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1.
Medicine (Baltimore) ; 103(30): e39069, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058823

RESUMO

Infertility can lead to significant psychological distress among women, yet the roles of hope and resilience in mitigating depressive symptoms remain inadequately explored, particularly within the Chinese context. We performed a cross-sectional observational study to investigate the psychological impacts of infertility among Chinese women as well as to discern whether hope and resilience can influence their depressive symptoms. We recruited 364 Chinese women seeking infertility treatment in the Shandong region. Participants completed validated assessments including the Hospital Anxiety and Depression Scale, Connor-Davidson Resilience Scale, and Herth Hope Index. Demographic and clinical data were also collected. We observed elevated levels of depressive symptoms and anxiety among women with infertility. Particularly, demographic factors such as an older age, rural residence, lower income, lower education, adverse life events, and longer infertility duration were associated with increased depressive symptoms. Individuals who experienced adverse life events were at a 2.42-fold increased risk of developing depressive symptoms (P = .04). Depressive symptoms were inversely correlated with both hope levels (r = -0.25; P < .05) and resilience levels (r = -0.32; P < .05). Hope levels were positively correlated with resilience (R = 0.67; P < .05). After controlling for the interaction of hope and resilience, we found that only depressive symptoms and resilience were negatively correlated. The psychological burden of infertility among Chinese women is widespread and affects many individuals from different demographic backgrounds. Interventions aimed at increasing resilience may be helpful to mitigate depressive symptoms.


Assuntos
Adaptação Psicológica , Depressão , Resiliência Psicológica , Humanos , Feminino , Estudos Transversais , Adulto , Depressão/psicologia , Depressão/epidemiologia , China/epidemiologia , Infertilidade Feminina/psicologia , Esperança , Capacidades de Enfrentamento
2.
Anal Chim Acta ; 1318: 342886, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39067906

RESUMO

BACKGROUND: There are billions of bacteria in the intestine, most of which are harmless and play important roles in humans. Although only a very small number of bacteria can cause diseases, once the pathogenic bacteria are ingested into the body and multiply in large quantities, it can lead to inflammatory diseases in the intestines and even other organs. Although polymerase chain reaction can specifically detect bacterial nucleic acid. However, the demand for temperature cycling limits its portability. Therefore, it is hoped to establish a high-throughput, highly specific and portable detection platform for directly detecting nucleic acid of intestinal pathogens. RESULTS: Herein, a one-pot chip based on RPA-CRCISPR/Cas12a platform was developed. The chip is the same size as a glass slide and allows detection at the same temperature. Multiple samples could be detected simultaneously on the one chip, achieved high-throughput detection and improved the integration of detection. The specific recognition of CRISPR/Cas12a avoided the influence of non-specific amplification of RPA and enhanced the specificity of the analysis. At the same time, the one-pot chip avoided secondary contamination when the lid was opened during the analysis process. And the bacterial concentration showed good linearity at 102-108 cfu mL-1. The limit of detection could be as low as 0.43 cfu mL-1. This method has been successfully used to detect pollution samples. It can provide a reliable platform for early screening of gastrointestinal and other inflammatory diseases. SIGNIFICANCE: The one-pot chip based on the RPA-CRISPR/Cas12a platform established can directly detect the nucleic acid of intestinal pathogens, with portability and specificity. It is worth noting that the platform has good programmability, can be used for other target detection by changing crRNA and RPA primers, it can achieve multi sample detection on the one chip.


Assuntos
Sistemas CRISPR-Cas , Sistemas CRISPR-Cas/genética , Humanos , DNA Bacteriano/análise , Bactérias/isolamento & purificação , Bactérias/genética , Limite de Detecção , Microbioma Gastrointestinal , Técnicas de Amplificação de Ácido Nucleico
3.
ACS Appl Mater Interfaces ; 16(26): 34167-34180, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38896470

RESUMO

Recently emerged lead halide perovskite CsPbX3 (X = Cl, Br, and I) nanocrystals (PNCs) have attracted tremendous attention due to their excellent optical properties. However, the poor water stability, unsatisfactory luminescence efficiency, disappointing lead leakage, and toxicity have restricted their practical applications in photoelectronics and biomedical fields. Herein, a controllable encapsulated strategy is investigated to realize CsPbX3 PNCs/PVP @PMMA composites with superior luminescence properties and excellent biocompatibility. Additionally, the synthesized CsPbBr3 and CsPbBr0.6I2.4 PNCs/PVP@PMMA structures exhibit green and red emissions with a maximal photoluminescence quantum yield (PLQY) of about 70.24% and 98.26%, respectively. These CsPbX3 PNCs/PVP@PMMA structures show high emission efficiency, excellent stability after water storage for 18 months, and low cytotoxicity at the PNC concentration at 500 µg mL-1. Moreover, white light-emitting diode (WLED) devices based on mixtures of CsPbBr3 and CsPbBr0.6I2.4 PNCs/PVP@PMMA perovskite structures are investigated, which exhibit excellent warm-white light emissions at room temperature. A flexible manipulation method is used to fabricate the white light emitters based on these perovskite composites, providing a fantastic platform for fabricating solid-state white light sources and full-color displays.

4.
Nano Lett ; 24(22): 6592-6600, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38787539

RESUMO

Monolayer transition metal dichalcogenides exhibit valley-dependent excitonic characters with a large binding energy, acting as the building block for future optoelectronic functionalities. Herein, combined with pump-probe ultrafast transient transmission spectroscopy and theoretical simulations, we reveal the chirality-dependent trion dynamics in h-BN encapsulated monolayer tungsten disulfide. By resonantly pumping trions in a single valley and monitoring their temporal evolution, we identify the temperature-dependent competition between two relaxation channels driven by chirality-dependent scattering processes. At room temperature, the phonon-assisted upconversion process predominates, converting excited trions to excitons within the same valley on a sub-picosecond (ps) time scale. As temperature decreases, this process becomes less efficient, while alternative channels, notably valley depolarization process for trions, assume importance, leading to an increase of trion density in the unpumped valley within a ps time scale. Our time-resolved valley-contrast results provide a comprehensive insight into trion dynamics in 2D materials, thereby advancing the development of novel valleytronic devices.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38507104

RESUMO

Cantharidin, a terpenoid produced by blister beetles, has been used in traditional Chinese medicine to treat various ailments and cancers. However, its biological activity, impact, and anticancer mechanisms remain unclear. The Cantharidin chemical gene connections were identified using various databases. The GSE21815 dataset was used to collect the gene expression information. Differential gene analysis and gene ontology analyses were performed. Gene set enrichment analysis was used to assess the activation of disease pathways. Weighted gene co-expression network analysis and differential analysis were used to identify illness-associated genes, examine differential genes, and discover therapeutic targets via protein-protein interactions. MCODE analysis of major subgroup networks was used to identify critical genes influenced by Cantharidin, examine variations in the expression of key clustered genes in colorectal cancer vs. control samples, and describe the subject operators. Single-cell GSE188711 dataset was preprocessed to investigate Cantharidin's therapeutic targets and signaling pathways in colorectal cancer. Single-cell RNA sequencing was utilized to identify 22 cell clusters and marker genes for two different cell types in each cluster. The effects of different Cantharidin concentrations on colorectal cancer cells were studied in vitro. One hundred and ninety-seven Cantharidin-associated target genes and 480 critical genes implicated in the development of the illness were identified. Cantharidin significantly inhibited the proliferation and migration of HCT116 cells and promoted apoptosis at certain concentrations. Patients on current therapy develop inherent and acquired resistance. Our study suggests that Cantharidin may play an anti-CRC role by modulating immune function.

7.
Nat Commun ; 15(1): 1747, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409100

RESUMO

Energy transfer is a ubiquitous phenomenon that delivers energy from a blue-shifted emitter to a red-shifted absorber, facilitating wide photonic applications. Two-dimensional (2D) semiconductors provide unique opportunities for exploring novel energy transfer mechanisms in the atomic-scale limit. Herein, we have designed a planar optical microcavity-confined MoS2/hBN/WS2 heterojunction, which realizes the strong coupling among donor exciton, acceptor exciton, and cavity photon mode. This configuration demonstrates an unconventional energy transfer via polariton relaxation, brightening MoS2 with a record-high enhancement factor of ~440, i.e., two-order-of-magnitude higher than the data reported to date. The polariton relaxation features a short characteristic time of ~1.3 ps, resulting from the significantly enhanced intra- and inter-branch exciton-exciton scattering. The polariton relaxation dynamics is associated with Rabi energies in a phase diagram by combining experimental and theoretical results. This study opens a new direction of microcavity 2D semiconductor heterojunctions for high-brightness polaritonic light sources and ultrafast polariton carrier dynamics.

8.
J Agric Food Chem ; 72(7): 3302-3313, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38330904

RESUMO

Nicotinamide mononucleotide (NMN) has garnered substantial interest as a functional food product. Industrial NMN production relies on chemical methods, facing challenges in separation, purification, and regulatory complexities, leading to elevated prices. In contrast, NMN biosynthesis through fermentation or enzyme catalysis offers notable benefits like eco-friendliness, recyclability, and efficiency, positioning it as a primary avenue for future NMN synthesis. Enzymatic NMN synthesis encompasses the nicotinamide-initial route and nicotinamide ribose-initial routes. Key among these is nicotinamide riboside kinase (NRK), pivotal in the latter route. The NRK-mediated biosynthesis is emerging as a prominent trend due to its streamlined route, simplicity, and precise specificity. The essential aspect is to obtain an engineered NRK that exhibits elevated activity and robust stability. This review comprehensively assesses diverse NMN synthesis methods, offering valuable insights into efficient, sustainable, and economical production routes. It spotlights the emerging NRK-mediated biosynthesis pathway and its significance. The establishment of an adenosine triphosphate (ATP) regeneration system plays a pivotal role in enhancing NMN synthesis efficiency through NRK-catalyzed routes. The review aims to be a reference for researchers developing green and sustainable NMN synthesis, as well as those optimizing NMN production.


Assuntos
Trifosfato de Adenosina , Mononucleotídeo de Nicotinamida , Mononucleotídeo de Nicotinamida/metabolismo , Trifosfato de Adenosina/metabolismo , Biocatálise , NAD/metabolismo
9.
BMC Ophthalmol ; 24(1): 76, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38373920

RESUMO

AIMS: To find potential relation between retrobulbar vessels and fundus microvessels and to detect sensitive and effective clinical indicators in predicting the progress of diabetic retinopathy (DR), ocular hemodynamics were measured using superb microvascular imaging (SMI) and ultrawide-field optical coherence tomography angiography (UWF-OCTA). METHODS: Observational, cross-sectional study evaluating ocular hemodynamics in patients with DR by SMI (Aplio i900, Canon Medical) and UWF-OCTA (BM-400 K BMizar, Tupai Medical Technology). The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) of the central retinal artery (CRA), posterior ciliary artery (PCA), and ophthalmic artery (OA) were measured by SMI. UWF-OCTA evaluated the fundus vascular parameters. A correlation analysis was used to determine the correlation between SMI and UWF-OCTA parameters. RESULTS: One hundred thirty-nine eyes of 139 diabetic patients were included: 29 without DR (NDR), 36 with mild to moderate nonproliferative DR (M-NPDR), 37 with severe NPDR (S-NPDR), and 37 with proliferative DR (PDR). PSV and EDV of retrobulbar vessels decreased from NDR to S-NPDR while increasing PDR. RI of OA showed a decreasing trend in the progression of DR, but other vessels didn't show the same trend. ROC curve analysis showed that CRAPSV, CRAEDV, PCAEDV, OAPSV, and OAEDV had diagnostic value distinguishing M-NPDR and S-NPDR. The correlation analysis observed a significant association between the SMI parameters of CRA and PCA and UWF-OCTA parameters. CRA hemodynamics were more associated with fundus vascular parameters, especially the retina, in the NDR group than in the M-NPDR group. In contrast, PCA consistently correlated with fundus vascular parameters, especially in the choroid, from the NDR to the M-NPDR group. However, OA showed a poor correlation with OCTA parameters. CONCLUSION: The velocity of retrobulbar vessels, mainly the CRA, may serve as a valuable predictor for assessing the progress of DR. The use of SMI in diabetic patients may help identify patients at risk of developing retinopathy.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Humanos , Retinopatia Diabética/diagnóstico , Tomografia de Coerência Óptica/métodos , Vasos Retinianos , Angiofluoresceinografia/métodos , Estudos Transversais , Corioide/irrigação sanguínea
10.
Gait Posture ; 108: 289-300, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38176149

RESUMO

BACKGROUND: People with central nervous system disorders typically have difficulties in coordination of the upper limb and hand movements, which significantly impairs their activities of daily living. Laboratory-based measures can provide quantitative and objective information about intra-limb coordination to aid the rehabilitation process of this population. However, there is currently no comprehensive review of laboratory-based measures. RESEARCH QUESTIONS: The aim of this review was to identify and summarize laboratory-based intra-limb coordination measures for different upper limb and hand movements. METHODS: Searches were performed in the CINAHL, Embase, IEEE Xplore, MEDLINE, PubMed and Web of Science databases to identify studies published between 2013 and 2022. Two authors independently performed paper selection, data extraction and quality assessment. RESULTS: 21 papers were identified, and six types of coordination measures were classified. These included principal component analysis, continuous relative phase analysis, correlation analysis, regression analysis, uncontrolled manifold analysis, and uncorrelated surrogate data analysis, in descending order of occurrence. Regarding psychometric properties, all measures demonstrated good discriminative validity. However, only the principal component analysis approach and the continuous relative phase analysis approach were found to have good convergent validity and responsiveness, respectively. In terms of their practicality, these measures were primarily utilized for quantifying coordination in individuals with neurological disorders, with a greater emphasis on the coordination of upper limb movements rather than hand movements. SIGNIFICANCE: This review summarized and critiqued the characteristics of six types of joint coordination measures. Researchers and clinicians should therefore select appropriate measures based on individual needs. Future research should continue on analysing coordination in individuals with pathological conditions and exploring the application of these measures in quantifying hand movement coordination, to advance current knowledge and inform rehabilitation practices.


Assuntos
Atividades Cotidianas , Acidente Vascular Cerebral , Humanos , Extremidade Superior , Mãos , Movimento
11.
Int J Ophthalmol ; 17(1): 82-91, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38239947

RESUMO

AIM: To evaluate the efficacy and safety of perfluoro-n-octane (PFO) for ophthalmic surgery versus F-Octane as an intraoperative tamponade in pars plana vitrectomy (PPV) in management of retinal detachment. METHODS: This multicenter, prospective, randomized, double-masked, parallel-controlled, non-inferiority trial was conducted in three ophthalmology clinical centers in China. Patients with retinal detachment, who were eligible for PPV were consecutively enrolled. Participants were assigned to PFO for ophthalmic surgery or F-Octane for intraocular tamponade in a 1:1 ratio. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) measurement, and dilated fundus examination were performed preoperatively and at 1, 7±1, 28±3d postoperatively. The primary outcome was complete retinal reattachment rate at postoperative day one. The non-inferiority margin was set at 9.8%. The secondary outcomes included intraoperative retinal reattachment rate, and mean changes in IOP and BCVA from baseline to 1, 7±1, 28±3d postoperatively, respectively. Safety analyses were presented for all randomly assigned participates in this study. RESULTS: Totally 124 eligible patients completed the study between Mar. 14, 2016 and Jun. 7, 2017. Sixty of them were randomly assigned to the PFO for ophthalmic surgery group, and 64 were assigned to the F-Octane group. Baseline characteristics were comparable between the two groups. Both groups achieved 100% retinal reattachment at postoperative day one (difference 0, 95%CI: -6.21% to 5.75%, P=1). The pre-defined noninferiority criterion was met. No significant difference was observed in intraoperative retinal reattachment rate (difference 1.77%, P=0.61), mean changes in IOP (difference 0.36, -0.09, 2.22 mm Hg at 1, 7±1, 28±3d postoperatively, with all P>0.05) and BCVA (difference 0.04, -0.02, 0.06 logMAR at 1, 7±1, 28±3d postoperatively, all P>0.05) between the two groups. No apparent adverse events related to the utilization of PFO were reported. CONCLUSION: In patients with retinal detachment undergoing PPV, PFO for ophthalmic surgery is non-inferior to F-Octane as an intraocular tamponade, and both are safe and well-tolerated.

12.
Cancer Chemother Pharmacol ; 93(4): 381-391, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38148335

RESUMO

BACKGROUND: Burkitt's lymphoma, one of the most common subtypes of pediatric malignant lymphoma, is notorious for its swift onset, aggressive proliferation, pronounced invasiveness, and marked malignancy. The therapeutic landscape for Burkitt's lymphoma currently falls short of providing universally effective and tolerable solutions. Andrographolide, a primary active component of Andrographis paniculata, is renowned for its properties of heat-clearing, detoxification, inflammation reduction, and pain relief. It is predominantly used in treating bacterial and viral infections of the upper respiratory tract, as well as dysentery. Various reports highlight the antitumor effects of andrographolide. Yet, its specific impact and the underlying mechanism of action on Burkitt's lymphoma remain an uncharted area of research. METHOD: We employed network pharmacology to pinpoint the targets of andrographolide's action on Burkitt's lymphoma and the associated pathways. We then evaluated the impact of andrographolide on Burkitt's lymphoma using both in vitro and in vivo patient-derived xenograft (PDX) models. Concurrently, we confirmed the molecular targets of andrographolide in Burkitt's lymphoma through immunofluorescence assays. RESULT: Utilizing network pharmacology, we identified 15 relevant targets, 60 interrelationships between these targets, and numerous associated signaling pathways for andrographolide's action on Burkitt's lymphoma. In vitro efficacy tests using High-throughput Drug Sensitivity Testing and in vivo PDX model evaluations revealed that andrographolide effectively curtailed the growth of Burkitt's lymphoma. Moreover, we observed a increased in the expression of JUN (c-Jun) and CASP3 (Caspase 3) proteins in Burkitt's lymphoma cells treated with andrographolide. CONCLUSION: Andrographolide inhibits the growth of Burkitt's lymphoma by inhibiting JUN and CASP3 proteins.


Assuntos
Linfoma de Burkitt , Diterpenos , Humanos , Criança , Linfoma de Burkitt/tratamento farmacológico , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Caspase 3
13.
Indian J Ophthalmol ; 72(Suppl 1): S66-S74, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38131545

RESUMO

PURPOSE: Our aim was to identify recent research trends on diabetic macular edema (DME) and focus on publications from different countries, institutions, and authors. METHODS: We retrieved and analyzed data from January 1, 2003 to December 31, 2022 on the DME research field from the Web of Science Core Collection (WoSCC) database. Microsoft Excel and VOSviewer were applied to perform visualization analysis and evaluate the trends. RESULTS: A total of 4482 publications were identified, and the annual global publications increased steadily, from 36 to 390, during this period. The United States (1339 publications, 71,754 citations), Johns Hopkins University (176 publications, 17,015 citations), and Bressler NM (76 publications, 9621 citations) were the most influential and productive countries, institutions, and authors, respectively. The top 100 keywords were classified into five clusters: (1) therapy and adverse effects of DME; (2) clinical biomarkers of DME; (3) mechanistic research on DME; (4) improving bioavailability and efficacy; and (5) early diagnosis of diabetic complications. "Diabetic macular edema," "retinopathy," "ranibizumab," and "optical coherence tomography angiography" were the most frequent keywords. Regarding the average appearing years (AAYs) of the keywords, "deep learning" (AAY:2020.83), "optical coherence tomography angiography" (AAY:2019.59), "intravitreal Aflibercept" (AAY:2019.29), and "dexamethasone implant" (AAY:2019.20) were recognized as the hotspots of the DME research area in the short run. CONCLUSION: In the past two decades, the United States was in master status in DME research. Although intravitreal drug injection has been the mainstream therapy for a long time, the effectiveness of different drugs, such as dexamethasone, new solutions for drug delivery, such as intravitreal implantation, and more accurate tools for the classification and follow-up of DME patients, such as deep learning systems, are still research hotspots.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Humanos , Edema Macular/diagnóstico , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Retinopatia Diabética/complicações , Ranibizumab/uso terapêutico , Tomografia de Coerência Óptica/métodos , Bibliometria , Dexametasona/uso terapêutico , Injeções Intravítreas
14.
Micromachines (Basel) ; 14(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38138360

RESUMO

With increasing interest in the rapid development of lattice structures, hybrid additive manufacturing (HAM) technology has become a competent alternative to traditional solutions such as water jet cutting and investment casting. Herein, a HAM technology that combines vat photopolymerization (VPP) and electroless/electroplating processes is developed for the fabrication of multifunctional polymer-metal lattice composites. A VPP 3D printing process is used to deliver complex lattice frameworks, and afterward, electroless plating is employed to deposit a thin layer of nickel-phosphorus (Ni-P) conductive seed layer. With the subsequent electroplating process, the thickness of the copper layer can reach 40 µm within 1 h and the resistivity is around 1.9×10-8 Ω⋅m, which is quite close to pure copper (1.7 ×10-8 Ω⋅m). The thick metal shell can largely enhance the mechanical performance of lattice structures, including structural strength, ductility, and stiffness, and meanwhile provide current supply capability for electrical applications. With this technology, the frame arms of unmanned aerial vehicles (UAV) are developed to demonstrate the application potential of this HAM technology for fabricating multifunctional polymer-metal lattice composites.

15.
Environ Technol ; : 1-18, 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38158759

RESUMO

Foreign direct investment (FDI) plays an important role in promoting industrial structure and curbing carbon emission. The study is based on panel data from 30 provinces in China from 2011 to 2021 and verifies the impact of FDI under environmental regulation on industrial structure upgrading and carbon emission. The empirical results show that FDI under environmental regulation can inhibit carbon emission and promote industrial structure upgrading. The carbon emission reduction effect and industrial structure upgrading effect of FDI show regional heterogeneity, with the strongest effect in the eastern region, followed by the central region, and no significant effect in the western region. The moderating effect examination of environmental regulation illustrates that formal and informal environmental regulation can effectively regulate the relationship between FDI and carbon emission, but due to differences in various factors such as economic development level and population quality, the moderating effect also exhibits regional heterogeneity. In the mechanism test, industrial structure upgrading plays a perfect mediating role in the path of FDI inhibiting carbon emission, and environmental regulation can further enhance the mediating effect of industrial structure upgrading. There is a threshold of industrial structure upgrading between FDI and carbon emission, and FDI can only suppress carbon emission after crossing the threshold of industrial structure upgrading.

16.
Micromachines (Basel) ; 15(1)2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38258148

RESUMO

Nowadays, additive manufacturing (AM) is advanced to deliver high-value end-use products rather than individual components. This evolution necessitates integrating multiple manufacturing processes to implement multi-material processing, much more complex structures, and the realization of end-user functionality. One significant product category that benefits from such advanced AM technologies is 3D microelectronics. However, the complexity of the entire manufacturing procedure and the various microstructures of 3D microelectronic products significantly intensified the risk of product failure due to fabrication defects. To respond to this challenge, this work presents a defect detection technology based on deep learning and machine vision for real-time monitoring of the AM fabrication process. We have proposed an enhanced YOLOv8 algorithm to train a defect detection model capable of identifying and evaluating defect images. To assess the feasibility of our approach, we took the extrusion 3D printing process as an application object and tailored a dataset comprising a total of 3550 images across four typical defect categories. Test results demonstrated that the improved YOLOv8 model achieved an impressive mean average precision (mAP50) of 91.7% at a frame rate of 71.9 frames per second.

17.
Micromachines (Basel) ; 15(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276830

RESUMO

Lattice structures are a group of cellular materials composed of regular repeating unit cells. Due to their extraordinary mechanical properties, such as specific mechanical strength, ultra-low density, negative Poisson's ratio, etc., lattice structures have been widely applied in the fields of aviation and aerospace, medical devices, architecture, and automobiles. Hybrid additive manufacturing (HAM), an integrated manufacturing technology of 3D printing processes and other complementary processes, is becoming a competent candidate for conveniently delivering lattice structures with multifunctionalities, not just mechanical aspects. This work proposes a HAM technology that combines vat photopolymerization (VPP) and electroless plating process to fabricate smart metal-coated lattice structures. VPP 3D printing process is applied to create a highly precise polymer lattice structure, and thereafter electroless plating is conducted to deposit a thin layer of metal, which could be used as a resistive sensor for monitoring the mechanical loading on the structure. Ni-P layer and copper layer were successfully obtained with the resistivity of 8.2×10-7Ω⋅m and 2.0 ×10-8 Ω⋅m, respectively. Smart lattice structures with force-loading self-sensing functionality are fabricated to prove the feasibility of this HAM technology for fabricating multifunctional polymer-metal lattice composites.

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