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Histone 2A monoubiquitination (uH2A) underscores a key epigenetic regulation of gene expression. In this report, we show that the deubiquitinase for uH2A, ubiquitin-specific peptidase 16 (USP16), is modified by O-linked N-acetylglucosamine (O-GlcNAc). O-GlcNAcylation involves the installation of the O-GlcNAc moiety to Ser/Thr residues. It crosstalks with Ser/Thr phosphorylation, affects protein-protein interaction, alters enzyme activity or protein folding, and changes protein subcellular localization. In our study, we first confirmed that USP16 is glycosylated on Thr203 and Ser214, as reported in a previous chemoenzymatic screen. We then discovered that mutation of the O-GlcNAcylation site Thr203, which is adjacent to deubiquitination-required Cys204, reduces the deubiquitination activity toward H2AK119ub in vitro and in cells, while mutation on Ser214 had the opposite effects. Using USP16 Ser552 phosphorylation-specific antibodies, we demonstrated that O-GlcNAcylation antagonizes cyclin-dependent kinase 1-mediated phosphorylation and promotes USP16 nuclear export. O-GlcNAcylation of USP16 is also required for deubiquitination of Polo-like kinase 1, a mitotic master kinase, and the subsequent chromosome segregation and cytokinesis. In summary, our study revealed that O-GlcNAcylation of USP16 at Thr203 and Ser214 coordinates deubiquitination of uH2A and Polo-like kinase 1, thus ensuring proper cell cycle progression.
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Acetilglucosamina , Ubiquitina Tiolesterase , Ubiquitinação , Humanos , Acetilglucosamina/metabolismo , Transporte Ativo do Núcleo Celular , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Glicosilação , Células HEK293 , Células HeLa , Histonas/metabolismo , Fosforilação , Quinase 1 Polo-Like , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Ubiquitina Tiolesterase/metabolismo , Ubiquitina Tiolesterase/genéticaRESUMO
AIMS: To identify and synthesise evidence related to ageism in older regulated nurses' practice settings. DESIGN: A systematic review following Joanna Briggs Institute methodology. METHODS: The review included empirical studies that involved older nurses as the primary study population and studies that focused on ageism in older nurses' work environments, including strategies or interventions to address ageism within the workplace. Following the initial screening, all relevant studies were critically appraised by two reviewers to ensure they were appropriate to include in the review. A synthesis without meta-analysis reporting (SWiM) guideline was employed in the review. DATA SOURCES: Medical Literature Analysis and Retrieval Systems Online, Scopus, Psychological Information Database and Cumulative Index to Nursing and Allied Health Literature and Google Scholar were searched to identify empirical studies and a range of academic institutional websites were accessed for master's and doctoral dissertations and theses. The search covered the period from January 2022 to May 2022, and only publications in English from 2000 onwards were considered. RESULTS: Nineteen studies were included, ten qualitative studies, seven quantitative studies and two mixed methods secondary analyses. Our results revealed that negative perceptions and beliefs about older nurses' competencies and skills prevail in their practice settings, which influences older nurses' health and well-being as well as their continuation of practice. Further, older nurses' continuation of practice can be facilitated by having a positive personal outlook on ageing, meaningful relationships in their practice settings and working in an environment that is age-inclusive. CONCLUSION: To combat ageism in older nurses' practice settings and support their continuation of practice, effective interventions should be organisational-led. The interventions should focus on fostering meaningful relationships between older nurses and their colleagues and managers. Further, healthcare institutions should implement initiatives to promote an age-inclusive work environment that supports an age-diverse nursing workforce. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: The review findings offer insights for healthcare managers, policymakers and researchers, emphasising the need for anti-ageism policies in healthcare organisations. According to WHO (2021), educational activities such as role-playing and simulation during in-service training may also be effective interventions. Additionally, incorporating anti-ageism initiatives into staff meetings and mandating anti-ageism training could support the continuation of practice for older nurses while fostering a more age-diverse nursing workforce. IMPACT: We found evidence on the presence of ageism in older nurses' workplace and the detrimental effects of ageism on older nurses' well-being and continuation of practice. Importantly, we identified a lack of organisational initiatives to address ageism and support older nurses. These findings should encourage healthcare organisations to address ageism in older nurses' practice settings and prompt policymakers to develop age-inclusive policies that support older nurses' continuation of practice. REPORTING METHOD: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesis Without Meta-analysis checklists were used to report the screening process. TRIAL AND PROTOCOL REGISTRATION: The PROSPERO registration number for the review was CRD42022320214 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022320214). No Patient or Public Contribution.
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Etarismo , Local de Trabalho , Humanos , Etarismo/psicologia , Local de Trabalho/psicologia , Pessoa de Meia-Idade , Idoso , Atitude do Pessoal de Saúde , Masculino , Feminino , Enfermeiras e Enfermeiros/psicologia , Enfermeiras e Enfermeiros/estatística & dados numéricosRESUMO
Currently, little is known about the characteristics of polyphenol oxidase from wheat bran, which is closely linked to the browning of wheat product. The wheat PPO was purified by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange column, and Superdex G-75 chromatography column. Purified wheat PPO activity was 11.05-fold higher, its specific activity was 1365.12 U/mg, and its yield was 8.46%. SDS-PAGE showed that the molecular weight of wheat PPO was approximately 21 kDa. Its optimal pH and temperature were 6.5 and 35 °C for catechol as substrate, respectively. Twelve phenolic substrates from wheat and green tea were used for analyzing the substrate specificity. Wheat PPO showed the highest affinity to catechol due to its maximum Vmax (517.55 U·mL-1·min-1) and low Km (6.36 mM) values. Docking analysis revealed strong affinities between catechol, gallic acid, EGCG, and EC with binding energies of -5.28 kcal/mol, -4.65 kcal/mol, -4.21 kcal/mol, and -5.62 kcal/mol, respectively, for PPO. Sodium sulfite, ascorbic acid, and sodium bisulfite dramatically inhibited wheat PPO activity. Cu2+ and Ca2+ at 10 mM were considered potent activators and inhibitors for wheat PPO, respectively. This report provides a theoretical basis for controlling the enzymatic browning of wheat products fortified with green tea.
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Catecol Oxidase , Fibras na Dieta , Catecol Oxidase/química , Fibras na Dieta/análise , Concentração de Íons de Hidrogênio , Cinética , Proteínas de Plantas/metabolismo , Catecóis/análise , Especificidade por Substrato , CháRESUMO
Sialylated immunoglobulin G (IgG) is a vital glycoprotein in breast milk with the ability to promote the growth of Bifidobacterium in gut microbiota and relieve inflammatory bowel disease (IBD) symptoms in vitro. Here, it was found that the microcapsules with sialylated IgG could protect and release sialylated IgG with its structure and function in the intestine. Furthermore, the sialylated IgG microcapsules alleviated the clinical symptoms (body weight, feed quantity, and colon length loss), decreased disease activity index score, suppressed the production of pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß, IFN-γ, and MCP-1) and endotoxin (lipopolysaccharide), and enhanced the intestinal mucosal barrier (Claudin1, Muc2, Occludin, and ZO-1) in dextran sulfate sodium (DSS)-induced colitis mice. Additionally, the sialylated IgG microcapsules improved the gut microbiota by increasing the relative abundance of critical microbe Bifidobacterium bifidum and promoted the production of short-chain fatty acids (SCFAs). Correlation analysis indicated that the key microbes were strongly correlated with pro-inflammatory factors, clinical symptoms, tight junction protein, and SCFAs. These findings suggest that the sialylated IgG microcapsules have the potential to be used as a novel therapeutic approach for treating IBD.
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Colite , Doenças Inflamatórias Intestinais , Humanos , Feminino , Animais , Camundongos , Imunoglobulina G , Sulfato de Dextrana/efeitos adversos , Cápsulas , Colite/induzido quimicamente , Colite/tratamento farmacológico , Citocinas , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , ColoRESUMO
Dynamic chromosome remodeling and nuclear compartmentalization take place during mammalian meiotic prophase I. We report here that the crucial roles of male pachynema-specific protein (MAPS) in pachynema progression might be mediated by its liquid-liquid phase separation in vitro and in cellulo. MAPS forms distinguishable liquid phases, and deletion or mutations of its N-terminal amino acids (aa) 2-9 disrupt its secondary structure and charge properties, impeding phase separation. Maps-/- pachytene spermatocytes exhibit defects in nucleus compartmentalization, including defects in forming sex bodies, altered nucleosome composition, and disordered chromatin accessibility. MapsΔ2-9/Δ2-9 male mice expressing MAPS protein lacking aa 2-9 phenocopy Maps-/- mice. Moreover, a frameshift mutation in C3orf62, the human counterpart of Maps, is correlated with nonobstructive azoospermia in a patient exhibiting pachynema arrest in spermatocyte development. Hence, the phase separation property of MAPS seems essential for pachynema progression in mouse and human spermatocytes.
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Cromatina , Meiose , Humanos , Masculino , Camundongos , Animais , Cromatina/metabolismo , Estágio Paquíteno , Separação de Fases , Prófase Meiótica I , Espermatócitos/metabolismo , Mamíferos/genéticaRESUMO
Ubiquitination of histone H2A at lysine 119 residue (H2AK119ub) plays critical roles in a wide range of physiological processes, including Polycomb gene silencing 1,2 , replication 3-5 , DNA damage repair 6-10 , X inactivation 11,12 , and heterochromatin organization 13,14 . However, the underlying mechanism and structural basis of H2AK119ub remains largely elusive. In this study, we report that H2AK119ub nucleosomes have a unique composition, containing histone variants H2BC1 and H2AZ.2, and importantly, this composition is required for H2AK119ub and Polycomb gene silencing. Using the UAB domain of RSF1, we purified H2AK119ub nucleosomes to a sufficient amount and purity. Mass spectrometry analyses revealed that H2AK119ub nucleosomes contain the histone variants H2BC1 and H2AZ.2. A cryo-EM study resolved the structure of native H2AK119ub nucleosomes to a 2.6A resolution, confirming H2BC1 in one subgroup of H2AK119ub nucleosomes. Tandem GST-UAB pulldown, Flag-H2AZ.2, and HA-H2BC1 immunoprecipitation revealed that H2AK119ub nucleosomes could be separated into distinct subgroups, suggesting their composition heterogeneity and potential dynamic organization. Knockout or knockdown of H2BC1 or H2AZ.2 reduced cellular H2AK119ub levels, establishing H2BC1 and H2AZ.2 as critical determinants of H2AK119ub. Furthermore, genomic binding profiles of H2BC1 and H2AZ.2 overlapped significantly with H2AK119ub binding, with the most significant overlapping in the gene body and intergenic regions. Finally, assays in developing embryos reveal an interaction of H2AZ.2, H2BC1, and RING1A in vivo . Thus, this study revealed, for the first time, that the H2AK119ub nucleosome has a unique composition, and this composition is required for H2AK119ub and Polycomb gene silencing.
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Polycomb group (PcG) proteins are key regulators of gene expression and developmental programs via covalent modification of histones, but the factors that interpret histone modification marks to regulate embryogenesis are less studied. We previously identified Remodeling and Spacing Factor 1 (RSF1) as a reader of histone H2A lysine 119 ubiquitination (H2AK119ub), the histone mark deposited by Polycomb Repressive Complex 1 (PRC1). In the current study, we used Xenopus laevis as a model to investigate how RSF1 affects early embryonic development and whether recognition of H2AK119ub is important for the function of RSF1. We showed that knockdown of Xenopus RSF1, rsf1, not only induced gastrulation defects as reported previously, but specific targeted knockdown in prospective neural precursors induced neural and neural crest defects, with reductions of marker genes. In addition, similar to knockdown of PRC1 components in Xenopus, the anterior-posterior neural patterning was affected in rsf1 knockdown embryos. Binding of H2AK119ub appeared to be crucial for rsf1 function, as a construct with deletion of the UAB domain, which is required for RSF1 to recognize the H2AK119ub nucleosomes, failed to rescue rsf1 morphant embryos and was less effective in interfering with early Xenopus development when ectopically expressed. Furthermore, ectopic deposition of H2AK119ub on the Smad2 target gene gsc using a ring1a-smad2 fusion protein led to ectopic recruitment of RSF1. The fusion protein was inefficient in inducing mesodermal markers in the animal region or a secondary axis when expressed in the ventral tissues. Taken together, our results reveal that rsf1 modulates similar developmental processes in early Xenopus embryos as components of PRC1 do, and that RSF1 acts at least partially through binding to the H2AK119ub mark via the UAB domain during development.
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The study analyzed the impact of oxygen defects and S-scheme heterojunction on the performance and stability of WO2.72/Zn0.5Cd0.5S-DETA (WO/ZCS) nanocomposites photocatalysts for hydrogen evolution. Results showed that ZCS alone under visible light had good photocatalytic hydrogen evolution activity (1.762 mmol g-1h-1) and stability (79.5 % activity retention rate after seven cycles, 21 h). The WO3/ZCS nanocomposites with S-scheme heterojunction had better hydrogen evolution activity (2.287 mmol g-1h-1), but poor stability (41.6 % activity retention rate). The WO/ZCS nanocomposites with S-scheme heterojunction and oxygen defects showed excellent photocatalytic hydrogen evolution activity (3.94 mmol g-1h-1) and stability (89.7 % activity retention rate). The specific surface area measurement and ultraviolet-visible spectroscopy diffuse reflectance spectroscopy indicate that oxygen defects lead to larger specific surface area and improved light absorption, respectively. The charge density difference confirms the existence of the S-scheme heterojunction and the amount of charge transfer, which accelerates the separation of photogenerated electron-hole pairs and enhances the utilization efficiency of light and charge. This study offers a new approach using the synergistic impact of oxygen defects and S-scheme heterojunction to enhance the photocatalytic hydrogen evolution activity and stability.
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Ubiquitin-specific peptidase 16 (USP16) is a deubiquitinase that plays a role in the regulation of gene expression, cell cycle progression, and various other functions. It was originally identified as the major deubiquitinase for histone H2A and has since been found to deubiquitinate a range of other substrates, including proteins from both the cytoplasm and nucleus. USP16 is phosphorylated when cells enter mitosis and dephosphorylated during the metaphase/anaphase transition. While much of USP16 is localized in the cytoplasm, separating the enzyme from its substrates is considered an important regulatory mechanism. Some of the functions that USP16 has been linked to include DNA damage repair, immune disease, tumorigenesis, protein synthesis, coronary artery health, and male infertility. The strong connection to immune response and the fact that multiple oncogene products are substrates of USP16 suggests that USP16 may be a potential therapeutic target for the treatment of certain human diseases.
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Histonas , Mitose , Humanos , Masculino , Histonas/metabolismo , Reparo do DNA , Proteases Específicas de Ubiquitina/metabolismo , Enzimas Desubiquitinantes/metabolismoRESUMO
The performance of chemical sensors is dominated by the perception of the target molecules via sensitive materials and the conduction of sensing signals through transducers. However, sensing and transduction are spatially and temporally independent in most chemical sensors, which poses a challenge for device miniaturization and integration. Herein, we proposed a sensing-transducing coupled strategy by embedding the high piezoresponse Sm-PMN-PT ceramic (d33 = â¼1500 pC N-1) into a moisture-sensitive polyetherimide (PEI) polymer matrix via electrospinning to conjugate the humidity perception and signal transduction synchronously and sympatrically. Through phase-field simulation and experimental characterization, we reveal the principle of design of the composition and topological structure of sensing-transducing coupled piezoelectric (STP) textiles in order to modulate the recognition, conversion, and sensitive component utilization ratio of the prepared active humidity sensors, achieving high sensitivity (0.9%/RH%) and fast response (20 s) toward ambient moisture. The prepared STP textile can be worn on the human body to realize emotion recognition, exercise status monitoring, and physiological stress identification. This work offers unprecedented insights into the coupling mechanism between chemisorption-related interfacial state and energy conversion efficiency and opens up a new paradigm for developing autonomous, multifunctional and highly sensitive flexible chemical sensors.
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Dispositivos Eletrônicos Vestíveis , Humanos , Umidade , Monitoramento Biológico , TêxteisRESUMO
Electronic textiles are fundamentally changing the way we live. However, the inability to effectively recycle them is a considerable burden to the environment. In this study, we developed a cotton fiber-based piezoresistive textile (CF p-textile) for biomonitoring which is biocompatible, biodegradable, and environmentally friendly. These CF p-textiles were fabricated using a scalable dip-coating method to adhere MXene flakes to porous cotton cellulose fibers. The adhesion is made stronger by strong hydrogen bonding between MXene flakes and hierarchically porous cotton cellulose fibers. This cotton-fiber system provides a high sensitivity of 17.73 kPa-1 in a wide pressure range (100 Pa-30 kPa), a 2 Pa subtle pressure detection limit, fast response/recovery time (80/40 ms), and good cycle stability (over 5, 000 cycles). With its compelling sensing performance, the CF p-textile can detect various human biomechanical activities, including pulsation, muscle movement, and swallowing, while still being comfortable to wear. Moreover, the cotton cellulose is decomposed into low-molecular weight cellulose or glucose as a result of the 1,4-glycosidic bond breakage when exposed to acid or during natural degradation, which allows the electronic textile to be biodegradable. This work offers an ecologically-benign, cost-effective and facile approach to fabricating high-performance wearable bioelectronics.
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Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Humanos , Fibra de Algodão , Monitoramento Biológico , Têxteis , CeluloseRESUMO
INTRODUCTION: Fluoride is widely presented in drinking water and foods. A strong relation between fluoride exposure and obesity has been reported. However, the potential mechanisms on fluoride-induced obesity remain unexplored. Objectives and methods The effects of fluoride on the obesity were investigated using mice model. Furthermore, the role of gut homeostasis in exacerbation of the obesity induced by fluoride was evaluated. Results The results showed that fluoride alone did not induce obesity in normal diet (ND) fed mice, whereas, it could trigger exacerbation of obesity in high-fat diet (HFD) fed mice. Fluoride impaired intestinal barrier and activated Toll-like receptor 4 (TLR4) signaling to induce obesity, which was further verified in TLR4-/- mice. Furthermore, fluoride could deteriorate the gut microbiota in HFD mice. The fecal microbiota transplantation from fluoride-induced mice was sufficient to induce obesity, while the exacerbation of obesity by fluoride was blocked upon gut microbiota depletion. The fluoride-induced bloom of Erysipelatoclostridium ramosum was responsible for exacerbation of obesity. In addition, a potential strategy for prevention of fluoride-induced obesity was proposed by intervention with polysaccharides from Fuzhuan brick tea. Conclusion Overall, these results provide the first evidence of a comprehensive cross-talk mechanism between fluoride and obesity in HFD fed mice, which is mediated by gut microbiota and intestinal barrier. E. ramosum was identified as a crucial mediator of fluoride induced obesity, which could be explored as potential target for prevention and treatment of obesity with exciting translational value.
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Fluoretos , Receptor 4 Toll-Like , Animais , Camundongos , Fluoretos/farmacologia , Dieta Hiperlipídica/efeitos adversos , Obesidade/prevenção & controleRESUMO
Fuzhuan brick tea (FBT) is a traditional popular beverage in the border regions of China. Nowadays, FBT has been attracted great attention due to its uniquely flavor and various health-promoting functions. An increasing number of efforts have been devoted to the studies on health benefits and chemistry of FBT over the last decades. However, FBT was still received much less attention than green tea, oolong tea and black tea. Therefore, it is necessary to review the current encouraging findings about processing, microorganisms, chemical constituents, health benefits and potential risk of FBT. The fungus fermentation is the key stage for processing of FBT, which is involved in a complex and unique microbial fermentation process. The fungal community in FBT is mainly dominated by "golden flower" fungi, which is identified as Aspergillus cristatus. A great diversity of novel compounds is formed and identified after a series of biochemical reactions during the fermentation process of FBT. FBT shows various biological activities, such as antioxidant, anti-inflammatory, anti-obesity, anti-bacterial, and anti-tumor activities. Furthermore, the potential risk of FBT was also discussed. It is expected that this review could be useful for stimulating further research of FBT.
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Camellia sinensis , Chá , Chá/química , Camellia sinensis/química , Fungos , Antioxidantes , China , FermentaçãoRESUMO
Polymer-ceramic piezoelectric composites, combining high piezoelectricity and mechanical flexibility, have attracted increasing interest in both academia and industry. However, their piezoelectric activity is largely limited by intrinsically low crystallinity and weak spontaneous polarization. Here, we propose a Ti3C2Tx MXene anchoring method to manipulate the intermolecular interactions within the all-trans conformation of a polymer matrix. Employing phase-field simulation and molecular dynamics calculations, we show that OH surface terminations on the Ti3C2Tx nanosheets offer hydrogen bonding with the fluoropolymer matrix, leading to dipole alignment and enhanced net spontaneous polarization of the polymer-ceramic composites. We then translated this interfacial bonding strategy into electrospinning to boost the piezoelectric response of samarium doped Pb (Mg1/3Nb2/3)O3-PbTiO3/polyvinylidene fluoride composite nanofibers by 160% via Ti3C2Tx nanosheets inclusion. With excellent piezoelectric and mechanical attributes, the as-electrospun piezoelectric nanofibers can be easily integrated into the conventional shoe insoles to form a foot sensor network for all-around gait patterns monitoring, walking habits identification and Metatarsalgi prognosis. This work utilizes the interfacial coupling mechanism of intermolecular anchoring as a strategy to develop high-performance piezoelectric composites for wearable electronics.
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Nanofibras , PolímerosRESUMO
Radiofrequency identification (RFID), particularly passive RFID, is extensively employed in industrial applications to track and trace products, assets, and material flows. The ongoing trend toward increasingly miniaturized RFID sensor tags is likely to continue as technology advances, although miniaturization presents a challenge with regard to the communication coverage area. Recently, efforts in applying metamaterials in RFID technology to increase power transfer efficiency through their unique capacity for electromagnetic wave manipulation have been reported. In particular, metamaterials are being increasingly applied in far-field RFID system applications. Here, we report the development of a magnetic metamaterial and local field enhancement package enabling a marked boost in near-field magnetic strength, ultimately yielding a dramatic increase in the power transfer efficiency between reader and tag antennas. The application of the proposed magnetic metamaterial and local field enhancement package to near-field RFID technology, by offering high power transfer efficiency and a larger communication coverage area, yields new opportunities in the rapidly emerging Internet of Things (IoT) era.
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Piezoelectric nanocomposites with oxide fillers in a polymer matrix combine the merit of high piezoelectric response of the oxides and flexibility as well as biocompatibility of the polymers. Understanding the role of the choice of materials and the filler-matrix architecture is critical to achieving desired functionality of a composite towards applications in flexible electronics and energy harvest devices. Herein, a high-throughput phase-field simulation is conducted to systematically reveal the influence of morphology and spatial orientation of an oxide filler on the piezoelectric, mechanical, and dielectric properties of the piezoelectric nanocomposites. It is discovered that with a constant filler volume fraction, a composite composed of vertical pillars exhibits superior piezoelectric response and electromechanical coupling coefficient as compared to the other geometric configurations. An analytical regression is established from a linear regression-based machine learning model, which can be employed to predict the performance of nanocomposites filled with oxides with a given set of piezoelectric coefficient, dielectric permittivity, and stiffness. This work not only sheds light on the fundamental mechanism of piezoelectric nanocomposites, but also offers a promising material design strategy for developing high-performance polymer/inorganic oxide composite-based wearable electronics.
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Nanocompostos , Eletrônica , Aprendizado de Máquina , Óxidos , PolímerosRESUMO
Electrode microfabrication technologies such as lithography and deposition have been widely applied in wearable electronics to boost interfacial coupling efficiency and device performance. However, a majority of these approaches are restricted by expensive and complicated processing techniques, as well as waste discharge. Here, helium plasma irradiation is employed to yield a molybdenum microstructured electrode, which is constructed into a flexible piezoresistive pressure sensor based on a Ti3 C2 Tx nanosheet-immersed polyurethane sponge. This electrode engineering strategy enables the smooth transition between sponge deformation and MXene interlamellar displacement, giving rise to high sensitivity (1.52 kPa-1 ) and good linearity (r2 = 0.9985) in a wide sensing range (0-100 kPa) with a response time of 226 ms for pressure detection. In addition, both the experimental characterization and finite element simulation confirm that the hierarchical structures modulated by pore size, plasma bias, and MXene concentration play a crucial role in improving the sensing performance. Furthermore, the as-developed flexible pressure sensor is demonstrated to measure human radial pulse, detect finger tapping, foot stomping, and perform object identification, revealing great feasibility in wearable biomonitoring and health assessment.
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Desenho de Equipamento/métodos , Determinação da Frequência Cardíaca/instrumentação , Dispositivos Eletrônicos Vestíveis , Análise de Elementos Finitos , Humanos , Microtecnologia , Poliuretanos/química , Titânio/química , TatoRESUMO
NiWO4 microflowers with a large surface area up to 79.77 m2·g-1 are synthesized in situ via a facile coprecipitation method. The NiWO4 microflowers are further decorated with multi-walled carbon nanotubes (MWCNTs) and assembled to form composites for NH3 detection. The as-fabricated composite exhibits an excellent NH3 sensing response/recovery time (53 s/177 s) at a temperature of 460 °C, which is a 10-fold enhancement compared to that of pristine NiWO4. It also demonstrates a low detection limit of 50 ppm; the improved sensing performance is attributed to the porous structure of the material, the large specific surface area, and the p-n heterojunction formed between the MWNTs and NiWO4. The gas sensitivity of the sensor based on daisy-like NiWO4/MWCNTs shows that the sensor based on 10 mol % (MWN10) has the best gas sensitivity, with a sensitivity of 13.07 to 50 ppm NH3 at room temperature and a detection lower limit of 20 ppm. NH3, CO2, NO2, SO2, CO, and CH4 are used as typical target gases to construct the NiWO4/MWCNTs gas-sensitive material and study the research method combining density functional theory calculations and experiments. By calculating the morphology and structure of the gas-sensitive material NiWO4(110), the MWCNT load samples, the vacancy defects, and the influence law and internal mechanism of gas sensitivity were described.
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Three-dimensional (3D) printing technologies are advanced manufacturing technologies based on computer-aided design digital models to create personalized 3D objects automatically. They have been widely used in the industry, design, engineering, and manufacturing fields for nearly 30 years. Three-dimensional printing has many advantages in process engineering, with applications in dentistry ranging from the field of prosthodontics, oral and maxillofacial surgery, and oral implantology to orthodontics, endodontics, and periodontology. This review provides a practical and scientific overview of 3D printing technologies. First, it introduces current 3D printing technologies, including powder bed fusion, photopolymerization molding, and fused deposition modeling. Additionally, it introduces various factors affecting 3D printing metrics, such as mechanical properties and accuracy. The final section presents a summary of the clinical applications of 3D printing in dentistry, including manufacturing working models and main applications in the fields of prosthodontics, oral and maxillofacial surgery, and oral implantology. The 3D printing technologies have the advantages of high material utilization and the ability to manufacture a single complex geometry; nevertheless, they have the disadvantages of high cost and time-consuming postprocessing. The development of new materials and technologies will be the future trend of 3D printing in dentistry, and there is no denying that 3D printing will have a bright future.
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Desenho Assistido por Computador , Impressão Tridimensional , OdontologiaRESUMO
K0.5Na0.5NbO3 is considered as one of the most promising lead-free piezoelectric ceramics in the field of wearable electronics because of its excellent piezoelectric properties and environmental friendliness. In this work, the temperature-dependent longitudinal piezoelectric coefficient d33* was investigated in K0.5Na0.5NbO3 single crystals via the Landau-Ginzburg-Devonshire theory. Results show that the piezoelectric anisotropy varies with the temperature and the maximum of d33max* deviates from the polar direction of the ferroelectric phase. In the tetragonal phase, d33maxt* parallels with cubic polarization direction near the tetragonal-cubic transition region, and then gradually switches toward the nonpolar direction with decreasing temperatures. The maximum of d33o* in the orthorhombic phase reveals a distinct varying trend in different crystal planes. As for the rhombohedral phase, slight fluctuation of the maximum of d33r* was observed and delivered a more stable temperature-dependent maximum d33maxr* and its corresponding angle θmax in comparison with tetragonal and orthorhombic phases. This work not only sheds some light on the temperature-dependent phase transitions, but also paves the way for the optimization of piezoelectric properties in piezoelectric materials and devices.