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1.
ACS Appl Mater Interfaces ; 15(19): 23844-23859, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37130321

RESUMO

Wettability patterning is a promising method to manipulate bubble dynamics in microscale boiling systems, allowing the transfer of large heat fluxes at low wall temperatures. Herein, we experimentally investigate the enhancement of flow boiling through exploitation of contact-line pinning using superbiphilic wettability patterns with a range of geometries and orientations. We compare the boiling performance on symmetrical (i.e., circular, square, and diamond-shaped) and asymmetrical (i.e., triangular) superhydrophobic patches and also create rings and chevrons through insertion of self-similar, recursive superhydrophilic cut-outs. Two main principles for boiling heat transfer enhancement are demonstrated: first, the ease of bubble departure from the superhydrophobic patches is shown to depend upon the interaction between the local contact angle and the bubble's tilt due to hydrodynamic drag; second, we find that ring-shaped superhydrophobic patches may trap droplets inside the forming bubbles, thus supplementing the heat transfer coefficient and critical heat flux through latent heat. Through application of these principles, the heat transfer coefficient and critical heat flux of heterogeneous surfaces was enhanced over the homogeneous analogues by 62% and 24%, respectively. Finally, we establish and validate a general model to estimate the ease of bubble departure through the use of geometric arguments.

2.
Mol Neurobiol ; 60(2): 687-731, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36357614

RESUMO

The lateral hypothalamus (LH) has a heterogeneous cytoarchitectonic organization that has not been elucidated in detail. In this work, we analyzed within the framework of the prosomeric model the differential expression pattern of 59 molecular markers along the ventrodorsal dimension of the medial forebrain bundle in the mouse, considering basal and alar plate subregions of the LH. We found five basal (LH1-LH5) and four alar (LH6-LH9) molecularly distinct sectors of the LH with neuronal cell groups that correlate in topography with previously postulated alar and basal hypothalamic progenitor domains. Most peptidergic populations were restricted to one of these LH sectors though some may have dispersed into a neighboring sector. For instance, histaminergic Hdc-positive neurons were mostly contained within the basal LH3, Nts (neurotensin)- and Tac2 (tachykinin 2)-expressing cells lie strictly within LH4, Hcrt (hypocretin/orexin)-positive and Pmch (pro-melanin-concentrating hormone)-positive neurons appeared within separate LH5 subdivisions, Pnoc (prepronociceptin)-expressing cells were mainly restricted to LH6, and Sst (somatostatin)-positive cells were identified within the LH7 sector. The alar LH9 sector, a component of the Foxg1-positive telencephalo-opto-hypothalamic border region, selectively contained Satb2-expressing cells. Published studies of rodent LH subdivisions have not described the observed pattern. Our genoarchitectonic map should aid in systematic approaches to elucidate LH connectivity and function.


Assuntos
Região Hipotalâmica Lateral , Neuropeptídeos , Camundongos , Animais , Região Hipotalâmica Lateral/metabolismo , Orexinas/metabolismo , Neuropeptídeos/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fatores de Transcrição Forkhead/metabolismo
3.
Artigo em Inglês | MEDLINE | ID: mdl-35542986

RESUMO

Direct top-down nanopatterning of semiconductors is a powerful tool for engineering properties of optoelectronic devices. Translating this approach to two-dimensional semiconductors such as monolayer transition metal dichalcogenides (TMDs) is challenging because of both the small scales required for confinement and the degradation of electronic and optical properties caused by high-energy and high-dose electron radiation used for high-resolution top-down direct electron beam patterning. We show that encapsulating a TMD monolayer with hexagonal boron nitride preserves the narrow exciton linewidths and emission intensity typical in such heterostructures after electron beam lithography, allowing direct patterning of functional optical monolayer nanostructures on scales of a few tens of nanometers. We leverage this fabrication method to study size-dependent effects on nanodot arrays of MoS2 and MoSe2 as well as laterally confined electrical transport devices, demonstrating the potential of top-down lithography for nanoscale TMD optoelectronics.

4.
Soc Stud Sci ; 52(4): 491-511, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35603800

RESUMO

In Mandarin, the English word 'nature' translates as 'ziran' (zìrán) in science, biomedicine and everyday life. At the same time, ziran indexes a second older set of meanings that make little immediate sense in English. Current in many Chinese medical practices as well as in classical Chinese philosophy, these include 'what is spontaneously so' or 'let the character of the self unfold'. In this article we explore how these two families of meaning are related by particular Taiwanese Chinese medical practitioners as they describe how they negotiate the relations between biomedicine and Chinese medicine in daily professional practice. At the same time, inspired by related logic-shifting writing in anthropology, postcolonial studies and postcolonial STS, we draw on the 'art of patterning' ( biàn zhèng) to understand how ziran-nature relations are specified in those accounts. Patterning is the art of specifying the shifting arrangements and misalignments that lead to ill health. Treating this as a way of thinking about ziran-related overlaps between biomedicine and Chinese medicine, we show that patterning attends not to objects 'out there' but to appearances (xiang, xiàng). Put into use as an STS term of art it therefore shifts the epistemological basis of inquiry because case-stories no longer reveal underlying mechanisms, but instead narrate patterned appearances. One implication of this is that any particular pattern diagnosis lies alongside a galaxy of alternatives that might be equally good to think with. Within the limits set by referential academic conventions, we thus attempt a postcolonial shi ()-inflected STS in this paper by resisting the use of a single analytical framework, instead setting different forms of patterning alongside one another.


Assuntos
Medicina Tradicional Chinesa , Filosofia , Conhecimento , Lógica
5.
Soc Sci Med ; 294: 114696, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34995988

RESUMO

BACKGROUND: Redlining was a racialized zoning practice in the U.S. that blocked fair access to home loans during the 1930s, and recent research is illuminating health problems in the current residents of these historically redlined areas. However, this work has not yet been holistically summarized. Here, we present the first systematic review and meta-analysis comparing health outcomes in redlined versus non-redlined neighborhoods in U.S. cities. METHODS: We extracted relevant articles in PubMed, Web of Science, Cochrane and Science Direct databases published from January 2010 to September 2021. RESULTS: The search revealed 12 studies on preterm births (n = 3), gunshot-related injuries (n = 2), cancer (n = 1), asthma (n = 1), self-rated health (n = 1), multiple health outcomes (n = 2), heat-related outcomes (n = 1) and COVID-19 incidence and mortality (n = 1). A meta-analysis of three studies found the odds of having preterm birth was significantly higher (OR = 1.41, 95% CI: 1.05, 1.88; p = 0.02) among women living in redlined areas compared to those in non-redlined areas. Review of other outcomes revealed that gunshot-related injuries, asthma, heat-related outcomes, and multiple chronic conditions were worse in redlined areas, while associations with cancer varied by cancer type. In terms of cause-specific mortality, one study revealed no link between residential redlining and infant mortality rate, while one study on COVID-19 outcomes was inconclusive. CONCLUSIONS: Overall, this review presents evidence that living in historically redlined areas is associated with increased risk of multiple serious adverse health outcomes. Further research on mechanisms, remediation, and neighborhood-level interventions is needed to strengthen the understanding of the impacts of redlining on health.


Assuntos
COVID-19 , Nascimento Prematuro , Racismo , Feminino , Humanos , Recém-Nascido , Avaliação de Resultados em Cuidados de Saúde , Nascimento Prematuro/epidemiologia , SARS-CoV-2
6.
Brain Behav Evol ; 96(4-6): 334-352, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35034027

RESUMO

This essay re-examines the singular case of the supposedly unique rostrally elongated notochord described classically in amphioxus. We start from our previous observations in hpf 21 larvae [Albuixech-Crespo et al.: PLoS Biol. 2017;15(4):e2001573] indicating that the brain vesicle has rostrally a rather standard hypothalamic molecular configuration. This correlates with the notochord across a possible rostromedian acroterminal hypothalamic domain. The notochord shows some molecular differences that specifically characterize its pre-acroterminal extension beyond its normal rostral end under the mamillary region. We explored an alternative interpretation that the putative extension of this notochord actually represents a variant form of the prechordal plate in amphioxus, some of whose cells would adopt the notochordal typology, but would lack notochordal patterning properties, and might have some (but not all) prechordal ones instead. We survey in detail the classic and recent literature on gastrulation, prechordal plate, and notochord formation in amphioxus, compare the observed patterns with those of some other vertebrates of interest, and re-examine the literature on differential gene expression patterns in this rostralmost area of the head. We noted that previous literature failed to identify the amphioxus prechordal primordia at appropriate stages. Under this interpretation, a consistent picture can be drawn for cephalochordates, tunicates, and vertebrates. Moreover, there is little evidence for an intrinsic capacity of the early notochord to grow rostralwards (it normally elongates caudalwards). Altogether, we conclude that the hypothesis of a prechordal nature of the elongated amphioxus notochord is consistent with the evidence presented.


Assuntos
Anfioxos , Animais , Hipotálamo , Anfioxos/genética , Notocorda/metabolismo , Vertebrados
7.
J Neuroendocrinol ; 33(11): e13042, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34748249

RESUMO

The plain title might have been an almost retro sounding grumpy retort, but it has inspired a journey of sorts, and something along the way I hope you won't have come across before. An opinionated exploration of the distinctive phasic spiking patterns of magnocellular vasopressin neurons of the supraoptic and paraventricular nuclei of the hypothalamus. A mostly life essential population of neurons that signal the kidneys to regulate water loss in response to signals that encode plasma volume and osmotic pressure, as well as regulating blood pressure, and possibly metabolism and social behaviour. The viewpoint of a modeller shorn of any explicit maths.


Assuntos
Núcleo Hipotalâmico Paraventricular , Núcleo Supraóptico , Hipotálamo/metabolismo , Neurônios/metabolismo , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Núcleo Supraóptico/metabolismo , Vasopressinas/metabolismo
8.
Development ; 147(15)2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32665247

RESUMO

Retinoic acid (RA), a vitamin A (retinol) derivative, has pleiotropic functions during embryonic development. The synthesis of RA requires two enzymatic reactions: oxidation of retinol into retinaldehyde by alcohol dehydrogenases (ADHs) or retinol dehydrogenases (RDHs); and oxidation of retinaldehyde into RA by aldehyde dehydrogenases family 1, subfamily A (ALDH1as), such as ALDH1a1, ALDH1a2 and ALDH1a3. Levels of RA in tissues are regulated by spatiotemporal expression patterns of genes encoding RA-synthesizing and -degrading enzymes, such as cytochrome P450 26 (Cyp26 genes). Here, we show that RDH10 is important for both sensory and non-sensory formation of the vestibule of the inner ear. Mice deficient in Rdh10 exhibit failure of utricle-saccule separation, otoconial formation and zonal patterning of vestibular sensory organs. These phenotypes are similar to those of Aldh1a3 knockouts, and the sensory phenotype is complementary to that of Cyp26b1 knockouts. Together, these results demonstrate that RDH10 and ALDH1a3 are the key RA-synthesis enzymes involved in vestibular development. Furthermore, we discovered that RA induces Cyp26b1 expression in the developing vestibular sensory organs, which generates the differential RA signaling required for zonal patterning.


Assuntos
Homeostase , Organogênese , Tretinoína/metabolismo , Vestíbulo do Labirinto/embriologia , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Animais , Camundongos , Camundongos Knockout , Retinal Desidrogenase/genética , Retinal Desidrogenase/metabolismo , Ácido Retinoico 4 Hidroxilase/genética , Ácido Retinoico 4 Hidroxilase/metabolismo , Vestíbulo do Labirinto/citologia
9.
J Holist Nurs ; 38(3): 263-277, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31619120

RESUMO

Purpose: The purpose of the study is to understand the meaning of folklore as a health patterning modality and to uncover its unique characteristics in the life-health process. Design: Hermeneutic phenomenological. Method: Max van Manen's methodology was used for this study. The sample was selected from the Afro-Caribbean American community in the United States. The criterion for selection was that participants used folklore healing practices for health and well-being on an ongoing basis. In-depth interviews were done. Purposive sampling with networking was done based on whether the participants used folk healing on a regular basis. Themes of the meaning of folklore healing practices were identified from participants' verbatim data. Findings: The meaning of folklore healing practices was interpreted as phenomena with six interconnected essential themes. Additionally, Barrett's nursing theory of power as knowing participation in change was used to reflect and understand the findings from a nursing perspective. Conclusion: The research findings have implications for nursing science, and the knowledge gleaned from the study may be applied to nursing practice.


Assuntos
Folclore/psicologia , Acontecimentos que Mudam a Vida , Medicina Tradicional/normas , Adulto , Idoso , Feminino , Hermenêutica , Humanos , Masculino , Medicina Tradicional/métodos , Medicina Tradicional/psicologia , Pessoa de Meia-Idade , Pesquisa Qualitativa , Estados Unidos , Índias Ocidentais/etnologia
10.
Nano Lett ; 19(9): 6173-6181, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31424942

RESUMO

Micronanotechnology-based multielectrode arrays have led to remarkable progress in the field of transmembrane voltage recording of excitable cells. However, providing long-term optoporation- or electroporation-free intracellular access remains a considerable challenge. In this study, a novel type of nanopatterned volcano-shaped microelectrode (nanovolcano) is described that spontaneously fuses with the cell membrane and permits stable intracellular access. The complex nanostructure was manufactured following a simple and scalable fabrication process based on ion beam etching redeposition. The resulting ring-shaped structure provided passive intracellular access to neonatal rat cardiomyocytes. Intracellular action potentials were successfully recorded in vitro from different devices, and continuous recording for more than 1 h was achieved. By reporting transmembrane action potentials at potentially high spatial resolution without the need to apply physical triggers, the nanovolcanoes show distinct advantages over multielectrode arrays for the assessment of electrophysiological characteristics of cardiomyocyte networks at the transmembrane voltage level over time.


Assuntos
Potenciais de Ação/fisiologia , Miócitos Cardíacos/química , Nanoestruturas/química , Neurônios/química , Animais , Membrana Celular/química , Membrana Celular/fisiologia , Citoplasma/química , Técnicas Eletrofisiológicas Cardíacas , Eletroporação , Humanos , Microeletrodos , Miócitos Cardíacos/fisiologia , Neurônios/fisiologia , Ratos
11.
Adv Sci (Weinh) ; 6(15): 1802318, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31406661

RESUMO

One of the main advantages of 2D materials for various applications is that they can be prepared in form of water-based solutions. The high yield and cost-effectiveness of this method make them of great interest for printed electronics, composites, and bio- and healthcare technologies. However, once deposited on a substrate, etching away these solution-processed materials is a difficult task, yet crucial for pattern definition and thus device fabrication. In particular, the realization of micrometer-sized patterns requires mesh and paste optimization when screen-printed or solvent-engineered and surface functionalization when inkjet-printed, both usually involving additional postdeposition steps. These constraints are holding back the integration of these 2D materials in devices and applications. In this work, a method for the fabrication of micrometer-sized well-defined patterns in water-based 2D materials is presented, with an extensive characterization of the films and patterns obtained. The method is ultimately used to create humidity sensors with performance comparable to that of commercial ones. These sensor devices are fabricated onto a 4' silicon and polyethylene terephthalate (PET) wafers to create all-graphene humidity sensors that are flexible, transparent, and compatible with current complementary metal-oxide-semiconductor (CMOS) and roll-to-roll workflows.

12.
Methods Mol Biol ; 2019: 209-224, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31359399

RESUMO

Retinoic acid modulates numerous cellular events, namely, proliferation, differentiation, apoptosis, and patterning, hence influencing both embryo development and adult homeostasis. In vitro explant culture is a valuable technique for studying the impact of growth factors and signaling molecules, such as retinoic acid, in organ development since tissue architecture is maintained. This technique allows controlled supplementation of culture medium and straightforward analysis of its effect on morphogenesis. This chapter describes the detailed protocol for culturing embryonic chick lung explants and testing the impact of retinoic acid in branching and patterning, based on morphometric and molecular analysis.


Assuntos
Pulmão/crescimento & desenvolvimento , Morfogênese/efeitos dos fármacos , Tretinoína/farmacologia , Animais , Padronização Corporal/efeitos dos fármacos , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hibridização In Situ , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Técnicas de Cultura de Órgãos , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOXB1/genética
13.
J Neurosci ; 39(13): 2398-2415, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30692221

RESUMO

Primary cilia are essential for CNS development. In the mouse, they play a critical role in patterning the spinal cord and telencephalon via the regulation of Hedgehog/Gli signaling. However, despite the frequent disruption of this signaling pathway in human forebrain malformations, the role of primary cilia in forebrain morphogenesis has been little investigated outside the telencephalon. Here we studied development of the diencephalon, hypothalamus and eyes in mutant mice in which the Ftm/Rpgrip1l ciliopathy gene is disrupted. At the end of gestation, Ftm-/- fetuses displayed anophthalmia, a reduction of the ventral hypothalamus and a disorganization of diencephalic nuclei and axonal tracts. In Ftm-/- embryos, we found that the ventral forebrain structures and the rostral thalamus were missing. Optic vesicles formed but lacked the optic cups. In Ftm-/- embryos, Sonic hedgehog (Shh) expression was virtually lost in the ventral forebrain but maintained in the zona limitans intrathalamica (ZLI), the mid-diencephalic organizer. Gli activity was severely downregulated but not lost in the ventral forebrain and in regions adjacent to the Shh-expressing ZLI. Reintroduction of the repressor form of Gli3 into the Ftm-/- background restored optic cup formation. Our data thus uncover a complex role of cilia in development of the diencephalon, hypothalamus and eyes via the region-specific control of the ratio of activator and repressor forms of the Gli transcription factors. They call for a closer examination of forebrain defects in severe ciliopathies and for a search for ciliopathy genes as modifiers in other human conditions with forebrain defects.SIGNIFICANCE STATEMENT The Hedgehog (Hh) signaling pathway is essential for proper forebrain development as illustrated by a human condition called holoprosencephaly. The Hh pathway relies on primary cilia, cellular organelles that receive and transduce extracellular signals and whose dysfunctions lead to rare inherited diseases called ciliopathies. To date, the role of cilia in the forebrain has been poorly studied outside the telencephalon. In this paper we study the role of the Ftm/Rpgrip1l ciliopathy gene in mouse forebrain development. We uncover complex functions of primary cilia in forebrain morphogenesis through region-specific modulation of the Hh pathway. Our data call for further examination of forebrain defects in ciliopathies and for a search for ciliopathy genes as modifiers in human conditions affecting forebrain development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Hedgehog/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Prosencéfalo/embriologia , Prosencéfalo/metabolismo , Proteína Gli3 com Dedos de Zinco/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Olho/embriologia , Olho/metabolismo , Hipotálamo/embriologia , Hipotálamo/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Tálamo/embriologia , Tálamo/metabolismo
14.
Adv Healthc Mater ; 8(2): e1801044, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30556328

RESUMO

Global increases in life expectancy drive increasing demands for bone regeneration. The gold standard for surgical bone repair is autografting, which enjoys excellent clinical outcomes; however, it possesses significant drawbacks including donor site morbidity and limited availability. Although collagen sponges delivered with bone morphogenetic protein, type 2 (BMP2) are a common alternative or supplement, they do not efficiently retain BMP2, necessitating extremely high doses to elicit bone formation. Hence, reports of BMP2 complications are rising, including cancer promotion and ectopic bone formation, the latter inducing complications such as breathing difficulties and neurologic impairments. Thus, efforts to exert spatial control over bone formation are increasing. Several tissue engineering approaches have demonstrated the potential for targeted and controlled bone formation. These approaches include biomaterial scaffolds derived from synthetic sources, e.g., calcium phosphates or polymers; natural sources, e.g., bone or seashell; and immobilized biofactors, e.g., BMP2. Although BMP2 is the only protein clinically approved for use in a surgical device, there are several proteins, small molecules, and growth factors that show promise in tissue engineering applications. This review profiles the tissue engineering advances in achieving control over the location and onset of bone formation (spatiotemporal control) toward avoiding the complications associated with BMP2.


Assuntos
Regeneração Óssea , Engenharia Tecidual/métodos , Animais , Proteínas Morfogenéticas Ósseas/administração & dosagem , Proteínas Morfogenéticas Ósseas/metabolismo , Fosfatos de Cálcio , Humanos , Medicina Regenerativa/métodos , Análise Espaço-Temporal , Alicerces Teciduais
15.
Anal Sci ; 35(1): 65-69, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30393243

RESUMO

Epithelial-mesenchymal transition (EMT), phenotypic changes in cell adhesion and migration, is involved in cancer invasion and metastasis, hence becoming a target for anti-cancer drugs. In this study, we report a method for the evaluation of EMT inhibitors by using a photoactivatable gold substrate, which changes from non-cell-adhesive to cell-adhesive in response to light. The method is based on the geometrical confinement of cell clusters and the subsequent migration induction by controlled photoirradiation of the substrate. As a proof-of-concept experiment, a known EMT inhibitor was successfully evaluated in terms of the changes in cluster area or leader cell appearance, in response to biochemically and mechanically induced EMT. Furthermore, an application of the present method for microbial secondary metabolites identified nanaomycin H as an EMT inhibitor, potentially killing EMTed cells in disseminated conditions. These results demonstrate the potential of the present method for screening new EMT inhibitors.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Ouro/química , Nitrobenzenos/química , Polietilenoglicóis/química , Raios Ultravioleta , Animais , Antineoplásicos/farmacologia , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cães , Células Madin Darby de Rim Canino , Nitrobenzenos/efeitos da radiação , Estudo de Prova de Conceito
16.
Dev Biol ; 439(2): 102-111, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29679559

RESUMO

Although the hypothalamus functions as a master homeostat for many behaviors, little is known about the transcriptional networks that control its development. To investigate this question, we analyzed mice deficient for the Forkhead domain transcription factor Foxd1. Foxd1 is selectively expressed in neuroepithelial cells of the prethalamus and hypothalamus prior to the onset of neurogenesis, and is later restricted to neural progenitors of the prethalamus and anterior hypothalamus. During early stages of neurogenesis, we observed that Foxd1-deficient mice showed reduced expression of Six3 and Vax1 in anterior hypothalamus, but overall patterning of the prethalamus and hypothalamus is unaffected. After neurogenesis is complete, however, a progressive reduction and eventual loss of expression of molecular markers of the suprachiasmatic, paraventricular and periventricular hypothalamic is observed. These findings demonstrate that Foxd1 acts in hypothalamic progenitors to allow sustained expression of a subset of genes selectively expressed in mature neurons of the anterior hypothalamus.


Assuntos
Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Animais , Núcleo Hipotalâmico Anterior/metabolismo , Núcleo Hipotalâmico Anterior/fisiologia , Padronização Corporal/genética , Diferenciação Celular/genética , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Fatores de Transcrição Forkhead/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Hipotálamo/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Células-Tronco/metabolismo , Células-Tronco/fisiologia , Fatores de Transcrição/metabolismo , Proteína Homeobox SIX3
17.
Colloids Surf B Biointerfaces ; 167: 126-133, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29635135

RESUMO

We report a one pot green strategy for the synthesis of carbon dots using tulsi leaves and their potential application in sensing of Cr(VI) selectively. The detection mechanism is based on the phenomenon called inner filter effect (IFE) and a good linear static quenching was observed in the range of 1.6 µM to 50 µM with a detection limit of 4.5 ppb. The reversible switching in fluorescence has been tested and a good recovery in fluorescence was observed up to three consecutive cycles upon addition of ascorbic acid as reducing agent. Also the low toxicity, high fluorescence and photostabilty of the CDs make them excellent imaging and patterning agent. The acid and alkali resistant property of these CDs makes it suitable for real sample analysis. The fluorescent CDs were applied for successful detection of Cr(VI) in water with spike-recoveries ranging from 93 to 99%.


Assuntos
Carbono/química , Cromo/análise , Fluorescência , Extratos Vegetais/química , Pontos Quânticos/química , Cromo/química , Corantes Fluorescentes/química , Microscopia Eletrônica de Transmissão , Ocimum sanctum/química , Folhas de Planta/química , Espectrometria de Fluorescência , Termogravimetria , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
18.
Sci Adv ; 3(6): e1602071, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28630898

RESUMO

A new lithographic editing system with an ability to erase and rectify errors in microscale with real-time optical feedback is demonstrated. The erasing probe is a conically shaped hydrogel (tip size, ca. 500 nm) template-synthesized from track-etched conical glass wafers. The "nanosponge" hydrogel probe "erases" patterns by hydrating and absorbing molecules into a porous hydrogel matrix via diffusion analogous to a wet sponge. The presence of an interfacial liquid water layer between the hydrogel tip and the substrate during erasing enables frictionless, uninterrupted translation of the eraser on the substrate. The erasing capacity of the hydrogel is extremely high because of the large free volume of the hydrogel matrix. The fast frictionless translocation and interfacial hydration resulted in an extremely high erasing rate (~785 µm2/s), which is two to three orders of magnitude higher in comparison with the atomic force microscopy-based erasing (~0.1 µm2/s) experiments. The high precision and accuracy of the polymeric lithography editor (PLE) system stemmed from coupling piezoelectric actuators to an inverted optical microscope. Subsequently after erasing the patterns using agarose erasers, a polydimethylsiloxane probe fabricated from the same conical track-etched template was used to precisely redeposit molecules of interest at the erased spots. PLE also provides a continuous optical feedback throughout the entire molecular editing process-writing, erasing, and rewriting. To demonstrate its potential in device fabrication, we used PLE to electrochemically erase metallic copper thin film, forming an interdigitated array of microelectrodes for the fabrication of a functional microphotodetector device. High-throughput dot and line erasing, writing with the conical "wet nanosponge," and continuous optical feedback make PLE complementary to the existing catalog of nanolithographic/microlithographic and three-dimensional printing techniques. This new PLE technique will potentially open up many new and exciting avenues in lithography, which remain unexplored due to the inherent limitations in error rectification capabilities of the existing lithographic techniques.


Assuntos
Modelos Teóricos , Polímeros/química , Algoritmos , Hidrogéis/química , Nanoporos/ultraestrutura
19.
ACS Appl Mater Interfaces ; 9(23): 19612-19621, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28534393

RESUMO

Recent efforts to develop stretchable resistive heaters open up the possibility for their use in wearable thermotherapy applications. Such heaters should have high electrothermal performance and stability to be used practically, and the fabrication must be simple, economic, reproducible, and scalable. Here we present a simple yet highly efficient way of producing high-performance stretchable heaters, which is based on a facile kirigami pattering (the art of cutting and folding paper) of a highly conductive paper for practical wearable thermotherapy. The resulting kirigami heater exhibits high heating performance at low voltage (>40 °C at 1.2 V) and fast thermal response (<60 s). The simple kirigami patterning approach enables the heater to be extremely stretchable (>400%) while stably retaining its excellent performance. Furthermore, the heater shows the uniform spatial distribution of heat over the whole heating area and is highly durable (1000 cycles at 300% strain). The heater attached to curvilinear body parts shows stable heating performance even under large motions while maintaining intimate conformal contact with the skin thanks to the high stretchability and sufficient restoring force. The usability of the heater as a wearable thermotherapy device is demonstrated by increased blood flow at the wrist during operation.


Assuntos
Dispositivos Eletrônicos Vestíveis , Calefação , Temperatura Alta , Hipertermia Induzida
20.
Cereb Cortex ; 27(2): 1137-1148, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-26656997

RESUMO

A key step in the development of the cerebral cortex is a patterning process, which subdivides the telencephalon into several molecularly distinct domains and is critical for cortical arealization. This process is dependent on a complex network of interactions between signaling molecules of the Fgf and Wnt gene families and the Gli3 transcription factor gene, but a better knowledge of the molecular basis of the interplay between these factors is required to gain a deeper understanding of the genetic circuitry underlying telencephalic patterning. Using DNA-binding and reporter gene assays, we here investigate the possibility that Gli3 and these signaling molecules interact by directly regulating each other's expression. We show that Fgf signaling is required for Wnt8b enhancer activity in the cortical hem, whereas Wnt/ß-catenin signaling represses Fgf17 forebrain enhancer activity. In contrast, Fgf and Wnt/ß-catenin signaling cooperate to regulate Gli3 expression. Taken together, these findings indicate that mutual interactions between Gli3, Wnt8b, and Fgf17 are crucial elements of the balance between these factors thereby conferring robustness to the patterning process. Hence, our study provides a framework for understanding the genetic circuitry underlying telencephalic patterning and how defects in this process can affect the formation of cortical areas.


Assuntos
Fatores de Crescimento de Fibroblastos/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Telencéfalo/fisiologia , Proteínas Wnt/fisiologia , Proteína Gli3 com Dedos de Zinco/fisiologia , Animais , Feminino , Fatores de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Gravidez , Prosencéfalo/metabolismo , Prosencéfalo/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Telencéfalo/embriologia , Telencéfalo/metabolismo , Tálamo/embriologia , Tálamo/fisiologia , Proteínas Wnt/genética , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia , Proteína Gli3 com Dedos de Zinco/genética
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