Unprecedented phytoplankton blooms in autumn/winter in the southern Bohai Sea (China) due to high Yellow River discharge: Implications of extreme rainfall events.

The occurrence of abnormal phytoplankton blooms is one of the significant changes in coastal ecosystems due to climate change. However, the underlying mechanism of such blooms remains poorly understood due to the complexity of the system. In this study, the data from numerous observations was used to elucidate the unprecedented phytoplankton blooms in the autumn and winter of 2021 in Laizhou Bay, a typical aquaculture bay in the southern Bohai Sea of China. The abundance of phytoplankton cells increased by more than tenfold in the southern waters compared to that in the same period from 2019 to 2020. The phytoplankton bloom was first observed in winter in the Bohai Sea, with the cell abundance in the southern bay exceeding 108 cells L-1 in December 2021. The diversity and evenness of phytoplankton communities decreased in the southern area. Cerataulina pelagica was the dominant algae, comprising 69 % of the total phytoplankton in October and 99 % in December. In autumn 2021, the largest flood of the Yellow River in recent decades occurred. This was attributed to extreme rainfall events within the river basin. The input of substantial riverine nutrients played a significant role in promoting phytoplankton blooms. Correlation analysis indicated the important cumulative impact of the Yellow River on phytoplankton blooms rather than a direct short-term effect. Numerical modeling results indicated that exceptionally high Yellow River discharge in autumn could significantly affect the entire bay from autumn to the following spring. This study may contribute to understanding the abnormal phytoplankton blooms in coastal waters and provide valuable insights for environmental management in river basins and coastal waters.

Role of brain-derived neurotrophic factor in endotoxaemia-induced acute lung injury.

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), which is a pulmonary manifestation of a systemic reactive inflammatory syndrome, is a serious disease with high mortality, and sepsis is an important risk factor in the development of ALI. Brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor family. It plays an essential role in the regulation of the modification of synaptic efficacy and brain metabolic activity and enhances neuronal survival. However, the role and underlying mechanism of BDNF in sepsis-induced ALI remain unclear. Here, we sought to observe the expression of BDNF in the lung tissues of mice. C57BL/6J mice were divided randomly into two groups: saline (n = 4) and lipopolysaccharide (LPS) (n = 4). We found that BDNF expression was elevated in the lung tissues of septic mice. Furthermore, we found that BDNF colocalized with aquaporin 5, a marker for type I alveolar epithelial cells, by immunofluorescence staining. In addition, we also found that tropomyosin-related kinase B, the specific receptor of BDNF, colocalized with surfactant protein C, a marker for type II alveolar epithelial cells, by immunofluorescence staining. Finally, the present study indicated that BDNF may alleviate excessive LPS-induced autophagy in alveolar epithelial cells. Overall, we hypothesize that BDNF expression increases in the lung tissues of septic mice as a compensatory mechanism to ameliorate sepsis-induced ALI by inhibiting excessive alveolar epithelial cell autophagy.

Atomic-Layer Engineering of La2-xSrxCuO4-La2-xSrxZnO4 Heterostructures.

The fabrication of trilayer superconductor-insulator-superconductor (SIS) Josephson junctions with high-temperature superconductor (HTS) electrodes requires atomically perfect interfaces. Therefore, despite great interest and efforts, this remained a challenge for over three decades. Here, we report the discovery of a new family of metastable materials, La2-xSrxZnO4 (LSZO), synthesized by atomic-layer-by-layer molecular beam epitaxy (ALL-MBE). We show that LSZO is insulating and epitaxially compatible with an HTS compound, La2-xSrxCuO4 (LSCO). Since the "parent" compound La2ZnO4 (LZO) is easier to grow, here we focus on this material as our insulating layer. Growing LZO at very low temperatures to reduce cation interdiffusion makes LSCO/LZO interfaces atomically sharp. We show that in LSCO/LZO/LSCO trilayers, the superconducting properties of the LSCO electrodes remain undiminished, unlike in previous attempts with insulator barriers made of other materials. This opens prospects to produce high-quality HTS tunnel junctions.

PKD2/polycystin-2 inhibits LPS-induced acute lung injury in vitro and in vivo by activating autophagy.

Polycystin-2 (PC2), which is a transmembrane protein encoded by the PKD2 gene, plays an important role in kidney disease, but its role in lipopolysaccharide (LPS)-induced acute lung injury (ALI) is unclear. We overexpressed PKD2 in lung epithelial cells in vitro and in vivo and examined the role of PKD2 in the inflammatory response induced by LPS in vitro and in vivo. Overexpression of PKD2 significantly decreased production of the inflammatory factors TNF-α, IL-1ß, and IL-6 in LPS-treated lung epithelial cells. Moreover, pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, reversed the inhibitory effect of PKD2 overexpression on the secretion of inflammatory factors in LPS-treated lung epithelial cells. We further demonstrated that overexpression of PKD2 could inhibit LPS-induced downregulation of the LC3BII protein levels and upregulation of SQSTM1/P62 protein levels in lung epithelial cells. Moreover, we found that LPS-induced changes in the lung wet/dry (W/D) weight ratio and levels of the inflammatory cytokines TNF-α, IL-6 and IL-1ß in the lung tissue were significantly decreased in mice whose alveolar epithelial cells overexpressed PKD2. However, the protective effects of PKD2 overexpression against LPS-induced ALI were reversed by 3-MA pretreatment. Our study suggests that overexpression of PKD2 in the epithelium may alleviate LPS-induced ALI by activating autophagy.

[Effects of Cow Manure Application on Soil Microbial Community in Farmland].

Although livestock manure serves as an effective source of nutrients for agricultural purposes, it also causes an obvious risk of contamination of heavy metals and pathogens in soil. Soil microorganisms are always considered a sensitive indicator for the change in soil quality. However, knowledge of the effects of cow manure application on soil microbial community is still scarce. Therefore, the characteristics of the soil microbial community and its influencing factors in the farmland with cow manure application were studied using dilution plate counting and high-throughput sequencing. The results showed that the ß diversity of the soil microbial community exhibited a significant difference between the cow manure application site and control site. The application of cow manure increased the relative abundance of Proteobacteria but decreased the relative abundances of Actinobacteria and Gemmatimonadetes. Furthermore, the cow manure application significantly changed the relative abundances of Sphingomonas,PLTA13, MSB-4B10, Halomonas, CCD24, Gaiella, Arthrobacter, Bacillus, and Entotheonellaceae. Both the content of soil water and actinomycete numbers were the important influencing factors of soil microbial community composition in the farmland with cow manure application. The cow manure application increased the relative abundance of pathogenic bacteria including Pseudomonas, Clostridium, and Streptococcus, which may have resulted in potential risks of pathogenic contamination for soil quality. The findings of this study are useful for understanding the effects of cow manure application on soil quality in farmland.

Resting-state brain functional alterations and their genetic mechanisms in drug-naive first-episode psychosis.

Extensive research has established the presence of resting-state brain functional damage in psychosis. However, the genetic mechanisms of such disease phenotype are yet to be unveiled. We investigated resting-state brain functional alterations in patients with drug-naive first-episode psychosis (DFP) by performing a neuroimaging meta-analysis of 8 original studies comprising 500 patients and 469 controls. Combined with the Allen Human Brain Atlas, we further conducted transcriptome-neuroimaging spatial correlations to identify genes whose expression levels were linked to brain functional alterations in DFP, followed by a range of gene functional characteristic analyses. Meta-analysis revealed a mixture of increased and decreased brain function in widespread areas including the default-mode, visual, motor, striatal, and cerebellar systems in DFP. Moreover, these brain functional alterations were spatially associated with the expression of 1662 genes, which were enriched for molecular functions, cellular components, and biological processes of the cerebral cortex, as well as psychiatric disorders including schizophrenia. Specific expression analyses demonstrated that these genes were specifically expressed in the brain tissue, in cortical neurons and immune cells, and during nearly all developmental periods. Concurrently, the genes could construct a protein-protein interaction network supported by hub genes and were linked to multiple behavioral domains including emotion, attention, perception, and motor. Our findings provide empirical evidence for the notion that brain functional damage in DFP involves a complex interaction of polygenes with various functional characteristics.

Brain function mediates the association between low vitamin D and neurocognitive status in female patients with major depressive disorder.

BACKGROUND: Vitamin D is engaged in various neural processes, with low vitamin D linked to depression and cognitive dysfunction. There are gender differences in depression and vitamin D level. However, the relationship between depression, gender, vitamin D, cognition, and brain function has yet to be determined. METHODS: One hundred and twenty-two patients with major depressive disorder (MDD) and 119 healthy controls underwent resting-state functional MRI and fractional amplitude of low-frequency fluctuations (fALFF) was calculated to assess brain function. Serum concentration of vitamin D (SCVD) and cognition (i.e. prospective memory and sustained attention) were also measured. RESULTS: We found a significant group-by-gender interaction effect on SCVD whereby MDD patients showed a reduction in SCVD relative to controls in females but not males. Concurrently, there was a female-specific association of SCVD with cognition and MDD-related fALFF alterations in widespread brain regions. Remarkably, MDD- and SCVD-related fALFF changes mediated the relation between SCVD and cognition in females. CONCLUSION: Apart from providing insights into the neural mechanisms by which low vitamin D contributes to cognitive impairment in MDD in a gender-dependent manner, these findings might have clinical implications for assignment of female patients with MDD and cognitive dysfunction to adjuvant vitamin D supplementation therapy, which may ultimately advance a precision approach to personalized antidepressant choice.

Genetic mechanisms underlying gray matter volume changes in patients with drug-naive first-episode schizophrenia.

Brain structural damage is a typical feature of schizophrenia. Investigating such disease phenotype in patients with drug-naive first-episode schizophrenia (DFSZ) may exclude the confounds of antipsychotics and illness chronicity. However, small sample sizes and marked clinical heterogeneity have precluded definitive identification of gray matter volume (GMV) changes in DFSZ as well as their underlying genetic mechanisms. Here, GMV changes in DFSZ were assessed using a neuroimaging meta-analysis of 19 original studies, including 605 patients and 637 controls. Gene expression data were derived from the Allen Human Brain Atlas and processed with a newly proposed standardized pipeline. Then, we used transcriptome-neuroimaging spatial correlations to identify genes associated with GMV changes in DFSZ, followed by a set of gene functional feature analyses. Meta-analysis revealed consistent GMV reduction in the right superior temporal gyrus, right insula and left inferior temporal gyrus in DFSZ. Moreover, we found that these GMV changes were spatially correlated with expression levels of 1,201 genes, which exhibited a wide range of functional features. Our findings may provide important insights into the genetic mechanisms underlying brain morphological abnormality in schizophrenia.

Numerical Study on Heat-Transfer Characteristics of Convection Melting in Metal Foam under Sinusoidal Temperature Boundary Conditions.

Convection melting in metal foam under sinusoidal temperature boundary conditions is numerically studied in the present study. A multiple-relaxation-time lattice Boltzmann method, in conjunction with the enthalpy approach, is constructed to model the melting process without iteration steps. The effects of the porosity, phase deviation, and periodicity parameter on the heat-transfer characteristics are investigated. For the cases considered in this work, it is found that the effects of the phase deviation and periodicity parameter on the melting rate are weak, but the melting front can be significantly affected by the sinusoidal temperature boundary conditions.

Brain Network Topology and Structural-Functional Connectivity Coupling Mediate the Association Between Gut Microbiota and Cognition.

Increasing evidence indicates that gut microbiota can influence cognition via the gut-brain axis, and brain networks play a critical role during the process. However, little is known about how brain network topology and structural-functional connectivity (SC-FC) coupling contribute to gut microbiota-related cognition. Fecal samples were collected from 157 healthy young adults, and 16S amplicon sequencing was used to assess gut diversity and enterotypes. Topological properties of brain structural and functional networks were acquired by diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (fMRI data), and SC-FC coupling was further calculated. 3-Back, digit span, and Go/No-Go tasks were employed to assess cognition. Then, we tested for potential associations between gut microbiota, complex brain networks, and cognition. The results showed that gut microbiota could affect the global and regional topological properties of structural networks as well as node properties of functional networks. It is worthy of note that causal mediation analysis further validated that gut microbial diversity and enterotypes indirectly influence cognitive performance by mediating the small-worldness (Gamma and Sigma) of structural networks and some nodal metrics of functional networks (mainly distributed in the cingulate gyri and temporal lobe). Moreover, gut microbes could affect the degree of SC-FC coupling in the inferior occipital gyrus, fusiform gyrus, and medial superior frontal gyrus, which in turn influence cognition. Our findings revealed novel insights, which are essential to provide the foundation for previously unexplored network mechanisms in understanding cognitive impairment, particularly with respect to how brain connectivity participates in the complex crosstalk between gut microbiota and cognition.

Short-term changes in algal blooms and phytoplankton community after the passage of Super Typhoon Lekima in a temperate and inner sea (Bohai Sea) in China.

Extensive multi-species harmful algal blooms (HABs) were triggered by Super Typhoon Lekima in Laizhou Bay (Bohai Sea) in August 2019. After conducting two field cruises before and after the typhoon passage, we employed both high-performance liquid chromatography (HPLC)-pigment and microscopic methods to study the changes in the phytoplankton community and biomass. Following the passage of Lekima, the average surface salinity decreased, while dissolved inorganic nitrogen and dissolved silicate concentrations increased in the study area. The phytoplankton abundance and Chl a significantly increased after the typhoon event. Post-typhoon, the highest abundance values of Pseudo-nitzschia spp., Noctiluca scintillans, and Coscinodiscus spp. reached 106 cells/L and those of Bacillaria paxillifera, Ceratium spp., and Gymnodinium catenatum were in the order of 105 cells/L. HPLC-pigment CHEMTAX analysis showed that the biomass (Chl a) of dinoflagellates, diatoms, cryptophytes, chlorophytes, and haptophytes increased significantly after the typhoon. The increase in Chl a concentration was mainly attributable to large-sized phytoplankton, which are mostly diatoms and dinoflagellates. This study highlights that typhoons may cause HABs by introducing large amounts of freshwater and nutrients and change the phytoplankton community in a temperate and inner bay.

Visualizing the unusual spectral weight transfer in DyBa2Cu3O7-δ thin film.

We report a Spectroscopic Imaging Scanning Tunneling Microscopy (SI-STM) study of a DyBa2Cu3O7-δ (DBCO) thin film (Tc ~ 79 K) synthesized by the molecular beam epitaxy (MBE). We observed an unusual transfer of spectral weight in the local density of states (LDOS) spectra occurring only within the superconducting gap. By a systematic control of the tip-sample distance and the junction resistance, we demonstrate that the spectral weight transfer can be switched at a nano-meter length scale. These results suggest that an interaction between the STM tip and the sample alters the electronic configurations in the film. This probably originates from a combination of an intrinsic band bending at the interface between the surface and the bulk, and a tip-induced band bending. These results may open a new avenue for band engineering and applications of thin films of high-Tc cuprates.

Genetic Architecture Underlying Differential Resting-state Functional Connectivity of Subregions Within the Human Visual Cortex.

The human visual cortex is a heterogeneous entity that has multiple subregions showing substantial variability in their functions and connections. We aimed to identify genes associated with resting-state functional connectivity (rsFC) of visual subregions using transcriptome-neuroimaging spatial correlations in discovery and validation datasets. Results showed that rsFC of eight visual subregions were associated with expression measures of eight gene sets, which were specifically expressed in brain tissue and showed the strongest correlations with visual behavioral processes. Moreover, there was a significant divergence in these gene sets and their functional features between medial and lateral visual subregions. Relative to those associated with lateral subregions, more genes associated with medial subregions were found to be enriched for neuropsychiatric diseases and more diverse biological functions and pathways, and to be specifically expressed in multiple types of neurons and immune cells and during the middle and late stages of cortical development. In addition to shared behavioral processes, lateral subregion associated genes were uniquely correlated with high-order cognition. These findings of commonalities and differences in the identified rsFC-related genes and their functional features across visual subregions may improve our understanding of the functional heterogeneity of the visual cortex from the perspective of underlying genetic architecture.

Metabolic and Neural Mechanisms Underlying the Associations Between Gut Bacteroides and Cognition: A Large-Scale Functional Network Connectivity Study.

There is a proof-of-concept that microbial metabolites provide a molecular connection between the gut and the brain. Extensive research has established a link between gut Bacteroides and human cognition, yet the metabolic and neural mechanisms underlying this association remain largely unknown. Here, we collected fecal samples, resting-state functional MRI, and cognitive data from a large and homogeneous sample of 157 healthy young adults. 16S rRNA gene sequencing was conducted with abundances of Bacteroides and metabolic pathways quantified by species annotation and functional prediction analyses, respectively. Large-scale intra- and internetwork functional connectivity was measured using independent component analysis. Results showed that gut Bacteroides were related to multiple metabolic pathways, which in turn were associated with widespread functional network connectivity. Furthermore, functional network connectivity mediated the associations between some Bacteroides-related metabolic pathways and cognition. Remarkably, arginine and proline metabolism, phenylalanine metabolism, and biosynthesis of unsaturated fatty acids act as the key metabolic pathways that are most contributive, and the executive control and sensorimotor systems contribute most strongly at the neural level. Our findings suggest complex poly-pathway and poly-network processes linking Bacteroides to cognition, more generally yielding a novel conceptualization of targeting gut Bacteroides as an intervention strategy for individuals with cognitive impairment.