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1.
Small ; 20(30): e2312041, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38438898

RESUMO

Despite the considerable significance of utilizing ultra-thin film (utf) hydrogels as multipurpose platforms for biomedical applications, there is still an important lack of adequate characterization techniques suitable for such materials. In this Perspective, the use of quartz crystal microbalance with dissipation (QCM-D) coupled with spectral ellipsometry (SE) is presented as a potential tool for the complete characterization of utf-hydrogels due to its nanometric sensitivity and high versatility. Herein, the fundaments for utf-hydrogel characterization are settled down as far as the QCM-D/SE response is explored under a wide range of different in operando wet working conditions measurements such as temperature or liquid media, among others. Therefore, the design of measuring protocols capable to perform is proposed and compiled, for the first time, complete and precise characterization of the cross-link density, thickness variations (swelling ratio determination), stability analyses, and mechanical studies (including the simultaneous generation of stress-strain curves and the evaluation of the viscoelastic; leading to the final determination of the Poisson's ratio) under different in operando conditions. Finally, the future challenges and implications for the general characterization of soft-thin films are discussed.

2.
Biomacromolecules ; 24(3): 1432-1444, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36821593

RESUMO

Multiresponsive hydrogels, which are smart soft materials that respond to more than one external stimulus, have emerged as powerful tools for biomedical applications, such as drug delivery. Within this context and with the aim of eliminating the systematic administration of antibiotics, special attention is being paid to the development of systems for controlled delivery of antibiotic for topical treatment of bacterial infections. In this work, an electro-chemo responsive hydrogel able to release chloramphenicol (CAM), a broad spectrum antibiotic also used for anticancer therapy, is proposed. This has been prepared by grafting poly(acrylic acid) (PAA) to sodium alginate (Alg) and in situ encapsulation of poly(3,4-ethylenedioxythiophene) nanoparticles loaded with CAM (PEDOT/CAM NPs), which were obtained by emulsion polymerization. Although the response to electrical stimuli of PEDOT was the main control for the release of CAM from PEDOT/CAM NPs, the release by passive diffusion had a relatively important contribution. Conversely, the passive release of antibiotic from the whole engineered hydrogel system, Alg-g-PAA/PEDOT/CAM, was negligible, whereas significant release was achieved under electrostimulation in an acid environment. Bacterial tests and assays with cancer cells demonstrated that the biological activity of CAM remained after release by electrical stimulation. Notably, the successful dual-response of the developed hydrogel to electrical stimuli and pH changes evidence the great prospect of this smart material in the biomedical field, as a tool to fight against bacterial infections and to provide local cancer treatment.


Assuntos
Infecções Bacterianas , Cloranfenicol , Humanos , Hidrogéis , Antibacterianos , Concentração de Íons de Hidrogênio
3.
Respirology ; 26(4): 352-359, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33167075

RESUMO

BACKGROUND AND OBJECTIVE: The relationship between IPF development and environmental factors has not been completely elucidated. Analysing geographic regions of idiopathic pulmonary fibrosis (IPF) cases could help identify those areas with higher aggregation and investigate potential triggers. We hypothesize that cross-analysing location of IPF cases and areas of consistently high air pollution concentration could lead to recognition of environmental risk factors for IPF development. METHODS: This retrospective study analysed epidemiological and clinical data from 503 patients registered in the Observatory IPF.cat from January 2017 to June 2019. Incident and prevalent IPF cases from the Catalan region of Spain were graphed based on their postal address. We generated maps of the most relevant air pollutant PM2.5 from the last 10 years using data from the CALIOPE air quality forecast system and observational data. RESULTS: In 2018, the prevalence of IPF differed across provinces; from 8.1 cases per 100 000 habitants in Barcelona to 2.0 cases per 100 000 in Girona. The ratio of IPF was higher in some areas. Mapping PM2.5 levels illustrated that certain areas with more industry, traffic and shipping maintained markedly higher PM2.5 concentrations. Most of these locations correlated with higher aggregation of IPF cases. Compared with other risk factors, PM2.5 exposure was the most frequent. CONCLUSION: In this retrospective study, prevalence of IPF is higher in areas of elevated PM2.5 concentration. Prospective studies with targeted pollution mapping need to be done in specific geographies to compile a broader profile of environmental factors involved in the development of pulmonary fibrosis.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Fibrose Pulmonar Idiopática , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Humanos , Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/etiologia , Estudos Prospectivos , Estudos Retrospectivos
4.
Langmuir ; 35(46): 14782-14790, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31647245

RESUMO

Semipermanently polarized hydroxyapatite, named SP/HAp(w), is obtained by applying a constant dc electric field of 1-10 kV/cm at 300-850 °C to the samples previously sintered in water vapor, while permanently polarized hydroxyapatite, PP/HAp(a), is produced by applying a dc electric field of 3 kV/cm at 1000 °C to the samples sintered in air. SP/HAp(w) has been used for biomedical applications, while PP/HAp(a) has been proved to be a valuable catalyst for N2 and CO2 fixation. In this work, structural differences between SP/HAp(w) and PP/HAp(a) have been ascertained using Raman microscopy, wide-angle X-ray diffraction, scanning electronic microscopy, high-resolution transmission electron microscopy, and grazing incidence X-ray diffraction. Results prove the existence of crystal distortion in the form of amorphous calcium phosphate and ß-tricalcium phosphate (ß-TCP) phases close to the surface because of the atmosphere used in the sintering process. The existence of an amorphous layer in the surface and the phase transition through ß-TCP of SP/HAp(w) are the structural factors responsible for the differences with respect to PP/HAp(a). Moreover, a superstructure has been identified in PP/HAp(a) samples, which could be another structural factor associated with enhanced conductivity, permanent polarization, and catalytic activity of this material.

5.
Cardiology ; 130(2): 120-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25612789

RESUMO

OBJECTIVES: This pilot trial evaluated the feasibility and safety of an early discharge strategy (EDS: ≤72 h, followed by outpatient lifestyle interventions), in comparison with a conventional discharge strategy (CDS) for low-risk (Zwolle risk score ≤3) ST-elevation myocardial infarction (STEMI) patients treated with primary angioplasty. METHODS: One hundred patients were randomized to an EDS (n = 54) or a CDS (n = 46). The primary end point was the feasibility of the EDS: (1) ≥70% of EDS patients discharged ≤72 h, (2) ≥70% visited by a nurse ≤7 days after discharge, (3) ≥70% with ≥3 visits by the nurse and (4) ≥70% visited by a cardiologist ≤3 months. RESULTS: The mean age was 59.2 ± 12.2 years and ejection fraction 54.0 ± 7.1%. Eighty-six percent were male (12% diabetics). Vascular access was radial in 91%. Ischemic time was ≤4 h in 75%. Length of stay was shorter in EDS as compared with CDS (70.1 ± 8.1 vs. 111.8 ± 28.3 h, p < 0.001). EDS feasibility was: (1) 72.2%; (2) 81.5%; (3) 76.9%; (4) 72.2%. There were no adverse events or differences in intervention goals and quality of life between groups. CONCLUSIONS: An EDS in low-risk STEMI patients is feasible and seems to be safe. A shorter hospital stay could benefit patients and health care systems.


Assuntos
Tempo de Internação , Infarto do Miocárdio/terapia , Alta do Paciente , Intervenção Coronária Percutânea/efeitos adversos , Qualidade de Vida , Idoso , Angioplastia Coronária com Balão , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Projetos Piloto , Fatores de Risco , Volume Sistólico , Fatores de Tempo , Ultrassonografia
6.
Mater Horiz ; 9(6): 1566-1576, 2022 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-35357375

RESUMO

Hydroxyapatite (HAp) is a well-known ceramic material widely used in the biomedical field. This review summarizes the very recent developments on permanently polarized HAp (pp-HAp), a HAp variety with tuned electrical properties that confer remarkable catalytic activity. pp-HAp is obtained by applying a thermal stimulation polarization process (TSP), which consists on a DC electric voltage of 500 V at 1000 °C, to previously sintered HAp. The TSP not only increases the crystallinity, reducing the defects in the crystal lattice, but also creates charges that accumulate at the crystalline boundaries and at the surface of microscopic grains, boosting the electrical conductivity. Finally, the successful utilization of pp-HAp in the catalytic fixation of carbon and nitrogen from CO2 and N2 gases, respectively, is reported and the formation of different products of chemical interest (e.g. amino acids, ethanol and ammonium) as a function of the reaction conditions (i.e. feeding gases and presence/absence of UV illumination) and catalyst plasticity is discussed. pp-HAp exhibits important advantages with respect to other consolidated catalysts, which drastically increases the final energetic net balance of the reactions.


Assuntos
Carbono , Durapatita , Cerâmica , Durapatita/química , Gases , Fixação de Nitrogênio
7.
ACS Appl Nano Mater ; 5(6): 8526-8536, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-36910876

RESUMO

Polarized hydroxyapatite (HAp) scaffolds with customized architecture at the nanoscale have been presented as a green alternative to conventional catalysts used for carbon and dinitrogen fixation. HAp printable inks with controlled nanoporosity and rheological properties have been successfully achieved by incorporating Pluronic hydrogel. Nanoporous scaffolds with good mechanical properties, as demonstrated by means of the nanoindentation technique, have been obtained by a sintering treatment and the posterior thermally induced polarization process. Their catalytic activity has been evaluated by considering three different key reactions (all in the presence of liquid water): (1) the synthesis of amino acids from gas mixtures of N2, CO2, and CH4; (2) the production of ethanol from gas mixtures of CO2 and CH4; and (3) the synthesis of ammonia from N2 gas. Comparison of the yields obtained by using nanoporous and nonporous (conventional) polarized HAp catalysts shows that both the nanoporosity and water absorption capacity of the former represent a drawback when the catalytic reaction requires auxiliary coating layers, as for example for the production of amino acids. This is because the surface nanopores achieved by incorporating Pluronic hydrogel are completely hindered by such auxiliary coating layers. On the contrary, the catalytic activity improves drastically for reactions in which the HAp-based scaffolds with enhanced nanoporosity are used as catalysts. More specifically, the carbon fixation from CO2 and CH4 to yield ethanol improves by more than 3000% when compared with nonporous HAp catalyst. Similarly, the synthesis of ammonia by dinitrogen fixation increases by more than 2000%. Therefore, HAp catalysts based on nanoporous scaffolds exhibit an extraordinary potential for scalability and industrial utilization for many chemical reactions, enabling a feasible green chemistry alternative to catalysts based on heavy metals.

8.
Chem Commun (Camb) ; 57(42): 5163-5166, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-33900306

RESUMO

Conversion of CO2 into valuable chemicals is not only a very challenging topic but also a socially demanding issue. In this work, permanently polarized hydroxyapatite obtained using a thermal stimulated polarization process is proposed as a highly selective catalyst for green production of ethanol starting from CO2 and CH4.

9.
ACS Omega ; 3(6): 6971-6975, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31458863

RESUMO

A commercial compact disk has been converted into an effective photocatalytic nanoreactor by depositing a catalyst layer inside the nanochannels by means of an electrophoretic method. The resultant device has been tested for water splitting, obtaining a high yield of hydrogen at an unbeatable low cost.

10.
Gen Hosp Psychiatry ; 25(1): 46-50, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12583928

RESUMO

Some studies on discharge against medical advice (AMA) in general hospitals report a prevalence between 0.7-7% with 11-42% of this population identified as psychiatric patients. To study the sociodemographic and psychopathological features of patients who leave AMA, we performed a retrospective case-control comparison study of length of hospitalization and presence of psychiatric disturbances on patients who left AMA from the University General Hospital in Catalan Spain over a two-year period. An analysis of the hospital epidemiological discharge register and retrospective chart review for presence of psychiatric disturbances found that AMA prevalence was 0.34%, the total discharge number in the 2-year period being 41,648. AMA rates by medical department were 0.44% for the internal medicine department; 0.24% for surgery; 0.26% for orthopedic surgery, 0.32% for obstetrics-gynecology and 0.93% for rehabilitation. The mean age for AMA patients was 38.63 years, with a higher number of men (59.9%). A total of 45.8% AMA discharges were from the internal medicine department. No significant differences were found in the average length of hospitalization between the AMA and control groups. The presence of psychiatric pathology was significantly higher among the AMA group (P<.05). The prevalence of AMA at our hospital was low in comparison to the rates reported in the literature. The patient at high risk for AMA discharge is a young man with a history of psychiatric pathology, mainly narcotic dependence.


Assuntos
Hospitais Gerais , Transtornos Mentais/reabilitação , Alta do Paciente/estatística & dados numéricos , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Hospitalização , Humanos , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Espanha/epidemiologia
11.
J Obes ; 2012: 287939, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22900151

RESUMO

Although obesity is a well-established cardiovascular risk factor, some controversy has arisen with regard to its effect on hospital mortality in patients admitted for acute coronary syndrome. Methods. Clinical and anthropometric variables were analyzed in patients consecutively admitted for acute coronary syndrome to a university hospital between 2009 and 2010, and the correlation of those variables with hospital mortality was examined. Results. A total of 824 patients with a diagnosis of myocardial infarction or unstable angina were analyzed. Body mass index was an independent factor in hospital mortality (odds ratio 0.739 (IC 95%: 0.597 - 0.916), P = 0.006). Mortality in normal weight (n = 218), overweight (n = 399), and obese (n = 172) subjects was 6.1%, 3.1%, and 4.1%, respectively, with no statistically significant differences between the groups. Conclusions. There is something of a paradox in the relationship between body mass index and hospital mortality in patients with acute coronary syndrome in that the mortality rate decreases as body mass index increases. However, no statistically significant differences have been found in normal weight, overweight, or obese subjects.

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