Search

The angular gyrus (AG), given its rich connectivity and its location where multisensory information converges, is a functionally and anatomically heterogeneous structure. Using the state‐of‐the‐art functional gradient approach and transcription‐neuroimaging association analysis, we sought to determine whether there is an overarching hierarchical organization of the AG and if so, how it is modulated by the underlying genetic architecture. Resting‐state functional MRI data of 793 healthy subjects were obtained from discovery and validation datasets. Functional gradients of the AG were calculated based on the voxel‐wise AG‐to‐cerebrum functional connectivity patterns. Combined with the Allen Human Brain Atlas, we examined the spatial correlations between the AG functional gradient and gene expression. The dominant gradient topography showed a dorsoanterior–ventroposterior hierarchical organization of the AG, which was related to its intrinsic geometry. Concurrently, AG functional subdivisions corresponding to canonical functional networks (behavioral domains) were distributed along the dominant gradient in a hierarchical manner, that is, from the default mode network (abstract cognition) at one extreme to the visual and sensorimotor networks (perception and action) at the other extreme. Remarkably, we established a link between the AG dominant gradient and gene expression, with two gene sets strongly contributing to this link but diverging on their functional annotation and specific expression. Our findings represent a significant conceptual advance in AG functional organization, and may introduce novel approaches and testable questions to the investigation of AG function and anatomy in health and disease. [ABSTRACT FROM AUTHOR]

The diverse functional roles of the insula may emerge from its heavy connectivity to an extensive network of cortical and subcortical areas. Despite several previous attempts to investigate the hierarchical organization of the insula by applying the recently developed gradient approach to insula‐to‐whole brain connectivity data, little is known about whether and how there is variability across connectivity gradients of the insula to different cerebral systems. Resting‐state functional MRI data from 793 healthy subjects were used to discover and validate functional connectivity gradients of the insula, which were computed based on its voxel‐wise functional connectivity profiles to distinct cerebral systems. We identified three primary patterns of functional connectivity gradients of the insula to distinct cerebral systems. The connectivity gradients to the higher‐order transmodal associative systems, including the prefrontal, posterior parietal, temporal cortices, and limbic lobule, showed a ventroanterior‐dorsal axis across the insula; those to the lower‐order unimodal primary systems, including the motor, somatosensory, and occipital cortices, displayed radiating transitions from dorsoanterior toward both ventroanterior and dorsoposterior parts of the insula; the connectivity gradient to the subcortical nuclei exhibited an organization along the anterior–posterior axis of the insula. Apart from complementing and extending previous literature on the heterogeneous connectivity patterns of insula subregions, the presented framework may offer ample opportunities to refine our understanding of the role of the insula in many brain disorders. [ABSTRACT FROM AUTHOR]

The human sensorimotor cortex has multiple subregions showing functional commonalities and differences, likely attributable to their connectivity profiles. However, the molecular substrates underlying such connectivity profiles are unclear. Here, transcriptome‐neuroimaging spatial correlation analyses were performed between transcriptomic data from the Allen human brain atlas and resting‐state functional connectivity (rsFC) of 24 fine‐grained sensorimotor subregions from 793 healthy subjects. Results showed that rsFC of six sensorimotor subregions were associated with expression measures of six gene sets that were specifically expressed in brain tissue. These sensorimotor subregions could be classified into the polygenic‐ and oligogenic‐modulated subregions, whose rsFC were related to gene sets diverging on their numbers (hundreds vs. dozens) and functional characteristics. First, the former were specifically expressed in multiple types of neurons and immune cells, yet the latter were not specifically expressed in any cortical cell types. Second, the former were preferentially expressed during the middle and late stages of cortical development, while the latter showed no preferential expression during any stages. Third, the former were prone to be enriched for general biological functions and pathways, but the latter for specialized biological functions and pathways. Fourth, the former were enriched for neuropsychiatric disorders, whereas this enrichment was absent for the latter. Finally, although the identified genes were commonly associated with sensorimotor behavioral processes, the polygenic‐modulated subregions associated genes were additionally related to vision and dementia. These findings may advance our understanding of the functional homogeneity and heterogeneity of the human sensorimotor cortex from the perspective of underlying genetic architecture. [ABSTRACT FROM AUTHOR]

To improve the flame retardancy of vinyl epoxy (VE) resins more effectively, a half‐cage and cage structure polyhedral oligomeric silsesquioxanes (P/N‐POSS) containing phosphorus and nitrogen was synthesized by a one‐step Kabachnik‐Fields reaction from paraformaldehyde, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and 3‐aminopropyltriethoxysilane. It was then blended with tetrabutyl titanate (TBT) in VE resins to construct a phosphorus‐nitrogen‐silicon‐titanium synergy flame retardant system. P/N‐POSS was well dispersed in the VE matrix at low loadings (≤4 wt%). With the addition of only 4 wt% P/N‐POSS and 0.2 wt% TBT, the LOI value reached 29.2 and the UL‐94 grade passed V‐1 rating. Moreover, compared with VE‐0, the peak heat release rate, total heat release, smoke production rate and total smoke production decreased significantly. The investigations on pyrolysis volatiles and char residue of cured VE composites revealed that the excellent flame retardancy of the VE composites were due to the superior free radical capturing ability, the dilution effect of P/N‐POSS in the gas phase, and the promoting the carbonation effect of P/N‐POSS, the catalyzing char formation ability of TBT in the condensed phase. Meanwhile, VE composites exhibited improved mechanical properties, thermal stabilities and retained the low viscosity and good processability of VE resins. [ABSTRACT FROM AUTHOR]

Network neuroscience has broadly conceptualized the functions of the brain as complex communication within and between large‐scale neural networks. Nevertheless, whether and how the gut microbiota influence functional network connectivity that in turn impact human behaviors has yet to be determined. We collected fecal samples from 157 healthy young adults and used 16S sequencing to assess gut microbial diversity and enterotypes. Large‐scale inter‐ and intranetwork functional connectivity was measured using a combination of resting‐state functional MRI data and independent component analysis. Sleep quality and core executive functions were also evaluated. Then, we tested for potential associations between gut microbiota, functional network connectivity and behaviors. We found significant associations of gut microbial diversity with internetwork functional connectivity between the executive control, default mode and sensorimotor systems, and intranetwork connectivity of the executive control system. Moreover, some internetwork functional connectivity mediated the relations of microbial diversity with sleep quality, working memory, and attention. In addition, there was a significant effect of enterotypes on intranetwork connectivity of the executive control system, which could mediate the link between enterotypes and executive function. Our findings not only may expand existing biological knowledge of the gut microbiota‐brain‐behavior relationships from the perspective of large‐scale functional network organization, but also may ultimately inform a translational conceptualization of how to improve sleep quality and executive functions through the regulation of gut microbiota. [ABSTRACT FROM AUTHOR]

Ethyl methyl carbonate is selective synthesized from dimethyl carbonate and ethanol via catalytic reactive distillation (RD) over heterogeneous MgO/HZSM‐5. It is shown that 2.3%MgO/HZSM‐5 catalyst has high catalytic activity with 99.4% conversion of ethanol (EtOH) and 98.1% selectivity to EMC, in a RD column. The prepared catalysts is characterized by XRD, SEM, N2 adsorption‐desorption CO2‐TPD and NH3‐TPD. The high performance of this catalyst is attributed to high basicity. According to the results of CO2‐TPD, this catalyst total basicity is 1.72 mmol/g. In order to optimize the catalytic reaction, the reaction conditions, such as amount of catalyst, reflux ratio and EtOH LHSV were studied. [ABSTRACT FROM AUTHOR]

Neurovascular coupling reflects the close relationship between neuronal activity and cerebral blood flow (CBF), providing a new mechanistic insight into health and disease. Neuromyelitis optica (NMO) is an autoimmune inflammatory demyelinating disease of the central nervous system and shows cognitive decline‐related brain gray matter abnormalities besides the damage of optic nerve and spinal cord. We aimed to investigate neurovascular coupling alteration and its clinical significance in NMO by using regional homogeneity (ReHo) to measure neuronal activity and CBF to measure vascular response. ReHo was calculated from functional MRI and CBF was computed from arterial spin labeling (ASL) in 56 patients with NMO and 63 healthy controls. Global neurovascular coupling was assessed by across‐voxel CBF‐ReHo correlations and regional neurovascular coupling was evaluated by CBF/ReHo ratio. Correlations between CBF/ReHo ratio and clinical variables were explored in patients with NMO. Global CBF‐ReHo coupling was decreased in patients with NMO relative to healthy controls (p = .009). Patients with NMO showed decreased CBF/ReHo ratio (10.9%–17.3% reduction) in the parietal and occipital regions and increased CBF/ReHo ratio (8.0%–13.3% increase) in the insular, sensorimotor, temporal and prefrontal regions. Some of these abnormalities cannot be identified by a single CBF or ReHo analysis. Both abnormally decreased and increased CBF/ReHo ratios were correlated with more severe clinical impairments and cognitive decline in patients with NMO. These findings suggested that patients with NMO show abnormal neurovascular coupling, which is associated with disease severity and cognitive impairments. [ABSTRACT FROM AUTHOR]

A series of mesogen-jacketed liquid crystalline polymers, poly{2,2,3,3,4,4,4-heptafluorobutyl 4′-hydroxy-2-vinylbiphenyl-4-carboxylate} (PF3C m, where m is the number of carbon atoms in the alkoxy groups, and m = 1, 4, 6, and 8), the side chain of which contains a biphenyl core with a fluorocarbon substituent at one end and an alkoxy unit of varying length on the other end, were designed and successfully synthesized via atom transfer radical polymerization. For comparison, poly{butyl 4′-hydroxy-2-vinylbiphenyl-4-carboxylate} (PC4C m), similar to PF3C m but with a butyl group instead of the fluorocarbon substituent, was also prepared. Differential scanning calorimetric results reveal that the glass transition temperatures ( Tgs) of the two series of polymers decrease as m increases and Tgs of the fluorocarbon-substituted polymers are higher than those of the corresponding butyl-substituted polymers. Wide-angle X-ray diffraction measurements show that the mesophase structures of these polymers are dependent on the number of the carbon atoms in the fluorocarbon substituent and the property of the other terminal substituent. Polymers with fluorocarbon substituents enter into columnar nematic phases when m ≥ 4, whereas the polymer PF3C1 exhibits no liquid crystallinity. For polymers with butyl substituents, columnar nematic phases form when the number of carbon atoms at both ends of the side chain is not equal at high temperatures and disappear after the polymers are cooled to ambient temperature. However, when the polymer has the same number of carbon atoms at both ends of the side chain, a hexagonal columnar phase develops, and this phase remains after the polymer is cooled. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 [ABSTRACT FROM AUTHOR]

The ability of titanium dioxide (TiO2) to generate reactive oxygen species (ROS) offers new opportunity to decontaminate perishable foods. The current study was aimed to prepare a TiO2 coated nonwoven fabric photocatalytic package (TiO2/NWF package) and assess the effects of in‐package photocatalysis on pork. In this study, layer by layer self‐assembly method was chosen to coat TiO2 nanoparticles on the NWF and eight layers TiO2 loading showed the higher photoactivity. A selected TiO2/NWF composite was combined with a package to form TiO2/NWF package. Pork was stored in the TiO2/NWF package, the antibacterial effects of TiO2 photocatalysis (TPC) on total viable count and Escherichia coli in pork were achieved. TPC treatment provided better antibacterial efficiency as compared with UV treatment alone. Moreover, TPC treatment significantly (p < .05) influenced pH and lipid oxidation after exposure for 45 min. These results indicate that TiO2/NWF package has the potential for preserving fresh foods. Practical applications: Traditional thermal treatment can adversely affect the sensory and nutritional quality of foods, titanium dioxide (TiO2) photocatalysis as a nonthermal disinfection technology can provide a low cost and convenient approach to reduce the risk of microbial contamination and enhance the safety of fresh products. The current study developed a TiO2 coated nonwoven fabric photocatalytic package (TiO2/NWF package) and evaluated effects of in‐package photocatalysis on pork samples. Results showed that photocatalytic reactions took place in the TiO2/NWF package and the generated active ROS contributed to the inactivation of microbes. Therefore, TiO2 photocatalysis has great potential for ensuring food safety for the food industry. [ABSTRACT FROM AUTHOR]