Application of multi-omics combined with bioinformatics techniques to assess salinity stress response and tolerance mechanisms of Pacific oyster (Crassostrea gigas) during depuration.

Depuration is a vital stage to ensure the safety of oyster consumption, and salinity had a great impact on the environmental adaptability of oysters, but the underlying molecular mechanism was poorly understood during depuration stage. Here, Crassostrea gigas was depurated for 72 h at different salinity (26, 29, 32, 35, 38 g/L, corresponding to ±20%, ±10% salinity fluctuation away from oyster's production area) and then analyzed by using transcriptome, proteome, and metabolome combined with bioinformatics techniques. The transcriptome showed that the salinity stress led to 3185 differentially expressed genes and mainly enriched in amino acid metabolism, carbohydrate metabolism, lipid metabolism, etc. A total of 464 differentially expressed proteins were screened by the proteome, and the number of up-regulated expression proteins was less than the down-regulated, indicating that the salinity stress would affect the regulation of metabolism and immunity in oysters. 248 metabolites significantly changed in response to depuration salinity stress in oysters, including phosphate organic acids and their derivatives, lipids, etc. The results of integrated omics analysis indicated that the depuration salinity stress induced abnormal metabolism of the citrate cycle (TCA cycle), lipid metabolism, glycolysis, nucleotide metabolism, ribosome, ATP-binding cassette (ABC) transport pathway, etc. By contrast with Pro-depuration, more radical responses were observed in the S38 group. Based on the results, we suggested that the 10% salinity fluctuation was suitable for oyster depuration and the combination of multi-omics analysis could provide a new perspective for the analysis of the mechanism changes.

EPA-Enriched Phospholipids Alleviate Renal Interstitial Fibrosis in Spontaneously Hypertensive Rats by Regulating TGF-ß Signaling Pathways.

Hypertensive nephropathy is a chronic kidney disease caused by hypertension. Eicosapentaenoic acid (EPA) has been reported to possess an antihypertensive effect, and our previous study suggested that EPA-enriched phospholipid (EPA-PL) had more significant bioactivities compared with traditional EPA. However, the effect of dietary EPA-PL on hypertensive nephropathy has not been studied. The current study was designed to examine the protection of EPA-PL against kidney damage in spontaneously hypertensive rats (SHRs). Treatment with EPA-PL for three weeks significantly reduced blood pressure through regulating the renin-angiotensin system in SHRs. Moreover, dietary EPA-PL distinctly alleviated kidney dysfunction in SHRs, evidenced by reduced plasma creatinine, blood urea nitrogen, and 24 h proteinuria. Histology results revealed that treatment of SHRs with EPA-PL alleviated renal injury and reduced tubulointerstitial fibrosis. Further mechanistic studies indicated that dietary EPA-PL remarkably inhibited the activation of TGF-ß and Smad 3, elevated the phosphorylation level of PI3K/AKT, suppressed the activation of NF-κB, reduced the expression of pro-inflammatory cytokines, including IL-1ß and IL-6, and repressed the oxidative stress and the mitochondria-mediated apoptotic signaling pathway in the kidney. These results indicate that EPA-PL has potential value in the prevention and alleviation of hypertensive nephropathy.

Effect of salinity stress on respiratory metabolism, glycolysis, lipolysis, and apoptosis in Pacific oyster (Crassostrea gigas) during depuration stage.

BACKGROUND: Depuration is an important process performed to ensure the safety of oyster consumption, and the effect of salinity stress on physiological and ecological characteristics of oyster remains unknow. In this study, the simulated depuration of Crassostrea gigas was performed with the salinities varying from ±10% to ±20% away from that of production area (26, 28, 32, 35, and 38 g L-1 ), as well as respiratory metabolism, glycolysis, lipolysis, and apoptosis were analyzed. RESULTS: (i) The oxygen consumption rate, ammonia discharge rate and enzyme activities related to respiratory metabolism were decreased significantly at salinities of 38 g L-1 , indicating that salinity stress triggered the abnormal respiratory metabolism of C. gigas, further, glycolysis was enhanced. (ii) Glycogen decomposition, lactic acid increase, and fatty acid composition modifications were caused by adenosine monophosphate (AMP)-activated protein kinase (AMPK) -mediated during salinity stress. (iii) There was a clear decrease of the condition index and meat yield of C. gigas after 72 h of depuration, especially in salinity 38 g L-1 . (iv) Salinity stress would lead to the increase of cytochrome c levels, then cause apoptosis of C. gigas, while heat shock protein 70 (HSP70) would interfere with this process. CONCLUSION: Salinity stress had a significant effect on the physiological and ecological response of C. gigas during the depuration process, including respiratory metabolism, glycolysis, lipolysis, and apoptosis. In general, the low depuration salinity fluctuation (±10%) is helpful to maintain quality of C. gigas, as well as the optimal depuration time was 48 h. © 2021 Society of Chemical Industry.

Temperature effects on the nutritional quality in Pacific oysters (Crassostrea gigas) during ultraviolet depuration.

BACKGROUND: Oysters are mainly consumed in the raw form, so it is important to get rid of bacteria and other harmful substances. Ultraviolet (UV) sterilization depuration is a commonly used method and does not produce chemical residues or act directly on shellfish, resulting in minimal adverse effects on flavor. This study simulated the industrial depuration process using UV sterilization to depurate Pacific oysters (Crassostrea gigas). The effects of different temperatures (15, 20, and 25 °C) on the quality and taste components of C. gigas were investigated by measuring changes in physiological and biochemical indexes in C. gigas tissue samples. RESULTS: At the end of depuration, no oyster mortality occurred, but it was up to 55% at 25 °C at 84 h. Glycogen content decreased the most at 25 °C at 48 h. The fatty acid content was higher at 20 and 25 °C. Succinic acid content decreased significantly and was higher at 20 and 25 °C at 48 h with no significant difference. Total free amino acid (FAA) content was significantly higher at 20 °C, however, there were no significant differences in nucleotide content at any temperature at 48 h. Adenylate energy charge (AEC) values decreased, with higher values at 15 and 25 °C, and equivalent umami concentration (EUC) values increased, with higher values at 20 and 25 °C. CONCLUSION: Considering the changes in flavor substances and mortality rate, 20 °C is the appropriate temperature for UV sterilization depuration of C. gigas to produce better edible quality. © 2021 Society of Chemical Industry.

Docosahexaenoic Acid-Acylated Astaxanthin Esters Exhibit Superior Renal Protective Effect to Recombination of Astaxanthin with DHA via Alleviating Oxidative Stress Coupled with Apoptosis in Vancomycin-Treated Mice with Nephrotoxicity.

Prevention of acute kidney injury caused by drugs is still a clinical problem to be solved urgently. Astaxanthin (AST) and docosahexaenoic acid (DHA) are important marine-derived active ingredients, and they are reported to exhibit renal protective activity. It is noteworthy that the existing forms of AST in nature are mainly fatty acid-acylated AST monoesters and diesters, as well as unesterified AST, in which DHA is an esterified fatty acid. However, no reports focus on the different bioactivities of unesterified AST, monoesters and diesters, as well as the recombination of DHA and unesterified AST on nephrotoxicity. In the present study, vancomycin-treated mice were used to evaluate the effects of DHA-acylated AST monoesters, DHA-acylated AST diesters, unesterified AST, and the recombination of AST and DHA in alleviating nephrotoxicity by determining serum biochemical index, histopathological changes, and the enzyme activity related to oxidative stress. Results found that the intervention of DHA-acylated AST diesters significantly ameliorated kidney dysfunction by decreasing the levels of urea nitrogen and creatinine, alleviating pathological damage and oxidative stress compared to AST monoester, unesterified AST, and the recombination of AST and DHA. Further studies revealed that dietary DHA-acylated AST esters could inhibit the activation of the caspase cascade and MAPKs signaling pathway, and reduce the levels of pro-inflammatory cytokines. These findings indicated that the administration of DHA-acylated AST esters could alleviate vancomycin-induced nephrotoxicity, which represented a potentially novel candidate or therapeutic adjuvant for alleviating acute kidney injury.

Evaluation indicators of Ruditapes philippinarum nutritional quality.

To access the nutritional quality of the Ruditapes philippinarum, a comprehensive quality evaluation procedure is always important to be established. In this study, fifteen nutritional quality evaluation indicators of R. philippinarum from 7 months were analyzed, and the most important indicators were determined using a combination of multiple chemometric methods such as correlation analysis (CA), principal component analysis (PCA), and system cluster analysis (SCA). Significant differences in nutritional quality were observed across the 7 months, as per the ANOVA results (P < 0.05). The coefficient of variation values for the fifteen evaluation indicators for R. philippinarum across 7 months was 1.67-43.47%. The CA results revealed that some indicators were correlated to each other within a certain range. Four principal components with eigen-values > 1 were obtained with PCA, and a cumulative contribution of 92.11% was achieved. In addition, four essential quality indicators were extracted using SCA. Using these four indicators, a simple and efficient procedure can be applied for quality control in aquaculture.

Protective Effects of Colivelin Against Alzheimer's Disease in a PDAPP Mouse Model.

BACKGROUND: Alzheimer's disease (AD) is characterized with progressive memory loss and severe cognitive impairments, which affect everyday life and human health in the elderly. It is required that an effective and safe protective reagent against AD should be developed. It has been reported that humanin (HN) exerts neuroprotective effects against AD. In this study, we investigated the effect of a novel and more effective HN derivative, Colivelin (CLN) on AD. METHODS: PDAPP(V717I) transgenic AD model mice (derived from parental C57/BL6 mice) were used in our study as AD model. Morris water maze test was used to test the memory impairment of AD mice and the levels of Aß40 and Aß42 were determined by an Elisa assay. We used an Immunohistochemistry and Immunofluorescence staining method to check the GFAP and MAP2 positive cells, and TUNEL to assess the apoptotic cells. Western blot assay was used to check the expression and phosphorylation level of p38. RESULTS: We found that CLN improved the memory impairment induced by AD and reduced the deposit of Aß40 and Aß42. CLN also inhibited cell apoptosis and activation of caspase 3 in brain tissues of AD mice. Inflammation in AD mice was alleviated by CLN treatment, including the accumulation of GFAP positive cells and the inflammatory cytokines. With both structure of AGA-HNG and ANDF, CLN exhibited significantly stronger effects than synchronously administration of AGA-HNG and ADNF, suggesting CLN as a novel potential effective therapeutic reagent for AD patients. Finally, we found that CLN inhibited phosphorylation of p38 in AD mice and p38 inhibitor, SB203580 weakened the therapeutic effect of CLN. CONCLUSION: CLN effectively improved the memory dysfunction in PDAPP mice, and our data suggests CLN as a novel and effective reagent which may have great potentials in AD therapy.

Photo-assisted splitting of dielectric microdroplets in a LN-based sandwich structure.

We demonstrate an active and controllable photo-assisted splitting of dielectric microdroplets inside a LiNbO3-based sandwich structure by utilizing the pyroelectric and photovoltaic effects of LiNbO3 crystals. Basing on electrostatic simulation results, the mechanism of the photo-assisted splitting is explained; meanwhile, the microdoplet pre-polarizing and the inclined electrostatic force induced by the photovoltaic charges inside the sandwich structure are emphasized. We also study the dependence of the splitting part size on the substrate temperature variation, the irradiation intensity, and the duration. Featured dependence is found to follow the theoretical curve predicted by the compensation between the photo-excited and bound surface charges.

Changes in Flavor-Related Biomarkers in Pacific Oysters (Crassostrea gigas) Following Microplastic Exposure.

Microplastics have been an emerging threat to filtering species and the ingestion and impacts of microplastics on oysters are a cause for concern. However, much remains unknown about the effects of microplastics on flavor-related biomarkers in oysters. Herein, a laboratory microplastic exposure with concentrations of 1, 10, and 100 mg/L for 15 days was performed to investigate the impacts of microplastics on the flavor parameters of oysters. Exposure to microplastics changed the odor characteristics of oysters. Microplastic exposure had minor effects on the fatty acid composition; however, significant alterations in free amino acids and nucleotides were observed under the 1 and 10 mg/L exposure groups, respectively. The overall results indicated 10 mg/L of microplastic exposure significantly increased the equivalent umami value of oysters. These findings stressed the effects of microplastics on oysters and would be an important reference for the assessment of the potential risks associated with microplastics in marine edible species.

Astaxanthin Esters as Functional Food: A Review of Their Nutrition, Phytochemical Structure, Biological Features, and Food Industry Prospects.

Astaxanthin (AST), mainly found in algae and shrimp, is a liposoluble ketone carotenoid with a wide range of biological activities and is commonly used in healthcare interventions and cosmetics. AST has a long chain of conjugated double bonds with hydroxyl and ketone groups at both ends, enabling it to form astaxanthin esters (AST-Es) through esterification with fatty acids. The fatty acid structure of AST plays a key role in the stability, antioxidant activity, and bioavailability of AST-Es. Antarctic krill (Euphausia superba) and blood-red algae Haematococcus Pluvialis (H pluvialis)-derived AST-Es exhibit strong antioxidant activity and numerous biological activities, such as improving insulin resistance, preventing Parkinson's disease, regulating intestinal flora, and alleviating inflammatory bowel disease. This review discusses the significance of AST-Es as functional food ingredients, highlighting their nutritional value, phytochemical structure, biological activities, and potential applications in the food industry.

Effects of liquid nitrogen freezing at different temperatures on the quality and flavor of Pacific oyster (Crassostrea gigas).

This study aimed to evaluate the effects of different liquid nitrogen freezing (LNF) temperatures (-20, -40, -60, -80, and -100 °C) on the water holding capacity, texture, microstructure, and flavor of Crassostrea gigas (C. gigas). The results showed that -40 °C LNF, -60 °C LNF, and -80 °C LNF improved the water holding capacity of C. gigas (P < 0.05); -60 °C LNF and -80 °C LNF could effectively maintain the hardness of the body trunk and adductor muscles. Compared with -20 °C refrigerator freezing (RF), the LNF group could form smaller ice crystals and thus reduce the damage to the muscle cell structure damage, especially LNF at -80 °C. Gas chromatography-ion mobility spectrometry (GC-IMS) and e-nose results indicated that -80 °C LNF maintained the flavor profile of few aldehydes and alcohols compared to other freezing groups. Therefore, -80 °C LNF effectively improved the quality and maintain the flavor characteristics of frozen C. gigas.

An overview of microplastics in oysters: Analysis, hazards, and depuration.

Microplastic pollution has become an emergent global environmental issue because of its ubiquitous nature and everlasting ecological impacts. In marine ecosystems, microplastics can serve as carriers to absorb various contaminants and the ingestion of microplastics in oysters is of concern because they can induce several adverse effects. The analytical process of microplastics in oysters commonly consists of separation, quantification, and identification. Quantification of microplastics is difficult since information regarding the analytical methods is incoherent, therefore, standard microplastic analytical methods for shellfish should be established in the future. The depuration process can be used to reduce the level of microplastics in oysters to ensure safe consumption of oysters and longer depuration time facilitates improved depuration efficacy. In summary, this review aims to help better understand microplastic pollution in oysters and provide useful suggestions and guidance for future research.

Evaluation of microalgae diets on flavor characteristics of Pacific oysters (Crassostrea gigas) during fattening.

Due to the large breeding density and the influence of seasonal changes, the quality of oysters declined. Oysters are often fattened with specific microalgae before sale to improve their quality. Here, the purpose of this study was to study the effects of different microalgae diets on the flavor characteristics of Crassostrea gigas (C. gigas) after three weeks of fattening. The result showed that there was a certain correlation between the fatty acid composition of C. gigas and microalgae. The equivalent umami concentration values of C. gigas fed with Chlorella vulgaris and Pavlova viridis (5.34 and 4.91 g/100 g, respectively) were significantly higher than that of the control group. Gas chromatography-ion mobility spectrometry analysis showed 48 volatile organic compounds, and the principal component analysis plot showed an obvious separation between the C. gigas. These results indicated that diets had a significant effect on the flavor components of oysters.

Molecular mechanism of protein dynamic change in Pacific oyster (Crassostrea gigas) during depuration at different salinities uncovered by mass spectrometry-based proteomics combined with bioinformatics.

Salinity stress during depuration of Pacific oysters (Crassostrea gigas) leads to degradation in quality; therefore, an understanding of the molecular mechanisms regulating dynamic changes during depuration is needed. Here, C. gigas was depurated for 72 h at salinities ranging from 26 to 38 g/L, a ± 10-20% fluctuation from that in the production area, and the gill proteomes were analyzed by sequential window acquisition of all theoretical fragment ion mass spectra (SWATH-MS). Of the 1218 proteins analyzed, 241 were differentiating proteins (DPs). Salinity stress led to increased levels of DPs associated with glycolysis and the extracellular matrix-receptor interaction pathway, and decreased levels of DPs associated with the citric acid cycle, lipid metabolism, genetic information processing, and cell transformation, especially in oysters exposed to 38 g/L salinity (+20%). Controlling salinity fluctuation within ± 10% of the production area during depuration was conducive to maintaining quality in C. gigas.

Sprayer boom height measurement in wheat field using ultrasonic sensor: An exploratory study.

In order to explore the influencing factors and laws of ultrasonic sensor detecting wheat canopy height, designed an ultrasonic sensor detection height test platform with speed adjustable function. Taking step surface, bare soil and wheat canopy as the research objects, a canopy height calculation method based on K-mean clustering is proposed, and the response characteristics of ultrasonic detection to three media under different operating speeds are explored. Firstly, the step detection test results show that the average detection error of ultrasonic sensor is 1.35%. When the sensor detection distance is switched at the step, with the increase of detection distance, the actual offset at the step increases first and then tends to be stable, and the maximum offset is 10.4cm. The test results of bare soil slope show that the relative error between the detection distance and the manual measurement distance is 1.4% under quasi-static conditions. The leading or lagging of detection under moving conditions is affected by multiple factors such as terrain undulation, speed and detection range. The detection test results of wheat canopy showed that the detection distance was larger than the manual measurement distance, and the smaller the canopy density, the greater the detection error and error variance. When the moving speed is 0.3m/s-1.2m/s, the average detection deviation of the ultrasonic sensor for five kinds of wheat canopy density is 0.14m, and the maximum variance of the detection deviation is 0.07cm2. In this paper, the research on the response characteristics of ultrasonic to the detection of bare soil and sparse canopy in wheat field can provide technical support for the detection of crop canopy in the field.

Docosahexaenoic acid-acylated curcumin diester alleviates cisplatin-induced acute kidney injury by regulating the effect of gut microbiota on the lipopolysaccharide- and trimethylamine-N-oxide-mediated PI3K/Akt/NF-κB signaling pathway in mice.

An increasing number of studies have reported the effects of curcumin (Cur) and docosahexaenoic acid (DHA) on alleviating acute kidney injury (AKI). In this work, we have performed a comparative investigation to determine the effect of dietary DHA-acylated Cur esters, ester derivatives of Cur, and recombination of curcumin and DHA on alleviating acute kidney injury in a mouse model induced by a single intraperitoneal injection with cisplatin (20 mg kg-1). The results showed that the DHA-acylated Cur diesters significantly decreased the abnormally increased blood urea nitrogen, creatinine, lipopolysaccharide (LPS) and trimethylamine-N-oxide (TMAO) in serum caused by AKI. Histopathological results confirmed that DHA-acylated Cur diesters clearly reduced the degree of renal tubular injury. The renal protective effect of the DHA-acylated Cur diester was better than that of the monoester and the recombination of Cur and DHA. Notably, we found that the DHA-acylated Cur diester treatment remarkably changed the relative abundance of microbiota related to LPS and TMAO/trimethylamine (TMA) metabolism. Moreover, dietary DHA-acylated Cur diesters clearly reduced the MDA content and elevated GSH levels in the kidney of AKI mice, as well as changed the fatty acid composition in the kidney. Further mechanism studies showed that DHA-acylated Cur diesters significantly inhibited inflammation, apoptosis and oxidative stress by preventing the LPS and TMAO-mediated PI3K/Akt/NF-κB signaling pathway. The above results indicate that DHA-acylated Cur diesters are a potentially novel candidate or targeted dietary pattern to prevent and treat drug-induced acute kidney injury.

The flavor profile changes of Pacific oysters (Crassostrea gigas) in response to salinity during depuration.

The effect of salinity on taste and odor characteristics of Pacific oyster (Crassostrea gigas) during depuration was investigated in this study. In combination with free amino acids (FAAs), 5'-nucleotides, and organic acids, electronic tongues were measured to evaluate the changes in taste-related compounds. Gas chromatography-ion mobility spectrometry (GC-IMS) and electronic nose were used to analyze the odor compounds of C. gigas at different depuration salinities. The results showed that bitter substances in C. gigas significantly decreased as salinity decreased. The equivalent umami concentration (EUC) was highest at a salinity of 29 g/L. The GC-IMS results were consistent with the electronic-nose test results. After low-salinity depuration, aldehyde and ketone levels were significantly reduced, and furan concentrations increased. In addition, multivariate analysis was used to determine the correlation between each component and flavor profile differences due to depuration at various salinities. Overall, salinity of 29 g/L could be optimal for oyster depuration.

Epitaxial III-V/Si Vertical Heterostructures with Hybrid 2D-Semimetal/Semiconductor Ambipolar and Photoactive Properties.

Hybrid materials taking advantage of the different physical properties of materials are highly attractive for numerous applications in today's science and technology. Here, it is demonstrated that epitaxial bi-domain III-V/Si are hybrid structures, composed of bulk photo-active semiconductors with 2D topological semi-metallic vertical inclusions, endowed with ambipolar properties. By combining structural, transport, and photoelectrochemical characterizations with first-principle calculations, it is shown that the bi-domain III-V/Si materials are able within the same layer to absorb light efficiently, separate laterally the photo-generated carriers, transfer them to semimetal singularities, and ease extraction of both electrons and holes vertically, leading to efficient carrier collection. Besides, the original topological properties of the 2D semi-metallic inclusions are also discussed. This comb-like heterostructure not only merges the superior optical properties of semiconductors with good transport properties of metallic materials, but also combines the high efficiency and tunability afforded by III-V inorganic bulk materials with the flexible management of nano-scale charge carriers usually offered by blends of organic materials. Physical properties of these novel hybrid heterostructures can be of great interest for energy harvesting, photonic, electronic or computing devices.

A generic intelligent tomato classification system for practical applications using DenseNet-201 with transfer learning.

A generic intelligent tomato classification system based on DenseNet-201 with transfer learning was proposed and the augmented training sets obtained by data augmentation methods were employed to train the model. The trained model achieved high classification accuracy on the images of different quality, even those containing high levels of noise. Also, the trained model could accurately and efficiently identify and classify a single tomato image with only 29 ms, indicating that the proposed model has great potential value in real-world applications. The feature visualization of the trained models shows their understanding of tomato images, i.e., the learned common and high-level features. The strongest activations of the trained models show that the correct or incorrect target recognition areas by a model during the classification process will affect its final classification accuracy. Based on this, the results obtained in this study could provide guidance and new ideas to improve the development of intelligent agriculture.

Uncovering proteome variations of differently heat-treated sea cucumber (Apostichopus japonicus) by label-free mass spectrometry.

The effects of heat treatment on the proteome of Apostichopus japonicus have been evaluated using label-free quantitative proteomics by ultrahigh performance liquid chromatography-quadrupole/time of flight (UHPLC-Q/TOF) mass spectrometry with sequential window acquisition of all the theoretical fragment ion (SWATH) acquisition mode. Chemometric tools are integrated to reveal proteomic changes by mining the protein quantitation data from fresh and differently heat-treated samples. SWATH allows the quantitation of 548 proteins, of which 24 proteins are significantly sensitive to heat treatment and 13 proteins vary significantly responding to different heat procedures (boiling, steaming, and microwave heating), and 5 of them are sharing proteins. Gene ontology (GO) annotation of the differentiating proteins highlights most of them are relevant to molecular functions. The results can be favorable to evaluate the effects of heat treatment on the nutrition and function of processed sea cucumbers and facilitate the selection of an optimal thermal treatment.