Improved discrete unified gas-kinetic scheme for interface capturing.

In this paper, we extend the improved discrete unified gas-kinetic scheme (DUGKS) from solving the hydrodynamic equations to addressing the phase field equations, building upon our prior work [Wang et al., Phys. Fluids 35, 017106 (2023)10.1063/5.0128912]. The conservative Allen-Cahn equation and its modified form are presented first, followed by the construction of two improved DUGKS methods for interface capturing, based on the corresponding kinetic equations. The improved DUGKS for interface capturing utilizes the node distribution function instead of the interface center distribution function for evaluating the interface flux. The improved DUGKS enhances the numerical stability of the original DUGKS, and the good stability allows the calculations to be performed using large time steps, reducing the cumulative error from which more accurate predictions can be obtained. To verify the validity of the scheme, a series of numerical experiments were further carried out, including the diagonal translation, Zalesak's disk rotation, reversed single vortex, and deformation field. The comparison with the benchmark data shows that the improved DUGKS can simply and effectively capture the sharp interface and complex deformation interface of the two-phase flow interface.

Efficacy, kinetics, inactivation mechanism and application of cold plasma in inactivating Alicyclobacillus acidoterrestris spores.

As spores of Alicyclobacillus acidoterrestris can survive traditional pasteurization, this organism has been suggested as a target bacterium in the fruit juice industry. This study aimed to investigate the inactivation effect of cold plasma on A. acidoterrestris spores and the mechanism behind the inactivation. The inactivation effect was detected by the plate count method and described by kinetic models. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), the detection of dipicolinic acid (DPA) release and heat resistance detection, the detection and scavenging experiment of reactive species, and cryo-scanning electron microscopy were used to explore the mechanism of cold plasma inactivation of A. acidoterrestris. The results showed that cold plasma can effectively inactivate A. acidoterrestris spores in saline with a 3.0 ± 0.3 and 4.4 ± 0.8 log reduction in CFU/mL, for 9 and 18 min, respectively. The higher the voltage and the longer the treatment time, the stronger the overall inactivation effect. However, a lower gas flow rate may increase the probability of spore contact with reactive species, resulting in better inactivation results. The biphasic model fits the survival curves better than the Weibull model. SEM and TEM revealed that cold plasma treatment can cause varying degrees of damage to the morphology and structure of A. acidoterrestris spores, with at least 50 % sustaining severe morphological and structural damage. The DPA release and heat resistance detection showed that A. acidoterrestris spores did not germinate but died directly during the cold plasma treatment. 1O2 plays the most important role in the inactivation, while O3, H2O2 and NO3- may also be responsible for inactivation. Cold plasma treatment for 1 min reduced A. acidoterrestris spores in apple juice by 0.4 ± 0.0 log, comparable to a 12-min heat treatment at 95 °C. However, as the treatment time increased, the survival curve exhibited a significant tailing phenomenon, which was most likely caused by the various compounds in apple juice that can react with reactive species and exert a physical shielding effect on spores. Higher input power and higher gas flow rate resulted in more complete inactivation of A. acidoterrestris spores in apple juice. What's more, the high inactivation efficiency in saline indicates the cold plasma device provides a promising alternative for controlling A. acidoterrestris spores during apple washing. Overall, our study provides adequate data support and a theoretical basis for using cold plasma to inactivate A. acidoterrestris spores in the food industry.

Remediation of Cr(VI)-contaminated soil mixed with chromite ore processing residue by ferrous sulfate and enzyme residue.

In this study, Cr(VI)-contaminated soil mixed with COPR by using ferrous sulfate (FeSO4), enzyme residue (ER), and their combination under aerobic or anaerobic condition were investigated. The concentration of Cr(VI) decreased from 1498.05 to 104.63 mg kg-1 after the simultaneous addition of FeSO4 (30 %, w/w as FeSO4·7H2O) and ER (30 %, w/w) at 45 d under the anaerobic condition with a reduction efficiency of 93.02 %, which is higher than that by single FeSO4 (72.39 %) or ER (75.47 %) under the anaerobic condition. XRD, XPS, FTIR, and fluorescence spectroscopy were conducted to characterize soil and ER composition. Metagenomic analysis was performed to reveal the reduction mechanisms of FeSO4 and ER. The anaerobic condition with lower Eh was beneficial for Cr(VI) reduction than aerobic condition, and Eh was the main driver for the evolution of Cr(VI) reduction-related microorganisms. Moreover, the addition of ER enriched the organic matter and microbials in the soil. During the decomposition of organic matter under the anaerobic condition, organic acids were generated, leading to a decrease in pH and promoting the release of Cr(VI) from minerals. They also served as electron donors in Cr(VI) reduction. Additionally, the addition of excess FeSO4 stimulated the growth of iron-reducing bacteria and sulfate-reducing bacteria, facilitating to Cr(VI) reduction. Metagenomic analysis showed that Acinetobacter, related to the nemA and nfsA genes, was the dominant Cr(VI) reduction genus. Thus, the combination of FeSO4 and ER is a promising method for the remediation of Cr(VI)-contaminated soils mixed with COPR.

Genome-wide DNA methylation analysis in families with multiple individuals diagnosed with schizophrenia and intellectual disability.

OBJECTIVES: Schizophrenia (SZ) and intellectual disability (ID) are both included in the continuum of neurodevelopmental disorders (NDDs). DNA methylation is known to be important in the occurrence of NDDs. The family study is conducive to eliminate the effects of relative epigenetic backgrounds, and to screen for differentially methylated positions (DMPs) and regions (DMRs) that are truly associated with NDDs. METHODS: Four monozygotic twin families were recruited, and both twin individuals suffered from NDDs (either SZ, ID, or SZ plus ID). Genome-wide methylation analysis was performed in all samples and each family. DMPs and DMRs between NDD patients and unaffected individuals were identified. Functional and pathway enrichment analyses were performed on the annotated genes. RESULTS: Two significant DMPs annotated to CYP2E1 were found in all samples. In Family One, 1476 DMPs mapped to 880 genes, and 162 DMRs overlapping with 153 unique genes were recognised. Our results suggested that the altered methylation levels of FYN, STAT3, RAC1, and NR4A2 were associated with the development of SZ and ID. Neurodevelopment and the immune system may participate in the occurrence of SZ and ID. CONCLUSIONS: Our findings suggested that DNA methylation participated in the development of NDDs by affecting neurodevelopment and the immune system.

Optimization-based Concurrent Control of a High Dexterity Robot for Vitreoretinal Surgery.

Vitreoretinal surgery requires dexterity and force sensitivity from the clinician. A system to cooperatively control an integrated surgical robot for high dexterity manipulation within the eye's vitreous space was developed and validated in simulation. The system is composed of a 2 degrees of freedom (DoF) snake-like continuum manipulator that is attached to the end-effector of a 5-DoF rigid robot arm. It is capable of receiving position and orientation commands from a 5-DoF input device in real-time, as well as following pre-planned trajectories. The manipulator is moved to each target pose in real-time, using an optimization method to calculate the inverse kinematics solution. Constraints on the position and orientation ensure the target pose does not harm the patient within the vitreous space, enabling the robot to safely assist the clinician with vitreoretinal surgery when operating in real-time. The simulation demonstrates the system's feasibility and benefits over the existing non-dexterous system.

Humic acid induced weak attachment of fullerene nC60 nanoparticles and subsequent detachment upon reduction of solution ionic strength in saturated porous media.

Sand column experiments were performed under saturated conditions to investigate impact of humic acid (HA) on attachment of nC60 nanoparticles (NPs) in NaCl and CaCl2 at ionic strengths (ISs) from 1 mM to 100 mM and subsequent detachment via reducing solution IS. The attachment increased with increasing IS due to reduced repulsive Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy and accordingly increased retention in primary energy wells. More attachments occurred in CaCl2 compared to NaCl because Ca2+ exhibited greater charge screen ability and served as a bridging agent between the NPs and sand surfaces. The presence of HA significantly reduced nC60 NPs attachment on sand surfaces (especially on nanoscale physical heterogeneities) in 10 mM NaCl and 1 mM CaCl2 because of enhanced electrostatic and steric repulsions. Interestingly, although the HA did not cause reduction of attachment in 100 mM NaCl and 10 mM CaCl2 compared to the case in absence of HA, the HA caused weak attachment of nC60 on sand surfaces and then much more significant detachment by decreasing IS. The HA did not alter both attachment and detachment in 100 mM CaCl2, because the Ca2+ at the high concentration caused formation of very stable complex of HA and NPs, and strong interaction of the complex with the sand surfaces via cation bridge. Our study highlighted that the HA can not only enhance the transport of NPs by inhibiting attachment as revealed in the literature, but also by the continuous capture and release of the NPs from surfaces in subsurface environments.