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1.
Environ Sci Technol ; 54(14): 9116-9123, 2020 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-32584558

RESUMEN

Electrochemical processes such as capacitive deionization have shown great promise for salt removal and nutrient recovery, but their effectiveness on phosphate removal was lower than other charged ions. This study hypothesized that the speciation and transport behaviors of phosphate ions are highly influenced by electrolyte pH, and it used experimental and modeling approaches to elucidate such impacts in flow-electrode capacitive deionization (FCDI) cells. Phosphate removal was investigated in either constant current (CC) or constant voltage (CV) charging mode with pH ranged from 5 to 9 in the feed solution. Results showed that the average P removal rate increased from 20.8 (CC mode) and 16.8 mg/min (CV mode) at pH 9 to 38.3 (CC mode) and 34.3 mg/min (CV mode) at pH 5 (84-104% in improvement), respectively. Correspondingly, the energy consumption reduced from 1.04 kWh/kg P at pH 9 to 0.59 kWh/kg P at pH 5 (42.9-56.1% in saving). Such benefits were attributed to the shift in dominant P-species from HPO42- to H2PO4-. Conversely, high-electrolyte pH (pH = 11) for flow-electrode led to ∼74.8% higher phosphate recovery during discharge compared with pH 5, which was associated with the higher distribution of phosphate ions in the electrolyte versus on the flow-electrodes due to surface charge change. These results improved our understanding in ion distribution and migration and indicate that solution pH is critical for operating FCDI reactors. It shed lights on the best practices on electrochemical phosphate removal and recovery.


Asunto(s)
Fósforo , Purificación del Agua , Electrodos , Concentración de Iones de Hidrógeno , Cloruro de Sodio
2.
Small ; 12(30): 4103-12, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27294601

RESUMEN

Novel antitumor system based on the targeting photothermal and pH-responsive nanocarriers, gold nanoshells coated oleanolic acid liposomes mediating by chitosan (GNOLs), is designed and synthesized for the first time. The GNOLs present spherical and uniform size (172.03 nm) with zeta potential (20.7 ± 0.4 mV), which are more easily accumulated in tumor. Meanwhile, the GNOLs exhibit a slow and controlled release of oleanolic acid at pH 7.4, as well as a rapid release at pH 5.5, which is beneficial for tumor-targeting drug release. Under near infrared (NIR) irradiation, hyperthermia can be generated by activated gold nanoshells to perform photothermal therapy effect, which triggers drug release from the carriers by activating the gel to liquid crystalline phase transition of the liposomes. Moreover, the NIR assisting drug release can be easily and selectively activated locally due to the spatially and real-timely controllable property of light. The experimental results also verify that the GNOLs with NIR irradiation achieve more ideal antitumor effects than other oleanolic acid formulations in vitro and in vivo. Hence, the drug delivery system exhibits a great potential in chemo-photothermal antitumor therapy.


Asunto(s)
Antineoplásicos/química , Quitosano/química , Oro/química , Hipertermia Inducida/métodos , Liposomas/química , Nanocáscaras/análisis , Ácido Oleanólico/química , Animales , Antineoplásicos/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Concentración de Iones de Hidrógeno , Ratones , Ácido Oleanólico/uso terapéutico , Espectroscopía Infrarroja por Transformada de Fourier
3.
Small ; 12(30): 4102, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27492497

RESUMEN

Gold nanoshell coated oleanolic acid liposomes mediating by chitosan (GNOLs), are designed and successfully synthesized for the first time by D. Gao and co-workers on page number 4103. An excellent near infrared (NIR) photothermal effect, pH-responsive drug controlled release and tumor targeting properties are demonstrated. By combining NIR photothermal therapy and chemotherapy, the smart drug delivery system exhibits a superior antitumor property in vitro and in vivo.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Oro/química , Hipertermia Inducida/métodos , Liposomas/química , Nanocáscaras/química , Fototerapia/métodos , Animales , Línea Celular Tumoral , Terapia Combinada/métodos , Doxorrubicina/administración & dosificación , Humanos
4.
Int J Mol Sci ; 17(9)2016 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-27563887

RESUMEN

In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC) sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD) and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI) is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR) is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity.


Asunto(s)
Fuentes de Energía Bioeléctrica , Técnicas Biosensibles/métodos , Monitoreo del Ambiente/métodos , Análisis de la Demanda Biológica de Oxígeno , Aguas Residuales/análisis
5.
Water Res ; 241: 120139, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37270949

RESUMEN

Microbial electrolysis cells (MECs) have demonstrated high-rate H2 production while concurrently treating wastewater, but the transition in scale from laboratory research to systems that can be practically applied has encountered challenges. It has been more than a decade since the first pilot-scale MEC was reported, and in recent years, many attempts have been made to overcome the barriers and move the technology to the market. This study provided a detailed analysis of MEC scale-up efforts and summarized the key factors that should be considered to further develop the technology. We compared the major scale-up configurations and systematically evaluated their performance from both technical and economic perspectives. We characterized how system scale-up impacts the key performance metrics such as volumetric current density and H2 production rate, and we proposed methods to evaluate and optimize system design and fabrication. In addition, preliminary techno-economic analysis indicates that MECs can be profitable in many different market scenarios with or without subsidies. We also provide perspectives on future development needed to transition MEC technology to the marketplace.


Asunto(s)
Fuentes de Energía Bioeléctrica , Aguas Residuales , Hidrógeno , Electrólisis , Tecnología
6.
ACS Environ Au ; 2(1): 20-29, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-37101761

RESUMEN

Cathode materials are critical for microbial electrolysis cell (MEC) development and its contribution to achieving a circular hydrogen economy. There are numerous reports on the progress in MEC cathode development during the past decade, but a comprehensive review on the quantitative comparisons and critical assessments of these works is lacking. This Review summarizes and analyzes the published literature on MEC cathode and catalyst development in the past decade, providing an overview of new materials examined during this time period and quantitative analyses on system performance and trends in materials development. Collected data indicate that hybrid materials have become the most popular catalyst candidate while nickel materials also attract increasing interest and exploration. However, the dilemma between higher H2 production rate and larger MEC volume remains and still requires more investigation of novel MEC cathode catalysts and configurations to offer a solution.

7.
Clin Imaging ; 79: 289-295, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34198113

RESUMEN

PURPOSE: Claustrophobia remains a challenging barrier for a significant number of patients to successfully complete a Magnetic Resonance Imaging (MRI) examination. While use of wide-bore machines and pre-exam administration of a low-dose benzodiazepine are commonly employed, there is little published research to determine which modality is the most efficacious based on the patient's specific degree of claustrophobia. This retrospective case-control study examines the efficacy of using a low-dose oral benzodiazepine and wide-bore magnet to successfully aid the claustrophobic patient in completing an MRI Brain examination. METHODS: 3966 non-contrast MRI brain examinations were considered for this study. The sample was filtered to include only patients who were older than 18 years of age, not currently experiencing symptoms which may hinder MRI examination, and did not undergo any additional MR studies at the time of their exam, resulting in a final sample of 2358 examinations for analysis. Patients were then sub-divided based on severity of claustrophobia and analyzed using logistic regression analysis. RESULTS: Use of wide-bore magnet increased odds of successfully completing the MRI Brain examination in mild, moderately, and severely claustrophobic patients (OR: 1.79, 95% CI: 1.17-2.75). The administration of pre-examination low-dose oral benzodiazepine increased odds of successfully completing the MRI Brain examination in severely claustrophobic patients (OR: 6.21, 95% CI: 1.63-19.28). CONCLUSION: Use of a wide-bore magnet is effective in assisting mild, moderately, and severely claustrophobic patients in completing an MRI Brain exam. However, the efficacy of low-dose oral benzodiazepine is limited to severely claustrophobic patients.


Asunto(s)
Benzodiazepinas , Imanes , Encéfalo/diagnóstico por imagen , Estudios de Casos y Controles , Humanos , Imagen por Resonancia Magnética , Estudios Retrospectivos
8.
Water Res ; 164: 114942, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31401327

RESUMEN

Limited understanding of wastewater streams produced from shale oil and gas wells impedes best practices of wastewater treatment and reuse. This study provides a comprehensive and comparative analysis of flowback and produced water from three major and newly developed shale plays (the Bakken shale, North Dakota; the Barnett shale, Texas; and the Denver-Julesburg (DJ) basin, Colorado) in central and western United States. Geochemical features that included more than 10 water quality parameters, dissolved organic matter, as well as microbial community structures were characterized and compared. Results showed that wastewater from Bakken and Barnett shales has extremely high salinity (∼295 g/L total dissolved solids (TDS)) and low organic concentration (80-252 mg/L dissolved organic carbon (DOC)). In contrast, DJ basin showed an opposite trend with low TDS (∼30 g/L) and high organic content (644 mg/L DOC). Excitation-emission matrix (EEM) fluorescence spectra demonstrated that more humic acid and fluvic acid-like organics with higher aromaticity existed in Bakken wastewater than that in Barnett and DJ basin. Microbial communities of Bakken samples were dominated by Fe (III)-reducing bacteria Geobacter, lactic acid bacteria Lactococcus and Enterococcus, and Bradyrhizobium, while DJ basin water showed higher abundance of Rhodococcus, Thermovirga, and sulfate reducing bacteria Thermotoga and Petrotoga. All these bacteria are capable of hydrocarbon degradation. Hydrogenotrophic methanogens dominated the archaeal communities in all samples.


Asunto(s)
Contaminantes Químicos del Agua , Agua , Colorado , Gas Natural , Yacimiento de Petróleo y Gas , Texas , Estados Unidos , Aguas Residuales
9.
J Nat Prod ; 71(7): 1254-7, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18557641

RESUMEN

Four new iridoids, valeriotetrates B and C (1 and 2), 8-methylvalepotriate (3), and 1,5-dihydroxy-3,8-epoxyvalechlorine A (4), together with three known iridoids, were isolated from the roots of Valeriana wallichii. The structures of the new compounds were elucidated by analysis of 1D and 2D NMR and HRESIMS data. Compound 4 is an unusual iridoid bearing a C-10 chloro group and an oxo bridge connecting C-3 and C-8, resulting in a rigid skeleton.


Asunto(s)
Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Iridoides/química , Iridoides/aislamiento & purificación , Plantas Medicinales/química , Valeriana/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Raíces de Plantas/química
10.
Psychometrika ; 83(2): 355-375, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29150816

RESUMEN

The focus of cognitive diagnosis (CD) is on evaluating an examinee's strengths and weaknesses in terms of cognitive skills learned and skills that need study. Current methods for fitting CD models (CDMs) work well for large-scale assessments, where the data of hundreds or thousands of examinees are available. However, the development of CD-based assessment tools that can be used in small-scale test settings, say, for monitoring the instruction and learning process at the classroom level has not kept up with the rapid pace at which research and development proceeded for large-scale assessments. The main reason is that the sample sizes of the small-scale test settings are simply too small to guarantee the reliable estimation of item parameters and examinees' proficiency class membership. In this article, a general nonparametric classification (GNPC) method that allows for assigning examinees to the correct proficiency classes with a high rate when sample sizes are at the classroom level is proposed as an extension of the nonparametric classification (NPC) method (Chiu and Douglas in J Classif 30:225-250, 2013). The proposed method remedies the shortcomings of the NPC method and can accommodate any CDM. The theoretical justification and the empirical studies are presented based on the saturated general CDMs, supporting the legitimacy of using the GNPC method with any CDM. The results from the simulation studies and real data analysis show that the GNPC method outperforms the general CDMs when samples are small.


Asunto(s)
Cognición , Evaluación Educacional/métodos , Psicometría/métodos , Simulación por Computador , Humanos , Aprendizaje , Conceptos Matemáticos , Análisis Multivariante , Pruebas Psicológicas , Programas Informáticos , Estadísticas no Paramétricas
11.
Zhong Yao Cai ; 30(11): 1452-5, 2007 Nov.
Artículo en Zh | MEDLINE | ID: mdl-18323220

RESUMEN

OBJECTIVE: To study the preparation of alpha-Hydrocycholic-beta-Cyclodextrin inclusion compound. METHODS: It was studied with orthogonal design to analysis three factors of inclusion rate such as the weight ratio between HDCA and beta-Cyclodextrin, the temperature and the reaction time. Fourier transform infrared spectroscopy, scanning electron microscopy, taste and solubility test were used to identify the inclusion compound. RESULTS: Stable inclusion compound was made by HDCA and beta-Cyclodextrin. The weight ratio between HDCA and beta-Cyclodextrin was the most important factor. The alpha-Hydrocycholic-beta-Cyclodextrin inclusion compound taste and the solubility were improved. CONCLUSION: The optimum preparation condition is alpha-Hydrocycholic : beta-Cyclodextrin = 8.67 : 1, the inclusion temperature is 60 degrees C and the inclusion time is 30 minutes.


Asunto(s)
Ácido Desoxicólico/química , Medicamentos Herbarios Chinos/química , Tecnología Farmacéutica/métodos , beta-Ciclodextrinas/química , Análisis de Varianza , Portadores de Fármacos , Composición de Medicamentos/métodos , Medicamentos Herbarios Chinos/análisis , Plantas Medicinales/química , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo
12.
Arch Pharm Res ; 39(2): 221-230, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25066072

RESUMEN

Gynostemma pentaphyllum (GP) is a natural plant resources for diabetes therapy, however, there is little research on the mechanisms of GP. The present study was undertaken to characterize if G. pentaphyllum saponins (GPs) is the principal active compound of GP responsible for anti-diabetes, and to examine the relativity between blood glucose modulate and antioxidation. The GPs-treated streptozotocin diabetic rats had a more effective hypoglycemic status than those of diabetic control rats, which also ameliorate dyslipidemia. GPs has increased SOD and GSH-px activities, and the spleen and thymus indexes in diabetic rats. The insulin levels in the GPs-treated groups were significantly higher than diabetic control group. Our finding provides a new insight into the application of GPs for the treatment of oxidative stress related diseases.


Asunto(s)
Glucemia/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Gynostemma/química , Hipoglucemiantes/farmacología , Factor 2 Relacionado con NF-E2/metabolismo , Extractos Vegetales/farmacología , Saponinas/farmacología , Transducción de Señal/efectos de los fármacos , Animales , Antioxidantes/aislamiento & purificación , Antioxidantes/farmacología , Biomarcadores/sangre , Glucemia/metabolismo , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/diagnóstico , Glutatión Peroxidasa/metabolismo , Hipoglucemiantes/aislamiento & purificación , Insulina/sangre , Riñón/efectos de los fármacos , Riñón/metabolismo , Lípidos/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Malondialdehído/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fitoterapia , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales , Ratas Wistar , Saponinas/aislamiento & purificación , Superóxido Dismutasa/metabolismo
13.
Biosens Bioelectron ; 81: 32-38, 2016 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-26918615

RESUMEN

A novel anode was developed by coating reduced graphene oxide (rGO) and manganese oxide (MnO2) composite on the carbon felt (CF) surface. With a large surface area and excellent electrical conductivity, this binder-free anode was found to effectively enhance the enrichment and growth of electrochemically active bacteria and facilitate the extracellular electron transfer from the bacteria to the anode. A microbial fuel cell (MFC) equipped with the rGO/MnO2/CF anode delivered a maximum power density of 2065mWm(-2), 154% higher than that with a bare CF anode. The internal resistance of the MFC with this novel anode was 79Ω, 66% lower than the regular one's (234Ω). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses affirmed that the rGO/MnO2 composite significantly increased the anodic reaction rates and facilitated the electron transfer from the bacteria to the anode. The findings from this study suggest that the rGO/MnO2/CF anode, fabricated via a simple dip-coating and electro-deposition process, could be a promising anode material for high-performance MFC applications.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Carbono/química , Grafito/química , Compuestos de Manganeso/química , Óxidos/química , Fibra de Carbono , Electricidad , Electrodos , Transporte de Electrón , Oxidación-Reducción
14.
Water Res ; 85: 371-6, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26360230

RESUMEN

A new design of membrane capacitive deionization (MCDI) cell was constructed by packing the cell's flow chamber with granular activated carbon (GAC). The GAC packed-MCDI (GAC-MCDI) delivered higher (1.2-2.5 times) desalination rates than the regular MCDI at all test NaCl concentrations (∼ 100-1000 mg/L). The greatest performance enhancement by packed GAC was observed when treating saline water with an initial NaCl concentration of 100 mg/L. Several different GAC materials were tested and they all exhibited similar enhancement effects. Comparatively, packing the MCDI's flow chamber with glass beads (GB; non-conductive) and graphite granules (GG; conductive but with lower specific surface area than GAC) resulted in inferior desalination performance. Electrochemical impedance spectroscopy (EIS) analysis showed that the GAC-MCDI had considerably smaller internal resistance than the regular MCDI (∼ 19.2 ± 1.2 Ω versus ∼ 1222 ± 15 Ω at 100 mg/L NaCl). The packed GAC also decreased the ionic resistance across the flow chamber (∼ 1.49 ± 0.05 Ω versus ∼ 1130 ± 12 Ω at 100 mg/L NaCl). The electric double layer (EDL) formed on the GAC surface was considered to store salt ions during electrosorption, and facilitate the ion transport in the flow chamber because of the higher ion conductivity in the EDLs than in the bulk solution, thereby enhancing the MCDI's desalination rate.


Asunto(s)
Carbón Orgánico/química , Salinidad , Purificación del Agua/métodos , Cloruro de Sodio/análisis , Cloruro de Sodio/química
15.
Bioresour Technol ; 190: 367-72, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25965954

RESUMEN

The application of microbial fuel cell (MFC)-based toxicity sensors to real-world water monitoring is partly impeded by the limited sensitivity. To address this limitation, this study optimized the flow configurations and the control modes. Results revealed that the sensitivity increased by ∼15-41times with the applying of a flow-through anode, compared to those with a flow-by anode. The sensors operated in the controlled anode potential (CP) mode delivered better sensitivity than those operated in the constant external resistance (ER) mode over a broad range of anode potentials from -0.41V to +0.1V. Electrodeposition of Cu(II) was found to bias the toxicity measurement at low anode potentials. The optimal anode potential was approximately -0.15V, at which the sensor achieved an unbiased measurement of toxicity and the highest sensitivity. This value was greater than those required for electrodeposition while smaller than those for power overshoot.


Asunto(s)
Fenómenos Fisiológicos Bacterianos/efectos de los fármacos , Fuentes de Energía Bioeléctrica/microbiología , Bioensayo/instrumentación , Cobre/análisis , Electrodos , Monitoreo del Ambiente/instrumentación , Técnicas Biosensibles/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Reología/instrumentación , Sensibilidad y Especificidad , Pruebas de Toxicidad/instrumentación , Contaminantes Químicos del Agua/análisis
16.
Mater Sci Eng C Mater Biol Appl ; 53: 196-203, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26042707

RESUMEN

While ursolic acid (UA), one of the most broadly known triterpene compounds, has proved to be effective in cancer therapy, the applications of UA is limited due to its poor aqueous solubility and low bioavailability. The aim of our study was to prolong circulation time and enhance uptake of liposomes in tumor tissues through the modification of UA liposomes via water-soluble polyethylene glycol (PEG). In addition, this research also focuses on physicochemical properties of the liposome formulations, including encapsulation efficiency, particle morphology, size, stability, release rate in vitro and cytotoxicity test. The obtained liposomes were spherical particles with mean particle diameters around 100-200 nm. And the Fourier transform infrared spectroscopy (FTIR) indicated that PEG had been anchored successfully to the liposomes. Based on our experimental data achieved, PEG-modified UA liposomes possessed higher stability than conventional liposomes, and the release rate of UA from PEG-modified liposomes was slower when compared with those of UA solution and conventional liposomes. Meanwhile, the liposomal UA showed relatively low cytotoxic effect than UA conventional liposomes within 24h, which was consistent with their release rates.


Asunto(s)
Liposomas/química , Liposomas/toxicidad , Polietilenglicoles/química , Polietilenglicoles/toxicidad , Triterpenos/química , Triterpenos/toxicidad , Antineoplásicos/química , Antineoplásicos/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Estabilidad de Medicamentos , Humanos , Ácido Ursólico
17.
Food Chem ; 179: 15-25, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25722134

RESUMEN

In this paper, an economical and efficient technology for the extraction of resveratrol from peanut sprouts by multi-stage countercurrent extraction (MSCE) was investigated based on the alkaline extraction and acid precipitation method (AEAP). Firstly, the MSCE equipment and operation procedures were designed. Then, the optimal parameters of MSCE were obtained by using single-factor experiments and Box-Behnken design (BBD) as follows: extraction temperature of 46.6 °C, CaO to raw material ratio of 6:100, water to raw material ratio of 8.8:1 and extraction time of 51.7 min. Finally, the performance of MSCE was compared against the single pot extraction (SPE) under optimal conditions. The results demonstrated that MSCE was a time-saving, energy-saving, and cost-saving extraction technology for manufacturing resveratrol from peanut sprouts.


Asunto(s)
Arachis/química , Distribución en Contracorriente/métodos , Estilbenos/aislamiento & purificación , Resveratrol , Extracción en Fase Sólida
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