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1.
Small ; 20(29): e2309216, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38334248

RESUMO

An effective synthesis of conductive polymer brushes, i.e., self-templating surface-initiated copolymerization (ST-SICP), is developed. It proceeds through copolymerization of pendant thiophene groups in the precursor multimonomer poly(3-methylthienyl methacrylate) (PMTM) brushes with free 3-methylthiophene (3MT) monomers leading to PMTM-co-P3MT brushes. This approach leads to improved conformational freedom of generated conjugated poly(thiophene)-based chains and their higher share in the brushes with respect to conjugation of pendant thiophene groups only. As a result, best performing conjugated PMTM-co-P3MT brushes demonstrate high ohmic conductivity in both out-of-plane and in-plane direction. Furthermore, thanks to the covalent anchoring as well as intra- and intermolecular connections, highly stable and mechanically robust nanocoatings are produced which can survive mechanical cleaning and long-term storage under ambient conditions. Grafting of ionic poly(sodium 4-styrenesulfonate) (PSSNa) in between PMTM-co-P3MT chains brings new properties to such binary mixed brushes that can operate as thin-film memristive coating with switchable conductance. It is worth mentioning that the crucial synthetic steps, i.e., grafting of precursor PMTM brushes by surface-initiated organocatalyzed atom transfer radical polymerization (SI-O-ATRP) and PSSNa chains by surface-initiated photoiniferter-mediated polymerization (SI-PIMP) are conducted under ambient conditions using only microliter volumes of reagents providing methodology that can be considered for use beyond the laboratory scale.

2.
Int J Mol Sci ; 23(11)2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35682563

RESUMO

The high stability and conductivity of 3,4-disubstituted polythiophenes such as poly(3,4-ethylenedioxythiophene) (PEDOT) make them attractive candidates for commercial applications. However, next-generation nanoelectronic devices require novel macromolecular strategies for the precise synthesis of advanced polymer structures as well as their arrangement. In this report, we present a synthetic route to make ladder-like polymer brushes with poly(3,4-propylenedioxythiophene) (PProDOT)-conjugated chains. The brushes were prepared via a self-templating surface-initiated technique (ST-SIP) that combines the surface-initiated atom transfer radical polymerization (SI-ATRP) of bifunctional ProDOT-based monomers and subsequent oxidative polymerization of the pendant ProDOT groups in the parent brushes. The brushes prepared in this way were characterized by grazing-angle FTIR, XPS spectroscopy, and AFM. Steady-state and time-resolved photoluminescence measurements were used to extract the information about the structure and effective conjugation length of PProDOT-based chains. Stability tests performed in ambient conditions and under exposure to standardized solar light revealed the remarkable stability of the obtained materials.


Assuntos
Polímeros , Polimerização , Polímeros/química , Propriedades de Superfície
3.
Molecules ; 27(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35164156

RESUMO

The article presents the modification of ash wood via surface initiated activators regenerated by electron transfer atom transfer radical polymerization mediated by elemental silver (Ag0 SI-ARGET ATRP) at a diminished catalyst concentration. Ash wood is functionalized with poly(methyl methacrylate) (PMMA) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) to yield wood grafted with PMMA-b-PDMAEMA-Br copolymers with hydrophobic and antibacterial properties. Fourier transform infrared (FT-IR) spectroscopy confirmed the covalent incorporation of functional ATRP initiation sites and polymer chains into the wood structure. The polymerization kinetics was followed by the analysis of the polymer grown in solution from the sacrificial initiator by proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The polymer layer covalently attached to the wood surface was observed by scanning electron microscopy (SEM). The hydrophobic properties of hybrid materials were confirmed by water contact angle measurements. Water and sodium chloride salt aqueous solution uptake tests confirmed a significant improvement in resistance to the absorption of wood samples after modification with polymers. Antibacterial tests revealed that wood-QPDMAEMA-Br, as well as wood-PMMA-b-QPDMAEMA-Br, exhibited higher antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) in comparison with Gram-negative bacteria (Escherichia coli). The paper presents an economic concept with ecological aspects of improving wood properties, which gives great opportunities to use the proposed approach in the production of functional hybrid materials for industry and high quality sports equipment, and in furniture production.

4.
J Am Chem Soc ; 143(29): 11052-11062, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34264655

RESUMO

Direct exfoliation of layered zeolites into solutions of monolayers has remained unresolved since the 1990s. Recently, zeolite MCM-56 with the MWW topology (layers denoted mww) has been exfoliated directly in high yield by soft-chemical treatment with tetrabutylammonium hydroxide (TBAOH). This has enabled preparation of zeolite-based hierarchical materials and intimate composites with other active species that are unimaginable via the conventional solid-state routes. The extension to other frameworks, which provides broader benefits, diversified activity, and functionality, is not routine and requires finding suitable synthesis formulations, viz. compositions and conditions, of the layered zeolites themselves. This article reports exfoliation and characterization of layers with ferrierite-related structure, denoted bifer, having rectangular lattice constants like those of the FER and CDO zeolites, and thickness of approximately 2 nm, which is twice that of the so-called fer layer. Several techniques were combined to prove the exfoliation, supported by simulations: AFM; in-plane, in situ, and powder X-ray diffraction; TEM; and SAED. The results confirmed (i) the structure and crystallinity of the layers without unequivocal differentiation between the FER and CDO topologies and (ii) uniform thickness in solution (monodispersity), ruling out significant multilayered particles and other impurities. The bifer layers are zeolitic with Brønsted acid sites, demonstrated catalytic activity in the alkylation of mesitylene with benzyl alcohol, and intralayer pores visible in TEM. The practical benefits are demonstrated by the preparation of unprecedented intimately mixed zeolite composites with the mww, with activity greater than the sum of the components despite high content of inert silica as pillars.

5.
Chemistry ; 23(47): 11239-11243, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28644908

RESUMO

Surface-grafted polymer brushes of novel ladder-like architecture were proposed for inducing ordering of chromophores embedded therein. The brushes with acetylene side groups were obtained by surface-initiated photoiniferter-mediated polymerization. The acetylene moieties reacted then through a "click" process with an axially azide-bifunctionalized silicon phthalocyanine bridging the neighboring chains that inherently adopt extended conformations in dense brushes. FTIR, quartz crystal microbalance, and atomic force microscopy were used to study formation and structure of the photoactive brushes varying in grafting densities. Importantly, photophysical properties of the chromophores were virtually unaffected upon embedding them into the brushes, as evidenced by UV/Vis absorption and emission spectroscopy. Owing to the unique ordering of the chromophores, the proposed method may open new opportunities for the fabrication of light-harvesting systems suitable for photovoltaic or sensing applications.


Assuntos
Polímeros/química , Azidas/química , Química Click , Indóis/química , Microscopia de Força Atômica , Compostos de Organossilício/química , Técnicas de Microbalança de Cristal de Quartzo , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Pol Merkur Lekarski ; 42(247): 21-25, 2017 Jan 23.
Artigo em Polonês | MEDLINE | ID: mdl-28134227

RESUMO

Diagnosis and treatment of infective endocarditis (IE) is still a challenge for physicians. Group of patients with the worst prognosis is treated in Intensive Cardiac Care Unit (ICCU). Etiologic agent can not be identified in a substantial number of patients. AIM: The aim of study is to find differences between patients with blood culture negative infective endocarditis (BCNIE) and blood culture positive infective endocarditis (BCPIE) treated in ICCU by comparing their clinical course and laboratory parameters. MATERIALS AND METHODS: Retrospective analysis of 30 patients with IE hospitalized in ICCU Swietokrzyskie Cardiac Centre between 2010 and 2016. This group consist of 26 men (86,67%) and 4 women (13,3%). Mean age was 58 years ±13. Most of the cases were new disease, recurrence of the disease was observed in 2 cases (6,7%). 8 patients (26,7%) required artificial ventilation, 11 (36,7%) received inotropes and 6 (20%) vasopresors. In 14 (46,7%) cases blood cultures was negative (BCNIE), the rest of patients (16, 53,3%) was blood cultures - positive infective endocarditis (BCIE). RESULTS: Both of the groups were clinically similar. There were no statistically significant differences in incidence of cardiac implants, localization of bacterial vegetations, administered catecholamines, antibiotic therapy, artificial ventilation, surgical treatment, complication and in-hospital mortality. Incidence of cardiac complications in all of BCNIE cases and in 81,3% cases of BCPIE draws attention, but it is not statistically significant difference (p=0,08). There was statistically significant difference in mean BNP blood concentration (3005,17 ng/ml ±2045,2 vs 1013,42 ng/ml ±1087,6; p=0,01), but there were no statistically significant differences in rest of laboratory parameters. CONCLUSIONS: BCNIE group has got higher mean BNP blood concentration than BCPIE group. There were no statistically significant differences between these groups in others laboratory parameters, clinical course and administered antibiotic therapy. In our endemic region major cause of BCNIE seems to be early antibiotic therapy prior to collection of blood samples, but further studies are necessary.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/epidemiologia , Endocardite/epidemiologia , Peptídeo Natriurético Encefálico/sangue , Adulto , Idoso , Antibacterianos/uso terapêutico , Infecções Bacterianas/sangue , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Hemocultura , Endocardite/sangue , Endocardite/diagnóstico , Endocardite/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polônia/epidemiologia , Estudos Retrospectivos , Fatores de Risco
7.
ScientificWorldJournal ; 2015: 626545, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26448964

RESUMO

The paper presents a method for precise estimation of evapotranspiration of selected turfgrass species. The evapotranspiration functions, whose domains are only two relatively easy to measure parameters, were developed separately for each of the grass species. Those parameters are the temperature and the volumetric moisture of soil at the depth of 2.5 cm. Evapotranspiration has the character of a modified logistic function with empirical parameters. It assumes the form ETR(θ (2.5 cm), T (2.5 cm)) = A/(1 + B · e (-C · (θ (2.5 cm) · T (2.5 cm)), where: ETR(θ (2.5 cm), T (2.5 cm)) is evapotranspiration [mm · h(-1)], θ (2.5 cm) is volumetric moisture of soil at the depth of 2.5 cm [m(3) · m(-3)], T (2.5 cm) is soil temperature at the depth of 2.5 cm [°C], and A, B, and C are empirical coefficients calculated individually for each of the grass species [mm · h(1)], and [-], [(m(3) · m(-3) · °C)(-1)]. The values of evapotranspiration calculated on the basis of the presented function can be used as input data for the design of systems for the automatic control of irrigation systems ensuring optimum moisture conditions in the active layer of lawn swards.

8.
Pol Merkur Lekarski ; 36(213): 203-5, 2014 Mar.
Artigo em Polonês | MEDLINE | ID: mdl-24779221

RESUMO

Infection with influenza type A virus may cause serious cardiovascular complications, such as myocarditis, heart failure, acute myocardial infarction. Also infection with influenza type AH1N1 may contribute to aggravation of cardiac disorders, i.e. acute coronary syndrome, heart failure, cardiogenic shock, severe ventricular arrythmias. One of the most fatal complication of influenza is pneumonia leading to acute respiratory insufficiency requiring artifitial ventilation. Symptoms of respiratory tract infections durnig influenza epidemy should always be treated with a high index of suspicion. Early diagnosis and adequate antiviral treatment may prevent those complications. A series of four cases of patients hospitalised in intensive cardiac care unit due to suspected cardiac dyspnea and finally diagnosed as a cardiac disease complicated by influenza pneumonia is presented.


Assuntos
Infecção Hospitalar/complicações , Infecção Hospitalar/diagnóstico , Cardiopatias/etiologia , Vírus da Influenza A , Influenza Humana/complicações , Influenza Humana/diagnóstico , Infecções Respiratórias/etiologia , Idoso , Antivirais/uso terapêutico , Serviço Hospitalar de Cardiologia , Comorbidade , Feminino , Cardiopatias/diagnóstico , Humanos , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/tratamento farmacológico , Unidades de Terapia Intensiva , Masculino , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/tratamento farmacológico
9.
Int J Biol Macromol ; 273(Pt 1): 132768, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823733

RESUMO

Polylactic acid (PLA), a polymer derived from renewable resources, is gaining increasing attention in the development of biomedical devices due to its cost-effectiveness, low immunogenicity, and biodegradability. However, its inherent hydrophobicity remains a problem, leading to poor cell adhesion features. On this basis, the aim of this work was to develop a method for functionalizing the surface of PLA films with a biopolymer, chitosan (CH), which was proved to be a material with intrinsic cell adhesive properties, but whose mechanical properties are insufficient to be used alone. The combination of the two polymers, PLA as a bulk scaffold and CH as a coating, could be a promising combination to develop a scaffold for cell growth. The modification of PLA films involved several steps: aminolysis followed by bromination to graft amino and then bromide groups, poly(glycidyl methacrylate) (PGMA) grafting by surface-initiated supplemental activator and reducing agent atom transfer radical polymerization (SI-SARA ATRP) and finally the CH grafting. To prove the effective adhesive properties, conjugated and non-conjugated films were tested in vitro as substrates for neuronal cell growth using differentiated neurons from human induced pluripotent stem cells. The results demonstrated enhanced cell growth in the presence of CH.


Assuntos
Proliferação de Células , Quitosana , Neurônios , Poliésteres , Alicerces Teciduais , Quitosana/química , Poliésteres/química , Humanos , Alicerces Teciduais/química , Neurônios/citologia , Neurônios/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Polimerização , Adesão Celular/efeitos dos fármacos , Materiais Biocompatíveis/química
10.
Minerva Med ; 115(1): 14-22, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38037701

RESUMO

BACKGROUND: This study aims to investigate the effect of arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb) suspended on particulate matters (PM) 2.5 and PM 10 taking into account clinical factors on 30-day and one-year survival after out-of-hospital cardiac arrest (OHCA). METHODS: A retrospective 4-year study that involved patients hospitalized after OHCA. Patients' data were obtained from Emergency Medical Services dispatch cards and the National Health Fund. The concentration of air pollutants was measured by the Environmental Protection Inspectorate in Poland. RESULTS: Among the 948 patients after OHCA, only 225 (23.7%) survived for 30 days, and 153 (16.1%) survived for 1 year. Survivors were more commonly affected by OHCA in urban areas (85 [55.6%] vs. 355 [44.7%]; P=0.013) and had slightly higher one-year mean concentration of As (0.78 vs. 0.77; P=0.01), Cd (0.34 vs. 0.34; P=0.012), and Pb (11.13 vs. 10.20; P=0.015) with no differences in daily mean concentration. Significant differences in mean concentrations of heavy metals and PM 2.5 and PM 10 were observed among different quarters. However, survival analysis revealed no differences in long-term survival between quarters. Heavy metals, PM 2.5, and PM 10 did not affect short-term and long-term survival in multivariable logistic regression. CONCLUSIONS: The group of survivors showed slightly higher mean one-year concentrations of As, Cd and Pb, but they also experienced a higher incidence of OHCA in urban areas. There were no differences in long-term survival between patients who suffer OHCA in different quarters. Heavy metals did not independently affect survival.


Assuntos
Metais Pesados , Parada Cardíaca Extra-Hospitalar , Humanos , Material Particulado/efeitos adversos , Parada Cardíaca Extra-Hospitalar/epidemiologia , Estudos Retrospectivos , Cádmio , Chumbo , Metais Pesados/análise , Sistema de Registros
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