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1.
Nature ; 623(7989): 927-931, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37968403

RESUMO

In recent years, certain luminous extragalactic optical transients have been observed to last only a few days1. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae), whose timescale is weeks2. Some short-duration transients, most notably AT2018cow (ref. 3), show blue optical colours and bright radio and X-ray emission4. Several AT2018cow-like transients have shown hints of a long-lived embedded energy source5, such as X-ray variability6,7, prolonged ultraviolet emission8, a tentative X-ray quasiperiodic oscillation9,10 and large energies coupled to fast (but subrelativistic) radio-emitting ejecta11,12. Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd (the 'Tasmanian Devil'). The flares occur over a period of months, are highly energetic and are probably nonthermal, implying that they arise from a near-relativistic outflow or jet. Our observations confirm that, in some AT2018cow-like transients, the embedded energy source is a compact object, either a magnetar or an accreting black hole.

2.
Sensors (Basel) ; 24(11)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38894458

RESUMO

The need to establish safe, accessible, and inclusive pedestrian routes is considered one of the European Union's main priorities. We have developed a method of assessing pedestrian mobility in the surroundings of urban public buildings to evaluate the level of accessibility and inclusion, especially for people with reduced mobility. In the first stage of assessment, artificial intelligence algorithms were used to identify pedestrian crossings and the precise geographical location was determined by deep learning-based object detection with satellite or aerial orthoimagery. In the second stage, Geographic Information System techniques were used to create network models. This approach enabled the verification of the level of accessibility for wheelchair users in the selected study area and the identification of the most suitable route for wheelchair transit between two points of interest. The data obtained were verified using inertial sensors to corroborate the horizontal continuity of the routes. The study findings are of direct benefit to the users of these routes and are also valuable for the entities responsible for ensuring and maintaining the accessibility of pedestrian routes.

3.
Strahlenther Onkol ; 199(9): 847-856, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37000224

RESUMO

PURPOSE: To assess the efficacy of lung low-dose radiotherapy (LD-RT) in the treatment of patients with COVID-19 pneumonia. MATERIALS AND METHODS: Ambispective study with two cohorts to compare treatment with standard of care (SoC) plus a single dose of 0.5 Gy to the whole thorax (experimental prospective cohort) with SoC alone (control retrospective cohort) for patients with COVID-19 pneumonia not candidates for admission to the intensive care unit (ICU) for mechanical ventilation. RESULTS: Fifty patients treated with LD-RT were compared with 50 matched controls. Mean age was 85 years in both groups. An increase in arterial oxygen partial pressure (PaO2)/fraction of inspired oxygen (PAFI) in the experimental LD-RT-treated group compared to the control group could not be found at 48 h after LD-RT, which was the primary endpoint of the study. However, PAFI values significantly improved after 1 month (473 vs. 302 mm Hg; p < 0.0001). Pulse oxymetric saturation/fraction of inspired oxygen (SAFI) values were also significantly higher in LD-RT-treated patients than in control patients at 1 week (405 vs. 334 mm Hg; p = 0.0157) and 1 month after LD-RT (462 vs. 326 mm Hg; p < 0.0001). All other timepoint measurements of the respiratory parameters were similar across groups. Patients in the experimental group were discharged from the hospital significantly earlier (23 vs. 31 days; p = 0.047). Fifteen and 26 patients died due to COVID-19 pneumonia in the experimental and control cohorts, respectively (30% vs. 48%; p = 0.1). LD-RT was associated with a decreased odds ratio (OR) for 1­month COVID-19 mortality (OR = 0.302 [0.106-0.859]; p = 0.025) when adjusted for potentially confounding factors. Overall survival was significantly prolonged in the LD-RT group compared to the control group (log-rank p = 0.027). No adverse events related to radiation treatment were observed. CONCLUSION: Treatment of frail patients with COVID-19 pneumonia with SoC plus single-dose LD-RT of 0.5 Gy improved respiratory parameters, reduced the period of hospitalization, decreased the rate of 1­month mortality, and prolonged actuarial overall survival compared to SoC alone.


Assuntos
COVID-19 , Idoso , Idoso de 80 Anos ou mais , Humanos , COVID-19/radioterapia , Idoso Fragilizado , Estudos Prospectivos , Estudos Retrospectivos , SARS-CoV-2 , Padrão de Cuidado , Resultado do Tratamento
4.
Sensors (Basel) ; 23(12)2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-37420655

RESUMO

The inclusive use of urban spaces necessitates detailed knowledge of the accessibility of public buildings or places where educational, health or administrative services are provided. Despite the improvements already made in many cities regarding architectural work, further changes to public buildings and other spaces, such as old buildings or areas of historical importance, are still required. To study this problem, we developed a model based on photogrammetric techniques and the use of inertial and optical sensors. The model allowed us to perform a detailed analysis of urban routes in the surroundings of an administrative building, by means of mathematical analysis of pedestrian routes. It was applied to the specific case of people with reduced mobility and included analysis of the building accessibility as well as detection of suitable transit routes, deterioration of the road surfaces and the presence of architectural obstacles on the route.


Assuntos
Acessibilidade Arquitetônica , Humanos , Cidades
5.
Biom J ; 65(7): e2200203, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37085745

RESUMO

Recently, the use of mobile technologies in ecological momentary assessments (EMAs) and interventions has made it easier to collect data suitable for intraindividual variability studies in the medical field. Nevertheless, especially when self-reports are used during the data collection process, there are difficulties in balancing data quality and the burden placed on the subject. In this paper, we address this problem for a specific EMA setting that aims to submit a demanding task to subjects at high/low values of a self-reported variable. We adopt a dynamic approach inspired by control chart methods and design optimization techniques to obtain an EMA triggering mechanism for data collection that considers both the individual variability of the self-reported variable and of the adherence. We test the algorithm in both a simulation setting and with real, large-scale data from a tinnitus longitudinal study. A Wilcoxon signed rank test shows that the algorithm tends to have both a higher F1 score and utility than a random schedule and a rule-based algorithm with static thresholds, which are the current state-of-the-art approaches. In conclusion, the algorithm is proven effective in balancing data quality and the burden placed on the participants, especially in studies where data collection is impacted by adherence.


Assuntos
Avaliação Momentânea Ecológica , Humanos , Estudos Longitudinais , Coleta de Dados
6.
Rep Prog Phys ; 85(5)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35522172

RESUMO

Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at Zenodo.

7.
Chemphyschem ; 23(10): e202100914, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35226788

RESUMO

This report describes the application of dielectric spectroscopy as a simple and fast way to guide protein adsorption experiments. Specifically, the polarization behavior of a layer of adsorbed lysozyme was investigated using a triangular-wave signal with frequencies varying from 0.5 to 2 Hz. The basic experiment, which can be performed in less than 5 min and with a single sample, not only allowed confirming the susceptibility of the selected protein towards the electric signal but also identified that this protein would respond more efficiently to signals with lower frequencies. To verify the validity of these observations, the adsorption behavior of lysozyme onto optically transparent carbon electrodes was also investigated under the influence of an applied alternating potential. In these experiments, the applied signal was defined by a sinusoidal wave with an amplitude of 100 mV and superimposed to +800 mV (applied as a working potential) and varying the frequency in the 0.1-10000 Hz range. The experimental data showed that the greatest adsorbed amounts of lysozyme were obtained at the lowest tested frequencies (0.1-1.0 Hz), results that are in line with the corresponding dielectric features of the protein.


Assuntos
Espectroscopia Dielétrica , Muramidase , Adsorção , Eletricidade , Eletrodos , Muramidase/química
8.
Arch Gynecol Obstet ; 305(4): 1089-1097, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35061067

RESUMO

PURPOSE: Hysterectomy has been associated with increased risk for developing stress urinary incontinence (SUI) and having a SUI operation. We examined the long-term rate of SUI operations after hysterectomy and associated risk factors. METHODS: We followed up 5000 women without prior urinary incontinence (UI) who had a hysterectomy in a prospective FINHYST 2006 cohort study until the end of 2016 through a national health register. The main outcome was SUI operations, and secondary outcomes were outpatient visits for UI, and their association of preoperative patient and operation factors. RESULTS: During the median follow-up time of 10.6 years (IQR 10.3-10.8), 111 (2.2%) women had a SUI operation and 241 (4.8%) had an outpatient visit for UI. The SUI operation rate was higher after vaginal hysterectomy and laparoscopic hysterectomy (n = 71 and 28, 3.3% and 1.8%, respectively) compared to abdominal hysterectomy (n = 11, 0.8%). In a multivariate risk analysis by Cox regression, the association with vaginal hysterectomy and SUI operation remained significant when adjusted for vaginal deliveries, preceding pelvic organ prolapse (POP), uterus size, age and BMI (HR 2.4, 95% CI 1.1-5.3). Preceding POP, three or more deliveries and laparoscopic hysterectomy were significantly associated with UI visits but not with SUI operations. CONCLUSION: After hysterectomy, 2.2% of women underwent operative treatment for SUI. The number of SUI operations was more than double after vaginal hysterectomy compared to abdominal hysterectomy, but preceding POP explained this added risk partially. Preceding POP and three or more vaginal deliveries were independently associated with UI visits after hysterectomy.


Assuntos
Prolapso de Órgão Pélvico , Incontinência Urinária por Estresse , Estudos de Coortes , Feminino , Seguimentos , Humanos , Histerectomia/efeitos adversos , Prolapso de Órgão Pélvico/cirurgia , Estudos Prospectivos , Incontinência Urinária por Estresse/epidemiologia , Incontinência Urinária por Estresse/etiologia , Incontinência Urinária por Estresse/cirurgia
9.
Pediatr Surg Int ; 38(10): 1445-1451, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35852592

RESUMO

AIM: Ectopic breast tissue (EBT) includes a spectrum of disease that entails other entities based on the presence of glandular tissue, nipple, or areola. The diagnosis in adolescents is infrequent. METHODS: A retrospective study was performed including girls with axillary EBT (class IV or V of Kajava's Classification) operated in 2006-2020. Imagining studies, clinical and surgical reports, and histopathology were reviewed. RESULTS: Eleven girls from 13 to 16 years old were included. Two patients (18.2%) presented bilateral EBT. The most frequent clinical manifestation was 2-5 cm mass (100%), associating cyclic pain with menstruation (45%) and fluctuating volume (36%). Bilateral axillary ultrasonography allowed preoperative diagnosis. All of them were treated by open excision, through small incisions located in an axillary y fold. Clinical and aesthetic results were self-assessed as "very good", with normalization of the axillary y hollow and imperceptible scars. No recurrences were observed after one year of follow-up. An immediate postoperative hematoma was reported, which did not require drainage. Histopathology showed mature breast tissue without atypia. CONCLUSIONS: Axillary accessory breasts must be included in differential diagnosis of pediatric axillary masses. Bilateral ultrasonography is recommended for the preoperative diagnosis. Excision through minimal incision at this age seems to be safe and effective.


Assuntos
Neoplasias da Mama , Coristoma , Adolescente , Axila/patologia , Axila/cirurgia , Mama/diagnóstico por imagem , Mama/patologia , Mama/cirurgia , Criança , Coristoma/diagnóstico por imagem , Coristoma/cirurgia , Cicatriz , Feminino , Humanos , Mamilos/patologia , Mamilos/cirurgia , Estudos Retrospectivos
10.
Gac Med Mex ; 158(6): 369-375, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36657112

RESUMO

INTRODUCTION: Heart valve bioprostheses are the gold standard for aortic valve surgical replacement in selected patients. OBJECTIVE: To evaluate the safety and efficacy of the National Institute of Cardiology (INC) bioprosthetic heart valve in humans. METHODS: Single-center study that included 341 patients who underwent single surgical aortic valve replacement with INC heart valve. RESULTS: 318 implants were performed de novo (93%) and 23 as redo surgery (7%); STS scores were 1.4 and 1.8%, and follow-up was for 42 and 46 months, respectively. There were no differences in clinical complications or pacemaker implantation rate. Both groups maintained a normal LVEF. Overall improvement in functional class was observed, with worsening only in two patients of the de novo group. INC prosthesis dysfunction requiring surgical reintervention was observed in eight patients (4.65%) of the de novo group vs. one patient in the redo group. CONCLUSIONS: The INC heart valve is efficacious and safe, and is associated with a low rate of complications and functional class improvement during long-term follow-up. Prospective, comparative studies of this valve are required.


INTRODUCCIÓN: Las bioprótesis de válvulas cardiacas son el estándar de oro para el reemplazo quirúrgico de la válvula aórtica en pacientes seleccionados. OBJETIVO: Evaluar la seguridad y eficacia de la válvula cardiaca bioprotésica del Instituto Nacional de Cardiología (INC) en humanos. MÉTODOS: Estudio unicéntrico que incluyó 341 pacientes que se sometieron a reemplazo valvular quirúrgico único de válvula aórtica con válvula INC. RESULTADOS: Se realizaron 318 implantes de novo (93 %) y 23 como segunda cirugía (7 %); las puntuaciones STS fueron de 1.4 y 1.8 % y el seguimiento de 42 y 46 meses, respectivamente. No existieron diferencias en las complicaciones ni en la tasa de implantación de marcapasos. Ambos grupos mantuvieron una FEVI normal. Se observó mejoría global en la clase funcional con empeoramiento solo en dos pacientes del grupo de novo. La disfunción de la prótesis INC que ameritó reintervención quirúrgica se observó en ocho pacientes (4.65 %) del grupo de novo versus un paciente (7.69 %) con segunda cirugía. CONCLUSIONES: La válvula cardiaca INC es eficaz y segura, se asocia a baja tasa de complicaciones y mejoría de la clase funcional durante el seguimiento a largo plazo. Se necesitan estudios prospectivos comparativos de esta válvula.


Assuntos
Estenose da Valva Aórtica , Cardiologia , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Humanos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Estudos Prospectivos , Valva Aórtica/cirurgia , Falha de Prótese , Resultado do Tratamento , Estenose da Valva Aórtica/cirurgia , Reoperação
11.
Plant Physiol ; 184(4): 2040-2051, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33051267

RESUMO

PSI is an essential component of the photosynthetic apparatus of oxygenic photosynthesis. While most of its subunits are conserved, recent data have shown that the arrangement of the light-harvesting complexes I (LHCIs) differs substantially in different organisms. Here we studied the PSI-LHCI supercomplex of Botryococccus braunii, a colonial green alga with potential for lipid and sugar production, using functional analysis and single-particle electron microscopy of the isolated PSI-LHCI supercomplexes complemented by time-resolved fluorescence spectroscopy in vivo. We established that the largest purified PSI-LHCI supercomplex contains 10 LHCIs (∼240 chlorophylls). However, electron microscopy showed heterogeneity in the particles and a total of 13 unique binding sites for the LHCIs around the PSI core. Time-resolved fluorescence spectroscopy indicated that the PSI antenna size in vivo is even larger than that of the purified complex. Based on the comparison of the known PSI structures, we propose that PSI in B. braunii can bind LHCIs at all known positions surrounding the core. This organization maximizes the antenna size while maintaining fast excitation energy transfer, and thus high trapping efficiency, within the complex.


Assuntos
Arabidopsis/química , Arabidopsis/ultraestrutura , Chlamydomonas reinhardtii/química , Chlamydomonas reinhardtii/ultraestrutura , Complexos de Proteínas Captadores de Luz/química , Complexos de Proteínas Captadores de Luz/ultraestrutura , Modelos Moleculares , Conformação Proteica , Subunidades Proteicas
12.
Lasers Surg Med ; 53(3): 377-389, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32614077

RESUMO

BACKGROUND AND OBJECTIVES: Using lasers instead of mechanical tools for bone cutting holds many advantages, including functional cuts, contactless interaction, and faster wound healing. To fully exploit the benefits of lasers over conventional mechanical tools, a real-time feedback to classify tissue is proposed. STUDY DESIGN/MATERIALS AND METHODS: In this paper, we simultaneously classified five tissue types-hard and soft bone, muscle, fat, and skin from five proximal and distal fresh porcine femurs-based on the laser-induced acoustic shock waves (ASWs) generated. For laser ablation, a nanosecond frequency-doubled Nd:YAG laser source at 532 nm and a microsecond Er:YAG laser source at 2940 nm were used to create 10 craters on the surface of each proximal and distal femur. Depending on the application, the Nd:YAG or Er:YAG can be used for bone cutting. For ASW recording, an air-coupled transducer was placed 5 cm away from the ablated spot. For tissue classification, we analyzed the measured acoustics by looking at the amplitude-frequency band of 0.11-0.27 and 0.27-0.53 MHz, which provided the least average classification error for Er:YAG and Nd:YAG, respectively. For data reduction, we used the amplitude-frequency band as an input of the principal component analysis (PCA). On the basis of PCA scores, we compared the performance of the artificial neural network (ANN), the quadratic- and Gaussian-support vector machine (SVM) to classify tissue types. A set of 14,400 data points, measured from 10 craters in four proximal and distal femurs, was used as training data, while a set of 3,600 data points from 10 craters in the remaining proximal and distal femur was considered as testing data, for each laser. RESULTS: The ANN performed best for both lasers, with an average classification error for all tissues of 5.01 ± 5.06% and 9.12 ± 3.39%, using the Nd:YAG and Er:YAG lasers, respectively. Then, the Gaussian-SVM performed better than the quadratic SVM during the cutting with both lasers. The Gaussian-SVM yielded average classification errors of 15.17 ± 13.12% and 16.85 ± 7.59%, using the Nd:YAG and Er:YAG lasers, respectively. The worst performance was achieved with the quadratic-SVM with a classification error of 50.34 ± 35.04% and 69.96 ± 25.49%, using the Nd:YAG and Er:YAG lasers. CONCLUSION: We foresee using the ANN to differentiate tissues in real-time during laser osteotomy. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.


Assuntos
Terapia a Laser , Lasers de Estado Sólido , Animais , Lasers de Estado Sólido/uso terapêutico , Aprendizado de Máquina , Osteotomia , Suínos , Transdutores
13.
Fish Physiol Biochem ; 47(1): 33-47, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33118089

RESUMO

Reproduction in vertebrates is a complex process regulated by many hormones, and by paracrine factors and their receptors. This study aimed to examine the expression of pjGonadotropin-releasing hormone (GnRH 1), the kisspeptin receptor 2 (kissr2), and estradiol receptors α and ß (ER α and ER ß) during different stages of the sexual cycle and their distribution within the anterior brain of females of Chirostoma humboldtianum. Among these molecules, the kissr2 showed the maximal variation in expression, while GnRH 1 showed minimal variation of expression, and ERß and ERα had intermediate variation of expression. The distribution of these molecules in the anterior brain was consistent with their levels of expression; kissr2 was widely distributed throughout the telencephalon and diencephalon, while ER and GnRH 1 showed more restricted distributions. No coexpression of kissr2 and ER in GnRH 1ergic neurons, suggesting that regulation of this GnRH variant is indirectly mediated by kisspeptin and estradiol.


Assuntos
Encéfalo/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Proteínas de Peixes/metabolismo , Peixes/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Kisspeptinas/metabolismo , Animais , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Feminino , Proteínas de Peixes/genética , Peixes/genética , Hormônio Liberador de Gonadotropina/genética , Kisspeptinas/genética , Hipófise/metabolismo
14.
Neuroimage ; 214: 116768, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32217163

RESUMO

The sensation of groove has been defined as the pleasurable desire to move to music, suggesting that both motor timing and reward processes are involved in this experience. Although many studies have investigated rhythmic timing and musical reward separately, none have examined whether the associated cortical and subcortical networks are engaged while participants listen to groove-based music. In the current study, musicians and non-musicians listened to and rated experimentally controlled groove-based stimuli while undergoing functional magnetic resonance imaging. Medium complexity rhythms elicited higher ratings of pleasure and wanting to move and were associated with activity in regions linked to beat perception and reward, as well as prefrontal and parietal regions implicated in generating and updating stimuli-based expectations. Activity in basal ganglia regions of interest, including the nucleus accumbens, caudate and putamen, was associated with ratings of pleasure and wanting to move, supporting their important role in the sensation of groove. We propose a model in which different cortico-striatal circuits interact to support the mechanisms underlying groove, including internal generation of the beat, beat-based expectations, and expectation-based affect. These results show that the sensation of groove is supported by motor and reward networks in the brain and, along with our proposed model, suggest that the basal ganglia are crucial nodes in networks that interact to generate this powerful response to music.


Assuntos
Percepção Auditiva/fisiologia , Gânglios da Base/fisiologia , Dança , Música , Prazer/fisiologia , Recompensa , Estimulação Acústica , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Motivação/fisiologia , Periodicidade
15.
Plant Physiol ; 179(3): 1132-1143, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30651303

RESUMO

In contrast to single cellular species, detailed information is lacking on the processes of photosynthetic acclimation for colonial algae, although these algae are important for biofuel production, ecosystem biodiversity, and wastewater treatment. To investigate differences between single cellular and colonial species, we studied the regulation of photosynthesis and photoprotection during photoacclimation for the colonial green alga Botryococcus braunii and made a comparison with the properties of the single cellular species Chlamydomonas reinhardtii We show that B. braunii shares some high-light (HL) photoacclimation strategies with C. reinhardtii and other frequently studied green algae: decreased chlorophyll content, increased free carotenoid content, and increased nonphotochemical quenching (NPQ). Additionally, B. braunii has unique HL photoacclimation strategies, related to its colonial form: strong internal shading by an increase of the colony size and the accumulation of extracellular echinenone (a ketocarotenoid). HL colonies are larger and more spatially heterogenous than low-light colonies. Compared with surface cells, cells deeper inside the colony have increased pigmentation and larger photosystem II antenna size. The core of the largest of the HL colonies does not contain living cells. In contrast with C. reinhardtii, but similar to other biofilm-forming algae, NPQ capacity is substantial in low light. In HL, NPQ amplitude increases, but kinetics are unchanged. We discuss possible causes of the different acclimation responses of C. reinhardtii and B. braunii Knowledge of the specific photoacclimation processes for this colonial green alga further extends the view of the diversity of photoacclimation strategies in photosynthetic organisms.


Assuntos
Aclimatação , Clorófitas/fisiologia , Fotossíntese , Clorófitas/efeitos da radiação , Cinética , Luz Solar
16.
Soft Matter ; 16(33): 7659-7666, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32724987

RESUMO

While thermal treatment of paper can lead to the formation of aromatic structures via hydrothermal treatment (low temperature) or pyrolysis (high temperature), neither of these approaches allow patterning the substrates. Somewhere in between these two extremes, a handful of research groups have used CO2 lasers to pattern paper and induce carbonization. However, none of the previously reported papers have focused on the possibility to form fluorescent derivatives via laser-thermal engraving. Exploring this possibility, this article describes the possibility of using a CO2 laser engraver to selectively treat paper, resulting in the formation of fluorescent compounds, similar to those present on the surface of carbon dots. To determine the most relevant variables controlling this process, 3 MM chromatography paper was treated using a standard 30 W CO2 laser engraver. Under selected experimental conditions, a blue fluorescent pattern was observed when the substrate was irradiated with UV light (365 nm). The effect of various experimental conditions (engraving speed, engraving power, and number of engraving steps) was investigated to maximize the fluorescence intensity. Through a comprehensive characterization effort, it was determined that 5-(hydroxymethyl)furfural and a handful of related compounds were formed (varying in amount) under all selected experimental conditions. To illustrate the potential advantages of this strategy, that could complement those applications traditionally developed from carbon dots (sensors, currency marking, etc.), a redox-based optical sensor for sodium hypochlorite was developed.

17.
Gac Med Mex ; 156(4): 279-285, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32831335

RESUMO

INTRODUCTION: A drug-eluting coronary stent is being developed at the National Institute of Cardiology of Mexico for the treatment of ischemic heart disease. OBJECTIVE: To establish the best animal model for the tests, to show the advances in the drug-eluting stent prototype, to assess two drugs' antiproliferative activity and histological results. METHOD: Smooth muscle cell culture tests were performed in order to assess sirolimus and paclitaxel antiproliferative properties. The drugs were encapsulated inside the polymeric matrix of the stents. Rabbits and pigs were used as animal models. RESULTS: Sirolimus and paclitaxel showed an inhibitory effect, which was higher for the latter. Infrared spectroscopy and light and optical microscopy showed that the drug/polymer layer properly adhered to the stent. At a four-week follow-up, both animal models showed satisfactory clinical evolution and adequate histological response, although the porcine model was shown to be more suitable for future protocols. CONCLUSIONS: Preliminary tests of the drug-eluting stent provided bases for the development of a study protocol with an adequate number of pigs and with clinical angiographic and histopathological three-month follow-up.


INTRODUCCIÓN: En el Instituto Nacional de Cardiología de México se desarrolla una endoprótesis (stent) coronaria liberadora de fármacos para el tratamiento de la cardiopatía isquémica. OBJETIVO: Establecer el mejor modelo animal para las pruebas, mostrar los avances en el prototipo del stent liberador de fármacos, evaluar la actividad antiproliferativa de dos fármacos y los resultados histológicos. MÉTODO: Se realizaron cultivos de células de músculo liso para evaluar las propiedades antiproliferativas de sirolimus y paclitaxel. Los fármacos fueron encapsulados en el interior de la matriz polimérica de los stents. Se emplearon conejos y cerdos como modelos animales. RESULTADOS: Sirolimus y paclitaxel mostraron efecto inhibitorio, mayor en el segundo. La espectroscopia infrarroja y la microscopia óptica y electrónica mostraron que la capa del polímero con el fármaco se adhería adecuadamente al stent. A las cuatro semanas de seguimiento, ambos modelos animales mostraron evolución clínica satisfactoria y adecuada respuesta histológica, si bien el modelo porcino resultó más conveniente para protocolos futuros. CONCLUSIONES: Las pruebas preliminares del stent liberador de fármaco brindó bases para desarrollar el protocolo con un número adecuado en cerdos y con seguimiento clínico angiográfico e histopatológico a tres meses.


Assuntos
Stents Farmacológicos , Paclitaxel/administração & dosagem , Sirolimo/administração & dosagem , Animais , Modelos Animais de Doenças , Feminino , Seguimentos , Masculino , Microscopia , Desenho de Prótese , Coelhos , Espectrofotometria Infravermelho , Suínos
18.
Foot Ankle Surg ; 26(2): 189-192, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30772132

RESUMO

BACKGROUND: Unstable ankle fractures in diabetics with peripheral neuropathy have an increased risk of postoperative complications, often leading to amputation. Primary ankle arthrodesis has been suggested as an alternative when acceptable reduction and mechanical stabilization cannot be obtained. METHODS: Over a fourteen year period, thirteen diabetic patients with peripheral neuropathy underwent an attempt at primary ankle arthrodesis following the early post-fracture development of acute neuropathic (Charcot) deformity of the ankle after sustaining a low energy unstable ankle fracture. Eight patients with open wounds and osteomyelitis underwent single stage debridement of the osteomyelitis and primary ankle fusion with an ankle fusion construct circular external fixator. Five patients without evidence of infection underwent primary arthrodesis with a retrograde locked intramedullary nail used for fixation. A successful clinical outcome was achieved with either successful radiographic arthrodesis or stable pseudarthrosis, when community ambulation was achieved with commercially-available therapeutic footwear and a short ankle orthosis. RESULTS: Eight of the thirteen patients achieved a successful clinical outcome at a mean follow-up of 48 (range 12-136) months following the initial surgery. Three achieved clinical stability following a second surgery and one following a third. One patient with radiographic nonunion expired due to unrelated causes. One patient underwent transtibial amputation due to persistent infection. Of the five patients with failure of radiographic union, three successfully ambulated in the community with a short ankle orthosis. Postoperative complications included wound and pin-site infection, infected nonunion, chronic wounds, and tibial stress fracture. CONCLUSION: In spite of the high risk for complications and initial failure, primary ankle fusion is a reasonable option for diabetic neuropathic patients who develop acute neuropathic arthropathy following ankle fracture. LEVEL OF EVIDENCE: Level IV retrospective case series.


Assuntos
Fraturas do Tornozelo/cirurgia , Articulação do Tornozelo/cirurgia , Artrodese , Artropatia Neurogênica/cirurgia , Neuropatias Diabéticas/complicações , Adulto , Idoso , Artropatia Neurogênica/etiologia , Desbridamento , Fixadores Externos , Feminino , Fixação Intramedular de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Osteomielite/terapia , Estudos Retrospectivos
19.
J Sports Sci Med ; 19(2): 364-373, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32390730

RESUMO

The presentation of unhealthy psychological symptoms are rising sharply in adolescents. Detrimental lifestyle behaviours are proposed as both possible causes and consequences. This study set out to compare selected measures of quality and quantity of movement between adolescents with and without unhealthy psychological symptoms. Using a cross sectional design, 96 participants completed the study from a whole year group of 166, age (13.36 ± 0.48) male 50.6% from a secondary school in Oxfordshire, England as a part of a larger study (EPIC) between January and April 2018. Measures were taken of quality and quantity of movement: reaction/movement time, gait pattern & physical activity, alongside psychological symptoms. Differences in movement behaviour in relation to psychological symptom and emotional problem presentation were determined using ANOVA. In the event of a significant result for the main factor of each parameter, a Bonferroni -corrected post hoc test was conducted to show the difference between categories in each group. Results for both unhealthy psychological symptoms and emotional problems were grouped into four categories ('Close to average', 'slightly raised', 'high' and 'very high'). Early adolescents with very high unhealthy psychological symptoms had 16.79% slower reaction times (p = 0.003, ηp2 = 0.170), 13.43% smaller walk ratio (p = 0.007, ηp2 = 0.152), 7.13% faster cadence (p = 0.005, ηp2 = 0.149), 6.95% less step time (p = 0.007, ηp2 = 0.153) and 1.4% less vigorous physical activity (p = 0.04, ηp2 = 0.102) than children with close to average psychological symptoms. Early adolescents with very high emotional problems had 12.25% slower reaction times (p = 0.05, ηp2 = 0.081), 10.61% smaller walk ratio (p = 0.02, ηp2 = 0.108), 6.03% faster cadence (p = 0.01, ηp2 = 0.134), 6.07% shorter step time (p = 0.007, ηp2 = 0.141) and 1.78% less vigorous physical activity (p = 0.009, ηp2 = 0.136) than children with close to average emotional problems. Different movement quality and quantity of was present in adolescents with unhealthy psychological symptoms and emotional problems. We propose movement may be used to both monitor symptoms, and as a novel therapeutic behavioural approach. Further studies are required to confirm our findings.


Assuntos
Comportamento do Adolescente/fisiologia , Sintomas Afetivos/diagnóstico , Cognição/fisiologia , Exercício Físico/fisiologia , Comportamentos Relacionados com a Saúde/fisiologia , Adolescente , Estudos Transversais , Feminino , Análise da Marcha , Humanos , Masculino , Movimento/fisiologia , Tempo de Reação
20.
Photosynth Res ; 135(1-3): 191-201, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28551868

RESUMO

The colonial green alga Botryococcus braunii (BB) is a potential source of biofuel due to its natural high hydrocarbon content. Unfortunately, its slow growth limits its biotechnological potential. Understanding its photosynthetic machinery could help to identify possible growth limitations. Here, we present the first study on BB light-harvesting complexes (LHCs). We purified two LHC fractions containing the complexes in monomeric and trimeric form. Both fractions contained at least two proteins with molecular weight (MW) around 25 kDa. The chlorophyll composition is similar to that of the LHCII of plants; in contrast, the main xanthophyll is loroxanthin, which substitutes lutein in most binding sites. Circular dichroism and 77 K absorption spectra lack typical differences between monomeric and trimeric complexes, suggesting that intermonomer interactions do not play a role in BB LHCs. This is in agreement with the low stability of the BB LHCII trimers as compared to the complexes of plants, which could be related to loroxanthin binding in the central (L1 and L2) binding sites. The properties of BB LHCII are similar to those of plant LHCII, indicating a similar pigment organization. Differences are a higher content of red chlorophyll a, similar to plant Lhcb3. These differences and the different Xan composition had no effect on excitation energy transfer or fluorescence lifetimes, which were similar to plant LHCII.


Assuntos
Clorófitas/metabolismo , Complexos de Proteínas Captadores de Luz/metabolismo , Proteínas de Plantas/metabolismo , Dicroísmo Circular , Complexos de Proteínas Captadores de Luz/isolamento & purificação , Pigmentos Biológicos/metabolismo , Proteínas de Plantas/isolamento & purificação , Desnaturação Proteica , Estabilidade Proteica , Espectrometria de Fluorescência , Temperatura , Tilacoides/metabolismo , Fatores de Tempo
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