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Dental caries is a chronic oral infectious disease, and Streptococcus mutans (S. mutans) plays an important role in the formation of dental caries. Trans-cinnamaldehyde (CA) exhibits broad-spectrum antibacterial activity; however, its target and mechanism of action of CA on S. mutans needs to be further explored. In this study, it was verified that CA could inhibit the growth and biofilm formation of S. mutans. Further proteomic analysis identified 33, 55, and 78 differentially expressed proteins (DEPs) in S. mutans treated with CA for 1, 2, and 4 h, respectively. Bioinformatics analysis showed that CA interfered with carbohydrate metabolism, glycolysis, pyruvate metabolism, and the TCA cycle, as well as amino acid metabolism of S. mutans. Protein interactions suggested that pyruvate dehydrogenase (PDH) plays an important role in the antibacterial effect of CA. Moreover, the upstream and downstream pathways related to PDH were verified by various assays, and the results proved that CA not only suppressed the glucose and sucrose consumption and inhibited glucosyltransferase (GTF) and lactate dehydrogenase (LDH) activities but also decreased the ATP production. Interestingly, the protein interaction, qRT-PCR, and molecular docking analysis showed that PDH might be the target of CA to fight S. mutans. In summary, the study shows that CA interferes with the carbohydrate metabolism of bacteria by inhibiting glycolysis and the tricarboxylic acid (TCA) cycle via binding to PDH, which verifies that PDH is a potential target for the development of new drugs against S. mutans.
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Acroleína , Metabolismo de los Hidratos de Carbono , Simulación del Acoplamiento Molecular , Complejo Piruvato Deshidrogenasa , Streptococcus mutans , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/genética , Streptococcus mutans/enzimología , Acroleína/farmacología , Acroleína/análogos & derivados , Acroleína/metabolismo , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Complejo Piruvato Deshidrogenasa/metabolismo , Complejo Piruvato Deshidrogenasa/antagonistas & inhibidores , Antibacterianos/farmacología , Glucólisis/efectos de los fármacos , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/antagonistas & inhibidores , Proteómica/métodos , Caries Dental/microbiología , Ciclo del Ácido Cítrico/efectos de los fármacos , Adenosina Trifosfato/metabolismoRESUMEN
OBJECTIVES: This study aims to develop an innovative, deep model for thymoma risk stratification using preoperative CT images. Current algorithms predominantly focus on radiomic features or 2D deep features and require manual tumor segmentation by radiologists, limiting their practical applicability. METHODS: The deep model was trained and tested on a dataset comprising CT images from 147 patients (82 female; mean age, 54 years ± 10) who underwent surgical resection and received subsequent pathological confirmation. The eligible participants were divided into a training cohort (117 patients) and a testing cohort (30 patients) based on the CT scan time. The model consists of two stages: 3D tumor segmentation and risk stratification. The radiomic model and deep model (2D) were constructed for comparative analysis. Model performance was evaluated through dice coefficient, area under the curve (AUC), and accuracy. RESULTS: In both the training and testing cohorts, the deep model demonstrated better performance in differentiating thymoma risk, boasting AUCs of 0.998 and 0.893 respectively. This was compared to the radiomic model (AUCs of 0.773 and 0.769) and deep model (2D) (AUCs of 0.981 and 0.760). Notably, the deep model was capable of simultaneously identifying lesions, segmenting the region of interest (ROI), and differentiating the risk of thymoma on arterial phase CT images. Its diagnostic prowess outperformed that of the baseline model. CONCLUSIONS: The deep model has the potential to serve as an innovative decision-making tool, assisting on clinical prognosis evaluation and the discernment of suitable treatments for different thymoma pathological subtypes. KEY POINTS: ⢠This study incorporated both tumor segmentation and risk stratification. ⢠The deep model, using clinical and 3D deep features, effectively predicted thymoma risk. ⢠The deep model improved AUCs by 16.1pt and 17.5pt compared to radiomic model and deep model (2D) respectively.
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Aprendizaje Profundo , Timoma , Neoplasias del Timo , Tomografía Computarizada por Rayos X , Humanos , Femenino , Timoma/diagnóstico por imagen , Timoma/patología , Persona de Mediana Edad , Masculino , Tomografía Computarizada por Rayos X/métodos , Medición de Riesgo/métodos , Neoplasias del Timo/patología , Neoplasias del Timo/diagnóstico por imagen , Adulto , Anciano , Estudios RetrospectivosRESUMEN
Psychological stress is a crucial factor in the development of many skin diseases, and the stigma caused by skin disorders may further increase the psychological burden, forming a vicious cycle of psychological stress leading to skin diseases. Therefore, understanding the relationship between stress and skin diseases is necessary. The skin, as the vital interface with the external environment, possesses its own complex immune system, and the neuroendocrine system plays a central role in the stress response of the body. Stress-induced alterations in the immune system can also disrupt the delicate balance of immune cells and inflammatory mediators in the skin, leading to immune dysregulation and increased susceptibility to various skin diseases. Stress can also affect the skin barrier function, impair wound healing, and promote the release of pro-inflammatory cytokines, thereby exacerbating existing skin diseases such as psoriasis, atopic dermatitis, acne, and urticaria. In the present review, we explored the intricate relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective. We explored the occurrence and development of skin diseases in the context of stress, the stress models for skin diseases, the impact of stress on skin function and diseases, and relevant epidemiological studies and clinical trials. Understanding the relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective provides a comprehensive framework for targeted interventions and new insights into the diagnosis and treatment of skin diseases.
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Dermatitis Atópica , Psoriasis , Enfermedades de la Piel , Humanos , Enfermedades de la Piel/psicología , Piel , Dermatitis Atópica/psicología , Sistemas Neurosecretores , Estrés PsicológicoRESUMEN
This study examined parental autonomy support and psychological control and their relations with child biobehavioral functioning. Participants included 238 Chinese parent-child dyads (Mage-child = 8.38 years, 42.0% girls) in two cohorts (2013 and 2021). Parents in the 2021 cohort displayed higher levels of autonomy support and psychological control during the parent-child interaction than in the 2013 cohort. Parental psychological control was positively associated with emotion regulation and negatively associated with externalizing problems in the 2013 cohort, but not in the 2021 cohort. Parental psychological control was also negatively associated with vagal suppression in the 2021 cohort, but not in the 2013 cohort. The result suggests that sociocultural contexts may shape the display of parental behaviors and their significance for child development.
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Chemical oxidation processes are widely used for the remediation of organically contaminated soils, but their potential impact on variable-valence and toxic metals such as chromium (Cr) is often overlooked. In this study, we investigated the risk of Cr(â ¢) oxidation in soils during the remediation of 2-chlorophenol (2-CP) contaminated soils using four different processes: Potassium permanganate (KMnO4), Modified Fenton (Fe2+/H2O2), Alkali-activated persulfate (S2O82-/OH-), and Fe2+-activated persulfate (S2O82-/Fe2+). Our results indicated that the KMnO4, Fe2+/H2O2, and S2O82-/Fe2+ processes progressively oxidized Cr(III) to Cr(â ¥) during the 2-CP degradation. The KMnO4 process likely involved direct electron transfer, while the Fe2+/H2O2 and S2O82-/Fe2+ processes primarily relied on HO⢠and/or SO4â¢- for the Cr(III) oxidation. Notably, after 4 h of 2-CP degradation, the Cr(VI) content in the KMnO4 process surpassed China's 3.0 mg kg-1 risk screening threshold for Class I construction sites, and further exceeded the 5.7 mg kg-1 limit for Class II construction sites after 8 h. Conversely, the S2O82-/OH- process exhibited negligible oxidation of Cr(III), maintaining a low oxidation ratio of 0.13%, as highly alkaline conditions induced Cr(III) precipitation, reducing its exposure to free radicals. Cr(III) oxidation ratio was directly proportional to oxidant dosage, whereas the Fe2+/H2O2 process showed a different trend, influenced by the concentration of reductants. This study provides insights into the selection and optimization of chemical oxidation processes for soil remediation, emphasizing the imperative for thorough risk evaluation of Cr(III) oxidation before their application.
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Clorofenoles , Cromo , Restauración y Remediación Ambiental , Oxidación-Reducción , Contaminantes del Suelo , Suelo , Cromo/química , Contaminantes del Suelo/química , Clorofenoles/química , Suelo/química , Peróxido de Hidrógeno/química , Permanganato de Potasio/químicaRESUMEN
Psoriasis is a chronic recurrent inflammatory skin disease that is characterized by abnormal proliferation and differentiation of keratinocytes (KCs), angiogenesis and skin inflammation. Transfer RNA fragments (tRFs) are tRNA-derived small RNAs (tsRNAs), which possess regulatory functions in many diseases. Their potential roles in the pathological development of psoriasis have not been established. We first identified differentially expressed (DE) tRFs from psoriatic skin lesions using small RNA sequencing, and collected additional clinical samples for validation. Then, we investigated the function and mechanism of target tRFs in vitro. As a result of our investigation: we identified 234 DE transcripts in psoriatic skin lesions compared with normal controls. Further functional analysis showed the downregulation of tRF-Ile-AAT-019 in psoriatic lesions plays a critical role in pathogenesis since it could target 3'UTR of the serine protease serpin protein E1 (SERPINE1) gene. We next demonstrated that tRF-Ile-AAT-019 could suppress SERPINE1, thus leading to decreased expressions of vascular endothelial growth factor but increased expressions of keratinocytes (KCs) differentiation markers including Keratin1 and Involucrin. In conclusion, tRF-Ile-AAT-019 plays a protective role in the pathological progression of psoriasis via targeting SERPINE1, resulting in regulation of KCs differentiation and vascular proliferation biomarkers and providing a potential novel targeting pathway for the disease treatment.
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Psoriasis , ARN , Humanos , Factor A de Crecimiento Endotelial Vascular/metabolismo , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Regulación hacia AbajoRESUMEN
The paper aims to develop prediction model that integrates clinical, radiomics, and deep features using transfer learning to stratifying between high and low risk of thymoma. Our study enrolled 150 patients with thymoma (76 low-risk and 74 high-risk) who underwent surgical resection and pathologically confirmed in Shengjing Hospital of China Medical University from January 2018 to December 2020. The training cohort consisted of 120 patients (80%) and the test cohort consisted of 30 patients (20%). The 2590 radiomics and 192 deep features from non-enhanced, arterial, and venous phase CT images were extracted and ANOVA, Pearson correlation coefficient, PCA, and LASSO were used to select the most significant features. A fusion model that integrated clinical, radiomics, and deep features was developed with SVM classifiers to predict the risk level of thymoma, and accuracy, sensitivity, specificity, ROC curves, and AUC were applied to evaluate the classification model. In both the training and test cohorts, the fusion model demonstrated better performance in stratifying high and low risk of thymoma. It had AUCs of 0.99 and 0.95, and an accuracy of 0.93 and 0.83, respectively. This was compared to the clinical model (AUCs of 0.70 and 0.51, accuracy of 0.68 and 0.47), the radiomics model (AUCs of 0.97 and 0.82, accuracy of 0.93 and 0.80), and the deep model (AUCs of 0.94 and 0.85, accuracy of 0.88 and 0.80). The fusion model integrating clinical, radiomics and deep features based on transfer learning was efficient for noninvasively stratifying high risk and low risk of thymoma. The models could help to determine surgery strategy for thymoma cancer.
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Timoma , Neoplasias del Timo , Humanos , Timoma/diagnóstico por imagen , Timoma/cirugía , Multiómica , Aprendizaje , Neoplasias del Timo/diagnóstico por imagen , Aprendizaje Automático , Estudios RetrospectivosRESUMEN
BACKGROUND: Promoting self-directed learning (SDL) among nursing undergraduates is crucial to meet the new requirements of the healthcare system and to adapt to online learning contexts during the COVID-19 pandemic. Therefore, identifying the classification features of SDL ability and developing targeted interventions are both critical. Professional identity (PI) may contribute to the cultivation of SDL ability, but their relationship remains relatively unknown. This study aimed to explore the subgroups of SDL ability and their differences in PI among nursing undergraduates during the COVID-19 pandemic. METHODS: A total of 2438 nursing undergraduates at four universities in China were enrolled in this cross-sectional study from November 2021 to February 2022. The Self-Directed Learning Scale of Nursing Undergraduates (SLSNU) and the Professional Identity Scale for Nursing Students (PISNS) were administered. A latent profile analysis was performed to explore SDL ability latent profiles. Multinomial logistic regression analysis was conducted to examine the predictors of profile membership, and a one-way analysis of variance was applied to compare the PI scores in each latent profile. RESULTS: Three latent profiles were identified and labeled 'low SDL ability' (n = 749, 30.7%), 'low initiative of help-seeking' (n = 1325, 54.4%) and 'high SDL ability' (n = 364, 14.9%). Multinomial logistic regression analysis suggested that nursing undergraduates who voluntarily chose a nursing major, had served as a student cadre, and had participated in clinical practicum were less likely to be included in the "low SDL ability" group. The average PI score was statistically different across the three profiles (F = 884.40, p < 0.001). CONCLUSION: The SDL ability among nursing undergraduates was divided into three profiles, and results show that promoting PI may effectively foster SDL ability. This study highlights the importance of targeted interventions by considering their distinct SDL ability patterns, especially during the COVID-19 pandemic.
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A novel gain medium structure is designed providing Q-switched pulses with high efficiency. The use of an improved corner-side hybrid pump structure achieves a high absorption efficiency of pump light by crossing through the active media 13 times Nd:YAG. A layer of Sm:YAG is bonded around the active media, which suppresses parasitic oscillation and amplified spontaneous emission (ASE) effectively. A high-efficient actively Q-switched laser is successfully realized with a pulse energy of 104 mJ. The corresponding optical-optical conversion efficiency is 30.5%. This is, to the best of our knowledge, the highest optical to optical efficiency for an actively Q-switched Nd:YAG laser at the hundred milli-joules level.
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Genes involved in latent membrane protein 1 (LMP1) signaling pathways have been suggested to play an important role in nasopharyngeal carcinogenesis. We investigated potentially functional genetic variants associated with the risk of nasopharyngeal carcinoma (NPC) in genes involved in the LMP1 signaling pathway. Altogether, 73 single nucleotide polymorphisms (SNPs) with MAF ≥ 10% were located within the regions of interest of the four genes TRAF3, NFKBIA, CHUK and MAP2K4. From these, 10 SNPs were selected for genotyping based on LD (r2 ≥ 0.80) in a hospital-based case-control study of 332 NPC cases and 585 healthy controls from the Chinese Han population. Minor allele carriers of the promoter SNP rs2233409 in NFKBIA, had an increased risk of NPC (AA vs GG: OR 7.14, 95%CI, 1.08-34.18, P = 0.04, dominant model). Based on the results, we concluded that rs2233409 polymorphism in NFKBIA may be moderately associated with the risk of NPC. Further studies with larger independent samples and functional analysis are needed to verify our results.
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Inhibidor NF-kappaB alfa/genética , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Alelos , Pueblo Asiatico , Carcinogénesis/genética , Estudios de Casos y Controles , China , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Quinasa I-kappa B/genética , MAP Quinasa Quinasa 4/genética , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo/etnología , Neoplasias Nasofaríngeas/etnología , Regiones Promotoras Genéticas , Riesgo , Transducción de Señal , Factor 3 Asociado a Receptor de TNF/genética , Adulto JovenRESUMEN
Atopic dermatitis (AD) is a chronic inflammatory skin disease involving skin barrier dysfunction and immune imbalance. However, the mechanism of AD is not clear completely and may be related to heredity and environment. Neuropeptides are a class of peptides secreted by nerve endings, they may play roles in promoting vasodilation, plasma extravasation, chemotaxis of inflammatory cells and mediating pruritus. Since itching and immune cell infiltration are the main manifestations of atopic dermatitis, to further investigate the impact of neuropeptides on AD, our review summarized the mechanisms of several common neuropeptides in AD and hypothesized that neuropeptides may be the novel potential targets in AD treatment.
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Dermatitis Atópica/etiología , Neuropéptidos/fisiología , HumanosRESUMEN
Urticaria is a type of skin disease characterized by rapid onset of hives (superficial dermis edema, erythema, pruritus, or burning sensation). According to whether the natural course exceeds 6 weeks, urticaria can be divided into acute and chronic urticaria (CU). At present, the evaluation of CU activity mainly depends on the Urticaria Activity Score (UAS), but the evaluation indicators are relatively single, and we need more reliable experimental data for evaluation. We typically summarize advanced biomarkers and several related pathogenic pathways discovered in recent years on urticaria, including the cell adhesion/chemotaxis pathway, interleukin (IL)-6/Janus tyrosine kinase/STAT pathway, IL-17/IL-23 pathway, basophil- and mast cell-related pathway, coagulation/fibrinolysis-related pathways, single-nucleotide polymorphism, and some other pathways. This review aims to find appropriate biomarkers so that we can evaluate disease activity, discover novel therapeutic targets, and predict the patients' response more accurately to therapeutic agents.
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Urticaria/diagnóstico , Urticaria/terapia , Animales , Basófilos/inmunología , Biomarcadores , Coagulación Sanguínea , Adhesión Celular , Quimiotaxis , Citocinas/inmunología , Humanos , Mastocitos/inmunología , Polimorfismo de Nucleótido Simple , Urticaria/genética , Urticaria/inmunologíaRESUMEN
BACKGROUND: Osteogenesis imperfecta (OI) is a heterogeneous connective tissue disorder characterized by increased bone fragility and a series of extraskeletal manifestations. Approximately 90 % of OI cases are caused by type I collagen variants encoded by the collagen type I alpha 1 (COL1A1) or type I alpha 2 (COL1A2) gene. Lumbar Scheuermann's disease is an atypical type of Scheuermann's disease accompanied by Schmorl's nodes and irregular endplates but without pronounced kyphosis. Although the etiology of Scheuermann's disease is unclear, genetic and environmental factors are likely. CASE PRESENTATION: Here, we report a 32-year-old male patient who experienced multiple brittle fractures. Gene sequencing revealed a heterozygous mutation, c.4048G > A (p.G1350S), in the COL1A2 gene, and the patient was diagnosed with OI. Magnetic resonance imaging of his thoracolumbar spine revealed multiple Schmorl's nodes. CONCLUSIONS: This is the first reported case of OI coexisting with the spinal presentation of Scheuermann's disease. It is speculated that the COL1A2 gene mutation might be an underlying novel genetic cause of Scheuermann's disease. In conclusion, this case demonstrates the relationship between Scheuermann's disease and OI for the first time and enriches the genotype-phenotype spectrum of OI.
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Desplazamiento del Disco Intervertebral , Osteogénesis Imperfecta , Enfermedad de Scheuermann , Adulto , Colágeno Tipo I/genética , Cadena alfa 1 del Colágeno Tipo I , Humanos , Masculino , Mutación , Osteogénesis Imperfecta/complicaciones , Osteogénesis Imperfecta/diagnóstico por imagen , Osteogénesis Imperfecta/genéticaRESUMEN
It has been reported that MicroRNAs (miRNAs) play pivotal roles in the occurrence and progression of a variety of cancers. As reported, miR-4295 promotes cell growth and metastasis in a lot of cancers. Nonetheless, the role and molecular mechanism of miR-4295 in HNSCC still remain unknown. In this study, we discovered miR-4295 expression was significantly upregulated in HNSCC tissues and cell lines, which is also associated with the overall survival of patients. Additionally, suppression of miR-4295 significantly inhibited cell proliferation, migration and EMT process in HNSCC. Through Targetscan website, it was predicted that NPTX1 might be a direct target gene of miR-4295. Then, we verified that NPTX1 could directly interact with miR-4295 via luciferase reporter and RNA assays. What's more, we discovered that there was a significantly negative correlation between NPTX1 and miR-4295 expression. It was indicated by further investigation that the effect of miR-4295 suppression on cell proliferation, migration and EMT process in HNSCC can be restored by knockdown of NPTX1 at the same time. Our results suggested that miR-4295 promoted the progression of HNSCC via regulating NPTX1 expression and miR-4295/NPTX1 axis, which may be a new therapeutic strategy for HNSCC.
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Proteína C-Reactiva/genética , MicroARNs/genética , Proteínas del Tejido Nervioso/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Adulto , Anciano , Anciano de 80 o más Años , Proteína C-Reactiva/metabolismo , Proliferación Celular/fisiología , Femenino , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , MicroARNs/metabolismo , Persona de Mediana Edad , Metástasis de la Neoplasia , Proteínas del Tejido Nervioso/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/patologíaRESUMEN
A smart watch is a kind of emerging wearable device in the Internet of Things. The security and privacy problems are the main obstacles that hinder the wide deployment of smart watches. Existing security mechanisms do not achieve a balance between the privacy-preserving and data access control. In this paper, we propose a fine-grained privacy-preserving access control architecture for smart watches (FPAS). In FPAS, we leverage the identity-based authentication scheme to protect the devices from malicious connection and policy-based access control for data privacy preservation. The core policy of FPAS is two-fold: (1) utilizing a homomorphic and re-encrypted scheme to ensure that the ciphertext information can be correctly calculated; (2) dividing the data requester by different attributes to avoid unauthorized access. We present a concrete scheme based on the above prototype and analyze the security of the FPAS. The performance and evaluation demonstrate that the FPAS scheme is efficient, practical, and extensible.
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With the development of information technology, films, music, and other publications are inclined to be distributed in digitalized form. However, the low cost of data replication and dissemination leads to digital rights problems and brings huge economic losses. Up to now, existing digital rights management (DRM) schemes have been powerless to deter attempts of infringing digital rights and recover losses of copyright holders. This paper presents a YODA-based digital watermark management system (Y-DWMS), adopting non-repudiation of smart contract and blockchain, to implement a DRM mechanism to infinitely amplify the cost of infringement and recover losses copyright holders suffered once the infringement is reported. We adopt game analysis to prove that in Y-DWMS, the decision of non-infringement always dominates rational users, so as to fundamentally eradicate the infringement of digital rights, which current mainstream DRM schemes cannot reach.
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A microwave photonic filter is demonstrated with both tunable center frequency and bandwidth. This filter is switchable from all-pass, bandpass to notch filter, and the notch filter is a result of the subtraction of a bandpass filter from an all-pass filter based on a balanced photodetector. The all-pass filter is achieved based on a single wavelength radio over fiber link, and the bandpass one is acquired by using the spectrum-sliced broadband optical source. Theoretical analysis and experimental results show that both the center frequency and the bandwidth of the notch filter can be widely tuned.
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A new optical-frequency comb-based microwave photonic harmonic down-convertor with tunable and reconfigurable filtering is proposed and experimentally demonstrated. The coherent evenly spaced optical carriers offer harmonic down-conversion for ultrahigh radio frequency signals with low-frequency local oscillator, and construct a tunable and reconfigurable bandpass filter for the intermediate-frequency (IF) signal combined with dispersion. This implementation features high conversion efficiency. Experimental results show the filtered output IF signal has a clean spectrum with high quality. Measured conversion loss is 8.3 dB without extra electrical amplification.
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A novel structure consisting of an idler-free microwave photonic mixer integrated with a widely tunable and highly selective microwave photonic filter is presented, which is comprised of a spectrum-sliced broadband optical source, a dual-parallel Mach-Zehnder modulator (DPMZM), and a spatial light amplitude and phase processor (SLAPP). By adjusting the optical phase shift in the DPMZM, the dispersion-induced mixing power fading can be eliminated. By applying a phase processor with the SLAPP, the distortion of the mixing filter brought upon by third-order dispersion is also compensated. Experiments are performed and show that the up/down-conversion signal has a clean spectrum and the mixing filter can be tuned from 12 to 20 GHz without any change to the passband shape. The out-of-band suppression ratio of the mixing filter is more than 40 dB, and the 3 dB bandwidth is 140 MHz.
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A system for generating radio frequency signals with orbital angular momentum (OAM) is proposed and certificated for the first time, which employs an array of multiple optical-true-time-delay elements and circular antennas array (CAAs). A constructive Fourier series theory about CAAs collectively forming an OAM radio beam is demonstrated. An optical spectrum processor offers the four lines high-resolution time delay by adding a series of linear optical phase shifts. The OAM radio beam with topological charge L=1 is produced and measured successfully.