18 research outputs found

    Altered dynamic functional network connectivity in drug-naïve Parkinson’s disease patients with excessive daytime sleepiness

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    BackgroundExcessive daytime sleepiness (EDS) is a frequent nonmotor symptoms of Parkinson’s disease (PD), which seriously affects the quality of life of PD patients and exacerbates other nonmotor symptoms. Previous studies have used static analyses of these resting-state functional magnetic resonance imaging (rs-fMRI) data were measured under the assumption that the intrinsic fluctuations during MRI scans are stationary. However, dynamic functional network connectivity (dFNC) analysis captures time-varying connectivity over short time scales and may reveal complex functional tissues in the brain.PurposeTo identify dynamic functional connectivity characteristics in PD-EDS patients in order to explain the underlying neuropathological mechanisms.MethodsBased on rs-fMRI data from 16 PD patients with EDS and 41 PD patients without EDS, we applied the sliding window approach, k-means clustering and independent component analysis to estimate the inherent dynamic connectivity states associated with EDS in PD patients and investigated the differences between groups. Furthermore, to assess the correlations between the altered temporal properties and the Epworth sleepiness scale (ESS) scores.ResultsWe found four distinct functional connectivity states in PD patients. The patients in the PD-EDS group showed increased fractional time and mean dwell time in state IV, which was characterized by strong connectivity in the sensorimotor (SMN) and visual (VIS) networks, and reduced fractional time in state I, which was characterized by strong positive connectivity intranetwork of the default mode network (DMN) and VIS, while negative connectivity internetwork between the DMN and VIS. Moreover, the ESS scores were positively correlated with fraction time in state IV.ConclusionOur results indicated that the strong connectivity within and between the SMN and VIS was characteristic of EDS in PD patients, which may be a potential marker of pathophysiological features related to EDS in PD patients

    From cropland to cropped field: A robust algorithm for national-scale mapping by fusing time series of Sentinel-1 and Sentinel-2

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    Detailed and updated maps of actively cropped fields on a national scale are vital for global food security. Unfortunately, this information is not provided in existing land cover datasets, especially lacking in smallholder farmer systems. Mapping national-scale cropped fields remains challenging due to the spectral confusion with abandoned vegetated land, and their high heterogeneity over large areas. This study proposed a large-area mapping framework for automatically identifying actively cropped fields by fusing Vegetation-Soil-Pigment indices and Synthetic-aperture radar (SAR) time-series images (VSPS). Three temporal indicators were proposed and highlighted cropped fields by consistently higher values due to cropping activities. The proposed VSPS algorithm was exploited for national-scale mapping in China without regional adjustments using Sentinel-2 and Sentinel-1 images. Agriculture in China illustrated great heterogeneity and has experienced tremendous changes such as non-grain orientation and cropland abandonment. Yet, little is known about the locations and extents of cropped fields cultivated with field crops on a national scale. Here, we produced the first national-scale 20 m updated map of cropped and fallow/abandoned land in China and found that 77 % of national cropland (151.23 million hectares) was actively cropped in 2020. We found that fallow/abandoned cropland in mountainous and hilly regions were far more than we expected, which was significantly underestimated by the commonly applied VImax-based approach based on the MODIS images. The VSPS method illustrates robust generalization capabilities, which obtained an overall accuracy of 94 % based on 4,934 widely spread reference sites. The proposed mapping framework is capable of detecting cropped fields with a full consideration of a high diversity of cropping systems and complexity of fallow/abandoned cropland. The processing codes on Google Earth Engine were provided and hoped to stimulate operational agricultural mapping on cropped fields with finer resolution from the national to the global scale

    Acute combined effects of concurrent physical activities on autonomic nervous activation during cognitive tasks

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    Backgrounds: The validity of heart rate variability (HRV) has been substantiated in mental workload assessments. However, cognitive tasks often coincide with physical exertion in practical mental work, but their synergic effects on HRV remains insufficiently established. The study aims were to investigate the combined effects of cognitive and physical load on autonomic nerve functions.Methods: Thirty-five healthy male subjects (aged 23.5 ± 3.3 years) were eligible and enrolled in the study. The subjects engaged in n-back cognitive tasks (1-back, 2-back, and 3-back) under three distinct physical conditions, involving isotonic contraction of the left upper limb with loads of 0 kg, 3 kg, and 5 kg. Electrocardiogram signals and cognitive task performance were recorded throughout the tasks, and post-task assessment of subjective experiences were conducted using the NASA-TLX scale.Results: The execution of n-back tasks resulted in enhanced perceptions of task-load feelings and increased reaction times among subjects, accompanied by a decline in the accuracy rate (p < 0.05). These effects were synchronously intensified by the imposition of physical load. Comparative analysis with a no-physical-load scenario revealed significant alterations in the HRV of the subjects during the cognitive task under moderate and high physical conditions. The main features were a decreased power of the high frequency component (p < 0.05) and an increased low frequency component (p < 0.05), signifying an elevation in sympathetic activity. This physiological response manifested similarly at both moderate and high physical levels. In addition, a discernible linear correlation was observed between HRV and task-load feelings, as well as task performance under the influence of physical load (p < 0.05).Conclusion: HRV can serve as a viable indicator for assessing mental workload in the context of physical activities, making it suitable for real-world mental work scenarios

    City Sonatas

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    Countries like the UK and France, as shown in Statista\u27s 2023 report, benefit from significant national cultural attractions and monuments that boost museum attendance by attracting tourists. The data suggests a positive correlation between museum attendance and the historical significance, as well as the suitability for tourism, of the institutions2. However, faced with rapid societal advancements, most museums\u27 responses to these challenges have been varied and slow. Contemporary museums, as crucial conduits for the dissemination and exchange of artistic culture, continue to face persistent challenges of low engagement and levels of attention in many countries. Furthermore, a series of remarkably similar and uniform patterns can be observed across museums globally, ranging from spatial design to exhibition methods. This thesis posits that contemporary museums throughout the world must adapt to these evolving dynamics by grounding themselves in an understanding of regional characteristics and contexts, including but not limited to local historical culture and the corresponding demographics of the community. The objective is to further adapt to and embrace the uniqueness of the context surrounding an institution, with the aim of spreading museums into the fabric of neighborhoods rather than drawing people towards a single institution. These new “museums” serve as a medium, bridging the gap between individuals and cultures. Shenzhen, once a fishing village in the 1980s, transformed into a highly industrialized, economically vibrant and internationally renowned city within four decades, serves as the focal point of this study. This thesis focuses on developing a new form of museum within the urban villages of Shenzhen, utilizing three common urban patterns found in this unique typology: linear alleys, traditional public spaces, and micro-plazas between buildings. The exhibition content for this project will explore sound. Sounds collected from the city will be transformed into a sonic map, integrated into the urban environment. A unique journey through the city that reflects local culture will demonstrate a new form of experiential museum, perfectly calibrated to its surroundings. Through the exploration of the three patterns found in urban villages, visitors can experience various hierarchies of sound, both artificial and natural. Different from the traditional form of museums, this immersive approach seeks to redefine the museum experience by fostering a deeper connection between visitors and the city\u27s sonic landscape. By intertwining the rich tapestry of local history, culture, and the evolving urban fabric, this innovative museum model strives to resonate with contemporary audiences, encouraging active participation and foster a renewed appreciation for the intricate layers of urban life

    Audit Committee Chair’s Geographic Distance and Cost of Equity Capital

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    Using a sample of A-share listed companies in China for the period of 2007-2018, this paper empirically tests the impact of the geographical distance of the audit committee chair (ACC) on the company’s cost of equity capital. The study found that there is a significant positive correlation between the geographical distance of ACC and the company’s cost of equity capital, and the regulatory strength will weaken the positive relationship between the two. This conclusion still holds after a series of robustness tests. The research conclusion of this paper not only enriches the research on the characteristics of audit committee chairs, expands the research extension of geographical economics in the field of financial accounting, but also provides certain theoretical support and test evidence for listed companies to select ACC and reduce the cost of equity capital. It is of great significance to improve the performance level of the audit committee and protect the interests of investors

    A prediction model for acute respiratory distress syndrome among patients with severe acute pancreatitis: a retrospective analysis

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    Background: Acute respiratory distress syndrome (ARDS) is a severe complication among patients with severe acute pancreatitis (SAP), which may be associated with increased mortality in hospitalized patients. Thus, an effective model to predict ARDS in patients with SAP is urgently required. Methods: We retrospectively analyzed the data from the patients with SAP who recruited in Xiangya Hospital between April 2017 and May 2021. Patients meeting the Berlin definition of ARDS were categorized into the ARDS group. Logistic regression models and a nomogram were utilized in the study. Descriptive statistics, logistic regression models, and a nomogram were used in the current study. Results: Comorbidity of ARDS occurred in 109 (46.58%) of 234 patients with SAP. The SAP patients with ARDS group had a higher 60-day mortality rate, an increased demand for invasive mechanical ventilation, and a longer intensive care unit (ICU) stay than those without ARDS ( p  250 U/L, creatinine >111 mg/dL, and procalcitonin >0.5 ng/mL were independent risk variables for development of ARDS in SAP patients. The area under the curve for the model was 0.814, and the model fit was acceptable [ p  = .355 (Hosmer–Lemeshow)]. Incorporating these 5 factors, a nomogram was established with sufficient discriminatory power (C-index 0.814). Calibration curve indicated the proper discrimination and good calibration in the predicting nomogram model. Conclusion: The prediction nomogram for ARDS in patients with SAP can be applied using clinical common variables after the diagnosis of SAP. Future studies would be warranted to verify the potential clinical benefits of this model

    Synthesis and catalytic activity of Ti-MCM-41 nanoparticles with highly active titanium sites

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    Ti-MCM-41 nanoparticles 80–160 nm in diameter (Ti-MCM-41 NP) were successfully prepared by a dilute solution route in sodium hydroxide medium at ambient temperature. Ti-MCM-41 NP were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, SEM, TEM, FT-IR, and UV–vis spectroscopy. The characterization results showed the existence of highly ordered hexagonal mesoporous structure and tetrahedral Ti species in Ti-MCM-41 NP. In the epoxidation of cyclohexene with aqueous H2O2, Ti-MCM-41 NP displayed higher conversion and initial reaction rate than a Ti-MCM-41 sample with normal particle size (Ti-MCM-41 LP). Diffusion of the reactants was accelerated and the accessibility to the catalytic Ti species was enhanced in the shorter channels in Ti-MCM-41 NP samples. Ti-MCM-41 NP showed much higher selectivity for cyclohexene oxide compared with Ti-MCM-41 LP, suggesting reduced hydrolysis of cyclohexene oxide with water in the former case. The increased selectivity for cyclohexene oxide can be attributed to the lower concentration of residual surface silanols in Ti-MCM-41 NP and the shorter residence time of epoxide in the shorter mesoporous channels. Ti-MCM-41 NP also appears to be a suitable catalyst in the epoxidation of a bulky substrate, like cholesterol, with tert-butyl hydroperoxide.status: publishe

    Integrative analysis of transcriptome and metabolome reveals the effect of DNA methylation of chalcone isomerase gene in promoter region on Lithocarpus polystachyus Rehd flavonoids

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    Metabolite biosynthesis is regulated by gene expression, which is altered by DNA methylation in the promoter region. Chalcone isomerase (CHI) gene encodes a key enzyme in the Lithocarpus polystachyus Rehd flavonoid pathway, and the expression of L. polystachyus CHI (LpCHI) is closely related to the synthesis of flavonoid metabolites. In this study, we analyzed the DNA methylation site of the LpCHI promoter and its effect on gene expression and metabolite accumulation. The proportions of three types of LpCHI promoter DNA methylation are 7.5%, 68.75%, 18.75%, determined by bisulfite sequencing. Transcriptome sequencing shows that LpCHI is strongly up-regulated in LpCHI promoter methylation Type A but down-regulated in LpCHI promoter methylation Type B and Type C. The expression of LpCHI shows no significant difference between Type B and Type C. Moreover, nine kinds of differentially expressed transcription factors (DETFs) bind to seven CpG-sites of the LpCHI promoter region to regulate LpCHI expression. The results of metabolomics show that differentially accumulated flavonoids are higher in LpCHI promoter methylation Type A than in LpCHI promoter methylation Type B and Type C. Additionally, a positive correlation was found between the LpCHI expression and flavonoids accumulation. These results show that the effect of CpG site-specificity on gene transcription is great than that of overall promoter DNA methylation on gene transcription. The mechanisms of flavonoid genes regulating metabolite accumulation are further revealed
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