamydia pneumoniae (CPn) infection as diagnosed by circulating CPn DNA is more common in subjects with coronary artery disease (CAD). BACKGROUND: Serological, pathological and animal studies have associated CPn with CAD and preliminary trials suggest antibiotics may prevent adverse coronary events. C. pneumoniae is thought to disseminate systemically within macrophages. We therefore detected CPn DNA in blood to determine whether its presence was a predictor of CAD. METHODS: One thousand, two hundred and five subjects attending for diagnostic and interventional coronary arteriography were recruited. The mononuclear cell layer and platelets were separated from collected blood and the polymerase chain reaction (PCR) was used to detect CPn DNA. RESULTS: Circulating CPn DNA was found in 8.8% of 669 men with CAD compared with 2.9% of 135 men with normal coronary arteries (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.1-8.9). In men with CAD, those with CPn DNA had higher mean platelet counts than those without CPn DNA. Monocyte counts and indirect fibrinogen levels were also raised but not significantly so. By contrast, no association of circulating CPn DNA and CAD was seen in women. CONCLUSIONS: Circulating CPn DNA is a predictor of CAD in men. Unlike serology, it is a specific indicator of current infection and is a means of identifying subjects who may potentially benefit from antichlamydial therapy.
Asunto(s)
Infecciones por Chlamydia/complicaciones , Chlamydophila pneumoniae/aislamiento & purificación , Enfermedad Coronaria/microbiología , ADN Bacteriano/sangre , Monocitos/microbiología , Anciano , Chlamydophila pneumoniae/genética , Enfermedad Crónica , Angiografía Coronaria , Enfermedad Coronaria/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Factores SexualesRESUMEN
We explored the feasibility and efficacy of an exercise programme for elderly people with knee pain conducted via videoconferencing. Twenty-two community-dwelling subjects aged 60 years or above with knee pain were recruited from two community centres in Hong Kong. A 12-week exercise programme, including strengthening and balance training, was given via videoconferencing to subjects at both centres, in conjunction with a home-based exercise programme. The outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quadriceps muscle strength, Berg's Balance Scale (BBS) and subjects' degree of acceptance of videoconferencing. Twenty subjects completed the 12-week programme and significant improvements occurred in all domains of the WOMAC score (P <0.003). There was a 44% and a 13% increase in quadriceps muscle strength (P <0.001) and BBS (P <0.001), respectively. Over 80% of the elderly subjects who joined the programme agreed or strongly agreed about all aspects of using videoconferencing. Most of them felt that the system was user-friendly and convenient. Videoconferencing appears to be a useful method of delivering a resistance-training programme for community-dwelling elderly persons with knee pain.