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1.
Reprod Sci ; 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650372

RESUMO

Endometriosis (EMS) is an estrogen-dependent disease. However, little is known about the regulation of estrogen, a potential therapeutic target, in EMS, which remains very poorly managed in the clinic. We hypothesized that microRNAs (miRNAs) can be exploited therapeutically to regulate transcription factor 21 (TCF21) and steroidogenic factor-1 (SF-1) gene expression. In our study, paired eutopic and ectopic endometrial samples were obtained from women with EMS and processed by a standard protocol to obtain human endometrial stromal cells (EMs) for in vitro studies. We found that miR-92a-3p levels were decreased in ectopic endometrium and ectopic stromal cells (ESCs) compared with paired eutopic lesions. miR-92a-3p overexpression significantly suppressed the proliferation and migration of ESCs, whereas a decreased level of miR-92a-3p generated the opposite results. Next, we identified TCF21 as a candidate target gene of miR-92a-3p. In vitro cell experiments showed that miR-92a-3p negatively regulated the expression of TCF21 and its downstream target gene SF-1. Moreover, cell proliferation and invasion ability decreased after the silencing of SF-1 and increased after SF-1 overexpression. We also observed that silencing SF-1 while inhibiting miR-92a-3p partially blocked the increase in cell proliferation and invasion ability caused by miR-92a-3p knockdown while overexpressing both SF-1 and miR-92a-3p mitigated the impairment in cell proliferation and invasion ability caused by miR-92a-3p overexpression. Our results may provide a novel potential therapeutic target for the treatment of EMS.

2.
Front Pharmacol ; 13: 1069204, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36467074

RESUMO

Background: TGF-ß signaling pathway plays an essential role in tumor progression and immune responses. However, the link between TGF-ß signaling pathway-related genes (TSRGs) and clinical prognosis, tumor microenvironment (TME), and immunotherapy in gastric cancer is unclear. Methods: Transcriptome data and related clinical data of gastric cancer were downloaded from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and 54 TSRGs were obtained from the Molecular Signatures Database (MSigDB). We systematically analyzed the expression profile characteristics of 54 TSRGs in 804 gastric cancer samples and examined the differences in prognosis, clinicopathological features, and TME among different molecular subtypes. Subsequently, TGF-ß-related prognostic models were constructed using univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analysis to quantify the degree of risk in each patient. Patients were divided into two high- and low-risk groups based on the median risk score. Finally, sensitivity to immune checkpoint inhibitors (ICIs) and anti-tumor agents was assessed in patients in high- and low-risk groups. Results: We identified two distinct TGF-ß subgroups. Compared to TGF-ß cluster B, TGF-ß cluster A exhibits an immunosuppressive microenvironment with a shorter overall survival (OS). Then, a novel TGF-ß-associated prognostic model, including SRPX2, SGCE, DES, MMP7, and KRT17, was constructed, and the risk score was demonstrated as an independent prognostic factor for gastric cancer patients. Further studies showed that gastric cancer patients in the low-risk group, characterized by higher tumor mutation burden (TMB), the proportion of high microsatellite instability (MSI-H), immunophenoscore (IPS), and lower tumor immune dysfunction and exclusion (TIDE) score, had a better prognosis, and linked to higher response rate to immunotherapy. In addition, the risk score and anti-tumor drug sensitivity were strongly correlated. Conclusion: These findings highlight the importance of TSRGs, deepen the understanding of tumor immune microenvironment, and guide individualized immunotherapy for gastric cancer patients.

3.
Adv Sci (Weinh) ; : e2204018, 2022 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-36504449

RESUMO

Closure of the neural tube represents a highly complex and coordinated process, the failure of which constitutes common birth defects. The serine/threonine kinase p21-activated kinase 2 (PAK2) is a critical regulator of cytoskeleton dynamics; however, its role in the neurulation and pathogenesis of neural tube defects (NTDs) remains unclear. Here, the results show that Pak2-/- mouse embryos fail to develop dorsolateral hinge points (DLHPs) and exhibit craniorachischisis, a severe phenotype of NTDs. Pak2 knockout activates BMP signaling that involves in vertebrate bone formation. Single-cell transcriptomes reveal abnormal differentiation trajectories and transcriptional events in Pak2-/- mouse embryos during neural tube development. Two nonsynonymous and one recurrent splice-site mutations in the PAK2 gene are identified in five human NTD fetuses, which exhibit attenuated PAK2 expression and upregulated BMP signaling in the brain. Mechanistically, PAK2 regulates Smad9 phosphorylation to inhibit BMP signaling and ultimately induce DLHP formation. Depletion of pak2a in zebrafish induces defects in the neural tube, which are partially rescued by the overexpression of wild-type, but not mutant PAK2. The findings demonstrate the conserved role of PAK2 in neurulation in multiple vertebrate species, highlighting the molecular pathogenesis of PAK2 mutations in NTDs.

5.
J Biochem Mol Toxicol ; : e23291, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36536508

RESUMO

The prognosis of esophageal cancer (ESCA) is very poor, with a 5-year survival rate of less than 20%. On the other hand, inflammation is the characteristic hallmark of ESCA; however, the prognostic relationship between inflammatory response-related genes and ESCA has not been clarified yet. Therefore, in the present manuscript, we intend to investigate the correlation and specific signature of inflammation for the prediction of the prognosis of ESCA. A total of 173 samples were obtained from The Cancer Genome Atlas (TCGA) database, including 162 tumors and 11 normal specimens. The prognostic signature was established by least absolute shrinkage and selection operator Cox regression analysis. The transcription factor regulatory network with genes of the prognostic signature was analyzed from the transcriptional regulatory relationships unravelled by sentence-based text-mining database. Chemotherapy sensitivity and immunotherapy analysis were also performed. Multivariate Cox analysis showed that the signature was an independent prognostic risk factor. The low-risk group had poorer outcomes than the high-risk group. In the high-risk group, the infiltration of most immune cells was high and strongly correlated with the riskScore. In chemotherapeutic drug sensitivity analysis, OSM, AHR, and BTG2 were significantly correlated with the current chemotherapeutic drugs of ESCA. We have demonstrated a valid prognostic signature of inflammatory response-related genes and found strong associations with immune cells, targeted genes, and chemotherapeutic agents.

6.
Cell Death Dis ; 13(12): 1028, 2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36477408

RESUMO

Tumor-derived exosomes participate in omental metastatic colonization of ovarian cancer by inducing an adaptive response in the tumor microenvironment. However, cell-cell communication via exosomes between primary tumor cells and the microenvironment of distant omentum and the mechanism of pre-metastatic niche formation are poorly understood. Here, we demonstrated that ETS1-overexpressing ovarian cancer cells secreted larger exosomes with higher laminin levels. In addition, ovarian cancer exosomes could be taken up by omental macrophages through integrin and laminin interaction. Compared with control exosomes, exosomes derived from ETS1-overexpressing ovarian cancer cells (LV-ETS1 Exos) stimulated the polarization of more macrophages toward the M2 phenotype (CD163 marker), as well as the production of more CXCL5 and CCL2 in macrophages, via integrin αvß5/AKT/Sp1 signaling. In vivo experiments showed that LV-ETS1 Exos promoted omental metastasis of ovarian cancer by mediating the tumor-promoting effect of macrophages, which could be neutralized by integrin ανß5 inhibitor cilengitide. These results indicated that ETS1 could drive ovarian cancer cells to release exosomes with higher laminin levels, thereby accelerating the exosome-mediated pro-metastatic effects of omental macrophages via the integrin αvß5/AKT/Sp1 signaling pathway, and the integrin ανß5 inhibitor cilengitide could inhibit omental metastasis of ovarian cancer driven by tumor-derived exosomes.


Assuntos
Laminina , Neoplasias Ovarianas , Feminino , Humanos , Neoplasias Ovarianas/genética , Integrinas , Microambiente Tumoral , Proteína Proto-Oncogênica c-ets-1/genética
7.
Soft Matter ; 18(45): 8675-8686, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36349798

RESUMO

Hydrogels are becoming increasingly popular in biomedical and soft machine manufacturing, but their practical application is limited by poor mechanical properties. In recent years, Hofmeister effect-enhanced gelatin hydrogels have become popular. However, the synergy of the Hofmeister effect using other toughening methods is still less investigated. We have fabricated an ultra-high strength gelatin-based hydrogel by introducing ligand cross-linking and hydrogen bonds. Unlike conventional double-network hydrogels, the dense physical cross-linking involving sacrificial bonds gives the hydrogel excellent fatigue resistance and self-recovery properties. The enhancement of mechanical properties by the Hofmeister effect is attributed to the disruption of the hydration shell of the gelatin molecular chains, which leads to stronger interactions between the molecular chains. The mechanical properties of the hydrogels are adjustable over a wide range by varying the concentration of the soaked (NH4)2SO4 solution. The fixation of the gelatin molecular chain orientation by the Hofmeister effect and the reorganization of the coordination bonds allow the hydrogels to be self-reinforced by pre-stretching. At the same time, the modulus contraction of hydrogels in high-concentration salt solutions, and relaxation and swelling in dilute solutions exhibit ionic stimulation responses and shape recovery capability, and hybrid hydrogels have great potential as bio-actuators.


Assuntos
Gelatina , Hidrogéis , Gelatina/química , Hidrogéis/química , Ligantes , Ligação de Hidrogênio , Íons/química
9.
ACS Appl Mater Interfaces ; 14(46): 52566-52573, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36355393

RESUMO

Low interlaminar shear stress, high mechanical strength, and tunable structure make Ti3C2Tx MXene a burgeoning star as solid lubricants and lubricant additives. Although surface modification strategy can improve its compatibility with base oils, it will eventually settle due to gravity. Additionally, base oils are prone to leakage, creep, and volatilization, which limit their application. To address these issues, supramolecular gels with surface-modified Ti3C2Tx were conceived. Apart from the lubrication effect, the high thermal conductivity of Ti3C2Tx MXene accelerated the phase transition rate of supramolecular gels. The thermal-reversible and creep-resistant properties distinguish them from other conventional lubricants. The tribological tests showed that the 500 solvent neutral (SN) supramolecular gel with 0.10 wt % Ti3C2Tx-octadecylphosphonic acid (Ti3C2Tx-ODPA) reduced the coefficient of friction (COF) by 46.32% and wear volume by 81.18% compared with pure 500SN oil. Moreover, they also performed well in load-carrying capacity, temperature tolerance, and speed adaptability. This work puts forward a new approach to prepare MXene-based lubricants tailored for some severe lubrication conditions. These exceptional features enable their application in rolling bearings, some gears, and other low maintenance mechanisms.

10.
J Oncol ; 2022: 4446243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36330355

RESUMO

Background: Intrahepatic cholangiocarcinoma (ICC) is the second most common liver malignancy after hepatocellular carcinoma (HCC), with a dismal prognosis and high heterogeneity. The oncological advantages of anatomical resection (AR) and nonanatomical resection (NAR) in HCC have been studied, but surgical strategies for ICC remain controversial with insufficient investigations. Materials and Methods: From Jan 2013 to Dec 2016, 3880 consecutive patients were retrospectively reviewed from a single center. Patients with ICC undergoing AR or NAR have been enrolled according to inclusion and exclusion criteria. Propensity score matching (PSM) analysis was performed between two groups with a 1 : 1 ratio. The primary endpoint was overall survival (OS), and the secondary endpoints included disease-free survival (DFS), intraoperative patterns, postoperative morbidity, mortality, complications and recurrence. A prognostic nomogram was developed by a multivariate Cox proportion hazard model. Results: After PSM, 99 paired cases were selected from 276 patients enrolled in this study. Patients in the AR group achieved better 1-, 3-, and 5-year OS (70%, 46%, and 34%, respectively) and DFS (61%, 21%, and 10%, respectively) than patients in the NAR group with statistical significance after PSM analysis. The postoperative complications and recurrence patterns were comparable between the two groups. Multivariate analysis identified NAR, tumor size >5 cm, multiple tumors, and poor differentiation as independent risk factors for OS (p < 0.05). Selected patients can benefit most from AR, according to subgroup analysis. A prognostic nomogram based on six independent risk factors for OS and factors with clinical significance was constructed to predict OS in ICC patients. Conclusion: AR improved the long-term survival of ICC with comparable postoperative complications and similar recurrence patterns. AR is suggested in ICC patients with sufficient remnant liver volume. In addition to surgery strategy, malignant characteristics of tumors are risk factors for ICC prognosis.

11.
Biomed Res Int ; 2022: 9710540, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36330457

RESUMO

Background: Several cancers, including lung adenocarcinoma (LUAD), are caused by genes related to necroptosis. However, it is still unknown how necroptosis-related long noncoding RNAs (lncRNAs) may be involved in LUAD. In order to predict the prognosis of LUAD patients and personalize immunotherapy, this study set out to construct a necroptosis-related lncRNA prognostic signature (NLPS). Methods: The Cancer Genome Atlas (TCGA) database was used to download the LUAD transcriptome data and the associated clinical data. lncRNAs associated with necroptosis were screened using coexpression analysis. An NLPS was built using univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses. The Gene Expression Omnibus (GEO) database's GSE30219 was used to validate the NLPS. The prognostic value of the risk score was assessed using Kaplan-Meier survival, receiver operating characteristic (ROC) Cox regression, multivariate Cox regression, and nomogram analyses. Then, we looked into the differences between the low- and high-risk groups in the tumor immune microenvironment, immunotherapy response, and half-maximal inhibitory concentration (IC50). Results: The 14 lncRNAs in a novel NLPS were created. With further validation in the GSE30219 dataset, the risk score according to the NLPS was an independent prognostic indicator for LUAD patients. Patients with better overall survival (OS) in the low-risk group, who were characterized by increased immune cell infiltration, tumor mutational burden (TMB), and immunophenoscore (IPS), may have hot tumors and higher immunotherapy response rates. In addition, the risk score was also closely linked to sensitivity to various anticancer medications. Conclusions: We constructed a novel NLPS that could predict OS and sensitivity to immunotherapy in LUAD patients.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Prognóstico , Necroptose/genética , Regulação Neoplásica da Expressão Gênica , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/patologia , Adenocarcinoma/genética , Pulmão/patologia , Microambiente Tumoral/genética
12.
Cancer Sci ; 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36445120

RESUMO

Naked Cuticle Homolog 1 (NKD1), which is expressed at low levels in many tumors, is considered an inhibitor of the Wnt/ß-catenin pathway but it is highly expressed in colon cancer and can promote colon cancer cell proliferation. miRNAs are involved in the occurrence and progression of many tumors. However, miRNAs that can regulate NKD1 and the mechanisms by which NKD1 regulates tumor progression remain ambiguous. This research aims to reveal the potential regulatory network of NKD1 in colon cancer. miRNA data downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were analyzed by bioinformatics to screen for potential miRNAs targeting NKD1. Let-7b-5p was found to inhibit proliferation, migration and invasion of colon cancer cells targeting NKD1. Further studies suggested that let-7b-5p can modulate Wnt signaling activity and the nuclear accumulation of ß-catenin was significantly restrained by let-7b-5p through targeting NKD1. Moreover, NKD1 could prohibit the expression of APC protein. Further studies manifested that NKD1 bound to APC and promoted the ubiquitination degradation of APC through restraining the expression of deubiquitinating enzyme USP15 and blocking the combination between USP15 and APC. Functionally, NKD1 enhanced the proliferation and migration of colon cancer cells by inhibiting APC expression. This research revealed a novel mechanism by which the let-7b-5p-NKD1-APC-ß-catenin signaling pathway inhibited colon cancer cell progression.

13.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36362185

RESUMO

Neuromedin S (NMS) plays various roles in reproductive regulation, while the mechanism by which NMS regulates ovarian steroidogenesis remains unclear. In the current study, we confirmed the enhancement role of NMS in steroidogenesis in goat ovarian granulosa cells (GCs). To further explore the specific mechanism, we conducted a knockdown of NMUR2 in GCs followed by treatment with NMS and determined the effects of NMS treatment on mitochondrial morphology and function. The results found that NMS treatment increased the production of estrogen and up-regulated the expression of STAR, CYP11A1, 3BHSD, and CYP19A1, while the effects of NMS treatment were blocked by the knockdown of NMUR2 in goat GCs. Moreover, NMS treatment enhanced the fusion of mitochondria and up-regulated the expression of OPA1, MFN1, and MFN2, and increased mitochondrial membrane potential, the activity of respiratory chain enzymes and ATP production by maintaining a low expression level of mitochondrial unfolded protein response markers. The effects of NMS treatment on mitochondria were reversed by NMUR2 knockdown and NMS cotreatment. The possible mechanism of the results above was revealed by NMS treatment activating the Hippo pathway effector YAP1 and then managing the expression of phosphorylation PPARGC1A (Ser571). Together, these data showed that NMS promoted the fusion of mitochondria and protected mitochondrial function from mitochondrial unfolded protein response possibly via the NMUR2/YAP1/PPARGC1A pathway, thereby affecting the steroidogenesis of goat GCs. By elaborating the potential mechanism of NMS in regulating estrogen production in goat GCs, our results can serve as the mechanism reference for follicular growth and development.


Assuntos
Cabras , Células da Granulosa , Animais , Feminino , Células da Granulosa/metabolismo , Mitocôndrias/metabolismo , Estrogênios/metabolismo
14.
Behav Sci (Basel) ; 12(10)2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36285924

RESUMO

The purpose of this study was to learn about the process of disclosing health information to a coworker friend using the lens of Communication Privacy Management Theory. The study explores emerging themes regarding health information disclosure and predicts associations between privacy, social support, risk, stigma, and the willingness to disclose health information to a friend at work. Employees were asked to recall a time they shared health information with a coworker friend and report about the interaction via open-ended items and scales on a survey. The study found that as emotional support, instrumental support, perceived risk, and stigma of the information increased, so did the tendency to disclose to a coworker friend. Increased privacy of the information was associated with a decrease in the tendency to disclose. A thematic analysis of the open-ended results also revealed that employees shared information associated with personal on-going health problems to seek support, to relate to their coworker friends, and to maintain their friendship. The findings also indicated that employees were likely to receive social support from their coworker friends even if they were not seeking it.

15.
Nature ; 611(7934): 68-73, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36289343

RESUMO

Objects that deform a liquid interface are subject to capillary forces, which can be harnessed to assemble the objects1-4. Once assembled, such structures are generally static. Here we dynamically modulate these forces to move objects in programmable two-dimensional patterns. We 3D-print devices containing channels that trap floating objects using repulsive capillary forces5,6, then move these devices vertically in a water bath. Because the channel cross-sections vary with height, the trapped objects can be steered in two dimensions. The device and interface therefore constitute a simple machine that converts vertical to lateral motion. We design machines that translate, rotate and separate multiple floating objects and that do work on submerged objects through cyclic vertical motion. We combine these elementary machines to make centimetre-scale compound machines that braid micrometre-scale filaments into prescribed topologies, including non-repeating braids. Capillary machines are distinct from mechanical, optical or fluidic micromanipulators in that a meniscus links the object to the machine. Therefore, the channel shapes need only be controlled on the scale of the capillary length (a few millimetres), even when the objects are microscopic. Consequently, such machines can be built quickly and inexpensively. This approach could be used to manipulate micrometre-scale particles or to braid microwires for high-frequency electronics.

16.
Sci Adv ; 8(43): eadd2000, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36306363

RESUMO

The mechanisms of Li deposition behaviors, which overwhelmingly affect battery performances and safety, are far to be understood in solid-state batteries. Here, using in situ micro-nano electrochemical scanning electron microscopy (SEM) manipulation platform, dynamic Li plating behaviors on 10 metallic substrates have been tracked, and the underlying mechanisms for dendrite-free Li plating are elucidated. Distinct Li deposition behaviors on Cu, Ti, Ni, Bi, Cr, In, Ag, Au, Pd, and Al are revealed quantitatively in nucleation densities, growth rates, and anisotropic ratios. For Li alloyable metals, the dynamic Li alloying process before Li growth is visually captured. It is concluded that a good affinity for Li and appropriate lattice compatibility between the substrate and Li are needed to facilitate homogeneous Li plating. Our work not only uncovers the Li plating dynamics, shedding light on the design of solid-state batteries, but also provides a powerful integrated SEM platform for future in-depth investigation of solid-state batteries.

17.
J Ovarian Res ; 15(1): 116, 2022 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-36273148

RESUMO

BACKGROUND: The possible impact of ovarian endometriomas (OMAs) on in vitro fertilization (IVF) outcomes remains controversial. Therefore, this study aimed to assess the impact of OMAs on IVF cycle parameters, including ovarian reserve and response to stimulation, embryo quality and pregnancy outcomes. METHODS: This retrospective cohort study included 2067 patients undergoing their first IVF/ICSI cycles between January 2018 and December 2020. The study group included 154 infertile women who had OMAs. The control group consisted of 1913 women without endometriosis, and finally 305 women were matched according to maternal age, body mass index (BMI), and infertility duration by propensity score matching (PSM). Cumulative live birth rate (CLBR) was set as the primary outcome measure. Logistic regression analysis was conducted on the basis of clinical covariates assessed for their association with CLBRs. Subgroup analyses were performed to evaluate the effect of ovarian surgery, cyst size and laterality on CLBRs. RESULTS: Women with OMAs had significantly lower ovarian reserve markers (AMH and AFC), number of follicles, oocytes, embryos, and top-quality embryos than women in the control group (p < 0.05). However, the CLBRs were comparable between the two groups (55.64% versus 54.34%, p = 0.806), regardless of previous history of ovarian surgery. Multivariate analysis revealed association between age (OR = 0.861; 95% CI [0.806-0.921]; p = 0.000), top-quality embryos (OR = 1.829; 95% CI [1.526-2.193]; p = 0.000) and the CLBRs. A negative correlation between OMA size and AFC levels in patients with unoperated OMAs was detected (r = -0.264, p = 0.007). Meanwhile, significant decrease in ovarian reserve with lower AFC, fewer oocytes, embryos and top-quality embryos were observed in patients with OMAs size ≥ 6 cm (p < 0.05). Moreover, ovaries with OMAs had a significantly lower AFC (P = 0.006) but similar number of oocytes when compared with contralateral ovaries without OMAs. CONCLUSION: Infertile women with OMAs were implicated in considerable decreases in ovarian reserve and response to stimulation, but no apparent adverse effects on oocyte quality or clinical outcomes. OMAs surgery and OMAs size may adversely affect ovarian reserve, but not CLBR.


Assuntos
Endometriose , Infertilidade Feminina , Reserva Ovariana , Gravidez , Humanos , Feminino , Reserva Ovariana/fisiologia , Infertilidade Feminina/terapia , Injeções de Esperma Intracitoplásmicas , Estudos Retrospectivos , Fertilização In Vitro
18.
Appl Opt ; 61(28): 8527-8532, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36256170

RESUMO

Bound states in the continuum (BICs) are perfectly confined resonances within the radiation continuum. The novel characteristics of single BICs have been studied in great detail in various wave systems, including electromagnetic waves, acoustic waves, water waves, and elastic waves in solids. In practice, the performance of BICs is limited by the finite size of the structure, while the combination of multiple BICs can further improve the localization of resonances. In this study, we experimentally demonstrate the combination of Fabry-Perot and symmetry-protected BICs at near infrared wavelengths by employing a compound photonic crystal system composed of a photonic crystal slab and a distributed Bragg reflector, resulting in an enhanced high quality factor.

19.
Opt Express ; 30(12): 22135-22142, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-36224919

RESUMO

Lithium niobate on insulator (LNOI) is a new photonic integrated platform that provides high optical confinement and retains the inherent excellent properties of lithium niobate (LN). Tunable filters are one of the indispensable devices for integrated optics. Here we design and fabricate a thermo-optic (TO) tunable optical filter using two cascaded racetrack microring resonators (MRRs) based on LNOI. The filter shows a narrow and flat top passband with intra band ripple less than 0.3 dB, 3 dB bandwidth of 4.8 GHz and out-of-band rejection of about 35 dB. The insertion loss of the filter is about -14 dB, including grating coupling loss about -6.5 dB and on-chip loss less than -1 dB. The heating power for center wavelength shift of the filter is about 89.4 mW per free spectral range (FSR). Relevant applications of such filters include optical information processing and microwave photonics.

20.
ISA Trans ; 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36229239

RESUMO

This paper mainly addresses the practical consensus problem of nonlinear multi-agent systems modeled by reaction-diffusion equations subject to the bounded external disturbances. Different from the existing consensus control methods associated with spatiotemporal dynamics, the proposed H∞ Neumann boundary controller based on distributed measurement data can guarantee the optimal disturbance attenuation performance under the actuator saturation. Initially, a consensus spatiotemporal error model is constructed by introducing the Kronecker product and equivalent directed graph. Subsequently, a linear matrix inequalities (LMIs)-based sufficient condition is derived by combining the improved Lyapunov-based approach and H∞ norm. Then, an optimization problem is proposed by applying invariant set, such that the consensus errors can converge to a minimized bounded region in the presence of actuator saturation. Finally, comparison simulations on the synchronization of FitzHugh-Nagumo (FHN) model are given to demonstrate the effectiveness of proposed methodology.

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