Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
ScientificWorldJournal ; 2012: 496341, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22927781

RESUMEN

China has experienced great social and economic vicissitudes that caused the vast complexity and uncertainty for electricity consumption. This paper attempts to identify the main determinants of the electricity consumption intensity by using the data from Chinese cities at subprovince and prefecture levels in 2009. The key category factors, including urban morphology, industrial structure, regulation context, urbanization degree, price, natural condition, and resource endowment, are abstracted and the influence of these determinants is evaluated by adopting the finite mixture models. The variation of each determinant across regions, the comparative weights of all the factors, and the detailed classifications of the cities are reported for facilitating the understanding of electricity consumption in China. The corresponding policies for electricity administration are addressed as well.


Asunto(s)
Ciudades/economía , Electricidad , Urbanización , China , Biología Computacional/métodos , Conservación de los Recursos Energéticos/legislación & jurisprudencia , Política Ambiental/legislación & jurisprudencia , Industrias/economía , Modelos Estadísticos , Análisis de Componente Principal , Cambio Social , Población Urbana
2.
ScientificWorldJournal ; 2012: 310407, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23365517

RESUMEN

The growth of China's industry has been seriously depending on energy and environment. This paper attempts to apply the directional distance function and the Luenberger productivity index to measure the environmental efficiency, environmental total factor productivity, and its components at the level of subindustry in China over the period from 1999 to 2009 while considering energy consumption and emission of pollutants. This paper also empirically examines the determinants of efficiency and productivity change. The major findings are as follows. Firstly, the main sources of environmental inefficiency of China's industry are the inefficiency of gross industrial output value, the excessive energy consumption, and pollutant emissions. Secondly, the highest growth rate of environmental total factor productivity among the three industrial categories is manufacturing, followed by mining, and production and supply of electricity, gas, and water. Thirdly, foreign direct investment, capital-labor ratio, ownership structure, energy consumption structure, and environmental regulation have varying degrees of effects on the environmental efficiency and environmental total factor productivity.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Eficiencia , Ambiente , Recursos en Salud/estadística & datos numéricos , Industrias/métodos , Algoritmos , China , Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/tendencias , Ecosistema , Fuentes Generadoras de Energía/estadística & datos numéricos , Monitoreo del Ambiente , Contaminación Ambiental/estadística & datos numéricos , Industrias/legislación & jurisprudencia , Industrias/tendencias , Modelos Teóricos
3.
Zhonghua Er Ke Za Zhi ; 59(2): 95-100, 2021 Feb 02.
Artículo en Zh | MEDLINE | ID: mdl-33548954

RESUMEN

Objective: To investigate the safety of warfarin for Kawasaki disease (KD) with coronary artery aneurysm (CAA) and its prognosis. Methods: Twenty one children with KD complicated with giant CAA, multiple CAA in one coronary artery or thrombosis in coronary artery were enrolled in this prospective study. Warfarin was used to control the goal international normalized ratio (INR) ranging from 2.0 to 3.0. The CAA diameter, number, location and thrombus in coronary artery were recorded at the beginning of treatment, 1, 2, 3, 4 weeks and 2, 3, 6, 12 months after treatment, as well as the influence on INR, electrocaroliogram, creatine kinase-MB (CK-MB), troponin I. Standardized warfarin bleeding risk training and management was implemented. Children were divided into implementation group and non-implementation group according to the status of actual implementation of their parents. The incidence of bleeding events was compared between the two groups. Comparisons between groups were performed using a Rank sum test and a Fisher exact test. Results: In the 21 patients (15 males and 6 females), the age of onset ranged from 2 months to 6 years. There were 4 cases with grade Ⅱ, 7 cases with grade Ⅲ, 7 cases with grade Ⅳ and 3 cases with grade Ⅴ according to the severity of coronary arterial lesions before treatment. The time of clinical detection of thrombus in 10 children with thrombosis ranged from the fourth day to the fourth month. The dose distribution of warfarin was 0.06-0.10 mg/(kg·d), and the INR was 1.80-2.59. Among the 10 cases with thrombus, 8 cases had disappearance of thrombi and 2 cases with grade Ⅴ had thrombus organization to different degree. After treatment, the coronary artery ectasia of the 4 cases with grade Ⅱ all returned to normal. Among the 7 cases with grade Ⅲ, 3 cases of coronary artery aneurysms returned to normal, and 4 cases did not change. Among the 7 cases with grade Ⅳ , 5 cases of coronary artery aneurysms shrank to grade Ⅲ, and 2 cases remained unchanged. Three cases with grade Ⅴ lesions had no changes in aneurysm. Neither new thrombus nor new CAA was detected during the treatment. There was no significant change in electrocardiogram before and after treatment. No statistically significant difference was found regarding the troponin I (0.07 (0-3.01) vs. 0.04 (0-0.29) µg/L, Z=0.932, P>0.05) and CK-MB (20.6 (11.2-58.2) vs. 29.0 (16.7-47.0) U/L, Z=1.906, P>0.05) before and after treatment. The incidence of bleeding events in the implementation group was significantly lower than that in the non-implementation group (2/15 vs. 4/6, Fisher=5.689, P=0.031). Conclusions: The application of goal INR of 2.0-3.0 and adjustment of warfarin dose according to the severity of CAA combined with standardized and strict warfarin bleeding risk training and management, can increase the safety of warfarin therapy in children with KD, improve the prognosis of coronary artery lesions, promote the dissolution of thrombi, prevent new thrombosis, and effectively reduce the incidence of bleeding complication.


Asunto(s)
Aneurisma Coronario , Síndrome Mucocutáneo Linfonodular , Anticoagulantes/efectos adversos , Niño , Aneurisma Coronario/tratamiento farmacológico , Aneurisma Coronario/etiología , Femenino , Humanos , Lactante , Masculino , Síndrome Mucocutáneo Linfonodular/complicaciones , Síndrome Mucocutáneo Linfonodular/tratamiento farmacológico , Estudios Prospectivos , Warfarina/efectos adversos
4.
J Colloid Interface Sci ; 560: 169-176, 2020 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-31670014

RESUMEN

Tin oxide (SnO2) has been widely used as an anode material for sodium-ion storage because of its high theoretical capacity. However, it suffers from large volume expansion and poor conductivity. To overcome these limitations, in this study, we have designed and prepared Mo-doped SnO2 nanoflake arrays anchored on carbon foam (Mo-SnO2@C-foam with 38.41 wt% SnO2 and 3.7 wt% Mo content) by a facile hydrothermal method. The carbon foam serves as a three-dimensional conductive network and a buffer skeleton, contributing to improved rate performance and cycling stability. In addition, Mo doping enhances the kinetics of sodium-ion transfer, and the interlaced SnO2 nanoflake arrays is beneficial to promote the conversion reactions during the charge/discharge process. The as-prepared composite with a unique structure demonstrate a high initial capacity of 1017.1 mAh g-1 at 0.1 A g-1, with a capacity retention over three times higher than that of the control sample (SnO2@C-foam) at 1 A g-1, indicating a remarkable rate performance.

5.
J Colloid Interface Sci ; 565: 218-226, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31972335

RESUMEN

Highly conductive cathode material with enhanced Na+ diffusion kinetics is of great importance in the exploration of sodium ion batteries. In this work, Na0.91MnO2 porous microcube which is coated with highly conductive polypyrrole (PPy) is obtained. The high Na content in the layered sodium manganate oxide brings about wider interlayer distance resulting in high capacity and electrochemical kinetics. The higher sodium content of Na0.91MO2 makes capacity increase up to 50 mAh g-1 compared with Na0.7MnO2.05. Furthermore, the well-designed combination between porous structure and conductive PPy coating exhibits fast ion/electron transfer inside the electrode and high cycling stability. The PPy coated Na0.91MnO2 delivers a high initial capacity of 208 mAh g-1, encouraging capacity retention and rate capability. Based on the porous Na0.91MnO2@PPy cathode, the sodium ion full cells with puffed millet porous carbon anode show remarkably stable cycling and high-rate performances.

6.
J Colloid Interface Sci ; 535: 300-307, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30316116

RESUMEN

Exploring high performance cathode materials is of great means for the development of bi-functional electrochromic energy storage devices. Herein, Nb-doped WO3 mesoporous films as integrated high-quality cathode are successfully constructed via a facile sol-gel method. Chemical state and crystallinity of the WO3 based films are significantly influenced by doping concentration. Compared with the pure WO3, the optimal Nb-doped film shows improved optical-electrochemical properties with high specific capacity (74.4 mAh g-1 at 2 A g-1), excellent high-rate capability, large optical contrast (61.7% at 633 nm), and ultra-fast switching speed (3.6 s and 2.1 s for coloring and bleaching process, respectively). These positive features suggest the potential application of Nb-doped WO3 mesoporous cathode. Our research paves the way for the development of multifunctional photoelectrochemical energy devices.

7.
J Colloid Interface Sci ; 551: 219-226, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31078977

RESUMEN

Improving the insulating nature of sulfur and retaining the soluble polysulfides in sulfur cathodes are crucial for realizing the practical application of lithium-sulfur batteries (LSBs). Biomass-based carbon is becoming increasingly popular for fabricating economical and efficient cathodes for LSBs owing to its unique structure. Herein, we report a facile strategy to transform bovine bone with an organic-inorganic structure into cellular hierarchical porous carbon via carbonization and KOH activation, followed by CoS2 modification through hydrothermal treatment. The synthesized composite can load abundant sulfur and produce a dual effect of "physical confinement and chemical entrapment" on polysulfides. The conductive carbon frame with the developed porous structure provides adequate space to accommodate sulfur and physically suppress the shuttle effect of polysulfides. The embedded half-metallic CoS2 sites can chemically anchor the polysulfides and enhance the electrochemical reaction activity as well. Owing to the multifunctional structure and dual restraint effect, the designed electrode exhibits enhanced electrochemical properties including high initial capacity (1230.9 mAh g-1 at 0.2 C), improved cycling stability and enhanced rate capability.


Asunto(s)
Huesos/química , Carbono/química , Cobalto/química , Suministros de Energía Eléctrica , Litio , Animales , Productos Biológicos/química , Bovinos , Conductividad Eléctrica , Técnicas Electroquímicas/métodos , Electrodos , Litio/química , Minerales/química , Estructura Molecular , Porosidad , Sulfuros/química
8.
Eur Rev Med Pharmacol Sci ; 21(6): 1248-1253, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28387906

RESUMEN

OBJECTIVE: Liver cancer severely threatens public health. Molecular targeted treatment is the further of cancer treatment. The functional role of Sir-related enzymes 4 (sirtuin 4) in treating liver cancer still requires further investigation. This study aimed to elucidate the effect of sirtuin 4 on aging of SMCC7721 liver cancer cell line, to underlying molecular mechanism and potential application in clinics. MATERIALS AND METHODS: Adriamycin-induced aging model was established on SMCC7721 liver cancer cell line. Sirtuin 4 over-expression or siRNA plasmid was transfected. Cell aging was measured by ß-galactosidase approach. Aging-related proteins P53 and P16 were quantified in Western blot, which also examined activation of Janus kinase 2 (JAK2) signal pathway. CP-690550 was used to suppress JAK2 signal pathway for measuring aging status of SMCC7721 cells. RESULTS: In aged SMCC7721 cells, sirtuin 4 was up-regulated, whilst P53 and P16 protein levels were elevated, in accompanied with JAK2/STAT3 signal pathway. Transfection of sirtuin 4 over-expression plasmid or siRNA increased or decreased sirtuin 4 expression. Adriamycin-induced aging was enhanced or suppressed, accompanied with inhibited or potentiated JAK2 signal pathway in sirtuin 4 up-regulation or down-regulation cells, respectively. The usage of JAK2 signal inhibitor, CP-690550, enhanced Adriamycin-induced cell aging. CONCLUSIONS: Sirtuin 4 facilitates Adriamycin-induced aging of SMCC7721 liver cancer cells via inhibiting JAK2/STAT3 signal pathway, thus providing one novel anti-cancer strategy.


Asunto(s)
Senescencia Celular , Janus Quinasa 2/metabolismo , Neoplasias Hepáticas/patología , Proteínas Mitocondriales/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Sirtuinas/metabolismo , Línea Celular Tumoral , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Doxorrubicina , Humanos , Piperidinas , Pirimidinas , Pirroles , Proteína p53 Supresora de Tumor/metabolismo
9.
Chemosphere ; 65(3): 457-66, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16540147

RESUMEN

The contamination of polycyclic aromatic hydrocarbons (PAHs) has become one of the major problems in the Yellow River of China. As the Yellow River is the most turbid large river in the world, it remains unknown to which extent the high suspended sediment content in the river may affect the fate and effect of PAHs. Here we report the effect of sediment on biodegradation of chrysene, benzo(a)pyrene and benzo(g,h,i)perylene with phenanthrene as a co-metabolism substrate in natural waters from the Yellow River. Biodegradation kinetics of the PAHs in the river water with various levels of sediment contents were studied in the laboratory by fitting with a biodegradation kinetics model for organic compounds not supporting growth. The results indicated that the biodegradation rates of PAHs increased with the sediment content in the water. When the sediment contents were 0, 4 and 10 g/l, the biodegradation rate constants of chrysene with the initial concentration of 3.80 microg/l were 0.053, 0.084 and 0.111 d(-1), respectively. Further studies suggested the enhanced biodegradation rate in the presence of sediment was caused by the following mechanisms: (1) the population of PAH-degrading bacteria in the water system was found to increase with the sediment content; the bacteria population on sediment phase was far greater than that on water phase during the cultivation process; (2) the sorption of PAHs on the sediment phase was well described by the dual adsorption-partition model. Although the sorption capacity of PAH per unit weight of sediment decreased with the increase of the sediment content, the amount of sorbed PAH increased with the sediment content; and, (3) the desorption of PAHs from the solid phase led to a higher concentration near the water-sediment interface. Since the bacteria were also attached to the interface, this resulted in an increased contact chance between the bacteria and PAHs.


Asunto(s)
Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Ríos , Contaminantes Químicos del Agua/análisis , Adsorción , Biodegradación Ambiental , China , Ríos/química , Ríos/microbiología
10.
J Colloid Interface Sci ; 465: 112-20, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26669497

RESUMEN

Metal-doping is considered to be an effective way for construction of advanced semiconducting metal oxides with tailored physicochemical properties. Herein, Mo-doped WO3 nanowire arrays are rationally fabricated by a sulfate-assisted hydrothermal method. Compared to the pure WO3, the optimized Mo-doped WO3 nanowire arrays exhibit improved electrochromic properties with fast switching speed (3.2s and 2.6s for coloration and bleaching, respectively), significant optical modulation (56.7% at 750nm, 83.0% at 1600nm and 48.5% at 10µm), high coloration efficiency (123.5cm(2)C(-1)) and excellent cycling stability. In addition, as a proof of concept, the Mo-doped WO3 nanowire arrays are demonstrated with electrochemical energy storage monitored by the electrochromism. This electrode design protocol can provide an alternative way for developing high-performance active materials for bi-functional electrochromic batteries.

11.
J Colloid Interface Sci ; 460: 200-8, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26321573

RESUMEN

High-performance electrochromic films with large color contrast and fast switching speed are of great importance for developing advanced smart windows. In this work, crystalline/amorphous WO3 core/shell (c-WO3@a-WO3) nanowire arrays rationally are synthesized by combining hydrothermal and electrodeposition methods. The 1D c-WO3@a-WO3 core/shell hierarchical structures show a synergistic effect for the enhancement of optical modulation, especially in the infrared (IR) region. By optimizing the electrodeposition time of 400s, the core/shell array exhibits a significant optical modulation (70.3% at 750nm, 42.0% at 2000nm and 51.4% at 10µm), fast switching speed (3.5s and 4.8s), high coloration efficiency (43.2cm(2)C(-1) at 750nm) and excellent cycling performance (68.5% after 3000 cycles). The crystalline/amorphous nanostructured film can provide an alternative way for developing high-performance electrochromic materials.

12.
Chemosphere ; 57(8): 1017-29, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15488592

RESUMEN

In this research, the mechanism regarding the effects of suspended solids on nitrification in freshwater systems with high solid contents was examined. Experimental studies were conducted for natural water of the Yellow River under laboratory conditions. Nitrification kinetics was investigated in water systems with various levels of suspended-solid contents. The associated mechanisms were analyzed through investigation of the adsorption-desorption of ammonium nitrogen, the process of bacteria growth, and the feature of nitrification kinetics. The results indicated that the presence of suspended solids could accelerate the nitrification process. The nitrification rate would increase non-linearly with the increase of suspended-solid content. When the initial concentration of ammonia nitrogen was 12.70 mg/l in the water system, the ratios of half-time duration for nitrification would be 1.88:1.23:1 under suspended-solid contents of 0, 1.84 and 5.00 g/l, respectively. When the initial concentration of ammonia nitrogen was around 1.0 mg/l in the water system, the nitrification rates in systems with suspended-solid contents of 1.81 and 3.42 g/l would then be approximately 9 and 12 times that without suspended solids, respectively. The populations of nitrifying bacteria would rise with increasing suspended-solid content. The existence of suspended solids would increase the contact chances between bacteria and nitrogen, resulting in accelerated nitrification processes; this was manifested by the increased K(4) (tau(max)/K(S)) along with the raised suspended-solid contents while fitting nitrification kinetics with the growth-based logistic model. Since the amount of ammonium nitrogen adsorbed on suspended-solid surface was non-linearly proportional to the suspended-solid content, the nitrification rate was also non-linearly proportional to the suspended-solid content.


Asunto(s)
Nitrógeno/metabolismo , Compuestos de Amonio Cuaternario/metabolismo , Ríos/química , Microbiología del Agua , Adsorción , China , Sedimentos Geológicos/química , Cinética , Modelos Logísticos , Nitrógeno/química , Compuestos de Amonio Cuaternario/química
13.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 21(2): 99-101, 2001 Feb.
Artículo en Zh | MEDLINE | ID: mdl-12577389

RESUMEN

OBJECTIVE: To observe the effect of infantile umbilical paste (IUP) in abating infantile fever. METHODS: Two hundred and twenty cases were randomly divided into two groups, the 120 cases in Group A were treated with IUP and the 100 cases in Group B treated with compound Aspirin (APC). The effect in abating fever and side-effects were observed. RESULTS: The total effective rate of the two groups were not statistically different (P > 0.05). But a better effect in abating fever was shown in Group A 4 hrs later (P < 0.01). The effect in patients of age under 1 year was the best. CONCLUSION: IUP has good effect in abating infantile fever, and it shows no influence on white blood cells, liver and kidney functions.


Asunto(s)
Resfriado Común/tratamiento farmacológico , Medicamentos Herbarios Chinos/administración & dosificación , Fiebre/tratamiento farmacológico , Fitoterapia , Administración Cutánea , Preescolar , Resfriado Común/complicaciones , Femenino , Fiebre/etiología , Humanos , Lactante , Masculino , Ombligo
14.
Nanotechnology ; 19(46): 465701, 2008 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-21836256

RESUMEN

A highly porous NiO/polyaniline (PANI) composite film was prepared on ITO glass by combining the chemical bath deposition and electro-polymerization methods, successively. The porous NiO film acts as a template for the preferential growth of PANI along NiO flakes, and the NiO/PANI composite film has an intercrossing net-like morphology. The electrochromic performance of the NiO/PANI composite film was investigated in 1 M LiClO(4)+1 mM HClO(4)/propylene carbonate (PC) by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The NiO/PANI thin film exhibits a noticeable electrochromism with reversible color changes from transparent yellow to purple and presents quite good transmittance modulation with a variation of transmittance up to 56% at 550 nm. The porous NiO/polyaniline (PANI) composite film also shows good reaction kinetics with fast switching speed, and the response time for oxidation and reduction is 90 and 110 ms, respectively.

15.
Int J Gynecol Cancer ; 16(5): 1868-72, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17009984

RESUMEN

Tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene in non-small cell lung cancer, and loss of TSLC1 gene expression has been observed in a number of epithelial carcinomas and cancer-derived cell lines. We analyzed TSLC1 gene expression by real-time reverse transcription-polymerase chain reaction in 39 invasive cervical carcinomas, 34 cervical intraepithelial neoplasia (CIN) IIIs, 35 CIN IIs, 32 CIN I, 36 inflammation cervical tissues, and 30 normal cervix samples. Loss of TSLC1 gene expression was observed in 30 of 39 (77%) cervical carcinomas, 25 of 34 (73%) CIN IIIs, 9 of 35 (26%) CIN IIs, and 7 of 32 (22%) CIN Is but was not found in inflammation and normal cervix samples. Compared to normal cervical tissue, loss of TSLC1 gene was significantly high in CIN IIIs and cervical cancer (P = 0.00). Moreover, loss of TSLC1 gene expression is observed at a significantly higher frequency in CIN IIIs and cervical cancers than in CIN IIs (P < 0.05). The results show that loss of TSLC1 gene expression is an early event in cervical carcinogenesis and often accompanies invasive cervical cancers.


Asunto(s)
Carcinoma/metabolismo , Cuello del Útero/metabolismo , Inmunoglobulinas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Cervicitis Uterina/metabolismo , Carcinoma/virología , Molécula 1 de Adhesión Celular , Moléculas de Adhesión Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Papillomaviridae , Infecciones por Papillomavirus/metabolismo , Reacción en Cadena de la Polimerasa , Neoplasias del Cuello Uterino/virología
16.
Artículo en Zh | MEDLINE | ID: mdl-21171437

RESUMEN

AIM AND METHODS: By using electrophysiological technique, the effects of nitric oxide (NO) and atrial natriuretic peptide (ANP) on renal afferent nerve activity (RANA) induced by intrarenal arterial injection of endothelin-1(ET-1) were examined in anesthetized rat. RESULTS: (1) In response to intrarenal arterial injection of ET-1 (1 microg/kg) MAP was initially decreased and subsequently increased, and RANA was increased to 208.33 +/- 16.60% (P < 0.001). (2) Pretreatment with L-Arg or ANP could effectively inhibit the above biological actions induced by ET-1. CONCLUSION: Intrarenal arterial injection of ET-1 can markedly induce the increase in RANA, an effect which is abolished by L-arg or ANP administered by the same route.


Asunto(s)
Vías Aferentes/efectos de los fármacos , Factor Natriurético Atrial/farmacología , Endotelina-1/farmacología , Riñón/inervación , Óxido Nítrico/farmacología , Vías Aferentes/fisiología , Animales , Masculino , Ratas , Ratas Sprague-Dawley
17.
Anal Bioanal Chem ; 379(7-8): 1062-7, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15221194

RESUMEN

Poly(dimethylsiloxane) microchip capillary electrophoresis with amperometric detection has been used for rapid separation and determination of acetaminophen and its hydrolysate, i.e. p-aminophenol. A Pt ultramicroelectrode with a diameter of 10 microm positioned at the outlet of the separation channel was used as a working electrode for amperometric detection. Factors influencing separation and detection were investigated and optimized. Results show that acetaminophen and p-aminophenol can be well separated within 35 s with RSD-1 (approximately 0.1 fmol) at S/ N=3. This method has been successfully applied to the detection of traces of p-aminophenol in paracetamol tablets.


Asunto(s)
Acetaminofén/análisis , Aminofenoles/análisis , Dimetilpolisiloxanos/química , Electroforesis Capilar/métodos , Electroforesis por Microchip/métodos , Polímeros/química , Acetaminofén/química , Electroquímica , Electroforesis Capilar/instrumentación , Electroforesis por Microchip/instrumentación , Hidrólisis , Sensibilidad y Especificidad , Factores de Tiempo
18.
Anal Bioanal Chem ; 379(7-8): 1025-30, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15179534

RESUMEN

A biocompatible and uniform interface based on silica nanoparticles derivatized with amino groups has been constructed for the effective immobilization and sensitive sequence-specific detection of calf thymus DNA. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) results showed that a monolayer of silica nanoparticles can be formed on a gold electrode under our experimental conditions using cysteine self-assembly monolayer as binder medium. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy (XPS) verified the successful immobilization of DNA on silica-nanoparticle-modified gold electrodes. Quantitative results demonstrated that enhanced immobilization of single-strand DNA (ss-DNA) up to 1.6 x 10(-8) mol cm(-2) could be achieved owing to the larger surface area and the special properties of silica nanoparticles. In addition, hybridization experiments demonstrated that the immobilized ss-DNA on silica nanoparticles could specifically interact with complementary DNA in solutions.


Asunto(s)
ADN/química , Nanoestructuras/química , Análisis de Secuencia de ADN/métodos , Dióxido de Silicio/química , Animales , Bovinos , ADN de Cadena Simple/química , Oro/química , Inmovilización , Sensibilidad y Especificidad , Propiedades de Superficie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA