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Controlling the growth of material is crucial in material processing for desired properties. Current approaches often involve sophisticated equipment for controlling precursors and monitoring material formation. Here we report a self-limiting material growth mechanism controlled by the experienced mechanical loading without the need for precise control over precursors or monitoring material growth. Material formation that reduces the driving force for growth is hypothesized to result in a saturation thickness that is dependent on the maximum driving force. Analytical relations based on the growth model are derived and verified using a piezoelectric substrate immersed in an electrolyte solution under fixed frequency cyclic loading to attract surrounding mineral ions to form mineral layers. Accumulating mineral layers decrease the driving force for further growth and the material eventually reaches a saturation thickness. This allows for loading force to control the saturation thickness of the self-limiting material growth. Experimental data supports the predicted exponential relations, offering guides to predict the saturation thickness and control the growth profile. The findings are envisioned to contribute to the fundamental understanding of the self-limiting material growth mechanism and could benefit a range of applications including coatings for orthopedic implants as well as marine surface and underwater vehicles.
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OBJECTIVES: Familism is a core ideology in Chinese society, yet it has been understudied in this cultural context, potentially attributed to the lack of quantifiable measures. This study sought to develop a reliable and valid scale, the Contemporary Chinese Familism Scale (CCFS), to assess Chinese familism and analyze its structural and psychological characteristics in contemporary China. METHOD: The scale development and validation process comprised four studies: in Study 1, literature review, qualitative interviews, and item evaluations by experts were conducted to develop the initial item pool for the CCFS; in Studies 2 and 3, item analysis, exploratory and confirmatory factor analyses, competing model comparisons, and measurement invariance tests were conducted to examine the structure underlying familism (N1 = 958, Mage = 25.4 years; N2 = 570, Mage = 32.01 years); in Study 4, reliability and validity assessments were conducted to further explore the psychometric properties of the final 27-item CCFS using three samples (N2 = 570, Mage = 32.01 years; N3 = 710, Mage = 22.37 years; N4 = 932, Mage = 40.98 years). RESULT: A bifactor structure with one general factor and five specific factors (Connection and Closeness, Offspring and Lineage, Honor and Reference, Harmony and Sacrifice, and Care and Help) demonstrated the best fit for the data and supported the multidimensionality of familism in contemporary China. Subsequent psychometric analyses provided initial evidence for the optimal psychometric properties of the CCFS. CONCLUSION: This study contributes to our understanding of the multifaceted nature of familism in contemporary China by developing a culturally sensitive scale on Chinese familism. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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BACKGROUND: COVID-19 saw an increase in child mental health presentations internationally. Clinicians analogised the exponential increase in anorexia nervosa to a 'tsunami' or 'outbreak', raising parallel concerns regarding medical and psychological risks (Marsh in The Guardian, 2021; Leask in NZ Herald, 2021; Monteleone et al. in Eat Weight Disord 26(8):2443-2452, 2021) . It is unclear whether Ireland emulated this picture of increased referrals with increased medical compromise. AIMS: This paper examines both rates and clinical profiles of child eating disorder presentations in the Republic of Ireland (ROI), across different clinical settings. METHODS: Following ethical approval, retrospective chart reviews were conducted in a community eating disorder service and in two paediatric hospital settings. The time frame of the different studies ranged from January 2016 to December 2022. RESULTS: Community eating disorder services saw significantly higher referral rates post COVID-19 (3.78/month vs. 2.31/month, p = 0.02), with a shorter duration of illness (4.8 months vs. 7.4 months, p = 0.001), but no significant difference in ideal body weight % (IBW%) at referral (85.32% vs. 83.7%, p = 0.1). Both paediatric hospitals witnessed significantly increased referrals post-COVID-19 (hospital 1; 4.38/month vs. 1.93/month, p = 0.0001; hospital 2; 2.8/month vs. 0.92/month, p < 0.0001), but no significant difference in IBW% at assessment (hospital 1; 82.7% vs. 81.39%, p = 0.673; hospital 2; 81.5% vs. 83%, p = 0.563). There was no significant difference in clinical profile, management, or duration of hospital stay. CONCLUSIONS: This study supports the growing consensus of a pandemic specific increase in eating disorder referrals to both medical and psychiatry services. However, there was little to indicate a change in clinical profile or severity. Ongoing monitoring of referrals is necessary to ensure adequate service availability and expertise.
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COVID-19 , Transtornos da Alimentação e da Ingestão de Alimentos , Humanos , COVID-19/epidemiologia , Irlanda/epidemiologia , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Estudos Retrospectivos , Criança , Feminino , Masculino , Adolescente , Encaminhamento e Consulta/estatística & dados numéricos , SARS-CoV-2RESUMO
A material with asymmetric mechanical responses offers diverse potential applications.
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The consumption of small fruits has increased in recent years. Besides their appealing flavor, the commercial success of small fruits has been partially attributed to their high contents of phenolic compounds with multiple health benefits. The phenolic profiles and contents in small fruits vary based on the genetic background, climate, growing conditions, and post-harvest handling techniques. In this review, we critically compare the profiles and contents of phenolics such as anthocyanins, flavonols, flavan-3-ols, and phenolic acids that have been reported in bilberries, blackberries, blueberries, cranberries, black and red currants, raspberries, and strawberries during fruit development and post-harvest storage. This review offers researchers and breeders a general guideline for the improvement of phenolic composition in small fruits while considering the critical factors that affect berry phenolics from cultivation to harvest and to final consumption.
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Antocianinas , Frutas , Frutas/química , Fenóis/análise , Flavonóis , AntioxidantesRESUMO
Robots with submillimeter dimensions are of interest for applications that range from tools for minimally invasive surgical procedures in clinical medicine to vehicles for manipulating cells/tissues in biology research. The limited classes of structures and materials that can be used in such robots, however, create challenges in achieving desired performance parameters and modes of operation. Here, we introduce approaches in manufacturing and actuation that address these constraints to enable untethered, terrestrial robots with complex, three-dimensional (3D) geometries and heterogeneous material construction. The manufacturing procedure exploits controlled mechanical buckling to create 3D multimaterial structures in layouts that range from arrays of filaments and origami constructs to biomimetic configurations and others. A balance of forces associated with a one-way shape memory alloy and the elastic resilience of an encapsulating shell provides the basis for reversible deformations of these structures. Modes of locomotion and manipulation span from bending, twisting, and expansion upon global heating to linear/curvilinear crawling, walking, turning, and jumping upon laser-induced local thermal actuation. Photonic structures such as retroreflectors and colorimetric sensing materials support simple forms of wireless monitoring and localization. These collective advances in materials, manufacturing, actuation, and sensing add to a growing body of capabilities in this emerging field of technology.
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Robótica , Materiais Inteligentes , Biomimética , Locomoção , CaminhadaRESUMO
Microscale programmable shape-memory actuators based on reversible electrochemical reactions can provide exciting opportunities for microrobotics.
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The rigidity and relatively primitive modes of operation of catheters equipped with sensing or actuation elements impede their conformal contact with soft-tissue surfaces, limit the scope of their uses, lengthen surgical times and increase the need for advanced surgical skills. Here, we report materials, device designs and fabrication approaches for integrating advanced electronic functionality with catheters for minimally invasive forms of cardiac surgery. By using multiphysics modelling, plastic heart models and Langendorff animal and human hearts, we show that soft electronic arrays in multilayer configurations on endocardial balloon catheters can establish conformal contact with curved tissue surfaces, support high-density spatiotemporal mapping of temperature, pressure and electrophysiological parameters and allow for programmable electrical stimulation, radiofrequency ablation and irreversible electroporation. Integrating multimodal and multiplexing capabilities into minimally invasive surgical instruments may improve surgical performance and patient outcomes.
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Cateteres Cardíacos , Eletrônica/instrumentação , Monitorização Intraoperatória/instrumentação , Monitorização Intraoperatória/métodos , Animais , Ablação por Cateter , Eletroporação , Desenho de Equipamento , Feminino , Análise de Elementos Finitos , Ventrículos do Coração/cirurgia , Humanos , Pressão , Coelhos , TemperaturaRESUMO
Mechanically guided, 3D assembly has attracted broad interests, owing to its compatibility with planar fabrication techniques and applicability to a diversity of geometries and length scales. Its further development requires the capability of on-demand reversible shape reconfigurations, desirable for many emerging applications (e.g., responsive metamaterials, soft robotics). Here, the design, fabrication, and modeling of soft electrothermal actuators based on laser-induced graphene (LIG) are reported and their applications in mechanically guided 3D assembly and human-soft actuators interaction are explored. Over 20 complex 3D architectures are fabricated, including reconfigurable structures that can reshape among three distinct geometries. Also, the structures capable of maintaining 3D shapes at room temperature without the need for any actuation are realized by fabricating LIG actuators at an elevated temperature. Finite element analysis can quantitatively capture key aspects that govern electrothermally controlled shape transformations, thereby providing a reliable tool for rapid design optimization. Furthermore, their applications are explored in human-soft actuators interaction, including elastic metamaterials with human gesture-controlled bandgap behaviors and soft robotic fingers which can measure electrocardiogram from humans in an on-demand fashion. Other demonstrations include artificial muscles, which can lift masses that are about 110 times of their weights and biomimetic frog tongues which can prey insects.
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Grafite/química , Lasers de Gás , Robótica , Biomimética , Eletromiografia , Dedos/fisiologia , Análise de Elementos Finitos , Humanos , Músculos/fisiologia , Temperatura , Dispositivos Eletrônicos VestíveisRESUMO
In addition to mechanical compliance, achieving the full potential of on-skin electronics needs the introduction of other features. For example, substantial progress has been achieved in creating biodegradable, self-healing, or breathable, on-skin electronics. However, the research of making on-skin electronics with passive-cooling capabilities, which can reduce energy consumption and improve user comfort, is still rare. Herein, we report the development of multifunctional on-skin electronics, which can passively cool human bodies without needing any energy consumption. This property is inherited from multiscale porous polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) supporting substrates. The multiscale pores of SEBS substrates, with characteristic sizes ranging from around 0.2 to 7 µm, can effectively backscatter sunlight to minimize heat absorption but are too small to reflect human-body midinfrared radiation to retain heat dissipation, thereby delivering around 6 °C cooling effects under a solar intensity of 840 Wâ m-2 Other desired properties, rooted in multiscale porous SEBS substrates, include high breathability and outstanding waterproofing. The proof-of-concept bioelectronic devices include electrophysiological sensors, temperature sensors, hydration sensors, pressure sensors, and electrical stimulators, which are made via spray printing of silver nanowires on multiscale porous SEBS substrates. The devices show comparable electrical performances with conventional, rigid, nonporous ones. Also, their applications in cuffless blood pressure measurement, interactive virtual reality, and human-machine interface are demonstrated. Notably, the enabled on-skin devices are dissolvable in several organic solvents and can be recycled to reduce electronic waste and manufacturing cost. Such on-skin electronics can serve as the basis for future multifunctional smart textiles with passive-cooling functionalities.
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A novel strategy for the synthesis of main-chain polymers through radical ring-closing/ring-opening cascade polymerization is reported. Efficient radical cyclopolymerization was achieved through systematic optimization of the electronic properties of 1,6-diene structures. Fusing 1,6-diene with allylic sulfide or allylic sulfone motifs enabled a ring-closing/ring-opening cascade reaction that provides a strong driving force for the ring-opening polymerization of large macrocyclic monomers. The ability of 1,6-diene-fused allylic sulfone to undergo efficient SO2 extrusion generated a propagating alkyl radical capable of reversible deactivation. This strategy provides a general platform for the synthesis of polymers incorporating complex main-chain structures and degradable functionalities.
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Three-dimensional (3D) cellular graphene structures have wide applications in energy storage, catalysis, polymer composites, electromagnetic shielding, and many others. However, the current strategies to form cellular graphene are only able to realize limited structure control and are hard to achieve the construction of 3D hierarchical architectures with complex, programmed configurations, limiting the design capabilities to satisfy various next-generation device applications. In addition, cellular graphene usually exhibits limited electromechanical properties, and its electrical and electrochemical performances are dramatically affected by mechanical deformations, constraining its applications in emerging wearable electronics and energy devices. Herein, we report a simple, general, and effective route to 3D hierarchical architectures of cellular graphene with desired geometries through the use of a mechanically guided, 3D assembly approach to overcome the aforementioned two challenges. Demonstrations include more than 10 3D hierarchical architectures with diverse configurations, ranging from mixed tables and tents, to double-floor helices, to kirigami/origami-inspired structures, and to fully separated multilayer architectures. The LED arrays interconnected with 3D helical coils and 3D interdigital supercapacitors fabricated with solid-state electrolytes provide prototypic examples of wearable devices that exhibit outstanding electromechanical properties and can maintain stable performances with little change in the electrical and electrochemical responses under extreme deformations, in both the static and cyclic loading conditions.
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Condutividade Elétrica , Grafite/química , Fenômenos Mecânicos , Elasticidade , Eletrólitos/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
Soft on-skin electronics have broad applications in human healthcare, human-machine interface, robotics, and others. However, most current on-skin electronic devices are made of materials with limited gas permeability, which constrain perspiration evaporation, resulting in adverse physiological and psychological effects, limiting their long-term feasibility. In addition, the device fabrication process usually involves e-beam or photolithography, thin-film deposition, etching, and/or other complicated procedures, which are costly and time-consuming, constraining their practical applications. Here, a simple, general, and effective approach for making multifunctional on-skin electronics using porous materials with high-gas permeability, consisting of laser-patterned porous graphene as the sensing components and sugar-templated silicone elastomer sponges as the substrates, is reported. The prototype device examples include electrophysiological sensors, hydration sensors, temperature sensors, and joule-heating elements, showing signal qualities comparable to conventional, rigid, gas-impermeable devices. Moreover, the devices exhibit high water-vapor permeability (≈18 mg cm-2 h-1 ), ≈18 times higher than that of the silicone elastomers without pores, and also show high water-wicking rates after polydopamine treatment, up to 1 cm per 30 s, which is comparable to that of cotton. The on-skin devices with such attributes could facilitate perspiration transport and evaporation, and minimize discomfort and inflammation risks, thereby improving their long-term feasiblity.
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Eletrônica/métodos , Gases/química , Grafite/química , Fenômenos Fisiológicos da Pele , Temperatura Corporal , Elastômeros/química , Eletrônica/instrumentação , Humanos , Lasers , Permeabilidade , Porosidade , Açúcares/química , Tampões de Gaze Cirúrgicos , Dispositivos Eletrônicos VestíveisRESUMO
A strategy for the controlled radical ring-opening polymerization of macrocyclic monomers is reported. Key to this approach is an allyl alkylsulfone-based ring-opening trigger that can undergo a radical cascade reaction to extrude sulfur dioxide and generate an alkyl radical for controlled chain propagation. A systematic study correlating reaction conditions with polymer molecular weight and molecular weight distribution allowed excellent control over polymerization. The versatility of this radical cascade-triggered ring-opening polymerization approach was further demonstrated through the first radical block copolymerization of macrocyclic monomers, and the incorporation of degradable functionality into the polymer backbone.