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1.
Allergol Immunopathol (Madr) ; 52(4): 68-72, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38970267

RESUMO

INTRODUCTION AND OBJECTIVES: Both asthma prevalence and the percentage of cesarean sections have increased in parallel in recent years. Research studies suggest an increased risk of developing atopic diseases and asthma after cesarean section birth compared to vaginal delivery. The main objective of this study is to analyze the risk of asthma admission after cesarean section birth compared to vaginal delivery in the pediatric population. POPULATION AND METHODS: Retrospective observational analytical case-control study from 1993 to 2020. The cases include all admitted patients to our health area hospital, for patients aged 7 to 16 diagnosed with asthma. For each case, a control without a diagnosis of asthma is selected with the same age, and that has also caused an episode of admission. RESULTS: A total of 290 admission episodes with a diagnosis of asthma were obtained, caused by 155 patients. Out of these, 145 cases with documented delivery types were selected. For cases, 155 controls were selected. The historical proportion of cesarean sections in the asthmatic group is 18.6%, compared to 14.2% in the non-asthmatic group. There is a statistically non-significant difference of 4.4% more cesarean sections in the asthmatic group compared to the control group. DISCUSSION: We have not demonstrated a statistically significant association between being born by cesarean section and an increased risk of asthma admission. Based on this finding, we cannot conclude that there is an association between being born by cesarean section and a higher risk of suffering from asthma, unlike what has been postulated in other research studies.


Assuntos
Asma , Cesárea , Humanos , Cesárea/estatística & dados numéricos , Cesárea/efeitos adversos , Asma/epidemiologia , Feminino , Estudos Retrospectivos , Criança , Estudos de Casos e Controles , Adolescente , Gravidez , Masculino , Fatores de Risco , Prevalência , Risco
2.
Inorg Chem ; 63(27): 12641-12650, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38920333

RESUMO

Metal halide perovskites with a two-dimensional structure are utilized in photovoltaics and optoelectronics. High-crystallinity CsSn2Br5 specimens have been synthesized via ball milling. Differential scanning calorimetry curves show melting at 553 K (endothermic) and recrystallization at 516 K (exothermic). Structural analysis using synchrotron X-ray diffraction data, collected from 100 to 373 K, allows for the determination of Debye model parameters. This analysis provides insights into the relative Cs-Br and Sn-Br chemical bonds within the tetragonal structure (space group: I4/mcm), which remains stable throughout the temperature range studied. Combined with neutron data, X-N techniques permit the identification of the Sn2+ lone electron pair (5s2) in the two-dimensional framework, occupying empty space opposite to the four Sn-Br bonds of the pyramidal [SnBr4] coordination polyhedra. Additionally, diffuse reflectance UV-vis spectroscopy unveils an indirect optical gap of approximately ∼3.3 eV, aligning with the calculated value from the B3LYP-DFT method (∼3.2 eV). The material exhibits a positive Seebeck coefficient as high as 6.5 × 104 µV K-1 at 350 K, which evolves down to negative values of -3.0 × 103 µV K-1 at 550 K, surpassing values reported for other halide perovskites. Notably, the thermal conductivity remains exceptionally low, between 0.32 and 0.25 W m-1 K-1.

3.
PLoS One ; 19(6): e0304313, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38838003

RESUMO

The Middle Ages in the Iberian Peninsula is a period of special interest for studying the relationship of climate change with historical and socioeconomic processes. Between the 8th and 15th centuries AD, the Peninsula was characterized not only by complex political, cultural, and social transitions but also by major variations in the climate. The objective of this study was to examine differences in diet and mobility between distinct populations of the Peninsula and explore the possible relationship of diet, mobility, and culture with environmental variables and geographical settings. For this purpose, we obtained stable isotopic ratios of carbon and oxygen (δ13C and δ18O) from the enamel apatite of first upper incisors from 145 individuals at eight archeological sites that represent both Christian and Islamic communities and both rural and urban social settings. Results revealed a dietary difference between Christian and Islamic populations, observing a greater contribution of C4 plants, possibly sorghum, in the diet of the latter, especially in a rural setting. The disparity in oxygen isotopic ratios between populations from the North and South of the Peninsula is consistent with modern climatic differences between these regions. In this line, intraregional variability in oxygen isotopic ratios may hint at diachronic occupation phases under varying climatic conditions. The few isotopic outliers in our sample suggest overall low mobility levels.


Assuntos
Isótopos de Carbono , Isótopos de Oxigênio , Humanos , Isótopos de Oxigênio/análise , Isótopos de Carbono/análise , História Medieval , Dieta/história , Espanha , Esmalte Dentário/química , Arqueologia , Mudança Climática/história
4.
ACS Appl Electron Mater ; 6(5): 2969-2977, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38828031

RESUMO

Thermoelectric materials offer a promising avenue for energy management, directly converting heat into electrical energy. Among them, AgSbTe2 has gained significant attention and continues to be a subject of research at further improving its thermoelectric performance and expanding its practical applications. This study focuses on Ag-deficient Ag0.7Sb1.12Te2 and Ag0.7Sb1.12Te1.95Se0.05 materials, examining the impact of compositional engineering within the AgSbTe2 thermoelectric system. These materials have been rapidly synthesized using an arc-melting technique, resulting in the production of dense nanostructured pellets. Detailed analysis through scanning electron microscopy (SEM) reveals the presence of a layered nanostructure, which significantly influences the thermoelectric properties of these materials. Synchrotron X-ray diffraction reveals significant changes in the lattice parameters and atomic displacement parameters (ADPs) that suggest a weakening of bond order in the structure. The thermoelectric characterization highlights the enhanced power factor of Ag-deficient materials that, combined with the low glass-like thermal conductivity, results in a significant improvement in the figure of merit, achieving zT values of 1.25 in Ag0.7Sb1.12Te2 and 1.01 in Ag0.7Sb1.12Te1.95Se0.05 at 750 K.

5.
Blood ; 2024 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-38843478

RESUMO

Fostamatinib, a recently approved syk inhibitor used in adult primary immune thrombocytopenia (ITP), has been shown to be safe and effective in this disorder. However, clinical trial results may not be similarly reproduced in clinical practice. Here 138 ITP patients (both primary and secondary) from 42 Spanish centers who had been treated with fostamatinib were evaluated prospectively and retrospectively. The median age of our cohort (55.8% women) was 66 years (interquartile range, IQR, 56-80 years). The median time since ITP diagnosis at fostamatinib initiation was 51 months (IQR, 10-166 months). The median number of therapies prior to fostamatinib initiation was 4 (IQR, 2-5), including eltrombopag (76.1%), romiplostim (57.2%) and intravenous immunoglobulins (IVIG) (44.2%). Fifty-eight patients (42.0%) had signs/symptoms of bleeding in the month prior to treatment initiation. 79.0% of patients responded to fostamatinib with 53.6% complete responses (platelet count > 100 x 109 /L). Eighty-three patients (60.1%) received fostamatinib monotherapy achieving a high response rate (85.4%). The proportion of time in response during the 27-month period examined was 83.3%. The median time to platelet response was 11 days (IQR, 7-21 days). Sixty-seven patients (48.5%) experienced adverse events, mainly grade 1-2, the commonest of which were diarrhea (n = 28) and hypertension (n = 21). One patient had deep venous thrombosis and one patient developed acute myocardial infarction. Fostamatinib was shown to be effective with good safety profile in patients with primary and secondary ITP across a wide age spectrum in this real-world study.

6.
Viruses ; 16(6)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38932159

RESUMO

In virology, the term reverse genetics refers to a set of methodologies in which changes are introduced into the viral genome and their effects on the generation of infectious viral progeny and their phenotypic features are assessed. Reverse genetics emerged thanks to advances in recombinant DNA technology, which made the isolation, cloning, and modification of genes through mutagenesis possible. Most virus reverse genetics studies depend on our capacity to rescue an infectious wild-type virus progeny from cell cultures transfected with an "infectious clone". This infectious clone generally consists of a circular DNA plasmid containing a functional copy of the full-length viral genome, under the control of an appropriate polymerase promoter. For most DNA viruses, reverse genetics systems are very straightforward since DNA virus genomes are relatively easy to handle and modify and are also (with few notable exceptions) infectious per se. This is not true for RNA viruses, whose genomes need to be reverse-transcribed into cDNA before any modification can be performed. Establishing reverse genetics systems for members of the Caliciviridae has proven exceptionally challenging due to the low number of members of this family that propagate in cell culture. Despite the early successful rescue of calicivirus from a genome-length cDNA more than two decades ago, reverse genetics methods are not routine procedures that can be easily extrapolated to other members of the family. Reports of calicivirus reverse genetics systems have been few and far between. In this review, we discuss the main pitfalls, failures, and delays behind the generation of several successful calicivirus infectious clones.


Assuntos
Caliciviridae , Genética Reversa , Genética Reversa/métodos , Caliciviridae/genética , Genoma Viral , Animais , Humanos , Replicação Viral
7.
Curr Opin Biotechnol ; 87: 103140, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38723389

RESUMO

Transgenic approaches are now standard in plant biology research aiming to characterize gene function or improve crops. Recent advances in DNA synthesis and assembly make constructing transgenes a routine task. What remains nontrivial is the selection of the DNA parts and optimization of the transgene design. Early career researchers and seasoned molecular biologists alike often face difficult decisions on what promoter or terminator to use, what tag to include, and where to place it. This review aims to inform about the current approaches being employed to identify and characterize DNA parts with the desired functionalities and give general advice on basic construct design. Furthermore, we hope to share the excitement about new experimental and computational tools being developed in this field.


Assuntos
Plantas Geneticamente Modificadas , Biologia Sintética , Biologia Sintética/métodos , Plantas Geneticamente Modificadas/genética , Engenharia Genética/métodos , Plantas/genética , Plantas/metabolismo , Transgenes , DNA/genética
8.
Org Lett ; 26(21): 4560-4565, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38767989

RESUMO

Allylic sulfone-embedded cyclobutenes have been prepared in one pot from alkynes. The carbocycle and the alkenyl sulfone moieties were installed through consecutive bis(triflyl)cyclobutenylation of a triple bond and tetra-n-butylammonium fluoride (TBAF)-assisted hydrodesulfonylation of an allylic bis(sulfone). It is noteworthy that 1,1-bis(triflyl)ethylene acts as a CF3SO2CH═CH2 source for the first time.

9.
Curr Biol ; 34(11): 2474-2486.e5, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38772362

RESUMO

ON and OFF thalamic afferents from the two eyes converge in the primary visual cortex to form binocular receptive fields. The receptive fields need to be diverse to sample our visual world but also similar across eyes to achieve binocular fusion. It is currently unknown how the cortex balances these competing needs between receptive-field diversity and similarity. Our results demonstrate that receptive fields in the cat visual cortex are binocularly matched with exquisite precision for retinotopy, orientation/direction preference, orientation/direction selectivity, response latency, and ON-OFF polarity/structure. Specifically, the average binocular mismatches in retinotopy and ON-OFF structure are tightly restricted to 1/20 and 1/5 of the average receptive-field size but are still large enough to generate all types of binocular disparity tuning. Based on these results, we conclude that cortical receptive fields are binocularly matched with the high precision needed to facilitate binocular fusion while allowing restricted mismatches to process visual depth.


Assuntos
Córtex Visual Primário , Visão Binocular , Animais , Gatos/fisiologia , Visão Binocular/fisiologia , Córtex Visual Primário/fisiologia , Campos Visuais/fisiologia , Córtex Visual/fisiologia , Disparidade Visual/fisiologia
10.
Animals (Basel) ; 14(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731304

RESUMO

The favourable geo-climatic conditions in Portugal have made it highly conducive to the development of Dirofilaria immitis in dogs, leading to its identification as an endemic region. This nematode is rapidly spreading across Europe, particularly in northeastern countries. The objective of this study was to provide an updated assessment of the prevalence of this disease in Portuguese dogs, analysing the results in relation to epidemiological and geo-environmental factors, and to identify potential risk factors. A total of 1367 dogs from all continental and insular districts were included in the study and tested for D. immitis antigens. The overall prevalence was found to be 5.9%. It was observed that the disease is spreading northward, with previously unaffected districts now reporting cases, and that the prevalence in coastal districts exceeded that of inland ones. Notably, the Aveiro district exhibited a significant increase in D. immitis prevalence, while in certain districts such as Setúbal, Santarém, Madeira, or Faro, a stabilisation or decrease in prevalence was noted. Furthermore, outdoor and older dogs were found to be at a higher risk of infection. No positive cases were detected in the Azores. Most of the infected dogs were located in areas of high and medium risk of infection. This study underscores the importance of implementing pharmacological prophylaxis, vector control strategies, and public awareness programs to control the spread of this zoonotic disease.

11.
ACS Mater Au ; 4(3): 324-334, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38737123

RESUMO

Among thermoelectric materials, skutterudites are the most prominent candidates in the mid-temperature range applications. In the multiple-filled Sr0.2Yb0.2Co4Sb12 skutterudite, with Sr and Yb as fillers, we have enhanced the thermoelectric performance of CoSb3 through the reduction of lattice thermal conductivity and the optimization of carrier concentration and electrical conductivity. The high-pressure synthesis of the double-filled derivative promotes filling fraction fluctuation. This is observed by high angular resolution synchrotron X-ray diffraction, showing a phase segregation that corresponds to an inhomogeneous distribution of the filler atoms, located at the 2a positions of the cubic space group Im3̅. In addition, scanning transmission electron microscopy (STEM) combined with EELS spectroscopy clearly shows a segregation of Sr atoms from the surface of the grains, which is compatible with the synchrotron X-ray powder diffraction results. Mean square displacement parameters analysis results in Einstein temperatures of ∼94 and ∼67 K for Sr and Yb, respectively, and a Debye temperature of ∼250 K. The strong effect on resonant and disorder scattering yields a significantly lower lattice thermal conductivity of 2.5 W m-1 K-1 at 773 K. Still, good weighed-mobility values were obtained, with high filling fraction of the Yb and Sr elements. This drives a reduced electrical resistivity of 2.1 × 10-5 Ω m, which leads to a peak zT of 0.26 at 773 K. The analysis and results performed for the synthesized (Sr,Yb)-double filled CoSb3, shed light on skutterudites for potential waste-heat recovery applications.

12.
Arch Cardiol Mex ; 2024 May 08.
Artigo em Espanhol | MEDLINE | ID: mdl-38718424

RESUMO

Objective: To describe and evaluate the outcomes of ductal angioplasty with stent placement at a single high-complexity center during the period 2016-2022. Method: A retrospective descriptive cross-sectional study was conducted, including patients under 3 months of age who underwent ductal stent implantation as initial palliative treatment. Demographic, clinical, and anatomical data were collected before the intervention. Mortality, intra- and post-procedural complications, need for re-intervention, intensive care requirements, and hospital stay were recorded. The characteristics at the time of definitive surgery are described. Discrete variables are presented as percentages, and continuous variables are presented with their medians and respective interquartile ranges. Results: Twenty patients who underwent this treatment were reviewed, revealing a success rate of 80%. Complications due to stent dysfunction required surgical resolution. 95% of patients were dischargedfrom the institution after the procedure, and 17 patients reached a second definitive surgical stage. Three patients died afterthe procedure, but with no direct relation to it. Conclusions: Indications for ductal angioplasty with stent as an alternative treatment to systemic-pulmonary anastomosis by surgery are not yet fully defined; the strategy represents a valid alternative in appropriately selected patients. The presented experience shows results similar to international reference centers.


Objetivo: Describir y evaluar los resultados de la angioplastia con stent ductal en un único centro de alta complejidad durante el periodo 2016-2022. Método: Estudio descriptivo retrospectivo de corte transversal en el que se incluyeron pacientes menores de 3 meses a quienes se implantó un stent en el conducto arterioso como tratamiento paliativo inicial. Se recolectaron datos demográficos, clínicos y anatómicos previos a la intervención. Se registraron la mortalidad, las complicaciones intra- y posprocedimiento, la necesidad de reintervención, los requerimientos de cuidados intensivos y la estadía hospitalaria. Se describen las características al momento de la cirugía definitiva. Las variables discretas son presentadas con porcentajes, y las variables continuas con sus medianas y sus respectivos intervalos intercuartílicos. Resultados: Se revisaron 20 pacientes que habían recibido este tratamiento y se evidenció una tasa de éxito del 80%. Las complicaciones por disfunción del stent requirieron resolución quirúrgica. Egresaron de la institución el 95% de los pacientes luego del procedimiento y lograron arribar a un segundo estadio quirúrgico definitivo 17 pacientes. Fallecieron tres pacientes luego del procedimiento, pero sin relación directa con este. Conclusiones: Las indicaciones de angioplastia del conducto con stent como tratamiento alternativo a la realización de una anastomosis sistémico-pulmonar por cirugía todavía no están completamente definidas; la estrategia constituye una alternativa válida en pacientes adecuadamente seleccionados. La experiencia presentada muestra resultados similares a los de otros centros de referencia internacional.

13.
J Physiol ; 602(10): 2227-2251, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38690610

RESUMO

Passive whole-body hyperthermia increases limb blood flow and cardiac output ( Q ̇ $\dot Q$ ), but the interplay between peripheral and central thermo-haemodynamic mechanisms remains unclear. Here we tested the hypothesis that local hyperthermia-induced alterations in peripheral blood flow and blood kinetic energy modulate flow to the heart and Q ̇ $\dot Q$ . Body temperatures, regional (leg, arm, head) and systemic haemodynamics, and left ventricular (LV) volumes and functions were assessed in eight healthy males during: (1) 3 h control (normothermic condition); (2) 3 h of single-leg heating; (3) 3 h of two-leg heating; and (4) 2.5 h of whole-body heating. Leg, forearm, and extracranial blood flow increased in close association with local rises in temperature while brain perfusion remained unchanged. Increases in blood velocity with small to no changes in the conduit artery diameter underpinned the augmented limb and extracranial perfusion. In all heating conditions, Q ̇ $\dot Q$ increased in association with proportional elevations in systemic vascular conductance, related to enhanced blood flow, blood velocity, vascular conductance and kinetic energy in the limbs and head (all R2 ≥ 0.803; P < 0.001), but not in the brain. LV systolic (end-systolic elastance and twist) and diastolic functional profiles (untwisting rate), pulmonary ventilation and systemic aerobic metabolism were only altered in whole-body heating. These findings substantiate the idea that local hyperthermia-induced selective alterations in peripheral blood flow modulate the magnitude of flow to the heart and Q ̇ $\dot Q$ through changes in blood velocity and kinetic energy. Localised heat-activated events in the peripheral circulation therefore affect the human heart's output. KEY POINTS: Local and whole-body hyperthermia increases limb and systemic perfusion, but the underlying peripheral and central heat-sensitive mechanisms are not fully established. Here we investigated the regional (leg, arm and head) and systemic haemodynamics (cardiac output: Q ̇ $\dot Q$ ) during passive single-leg, two-leg and whole-body hyperthermia to determine the contribution of peripheral and central thermosensitive factors in the control of human circulation. Single-leg, two-leg, and whole-body hyperthermia induced graded increases in leg blood flow and Q ̇ $\dot Q$ . Brain blood flow, however, remained unchanged in all conditions. Ventilation, extracranial blood flow and cardiac systolic and diastolic functions only increased during whole-body hyperthermia. The augmented Q ̇ $\dot Q$ with hyperthermia was tightly related to increased limb and head blood velocity, flow and kinetic energy. The findings indicate that local thermosensitive mechanisms modulate regional blood velocity, flow and kinetic energy, thereby controlling the magnitude of flow to the heart and thus the coupling of peripheral and central circulation during hyperthermia.


Assuntos
Débito Cardíaco , Hipertermia , Humanos , Masculino , Adulto , Hipertermia/fisiopatologia , Débito Cardíaco/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Febre/fisiopatologia , Adulto Jovem , Temperatura Alta , Hemodinâmica
14.
Arch Public Health ; 82(1): 77, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769585

RESUMO

BACKGROUND: The increase in life expectancy and long-lived individuals is a challenge for public health and provides an opportunity to understand the determinants of longevity. However, few studies have addressed the factors associated with the health status and quality of life in a long-lived individual population. We described the perceived health, clinical status, quality of life, and dependency for activities of daily living in a representative population in Castile and Leon, Spain. METHODS: A sample of 759 long-lived individuals aged 95 years and older was studied by the Health Sentinel Network of Castile and Leon (Spain) through a health examination and a structured questionnaire covering quality of life (EQ-5D-3), lifestyle habits, diet, working life and family health. A blood sample was taken for the study of biological and genetic markers. Chi Square and logistic regression OR with 95% confidence intervals were used to analyze the determinants of the long-lived individuals' health status. The significant level for the bivariate analysis was established at 0.05. RESULTS: Perceived health was good, very good or excellent in 64.2%, while only 46.0% had a quality-of-life index above 0.5 (ranging from 0 to 1) and 44.1% maintained acceptable independence for activities of daily living. Quality-of-life index was higher in the oldest, (OR 7.98 [2,32-27.41]) above 100 years compared to those under 98, and men had better values for independence than women (OR 2.43 [1.40-4.29]). Cardiovascular diseases were the most prevalent (85.5%), but neurological and mental diseases and vision problems had the highest impact on quality of life and independence. CONCLUSION: The long-lived individuals of Castile and Leon have a relatively well-preserved health status, although the perception of health is higher than that describing their quality of life and dependence. The quality of life was higher in the oldest age group and showed differences according to sex, with a better quality of life in men. Public health policies and programs should take in account the differences by sex and age as well as the prevention and control of the main conditions related with poor quality of life or dependence. Future research must include the interaction among genetic, socioeconomic, environmental, and other clinical factors in the quality of life and disability of long-lived individuals.

15.
Eur J Neurol ; 31(8): e16349, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38770742

RESUMO

BACKGROUND AND PURPOSE: Influenza is a common cause of acute respiratory infection, with headache being one of the symptoms included in the European Commission case definition. The prevalence of headache as a symptom of influenza remains unknown. We aimed to describe the incidence and prevalence of headache in patients with influenza. METHODS: All consecutive patients who met the definition criteria of influenza-like illness during the influenza seasons 2010-2011 through 2021-2022 were included. The seasonal cumulative incidence of influenza per 1000 patients at risk and the prevalence of headache as an influenza symptom were calculated, including the 95% confidence intervals (CIs). Subgroup analyses were done based on patients' sex, age group, microbiological confirmation, vaccination status, and influenza type/subtype/lineage. RESULTS: During the study period, 8171 patients were eligible. The incidence of headache in the context of influenza varied between 0.24 cases per 1000 patients (season 2020-2021) and 21.69 cases per 1000 patients (season 2017-2018). The prevalence of headache was 66.1% (95% CI = 65.1%-67.1%), varying between 49.6% (season 2021-2022) and 80.1% (season 2010-2011). The prevalence of headache was higher in women (67.9% vs. 65.7%, p = 0.03) and higher in patients between 15 and 65 years old. Headache was more prevalent in patients infected with B subtypes than A subtypes (68.7% vs. 56.9%, p < 0.001). There were no notable differences regarding vaccination status or microbiological confirmation of the infection. CONCLUSIONS: Headache is a common symptom in patients with influenza, with a prevalence higher than that observed in other viral infections.


Assuntos
Cefaleia , Influenza Humana , Humanos , Masculino , Feminino , Incidência , Pessoa de Meia-Idade , Adulto , Cefaleia/epidemiologia , Influenza Humana/epidemiologia , Influenza Humana/complicações , Prevalência , Idoso , Adolescente , Adulto Jovem , Criança , Pré-Escolar , Idoso de 80 Anos ou mais , Lactente
16.
Polymers (Basel) ; 16(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38794525

RESUMO

Traditional wound dressings have not been able to satisfy the needs of the regenerative medicine biomedical area. With the aim of improving tissue regeneration, nanofiber-based wound dressings fabricated by electrospinning (ES) processes have emerged as a powerful approach. Nowadays, nanofiber-based bioactive dressings are mainly developed with a combination of natural and synthetic polymers, such as polycaprolactone (PCL) and chitosan (CHI). Accordingly, herein, PCL/CHI nanofibers have been developed with varying PCL:CHI weight ratios (9:1, 8:2 and 7:3) or CHI viscosities (20, 100 and 600 mPa·s) using a novel alternating current ES (ACES) process. Such nanofibers were thoroughly characterized by determining physicochemical and nanomechanical properties, along with wettability, absorption capacity and hydrolytic plus enzymatic stability. Furthermore, PCL/CHI nanofiber biological safety was validated in terms of cytocompatibility and hemocompatibility (hemolysis < 2%), in addition to a notable antibacterial performance (bacterial reductions of 99.90% for S. aureus and 99.91% for P. aeruginosa). Lastly, the enhanced wound healing activity of PCL/CHI nanofibers was confirmed thanks to their ability to remarkably promote cell proliferation, which make them ideal candidates for long-term applications such as wound dressings.

17.
ACS Appl Mater Interfaces ; 16(14): 17474-17482, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38563237

RESUMO

A new anode material, Ru-SrMo0.9O3-δ, with a perovskite structure and segregated metallic Ru, has been tested in an intermediate-temperature solid oxide fuel cell (IT-SOFC) in an electrolyte-supported configuration giving substantial power densities as high as 840 mW/cm2 at 850 °C using pure H2 as fuel. This material has been prepared by the citrate method and structurally and microstructurally characterized at room temperature by different techniques such as X-ray diffraction (XRD), neutron powder diffraction (NPD), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM). NPD was very useful to determine oxygen positions and vacancies, unveiling a cubic and oxygen-deficient perovskite SrMo0.9O3-δ oxide with a Pm-3m space group and potential ionic mobility. On the other hand, SEM and STEM studies have allowed to identify metallic segregated Ru nanoparticles providing the material with an excellent catalytic activity. Other properties such as the thermal expansion coefficient (TEC) and chemical compatibility with other cell components or electrical conductivity have also been studied to understand the excellent performance of this material as anode in IT-SOFC and correlate it with the crystallographic structure.

18.
Phys Rev Lett ; 132(15): 156701, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38682975

RESUMO

A new perovskite KOsO_{3} has been stabilized under high-pressure and high-temperature conditions. It is cubic at 500 K (Pm-3m) and undergoes subsequent phase transitions to tetragonal at 320 K (P4/mmm) and rhombohedral (R-3m) at 230 K as shown from refining synchrotron x-ray powder diffraction (SXRD) data. The larger orbital overlap integral and the extended wave function of 5d electrons in the perovskite KOsO_{3} allow to explore physics from the regime where Mott and Hund's rule couplings dominate to the state where the multiple interactions are on equal footing. We demonstrate an exotic magnetic ordering phase found by neutron powder diffraction along with physical properties via a suite of measurements including magnetic and transport properties, differential scanning calorimetry, and specific heat, which provide comprehensive information for a system at the crossover from localized to itinerant electronic behavior.

19.
Inorg Chem ; 63(15): 7007-7018, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38557070

RESUMO

Double perovskite oxides, characterized by their tunable magnetic properties and robust interconnection between the lattice and magnetic degrees of freedom, present an enticing foundation for advanced magnetic refrigeration materials. Herein, we delve into the influence of rare-earth elements on RSrCoFeO6 (R = Sm, Eu) disordered double perovskites by examining their structural, electronic, magnetic, and magnetocaloric properties. Temperature-dependent synchrotron X-ray diffraction analysis confirmed the stability of the orthorhombic phase (Pnma) across a wide temperature range. X-ray photoemission spectroscopy revealed that both Sm and Eu are in the 3+ state, whereas multiple states for Co2+/3+ and Fe3+/4+ are identified. The magnetic investigation and magnetocaloric effect (MCE) analysis brought to light the presence of a long-range antiferromagnetic (AFM) order with a second-order phase transition (SOPT) in both samples. The maximum magnetic entropy change ΔSMmax was approximately 0.9 J/kg K for both samples at applied field 0-7 T, manifesting prominently above Neel temperatures TN ≈ 93 K (Sm) and 84 K (Eu). Nevertheless, different relative cooling powers (RCP) of 112.6 J/kg (Sm) and 95.5 J/kg (Eu) were observed. A detailed analysis of the temperature-dependent lattice parameters shed light on a distinct magnetocaloric effect across the magnetic transition temperature, unveiling an anisotropic thermal expansion [αV = 1.41 × 10-5 K-1 (Sm) and αV = 1.54 × 10-5 K-1 (Eu)] wherein the thermal expansion axial ratio αbSm/αbEu = 0.61 became lower with increasing temperature, which suggests that the Eu sample experiences a greater thermal expansion in the b-axis direction. At the atomic bonding level, the evidence for magnetoelastic coupling around the magnetic transition temperatures TN was found through the anomalies along the average Co/Fe-O bond distance, formal valence, octahedral distortion, as well as an anisotropic lattice expansion.

20.
Artigo em Inglês | MEDLINE | ID: mdl-38430228

RESUMO

PURPOSE: This review explores mathematical models, blinking characterization, and non-invasive techniques to enhance understanding and refine clinical interventions for ocular conditions, particularly for contact lens wear. METHODS: The review evaluates mathematical models in tear film dynamics and their limitations, discusses contact lens wear models, and highlights computational mechanical models. It also explores computational techniques, customization of models based on individual blinking dynamics, and non-invasive diagnostic tools like high-speed cameras and advanced imaging technologies. RESULTS: Mathematical models provide insights into tear film dynamics but face challenges due to simplifications. Contact lens wear models reveal complex ocular physiology and design aspects, aiding in lens development. Computational mechanical models explore eye biomechanics, often integrating tear film dynamics into a Multiphysics framework. While different computational techniques have their advantages and disadvantages, non-invasive tools like OCT and thermal imaging play a crucial role in customizing these Multiphysics models, particularly for contact lens wearers. CONCLUSION: Recent advancements in mathematical modeling and non-invasive tools have revolutionized ocular health research, enabling personalized approaches. The review underscores the importance of interdisciplinary exploration in the Multiphysics approach involving tear film dynamics and biomechanics for contact lens wearers, promoting advancements in eye care and broader ocular health research.

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