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1.
BMC Public Health ; 24(1): 494, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365650

RESUMEN

BACKGROUND: Quantitative evidence on the impact of meteorological factors on influenza transmissibility across different virus types/subtypes is scarce, and no previous studies have reported the effect of hourly temperature variability (HTV) on influenza transmissibility. Herein, we explored the associations between meteorological factors and influenza transmissibility according to the influenza type and subtype in Guangzhou, a subtropical city in China. METHODS: We collected influenza surveillance and meteorological data of Guangzhou between October 2010 and December 2019. Influenza transmissibility was measured using the instantaneous effective reproductive number (Rt). A gamma regression with a log link combined with a distributed lag non-linear model was used to assess the associations of daily meteorological factors with Rt by influenza types/subtypes. RESULTS: The exposure-response relationship between ambient temperature and Rt was non-linear, with elevated transmissibility at low and high temperatures. Influenza transmissibility increased as HTV increased when HTV < around 4.5 °C. A non-linear association was observed between absolute humidity and Rt, with increased transmissibility at low absolute humidity and at around 19 g/m3. Relative humidity had a U-shaped association with influenza transmissibility. The associations between meteorological factors and influenza transmissibility varied according to the influenza type and subtype: elevated transmissibility was observed at high ambient temperatures for influenza A(H3N2), but not for influenza A(H1N1)pdm09; transmissibility of influenza A(H1N1)pdm09 increased as HTV increased when HTV < around 4.5 °C, but the transmissibility decreased with HTV when HTV < 2.5 °C and 3.0 °C for influenza A(H3N2) and B, respectively; positive association of Rt with absolute humidity was witnessed for influenza A(H3N2) even when absolute humidity was larger than 19 g/m3, which was different from that for influenza A(H1N1)pdm09 and influenza B. CONCLUSIONS: Temperature variability has an impact on influenza transmissibility. Ambient temperature, temperature variability, and humidity influence the transmissibility of different influenza types/subtypes discrepantly. Our findings have important implications for improving preparedness for influenza epidemics, especially under climate change conditions.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Humanos , Gripe Humana/epidemiología , Subtipo H3N2 del Virus de la Influenza A , Conceptos Meteorológicos , Temperatura , Humedad , China/epidemiología
2.
J Cardiovasc Pharmacol ; 77(6): 805-813, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-34001722

RESUMEN

ABSTRACT: Levosimendan, a calcium sensitizer, exerts inotropic action through improving left ventricular ejection fraction. We noticed that only few clinical studies are published in which the effects of levosimendan on cardiac function are studied by echocardiography. When screening the literature (PubMed, Embase, and CENTRAL, from inception to August 2020), we found 29 randomized controlled trials on levosimendan containing echocardiographic data. We included those studies, describing a total of 574 heart failure patients, in our meta-analysis and extracted 14 ultrasonic parameters, pooling the effect estimates using a random-effect model. Our analysis of the diastolic parameters of the left ventricle shows that levosimendan reduce the early/late transmitral diastolic peak flow velocity ratio [standardized mean difference (SMD) -0.45 to 95% confidence interval (CI) (-0.87 to -0.03), P = 0.037] and E/e' (e': mitral annulus peak early diastolic wave velocity using tissue-doppler imaging) [SMD -0.59, 95% CI (-0.8 to -0.39), P < 0.001]. As it regards the systolic parameters of the right ventricle, levosimendan increased tricuspid annular plane systolic excursion [SMD 0.62, 95% CI (0.28 to 0.95), P < 0.001] and tricuspid annular peak systolic velocity [SMD 0.75, 95% CI (0.35 to 1.16), P < 0.001], and reduced systolic pulmonary artery pressure [SMD -1.02, 95% CI (-1.32, -0.73), P < 0.001]. As it regards the diastolic parameters of the right ventricle, levosimendan was associated with the decrease of Aa (peak late diastolic tricuspid annular velocity using tissue-doppler imaging) [SMD -0.38, 95% CI (-0.76 to 0), P = 0.047] and increase of Ea (peak early diastolic tricuspid annular velocity using tissue-doppler imaging) [SMD 1.03, 95% CI (0.63 to 1.42), P < 0.001] and Ea/Aa [SMD 0.86, 95% CI (0.18 to 1.54), P = 0.013]. We show that levosimendan is associated with an amelioration in the diastolic and systolic functions of both ventricles in heart failure patients.


Asunto(s)
Cardiotónicos/farmacología , Insuficiencia Cardíaca/tratamiento farmacológico , Simendán/farmacología , Diástole/efectos de los fármacos , Ecocardiografía , Insuficiencia Cardíaca/fisiopatología , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Volumen Sistólico/efectos de los fármacos , Sístole/efectos de los fármacos , Función Ventricular Izquierda/efectos de los fármacos , Función Ventricular Derecha/efectos de los fármacos
3.
Pacing Clin Electrophysiol ; 44(2): 225-234, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33372697

RESUMEN

BACKGROUND: Current guidelines did not provide recommendations on indications of an additional implantable cardioverter-defibrillator (ICD) to patients receiving cardiac resynchronization therapy (CRT), and it still remains controversial due to lack of evidence from randomized controlled trials. METHOD: PubMed, Embase, and Cochrane CENTRAL from the inception to May 2020 were systematically screened for studies reporting on the comparison of cardiac resynchronization therapy with defibrillator (CRT-D) and cardiac resynchronization therapy with pacemaker (CRT-P), focusing on the adjusted hazard ratio (aHR) of all-cause mortality. We pooled the effects using a random-effect model. RESULTS: Twenty-one studies encompassing 69,919 patients were included in this meta-analysis. With no restriction to characteristics of including population, CRT-D was associated with a lower all-cause mortality compared with CRT-P significantly (aHR: 0.80, 95% confidence interval [CI]: 0.74-0.87, I2  = 36.8%, p < .001). This mortality benefit was also observed in patients with ischemic cardiomyopathy (aHR: 0.74, 95% CI: 0.64-0.86, I2  = 0%, p < .001). However, there is no significant difference in patients with nonischemic cardiomyopathy (NICM) (aHR: 0.91, 95% CI: 0.82-1.01, I2  = 0%, p = .087), older age (age ≥75 years, aHR: 0.96, 95% CI: 0.83-1.12, I2  = 0%, p = .610). Subgroup analysis was performed and indicated the survival benefit of CRT-D for primary prevention compared with CRT-P (aHR: 0.87, 95% CI: 0.79-0.95, I2  = 0%, p = .003). CONCLUSION: After adjusted the differences in clinical characteristics, additional ICD therapy was associated with a reduced all-cause mortality in patients receiving CRT. However, our work suggested that additional ICD may not be applied to elderly (≥75 years) or patients with NICM.


Asunto(s)
Terapia de Resincronización Cardíaca , Desfibriladores Implantables , Insuficiencia Cardíaca/terapia , Humanos
4.
J Interv Cardiol ; 2020: 4075792, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33214775

RESUMEN

BACKGROUND: Transcatheter aortic valve replacement (TAVR), widely used as an alternative therapy in patients with severe aortic stenosis, is expected to be offered to low-risk patents with a longer life expectancy. The durability of transcatheter aortic valve is becoming of increasing importance. METHOD: PubMed, Embase, and Cochrane CENTRAL from the inception to March 2020 were systematically screened for studies reporting on structural valve deterioration (SVD) in TAVR patients. Incidence of SVD was diagnosed according to the latest European consensus as the primary end point. Predictors of SVD evaluated at multivariable analysis and cumulative incidence function (CIF) of SVD were the secondary end point. RESULT: Twelve studies encompassing 10031 patients evaluating the incidence of SVD were included, with a follow-up between 1 and 8 years. The pooled incidence of SVD was 4.93% (95% CI, 2.75%-7.70%, I 2 = 96%) at 1 year and 8.97% (95% CI, 6.89%-11.29%, I 2 = 86%) in the long term (≥5 years). Subgroup analysis was performed to identify the valve type that may result in partial heterogeneity. SVD was more frequent in patents with a valve diameter of <26 mm (HR: 3.57, 1.47-8.69), oral anticoagulants (OAC), exposure at discharge (OR: 0.48, 0.38-0.61), or by a disease of renal dysfunction (OR 1.42, 1.03-1.96). CONCLUSION: SVD represents infrequent events after TAVR in the long term (>5 years), occurring more commonly in renal dysfunction patients, with small valve diameter and without OAC exposure. There may be an underestimation of the incidence if we assume death as a competing risk.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas/efectos adversos , Efectos Adversos a Largo Plazo , Falla de Prótesis/efectos adversos , Humanos , Incidencia , Efectos Adversos a Largo Plazo/epidemiología , Efectos Adversos a Largo Plazo/etiología , Insuficiencia Renal/epidemiología , Medición de Riesgo , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Reemplazo de la Válvula Aórtica Transcatéter/métodos
5.
Appl Opt ; 57(30): 9040-9045, 2018 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-30461892

RESUMEN

We demonstrated a tunable structural color filter based on an asymmetric Fabry-Perot cavity employing germanium antimony tellurium alloy Ge2Sb2Te5 (GST) as a switchable ultrathin lossy layer. The color tunability and switch mechanism of our designed structure were investigated by both simulation and analytical approaches. Both numerical simulations and analytical results show that the tunable reflective colors can be generated through the reversible phase transition of GST from amorphous to crystalline. Additionally, the generated colors possess high brightness, high saturation, and a wide gamut. Our designed structure will inspire phase-transition-based systems' potential applications in colorimetric sensing, smart windows, full-color printing and displays, anti-counterfeiting, and data encryption.

6.
Front Nutr ; 11: 1418120, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38887503

RESUMEN

Composite natural emulsifiers such as whey protein isolate (WPI) and chitosan (CS) are commonly used in Pickering emulsions to address the effect of thermal deformation of proteins before complexation with CS and heating after complexation. In this study, the properties of WPI and CS composites were investigated by complexing CS with either unmodified WPI or thermally denatured WPI (DWPI). Three types of composite particles were prepared, WPI-CS, DWPI-CS, and D(WPI-CS). Atomic force microscopy revealed that the composite particles formed larger aggregates with increased contour size and surface roughness compared to CS and WPI, whereas the interfacial tension decreased, indicating improved emulsifying abilities. Fourier-transform infrared analysis revealed differences in the hydrogen bonds between CS and WPI/DWPI. All three composite particles formed stable emulsions with droplet sizes of 20.00 ± 0.15, 27.80 ± 0.35, and 16.77 ± 0.51 µm, respectively. Thermal stability experiments revealed that the curcumin emulsion stabilized with WPI-CS and DWPI-CS exhibited relatively better thermal stability than that stabilized with D(WPI-CS). In vitro experiments results indicated that the bioaccessibility of the curcumin emulsion stabilized with WPI-CS was 61.18 ± 0.16%, significantly higher than that of the emulsions prepared with the other two composite particles (p < 0.05). This study will enable the customized design of WPI composite-based Pickering emulsions for application in the food and nutrition industries.

7.
Angiology ; : 33197231196174, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37586709

RESUMEN

The present study aimed to explore the association between the neutrophil-to-lymphocyte ratio (NLR) and prognosis of critically ill chronic heart failure patients. The records of 5298 patients who met the inclusion criteria were extracted from the Medical Information Mart for Intensive Care IV database. The primary outcome was 30-days all-cause mortality and the secondary outcome was 90-days all-cause mortality. Multivariable logistic regression analysis was performed to examine the relationship between NLR and 30-days mortality. Subgroup analysis was carried out to identify whether the association between NLR and 30-days mortality differed across various subgroups. For 30-days mortality, after adjusting for multiple confounders, the odds ratio (OR) (95% confidence interval [CI]) for the second (NLR 4.0-8.4) and the third (NLR ≥8.4) tertiles were 1.52 (1.13-2.03) and 2.53 (1.92-3.34), respectively, compared with the first tertile (NLR <4.0). As for 90-days mortality, the OR for the second (NLR 4.0-8.4) was 1.34 (1.07-1.67) and 2.23 (1.81-2.76) for the third (NLR ≥8.4) tertiles compared with the reference (NLR<4.0). The interactions between the sepsis subgroup and 30-days mortality were significant. Our study concluded that the NLR was an independent predictor of 30- and 90-days mortality for critically ill patients with chronic heart failure.

8.
Sci Rep ; 13(1): 2161, 2023 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-36750601

RESUMEN

With a long epidemic history and a large number of dengue cases, Guangzhou is a key city for controlling dengue in China. The demographic information regarding dengue cases, and the genomic characteristics of the envelope gene of dengue viruses, as well as the associations between these factors were investigated from 2010 to 2019, to improve the understanding of the epidemiology of dengue in Guangzhou. Demographic data on 44,385 dengue cases reported to the Notifiable Infectious Disease Report System were analyzed using IBM SPSS Statistics v. 20. Dengue virus isolates from patient sera were sequenced, and phylogenetic trees were constructed using PhyML 3.1. There was no statistical difference in the risk of dengue infection between males and females. Unlike other areas in which dengue is endemic, the infection risk in Guangzhou increased with age. Surveillance identified four serotypes responsible for dengue infections in Guangzhou. Serotype 1 remained prevalent for most of the study period, whereas serotypes 3 and 4 were prevalent in 2012 and 2010, respectively. Different serotypes underwent genotype and sublineage shifts. The epidemiological characteristics and phylogeny of dengue in Guangzhou suggested that although it has circulated in Guangzhou for decades, it has not been endemic in Guangzhou. Meanwhile, shifts in genotypes, rather than in serotypes, might have caused dengue epidemics in Guangzhou.


Asunto(s)
Virus del Dengue , Dengue , Masculino , Femenino , Humanos , Virus del Dengue/genética , Filogenia , Genotipo , China/epidemiología , Serogrupo , Genómica
9.
Parasit Vectors ; 16(1): 382, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37880803

RESUMEN

BACKGROUND: Aedes albopictus is an invasive vector of serious Aedes-borne diseases of global concern. Habitat management remains a critical factor for establishing a cost-effective systematic strategy for sustainable vector control. However, the community-based characteristics of Ae. albopictus habitats in complex urbanization ecosystems are still not well understood. METHODS: A large-scale investigation of aquatic habitats, involving 12 sites selected as representative of four land use categories at three urbanization levels, was performed in Guangzhou, China during 2015-2017. The characteristics and dynamics of these Ae. albopictus habitats were assessed using habitat-type composition, habitat preference, diversity indexes and the Route index (RI), and the temporal patterns of these indexes were evaluated by locally weighted scatterplot smoothing models. The associations of RI with urbanization levels, land use categories and climatic variables were inferred using generalized additive mixed models. RESULTS: A total of 1994 potential habitats and 474 Ae. albopictus-positive habitats were inspected. The majority of these habitats were container-type habitats, with Ae. albopictus showing a particularly higher habitat preference for plastic containers, metal containers and ceramic vessels. Unexpectedly, some non-container-type habitats, especially ornamental ponds and surface water, were found to have fairly high Ae. albopictus positivity rates. Regarding habitats, the land use category residential and rural in Jiangpu (Conghua District, Guangzhou) had the highest number of Ae. albopictus habitats with the highest positive rates. The type diversity of total habitats (H-total) showed a quick increase from February to April and peaked in April, while the H-total of positive habitats (H-positive) and RIs peaked in May. RIs mainly increased with the monthly average daily mean temperature and monthly cumulative rainfall. We also observed the accumulation of diapause eggs in the winter and diapause termination in the following March. CONCLUSIONS: Ecological heterogeneity of habitat preferences of Ae. albopictus was demonstrated in four land use categories at three urbanization levels. The results reveal diversified habitat-type compositions and significant seasonal variations, indicating an ongoing adaptation of Ae. albopictus to the urbanization ecosystem. H-positivity and RIs were inferred as affected by climatic variables and diapause behavior of Ae. albopictus, suggesting that an effective control of overwintering diapause eggs is crucial. Our findings lay a foundation for establishing a stratified systematic management strategy of Ae. albopictus habitats in cities that is expected to complement and improve community-based interventions and sustainable vector management.


Asunto(s)
Aedes , Ecosistema , Animales , Urbanización , Mosquitos Vectores , Óvulo , Larva
10.
Cancer Lett ; 503: 54-68, 2021 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-33476649

RESUMEN

Glioma is the most prevalent intracranial tumour, with considerable morbidity. Long non-coding RNAs are important in the biological processes of various cancers. However, little is known about ST7 antisense RNA 1 (ST7-AS1) and its role in glioma progression. ST7-AS1 expression was reduced in glioma tissues and cells in comparison to normal brain tissues. p53 transcriptionally targeted the ST7-AS1 promoter in U251 glioma cells. The targeting significantly inhibited cell migration, invasion, and proliferation, and promoted apoptosis. ST7-AS1 directly bound to and downregulated polypyrimidine tract-binding protein 1 (PTBP1) at the post-transcriptional level. ST7-AS1 overexpression inhibited glioma progression by suppressing Wnt/ß-catenin signalling by downregulating PTBP1 expression. Additionally, p53 expression negatively correlated with PTBP1 expression. Glioma progression is regulated by a positive feedback loop involving the p53/ST7-AS1/PTBP1 axis, which might be a promising therapeutic target for glioma treatment.


Asunto(s)
Neoplasias Encefálicas/patología , Glioma/patología , Ribonucleoproteínas Nucleares Heterogéneas/genética , Proteína de Unión al Tracto de Polipirimidina/genética , ARN Largo no Codificante/genética , Proteína p53 Supresora de Tumor/metabolismo , Animales , Apoptosis , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Progresión de la Enfermedad , Retroalimentación Fisiológica , Regulación Neoplásica de la Expresión Génica , Glioma/genética , Glioma/metabolismo , Humanos , Masculino , Ratones , Trasplante de Neoplasias , Regiones Promotoras Genéticas , Vía de Señalización Wnt
11.
Expert Opin Drug Saf ; 20(11): 1411-1420, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34214005

RESUMEN

OBJECTIVE: Levosimendan, an inotrope, is widely used in the management of heart failure (HF) and cardiac surgery, but it remains uncertain whether levosimendan can improve renal function in patients with left ventricular dysfunction (LVD). METHODS: PubMed, Embase, and Cochrane CENTRAL from the inception to June 2020 were systematically screened for randomized controlled trials (RCTs) to investigate whether levosimendan offers kidney-related advantages in cardiovascular patients with LVD. We pooled the effects using a random-effect model. RESULTS: Twenty-eight studies enrolling 5069 patients were included. Levosimendan reduced the sCr (SMD -0.28, 95% CI (-0.48, -0.09), P = 0.005, I2 = 52.5%, high quality) and the risk of ARF (relative risk 0.75, 95%CI (0.60, 0.95), P = 0.017, I2 = 11.3%, moderate-quality) in patients with LVD compared with control group. The reduction of sCr was more pronounced in patients with a relatively higher baseline sCr level. For secondary outcomes, levosimendan therapy was associated with the improvement of GFR (SMD 0.32, 95%CI (-0.05, 0.68), P = 0.092, I2 = 55.1%, low-quality) and urine output (SMD 0.42, 95%CI (0.06, 0.79), P = 0.024, I2 = 50.0%, very low-quality), but there was no significant reduction in BUN (SMD -0.14, 95%CI (-0.97, 0.70), P = 0.774, I2 = 77.9%, very low-quality). CONCLUSIONS: Levosimendan might improve renal function of patients with LVD.


Asunto(s)
Cardiotónicos/administración & dosificación , Simendán/administración & dosificación , Disfunción Ventricular Izquierda/tratamiento farmacológico , Cardiotónicos/farmacología , Tasa de Filtración Glomerular , Humanos , Riñón/efectos de los fármacos , Riñón/metabolismo , Pruebas de Función Renal , Ensayos Clínicos Controlados Aleatorios como Asunto , Simendán/farmacología , Disfunción Ventricular Izquierda/fisiopatología
12.
Cancer Manag Res ; 12: 1151-1161, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32104095

RESUMEN

INTRODUCTION: Numerous studies have demonstrated that long noncoding RNAs (lncRNAs) are deregulated in many cancers and exert their functions through multiple cancer-related biological processes. Glioma is the most common primary malignant central nervous system tumor and has a high fatality rate in adults. In current study, we aimed to determine the role and functional mechanism of the lncRNA BCYRN1 in glioma. METHODS: Gain-of-function and loss-of function approaches were used to investigate the function of BCYRN1. The effects of BCYRN1 on glioma cell proliferation, migration and invasion were evaluated using MTS, Transwell and wound-healing assays. The correlation between the expression of BCYRN1 and miR-125a-5p was verified by quantitative real-time PCR. RESULTS: The upregulation of BCYRN1 promoted the proliferation, migration and invasion of glioma cells. Meanwhile, the knockdown of BCYRN1 had the opposite effects. BCYRN1 was negatively correlated with miR-125a-5p. Additionally, TAZ, the endogenous target of miR-125a-5p, could be regulated by BCYRN1 in RNA and protein levels. A miR-125a-5p inhibitor restored BCYRN1 siRNA function in glioma. CONCLUSION: The present study indicates that BCYRN1 promotes glioma cell proliferation, invasion and migration in vitro. Mechanistically, upregulated expression of BCYRN1 in glioma acts as a sponge to sequester the endogenous tumor suppressor miR-125a-5p and to further increase the expression TAZ. Our findings suggest that BCYRN1 is a novel oncogene and a new therapeutic target for glioma.

13.
Research (Wash D C) ; 2018: 8109054, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31549038

RESUMEN

Visible-light color filters using patterned nanostructures have attracted much interest due to their various advantages such as compactness, enhanced stability, and environmental friendliness compared with traditional pigment or dye-based optical filters. While most existing studies are based on planar nanostructures with lateral variation in size, shape, and arrangement, the vertical dimension of structures is a long-ignored degree of freedom for the structural colors. Herein, we demonstrate a synthetic platform for transmissive color filter array by coordinated manipulations between height-varying nanocavities and their lateral filling fractions. The thickness variation of those nanocavities has been fully deployed as an alternative degree of freedom, yielding vivid colors with wide gamut and excellent saturation. Experimental results show that the color-rendering capability of the pixelated nanocavities can be still retained as pixels are miniaturized to 500 nm. Crosstalk between closely spaced pixels of a Bayer color filter arrangement was calculated, showing minimal crosstalk for 1 µm2 square subpixels. Our work provides an approach to designing and fabricating ultracompact color filter arrays for various potential applications including stained-glass microprints, microspectrometers, and high-resolution image sensing systems.

14.
Dalton Trans ; 39(32): 7588-94, 2010 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-20625599

RESUMEN

Three sandwich-type silicotungstates, formulated as [Cu4(H2O)2(SiW9O34)2] x 12 NH4 x 22 H2O (1), [Cu4(H2O)2(SiW9O34)2] x 12 NH4 x 11 H2O (2) and {[Cu(NH3)4]2[Cu(H2O)4][Cu4(H2O)2(SiW9O34)2]} 2[Cu(NH3)4(H2O)] x 2 NH4 x 6 H2O (3), were synthesized by microwave irradiation and hydrothermal reaction. Crystal structural analysis reveals that 1-3 possess the same dimeric polyoxoanions [Cu2SiW9O34(H2O)]2(12-) featuring tetranuclear copper(II) clusters. Magnetic studies indicate that the Cu4 clusters exhibit ferromagnetic coupling interactions. Investigation on their catalytic activity for the oxidation of ethylbenzene suggests that catalytic activity of 1-3 is closely related to the acidity of complexes and the existence of unsaturated coordination sites in the complex.

15.
Inorg Chem ; 45(26): 10702-11, 2006 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-17173426

RESUMEN

A series of polyoxometalates (POMs)-based coordination polymers, namely, {[Cu(2,3-Me2pz)(2,5-Me2pz)0.5]4(SiW12O40)(2,5-Me2pz)}n (2,3-Me2pz = 2,3-dimethylpyrazine; 2,5-Me2pz = 2,5-dimethylpyrazine; 1), {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(H2O)18}n (4,4'-bipy = 4,4'-bipyridine; 2), {[Cu(2-Mepz)1.5]3(PMo12O40)(H2O)3.5}n (2-Mepz = 2-methylpyrazine; 3), {[Ag(2,3-Me2pz)1.5]4(SiW12O40}n (4), {[Cu(pz)1.5]4(SiW12O40)(H2O)3}n (pz = pyrazine; 5), {[Cu(2,3-Me2pz)1.5]4(SiW12O40)}n (6), {[Cu(4,4'-bipy)1.75]4(SiW12O40)(H2O)2}n (7), and {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(4,4'-bipy)2(H2O)4}n (8), were synthesized through direct incorporation between POMs and the voids of the 2D network. Crystal structural analysis reveals that the relationship between the size of the void of the 2D network and that of POMs is of key importance for successful synthesis of POMs-based open metal-organic frameworks. Guest replacement shows that the pore size of the framework constructed through direct incorporation between POMs and the voids of the 2D network is very sensitive to guest molecules.

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