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1.
Ann Med Surg (Lond) ; 86(7): 4217-4221, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38989227

RESUMO

Introduction and Importance: Postoperative neck hematoma (PNH), a rare complication following thyroidectomy, occurs in only 1.1-3.15% of cases and can lead to life-threatening outcomes. More rarely, delayed PNHs with atypical clinical manifestations and positions have not yet been reported. Early identification and immediate medical intervention are of utmost importance in such cases. Case Presentation: The authors represented a patient with thyroid cancer adherent to the trachea, who underwent post-thyroidectomy, experienced delayed PNH in the retrosternal region and was infected by respiratory pathogens. Meanwhile, the patient developed recurrent laryngeal nerve (RLN) paralysis after surgery. PNH was not identified in the clinical manifestations; instead, it was detected only through successive cervical ultrasound examinations. Clinical Discussion: Although rare, PNH can lead to serious complications, especially delayed complications or those in atypical positions, without neck swelling. When simultaneously with RLN paralysis, the hematoma may be neglected. Therefore, early diagnosis and treatment are crucial. Conclusion: Clinicians should be vigilant of atypical PNH because neck swelling may be absent. Cervical ultrasonography is essential for diagnosis and can be performed multiple times. Cervical CT scans should be part of the routine procedure, while contrast-enhanced ultrasound can help detect active bleeding. Early postoperative antibiotics are recommended if the tumor is closely attached to the trachea.

2.
Sensors (Basel) ; 24(11)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38894231

RESUMO

An investigation was performed to develop a process to design and manufacture a 3-D smart skin with an embedded network of distributed sensors for non-developable (or doubly curved) surfaces. A smart skin is the sensing component of a smart structure, allowing such structures to gather data from their surrounding environments to make control and maintenance decisions. Such smart skins are desired across a wide variety of domains, particularly for those devices where their surfaces require high sensitivity to external loads or environmental changes such as human-assisting robots, medical devices, wearable health components, etc. However, the fabrication and deployment of a network of distributed sensors on non-developable surfaces faces steep challenges. These challenges include the conformal coverage of a target object without causing prohibitive stresses in the sensor interconnects and ensuring positional accuracy in the skin sensor deployment positions, as well as packaging challenges resulting from the thin, flexible form factor of the skin. In this study, novel and streamlined processes for making such 3-D smart skins were developed from the initial sensor network design to the final integrated skin assembly. Specifically, the process involved the design of the network itself (for which a physical simulation-based optimization was developed), the deployment of the network to a targeted 3D surface (for which a specialized tool was designed and implemented), and the assembly of the final skin (for which a novel process based on dip coating was developed and implemented.).

3.
BMC Psychiatry ; 24(1): 177, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38439019

RESUMO

BACKGROUND: Healthy lifestyle is an important protective factor of developing cardiovascular disease in people with schizophrenia. However, little is known about the determinants of lifestyle and its contribution to metabolic syndrome. This study aimed to explore the influencing factors of health-promoting lifestyle (HPL) and its association with metabolic syndrome among people with schizophrenia. METHODS: A cross-sectional study was conducted in twenty-two primary health centers of Guangzhou, China between December 2022 and April 2023. A total of 538 patients with schizophrenia were recruited through convenience sampling. Self-administered scales, questionnaires, and clinical data were collected. Scales and questionnaires included social-demographic information, Health-Promoting Lifestyles Profile (HPLP-C), UCLA Loneliness Scale (ULS), and International Physical Activity Questionnaire-Short Form (IPAQ-SF). Cluster analyses were used to divide participants into two groups based on the distribution characteristics of HPLP-C scores. Logistic regression models were used to identify factors associated with HPL and the association between HPL and metabolic syndrome. RESULTS: There were 271 participants in the high HPL group and 267 participants in the low HPL group. Logistic regression analysis revealed that loneliness posed a risk factor for high HPL, while high education and moderate-vigorous physical activity served as protective factors for high HPL. Low HPL was a risk factor for the prevalence of metabolic syndrome. CONCLUSIONS: Promotion of high education literacy and a physically active lifestyle should be priority targets in the health management of schizophrenia. Primary healthcare providers can play a pivotal role in assisting patients to mitigate metabolic syndrome by reinforcing healthy lifestyle strategies.


Assuntos
Síndrome Metabólica , Esquizofrenia , Humanos , Esquizofrenia/complicações , Estudos Transversais , Estilo de Vida Saudável , Estilo de Vida
5.
Heliyon ; 9(4): e15121, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37095968

RESUMO

Background: Although both spinal and general anaesthesia provides good anaesthesia for cervical conization, spinal anaesthesia delays the return of lower limb movements and urinary function, whereas general anaesthesia requires the patient to be unconscious. It is unclear which anaesthetic technique is more conducive to early postoperative recovery in patients undergoing cervical conization. Patients and methods: 140 patients undergoing cervical conization underwent either laryngeal mask general anaesthesia (LMA, n = 70) or spinal anaesthesia (SA, n = 70). In the LMA group, an i-gel mask was used for airway management. In the SA group, spinal anaesthesia was received with 0.75% ropivacaine (15 mg) in the L3-4 interval. The quality of recovery score (QoR-15) was the primary endpoint of the study. Secondary endpoints included incidence of adverse 24-h analgesia (NRS>3); return of lower limb activity; first bed activity and feeding; and the number of catheters removed at 6, 12 and 24 h postoperatively. Result: The LMA group significantly improved QoR-15 scores (136.62 ± 11.02 vs 119.97 ± 12.75; P < 0.001); and reduced the incidence of poor analgesia (NRS >3) within 24 h postoperatively (20% vs 42.8%, P = 0.006); reduced time in bed (15.62 ± 3.83 h vs 18.27 ± 5.57 vs, P = 0.001); improved patient satisfaction (86% vs 27%; P < 0.001); and catheters removal within 24 h (70/70 vs 42/70, P < 0.001). Conclusion: LMA general anaesthesia can facilitate early postoperative recovery in patients undergoing cervical conization compared with conventional spinal anaesthesia. Trial registration: Chinese Clinical Trial Registry (ID: ChiCTR1800019384), http://www.chictr.org.cn/listbycreater.aspx (08/11/2018).

6.
Asian J Psychiatr ; 80: 103433, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36586356

RESUMO

The 686 Program has covered mainland China but lacks empirical research. We aimed to examine potential influencing factors associated with the registration and management of the Program. 3993 patients with schizophrenia discharged in 2019 were included. We found that approximately two-thirds of patients were registered. 88.9 % registered patients accepted the follow-up management. Males, unemployment, lower education, longer duration of illness, more hospitalization positively affected the registration and management. Individuals with violent behavior and local Hukou were more likely to be registered. Future evaluation of the Program should take these factors into account.


Assuntos
Esquizofrenia , Masculino , Humanos , Esquizofrenia/terapia , Estudos Transversais , China , Escolaridade
7.
Sensors (Basel) ; 22(13)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35808351

RESUMO

An investigation was conducted to develop an effective automated tool to deploy micro-fabricated stretchable networks of distributed sensors onto the surface of large structures at macroscale to create "smart" structures with embedded distributed sensor networks. Integrating a large network of distributed sensors with structures has been a major challenge in the design of so-called smart structures or devices for cyber-physical applications where a large amount of usage data from structures or devices can be generated for artificial intelligence applications. Indeed, many "island-and-serpentine"-type distributed sensor networks, while promising, remain difficult to deploy. This study aims to enable such networks to be deployed in a safe, automated, and efficient way. To this end, a scissor-hinge controlled system was proposed as the basis for a deployment mechanism for such stretchable sensor networks (SSNs). A model based on a kinematic scissor-hinge mechanism was developed to simulate and design the proposed system to automatically stretch a micro-scaled square network with uniformly distributed sensor nodes. A prototype of an automatic scissor-hinge stretchable tool was constructed during the study with an array of four scissor-hinge mechanisms, each belt-driven by a single stepper motor. Two micro-fabricated SSNs from a 100 mm wafer were fabricated at the Stanford Nanofabrication Facility for this deployment study. The networks were designed to be able to cover an area 100 times their manufacturing size (from a 100 mm diameter wafer to a 1 m2 active area) once stretched. It was demonstrated that the proposed deployment tool could place sensor nodes in prescribed locations efficiently within a drastically shorter time than in current labor-intensive manual deployment methods.


Assuntos
Inteligência Artificial , Dispositivos Eletrônicos Vestíveis
8.
Front Cell Infect Microbiol ; 12: 892087, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35755839

RESUMO

Background: Differential diagnosis of patients with suspected infections is particularly difficult, but necessary for prompt diagnosis and rational use of antibiotics. A substantial proportion of these patients have non-infectious diseases that include malignant tumors. This study aimed to explore the clinical value of metagenomic next-generation sequencing (mNGS) for tumor detection in patients with suspected infections. Methods: A multicenter, prospective case study involving patients diagnosed with suspected infections was conducted in four hospitals in Shanghai, China between July 2019 and January 2020. Based upon mNGS technologies and chromosomal copy number variation (CNV) analysis on abundant human genome, a new procedure named Onco-mNGS was established to simultaneously detect pathogens and malignant tumors in all of the collected samples from patients. Results: Of 140 patients screened by Onco-mNGS testing, 115 patients were diagnosed with infections; 17 had obvious abnormal CNV signals indicating malignant tumors that were confirmed clinically. The positive percent agreement and negative percent agreement of mNGS testing compared to clinical diagnosis was 53.0% (61/115) and 60% (15/25), vs. 20.9% (24/115) and 96.0% (24/25), respectively, for conventional microbiological testing (both P <0.01). Klebsiella pneumoniae (14.8%, 9/61) was the most common pathogen detected by mNGS, followed by Escherichia coli (11.5%, 7/61) and viruses (11.5%, 7/61). The chromosomal abnormalities of the 17 cases included genome-wide variations and local variations of a certain chromosome. Five of 17 patients had a final confirmed with malignant tumors, including three lung adenocarcinomas and two hematological tumors; one patient was highly suspected to have lymphoma; and 11 patients had a prior history of malignant tumor. Conclusion: This preliminary study demonstrates the feasibility and clinical value of using Onco-mNGS to simultaneously search for potential pathogens and malignant tumors in patients with suspected infections.


Assuntos
Variações do Número de Cópias de DNA , Neoplasias , China , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Metagenômica/métodos , Neoplasias/diagnóstico , Neoplasias/genética , Sensibilidade e Especificidade
9.
Elife ; 112022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35286255

RESUMO

Humans can often handle daunting tasks with ease by developing a set of strategies to reduce decision-making into simpler problems. The ability to use heuristic strategies demands an advanced level of intelligence and has not been demonstrated in animals. Here, we trained macaque monkeys to play the classic video game Pac-Man. The monkeys' decision-making may be described with a strategy-based hierarchical decision-making model with over 90% accuracy. The model reveals that the monkeys adopted the take-the-best heuristic by using one dominating strategy for their decision-making at a time and formed compound strategies by assembling the basis strategies to handle particular game situations. With the model, the computationally complex but fully quantifiable Pac-Man behavior paradigm provides a new approach to understanding animals' advanced cognition.


Assuntos
Tomada de Decisões , Jogos de Vídeo , Animais , Cognição , Haplorrinos , Heurística , Humanos
10.
Environ Sci Pollut Res Int ; 29(10): 14903-14913, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34623588

RESUMO

Our aim was to clarify the main factors associated with lung function and to analyze the correlation between fine particulate matter (PM2.5) and lung function in a rural Chinese population. We analyzed data of 5195 participants in the China Northwest Natural Population Cohort: Ningxia Project who were ≥ 30 years old. They were recruited from 2018 to 2019, underwent spirometry during the physical examination, and completed a self-report questionnaire. A satellite-based spatiotemporal model was used to estimate the 2-year average PM2.5 exposure based on participants' home addresses. A generalized linear mixed model was used to test the relationship between PM2.5 concentration and lung function. Sex, age, exposure to cooking oil fumes, and occupational exposure were negatively correlated (P < 0.05) with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). Educational status, economic level, tea consumption, and alcohol consumption were positively correlated (P < 0.05) with FVC and FEV1. The adjusted results of each model revealed that FVC and FEV1 decreased with increased exposure to PM2.5. There was a strong negative correlation between a PM2.5 concentration of 35.66 µg/m3 and FVC, FEV1, and FEV1/FVC, with unadjusted hazard ratios of - 0.06 (95% confidence interval, - 0.10 to - 0.01), - 0.13 (- 0.17 to - 0.10), and - 22.10 (- 24.62 to - 19.26), respectively. In conclusion, long-term exposure to high concentrations of ambient PM2.5 is related to reduce lung function among people in rural areas in northwestern China.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Adulto , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Exposição Ambiental/análise , Volume Expiratório Forçado , Humanos , Pulmão , Material Particulado/análise
11.
Front Cardiovasc Med ; 8: 711465, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938777

RESUMO

Background: Previous studies have shown that diazoxide can protect against myocardial ischemia-reperfusion injury (MIRI). The intranuclear hypoxia-inducible factor-1 (HIF-1)/hypoxia-response element (HRE) pathway has been shown to withstand cellular damage caused by MIRI. It remains unclear whether diazoxide post-conditioning is correlated with the HIF-1/HRE pathway in protective effect on cardiomyocytes. Methods: An isolated cardiomyocyte model of hypoxia-reoxygenation injury was established. Prior to reoxygenation, cardiomyocytes underwent post-conditioning treatment by diazoxide, and 5-hydroxydecanoate (5-HD), N-(2-mercaptopropionyl)-glycine (MPG), or dimethyloxallyl glycine (DMOG) followed by diazoxide. At the end of reoxygenation, ultrastructural morphology; mitochondrial membrane potential; interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), reactive oxygen species (ROS), and HIF-1α levels; and downstream gene mRNA and protein levels were analyzed to elucidate the protective mechanism of diazoxide post-conditioning. Results: Diazoxide post-conditioning enabled activation of the HIF-1/HRE pathway to induce myocardial protection. When the mitoKATP channel was inhibited and ROS cleared, the diazoxide effect was eliminated. DMOG was able to reverse the effect of ROS absence to restore the diazoxide effect. MitoKATP and ROS in the early reoxygenation phase were key to activation of the HIF-1/HRE pathway. Conclusion: Diazoxide post-conditioning promotes opening of the mitoKATP channel to generate a moderate ROS level that activates the HIF-1/HRE pathway and subsequently induces myocardial protection.

12.
Hum Exp Toxicol ; 40(12_suppl): S763-S774, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34779285

RESUMO

Silicosis is a lung fibrotic disease caused by chronic silica exposure. Aberrations in long non-coding RNA (lncRNA) expression are associated with fibrotic diseases, but the role of lncRNAs in silicosis pathogenesis remains unclear. Here, we investigated the expression of lncRNAs during silicosis and the role of MRAK050699 in epithelial-mesenchymal transition (EMT). Differentially expressed lncRNAs in the lung tissues of normal and silicosis rats were compared, and their biological effects were determined using the Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. There were 1077 differentially expressed lncRNAs (378 upregulated and 699 downregulated). MRAK052509, MRAK139674, AY539881, MRAK050699, XR_6113, and BC167061 were selected to verify expression in silicosis rats using quantitative reverse transcription polymerase chain reaction. MRAK050699 was knocked down in rat alveolar type II epithelial cells, and the molecular mechanism of transforming growth factor-ß (TGF-ß)-induced EMT in these cells was studied. All selected lncRNAs were upregulated in the silicosis rats, consistent with the sequencing results. MRAK050699 knockdown inhibited EMT of RLE-6TN cells by regulating the TGF-ß/Smad3 signaling pathway. Thus, the differential expression of lncRNAs is related to silicosis development, and MRAK050699 plays an important role in EMT, suggesting a potential therapeutic target for silicosis.


Assuntos
Transição Epitelial-Mesenquimal , RNA Longo não Codificante/metabolismo , Silicose/metabolismo , Animais , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Comput Intell Neurosci ; 2021: 1616806, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34712315

RESUMO

Accurate monitoring of air quality can no longer meet people's needs. People hope to predict air quality in advance and make timely warnings and defenses to minimize the threat to life. This paper proposed a new air quality spatiotemporal prediction model to predict future air quality and is based on a large number of environmental data and a long short-term memory (LSTM) neural network. In order to capture the spatial and temporal characteristics of the pollutant concentration data, the data of the five sites with the highest correlation of time-series concentration of PM2.5 (particles with aerodynamic diameter ≤2.5 mm) at the experimental site were first extracted, and the weather data and other pollutant data at the same time were merged in the next step, extracting advanced spatiotemporal features through long- and short-term memory neural networks. The model presented in this paper was compared with other baseline models on the hourly PM2.5 concentration data set collected at 35 air quality monitoring sites in Beijing from January 1, 2016, to December 31, 2017. The experimental results show that the performance of the proposed model is better than other baseline models.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Previsões , Humanos , Redes Neurais de Computação , Material Particulado/análise
14.
Diabetes Metab Syndr Obes ; 14: 3965-3973, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34531669

RESUMO

BACKGROUND: Recently, the association between lifestyle-related diseases and free amino acids in the blood plasma-especially branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs)-has been highlighted. However, few studies have been carried out on 24-hour urine samples. Therefore, we aimed to explore the relationships between 24-hour urinary BCAAs and AAAs excretion rate and blood pressure (BP) in elderly patients with hypertension. METHODS AND RESULTS: Each of the 322 elderly patients with hypertension completed an in-person questionnaire interview, underwent a physical examination, and provided a 24-hour urine specimen. We measured their BCAAs and AAAs excretion rate, and used multiple linear regression analysis with variable selection to construct models describing the relationships between their BCAAs and AAAs excretion rate and BP. After adjusted for age, gender, height, and weight, valine was inversely associated with both systolic blood pressure (SBP) (ß: -0.232, 95% CI: -0.16, -0.006) and diastolic blood pressure (DBP) (ß: -0.144, 95% CI: -0.089, -0.005). These findings were invariant even following adjustment for urine volume and drugs history, and Ile was positively associated with DBP (ß: 0.170, 95% CI: 0.001, 0.066). CONCLUSION: The data revealed that the excretion rate of 24-hour urinary BCAAs was closely related to BP in elderly hypertension patients, and these findings will provide new insights into the association between BACC metabolism and BP.

15.
Artigo em Inglês | MEDLINE | ID: mdl-34188689

RESUMO

BACKGROUND: A considerable uncertainty exists about the relationship between adult metabolic syndrome (MS) and obstructive lung disease (OLD), perhaps owing to systemic inflammation. Therefore, this study aimed to investigate the relationship between MS (with its components) and the patterns of lung function impairment. METHODS: The participants in this study were 3978 adults aged 30-78 years from the baseline cohort of the Ningxia Cohort Study. The participants underwent pulmonary function tests, questionnaire surveys, physical examinations, and analysis of blood specimens. RESULTS: No significant difference in the prevalence of OLD was observed between male (15.9%) and female (14.2%) participants. After adjusting for possible confounding factors (e.g., age and family income), impaired lung function was found to be related to some MS components, such as abdominal obesity, high blood pressure, and low levels of high-density lipoprotein cholesterol (HDL-C) (all P < 0.05). CONCLUSIONS: As an important component of MS, abdominal obesity is related to impaired lung function. Surprisingly, this study found that increased HDL-C levels could accelerate the decline of lung function; it also suggests that in the presence of different metabolic health conditions, especially abdominal obesity and low levels of HDL-C, various metabolic indicators should be comprehensively considered to prevent the decline of lung function. This partly explains the increase in the incidence of two or more chronic diseases. Therefore, the prevention of chronic diseases should shift from single-disease prevention to a comprehensive consideration of multi-disease prevention in the future. Therefore, a more sensitive evaluation of the role of HDL-C in lung function is warranted.

16.
Exp Ther Med ; 21(5): 427, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33747166

RESUMO

The aim of the present study was to compare the effects of two methods of dexmedetomidine (Dex) administration on myocardial injury, inflammation and stress in ischemic myocardium during rheumatic heart valve replacement. In total, 90 patients were included in the present study and were divided into the following three groups: i) Dex group (1.0 µg/kg Dex pre-administered 10 min prior to anesthesia, then 0.5 µg/kg/h Dex for maintenance); ii) Dex pre-conditioning group (Pre-Dex; 1.0 µg/kg Dex administered 10 min prior to anesthesia, then saline for maintenance); and iii) control group (saline 10 min prior to anesthesia and saline during maintenance), with 30 patients in each group. Heart rate (HR) and mean artery pressure (MAP) were recorded at eight time-points: i) T1, pre-medication; ii) T2, 10 min post-medication; iii) T3, immediately post-intubation; iv) T4, upon skin incision; v) T5, upon sawing the sternum; vi) T6, immediately post-cardiopulmonary bypass; vii) T7, immediately post-operation; and viii) T8, 24 h post-operation. The serum cardiac troponin I (cTnI), interleukin (IL)-8, IL-10 and malondialdehyde (MDA) levels were also detected at T1, T6, T7 and T8. Blood glucose levels were detected at T1, T5, T6 and T7. In comparison with the control group, patients in the Dex group exhibited a significant increase in cardiac function, as indicated by an increase in HR, MAP and IL-10 levels, and a significant decrease in cTnI, IL-8, MDA and glucose levels. Both Dex perfusion and Dex preconditioning were able to reduce myocardial injury, inflammation, oxidative stress and stress response in rheumatic heart valve replacement surgery. However, Dex perfusion during the whole surgery was more effective than Dex preconditioning treatment. The study was registered with the Chinese Clinical Trial Registry (ChiCTR; no. ChiCTR-INR-17011955).

17.
J Int Med Res ; 49(3): 3000605211003014, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33771069

RESUMO

A paraganglioma is an extra-adrenal tumor of the paraganglia often found in association with sympathetic and parasympathetic nerves. A primary pulmonary paraganglioma generally presents as multiple small tumors or a solitary mass; however, endobronchial involvement is extremely rare. A 49-year-old man was admitted to our hospital because of a chronic cough, intermittent dyspnea, and chest pain. Chest computed tomography revealed a rounded, high-density lesion in the left lower lung lobe. Fiberoptic bronchoscopy demonstrated an endobronchial mass characterized by smooth, hypervascularized mucosa. Transbronchial biopsy of the mass and immunohistochemistry results suggested a paraganglioma. The patient fully recovered after lobectomy and lymphadenectomy. Pulmonary paragangliomas are rarely reported. Complete surgical resection is considered the treatment of choice for pulmonary paragangliomas, and the long-term prognosis is generally good. However, life-long follow-up is mandatory because of the possibility of recurrence and metastasis. This case report adds valuable knowledge to the literature on pulmonary paragangliomas.


Assuntos
Recidiva Local de Neoplasia , Paraganglioma , Broncoscopia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Paraganglioma/diagnóstico por imagem , Paraganglioma/cirurgia , Tomografia Computadorizada por Raios X
18.
Cogn Neurodyn ; 15(1): 17-26, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33786076

RESUMO

The basal ganglia have been increasingly recognized as an important structure involved in decision making. Neurons in the basal ganglia were found to reflect the evidence accumulation process during decision making. However, it is not well understood how the direct and indirect pathways of the basal ganglia work together for decision making. Here, we create a recurrent neural network model that is composed of the direct and indirect pathways and test it with the classic random dot motion discrimination task. The direct pathway drives the outputs, which are modulated through a gating mechanism controlled by the indirect pathway. We train the network to learn the task and find that the network reproduces the accuracy and reaction time patterns of previous animal studies. Units in the model exhibit ramping activities that reflect evidence accumulation. Finally, we simulate manipulations of the direct and indirect pathways and find that the manipulations of the direct pathway mainly affect the choice while the manipulations of the indirect pathway affect the model's reaction time. These results suggest a potential circuitry mechanism of the basal ganglia's role in decision making with predictions that can be tested experimentally in the future.

19.
Sensors (Basel) ; 21(4)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671346

RESUMO

Intense solar radio bursts (SRBs) can increase the energy noise and positioning error of the bandwidth of global navigation satellite system (GNSS). The study of the interference from intense L-band SRBs is of great importance to the steady operation of GNSS receivers. Based on the fact that intense L-band SRBs lead to a decrease in the carrier-to-noise ratio (C/N0) of multiple GNSS satellites over a large area of the sunlit hemisphere, an intense L-band SRB detection method without the aid of a radio telescope is proposed. Firstly, the valley period of a single satellite at a single monitoring station is detected. Then, the detection of SRBs is achieved by calculating the intersection of multiple satellites and multiple stations. The experimental results indicate that the detection rates of GPS L2 and GLONASS G2 are better than those of GPS L1 L5, GLONASS G1, and Galileo E1 E5. The detection rate of SRBs can reach 80% with a flux density above 800 solar flux unit (SFU) at the L2 frequency of GPS. Overall, the detection rate is not affected by the satellite distribution relative to the Sun. The proposed detection method is low-cost and has a high detection rate and low false alarm rate. This method is a noteworthy reference for coping with interference in GNSS from intense L-band SRBs.

20.
ISA Trans ; 108: 295-304, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32873373

RESUMO

Aiming at the problem that the navigation performances of unmanned underwater vehicle (UUV) may be affected by inaccurate prior navigation information and external environmental interference, which may make the accuracy and reliability of strapdown inertial navigation system (SINS) and global position system (GPS) integrated navigation results worse, positioning divergent and system even invalid, an adaptive H-infinite kalman filtering algorithm based on multiple fading factors (MAHKF) is proposed in this paper. Firstly, the time-varying adaptive fading factor is used to modify the filter parameters on-line to make the initial error of navigation filter converge quickly. Secondly, the H-infinite kalman filter of the SINS/GPS system is built on combining the advantages of robust control, which improved the system robustness under extreme external environment. Further, the adaptive thresholdγ of the H-infinite kalman filter is introduced to make the filter adaptive to the environment change. Results of the simulation and experiment demonstrate that the initial error is converged at the beginning stage of navigation process, and the interference from external uncertainty inputs to the integrated navigation system are suppressed effectively with the proposed algorithm. Compared with the conventional kalman filter algorithm (KF), the position errors in three directions of the UUV are reduced by 66.57%,67.98% and 64.51% respectively with the proposed MAHKF.

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