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1.
JTO Clin Res Rep ; 5(6): 100678, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38846810

RESUMO

Introduction: The available approved anticancer drugs for Chinese patients are relatively limited because of China's low participation rate in international clinical trials. Therefore, a focus on approved anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) drugs in China is needed. This study aims to assess the heterogeneity of anti-PD-1/PD-L1 antibodies manufactured in China (domestic PD-1/PD-L1) and overseas (imported PD-1/PD-L1) when combined with chemotherapy as the first-line treatment of NSCLC. Methods: A systematic search was performed using PubMed, EMBASE, and Cochrane Library of publications up to July 13, 2023. Meta-analysis was applied to compare the efficacy and safety profile between anti-PD-1/PD-L1 antibodies plus chemotherapy (PD-1/PD-L1+Chemo) and chemotherapy alone using STATA software. Pooled hazard ratios for progression-free survival and overall survival, odds ratios for objective response rate, and incidence rate of grade greater than or equal to three treatment-related adverse events with 95% confidence intervals were calculated in the domestic group and imported group by a random-effects model, and the heterogeneity between the two estimates was assessed. Results: There were 14 eligible clinical studies with a total of 3951 patients involved in this analysis, including eight studies of domestic PD-1/PD-L1+Chemo and six studies of imported PD-1/PD-L1+Chemo. The study revealed that there was no significant difference between domestic and imported PD-1/PD-L1+Chemo in overall survival (p = 0.80), progression-free survival (p = 0.53), and incidence rate of grade greater than or equal to three treatment-related adverse events (p = 0.10). Nevertheless, the objective response rate of imported PD-1/PD-L1+Chemo was significantly higher than that of domestic PD-1/PD-L1+Chemo (p = 0.03). Conclusions: Domestic anti-PD-1/PD-L1 antibodies plus chemotherapy were found to have comparable efficacy and safety to those combined with imported anti-PD-1/PD-L1 antibodies based on current evidence.

2.
Biochem Biophys Res Commun ; 723: 150163, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-38820626

RESUMO

Excitation-contraction coupling in skeletal muscle myofibers depends upon Ca2+ release from the sarcoplasmic reticulum through the ryanodine receptor/Ca2+-release channel RyR1. The RyR1 contains ∼100 Cys thiols of which ∼30 comprise an allosteric network subject to posttranslational modification by S-nitrosylation, S-palmitoylation and S-oxidation. However, the role and function of these modifications is not understood. Although aberrant S-nitrosylation of multiple unidentified sites has been associated with dystrophic diseases, malignant hyperthermia and other myopathic syndromes, S-nitrosylation in physiological situations is reportedly specific to a single (1 of ∼100) Cys in RyR1, Cys3636 in a manner gated by pO2. Using mice expressing a form of RyR1 with a Cys3636→Ala point mutation to prevent S-nitrosylation at this site, we showed that Cys3636 was the principal target of endogenous S-nitrosylation during normal muscle function. The absence of Cys3636 S-nitrosylation suppressed stimulus-evoked Ca2+ release at physiological pO2 (at least in part by altering the regulation of RyR1 by Ca2+/calmodulin), eliminated pO2 coupling, and diminished skeletal myocyte contractility in vitro and measures of muscle strength in vivo. Furthermore, we found that abrogation of Cys3636 S-nitrosylation resulted in a developmental defect reflected in diminished myofiber diameter, altered fiber subtypes, and altered expression of genes implicated in muscle development and atrophy. Thus, our findings establish a physiological role for pO2-coupled S-nitrosylation of RyR1 in skeletal muscle contractility and development and provide foundation for future studies of RyR1 modifications in physiology and disease.


Assuntos
Músculo Esquelético , Canal de Liberação de Cálcio do Receptor de Rianodina , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Animais , Músculo Esquelético/metabolismo , Camundongos , Cálcio/metabolismo , Cisteína/metabolismo , Processamento de Proteína Pós-Traducional , Desenvolvimento Muscular , Camundongos Transgênicos , Sinalização do Cálcio
3.
Int J Stem Cells ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38658195

RESUMO

Tissue engineering envisions functional substitute creation for damaged tissues. Insulin-like growth factor-1 (IGF-1) plays roles in bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation (OD), and we investigated its specific mechanism. BMSCs were cultured and OD was induced. Surface antigens (CD105, CD90, CD44, CD45, CD34) were identified by flow cytometry. Adipogenic, chondrogenic, and osteogenic differentiation abilities of BMSCs were observed. BMSCs were cultured in osteogenic medium containing 80 ng/mL IGF-1 for 3 weeks. Alkaline phosphatase activity, calcification level, osteogenic factor (runt related protein 2 [RUNX2], osteocalcin [OCN], osterix [OSX]), total (t-) ERK1/2 and phosphorylated- (p-) ERK1/2 levels, and SRY-related high-mobility-group box 4 (SOX4) levels were assessed by alkaline phosphatase staining and Alizarin Red staining, Western blot, and reverse transcription-quantitative polymerase chain reaction. The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway inhibitor (PD98059) was used to inhibit the MAPK/ERK pathway in IGF-1-treated BMSCs. Small interfering-SOX4 was transfected into BMSCs to down-regulate SOX4. IGF-1 increased alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels in BMSCs, indicating that IGF-1 induced rat BMSC OD. SOX4, and p-ERK1/2 and t-ERK1/2 levels were elevated in IGF-1-induced BMSCs, which were annulled by PD98059. PD98059 partly averted IGF-1-induced rat BMSC OD. SOX4 levels, alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels were reduced after SOX4 down-regulation, showing that downregulation of SOX4 averted the effect of IGF-1 on inducing rat BMSC OD. IGF-1 induced rat BMSC OD by stimulating SOX4 via the MAPK/ERK pathway.

5.
Macromol Rapid Commun ; : e2400059, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538294

RESUMO

Many crucial components inside electronic devices are made from non-renewable, non-biodegradable, and potentially toxic materials, leading to environmental damage. Finding alternative green dielectric materials is mandatory to align with global sustainable goals. Carboxymethyl cellulose (CMC) is a bio-polymer derived from cellulose and has outstanding properties. Herein, citric acid, dextrin, and CMC based hydrogels are prepared, which are biocompatible and biodegradable and exhibit rubber-like mechanical properties, with Young modulus values of 0.89 MPa. Hence, thin film CMC-based hydrogel is explored as a suitable green high-k dielectric candidate for operation at low voltages, demonstrating a high dielectric constant of up to 78. These fabricated transistors reveal stable high capacitance (2090 nF cm-2) for ≈±3 V operation. Using a polyelectrolyte-type approach and poly-(2-vinyl anthracene) (PVAn) surface modification, this study demonstrates a thin dielectric layer (d ≈30 nm) with a small voltage threshold (Vth ≈-0.8 V), moderate transconductance (gm ≈65 nS), and high ON-OFF ratio (≈105). Furthermore, the dielectric layer exhibits stable performance under bias stress of ± 3.5 V and 100 cycles of switching tests. The modified CMC-based hydrogel demonstrates desirable performance as a green dielectric for low-voltage operation, further highlighting its biocompatibility.

6.
Sci Rep ; 14(1): 6183, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485982

RESUMO

Digital transformation has emerged as a powerful force in reshaping the business landscape and enabling organizations to enhance their capabilities. One critical aspect of this change is how it impacts an enterprise's innovation ability. To explore this question, we select data regarding China's A-share listed enterprises from 2007 to 2021 as the research sample. We employ crawler technology to gather keywords related to "digital transformation" from annual reports, portraying detailed journeys of enterprises' digital transformation. Through descriptive statistics and multiple covariance tests, a linear relationship is established between digital transformation and innovation ability. Benchmark regression is conducted and a robustness test is utilized to determine the robustness of the benchmark regression. The mechanism, heterogeneity, and moderating effects of this study are also tested. The results reveal that digital transformation makes a significant positive contribution to the innovation capability of enterprises. Meanwhile, among different types of enterprises, the impact of digital transformation on enterprise innovation capability shows heterogeneity. In terms of the impact mechanism, digital transformation can enhance the innovation output of enterprises by reducing the agency cost and improving the risk-taking level of enterprises, so as to further improve the innovation capability of enterprises. The research results of this paper provide essential theoretical support for the digital transformation of enterprises and the government's formulation of enterprises' digitalization strategies. More profoundly, it provides significant reference for how to further promote the digital transformation of Chinese enterprises.

7.
Sci Rep ; 14(1): 6177, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38486068

RESUMO

With advanced science and digital technology, digital transformation has become an important way to promote the sustainable development of enterprises. However, the existing research only focuses on the linear relationship between a single characteristic and digital transformation. In this study, we select the data of Chinese A-share listed companies from 2010 to 2020, innovatively use the machine learning method and explore the differences in the predictive effects of multi-dimensional features on the digital transformation of enterprises based on the Technology-Organization-Environment (TOE) theory, thus identifying the main drivers affecting digital transformation and the fitting models with stronger predictive effect. The study found that: first, by comparing machine learning and traditional linear regression models, it is found that the prediction ability of ensemble earning method is generally higher than that of tradition measurement method. For the sample data selected in this research, XGBoost and LightGBM have strong explanatory ability and high prediction accuracy. Second, compared with the technical driving force and environmental driving force, the organizational driving force has a greater impact. Third, among these characteristics, equity concentration and executives' knowledge level in organizational dimension have the greatest impact on digital transformation. Therefore, enterprise managers should always pay attention to the decision-making role of equity concentration and executives' knowledge level. This study further enriches the literature on digital transformation in enterprises, expands the application of machine learning in economics, and provides a theoretical basis for enterprises to enhance digital transformation.

8.
Chemosphere ; 354: 141739, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38503383

RESUMO

Considering the persistent and covert nature of heavy metal soil contamination, the sustainable development of ecological environments and food safety is at significant risk. Our study focuses on remediating soils contaminated with chromium (Cr); we introduce an advanced remediation material, iron oxide phosphoric acid-loaded activated biochar (HFBC), synthesized through pyrolysis. This HFBC displays greater microporosity, fewer impurities, and enhanced efficiency for the remediation process. Our research utilized a comprehensive set of analytical techniques, including Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS), alongside adsorption studies to elucidate the Cr removal mechanism. The effectiveness of HFBC in remediation was influenced by several factors: the pH level, dosage of HFBC, the initial concentration of Cr, and the ambient temperature. Our results indicated an optimal chromium (VI) adsorption capacity of 55.5 mg/g by HFBC at a pH of 6.0 and a temperature of 25 °C, with the process adhering to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm, thus suggesting spontaneity in the uptake method. Moreover, this mechanism encompasses both adsorption and reduction reactions. Using HFBC in pot experiments with cabbage indicated not only an increase in soil pH and cation exchange capacity (CEC), but also a surge in bacterial community abundance. Significant reductions in bioavailable chromium were also recorded. Interestingly, HFBC addition bolstered the growth of cabbage, while concurrently diminishing chromium accumulation within the plant, particularly notable as the HFBC application rate increased. In summation, the HFBC produced in our study has demonstrated convincing efficacy in removing chromium from aqueous solutions and soil. Moreover, the positive agronomic implications of its use, such as enhanced plant growth and reduced heavy metal uptake by plants, indicate its high potential for operational value in the domain of environmental remediation of heavy metals.


Assuntos
Cloretos , Compostos Férricos , Ácidos Fosfóricos , Typhaceae , Poluentes Químicos da Água , Água , Solo/química , Cromo/química , Carvão Vegetal/química , Adsorção , Poluentes Químicos da Água/análise , Cinética
9.
Biochem Biophys Res Commun ; 706: 149765, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38484573

RESUMO

Bacterial chemoreceptors sense the extracellular signals and regulate bacterial motilities, biofilm formation, etc. The periplasmic ligand binding domains of chemoreceptors occur as different structural folds and recognize a diversity of chemical molecules. In Pseudomonas aeruginosa (PAO1), two bacterial chemoreceptors, McpN (PA2788) and PilJ (PA0411), are proposed to both contain a PilJ-like ligand-binding domain (LBD) (Pfam motif PF13675) and involved in nitrate chemotaxis and type IV pilus-mediated motility, respectively. The LBDs of McpN and PilJ consist of 135 and 263 residues, respectively, and share very low sequence identity, suggesting they might occur as different structures. Here, we found that PilJ-LBD folded into an HBM module, the same as the sensor domains of McpS-LBD and TorS-LBD, but it differed from that of McpN-LBD. We also observed a trimer in SEC and AUC and proposed a trimeric model based on the crystal structure. Based on the sequence, we classified the Pfam containing McpN-LBD and PilJ-LBD into three classes: sPilJ (single PilJ) represented by McpN-LBD with only one PilJ domain, dPilJ (dual PilJ) that contained dual PilJ domains, and hPilJ (hybrid PilJ) that comprises of a PilJ domain and another non-PilJ domain. Our work indicates a significant structural difference between the ligand binding domains of PilJ and McpN and will help our further study on both kinds of chemoreceptors.


Assuntos
Proteínas de Bactérias , Fímbrias Bacterianas , Proteínas de Bactérias/metabolismo , Ligantes , Fímbrias Bacterianas/metabolismo , Domínios Proteicos , Quimiotaxia , Bactérias/metabolismo
10.
Sci Rep ; 14(1): 6243, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38486045

RESUMO

In an era where digital technology is reshaping business landscapes, understanding the factors that drive corporate digital transformation is essential. In this paper we explore these influencing factors, focusing on Chinese A-share listed companies from 2007 to 2021. Our approach involved a comprehensive analysis of multiple variables through regression techniques to determine their impact on digital transformation. The findings reveal the drive for reform in the digital transformation endeavours of enterprises. Notably, companies with higher gearing, overhead, and accounts receivable ratios exhibit a stronger inclination towards digital transformation. Conversely, enterprises in monopolistic industries and those at the inception stage of their life cycle show less propensity for such transformation. The findings of this research not only shed light on the strategic decisions behind digital transformation in response to financial and competitive challenges but also provide actionable insights for policymakers and business strategists. This study underscores the importance of contextualizing digital transformation efforts within the unique framework of industry characteristics and company development phases.

11.
ChemSusChem ; 17(6): e202301538, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38376216

RESUMO

Construction of S-scheme heterojunction offers a promising way to enhance the photocatalytic performance of photocatalysts for converting solar energy into chemical energy. However, the photocatalytic H2 production in pure water without sacrificial agents is still a challenge. Herein, the IEF-11 with the best photocatalytic H2 production performance in MOFs and suitable band structure was selected and firstly constructed with g-C3N4 to obtain a S-scheme heterojunction for photocatalytic H2 production from pure water. As a result, the novel IEF-11/g-C3N4 heterojunction photocatalysts exhibited significantly improved photocatalytic H2 production performance in pure water without any sacrificial agent, with a rate of 576 µmol/g/h, which is about 8 times than that of g-C3N4 and 23 times of IEF-11. The novel IEF-11/g-C3N4 photocatalysts also had a photocatalytic H2 production rate of up to 92 µmol/g/h under visible light and a good photocatalytic stability. The improved performance can be attributed to the efficient separation of photogenerated charge carriers, faster charge transfer efficiency and longer photogenerated carrier lifetimes, which comes from the forming of S-scheme heterojunction in the IEF-11/g-C3N4 photocatalyst. This work is a promising guideline for obtaining MOF-based or g-C3N4-based photocatalysts with great photocatalytic water splitting performance.

12.
BMC Genomics ; 25(1): 136, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38308218

RESUMO

Microbial remediation of heavy metal polluted environment is ecofriendly and cost effective. Therefore, in the present study, Shewanella putrefaciens stain 4H was previously isolated by our group from the activated sludge of secondary sedimentation tank in a dyeing wastewater treatment plant. The bacterium was able to reduce chromate effectively. The strains showed significant ability to reduce Cr(VI) in the pH range of 8.0 to 10.0 (optimum pH 9.0) and 25-42 ℃ (optimum 30 ℃) and were able to reduce 300 mg/L of Cr(VI) in 72 h under parthenogenetic anaerobic conditions. In this paper, the complete genome sequence was obtained by Nanopore sequencing technology and analyzed chromium metabolism-related genes by comparative genomics The genomic sequence of S. putrefaciens 4H has a length of 4,631,110 bp with a G + C content of 44.66% and contains 4015 protein-coding genes and 3223,  2414, 2343 genes were correspondingly annotated into the COG, KEGG, and GO databases. The qRT-PCR analysis showed that the expression of chrA, mtrC, and undA genes was up-regulated under Cr(VI) stress. This study explores the Chromium Metabolism-Related Genes of S. putrefaciens 4H and will help to deepen our understanding of the mechanisms of Cr(VI) tolerance and reduction in this strain, thus contributing to the better application of S. putrefaciens 4H in the field of remediation of chromium-contaminated environments.


Assuntos
Shewanella putrefaciens , Shewanella putrefaciens/genética , Shewanella putrefaciens/metabolismo , Oxirredução , Cromo/toxicidade , Cromo/metabolismo , Bactérias/metabolismo
13.
Pharmacol Res ; 200: 107060, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185210

RESUMO

OBJECTIVE: To assess the efficacy and safety of FDA-approved KRASG12C inhibitors in patients with KRASG12C-mutated solid tumors. METHODS: We searched PubMed, EMBASE, Cochrane Library, and major international conferences for clinical trials published in English up to March 6, 2023. Clinical trials investigating sotorasib or adagrasib and reporting the clinical outcomes of the objective response rate (ORR), disease control rate (DCR), or incidence rate of grade ≥ 3 adverse events (AEs) were eligible. The primary endpoint was the ORR. Secondary endpoints included the DCR, incidence rate of grade ≥ 3 AEs, and odds ratio (OR) of the ORR between patients with or without co-mutation. The Random-effects model was applied for the outcomes of interest. RESULTS: 18 studies with 1224 patients were included in this meta-analysis. The pooled ORR, DCR, and incidence rate of grade ≥ 3 AEs were 31 % (95 % CI, 25-37 %), 86 % (95 % CI, 82-89 %), and 29 % (95 % CI, 23-36 %), respectively. KRASG12C-mutated NSCLC patients with a co-mutation of KEAP1 exhibited a worse ORR than those with wild-type KEAP1 (OR: 0.35, 95 % CI: 0.16-0.77). CONCLUSIONS: This study provided a comprehensive understanding of the efficacy and safety of KRASG12C inhibitors in treating solid tumors and identified KEAP1 mutation as a potential predictive biomarker of inferior response in patients treated with KRASG12C inhibitors. These findings may assist in the design of future clinical trials for identifying populations that may benefit from KRASG12C inhibitor treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch , Proteínas Proto-Oncogênicas p21(ras) , Fator 2 Relacionado a NF-E2 , Mutação
14.
Int J Biol Macromol ; 254(Pt 1): 127624, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37918610

RESUMO

Exopolysaccharide (EPS-09) from L. plantarum WLPL09 was systemically investigated for the antitumor effect in B16F10 melanoma bearing mice model. The results showed that administraion of EPS-09 (200 mg/kg) could sigificantly inhibit the tumor growth of melanoma bearing mice, with a inhibition rate of 42.53 %. Meanwhile, compared to the Model group, high dose of EPS-09 (200 mg/kg) administraion could increase the spleen index (P = 0.10), promote the splenic lymphocytes proliferation under the stimulation of ConA and LPS with a proliferation rate of 120.58 % and 169.88 %, respectively, enhance the amount of CD4+ and CD8+ T cells (P < 0.0001, P = 0.0149) in tumor tissue, as well as the serum content of cytokines, i.e., TNF-α, IFN-γ, IL-2 (P < 0.05) and IL-6 (P = 0.039) of B16F10 melanoma bearing mice. The transcriptional level analysis revealed that EPS-09 (200 mg/kg) administraion could sigificantly (P < 0.05) upregulate the transcription of apoptosis raleted genes, i.e., P53, Caspase-3 and Caspase-9, and the ratio of Bax/Bcl-2, downregulate the transcription of angiogenesis markers, i.e., Vegf and Fgf2 compared with Model group. Furthermore, administration of EPS-09 could increase the abundance of phylum Firmicutes, family Ruminococcaceae and Lachnospiraceae, and genus Ruminococcus, but reduce the abundance of genus Prevotella, Akkermansia and Oscillospira. Taken together, these results indicate that administration of EPS-09 can induce apoptosis of tumor cell, inhibit tumor angiogenesis, improve the immunity, regulate the intestinal microbiota composition of B16F10 melanoma bearing mice, and play positive roles in the antitumor activity against melanoma.


Assuntos
Microbioma Gastrointestinal , Melanoma , Camundongos , Animais , Melanoma/patologia , Linfócitos T CD8-Positivos/patologia , Citocinas , Fator de Necrose Tumoral alfa/farmacologia
15.
Small ; 20(8): e2307354, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37821406

RESUMO

Aqueous all-iron redox flow batteries (RFBs) are promising competitors for next-generation grid-scale energy storage applications. However, the high-performance operation of all-iron RFBs in a wider temperature range is greatly hindered by inferior iron plating/stripping reaction and low solid-liquid transition temperature at Fe anode. Herein, a universal electrolyte additive design strategy for all-iron RFBs is reported, which realizes a highly reversible and dendrite-free Fe anode at low temperatures. Quantum chemistry calculations first screen several organic molecules with oxygen-containing functional groups and identify N,N-Dimethylacetmide (DMAc) as a potential candidate with low cost, high solubility, and strong interactions with Fe2+ and H2 O. Combined experimental characterizations and theoretical calculations subsequently demonstrate that adding DMAc into the FeCl2 solution effectively reshapes the primary solvation shell of Fe2+ via the Fe2+ -O (DMAc) bond and breaks hydrogen-bonding network of water through intensified H-bond interaction between DMAc and H2 O, thereby affording the Fe anode with enhanced Fe/Fe2+ reversibility and lower freezing point. Consequently, the assembled all-iron RFB achieves an excellent combination of high power density (25 mW cm-2 ), long charge-discharge cycling stability (95.59% capacity retention in 103 h), and preeminent battery efficiency at -20 °C (95% coulombic efficiency), which promise a future for wider temperature range operation of all-iron RFBs.

16.
Rev Sci Instrum ; 94(4)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38081268

RESUMO

A resonant inertial impact rotary piezoelectric motor based on a self-clamping structure is designed, assembled, and tested. The designed piezoelectric motor mainly includes a rotor (two vibrators, preload mechanism, and intermediate connection mechanism), a clamping mechanism, and another auxiliary mechanism. The piezoelectric ceramic sheet on the rotor drives the vibrator to swing under the excitation of a single harmonic wave. Because there is a clamping mechanism formed by the combination of clamp baffle and fixed clamp ring, thus the half-cycle resonant rotation of the rotor can be effectively completed, and repeated harmonic excitation can realize the unidirectional continuous rotation and swing of the rotor. The whole excitation process of the motor is in a resonance state, which has significant advantages, such as low friction and simple structure, compared with the traditional quasi-static piezoelectric motor. The structure of the piezoelectric motor is designed and analyzed using COMSOL5.5 software and then the motor performance is tested and analyzed by building an experimental platform to verify the feasibility of the motor design. The final experimental results show that the optimal working frequency of the piezoelectric motor is 150 Hz, which is consistent with the characteristic frequency of the simulation. When the motor prototype is under the conditions of optimal operating frequency 150 Hz, voltage 240 Vp-p, and preload torque 7.8 N.mm, the maximum angular speed can reach 2.4 rad/s, the maximum load can reach 27.8 N mm and the maximum resolution of the movement angle can reach 0.941°.

17.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38065139

RESUMO

A new working principle for multimodal excitation of a resonant bidirectional rotary inertial impact piezoelectric motor with a self-clamping structure was developed based on previous research on piezoelectric motors. Unlike previous piezoelectric motors that relied on single harmonic waves for unidirectional rotation, in this motor, we can simply change the driving signal characteristics of the motor without changing the structure of the piezoelectric motor to excite multiple vibration modes, thereby achieving rotation in both directions. Compared with other bidirectional resonant motors, the structure and control signal are simpler. The finite element simulation software COMSOL5.5 was used to simulate the working mode of the motor, and the results were in good agreement with the final experiment. During the experiments, the optimal operating frequency of the motor prototype was 900 Hz. The maximum output speed of the motor prototype was 3.9 rad/s, the maximum output torque was 15 N mm, and the maximum resolution was 0.248° under the conditions of 240 Vp-p voltage, 900 Hz frequency, and 7.8 N mm preload torque.

18.
Rev Sci Instrum ; 94(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38051178

RESUMO

Based on our previous research, this article adds new research content and further refines the previous research on bionic motors. It is in the form of note as a complementary improvement to the previous article. This article proposes a novel approach to achieving reversal motion in such motors driven by a single harmonic signal, specifically the multimode mode of the vibrator. In contrast to the conventional inertial impact piezoelectric motor, we propose a bidirectional piezoelectric motor that can achieve bidirectional motion only by altering the driving signal characteristics. Compared to other bidirectional piezoelectric motors, this motor features a simpler structure and more convenient control. The COMSOL6.0 finite element analysis software was utilized to optimize the working mode of the piezoelectric motor, and an experimental platform was constructed for testing and verifying the performance of the designed prototype. The final experimental data demonstrate that, with an excitation voltage of 300 Vp-p, a preload of 2 N, and an excitation frequency of 781 Hz, the motor prototype achieves a maximum no-load speed of 12.15 mm/s, a maximum resolution of 15.27 µm, and a maximum load of 14 g. These results confirm the validity of the new working mode.

19.
Curr Treat Options Oncol ; 24(12): 1683-1702, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37938503

RESUMO

OPINION STATEMENT: Inflammatory myofibroblastic tumor (IMT), characterized by intermediate malignancy and a propensity for recurrence, has presented a formidable clinical challenge in diagnosis and treatment. Its pathological characteristics may resemble other neoplasms or reactive lesions, and the treatment was limited, taking chemotherapies as the only option for those inoperable. However, discovering anaplastic lymphoma kinase (ALK) protein expression in approximately 50% of IMT cases has shed light on a new diagnostic approach and application of targeted therapies. With the previous success of combating ALK+ non-small-cell lung cancers with ALK tyrosine kinase inhibitors (TKIs), crizotinib, a first-generation ALK-TKI, was officially approved by the U.S. Food and Drug Administration in 2020, to treat unresectable ALK+ IMT. After the approval of crizotinib, other ALK-TKIs, such as ceritinib, alectinib, brigatinib, and lorlatinib, have proven their efficacy on ALK+ IMT with sporadic case reports. The sequential treatments of targeted therapies in may provide the insight into the choice of ALK-TKIs in different lines of treatment for unresectable ALK+ IMT.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Quinase do Linfoma Anaplásico , Carcinoma Pulmonar de Células não Pequenas/patologia , Crizotinibe/uso terapêutico , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Receptores Proteína Tirosina Quinases , Antineoplásicos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases , Inflamação/diagnóstico , Inflamação/tratamento farmacológico , Inflamação/etiologia
20.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37862486

RESUMO

In this study, a resonant single-wing bionic piezoelectric motor based on a biasing self-clamping mechanism inspired by dragonfly flight was designed, assembled, and tested. The main mechanism of the designed piezoelectric motor includes a mover (including a vibrator, clamping foot, bionic pedestal, etc.), a stator, and other auxiliary components. The clamping foot of the mover contacts the side of the stator to form a biasing self-clamping mechanism, which can achieve a clamping effect within half a cycle of the vibrator's resonant vibration. The piezoelectric plate on the vibrator receives a single harmonic excitation from the signal generator, causing the base plate to bend and distort. The base plate drives the clamping foot to move regularly, causing the mover to perform a linear motion. Moreover, repeated single harmonic excitations can realize the continuous movement of the mover. The structure of the piezoelectric motor was optimized using COMSOL6.0, which is a finite element analysis software. The first-order bending vibration of the vibrator was chosen as the working mode through finite element simulation, and an experimental platform was built. The performance of the prototype piezoelectric motor was tested and verified on the experimental platform. The final experimental data show that under the conditions of 300 Vp-p excitation voltage and 109 Hz driving frequency, the maximum no-load speed of the prototype reaches 6.184 mm/s, and the maximum load of the motor is 4 g.

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