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1.
Entropy (Basel) ; 26(5)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38785624

RESUMO

In unsupervised learning, clustering is a common starting point for data processing. The convex or concave fusion clustering method is a novel approach that is more stable and accurate than traditional methods such as k-means and hierarchical clustering. However, the optimization algorithm used with this method can be slowed down significantly by the complexity of the fusion penalty, which increases the computational burden. This paper introduces a random projection ADMM algorithm based on the Bernoulli distribution and develops a double random projection ADMM method for high-dimensional fusion clustering. These new approaches significantly outperform the classical ADMM algorithm due to their ability to significantly increase computational speed by reducing complexity and improving clustering accuracy by using multiple random projections under a new evaluation criterion. We also demonstrate the convergence of our new algorithm and test its performance on both simulated and real data examples.

2.
Lupus Sci Med ; 11(1)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637124

RESUMO

BACKGROUND: Lupus nephritis (LN) is a complication of SLE characterised by immune dysfunction and oxidative stress (OS). Limited options exist for LN. We aimed to identify LN-related OS, highlighting the need for non-invasive diagnostic and therapeutic approaches. METHODS: LN-differentially expressed genes (DEGs) were extracted from Gene Expression Omnibus datasets (GSE32591, GSE112943 and GSE104948) and Molecular Signatures Database for OS-associated DEGs (OSEGs). Functional enrichment analysis was performed for OSEGs related to LN. Weighted gene co-expression network analysis identified hub genes related to OS-LN. These hub OSEGs were refined as biomarker candidates via least absolute shrinkage and selection operator. The predictive value was validated using receiver operating characteristic (ROC) curves and nomogram for LN prognosis. We evaluated LN immune cell infiltration using single-sample gene set enrichment analysis and CIBERSORT. Additionally, gene set enrichment analysis explored the functional enrichment of hub OSEGs in LN. RESULTS: The study identified four hub genes, namely STAT1, PRODH, TXN2 and SETX, associated with OS related to LN. These genes were validated for their diagnostic potential, and their involvement in LN pathogenesis was elucidated through ROC and nomogram. Additionally, alterations in immune cell composition in LN correlated with hub OSEG expression were observed. Immunohistochemical analysis reveals that the hub gene is most correlated with activated B cells and CD8 T cells. Finally, we uncovered that the enriched pathways of OSEGs were mainly involved in the PI3K-Akt pathway and the Janus kinase-signal transducer and activator of transcription pathway. CONCLUSION: These findings contribute to advancing our understanding of the complex interplay between OS, immune dysregulation and molecular pathways in LN, laying a foundation for the identification of potential diagnostic biomarkers and therapeutic targets.


Assuntos
Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Humanos , Nefrite Lúpica/diagnóstico , Nefrite Lúpica/genética , Fosfatidilinositol 3-Quinases , Estresse Oxidativo/genética , Aprendizado de Máquina , DNA Helicases , RNA Helicases , Enzimas Multifuncionais
3.
Nat Commun ; 15(1): 3163, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605025

RESUMO

The transcription and replication processes of non-segmented, negative-strand RNA viruses (nsNSVs) are catalyzed by a multi-functional polymerase complex composed of the large protein (L) and a cofactor protein, such as phosphoprotein (P). Previous studies have shown that the nsNSV polymerase can adopt a dimeric form, however, the structure of the dimer and its function are poorly understood. Here we determine a 2.7 Å cryo-EM structure of human parainfluenza virus type 3 (hPIV3) L-P complex with the connector domain (CD') of a second L built, while reconstruction of the rest of the second L-P obtains a low-resolution map of the ring-like L core region. This study reveals detailed atomic features of nsNSV polymerase active site and distinct conformation of hPIV3 L with a unique ß-strand latch. Furthermore, we report the structural basis of L-L dimerization, with CD' located at the putative template entry of the adjoining L. Disruption of the L-L interface causes a defect in RNA replication that can be overcome by complementation, demonstrating that L dimerization is necessary for hPIV3 genome replication. These findings provide further insight into how nsNSV polymerases perform their functions, and suggest a new avenue for rational drug design.


Assuntos
Nucleotidiltransferases , Vírus de RNA , Humanos , Dimerização , Domínio Catalítico , Replicação Viral
4.
Photodiagnosis Photodyn Ther ; 46: 104098, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38642727

RESUMO

Intraductal papillary mucinous neoplasm of the bile tract is a rare biliary tumor characterized by mucin growth within the bile duct. In the early stages, it often presents without significant obstruction, this often leads to its discovery in the advanced stages. We report a case of a 63-year-old female with an intraductal papillary mucinous neoplasm of the bile duct (IPMN-B). The patient had a history of intrahepatic bile duct stones and biliary ascariasis. She gradually developed symptoms such as jaundice and intermittent fever before admission, and a bile duct biopsy confirmed the diagnosis of IPMN-B. Currently, endoscopic photodynamic therapy (PDT) is considered an effective treatment for bile duct cancer. In this case, we performed two sessions of PDT guided by SpyGlass. The patient experienced complete remission postoperatively, and there has been no evidence of tumor recurrence or metastasis in the three years following the procedure.


Assuntos
Neoplasias dos Ductos Biliares , Fotoquimioterapia , Fármacos Fotossensibilizantes , Humanos , Feminino , Pessoa de Meia-Idade , Fotoquimioterapia/métodos , Neoplasias dos Ductos Biliares/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Adenocarcinoma Mucinoso/tratamento farmacológico , Ácido Aminolevulínico/uso terapêutico
5.
Photodiagnosis Photodyn Ther ; 47: 104104, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38679154

RESUMO

BACKGROUND: Cholangiocarcinoma (CCA) is a malignant tumor with a poor prognosis. The specific mechanism of photodynamic therapy (PDT) in treating CCA remains unclear. This study aims to investigate the mechanisms of PDT in the treatment of CCA and try to improve the therapeutic effect of PDT by intervening associated signaling pathways. METHODS: The Cell Counting Kit-8 (CCK-8) was used to examine the cytotoxicity of CCA cell lines following PDT. Apoptosis and reactive oxygen species (ROS) levels were measured by flow cytometry. A transmission electron microscope was used to study the changes in cell mitochondria after PDT. The levels of glutathione (GSH), malondialdehyde (MDA), ferrous iron (Fe2+), lactate dehydrogenase (LDH), and lipid peroxide (LPO) were determined. Changes in the expression of apoptosis and ferroptosis-related proteins were determined using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Xenograft tumor models were developed to investigate the effects of PDT on tumor proliferation, apoptosis, and ferroptosis in vivo. RESULTS: PDT inhibited tumor proliferation and induced apoptosis both in vivo and in vitro. This treatment led to swelling and damage of the mitochondria in affected cells. Furthermore, ROS levels rose, accompanied by an increase in the proportion of apoptotic-positive cells. The expressions of Bax and Caspase-3 were upregulated, while the Bcl-2 was downregulated. Meanwhile, PDT triggered ferroptosis, marked by decreased expressions of GPX4 and SLC7A11, and reduced GSH levels. This was accompanied by upregulation of P53 expression and heightened levels of Fe2+, LPO, MDA, and LDH. After inducing the ferroptosis pathway, the therapeutic effect of PDT was enhanced, the tumor tissue was further reduced, and the degree of malignancy was reduced. CONCLUSION: PDT promotes apoptosis and ferroptosis of cholangiocarcinoma cells by activating the P53/SLC7A11/GPX4 signaling pathway and inhibits the growth of cholangiocarcinoma. Inducing ferroptosis can enhance the effectiveness of photodynamic therapy.

6.
Mater Horiz ; 11(8): 2041-2042, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38506055

RESUMO

Correction for 'Exploring the Mpemba effect: a universal ice pressing enables porous ceramics' by Xiaodan Yang et al., Mater. Horiz., 2024, DOI: https://doi.org/10.1039/d3mh01869e.

9.
Mater Horiz ; 11(8): 1899-1907, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38314804

RESUMO

Piezoceramics with global porosity and local compaction are highly desired to exploit the combination of mechanical and electrical properties. However, achieving such a functional combination is challenging because of the lack of techniques for applying uniform pressure inside porous ceramic green parts. Nature provides many examples of generating strong forces inside the macro and micro channels via the state transformation of water. Inspired by these phenomena, we present a technique of "ice and fire", that is, water freezing (ice pressing) and high-temperature sintering (fire), to produce ideal porous piezoceramics. We introduce a new compaction method called the "ice pressing method", which manipulates liquid phase transition for compaction. This method has several advantages, including uniform pressure distribution, a wide pressure range, high effectiveness, and selective freezing. It can generate an ultrahigh pressure of up to 180 MPa on the piezoceramic green skeletons in minutes while retaining their functional pore structures. By exploiting the Mpemba phenomenon, we further accelerate the compaction procedure by 11%. The first ice-pressed and second fire-consolidated lead zirconate titanate (PZT) ceramics are highly densified and exhibit an outstanding piezoelectric response (d33 = 531 pC N-1), comparable to conventional pressed bulk counterparts and 10-20 times higher than those of unpressed materials. The novel ice pressing method breaks the limitation of lacking a compaction technique for porous ceramics. The versatile and effective ice pressing method is a green and low-cost route promoting applications in sensors, acoustics, water filtration, catalyst substrates, and energy harvesting.

10.
J Alzheimers Dis Rep ; 8(1): 101-128, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38312534

RESUMO

Background: The investigation of mitophagy in Alzheimer's disease (AD) remains relatively underexplored in bibliometric analysis. Objective: To delve into the progress of mitophagy, offering a comprehensive overview of research trends and frontiers for researchers. Methods: Basic bibliometric information, targets, and target-drug-clinical trial-disease extracted from publications identified in the Web of Science Core Collection from 2007 to 2022 were assessed using bibliometric software. Results: The study encompassed 5,146 publications, displaying a consistent 16-year upward trajectory. The United States emerged as the foremost contributor in publications, with the Journal of Alzheimer's Disease being the most prolific journal. P. Hemachandra Reddy, George Perry, and Xiongwei Zhu are the top 3 most prolific authors. PINK1 and Parkin exhibited an upward trend in the last 6 years. Keywords (e.g., insulin, aging, epilepsy, tauopathy, and mitochondrial quality control) have recently emerged as focal points of interest within the past 3 years. "Mitochondrial dysfunction" is among the top terms in disease clustering. The top 10 drugs/molecules (e.g., curcumin, insulin, and melatonin) were summarized, accompanied by their clinical trials and related targets. Conclusions: This study presents a comprehensive overview of the mitophagy research landscape in AD over the past 16 years, underscoring mitophagy as an emerging molecular mechanism and a crucial focal point for potential drug in AD. This study pioneers the inclusion of targets and their correlations with drugs, clinical trials, and diseases in bibliometric analysis, providing valuable insights and inspiration for scholars and readers of JADR interested in understanding the potential mechanisms and clinical trials in AD.

11.
Environ Sci Pollut Res Int ; 31(8): 11749-11765, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38224431

RESUMO

Spatial and temporal distributions and influencing factors of extreme precipitation are important bases for coping with future climate change. The spatiotemporal variability and affecting factors of extreme precipitation indices (EPIs) in east of northwest China (ENW) during 1961-2015 were investigated using a series of approaches such as modified Mann-Kendall trend test, Hurst exponent, ensemble empirical mode decomposition (EEMD), and geodetector model. The results showed that CDD and CWD decreased significantly (P < 0.01), with rates of 1.4 days/decade and 0.07 days/decade, respectively. EPIs in ENW exhibited an obvious heterogeneity. CDD gradually increased from the southeast to the northwest. The remaining EPIs generally showed the opposite trend. Geodetector results demonstrated that large-scale circulation factors had a significant impact on EPIs in ENW. The influence of large-scale climate factors on EPIs was concentrated in nonlinear enhancement, and Nino3.4 and SO were the dominant driving factors that played a major role in the variability of EPIs. The results of this study provided a reference for ENW and other arid and semi-arid regions to cope with extreme climates and develop corresponding strategies.


Assuntos
Mudança Climática , Clima Desértico , China , Temperatura
12.
ACS Appl Mater Interfaces ; 16(2): 2847-2860, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38170963

RESUMO

Inconsistent interface control in devices based on two-dimensional materials (2DMs) has limited technological maturation. Astounding variability of 2D/three-dimensional (2D/3D) interface properties has been reported, which has been exacerbated by the lack of direct investigations of buried interfaces commonly found in devices. Herein, we demonstrate a new process that enables the assembly and isolation of device-relevant heterostructures for buried interface characterization. This is achieved by implementing a water-soluble substrate (GeO2), which enables deposition of many materials onto the 2DM and subsequent heterostructure release by dissolving the GeO2 substrate. Here, we utilize this novel approach to compare how the chemistry, doping, and strain in monolayer MoS2 heterostructures fabricated by direct deposition vary from those fabricated by transfer techniques to show how interface properties differ with the heterostructure fabrication method. Direct deposition of thick Ni and Ti films is found to react with the monolayer MoS2. These interface reactions convert 50% of MoS2 into intermetallic species, which greatly exceeds the 10% conversion reported previously and 0% observed in transfer-fabricated heterostructures. We also measure notable differences in MoS2 carrier concentration depending on the heterostructure fabrication method. Direct deposition of thick Au, Ni, and Al2O3 films onto MoS2 increases the hole concentration by >1012 cm-2 compared to heterostructures fabricated by transferring MoS2 onto these materials. Thus, we demonstrate a universal method to fabricate 2D/3D heterostructures and expose buried interfaces for direct characterization.

13.
J Orthop Surg Res ; 19(1): 101, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38297343

RESUMO

BACKGROUND: Lumbar revision surgery can be performed by simple lumbar nerve decompression or lumbar interbody fusion, including percutaneous endoscopic lumbar discectomy, transforaminal lumbar interbody fusion (TLIF), etc. However, lumbar revision surgery is very difficult in surgical operation. We sought to explore the technique safety and efficacy of microscope-assisted minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) in lumbar revision surgery. METHODS: Cases of postoperative recurrence following lumbar spine surgery (n = 63) treated from December 2016 to July 2021 were retrospectively analyzed, including 24 cases of microscope-assisted MI-TLIF (microscopic group) and 39 cases of naked-eye MI-TLIF (naked-eye group). The operation time, intraoperative blood loss, incision length, postoperative drainage, length of hospital stay, initial operation, and visual analog score (VAS) of low back and leg pain before and at 7 days and 3 months after the operation and the last follow-up were compared between the two groups. The Oswestry Dysfunction Index (ODI) and the Japanese Orthopaedic Association (JOA) scores before and after the operation and the Bridwell interbody fusion grades at 1 year were compared. The independent t tests, Mann-Whitney U tests, and Chi-square tests were used for analysis. RESULTS: All 63 patients were successfully treated by operation and were followed up for an average of 31.5 ± 8.6 months (range 12-48 months). The two groups had no significant difference in sex, age, incision length, initial operation, or operative segment (P > 0.05). There was no significance in operation time, VAS score, ODI score, and JOA score of low back pain or Bridwell interbody fusion grade between the two groups (P > 0.05). Significant differences in intraoperative blood loss, postoperative drainage, and the lengths of hospital stay were observed between the two groups (P < 0.05). Cerebrospinal fluid leakage (n = 2), edema of nerve roots (n = 2), and incision infection (n = 1) were observed in the naked-eye group. There were no complications in the microscopic group, such as cerebrospinal fluid leakage, edema of nerve roots, and incision infection. CONCLUSION: Although microscope-assisted MI-TLIF and naked-eye MI-TLIF are both effective during lumbar revision surgery, microscope-assisted MI-TLIF brings less trauma, less bleeding, shorter postoperative hospital stay, and faster recovery. Unlike traditional surgery, microscope-assisted MI-TLIF provides a clear visual field, adequate hemostasis, and nerve decompression.


Assuntos
Discotomia Percutânea , Deslocamento do Disco Intervertebral , Fusão Vertebral , Humanos , Resultado do Tratamento , Reoperação , Vértebras Lombares/cirurgia , Estudos Retrospectivos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Fusão Vertebral/métodos , Deslocamento do Disco Intervertebral/cirurgia , Infecção da Ferida Cirúrgica/cirurgia , Perda Sanguínea Cirúrgica , Vazamento de Líquido Cefalorraquidiano/cirurgia , Edema
14.
Small ; 20(14): e2307809, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988684

RESUMO

Multi-shelled hollow metal-organic frameworks (MH-MOFs) are highly promising as electrode materials due to their impressive surface area and efficient mass transfer capabilities. However, the fabrication of MH-MOFs has remained a formidable challenge. In this study, two types of double-shelled open hollow Prussian blue analogues, one with divalent iron (DHPBA-Fe(II)) and the other with trivalent iron (DHPBA-Fe(III)), through an innovative inner-outer growth strategy are successfully developed. The growth mechanism is found to involve lattice matching growth and ligand exchange processes. Subsequently, DHPBA-Fe(II) and DHPBA-Fe(III) are employed as cathodes in aqueous Zn-ion batteries. Significantly, DHPBA-Fe(II) demonstrated exceptional performance, exhibiting a capacity of 92.5 mAh g-1 at 1 A g-1, and maintaining remarkable stability over an astounding 10 000 cycles. This research is poised to catalyze further exploration into the fabrication techniques of MH-MOFs and offer fresh insights into the intricate interplay between electronic structure and battery performance.

15.
J Ethnopharmacol ; 321: 117565, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38081397

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Baiheqingjin Decoction (BHQJ), which consists of 7 traditional Chinese herbs including Baibu (Stemona tuberosa Lour.), Hezi (Terminalia chebula Retz.), Mahuang (Ephedra sinica Stapf.), Ziwan (Aster tataricus L. f.), Dilong (Pheretima), Sangbaipi (Morus alba L.), and Xianhecao (Agrimonia pilosa Ledeb.). BHQJ is commonly used for treating cough asthma, and variant cough-variant asthma as it, is effective in improving asthma symptoms and reducing airway inflammation. AIM OF THE STUDY: To investigate the mechanisms of BHQJ in treating allergic asthma. MATERIALS AND METHODS: We collected information about the components and targets of 6 Chinese medicines (excluding Pheretima) from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Additionally, we obtained genes associated with asthma from six disease databases. To create a protein-protein interaction network, we conducted an intersection analysis using differentially expressed genes derived from RNA transcriptome data. Subsequently, we carried out Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. To validate the findings from network pharmacology and transcriptomics, we established an allergic asthma mouse model induced by ovalbumin and conducted in vivo experiments. RESULTS: Using network pharmacology and transcriptomics analyses, we identified the pathways including the PI3K/AKT signaling pathway, and NF-κB signaling pathway. Among these, the involvement of the PI3K/AKT/NF-κB signaling pathway in various pathological processes of asthma, such as airway inflammation, smooth muscle contraction, and excessive mucus production, are well-documented. Histopathological examinations indicated that BHQJ had the potential to mitigate inflammatory cell infiltration and the excessive growth of goblet cells in the airways of asthmatic mice, consequently reducing mucus secretion. Results from Western blot demonstrated that BHQJ could inhibit the activation of the PI3K/AKT/NF-κB pathway at the protein levels. Enzyme-linked immunosorbent assay findings revealed that BHQJ could reduce the production of typical "type 2 asthma" cytokines and immunoglobulin (Ig) E in the blood. These discoveries imply that BHQJ has the potential to reduce the release of inflammatory cytokines and suppress the overactivation of the PI3K/AKT/NF-κB signaling pathway, thus offering a therapeutic approach for asthma. CONCLUSION: Our research offers initial insights into the fundamental mechanisms through which BHQJ treats asthma. This study reveals the potential mechanism of BHQJ in treating asthma, particularly its role in reducing inflammatory cytokines, mucus production, and cell infiltration, as well as inhibiting the expression of PI3K/AKT/P65 phosphorylated protein. These findings indicate the potential of BHQJ in treating asthma. In summary, our study provides preliminary insights into the asthma treatment mechanism of BHQJ and provides guidance for future research.


Assuntos
Asma , Medicamentos de Ervas Chinesas , Camundongos , Animais , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Líquido da Lavagem Broncoalveolar , Asma/patologia , Transdução de Sinais , Inflamação/tratamento farmacológico , Citocinas/metabolismo , Imunoglobulina E , Medicamentos de Ervas Chinesas/efeitos adversos
16.
Adv Sci (Weinh) ; 11(4): e2305442, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38009491

RESUMO

Neuroinflammation is associated with poor outcomes in patients with spinal cord injury (SCI). Recent studies have demonstrated that stimulator of interferon genes (Sting) plays a key role in inflammatory diseases. However, the role of Sting in SCI remains unclear. In the present study, it is found that increased Sting expression is mainly derived from activated microglia after SCI. Interestingly, knockout of Sting in microglia can improve the recovery of neurological function after SCI. Microglial Sting knockout restrains the polarization of microglia toward the M1 phenotype and alleviates neuronal death. Furthermore, it is found that the downregulation of mitofusin 2 (Mfn2) expression in microglial cells leads to an imbalance in mitochondrial fusion and division, inducing the release of mitochondrial DNA (mtDNA), which mediates the activation of the cGas-Sting signaling pathway and aggravates inflammatory response damage after SCI. A biomimetic microglial nanoparticle strategy to deliver MASM7 (named MSNs-MASM7@MI) is established. In vitro, MSNs-MASM7@MI showed no biological toxicity and effectively delivered MASM7. In vivo, MSNs-MASM7@MI improves nerve function after SCI. The study provides evidence that cGas-Sting signaling senses Mfn2-dependent mtDNA release and that its activation may play a key role in SCI. These findings provide new perspectives and potential therapeutic targets for SCI treatment.


Assuntos
Microglia , Traumatismos da Medula Espinal , Humanos , Microglia/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Regulação para Baixo , Inflamação/metabolismo , Traumatismos da Medula Espinal/metabolismo , Nucleotidiltransferases/metabolismo
17.
Nature ; 624(7992): 551-556, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38123805

RESUMO

Moiré quantum materials host exotic electronic phenomena through enhanced internal Coulomb interactions in twisted two-dimensional heterostructures1-4. When combined with the exceptionally high electrostatic control in atomically thin materials5-8, moiré heterostructures have the potential to enable next-generation electronic devices with unprecedented functionality. However, despite extensive exploration, moiré electronic phenomena have thus far been limited to impractically low cryogenic temperatures9-14, thus precluding real-world applications of moiré quantum materials. Here we report the experimental realization and room-temperature operation of a low-power (20 pW) moiré synaptic transistor based on an asymmetric bilayer graphene/hexagonal boron nitride moiré heterostructure. The asymmetric moiré potential gives rise to robust electronic ratchet states, which enable hysteretic, non-volatile injection of charge carriers that control the conductance of the device. The asymmetric gating in dual-gated moiré heterostructures realizes diverse biorealistic neuromorphic functionalities, such as reconfigurable synaptic responses, spatiotemporal-based tempotrons and Bienenstock-Cooper-Munro input-specific adaptation. In this manner, the moiré synaptic transistor enables efficient compute-in-memory designs and edge hardware accelerators for artificial intelligence and machine learning.

18.
Chem Sci ; 14(42): 11768-11774, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37920350

RESUMO

The water oxidation reaction plays an important role in clean energy conversion, utilization, and storage, but mimicking the oxygen-evolving complex of photosystem II for designing active and stable water oxidation catalysts (WOCs) is still an appealing challenge. Here, we innovatively engineered a molecular ruthenium WOC as a metal complex building unit to construct a series of three-dimensional metal covalent organic frameworks (3D MCOFs) for realizing efficient oxidation catalysis. The resultant MCOFs possessed rare 3D interlocking structures with inclined interpenetration of two-dimensional covalent rhombic nets, and the Ru sites were periodically arranged in the crystalline porous frameworks. Impressively, these MCOFs showed excellent performance towards water oxidation (the O2 evolution rate is as high as 2830 nmol g-1 s-1) via the water nucleophilic attack pathway. Besides, the MCOFs were also reactive for oxidizing organic substrates. This work highlights the potential of MCOFs as a designable platform in integrating molecular catalysts for various applications.

19.
Langmuir ; 39(46): 16261-16271, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37945037

RESUMO

Artificial joint replacement is the most effective way to treat osteoarthritis. However, these artificial joints are too stiff with high interfacial contact stress and poor surface lubrication, resulting in stress shielding and severe wear and tear lead to an extremely high failure rate. At present, hydrogels are considered the most promising substitute for artificial joint prostheses owing to their good biocompatibility, adjustable mechanical properties, and excellent flexibility. Nevertheless, a traditional single-layer hydrogel has poor bearing capacity and lubrication, which are far from the properties of natural articular cartilage. The high strength and low friction properties of natural articular cartilage are based on its own multilayer fibrous structure. Therefore, by simulating the multilayer structure of natural cartilage, a bilayer bionic cartilage hydrogel was prepared; that is, the upper hydrogel realized excellent lubrication and the lower hydrogel realized high load-bearing capacity. However, the interface binding of bilayer hydrogels is a challenge at present. Therefore, the interfacial adhesion of the bilayer hydrogel is improved by adding tannic acid (TA) based on the adhesion of the natural polyphenol structure. The average interfacial toughness reaches 3650 J/m2, and the average interfacial shear force reaches 800 kPa. In the preparation of the bilayer hydrogel, taking advantage of the coordination reaction between TA and metal cations, Fe3+ is further added to endow the bilayer hydrogel with excellent mechanical properties and good sliding friction performance. Therefore, this work opens up a new way to construct cartilage-like materials with high toughness and a soft-soft interface.

20.
Nat Commun ; 14(1): 6488, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37838731

RESUMO

Nanoparticles, films, and patterns are three critical piezoelectric elements with widespread applications in sensing, actuations, catalysis and energy harvesting. High productivity and large-area fabrication of these functional elements is still a significant challenge, let alone the control of their structures and feature sizes on various substrates. Here, we report a fast and versatile electrostatic disc microprinting, enabled by triggering the instability of liquid-air interface of inks. The printing process allows for fabricating lead zirconate titanate free-standing nanoparticles, films, and micro-patterns. The as-fabricated lead zirconate titanate films exhibit a high piezoelectric strain constant of 560 pm V-1, one to two times higher than the state-of-the-art. The multiplexed tip jetting mode and the large layer-by-layer depositing area can translate into depositing speeds up to 109 µm3 s-1, one order of magnitude faster than current techniques. Printing diversified functional materials, ranging from suspensions of dielectric ceramic and metal nanoparticles, to insulating polymers, to solutions of biological molecules, demonstrates the great potential of the electrostatic disc microprinting in electronics, biotechnology and beyond.

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