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1.
Cell Metab ; 36(7): 1482-1493.e7, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38959862

ABSTRACT

Although human core body temperature is known to decrease with age, the age dependency of facial temperature and its potential to indicate aging rate or aging-related diseases remains uncertain. Here, we collected thermal facial images of 2,811 Han Chinese individuals 20-90 years old, developed the ThermoFace method to automatically process and analyze images, and then generated thermal age and disease prediction models. The ThermoFace deep learning model for thermal facial age has a mean absolute deviation of about 5 years in cross-validation and 5.18 years in an independent cohort. The difference between predicted and chronological age is highly associated with metabolic parameters, sleep time, and gene expression pathways like DNA repair, lipolysis, and ATPase in the blood transcriptome, and it is modifiable by exercise. Consistently, ThermoFace disease predictors forecast metabolic diseases like fatty liver with high accuracy (AUC > 0.80), with predicted disease probability correlated with metabolic parameters.


Subject(s)
Aging , Face , Metabolic Diseases , Humans , Middle Aged , Aged , Adult , Male , Female , Aged, 80 and over , Young Adult , Deep Learning , Body Temperature , Image Processing, Computer-Assisted
2.
Zhonghua Yan Ke Za Zhi ; 60(6): 537-540, 2024 Jun 11.
Article in Chinese | MEDLINE | ID: mdl-38825953

ABSTRACT

A 21-year-old female patient presented to the Ophthalmology Department of Yunnan University Affiliated Hospital with complaints of "bilateral blurred vision accompanied by diplopia for 3 weeks". The patient's main symptoms included intermittent visual blurring, diplopia, headaches, and ocular discomfort. Ocular examination revealed intermittent exotropia, sometimes accompanied by esotropia or orthotropia, along with signs of pupillary constriction and pseudomyopia. Based on the clinical presentation, a diagnosis of intermittent exotropia complicated by spasm of the near reflex (SNR) was made. The patient underwent bilateral exotropia surgery, which corrected the ocular alignment and resolved the symptoms and signs of SNR postoperatively.


Subject(s)
Exotropia , Humans , Female , Young Adult , Spasm/complications , Diplopia/etiology
3.
Aging Cell ; : e14196, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38845183

ABSTRACT

Stroke is a major threat to life and health in modern society, especially in the aging population. Stroke may cause sudden death or severe sequela-like hemiplegia. Although computed tomography (CT) and magnetic resonance imaging (MRI) are standard diagnosis methods, and artificial intelligence models have been built based on these images, shortage in medical resources and the time and cost of CT/MRI imaging hamper fast detection, thus increasing the severity of stroke. Here, we developed a convolutional neural network model by integrating four networks, Xception, ResNet50, VGG19, and EfficientNetb1, to recognize stroke based on 2D facial images with a cross-validation area under curve (AUC) of 0.91 within the training set of 185 acute ischemic stroke patients and 551 age- and sex-matched controls, and AUC of 0.82 in an independent data set regardless of age and sex. The model computed stroke probability was quantitatively associated with facial features, various clinical parameters of blood clotting indicators and leukocyte counts, and, more importantly, stroke incidence in the near future. Our real-time facial image artificial intelligence model can be used to rapidly screen and prediagnose stroke before CT scanning, thus meeting the urgent need in emergency clinics, potentially translatable to routine monitoring.

4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 45(6): 844-851, 2024 Jun 10.
Article in Chinese | MEDLINE | ID: mdl-38889985

ABSTRACT

Objective: To understand the characteristics and trends of acute myocardial infarction (AMI) in Shandong Province and to provide evidence for formulating prevention and control strategies. Methods: Data were derived from the AMI incidence reports of Shandong Province's Chronic Disease Surveillance Information Management System in 2012-2021. The crude and standardized incidence rates were used as indicators to describe the incidence level of AMI. Joinpoint regression analysis was used to analyze the trends in the incidence and age of onset over the years. The contribution of population aging to the increase in AMI incidence was assessed using the rate difference decomposition method. The incidence of AMI in each district (county) in Shandong Province was visualized using ArcGIS 10.8 software, and global and local spatial autocorrelation analysis was performed using DeoDa 1.12 software. Results: From 2012 to 2021, 198 233 cases of AMI were reported from 19 provincial monitoring sites in Shandong Province, of which 53.13% were males and 97.12% were ≥45 years old. The reported crude incidence increased from 90.12 per 100 000 in 2012 to 176.54 per 100 000 in 2021, with an average annual increase of 7.01% (Z=7.35, P<0.001). There was no significant upward trend in standardized incidence (Z=1.64, P=0.140), but the standardized incidence of male residents showed an increasing trend (Z=2.76, P=0.028). Before 2014, the reported crude incidence of males was similar to that of females, but after 2014, the reported crude incidence of males was continuously higher than that of females. However, males' standardized incidence was higher than females in all years. Both crude and standardized incidence rates were higher in rural residents than in urban areas. The median onset of AMI increased from 71.6 years old in 2012 to 73.5 years old in 2021. The median age of onset in males was lower than that in females in all years, and in most years, the median age of onset in urban residents was lower than that in rural residents. The incidence of AMI in males showed a trend in younger age groups. According to the seasonal decomposition, the incidence peak of AMI was in January, and the trough was in September. The contribution of aging population to the increase in crude incidence of AMI increased from 8.63% in 2013 to 52.58% in 2021. The global spatial autocorrelation analysis showed that the incidence of AMI presented an obvious spatial clustering distribution. Local spatial autocorrelation analysis found that the high-incidence areas (counties) were mainly concentrated in Liaocheng City and Dezhou City in the northwest region of Shandong Province and Heze City in the southwest. Conclusions: The incidence of AMI among residents in Shandong Province was rising, with spatial clustering and seasonal clustering characteristics. People aged 45 years and older, male residents, and rural residents were at high risk of developing AMI. There was a certain trend of younger age at onset among men. Targeted prevention and control measures should be taken for high-incidence seasons, high-risk groups, and high-incidence clustering areas in northwestern Shandong Province.


Subject(s)
Myocardial Infarction , Humans , Myocardial Infarction/epidemiology , China/epidemiology , Incidence , Male , Female , Middle Aged , Aged , Prevalence , Spatial Analysis
5.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(4): 727-738, 2024 Apr 20.
Article in Chinese | MEDLINE | ID: mdl-38708507

ABSTRACT

OBJECTIVE: To identify the key genes differentially expressed in Wilms tumor and analyze their potential impacts on prognosis and immune responses of the patients. METHODS: High-throughput RNA sequencing was used to identify the differentially expressed mRNAs in clinical samples of Wilms tumor and paired normal tissues, and their biological functions were analyzed using GO, KEGG and GSEA enrichment analyses. The hub genes were identified using STRING database, based on which a prognostic model was constructed using LASSO regression. The mutations of the key hub genes were analyzed and their impacts on immunotherapy efficacy was predicted using the cBioPortal platform. RT-qPCR was used to verify the differential expressions of the key hub genes in Wilms tumor. RESULTS: Of the 1612 differentially expressed genes identified in Wilms tumor, 1030 were up-regulated and 582 were down-regulated, involving mainly cell cycle processes and immune responses. Ten hub genes were identified, among which 4 genes (TP53, MED1, CCNB1 and EGF) were closely related to the survival of children with Wilms tumor. A 3-gene prognostic signature was constructed through LASSO regression analysis, and the patients stratified into with high- and low-risk groups based on this signature had significantly different survival outcomes (HR=1.814, log-rank P=0.002). The AUCs of the 3-, 5- and 7-year survival ROC curves of this model were all greater than 0.7. The overall mutations in the key hub genes or the individual mutations in TP53/CCNB1 were strongly correlated with a lower survival rates, and a high TP53 expression was correlated with a poor immunotherapy efficacy. RT-qPCR confirmed that the key hub genes had significant differential expressions in Wilms tumor tissues and cells. CONCLUSION: TP53 gene plays an important role in the Wilms tumor and may potentially serve as a new immunotherapeutic biomarker as well as a therapeutic target.


Subject(s)
Kidney Neoplasms , Wilms Tumor , Humans , Wilms Tumor/genetics , High-Throughput Nucleotide Sequencing , Prognosis , Kidney Neoplasms/genetics , Genes, Wilms Tumor , Tumor Microenvironment
6.
Sci China Life Sci ; 67(7): 1489-1501, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38573362

ABSTRACT

The human face is a valuable biomarker of aging, but the collection and use of its image raise significant privacy concerns. Here we present an approach for facial data masking that preserves age-related features using coordinate-wise monotonic transformations. We first develop a deep learning model that estimates age directly from non-registered face point clouds with high accuracy and generalizability. We show that the model learns a highly indistinguishable mapping using faces treated with coordinate-wise monotonic transformations, indicating that the relative positioning of facial information is a low-level biomarker of facial aging. Through visual perception tests and computational 3D face verification experiments, we demonstrate that transformed faces are significantly more difficult to perceive for human but not for machines, except when only the face shape information is accessible. Our study leads to a facial data protection guideline that has the potential to broaden public access to face datasets with minimized privacy risks.


Subject(s)
Aging , Face , Imaging, Three-Dimensional , Privacy , Humans , Imaging, Three-Dimensional/methods , Aging/physiology , Deep Learning , Female , Male , Adult , Young Adult , Aged , Middle Aged , Visual Perception/physiology
7.
Plant Biol (Stuttg) ; 26(4): 532-543, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38597809

ABSTRACT

Peanut production is threatened by climate change. Damage to seedlings from low temperatures in early spring can limit yield. Plant adaptations to chilling stress remain unclear in peanut seedlings. It is essential to understand how peanut acquires chilling tolerance. We evaluated effects of chilling stress on growth and recovery of peanut seedlings. We compared and analysed biological characteristics, antioxidants, photosynthesis, biochemical and physiological responses, and nutrient absorption at varying levels of chilling. Compared with chilling-sensitive FH18, the reduced impact of chilling stress on chilling-tolerant NH5 was associated with reduced ROS accumulation, higher ascorbate peroxidase activity and soluble sugar content, lower soluble protein content, and smaller reductions in nutrient content during stress. After removal of chilling stress, FH18 had significant accumulation of O2 •- and H2O2, which decreased photosynthesis, nutrient absorption, and transport. ROS-scavenging reduced damage from chilling stress, allowed remobilization of nutrients, improved chilling tolerance, and restored plant functioning after chilling stress removal. These findings provide a reference for targeted research on peanut seedling tolerance to chilling and lay the foundation for bioinformatics-based research on peanut chilling tolerance mechanisms.


Subject(s)
Antioxidants , Arachis , Cold Temperature , Photosynthesis , Reactive Oxygen Species , Seedlings , Arachis/physiology , Arachis/metabolism , Seedlings/physiology , Photosynthesis/physiology , Antioxidants/metabolism , Reactive Oxygen Species/metabolism , Nutrients/metabolism , Hydrogen Peroxide/metabolism
8.
Cell Metab ; 36(5): 1126-1143.e5, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38604170

ABSTRACT

Cellular senescence underlies many aging-related pathologies, but its heterogeneity poses challenges for studying and targeting senescent cells. We present here a machine learning program senescent cell identification (SenCID), which accurately identifies senescent cells in both bulk and single-cell transcriptome. Trained on 602 samples from 52 senescence transcriptome datasets spanning 30 cell types, SenCID identifies six major senescence identities (SIDs). Different SIDs exhibit different senescence baselines, stemness, gene functions, and responses to senolytics. SenCID enables the reconstruction of senescent trajectories under normal aging, chronic diseases, and COVID-19. Additionally, when applied to single-cell Perturb-seq data, SenCID helps reveal a hierarchy of senescence modulators. Overall, SenCID is an essential tool for precise single-cell analysis of cellular senescence, enabling targeted interventions against senescent cells.


Subject(s)
COVID-19 , Cellular Senescence , Machine Learning , Single-Cell Analysis , Transcriptome , Humans , SARS-CoV-2/metabolism , Aging
9.
Br Poult Sci ; 65(3): 352-360, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38466183

ABSTRACT

1. The objective of this study was to investigate the protective effects of a peptidoglycan produced by Limosilactobacillus reuteri against aflatoxin B1 (AFB1) induced toxicity in vitro and in vivo in broiler chicks.2. Toxin adsorption experiments were carried out firstly in vitro. These experiments indicated that the absorption efficiency of the peptidoglycan for AFB1 was 64.3-75.9%.3. In the in vivo experiments, Hy-Line Brown chicks were fed a diet containing AFB1 at 71.43 µg/kg with and without peptidoglycan supplementation at concentrations of 100, 200, or 300 g/kg feed from 0-42 d of age.4. The peptidoglycan supplementation in AFB1-contaminated diets resulted in significant improvements in terms of average daily gain, feed intake, feed conversion ratio, white blood cell count, haemoglobin content, glutathione peroxidase activity, immunoglobulin (Ig) A, IgG, IgM and Newcastle disease virus antibody titres (p < 0.05) and diminished liver steatosis.5. In conclusion, peptidoglycan supplementation alleviated AFB1-induced toxicity through adsorbing toxins and improving growth performance, antioxidant ability, immunity and liver pathological changes in chicks. The optimal supplemental dose was 200 mg/kg in feed.


Subject(s)
Aflatoxin B1 , Animal Feed , Antioxidants , Chickens , Diet , Limosilactobacillus reuteri , Peptidoglycan , Poultry Diseases , Animals , Chickens/growth & development , Chickens/immunology , Aflatoxin B1/toxicity , Animal Feed/analysis , Peptidoglycan/pharmacology , Diet/veterinary , Poultry Diseases/prevention & control , Poultry Diseases/chemically induced , Poultry Diseases/microbiology , Antioxidants/metabolism , Dietary Supplements/analysis , Liver/drug effects , Male , Random Allocation , Dose-Response Relationship, Drug
11.
Phys Rev Lett ; 132(7): 076701, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38427900

ABSTRACT

Magnon transistors that can effectively regulate magnon transport by an electric field are desired for magnonics, which aims to provide a Joule-heating free alternative to the conventional electronics owing to the electric neutrality of magnons (the key carriers of spin-angular momenta in the magnonics). However, also due to their electric neutrality, magnons have no access to directly interact with an electric field and it is thus difficult to manipulate magnon transport by voltages straightforwardly. Here, we demonstrated a gate voltage (V_{g}) applied on a nonmagnetic metal and magnetic insulator (MI) interface that bent the energy band of the MI and then modulated the probability for conduction electrons in the nonmagnetic metal to tunnel into the MI, which can consequently enhance or weaken the spin-magnon conversion efficiency at the interface. A voltage-controlled magnon transistor based on the magnon-mediated electric current drag (MECD) effect in a Pt-Y_{3}Fe_{5}O_{12}-Pt sandwich was then experimentally realized with V_{g} modulating the magnitude of the MECD signal. The obtained efficiency (the change ratio between the MECD voltage at ±V_{g}) reached 10%/(MV/cm) at 300 K. This prototype of magnon transistor offers an effective scheme to control magnon transport by a gate voltage.

12.
Article in Chinese | MEDLINE | ID: mdl-38311957

ABSTRACT

Fat emulsion is a drug commonly used clinically for parenteral nutrition support in critically ill patients.With the development of the pharmaceutical industry, fat emulsion has formed a variety of different formulations, among which different types of fat emulsion have their own metabolic and body energy supply characteristics, and the application indications are also different. In addition to providing the supply of nutrients, the role of fat emulsion in anti-toxicity, immune regulation, anti-inflammatory, anti-shock, cardiopulmonary resuscitation and other aspects has gradually been discovered. This article reviews the existing evidence-based medical evidence and expounds the mechanism and therapeutic role of fat emulsion in the treatment of critically ill patients with poisoning. Its value in the treatment of critically ill patients with poisoning was discussed, and some references were provided for the application of non-nutritional functions of fat emulsion in the future.


Subject(s)
Critical Illness , Fat Emulsions, Intravenous , Humans , Fat Emulsions, Intravenous/therapeutic use , Fat Emulsions, Intravenous/metabolism , Critical Illness/therapy , Parenteral Nutrition
13.
Sci Adv ; 10(8): eadl2238, 2024 Feb 23.
Article in English | MEDLINE | ID: mdl-38394209

ABSTRACT

Skeletal stem cells (SSCs) that are capable of self-renewal and multipotent differentiation contribute to bone development and homeostasis. Several populations of SSCs at different skeletal sites have been reported. Here, we identify a metaphyseal SSC (mpSSC) population whose transcriptional landscape is distinct from other bone mesenchymal stromal cells (BMSCs). These mpSSCs are marked by Sstr2 or Pdgfrb+Kitl-, located just underneath the growth plate, and exclusively derived from hypertrophic chondrocytes (HCs). These HC-derived mpSSCs have properties of self-renewal and multipotency in vitro and in vivo, producing most HC offspring postnatally. HC-specific deletion of Hgs, a component of the endosomal sorting complex required for transport, impairs the HC-to-mpSSC conversion and compromises trabecular bone formation. Thus, mpSSC is the major source of BMSCs and osteoblasts in bone marrow, supporting the postnatal trabecular bone formation.


Subject(s)
Cancellous Bone , Mesenchymal Stem Cells , Stem Cells , Bone and Bones , Cell Differentiation , Osteoblasts , Osteogenesis/genetics
14.
Curr Opin Struct Biol ; 85: 102777, 2024 04.
Article in English | MEDLINE | ID: mdl-38310737

ABSTRACT

The development of anti-aging interventions requires quantitative measurement of biological age. Machine learning models, known as "aging clocks," are built by leveraging diverse aging biomarkers that vary across lifespan to predict biological age. In addition to traditional aging clocks harnessing epigenetic signatures derived from bulk samples, emerging technologies allow the biological age estimating at single-cell level to dissect cellular diversity in aging tissues. Moreover, imaging-based aging clocks are increasingly employed with the advantage of non-invasive measurement, making it suitable for large-scale human cohort studies. To fully capture the features in the ever-growing multi-modal and high-dimensional aging-related data and uncover disease associations, deep-learning based approaches, which are effective to learn complex and non-linear relationships without relying on pre-defined features, are increasingly applied. The use of big data and AI-based aging clocks has achieved high accuracy, interpretability and generalizability, guiding clinical applications to delay age-related diseases and extend healthy lifespans.


Subject(s)
Aging , Longevity , Humans , Machine Learning , Biomarkers
15.
Nat Commun ; 15(1): 955, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38302463

ABSTRACT

Ageing exhibits common and distinct features in various tissues, making it critical to decipher the tissue-specific ageing mechanisms. MiRNAs are essential regulators in ageing and are recently highlighted as a class of intercellular messengers. However, little is known about the tissue-specific transcriptomic changes of miRNAs during ageing. C. elegans is a well-established model organism in ageing research. Here, we profile the age-dependent miRNAomic changes in five isolated worm tissues. Besides the diverse ageing-regulated miRNA expression across tissues, we discover numerous miRNAs in the tissues without their transcription. We further profile miRNAs in the extracellular vesicles and find that worm miRNAs undergo inter-tissue trafficking via these vesicles in an age-dependent manner. Using these datasets, we uncover the interaction between body wall muscle-derived mir-1 and DAF-16/FOXO in the intestine, suggesting mir-1 as a messenger in inter-tissue signalling. Taken together, we systematically investigate worm miRNAs in the somatic tissues and extracellular vesicles during ageing, providing a valuable resource to study tissue-autonomous and nonautonomous functions of miRNAs in ageing.


Subject(s)
Caenorhabditis elegans Proteins , MicroRNAs , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Aging/genetics , Intestines , MicroRNAs/metabolism , Longevity/genetics
16.
Rhinology ; 62(2): 223-235, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38010118

ABSTRACT

BACKGROUND: Topical intranasal medication is required following functional endoscopic sinus surgery (FESS). The optimal particle size of transnasal nebulization aimed at the sinonasal cavities is not conclusive. The current study aims to evaluate the effect of particle size and various surgery scope of middle turbinectomy (MT) on post-full FESS drug delivery to the sinonasal cavities. METHODS: Sinonasal reconstructions were performed from post-full FESS CT scans in 6 chronic rhinosinusitis with nasal polyps (CRSwNP) patients. Four additional models representing alternative surgery scopes of MT were established from each post-FESS reconstruction for simulation data comparison. Airflow and particle deposition of nebulized delivery were simulated via computational fluid dynamics (CFD) and validated through in vitro experiments. The optimal particle sizes reaching a deposition of at least 75% of the maximum in the targeted regions were identified. RESULTS: The drug deposition rate onto the targeted regions increased following MT, with the greatest deposition following posterior MT (P-MT). Droplets in the range of 18-26 λm reached a deposition of larger than 75% of the maximum onto the targeted regions. Drug delivery rate in the sinonasal cavities varied significantly among individuals and across different types of MT with varying surgical scopes. CONCLUSIONS: This study is the first to investigate the effect of various surgery scope on drug delivery by transnasal nebulization to the sinonasal cavities. The findings strongly affirm the vast potential of transnasal nebulization as an effective post-FESS treatment option. Moreover, it emphasizes that the drug delivery process via atomizers to the nasal cavity and paranasal sinuses is highly sensitive to the particle size.


Subject(s)
Paranasal Sinuses , Sinusitis , Humans , Sinusitis/surgery , Paranasal Sinuses/surgery , Nasal Cavity/surgery , Turbinates , Pharmaceutical Preparations
17.
Trends Endocrinol Metab ; 35(1): 11-22, 2024 01.
Article in English | MEDLINE | ID: mdl-37880054

ABSTRACT

Computational models that measure biological age and aging rate regardless of chronological age are called aging clocks. The underlying counting mechanisms of the intrinsic timers of these clocks are still unclear. Molecular mediators and determinants of aging rate point to the key roles of DNA damage, epigenetic drift, and inflammation. Persistent DNA damage leads to cellular senescence and the senescence-associated secretory phenotype (SASP), which induces cytotoxic immune cell infiltration; this further induces DNA damage through reactive oxygen and nitrogen species (RONS). I discuss the possibility that DNA damage (or the response to it, including epigenetic changes) is the fundamental counting unit of cell cycles and cellular senescence, that ultimately accounts for cell composition changes and functional decline in tissues, as well as the key intervention points.


Subject(s)
Aging , Cellular Senescence , Humans , Aging/genetics , Cellular Senescence/genetics , DNA Damage/genetics , Reactive Oxygen Species
18.
Scand J Rheumatol ; 53(1): 59-62, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37650252

ABSTRACT

OBJECTIVE: To observe the effect of belimumab treatment in refractory anti-phospholipid antibody-associated immune thrombocytopenia with systemic lupus erythematosus (SLE). METHOD: Four SLE patients with refractory anti-phospholipid antibody-associated immune thrombocytopenia were included in this one-arm observational study. Inclusion criteria were a diagnosis of SLE according to 1997 American College of Rheumatology criteria, severe immune thrombocytopenia (platelets <30 × 109/L), no bleeding symptoms, lack of satisfactory response to traditional treatment, and high-titre anti-phospholipid antibodies. All patients received belimumab (Benlysta®) for 6 months. RESULTS: The mean platelet count was 21.8 × 109 cells/L, ranging between 16 and 29 × 109/L at baseline, 123.3 × 109/L at 1 month, and 172.5 × 109/L at the end of 6 months after belimumab treatment. No bleeding complications occurred during the entire follow-up period. CONCLUSION: In this study, belimumab reduced the anti-phospholipid antibodies while increasing the platelet count in SLE patients with anti-phospholipid antibody-associated immune thrombocytopenia.


Subject(s)
Lupus Erythematosus, Systemic , Purpura, Thrombocytopenic, Idiopathic , Humans , Immunosuppressive Agents/therapeutic use , Treatment Outcome , Severity of Illness Index , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/drug therapy
20.
Opt Express ; 31(24): 40166-40178, 2023 Nov 20.
Article in English | MEDLINE | ID: mdl-38041323

ABSTRACT

Integrated microring resonators are well suited for wavelength-filtering applications in optical signal processing, and cascaded microring resonators allow flexible filter design in coupled-resonator optical waveguide (CROW) configurations. However, the implementation of high-order cascaded microring resonators with high extinction ratios (ERs) remains challenging owing to stringent fabrication requirements and the need for precise resonator tunability. We present a fully integrated on-chip second-order CROW filter using silicon photonic microelectromechanical systems (MEMS) to adjust tunable directional couplers and a phase shifter using nanoscale mechanical out-of-plane waveguide displacement. The filter can be fully reconfigured with regard to both the ER and center wavelength. We experimentally demonstrated an ER exceeding 25 dB and continuous wavelength tuning across the full free spectral range of 0.123 nm for single microring resonator, and showed reconfigurability in second-order CROW by tuning the ER and resonant wavelength. The tuning energy for an individual silicon photonic MEMS phase shifter or tunable coupler is less than 22 pJ with sub-microwatt static power consumption, which is far better than conventional integrated phase shifters based on other physical modulation mechanisms.

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