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1.
Talanta ; 275: 126086, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38663071

RESUMO

Laser-induced breakdown spectroscopy (LIBS), as an elemental composition analysis technique, has many unique advantages and great potential for applications in water detection. However, the quality of LIBS spectral signals, such as signal-to-noise ratio and stability, is often poor due to the matrix effects of water, limiting its practical performance. To effectively remove the inherent weak radiation in experimental spectral data that can be easily mistaken for noise, this paper proposes a denoising algorithm for processing spectral data using a self-built blank sample spectral database of deionized water samples, and designs a complete data processing workflow. It includes steps such as blank sample data screening, internal standard correction, blank sample correction, and spectral smoothing. Against the backdrop of marine applications, experimental spectral data for target elements Na, Mg, Ca, K, Sr, and Li were processed with this algorithm. The results show that after algorithm processing, the spectral quality was significantly improved, with the signal-to-noise ratio and detection limits of various elements improved by at least one order of magnitude. The signal-for Li increased by up to 36 times, and the detection limit for K decreased by up to 25.2 times. Additionally, tiny spectral peaks that could not be observable in the original spectral data could be effectively extracted after processing. From a technical implementation perspective, the database establishment and data process are simple and practical, with universal applicability. Therefore, this method has good potential and wide foregrounds in many other water sample LIBS detection technologies.

2.
FEBS Lett ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664231

RESUMO

Mitochondria harbor the oxidative phosphorylation (OXPHOS) system to sustain cellular respiration. However, the transcriptional regulation of OXPHOS remains largely unexplored. Through the cancer genome atlas (TCGA) transcriptome analysis, transcription factor THAP domain-containing 3 (THAP3) was found to be strongly associated with OXPHOS gene expression. Mechanistically, THAP3 recruited the histone methyltransferase SET and MYND domain-containing protein 3 (SMYD3) to upregulate H3K4me3 and promote OXPHOS gene expression. The levels of THAP3 and SMYD3 were altered by metabolic cues. They collaboratively supported liver cancer cell proliferation and colony formation. In clinical human liver cancer, both of them were overexpressed. THAP3 positively correlated with OXPHOS gene expression. Together, THAP3 cooperates with SMYD3 to epigenetically upregulate cellular respiration and liver cancer cell proliferation.

3.
Cancer Lett ; 591: 216893, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636892

RESUMO

The oncogenic properties of Nucleobindin2 (NUCB2) have been observed in various cancer types. Nevertheless, the precise understanding of the biological functions and regulatory mechanisms of NUCB2 in osteosarcoma remains limited. This investigation reported that NUCB2 was significantly increased upon glucose deprivation-induced metabolic stress. Elevated NUCB2 suppressed glucose deprivation-induced cell death and reactive oxygen species (ROS) increase. Depletion of NUCB2 resulted in a reduction in osteosarcoma cell proliferation as well as metastatic potential in vitro and in vivo. Mechanically, NUCB2 ablation suppressed C-X-C Motif Chemokine Ligand 8 (CXCL8) expression which then reduced programmed cell death 1 ligand 1 (PD-L1) expression and stimulated anti-tumor immunity mediated through cytotoxic T cells. Importantly, a combination of NUCB2 depletion with anti-PD-L1 treatment improved anti-tumor T-cell immunity in vivo. Moreover, we further demonstrated that NUCB2 interacted with NUCKS1 to inhibit its degradation, which is responsible for the transcriptional regulation of CXCL8 expression. Altogether, the outcome emphasizes the function of NUCB2 in osteosarcoma and indicates that NUCB2 elevates osteosarcoma progression and immunosuppressive microenvironment through the NUCKS1/CXCL8 pathway.

4.
Opt Express ; 32(6): 9857-9866, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571210

RESUMO

The three-dimensional (3D) light field display (LFD) with dense views can provide smooth motion parallax for the human eye. Increasing the number of views will widen the lens pitch, however, resulting in a decrease in view resolution. In this paper, an approach to smooth motion parallax based on optimizing the divergence angle of the light beam (DALB) for 3D LFD with narrow pitch is proposed. DALB is controlled by lens design. A views-fitting optimization algorithm is established based on a mathematical model between DALB and view distribution. Subsequently, the lens is reversely designed based on the optimization results. A co-designed convolutional neural network (CNN) is used to implement the algorithm. The optical experiment shows that a smooth motion parallax 3D image is achievable through the proposed method.

5.
BMC Psychiatry ; 24(1): 249, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38565988

RESUMO

BACKGROUND: Both genetic and environmental factors play crucial roles in the development of major depressive disorder (MDD) and suicide attempts (SA). However, the interaction between both items remains unknown. This study aims to explore the interactions between the genetic variants of the serotonin 2 A receptor (HTR2A) and the nitric oxide synthase 1 (NOS1) and environmental factors in patients who experience MDD and SA. METHODS: A total of 334 patients with MDD and a history of SA (MDD-SA) were recruited alongside 518 patients with MDD with no history of SA (MDD-NSA), and 716 healthy controls (HC). The demographic data and clinical characteristics were collected. Sequenom mass spectrometry was used to detect eight tag-single nucleotide polymorphisms (tagSNPs) in HTR2A (rs1328683, rs17068986, and rs3125) and NOS1 (rs1123425, rs2682826, rs3741476, rs527590, and rs7959232). Generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene-environment interactions. RESULTS: Four tagSNPs (rs17068986, rs3125, rs527590, and rs7959232) exhibited significant differences between the three groups. However, these differences were not significant between the MDD-SA and MDD-NSA groups after Bonferroni correction. A logistic regression analysis revealed that negative life events (OR = 1.495, 95%CI: 1.071-2.087, P = 0.018), self-guilt (OR = 2.263, 95%CI: 1.515-3.379, P < 0.001), and negative cognition (OR = 2.252, 95%CI: 1.264-4.013, P = 0.006) were all independently associated with SA in patients with MDD. Furthermore, GMDR analysis indicated a significant interaction between HTR2A rs3125 and negative life events. Negative life events in conjunction with the HTR2A rs3125 CG + GG genotype were associated with a higher SA risk in patients with MDD when compared to the absence of negative life events in conjunction with the CC genotype (OR = 2.547, 95% CI: 1.264-5.131, P = 0.009). CONCLUSION: Several risk factors and a potential interaction between HTR2A rs3125 and negative life events were identified in patients with SA and MDD. The observed interaction likely modulates the risk of MDD and SA, shedding light on the pathogenesis of SA in patients with MDD.


Assuntos
Transtorno Depressivo Maior , Humanos , Estudos Transversais , Transtorno Depressivo Maior/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Tentativa de Suicídio
6.
EMBO J ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649537

RESUMO

Mitochondria are cellular powerhouses that generate energy through the electron transport chain (ETC). The mitochondrial genome (mtDNA) encodes essential ETC proteins in a compartmentalized manner, however, the mechanism underlying metabolic regulation of mtDNA function remains unknown. Here, we report that expression of tricarboxylic acid cycle enzyme succinate-CoA ligase SUCLG1 strongly correlates with ETC genes across various TCGA cancer transcriptomes. Mechanistically, SUCLG1 restricts succinyl-CoA levels to suppress the succinylation of mitochondrial RNA polymerase (POLRMT). Lysine 622 succinylation disrupts the interaction of POLRMT with mtDNA and mitochondrial transcription factors. SUCLG1-mediated POLRMT hyposuccinylation maintains mtDNA transcription, mitochondrial biogenesis, and leukemia cell proliferation. Specifically, leukemia-promoting FMS-like tyrosine kinase 3 (FLT3) mutations modulate nuclear transcription and upregulate SUCLG1 expression to reduce succinyl-CoA and POLRMT succinylation, resulting in enhanced mitobiogenesis. In line, genetic depletion of POLRMT or SUCLG1 significantly delays disease progression in mouse and humanized leukemia models. Importantly, succinyl-CoA level and POLRMT succinylation are downregulated in FLT3-mutated clinical leukemia samples, linking enhanced mitobiogenesis to cancer progression. Together, SUCLG1 connects succinyl-CoA with POLRMT succinylation to modulate mitochondrial function and cancer development.

7.
Front Cardiovasc Med ; 11: 1334457, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38606383

RESUMO

Early-stage infective endocarditis (IE) can lead to severe complications, including infarctions and metastatic infections caused by inflammatory embolus shedding. Common embolism sites include the brain, spleen, kidneys, lungs, and intestines. Additionally, acute heart failure (AHF) can occur in up to 40% of cases, and its presence can impact the clinical outcomes of patients with IE. Cardiogenic shock (CGS) is often more likely to occur after AHF has taken place. If bacteria invade the blood, infectious shock can occur. Patients with IE can experience simple CGS, septic shock, or a combination of the two. Extracorporeal membrane oxygenation (ECMO) typically serves as a Bridge for Heart failure and Cardiogenic shock. Previous research indicates that there are limited reports of ECMO support for patients with IE after CGS has occurred. Because CGS may occur at any time during IE treatment, it is important to understand the timing of ECMO auxiliary support and how to carry out comprehensive treatment after support. Timely treatment can help to reduce or avoid the occurrence of serious complications and improve the prognosis of patients with IE. Our work combines a case study to review the ECMO support of IE patients after CGS through a literature review. Overall, we suggest that when patients with IE have large bacterial thrombosis and a greater risk of shedding, it is recommended to carefully evaluate the indications and contraindications for ECMO after discussion by a multidisciplinary team (MDT). Still, active surgical treatment at an early stage is recommended.

8.
J Virol ; : e0195923, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634598

RESUMO

The role of Culex mosquitoes in the transmission of Japanese encephalitis virus (JEV) is crucial, yet the mechanisms of JEV infection in these vectors remain unclear. Previous research has indicated that various host factors participate in JEV infection. Herein, we present evidence that mosquito sialic acids enhance JEV infection both in vivo and in vitro. By treating mosquitoes and C6/36 cells with neuraminidase or lectin, the function of sialic acids is effectively blocked, resulting in significant inhibition of JEV infection. Furthermore, knockdown of the sialic acid biosynthesis genes in Culex mosquitoes also leads to a reduction in JEV infection. Moreover, our research revealed that sialic acids play a role in the attachment of JEV to mosquito cells, but not in its internalization. To further explore the mechanisms underlying the promotion of JEV attachment by sialic acids, we conducted immunoprecipitation experiments to confirm the direct binding of sialic acids to the last α-helix in JEV envelope protein domain III. Overall, our study contributes to a molecular comprehension of the interaction between mosquitoes and JEV and offers potential strategies for preventing the dissemination of flavivirus in natural environments.IMPORTANCEIn this study, we aimed to investigate the impact of glycoconjugate sialic acids on mosquito infection with Japanese encephalitis virus (JEV). Our findings demonstrate that sialic acids play a crucial role in enhancing JEV infection by facilitating the attachment of the virus to the cell membrane. Furthermore, our investigation revealed that sialic acids directly bind to the final α-helix in the JEV envelope protein domain III, thereby accelerating virus adsorption. Collectively, our results highlight the significance of mosquito sialic acids in JEV infection within vectors, contributing to a better understanding of the interaction between mosquitoes and JEV.

9.
Front Immunol ; 15: 1383936, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638432

RESUMO

In the quest to address the critical shortage of donor organs for transplantation, xenotransplantation stands out as a promising solution, offering a more abundant supply of donor organs. Yet, its widespread clinical adoption remains hindered by significant challenges, chief among them being immunological rejection. Central to this issue is the role of the complement system, an essential component of innate immunity that frequently triggers acute and chronic rejection through hyperacute immune responses. Such responses can rapidly lead to transplant embolism, compromising the function of the transplanted organ and ultimately causing graft failure. This review delves into three key areas of xenotransplantation research. It begins by examining the mechanisms through which xenotransplantation activates both the classical and alternative complement pathways. It then assesses the current landscape of xenotransplantation from donor pigs, with a particular emphasis on the innovative strides made in genetically engineering pigs to evade complement system activation. These modifications are critical in mitigating the discordance between pig endogenous retroviruses and human immune molecules. Additionally, the review discusses pharmacological interventions designed to support transplantation. By exploring the intricate relationship between the complement system and xenotransplantation, this retrospective analysis not only underscores the scientific and clinical importance of this field but also sheds light on the potential pathways to overcoming one of the major barriers to the success of xenografts. As such, the insights offered here hold significant promise for advancing xenotransplantation from a research concept to a viable clinical reality.


Assuntos
Ativação do Complemento , Rejeição de Enxerto , Animais , Humanos , Suínos , Transplante Heterólogo , Animais Geneticamente Modificados , Estudos Retrospectivos , Rejeição de Enxerto/prevenção & controle , Proteínas do Sistema Complemento
10.
Biomed Pharmacother ; 174: 116585, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615611

RESUMO

Emerging research into metabolic dysfunction-associated steatotic liver disease (MASLD) up until January 2024 has highlighted the critical role of cuproptosis, a unique cell death mechanism triggered by copper overload, in the disease's development. This connection offers new insights into MASLD's complex pathogenesis, pointing to copper accumulation as a key factor that disrupts lipid metabolism and insulin sensitivity. The identification of cuproptosis as a significant contributor to MASLD underscores the potential for targeting copper-mediated pathways for novel therapeutic approaches. This promising avenue suggests that managing copper levels could mitigate MASLD progression, offering a fresh perspective on treatment strategies. Further investigations into how cuproptosis influences MASLD are essential for unraveling the detailed mechanisms at play and for identifying effective interventions. The focus on copper's role in liver health opens up the possibility of developing targeted therapies that address the underlying causes of MASLD, moving beyond symptomatic treatment to tackle the root of the problem. The exploration of cuproptosis in the context of MASLD exemplifies the importance of understanding metal homeostasis in metabolic diseases and represents a significant step forward in the quest for more effective treatments. This research direction lights path for innovative MASLD management and reversal.

11.
Int J Mol Med ; 53(5)2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38577932

RESUMO

Pyroptosis, a programmed cell death marked by lytic and inflammatory characteristics, plays a crucial role in non­infectious inflammation­related diseases but can lead to detrimental outcomes when dysregulated. Stem cells have emerged as key players in modulating pyroptosis through paracrine signaling, offering a novel avenue for tissue repair and regeneration. The present review delved into previous studies elucidating the intricate interplay between stem cells and pyroptosis, emphasizing the potential of stem cell­based therapies in regulating pyroptotic pathways. The exploration of this dynamic interaction holds promise for developing strategies to harness stem cells for effective tissue repair and regeneration in the context of inflammation­related diseases.


Assuntos
Apoptose , Piroptose , Humanos , Células-Tronco , Inflamação
12.
Molecules ; 29(5)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38474686

RESUMO

The combustion behavior of various propellant samples, including double-base propellants, pressed nitramine powders, and modified double-base propellants containing nitramine, was examined using OH-PLIF technology. The combustion process took place within a combustion chamber, and images capturing the flame at the moment of stable combustion were selected for further analysis. The distribution and production rate of OH radicals in both the double-base propellant and the nitramine-modified double-base propellant were simulated using Chemkin-17.0 software. The outcomes from both the experimental and simulation studies revealed that the concentration of OH radicals increased with a higher content of NG in the double-base propellant. In the modified double-base propellant containing RDX, the OH radical concentration decreased as the RDX content increased, with these tendencies of change aligning closely with the simulation results.

13.
Nature ; 628(8008): 515-521, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38509374

RESUMO

The convergence of topology and correlations represents a highly coveted realm in the pursuit of new quantum states of matter1. Introducing electron correlations to a quantum spin Hall (QSH) insulator can lead to the emergence of a fractional topological insulator and other exotic time-reversal-symmetric topological order2-8, not possible in quantum Hall and Chern insulator systems. Here we report a new dual QSH insulator within the intrinsic monolayer crystal of TaIrTe4, arising from the interplay of its single-particle topology and density-tuned electron correlations. At charge neutrality, monolayer TaIrTe4 demonstrates the QSH insulator, manifesting enhanced nonlocal transport and quantized helical edge conductance. After introducing electrons from charge neutrality, TaIrTe4 shows metallic behaviour in only a small range of charge densities but quickly goes into a new insulating state, entirely unexpected on the basis of the single-particle band structure of TaIrTe4. This insulating state could arise from a strong electronic instability near the van Hove singularities, probably leading to a charge density wave (CDW). Remarkably, within this correlated insulating gap, we observe a resurgence of the QSH state. The observation of helical edge conduction in a CDW gap could bridge spin physics and charge orders. The discovery of a dual QSH insulator introduces a new method for creating topological flat minibands through CDW superlattices, which offer a promising platform for exploring time-reversal-symmetric fractional phases and electromagnetism2-4,9,10.

14.
Patient ; 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483691

RESUMO

BACKGROUND: Chinese rural women aged 35-64 years are encouraged to complete breast cancer screening (BCS) free of charge. However, it is challenging to reach a satisfying BCS uptake rate. In this study, rural women's preferences and preferences heterogeneity were measured for the development of strategies to enhance participation in BCS. METHODS: A cross-sectional survey with a discrete choice experiment (DCE) was conducted via convenience sampling via face-to-face interviews in Jiangsu, China. Six DCE attributes were identified through a systematic literature review; our previous study of Chinese rural women's BCS intentions; a qualitative work involving in-depth interviews with rural women (n = 13), medical staff (n = 4), and health care managers (n = 2); and knowledge of realistic and actionable policy. The D-efficient design was generated using Ngene 1.3.0. A mixed logit model (MXL) in Stata 18.0 was used to estimate the main effect of attribute levels on rural women's preferences. The relative importance and willingness to utilize BCS services (WTU) were also estimated. The heterogeneous preferences were analyzed by a latent class model (LCM). Sociodemographic status was used to predict the characteristics of class membership. The WTU for different classes was also calculated. RESULTS: A total of 451 rural women, aged 35-64 years, were recruited. The MXL results revealed that the screening interval (SI) was the most important attribute for rural women with regard to utilizing BCS services, followed by the level of screening, the attitude of medical staff, ways to get knowledge and information, people who recommend screening, and time spent on screening (TSS). Rural women preferred a BCS service with a shorter TSS; access to knowledge and information through multiple approaches; a shorter SI; a recommendation from medical staff or workers from the village or community, and others; the enthusiasm of medical staff; and medical staff with longer tenures in the field. Two classes named "process driven" and "efficiency driven" were identified by the preference heterogeneity analysis of the LCM. CONCLUSION: There is a higher uptake of breast cancer screening when services are tailored to women's preferences. The screening interval was the most important attribute for rural women in China with a preference for a yearly screening interval versus longer intervals.

15.
Adv Mater ; : e2310944, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470991

RESUMO

Anomalous transport of topological semimetals has generated significant interest for applications in optoelectronics, nanoscale devices, and interconnects. Understanding the origin of novel transport is crucial to engineering the desired material properties, yet their orders of magnitude higher transport than single-particle mobilities remain unexplained. This work demonstrates the dramatic mobility enhancements result from phonons primarily returning momentum to electrons due to phonon-electron dominating over phonon-phonon scattering. Proving this idea, proposed by Peierls in 1932, requires tuning electron and phonon dispersions without changing symmetry, topology, or disorder. This is achieved by combining de Haas - van Alphen (dHvA), electron transport, Raman scattering, and first-principles calculations in the topological semimetals MX2 (M = Nb, Ta and X = Ge, Si). Replacing Ge with Si brings the transport mobilities from an order magnitude larger than single particle ones to nearly balanced. This occurs without changing the crystal structure or topology and with small differences in disorder or Fermi surface. Simultaneously, Raman scattering and first-principles calculations establish phonon-electron dominated scattering only in the MGe2 compounds. Thus, this study proves that phonon-drag is crucial to the transport properties of topological semimetals and provides insight to engineer these materials further.

16.
Opt Lett ; 49(5): 1233-1236, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426981

RESUMO

We demonstrate a novel, to the best of our knowledge, high-temperature pressure sensor based on a highly birefringent fiber Bragg grating (Hi-Bi FBG) fabricated in a dual side-hole fiber (DSHF). The Hi-Bi FBG is generated by a femtosecond laser directly written sawtooth structure in the DSHF cladding along the fiber core through the slow axis (i.e., the direction perpendicular to the dual-hole axis). The sawtooth structure serves as an in-fiber stressor and also generates Bragg resonance due to its periodicity. The DSHF was etched by hydrofluoric acid to increase its pressure sensitivity, and the diameter of two air holes was enlarged from 38.2 to 49.6 µm. A Hi-Bi FBG with a birefringence of up to 1.8 × 10-3 was successfully created in the etched DSHF. Two distinct reflection peaks could be observed by using a commercial FBG interrogator. Moreover, pressure measurement from 0 to 3 MPa at a high temperature of 700°C was conducted by monitoring the birefringence-induced peak splits and achieved a high-pressure sensitivity of -21.2 pm/MPa. The discrimination of the temperature and pressure could be realized by simultaneously measuring the Bragg wavelength shifts and peak splits. Furthermore, a wavelength-division-multiplexed (WDM) Hi-Bi FBG array was also constructed in the DSHF and was used for quasi-distributed high-pressure sensing up to 3 MPa. As such, the proposed femtosecond laser-inscribed Hi-Bi FBG is a promising tool for high-temperature pressure sensing in harsh environments, such as aerospace vehicles, nuclear reactors, and petrochemical industries.

17.
Opt Lett ; 49(5): 1273-1276, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426991

RESUMO

An optical frequency domain reflectometry (OFDR) shape sensor was demonstrated based on a femtosecond-laser-inscribed weak fiber Bragg grating (WFBG) array in a multicore fiber (MCF). A WFBG array consisting of 60 identical WFBGs was successfully inscribed in each core along a 60 cm long MCF using the femtosecond-laser point-by-point technology, where the length and space of each WFBG were 2 and 8 mm, respectively. The strain distribution of each core in two-dimensional (2D) and three-dimensional (3D) shape sensing was successfully demodulated using the traditional cross correlation algorithm, attributed to the accurate localization of each WFBG. The minimum reconstruction error per unit length of the 2D and 3D shape sensors has been improved to 1.08% and 1.07%, respectively, using the apparent curvature vector method based on the Bishop frame.

19.
Opt Express ; 32(2): 1207-1217, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297677

RESUMO

The investigation into the spectral properties and refractive index (RI) sensitivities at low RI region of helical intermedium-period fiber gratings (HIPFGs) with varied periods ranging from 10-48 µm is presented in detail for the first time. The structure of HIPFG is optimized for RI sensing in the RI range of 1.3-1.33 by comparing the optical properties of HIPFGs with different grating periods. The HIPFG with optimized structure is demonstrated to have a high average sensitivity of 302.5 nm/RIU in the RI ranging from 1.3 to 1.33, which is two orders more elevated than the traditional long-period fiber gratings. The improved HIPFG is also experimentally applied to breath monitoring in different states. Normal breath, slow breath, fast breath, and unhealthy breath are distinguished based on breathing rate, intensity, and time of exhalation and inhalation. The fastest response time is determined to be 10 ms. The results demonstrate that the optical fiber's sensitivity in the low RI region can be increased by shortening its period, offering a special strategy for improving detection performance of HIPFGs. By verifying its performance in breathing monitoring, it is proved that the optimized HIPFG sensor has the great potential to expand medical applications.

20.
Opt Lett ; 49(3): 446-449, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300027

RESUMO

Sapphire fiber Bragg grating (SFBG) is a promising high-temperature strain sensor due to its melting point of 2045°C. However, the study on the long-term stability of SFBG under high temperature with an applied strain is still missing. In this paper, we reported for the first time to our knowledge on the critical temperature point of plastic deformation of the SFBG and demonstrated that the SFBG strain sensor can operate stably below 1200°C. At first, we experimentally investigated the topography and the spectral characteristics of the SFBG at different temperatures (i.e., 25°C, 1180°C, and 1600°C) with applied 650 µÎµ. The reflection peak of the SFBG exhibits a redshift of about 15 nm and broadens gradually within 8 h at 1600°C, and the tensile force value decreases by 0.60 N in this process. After the test, the diameter of the SFBG region decreases from 100 to 88.6 µm, and the grating period is extended from 1.76 to 1.79 µm. This indicates that the plastic deformation of the SFBG happened indeed, and it was elongated irreversibly. Moreover, the stability of the Bragg wavelength of the SFBG under high temperature with the applied strain was evaluated. The result demonstrates the SFBG can be used to measure strain reliably below 1200°C. Furthermore, the strain experiments of SFBG at 25°C, 800°C, and 1100°C have been carried out. A linear fitting curve with high fitness (R2 > 0.99) and a lower strain measurement error (<15 µÎµ) can be obtained. The aforementioned results make SFBG promising for high-temperature strain sensing in many fields, such as, power plants, gas turbines, and aerospace vehicles.

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