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1.
Artigo em Espanhol | MEDLINE | ID: mdl-38991862

RESUMO

OBJECTIVE: This study aims to analyze the prescription of antihypertensive drugs in patients with type 2 diabetes (T2D) in Andalusia, comparing it with the SEH-LELHA 2022 guidelines, and to assess the direct cost of these treatments. MATERIALS AND METHODS: A multicentric, cross-sectional, and descriptive study was conducted with 385 T2D patients. Participants were randomly selected from the patient lists of 120 primary care physicians from Andalusia. Inclusion criteria included a diagnosis of T2D and complete clinical records for the year 2022. Demographic data and drug prescription information were collected, with the average cost per patient being calculated. RESULTS: The mean age of the subjects was 70.72 years, with 53.51% being male. A total of 70.9% of the patients were taking antihypertensive drugs, the most common being ACE inhibitors/ARBs (70.9%), diuretics (70.1%), beta-blockers (40.0%), and calcium channel blockers (20.0%). Each patient took an average of 2.46±1.06 antihypertendsive, and fixed association of 2 or more antihypertensive drugs were used by 40.9% of the studied patients. The annual cost per patient was 141.45€/year. CONCLUSIONS: The study reveals strong adherence to the SEH-LELHA 2022 guidelines among physicians in Andalusia regarding the of antihypertensives for T2D patients, with a significant preference for Renin-Angiotensin System blockers, diuretics, and beta-blockers. However, a notable deviation in prescription practices was observed with the frequent choice of doxazosin over spironolactone, despite the latter being the recommended option for resistant hypertension. Although the overall expenditure on antihypertensives is moderate, their cost-effectiveness is enhanced by the efficacy of these treatments in preventing cardiovascular complications.

2.
Sci Rep ; 14(1): 15112, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956203

RESUMO

Cancer mice models are critical for immune-oncology research; they provide conditions to explore tumor immunoenviroment aiming to advance knowledge and treatment development. Often, research groups breed their own mice colonies. To assess the effect of C57BL/6 mice breeding nuclei in prostate cancer development and intratumoral macrophage populations, an isotransplantation experiment was performed. C57BL/6J mice from two breeding nuclei (nA and nB) were employed for prostate adenocarcinoma TRAMP-C1 cell implantation; tumor growth period and intratumoral macrophage profile were measured. BL/6nB mice (54%) showed tumor implantation after 69-day growth period while BL/6nA implantation reached 100% across tumor growth period (28 days). No difference in total macrophage populations was observed between groups within several tumoral regions; significantly higher M2 macrophage profile was observed in tumor microenvironments from both mice groups. Nevertheless, BL/6nB tumors showed around twice the population of M1 profile (11-27%) than BL6nA (4-15%) and less non-polarized macrophages. The M1:M2 average ratio was 1:8 for group A and 1:4 for B. Our results demonstrate different tumor progression and intratumoral macrophage populations among mice from the same substrain. Data obtained in this study shows the relevance of animal source renewal for better control of murine cancer model variables.


Assuntos
Modelos Animais de Doenças , Progressão da Doença , Macrófagos , Camundongos Endogâmicos C57BL , Neoplasias da Próstata , Microambiente Tumoral , Animais , Neoplasias da Próstata/patologia , Masculino , Camundongos , Macrófagos/imunologia , Linhagem Celular Tumoral
3.
Front Pediatr ; 12: 1397398, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952433

RESUMO

Introduction: Preterm birth is a growing problem worldwide. Staying at a neonatal intensive care unit (NICU) after birth is critical for the survival of preterm infants whose feeding often requires the use of nasogastric enteral feeding tubes (NEFT). These can be colonized by hospital-associated pathobionts that can access the gut of the preterm infants through this route. Since the gut microbiota is the most impactful factor on maturation of the immune system, any disturbance in this may condition their health. Therefore, the aim of this study is to assess the impact of NEFT-associated microbial communities on the establishment of the gut microbiota in preterm infants. Material and methods: A metataxonomic analysis of fecal and NEFT-related samples obtained during the first 2 weeks of life of preterm infants was performed. The potential sharing of strains isolated from the same set of samples of bacterial species involved in NICU's outbreaks, was assessed by Random Amplification of Polymorphic DNA (RAPD) genotyping. Results: In the samples taken 48 h after birth (NEFT-1 and Me/F1), Staphylococcus spp. was the most abundant genera (62% and 14%, respectively) and it was latter displaced to 5.5% and 0.45%, respectively by Enterobacteriaceae. Significant differences in beta diversity were detected in NEFT and fecal samples taken at day 17 after birth (NEFT-3 and F3) (p = 0.003 and p = 0.024, respectively). Significant positive correlations were found between the most relevant genera detected in NEFT-3 and F3. 28% of the patients shared at least one RAPD-PCR profile in fecal and NEFT samples and 11% of the total profiles were found at least once simultaneously in NEFT and fecal samples from the same patient. Conclusion: The results indicate a parallel bacterial colonization of the gut of preterm neonates and the NEFTs used for feeding, potentially involving strain sharing between these niches. Moreover, the same bacterial RAPD profiles were found in neonates hospitalized in different boxes, suggesting a microbial transference within the NICU environment. This study may assist clinical staff in implementing best practices to mitigate the spread of pathogens that could threaten the health of preterm infants.

5.
Acta Ortop Mex ; 38(3): 155-163, 2024.
Artigo em Espanhol | MEDLINE | ID: mdl-38862145

RESUMO

INTRODUCTION: metatarsophalangeal resection arthroplasty is considered a salvage surgical procedure able to improve the quality of life of patients with major forefoot deformities. MATERIAL AND METHODS: a retrospective observational study of 31 patients (36 feet) with major forefoot deformities operated at our institution was performed. Thirty two feet required additional surgery involving the first ray, most of them (72.2%) through MTP joint fusion. The mean follow-up period was 10.3 ± 4.6 years. Most patients were women (87.1%), the mean age was 74.2 ± 11.5 years. RESULTS: at the final follow-up, mean AOFAS score was 77.9 ± 10.2 points and mean MOxFQ score was 18.3 ± 8.3 points. Visual analog scale (VAS) for pain improved significantly from 7.5 ± 1.2 points to 3.4 ± 2.1 points on average. Good clinical results were also reported on ability to put on shoes comfortably. The mean resection arthroplasty spaces at the end of the study were 1.3, 1.8, 2.5 and 4.4 mm, for second to fifth rays, respectively. The mean sizes of remodeling osteophytes at the end of the study were 1.6, 1.4, 1.1 and 0.7 mm, respectively. Significant improvement was also achieved in the hallux valgus angle (HVA) and intermetatarsal angle (IMA) at the end of the study. CONCLUSION: in our experience, metatarsophalangeal resection arthroplasty continues to be a valid choice in patients with major forefoot deformities, with satisfactory long-term clinical and radiographic results.


INTRODUCCIÓN: la artroplastía de resección metatarsofalángica se considera un procedimiento quirúrgico de salvamento capaz de mejorar la calidad de vida de pacientes con deformidades importantes en el antepié. MATERIAL Y MÉTODOS: se realizó un estudio observacional retrospectivo de 31 pacientes (36 pies) con deformidades importantes en el antepié operados en nuestra institución. Treinta y dos pies requirieron cirugía adicional que involucró el primer metatarsiano, la mayoría de ellos (72.2%) a través de la fusión de la articulación metatarsofalángica. El período de seguimiento promedio fue 10.3 ± 4.6 años. La mayoría de los pacientes fueron mujeres (87.1%), con una edad promedio de 74.2 ± 11.5 años. RESULTADOS: en la última visita de seguimiento, la puntuación AOFAS promedio fue de 77.9 ± 10.2 puntos y la puntuación MOxFQ promedio fue de 18.3 ± 8.3 puntos. La escala visual analógica (EVA) para el dolor mejoró significativamente, pasando de 7.5 ± 1.2 puntos a 3.4 ± 2.1 puntos de media. También se constataron buenos resultados clínicos en cuanto a la capacidad de calzarse con comodidad. Los espacios de resección promedio al final del estudio fueron 1.3, 1.8, 2.5 y 4.4 mm para el segundo al quinto radio, respectivamente. Los tamaños promedio de los osteofitos por remodelación al final del estudio fueron de 1.6, 1.4, 1.1 y 0.7 mm, respectivamente. También se logró una mejora significativa en el ángulo de hallux valgus (AHV) y en el ángulo intermetatarsiano (IMA) al final del estudio. CONCLUSIÓN: en nuestra experiencia, la artroplastía de resección metatarsofalángica sigue siendo una opción válida en pacientes con deformidades graves del antepié, con resultados clínicos y radiográficos satisfactorios a largo plazo.


Assuntos
Artroplastia , Humanos , Feminino , Estudos Retrospectivos , Masculino , Idoso , Pessoa de Meia-Idade , Artroplastia/métodos , Idoso de 80 Anos ou mais , Fatores de Tempo , Articulação Metatarsofalângica/cirurgia , Articulação Metatarsofalângica/diagnóstico por imagem , Seguimentos , Radiografia , Resultado do Tratamento , Deformidades do Pé/cirurgia , Deformidades do Pé/diagnóstico por imagem
7.
Clin Exp Allergy ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38938054

RESUMO

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

8.
Bioresour Technol ; 406: 131024, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38914238

RESUMO

The rising prices of fishery derivatives limits their use in aquafeeds. Therefore, other alternatives are used to replace those ingredients. Among them, microalgae are of great interest both as an ingredient and as a potential stabilising agent against lipid oxidation. This study evaluates on the use of Nannochloropsis gaditana to prevent lipid oxidation in a set of 12 aquafeeds over 540 days of storage. Aquafeeds were formulated with/without 15 % N. gaditana combined with two antioxidants -butylhydroxytoluene (25-150 mg·kg-1) or vitamin E (500-3000 mg·kg-1). The effect of i) storage period, ii) presence of microalgae and iii) antioxidant addition on lipid oxidation was assessed. Results showed higher fatty acid degradation in diets lacking microalgae. The microalgae supplemented diets is enough for preserving feeds presenting the highest antioxidant effect at the end, without significant differences with the microalgae-supplemented feeds and those including antioxidants after 540 days of storage.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38700815

RESUMO

Immunotherapy has emerged as a promising approach to cancer treatment, offering improved survival rates and enhanced patients' quality of life. However, realizing the full potential of immunotherapy in clinical practice remains a challenge, as there is still plenty of room for modulating the complexity of the human immune system in favor of an antitumor immunogenicity. Nanotechnology, with its unique properties, holds promise in augmenting the efficacy of cancer immunotherapies in biotherapeutic protection and site- and time-controlled delivery of the immune modulator biologicals. Polymeric nanoparticles are promising biomaterials among different nanocarriers thanks to their robustness, versatility, and cost-efficient design and production. This perspective paper overviews critical concepts in nanometric advanced delivery systems applied to cancer immunotherapy. We focus on a detailed exploration of the current state of the art and trends in using poly(beta-aminoester) (pBAE) polymers for nucleic acid-based antitumor immunotherapies. Through different examples of the use of pBAE polymers reported in the literature, we revise the main advantages these polymers offer and some challenges to overcome. Finally, the paper provides insights and predictions on the path toward the clinical implementation of cancer nano-immunotherapies, highlighting the potential of pBAE polymers for advancements in this field.

10.
J Endocrinol Invest ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696124

RESUMO

PURPOSE: Nutritional ketosis synergistically with body-weight loss induced by a very-low-calorie ketogenic diet (VLCKD) has proven to be effective in improving obesity-related pathophysiology. Recently, growing attention has been focused on the relation between erythropoietin (EPO) and obesity. Thus, this study aims to investigate whether nutritional ketosis and weight loss induced by a VLCKD modify the circulating levels of EPO in patients with obesity in comparison with the effect of low-calorie diet (LCD) or bariatric surgery (BS). METHODS: EPO levels, iron status and body composition parameters were evaluated in 72 patients with overweight or obesity and 27 normal-weight subjects at baseline and after the three different weight-reduction therapies (VLCKD, LCD and BS) in 69 patients with excess body weight. ß-hydroxybutyrate levels were also measured in the VLCKD group. The follow-up was established at 2-3 months and 4-6 months. RESULTS: It was found that EPO levels were higher in morbid obesity and correlated with higher basal weight, fat mass (FM) and fat-free mass (FFM) in the overall sample. High baseline EPO levels were also correlated with higher impact on the course of weight loss and changes in FM and FFM induced by the three weight-loss interventions. Furthermore, the VLCKD induced a decrease in EPO levels coinciding with maximum ketosis, which was maintained over time, while statistically significant changes were not observed after LCD and BS. CONCLUSION: The obesity-related increased EPO levels are restored after VLCKD intervention at the time of maximum ketosis, suggesting a potential role of the nutritional ketosis induced by the VLCKD. Baseline EPO levels could be a biomarker of response to a weight-loss therapy.

11.
J Ophthalmic Inflamm Infect ; 14(1): 19, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38700565

RESUMO

PURPOSE: To report the use of Fluocinolone intravitreal implant (Iluvien) for the treatment of persistent cystoid macular edema (CME) due to immune recovery uveitis syndrome in a patient with previous cytomegalovirus retinitis and acute myeloid leukemia. DESIGN: Case report. METHODS: The clinical history of a patient who received an Iluvien implant in one eye for the treatment of cystoid macular edema due to immune recovery uveitis syndrome, previously treated with peribulbar Triamcinolone and intravitreal Dexamethasone injections, was reviewed. RESULTS: A 48-year-old woman presented with cystoid macular edema due to immune recovery uveitis syndrome. The patient had a history of cytomegalovirus retinitis 3.5 years prior, secondary to immunosuppressive treatment for an acute myeloid leukemia. Three periocular triamcinolone injections and two dexamethasone intravitreal implants were performed, but the edema recurred, so fluocinolone intravitreal implant was used, achieving a sustained control of the condition at one year of follow-up. CONCLUSION: The Fluocinolone intravitreal implant may be an effective treatment for persistent CME in patients with immune recovery uveitis syndrome.

12.
Eur Phys J C Part Fields ; 84(5): 518, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784120

RESUMO

Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored. Data from the NEXT-White detector demonstrate the ability to achieve good position assignment accuracy for both high- and low-energy events. Using point-like energy deposits from 83mKr calibration electron captures (E∼45 keV), the position of origin of low-energy events is determined to 2 cm precision with bias <1mm. A convolutional neural network approach is then used to quantify diffusion for longer tracks (E≥1.5 MeV), from radiogenic electrons, yielding a precision of 3 cm on the event barycenter. The precision achieved with these methods indicates the feasibility energy calibrations of better than 1% FWHM at Qßß in pure xenon, as well as the potential for event fiducialization in large future detectors using an alternate method that does not rely on primary scintillation.

13.
Plant J ; 119(2): 844-860, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38812347

RESUMO

Transcriptome-wide association studies (TWAS) can provide single gene resolution for candidate genes in plants, complementing genome-wide association studies (GWAS) but efforts in plants have been met with, at best, mixed success. We generated expression data from 693 maize genotypes, measured in a common field experiment, sampled over a 2-h period to minimize diurnal and environmental effects, using full-length RNA-seq to maximize the accurate estimation of transcript abundance. TWAS could identify roughly 10 times as many genes likely to play a role in flowering time regulation as GWAS conducted data from the same experiment. TWAS using mature leaf tissue identified known true-positive flowering time genes known to act in the shoot apical meristem, and trait data from a new environment enabled the identification of additional flowering time genes without the need for new expression data. eQTL analysis of TWAS-tagged genes identified at least one additional known maize flowering time gene through trans-eQTL interactions. Collectively these results suggest the gene expression resource described here can link genes to functions across different plant phenotypes expressed in a range of tissues and scored in different experiments.


Assuntos
Flores , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Transcriptoma , Zea mays , Zea mays/genética , Zea mays/fisiologia , Flores/genética , Flores/fisiologia , Locos de Características Quantitativas/genética , Genótipo , Fenótipo , Genes de Plantas/genética , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/metabolismo , Perfilação da Expressão Gênica
14.
Artigo em Inglês | MEDLINE | ID: mdl-38704092

RESUMO

PURPOSE: It is unclear whether preoperative serum uric acid (SUA) elevation may play a role in the development of acute kidney injury (AKI) associated with cardiac surgery (CSA-AKI). We conducted a cohort study to evaluate the influence of preoperative hyperuricemia on AKI in patients at high risk for developing SC-AKI. DESIGN: Multicenter prospective international cohort study. SETTING: Fourteen university hospitals in Spain and the United Kingdom. PARTICIPANTS: We studied 261 consecutive patients at high risk of developing CSA-AKI, according to a Cleveland score ≥ 4 points, from July to December 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: AKIN criteria were used for the definition of AKI. Multivariable logistic regression models and propensity score-matched pairwise analysis were used to determine the adjusted association between preoperative hyperuricemia (≥7 mg/dL) and AKI. Elevated preoperative AUS (≥7 mg/dL) was present in 190 patients (72.8%), whereas CSA-AKI occurred in 145 patients (55.5%). In multivariable logistic regression models, hyperuricemia was not associated with a significantly increased risk of AKI (adjusted Odds Ratio [OR]: 1.58; 95% confidence interval [CI]: 0.81-3; P = .17). In propensity score-matched analysis of 140 patients, the hyperuricemia group experienced similar adjusted odds of AKI (OR 1.05, 95%CI 0.93-1.19, P = .37). CONCLUSIONS: Hyperuricemia was not associated with an increased risk of AKI in this cohort of patients undergoing cardiac surgery at high risk of developing CSA-AKI.

16.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38734070

RESUMO

BACKGROUND: Testicular cancer, primarily affecting young men, has seen an alarming rise globally. This study delves into incidence and mortality trends in Spain from 1990 to 2019 using the Global Burden of Disease (GBD) database and the Age-Period-Cohort (A-P-C) model. METHODS: We analyzed GBD data on testicular cancer cases and deaths in Spain, calculating age-standardized rates (ASIR and ASMR) and employing Joinpoint regression to identify significant shifts. The A-P-C model further dissected the effects of age, period, and birth cohort on these trends. RESULTS: A striking doubling in testicular cancer incidence was observed, from 3.09 to 5.40 per 100,000 men (1.9% annual increase), while mortality rates remained stable and even decreased in younger age groups (0.34 to 0.26 per 100,000, 0.8% annual decrease). Joinpoint analysis revealed four distinct periods of increasing incidence, with a recent slowdown. The A-P-C model highlighted a consistent rise in incidence risk with each successive generation born after 1935, contrasting with a progressive decline in mortality risk across cohorts, particularly marked for those born since the 1960s. CONCLUSION: While mortality rates are encouraging, Spain reflects the global trend of escalating testicular cancer incidence. The A-P-C analysis suggests a generational influence, but the underlying causes remain elusive. Further research is crucial to understand these trends and implement effective prevention strategies to combat this growing health concern.

17.
Actas urol. esp ; 48(3): 218-227, abr. 2024. tab
Artigo em Espanhol | IBECS | ID: ibc-231927

RESUMO

Introducción El tratamiento de los pacientes con cáncer de próstata (CaP) está establecido en las guías de práctica clínica, las cuales se basan en estudios aleatorizados según el nivel de evidencia. En España se desconoce el grado de cumplimiento de estas guías en la práctica clínica. Objetivos Describir los perfiles de los pacientes con CaP en el momento del diagnóstico y el manejo de los pacientes con CaP localizado y con recurrencia bioquímica (RBQ) en España. Materiales y métodos Se realizó una encuesta médica en 3 especialidades médicas (85 urólogos [URO], 64 oncólogos radioterápicos [OR] y 21 oncólogos médicos [OM]). Para este estudio se elaboraron 3 cuestionarios, 2 con 22 preguntas (URO y OR) y uno con 21 preguntas (OM). Resultados La incidencia anual de CaP en los hospitales participantes (N=131) fue de 24.057 casos. La incidencia anual extrapolada a España fue de 40.531 casos. La prevalencia estimada de CaP en España es de 221.689. Cabe destacar que el 79 y el 80% de los pacientes atendidos por URO y OR, respectivamente, presentaban CaP localizado en el momento del diagnóstico. La biopsia fue la prueba diagnóstica más utilizada en las 3 especialidades, seguida de la tomografía computarizada abdominopélvica. Más del 90% de los pacientes con RBQ se sometieron a pruebas estándar. Las técnicas de imagen de nueva generación y la PET con colina/PSMA se siguen utilizando en menor medida. Actualmente, la mayoría de los pacientes con CaP localizado reciben tratamiento con cirugía o radioterapia, pero en el caso de los pacientes con RBQ, los URO y OR prefieren la radioterapia y los OM la terapia de privación androgénica exclusiva o combinada. Conclusión Este estudio describe los perfiles de los pacientes en el momento del diagnóstico y proporciona una visión general del manejo terapéutico actual del CaP localizado y con RBQ en la práctica clínica en España. (AU)


Introduction The management of patients with prostate cancer (PCa) is established in clinical practice guidelines, which are based on randomized studies according to the level of evidence. In Spain, the degree of compliance with these guidelines in clinical practice is unknown. Objectives To describe the profiles of PCa patients at the time of diagnosis and the management of patients with localized PCa and those with biochemical recurrence (BCR) in Spain. Materials and methods A medical survey was conducted in specialized care (85 urologists [UROs], 64 radiation oncologists [ROs], and 21 medical oncologists [MOs]). Three questionnaires were developed for this study with 22 (UROs and ROs) or 21 questions (MOs). Results The annual incidence of PCa was 24,057 in participating hospitals (N=131). The extrapolated annual incidence in Spain is 40,531 cases. The estimated prevalence of PCa in Spain is 221,689. Of note, 79 and 80% of patients seen by UROs and ROs, respectively had localized PCa at diagnosis. Biopsy was the most used diagnostic test among the 3 specialties, followed by abdominopelvic computer tomography. More than 90% of patients with BCR underwent standard tests. Next generation imaging tests and PET-choline/PSMA are still used residually. Most patients with localized PCa are currently treated with either surgery or radiotherapy, while for BCR patients, UROs and ROs prefer radiotherapy and MOs androgen deprivation therapy alone or in combination. Conclusion This study describes patient profiles at the time of diagnosis and provides an overview of the current therapeutic management of localized PCa and BCR in clinical practice in Spain. (AU)


Assuntos
Neoplasias da Próstata , Reações Bioquímicas , Inquéritos e Questionários , Espanha
18.
ACS Appl Mater Interfaces ; 16(17): 21877-21884, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38648335

RESUMO

The hydrogen evolution reaction (HER) is a crucial electrochemical process for the proposed hydrogen economy since it has the potential to provide pure hydrogen for fuel cells. Nowadays, hydrogen electroproduction is considerably expensive, so promoting the development of new non-noble catalysts for the cathode of alkaline electrolyzers appears as a suitable way to reduce the costs of this technology. In this sense, a series of tungsten-based carbide materials have been synthesized by the urea-glass route as candidates to improve the HER in alkaline media. Moreover, two different pyridinium-based ionic liquids were employed to modify the surface of the carbide grains and control the amount and nature of their surface species. The main results indicate that the catalyst surface composition is modified in the hybrid materials, which are then distinguished by the appearance of tungsten suboxide structures. This implies the action of ionic liquids as reducing agents. Consequently, differential electrochemical mass spectrometry (DEMS) is used to precisely determine the onset potentials and rate-determining steps (RDS) for the HER in alkaline media. Remarkably, the modified surfaces show high catalytic performance (overpotentials between 45 and 60 mV) and RDS changes from Heyrovsky-Volmer to Heyrovsky as the surface oxide structures get reduced. H2O molecule reduction is then faster at tungsten suboxide, which allows the formation of the adsorbed hydrogen at the surface, boosting the catalytic activity and the kinetics of the alkaline HER.

19.
Polymers (Basel) ; 16(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38674981

RESUMO

Polymeric blends are employed in the production of filaments for additive manufacturing to balance mechanical and processability properties. The mechanical and thermal properties of polymeric filaments made of poly (lactic acid) (PLA), polyhydroxyalkanoates (PHA), and its blend (PLA-PHA) are investigated herein and correlated to their measured structural and physicochemical properties. PLA exhibits the highest stiffness and tensile strength, but lower toughness. The mechanical properties of the PLA-PHA blend were similar to those of PLA, but with a significantly higher toughness. Despite the lower mechanical properties of neat PHA, incorporating a small amount (12 wt.%) of PHA into PLA significantly enhances toughness (approximately 50%) compared to pure PLA. The synergistic effect is attributed to the spherulitic morphology of blended PHA in PLA, promoting interactions between the amorphous regions of both polymers. Thermal stability is notably improved in the PLA-PHA blend, as determined by thermogravimetric analysis. The blend also exhibits lower cold crystallization and glass transition temperatures as compared to PLA, which is beneficial for additive manufacturing. Following additive manufacturing, X-ray photoelectron spectroscopic showed that the three filaments present an increase in C-C and C=O bonds associated with the loss of C-O bonds. The thermal process induces a slight increase in crystallinity in PHA due to chain reorganization. The study provides insights into the thermal and structural changes occurring during the melting process of additive manufacturing.

20.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38643855

RESUMO

BACKGROUND: Cementless fixation for hip arthroplasties has increased in the last decades, particularly in younger patients. The purpose of this study was to compare the long-term results three different types of fixations in patients under 50years old. METHODS: Cemented, hybrid and cementless fixations were assessed in patients under 50years old with a minimum follow-up of 8years. Loosening, demarcation, complications, and prosthesis survival were assessed. Functional analysis was performed with the modified Harris Hip Score and Visual analogue scale was collected. RESULTS: Final series consisted in 222 patients. Significant improvement was observed regarding mHHS and VAS score in each group. We observed statistically significant difference regarding demarcation between the groups (P<.001). The higher rate of acetabular and femoral stem loosening was observed in the cemented (20.0%) and hybrid (18.9%) group. The lowest prosthesis survival rate after 16 years was observed in hybrid group (P<.001). CONCLUSION: Total hip replacement has good long-term clinical and functional outcomes. The lowest rate of prosthesis survival was observed in hybrid group with 84.2% after 16years.

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