Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 323
Filtrar
1.
BMC Pulm Med ; 24(1): 324, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965571

RESUMO

BACKGROUND: The advent of immunotherapy targeting immune checkpoints has conferred significant clinical advantages to patients with lung adenocarcinoma (LUAD); However, only a limited subset of patients exhibit responsiveness to this treatment. Consequently, there is an imperative need to stratify LUAD patients based on their response to immunotherapy and enhance the therapeutic efficacy of these treatments. METHODS: The differentially co-expressed genes associated with CD8 + T cells were identified through weighted gene co-expression network analysis (WGCNA) and the Search Tool for the Retrieval of Interacting Genes (STRING) database. These gene signatures facilitated consensus clustering for TCGA-LUAD and GEO cohorts, categorizing them into distinct immune subtypes (C1, C2, C3, and C4). The Tumor Immune Dysfunction and Exclusion (TIDE) model and Immunophenoscore (IPS) analysis were employed to assess the immunotherapy response of these subtypes. Additionally, the impact of inhibitors targeting five hub genes on the interaction between CD8 + T cells and LUAD cells was evaluated using CCK8 and EDU assays. To ascertain the effects of these inhibitors on immune checkpoint genes and the cytotoxicity mediated by CD8 + T cells, flow cytometry, qPCR, and ELISA methods were utilized. RESULTS: Among the identified immune subtypes, subtypes C1 and C3 were characterized by an abundance of immune components and enhanced immunogenicity. Notably, both C1 and C3 exhibited higher T cell dysfunction scores and elevated expression of immune checkpoint genes. Multi-cohort analysis of Lung Adenocarcinoma (LUAD) suggested that these subtypes might elicit superior responses to immunotherapy and chemotherapy. In vitro experiments involved co-culturing LUAD cells with CD8 + T cells and implementing the inhibition of five pivotal genes to assess their function. The inhibition of these genes mitigated the immunosuppression on CD8 + T cells, reduced the levels of PD1 and PD-L1, and promoted the secretion of IFN-γ and IL-2. CONCLUSIONS: Collectively, this study delineated LUAD into four distinct subtypes and identified five hub genes correlated with CD8 + T cell activity. It lays the groundwork for refining personalized therapy and immunotherapy strategies for patients with LUAD.


Assuntos
Adenocarcinoma de Pulmão , Linfócitos T CD8-Positivos , Neoplasias Pulmonares , Humanos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Linfócitos T CD8-Positivos/imunologia , Imunoterapia , Regulação Neoplásica da Expressão Gênica , Perfilação da Expressão Gênica , Linhagem Celular Tumoral
2.
Adv Sci (Weinh) ; : e2402530, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970208

RESUMO

Recently, metasurface-based photodetectors (metaphotodetectors) have been developed and applied in various fields. Metasurfaces are artificial materials with unique properties that have emerged over the past decade, and photodetectors are powerful tools used to quantify incident electromagnetic wave information by measuring changes in the conductivity of irradiated materials. Through an efficient microstructural design, metasurfaces can effectively regulate numerous characteristics of electromagnetic waves and have demonstrated unique advantages in various fields, including holographic projection, stealth, biological image enhancement, biological sensing, and energy absorption applications. Photodetectors play a crucial role in military and civilian applications; therefore, efficient photodetectors are essential for optical communications, imaging technology, and spectral analysis. Metaphotodetectors have considerably improved sensitivity and noise-equivalent power and miniaturization over conventional photodetectors. This review summarizes the advantages of metaphotodetectors based on five aspects. Furthermore, the applications of metaphotodetectors in various fields including military and civil applications, are systematically discussed. It highlights the potential future applications and developmental trends of metasurfaces in metaphotodetectors, provides systematic guidance for their development, and establishes metasurfaces as a promising technology.

3.
Chem Commun (Camb) ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976312

RESUMO

A polarity-sensitive probe was developed to simultaneously label lysosomes and endoplasmic reticulum (ER) via its dansylamide and rhodamine fluorescence, respectively, enabling ratiometric polarity detection and stable dual-labeling. The fragmented ER network and increased lysosomal polarity during ferroptosis were revealed, which facilitates the understanding of ferroptotic mechanisms.

4.
Int J Biol Markers ; : 3936155241261390, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881381

RESUMO

PURPOSE: Gastric cancer is the most common malignancy worldwide and is the third leading cause of cancer-related deaths, urgently requiring an early and non-invasive diagnosis. Circulating extracellular vesicles may emerge as promising biomarkers for the rapid diagnosis in a non-invasive manner. METHODS: Using high-throughput small RNA sequencing, we profiled the small RNA population of serum-derived extracellular vesicles from healthy controls and gastric cancer patients. Differentially expressed microRNAs (miRNAs) were randomly selected and validated by reverse transcription-quantitative real-time polymerase chain reaction. Receiver operating characteristic curves were employed to assess the predictive value of miRNAs for gastric cancer. RESULTS: In this study, 193 differentially expressed miRNAs were identified, of which 152 were upregulated and 41 were significantly downregulated. Among the differently expressed miRNA, the expression levels of miR-21-5p, miR-26a-5p, and miR-27a-3p were significantly elevated in serum-derived extracellular vesicles of gastric cancer patients. The miR-21-5p and miR-27a-3p were closely correlated with the tumor size. Moreover, the expression levels of serum miR-21-5p and miR-26a-5p were significantly decreased in gastric cancer patients after surgery. CONCLUSIONS: The present study discovered the potential of serum miR-21-5p and miR-26a-5p as promising candidates for the diagnostic and prognostic markers of gastric cancer.

5.
Angew Chem Int Ed Engl ; : e202405396, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38818672

RESUMO

Reactive oxygen species (ROS) play a crucial role in determining photocatalytic reaction pathways, intermediate species, and product selectivity. However, research on ROS regulation in polymer photocatalysts is still in its early stages. Herein, we successfully achieved series of modulations to the skeleton of Pyrene-alkyne-based (Tetraethynylpyrene (TEPY)) conjugated porous polymers (CPPs) by altering the linkers (1,4-dibromobenzene (BE), 4,4'-dibromobiphenyl (IP), and 3,3'-dibromobiphenyl (BP)). Experiments combined with theoretical calculations indicate that BE-TEPY exhibits a planar structure with minimal exciton binding energy, which favors exciton dissociation followed by charge transfer with adsorbed O2 to produce ⋅O2 -. Thus BE-TEPY shows optimal photocatalytic activity for phenylboronic acid oxidation and [3+2] cycloaddition. Conversely, the skeleton of BP-TEPY is significantly distorted. Its planar conjugation decreases, intersystem crossing (ISC) efficiency increases, which makes it more prone for resonance energy transfer to generate 1O2. Therefore, BP-TEPY displays best photocatalytic activity in [4+2] cycloaddition and thioanisole oxidation. Both above reactant conversion and its product selectivity exceed 99 %. This work systematically reveals the intrinsic structure-activity relationship among the skeleton structure of CPPs, excitonic behavior, and selective generation of ROS, providing new insights for the rational design of highly efficient and selective CPPs photocatalysts.

6.
Nat Commun ; 15(1): 4474, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796514

RESUMO

Olfaction feedback systems could be utilized to stimulate human emotion, increase alertness, provide clinical therapy, and establish immersive virtual environments. Currently, the reported olfaction feedback technologies still face a host of formidable challenges, including human perceivable delay in odor manipulation, unwieldy dimensions, and limited number of odor supplies. Herein, we report a general strategy to solve these problems, which associates with a wearable, high-performance olfactory interface based on miniaturized odor generators (OGs) with advanced artificial intelligence (AI) algorithms. The OGs serve as the core technology of the intelligent olfactory interface, which exhibit milestone advances in millisecond-level response time, milliwatt-scale power consumption, and the miniaturized size. Empowered by robust AI algorithms, the olfactory interface shows its great potentials in latency-free mixed reality (MR) and fast olfaction enhancement, thereby establishing a bridge between electronics and users for broad applications ranging from entertainment, to education, to medical treatment, and to human machine interfaces.


Assuntos
Algoritmos , Inteligência Artificial , Odorantes , Olfato , Dispositivos Eletrônicos Vestíveis , Humanos , Olfato/fisiologia , Interface Usuário-Computador , Adulto , Masculino
7.
World J Gastrointest Oncol ; 16(5): 1965-1994, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38764819

RESUMO

BACKGROUND: Yigong San (YGS) is a representative prescription for the treatment of digestive disorders, which has been used in clinic for more than 1000 years. However, the mechanism of its anti-gastric cancer and regulate immunity are still remains unclear. AIM: To explore the mechanism of YGS anti-gastric cancer and immune regulation. METHODS: Firstly, collect the active ingredients and targets of YGS, and the differentially expressed genes of gastric cancer. Secondly, constructed a protein-protein interaction network between the targets of drugs and diseases, and screened hub genes. Then the clinical relevance, mutation and repair, tumor microenvironment and drug sensitivity of the hub gene were analyzed. Finally, molecular docking was used to verify the binding ability of YGS active ingredient and hub genes. RESULTS: Firstly, obtained 55 common targets of gastric cancer and YGS. The Kyoto Encyclopedia of Genes and Genomes screened the microtubule-associated protein kinase signaling axis as the key pathway and IL6, EGFR, MMP2, MMP9 and TGFB1 as the hub genes. The 5 hub genes were involved in gastric carcinogenesis, staging, typing and prognosis, and their mutations promote gastric cancer progression. Finally, molecular docking results confirmed that the components of YGS can effectively bind to therapeutic targets. CONCLUSION: YGS has the effect of anti-gastric cancer and immune regulation.

8.
Mol Ther Nucleic Acids ; 35(2): 102213, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38784178

RESUMO

[This retracts the article DOI: 10.1016/j.omtn.2019.07.012.].

9.
FASEB J ; 38(8): e23590, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38656553

RESUMO

Studies have suggested that microglial IL-6 modulates inflammatory pain; however, the exact mechanism of action remains unclear. We therefore hypothesized that PKCε and MEG2 competitively bind to STAT3 and contribute to IL-6-mediated microglial hyperalgesia during inflammatory pain. Freund's complete adjuvant (FCA) and lipopolysaccharide (LPS) were used to induce hyperalgesia model mice and microglial inflammation. Mechanical allodynia was evaluated using von Frey tests in vivo. The interaction among PKCε, MEG2, and STAT3 was determined using ELISA and immunoprecipitation assay in vitro. The PKCε, MEG2, t-STAT3, pSTAT3Tyr705, pSTAT3Ser727, IL-6, GLUT3, and TREM2 were assessed by Western blot. IL-6 promoter activity and IL-6 concentration were examined using dual luciferase assays and ELISA. Overexpression of PKCε and MEG2 promoted and attenuated inflammatory pain, accompanied by an increase and decrease in IL-6 expression, respectively. PKCε displayed a stronger binding ability to STAT3 when competing with MEG2. STAT3Ser727 phosphorylation increased STAT3 interaction with both PKCε and MEG2. Moreover, LPS increased PKCε, MEG2, pSTAT3Tyr705, pSTAT3Ser727, IL-6, and GLUT3 levels and decreased TREM2 during microglia inflammation. IL-6 promoter activity was enhanced or inhibited by PKCε or MEG2 in the presence of STAT3 and LPS stimulation, respectively. In microglia, overexpression of PKCε and/or MEG2 resulted in the elevation of tSTAT3, pSTAT3Tyr705, pSTAT3Ser727, IL-6, and TREM2, and the reduction of GLUT3. PKCε is more potent than MEG2 when competitively binding to STAT3, displaying dual modulatory effects of IL-6 production, thus regulating the GLUT3 and TREM2 in microglia during inflammatory pain sensation.


Assuntos
Hiperalgesia , Inflamação , Interleucina-6 , Microglia , Proteína Quinase C-épsilon , Fator de Transcrição STAT3 , Animais , Masculino , Camundongos , Adjuvante de Freund , Hiperalgesia/metabolismo , Inflamação/metabolismo , Interleucina-6/metabolismo , Interleucina-6/genética , Lipopolissacarídeos/toxicidade , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Dor/metabolismo , Fosforilação , Ligação Proteica , Proteína Quinase C-épsilon/metabolismo , Proteína Quinase C-épsilon/genética , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Fator de Transcrição STAT3/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo
10.
Nat Rev Microbiol ; 22(7): 408-419, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38491185

RESUMO

The ocean has been a regulator of climate change throughout the history of Earth. One key mechanism is the mediation of the carbon reservoir by refractory dissolved organic carbon (RDOC), which can either be stored in the water column for centuries or released back into the atmosphere as CO2 depending on the conditions. The RDOC is produced through a myriad of microbial metabolic and ecological processes known as the microbial carbon pump (MCP). Here, we review recent research advances in processes related to the MCP, including the distribution patterns and molecular composition of RDOC, links between the complexity of RDOC compounds and microbial diversity, MCP-driven carbon cycles across time and space, and responses of the MCP to a changing climate. We identify knowledge gaps and future research directions in the role of the MCP, particularly as a key component in integrated approaches combining the mechanisms of the biological and abiotic carbon pumps for ocean negative carbon emissions.


Assuntos
Ciclo do Carbono , Carbono , Mudança Climática , Água do Mar , Carbono/metabolismo , Água do Mar/microbiologia , Água do Mar/química , Bactérias/metabolismo , Dióxido de Carbono/metabolismo , Oceanos e Mares
11.
Vaccine ; 42(11): 2886-2894, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38519342

RESUMO

Vaccination is an effective method to prevent viral diseases. However, the biological barrier prevents the immersion vaccine from achieving the best effect without adding adjuvants and carriers. Researches on the targeted presentation technology of vaccines with nanocarriers are helpful to develop immersion vaccines for fish that can break through biological barriers and play an effective role in fish defense. In our study, functionally modified single-walled carbon nanotubes (SWCNTs) were used as carriers to construct a targeted immersion vaccine (SWCNTs-M-MCP) with mannose modified major capsid protein (MCP) to target antigen-presenting cells (APCs), against iridovirus diseases. After bath immunization, our results showed that SWCNTs-M-MCP induced the presentation process and uptake of APCs, triggering a powerful immune response. Moreover, the highest relative percent survival (RPS) was 81.3% in SWCNTs-M-MCP group, which was only 41.5% in SWCNTs-MCP group. Altogether, this study indicates that the SWCNTs-based targeted immersion vaccine induces strong immune response and provided an effective protection against iridovirus diseases.


Assuntos
Doenças dos Peixes , Iridoviridae , Nanotubos de Carbono , Vacinas Virais , Animais , Manose , Imersão , Proteínas do Capsídeo
12.
Environ Res ; 251(Pt 2): 118692, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38493856

RESUMO

Overloading of nutrients such as nitrogen causes eutrophication of freshwater bodies. The spread of antibiotic resistance genes (ARGs) poses a threat to ecosystems. However, studies on the enrichment and spread of ARGs from increased nitrogen loading in algal-bacterial symbiotic systems are limited. In this study, the transfer of extracellular kanamycin resistance (KR) genes from large (RP4) small (pEASY-T1) plasmids into the intracellular and extracellular DNA (iDNA, eDNA) of the inter-algal environment of Chlorella pyrenoidosa was investigated, along with the community structure of free-living (FL) and particle-attached (PA) bacteria under different nitrogen source concentrations (0-2.5 g/L KNO3). The results showed that KR gene abundance in the eDNA adsorbed on solid particles (D-eDNA) increased initially and then decreased with increasing nitrogen concentration, while the opposite was true for the rest of the free eDNA (E-eDNA). Medium nitrogen concentrations promoted the transfer of extracellular KR genes into the iDNA attached to algal microorganisms (A-iDNA), eDNA attached to algae (B-eDNA), and the iDNA of free microorganisms (C-iDNA); high nitrogen contributed to the transfer of KR genes into C-iDNA. The highest percentage of KR genes was found in B-eDNA with RP4 plasmid treatment (66.2%) and in C-iDNA with pEASY-T1 plasmid treatment (86.88%). In addition, dissolved oxygen (DO) significantly affected the bacterial PA and FL community compositions. Nephelometric turbidity units (NTU) reflected the abundance of ARGs in algae. Proteobacteria, Cyanobacteria, Bacteroidota, and Actinobacteriota were the main potential hosts of ARGs. These findings provide new insights into the distribution and dispersal of ARGs in the phytoplankton inter-algal environment.


Assuntos
Bactérias , Resistência Microbiana a Medicamentos , Eutrofização , Transferência Genética Horizontal , Microalgas , Simbiose , Microalgas/genética , Microalgas/efeitos dos fármacos , Bactérias/genética , Bactérias/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Chlorella/genética , Chlorella/efeitos dos fármacos , Nitrogênio
13.
Environ Sci Technol ; 58(11): 5129-5138, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38385684

RESUMO

Attention has been drawn to the associations between PFASs and human cognitive decline. However, knowledge on the occurrence and permeability of PFASs in the brains of patients with cognitive impairment has not been reported. Here, we determined 30 PFASs in paired sera and cerebrospinal fluids (CSFs) from patients with cognitive impairment (n = 41) and controls without cognitive decline (n = 18). We revealed similar serum PFAS levels but different CSF PFAS levels, with lower CSF PFOA (median: 0.125 vs 0.303 ng/mL, p < 0.05), yet higher CSF PFOS (0.100 vs 0.052 ng/mL, p < 0.05) in patients than in controls. Blood-brain transfer rates also showed lower RCSF/Serum values for PFOA and higher RCSF/Serum values for PFOS in patients, implying potential heterogeneous associations with cognitive function. The RCSF/Serum values for C4-C14 perfluoroalkyl carboxylates exhibited a U-shape trend with increasing chain length. Logistic regression analyses demonstrated that CSF PFOS levels were linked to the heightened risk of cognitive impairment [odds ratio: 3.22 (1.18-11.8)] but not for serum PFOS. Toxicity inference results based on the Comparative Toxicogenomics Database suggested that PFOS in CSF may have a greater potential to impair human cognition than other PFASs. Our results contribute to a better understanding of brain PFAS exposure and its potential impact on cognitive function.


Assuntos
Ácidos Alcanossulfônicos , Disfunção Cognitiva , Poluentes Ambientais , Fluorocarbonos , Humanos , Ácidos Alcanossulfônicos/toxicidade , Fluorocarbonos/toxicidade , Ácidos Carboxílicos , Permeabilidade
14.
World J Clin Oncol ; 15(1): 32-44, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38292665

RESUMO

BACKGROUND: Glioma is one of the most common intracranial tumors, characterized by invasive growth and poor prognosis. Actin cytoskeletal rearrangement is an essential event of tumor cell migration. The actin dynamics-related protein scinderin (SCIN) has been reported to be closely related to tumor cell migration and invasion in several cancers. AIM: To investigate the role and mechanism of SCIN in glioma. METHODS: The expression and clinical significance of SCIN in glioma were analyzed based on public databases. SCIN expression was examined using real-time quantitative polymerase chain reaction and Western blotting. Gene silencing was performed using short hairpin RNA transfection. Cell viability, migration, and invasion were assessed using cell counting kit 8 assay, wound healing, and Matrigel invasion assays, respectively. F-actin cytoskeleton organization was assessed using F-actin staining. RESULTS: SCIN expression was significantly elevated in glioma, and high levels of SCIN were associated with advanced tumor grade and wild-type isocitrate dehydrogenase. Furthermore, SCIN-deficient cells exhibited decreased proliferation, migration, and invasion in U87 and U251 cells. Moreover, knockdown of SCIN inhibited the RhoA/focal adhesion kinase (FAK) signaling to promote F-actin depolymerization in U87 and U251 cells. CONCLUSION: SCIN modulates the actin cytoskeleton via activating RhoA/FAK signaling, thereby promoting the migration and invasion of glioma cells. This study identified the cancer-promoting effect of SCIN and provided a potential therapeutic target for the treatment of glioma.

15.
ACS Appl Mater Interfaces ; 16(1): 228-244, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38055273

RESUMO

Viral diseases have constantly caused great threats to global public health, resulting in an urgent need for effective vaccines. However, the current viral vaccines often show low immunogenicity. To counter this, we report a smart strategy of a well-designed modular nanoparticle (LSG-TDH) that recapitulates the dominant antigen SG, low-molecular-weight protamine, and tetralysine-modified H-chain apoferritin (TDH). The constructed LSG-TDH nanovaccine could self-assemble into a nanocage structure, which confers excellent mucus-penetrating, cellular affinity, and uptake ability. Studies demonstrate that the LSG-TDH nanovaccine could strongly activate both mucosal and systemic immune responses. Importantly, by immunizing wild-type and TLR2 knockout (TLR2-KO) zebrafish, we found that TLR2 could mediate LSG-TDH-induced adaptive mucosal and systemic immune responses by activating antigen-presenting cells. Collectively, our findings offer new insights into rational viral vaccine design and provide additional evidence of the vital role of TLR2 in regulating adaptive immunity.


Assuntos
Nanopartículas , Rhabdoviridae , Vacinas , Animais , Nanovacinas , Receptor 2 Toll-Like , Peixe-Zebra , Nanopartículas/química
16.
Biosystems ; 236: 105111, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159672

RESUMO

Circadian rhythm is an essential component of biology that organizes the internal synchrony of the organism in response to the environment. Aging significantly impacts circadian rhythm and is also associated with specific sleep complaints in mammals, including earlier awakening and decreased sleep consolidation at the end of the night. However, the regulation mechanism of aging on the circadian rhythm is far from clear. To further understand the impact of aging, we use an existing mathematical model of circadian rhythm combined with the aging system to explore the effects of aging on circadian rhythm and two kinds of sleep disorders, familial late sleep syndrome (FASPS) and delayed sleep syndrome (DSPS). We get a few intriguing findings from numerical simulations. Aging weakens rhythmicity by reducing the amplitude of circadian rhythm. Aging exacerbates the sleep pattern of being early to bed and early to rise by shortening the period of circadian rhythm and advancing the entrainment phase. Aging reduces the ability of the circadian rhythm to respond to light. The elderly need stronger light to get entrainment with the environmental light cycle. It is more difficult for the elderly to recover from disturbed light. Especially elderly people take a longer time to overcome jet lag. Aging worsens the "morningness" of FASPS disorder patients and improves the symptoms of DSPS disorder patients. This study helps to better understand the impacts of aging on circadian rhythm and sleep disorders and provides theoretical support for the treatment of circadian disorders in the elderly.


Assuntos
Transtornos do Sono do Ritmo Circadiano , Transtornos do Sono-Vigília , Animais , Humanos , Idoso , Transtornos do Sono do Ritmo Circadiano/diagnóstico , Transtornos do Sono do Ritmo Circadiano/terapia , Ritmo Circadiano/fisiologia , Transtornos do Sono-Vigília/terapia , Envelhecimento , Mamíferos
17.
Sensors (Basel) ; 23(24)2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38139566

RESUMO

An accurate estimation of the time difference of arrival (TDOA) is crucial in localization, communication, and navigation. However, a low signal-to-noise ratio (SNR) can decrease the reliability of the TDOA estimation result. Therefore, this study aims to improve the performance of the TDOA estimation of dual-channel sensors for single-sound sources in low-SNR environments. This study introduces the theory of time rearrangement synchrosqueezing transform (TRST) into the time difference of arrival estimation. While the background noise TF points show random time delays, the signal time-frequency (TF) points originating from uniform directions that exhibit identical lags are considered in this study. In addition, the time difference rearrangement synchrosqueezing transform (TDST) algorithm is developed to separate the signal from the background noise by exploiting its distinct time delay characteristics. The implementation process of the proposed algorithm includes four main steps. First, a rough estimation of the time delay is performed by calculating the partial derivative of the short-time cross-power spectrum. Second, a rearrangement operation is conducted to separate the TF points of the signal and noise. Third, the TF points on both sides of the time-delay energy ridge are extracted. Finally, a refined TDOA estimation is realized by applying the inverse Fourier transformation on the extracted TF points. Furthermore, a second-order-based time difference reassigned synchrosqueezing transform algorithm is proposed to improve the robustness of the TDOA estimation by enhancing the TF energy aggregation. The proposed algorithms are verified by simulations and experiments. The results show that the proposed algorithms are more robust and accurate than the existing algorithms.

18.
Math Biosci Eng ; 20(9): 16663-16677, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37920028

RESUMO

The circadian clock is an autonomous timing system that regulates the physiological and behavioral activities of organisms. Dopamine (DA) is an important neurotransmitter that is associated with many biological activities such as mood and movement. Experimental studies have shown that the circadian clock influences the DA system and disorders in the circadian clock lead to DA-related diseases. However, the regulatory mechanism of the circadian clock on DA is far from clear. In this paper, we apply an existing circadian-dopamine mathematical model to explore the effects of the circadian clock on DA. Based on numerical simulations, we find the disturbance of the circadian clock, including clock gene mutations, jet lag and light pulses, leads to abnormal DA levels. The effects of mutations in some clock genes on the mood and behavior of mice are closely related to DA disruptions. By sensitivity analysis of DA levels to parameter perturbation, we identify key reactions that affect DA levels, which provides insights into modulating DA disorders. Sudden changes in external light influence the circadian clock, bringing about effects on the DA system. Jet lag causes transient DA rhythm desynchronization with the environment and the influence of jet lag in different directions on DA level and phase varies. Light pulses affect the amplitude and phase shift of DA, which provides a promising method for treating DA disorders through light exposure. This study helps to better understand the impact of the circadian clock on the DA system and provides theoretical support for the treatment of DA disorders.


Assuntos
Relógios Circadianos , Animais , Camundongos , Relógios Circadianos/fisiologia , Síndrome do Jet Lag/terapia , Ritmo Circadiano/fisiologia , Dopamina/farmacologia , Modelos Teóricos
19.
Artigo em Inglês | MEDLINE | ID: mdl-37945950

RESUMO

The reduction of haze and carbon emissions is extremely important for promoting sustainable development, improving air quality, enhancing health, and mitigating climate change. However, there is not enough research available on the impact of fiscal decentralization in China on the management of carbon and haze reduction. In order to thoroughly examine the effects of Chinese-style fiscal decentralization on the synergy between haze reduction and carbon reduction in different provinces, this study utilizes a dynamic spatial panel Durbin model using Han-Phillips Generalized Method of Moments (GMM) estimation and a multi-scale geographically and temporally weighted regression model. Our findings indicate that the eastern region consistently takes the lead in reducing haze and achieving carbon synergy. Fiscal technology decentralization has a direct positive impact and spatial spillover effect on carbon haze synergy with significant inverted U-shaped characteristics. These effects primarily arise from the promotion of technological innovation through fiscal technology decentralization. Furthermore, the influence of decentralizing fiscal technology expenditures on the degree of synergy between haze mitigation and carbon reduction varies significantly across China's provinces, both spatially and temporally. This entails promoting coordination between fiscal decentralization and policies related to haze and carbon emission reduction and encouraging information sharing, technology exchange, and collaborative projects between different regions to create a synergistic linkage effect. This will help achieve joint development and environmental protection goals in all regions. The discoveries carry significant consequences for directing the synchronized administration of haze and carbon and can serve as a solid basis for governmental decision-making aimed at enhancing air quality and attaining carbon neutrality through collaborative actions and policies.

20.
ACS Nano ; 17(21): 21947-21961, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37917185

RESUMO

Deaf-blindness limits daily human activities, especially interactive modes of audio and visual perception. Although the developed standards have been verified as alternative communication methods, they are uncommon to the nondisabled due to the complicated learning process and inefficiency in terms of communicating distance and throughput. Therefore, the development of communication techniques employing innate sensory abilities including olfaction related to the cerebral limbic system processing emotions, memories, and recognition has been suggested for reducing the training level and increasing communication efficiency. Here, a skin-integrated and wireless olfactory interface system exploiting arrays of miniaturized odor generators (OGs) based on melting/solidifying odorous wax to release smell is introduced for establishing an advanced communication system between deaf-blind and non-deaf-blind. By optimizing the structure design of the OGs, each OG device is as small as 0.24 cm3 (length × width × height of 11 mm × 10 mm × 2.2 mm), enabling integration of up to 8 OGs on the epidermis between nose and lip for direct and rapid olfactory drive with a weight of only 24.56 g. By generating single or mixed odors, different linked messages could be delivered to a user within a short period in a wireless and programmable way. By adopting the olfactory interface message delivery system, the recognition rates for the messages have been improved 1.5 times that of the touch-based method, while the response times were immensely decreased 4 times. Thus, the presented wearable olfactory interface system exhibits great potential as an alternative message delivery method for the deaf-blind.


Assuntos
Odorantes , Olfato , Humanos , Olfato/fisiologia , Aprendizagem , Pele , Eletrônica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...