Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Más filtros

Intervalo de año de publicación
1.
Small ; : e2400345, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38830337

RESUMEN

The development of wearable thermoelectric generators (wTEG) represents a promising strategy to replace batteries and supercapacitors required to supply electrical energy for portable electronic devices. However, the main drawback of wTEGs is that the thermal gradient between the skin and the ambient is minimal, reducing the power output produced by the generator. Therefore, it is necessary to improve the thermal management of wTEG in order to increase its efficiency. This work deals with the preparation of a thermoelectric generator that harnesses the plasmonic heating effect to enhance the thermal gradient of the final device. The thermoelectric layer is created through the in situ polymerization of terthiophene (3T) within a polyurethane matrix, utilizing silver (Ag) (I) and copper (II) perchlorate as oxidants. The plasmonic film, composed of Ag-NP (nanoparticles), is formed via photocatalytic reduction of silver nitrate in the presence of titanium oxide. These layers are then meticulously assembled to yield the hybrid plasmonic/thermoelectric generator.

3.
PLoS Pathog ; 18(7): e1010631, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35816514

RESUMEN

The S:A222V point mutation, within the G clade, was characteristic of the 20E (EU1) SARS-CoV-2 variant identified in Spain in early summer 2020. This mutation has since reappeared in the Delta subvariant AY.4.2, raising questions about its specific effect on viral infection. We report combined serological, functional, structural and computational studies characterizing the impact of this mutation. Our results reveal that S:A222V promotes an increased RBD opening and slightly increases ACE2 binding as compared to the parent S:D614G clade. Finally, S:A222V does not reduce sera neutralization capacity, suggesting it does not affect vaccine effectiveness.


Asunto(s)
COVID-19 , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2/genética , COVID-19/genética , Antecedentes Genéticos , Humanos , Mutación , Peptidil-Dipeptidasa A/metabolismo , Unión Proteica , Receptores Virales/metabolismo , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo
4.
Mycoses ; 67(1): e13661, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37840157

RESUMEN

BACKGROUND: Methylene blue (MB) and flavin mononucleotide (FMN)-mediated photodynamic therapy (PDT) have demonstrated local antimicrobial effect, but no direct comparative study has been published so far for the treatment of toenail onychomycosis. OBJECTIVES: To directly compare the short and medium-term efficacy of MB versus FMN as photosensitizers in PDT for toenail onychomycosis by applying them in a 40% w/w urea cream in two different dye concentrations. METHODS: Forty toenails with distal and lateral subungual moderate onychomycosis due to dermatophyte fungi were randomised to receive 10 weekly sessions of PDT mediated by four topical formulations including MB or FMN at two different concentrations: Group I: 0.1% w/w MB; Group II: 2% w/w MB; Group III: 0.1% w/w FMN; and Group IV: 2% w/w FMN. Photographs were used for onychomycosis severity index (OSI) estimation allowing clinical assessment at any point of the study. Microscopic and microbiological evaluations were carried out at baseline, 27- and 35-week follow-ups. Side effects were recorded along with patient satisfaction. RESULTS: At week 27, mycological cure rates were 60%, 30%, 50% and 40% and complete cure rates were 0%, 20%, 10% and 20%, for Groups I, II, III and IV respectively. At week 35, mycological cure rates were 70%, 70%, 70% and 60% and complete cure rates were 30%, 50%, 70% and 30%, for Groups I, II, III and IV respectively. All cream formulations were safe and patients were fairly satisfied. CONCLUSIONS: Results of the present work confirm PDT as a therapeutic alternative for onychomycosis. Although all cream formulations were safe and effective, with a good degree of satisfaction, higher cure rates were obtained with 2% w/w MB cream and 0.1% w/w FMN cream.


Asunto(s)
Dermatosis del Pie , Onicomicosis , Humanos , Antifúngicos/uso terapéutico , Onicomicosis/tratamiento farmacológico , Uñas , Azul de Metileno/uso terapéutico , Mononucleótido de Flavina/uso terapéutico , Dermatosis del Pie/tratamiento farmacológico , Urea , Resultado del Tratamiento
5.
Int J Mol Sci ; 24(14)2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37511355

RESUMEN

SARS-CoV-2, the causal agent of COVID-19, is a new coronavirus that has rapidly spread worldwide and significantly impacted human health by causing a severe acute respiratory syndrome boosted by a pulmonary hyperinflammatory response. Previous data from our lab showed that the newly excysted juveniles of the helminth parasite Fasciola hepatica (FhNEJ) modulate molecular routes within host cells related to vesicle-mediated transport and components of the innate immune response, which could potentially be relevant during viral infections. Therefore, the aim of the present study was to determine whether FhNEJ-derived molecules influence SARS-CoV-2 infection efficiency in Vero cells. Pre-treatment of Vero cells with a tegument-enriched antigenic extract of FhNEJ (FhNEJ-TEG) significantly reduced infection by both vesicular stomatitis virus particles pseudotyped with the SARS-CoV-2 Spike protein (VSV-S2) and live SARS-CoV-2. Pre-treatment of the virus itself with FhNEJ-TEG prior to infection also resulted in reduced infection efficiency similar to that obtained by remdesivir pre-treatment. Remarkably, treatment of Vero cells with FhNEJ-TEG after VSV-S2 entry also resulted in reduced infection efficiency, suggesting that FhNEJ-TEG may also affect post-entry steps of the VSV replication cycle. Altogether, our results could potentially encourage the production of FhNEJ-derived molecules in a safe, synthetic format for their application as therapeutic agents against SARS-CoV-2 and other related respiratory viruses.


Asunto(s)
COVID-19 , Fasciola hepatica , Animales , Chlorocebus aethiops , Humanos , SARS-CoV-2 , Células Vero , Antivirales/farmacología
6.
Rev Esp Enferm Dig ; 114(11): 660-662, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35170327

RESUMEN

Esophageal fish bone impaction (EFBI) is a common reason for presentation in the emergency department and a frequent indication for urgent esophagogastroduodenoscopy (EGD). Although it is usually effectively diagnosed and treated by EGD, a confirmed diagnosis prior to the endoscopy is rare as blood tests, radiography and direct laryngoscopy are usually normal. We herein report three cases of EFBI. Two patients had been previously discharged without a correct diagnosis. In one case, the patient had a severe complication that required urgent surgery which could have probably been averted with an early diagnosis. Remarkably, a cervical CT scan was key to diagnose the EFBI in one case and a large retroesophageal abscess in another cases, thus guiding their management. Both patients that underwent an urgent EGD had a favorable outcome without the need for hospitalization. Therefore, meticulous anamnesis, adequate imaging and urgent EGD are key to treat patients with EFBI.


Asunto(s)
Cuerpos Extraños , Humanos , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía , Esófago/cirugía , Endoscopía Gastrointestinal , Servicio de Urgencia en Hospital , Diagnóstico Precoz
7.
J Med Virol ; 93(4): 2301-2306, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33236799

RESUMEN

Assessment of commercial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoassays for their capacity to provide reliable information on sera neutralizing activity is an emerging need. We evaluated the performance of two commercially available lateral flow immunochromatographic assays (LFIC; Wondfo SARS-CoV-2 Antibody test and the INNOVITA 2019-nCoV Ab test) in comparison with a SARS-CoV-2 neutralization pseudotyped assay for coronavirus disease 2019 (COVID-19) diagnosis in hospitalized patients and investigate whether the intensity of the test band in LFIC associates with neutralizing antibody (NtAb) titers. Ninety sera were included from 51 patients with moderate to severe COVID-19. A green fluorescent protein (GFP) reporter-based pseudotyped neutralization assay (vesicular stomatitis virus coated with SARS-CoV-2 spike protein) was used. Test line intensity was scored using a 4-level scale (0 to 3+). The overall sensitivity of LFIC assays was 91.1% for the Wondfo SARS-CoV-2 Antibody test, 72.2% for the INNOVITA 2019-nCoV IgG, 85.6% for the INNOVITA 2019-nCoV IgM, and 92.2% for the NtAb assay. Sensitivity increased for all assays in sera collected beyond day 14 after symptoms onset (93.9%, 79.6%, 93.9%, and 93.9%, respectively). Reactivities equal to or more intense than the positive control line (≥2+) in the Wondfo assay had a negative predictive value of 100% and a positive predictive value of 96.4% for high NtAb50 titers (≥1/160). Our findings support the use of LFIC assays evaluated herein, particularly the Wondfo test, for COVID-19 diagnosis. We also find evidence that these rapid immunoassays can be used to predict high SARS-CoV-2-S NtAb50 titers.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Prueba de COVID-19/métodos , COVID-19/inmunología , Inmunoensayo/métodos , SARS-CoV-2/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , COVID-19/sangre , COVID-19/diagnóstico , COVID-19/virología , Proteínas Fluorescentes Verdes , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Glicoproteína de la Espiga del Coronavirus/inmunología
8.
Eur J Clin Microbiol Infect Dis ; 40(3): 485-494, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33404891

RESUMEN

Whether antibody levels measured by commercially available enzyme or chemiluminescent immunoassays targeting the SARS-CoV-2 spike (S) protein can act as a proxy for serum neutralizing activity remains to be established for many of these assays. We evaluated the degree of correlation between neutralizing antibodies (NtAb) binding the SARS-CoV-2 spike (S) protein and SARS-CoV-2-S-IgG levels measured by four commercial immunoassays in sera drawn from hospitalized COVID-19 patients. Ninety sera from 51 hospitalized COVID-19 patients were tested by a pseudotyped virus neutralization assay, the LIAISON SARS-CoV-2 S1/S2 IgG, the Euroimmun SARS-CoV-2 IgG ELISA, the MAGLUMI 2019-nCoV IgG, and the COVID-19 ELISA IgG assays. Overall, the results obtained with the COVID-19 ELISA IgG test showed the highest agreement with the NtAb assay (κ, 0.85; 95% CI, 0.63-1). The most sensitive tests were the pseudotyped virus NtAb assay and the COVID-19 ELISA IgG assay (92.2% for both). Overall, the degree correlation between antibody titers resulting in 50% virus neutralization (NtAb50) in the pseudotyped virus assay and SARS-CoV-2 IgG levels was strong for the Euroimmun SARS-CoV-2 IgG ELISA (rho = 0.73) and moderate for the remaining assays (rho = 0.48 to 0.59). The kinetic profile of serum NtAb50 titers could not be reliably predicted by any of the SARS-CoV-2 IgG immunoassays. The suitability of SARS-CoV-2-S-IgG commercial immunoassays for inferring neutralizing activity of sera from hospitalized COVID-19 patients varies widely across tests and is influenced by the time of sera collection after the onset of symptoms.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Prueba Serológica para COVID-19/métodos , COVID-19/diagnóstico , Inmunoensayo/métodos , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anciano , Anticuerpos Antivirales/sangre , COVID-19/sangre , Femenino , Hospitalización , Humanos , Inmunoglobulina G/sangre , Cinética , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Sensibilidad y Especificidad
9.
Transpl Infect Dis ; 23(4): e13602, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33728702

RESUMEN

Cellular and humoral response to acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is on focus of research. We evaluate herein the feasibility of expanding virus-specific T cells (VST) against SARS-CoV-2 ex vivo through a standard protocol proven effective for other viruses. The experiment was performed in three different donors' scenarios: (a) SARS-CoV-2 asymptomatic infection/negative serology, (b) SARS-CoV-2 symptomatic infection/positive serology, and (c) no history of SARS-CoV-2 infection/negative serology. We were able to obtain an expanded VST product from donors 1 and 2 (1.6x and 1.8x increase of baseline VST count, respectively) consisting in CD3 + cells (80.3% and 62.7%, respectively) with CD4 + dominance (60% in both donors). Higher numbers of VST were obtained from the donor 2 as compared to donor 1. T-cell clonality test showed oligoclonal reproducible peaks on a polyclonal background for both donors. In contrast, VST could be neither expanded nor primed in a donor without evidence of prior infection. This proof-of-concept study supports the feasibility of expanding ex vivo SARS-CoV-2-specific VST from blood of convalescent donors. The results raise the question of whether the selection of seropositive donors may be a strategy to obtain cell lines enriched in their SARS-CoV-2-specificity for future adoptive transfer to immunosuppressed patients.


Asunto(s)
COVID-19 , SARS-CoV-2 , Traslado Adoptivo , Linfocitos T CD4-Positivos , Humanos
10.
Dermatol Ther ; 33(6): e14280, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32890444

RESUMEN

Photodynamic therapy (PDT) has emerged as an interesting alternative option for onychomycosis treatment. The impact of a specific photosensitizer (PS) on the final result is an important factor to consider. We conducted a short- and medium-term controlled trial to compare the effectiveness of PDT in the treatment of mild-to-moderate onychomycosis when it is mediated by two different PSs. Twenty patients were randomized to receive nine sessions of PDT distributed over 16 weeks mediated either by methylene blue (MB/PDT group) or methyl aminolevulinate (MAL/PDT group). Onychomycosis severity index (OSI) and nail involvement were checked along the study. Complete cure, treatment success, and clinical improvement were tabulated at 16 and 40-week follow-ups. OSI scores decreased significantly along the study, from 12.1 ± 5.4 to 3.6 ± 3.2 (MB/PDT group) and from 14.8 ± 6.0 to 5.4 ± 4.4 (MAL/PDT group). At 16-week follow-up, only 20% of the patients in the MB/PDT group reached complete cure and none in the group of MAL/PDT. At 40-week follow-up, complete cure rates were 70% and 40% in the MB/PDT group and MAL/PDT group respectively. Both modalities showed good outcomes in treatment of moderate toenail onychomycosis. MB/PDT showed a faster action but with relapse rates slightly higher than MAL/PDT.


Asunto(s)
Onicomicosis , Fotoquimioterapia , Ácido Aminolevulínico/efectos adversos , Humanos , Azul de Metileno/efectos adversos , Uñas , Onicomicosis/diagnóstico , Onicomicosis/tratamiento farmacológico , Fármacos Fotosensibilizantes/efectos adversos , Resultado del Tratamiento
11.
Photodermatol Photoimmunol Photomed ; 36(4): 308-312, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32191815

RESUMEN

BACKGROUND: Although systemic therapies are recommended for severe or recalcitrant cases of pityriasis versicolor (PV), they are not free of important side effects and drug interactions. Photodynamic therapy (PDT) utilizes the action of singlet oxygen and free radicals produced by a light-activated photosensitizer to kill viruses, bacteria, or fungi. In this study, the effect of a PDT mediated by methylene blue (MB) in PV was evaluated. METHODS: Five women with PV disseminated on the back and diagnosed by fresh microscopic analysis were treated with a solution of MB (2%) applied to the PV lesions for 3 minutes. Next, a red LED lamp (λ = 630±5 nm, 37 J/cm2 ), placed 100 mm from the skin for 10 minutes, was applied on the dyed PV lesions. Six sessions of MB/PDT were implemented with a 2-week interval in between. Wood's lamp examination was used to monitor fungal infection at each time point. RESULTS: Complete cure was observed in the five women at the 4 weeks post-treatment follow-up. Fluoresce images from PV lesions by Wood's lamp allowed to evaluate whether the lesions were healed or not at each time point. No patient showed relapse at the 6-month follow-up. The patients did not have any adverse effect, and good cosmetic outcome was observed. CONCLUSIONS: Six sessions of MB/PDT spaced at 14-day intervals are sufficient for the treatment for PV in healthy patients.


Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Azul de Metileno/uso terapéutico , Fotoquimioterapia , Tiña Versicolor/tratamiento farmacológico , Adulto , Femenino , Humanos , Persona de Mediana Edad , Fotoquimioterapia/métodos , Resultado del Tratamiento
12.
Mycoses ; 63(8): 859-868, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32506733

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) kills target microorganisms via reactive oxygen species (ROS) production. PDT seems to be a good alternative treatment option for onychomycosis. OBJECTIVE: To compare the efficacy of combined therapies based on oral terbinafine (TN) plus adjunctive PDT mediated by methylene blue (MB) (TN + MB/PDT) or methyl aminolevulinate (MAL) (TN + MAL/PDT) in the treatment of onychomycosis. METHODS: Twenty patients affected by severe dermatophyte onychomycosis in the nails of the big toe (>60% disease involvement of target nail) received oral TN for 12 weeks and concomitantly were randomly allocated to receive nine sessions, separated by 2-week intervals, of urea (40%) plus a PDT protocol mediated by MB (TN + MB/PDT: group I) or mediated by MAL (TN + MAL/PDT: group II). Clinical and mycological efficacy was evaluated at 16-, 40- and 52-week follow-up. RESULTS: Both protocols showed a significant decrease in Onychomycosis Severity Index (OSI) scores (P < .05), from 24.2 ± 4.6 to 0.7 ± 0.6 (group I)) and from 18.5 ± 10.1 to 2.1 ± 2.0 (group II). No side effects or complications were reported in any of the combinations used. Mycological cure rates were significantly higher during the last third of the evaluated period of time, reaching 100% and 90% in group I and group II, respectively, at the 52-week follow-up. In both modalities, complete cure was achieved in 70% of the patients at the 52-week follow-up. CONCLUSIONS: TN + MB/PDT and TN + MAL/PDT show similar outcomes in the treatment of toenails with severe onychomycosis. PDT is an effective method to accelerate the TN-mediated healing process.


Asunto(s)
Antifúngicos/farmacología , Onicomicosis/tratamiento farmacológico , Fotoquimioterapia/métodos , Ácido Aminolevulínico/análogos & derivados , Ácido Aminolevulínico/farmacología , Combinación de Medicamentos , Femenino , Dermatosis del Pie , Humanos , Masculino , Azul de Metileno/farmacología , Uñas/microbiología , Uñas/patología , Terbinafina/farmacología , Resultado del Tratamiento
13.
Photodermatol Photoimmunol Photomed ; 35(2): 69-77, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30168611

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) or intense pulsed light (IPL) are efficient therapeutic methods in the treatment of superficial skin infections, and thus, they could be good options for onychomycosis treatment, the most common nail disorder. METHODS: Forty patients, affected with different diagnosed types of onychomycosis in nails of the first toe, were randomly divided into two groups of 20 patients to be treated by PDT or IPL. Nail plates were softened with urea 40% by occlusive dressing for 12 hours during 3-7 days before treatments. Then, eight sessions separated by an interval of 2 weeks of a PDT protocol mediated by methylene blue (MB) and red laser diode (Periowave® , λ = 670 nm, 200 mW) or an IPL protocol based on 10 pulses/cm2 (Dye-VL-F module, Alma Lasers, λ = 500-600 nm, 10 J) were applied. RESULTS: Both treatments reduced significantly the Onychomycosis Severity Index (OSI) (P < 0.05). In terms of complete cure: 70% (PDT) and 80% (IPL) of the patients reached it after 12 weeks post-treatment. No patient reported any adverse effects or complications, although in the IPL Group, some referred pain sensation during light irradiation and hematomas apparition. CONCLUSIONS: Photodynamic therapy and IPL were effective for onychomycosis cure of any etiology.


Asunto(s)
Azul de Metileno/administración & dosificación , Onicomicosis/tratamiento farmacológico , Fotoquimioterapia , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Uñas/metabolismo , Uñas/microbiología , Uñas/patología , Onicomicosis/metabolismo , Onicomicosis/patología
14.
Lasers Surg Med ; 51(3): 256-267, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30575059

RESUMEN

OBJECTIVES: Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment. METHODS: Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Agreggatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytopaga sp.] and protein markers [IL-1ß;IL-1ra;IL-6;IL-10;TNF-α;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student's t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05). RESULTS: Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1ß, IL-10, and TNF-α, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups. CONCLUSION: Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances. Lasers Surg. Med. 51:256-267, 2019. © 2018 Wiley Periodicals, Inc.


Asunto(s)
Raspado Dental/métodos , Gingivitis/prevención & control , Aparatos Ortodóncicos Fijos , Fotoquimioterapia , Terapia por Ultrasonido , Adolescente , Niño , Femenino , Gingivitis/microbiología , Humanos , Masculino , Índice Periodontal
15.
Sensors (Basel) ; 19(20)2019 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-31652607

RESUMEN

Exploration of unknown environments is a fundamental problem in autonomous robotics that deals with the complexity of autonomously traversing an unknown area while acquiring the most important information of the environment. In this work, a mobile robot exploration algorithm for indoor environments is proposed. It combines frontier-based concepts with behavior-based strategies in order to build a topological representation of the environment. Frontier-based approaches assume that, to gain the most information of an environment, the robot has to move to the regions on the boundary between open space and unexplored space. The novelty of this work is in the semantic frontier classification and frontier selection according to a cost-utility function. In addition, a probabilistic loop closure algorithm is proposed to solve cyclic situations. The system outputs a topological map of the free areas of the environment for further navigation. Finally, simulated and real-world experiments have been carried out, their results and the comparison to other state-of-the-art algorithms show the feasibility of the exploration algorithm proposed and the improvement that it offers with regards to execution time and travelled distance.

16.
Sensors (Basel) ; 17(2)2017 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-28146049

RESUMEN

In this work, a system is developed for semantic labeling of locations based on what people do. This system is useful for semantic navigation of mobile robots. The system differentiates environments according to what people do in them. Background sound, number of people in a room and amount of movement of those people are items to be considered when trying to tell if people are doing different actions. These data are sampled, and it is assumed that people behave differently and perform different actions. A support vector machine is trained with the obtained samples, and therefore, it allows one to identify the room. Finally, the results are discussed and support the hypothesis that the proposed system can help to semantically label a room.

17.
Sensors (Basel) ; 16(8)2016 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-27483264

RESUMEN

To move around the environment, human beings depend on sight more than their other senses, because it provides information about the size, shape, color and position of an object. The increasing interest in building autonomous mobile systems makes the detection and recognition of objects in indoor environments a very important and challenging task. In this work, a vision system to detect objects considering usual human environments, able to work on a real mobile robot, is developed. In the proposed system, the classification method used is Support Vector Machine (SVM) and as input to this system, RGB and depth images are used. Different segmentation techniques have been applied to each kind of object. Similarly, two alternatives to extract features of the objects are explored, based on geometric shape descriptors and bag of words. The experimental results have demonstrated the usefulness of the system for the detection and location of the objects in indoor environments. Furthermore, through the comparison of two proposed methods for extracting features, it has been determined which alternative offers better performance. The final results have been obtained taking into account the proposed problem and that the environment has not been changed, that is to say, the environment has not been altered to perform the tests.


Asunto(s)
Inteligencia Artificial , Reconocimiento de Normas Patrones Automatizadas/métodos , Robótica , Algoritmos , Color , Humanos , Máquina de Vectores de Soporte
18.
Phys Chem Chem Phys ; 17(23): 15140-5, 2015 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-25990660

RESUMEN

Poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) films have been prepared by an electrochemical method in a three electrode cell. The films have been obtained at different oxidation levels regarded as bipolaron, polaron and neutral states by varying the voltage, as is usually done in conjugated heterocyclic polymers. The voltage (-0.2 < V < 1.0 V) has been applied versus a Ag/AgCl reference electrode, producing a variation of one order of magnitude in the electrical conductivity and the Seebeck coefficient of the films. In the voltage range explored, the electrical conductivity increases from 80 to 766 S cm(-1) in PEDOT and from 15 to 160 S cm(-1) in PPy, while the Seebeck coefficient decreases from 37.0 to 9.6 µV K(-1) for PEDOT and from 51.0 to 6.7 µV K(-1) for PPy. The thermal conductivity remains unchanged with the oxidation state of the film, κ ≈ 0.35 ± 0.02 W m(-1) K(-1) for PEDOT and 0.17 ± 0.02 W m(-1) K(-1) for PPy. A maximum thermoelectric efficiency of 1.4 × 10(-2) for PEDOT and 6.8 × 10(-3) for PPy has been achieved. These changes are related to the doping level of the polymer films and they can be accurately controlled by the applied voltage. In this work, we provide a very simple method to control and optimize the power factor or the figure of merit of conducting polymers.

19.
Lasers Med Sci ; 30(2): 915-23, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24346335

RESUMEN

The aim of the study was evaluate tooth movement, receptor activator of nuclear factor KB ligand (RANKL), osteoprotegerin (OPG), and RANKL/OPG ratio in gingival crevicular fluid (GCF) in compression side and pain level during initial orthodontic tooth treatment to determine the efficacy of low-level laser therapy (LLLT). Ten volunteers who required fixed appliance positioned from the upper first premolars to upper first molars were selected. For each patient, the upper first premolar of the quadrant 1 was chosen to be irradiated with a laser diode at 670 nm, 200 mW, and 6.37 W/cm(2), applied on the distal, buccal, and lingual sides during 9 min on days 0, 1, 2, 3, 4, and 7. The same procedure was applied in the first premolar of the contralateral quadrant inserting the tip but without laser emission. Samples of GCF from the compression side of the upper first premolars to distalize were collected at baseline and after 2, 7, 30, and 45 days posttreatment for determination of RANKL and OPG by enzyme-linked immunosorbent assay. In addition, tooth movement was assessed by scanning models and pain intensity was assessed using a visual analog scale. There was improvement in the parameters studied (pain, tooth movement, levels of RANKL in GCF, and RANKL/OPG ratio) in the laser group when compared to the control group, although differences were not statistically significant. The accumulated retraction of the upper premolar at 30 days was higher in the laser group, and this difference was statistically significant between groups. LLLT delivered in repeated doses (six times in the initial 2 weeks) leads in some extent to a slight orthodontical improvement.


Asunto(s)
Líquido del Surco Gingival/metabolismo , Terapia por Luz de Baja Intensidad , Ortodoncia , Osteoprotegerina/metabolismo , Dolor/radioterapia , Ligando RANK/metabolismo , Técnicas de Movimiento Dental , Adolescente , Niño , Femenino , Líquido del Surco Gingival/efectos de la radiación , Humanos , Láseres de Semiconductores , Masculino , Dimensión del Dolor , Factores de Tiempo
20.
Materials (Basel) ; 17(5)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38473595

RESUMEN

In this study, we have improved the power factor of conductive polymer nanocomposites by combining layer-by-layer assembly with electrochemical deposition to produce flexible thermoelectric materials based on PEDOT/carbon nanotubes (CNTs)-films. To produce films based on CNTs and PEDOT, a dual approach has been employed: (i) the layer-by-layer method has been utilized for constructing the CNTs layer and (ii) electrochemical polymerization has been used in the synthesis of the conducting polymer. Moreover, the thermoelectric properties were optimized by controlling the experimental conditions including the number of deposition cycles and electropolymerizing time. The electrical characterization of the samples was carried out by measuring the Seebeck voltage produced under a small temperature difference and by measuring the electrical conductivity using the four-point probe method. The resulting values of the Seebeck coefficient S and σ were used to determine the power factor. The structural and morphological analyses of CNTs/PEDOT samples were carried out using scanning electron microscopy (SEM) and Raman spectroscopy. The best power factor achieved was 131.1 (µWm-1K-2), a competitive value comparable to some inorganic thermoelectric materials. Since the synthesis of the CNT/PEDOT layers is rather simple and the ingredients used are relatively inexpensive and environmentally friendly, the proposed nanocomposites are a very interesting approach as an application for recycling heat waste.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA