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1.
Polymers (Basel) ; 15(13)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37447577

RESUMO

Carbazole derivatives, carbazole-containing polymers and iridium complexes are of interest due to many possible applications in photonics, electronics and biology, particularly as active or hole-transporting layers in organic as well as perovskite devices due to their interesting properties. Here, a series of carbazole-fluorene conjugated copolymers with various substituents at the N-carbazole position (2-methoxycarbonylethyl, 2-carboxyethyl, 2-ethylhexyl, and nonan-2,4-dionatoiridium(III)bis(2-phenylpyridine-N,C2')-9-yl) was prepared by Suzuki coupling. Their photophysical, electrochemical and electroluminescence (EL) properties were studied. Effects of molecular weight and substituents attached to carbazole unit on their properties are reported. The carbazole-fluorene copolymers in dilute solutions exhibited intense photoluminescence (PL) emission in the blue spectral region with high PL quantum yields (78-87%) except for the copolymer with the iridium complex (23%). Similar PL spectra were observed in dilute solutions. More pronounced differences were found in thin film PL and EL properties due to excimer/aggregate formation. Light-emitting devices (LEDs) made of copolymers with 2-ethylhexyl as N-carbazole substituent exhibited efficient EL emission with the best performance and the lowest EL onset voltages (3-4 V), while the LEDs made of copolymers with other substituents were not as efficient, but showed anomalous behavior and memory effects in current-voltage characteristics promising also for bio-inspired electronics.

2.
Nanomaterials (Basel) ; 13(12)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37368260

RESUMO

Donor-acceptor (D-A) copolymers containing perylene-3,4,9,10-tetracarboxydiimide (PDI) electron-acceptor (A) units belonging to n-type semiconductors are of interest due to their many potential applications in photonics, particularly for electron-transporting layers in all-polymeric or perovskite solar cells. Combining D-A copolymers and silver nanoparticles (Ag-NPs) can further improve material properties and device performances. Hybrid layers of D-A copolymers containing PDI units and different electron-donor (D) units (9-(2-ethylhexyl)carbazole or 9,9-dioctylfluorene) with Ag-NPs were prepared electrochemically during the reduction of pristine copolymer layers. The formation of hybrid layers with Ag-NP coverage was monitored by in-situ measurement of absorption spectra. The Ag-NP coverage of up to 41% was higher in hybrid layers made of copolymer with 9-(2-ethylhexyl)carbazole D units than in those made of copolymer with 9,9-dioctylfluorene D units. The pristine and hybrid copolymer layers were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, which proved the formation of hybrid layers with stable Ag-NPs in the metallic state with average diameters <70 nm. The influence of D units on Ag-NP diameters and coverage was revealed.

3.
Polymers (Basel) ; 13(3)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33573074

RESUMO

Hybrid layers of donor-acceptor (D-A) copolymers containing N,N'-dialkylperylene-3,4,9,10-tetracarboxydiimide electron-acceptor units covered with silver nanoparticles (Ag-NPs) were prepared by electrochemical doping of pristine layers during reduction processes. In situ optical absorption spectra of the layers were recorded during the formation of Ag-NP coverage. The hybrid layers were characterized by absorption spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDX). In the absorption spectra of the hybrid layers, a surface plasmon band characteristic of Ag-NPs appeared. Significant improvements in light absorption due to the plasmonic effects of Ag NPs were observed. Stable Ag-NPs with an average diameter of 41-63 nm were formed on the surface, as proven by SEM and XPS. The Ag-NP coverage and size depended on the hybrid layer preparation conditions and on the copolymer composition. The metallic character of the Ag-NPs was proven by XPS. The location in the surface layer was further confirmed by EDX analysis. To the best of our knowledge, this is the first report on such hybrid layers having the potential for a variety of photonic and electronic applications.

4.
Vnitr Lek ; 66(5): 76-79, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32942875

RESUMO

We present a case report of a patient with acute upper and lower limb ischemia due to paradoxical embolism. A 67-year old woman without history of venous thromboembolism suffered dislocated patellar fracture requiring surgery in November 2017. Two months after surgery she presented to the emergency room with bilateral pulmonary embolism, occlusion of the left subclavian artery, left common femoral artery and superior mesenteric artery. Transesophageal echocardiography detected patent foramen ovale. Vascular surgeon decided against embolectomy, interventional radiologist against pharmacomechanical thrombolysis due to the extent of the occlusions. Systemic thrombolysis (alteplase) was administered successfully with resolution of the emboli in the left subclavian artery, left common femoral artery and superior mesenteric artery.


Assuntos
Embolia Paradoxal , Forame Oval Patente , Embolia Pulmonar , Idoso , Embolectomia , Embolia Paradoxal/tratamento farmacológico , Embolia Paradoxal/cirurgia , Feminino , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico por imagem , Forame Oval Patente/tratamento farmacológico , Humanos , Isquemia/tratamento farmacológico , Embolia Pulmonar/cirurgia , Terapia Trombolítica
5.
Macromolecules ; 50(21): 8357-8371, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29151617

RESUMO

Anthanthrone and its derivatives are large polycyclic aromatic compounds (PACs) that pose a number of challenges for incorporation into the structure of soluble conjugated polymers. For the first time, this group of PACs was employed as the building blocks for the synthesis of copolymers (P1-P5) based on poly[(arylene ethynylene)-alt-(arylene vinylene)]s backbone (-Ph-C≡C-Anth-C≡C-Ph-CH=CH-Ph-CH=CH-) n . During the synthesis of P1-P5, different alkyloxy side chains were incorporated in order to tune the properties of the polymers. Of the copolymer series only P1 (containing anthanthrone and branched 2-ethylhexyloxy side chains on phenylenes), P2 and P3 (for which the anthanthrones containing carbonyl groups were converted to anthanthrene containing alkyloxy substituents) were soluble. The photophysical, electrochemical, electroluminescent and photovoltaic properties of P1-P3 are reported, compared and discussed with respect to the effects of side chains.

6.
Vnitr Lek ; 62(4): 263-7, 2016 Apr.
Artigo em Tcheco | MEDLINE | ID: mdl-27250603

RESUMO

INTRODUCTION: One of the risks of diuretic therapy for pulmonary edema is the development of hyponatremia and hypokalemia with pro-arrhythmic potential. The aim of our study was to analyze the incidence of hyponatremia and hypokalemia after the first day of treatment in a real clinical practice. METHODS: We performed a retrospective analysis of data obtained from medical records. We included all patients with pulmonary edema admitted to the coronary care unit, only patients which died within the first day of treatment were excluded. Absolute dose of administered furosemide, total fluid intake and urine output, saline and pottasium intake were analyzed. Nonparametric paired Wilcoxon test was used to compare natrium and pottasium levels changes. RESULTS: 37 patients were included into analysis. The median dose of furosemide administered during the first day of treatment was 120 mg (IQR 20-300 mg). Median diuresis was 2 400 ml (IQR 1 425-3 225 ml). The median of difference between diuresis and total fluid intake was 315 ml (IQR 538-1 380 ml). Wilcoxon test confirmed a prevailing statistically significant trend of slight rise in serum sodium within the first day of treatment (serum sodium 138.0 IQR 132.8-139.6 vs 138.1 IQR 134,0-141,7 mmol/l, p = 0.0046). The difference in serum potassium was not statistically significant (serum potassium 4.2 IQR 3.9-4.8 vs 4.2, IQR 3.8-4.8 mmol/l). CONCLUSION: Results did not confirmed the need for a substitution of sodium and potassium losses during the first day of diuretic therapy to prevent hyponatriemia and hypokalemia in patients with pulmonary edema.


Assuntos
Diuréticos/uso terapêutico , Furosemida/uso terapêutico , Edema Pulmonar/tratamento farmacológico , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sódio/sangue
7.
Macromolecules ; 49(2): 455-464, 2016 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-26877550

RESUMO

The synthesis and characterization of a set of conjugated polymers, poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene)s (PPE-PPVs), with a dissymmetrical configuration (partial or total) of alkoxy side chains is reported. Five new polymers bearing octyloxy and/or octadecyloxy side chains at the phenylene-ethynylene and phenylene-vinylene segments, respectively, were obtained. Two symmetrical substituted polymers were used for comparison. Polymers with weight-average molecular weight, Mw, up to 430 000 g/mol and degree of polymerization between 17 and 322 were obtained by a Horner-Wadsworth-Emmons olefination polycondensation reaction of the respective luminophoric dialdehydes and bisphosphonates. As expected, identical conjugated backbones in all polymers results in very similar photophysical response in dilute solution, with high fluorescence quantum yields between 50% and 80%. In contrast, the thin film properties are dependent on the combinatorial effects of side chain configuration, molecular weight, and film thickness parameters, which are the basis of the resulting comparison and discussion.

8.
Acta Cardiol ; 70(4): 387-93, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26455239

RESUMO

OBJECTIVE: The prognostic impact of right ventricular systolic dysfunction (RVSD) in heart failure (HF) with preserved ejection fraction (HFPEF) is not sufficiently understood. This pilot study evaluates the prevalence and prognostic impact of RVSD in HFPEF. METHODS: Ninety-five consecutive patients, admitted due to HF within one year were included and followed up for 12 months. Patients were classified based on left ventricular ejection fraction (LVEF) into two groups: HFPEF (LVEF >40%; n = 54), and heart failure with reduced ejection fraction (HFREF) (LVEF < or = 40%; n = 41). RVSD was defined as peak systolic tricuspid annular velocity (S') <10.8 cm/s. RESULTS: The prevalence of RVSD was 22% vs 59%, in HFPEF vs HFREF, respectively (P < 0.001). Patients with HFPEF and RVSD had significantly higher one-year all-cause mortality compared to HFPEF with normal RV function (41.7% vs. 4.8%, P = 0.004). The same trend was found in HFREF (33.3% vs. 5.9%, P = 0.057). A similar outcome was obser ved in cardiovascular mortality (H FPEF 33.3% vs. 0%, P = 0.002 and HFREF 20.8% vs. 0%, P= 0.06). RVSD was the only independent predictor of all-cause one-year mortality in patients with HFPEF (HR 11.5, 95% Cl 2.2 to 59.5, p = 0.004). CONCLUSION: RVSD is an independent predictor of all-cause mortality in HFPEF. Patients with HFPEF and RVSD had significantly higher one-year all-cause and cardiovascular mortality than those with normal RV function.


Assuntos
Insuficiência Cardíaca , Função Ventricular Esquerda , Função Ventricular Direita , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Eslováquia/epidemiologia , Volume Sistólico , Análise de Sobrevida , Valva Tricúspide/fisiopatologia
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