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1.
Neural Regen Res ; 20(3): 695-714, 2025 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38886936

RESUMEN

Alzheimer's disease, the primary cause of dementia, is characterized by neuropathologies, such as amyloid plaques, synaptic and neuronal degeneration, and neurofibrillary tangles. Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs, targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment. Metabolic abnormalities are commonly observed in patients with Alzheimer's disease. The liver is the primary peripheral organ involved in amyloid-beta metabolism, playing a crucial role in the pathophysiology of Alzheimer's disease. Notably, impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease. In this review, we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism. Furthermore, we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.

2.
Eur J Neurosci ; 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39161987

RESUMEN

Readers of Chinese characters need to recognize how they are formed in order to identify them correctly. However, our understanding of the cognitive processing of characters in working memory is limited. In Experiment 1, using the character N-back task paradigm, electrophysiological data were recorded from 26 participants to investigate the effects of the visual feature of radicals on neural activity during the character recognition, updating and maintenance in the N-back task. Results showed that compound characters required longer response times than single-component characters. For the event-related potentials (ERPs), the compound character condition had more negative N2pc and lower P300 amplitudes than the single-component character condition. In Experiment 2, data from 26 participants were used to analyse the effect of the phonological feature of radicals on neural activity during the character recognition, updating and maintenance in the N-back task. Results showed that there was a larger P200 in the irregular character condition than in the regular character condition, but there was no difference between the regular and the irregular characters in the N2pc, P300 and slow wave (SW) components. The visual feature and the phonological feature of the radicals may have different effects on the character processing. This study reveals the neural effects of Chinese character radicals on cognitive processing in a working memory task and provides behavioural and electrophysiological evidence for a theoretical model of verbal working memory subprocesses.

3.
Adv Sci (Weinh) ; : e2308974, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39099402

RESUMEN

Dopaminergic (DA) neurons are known to play a key role in controlling behaviors. While DA neurons in other brain regions are extensively characterized, those in zona incerta (ZITH or A13) receive much less attention and their function remains to be defined. Here it is shown that optogenetic stimulation of these neurons elicited intensive self-grooming behaviors and promoted place preference, which can be enhanced by training but cannot be converted into contextual memory. Interestingly, the same stimulation increased DA release to periaqueductal grey (PAG) neurons and local PAG antagonism of DA action reduced the elicited self-grooming. In addition, A13 neurons increased their activity in response to various external stimuli and during natural self-grooming episodes. Finally, monosynaptic retrograde tracing showed that the paraventricular hypothalamus represents one of the major upstream brain regions to A13 neurons. Taken together, these results reveal that A13 neurons are one of the brain sites that promote appetitive self-grooming involving DA release to the PAG.

5.
Talanta ; 280: 126680, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39128317

RESUMEN

Characterization of chemical composition in cigarette smoke is essential for establishing smoke-related exposure estimates. Currently used methods require complex sample preparation with limited capability for obtaining accurate chemical information. We have developed an in situ solid-phase microextraction (SPME) method for online processing of smoke aerosols and directly coupling the SPME probes with confined-space direct analysis in real time (cDART) ion source for high-resolution mass spectrometry (MS) analysis. In a confined space, the substances from SPME probes can be efficiently desorbed and ionized using the DART ion source, and the diffusion and evaporation of volatile species into the open air can be largely avoided. Using SPME-cDART-MS, mainstream smoke (MSS) and side-stream smoke (SSS) can be investigated and the whole analytical protocol can be accomplished in a few min. More than five hundred substances and several classes of compounds were detected and identified. The relative contents of 13 tobacco alkaloids were compared between MSS and SSS. Multivariate data analysis unveiled differences between different types of cigarette smoke and also discovered the characteristic ions. The method is reliable with good reproducibility and repeatability, and has the potential to be quantitative. This study provides a simple and high-efficiency method for smokeomics profiling of complex aerosol samples with in situ online extraction of volatile samples, and direct integration of extracted probes with a modified ambient ionization technique.

6.
J Appl Res Intellect Disabil ; 37(5): e13246, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38982871

RESUMEN

BACKGROUND: Measurement instruments to understand self-determined motivation towards physical activity among college students with intellectual disabilities are needed to develop programs to support physical and psychological health and well-being. The purpose of the current study was to validate a modified questionnaire measuring basic psychological needs towards physical activity among college students with intellectual disabilities. METHODS: A total of 108 college students with intellectual disabilities completed the modified questionnaire. Validity and reliability of the questionnaire was examined. RESULTS: Confirmatory factor analysis demonstrated a six-factor model had good model fit. Cronbach's alpha values showed acceptable reliability evidence of the instrument as a whole, although some alpha values in subdomains of the instrument were below acceptable values. CONCLUSION: The modified questionnaire was found to have acceptable validity evidence. Further studies are needed with refinement of answer options and the addition of more questions to increase reliability.


Asunto(s)
Ejercicio Físico , Discapacidad Intelectual , Estudiantes , Humanos , Discapacidad Intelectual/psicología , Masculino , Femenino , Adulto Joven , Estudiantes/psicología , Adulto , Reproducibilidad de los Resultados , Universidades , Psicometría/normas , Psicometría/instrumentación , Adolescente , Encuestas y Cuestionarios , Motivación
7.
Anal Chim Acta ; 1317: 342919, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39030015

RESUMEN

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in widespread disease transmission, challenging the stability of global healthcare systems. Surface-enhanced Raman scattering (SERS) as an easy operation, fast, and low-cost technology illustrates a good potential in detecting SARS-CoV-2. In the study, one-step fabrication of gold-silver alloy nanoparticles (AuAgNPs) with adjustable metal proportions and diameters is employed as SERS substrates. The angiotensin-converting enzyme 2 (ACE2) functionalized AuAgNPs are applied as sensor surfaces to detect SARS-CoV-2 S protein. By optimizing the SERS substrates, ACE2/Au35Ag65NPs illustrate higher performance in detecting the SARS-CoV-2 S protein with a limit of detection (LOD) of 10 fg/mL in both phosphate-buffered saline (PBS) and pharyngeal swabs solution (PSS). It also provides excellent reproducibility with a relative standard deviation (RSD) of 7.7 % and 7.9 %, respectively. This easily preparable and highly reproducible SERS substrate has good potential in the practical application of detecting SARS-CoV-2.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Oro , Límite de Detección , Nanopartículas del Metal , SARS-CoV-2 , Plata , Espectrometría Raman , Glicoproteína de la Espiga del Coronavirus , Espectrometría Raman/métodos , Plata/química , Glicoproteína de la Espiga del Coronavirus/análisis , Nanopartículas del Metal/química , SARS-CoV-2/aislamiento & purificación , Humanos , Oro/química , COVID-19/diagnóstico , COVID-19/virología , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/química , Aleaciones/química
8.
J Nutr Biochem ; 133: 109708, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39059479

RESUMEN

Gut flora is considered to modulate lipid transport from the intestine into the bloodstream, and thus may potentially participate in the development of GDM. Although previous studies have shown that the intestinal microbiota influences lipid transport and metabolism in GDM, the precise mechanisms remain elusive. To address this, we used a high-fat diet (HFD)-induced GDM mouse model and conducted 16s rRNA sequencing and fecal metabolomics to assess gut microbial community shifts and associated metabolite changes. Western blot, ELISA, and chromatin immunoprecipitation (ChIP) were utilized to elucidate how gut microbiota affect intestinal lipid transport and the insulin sensitivity of hepatic, adipose, and skeletal muscle tissues. We found that HFD impaired the oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) in pregnant mice. 16s rRNA sequencing demonstrated profound compositional changes, especially in the relative abundances of Firmicutes and Bacteroidetes. Metabolomics analysis presented a decline in the concentration of short-chain fatty acids (SCFAs) in the GDM group. Western blot analyses showed an upregulation of HDAC3 and a concurrent reduction in H3K27 acetylation in the intestine. ChIP-qPCR showed that PPAR-γ was inhibited, which in turn activated lipid-transporter CD36. ELISA and insulin signaling pathway detection in insulin-target organs showed high concentrations of circulating fatty acids and triglycerides and insulin resistance in insulin-target organs. Our results suggest that gut microbiota is closely associated with the development of GDM, partly because decreased gut flora-associated SCFAs activate CD36 by suppressing the HDAC3-H3K27ac-PPAR-γ axis to transport excessive fatty acids and triglycerides into blood circulation, thereby dysregulating the insulin sensitivity of insulin target organs.

9.
Zool Res ; 45(4): 877-909, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39004865

RESUMEN

The tree shrew ( Tupaia belangeri) has long been proposed as a suitable alternative to non-human primates (NHPs) in biomedical and laboratory research due to its close evolutionary relationship with primates. In recent years, significant advances have facilitated tree shrew studies, including the determination of the tree shrew genome, genetic manipulation using spermatogonial stem cells, viral vector-mediated gene delivery, and mapping of the tree shrew brain atlas. However, the limited availability of tree shrews globally remains a substantial challenge in the field. Additionally, determining the key questions best answered using tree shrews constitutes another difficulty. Tree shrew models have historically been used to study hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, myopia, and psychosocial stress-induced depression, with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases. Despite these efforts, the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research. This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model. We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies. The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models, meeting the increasing demands of life science and biomedical research.


Asunto(s)
Investigación Biomédica , Animales , Investigación Biomédica/tendencias , Tupaiidae , Modelos Animales de Enfermedad , Tupaia , Modelos Animales
10.
Artículo en Inglés | MEDLINE | ID: mdl-38980778

RESUMEN

This article is committed to studying projective synchronization and complete synchronization (CS) issues for one kind of discrete-time variable-order fractional neural networks (DVFNNs) with time-varying delays. First, two new variable-order fractional (VF) inequalities are built by relying on nabla Laplace transform and some properties of Mittag-Leffler function, which are extensions of constant-order fractional (CF) inequalities. Moreover, the VF Halanay inequality in discrete-time sense is strictly proved. Subsequently, some sufficient projective synchronization and CS criteria are derived by virtue of VF inequalities and hybrid controllers. Finally, we exploit numerical simulation examples to verify the validity of the derived results, and a practical application of the obtained results in image encryption is also discussed.

11.
Talanta ; 279: 126595, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39053356

RESUMEN

Multivariate calibration models often encounter challenges in extrapolating beyond the calibration instruments due to variations in hardware configurations, signal processing algorithms, or environmental conditions. Calibration transfer techniques have been developed to mitigate this issue. In this study, we introduce a novel methodology known as Supervised Factor Analysis Transfer (SFAT) aimed at achieving robust and interpretable calibration transfer. SFAT operates from a probabilistic framework and integrates response variables into its transfer process to effectively align data from the target instrument to that of the source instrument. Within the SFAT model, the data from the source instrument, the target instrument, and the response variables are collectively projected onto a shared set of latent variables. These latent variables serve as the conduit for information transfer between the three distinct domains, thereby facilitating effective spectra transfer. Moreover, SFAT explicitly models the noise variances associated with each variable, thereby minimizing the transfer of non-informative noise. Furthermore, we provide empirical evidence showcasing the efficacy of SFAT across three real-world datasets, demonstrating its superior performance in calibration transfer scenarios.

13.
Entropy (Basel) ; 26(6)2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38920454

RESUMEN

Salient object detection (SOD) aims to accurately identify significant geographical objects in remote sensing images (RSI), providing reliable support and guidance for extensive geographical information analyses and decisions. However, SOD in RSI faces numerous challenges, including shadow interference, inter-class feature confusion, as well as unclear target edge contours. Therefore, we designed an effective Global Semantic-aware Aggregation Network (GSANet) to aggregate salient information in RSI. GSANet computes the information entropy of different regions, prioritizing areas with high information entropy as potential target regions, thereby achieving precise localization and semantic understanding of salient objects in remote sensing imagery. Specifically, we proposed a Semantic Detail Embedding Module (SDEM), which explores the potential connections among multi-level features, adaptively fusing shallow texture details with deep semantic features, efficiently aggregating the information entropy of salient regions, enhancing information content of salient targets. Additionally, we proposed a Semantic Perception Fusion Module (SPFM) to analyze map relationships between contextual information and local details, enhancing the perceptual capability for salient objects while suppressing irrelevant information entropy, thereby addressing the semantic dilution issue of salient objects during the up-sampling process. The experimental results on two publicly available datasets, ORSSD and EORSSD, demonstrated the outstanding performance of our method. The method achieved 93.91% Sα, 98.36% Eξ, and 89.37% Fß on the EORSSD dataset.

15.
Respir Res ; 25(1): 261, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38943142

RESUMEN

AIMS: To detect the expression of autophagy components, p38 MAPK (p38) and phosphorylated forkhead box transcription factor O-1 (pFoxO1) in pulmonary vascular endothelial cells of chronic thromboembolic pulmonary hypertension (CTEPH) rats and to investigate the possible mechanism through which tissue factor (TF) regulates autophagy. METHODS: Pulmonary artery endothelial cells (PAECs) were isolated from CTEPH (CTEPH group) and healthy rats (control group (ctrl group)) which were cocultured with TF at different time points including 12 h, 24 h, 48 h and doses including 0 nM,10 nM, 100 nM, 1µM, 10µM, 100µM and cocultured with TFPI at 48 h including 0 nM, 2.5 nM, 5 nM. The expression of forkhead box transcription factor O-1 (FoxO1), pFoxO1, p38, Beclin-1 and LC3B in PAECs was measured. Coimmunoprecipitation (co-IP) assays were used to detect the interaction between FoxO1 and LC3. RESULTS: The protein expression of p-FoxO1/FoxO1 was significantly lower in the CTEPH groups (cocultured with TF from 0 nM to 100 µM) than in the ctrl group at 12 h, 24 h, and 48 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of p38 in the CTEPH groups treated with 0 nM, 10 nM, 100 nM or 1 µM TF for 48 h significantly increased than ctrl groups (P < 0.05) and was significantly increased in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of Beclin1 at the same concentration (cocultured with TF from 0 nM to 100 µM) was significantly lower in the CTEPH groups than ctrl groups after 24 h and 48 h (P < 0.05) and was significantly decreased in the CTEPH groups (cocultured with TFPI concentration from 2.5 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of LC3-II/LC3-I at the same concentration (cocultured with TF 0 nM, 1 µM, 10 µM, and 100 µM) was significantly lower in the CTEPH than in the ctrl groups after 12 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). There were close interactions between FoxO1 and LC3 in the control and CTEPH groups at different doses and time points. CONCLUSION: The autophagic activity of PAECs from CTEPH rats was disrupted. TF, FoxO1 and p38 MAPK play key roles in the autophagic activity of PAECs. TF may regulate autophagic activity through the p38 MAPK-FoxO1 pathway.


Asunto(s)
Autofagia , Células Endoteliales , Hipertensión Pulmonar , Arteria Pulmonar , Ratas Sprague-Dawley , Tromboplastina , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , Autofagia/fisiología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , Ratas , Masculino , Células Endoteliales/metabolismo , Células Cultivadas , Tromboplastina/metabolismo , Tromboplastina/biosíntesis , Hipertensión Pulmonar/metabolismo , Embolia Pulmonar/metabolismo , Embolia Pulmonar/patología , Enfermedad Crónica , Transducción de Señal/fisiología , Proteína Forkhead Box O1
16.
Avian Pathol ; : 1-10, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38922304

RESUMEN

RESEARCH HIGHLIGHTS: First confirmation of AOAV-16 in domestic and wild birds in China.AOAV-16 are low virulent viruses for chickens.Co-circulation/co-infection of AOAV-16 and H9N2 subtype AIV enhanced pathogenicity.Different intergenic sequences and recombination events exist within AOAV-16.

17.
MedComm (2020) ; 5(7): e617, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38887468

RESUMEN

Coffee, a widely consumed beverage, has shown benefits for human health but lacks sufficient basic and clinical evidence to fully understand its impacts and mechanisms. Here, we conducted a cross-sectional observational study of coffee consumption and a 1-month clinical trial in humans. We found that coffee consumption significantly reshaped the immune system and metabolism, including reduced levels of inflammatory factors and a reduced frequency of senescent T cells. The frequency of senescent T cells and the levels of the senescence-associated secretory phenotype were lower in both long-term coffee consumers and new coffee consumers than in coffee nondrinking subjects, suggesting that coffee has anti-immunosenescence effects. Moreover, coffee consumption downregulated the activities of the The Janus kinase/signal transduction and activator of transcription (JAK/STAT) and mitogen-activated protein kinases (MAPK) signaling pathways and reduced systemic proinflammatory cytokine levels. Mechanistically, coffee-associated metabolites, such as 1-methylxanthine, 3-methylxanthine, paraxanthine, and ceramide, reduced the frequency of senescent CD4+CD57+ T cells in vitro. Finally, in vivo, coffee intake alleviated inflammation and immunosenescence in imiquimod-induced psoriasis-like mice. Our results provide novel evidence of the anti-inflammatory and anti-immunosenescence effects of coffee, suggesting that coffee consumption could be considered a healthy habit.

18.
Cancer Immunol Immunother ; 73(8): 154, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38833154

RESUMEN

BACKGROUND: Alpha-fetoprotein elevated gastric cancer (AFPGC) got growing interests for its aggressive nature and unfavorable prognosis. Here, a phase 1 dose escalation study was conducted to evaluate safety and efficacy of zimberelimab (GLS-010, anti-PD-1) plus lenvatinib and chemotherapy (XELOX) as the first-line treatment for AFPGC. METHODS: Histologically confirmed HER2-negative, advanced GC patients with elevated serum AFP level (≥ 20 ng/ml) were screened. Using a 3 + 3 dose escalation design, patients were administered varying doses of lenvatinib (12, 16, 20 mg) with GLS-010 and XELOX. The primary endpoints were safety and determination of recommended phase II dose (RP2D). Secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and disease control rate. RESULTS: Nine patients were enrolled with no dose-limiting toxicities observed. Most frequent treatment-related AEs were fatigue (55.6%), hand-foot syndrome (55.6%) and rash (55.6%), and no grade ≥ 4 AEs were reported. All patients exhibited disease control with ORR reaching 33.3%. The median PFS and OS reached 7.67 months (95% CI 4.07-11.27) and 13.17 months (95% CI 2.78-23.56), respectively. Serum AFP level was found correlated with therapeutic responses. Further 16s rRNA sequencing analysis demonstrated altered gut microbiota with elevated abundance of Lachnospiraceae bacterium-GAM79 and Roseburia hominis A2-183. CONCLUSIONS: GLS-010 plus lenvatinib and XELOX demonstrated a manageable safety profile with promising efficacy for AFPGC. With RP2D of lenvatinib determined as 16 mg, further expansion cohort is now ongoing. Translational investigation suggested that serum AFP can be indictive for therapeutic responses and certain microbiota species indicating favorable responses to immunotherapy was elevated after the combinational treatment.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Compuestos de Fenilurea , Quinolinas , Neoplasias Gástricas , alfa-Fetoproteínas , Humanos , Quinolinas/uso terapéutico , Quinolinas/administración & dosificación , Masculino , Femenino , Persona de Mediana Edad , Compuestos de Fenilurea/uso terapéutico , Compuestos de Fenilurea/administración & dosificación , Compuestos de Fenilurea/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/mortalidad , Anciano , alfa-Fetoproteínas/metabolismo , alfa-Fetoproteínas/análisis , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Adulto , Pronóstico
19.
Endocr Relat Cancer ; 31(9)2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38904412

RESUMEN

Scientific evidence has linked diabetes to a higher incidence and increased aggressiveness of breast cancer; however, mechanistic studies of the numerous regulators involved in this process are insufficiently thorough. Advanced glycation end products (AGEs) play an important role in the chronic complications of diabetes, but the mechanisms of AGEs in breast cancer are largely unexplored. In this study, we first demonstrate that high AGE levels in breast cancer tissues are associated with the diabetic state and poor patient outcomes. Furthermore, AGEs interact with the receptor for AGEs (RAGE) to promote breast cancer cell migration and invasion. Mechanistically, based on RNA sequencing (RNA-seq) analysis, we reveal that growth arrest and DNA damage gene 45α (GADD45α) is a vital protein upregulated by AGEs through a P53-dependent pathway. Next, GADD45α recruits thymine DNA glycosylase for base excision repair to form the demethylation complex at the promoter region of MMP-9 and enhance MMP-9 transactivation through DNA demethylation. Overall, our results indicate a critical regulatory role of AGEs in patients with breast cancer and diabetes and reveal a novel mechanism of epigenetic modification in promoting breast cancer metastasis.


Asunto(s)
Neoplasias de la Mama , Proteínas de Ciclo Celular , Productos Finales de Glicación Avanzada , Metaloproteinasa 9 de la Matriz , Regiones Promotoras Genéticas , Humanos , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Femenino , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Productos Finales de Glicación Avanzada/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Reparación del ADN , Metástasis de la Neoplasia , Línea Celular Tumoral , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Animales , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Persona de Mediana Edad , Proteinas GADD45
20.
Rev Sci Instrum ; 95(5)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38739424

RESUMEN

Multidimensional microdriving stage is one of the key components to realize precision driving and high-precision positioning. To meet nanometer displacement and positioning in the fields of micro-/nano-machining and precision testing, a new six-degree-of-freedom microdriving stage (6-DOF-MDS) of multilayer spatially distributed piezoelectric ceramic actuators (PZTs) is proposed and designed. The interior of the 6-DOF-MDS is a hollow design. The flexure hinge is used as the transmission mechanism, and the series-parallel hybrid driving of the corresponding PZTs achieves the microtranslation in the X, Y, and Z directions and the microrotation around the three axes of the microdriving stage, forming a microdisplacement mechanism with high rigidity and simple structure, which can realize the microfeed of 6-DOF. The force-displacement theory and lug boss structure optimization of the 6-DOF-MDS are analyzed, while the strength checking and natural frequency of the 6-DOF-MDS are also simulated by the finite element method. In addition, the real-time motion control system of the 6-DOF-MDS is designed based on Advanced RISC Machines. Through a series of verification experiments, the stroke and resolution results of the 6-DOF-MDS are obtained, where the displacements in the X, Y, and Z directions are 20.72, 20.02, and 37.60 µm, respectively. The resolution is better than 0.68 nm. The rotation angles around X, Y, and Z are 38.96″, 33.80″, and 27.87″, respectively, with an angular resolution of 0.063″. Relevant coupling experiments were also performed in this paper; in the full stroke linear running of X-axis, the maximum coupling displacements of the Y- and Z-axes are 1.04 and 0.17 µm, respectively, with the corresponding coupling rates of ∼5.0% and 0.8%. The maximum coupling angles for the X-, Y-, and Z-axes are 0.33″, 0.14″, and 2.30″, respectively. Considering the coupling of the 6-DOF-MDS, decoupling measures and specific mathematical models have also been proposed. The proposed multidimensional microdriving stage achieves subnanometer resolution and can be used for the precise positioning and attitude control of precision instruments at the nano-/subnanometer level.

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