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1.
Sensors (Basel) ; 23(6)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36991626

RESUMO

Water scarcity in arid and semi-arid areas has led to the development of regulated deficit irrigation (RDI) strategies on most species of fruit trees in order to improve water productivity. For a successful implementation, these strategies require continuous feedback of the soil and crop water status. This feedback is provided by physical indicators from the soil-plant-atmosphere continuum, as is the case of the crop canopy temperature, which can be used for the indirect estimation of crop water stress. Infrared Radiometers (IRs) are considered as the reference tool for temperature-based water status monitoring in crops. Alternatively, in this paper, we assess the performance of a low-cost thermal sensor based on thermographic imaging technology for the same purpose. The thermal sensor was tested in field conditions by performing continuous measurements on pomegranate trees (Punica granatum L. 'Wonderful') and was compared with a commercial IR. A strong correlation (R2 = 0.976) between the two sensors was obtained, demonstrating the suitability of the experimental thermal sensor to monitor the crop canopy temperature for irrigation management.


Assuntos
Frutas , Punica granatum , Temperatura , Solo , Produtos Agrícolas , Árvores
2.
Virtual Real ; 27(2): 651-675, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36034584

RESUMO

We created a virtual reality version of a 1983 performance by Dire Straits, this being a highly complex scenario consisting of both the virtual band performance and the appearance and behaviour of the virtual audience surrounding the participants. Our goal was to understand the responses of participants, and to learn how this type of scenario might be improved for later reconstructions of other concerts. To understand the responses of participants we carried out two studies which used sentiment analysis of texts written by the participants. Study 1 (n = 25) (Beacco et al. in IEEE Virtual Reality: 538-545, 2021) had the unexpected finding that negative sentiment was caused by the virtual audience, where e.g. some participants were fearful of being harassed by audience members. In Study 2 (n = 26) notwithstanding some changes, the audience again led to negative sentiment-e.g. a feeling of being stared at. For Study 2 we compared sentiment with questionnaire scores, finding that the illusion of being at the concert was associated with positive sentiment for males but negative for females. Overall, we found sentiment was dominated by responses to the audience rather than the band. Participants had been placed in an unusual situation, being alone at a concert, surrounded by strangers, who seemed to pose a social threat for some  of them. We relate our findings to the concept of Plausibility, the illusion that events and situations in the VR are really happening. The results indicate high Plausibility, since the negative sentiment, for example in response to being started at, only makes sense if the events are experienced as actually happening. We conclude with the need for co-design of VR scenarios, and the use of sentiment analysis in this process, rather than sole reliance on concepts proposed by researchers, typically expressed through questionnaires, which may not reflect the experiences of participants. Supplementary Information: The online version contains supplementary material available at 10.1007/s10055-022-00685-9.

3.
Chemphyschem ; 23(11): e202200152, 2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35481907

RESUMO

There is an ongoing effort to replace rare and expensive noble-element catalysts with more abundant and less expensive transition metal oxides. With this goal in mind, the intrinsic defects of a rhombohedral perovskite-like structure of LaMnO3 and their implications on CO catalytic properties were studied. Surface thermodynamic stability as a function of pressure (P) and temperature (T) were calculated to find the most stable surface under reaction conditions (P=0.2 atm, T=323 K to 673 K). Crystallographic planes (100), (111), (110), and (211) were evaluated and it was found that (110) with MnO2 termination was the most stable under reaction conditions. Adsorption energies of O2 and CO on (110) as well as the effect of intrinsic defects such as Mn and O vacancies were also calculated. It was found that O vacancies favor the interaction of CO on the surface, whereas Mn vacancies can favor the formation of carbonate species.

4.
Rev Panam Salud Publica ; 46: e22, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-35350451

RESUMO

Objective: Identify publications from 2000 to 2020 on hepatitis B in indigenous people in Latin America, to learn about advances and gaps in this field in the last 20 years. Methods: Exploratory review and systematic evidence review. Documents were organized using Excel and Rayyan® software. Results: We selected 30 of 107 articles found: 17 epidemiological studies, 10 document reviews, 2 clinical studies, and 1 letter to the editor. Brazil was the country with the most publications (50%), most of them with an epidemiological approach. The topic most often addressed was hepatitis B prevalence with 22 publications, followed by 11 studies reporting results of molecular studies of the virus, 7 studies on vaccination, 5 studies on risk factors, and 4 publications with topics such as vertical transmission and studies of social issues. Conclusion: Compared to previous reviews by other authors, we saw greater diversity in topics and research methods; however, conventional epidemiological approaches that focus on measuring prevalence of serological markers still predominate. Thus, there is a need for other types of research focused on sociocultural determinants.


Objetivo: Identificar artigos publicados entre 2000 e 2020 sobre hepatite B em indígenas da América Latina, visando a conhecer as conquistas obtidas nos últimos 20 anos e as lacunas existentes com relação a esta doença. Métodos: Foi realizada uma revisão exploratória da literatura com síntese das evidências. O material obtido foi organizado com o uso de Excel® e Rayyan®. Resultados: De 107 artigos encontrados, 30 foram selecionados ­ 17 estudos epidemiológicos, 10 revisões documentais, 2 estudos clínicos e 1 carta ao editor. O Brasil foi o país com o maior percentual de artigos publicados (50%), na sua maioria estudos com enfoque epidemiológico. As áreas temáticas abordadas foram a prevalência de infecção pelo vírus da hepatite B (22 artigos), estudos moleculares do vírus da hepatite (11 estudos), vacinação (7), fatores de risco (5), e temas como transmissão materno-fetal e aspectos sociais (4). Conclusões: Comparado aos estudos de revisão anteriores conduzidos por outros autores, o presente estudo demonstra uma maior variedade de áreas temáticas e metodologias empregadas. No entanto, ainda predominam enfoques epidemiológicos convencionais com foco na avaliação da prevalência de marcadores sorológicos. São necessárias outras linhas de pesquisas enfocando os determinantes socioculturais.

5.
Opt Lett ; 46(13): 3061-3064, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34197379

RESUMO

We report on the enhancement of responsivity by more than one order of magnitude of a silicon-based sub-terahertz detector when a mesoscopic dielectric particle was used to localize incident radiation to a sub-wavelength volume and focus it directly onto the detector. A strained-silicon modulation field-effect transistor was used as a direct detector on an incident terahertz beam at 0.3 THz. A systematic study in which Teflon cubes were placed in front of the detector to focus the terahertz beam was performed. In this study, cubes with different sizes were investigated, and an enhancement of the responsivity up to 11 dB was observed for a cube with an edge length of 3.45 mm (or 3.45λ). Electromagnetic simulation results were in good agreement with the experimental ones and demonstrated that the size of the mesoscopic particle plays an important role in focalizing the electric field within an area below the diffraction limit. This approach provides an efficient, uncostly, and easy to implement method to substantially improve the responsivity and noise equivalent power of sub-terahertz detectors.

6.
Sensors (Basel) ; 21(3)2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33498386

RESUMO

This paper reports on a study of the response of a T-gate strained-Si MODFETs (modulation-doped field-effect transistor) under continuous-wave sub-THz excitation. The sub-THz response was measured using a two-tones solid-state source at 0.15 and 0.30 THz. The device response in the photovoltaic mode was non-resonant, in agreement with the Dyakonov and Shur model for plasma waves detectors. The maximum of the photoresponse was clearly higher under THz illumination at 0.15 THz than at 0.3 THz. A numerical study was conducted using three-dimensional (3D) electromagnetic simulations to delve into the coupling of THz radiation to the channel of the transistor. 3D simulations solving the Maxwell equations using a time-domain solver were performed. Simulations considering the full transistor structure, but without taking into account the bonding wires used to contact the transistor pads in experiments, showed an irrelevant role of the gate length in the coupling of the radiation to the device channel. Simulations, in contradiction with measurements, pointed to a better response at 0.3 THz than under 0.15 THz excitation in terms of the normalized electric field inside the channel. When including four 0.25 mm long bonding wires connected to the contact pads on the transistor, the normalized internal electric field induced along the transistor channel by the 0.15 THz beam was increased in 25 dB, revealing, therefore, the important role played by the bonding wires at this frequency. As a result, the more intense response of the transistor at 0.15 THz than at 0.3 THz experimentally found, must be attributed to the bonding wires.

7.
Molecules ; 24(18)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546753

RESUMO

The main objective of this study is to develop a novel dual-purpose material based on carbon xerogel microspheres (CXMs) that permits the delayed release of cannabidiol (CBD) and the removal of aflatoxin. The CXMs were prepared by the sol-gel method and functionalized with phosphoric acid (CXMP) and melamine (CXMN). The support and the modified materials were characterized by scanning electronic microscopy (SEM), N2 adsorption at -196 °C, X-ray photoelectron spectroscopy (XPS), and zeta potential. For the loading of the cannabidiol (CBD) in the porous samples, batch-mode adsorption experiments at 25 °C were performed, varying the concentration of CBD. The desorption kinetics was performed at two conditions for simulating the gastric (pH of 2.1) and intestinal (pH of 7.4) conditions at 37 °C based on in vitro CBD release. Posteriorly, the samples obtained after desorption were used to study aflatoxin removal, which was evaluated through adsorption experiments at pH = 7.4 and 37 °C. The adsorption isotherms of CBD showed a type I(b) behavior, with the adsorbed uptake being higher for the support than for the modified materials with P and N. Meanwhile, the desorption kinetics of CBD at gastric conditions indicated release values lower than 8%, and the remaining amount was desorbed at pH = 7.4 in three hours until reaching 100% based on the in vitro experiments. The results for aflatoxin showed total removal in less than 30 min for all the materials evaluated. This study opens a broader landscape in which to develop dual-purpose materials for the delayed release of CBD, improving its bioavailability and allowing aflatoxin removal in gastric conditions.


Assuntos
Aflatoxinas/isolamento & purificação , Canabidiol/farmacologia , Carbono/química , Microesferas , Adsorção , Preparações de Ação Retardada/farmacologia , Cinética , Nitrogênio/química , Eletricidade Estática , Temperatura
8.
Int J Mol Sci ; 19(2)2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29414888

RESUMO

Thrombotic material retrieved from acute ischemic stroke (AIS) patients represents a valuable source of biological information. In this study, we have developed a clinical proteomics workflow to characterize the protein cargo of thrombi derived from AIS patients. To analyze the thrombus proteome in a large-scale format, we developed a workflow that combines the isolation of thrombus by endovascular thrombectomy and peptide chromatographic fractionation coupled to mass-spectrometry. Using this workflow, we have characterized a specific proteomic expression profile derived from four AIS patients included in this study. Around 1600 protein species were unambiguously identified in the analyzed material. Functional bioinformatics analyses were performed, emphasizing a clustering of proteins with immunological functions as well as cardiopathy-related proteins with blood-cell dependent functions and peripheral vascular processes. In addition, we established a reference proteomic fingerprint of 341 proteins commonly detected in all patients. Protein interactome network of this subproteome revealed protein clusters involved in the interaction of fibronectin with 14-3-3 proteins, TGFß signaling, and TCP complex network. Taken together, our data contributes to the repertoire of the human thrombus proteome, serving as a reference library to increase our knowledge about the molecular basis of thrombus derived from AIS patients, paving the way toward the establishment of a quantitative approach necessary to detect and characterize potential novel biomarkers in the stroke field.


Assuntos
Isquemia Encefálica/metabolismo , Proteômica , Acidente Vascular Cerebral/metabolismo , Trombose/metabolismo , Idoso , Biomarcadores/análise , Isquemia Encefálica/cirurgia , Procedimentos Endovasculares , Perfilação da Expressão Gênica , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Mapeamento de Interação de Proteínas , Proteoma/análise , Acidente Vascular Cerebral/cirurgia , Trombectomia , Trombose/cirurgia
9.
Genet Mol Biol ; 41(2): 426-433, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30088613

RESUMO

The linkage disequilibrium (LD) between molecular markers affects the accuracy of genome-wide association studies and genomic selection application. High-density genotyping platforms allow identifying the genotype of thousands of single nucleotide polymorphisms (SNPs) distributed throughout the animal genomes, which increases the resolution of LD evaluations. This study evaluated the distribution of minor allele frequencies (MAF) and the level of LD in the Colombian Creole cattle breeds Blanco Orejinegro (BON) and Romosinuano (ROMO) using a medium density SNP panel (BovineSNP50K_v2). The LD decay in these breeds was lower than those reported for other taurine breeds, achieving optimal LD values (r2 ≥ 0.3) up to a distance of 70 kb in BON and 100 kb in ROMO, which is possibly associated with the conservation status of these cattle populations and their effective population size. The average MAF for both breeds was 0.27 ± 0.14 with a higher SNP proportion having high MAF values (≥ 0.3). The LD levels and distribution of allele frequencies found in this study suggest that it is possible to have adequate coverage throughout the genome of these breeds using the BovineSNP50K_v2, capturing the effect of most QTL related with productive traits, and ensuring an adequate prediction capacity in genomic analysis.

10.
J Neurooncol ; 116(1): 169-75, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24135848

RESUMO

Our purpose was to analyze the pattern of failure in glioblastoma (GBM) patients at first recurrence after radiotherapy and temozolomide and its relationship with different factors. From 77 consecutive GBM patients treated at our institution with fluorescence guided surgery and standard radiochemotherapy, 58 first recurrences were identified and included in a retrospective review. Clinical data including age, Karnofsky performance score, preoperative tumor volume and location, extend of resection, MGMT promoter methylation status, time to progression (PFS), overall survival (OS) and adjuvant therapies were reviewed for every patient. Recurrent tumor location respect the original lesion was the end point of the study. The recurrence pattern was local only in 65.5% of patients and non-local in 34.5%. The univariate and multivariate analysis showed that greater preoperative tumor volume in T1 gadolinium enhanced sequences, was the only variable with statistical signification (p < 0.001) for increased rate of non-local recurrences, although patients with MGMT methylation and complete resection of enhancing tumor presented non-local recurrences more frequently. PFS was longer in patients with non-local recurrences (13.8 vs. 6.4 months; p = 0.019, log-rank). However, OS was not significantly different in both groups (24.0 non-local vs. 19.3 local; p = 0.9). Rate of non-local recurrences in our series of patients treated with fluorescence guided surgery and standard radiochemotherapy was higher than previously published in GBM, especially in patients with longer PFS. Greater preoperative enhancing tumor volume was associated with increased rate of non-local recurrences.


Assuntos
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Recidiva Local de Neoplasia/etiologia , Antineoplásicos Alquilantes/efeitos adversos , Neoplasias Encefálicas/genética , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Dacarbazina/efeitos adversos , Dacarbazina/análogos & derivados , Progressão da Doença , Feminino , Glioblastoma/genética , Humanos , Avaliação de Estado de Karnofsky , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/genética , Regiões Promotoras Genéticas/genética , Radioterapia/efeitos adversos , Temozolomida , Proteínas Supressoras de Tumor/genética
11.
Biomedica ; 44(2): 144-154, 2024 05 30.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-39088527

RESUMO

Introduction. Colombia is home to 2 million indigenous people who live in conditions of poverty and with health deficiencies, making them vulnerable to contracting hepatitis B (HBV). Amazonas has a high virus prevalence, and there are barriers to accessing vaccination; thus, part of the population is susceptible to infection. Objective. To identify factors associated with HBV in Colombian indigenous people. Materials and Methods. A case-control study of people over 18 years from four departments of Colombia. Cases were identified through the national hepatitis B notification registry (2015-2022). Controls were selected and matched to cases (2:1) by age, sex, ethnicity, and department. Sociodemographic characteristics, factors associated with contact with body fluids, cultural practices, and vaccination history were identified by means of a survey. The ethics committee of the Universidad de Antioquia approved the project. Results. Seventy five cases and 150 controls from 13 ethnic groups were surveyed. Amazonas contributed 49% of participants, 83% were women, and the median age of cases was 30 years (IQ range: 27-37). The associated factors were a family history of hepatitis B [adjusted OR: 2.61 (95% CI: 1.09-6.27)] and, in women, the number of pregnancies [adjusted OR: 1.61 (95% CI 1.02- 2.54)]. The vaccination history showed a protective effect, but the association was not significant. Conclusion. Aspects associated with family life and unprotected sexual relations seem to be responsible for the potential transmission of the virus. It was not possible to identify associated cultural practices. Innovative and differential strategies are required for indigenous people to achieve a reduction of HBV.


Introducción. Colombia alberga dos millones de indígenas, que viven en condiciones de pobreza y tienen deficiencias en salud, por lo cual están expuestos a contraer infecciones virales como la hepatitis B. El departamento del Amazonas presenta una gran prevalencia del virus y barreras para acceder a la vacunación; por esto, parte de la población es propensa a la infección. Objetivo. Identificar factores asociados con la infección por el virus de la hepatitis B en indígenas colombianos. Materiales y métodos. Se llevó a cabo un estudio de casos y controles en mayores de 18 años de cuatro departamentos del país. Los casos se identificaron mediante el registro nacional de notificación de hepatitis B (2015-2022). Los controles seleccionados de manera concurrente fueron pareados con los casos por edad, sexo, etnia y departamento. En una encuesta se consignaron las características sociodemográficas, los factores asociados con el contacto con sangre y fluidos, las prácticas socioculturales y los antecedentes de vacunación. El proyecto fue aprobado por Comité de Ética de la Universidad de Antioquia. Resultados. Participaron 75 casos y 150 controles de 13 grupos étnicos. El departamento del Amazonas aportó el 49 % de los participantes (83 % mujeres) con una mediana de edad de 30 años (RIC = 27-37). Los factores asociados con una mayor probabilidad de contraer la infección fueron el antecedente de algún familiar infectado con el virus de la hepatitis B (OR ajustado = 2,61) (IC95%: 1,09-6,27) y número de embarazos en mujeres, (OR ajustado = 1,61) (IC95%: 1,02-2,54). La vacunación mostró un efecto protector sin asociación significativa. Conclusión. Los aspectos asociados con la convivencia familiar y el número de embarazos contribuyen a una potencial transmisión vertical y horizontal del virus. No se identificaron prácticas culturales asociadas. Se requieren estrategias novedosas y diferenciales para reducir la transmisión del virus de la hepatitis B en poblaciones indígenas.


Assuntos
Hepatite B , Humanos , Colômbia/epidemiologia , Estudos de Casos e Controles , Adulto , Feminino , Hepatite B/epidemiologia , Hepatite B/transmissão , Masculino , Indígenas Sul-Americanos/estatística & dados numéricos , Fatores de Risco , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Vacinas contra Hepatite B/administração & dosagem
12.
Vis Comput ; 39(11): 5421-5436, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37899958

RESUMO

This work deals with the automatic 3D reconstruction of objects from frontal RGB images. This aims at a better understanding of the reconstruction of 3D objects from RGB images and their use in immersive virtual environments. We propose a complete workflow that can be easily adapted to almost any other family of rigid objects. To explain and validate our method, we focus on guitars. First, we detect and segment the guitars present in the image using semantic segmentation methods based on convolutional neural networks. In a second step, we perform the final 3D reconstruction of the guitar by warping the rendered depth maps of a fitted 3D template in 2D image space to match the input silhouette. We validated our method by obtaining guitar reconstructions from real input images and renders of all guitar models available in the ShapeNet database. Numerical results for different object families were obtained by computing standard mesh evaluation metrics such as Intersection over Union, Chamfer Distance, and the F-score. The results of this study show that our method can automatically generate high-quality 3D object reconstructions from frontal images using various segmentation and 3D reconstruction techniques.

13.
Heliyon ; 9(4): e15561, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37151713

RESUMO

The biodiesel industry currently generates large amounts of crude glycerol that are not marketed, thus accumulating, and causing environmental problems. This study evaluates the catalytic potential of Colombian olivine, using glycerol steam reforming to assess valorization alternatives for this by-product. The analyzed olivine was thermally treated at 1200 °C and reduced at 900 °C, then producing nanometer-sized Fe compounds. The catalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electron microscopy (SEM), temperature-programmed reduction (TPR), and transmission electron microscopy (TEM). Calcined olivine increased glycerol conversion at 600 °C from 43% (without catalyst) to 96% with the formation of liquid-phase products such as aldehydes and carboxylic acids. In addition, syngas with H2/CO ratios of 1.1 and 1.5 was generated at reaction temperatures of 700 °C and 800 °C, respectively, with low CH4 content. Finally, it was established that olivine from Medellín, under the conditions used for glycerol steam reforming, is a viable and interesting alternative to valorize glycerol into gas- or liquid-phase products.

14.
Sci Rep ; 13(1): 5709, 2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029169

RESUMO

This article presents a novel multiple organ localization and tracking technique applied to spleen and kidney regions in computed tomography images. The proposed solution is based on a unique approach to classify regions in different spatial projections (e.g., side projection) using convolutional neural networks. Our procedure merges classification results from different projection resulting in a 3D segmentation. The proposed system is able to recognize the contour of the organ with an accuracy of 88-89% depending on the body organ. Research has shown that the use of a single method can be useful for the detection of different organs: kidney and spleen. Our solution can compete with U-Net based solutions in terms of hardware requirements, as it has significantly lower demands. Additionally, it gives better results in small data sets. Another advantage of our solution is a significantly lower training time on an equally sized data set and more capabilities to parallelize calculations. The proposed system enables visualization, localization and tracking of organs and is therefore a valuable tool in medical diagnostic problems.


Assuntos
Imageamento Tridimensional , Baço , Baço/diagnóstico por imagem , Imageamento Tridimensional/métodos , Abdome , Rim/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Processamento de Imagem Assistida por Computador/métodos
15.
iScience ; 26(10): 107938, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37876610

RESUMO

Change blindness (CB) is the perceptual phenomenon whereby people are blind to dramatic changes in their visual environment. In virtual reality (VR) a person's body can be substituted by a life-sized virtual one that moves synchronously with their real body movements as their self-representation. We consider whether CB occurs in VR, and whether there are differences in the case of changes to their own virtual body compared with the body of another. Forty people took part in a Qi Gong lesson in VR led by a virtual instructor. During the lesson both their own and the instructor's face dramatically changed in appearance. Overall, 73% and 85% did not notice the changes to their own and instructor's face respectively. People make iconic inferences about their visual surroundings without sampling detail, and reduced CB in the case of their own body may be a marker for self-representation.

16.
IEEE Comput Graph Appl ; 43(6): 117-125, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37930892

RESUMO

VR United is a virtual reality application that we have developed to support multiple people simultaneously interacting in the same environment. Each person is represented with a virtual body that looks like themselves. Such immersive shared environments have existed and been the subject of research for the past 30 years. Here, we demonstrate how VR United meets criteria for successful interaction, where a journalist from the Financial Times in London interviewed a professor in New York for two hours. The virtual location of the interview was a restaurant, in line with the series of interviews published as "Lunch with the FT." We show how the interview was successful, as a substitute for a physically present one. The article based on the interview was published in the Financial Times as normal for the series. We finally consider the future development of such systems, including some implications for immersive journalism.

17.
Nanoscale ; 15(2): 522-531, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36511088

RESUMO

As a semiconductor used for the photocatalytic hydrogen evolution reaction (HER), BiOBr has received intensive attention in recent years. However, the high recombination of photoexcited charge carriers results in poor photocatalytic efficiency. The combination with other photoactive semiconductors might represent a valuable approach to deal with the intrinsic limitations of the material. Given that BiOBr has a 2D structure, we propose a simple liquid-phase exfoliation method to peel BiOBr microspheres into few-layer nanosheets. By tuning the weight ratio between the precursors, we prepare a series of 2D MoS2/BiOBr van der Waals (vdW) heterojunctions and study their behaviour as (photo)electrocatalysts for the HER, finding dramatic differences as a function of weight composition. Moreover, we found that pristine 2D BiOBr and the heterojunctions, with the exception of the 1% MoS2/BiOBr composition, undergo photocorrosion, with BiOBr being reduced to metallic Bi. These findings provide useful guidelines to design novel 2D material-based (photo)electrocatalysts for the production of sustainable fuels.

18.
Front Neurol ; 14: 1127585, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36908619

RESUMO

In the reperfusion era, a new paradigm of treating patients with endovascular treatment (EVT) and neuroprotective drugs is emerging as a promising therapeutic option for patients with acute ischemic stroke (AIS). In this context, ApTOLL, a Toll-like receptor 4 (TLR4) antagonist with proven neuroprotective effect in preclinical models of stroke and a very good pharmacokinetic and safety profile in healthy volunteers, is a promising first-in-class aptamer with the potential to address this huge unmet need. This protocol establishes the clinical trial procedures to conduct a Phase Ib/IIa clinical study (APRIL) to assess ApTOLL tolerability, safety, pharmacokinetics, and biological effect in patients with AIS who are eligible for EVT. This will be a multicenter, double-blind, randomized, placebo-controlled, Phase Ib/IIa clinical study to evaluate the administration of ApTOLL together with EVT in patients with AIS. The study population will be composed of men and non-pregnant women with confirmed AIS with a <6h window from symptoms onset to ApTOLL/placebo administration. The trial is currently being conducted and is divided into two parts: Phase Ib and Phase IIa. In Phase Ib, 32 patients will be allocated to four dose ascending levels to select, based on safety criteria, the best two doses to be administered in the following Phase IIa in which 119 patients will be randomized to three arms of treatment (dose A, dose B, and placebo). Identification of the trial: EudraCT: 2020-002059-38 and ClinicalTrials.gov Identifier: NCT04734548 https://clinicaltrials.gov/ct2/show/NCT04734548?term=ApTOLL&cond=Stroke&draw=2&rank=1.

19.
JAMA Neurol ; 80(8): 779-788, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37338893

RESUMO

Importance: ApTOLL is a TLR4 antagonist with proven preclinical neuroprotective effect and a safe profile in healthy volunteers. Objective: To assess the safety and efficacy of ApTOLL in combination with endovascular treatment (EVT) for patients with ischemic stroke. Design, Setting, and Participants: This phase 1b/2a, double-blind, randomized, placebo-controlled study was conducted at 15 sites in Spain and France from 2020 to 2022. Participants included patients aged 18 to 90 years who had ischemic stroke due to large vessel occlusion and were seen within 6 hours after stroke onset; other criteria were an Alberta Stroke Program Early CT Score of 6 to 10, estimated infarct core volume on baseline computed tomography perfusion of 5 to 70 mL, and the intention to undergo EVT. During the study period, 4174 patients underwent EVT. Interventions: In phase 1b, 0.025, 0.05, 0.1, or 0.2 mg/kg of ApTOLL or placebo; in phase 2a, 0.05 or 0.2 mg/kg of ApTOLL or placebo; and in both phases, treatment with EVT and intravenous thrombolysis if indicated. Main Outcomes and Measures: The primary end point was the safety of ApTOLL based on death, symptomatic intracranial hemorrhage (sICH), malignant stroke, and recurrent stroke. Secondary efficacy end points included final infarct volume (via MRI at 72 hours), NIHSS score at 72 hours, and disability at 90 days (modified Rankin Scale [mRS] score). Results: In phase Ib, 32 patients were allocated evenly to the 4 dose groups. After phase 1b was completed with no safety concerns, 2 doses were selected for phase 2a; these 119 patients were randomized to receive ApTOLL, 0.05 mg/kg (n = 36); ApTOLL, 0.2 mg/kg (n = 36), or placebo (n = 47) in a 1:1:√2 ratio. The pooled population of 139 patients had a mean (SD) age of 70 (12) years, 81 patients (58%) were male, and 58 (42%) were female. The primary end point occurred in 16 of 55 patients (29%) receiving placebo (10 deaths [18.2%], 4 sICH [7.3%], 4 malignant strokes [7.3%], and 2 recurrent strokes [3.6%]); in 15 of 42 patients (36%) receiving ApTOLL, 0.05 mg/kg (11 deaths [26.2%], 3 sICH [7.2%], 2 malignant strokes [4.8%], and 2 recurrent strokes [4.8%]); and in 6 of 42 patients (14%) receiving ApTOLL, 0.2 mg/kg (2 deaths [4.8%], 2 sICH [4.8%], and 3 recurrent strokes [7.1%]). ApTOLL, 0.2 mg/kg, was associated with lower NIHSS score at 72 hours (mean difference log-transformed vs placebo, -45%; 95% CI, -67% to -10%), smaller final infarct volume (mean difference log-transformed vs placebo, -42%; 95% CI, -66% to 1%), and lower degrees of disability at 90 days (common odds ratio for a better outcome vs placebo, 2.44; 95% CI, 1.76 to 5.00). Conclusions and Relevance: In acute ischemic stroke, 0.2 mg/kg of ApTOLL administered within 6 hours of onset in combination with EVT was safe and associated with a potential meaningful clinical effect, reducing mortality and disability at 90 days compared with placebo. These preliminary findings await confirmation from larger pivotal trials. Trial Registration: ClinicalTrials.gov Identifier: NCT04734548.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/cirurgia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/complicações , Resultado do Tratamento , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Infarto Cerebral/complicações , Hemorragias Intracranianas/etiologia , Trombectomia/métodos , Procedimentos Endovasculares/métodos
20.
Front Chem ; 10: 1000910, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36186583

RESUMO

2D materials are interesting flat nanoplatforms for the implementation of different electrochemical processes, due to the high surface area and tunable electronic properties. 2D transition metal dichalcogenides (TMDs) can be produced through convenient top-down liquid-phase exfoliation (LPE) methods and present capacitive behaviour that can be exploited for energy storage applications. However, in their thermodynamically stable 2H crystalline phase, they present poor electrical conductivity, being this phase a purely semiconducting one. Combination with conducting polymers like polyaniline (PANI), into nanohybrids, can provide better properties for the scope. In this work, we report on the preparation of 2D WS2@PANI hybrid materials in which we exploit the LPE TMD nanoflakes as scaffolds, onto which induce the in-situ aniline polymerization and thus achieve porous architectures, with the help of surfactants and sodium chloride acting as templating agents. We characterize these species for their capacitive behaviour in neutral pH, achieving maximum specific capacitance of 160 F/g at a current density of 1 A/g, demonstrating the attractiveness of similar nanohybrids for future use in low-cost, easy-to-make supercapacitor devices.

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