Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.874
Filtrar
1.
J Phys Chem Lett ; 12(32): 7768-7776, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34374542

RESUMO

During the maturation step, the retroviral capsid proteins (CAs) assemble into polymorphic capsids. Their acute curvature is largely determined by 12 pentamers inserted into the hexameric lattice. However, how the CA switches its conformation to control assembly curvature remains unclear. We report the high-resolution structural model of the Rous sarcoma virus (RSV) CA T = 1 capsid, established by molecular dynamics simulations combining solid-state NMR and prior cryoelectron tomography restraints. Comparing this with our previous model of the RSV CA tubular assembly, we identify the key residues for dictating the incorporation of acute curvatures. These residues undergo large torsion angle changes, resulting in a 34° rotation of the C-terminal domain relative to its N-terminal domain around the flexible interdomain linker, without substantial changes of either the conformation of individual domains or the assembly contact interfaces. This knowledge provides new insights to help decipher the mechanism of the retroviral capsid assembly.


Assuntos
Proteínas do Capsídeo/química , Capsídeo/química , Vírus do Sarcoma de Rous/química , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Maleabilidade , Conformação Proteica , Domínios Proteicos
2.
Nature ; 596(7871): 238-243, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34381233

RESUMO

Structured fabrics, such as woven sheets or chain mail armours, derive their properties both from the constitutive materials and their geometry1,2. Their design can target desirable characteristics, such as high impact resistance, thermal regulation, or electrical conductivity3-5. Once realized, however, the fabrics' properties are usually fixed. Here we demonstrate structured fabrics with tunable bending modulus, consisting of three-dimensional particles arranged into layered chain mails. The chain mails conform to complex shapes2, but when pressure is exerted at their boundaries, the particles interlock and the chain mails jam. We show that, with small external pressure (about 93 kilopascals), the sheets become more than 25 times stiffer than in their relaxed configuration. This dramatic increase in bending resistance arises because the interlocking particles have high tensile resistance, unlike what is found for loose granular media. We use discrete-element simulations to relate the chain mail's micro-structure to macroscale properties and to interpret experimental measurements. We find that chain mails, consisting of different non-convex granular particles, undergo a jamming phase transition that is described by a characteristic power-law function akin to the behaviour of conventional convex media. Our work provides routes towards lightweight, tunable and adaptive fabrics, with potential applications in wearable exoskeletons, haptic architectures and reconfigurable medical supports.


Assuntos
Fenômenos Mecânicos , Têxteis , Exoesqueleto Energizado , Humanos , Maleabilidade , Pressão , Resistência à Tração , Dispositivos Eletrônicos Vestíveis
3.
J Mech Behav Biomed Mater ; 122: 104658, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34214922

RESUMO

AIM: The aim of this study was to investigate whether there is a relation between impact strength and flexural strength of different composite and ceramic materials used in dental restorations. MATERIALS AND METHODS: The three-point-bending test was used to determine the flexural strength and flexural modulus, and the Dynstat impact test was used to determine the impact strength of different composite and ceramic dental materials. The relation between the flexural strength and impact strength was mathematically investigated and a three-dimensional finite element analysis model of the impact test set-up was created to verify these results. RESULTS: We found a relation between the impact strength, adU, the flexural strength, σ, and the flexural modulus, E, which can be represented by the formula: adU=λDK(σ2/E), where λDK is a constant dependent on the test set-up. CONCLUSION: The obtained impact strength of materials is specific to the test set-up and dependent on the geometric configuration of the test set-up and the specimen thickness. The clinical significance of this investigation is that roughness and fatigue have far more influence on the impact strength than the flexure strength.


Assuntos
Cerâmica , Resistência à Flexão , Materiais Dentários , Porcelana Dentária , Humanos , Teste de Materiais , Maleabilidade , Propriedades de Superfície
4.
ACS Appl Mater Interfaces ; 13(25): 29780-29787, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34128631

RESUMO

To meet the increasing demand for wearable sensing devices, flexible supercapacitors (SCs) as energy storage devices play significant roles in powering sensors/biosensors for healthcare monitoring. Because of its high conductivity and remarkable specific capacitance in SCs, molybdenum nitride (MoN) has been widely used. Herein, a flexible helical structure of MoN modified on nitrogen-doped carbon cloth (CC@CN@MoN) has been prepared by a simple nitride process, delivering an ultralong cycle life of 10,000 cycles and high areal capacitance of 467.6 mF cm-2 as SCs. Moreover, the as-fabricated flexible all-solid-state asymmetrical SCs (ASCs) of CC@CN@MoN//CC@NiCo2O4 demonstrated outstanding electrochemical behavior after 10,000 cycles and over 90% retention, and the value of areal capacitance could reach 90.8 mF cm-2 at 10 mA cm-2. Integrated with solar energy, ASCs could be used as a self-powered energy system for strain sensors in detecting human movement, and finger movements could be further real-time monitored remotely via a smartphone. Prospectively, wearable helical MoN solid-state SCs for self-powered strain smartsensors would inspire the development of structured materials in the application of energy storage, portable self-powering, and strain or chemical/biochemical smartsensors.


Assuntos
Molibdênio/química , Monitorização Fisiológica/instrumentação , Dispositivos Eletrônicos Vestíveis , Equipamentos e Provisões Elétricas , Desenho de Equipamento , Humanos , Maleabilidade , Smartphone
5.
ACS Appl Mater Interfaces ; 13(26): 31285-31297, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34170664

RESUMO

Wearable superwettable surfaces with dynamic tunable wettability and self-healability are promising for advanced wearable electronics, whereas have been rarely reported. Herein, a flexible superhydrophobic shape memory film (SSMF) with switchable surface wettability and high strain sensitivity has been conveniently fabricated. The surface topography of the SSMF can be finely adjusted by a reversible stretching (bending)/recovery way, which makes it feasible to control the surface-switchable adhesive superhydrophobicity by simple body movements, demonstrating great advantages in selective droplet manipulation and smart control of droplet movement. Moreover, benefitting from the hierarchical micro/nanostructures and outstanding sensing performance, the flexible SSMFs with good adaptivity and durability can serve as smart wearable sensors attached to human skin to achieve full-range and real-time detection of human motions and intelligent control of Internet of Things. More interestingly, the unique dynamic dewetting property enables the sensors to work in a humid environment or rainy days. Overall, this work successfully integrates dynamic tunable superwettability into design of intelligent wearable electronics with multifunctions. The obtained SSMF-based wearable surface with dynamic dewetting properties reveals great potential in versatile application fields such as liquid-repellent electronics, wearable droplet manipulators, and all-weather intelligent actuators.


Assuntos
Materiais Inteligentes/química , Dispositivos Eletrônicos Vestíveis , Condutividade Elétrica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Monitorização Fisiológica/métodos , Movimento , Nanotubos de Carbono/química , Nanofios/química , Maleabilidade , Poliésteres/química , Poliuretanos/química , Prata/química , Molhabilidade
6.
J Dent ; 110: 103682, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33933556

RESUMO

OBJECTIVES: The study aimed to find a relationship between the most common standards used in testing resin-based materials (RBC) in a three-point bend test - ISO 4049 and NIST 4877 - using a size-strength relationship defined by the Weibull model. The direct comparison of calculated and measured data is used for validation. METHODS: 280 (n = 20) specimens were prepared from seven different light-cured RBCs. The flexural strength, FS, and modulus, E, were measured with a span of 12 mm (NIST) or 20 mm (ISO). A fractographic analysis determined the origin of fracture. One and multiple-way analysis of variance (ANOVA), the Tukey honestly significant difference (HSD) post-hoc tests (α = 0.05), Weibull statistics and Pearson correlation analysis were used for data analysis. RESULTS: Calculated data approximate the measured data very well. FS measured according to ISO is 11 % lower and E is 17 % higher than the NIST data. The test method influenced the properties measured, but not the material ranking or the fracture mode. Fractures originated from volume defects (sub-surface) were the most common type of fracture. CONCLUSIONS: Weibull analysis is successful to predict the scaling of strengths to other configurations in RBCs. CLINICAL SIGNIFICANCE: The need to limit the sample size of RBCs up to the dimensions of their clinical use can benefit from the use of Weibull statistics. Weibull size-strength relationship and fractographic analysis can help to better assess the clinical behaviour of the RBCs, calculate the reliability of a restoration, and assess the nature of the flaws in the material.


Assuntos
Resinas Compostas , Resistência à Flexão , Materiais Dentários , Análise do Estresse Dentário , Teste de Materiais , Maleabilidade , Reprodutibilidade dos Testes , Propriedades de Superfície
7.
J Mech Behav Biomed Mater ; 120: 104591, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34052729

RESUMO

This study utilized a statistical nanoindentation analysis technique (SNT) to measure the amount of organic and inorganic constituents of twenty different brands of dental resin-based composites (RBCs) and tested whether their macro-property such as flexural modulus could be approximated by the proportions of constituents' micromechanical signatures using various rules of mixtures. The probability density function (PDF) of constitutive moduli per RBC brand were measured for three groups, comprised of different indent arrays and inter-indent spacings. SNT was then applied to deconvolute each PDF, from which the effective filler (µF) and matrix (µM) moduli and filler (VF) and matrix (VM) volume fractions per RBC brand were computed. VF and VM values obtained via SNT were strongly correlated with VF and VM obtained via Thermogravimetric Analysis and Archimedes method. The "observed" flexural modulus (EcFS) measured under macro-experiment were well associated with "predicted" effective modulus (EcEff) measured under nano-experiment, thereby establishing that global modulus was strongly affected by the constituents' micromechanics. However, the "predicted" EcEff were proportionally higher than the "observed" EcFS. VF was a confounder to EcFS and EcEff, whereby the influence of VF on both modular ratios (EcFS/µM and EcEff/µM) was best modeled by an exponential regression.


Assuntos
Resinas Compostas , Materiais Dentários , Módulo de Elasticidade , Teste de Materiais , Maleabilidade , Propriedades de Superfície
8.
Biomed Res Int ; 2021: 9927498, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33954204

RESUMO

Background: Sepsis is a potentially lethal complication for both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL). This study is aimed at comparing the sepsis rate after fURS and PCNL and the risk factors for sepsis in patients with solitary proximal ureteral stone. Methods: We reviewed the data of patients with calculi between 10 mm to 20 mm who underwent fURS or PCNL surgery from Tongji Hospital's database. A total of 910 patients were eligible with 412 fURS cases and 498 PCNL cases. We used univariate analysis and multivariate logistic regression analysis to identify the risk factors for sepsis. Subgroup analysis was performed using logistic regression analysis. Results: In the cohort, 27 (6.6%) and 19 (3.8%) patients developed sepsis after fURS and PCNL, respectively. Multivariate analysis shows that the risk factors for sepsis are fURS (OR = 3.160, P = 0.004), serum WBC ≥ 10,000 cells/µL (OR = 3.490, P = 0.008), albumin - globulin ratio < 1.2 (OR = 2.192, P = 0.029), positive urine culture (OR = 6.145, P < 0.001), and prolonged operation time (OR = 1.010, P = 0.046). Subgroup analysis was conducted using potential risk factors: stone size, serum WBC, urine culture, and albumin-globulin ratio (AGR). In subgroup of positive urine culture, patients were more likely to develop sepsis after fURS than PCNL. Conclusions: PCNL may be a better choice than fURS to reduce postoperative sepsis, especially for patients with positive urine culture.


Assuntos
Nefrolitotomia Percutânea/efeitos adversos , Sepse/epidemiologia , Sepse/etiologia , Cálculos Ureterais/cirurgia , Cálculos Ureterais/urina , Ureteroscopia/efeitos adversos , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Maleabilidade , Fatores de Risco
9.
Proteins ; 89(9): 1158-1166, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33893649

RESUMO

The 2019-novel coronavirus also known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is a common threat to animals and humans, and is responsible for the human SARS pandemic in 2019 to 2021. The infection of SARS-CoV-2 in humans involves a viral surface glycoprotein named as spike proteins, which bind to the human angiotensin-converting enzyme 2 (ACE2) proteins. Particularly, the receptor binding domains (RBDs) mediate the interaction and contain several disordered regions, which help in the binding. Investigations on the influence of disordered residues/regions in stability and binding of spike protein with ACE2 help to understand the disease pathogenesis, which has not yet been studied. In this study, we have used molecular-dynamics simulations to characterize the structural changes in disordered regions of the spike protein that result from ACE2 binding. We observed that the disordered regions undergo disorder-to-order transition (DOT) upon binding with ACE2, and the DOT residues are located at functionally important regions of RBD. Although the RBD is having rigid structure, DOT residues make conformational rearrangements for the spike protein to attach with ACE2. The binding is strengthened via hydrophilic and aromatic amino acids mainly present in the DOTs. The positively correlated motions of the DOT residues with its nearby residues also explain the binding profile of RBD with ACE2, and the residues are observed to be contributing more favorable binding energies for the spike-ACE2 complex formation. This study emphasizes that intrinsically disordered residues in the RBD of spike protein may provide insights into its etiology and be useful for drug and vaccine discovery.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/tratamento farmacológico , COVID-19/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Humanos , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Maleabilidade , Ligação Proteica , Eletricidade Estática
10.
Anesth Analg ; 133(1): 151-159, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33835077

RESUMO

BACKGROUND: While flexible epidural catheters reduce the risk of paresthesia and intravascular cannulation, they may be more challenging to advance beyond the tip of a Tuohy needle. This may increase placement time, number of attempts, and possibly complications when establishing labor analgesia. This study investigated the ability to advance flexible epidural catheters through different epidural needles from 2 commonly used, commercially available, epidural kits. METHODS: We hypothesized that the multiorifice wire-reinforced polyamide nylon blend epidural catheters will have a higher rate of successful first attempt insertion than the single-end hole wire-reinforced polyurethane catheters for the establishment of labor analgesia. The primary outcome was a difference in proportions of failure to advance the epidural catheter between the 2 epidural kits and was tested by a χ2 test. Two-hundred forty epidural kits were collected (n = 120/group) for 240 laboring patients requesting epidural analgesia in this open-label clinical trial from November 2018 to September 2019. Two-week time intervals were randomized for the exclusive use of 1 of the 2 kits in this study, where all patients received labor analgesia through either the flexible epidural catheter "A" or the flexible epidural catheter "B." Engineering properties of the equipment used were then determined. RESULTS: Flexible epidural catheter "A," the single-end hole wire-reinforced polyurethane catheter, did not advance at the first attempt in 15% (n = 18 of 120) of the parturients compared to 0.8% (n = 1 of 120) of the catheter "B," the multiorifice wire-reinforced polyamide nylon blend epidural catheter (P < .0001). Twenty-five additional epidural needle manipulations were recorded in the laboring patients who received catheter "A," while 1 epidural needle manipulation was recorded in the parturients who received catheter "B" (P < .0001). Bending stiffness of the epidural catheters used from kit "B" was twice the bending stiffness of the catheters used from kit "A" (bending stiffness catheters "A" 0.64 ± 0.04 N·mm2 versus bending stiffness catheters "B" 1.28 ± 0.20 N·mm2, P = .0038), and the angle formed by the needle and the epidural catheter from kit "A" was less acute than the angle formed from kit "B" (kit "A" 14.17 ± 1.72° versus kit "B" 21.83 ± 1.33°, P = .0036), with a mean difference of 7.66° between the 2 kits' angles. CONCLUSIONS: The incidence of an inability to advance single-end hole wire-reinforced polyurethane catheter was higher compared to the use of multiorifice wire-reinforced polyamide nylon blend epidural catheter. Variation of morphological features of epidural needles and catheters may play a critical role in determining the successful establishment of labor epidural analgesia.


Assuntos
Analgesia Epidural/instrumentação , Analgésicos/administração & dosagem , Cateteres , Desenho de Equipamento/instrumentação , Trabalho de Parto/efeitos dos fármacos , Maleabilidade , Adulto , Analgesia Epidural/métodos , Desenho de Equipamento/métodos , Feminino , Humanos , Trabalho de Parto/fisiologia , Gravidez , Estudos Prospectivos
11.
Carbohydr Polym ; 263: 117977, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33858574

RESUMO

We prepared a self-dispersed cellulose-based microgel via chemically bonding hydrophilic gelatin peptide chain onto cellulose glucose chain. Following, a variety of highly transparent, foldable, and writable photoluminescent polymer films was obtained through loading organic dyes and inorganic pigments onto cellulose-based microgel matrix, respectively. Benefiting from the coupling sites and network effect of microgel as well as the abundant hydroxyl, amino, and imino groups in its structure, the microgel containing organic dyes and inorganic pigments exhibit good dispersion and stability, and the resultant photoluminescent films emit bright yellow, orange, yellow-green, and blue-green fluorescence under UV light, respectively, especially the cellulose-based microgel stabilized inorganic alkaline earth aluminate hybrids exhibit continuous luminescence for a long time in the dark. Compared with the existing regenerated cellulose or CNCs-based fluorescent films, the cellulose-based microgel fluorescent films present higher transmittance and good biodegradability. This study can bring new ideas for the development of flexible luminescent devices.


Assuntos
Celulose/síntese química , Corantes Fluorescentes/química , Microgéis/química , Polímeros/síntese química , Plásticos Biodegradáveis , Celulose/química , Gelatina/química , Interações Hidrofóbicas e Hidrofílicas , Luminescência , Fenômenos Mecânicos , Processos Fotoquímicos , Maleabilidade , Polímeros/química , Espectrometria de Fluorescência , Raios Ultravioleta
13.
ACS Appl Mater Interfaces ; 13(13): 15727-15737, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33779131

RESUMO

Healthcare monitoring, especially for respiration, has attracted tremendous attention from academics considering the great significance of health information feedback. The respiratory rate, as a critical health indicator, has been used to screen and evaluate potential illness risks in early medical diagnoses. A self-powered sensing system for medical monitoring is critical and imperative due to needless battery replacement and simple assembly. However, the development of a self-powered respiratory sensor with highly sensitive performance is still a daunting challenge. In this work, a compressible and stretchable magnetoelectric sensor (CSMS) with an arch-shaped air gap is reported, enabling self-powered respiratory monitoring driven by exhaled/inhaled breath. The CSMS contains two key functional materials: liquid metals and magnetic powders both with low Young's modulus, allowing for sensing compressibility and stretchability simultaneously. More importantly, such a magnetoelectric sensor exhibits mechanoelectrical converting capacity under an external force, which has been verified by Maxwell numerical simulation. Owing to the air-layer introduction, the magnetoelectric sensors achieve high sensitivity (up to 17.73 kPa-1), fast response, and long-term stability. The highly sensitive and self-powered magnetoelectric sensor can be further applied as a noninvasive, miniaturized, and portable respiratory monitoring system with the aim of warning for potential health risks. We anticipate that this technique will create an avenue for self-powered respiratory monitoring fields.


Assuntos
Taxa Respiratória , Dispositivos Eletrônicos Vestíveis , Força Compressiva , Elasticidade , Fontes de Energia Elétrica , Desenho de Equipamento , Humanos , Monitorização Fisiológica/instrumentação , Maleabilidade
14.
Dent Mater ; 37(6): e360-e374, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33663884

RESUMO

OBJECTIVE: To characterize and investigate efficacy of loading functionalized ZrO2 nanoparticles in 3-dimensional (3D) printed acrylate ester-based resin subjected to accelerated aging in artificial saliva. As well as to evaluate the effect of ZrO2 nanoparticle volume fraction addition on mechanical and physical properties of printed composite. METHODS: Functionalized ZrO2 nanoparticles were characterized using TEM and Raman spectroscopy. 3D printed dental resin was reinforced, with ZrO2 nanoparticles, in the concentration range (0-5wt.%). The resulted nanocomposites, in term of structure and physical/mechanical properties were evaluated using different mechanical testing, microscopic and spectroscopic techniques. RESULTS: ZrO2 based nanocomposite was successful and formed composites were more ductile. Degree of conversion was significant at the highest level with blank resin and 1wt.%. Sorption revealed reduction associated with volume fraction significant to neat resin, however solubility indicated neat and 4wt.% had the lowest significant dissolution. Vickers represented critical positive correlation with filler content, while nanohardness and elasticity behaved symmetrically and had the maximum strength at 3wt.% addition. In addition, 3wt.% showed the highest fracture toughness and modulus. Improvement of flexural strength was significantly linked to filler concentration. Overall properties dramatically were enhanced after 3 months aging in artificial saliva, especially degree of conversion, microhardness, nanoindentation/elasticity, and flexural modulus. However, significant reduction was observed with flexural modulus and fracture toughness. SIGNIFICANCE: The outcomes suggest that the newly developed 3D printed nanocomposites modified with ZrO2 nanoparticle have the superior potential and efficacy as long-term provisional dental restoration materials.


Assuntos
Resinas Compostas , Nanopartículas , Materiais Dentários , Teste de Materiais , Maleabilidade , Impressão Tridimensional , Propriedades de Superfície
15.
Nature ; 591(7849): 240-245, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33692559

RESUMO

Displays are basic building blocks of modern electronics1,2. Integrating displays into textiles offers exciting opportunities for smart electronic textiles-the ultimate goal of wearable technology, poised to change the way in which we interact with electronic devices3-6. Display textiles serve to bridge human-machine interactions7-9, offering, for instance, a real-time communication tool for individuals with voice or speech difficulties. Electronic textiles capable of communicating10, sensing11,12 and supplying electricity13,14 have been reported previously. However, textiles with functional, large-area displays have not yet been achieved, because it is challenging to obtain small illuminating units that are both durable and easy to assemble over a wide area. Here we report a 6-metre-long, 25-centimetre-wide display textile containing 5 × 105 electroluminescent units spaced approximately 800 micrometres apart. Weaving conductive weft and luminescent warp fibres forms micrometre-scale electroluminescent units at the weft-warp contact points. The brightness between electroluminescent units deviates by less than 8 per cent and remains stable even when the textile is bent, stretched or pressed. Our display textile is flexible and breathable and withstands repeated machine-washing, making it suitable for practical applications. We show that an integrated textile system consisting of display, keyboard and power supply can serve as a communication tool, demonstrating the system's potential within the 'internet of things' in various areas, including healthcare. Our approach unifies the fabrication and function of electronic devices with textiles, and we expect that woven-fibre materials will shape the next generation of electronics.


Assuntos
Terminais de Computador , Eletrônica/instrumentação , Têxteis , Humanos , Maleabilidade , Dispositivos Eletrônicos Vestíveis
16.
J Mol Biol ; 433(9): 166901, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33647290

RESUMO

Striated muscle responds to mechanical overload by rapidly up-regulating the expression of the cardiac ankyrin repeat protein, CARP, which then targets the sarcomere by binding to titin N2A in the I-band region. To date, the role of this interaction in the stress response of muscle remains poorly understood. Here, we characterise the molecular structure of the CARP-receptor site in titin (UN2A) and its binding of CARP. We find that titin UN2A contains a central three-helix bundle fold (ca 45 residues in length) that is joined to N- and C-terminal flanking immunoglobulin domains by long, flexible linkers with partial helical content. CARP binds titin by engaging an α-hairpin in the three-helix fold of UN2A, the C-terminal linker sequence, and the BC loop in Ig81, which jointly form a broad binding interface. Mutagenesis showed that the CARP/N2A association withstands sequence variations in titin N2A and we use this information to evaluate 85 human single nucleotide variants. In addition, actin co-sedimentation, co-transfection in C2C12 cells, proteomics on heart lysates, and the mechanical response of CARP-soaked myofibrils imply that CARP induces the cross-linking of titin and actin myofilaments, thereby increasing myofibril stiffness. We conclude that CARP acts as a regulator of force output in the sarcomere that preserves muscle mechanical performance upon overload stress.


Assuntos
Actinas/química , Actinas/metabolismo , Conectina/química , Conectina/metabolismo , Proteínas Musculares/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Reagentes para Ligações Cruzadas/química , Reagentes para Ligações Cruzadas/metabolismo , Masculino , Camundongos , Proteínas Musculares/química , Proteínas Musculares/genética , Mutação , Miofibrilas/química , Miofibrilas/metabolismo , Ressonância Magnética Nuclear Biomolecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Maleabilidade , Ligação Proteica , Coelhos , Proteínas Repressoras/química , Proteínas Repressoras/genética , Sarcômeros/química , Sarcômeros/metabolismo
17.
Respir Investig ; 59(3): 350-355, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33518471

RESUMO

BACKGROUND: The role of topical nasal vasoconstrictor administration during flexible bronchoscopy is unclear. METHODS: Consecutive subjects undergoing flexible bronchoscopy were randomized to receive either topical xylometazoline (0.1%) or placebo (saline nasal spray, 0.74% w/v isotonic solution) before bronchoscopy. Background topical anesthesia included 2% nasal lignocaine gel, pharyngeal spray of 10% lignocaine, and 1% lignocaine solution for spray-as-you-go administration. The primary outcome was the operator rated ease of nasal negotiation of the bronchoscope on the visual analog scale (Negotiation VAS). Secondary objectives included assistant rated facial pain scale score, patient-rated nasal pain score (Pain VAS), time to reach the vocal cords after bronchoscope insertion, operator rated nasal mucosal trauma score (Trauma VAS), hemodynamic changes, and complications between the groups. RESULTS: In all, 148 subjects were recruited and randomized to the placebo (73) and xylometazoline groups (75). Operator rated ease of nasal bronchoscope negotiation (Negotiation VAS) was similar in both the groups [Median (IQR), 1 (1-2) in both groups, p = 0.79]. There were no differences in the other outcomes including assistant rated score of facial pain [(Median (IQR), 2 (2-4) placebo and 2 (2-4) xylometazoline, p = 0.36], Pain VAS [Median (IQR), placebo 2 (1-2) and xylometazoline 2 (1-3), p = 0.28], Trauma VAS, [Median (IQR), placebo 1 (0-2) and xylometazoline 1 (0-1), p = 0.28], hemodynamic changes, or complications between the two groups. CONCLUSION: The findings of this study do not support the administration of topical nasal xylometazoline in flexible bronchoscopy. TRIAL REGISTRY: Trial registered on Clinicaltrials.gov, www.clinicaltrials.govNCT03424889, on January 02, 2018.


Assuntos
Broncoscopia/métodos , Dor Facial/prevenção & controle , Imidazóis/administração & dosagem , Complicações Intraoperatórias/prevenção & controle , Maleabilidade , Vasoconstritores/administração & dosagem , Adulto , Broncoscopia/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sprays Nasais , Resultados Negativos
18.
ACS Appl Mater Interfaces ; 13(8): 10301-10312, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33591732

RESUMO

Polymer thin films containing fluorine are attracting much attention in various high-tech industries owing to their transparency, flexibility, and excellent water repellency. However, the generation of static electricity due to high electrical resistance limits their application. In this study, highly transparent and flexible Cu-plasma-polymerized fluorocarbon (PPFC) nanocomposite thin films that exhibit hydrophobicity and antistatic properties are proposed. These films, obtained using the mid-range frequency sputtering, exhibited a light transmittance of 84.2%, a water contact angle of 94.6°, and a sheet resistance of 1.2 × 1012 Ω/□. Transmission electron microscopy and small angle X-ray scattering confirmed that Cu nanoparticles with an average size of 4-5 nm were distributed uniformly in the PPFC matrix. In repeated fatigue bending tests, the Cu-PPFC nanocomposite thin films exhibited excellent mechanical robustness and flexibility. Antiviral properties of the Cu-PPFC nanocomposite thin films were evaluated against influenza A virus, and the number decreased by 96.9% after 30 min. Carbon nanotube-Cu-polytetrafluoroethylene composite targets are advantageous for large-area coating and mass production because they can be applied in large-area sputtering and roll-to-roll processes. The transparency, charging characteristics, and water repellency can be easily controlled in Cu-PPFC nanocomposite thin films by controlling the sputtering power density according to the required product. Therefore, these films can be applied in various industries such as flexible displays, medical, automobiles, functional textiles, and aerospace.


Assuntos
Substâncias Antieletricidade Estática/farmacologia , Antivirais/farmacologia , Cobre/farmacologia , Polímeros de Fluorcarboneto/farmacologia , Membranas Artificiais , Nanocompostos/química , Substâncias Antieletricidade Estática/química , Antivirais/química , Cobre/química , Polímeros de Fluorcarboneto/química , Interações Hidrofóbicas e Hidrofílicas , Vírus da Influenza A/efeitos dos fármacos , Nanotubos de Carbono/química , Gases em Plasma/química , Maleabilidade , Polimerização , Água/química
19.
ACS Appl Mater Interfaces ; 13(8): 10013-10025, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33595267

RESUMO

Wearable electronic textiles are used in sensors, energy-harvesting devices, healthcare monitoring, human-machine interfaces, and soft robotics to acquire real-time big data for machine learning and artificial intelligence. Wearability is essential while collecting data from a human, who should be able to wear the device with sufficient comfort. In this study, reduced graphene oxide (rGO) and silver nanowires (AgNWs) were supersonically sprayed onto a fabric to ensure good adhesiveness, resulting in a washable, stretchable, and wearable fabric without affecting the performance of the designed features. This rGO/AgNW-decorated fabric can be used to monitor external stimuli such as strain and temperature. In addition, it is used as a heater and as a supercapacitor and features an antibacterial hydrophobic surface that minimizes potential infection from external airborne viruses or virus-containing droplets. Herein, the wearability, stretchability, washability, mechanical durability, temperature-sensing capability, heating ability, wettability, and antibacterial features of this metallized fabric are explored. This multifunctionality is achieved in a single fabric coated with rGO/AgNWs via supersonic spraying.


Assuntos
Antibacterianos/farmacologia , Grafite/química , Nanofios/química , Prata/farmacologia , Dispositivos Eletrônicos Vestíveis , Antibacterianos/química , Capacitância Elétrica , Escherichia coli/efeitos dos fármacos , Calefação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Maleabilidade , Prata/química , Staphylococcus aureus/efeitos dos fármacos , Termômetros , Ondas Ultrassônicas , Molhabilidade
20.
ACS Appl Mater Interfaces ; 13(9): 11344-11355, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33620195

RESUMO

Hydrogel-based wearable devices have attracted tremendous interest due to their potential applications in electronic skins, soft robotics, and sensors. However, it is still a challenge for hydrogel-based wearable devices to be integrated with high conductivity, a self-healing ability, remoldability, self-adhesiveness, good mechanical strength and high stretchability, good biocompatibility, and stimulus-responsiveness. Herein, multifunctional conductive composite hydrogels were fabricated by a simple one-pot method based on poly(vinyl alcohol) (PVA), sodium alginate (SA), and tannic acid (TA) using borax as a cross-linker. The composite hydrogel network was built by borate ester bonds and hydrogen bonds. The obtained hydrogel exhibited pH- and sugar-responsiveness, high stretchability (780% strain), and fast self-healing performance with healing efficiency (HE) as high as 93.56% without any external stimulus. Additionally, the hydrogel displayed considerable conductive behavior and stable changes of resistance with high sensitivity (gauge factor (GF) = 15.98 at a strain of 780%). The hydrogel was further applied as a strain sensor for monitoring large and tiny human motions with durable stability. Significantly, the healed hydrogel also showed good sensing behavior. This work broadens the avenue for the design and preparation of biocompatible polymer-based hydrogels to promote the application of hydrogel sensors with comfortable wearing feel and high sensitivity.


Assuntos
Alginatos/química , Hidrogéis/química , Monitorização Fisiológica/instrumentação , Movimento , Álcool de Polivinil/química , Dispositivos Eletrônicos Vestíveis , Boratos/química , Condutividade Elétrica , Humanos , Monitorização Fisiológica/métodos , Maleabilidade , Taninos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...