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1.
Reprod Biomed Online ; 49(3): 104078, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-39024925

RESUMEN

RESEARCH QUESTION: Does hyperandrogenaemia affect the function of ovarian granulosa cells by activating ferroptosis, and could this process be regulated by endoplasmic reticulum stress? DESIGN: Levels of ferroptosis and endoplasmic reticulum stress in granulosa cells were detected in women with and without polycystic ovary syndrome (PCOS) undergoing IVF. Ferroptosis and endoplasmic reticulum stress levels of ovarian tissue and follicle development were detected in control mice and PCOS-like mice models, induced by dehydroepiandrosterone. An in-vitro PCOS model of KGN cells was constructed with testosterone and ferroptosis inhibitor Fer-1. Endoplasmic reticulum stress inhibitor, tauroursodeoxycholate (TUDCA), determined the potential mechanism associated with excessive induction of ferroptosis in granulosa cells related to PCOS, and levels of ferroptosis and endoplasmic reticulum stress were detected. RESULTS: Activation of ferroptosis and endoplasmic reticulum stress occurred in granulosa cells of women with PCOS and the varies of PCOS-like mice. The findings in KGN cells demonstrated that testosterone treatment results in elevation of oxidative stress levels, particularly lipid peroxidation, and intracellular iron accumulation in granulosa cells. The expression of genes and proteins associated with factors related to ferroptosis, mitochondrial membrane potential and ultrastructure showed that testosterone activated ferroptosis, whereas Fer-1 reversed these alterations. During in-vitro experiments, activation of endoplasmic reticulum stress induced by testosterone treatment was detected in granulosa cells. In granulosa cells, TUDCA, an inhibitor of endoplasmic reticulum stress, significantly mitigated testosterone-induced ferroptosis. CONCLUSIONS: Ferroptosis plays a part in reproductive injury mediated by hyperandrogens associated with PCOS, and may be regulated by endoplasmic reticulum stress.

2.
J Youth Adolesc ; 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38851651

RESUMEN

Emerging adulthood is a pivotal period for romantic relationships, yet the specific mechanisms through which attachment anxiety influences relationship dynamics and psychological outcomes in this phase are poorly understood. Particularly, in the context of romantic dyads, understanding how partners' behaviors and emotional patterns reciprocally influence each other remains underexplored. This study utilizes the Actor-Partner Interdependence Model and Actor-Partner Interdependence Mediator Model to explore the relationship between attachment anxiety,relational aggression (both perpetration and victimization), and depressive symptoms among emerging adults. A sample of 138 mixed-sex emerging adulthood couples from China, was recruited (Mage = 21.40, SD = 2.54; 50% female, 62.6% reporting that this relationship was ongoing for more than a year). Attachment anxiety significantly predicted relational aggression in both partners, with male attachment anxiety also significantly predicted female relational aggression. Significant indirect effects of both partners' relational aggression perpetration and victimization on their own and each other's relationship between attachment anxiety and depressive symptoms. These findings contribute to understanding the intricate dynamics of attachment anxiety and relational aggression in romantic relationships during emerging adulthood, emphasizing the need for targeted interventions to mitigate these risks.

3.
PLoS One ; 19(4): e0301206, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38598459

RESUMEN

The Easterlin paradox questions the link between economic growth and national well-being, emphasizing the necessity to explore the impact of economic elasticity, income inequality, and their temporal and spatial heterogeneity on subjective happiness. Despite the importance of these factors, few studies have examined them together, thus ongoing debates about the impact of economics on well-being persist. To fill this gap, our analysis utilizes 11 years of panel data from 31 provinces in China, integrating macroeconomic indicators and social media content to reassess the Easterlin paradox. We use GDP per capita and the Gini coefficient as proxies for economic growth and income inequality, respectively, to study their effects on the subjective well-being expressed by citizens on social media in mainland China. Our approach combines machine learning and fixed effects models to evaluate these relationships. Key findings include: (1) In temporal relationships, a 46.70% increase in GDP per capita implies a 0.38 increase in subjective well-being, while a 0.09 increase in the Gini coefficient means a 1.47 decrease in subjective well-being. (2) In spatial relationships, for every 46.70% increase in GDP per capita, subjective well-being rises by 0.51; however, this relationship is buffered by unfair distribution, and GDP per capita no longer significantly affects subjective well-being when the Gini index exceeds 0.609. This study makes a synthetic contribution to the debate on the Easterlin paradox, indicating that economic growth can enhance well-being if income inequality is kept below a certain level. Although these results are theoretically enlightening for the relationship between economics and national well-being globally, this study's sample comes from mainland China. Due to differences in cultural, economic, and political factors, further research is suggested to explore these dynamics globally.


Asunto(s)
Felicidad , Medios de Comunicación Sociales , Humanos , Factores Socioeconómicos , Renta , Desarrollo Económico
4.
J Youth Adolesc ; 53(6): 1428-1440, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38555341

RESUMEN

Despite extensive research on the psychological impacts of digital technology, the nuanced dynamics between adolescent loneliness and problematic smartphone use, particularly across different educational levels and genders, remain underexplored. This study aims to fill this gap by employing a Random Intercept Cross-Lagged Panel Model to dissect the bidirectional relationship between loneliness and problematic smartphone use among adolescents, with a focus on the moderating roles of educational levels and gender. Engaging 3132 students from various educational institutions in China, the research conducted a three-wave longitudinal analysis across 2022-2023. The final number of participants included 1120 adolescents (53.5% female; age in 2022: M = 14.57 years, SD = 1.57). Results reveal that loneliness significantly predicts problematic smartphone use, but not vice versa, highlighting a unidirectional influence. The study uncovers crucial differences across educational levels and gender, emphasizing the stronger effect of loneliness on problematic smartphone use among junior high students and female adolescents. These findings underscore the complexity of adolescent loneliness and its relationship with digital behavior, suggesting a need for tailored interventions considering both gender and developmental stages.


Asunto(s)
Conducta del Adolescente , Soledad , Teléfono Inteligente , Humanos , Soledad/psicología , Adolescente , Femenino , Masculino , Conducta del Adolescente/psicología , Estudios Longitudinales , China , Estudiantes/psicología , Estudiantes/estadística & datos numéricos , Trastorno de Adicción a Internet/psicología , Factores Sexuales , Escolaridad
5.
Int Immunopharmacol ; 125(Pt A): 111141, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37918087

RESUMEN

Hyperandrogenemia and persistent chronic inflammation, two main striking features of polycystic ovary syndrome (PCOS), have been proven involved in follicular dysgenesis in PCOS. However, the association between hyperandrogenism and inflammation activation in PCOS is not fully understood. Excess testosterone(T) induces inflammation and pyroptosis activation in a mouse model of PCOS, leading to ovarian dysfunction and fibrosis. Excessive endoplasmic reticulum (ER) stress is present in ovarian granulosa cells (GCs), testosterone-induced PCOS mouse and cellular models. This study found higher levels of interleukin (IL)-1ß, IL-8, IL-17, and IL-18 in the follicular fluid of PCOS patients with hyperandrogenemia undergoing IVF treatment. In addition, pyroptosis in GCs was demonstrated, which was significantly elevated in PCOS patients. To clarify the association of hyperandrogenism, inflammation, and pyroptosis activation in PCOS, dehydroepiandrosterone(DHEA)-treated mouse PCOS model and T-treated KGN cell line were explored for PCOS mechanism. Markers of inflammatory activation and pyroptosis were significantly increased after DHEA treatment in mice and T treatment in KGN cells. In addition, ER stress sensor proteins were increased simultaneously. However, suppression of inflammation by genipin(GP) led to decreased pyroptosis in KGN cells but no variation in ER stress sensor proteins. In contrast, when treated with tauroursodeoxycholic acid(TUDCA) to attenuate ER stress, the markers of inflammatory factors were significantly reduced, accompanied by a reduction in pyroptosis. Our results suggest that persistent hyperandrogenemia of PCOS promotes local inflammatory activation of the ovary, and the imbalanced inflammatory microenvironment leads to pyroptosis of GCs, which is mediated by ER stress activation.


Asunto(s)
Hiperandrogenismo , Síndrome del Ovario Poliquístico , Humanos , Femenino , Ratones , Animales , Síndrome del Ovario Poliquístico/metabolismo , Síndrome del Ovario Poliquístico/patología , Piroptosis , Testosterona , Inflamación , Deshidroepiandrosterona , Microambiente Tumoral
6.
iScience ; 26(10): 107838, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-37752950

RESUMEN

HS3ST3B1-IT1 was identified as a downregulated long noncoding RNA in osteoarthritic cartilage. However, its roles and mechanisms in the pathogenesis of osteoarthritis (OA) are unclear. In this study, we demonstrated that the expressions of HS3ST3B1-IT1 and its maternal gene HS3ST3B1 were downregulated and positively correlated in osteoarthritic cartilage. Overexpression of HS3ST3B1-IT1 significantly increased chondrocyte viability, inhibited chondrocyte apoptosis, and upregulated extracellular matrix (ECM) proteins, whereas HS3ST3B1-IT1 knockdown had the opposite effects. In addition, HS3ST3B1-IT1 significantly ameliorated monosodium-iodoacetate-induced OA in vivo. Mechanistically, HS3ST3B1-IT1 upregulated HS3ST3B1 expression by blocking its ubiquitination-mediated degradation. Knockdown of HS3ST3B1 reversed the effects of HS3ST3B1-IT1 on chondrocyte viability, apoptosis, and ECM metabolism. AlkB homolog 5 (ALKBH5)-mediated N6-methyladenosine (m6A) demethylation stabilized HS3ST3B1-IT1 RNA. Together, our data revealed that ALKBH5-mediated upregulation of HS3ST3B1-IT1 suppressed OA progression by elevating HS3ST3B1 expression, suggesting that HS3ST3B1-IT1/HS3ST3B1 may serve as potential therapeutic targets for OA treatment.

7.
Zhongguo Zhen Jiu ; 43(2): 239-44, 2023 Feb 12.
Artículo en Chino | MEDLINE | ID: mdl-36808522

RESUMEN

Electroacupuncture may play a role in treatment of learning and memory impairment after ischemic stroke by regulating phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) signaling pathway, nerve growth factor (NGF)/tyrosine kinase-A (TrkA) signaling pathway, Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, Notch signaling pathway, erythropoietin-producing hepatocyte (Eph)/ephrin signaling pathway. The interactions among these pathways should be further explored in treatment of learning and memory impairment after ischemic stroke.


Asunto(s)
Electroacupuntura , Accidente Cerebrovascular Isquémico , Humanos , Aprendizaje , Transducción de Señal/fisiología
8.
Adv Mater ; 35(7): e2208846, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36444853

RESUMEN

The elaborate design of powerful Li-S binders with extended-functions like polysulfides adsorption/catalysis and Li+ hopping/transferring in addition to robust adhesion-property has remained a challenge. Here, an in situ cathode-interweaving strategy based on metalloporphyrin based covalent-bonding organic polymer (M-COP, M = Mn, Ni, and Zn) binders is reported for the first time. Thus-produced functional binders possess excellent mechanical-strengths, polysulfides adsorption/catalysis, and Li+ hopping/transferring ability. Specifically, the modulus of Mn-COP can reach up to ≈54.60 GPa (≈40 times higher than poly(vinylidene fluoride)) and the relative cell delivers a high initial-capacity (1027 mAh g-1 , 1 C and 913 mAh g-1 , 2 C), and excellent cycling-stability for >1000 cycles even at 4 C. The utilization-rate of sulfur can reach up to 81.8% and the electrodes based on these powerful binders can be easily scale-up fabricated (≈20 cm in a batch-experiment). Noteworthy, Mn-COP based cell delivers excellent capacities at a high sulfur-loading (8.6 mg cm-2 ) and low E/S ratio (5.8 µL mg-1 ). In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea-groups in enhancing the battery-performance.

9.
Opt Express ; 30(26): 47361-47374, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36558666

RESUMEN

Fiber Bragg gratings with a very low insertion loss are inscribed using the phase mask technique and a single infrared (800 nm) femtosecond laser pulse. The morphology of the resultant light-induced structural changes in the Ge-doped silica fiber (SMF-28) is analyzed using scanning electron microscopy. The electron microscopy images reveal that each Bragg grating period incorporates an elongated micropore embedded in a region of homogeneous material modification. The Bragg wavelength drift and reflectivity of fiber Bragg gratings produced with single pulses having the same energy but different duration (80 fs and 350 fs) are monitored for 1000 hours in the course of isothermal annealing at 1000°C. The annealing data demonstrate that both the isothermal Bragg wavelength drift and the decrease in the reflectivity of the fiber Bragg gratings under test are statistically slower for the 350 fs inscription pulses.

10.
Angew Chem Int Ed Engl ; 61(50): e202212162, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36229417

RESUMEN

Strategy that can design powerful photothermal-catalysts to achieve photothermal-effect assisted coupling-catalysis is much desired for the improvement of energy conversion efficiency and redox product value in CO2 electroreduction system. Herein, a kind of bifunctional viologen-containing covalent organic framework (Ni-2CBpy2+ -COF) has been prepared and successfully applied in photothermal-assisted co-electrolysis of CO2 and methanol. Specifically, the FECO (cathode) and FEHCOOH (anode) for Ni-2CBpy2+ -COF can reach up to ≈100 % at 1.9 V with ≈31.5 % saved overall electricity-consumption when the anodic oxygen evolution reaction (OER) is replaced by methanol oxidation. The superior performance could be attributed to the cyclic diquats in Ni-2CBpy2+ -COF that enhance the photothermal effect (ΔT=49.1 °C) to accelerate faster charge transfer between catalyst and immediate species as well as higher selectivity towards desired products as revealed by DFT calculations and characterizations.

11.
Artículo en Inglés | MEDLINE | ID: mdl-36231539

RESUMEN

Based on the experiential avoidance model, the current study aims to test the relationship between cyber-ostracism and adolescents' non-suicidal self-injury and to explore the mediating roles of depression and experiential avoidance. A sample of 1062 middle school students completed questionnaires on cyber-ostracism, depression, experiential avoidance, and self-injurious behavior. The results showed that cyber-ostracism, depression, experiential avoidance, and non-suicidal self-injury were positively correlated with each other. After controlling for gender and age, the mediation model test shows that cyber-ostracism was significantly and positively associated with non-suicidal self-injury. Depression and experiential avoidance mediated the relationship between cyber-ostracism and non-suicidal self-injury parallelly and sequentially. This study highlights the potential mechanisms of action between cyber-ostracism and adolescent non-suicidal self-injury and finds that cyber-ostracism is a risk factor for non-suicidal self-injury. This founding suggests that extra attention should be paid to the role of the online environment in addition to the offline environment experiences for the intervention of non-suicidal self-injury.


Asunto(s)
Depresión , Conducta Autodestructiva , Adolescente , Depresión/epidemiología , Humanos , Ostracismo , Factores de Riesgo , Conducta Autodestructiva/epidemiología , Encuestas y Cuestionarios
12.
Adv Mater ; 34(44): e2206706, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36088527

RESUMEN

Porous heterostructured electrocatalysts with multifunctionality and synergistic effect have much benefit for efficient electrocatalytic CO2 reduction reaction (CO2 RR), yet it still remains a daunting challenge to explore heterostructures based on covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) in this field. Here, a series of honeycomb-like porous crystalline hetero-electrocatalysts (MCH-X, X = 1-4, X stands for the numbered sample obtained from different MOF doses in the synthesis of the MCH) are synthesized, and these are successfully applied in electrocatalytic CO2 RR. The specially designed heterostructures with integrated porous MOF-template and ultrathin COF-coating enable efficient CO2 adsorption/activation and conversion into CH4 . The best of them, MCH-3, shows greatly inhibited H2 evolution, excellent current density (-398.1 mA cm-2 ), and superior FE CH 4 ${\rm{F}}{{\rm{E}}_{{\rm{C}}{{\rm{H}}_4}}}$ (76.7%) to the physical mixture (38.0%), the MOF@COF without the honeycomb-like morphology (47.7%), and the bare COF (37.5%) and MOF (15.9%) at -1.0 V. Based on the density functional theory calculations and various characterizations, the vital roles of the MOF in facilitating CO2 adsorption/activation, stabilizing intermediates, and conquering the energy barrier of rate-determining step are intensively studied.

13.
Artículo en Inglés | MEDLINE | ID: mdl-35954551

RESUMEN

As suicides incurred by the COVID-19 outbreak keep happening in many countries, researchers have raised concerns that the ongoing pandemic may lead to "a wave of suicides" in society. Suicidal ideation (SI) is a critical factor in conducting suicide intervention and also an important indicator for measuring people's mental health. Therefore, it is vital to identify the influencing factors of suicidal ideation and its psychological mechanism during the outbreak. Based on the terror management theory, in the present study we conducted a social media big data analysis to explore the joint effects of mortality salience (MS), negative emotions (NE), and cultural values on suicidal ideation in 337 regions on the Chinese mainland. The findings showed that (1) mortality salience was a positive predictor of suicidal ideation, with negative emotions acting as a mediator; (2) individualism was a positive moderator in the first half-path of the mediation model; (3) collectivism was a negative moderator in the first half-path of the mediation model. Our findings not only expand the application of the terror management theory in suicide intervention but provide some insights into post-pandemic mental healthcare. Timely efforts are needed to provide psychological interventions and counseling on outbreak-caused negative emotions in society. Compared with people living in collectivism-prevailing regions, those living in individualism-prevailing regions may be more vulnerable to mortality salience and negative emotions and need more social attention.


Asunto(s)
COVID-19 , Suicidio , COVID-19/epidemiología , Emociones , Humanos , Pandemias , Ideación Suicida
14.
Angew Chem Int Ed Engl ; 61(37): e202209289, 2022 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-35851736

RESUMEN

The selective photo-oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is important due to its substitute-role in polyester-fabrication. Here, a titanium-cluster based metal-covalent organic framework nanosheet has been synthesized through the covalent-coupling between Ti6 -NH2 and benzotrithiophene tricarbaldehyde (BTT). The integration of them endows the nanosheet with a visible-light-adsorption region, effective electron-hole separation-efficiency and suitable photo-oxidation ability. Specifically, its photo-selectivity for HMF-to-FDCA can be >95 % with ≈100 % conversion, which is more than 2, 5, and 10 times higher than MOF-901 (43 %), Ti6 -NH2 (19 %) and under-darkness (9 %), respectively. Notably, an O2 -based mechanism is proposed and the vital roles of Ti6 -NH2 and BTT are verified by DFT calculations. This work might facilitate the exploration of porous-crystalline-catalysts for selective biomass-valorization.


Asunto(s)
Ácidos Dicarboxílicos , Titanio , Biomasa , Ácidos Dicarboxílicos/química , Furaldehído/química , Furanos/química , Porosidad , Titanio/química
15.
Angew Chem Int Ed Engl ; 61(5): e202114648, 2022 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-34806265

RESUMEN

Strategies that enable simultaneous morphology-tuning and electroreduction performance boosting are much desired for the exploration of covalent organic frameworks in efficient CO2 electroreduction. Herein, a kind of functionalizing exfoliation agent has been selected to simultaneously modify and exfoliate bulk COFs into functional nanosheets and investigate their CO2 electroreduction performance. The obtained nanosheets (Cu-Tph-COF-Dct) with large-scale (≈1.0 µm) and ultrathin (≈3.8 nm) morphology enable a superior FECH4 (≈80 %) (almost doubly enhanced than bare COF) with large current-density (-220.0 mA cm-2 ) at -0.9 V. The boosted performance can be ascribed to the immobilized functionalizing exfoliation agent (Dct groups) with integrated amino and triazine groups that strengthen CO2 absorption/activation, stabilize intermediates and enrich the CO concentration around the Cu active sites as revealed by DFT calculations. The point-to-point functionalization strategy for modularly assembling Dct-functionalized COF catalyst for CO2 electroreduction will open up the attractive possibility of developing COFs as efficient CO2 RR electrocatalysts.

16.
J Colloid Interface Sci ; 610: 446-454, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-34933196

RESUMEN

Covalent organic frameworks (COFs) have recently gained rising consideration for visible light photocatalysis. Their property could be accurately established with specific reactions in which the most investigated one turns out to be the aerobic oxidation of amines. In this contribution, a hydrazone-linked 2D (two-dimensional) porphyrinic COF, Por-DETH-COF, was assembled from 5,10,15,20-tetrakis(4-benzaldehyde)porphyrin (p-Por-CHO) and 2,5-diethoxyterephthalohydrazide (DETH) and its photocatalytic activity was duly appraised with the aerobic oxidation of amines. Thereby, the red light-driven selective oxidation of benzyl amines to imines was obtained in very high conversions and selectivities with ambient air as the oxidant. Importantly, the photocatalytic system exhibited remarkable compatibility of functional groups and extensive scope of benzyl amines. Notably, the Por-DETH-COF photocatalyst displayed outstanding recyclability after five successive cycles. This work suggests that 2D COFs could contribute a unique juncture for selective organic transformations by photocatalysis.

17.
Nanomaterials (Basel) ; 13(1)2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36615979

RESUMEN

Metasurfaces with a high engineering degree of freedom are promising building blocks for applications in metalenses, beam deflectors, metaholograms, sensing, and many others. Though the fundamental and technological challenges, proposing tunable metasurfaces is still possible. Previous efforts in this field are mainly taken on designing sophisticated structures with active materials introduced. Here, we present a generic kind of monolithic dielectric metasurfaces for tunable light field modulations. Changes in the period number and surrounding refractive index enable discrete and continuous modulations of spatial light fields, respectively. We exemplify this concept in monolithic Lithium Niobate metasurfaces for tunable metalenses and beam deflectors. The utilization of monolithic dielectric materials facilitates the ready integration of the metasurfaces with both chip and optical fiber platforms. This concept is not limited by the availability of active materials or expensive and time-consuming fabrication techniques, which can be applied to any transparent dielectric materials and various optical platforms.

18.
Angew Chem Int Ed Engl ; 60(40): 21952-21958, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34387026

RESUMEN

The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2 RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well-designed electrocatalysts with advantages like proton generation/transferring and intermediate-fixating for efficient CO2 RR are much preferred yet largely unexplored. In this work, a kind of Cu-porphyrin-based large-scale (≈1.5 µm) and ultrathin nanosheet (≈5 nm) has been successfully applied in electrochemical CO2 RR. It exhibits a superior FE CH 4 of 70 % with a high current density (-183.0 mA cm-2 ) at -1.6 V under rarely reported neutral conditions and maintains FE CH 4 >51 % over a wide potential range (-1.5 to -1.7 V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen-bonding networks through the integration of diaminotriazine with Cu-porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen-bonding-based materials as efficient CO2 RR catalysts.

19.
Sensors (Basel) ; 21(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669717

RESUMEN

A review of recent progress in the use of infrared femtosecond lasers to fabricate optical fiber sensors that incorporate fiber Bragg gratings (FBG) and random fiber gratings (RFG) is presented. The important advancements in femtosecond laser writing based on the phase mask technique now allow through-the-coating (TTC) fabrication of Bragg gratings in ultra-thin fiber filaments, tilted fiber Bragg gratings, and 1000 °C-resistant fiber Bragg gratings with very strong cladding modes. As an example, through-the-coating femtosecond laser writing is used to manufacture distributed fiber Bragg grating sensor arrays for oil pipeline leak detection. The plane-by-plane femtosecond laser writing technique used for the inscription of random fiber gratings is also reviewed and novel applications of the resultant devices in distributed temperature sensing, fiber lasers and fiber laser sensors are discussed.

20.
Sensors (Basel) ; 21(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669718

RESUMEN

High-temperature-resistant fiber Bragg gratings (FBGs) are the main competitors to thermocouples as sensors in applications for high temperature environments defined as being in the 600-1200 °C temperature range. Due to their small size, capacity to be multiplexed into high density distributed sensor arrays and survivability in extreme ambient temperatures, they could provide the essential sensing support that is needed in high temperature processes. While capable of providing reliable sensing information in the short term, their long-term functionality is affected by the drift of the characteristic Bragg wavelength or resonance that is used to derive the temperature. A number of physical processes have been proposed as the cause of the high temperature wavelength drift but there is yet no credible description of this process. In this paper we review the literature related to the long-term wavelength drift of FBGs at high temperature and provide our recent results of more than 4000 h of high temperature testing in the 900-1000 °C range. We identify the major components of the high temperature wavelength drift and we propose mechanisms that could be causing them.

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