The cerebellum has been implicated in a number of nonmotor mental disorders such as autism spectrum disorder, schizophrenia, and addiction. However, its contribution to these disorders is not well ...understood. In mice, we found that the cerebellum sends direct excitatory projections to the ventral tegmental area (VTA), one of the brain regions that processes and encodes reward. Optogenetic activation of the cerebello-VTA projections was rewarding and, in a three-chamber social task, these projections were more active when the animal explored the social chamber. Intriguingly, activity in the cerebello-VTA pathway was required for the mice to show social preference in this task. Our data delineate a major, previously unappreciated role for the cerebellum in controlling the reward circuitry and social behavior.
Rapid-eye-movement (REM) sleep is a distinct behavioral state associated with vivid dreaming and memory processing. Phasic bursts of electrical activity, measurable as spike-like pontine (P)-waves, ...are a hallmark of REM sleep implicated in memory consolidation. However, the brainstem circuits regulating P-waves, and their interactions with circuits generating REM sleep, remain largely unknown. Here, we show that an excitatory population of dorsomedial medulla (dmM) neurons expressing corticotropin-releasing-hormone (CRH) regulates both REM sleep and P-waves in mice. Calcium imaging showed that dmM CRH neurons are selectively activated during REM sleep and recruited during P-waves, and opto- and chemogenetic experiments revealed that this population promotes REM sleep. Chemogenetic manipulation also induced prolonged changes in P-wave frequency, while brief optogenetic activation reliably triggered P-waves along with transiently accelerated theta oscillations in the electroencephalogram (EEG). Together, these findings anatomically and functionally delineate a common medullary hub for the regulation of both REM sleep and P-waves.
The ability to accurately simulate the realistic behavior of granular materials is one of the challenging issues of the numerical techniques. The first purpose of this study is to calibrate the ...microscopic properties of granular materials by Discrete Element Method (DEM). Coefficients of rolling and sliding friction as two main microscopic properties of granular material have a significant effect on the amount of macroscopic properties like Angle of Repose (AoR). Earlier studies indicated that the same AoR can be demonstrated by different combinations of the microscopic properties of materials. Therefore the AoR cannot singly be considered as a reliable criterion for DEM calibration, hence time as the second macroscopic property was considered along with the AoR for the calibration of microscopic properties. Furthermore, the need for further study in the field of fine particles led to the use of quartz sand with the diameter in the range of 300 to 600μm in this study. It was assumed that the sand grains are spherical particles and dry material (non-cohesive).
In the first step of the calibration process, the Sandglass test was performed to measure the macroscopic properties of quartz sand. Then the Sandglass was simulated by DEM for a varied range of coefficients of rolling and sliding friction. A comparison between the AoR and discharging time of materials and DEM results indicated that the coefficients of rolling and sliding friction of sand particles are 0.3 and 0.52 respectively. The calibrated model was verified by performing a comparison between the experimental and simulation results of the conical pile test.
The second purpose of this research is to decrease the computational time of DEM simulation through utilizing a slice of a domain instead of the whole domain where the material slice represents the realistic mechanical behavior of materials. Therefore, a rectangular container was experimentally tested and numerically simulated at different thicknesses of the container. Both experimental and numerical results indicated that the critical thickness of the cabin is 32 times of the particle diameter at which the front and rear walls of the cabin do not restrict the mobility of particles in the median plane. In addition, when the wall boundary condition was replaced by periodic boundary condition, the critical thickness decreased to 4 times of particle diameter which significantly improved the computational speed.
The microscopic properties of quartz sand were calibrated by Discrete Element Method (DEM). The calibrated coefficients of rolling and sliding friction are 0.3 and 0.52 respectively. By using Periodic B.C. instead of Wall B.C., the critical ratio of container thickness to particle diameter (W/D) decreased from 32 to 4 and the computational speed was 15 times faster. Display omitted
•DEM was utilized to determine the microscopic properties (μs & μr) of sand particles.•Time as a macroscopic property was used to increase the accuracy of DEM calibration.•For Wall B.C., the critical ratio of container thickness to particle diameter (W/D) is 32.•For Periodic Boundary Condition (PBC), the critical ratio of W/D is 4.•The PBC is about 15 times faster than the WBC in terms of computational speed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The international biomass market is growing, and is expected to be a large-scale trading market in the long term future. The demand within the European Union, however, cannot be met by local supply. ...Therefore, a large-scale biomass bulk terminal for both solid and liquid biomass and liquid biofuels is required to accommodate the biomass flows.
The capacity for the large-scale biomass bulk terminal is set at a maximum of 40 million tons per annum, with the estimated share of solid biomass of 40–50 percent. Although some of the issues or concerns (e. g. particle breakage that leads to downstream segregation problems) with regard to storage and handling of biomass can be addressed with the knowledge gained from existing dry bulk terminals, little information is available from the perspective of biomass. Therefore, experiments have been done to determine physical properties of some biomass materials. They are required to allow the design of suitable equipment (e.g. hopper) and handle biomass materials properly, i.e. the materials are handled based on first in first out stock rotation within storage vessel and/or ground storage scheme. Failure to achieve this goal will lead to the risk of negative effects and incidents such as material degradation (due to e.g. fermentation, biological reactions), self-heating (due to exothermic reaction), health hazard, and explosion.
The objective of this paper is to present various decisive physical material properties of three types of solid biomass fuels: wood pellets, wood chips and torrefied pellets. The properties studied are physical material properties and the characteristics when the materials interact with the storage and handling equipment. In addition to the results, among which particle size distribution and angle of internal friction, the experimental setup as well as the relevant standards (e.g. ASTM and CEN) will be described.
► Physical properties of wood pellets, wood chips, and torrefied pellets are shown. ► Characteristics of materials in contact with equipment (e.g. breakage) are studied. ► Significant flow properties (e.g. angle of repose, wall friction angle) are given. ► Wood pellets have best flowability, followed by torrefied pellets and wood chips.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
With the recent increase in biomass pellet consumption, the mechanical degradation of pellets during transport and handling has become more important. ISO standard 17831-1 is an accepted global ...standard that is commonly used amongst researchers and industries to determine the mechanical durability of pellets. However, the measured mechanical durability sometimes fails to match the certificate accompanying the shipment. In such cases, pellet length specifications are suspected to play a role. This paper studies the effect of pellet length on mechanical durability for various types of commercially produced biomass pellets. In addition, the effect of test conditions and torrefaction on the mechanical durability of biomass pellets has been investigated. To study the effect of pellet length, pellets were classified into three groups: shorter than 15 mm, 15 to 30 mm, and longer than 30 mm, and their length distributions were measured using an in-house image processing tool. Then, the mechanical durability of pellets was measured using ISO standard 17831-1. The mechanical durability results were compared to random-sized pellet samples. To study the effect of test conditions, the mechanical durability test was operated at different time intervals to elucidate the effect of tumbling at different conditions. The results show that the mechanical durability depends highly on the length distribution of the pellets, with a difference between categories of up to 13%. It was also observed that the mechanical durability remains relatively constant after a specific time interval. Based on the results, we highly recommend modifying the current ISO standard to account for the pellet length distribution (PLD).
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Segregation control is a challenging yet crucial aspect of bulk material handling processes. The discrete element method (DEM) can offer useful insights into segregation phenomena, provided that ...reliable models are developed. The main challenge in this regard is finding a good balance between including particle-level details and managing the computational load. This is especially true for industrial applications, where multi-component flows consisting of particles with various irregular shapes and wide size distributions are encountered in huge amounts. In this work, we review the state of the art in DEM modelling of segregation in industrial applications involving the gravity-driven flow of dry, cohesionless granular materials. We start by introducing a novel scientific notation to distinguish between different types of mixtures. Next, we review how parameters for mixture models are determined in the current literature, and how segregation is affected by material, geometric and operational parameters based on these models. Finally, we review existing segregation indices and their applicability to multi-component segregation. We conclude that systematic calibration procedures for segregation models are currently missing in the literature, and realistic models representing multi-component mixtures have not yet been developed. Filling these gaps will pave the way for optimising industrial processes dealing with segregation.
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FFLJ, NUK, ODKLJ, UL, UM, UPUK
Arginine-supplemented enteral immunonutrition has been designed to optimize outcomes in critical care patients. Existing formulas may be isocaloric and isoproteic, yet differ in L-arginine content, ...energy distribution, and in source and amount of many other specialized ingredients. The individual contributions of each may be difficult to pinpoint; however, all cumulate in the body's response to illness and injury. The study objective was to compare health outcomes between different immunonutrition formulas.
Real-world data from October 2015 -February 2019 in the PINC AI™ Healthcare Database (formerly the Premier Healthcare Database) was reviewed for patients with an intensive care unit (ICU) stay and ≥3 days exclusive use of either higher L-arginine formula (HAF), or lower L-arginine formula (LAF). Multivariable generalized linear model regression was used to check associations between formulas and ICU length of stay.
3,284 patients (74.5% surgical) were included from 21 hospitals, with 2,525 receiving HAF and 759 LAF. Inpatient mortality (19.4%) and surgical site infections (6.2%) were similar across groups. Median hospital stay of 17 days (IQR: 16) did not differ by immunonutrition formula. Median ICU stay was shorter for patients receiving HAF compared to LAF (10 vs 12 days; P<0.001). After adjusting for demographics, visit, severity of illness, and other clinical characteristics, associated regression-adjusted ICU length of stay for patients in the HAF group was 11% shorter 0.89 (95% CI: 0.84, 0.94; P<0.001) compared to patients in the LAF group. Estimated adjusted mean ICU length of stay was 9.4 days (95% CI: 8.9, 10.0 days) for the HAF group compared to 10.6 days (95% CI: 9.9, 11.3 days) for the LAF group (P<0.001).
Despite formulas being isocaloric and isoproteic, HAF use was associated with significantly reduced ICU length of stay, compared to LAF. Higher arginine immunonutrition formula may play a role in improving health outcomes in primarily surgical critically ill patients.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The antioxidant properties of organoselenium compounds have been extensively investigated with the aim of developing new drugs, since oxidative stress is responsible for a variety of chronic human ...diseases. Herein, we reported the synthesis of new nitrogen-containing diselenides by a simple and efficient synthetic route. The products were obtained in good to excellent yields and their identification and characterization were achieved by NMR and HRMS techniques. The new derivatives may represent promising structures with different biological activities, which can act against oxidative stress through diverse mechanisms of action. The glutathione peroxidase-like assay (GPx-like activity) of the new synthesized compounds indicated that they reduced H2O2 to water at the expense of PhSH. The best results were obtained with diselenide 2b, which was 9 times more active than the standard organoselenium drug ebselen and, in contrast, this compound was not reduced by hepatic TrxR. All of the new compounds inhibited Fe(II)-induced TBARS.
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•New Nitrogen-containing diselenides were synthesized.•The compounds were evaluated “in vitro” for their antioxidant activity.•These novel diselenides show better GPx-like activity than the standards.•All of the new compounds inhibited Fe(II)-induced TBARS.•Some compounds were good substrates for TrxR.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The presence and generation of fines and dust in the bulk of biomass pellets have inflicted several problems in the supply chain during transportation and storage, and the breakage behavior of ...pellets has been scarcely studied so far. Fines and dust are the consequences of impact and abrasive forces through the whole supply chain; however, the breakage happens at the particle level. Therefore, to study the fines generation, first, the breakage behavior of individual pellets should be understood, and then, the behavior of the bulk materials in operational conditions can be investigated. This paper aims to investigate the breakage behavior of individual pellets under experimental compression tests and to introduce a calibrated numerical model using discrete element method (DEM) in order to pave the way for further studies on pellet breakage. For that purpose, seven different types of biomass pellets were studied experimentally, and then, a calibrated model was introduced via the Timoshenko–Ehrenfest beam theory using DEM. Results show that the model could reasonably predict the breakage behavior of pellets under uniaxial and diametrical compressions. The findings could help to develop a new design of the equipment for transportation and handling of biomass pellets with the aim to reduce the amount of generating fines and dust.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Biomass pellets provide a pivotal opportunity in promising energy transition scenarios as a renewable source of energy. A large share of the current utilization of pellets is facilitated by intensive ...global trade operations. Considering the long distance between the production site and the end-user locations, pellets may face fluctuating storage conditions, resulting in their physical and chemical degradation. We tested the effect of different storage conditions, from freezing temperatures (-19 °C) to high temperature (40 °C) and humidity conditions (85% relative humidity), on the physicochemical properties of untreated and torrefied biomass pellets. Moreover, the effect of sudden changes in the storage conditions on pellet properties was studied by moving the pellets from the freezing to the high temperature and relative humidity conditions and vice versa. The results show that, although storage at one controlled temperature and RH may degrade the pellets, a change in the temperature and relative humidity results in higher degradation in terms of higher moisture uptake and lower mechanical strength.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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