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Sebastes schlegelii is a cold temperate ovoviviparous fish found near the seabed layer and is widely distributed in the Yellow Sea and Bohai Sea of China, as well as in the coasts of South Korea and Japan. It is characterized by its tender meat, delicious taste, rich nutrition, and high medicinal value, thus it is an economically important marine fish species in the northern coastal areas of China. In recent years, deep-water cage cultures have rapidly developed in China. Among the economically important fish species suitable for cage culture in northern China, S. schlegelii is the most important local breed with excellent quality and characteristics. However, with the expansion of the scale of the aquaculture industry, aquaculture diseases including those caused by Vibrio harveyi, Vibrio anguillarum, and Photobacterium damselae subsp. damselae, occur frequently. The authors isolated and identified a dominant pathogenic bacterium, the P5W of V. harveyi, from the lesions of diseased S. schlegelii and studied the response of S. schlegelii to V. harveyi infection. Multitissue transcriptome analysis screened the immune differential gene protein kinase B. Protein kinase B, also known as Akt protein, is a serine or threonine protein kinase, which mainly conducts signal transduction by phosphorylating other proteins. It plays an important role in various biological processes such as cell metabolism, transcriptional regulation, cell cycle regulation, immune defense, and embryonic development. Many studies have shown that during viral infection of cells, the Akt pathway is activated, thereby inhibiting viral proliferation. To clarify the sequence information, evolutionary characteristics, and biological functions of the Akt gene in S. schlegelii and to understand the immune response mechanism of S. schlegelii to bacterial invasion, the full-length cDNA of the SsAkt gene was obtained using molecular biology, and the sequence characteristics, tissue expression rules of the gene, and the response rules to Micrococcus luteus and V. anguillarum were studied. The results showed that the length of the open reading frame was 1 440 bp. The predicted relative molecular mass of the SsAkt protein was 55.80 kDa and the isoelectric point was 5.64. Sequence analysis revealed that the SsAkt protein contains three conserved domains: the PH domain (residues 6–109), serine/threonine protein kinase catalytic (S_TKc) domain (residues 148–405), and serine/threonine protein kinase (S_TK_X) domain (residues 406–475). The conserved amino acid site appears in the center of the S_TKc domain and at the end of the S_TK_ X domain: Thr305 and Ser472. Homologous alignment showed that the amino acid sequence of this gene was highly conserved among different species. Phylogenetic tree analysis showed that SsAkt is closely related to Akt in vertebrates, such as Sebastes umbrosus, Lates calcarifer, Larimichthys crocea, and Cyprinus carpio. The relative expression of SsAkt in different tissues of S. schlegelii was detected by real-time fluorescence quantitative PCR. The results showed that SsAkt was expressed in all tested healthy tissues of S. schlegelii, which indicated the relative expression of the SsAkt gene in S. schlegelii. This expression has distinct tissue specificity. The expression of SsAkt in the kidney is the highest, and in the blood and brain, it is also higher than that in other tissues. Therefore, it is speculated that higher expression of SsAkt in the kidney and brain is closely related to immune defense, neurodevelopment, and other processes. To study the role of SsAkt in the immune response of S. schlegelii, we designed a bacterial challenge experiment. The results showed that the transcription level of SsAkt changed significantly, and the relative expression of SsAkt in the three tissues increased after stimulation with M. luteus and V. anguillarum compared with the control group (PBS). After infection with M. luteus, its expression only increased sharply in the kidney, whereas its expression increased slowly in the blood and liver. In the experimental group infected with V. anguillarum, the expression increased significantly in the liver and kidney, and the two relative expression peaks in the kidney occurred at 12 h and 72 h after infection, respectively. The results revealed that the SsAkt gene may play an important role in the immune defense of S. schlegelii, which can further enrich the sequence information and evolutionary data of the Akt gene in marine fish and provide reference materials for an in-depth study of the biological function of this gene. In follow-up experiments, we will explore the specific mechanism of SsAkt in the innate immune defense of S. schlegelii to provide theoretical guidance for the study of the immune signaling pathway of S. schlegelii and to lay a theoretical foundation for revealing the role of SsAkt in other important biological functions in growth and development.

Marine fish are rich in minerals (calcium and iron), vitamins (riboflavin and niacin), nutrients that are beneficial for brain (fatty acids), docosahexaenoic acid that prevent cardiovascular and cerebrovascular diseases, and are an important source of protein for humans. In recent years, the nexus between the increased demand of high-quality protein and the decrease in marine fishery resources resulted in the intensification of marine farming. However, this high-density farming has led to various bacterial diseases frequently due to lack of disease control methods, which has caused economic losses in the farming industry and impeded the healthy development of the industry. Therefore, it is particularly important to reduce the rates of bacterial diseases and improve the survival rate of cultured fish. It is of particular concern on how to maintain intestinal health of cultured fish under this farming method. Probiotics, a kind of living microorganisms, are beneficial to the health of the host. In the 1980s, probiotics have been viewed as an environmentally friendly and effective product in aquaculture; they improve the host health by influencing intestinal microbiota and nonspecific immunity to increase disease resistance ability. Moreover, they can be used as an ideal substitute for antibiotics in aquaculture production. Probiotics from Bacillus, lactic acid bacteria, saccharomyces, and nitrobacteria are diverse, and the function of each varies widely. As the typical representative of probiotics, lactic acid bacteria, may inhibit the growth of pathogens by the production of its metabolites, such as lactic acid, acetic acid, peroxide hydrogen, and bacteriocin. Lactic acid bacteria are also able to balance intestinal microecological imbalance and maintain intestinal microbiota balance when the intestinal microbiota contains pathogenic bacteria or the host is treated with antibiotics. Bacillus is an aerobic or facultative anaerobic gram-positive bacteria, which is stable, possesses strong stress resistance and high resurrection rate, and can produce various macromolecules, such as proteases and amylases and thus can improve the digestive function of the host by promoting the absorption of nutrients. Furthermore, as a non-specific immune antigen, Bacillus can improve the immune resistance of the host by stimulation of the components of cells or cell walls. The application of lactic acid bacteria and Bacillus has demonstrated favorable results, but this has been limited in marine fish culture because the non-fish origin of some strains and the different specificity of strains for different fish species or the same growth stage make their application difficult. Thus, it is essential to develop marine fish-derived probiotics, analyze their characteristics, define growth conditions, verify safety effects, and determine dosage and methods for their administer in marine fish culture. In this study, probiotics from marine fish were screened for the development of microbial ecological agents; 80 strains of culturable bacteria were obtained by separating bacteria from the mucosa samples of the digestive tract of wild Sebastes schlegelii and Hexagrammos otakii. The enzyme-producing ability of the strains was determined using a selective culture medium. The common pathogenic bacteria infecting marine fish were selected as indicator bacteria to determine the antibacterial activity of the isolated strains. Two potential probiotics, strains TS2 and TH8, were screened, and their physiological and biochemical identification, 16S rDNA sequence, growth characteristics, and host safety were determined. The results showed that TS2 had the strongest ability to hydrolyze starch, protein, and fat, and its sterile culture products could significantly inhibit the growth of Vibrio anguillarum, V. parahaemolyticus, V. Harvey, and Pseudoalteromonas nigrifaciens. TH8 has the strongest ability to hydrolyze protein and fat, and its sterile culture products could significantly inhibit the growth of V. anguillarum, V. alginolyticus, V. parahaemolyticus, P. nigrifaciens, Aeromonas hydrophila, Staphyloccocus aureus, and Escherichia coli. According to the analysis of the physiological and biochemical characteristics of the bacteria and 16S rDNA sequence alignment analysis, strain TS2 was identified as Bacillus subtilis and strain TH8 as Vagococcus fluvialis. Strain TS2 showed significant growth at 15–40 ℃, sodium chloride concentration of 0–0.08 g/L, and pH of 5–9; it entered the logarithmic phase after 6 h and the stable phase after 26 h. TH8 grew rapidly at 20–40 ℃, sodium chloride concentration of 0–0.08 g/L, and pH of 5–12; it entered the logarithmic phase after 2 h and the stable phase after 14 h. The safety of strains TS2 and TH8 was analyzed on a homologous host, and it was found that the strains were relatively safe for the homologous host at the concentration of 108 CFU/mL. The screened B. subtilis TS2 and V. fluvialis TH8 strains have a strong enzyme production ability and inhibit the growth of various pathogens by their metabolites; they have the following advantages: Wide temperature and salt tolerance, acid and alkali resistance, and fast growth speed. Thus, they could be considered as potential probiotic candidates for the development of microbial pharmaceuticals and can be used in more applications in marine aquaculture.

A large number of tidal flats around Pulandian Bay have gradually been developed into cofferdam ponds of Sea Cucumber and shellfish, which have resulted in a series of problems such as shrinking natural coastlines and blocking water exchange channels in Pulandian Bay. One of the important means is to restore the hydrologic and hydrodynamic conditions by widening the water exchange channel in this Bay. In this paper, the MIKE21 model was used to simulate the distribution characteristics of tidal current in the Pulandian Bay. Based on the simulation and verification for tidal levels and tidal velocities, the hydrodynamics of Pulandian Bay were compared under the different conditions before and after the project. The results showed that the increase of tidal current velocity was about 0.3 ~ 0.4 m/s inside of the culture cofferdam removal area, and the removal of the cofferdam had some influence on these areas within 1.5 km. However, it had no effect on the flow field of other areas far away from Pulandian Bay in distant Jinzhou Bay and the open sea. The removal of the culture cofferdam broadened the water areas of Pulandian Bay and increased the ebb and flow velocities in this bay, the tidal prism was increased by 8.535% after the project. The flow field in the north side of removal area showed obvious tidal flat characteristics, which was beneficial to the nutrient exchange for habitat of salt marsh plants and marine life.

Aiming at the problem that is difficult to accurately identify rolling bearing faults， a fault diagnosis method based on sensitive components and Multi Convolution Pooling Group （MCPG） is proposed. Firstly， the Empirical Mode Decomposition （EMD） is used to decompose the original signal into multiple Intrinsic Mode Function（IMF）， and the discrete Fréchet distance is used as the measurement index， the fault sensitive components are selected as the fault data sources representing different fault types. Then， a MCPG deep neural network architecture is proposed， and sensitive data sources are used to train and test the model to achieve the data-driven bearing fault diagnosis. Through experimental verification， it is proved that the method has good recognition effect on different types of vibration data （different speeds， different damage types， different damage degrees）.

Background Non-alcoholic fatty liver disease has showed a high prevalence and a increasing trend especially towards younger age. It is of great public health significance to reduce damage through early detection of NAFLD in physical examination and intervention in time. Objective To investigate the detection rate of NAFLD in the Beijing physical examination population from 2018 to 2021, and analyze its related influencing factors. Methods People who received physical examinations at the Beijing Physical Examination Center from 2018-01-01 to 2021-12-31 were selected based on the inclusion criteria, the results of physical examination, laboratory examination, and liver ultrasonography were collected for analysis. Univariate analysis was performed using t-test, Mann-Whitney U test and Chi-square test. Multivariate Logistic regression was used to explore the influencing factors of NAFLD. Results A total 325 726 people were included in the study, of which 108 512 cases of NAFLD were detected, with a detection rate of 33.31%. The results of liver ultrasonography revealed that the number of mild, moderate and severe NAFLD detections were 74 062, 33 281 and 1 169 cases, accounting for 68.25%, 30.67% and 1.08% of the detection population, respectively. The detection rate of NAFLD was higher in males than females (χ2=17 518.893, P420 μmol/L, SUAfemale>360 μmol/L: OR=2.067) were influencing factors for NAFLD (P