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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
Psicol. ciênc. prof ; 43: e250265, 2023. tab
Artigo em Português | LILACS, Index Psicologia - Periódicos | ID: biblio-1422421

RESUMO

Esta pesquisa qualitativa objetivou compreender, fenomenologicamente, a experiência vivida por psicoterapeutas e crianças no acontecer clínico da ludoterapia humanista. Foram realizados 26 encontros dialógicos individuais com nove psicoterapeutas e sete crianças, registrados pela pesquisadora na forma de Narrativas Compreensivas que incluíram suas impressões impactadas subjetivamente pelas falas e expressões corporais dos participantes. A análise fenomenológica culminou com a escrita de uma Narrativa Síntese. Os resultados indicam que a relação psicoterapêutica é percebida como: facilitadora do crescimento psicológico da criança; intensificadora do fluxo de mudanças ao dinamizar os processos pessoais infantis; geradora de motivação na criança para a relação interpessoal, a partir do envolvimento subjetivo do terapeuta; potencializadora da tomada de consciência com base na corporeidade; propiciadora da integração de experiências por meio do brincar; reveladora das singularidades individuais, catalisando o desenvolvimento; e, por fim, benéfica à atualização de significados e sentidos da experiência pessoal e relacional. Evidenciou-se, entre os psicoterapeutas, uma concepção da ludoterapia humanista que prioriza a compreensão dirigida ao estilo próprio de cada cliente em relação aos modos de sentir e expressar-se no mundo e à estruturação do processo psicoterapêutico a partir do relacionamento com a criança. Concluiu-se, assim, que a experiência desse tipo de relação interpessoal facilita a constituição na criança de singularidades que imprimem um sentido existencial próprio ao seu mundo de relações e historicidade. A relevância do processo psicoterapêutico para o crescimento psicológico da criança apresentou-se também pelo seu caráter psicoprofilático, reverberado no encadeamento de processos associados à experiência pessoal dela.(AU)


This qualitative research aimed to understand, phenomenologically, the lived experience of psychotherapists and children in the clinical event of humanistic play therapy. A total of 26 individual dialogical encounters were held with nine psychotherapists and seven children, registered in the form of Comprehensive Narratives by the researcher, which included her subjectively impacted impressions about the participants' speeches and body expressions. The phenomenological analysis culminated in a Synthesis Narrative. The results demonstrate that the psychotherapeutic relationship is perceived as: facilitating the child's psychological growth; intensifying the flow of change by streamlining children's personal processes; generating motivation for the child to get involved with interpersonal relationship, based on the subjective involvement of the therapist; potentiating awareness raising based on the corporeality; enabling the integration of experiences by playing; revealing the uniqueness, catalyzing development; and, finally, benefiting the updating of meanings and senses of personal and relational experience. A conception of humanistic play therapy became evident among the psychotherapists, which prioritizes the understanding directed to the own way of each client regarding how to feel and express themselves in the world and the structuring of the psychotherapeutic process based on the relationship with the child. Thus, it was concluded that the experience of this interpersonal relationship facilitates the constitution in the child of singularities that bring their own existential meaning to their world of relationships and historicity. The relevance of the psychotherapeutic process for the child's psychological growth was also shown by the psycho-prophylactic character reverberated in the processes associated with the child's personal experience.(AU)


Esta investigación cualitativa tuvo por objetivo comprender, fenomenológicamente, la experiencia vivida por psicoterapeutas y niños en ludoterapia de orientación humanista. La investigadora desarrolló 26 conversaciones dialógicas individuales con nueve psicoterapeutas y siete niños, registradas como narrativas comprensivas que incluyeron sus impresiones impactadas subjetivamente por los discursos y expresiones corporales de los participantes. El análisis fenomenológico culminó con una síntesis narrativa. Los resultados demuestran que la relación psicoterapéutica se percibe como facilitadora del crecimiento psicológico del niño; intensificadora del flujo de cambio, optimizando su procesos personales; generadora de motivación para que el niño se involucre en la relación interpersonal a partir del envolvimiento subjetivo del terapeuta; potenciadora de la toma de conciencia a partir de la corporeidad; propiciadora de la integración de las experiencias por medio del juego; reveladora de singularidades individuales al catalizar el desarrollo; y beneficiosa para actualizar los significados y sentidos de la experiencia personal e relacional. Entre los psicoterapeutas se hizo evidente una concepción de ludoterapia humanista que prima por comprender la forma propia del cliente de sentirse y expresarse y la estructuración del proceso psicoterapéutico a partir de la relación con el niño. Se concluyó que la vivencia de este tipo de relación facilita la constitución en el niño de singularidades que le aportan un sentido existencial a su mundo de relación e historicidad. La relevancia del proceso psicoterapéutico para el crecimiento psicológico también se mostró por su carácter psicoprofiláctico, que reverberó en la cadena de procesos asociados con la experiencia personal del niño.(AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Ludoterapia , Fenômenos Psicológicos , Psicologia Clínica , Individualidade , Aprendizagem , Ansiedade , Pediatria , Personalidade , Arte , Arteterapia , Resolução de Problemas , Psicologia , Psicologia Social , Agitação Psicomotora , Psicoterapia , Recreação , Atenção , Instituições Acadêmicas , Autocuidado , Autoimagem , Sinais e Sintomas , Comportamento Social , Esportes , Terapêutica , Terapia Comportamental , Estimulação Acústica , Timidez , Luto , Caricaturas como Assunto , Divórcio , Criança , Comportamento Infantil , Transtornos do Comportamento Infantil , Desenvolvimento Infantil , Psicologia da Criança , Educação Infantil , Saúde da Criança , Cognição , Violência Doméstica , Transtornos da Comunicação , Ciência Cognitiva , Vida , Disciplinas e Atividades Comportamentais , Desenho , Literatura Infantojuvenil , Criatividade , Afeto , Vulnerabilidade a Desastres , Terapias Sensoriais através das Artes , Confiança , Pesquisa Qualitativa , Agressão , Depressão , Crescimento e Desenvolvimento , Dislexia , Educação , Emoções , Empatia , Gravuras e Gravação , Ética , Centros de Convivência e Lazer , Relações Familiares , Resiliência Psicológica , Teoria Social , Experiências Adversas da Infância , Separação da Família , Respeito , Psicoterapia Interpessoal , Angústia Psicológica , Funcionamento Psicossocial , Terapia Gestalt , Diversidade, Equidade, Inclusão , Capacidades de Enfrentamento , Desenvolvimento Humano , Humanismo , Identificação Psicológica , Aculturação , Relações Interpessoais , Transtornos da Linguagem , Deficiências da Aprendizagem , Musicoterapia , Psicoterapia Centrada na Pessoa , Apego ao Objeto
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.
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
11.
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
12.
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
13.
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 , Alicerces Teciduais
14.
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
15.
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
16.
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
17.
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
18.
PLoS One ; 15(10): e0240481, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33112862

RESUMO

The renewal of the archaeological record, mainly through the discovery of unpublished sites, provides information that sometimes qualifies or even reformulates previous approaches. One of the latter cases is represented by the three new decorated caves found in 2015 in Aitzbitarte Hill. Their exhaustive study shows the presence of engraved animals, mainly bison, with formal characteristics unknown so far in the Palaeolithic art of the northern Iberian Peninsula. However, parallels are located in caves in southern France such as Gargas, Cussac, Roucadour or Cosquer. All of them share very specific graphic conventions that correspond to human occupations assigned basically to the Gravettian cultural complex. The new discovery implies the need to reformulate the iconographic exchange networks currently accepted, as well as their correspondence with other elements of the material culture at the same sites. Thus, we have carried out a multiproxy approach based in statistical analysis. The updated data reveals a greater complexity in artistic expression during the Gravettian that had not been considered so far, and also challenges the traditional isolation that had been granted to Cantabrian symbolic expressions during pre-Magdalenian times.


Assuntos
Gravuras e Gravação/história , Atividades Humanas/história , Animais , Arqueologia , Cavernas , Europa (Continente) , História Antiga , Humanos , Datação Radiométrica , Espanha
19.
PLoS One ; 15(8): e0236875, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813748

RESUMO

The Upper Palaeolithic is characterised by the appearance of iconographic expressions most often depicting animals, including anthropomorphic forms, and geometric signs. The Late Upper Palaeolithic Magdalenian saw a flourishing of such depictions, encompassing cave art, engraving of stone, bone and antler blanks and decoration of tools and weapons. Though Magdalenian settlement exists as far northwest as Britain, there is a limited range of art known from this region, possibly associated with only fleeting occupation of Britain during this period. Stone plaquettes, flat fragments of stone engraved on at least one surface, have been found in large quantities at numerous sites spanning the temporal and geographical spread of the Magdalenian, but they have been absent so far from the archaeological record of the British Isles. Between 2015 and 2018, ten fragments of stone plaquettes extensively engraved with abstract designs were uncovered at the Magdalenian site of Les Varines, Jersey, Channel Islands. In this paper, we report detailed analyses of these finds, which provide new evidence for technologies of abstract mark-making, and their significance within the lives of people on the edge of the Magdalenian world. These engraved stone fragments represent important, rare evidence of artistic expression in what is the far northern and western range of the Magdalenian and add new insight to the wider significance of dynamic practices of artistic expression during the Upper Palaeolithic.


Assuntos
Arqueologia , Arte , Gravuras e Gravação , Ilhas
20.
Proc Natl Acad Sci U S A ; 117(9): 4578-4584, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32071236

RESUMO

How did human symbolic behavior evolve? Dating up to about 100,000 y ago, the engraved ochre and ostrich eggshell fragments from the South African Blombos Cave and Diepkloof Rock Shelter provide a unique window into presumed early symbolic traditions of Homo sapiens and how they evolved over a period of more than 30,000 y. Using the engravings as stimuli, we report five experiments which suggest that the engravings evolved adaptively, becoming better-suited for human perception and cognition. More specifically, they became more salient, memorable, reproducible, and expressive of style and human intent. However, they did not become more discriminable over time between or within the two archeological sites. Our observations provide support for an account of the Blombos and Diepkloof engravings as decorations and as socially transmitted cultural traditions. By contrast, there was no clear indication that they served as denotational symbolic signs. Our findings have broad implications for our understanding of early symbolic communication and cognition in H. sapiens.


Assuntos
Evolução Biológica , Gravuras e Gravação/história , Comportamento Social , Simbolismo , História Antiga , Humanos
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