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1.
Yakugaku Zasshi ; 139(12): 1549-1551, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31787643

RESUMO

Intercellular lipids in the stratum corneum (SC), including ceramides (CERs), cholesterol, and fatty acids, are important for maintaining the skin barrier function. CERs in the SC have vital roles in water retention and the barrier function. A decrease in intercellular lipids, however, reduces the skin barrier function. In this study, the ability of CER precursors to increase the level of CERs in the SC and improve the skin barrier function was examined. Glucosylceramide and sphingomyelin liposomes were used as CER precursors and prepared with a thin-film method. The particle diameter and surface potential of glucosylceramide liposomes were 120.0 nm and -20 mV, while those of sphingomyelin liposomes were 153.3 nm and -11.4 mV, respectively. Transmission electron microscopy images showed that both liposomes were closed vesicles having a lamellar structure. These liposomes were applied from the SC side of a three-dimensional cultured human epidermis model, and the level of CERs in the epidermis was measured by high-performance thin-layer chromatography. In this study, the application of glucosylceramide or sphingomyelin liposomes increased the amount of CERs. In addition, the precursors of CERs were effective in improving the skin barrier function.


Assuntos
Ceramidas/metabolismo , Glucosilceramidas , Lipossomos , Fenômenos Fisiológicos da Pele , Pele/metabolismo , Esfingomielinas , Colesterol/metabolismo , Epiderme/metabolismo , Ácidos Graxos/metabolismo , Humanos , Lipossomos/ultraestrutura , Pele/citologia , Pele/imunologia , Perda Insensível de Água
2.
Yakugaku Zasshi ; 139(12): 1553-1556, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31787644

RESUMO

The skin is the largest human organ, comprising the epidermis that is composed of epithelial tissue, the dermis composed of connective tissue, and the innermost subcutaneous tissue. Generally, skin conditions are due to aging and the influence of the external environment, but empirically patients with gastrointestinal diseases are more prone to pruritus and inflammation caused by dry skin. A decrease in the skin barrier function, involving immunocompetent mast cells and oxidative stress, was noted in indomethacin-induced small intestine inflammation, dextran sodium sulfate (DSS)-induced ulcerative colitis, and azoxymethane+DSS-induced colorectal cancer. A possible correlation was found to exist between inflammatory gastrointestinal diseases and the skin, and this correlation was investigated using a rheumatoid arthritis model as representative of inflammatory diseases. Similar to previously reported results, deterioration of the skin barrier function was observed, and new information was obtained by analyzing changes in inflammatory markers in the blood and skin tissues. Understanding the underlying mechanism of decreased skin barrier function will help in establishing effective prophylaxis and treatment methods and clarify the importance of crosstalk between organs. It will also help accelerate drug development.


Assuntos
Artrite Reumatoide/complicações , Gastroenterite/complicações , Dermatopatias/etiologia , Fenômenos Fisiológicos da Pele , Pele/fisiopatologia , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Envelhecimento da Pele
3.
Int. j. morphol ; 37(4): 1234-1244, Dec. 2019. graf
Artigo em Espanhol | LILACS | ID: biblio-1040118

RESUMO

La cicatrización de la piel es un proceso complejo y organizado que involucra tres fases: inflamatoria, proliferativa y de remodelación. Es indispensable el análisis de este proceso biomolecularmente para investigar y proponer nuevas estrategias terapéuticas que mejoren la cicatrización o promuevan la regeneración. El objetivo de este proyecto fue analizar histológica y biomolecularmente mediante microespectroscopía infrarroja por transformada de Fourier (MFTIR) y su función de mapeo bioquímico, muestras de lesiones excisionales de piel, comparando los cambios morfológicos y espectroscópicos entre piel sana y piel cicatrizada. Se estandarizó un modelo de lesión excisional de piel en ratones hembra de la cepa NIH de 8 semanas de edad (n=16), provocando una herida excisional de 1 cm2. Se analizó piel sana (día 0) y cicatrizada (día 15 post-lesión) morfométrica, histológica y biomolecularmente mediante análisis fotográfico, técnica histológica y MFTIR con su función de mapeo. El análisis morfométrico demostró una reducción del área de la herida en un 87,6 % al día 15 post-lesión. Histológicamente, en la piel cicatrizada se evidenció un adelgazamiento de la epidermis y menor celularidad en la dermis, observándose la formación de tejido de granulación y fibras de colágena desorganizadas. Espectroscópicamente, se apreciaron cambios entre los dos grupos de estudio, principalmente en las bandas de lípidos y en la región de proteínas. El cálculo de las áreas bajo la curva y el mapeo bioquímico mostraron menor concentración de queratina y colágena en la piel cicatrizada, así como desorganización de las fibras de colágena. Se demostró la capacidad de la MFTIR para caracterizar de forma precisa los cambios biomoleculares en la cicatrización, entre ellos la cantidad de queratina, colágena, y el depósito y ordenamiento de las fibras de colágena asociadas a su maduración.


The skin cicatrization is a complex and organized process that involves three phases: inflammatory, proliferative, and remodeling. It is essential to analyze this process biomolecularly, in order to investigate and propose new therapeutic strategies that improve the healing or promote regeneration. The objective of this project was to analyze histological and biomolecularly through Fourier Transform infrared microspectroscopy (FTIRM) and its biochemical mapping function, samples of an excisional skin wound, comparing the morphological and spectroscopic changes between healthy skin and scarred skin. An excisional skin wound healing model was standardized using female, NIH strain 8-week-old mice (n = 16), provoking an excisional wound of 1 cm2. Healthy skin (day 0) and scarring skin (day 15 post-injury) were morphometrical, histological, and biomolecularly analyzed by digital picture analysis, histological technique, and FTIRM with its mapping function. The morphometric analysis showed a reduction of the wound area of 87.6 % at day 15 after wound. Histologically, in the scarred skin a thinning of the epidermis was evidenced, besides reduced cellularity in the dermis, granulation tissue formation, and disorganized collagen fibers were observed. Spectroscopically, changes between the study groups were appreciated, mainly in the lipid bands and in the protein region. The calculation of the areas under the curve and the biochemical mapping showed a lower concentration of keratin and collagen in the scarred skin, as well as collagen fibers disorganization. The ability of the FTIRM to accurately characterize biomolecular changes in cicatrization process was demonstrated, such as the amount of keratin, collagen, and the deposition and ordering of the collagen fibers associated with their maturation.


Assuntos
Animais , Feminino , Camundongos , Pele/lesões , Cicatrização/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Pele/patologia , Fenômenos Fisiológicos da Pele , Modelos Animais de Doenças
4.
PLoS One ; 14(12): e0226692, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877152

RESUMO

Autonomous sensory meridian response (ASMR) is a sensory phenomenon commonly characterized by pleasant tingling sensations arising from the back of the head and accompanied by feelings of relaxation and calmness. Although research has found ASMR to have a distinct physiological pattern with increased skin conductance levels and reduced heart rate, the specific tingles felt in ASMR have not received much investigation. The aim of the present study was to investigate the physiology and characteristics of ASMR further by examining whether experiencing ASMR is visible from the pupil of the eye. A total of 91 participants were recruited and assigned to three different groups based on their experience of ASMR (ASMR vs. non-ASMR vs. unsure). Participants were instructed to watch a control video and an ASMR video and to report any tingling sensations by pressing down a button on the keyboard. Pupil diameter was measured over the duration of both videos using a tower-mounted eye tracker. Data was analyzed on a general level, averaging pupil diameter over each video, as well as on a more specific level, comparing pupil diameter during reported episodes of tingling sensations to pupil diameter outside of those episodes. On the general level, results revealed no significant differences between the groups. On the specific level, however, the tingling sensations experienced in ASMR were found to cause statistically significant increases in pupil diameter, demonstrating that they have a physiological basis. The results of the study further reinforce the credibility of ASMR and suggest that the tingles felt in ASMR are at the very core of the experience itself.


Assuntos
Pupila/fisiologia , Campos Visuais , Adulto , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenômenos Fisiológicos Oculares , Óptica e Fotônica , Sensação , Fenômenos Fisiológicos da Pele , Adulto Jovem
5.
Plast Reconstr Surg ; 144(5): 784e-797e, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31688753

RESUMO

BACKGROUND: Autologous lipografting for improvement of facial skin quality was first described by Coleman in 2006. The current dogma dictates that adipose tissue-derived stromal cells that reside in the stromal vascular fraction of lipograft contribute to skin rejuvenation (e.g., increased skin elasticity), a more homogenous skin color, and softening of skin texture. Nowadays, many studies have been reported on this "skin rejuvenation" effect of autologous fat grafting. This systematic review was undertaken to assess the efficacy of autologous lipografting on skin quality. METHODS: The MEDLINE, Embase, Cochrane Central, Web of Science, and Google Scholar databases were searched for studies evaluating the effect of autologous lipografting on facial skin quality (May 11, 2018). Outcomes of interest were skin texture, color, and elasticity in addition to histologic outcomes and number of complications. RESULTS: Nine studies were included, with 301 patients treated in total. No meta-analysis could be performed because of heterogeneity of the metrics and outcomes. Eight studies reported increased skin elasticity; improvement in skin texture; and a more homogeneous skin color after treatment with lipografting, cellular stromal vascular fraction, or nanofat. One study reported no increased skin elasticity after lipografting. Histologic improvement was seen after lipografting and adipose tissue-derived stromal cell injections. However, in general, the level of evidence of the included studies was low. No serious complications were reported. CONCLUSION: Autologous facial lipografting and cellular stromal vascular fraction and adipose tissue-derived stromal cell injections hardly seem to improve facial skin quality but can be considered a safe procedure.


Assuntos
Tecido Adiposo/transplante , Envelhecimento da Pele/fisiologia , Fenômenos Fisiológicos da Pele , Pigmentação da Pele/fisiologia , Células Estromais/transplante , Estética , Face/cirurgia , Seguimentos , Sobrevivência de Enxerto , Humanos , Lipectomia/métodos , Ritidoplastia/métodos , Medição de Risco , Transplante Autólogo/métodos , Resultado do Tratamento
6.
J Mater Sci Mater Med ; 30(9): 106, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31502009

RESUMO

With the advantage of handy process, random pattern skin flaps are generally applied in limb reconstruction and wound repair. Apelin-13 is a discovered endogenous peptide, that has been shown to have potent multiple biological functions. Recently, thermosensitive gel-forming systems have gained increasing attention as wound dressings due to their advantages. In the present study, an apelin-13-loaded chitosan (CH)/ß-sodium glycerophosphate (ß-GP) hydrogel was developed for promoting random skin flap survival. Random skin flaps were created in 60 rats after which the animals were categorized to a control hydrogel group and an apelin-13 hydrogel group. The water content of the flap as well as the survival area were then measured 7 days post-surgery. Hematoxylin and eosin staining was used to evaluate the flap angiogenesis. Cell differentiation 34 (CD34) and vascular endothelial growth factor (VEGF) levels were detected by immunohistochemistry and Western blotting. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were assessed by enzyme linked immunosorbent assays (ELISAs). Oxidative stress was estimated via the activity of tissue malondialdehyde (MDA) and superoxide dismutase (SOD). Our results showed that CH/ß-GP/apelin-13 hydrogel could not only reduce the tissue edema, but also improve the survival area of flap. CH/ß-GP/apelin-13 hydrogel also upregulated levels of VEGF protein and increased mean vessel densities. Furthermore, CH/ß-GP/apelin-13 hydrogel was shown to significantly inhibit the expression of TNF-α and IL-6, along with increasing the activity of SOD and suppressing the MDA content. Taken together, these results indicate that this CH/ß-GP/apelin-13 hydrogel may be a potential therapeutic way for random pattern skin flap.


Assuntos
Sobrevivência de Enxerto/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Peptídeos e Proteínas de Sinalização Intercelular/farmacocinética , Transplante de Pele/métodos , Pele/efeitos dos fármacos , Temperatura Ambiente , Animais , Temperatura Corporal/fisiologia , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Hidrogéis/administração & dosagem , Hidrogéis/farmacocinética , Masculino , Malondialdeído/metabolismo , Necrose/patologia , Necrose/prevenção & controle , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Pele/metabolismo , Pele/patologia , Fenômenos Fisiológicos da Pele/efeitos dos fármacos , Retalhos Cirúrgicos/fisiologia , Retalhos Cirúrgicos/transplante
7.
Nat Commun ; 10(1): 4405, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31562319

RESUMO

The emergence of smart electronics, human friendly robotics and supplemented or virtual reality demands electronic skins with both tactile and touchless perceptions for the manipulation of real and virtual objects. Here, we realize bifunctional electronic skins equipped with a compliant magnetic microelectromechanical system able to transduce both tactile-via mechanical pressure-and touchless-via magnetic fields-stimulations simultaneously. The magnetic microelectromechanical system separates electric signals from tactile and touchless interactions into two different regions, allowing the electronic skins to unambiguously distinguish the two modes in real time. Besides, its inherent magnetic specificity overcomes the interference from non-relevant objects and enables signal-programmable interactions. Ultimately, the magnetic microelectromechanical system enables complex interplay with physical objects enhanced with virtual content data in augmented reality, robotics, and medical applications.


Assuntos
Fenômenos Fisiológicos da Pele , Percepção do Tato/fisiologia , Tato , Dispositivos Eletrônicos Vestíveis , Algoritmos , Eletricidade , Fenômenos Eletromagnéticos , Eletrônica/instrumentação , Eletrônica/métodos , Humanos , Magnetismo , Robótica , Transdutores
8.
J Physiol Pharmacol ; 70(3)2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31539880

RESUMO

The local renin-angiotensin-aldosterone system (RAAS) is fully expressed in the human skin at the mRNA and protein level. Local RAAS is known to play a regulatory function in epidermal proliferation, wound healing, scarring, cutaneous heating adaptation, and aging. There are also some indications of its role in the regulation of hair growth and sebum secretion. Impaired wound healing, skin diseases associated with diabetes, cancer development, psoriasis, and scleroderma may be related to changes in skin RAAS activity. Extensive research has shown that RAAS-modulating drugs can affect the skin when applied orally or topically, creating new therapeutic approaches against dermatological diseases.


Assuntos
Aldosterona/metabolismo , Sistema Renina-Angiotensina/fisiologia , Dermatopatias/fisiopatologia , Pele/fisiopatologia , Animais , Humanos , Fenômenos Fisiológicos da Pele
9.
Sensors (Basel) ; 19(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500135

RESUMO

Simultaneous measurement of skin physiological and physical properties are important for the diagnosis of skin diseases and monitoring of human performance, since it provides more comprehensive understanding on the skin conditions. Current skin analysis devices, however, require each of probes and unique protocols for the measurement of individual skin properties, resulting in inconvenience and increase of measurement uncertainty. This paper presents a pen-type skin analyzing device capable tomeasure three key skin properties at the same time: transepidermal water loss (TEWL), skin conductance, and skin hardness. It uses a single truncated hollow cone (THC) probe integrated with a humidity sensor, paired electrodes, and a load cell for the multimodal assessment of the skin properties. The present device measured TEWL with a sensitivity of 0.0068 (%/s)/(g/m2/h) and a linearity of 99.63%, conductance with a sensitivity of 1.02 µS/µS and a linearity of 99.36%, and hardness with a sensitivity of 0.98 Shore 00/Shore 00 and a linearity of 99.85%, within the appropriate ranges for the human skin. The present pen-type device has a high potential for the skin health diagnosis as well as the human performance monitoring applications.


Assuntos
Resposta Galvânica da Pele/fisiologia , Dermatopatias/diagnóstico , Fenômenos Fisiológicos da Pele , Pele/química , Dureza , Humanos , Água/química
10.
Adv Exp Med Biol ; 1178: 155-174, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31493227

RESUMO

Skin aging is a complex process induced by intrinsic and extrinsic factors and causes alterations to the structural and functional aspects of the skin. Skin aging affects patients physically and physiologically. Understanding the process of skin aging can provide new knowledge on how to attenuate or reduce skin disorder symptoms. Herbs have been used for ages to prevent and treat skin aging, yet there are growing interests by researchers in this field globally. Various strategies have been developed for improving the quality and effectivity of herbal skin care products, both for topical and oral applications. This review will provide an overview of the relationship between herbal skin care products and the skin aging process.


Assuntos
Preparações de Plantas , Regeneração , Envelhecimento da Pele , Fenômenos Fisiológicos da Pele , Humanos , Preparações de Plantas/farmacologia , Regeneração/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Higiene da Pele , Fenômenos Fisiológicos da Pele/efeitos dos fármacos
11.
Nat Commun ; 10(1): 4019, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488820

RESUMO

Biological cellular structures have inspired many scientific disciplines to design synthetic structures that can mimic their functions. Here, we closely emulate biological cellular structures in a rationally designed synthetic multicellular hybrid ion pump, composed of hydrogen-bonded [EMIM+][TFSI-] ion pairs on the surface of silica microstructures (artificial mechanoreceptor cells) embedded into thermoplastic polyurethane elastomeric matrix (artificial extracellular matrix), to fabricate ionic mechanoreceptor skins. Ionic mechanoreceptors engage in hydrogen bond-triggered reversible pumping of ions under external stimulus. Our ionic mechanoreceptor skin is ultrasensitive (48.1-5.77 kPa-1) over a wide spectrum of pressures (0-135 kPa) at an ultra-low voltage (1 mV) and demonstrates the ability to surpass pressure-sensing capabilities of various natural skin mechanoreceptors (i.e., Merkel cells, Meissner's corpuscles, Pacinian corpuscles). We demonstrate a wearable drone microcontroller by integrating our ionic skin sensor array and flexible printed circuit board, which can control directions and speed simultaneously and selectively in aerial drone flight.


Assuntos
Técnicas Biossensoriais/instrumentação , Eletroquímica/instrumentação , Ligações de Hidrogênio , Mecanorreceptores/fisiologia , Mecanotransdução Celular/fisiologia , Fenômenos Fisiológicos da Pele , Adulto , Biomimética/instrumentação , Técnicas Biossensoriais/métodos , Humanos , Mecanorreceptores/química , Mecanorreceptores/citologia , Células de Merkel/metabolismo , Estimulação Física , Poliuretanos , Pressão , Sílica Gel , Pele/citologia , Tato/fisiologia
12.
EMBO J ; 38(19): e101688, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31475747

RESUMO

Lymphatic vessels are essential for skin fluid homeostasis and immune cell trafficking. Whether the lymphatic vasculature is associated with hair follicle regeneration is, however, unknown. Here, using steady and live imaging approaches in mouse skin, we show that lymphatic vessels distribute to the anterior permanent region of individual hair follicles, starting from development through all cycle stages and interconnecting neighboring follicles at the bulge level, in a stem cell-dependent manner. Lymphatic vessels further connect hair follicles in triads and dynamically flow across the skin. At the onset of the physiological stem cell activation, or upon pharmacological or genetic induction of hair follicle growth, lymphatic vessels transiently expand their caliber suggesting an increased tissue drainage capacity. Interestingly, the physiological caliber increase is associated with a distinct gene expression correlated with lymphatic vessel reorganization. Using mouse genetics, we show that lymphatic vessel depletion blocks hair follicle growth. Our findings point toward the lymphatic vasculature being important for hair follicle development, cycling, and organization, and define lymphatic vessels as stem cell niche components, coordinating connections at tissue-level, thus provide insight into their functional contribution to skin regeneration.


Assuntos
Folículo Piloso/crescimento & desenvolvimento , Vasos Linfáticos/metabolismo , Regeneração , Fenômenos Fisiológicos da Pele , Animais , Ciclo Celular , Camundongos , Nicho de Células-Tronco
13.
Artigo em Inglês | MEDLINE | ID: mdl-31438489

RESUMO

Children's favourite food and beverage brands use various tactics to foster positive associations and loyalty. This brand-consumer dynamic is frequently influenced by the use of implicit techniques and emotional appeals. Few studies have used physiological methods to examine the connections that brands build with children and the influence this has on their automatic responses. These techniques are potentially less prone to bias than behavioural or cognitive methods. This is the first study to explore the implicit response that children have to images of their favourite food and beverage brands using skin conductance responses as a marker of arousal. Australian children aged 8-11 years (n = 48) were recruited. Images of the participants' favourite branded food and beverage products, alongside images of the same products unpackaged, their family and friends, and neutral objects were presented in a randomised order with a standard timed interval between images. Children were significantly more aroused by branded images of their favourite food and beverage products than by their unpackaged counterparts (p < 0.042, d = 0.4). The physiological response to the branded products was similar to the response to the children's family and friends (p = 0.900, d = -0.02). These findings suggest that children may have an implicit connection to their favourite branded products.


Assuntos
Bebidas , Embalagem de Alimentos , Preferências Alimentares/fisiologia , Alimentos , Fenômenos Fisiológicos da Pele , Nível de Alerta/fisiologia , Austrália , Criança , Feminino , Humanos , Masculino
15.
Elife ; 82019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31407662

RESUMO

Touch sensation hinges on force transfer across the skin and activation of mechanosensitive ion channels along the somatosensory neurons that invade the skin. This skin-nerve sensory system demands a quantitative model that spans the application of mechanical loads to channel activation. Unlike prior models of the dynamic responses of touch receptor neurons in Caenorhabditis elegans (Eastwood et al., 2015), which substituted a single effective channel for the ensemble along the TRNs, this study integrates body mechanics and the spatial recruitment of the various channels. We demonstrate that this model captures mechanical properties of the worm's body and accurately reproduces neural responses to simple stimuli. It also captures responses to complex stimuli featuring non-trivial spatial patterns, like extended or multiple contacts that could not be addressed otherwise. We illustrate the importance of these effects with new experiments revealing that skin-neuron composites respond to pre-indentation with increased currents rather than adapting to persistent stimulation.


Assuntos
Mecanorreceptores/fisiologia , Células Receptoras Sensoriais/fisiologia , Fenômenos Fisiológicos da Pele , Pele/anatomia & histologia , Estresse Mecânico , Tato , Animais , Caenorhabditis elegans , Modelos Neurológicos
16.
J Therm Biol ; 84: 208-213, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466755

RESUMO

There was no clear evidence of the TRPA1 ion channel involvement in the formation of thermoregulatory responses. The present results convincingly show that the skin TRPA1 ion channel activation has significant influence on the formation of thermoregulatory responses of the body to cooling; it is especially strongly manifested for the metabolic component. At the TRPA1 activation by its agonist AITC (0.04%), an enhancement in thermoregulatory responses is observed: the temperature thresholds for the first phase and the second one of the metabolic response decrease, the values of all components of the metabolic response considerably increase: the increment of oxygen consumption in the first phase increases from 1.8 ± 0.24 in the control to 2.9 ± 0.35 ml/min*kg under AITC, P = 0.04; the increment of oxygen consumption in the second phase increases from 6.2 ± 2.06 to 17.4 ± 1.20 ml/min*kg, P = 0.002, as well as shivering rises from 7.8 ± 1.79 to 15.4 ± 1.87 mV, P = 0.011. In consideration of our previous results on the influence of TRPM8 ion channel activation on thermoregulatory responses (Kozyreva et al., J. Therm.Biol., 2010) it is obvious that the TRPM8 and TRPA1 ion channels have a pronounced, but unequal effects on the values of different phases of the metabolic response to cold. The TRPM8 activation manifests itself in an increase of value only the urgent first phase, this phase is associated with carbohydrate metabolism. As the recent results have shown the influence of the TRPA1 activation is realized predominantly in the clearly marked increase in the second phase of the metabolic response associated with lipid metabolism, as well as in evident shivering gain. The ability to predominantly control different parameters of thermoregulatory responses to cold may indicate the importance of both the TRPM8 and the TRPA1 ion channels in the processes of maintaining temperature homeostasis. The obtained data testify to the joint sequential operation of these thermosensitive ion channels.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Fenômenos Fisiológicos da Pele , Canal de Cátion TRPA1/fisiologia , Canais de Cátion TRPM/fisiologia , Animais , Temperatura Baixa , Masculino , Ratos Wistar
17.
J Therm Biol ; 84: 274-284, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466765

RESUMO

In this paper, a fractional non-Fourier heat conduction model is employed to simulate the heat diffusion through the skin tissue, as a biological system, upon immediate contact with a heat source. In order to study skin models and different boundary aspects, two problems: the three-layer skin tissue in contact with a hot water source and a single-layer skin tissue exposed suddenly to a heat source generated by a laser are investigated. In both cases, the super-diffusion fractional non-Fourier model is used to simulate the heat transfer diffused through the skin tissue. In the first case, the governing equation is solved using an implicit method, and in the second problem, its governing equation is solved using a finite volume method. In the fractional non-Fourier model, the effect of the model's essential parameters (αand τ) on the prediction of temperature distribution in skin tissue is studied as well as the effect of other parameters such as the blood rate is studied. In addition, grid study has been investigated and the most efficient and appropriate gird is obtained. The results are validated against the DPL (Dual-Phase Lag) model's results. The fractional single-phase-lag model's results indicate that this model is highly precise and encompasses all the results of the dual-phase-lag model. The results also show the high precision of the model, taking into account both the microstructure interactions and the lags.


Assuntos
Modelos Biológicos , Fenômenos Fisiológicos da Pele , Condutividade Térmica , Simulação por Computador , Lasers , Temperatura Cutânea
18.
J Therm Biol ; 84: 323-330, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466770

RESUMO

Local heat can accelerate the blood circulation and induce the vasodilatation. Investigators reported that local heat causes an increase in skin blood flow consisting of two phases. The first is solely sensory neural, and the second is nitric oxide mediated. However, the mechanism underlying the skin blood flow response to local heating are complex and poorly understood. The mechanisms behind these two phases are deduced to be linked by flow-mediated dilation. In this study, the variation of the blood flow and the blood vessel diameter are monitored during local heating. According to the dynamic blood flow, the theoretical model of flow mediated dilation involving the key agents production and transportation was first used to study vasodilatation process during heating, and the variations of blood vessel was obtained. Finally, accurate distributions of the nitric oxide, calcium and myosin concentrations in the arterial wall were found during autoregulation. We evaluated the time course of the blood vessel changing and verified the fact that the second increase in blood flow is the result of flow dilation mediation. The effects of dilation of blood vessel were also analyzed.


Assuntos
Temperatura Alta , Modelos Biológicos , Fenômenos Fisiológicos da Pele , Pele/irrigação sanguínea , Vasodilatação , Animais , Vasos Sanguíneos/fisiologia , Simulação por Computador , Camundongos , Camundongos Nus , Fluxo Sanguíneo Regional
19.
Biomed Res Int ; 2019: 2183712, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467873

RESUMO

Cats are able to jump from a high-rise without any sign of injury, which is attributed in large part to their impact-resistant paw pads. The biomechanical study of paw pads may therefore contribute to improving the impact resistance of specific biomimetic materials. The present study is aimed at investigating the mechanics of the paw pads, revealing their impact-resistant biomechanism from macro- and microscopic perspectives. Histological and micro-CT scanning methods were exploited to analyze the microstructure of the pads, and mechanical testing was conducted to observe the macroscopic mechanical properties at different loading frequencies. Numerical micromodels of the ellipsoidal and cylindrical adipose compartments were developed to evaluate the mechanical functionality as compressive actions. The results show that the stiffness of the pad increases roughly in proportion to strain and mechanical properties are almost impervious to strain rate. Furthermore, the adipose compartment, which comprises adipose tissue enclosed within collagen septa, in the subcutaneous tissue presents an ellipsoid-like structure, with a decreasing area from the middle to the two ends. Additionally, the finite element results show that the ellipsoidal structure has larger displacement in the early stage of impact, which can absorb more energy and prevent instability at touchdown, while the cylindrical structure is more resistant to deformation. Moreover, the Von Mises of the ellipsoidal compartment decrease gradually from both ends to the middle, making it change to a cylindrical shape, and this may be the reason why the macroscopic stiffness increases with increasing time after contact. This preliminary investigation represents the basis for biomechanical interpretation and can accordingly provide new inspirations of shock-absorbing composite materials in engineering.


Assuntos
Tecido Adiposo/fisiologia , Força Compressiva/fisiologia , Estresse Mecânico , Tela Subcutânea/fisiologia , Animais , Fenômenos Biomecânicos , Gatos , Análise de Elementos Finitos , Humanos , Modelos Biológicos , Fenômenos Fisiológicos da Pele
20.
Sensors (Basel) ; 19(17)2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31450666

RESUMO

In recent years, physiological features have gained more attention in developing models of personal thermal comfort for improved and accurate adaptive operation of Human-In-The-Loop (HITL) Heating, Ventilation, and Air-Conditioning (HVAC) systems. Pursuing the identification of effective physiological sensing systems for enhancing flexibility of human-centered and distributed control, using machine learning algorithms, we have investigated how heat flux sensing could improve personal thermal comfort inference under transient ambient conditions. We have explored the variations of heat exchange rates of facial and wrist skin. These areas are often exposed in indoor environments and contribute to the thermoregulation mechanism through skin heat exchange, which we have coupled with variations of skin and ambient temperatures for inference of personal thermal preferences. Adopting an experimental and data analysis methodology, we have evaluated the modeling of personal thermal preference of 18 human subjects for well-known classifiers using different scenarios of learning. The experimental measurements have revealed the differences in personal thermal preferences and how they are reflected in physiological variables. Further, we have shown that heat exchange rates have high potential in improving the performance of personal inference models even compared to the use of skin temperature.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Aprendizado de Máquina , Monitorização Fisiológica , Fenômenos Fisiológicos da Pele , Ar Condicionado , Algoritmos , Temperatura Alta , Humanos , Temperatura Cutânea/fisiologia , Sensação Térmica/fisiologia , Ventilação
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