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1.
J Epidemiol ; 30(10): 429-435, 2020 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-31548437

RESUMEN

BACKGROUND: We sought to investigate epidemiologic features of Kawasaki disease (KD) in Shanghai from 2013 through 2017 and identify risk factors for coronary artery lesions (CAL). METHODS: As in our previous three surveys, a set of questionnaires and diagnostic guidelines for KD were sent to 50 hospitals providing pediatric medical care in Shanghai. Medical records of KD patients diagnosed from January 2013 through December 2017 were retrospectively analyzed. Multivariate logistic regression analysis was performed to identify risk factors for CAL. RESULTS: A total of 4,452 cases were enrolled. Male-to-female ratio was 1.7:1. The incidence of KD was 68.8 to 107.3 per 100,000 children aged <5 years from 2013 to 2017. Age at onset ranged from 15 days to 14.0 years (median: 1.8 years). KD occurred more frequently in spring and summer. Of 4,325 patients (97.0%) receiving intravenous immunoglobulin (IVIG), 362 (8.4%) were resistant to initial IVIG. CAL occurred in 406 (9.1%) patients, including 118 (2.7%) with medium aneurysms and 31 (0.7%) with giant aneurysms. Recurrent cases were 60 (1.3%). No death was found in this survey. Higher platelet levels, lower albumin levels, male sex, incomplete KD, IVIG resistance, and receiving initial IVIG ≤4 days or >10 days, were independently associated with CAL. CONCLUSIONS: The incidence of KD in Shanghai had substantially increased while the proportion of CAL had substantially decreased as compared with our previous surveys. Higher platelet levels, lower albumin levels, male sex, incomplete KD, IVIG resistance, and receiving initial IVIG ≤4 days or >10 days, were risk factors for CAL.


Asunto(s)
Enfermedad de la Arteria Coronaria/epidemiología , Síndrome Mucocutáneo Linfonodular/epidemiología , Adolescente , Edad de Inicio , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Inmunoglobulinas Intravenosas/administración & dosificación , Incidencia , Lactante , Masculino , Síndrome Mucocutáneo Linfonodular/diagnóstico , Síndrome Mucocutáneo Linfonodular/tratamiento farmacológico , Estudios Retrospectivos , Factores de Riesgo , Encuestas y Cuestionarios
2.
Mikrochim Acta ; 186(4): 208, 2019 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-30826944

RESUMEN

Poly(1,5-diaminonaphthalene) microparticles with abundant reactive amino and imino groups on their surface were synthesized by one-step oxidative polymerization of 1,5-diaminonaphthalene using ammonium persulfate as the oxidant. The molecular, supramolecular, and morphological structures of the microparticles were systematically characterized by IR and UV-vis spectroscopies, elementary analysis, wide-angle X-ray diffractometry, and transmission electron microscopy. The microparticles demonstrate electrical semiconductivity and high resistance to strong acid and alkali, and strong adsorption capability for lead(II), mercury(II), and silver(I) ions. The experimental conditions for adsorption of Pb(II) were optimized by varying the persulfate/monomer ratio, adsorption time, sorbent concentration, and pH value of the Pb(II) solution. The maximum adsorption capacity is 241 mg·g-1 for particles after a 24 h-exposure to a solution at an initial Pb(II) concentration of 29 mM. The adsorption data fit a Langmuir isotherm and follow a pseudo-second-order reaction kinetics. This indicates a chemical adsorption that is typical for a chelation interaction between Pb(II) and amino/imino groups on the sorbent. Graphical abstract Poly(1,5-diaminonaphthalene) microparticles with abundant functional amino and imino groups have been synthesized by one-step direct polymerization of non-volatile 1,5-diaminonaphthalene in aqueous medium for sustainable preparation of high-performance adsorbents to strongly adsorb lead(II), mercury(II), and silver(I) ions.

3.
J Clin Ultrasound ; 43(1): 39-46, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24975134

RESUMEN

OBJECTIVE: In children with coronary disease, clinical decision should be based on detailed measurements of the coronary arteries by two-dimensional echocardiography. We aimed to establish coronary artery reference indexed diameter and z scores regression equations in a large cohort of Chinese Han children. METHODS: We measured the diameter of the proximal right (RCA), left main (LMCA), left anterior descending, and left circumflex coronary artery, and of the aortic annulus, and calculated the coronary-aorta index (coronary artery-to-aortic annulus ratio) in 506 Chinese Han children with normal hearts whose ages ranged from 1 day to 18 years. Regression analyses were performed, relating the coronary artery dimensions to body surface area (BSA). Several models were used, and the best model (yielding the maximum adjusted R(2) ) was chosen to establish a z score calculator. RESULTS: Based on cubic regression, (M) = ß0 + ß1 × BSA + ß2 × BSA(2) + ß3 × BSA(3) , the adjusted R(2) values were 0.515, 0.553, 0.505, and 0.518 for the RCA, LMCA, left anterior descending, and left circumflex coronary artery models, respectively. RCA/aortic annulus was 0.14 ± 0.02 (range, 0.07-0.24) and LMCA/AOA was 0.15 ± 0.03 (range, 0.10-0.28). CONCLUSIONS: Our results provide reference values of coronary artery z scores, regression equation, and coronary-aorta index as a quick guide to determine coronary dilation in Chinese Han children.


Asunto(s)
Vasos Coronarios/anatomía & histología , Adolescente , Aorta/anatomía & histología , Aorta/diagnóstico por imagen , Pesos y Medidas Corporales , Niño , Preescolar , China , Estudios de Cohortes , Vasos Coronarios/diagnóstico por imagen , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Valores de Referencia , Ultrasonografía
4.
Analyst ; 138(13): 3820-9, 2013 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-23702850

RESUMEN

A potentiometric sensor to detect lead ions using newly synthesized conducting copolymer microparticles as an ionophore in self-supporting poly(vinyl chloride) membrane matrix plasticized with dioctyl phthalate was developed. The copolymer microparticles containing many ligating functional groups including amino, imino and sulfonic groups were synthesized by a chemical oxidative copolymerization of m-phenylenediamine (mPD) and p-sulfonic-m-phenylenediamine (SPD) in pure water. Due to the presence of -NH-, -N=, -NH2, and -SO3H ligating groups on the microparticles, a linear Nernstian response is obtained within a Pb(II) activity range from 1.00 × 10(-6) M to 1.00 × 10(-3) M. The Pb(II)-sensor containing the mPD/SPD (95/5) copolymer microparticles with the maximal electrical conductivity demonstrates a superior detection limit down to 1.26 × 10(-7) M, short response time to 14 s, and long lifetime of up to 4 months. The Pb(II)-sensor also exhibits a selective response to Pb(II) over 9 other metal ions and a pH independent plateau between 2.7 and 5.0. These advantages could make for a robust sensor performing credible analysis of Pb(II) concentration in real-world samples at trace levels.


Asunto(s)
Aminas/química , Técnicas de Química Analítica/instrumentación , Conductividad Eléctrica , Plomo/análisis , Microesferas , Polímeros/química , Concentración de Iones de Hidrógeno , Ionóforos/química , Plomo/química , Potenciometría
5.
Zhonghua Yi Xue Za Zhi ; 93(20): 1567-70, 2013 May 28.
Artículo en Zh | MEDLINE | ID: mdl-24028725

RESUMEN

OBJECTIVE: To explore the clinical characteristics and prognosis of infantile-onset glycogen storage disease type II (GSDII) in Chinese patients. METHODS: Sixteen children diagnosed as infantile-onset GSDII in Shanghai Children's Medical Center during Jan 2005 to Dec 2012 were recruited. Their disease history, presenting symptom, physical signs, biochemical tests and examinations of electrocardiogram and echocardiography were analyzed retrospectively. Follow-up data on motor development and survival were also collected and analyzed retrospectively. RESULTS: 16 cases were diagnosed as infantile-onset GSDII (10 males, 6 females), in which the peripheral blood levels of acidic α-glucosidase were remarkably low or completely absent. All of them were complicated with cardiac hypertrophy and left ventricular mass index was 161-616 g/m(2). Severe muscular weakness, hypotonia and development lag were found in all during the follow-up. Creatine kinase was detected in 15 patients and its level became significantly elevated in 14 of them. Alanine aminotransferase and aspartate aminotransferase were detected in 15 patients and their levels became significantly elevated in all of them. The median age was 3.6 (2.0-6.8) months at symptom onset and 6.5 (3.8-9.3) months at diagnosis. And 14 of them died during the follow-up and the median age at death was 9.0 (4.7-18.7) months. CONCLUSIONS: As a fatal disease, infantile-onset GSDIIhas the prominent clinical manifestations of progressive cardiac hypertrophy and muscular weakness or hypotonia. The clinical features and nature history of Chinese patients are similar as those reported in other countries. Detection of acidic α-glucosidase activity in peripheral blood is an effective way of screening for infantile-onset GSDII.


Asunto(s)
Enfermedad del Almacenamiento de Glucógeno Tipo II/diagnóstico , Pueblo Asiatico , Femenino , Enfermedad del Almacenamiento de Glucógeno Tipo II/etnología , Humanos , Lactante , Masculino , Pronóstico , Estudios Retrospectivos
6.
Anal Chem ; 84(1): 134-40, 2012 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-22098529

RESUMEN

A newly designed Pb(II) potentiometric sensor based on intrinsically conducting nanoparticles of solid poly(aniline-co-2-hydroxy-5-sulfonic aniline) possessing many ligating functional groups like -NH-, -N=, -OH, -SO(3)H, -NH(2) as ionophores in plasticizer-free vinyl resin solid membranes has been fabricated. A linear Nernstian response is obtained within a wide Pb(II) activity range from 1.0 × 10(-3) to 1.0 × 10(-10) M with a detection limit as low as 2.2 × 10(-11) M. The pH independent plateau ranges between 3.5 and 7.0. After 15 months' usage, the sensor maintains 95% performance parameters. Its anti-interference ability to Cu(II), Cd(II), Ag(I), and Hg(II) is much stronger than other sensors with a detection limit at (sub)nanomolar level. Electrochemical impedance spectroscopy reveals that the solid sensing membrane has a diffusion coefficient of around 5 × 10(-14) to 1 × 10(-13) cm(2) s(-1). The much lower diffusion coefficient for Pb(II) is highly beneficial for the elimination of Pb(II) flux across the membrane. The wide detection concentration range, low detection limit, high selectivity, extensive pH window, and long lifetime make for a robust sensor giving reliable measurement of Pb(II) content with potential application in real-world samples at trace levels.

7.
Chemistry ; 18(32): 9877-85, 2012 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-22782853

RESUMEN

A simple and effective template-free synthesis method for nanosized conducting polymers with self-stability and functionality is a main challenge. Herein, a strategy is reported for the facile synthesis of poly(1,5-diaminonaphthalene) nanospherical particles by an interfacial miniemulsion oxidative polymerization of 1,5-diaminonaphthalene at mobile microinterfaces between a stirred biphase without external emulsifiers. The size of the nanospheres was carefully optimized by controlling the polymerization conditions. Formation and self-stabilization mechanisms of the nanoparticles are proposed. The constantly movable and refreshed microinterface is a key to successful synthesis of the nanospheres, for significantly suppressing secondary growth leading to agglomerated particles because vigorous stirring makes as-formed self-stabilized nanospheres instantly leave the microinterfaces. The resulting nanospheres possess several advantages: clean surface, self-stability, redispersibility, semiconductivity, electroactivity, and fluorescence emission. The fluorescence emission can be quenched by specific quenchers, thus enabling low-cost, high-performance chemosensors to be obtained for the sensitive detection of Zn(II) ions in a wide linear concentration range of more than five orders of magnitude with a superior detection limit down to 1 nM.


Asunto(s)
2-Naftilamina/análogos & derivados , Zinc/química , 2-Naftilamina/síntesis química , 2-Naftilamina/química , Conductividad Eléctrica , Estructura Molecular , Nanopartículas/química , Tamaño de la Partícula , Polimerizacion , Polímeros/síntesis química , Polímeros/química
8.
Zhonghua Xin Xue Guan Bing Za Zhi ; 40(10): 817-20, 2012 Oct.
Artículo en Zh | MEDLINE | ID: mdl-23302666

RESUMEN

OBJECTIVES: To evaluate the feasibility and efficacy of transcatheter closure of perimembranous ventricular septal defects (pmVSD) with aneurysmatic formation and muscular ventricular septal defects (mVSD) with Amplatzer duct occluder II. METHODS: This retrospective analysis included 48 cases received transcatheter closure of pmVSD aneurysmatic formation or mVSD from February 2011 to March 2012 in our hospital (42 pmVSD with aneurysmatic formation and 6 mVSD). Median age was 5.2 years (range: 1.8 - 15 years), and median weight was 20.2 kg (range: 12 - 44 kg). Amplatzer duct occluder II was selected depending on the condition of ventricular septal defect. The device was implanted by antegrade or retrograde approach. Complications such as residual shunt, valvular regurgitation and arrhythmia were evaluated by echocardiography or angiography. Median follow-up was 9.5 months (range: 1 - 13 months). RESULTS: The mean ratio of pulmonary (Qp) to systemic (Qs) blood flow was 1.35 ± 0.15 before transcatheter closure. The diameter of exit hole of ventricular septal defects was (2.46 ± 0.53) mm measured by transthoracic echocardiography, and (2.35 ± 0.40) mm by angiography. Successful implantation of the device was achieved in 46 patients (96%) and unsuccessful in two cases due to acute aortic insufficiency. Forty-two (92%) patients were closed successfully, and trivial residual leak was evidenced in four patients and remained unchanged during follow-up. One patient with mVSD still had trivial residual shunt at 6 months post procedure. New trivial tricuspid insufficiency was observed in 1 patient (2.1%) during follow-up. Two patients developed procedural related left anterior fascicular block and remained unchanged during follow-up. CONCLUSIONS: pmVSD with aneurysm and mVSD could be successfully treated with Amplatzer duct occluder II. However, the long waist and large disc of the device could interfere with tricuspid valve function and cause tricuspid insufficiency.


Asunto(s)
Cateterismo Cardíaco/instrumentación , Cateterismo Cardíaco/métodos , Defectos del Tabique Interventricular/cirugía , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Dispositivo Oclusor Septal , Resultado del Tratamiento
9.
Zhongguo Dang Dai Er Ke Za Zhi ; 13(6): 490-4, 2011 Jun.
Artículo en Zh | MEDLINE | ID: mdl-21672425

RESUMEN

OBJECTIVE: Anthracyclines (ANT) are effective for leukemia and solid tumors. However the long-term life quality of patients is seriously affected by ANT-related cardiotoxicity. The aim of this study was to evaluate the value of two dimension echocardiography (2DE) and serum biochemical indicators in monitoring ANT-related cardiotoxicity. METHODS: Seventy children who received ANT chemotherapy (ANT dose: 124 ± 73 mg/m2) and were followed up for 22 ± 13 months were enrolled. 2DE with aspects of conventional indexes (left ventricular diameter and wall thickness, ejection fraction, E/A), myocardial performance index (MPI) and tissue Doppler imaging (TDI) were performed. Serum levels of troponin (CTnI) and brain natriuretic peptide (BNP) were measured. Thirty-seven healthy children served as the control group. RESULTS: There were no significant differences in conventional indexes of 2DE between the ANT and the control groups. The MPI of left and right ventricular in the ANT group increased significantly compared with that in the control group (0.237 ± 0.06 vs 0.203 ± 0.06, 0.171 ± 0.05 vs 0.140 ± 0.04 respectively; P<0.01). TDI showed the late diastolic peak velocity in the basal and middle sections of left ventricular, interventricular septum and right ventricular in the ANT group were significantly higher than the controls. There were significant differences in the ratio of early to late diastolic peak velocity of the middle section of left ventricular and the basal and middle sections of the interventricular septum between the two groups (P<0.05). The changes of MPI and TDI became more obvious with the increased dose of ANT. There were no significant differences in serum CtnI and BNP levels between the two groups. CONCLUSIONS: The heart function of patients who received ANT chemotherapy needs to be monitored for a long term. MPI and TDI can be used as early indexes for monitoring the heart function.


Asunto(s)
Antraciclinas/toxicidad , Corazón/efectos de los fármacos , Adolescente , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Ecocardiografía , Femenino , Humanos , Lactante , Masculino , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre , Troponina I/sangre
10.
Clin Rheumatol ; 40(4): 1515-1523, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32845440

RESUMEN

OBJECTIVE: To explore the trends in diagnosis of Kawasaki disease (KD) and determine the characteristics for patients outside the usual age range of 6 months to 4 years. METHOD: A retrospective review of patients with KD identified in four epidemiological surveys spanning 20 years (1998-2017) in Shanghai was performed. RESULTS: A total of 8416 patients were included. All in all, 223 (2.6%) were aged 0 to 2 months, 639 (7.6%) were 3 to 5 months, 6556 (77.9%) were 6 months to 4 years, 915 (10.9%) were 5 to 9 years, and 83 (1.0%) were ≥ 10 years. The use of intravenous immunoglobulin increased in all extreme age groups, and delayed treatment rates decreased in all patients except in those aged 0 to 2 months and ≥ 10 years. The number of patients outside the usual age increased over time, but the proportion of these patients did not change significantly. They had more incomplete KD and coronary artery aneurysms (CAA), while those aged 0 to 2 months and ≥ 10 years had more delayed diagnoses in their respective age groups. The incidence of CAA was similar in younger and older children, but the former group had more cases of incomplete KD and abnormal laboratory parameters, while the latter group had longer duration of fever and was more difficult to diagnose promptly. CONCLUSIONS: The proportion of KD outside the usual age range did not increase over time. Older and younger children have different clinical and laboratory characteristics. Key Points • The number of patients outside the usual age increased over time, but the proportion of these patients did not increase. • Patients aged 0 to 2 months and ≥ 10 years had more delayed diagnoses in their respective age groups. • Younger children had more cases of incomplete KD and abnormal laboratory parameters, while older children had longer duration of fever and were more difficult to diagnose promptly.


Asunto(s)
Aneurisma Coronario , Síndrome Mucocutáneo Linfonodular , Adolescente , Niño , China/epidemiología , Aneurisma Coronario/diagnóstico , Aneurisma Coronario/epidemiología , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Lactante , Recién Nacido , Síndrome Mucocutáneo Linfonodular/diagnóstico , Síndrome Mucocutáneo Linfonodular/epidemiología , Estudios Retrospectivos
11.
Chemistry ; 16(33): 10113-23, 2010 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-20645338

RESUMEN

Poly[aniline(AN)-co-5-sulfo-2-anisidine(SA)] nanograins with rough and porous structure demonstrate ultrastrong adsorption and highly efficient recovery of silver ions. The effects of five key factors-AN/SA ratio, Ag(I) concentration, sorption time, ultrasonic treatment, and coexisting ions-on Ag(I) adsorbability were optimized, and AN/SA (50/50) copolymer nanograins were found to exhibit much stronger Ag(I) adsorption than polyaniline and all other reported sorbents. The maximal Ag(I) sorption capacity of up to 2034 mg g(-1) (18.86 mmol g(-1)) is the highest thus far and also much higher than the maximal Hg-ion sorption capacity (10.28 mmol g(-1)). Especially at or=99.98 % adsorptivity, and thus achieve almost complete Ag(I) sorption. The sorption fits the Langmuir isotherm well and follows pseudo-second-order kinetics. Studies by IR, UV/Vis, X-ray diffraction, polarizing microscopy, centrifugation, thermogravimetry, and conductivity techniques showed that Ag(I) sorption occurs by a redox mechanism mainly involving reduction of Ag(I) to separable silver nanocrystals, chelation between Ag(I) and -NH-/-N=/-NH(2)/-SO(3)H/-OCH(3), and ion exchange between Ag(I) and H(+) on -SO(3) (-)H(+). Competitive sorption of Ag(I) with coexisting Hg, Pb, Cu, Fe, Al, K, and Na ions was systematically investigated. In particular, the copolymer nanoparticles bearing many functional groups on their rough and porous surface can be directly used to recover and separate precious silver nanocrystals from practical Ag(I) wastewaters containing Fe, Al, K, and Na ions from Kodak Studio. The nanograins have great application potential in the noble metals industry, resource reuse, wastewater treatment, and functional hybrid nanocomposites.


Asunto(s)
Compuestos de Anilina/química , Nanopartículas del Metal/química , Plata/química , Adsorción , Oxidación-Reducción
12.
Chemistry ; 16(16): 4803-13, 2010 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-20213778

RESUMEN

A wholly aromatic polypyrene was synthesized by direct chemical oxidative polymerization of pyrene with ferric chloride as oxidant in hexane/nitromethane. Successful synthesis of polypyrene was thoroughly confirmed by IR, UV/Vis, 1D (1)H NMR, 2D (1)H-(1)H COSY, 2D (1)H-(13)C HSQC, MALDI-TOF MS, elemental analysis, and X-ray diffraction methods. The results indicated that the polypyrene was formed mainly through dehydro coupling between 2- or 1- and 2'- or 1'-positions on pyrene rings having a degree of polymerization of around 24. The polypyrene was purified and then separated into THF-soluble (ca. 10 %) and THF-insoluble (ca. 90 %) fractions. Compared with insulating pyrene monomer, the polypyrene is a controllably conducting polymer that has low conductivity of 3.4x10(-8) S cm(-1) in its virgin state, moderate conductivity of 2.28x10(-4) S cm(-1) upon iodine doping, but much higher conductivity of up to 81.2 S cm(-1) after the insoluble polypyrene was heated up to 1300 degrees C in nitrogen with a high char yield of 70.6 %. In particular, the soluble polypyrene demonstrates much stronger visible color fluorescence and much lower toxicity than pyrene. The soluble polypyrene would be advantageous for detecting Fe(3+) with almost no interference of other metal ions. The soluble and insoluble polypyrene fractions have potential applications as intrinsically luminescent and highly conducting carbon materials, respectively.

13.
Chemistry ; 15(18): 4573-81, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19296485

RESUMEN

The highest Hg-ion adsorbance so far, namely up to 2063 mg g(-1), has been achieved by poly(aniline-co-5-sulfo-2-anisidine) nanosorbents. Sorption of Hg ions occurs mainly by redox and chelation mechanisms (see scheme), but also by ion exchange and physisorption.Poly(aniline (AN)-co-5-sulfo-2-anisidine (SA)) nanoparticles were synthesized by chemical oxidative copolymerization of AN and SA monomers, and their extremely strong adsorption of mercury ions in aqueous solution was demonstrated. The reactivity ratios of AN and SA comonomers were found to be 2.05 and 0.02, respectively. While AN monomer tends to homopolymerize, SA monomer tends to copolymerize with AN monomer because of the great steric hindrance and electron-attracting effect of the sulfo groups, despite the effect of conjugation of the methoxyl group with the benzene ring. The effects of initial mercury(II) concentration, sorption time, sorption temperature, ultrasonic treatment, and sorbent dosage on mercury-ion sorption onto AN/SA (50/50) copolymer nanoparticles with a number-average diameter of around 120 nm were significantly optimized. The results show that the maximum Hg-ion sorption capacity on the particulate nanosorbents can even reach 2063 mg of Hg per gram of sorbent, which would be the highest Hg-ion adsorbance so far. The sorption data fit to the Langmuir isotherm, and the process obeys pseudo-second-order kinetics. The IR and UV/Vis spectral data of the Hg-loaded copolymer particles suggest that some mercury(II) was directly reduced by the copolymer to mercury(I) and even mercury(0). A mechanism of sorption between the particles and Hg ions in aqueous solution is proposed, and a physical/ion exchange/chelation/redox sorption ratio of around 2/3/45/50 was found. Copolymer nanoparticles may be one of the most powerful and cost-effective sorbents of mercury ions, with a wide range of potential applications for the efficient removal and even recovery of the mercury ions from aqueous solution.


Asunto(s)
Compuestos de Anilina/química , Mercurio/química , Nanopartículas/química , Polímeros/química , Adsorción , Compuestos de Anilina/síntesis química , Oxidación-Reducción , Polímeros/síntesis química , Propiedades de Superficie
14.
Chemistry ; 15(26): 6446-55, 2009 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-19466721

RESUMEN

The straight dope: Polythiophene (PTh) nanoparticles with a narrow size distribution were successfully synthesized by a chemical oxidative polymerization (see image). The highest conductivity of virgin PTh is 3.1x10(-4) S cm(-1) and can be dramatically enhanced to 50 S cm(-1) by doping in iodine vapor.Polythiophene (PTh) nanoparticles were successfully synthesized by a simple chemical oxidative polymerization in the presence of a very small amount of cetyltrimethylammonium bromide (CTAB). The polymerization yield, particle size, bulk electrical conductivity, and solubility of the PTh nanoparticles have been optimized by adjusting the CTAB/FeCl(3) oxidant/thiophene monomer ratio, thiophene concentration, polymerization temperature, and reaction time. The structure of the PTh nanoparticles was systematically characterized by IR and UV/Vis spectroscopy, wide-angle X-ray diffraction, laser particle-size analysis, field-emission scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that the number-average diameter (D(n)) and size polydispersity index (PDI) of the particles decrease significantly from 4.19 microm and 1.21 to 203 nm and 1.056, respectively, with a slightly increasing CTAB concentration. SEM and TEM reveal that the PTh particle size is reduced to 67 and 36 nm, respectively. The conductivity increases on raising the FeCl(3)/thiophene ratio or on lowering the CTAB concentration and polymerization temperature. A moderate monomer concentration and polymerization time are very beneficial for achieving highly conducting PTh. The highest conductivity of virgin PTh is 3.1x10(-4) S cm(-1) and can be further elevated to 50 S cm(-1) by doping in iodine vapor. Under optimized polymerization conditions, the significant variation of the conductivity of the PTh particles in virgin and doped states was well confirmed by the intensity and wavelength of the UV/Vis spectral band owing to the large pi conjugation. The PTh particles demonstrate uncommon characteristics including easy synthesis, low cost of production, large pi-conjugated structure, high conductivity, solution processability, and extensive potential for further application.

15.
J Phys Chem B ; 113(29): 9718-27, 2009 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-19552391

RESUMEN

Fine polythiophene (PTh) microparticles were successfully synthesized by a novel interfacial polymerization at a dynamic interface between two immiscible solvents, i.e., n-hexane and acetonitrile or nitromethane containing thiophene and oxidant, respectively. The polymerization yield, size, and electrical conductivity of the microparticles are optimized by facilely regulating the medium species, oxidant species, oxidant/monomer ratio, monomer concentration, and polymerization temperature. The microparticles were thoroughly characterized by IR, UV-vis spectroscopy, wide-angle X-ray diffractometry, laser particle-size analyzer, and simultaneous TG-DSC technique. The yield rises with increasing oxidant/monomer ratio, monomer concentration, and polymerization temperature. However, low monomer concentration, low polymerization temperature, and modest oxidant/monomer ratio are all favorable for the formation of the PTh with good, large pi-conjugation and high conductivity. With decreasing the thiophene concentration from 200 to 50 mM at a fixed FeCl3/thiophene molar ratio of 3 at 0 degrees C in hexane/nitromethane biphase system, the PTh obtained exhibits a steadily enhanced conductivity from 10(-12) to 0.01 S cm(-1) and gradually darkening color from crimson to black. Under the same conditions, the PTh obtained in hexane/acetonitrile usually possesses lower yield but higher conductivity than that in hexane/nitromethane. The conductivity will be further enhanced to 1.1 and 4.4 S cm(-1) if the PTh powders are doped in iodine vapor and simply carbonized at 25 through 999 degrees C in nitrogen, respectively. The PTh is fine particles with the number-average diameter of 2.67-3.95 microm and low size polydispersity index between 1.12 and 1.23. The black particles carbonized at 25 to 999 degrees C are much smaller than original PTh particles, with the number-average diameter of 279 nm and size polydispersity index of 1.09. This interfacial approach provides an optimal synthesis of unique PTh microparticles with large pi-conjugation, high conductivity, black color, uniform size, good insolubility, excellent infusibility, high thermostability, and high yield of electrically conducting char at 999 degrees C.


Asunto(s)
Polímeros/química , Polímeros/síntesis química , Tiofenos/química , Tiofenos/síntesis química , Conductividad Eléctrica , Tamaño de la Partícula
16.
Zhonghua Xin Xue Guan Bing Za Zhi ; 37(10): 917-9, 2009 Oct.
Artículo en Zh | MEDLINE | ID: mdl-20137544

RESUMEN

OBJECTIVE: To observe the operative efficacy of patients with complete atrioventricular septal defect (CAVSD). METHODS: From January 2003 to June 2006, CAVSD patients underwent operative closure were included in this study. Color Doppler with apical four-chamber view was used to evaluate the degree of valve insufficiency before surgery and 2 days, 1 month, 6 months and 1 year after the surgery. Cardiac catheterization was performed to evaluate pulmonary artery pressure and pulmonary arteriolar resistance (PAR) before surgery in patients whose age were over 6 months. The time of staying at ICU, ventilation time after surgery and the occurrence of pulmonary artery hypertension crisis were recorded. RESULTS: 105 CAVSD patients underwent operative closure were enrolled in this study. The mean staying time at ICU was (4.7 +/- 2.4) days, and the mean ventilation time was (1.7 +/- 1.0)days, 9 patients (8.5%) developed pulmonary artery hypertension crisis after surgery. Patients with PAR > 8 Wood unit were older, staying time at ICU and ventilation time were longer compared patients with PAR < 8 Wood unit (all P < 0.05). The incidence of pulmonary artery hypertension crisis after surgery was also significantly higher in patients with PAR > 8 Wood unit compared patients with PAR < 8 Wood unit (P < 0.05). Hospital mortality was 3.8% (4/105). Three out of 4 hospital-dead patients had severe hypoplasia of the atrioventricular valve. Compared with preoperative, degree of valve insufficiency in both sides were relieved after surgery (P < 0.05). The valve insufficiency remained unchanged in 81 patients (77.1%), worsened in 14 patients (13.3%) and improved in 10 patients (9.6%) after surgery. CONCLUSIONS: Our results suggested that early surgical repair for CAVSD was safe and beneficial. Preoperative PAR > 8 Wood unit was associated with increased risk of pulmonary artery hypertension crisis after surgery in patients with CAVSD.


Asunto(s)
Defectos de los Tabiques Cardíacos/cirugía , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Resultado del Tratamiento
17.
Small ; 4(8): 1201-9, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18666162

RESUMEN

Novel copolymer nanoparticles with inherent self-stability, narrow size distribution, and high electrical conductivity are facilely and productively synthesized by the oxidative precipitation polymerization of 5-sulfonic-2-anisidine and aniline in acidic medium without any external stabilizer. The structures of the copolymer particles are systematically characterized by IR and UV/Vis spectroscopy, X-ray diffraction, laser particle-size analysis, atomic force microscopy, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The comonomer ratio, oxidant/monomer ratio, and polymerization temperature and medium can be used to optimize the size and conductivity of the nanoparticles. It is found that the nanoparticles exhibit a minimal size and polydispersity index of around 53 nm and 1.045, respectively. Nanocomposite films of the nanoparticles with diacetyl and ethyl celluloses show good thermostability and a low percolation threshold of 0.08 wt%, at which the films retain 89% of the transparency, 96-98% of the strength, and 10(8) times the conductivity of the matrix film. The synthesis of sulfoanisidine copolymer nanoparticles is thus achieved without the use of external stabilizer, which opens up a simple and general route to the fabrication of nanostructured polymer materials with controllable size, narrow size distribution, intrinsic self-stability, strong dispersibility, high purity, and optimizable electroconductivity.


Asunto(s)
Compuestos de Anilina/química , Conductividad Eléctrica , Nanopartículas/química , Polímeros/química , Ácidos Sulfónicos/química , Celulosa/análogos & derivados , Celulosa/química , Microscopía de Fuerza Atómica , Nanocompuestos/química , Nanocompuestos/ultraestructura , Nanopartículas/ultraestructura , Nanotecnología , Tamaño de la Partícula , Espectrofotometría Infrarroja
18.
Chemistry ; 14(33): 10309-17, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18830982

RESUMEN

Chemical oxidative polymerization at 15 degrees C was used for the simple and productive synthesis of polyaniline (PAN) nanosticks. The effect of polymerization media on the yield, size, stability, and electrical conductivity of the PAN nanosticks was studied by changing the concentration and nature of the acid medium and oxidant and by introducing organic solvent. Molecular and supramolecular structure, size, and size distribution of the PAN nanosticks were characterized by UV/Vis and IR spectroscopy, X-ray diffraction, laser particle-size analysis, and transmission electron microscopy. Introduction of organic solvent is advantageous for enhancing the yield of PAN nanosticks but disadvantageous for formation of PAN nanosticks with small size and high conductivity. The concentration and nature of the acid medium have a major influence on the polymerization yield and conductivity of the nanosized PAN. The average diameter and length of PAN nanosticks produced with 2 M HNO(3) and 0.5 M H(2)SO(4) as acid media are about 40 and 300 nm, respectively. The PAN nanosticks obtained in an optimal medium (i.e., 2 M HNO(3)) exhibit the highest conductivity of 2.23 S cm(-1) and the highest yield of 80.7 %. A mechanism of formation of nanosticks instead of nanoparticles is proposed. Nanocomposite films of the PAN nanosticks with poly(vinyl alcohol) show a low percolation threshold of 0.2 wt %, at which the film retains almost the same transparency and strength as pure poly(vinyl alcohol) but 262 000 times the conductivity of pure poly(vinyl alcohol) film. The present synthesis of PAN nanosticks requires no external stabilizer and provides a facile and direct route for fabrication of PAN nanosticks with high yield, controllable size, intrinsic self-stability, strong redispersibility, high purity, and optimizable conductivity.

19.
Chin Med J (Engl) ; 121(5): 399-404, 2008 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-18364108

RESUMEN

BACKGROUND: Familial pulmonary arterial hypertension (FPAH) is an autosomal dominant disorder characterized by plexiform lesions of endothelial cells in pulmonary arterioles which leads to elevated pulmonary arterial pressure, right-sided heart failure and death. Heterozygous mutations in the bone morphogenetic protein type II receptor gene (BMPR2) have been found to underlie a majority of FPAH cases. More than 140 distinct mutations have been identified in FPAH cases and in idiopathic pulmonary arterial hypertension (IPAH) cases, but only one mutation has been reported in Chinese patients. METHODS: A three-generation pedigree of FPAH and another 10 patients with IPAH were collected. In the family, two of the 9 surviving and one deceased family member were diagnosed as FPAH. The entire protein-coding region and intron/exon boundaries of the BMPR2 gene were amplified by PCR using DNA samples from affected individuals. Direct sequencing of PCR products was performed on both the sense and antisense strands. To confirm the segregation of the mutation within the family and exclude the presence of the mutation in normal subjects, the relevant exon was amplified by PCR, followed by mutation-specific RPLP analysis. RESULTS: In the Chinese pedigree with FPAH an A-to-T transition at position 1157 in exon 9 of the BMPR2 gene was identified which resulted in a Glu386Val mutation. We confirmed the segregation of the mutation within the family and excluded the presence of the mutation in a panel of 200 chromosomes from normal subjects. No mutation was detected in BMPR2 in the other 10 patients with IPAH. CONCLUSIONS: This amino acid substitution occurs at a glutamic acid that is highly conserved in all type II TGF-beta receptors. The nearly invariant Glu forms an ion pair with an invariant Arg at position 491 thereby helping to stabilize the large lobe. Substitution of Arg at position 491 is the most frequently observed missense mutation in FPAH, but until now no mutations at position 386 have been found in FPAH. The predicted functional impact of the Glu386Val mutation and its absence in healthy controls support the mutation as the cause of FPAH.


Asunto(s)
Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Hipertensión Pulmonar/genética , Mutación , Adolescente , Secuencia de Aminoácidos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Linaje
20.
J Phys Chem B ; 111(21): 5829-36, 2007 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-17480070

RESUMEN

Intrinsically self-stabilized nanoparticles of a copolymer from 4-sulfonic diphenylamine (SD) and pyrrole (PY) were facilely synthesized in HCl solution at 10 degrees C by a chemically oxidative polymerization. The critical reaction parameters such as SD/PY ratio, polymerization time, and oxidant species were studied to significantly optimize the polymerization yield, size, conductivity, and solubility of the final copolymer particles. The molecular structure, size, size distribution, and morphology of the particles were analyzed by IR spectroscopy, laser particle-size analysis (LPA), atomic force microscopy, and transmission electron microscopy (TEM). It was found that the polymerization yield of the SD/PY (50/50) copolymers increased dramatically in the initial 2 h of polymerization and then slowly enlarged in the subsequent 22 h. However, the copolymerization yield for the polymerization time of 24 h exhibited a nonlinear dependence on the SD/PY molar ratio, i.e., a maximum at 10/90 and a minimum at 80/20. The number-average diameter, Dn, of the copolymer particles strongly depended on the SD/PY ratio, decreasing rapidly from 6402 to 291 nm as the SD/PY molar ratio changed from 30/70 to 50/50, whereas the polydispersity index, PDI = Dw/Dn (where Dw is the weight-average diameter), surprisingly maintained very small values, decreasing slightly from 1.21 to 1.08. The SD/PY (80/20) copolymer particles prepared with (NH4)2S2O8 as the oxidant had the smallest size of ca. 10 nm by TEM and the lowest Dw/Dn value of 1.03 by LPA, whereas the copolymer particles prepared with FeCl3 as the oxidant exhibited the second smallest size of ca. 20 nm by TEM and the highest conductivity. The conductivity of the SD/PY (50/50) copolymers rose first and then decreased with increasing polymerization time from 10 min to 24 h, exhibiting a maximum (0.217 S/cm) at 12 h. It is of interest that the copolymer particles with SD/PY molar ratios in the range between 50/50 and 80/20 surprisingly exhibited the smallest size, the narrowest size distribution, and the highest conductivity at the same time. In particular, the copolymer nanoparticles exhibited high purity, clean surfaces, good self-stability, high conductivity, and strong chemoresistance that were very important to nanomaterial processibility and application. The obtained copolymers were partially soluble in concentrated H2SO4, demonstrating a new direction for synthesizing a soluble pyrrole copolymer.


Asunto(s)
Bencenosulfonatos/química , Difenilamina/análogos & derivados , Nanopartículas/química , Polímeros/síntesis química , Pirroles/química , Difenilamina/química , Conductividad Eléctrica , Micelas , Estructura Molecular , Oxidación-Reducción , Tamaño de la Partícula , Polímeros/química
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