ARTICLE | doi:10.20944/preprints202305.1140.v1
Subject: Engineering, Civil Engineering Keywords: temperature stress test machine; concrete; hydration heat; shaft lining; degree of restraint
Online: 16 May 2023 (09:35:14 CEST)
To study the anti-cracking performance of cast-in-place concrete inner shaft lining structure under the combined effects of temperature and constraint, this paper first developed a novel temperature stress test machine suitable for the shape of the inner shaft lining structure and with adjustable endpoint constraint, providing specialized experimental equipment for subsequent cast-in-place concrete inner shaft lining temperature stress simulation experiments. Then, this paper preliminarily studied the temperature, strain, and stress changes of the cast-in-place inner shaft lining under the condition of 100% endpoint constraint by simulating the internal hydration heating and cooling process of the cast-in-place inner shaft lining and using the temperature stress test machine to accurately control the endpoint constraint conditions of the inner shaft lining scaled model.
ARTICLE | doi:10.20944/preprints202308.2102.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: BCI, rt-fMRI, MI, DWGC, svm
Online: 31 August 2023 (09:43:14 CEST)
This article presents a method for extracting neural signal features to identify the imagination of left and right hand grasping movements. A functional magnetic resonance imaging (fMRI) experiment is employed to identify four brain regions with significant activations during motor imagery(MI) and the effective connections between these regions of interest (ROIs) were calculated using Dynamic Window-level Granger Causality (DWGC). Then, a real-time fMRI(rt-fMRI) classification system for left and right hand MI is developed using the Open-NFT platform. The experimental results show that incorporating effective connections can enhance the average accuracy of real-time three-class classification (rest, left hand and right hand) by 3% in comparison to traditional multivoxel pattern classification analysis(MVPA). Moreover, it significantly improves classification accuracy during the initial stage of MI tasks while reducing the latency effects in real-time decoding. The study suggests that the effective connections obtained through the DWGC method serve as valuable features for real-time decoding of MI using fMRI. Moreover, they exhibit higher sensitivity to changes in brain states. This research offers theoretical support and technical guidance for extracting neural signal features in the context of fMRI-based studies.
ARTICLE | doi:10.20944/preprints202306.0719.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: aqueous zinc ion batteries; separator; modification
Online: 9 June 2023 (12:39:37 CEST)
Much attention has been attracted by aqueous zinc zinc-ion batteries (AZIBs) due to the features of inherent safety, environmental compatibility, low cost and fantastic energy density. Nevertheless, chemical corrosion and dendrite growth occurring on Zn anode during the charge/discharge process usually cause the surface passivation and short circuit of cells, seriously hindering the development of AZIBs. To settle these problems, a Cu(II)/polydopamine modified glass fiber (Cu-PDA/GF) is designed as separator. Due to the enhanced ionic conductivity of Cu(II) and PDA modified glass fiber separator, reversible zinc plating/striping is achieved in symmetric cells, which display long cycle life of over 1800 h at the current density of 1 mA cm−2 with the fixed capacity of 1 mAh cm−2. Moreover, the assembled Zn//V2O5 cells using Cu-PDA/GF separator also demonstrate improved capacity retention. The present study provides a simple separator modification strategy for high-performance and reliable AZIBs, which are conducive to energy storage devices.
ARTICLE | doi:10.20944/preprints202308.2046.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: fMRI; MVPA; PPI; dACC; occipital lobe; occluded object recognition
Online: 30 August 2023 (15:28:29 CEST)
Recognizing highly occluded objects is believed to arises from the interaction between the brain's vision and cognition controlling areas, although supporting neuroimaging data is currently limited. To explore the neural mechanism during this activity, we conducted an occlusion object recognition experiment using functional magnetic resonance imaging (fMRI). During magnet resonance examinations, 66 subjects engaged in object recognition tasks with three different occlusion degrees. Generalized linear model (GLM) analysis showed that the activation degree of occipital lobe (inferior occipital gyrus, middle occipital gyrus, and occipital fusiform gyrus) and dorsal anterior cingulate cortex (dACC) was related to the occlusion degree of the objects. Multivariate pattern analysis (MVPA) further unearthed a considerable surge in classification precision when dACC activation was incorporated as a feature. This suggested the combined role of dACC and occipital lobe in occluded object recognition tasks. Moreover, psychophysiological interaction (PPI) analysis disclosed that functional connectivity (FC) between the dACC and the occipital lobe was enhanced with increased occlusion, highlighting the necessity of FC between these two brain regions in effectively identifying exceedingly occluded objects. In conclusion, these findings contribute to understanding the neural mechanisms of highly occluded objects recognition, augmenting our appreciation of how the brain manages incomplete visual data.
ARTICLE | doi:10.20944/preprints202307.0810.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: IMM−H014; extended–release tablet; hydrophilic polymers; in vitro−in vivo correlation; non–alcoholic fatty liver disease
Online: 12 July 2023 (21:28:22 CEST)
This study aimed to develop extended–release tablets containing 25 mg IMM−H014, an original drug formulated by a direct powder pressing method based on pharmaceutical–grade hydrophilic matrix polymers, such as hydroxypropyl methylcellulose, to establish an in vitro−in vivo corre-lation (IVIVC) to predict bioavailability. The tablets’ mechanical properties and in vitro and in vivo performance were studied. The formulation was optimized using a single factor experiment and the reproducibility was confirmed. The in vitro dissolution profiles of the tablet were de-termined in five dissolution media, in which the drug released from the hydrophilic tablets fol-lowed Ritger–Peppas model kinetics in 0.01 N HCl medium for the first 2 h, and in phosphate buffer saline medium (pH 7.5) for further 24 h. Accelerated stability studies (40°C, 75% relative humidity) proved that the optimal formulation was stable for 6 months. The in vivo pharmaco-kinetics study in beagle dogs showed that compared to the IMM−H014 immediate release prep-aration, the maximum plasma concentration of the extended release (ER) preparation was sig-nificantly decreased, while the maximum time to peak and mean residence time were significantly prolonged. The relative bioavailability was 97.9% based on an area under curve, indicating that the optimal formulation has an obvious ER profile. And a good IVIVC was established, which could be used to predict in vivo pharmacokinetics from the formulation composition.