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1.
Cult. cuid ; 28(68): 103-116, Abr 10, 2024. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-VR-414

RESUMO

El presente trabajo analiza la repercusión de la técnica de grabadono tóxica Collagraph, en personas con Demencia tempranatipo Alzhéimer, en el programa de educación artística “Retalesde una vida”. El objetivo es conectar a los participantes conprogramas de carácter cultural para fomentar la comunicacióne interacción entre participantes. La experiencia se llevó a caboen el Centro de Referencia Estatal para personas con Alzheimery otras Demencias de Salamanca (CREA). Una vez adaptadala metodología del taller a las características personales y desalud de las personas enfermas de Alzheimer, se considera lautilización del grabado genera importantes beneficios en losparticipantes, relacionados con el incremento de la inteligenciacristalizada, la conducta prosocial y la valoración positiva desí mismos, favoreciendo la inclusión social y familiar.Asimismo, el empleo del grabado puede ofrecer un soporte deayuda terapéutica individual y cooperativa a los participantes,desarrollar habilidades funcionales, sociales y cognitivas, ampliandosus recursos emocionales y disfrutar de la experiencia. A suvez fortalecen su autoestima y seguridad ante su capacidady valía. Por último, planteamos una serie de pautas para laplanificación e implementación de este proceso artístico paraque sirva de referente a profesionales de la salud.(AU)


The present work analyzes the repercussion of the non-toxic engraving technique Collagraph, in people with EarlyAlzheimer’s Dementia, in the artistic education program “Retalesde una vida”. The objective is to connect the participants withprograms of a cultural nature to encourage communication and interaction between participants. The experience wascarried out at the State Reference Center for people withAlzheimer’s and other Dementias of Salamanca (CREA). Oncethe methodology of the workshop has been adapted to thepersonal and health characteristics of people with Alzheimer'sdisease, it is considered that the use of engraving generatesimportant benefits in the participants, related to the increasein crystallized intelligence, prosocial behavior and positiveassessment. of themselves, favoring social and family inclusion.Likewise, the use of engraving can offer support for individualand cooperative therapeutic help to the participants, developfunctional, social and cognitive skills, expanding theiremotional resources and enjoying the experience. In turn,they strengthen their self-esteem and security in the faceof their ability and worth. Finally, we propose a series ofguidelines for the planning and implementation of this artisticprocess so that it serves as a reference for health professionals.(AU)


O presente trabalho analisa a repercussão da técnica degravura atóxica Collagraph, em pessoas com DemênciaInicial de Alzheimer, no programa de educação artística“Retales de una vida”. O objetivo é conectar os participantes aprogramas de cunho cultural para estimular a comunicação ea interação entre os participantes. A experiência foi realizadano Centro Estadual de Referência para Pessoas com Alzheimere outras Demências de Salamanca (CREA). Uma vez quea metodologia da oficina foi adaptada às característicaspessoais e de saúde das pessoas com doença de Alzheimer,considerase que o uso da gravura gera importantes benefíciosnos participantes, relacionados ao aumento da inteligênciacristalizada, comportamento prósocial e avaliação positivade si mesmos, favorecendo a inclusão social e familiar.Da mesma forma, o uso da gravura pode oferecer suporte paraajuda terapêutica individual e cooperativa aos participantes,desenvolver habilidades funcionais, sociais e cognitivas, ampliandoseus recursos emocionais e desfrutando da experiência. Porsua vez, fortalecem sua auto-estima e segurança diante de suacapacidade e valor. Por fim, propomos uma série de diretrizespara o planejamento e implementação desse processo artísticopara que sirva de referência para os profissionais de saúde.(AU)


Assuntos
Humanos , Masculino , Feminino , Cuidados de Enfermagem , Demência/enfermagem , Doença de Alzheimer , Arte , Gravuras e Gravação , Comunicação
2.
Environ Sci Technol ; 58(14): 6435-6443, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38551393

RESUMO

Nanovoids within a polyamide layer play an important role in the separation performance of thin-film composite (TFC) reverse osmosis (RO) membranes. To form more extensive nanovoids for enhanced performance, one commonly used method is to incorporate sacrificial nanofillers in the polyamide layer during the exothermic interfacial polymerization (IP) reaction, followed by some post-etching processes. However, these post-treatments could harm the membrane integrity, thereby leading to reduced selectivity. In this study, we applied in situ self-etchable sacrificial nanofillers by taking advantage of the strong acid and heat generated in IP. CaCO3 nanoparticles (nCaCO3) were used as the model nanofillers, which can be in situ etched by reacting with H+ to leave void nanostructures behind. This reaction can further degas CO2 nanobubbles assisted by heat in IP to form more nanovoids in the polyamide layer. These nanovoids can facilitate water transport by enlarging the effective surface filtration area of the polyamide and reducing hydraulic resistance to significantly enhance water permeance. The correlations between the nanovoid properties and membrane performance were systematically analyzed. We further demonstrate that the nCaCO3-tailored membrane can improve membrane antifouling propensity and rejections to boron and As(III) compared with the control. This study investigated a novel strategy of applying self-etchable gas precursors to engrave the polyamide layer for enhanced membrane performance, which provides new insights into the design and synthesis of TFC membranes.


Assuntos
Incrustação Biológica , Nanopartículas , Osmose , Nylons/química , Gravuras e Gravação , Membranas Artificiais , Água/química
3.
Sci Rep ; 13(1): 17340, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833336

RESUMO

Atxurra cave has a decorated assemblage composed of more than a hundred engraved animal depictions. All of them are located in deep parts of the cave and most of them are hidden in raised areas, away from the main path. The main sector is the "Ledge of the Horses", located at 330 m from the entrance of the cave. It is a space of 12 m long and 1.5 m wide, elevated 4 m above the cave floor. This area includes almost fifty engraved and painted animals accompanied by a dozen flint tools, three fireplaces, and around one hundred charcoal fragments from torches. This extraordinary archaeological record allows us to value the complexity of the artistic production inside the caves during the Upper Palaeolithic. Our study has confirmed that there is planning prior to artistic production, both in terms of the iconographic aspects (themes, techniques, formats), its location (visibility, capacity), and the lighting systems. Furthermore, the data indicates the panel was decorated to be seen by third parties from different positions and was expressly illuminated for this purpose. This evidence supports the role of rock art as a visual communication system in Upper Palaeolithic societies.


Assuntos
Arte , Cavernas , Animais , Cavalos , Espanha , Motivação , Gravuras e Gravação , Arqueologia
4.
J Basic Microbiol ; 63(10): 1085-1094, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37551023

RESUMO

Interdisciplinary studies on cultural heritage artworks provide efficient solutions to control fungal growth and the negative effects of biodeterioration. In this study, we aimed to identify the population of filamentous fungi colonizing an engraving by the Dutch painter Rembrandt, whose conservation status was compromised and showed visible stains of biodeterioration. Microbiological techniques, such as cultivation-dependent approaches and molecular biology, have been used to identify fungal populations. In addition, the anaerobic atmosphere technique and eco-friendly antifungal agents, such as essential oils (EOs) of Curcuma longa, Thymus vulgaris, and Melaleuca alternifolia, were tested against the metabolically active fungal population Cladoposporium spinulosum. Furthermore, in vitro assays revealed that the interaction between the fungal strains and EO was positive, inhibiting the growth of these fungi, and the EOs from T. vulgaris and M. alternifolia showed low minimum inhibitory concentration values. Exposure to anaerobic conditions for 35 days was effective in the total elimination of isolated fungal strains. In conclusion, this study demonstrated the effectiveness of a nondestructive technique for artwork on engraving colonized by fungal strains and using EO as an alternative to toxic antifungals used in conventional treatments in artworks. Thus, this interdisciplinary study involving applied microbiology and botanical and preventive conservation presents a tool to control microbial growth while maintaining artwork integrity.


Assuntos
Antifúngicos , Óleos Voláteis , Antifúngicos/farmacologia , Gravuras e Gravação , Fungos , Cladosporium , Óleos Voláteis/farmacologia , Testes de Sensibilidade Microbiana
5.
PLoS One ; 18(6): e0286568, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37343032

RESUMO

Here we report on Neanderthal engravings on a cave wall at La Roche-Cotard (LRC) in central France, made more than 57±3 thousand years ago. Following human occupation, the cave was completely sealed by cold-period sediments, which prevented access until its discovery in the 19th century and first excavation in the early 20th century. The timing of the closure of the cave is based on 50 optically stimulated luminescence ages derived from sediment collected inside and from around the cave. The anthropogenic origin of the spatially-structured, non-figurative marks found within the cave is confirmed using taphonomic, traceological and experimental evidence. Cave closure occurred significantly before the regional arrival of H. sapiens, and all artefacts from within the cave are typical Mousterian lithics; in Western Europe these are uniquely attributed to H. neanderthalensis. We conclude that the LRC engravings are unambiguous examples of Neanderthal abstract design.


Assuntos
Homem de Neandertal , Humanos , Animais , Gravuras e Gravação , Cavernas , França , Europa (Continente) , Fósseis , Arqueologia
6.
PLoS One ; 18(5): e0277927, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37196043

RESUMO

Data on how Stone Age communities conceived domestic and utilitarian structures are limited to a few examples of schematic and non-accurate representations of various-sized built spaces. Here, we report the exceptional discovery of the up-to-now oldest realistic plans that have been engraved on stones. These engravings from Jordan and Saudi Arabia depict 'desert kites', humanmade archaeological mega-traps that are dated to at least 9,000 years ago for the oldest. The extreme precision of these engravings is remarkable, representing gigantic neighboring Neolithic stone structures, the whole design of which is impossible to grasp without seeing it from the air or without being their architect (or user, or builder). They reveal a widely underestimated mental mastery of space perception, hitherto never observed at this level of accuracy in such an early context. These representations shed new light on the evolution of human discernment of space, communication, and communal activities in ancient times.


Assuntos
Arqueologia , Gravuras e Gravação , Humanos , História Antiga , Arábia Saudita , Jordânia , Tempo
7.
Anal Chem ; 95(17): 6765-6768, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37079776

RESUMO

Since wood is a renewable, biodegradable naturally occurring material, the development of conductive patterns on wood substrates is a new and innovative chapter in sustainable electronics and sensors. Herein, we describe the first wooden (bio)sensing device fabricated via diode laser-induced graphitization. For this purpose, a wooden tongue depressor (WTD) is laser-treated and converted to an electrochemical multiplex biosensing device for oral fluid analysis. A low-cost laser engraver, equipped with a low-power (0.5 W) diode laser, programmably irradiates the surface of the WTD, forming two mini electrochemical cells (e-cells). The two e-cells consist of four graphite electrodes: two working electrodes, a common counter, and a common reference electrode. The two e-cells are spatially separated via programmable pen-plotting, using a commercial hydrophobic marker pen. Proof-of-principle for biosensing is demonstrated for the simultaneous determination of glucose and nitrite in artificial saliva. This wooden electrochemical biodevice is an easy-to-fabricate disposable point-of-care chip with a wide scope of applicability to other bioassays, while it paves the way for the low-cost and straightforward production of wooden electrochemical platforms.


Assuntos
Técnicas Biossensoriais , Saliva , Madeira , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Saliva/química , Gravuras e Gravação , Lasers Semicondutores , Língua , Técnicas Eletroquímicas , Eletrodos
8.
Sci Rep ; 12(1): 19227, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456596

RESUMO

In the Copper Age, slate engraved plaques were produced massively in the southwestern corner of the Iberian Peninsula. Researchers have speculated about the function of these palm-sized stone objects for more than a century, although most have favored the idea that they represented goddesses, and served ritual purposes. The plaques are engraved with different designs of varying complexity. In some of them, the ones sporting two large frontal eyes, we clearly see owls modelled after two species present in the area: the little owl (Athene noctua), and the long-eared owl (Asio otus). These two species, living in semi-open habitats, were possibly the most abundant owls around the human settlements and surrounding cultivated fields of the Chalcolithic period. People must have been aware of the owl presence and possibly interacted with them. Why owls but no other animals have been the models may relate to the fact they are the most anthropomorphic of all animals, with large frontally-placed eyes in their enormous heads. In the iconography, owls are systematically represented, even today, with their two eyes staring at the observer, as opposed to the lateral view used for any other animal. Additionally, slate is one of the commonest surface rocks in southwestern Iberia, and it provides a blank canvas for engraving lines using pointed tools made of flint, quartz or copper. The way slates exfoliate makes easy to craft owl-looking plaques. To silhouette animals other than owls in a recognizable way would request extra carving abilities and specific tools. Plaque manufacture and design were simple and did not demand high skills nor intensive labor as demonstrated in replication experiments. Owl engravings could have been executed by youngsters, as they resemble owls painted today by elementary school students. This also suggests that schematic drawings are universal and timeless. We propose that the owl-like slate plaques are the remains of a set of objects used in both playful activities and in ritual ceremonies. The actual engraving of the plaques may have been part of the game. Owlish slate plaques were often perforated twice at the top. We interpret this as insertion points for actual bird feathers added to the plaques, right at the place where tufts emerge in live owls. The frontier among play and ritual is diffuse in liminal societies and there is no contradiction in playing with animal-like toys and, at some point, using them as offerings as part of community rituals related, for instance, to the colossal megalithic tombs so characteristic of the Copper Age.


Assuntos
Estrigiformes , Animais , Criança , Humanos , Conscientização , Plumas , Comportamento Ritualístico , Gravuras e Gravação/história , História Antiga
9.
Ambix ; 69(4): 341-373, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36317883

RESUMO

Robert Fludd was a thinker full of contradictions. He is famous for his theosophical system and for his experimental chymical constructions as well as for his Galenic medical practices. Furthermore, Fludd had his works published in luxurious folio formats by the publisher Johann Theodor de Bry, and the spectacular etchings and many of the engravings in his books were executed by Matthäus Merian the Elder. Fludd's elaborate explanations of these images reveal him to be a natural philosopher who expressed his thoughts graphically. To what extent, however, were the ideas for the images, and the images in Fludd's books themselves, his own? A discussion of preserved textual and image sources suggests that Fludd can indeed be understood as a chymical thinker and practitioner who contributed to the visual and artisanal episteme of his time. This article demonstrates this interpretation by using both well-known sources and the recently rediscovered, lavishly illustrated, master copy, Universitätsbibliothek Johann Christian Senckenberg Frankfurt am Main, MS lat. qu. 15, which served as a template for the section De technica microcosmi historia of Fludd's main work Utriusque cosmi historia.


Assuntos
Livros , Gravuras e Gravação , Cristianismo
10.
Arch. Soc. Esp. Oftalmol ; 97(9): 510-513, sept. 2022. ilus
Artigo em Espanhol | IBECS | ID: ibc-209105

RESUMO

Objetivo Digitalizar nuestro archivo antiguo y evaluar la eficiencia de esta tarea, tanto en términos médicos como económicos. Material y métodos Se recogieron todas las diapositivas y negativos (8254) archivados en nuestro servicio, digitalizándose con un escáner de diapositivas de 5 megapíxeles. La antigüedad de las imágenes comprendía de 1972 a 1999. Se valoró la calidad y utilidad de las imágenes frente al coste del proceso, que ascendió a 2100euros, siendo realizado por el mismo oftalmólogo. esultados De aquellas cuyo paciente era identificable, un 62% ya habían fallecido. Solo un 1,5% del total de diapositivas fueron archivadas para su uso; 70 imágenes por razones docentes y 60 por razones médicas, siendo incorporadas al historial del paciente. Se calcularon unas 210horas invertidas en el escaneo, identificación, comprobación y subida de imágenes. El 84% correspondían a patología retiniana, 4% a patología glaucomatosa, 3% a patología de segmento anterior y el resto a material docente. La calidad de la mayoría de imágenes es buena, y, en algunos casos, fueron cruciales para el diagnóstico correcto de la patología. Si atendemos únicamente a razones asistenciales, la cantidad de diapositivas incorporables a la historia clínica es muy baja en archivos de más de 50 años. Conclusiones Aunque el porcentaje de imágenes escaneadas es bajo, consideramos la tarea eficiente puesto que el coste es bajo. Los archivos de más de 50 años de antigüedad deben ser evaluados antes de su escaneo por su baja utilidad (AU)


Objective To digitise our old archive and evaluate the efficiency of this task, both in medical and economic terms. Material and methods All slides and negatives (8,254) archived in our clinic were collected, digitised with a 5-megapixel slide scanner. The images were taken from 1972 to 1999. Quality and utility of images were taken into account, as far as costs of the task (up to 2,100 euros), all the work done by the same ophthalmologist. Results Of those identifiable, 62% of the patients had already died. Only 1.5% were archived for use; 70 images for teaching reasons and 60 for medical reasons, being incorporated into the patient's history. About 210hours were spent on scanning, identifying, checking and uploading images. 84% corresponded to retinal pathology, 4% to glaucomatous pathology, 3% to anterior segment pathology and the last 9% to learning material. The quality of most images is good, and, in some cases, were important for the correct diagnosis of the pathology. If only medical reasons are taken into account, the number of images uploaded is very low when working with archives older than 50 years. Conclusions Although there was a low percentage of scanned images, the task was efficient because of a low cost. Images older than 50 years must be evaluated before scanning because of their low utility (AU)


Assuntos
Humanos , Armazenamento e Recuperação da Informação/métodos , Gravuras e Gravação , Oftalmologia , Armazenamento e Recuperação da Informação/economia , Eficácia
11.
PLoS One ; 17(8): e0271732, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35921273

RESUMO

It has been suggested that engraved abstract patterns dating from the Middle and Lower Palaeolithic served as means of representation and communication. Identifying the brain regions involved in visual processing of these engravings can provide insights into their function. In this study, brain activity was measured during perception of the earliest known Palaeolithic engraved patterns and compared to natural patterns mimicking human-made engravings. Participants were asked to categorise marks as being intentionally made by humans or due to natural processes (e.g. erosion, root etching). To simulate the putative familiarity of our ancestors with the marks, the responses of expert archaeologists and control participants were compared, allowing characterisation of the effect of previous knowledge on both behaviour and brain activity in perception of the marks. Besides a set of regions common to both groups and involved in visual analysis and decision-making, the experts exhibited greater activity in the inferior part of the lateral occipital cortex, ventral occipitotemporal cortex, and medial thalamic regions. These results are consistent with those reported in visual expertise studies, and confirm the importance of the integrative visual areas in the perception of the earliest abstract engravings. The attribution of a natural rather than human origin to the marks elicited greater activity in the salience network in both groups, reflecting the uncertainty and ambiguity in the perception of, and decision-making for, natural patterns. The activation of the salience network might also be related to the process at work in the attribution of an intention to the marks. The primary visual area was not specifically involved in the visual processing of engravings, which argued against its central role in the emergence of engraving production.


Assuntos
Gravuras e Gravação , Lobo Occipital , Arqueologia , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética/métodos , Lobo Occipital/fisiologia , Reconhecimento Psicológico
12.
Opt Lett ; 47(9): 2298-2301, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35486785

RESUMO

Focimeters, especially manual versions, are the most used ophthalmic devices for dioptric power measurement in optometric clinical care. In the particular case of progressive addition lenses (PALs), they are used to determine far/near vision correction powers, but the user/clinician needs to know at which part of the PAL the measurement must be taken. For this reason, PALs have permanent engravings acting as reference marks to define the far/near vision areas for every PAL design. However, for several reasons these engravings are often difficult to localize and identify, making an accurate dioptric power determination difficult. In this Letter, we present an adaptation of the Gabor holographic principle to a manual focimeter and describe the methodology for the correct localization, visualization, and marking process of the reference engravings in PALs. Experimental results considering different types of PALs are included and the main limitations of the technique are also discussed.


Assuntos
Gravuras e Gravação , Holografia , Desenho de Equipamento , Óculos , Visão Ocular
13.
PLoS One ; 17(4): e0266146, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35442964

RESUMO

Palaeolithic stone plaquettes are a type of mobiliary art featuring engravings and recovered primarily from Magdalenian sites, where they can number from single finds to several thousand examples. Where context is available, they demonstrate complex traces of use, including surface refreshing, heating, and fragmentation. However, for plaquettes with limited or no archaeological context, research tends to gravitate toward their engraved surfaces. This paper focuses on 50 limestone plaquettes excavated by Peccadeau de l'Isle from Montastruc, a Magdalenian rockshelter site in southern France with limited archaeological context; a feature common to many art bearing sites excavated across the 19th and early 20th Centuries. Plaquette use at Montastruc was explored via a programme of microscopy, 3D modelling, colour enhancement using DStretch©, virtual reality (VR) modelling, and experimental archaeology, the latter focusing on limestone heating related to different functional and non-functional uses. While the limited archaeological context available ensures the results remain only indicative, the data generated suggests plaquettes from Montastruc were likely positioned in proximity to hearths during low ambient light conditions. The interaction of engraved stone and roving fire light made engraved forms appear dynamic and alive, suggesting this may have been important in their use. Human neurology is particularly attuned to interpreting shifting light and shadow as movement and identifying visually familiar forms in such varying light conditions through mechanisms such as pareidolic experience. This interpretation encourages a consideration of the possible conceptual connections between art made and experienced in similar circumstances, such as parietal art in dark cave environments. The toolset used to investigate the Montastruc assemblage may have application to other collections of plaquettes, particularly those with limited associated context.


Assuntos
Arqueologia , Gravuras e Gravação , Arqueologia/métodos , Carbonato de Cálcio , Cavernas , França , Humanos
14.
Cartilage ; 13(1): 19476035221075951, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35189712

RESUMO

OBJECTIVE: Implantation of tissue-engineered tracheal grafts represents a visionary strategy for the reconstruction of tracheal wall defects after resections and may develop into a last chance for a number of patients with severe cicatricial stenosis. The use of a decellularized tracheal substrate would offer an ideally stiff graft, but the matrix density would challenge efficient remodeling into a living cartilage. In this study, we hypothesized that the pores of decellularized laser-perforated tracheal cartilage (LPTC) tissues can be colonized by adult nasal chondrocytes (NCs) to produce new cartilage tissue suitable for the repair of tracheal defects. DESIGN: Human, native tracheal specimens, isolated from cadaveric donors, were exposed to decellularized and laser engraving-controlled superficial perforation (300 µm depth). Human or rabbit NCs were cultured on the LPTCs for 1 week. The resulting revitalized tissues were implanted ectopically in nude mice or orthotopically in tracheal wall defects in rabbits. Tissues were assayed histologically and by microtomography analyses before and after implantation. RESULTS: NCs were able to efficiently colonize the pores of the LPTCs. The extent of colonization (i.e., percentage of viable cells spanning >300 µm of tissue depth), cell morphology, and cartilage matrix deposition improved once the revitalized constructs were implanted ectopically in nude mice. LPTCs could be successfully grafted onto the tracheal wall of rabbits without any evidence of dislocation or tracheal stenosis, 8 weeks after implantation. Rabbit NCs, within the LPTCs, actively produced new cartilage matrix. CONCLUSION: Implantation of NC-revitalized LPTCs represents a feasible strategy for the repair of tracheal wall defects.


Assuntos
Gravuras e Gravação , Engenharia Tecidual , Animais , Cartilagem/transplante , Humanos , Lasers , Camundongos , Camundongos Nus , Coelhos , Engenharia Tecidual/métodos , Tecidos Suporte
15.
Trends Immunol ; 42(11): 951-952, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635394

RESUMO

Memory B cells are central to effective protection against reinfection. Glaros et al. used single-cell techniques to illuminate how activated mouse B cells are diverted into forming memory cells a few days post-immunogenic exposure. Early memory subsets contribute to a crucial goal: building a diverse and agile humoral defense system.


Assuntos
Subpopulações de Linfócitos B , Gravuras e Gravação , Animais , Formação de Anticorpos , Linfócitos B , Centro Germinativo , Humanos , Memória Imunológica , Células B de Memória , Camundongos
16.
Phys Med Biol ; 66(17)2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34325418

RESUMO

Sensitivity and spatial resolution of positron emission tomography (PET) scanners can be improved by using thicker scintillation crystals with depth-of-interaction (DOI) encoding. Subsurface laser engraving (SSLE) can be used to segment crystals of a scintillation detector in order to fabricate a DOI detector. We previously applied SSLE to crystal bars of 3 × 3 × 20 mm3and 1.5 × 1.5 × 20 mm3and developed two dual-ended detectors with DOI segments of 3 mm and 1.5 mm, respectively. To further improve the DOI resolution, our SSLE detector design can be used with smaller pitch crystal bars, making them excellent detector candidates for small animal PET scanners with submillimetre resolution. In the present study, three small crystal bars of 1 × 1 × 20 mm3, 2 × 1 × 20 mm3, and 2 × 1 × 40 mm3were laser engraved to 12, 20 and 40 segments, respectively, by applying SSLE in their height directions. The segmented crystal bars were characterised in three prototype detector arrangements. First, the 1 × 1 × 20 mm3crystal bars were characterised in an 8 × 8 crystal array designed for DOI encoding along crystal height in a conventional small animal PET design. Second, a 4 × 8 crystal array of 2 × 1 × 20 mm3crystal bars was characterised for using the DOI information for crystal interaction positioning along the axial axis of a small animal PET scanner. Finally, the third part of the study was performed on a single 2 × 1 × 40 mm3crystal bar with 40 segments to investigate the feasibility of DOI estimation in longer crystals for application in a system with extended axial length. We evaluated the capability of segment identification and energy resolution of theses detectors. The 3D position maps of the detectors were obtained using the Anger-type calculation and the crystal identification performance was evaluated for each detector. Clear segment separation was obtained for the crystal arrays with 12 (segment pitch of 1.67 mm) and 20 (segment pitch of 1 mm) segments. Mean energy resolutions of 8.8% ± 0.4% and 9.6% ± 0.8% at 511 keV were obtained for the segments in the central regions of the 8 × 8 array with 12 segments and the 4 × 8 array with 20 segments, respectively. Clear segment identification was found to be difficult for the detector with 40 segments, especially for the segments at the middle of the crystal. Energy and interaction positioning characterisation results suggest that both prototype detectors with 12 and 20 segments are well suited for small animal PET scanners with high spatial resolution.


Assuntos
Lasers , Tomografia por Emissão de Pósitrons , Animais , Gravuras e Gravação , Desenho de Equipamento , Luz
17.
Rev. med. cine ; 17(2)6 May. 2021. ilus
Artigo em Espanhol | IBECS | ID: ibc-228653

RESUMO

Las mascarillas, de demostrada eficacia a partir del siglo XIX (antisepsia-asepsia), se han visto reactualizadas debido a la pandemia COVID-19. En 1897, el cirujano Jan Mikulicz (1850-1905) fue el creador de las mascarillas quirúrgicas, al demostrar la teoría de la infección por las gotas de saliva (Flügge). No obstante, existen precedentes «pre-científicos» que conocemos fundamentalmente a través de grabados (s. XVII) y pinturas (s. XVIII). Presentamos una obra del pintor barroco Michel Serre (1658-1773), donde se observan personas utilizando mascarillas durante la gran peste de Marsella de 1720. (AU)


The masks, of proven efficacy from the 19th century (antisepsis-asepsis), have been updated due to the COVID-19 pandemic. In 1897, the surgeon Jan Mikulicz (1850-1905) was the creator of surgical masks, by demonstrating the theory of infection by drops of saliva (Flügge). However, there are «pre-scientific» precedents that we know mainly through engravings (17th century) and paintings (18th century). We present a work by the Baroque painter Michel Serre (1658-1773), where people are seen wearing masks during the great plague of Marseille in 1720. (AU)


Assuntos
Humanos , Máscaras/história , Assepsia/história , Assepsia/métodos , Gravuras e Gravação/história , Pinturas/história
19.
Dent Mater ; 37(3): 547-558, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33461762

RESUMO

OBJECTIVE: Micro-nano scale surface modification of Ti-6Al-4V was investigated through the fascinated modern fiber engraving laser method. The process was performed at a high laser speed of 2000mm/s, under different laser frequencies (20-160kHz) and groove distances (0.5-50µm). METHODS: Topographic evaluations such as Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FE-SEM) were used to identify the quality and regularity of patterns. The proliferation of human osteoblast-like osteosarcoma cells (MG63) was analyzed by MTT assay for up to 72h. Also, the plate counting method was used to quantify the viability potential of the modified surface against Escherichia coli bacteria. RESULTS: The cellular viability of the sample modified at the laser frequency of 20kHz and grooving distance of 50µm increased up to 35 and 10% compared to the non-treated and control samples, respectively. In the case of the surface modification at lower grooving distances range between 0.5-50µm, the maximum laser frequency (160kHz) applied leads to lower pulse's energies and less bacterial adhesion. Otherwise, at groove distances more than 50µm, the minimum laser frequency (20kHz) applied reduces the laser pulse overlaps, increases the cell adhesion and antibacterial properties. SIGNIFICANCE: Surface modification by the fiber engraving laser process significantly enhances the cell adhesion on the surface. As a result of such roughness and cell adhesion enhancement, the surface toxicity feature diminished, and its antibacterial properties improved.


Assuntos
Implantes Dentários , Titânio , Antibacterianos/farmacologia , Adesão Celular , Gravuras e Gravação , Humanos , Lasers , Propriedades de Superfície
20.
J Hazard Mater ; 402: 123774, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33254785

RESUMO

Polyimide-laser-engraved porous graphene (LEPG) are hopeful electrode modification materials for flexible electrochemical sensing based on its high-efficiency preparation and low cost. Herein, a flexible, multi-patterned, and miniaturized electrode was fabricated via a simple and novel direct laser engraving. 3D LEPG with porous network structure can selective decorated with Pt nanoparticles (Pt NPs) by in situ electrochemical depositions (Pt-LEPG) as sensitively H2O2 sensors with a wide range of linear (0.01-29 nM) and high sensitivity (575.75 µA mM-1 cm-2). Subsequently, a glucose biosensor was successfully constructed through immobilized glucose oxidases (GOD) onto Pt-LEPG electrode. New-designed GOD/Pt-LEPG glucose sensor exhibited a noteworthy lower limit of detection (0.3 µM, S/N = 3) and high sensitivity (241.82 µA mM-1 cm-2), as much a wide-range of linear (0.01-31.5 mM) at near-neutral pH conditions, enabling detect glucose in real human serum specimens with satisfactory results. Predictably, these outstanding performance sensors have great potential in terms of flexible and wearable electronics.


Assuntos
Técnicas Biossensoriais , Grafite , Técnicas Eletroquímicas , Eletrodos , Gravuras e Gravação , Glucose , Humanos , Peróxido de Hidrogênio , Lasers , Platina , Porosidade
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