Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Opt Express ; 31(1): 469-478, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36606981

RESUMO

In this study, we have designed an electrically tunable multi-band terahertz (THz) metamaterial filter based on graphene and multiple-square-loop structures. The structure contains multiple metal square loops, and these loops with different sizes correspond to different THz frequencies, achieving our expected efficacy of a multiband wave filter. Furthermore, by sweeping external voltages, we could change graphene's Fermi levels, and thus the high-sensitivity THz filter's capability from single-band to multi-band filtering can be modulated. We expect that this study of a hybrid THz wave filter would be promising for the development of selecting channels in THz and 6 G communications.

2.
Langmuir ; 33(27): 6778-6784, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28605895

RESUMO

Many naturally occurring cells possess an intrinsic ability to cross biological barriers that block conventional drug delivery, and these cells offer a possible mode of active transport across the blood-brain barrier or into the core of tumor masses. While many technologies for the formation of complete, nanoparticle-loaded coatings on cells exist, a complete coating on the cell surface would disrupt the interaction of cells with their environments. To address this issue, cell surface patches that partially cover cell surfaces might provide a superior approach for cell-mediated therapeutic delivery. The goal of this study is to establish a simplified approach to producing polymeric patches of arbitrary shapes on a live cell via surface-mediated photopolymerization. Cell surfaces were nonspecifically labeled with eosin, and polyethylene (glycol) diacrylate (PEGDA) coatings were directed to specific sites using 530 nm irradiation through a chrome-coated photomask. These coatings may entrap drug-loaded or imaging particles. The extent of nonspecific formation of PEGDA hydrogel coatings increased with irradiation time, light intensity, and initiating species; 40 mW/cm2 irradiation for 5 min delivered high-resolution patterns on the surface of A549 cells, and these cells remained viable for 48 h postpatterning with fluorescent nanoparticle-loaded coatings. This work first demonstrated the feasibility of photopatterning polymer patches directly on the surface of cells.


Assuntos
Hidrogéis/química , Animais , Sobrevivência Celular , Humanos , Polietilenoglicóis , Polimerização , Ratos , Soroalbumina Bovina
3.
Neuroimmunomodulation ; 24(1): 29-39, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28618410

RESUMO

OBJECTIVE: Inflammation is clearly associated with Alzheimer disease (AD). Knockout of Nlrp3, a gene encoding an inflammasome sensor, has been shown to ameliorate AD pathology in a mouse model. Because AIM2 is the most dominant inflammasome sensor expressed in mouse brains, here we investigate whether Aim2 deletion also influences the phenotype of a 5XFAD AD mouse model. METHODS: Quantitative RT-PCR, immunostaining, immunoblotting, and behavioral analyses were applied to compare wild-type, Aim2-/-, 5XFAD, and Aim2-/-;5XFAD mice. RESULTS: We found that Aim2 knockout mitigates Aß deposition in the cerebral cortex and hippocampus of 5XFAD mice. The activation of microglial cells is also reduced in Aim2-/-;5XFAD brains compared with 5XFAD brains. However, Aim2 knockout does not improve memory and anxiety phenotypes of 5XFAD mice in an open field, cued Y-maze, or Barnes maze. Compared with 5XFAD mice, Il-1 expression levels are not reduced in Aim2-/-;5XFAD mice. Unexpectedly, Il-6 and Il-18 expression levels in 5XFAD brains were further increased when Aim2 was deleted. Thus, inflammatory cytokine expression in 5XFAD brains is upregulated by Aim2 deletion through an unknown mechanism. CONCLUSION: Although Aim2 knockout mitigates Aß deposition and microglial activation, Aim2 deletion does not have a beneficial effect on the spatial memory or cytokine expression of 5XFAD mice. Our findings suggest that Aß aggregation and microglial activation may not always be correlated with the expression of inflammatory cytokines or cognitive function of 5XFAD mice. Our study also implies that different inflammasomes likely perform distinct roles in different physiological and/or pathological events.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/metabolismo , Citocinas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/genética , Microglia/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Comportamento Exploratório/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas dos Microfilamentos/metabolismo , Mutação/genética , Presenilina-1/genética , Presenilina-1/metabolismo , Fatores de Tempo
5.
J Immunol ; 193(4): 1672-80, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25000980

RESUMO

The generation of T cell anergy is associated with upregulation of ubiquitin E3 ligases including Casitas B-lineage lymphoma (Cbl-b), Itch, gene related to anergy in lymphocyte, and deltex1 (DTX1). These E3 ligases attenuate T cell activation by targeting to signaling molecules. For example, Cbl-b and Itch promote the degradation of protein kinase Cθ (PKCθ) and phospholipase C-γ1 (PLC-γ1) in anergic Th1 cells. How these anergy-associated E3 ligases coordinate during T cell anergy remains largely unknown. In the current study, we found that PKCθ and PLC-γ1 are also downregulated by DTX1. DTX1 interacted with PKCθ and PLC-γ1 and stimulated the degradation of PKCθ and PLC-γ1. T cell anergy-induced proteolysis of PKCθ was prevented in Dtx1(-/-) T cells, supporting the essential role of DTX1 in PKCθ downregulation. Similar to Cbl-b and Itch, DTX1 promoted monoubiquitination of PKCθ. Proteasome inhibitor did not inhibit DTX1-directed PKCθ degradation, but instead DTX1 directed the relocalization of PKCθ into the lysosomal pathway. In addition, DTX1 interacted with Cbl-b and increased the protein levels of Cbl-b. We further demonstrated the possibility that, through the downregulation of PKCθ, DTX1 prevented PKCθ-induced Cbl-b degradation and increased Cbl-b protein stability. Our results suggest the coordination between E3 ligases during T cell anergy; DTX1 acts with Cbl-b to assure a more extensive silencing of PKCθ, whereas DTX1-mediated PKCθ degradation further stabilizes Cbl-b.


Assuntos
Proteínas de Ligação a DNA/genética , Isoenzimas/metabolismo , Proteína Oncogênica v-cbl/biossíntese , Proteína Quinase C/metabolismo , Proteólise , Células Th1/imunologia , Animais , Calcimicina/farmacologia , Linhagem Celular , Anergia Clonal , Proteínas de Ligação a DNA/biossíntese , Regulação para Baixo , Células HEK293 , Humanos , Isoenzimas/biossíntese , Isoenzimas/genética , Células Jurkat , Ativação Linfocitária/imunologia , Lisossomos/imunologia , Camundongos , Camundongos Knockout , Proteína Oncogênica v-cbl/genética , Fosfolipase C gama/biossíntese , Fosfolipase C gama/metabolismo , Inibidores de Proteassoma/farmacologia , Proteína Quinase C/biossíntese , Proteína Quinase C/genética , Proteína Quinase C-theta , Interferência de RNA , RNA Interferente Pequeno , Ubiquitina-Proteína Ligases/biossíntese , Ubiquitina-Proteína Ligases/genética , Ubiquitinação , Proteína-Tirosina Quinase ZAP-70/biossíntese
6.
BMC Cardiovasc Disord ; 15: 34, 2015 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-25956814

RESUMO

BACKGROUND: Vascular closure devices such as angioseal are used as alternatives to traditional compression haemostasis. Although the safety and efficacy of angioseal are confirmed, their use remains controversial because of the potential complications of these devices compared with those of traditional compression haemostasis. The aim of this study was to compare the access site complication rate, the predictive factors for these complications, and patient comfort levels after coronary procedures with traditional compression or angioseal haemostasis. METHODS: Data were collected from a cardiac unit in a medical center in northern Taiwan. A total of 130 adult patients were recruited and equally divided into two groups according to the method of haemostasis used after the coronary procedure: a traditional compression group and an angioseal group. We observed the incidence of access site complications, including bleeding, oozing, haematoma formation, and arteriovenous fistula formation. In addition, we used a 0-10 numeric rating scale to assess soreness, numbness, and back and groin access site pain after 1 h of catheter removal and immediately before getting out of bed. RESULTS: The overall incidence of complications was 3.8 % (n = 5), which was not significantly different between the two groups (p = .06). The propensity score--adjusted multivariate analyses revealed that the only independent predictor for access site complications was an age of >70 years (OR, 10.44; 95 % CI, 1.81-60.06; p = .009). Comfort levels were higher in the angioseal group than in the traditional compression group. CONCLUSIONS: Angioseal used after coronary procedures did not increase the incidence of complications relative to that associated with traditional compression haemostasis; however, it increased patient comfort levels. Health personnel should pay special attention to the predictive factor for access site complications after coronary procedures, such as age >70 years.


Assuntos
Cateterismo Cardíaco/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Bandagens Compressivas , Artéria Femoral/cirurgia , Técnicas Hemostáticas , Hemorragia Pós-Operatória/prevenção & controle , Dispositivos de Oclusão Vascular , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cateterismo Cardíaco/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan
7.
Appl Opt ; 53(27): G163-8, 2014 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-25322125

RESUMO

A speckleless illuminated modified-Gerchberg-Saxton-algorithm-type computer-generated hologram, which adopts a lower frequency of the iterative algorithm and calculation time, is proposed to code a hologram with two signals and position a multiplexing phase-only function, which can reconstruct the left and the right viewing holograms on the pupillary-distance position after the decryption and still maintain the content with high contrast and definition. The reconstructed image quality presents root mean square error of 0.03, with a diffraction efficiency of 87%, and signal-to-noise ratio of 8 dB after the analysis. Furthermore, two denoising techniques for the digital filter and optical suppression are combined, in which the speckle suppression with pseudorandom phase modulation and a rotating diffuser are utilized for successfully reducing the speckle contrast, which was reduced to below 4%. The goal was to reduce visual fatigue for the viewers.

8.
Front Hum Neurosci ; 18: 1415904, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38873654

RESUMO

Noninvasive brain stimulation (NIBS) techniques, including transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS), are emerging as promising tools for enhancing cognitive functions by modulating brain activity and enhancing cognitive functions. Despite their potential, the specific and combined effects of tDCS and tRNS on brain functions, especially regarding functional connectivity, cortical inhibition, and memory performance, are not well-understood. This study aims to explore the distinct and combined impacts of tDCS and tRNS on these neural and cognitive parameters. Using a within-subject design, ten participants underwent four stimulation conditions: sham, tDCS, tRNS, and combined tDCS + tRNS. We assessed the impact on resting-state functional connectivity, cortical inhibition via Cortical Silent Period (CSP), and visuospatial memory performance using the Corsi Block-tapping Test (CBT). Our results indicate that while tDCS appears to induce brain lateralization, tRNS has more generalized and dispersive effects. Interestingly, the combined application of tDCS and tRNS did not amplify these effects but rather suggested a non-synergistic interaction, possibly due to divergent mechanistic pathways, as observed across fMRI, CSP, and CBT measures. These findings illuminate the complex interplay between tDCS and tRNS, highlighting their non-additive effects when used concurrently and underscoring the necessity for further research to optimize their application for cognitive enhancement.

9.
Opt Express ; 21(25): 31062-71, 2013 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-24514680

RESUMO

We propose a system that reduces laser display speckles by vibrating the light pipe. A small displacement of the light pipe appears to allow the total reflection of the laser, thereby resulting in a homogenized speckle field that changes with time. In this case, the speckle interference generated by the pattern projected by the laser through the light pipe destroys the spatial homogenization of the laser beams when the light pipe is vibrated. Moreover, when the light pipe begins the sequential vibration, the phases and paths of the beams are changed after the beams traverse the light pipe. Consequently, temporal speckle wavefront superposition can homogenize the luminous intensity distribution of the speckle pattern. This process reduces the speckle contrast to less than 4% while maintaining a luminous intensity of greater than 70%.

10.
Adv Sci (Weinh) ; 10(36): e2301240, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37964407

RESUMO

Over 90% of patients with pancreatic ductal adenocarcinoma (PDAC) have oncogenic KRAS mutations. Nevertheless, mutated KRAS alone is insufficient to initiate pancreatic intraepithelial neoplasia (PanIN), the precursor of PDAC. The identities of the other factors/events required to drive PanIN formation remain elusive. Here, optic-clear 3D histology is used to analyze entire pancreases of 2-week-old Pdx1-Cre; LSL-KrasG12D/+ (KC) mice to detect the earliest emergence of PanIN and observed that the occurrence is independent of physical location. Instead, it is found that the earliest PanINs overexpress Muc4 and associate with αSMA+ fibroblasts in both transgenic mice and human specimens. Mechanistically, KrasG12D/+ pancreatic cells upregulate Muc4 through genetic alterations to increase proliferation and fibroblast recruitments via Activin A secretion and consequently enhance cell transformation for PanIN formation. Inhibition of Activin A signaling using Follistatin (FST) diminishes early PanIN-associated fibroblast recruitment, effectively curtailing PanIN initiation and growth in KC mice. These findings emphasize the vital role of interactions between oncogenic KrasG12D/+ -driven genetic alterations and induced microenvironmental changes in PanIN initiation, suggesting potential avenues for early PDAC diagnostic and management approaches.


Assuntos
Carcinoma in Situ , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Camundongos , Humanos , Animais , Proteínas Proto-Oncogênicas p21(ras)/genética , Mucina-4 , Neoplasias Pancreáticas/genética , Carcinoma Ductal Pancreático/genética , Camundongos Transgênicos , Carcinoma in Situ/genética , Carcinoma in Situ/patologia
11.
Am J Cancer Res ; 12(4): 1556-1576, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35530290

RESUMO

Aberrant sugar metabolism is linked to an increased risk of pancreatic cancer. Previously, we found that high glucose induces genome instability and de novo oncogenic KRAS mutation preferentially in pancreatic cells through dysregulation of O-GlcNAcylation. Increasing O-GlcNAcylation by extrinsically supplying N-acetyl-D-glucosamine (GlcNAc) causes genome instability in all kinds of cell types regardless of pancreatic origin. Since many people consume excessive amount of sugar (glucose, fructose, and sucrose) in daily life, whether high sugar consumption directly causes genome instability in animals remains to be elucidated. In this communication, we show that excess sugar in the daily drink increases DNA damage and protein O-GlcNAcylation preferentially in pancreatic tissue but not in other kinds of tissue of mice. The effect of high sugar on the pancreatic tissue may be attributed to the intrinsic ratio of GFAT and PFK activity, a limiting factor that dictates UDP-GlcNAc levels. On the other hand, GlcNAc universally induces DNA damage in all six organs examined. Either inhibiting O-GlcNAcylation or supplementing dNTP pool diminishes the induced DNA damage in these organs, indicating that the mechanism of action is similar to that of high glucose treatment in pancreatic cells. Taken together, these results suggest the potential hazards of high sugar drinks and high glucosamine intake to genomic instability and possibly cancer initiation.

12.
Clin Cancer Res ; 28(9): 1979-1990, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35140124

RESUMO

PURPOSE: Proficient DNA repair by homologous recombination (HR) facilitates resistance to chemoradiation in glioma stem cells (GSC). We evaluated whether compromising HR by targeting HSP90, a molecular chaperone required for the function of key HR proteins, using onalespib, a long-acting, brain-penetrant HSP90 inhibitor, would sensitize high-grade gliomas to chemoradiation in vitro and in vivo. EXPERIMENTAL DESIGN: The ability of onalespib to deplete HR client proteins, impair HR repair capacity, and sensitize glioblastoma (GBM) to chemoradiation was evaluated in vitro in GSCs, and in vivo using zebrafish and mouse intracranial glioma xenograft models. The effects of HSP90 inhibition on the transcriptome and cytoplasmic proteins was assessed in GSCs and in ex vivo organotypic human glioma slice cultures. RESULTS: Treatment with onalespib depleted CHK1 and RAD51, two key proteins of the HR pathway, and attenuated HR repair, sensitizing GSCs to the combination of radiation and temozolomide (TMZ). HSP90 inhibition reprogrammed the transcriptome of GSCs and broadly altered expression of cytoplasmic proteins including known and novel client proteins relevant to GSCs. The combination of onalespib with radiation and TMZ extended survival in a zebrafish and a mouse xenograft model of GBM compared with the standard of care (radiation and TMZ) or onalespib with radiation. CONCLUSIONS: The results of this study demonstrate that targeting HR by HSP90 inhibition sensitizes GSCs to radiation and chemotherapy and extends survival in zebrafish and mouse intracranial models of GBM. These results provide a preclinical rationale for assessment of HSP90 inhibitors in combination with chemoradiation in patients with GBM.


Assuntos
Antineoplásicos , Neoplasias Encefálicas , Glioblastoma , Glioma , Animais , Antineoplásicos/farmacologia , Benzamidas , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Reparo do DNA , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/radioterapia , Glioma/tratamento farmacológico , Glioma/genética , Glioma/radioterapia , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Choque Térmico/metabolismo , Humanos , Isoindóis , Camundongos , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra
13.
J Healthc Eng ; 2021: 6697701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34462649

RESUMO

Overloaded work and life stress often result in excessive fatigue and stresses in people, further leading to psychological burden and physiological disease. In this case, good rest is important in busy life. Good rest could result in good quality of life and work efficiency. In order to assist people in getting into deep rest to obtain a restorative state after fatigue, a dynamic lighting system with low-frequency change for assisting users in effective relaxation is proposed in this study. Heart rate variability analysis is used for discussing the change in the autonomic nervous system of the subjects under dynamic lighting environment, and a self-report questionnaire is applied to understand the subjects' psychological feeling. The research results indicate that the subjects significantly showed enhancement in the activities of parasympathetic nervous system within 25 minutes in the dynamic lighting process, in comparison with the steady lighting system. The questionnaire survey results also reveal that the subjects receive higher quality of rest, after the dynamic and low-illuminance lighting stimuli, with good feeling.


Assuntos
Iluminação , Qualidade de Vida , Sistema Nervoso Autônomo/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Descanso
14.
Heliyon ; 7(4): e06877, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33981906

RESUMO

A prism device is utilized in this study for modifying the eye convergence to reduce eye accommodation and enhance the comfort in viewing 3D video. Without changing the contents of 3D films, it aims to apply the myosis, convergence, and accommodation visual triad of eyeballs viewing near distance to not change the eyeball pupillary distance when viewing 3D films. Without convergence, the discomfort caused by intraocular muscle contraction when viewing near distance is reduced. Such an effect of a small prism lens is also proven in this study. When viewing 3D films with 1.0△ lenses, the physiological accommodation reaction of eyes would reduce (the right eye decreases 65% and the left eye decreases 70%), revealing the decreasing tension of intraocular muscle. The subjective psychological evaluation result also shows that viewing 3D images with small prism lenses could enhance the comfort. The evaluation of optical simulation, physiological reaction, and mental fatigue proves that the small prism lens proposed in this study could actually improve the comfort in viewing 3D films.

15.
ACS Appl Bio Mater ; 3(5): 2930-2939, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33225239

RESUMO

Injection into the heart tissue is a direct route for optimally placing mesenchymal stem cells (MSC) to regulate local inflammation following a heart attack. The retention of MSCs at the injection site is severely limited by the fluid flows that rapidly wash cells away and minimize their capacity to modulate cardiac inflammation. To prevent this loss of MSCs and their function, antibody coatings were designed for the surface of MSCs to enhance their adhesion to the inflamed tissue. MSCs were biotinylated, and biotinylated antibodies against intercellular cell adhesion molecules were conjugated to the cell surface through an intermediate layer of streptavidin. MSC surfaces were modified with ~7,000 biotin/µm2 and ~23 antibodies/µm2. The heart tissue injection of antibody-coated MSCs offered a 3-fold increase of cell retention in an infarcted heart over the injection of uncoated MSCs. We supported the mechanism of adhesion through analysis of MSC adhesion to inflamed endothelial cells and also surfaces of purified adhesion molecules on glass under microfluidic shear flow.

16.
Nutrients ; 12(5)2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32397609

RESUMO

Cognitive decline is an important issue of global public health. Cognitive aging might begin at middle adulthood, the period particularly vulnerable to stress in lifespan. Essence of chicken (EOC) has consistently demonstrated its beneficial effects on various cognitive domains as nutritional supplementation. This study primarily aimed to examine the cognitive enhancement effects of ProBeptigen® (previously named CMI-168), hydrolyzed peptides extracted from EOC, in healthy middle-aged people under mild stress. Ninety healthy subjects were randomly assigned into the ProBeptigen® or placebo group for eight weeks. Neurocognitive assessment, event-related potentials (ERPs), and blood tests were conducted before, during, and after the treatment. The ProBeptigen® group outperformed placebo group on Logical Memory subtests of Wechsler Memory Scale-third edition (WMS-III) and Spatial Working Memory task in the Cambridge Neuropsychological Test Automated Battery (CANTAB). The anti-inflammatory effects of ProBeptigen® in humans were also confirmed, with progressively declining high-sensitivity C-reactive protein (hs-CRP) levels. Regular dietary supplementation of ProBeptigen® is suggested to improve verbal short- and long-term memory as well as spatial working memory, and reduce inflammation in middle-aged healthy individuals with stress. The effects of ProBeptigen® on cognition warrant further investigation. (NCT03612752).


Assuntos
Galinhas , Cognição/efeitos dos fármacos , Suplementos Nutricionais , Voluntários Saudáveis , Nootrópicos , Fenômenos Fisiológicos da Nutrição/fisiologia , Extratos de Tecidos/farmacologia , Adulto , Idoso , Animais , Anti-Inflamatórios , Proteína C-Reativa/metabolismo , Método Duplo-Cego , Feminino , Humanos , Hidrólise , Masculino , Memória/efeitos dos fármacos , Pessoa de Meia-Idade , Testes Neuropsicológicos
17.
Nat Commun ; 11(1): 512, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980605

RESUMO

Mechanisms for human sinoatrial node (SAN) dysfunction are poorly understood and whether human SAN excitability requires voltage-gated sodium channels (Nav) remains controversial. Here, we report that neuronal (n)Nav blockade and selective nNav1.6 blockade during high-resolution optical mapping in explanted human hearts depress intranodal SAN conduction, which worsens during autonomic stimulation and overdrive suppression to conduction failure. Partial cardiac (c)Nav blockade further impairs automaticity and intranodal conduction, leading to beat-to-beat variability and reentry. Multiple nNav transcripts are higher in SAN vs atria; heterogeneous alterations of several isoforms, specifically nNav1.6, are associated with heart failure and chronic alcohol consumption. In silico simulations of Nav distributions suggest that INa is essential for SAN conduction, especially in fibrotic failing hearts. Our results reveal that not only cNav but nNav are also integral for preventing disease-induced failure in human SAN intranodal conduction. Disease-impaired nNav may underlie patient-specific SAN dysfunctions and should be considered to treat arrhythmias.


Assuntos
Arritmias Cardíacas/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Neurônios/metabolismo , Nó Sinoatrial/fisiopatologia , Canais de Sódio/metabolismo , Potenciais de Ação/fisiologia , Adulto , Idoso , Alcoolismo/genética , Arritmias Cardíacas/genética , Doença Crônica , Simulação por Computador , Feminino , Átrios do Coração/metabolismo , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/metabolismo , Insuficiência Cardíaca/genética , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Imagem Óptica , Subunidades Proteicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Nó Sinoatrial/metabolismo , Canais de Sódio/genética , Estresse Fisiológico , Adulto Jovem
18.
J Biol Eng ; 13: 5, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30675178

RESUMO

The research community is intent on harnessing increasingly complex biological building blocks. At present, cells represent a highly functional component for integration into higher order systems. In this review, we discuss the current application space for cellular coating technologies and emphasize the relationship between the target application and coating design. We also discuss how the cell and the coating interact in common analytical techniques, and where caution must be exercised in the interpretation of results. Finally, we look ahead at emerging application areas that are ideal for innovation in cellular coatings. In all, cellular coatings leverage the machinery unique to specific cell types, and the opportunities derived from these hybrid assemblies have yet to be fully realized.

19.
Biomed Opt Express ; 10(5): 2457-2466, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31143498

RESUMO

The degeneration of articular cartilage (AC) occurs in osteoarthritis (OA), which is a leading cause of pain and disability in middle-aged and older people. The early disease-related changes in cartilage extra-cellular matrix (ECM) start with depletion of proteoglycan (PG), leading to an increase in tissue hydration and permeability. These early compositional changes are small (<10%) and hence difficult to register with conventional non-invasive imaging technologies (magnetic resonance and ultrasound imaging). Here we apply Brillouin microscopy for detecting changes in the mechanical properties and composition of porcine AC. OA-like degradation is mimicked by enzymatic tissue digestion, and we compare Brillouin microscopy measurements against histological staining of PG depletion over varying digestion times and enzyme concentrations. The non-destructive nature of Brillouin imaging technology opens new avenues for creating minimally invasive arthroscopic devices for OA diagnostics and therapeutic monitoring.

20.
IEEE J Biomed Health Inform ; 22(3): 799-805, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28475070

RESUMO

Recently, 2-D/3-D switchable displays have become the mainstream in 3-D display technologies, and people can now watch 3-D movies with a naked 2-D/3-D switchable display at home. However, some studies have indicated that people might encounter visual fatigue after enjoying a 3-D film in the theater. Although 2-D/3-D switchable technologies have been widely developed, 3-D display technologies are still lacking in ergonomic and human-care factors such as reducing visual fatigue. This study proposes a novel 2-D/3-D display autoadjustment switch system to provide biofeedback functions to reduce users' visual fatigue. In addition, the relationship between the blink rate and the visual fatigue state while watching 3-D films was investigated and quantified. In this study, liquid crystal barrier technology was used to develop a 2-D/3-D switchable display, and a wearable EOG acquisition device was also designed to monitor electro-oculography signals to estimate the blink rate. Here, the 2-D/3-D display autoadjustment criterion of the proposed system was designed according to the change in the visual fatigue state as estimated from the blink rate. Finally, the experimental results show that the proposed system could effectively reduce users' visual fatigue while watching 3-D films.


Assuntos
Eletroculografia/métodos , Imageamento Tridimensional/métodos , Processamento de Sinais Assistido por Computador , Adolescente , Adulto , Algoritmos , Piscadela/fisiologia , Humanos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA