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Extracellular vesicles (EVs) and their exosome subsets are vesicle-like nanoparticles (EVs) that are secreted by cells and contain various factors that treat various diseases. However, studies on extracting EVs from marine shellfish are still relatively lacking. In this study, EVs were isolated from Pinctada martensii mucus and the efficacy of EVs in modulating the inflammatory environment was demonstrated. A human skin inflammatory cell model was established to investigate the effect of Pinctada martensii mucus-derived EVs on inflammation. The results showed that EVs could restore the viability of inflammatory HaCaT cells and decrease the level of reactive oxygen species (ROS), as well as the mRNA expression of IL-6, IL-8 and TNF-α. The inflammation of HaCaT cells was treated by inhibiting the activation of the MAPK, NF-κB and NLRP3 inflammasome signaling pathways, which prevented the phosphorylation of related inflammatory proteins and the entry of P65 protein into the nucleus. This study provides novel EVs from marine shellfish-derived bioactive materials.

Microplastics (MPs) are widespread in the environment and can be ingested through food, water, and air, posing a threat to human health. In addition, MPs can have a potential combined effect with other toxic compounds. Polystyrene (PS) has been shown to enhance the cytotoxicity of okadaic acid (OA). However, it remains unclear whether this enhancement effect is related to the size of PS particles. In this study, we investigated the mechanism of the combined effect of PS microplastics (PS-MPs) or PS nanoplastics (PS-NPs) and OA on Caco-2 cells. The results indicated that PS-NPs enhanced the cytotoxicity of OA and induced endoplasmic reticulum (ER) stress-mediated apoptosis in Caco-2 cells, compared to PS-MPs. Specifically, PS-NPs and OA cause more severe oxidative stress, lactate dehydrogenase (LDH) release, and mitochondrial membrane depolarization. Furthermore, it induced intracellular calcium overload through store-operated channels (SOCs) and activated the PERK/ATF-4/CHOP pathway to cause ER stress. ER stress promoted mitochondrial damage and finally activated the caspase family to induce apoptosis. This study provided an indirect basis for the assessment of the combined toxicity of MPs or NPs with OA.

Soil salinization has been recognized as one of the main factors causing the decrease of cultivated land area and global plant productivity. Application of salt tolerant plants and improvement of plant salt tolerance are recognized as the major routes for saline soil restoration and utilization. Sea rice 86 (SR86) is known as a rice cultivar capable of growing in saline soil. Genome sequencing and transcriptome analysis of SR86 have been conducted to explore its salt tolerance mechanisms while the contribution of rhizobacteria is underexplored. In the present study, we examined the rhizosphere bacterial diversity and soil metabolome of SR86 seedlings under different salinity to understand their contribution to plant salt tolerance. We found that salt stress could significantly change rhizobacterial diversity and rhizosphere metabolites. Keystone taxa were identified via co-occurrence analysis and the correlation analysis between keystone taxa and rhizosphere metabolites indicated lipids and their derivatives might play an important role in plant salt tolerance. Further, four plant growth promoting rhizobacteria (PGPR), capable of promoting the salt tolerance of SR86, were isolated and characterized. These findings might provide novel insights into the mechanisms of plant salt tolerance mediated by plant-microbe interaction, and promote the isolation and application of PGPR in the restoration and utilization of saline soil.

In the field of microplastics research, more accurate standardised methods and analytical techniques still need to be explored. In this study, a new method for the microplastics quantitatively and qualitatively analysis by two-phase (ethyl acetate-water) system combined with confocal Raman spectroscopy was developed. Microplastics can be separated from false-positive microplastics in beach sand and marine sediment, attributing to the hydrophobic-lipophilic interaction (HLI) of the two-phase system. Results show that the recovery rates of complex environment microplastics (polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide 66 (PA 66), polycarbonate (PC) and polyethylene (PE)) are higher than 92.98%. Moreover, the new technique can also be used to detect hydrophobic and lipophilic antibiotics, such as sulfamethoxazole (SMX), erythromycin (EM), madimycin (MD), and josamycin (JOS), which adsorbed on microplastics and are extracted based on the dissolving-precipitating mechanism. This innovative research strategy provides a new scope for further detection of marine environment microplastics and toxic compounds adsorbed on its surface.

The pollution of antibiotic resistance genes (ARGs) carried by microplastics (MPs) is a growing concern. Mangroves are located at the intersection of land and sea and are seriously affected by MP pollution. However, few studies have systematic research evaluating the transmission risk of ARGs carried by MPs in mangroves. We conducted in situ experiments by burying five different MPs (polypropylene, high-density polyethylene, polystyrene, polyethylene glycol terephthalate, and polycaprolactone particles) in mangroves with different surrounding environments. A total of 10 genes in the MPs of mangroves were detected using quantitative real-time polymerase chain reactions, including eight ARGs and two mobile genetic elements (MGEs). The abundance of ARGs in Guanhai park mangroves in living areas (GH) was higher than that of Gaoqiao mangroves in protected areas (GQ) and Beiyue dike mangroves in aquaculture pond areas (BY). Pathogenic bacteria, such as Acinetobacter, Bacillus, and Vibrio were found on the MP surfaces of the mangroves. The number of ARGs carried by multiple drug-resistant bacteria in the GH mangroves was greater than that in the GQ and BY mangroves. Moreover, the ARGs carried by MPs in GH mangroves had the highest potential transmission risk by horizontal gene transfer. Sociometric and environmental factors were the main drivers shaping the distribution characteristics of ARGs and MGEs. Polypropylene and high-density polyethylene particles are preferred substrates for obtaining diffuse ARGs. This study investigated the drivers of ARGs in the MPs of mangroves and provided essential guidance on the use and handling of plastics.

Seahorse has been used as a traditional medicine in Southeast Asian countries for a long time. A compound, 2'-Hydroxy-5'-Methoxyacetophenone (2H5M) isolated from seahorse, Hippocampus kuda, was tested for its anti-inflammatory effect in lipopolysaccharides (LPS)-stimulated BV-2 cells and RAW264.7 cells. MTT assay indicated that 2H5M has no cytotoxicity on two kinds of cells. The concentration of nitric oxide (NO) measured by Griess Reaction System showed that 2H5M could significantly inhibit the NO concentration. The ELISA results showed that 2H5M could suppress the secretion of TNF-α in a dose-dependent manner. Moreover, western blot analysis was utilized to measure the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Electrophoretic mobility shift assay (EMSA) demonstrated that 2H5M reduced NF-κB DNA binding activity. Furthermore, the molecular docking study showed that 2H5M can form active sites with NF-κB. Collectively, these results indicated that 2H5M possesses anti-inflammatory effects and may have a potential application in inflammatory disorders in the future.

A new nanopore array/Au electrode was fabricated and applied to the detection of microRNA. The electrode was prepared via alternating current electrodeposition of Au nanowires in the nanopores of a porous anodic alumina membrane (without the need to remove aluminum or any barrier layer). The internal surface of the nanopores was then functionalized with an electrically neutral morpholino with a specially designed sequence. The resulting electrode shows excellent sensitivity and selectivity in detection of the target miRNA-155. The detection limit is 10 aM and the linear range 10 aM–1 nM in aqueous solution and the electrode can be reused in 6 M urea solution. In addition, it shows good linearity (100 aM–0.1 nM) in a serum sample. This new biosensor is expected to enhance miRNA detection in clinical diagnosis. Keywords: Nanopores, Label-free detection, microRNA, Porous anodic alumina

The enrichment of various pollutants in mangrove has attracted widespread attention. Especially, microplastics accumulation in mangrove may provide a more challenging ecological colonization site by enriching pollutants, thus affecting the change of microplastics antibiotic resistance and increasing the risk of antibiotic failure. Herein, the antibiotic-resistant of microplastics and sediment from mangrove were investigated. The results show that isolates are mainly colonized by Vibrio parahemolyticus (V. parahemolyticus), Vibrio alginolyticus (V. alginolyticus), and Shewanella. 100% mangrove microplastics isolates are resistant to chloramphenicol, cefazolin, and tetracycline, especially amoxicillin clavulanate and ampicillin. Meanwhile, the multiple antibiotics resistance (MAR) indexes of V. parahaemolyticus, Shewanella, and V. alginolyticus in mangrove microplastics are 0.72, 0.77, and 0.77, respectively, which are far higher than the MAR index standard (0.2) and that of mangrove sediment isolates. Furthermore, compared with V. parahaemolyticus isolated from the same mangrove microplastics, Shewanella and V. alginolyticus show stronger drug resistance. It should be noted that there is a closely related relationship between the type of microplastics and the antibiotics resistance of isolated bacteria. For the antibiotics sensitivity test of norfloxacin, streptomycin, amoxicillin, and chloramphenicol, V. parahaemolyticus have the lower antibiotics resistance than that of V. alginolyticus isolated from the same mangrove microplastics. However, Vibrio isolated from PE has stronger antibiotics resistance. Results reveal that mangrove may be one of the potential risks for emergence and spread of bacterial antibiotics-resistant and multidrug-resistant, and microplastic biofilms may act as promoters of bacterial antibiotic resistance.

Background: With the closure of Hubei Province on January 25, 2020, the Chinese government divided the program for control and prevention measures against COVID-19 into two parts: reinforcement of medical resources for diagnosis and treatment in Hubei province and reduction of the spread of the epidemic to control and prevention outside Hubei Province. Methods: We collected 4,959 COVID-19 cases from eight districts in China up to February 13, 2020, and analysed the epidemiological characteristics. Findings: The median age was 46 years old, and 46⋅7% were female. It is estimated that the confirmed diagnosis rate of the inflow population in Wuhan from eight districts is 0⋅16% (range 0⋅10-0⋅38%). Fever was the most common symptom (65⋅1%). The growth trends of imported and non-imported cases were similar with two peak periods separated by six days. The second-generation began to decline five days after the first-generation reached the peak. The second-generation cases had no exact peak. Five days after entering the high plateau period of the second-generation, the third-generation cases reached a peak and gradually declined. Meanwhile, new cases nationwide (except Hubei) have entered a rapid downward trend. The median time from visit to hospitalization for imported patients was seven days (4–10), and the median time from illness onset to hospital for non-import patients was two days (0–5). A total of 647 clustering events that caused 1,398 cases of infection were found. Interpretation: The incubation period of COVID-19 is verified to be approximately 5-6 days. The first- and second-generation cases have been well controlled, and the daily number of third-generation cases is gradually decreasing. The epidemic reached a turning point in China except for Hubei on February 6. The control and prevention of cluster events may be the key to final victory. Funding Statement: The authors stated that this study was not funded. Declaration of Interests: All authors declare no competing interests. Ethics Approval Statement: All data have been released publicly by the Chinese (CDC) and the provincial and local municipal Health Commission; therefore, this study was exempted from institutional review board approval.

Microbial degradation is an effective approach for the removal of Bisphenol A (BPA). During the biodegradation process, quorum sensing (QS) is a phenomenon that enables bacteria to coordinate collective behaviors based on cell density-dependent chemical signals. However, whether the degradation of BPA can be facilitated by this QS system (such as acyl-homoserine lactone, AHL) is unclear. To answer this question, the bifunctional Sphingonomas sp. strain YK5 that had BPA-degrading and AHL-producing properties was used. Biochemical analysis revealed that this bacterial strain mainly produced C8-HSL signals. Gene knockout experiments indicated that the AHL-system (LuxI1/LuxI2) was required for efficient BPA degradation. RT-PCR analyses revealed that the AHL system positively regulated the relative expression of genes (bisdA, CYP450, hapA, ligAB, and proB) involved in BPA degradation. Given that AHL signaling may be a common trait among BPA-degrading microorganisms and AHL system can regulate the degradation activity, manipulation of this system may be a valuable strategy to control BPA biodegradation.

Au nanoclusters were synthetized through chemical reduction based on glutathione template. The fluorescence excitation and emission wavelength is 375 nm and 565 nm, respectively. The fluorescence would be quenched at the presence of ferrous and hydrogen peroxide and recovered as ascorbic acid added. It can be used for qualitative analysis of ascorbic acid according to fluorescence recovery. The fluorescence intensity is positive correlation with the concentration of ascorbic acid. The detection limit is 200 μM and linear range is 350–700 μM. It offers an easy and convenient method to detect of ascorbic acid.

Androstenedione (AED) is a naturally occurring androgen that is released into the environment through human and animal excretion. Several studies have shown that AED can interfere with the normal growth, development, and reproduction of organisms. However, studies examining the thyroid system, an important part of endocrine system of fish, are still lacking. This study examines thyroid hormone levels including T3 and T4, and transcriptional expression levels of genes associated with the hypothalamic-pituitary-thyroid axis (HPT axis) in adult zebrafish. Fish were exposed to a solvent control and three other concentrations of AED (0.2, 2.3, and 23.7 μg/L) for 60 days. Results indicated that AED significantly increased T4 levels but inhibited transcription of some HPT axis-related genes (nis, tpo, tg, dio1, dio2, sult1 st5, pax8, and nkx2.1) in female zebrafish. The adverse effects of AED on the thyroid system in males were very low, only affecting down-regulation of the tshb gene and up-regulation of the thrb gene. The overall results demonstrated that AED interferes with the thyroid endocrine system in fish.

Dense phase carbon dioxide (DPCD) could induce protein conformation changes. Myosin and shrimp surimi from Litopenaeus vannamei were treated with DPCD at 5-25MPa and 40-60°C for 20min. Myosin secondary structure was investigated by circular dichroism and shrimp surimi gel strength was determined using textural analysis to develop correlations between them. DPCD had a greater effect on secondary structure and gel strength than heating. With increasing pressure and temperature, the α-helix content of DPCD-treated myosin decreased, while the β-sheet, β-turn and random coil contents increased, and the shrimp surimi gel strength increased. The α-helix content was negatively correlated with gel strength, while the β-sheet, β-turn and random coil contents were positively correlated with gel strength. Therefore, when DPCD induced myosin to form a gel, the α-helix of myosin was unfolded and gradually converted to a β-sheet. Such transformations led to protein-protein interactions and cross-linking, which formed a three-dimensional network to enhance the gel strength.

Microplastics pollution poses a new threat to the environment of intertidal zone. The sea forest, mangrove, has been polluted by a large number of plastic debris worldwide. To fill the gaps in knowledge of mangrove rhizosphere microbes connected with the ‘plasticsphere’, a semi-controlled in situ exposure experiment for nine different types of microplastics were conducted in mangrove ecosystem. A sign of biodegrading was observed on polyethylene, polyamide 6 and polyvinyl chloride microplastics surface after 3 months exposure. We discovered that the metabolic activities of the dominant bacteria on certain microplastics were related to the specific groups on polymers molecule. The selective colonization may be driven by the chemotaxis of bacteria. Specially, microplastics biofilms of polyethylene, polyamide 6, polyvinyl chloride and expanded polystyrene possess distinctive dominant bacteria assemblages which have great significance in ecosystem processes involving carbon cycle or sulfur cycle. Community of mangrove soil microorganism and microplastic biofilm varies as the seasons changes. As a new niche, microplastics has higher inclusivity to bacteria than surrounding soil. Additionally, pathogens for human beings (Vibrio parahaemolyticus and Escherichia-Shigella) were detected both in microplastics and soil. We stress that the interaction between microplastics and rhizosphere microorganisms may affect the growth and health of mangrove plants. Besides, we point out that mangrove rhizosphere microorganism can be an ideal candidate for plastics-degradation.

The detection of microplastics and nanoplastics in the environment, especially plastic particles in aquatic environments in situ, still faces challenges due to the limitations of current methods, instruments and size of plastic particles. This paper evaluates the potential of surface-enhanced Raman spectroscopy for the analysis of microplastics and nanoplastics. The condition of different tests including the volume ratio of sample to silver colloid, the concentrations of NaCl, and the concentrations of the samples, are assessed for the study of microplastics and nanoplastics (polystyrene (PS), polyethylene (PE) and polypropylene (PP)) in pure water and seawater. A method based on SERS, that uses silver colloid as the active substrate, is developed for the qualitative analysis of microplastics and nanoplastics in aquatic environments. The particle sizes of microplastics and nanoplastics include 100 nm, 500 nm and 10 μm. The Raman signals of microplastics and nanoplastics in pure water and seawater both show good enhancement efficiency. The optimal enhancement factor is 4 × 104. The SERS-based detection method overcomes the limitations of microplastics and nanoplastics in liquids and can detect 100 nm plastics down to 40 μg/mL. It provides more possibility for the rapid detection of microplastics and nanoplastics in aquatic environments in the future.

Microplastics (particle size

Two carbonyl groups modified XAD-4 resins (XAD-4-I and XAD-4-II) were synthesized by chemically modifying Amberlite XAD-4 with carbon tetrachloride and benzoyl chloride according to the Friedel–Crafts reaction. After the chemical modification, the Brunauer–Emmet–Teller (BET) surface area and pore volume of the resins increased about 50% while their median pore size remained constant. More importantly, the modified resins adsorbed about 20% more phenol from aqueous solutions than the original XAD-4 at 298, 308 and 318 K, respectively; and the modified resins could be used directly in water without pre-wetting. The Freundlich and Sips models fitted the isotherm data better than the Langmuir model. Analysis of isosteric adsorption enthalpy indicated that XAD-4 has a more heterogeneous surface than the modified resins. Adsorption kinetics data suggested that the three resins could reach equilibrium within 1 h, and the pseudo-first-order and pseudo-second-order rate models could describe the kinetic data effectively. At a phenol feed concentration of 574.0 mg/L, the dynamic adsorption capacities of XAD-4, XAD-4-I and XAD-4-II were measured to be 80.6, 94.8 and 93.6 mg/g, respectively. Desorption experiments showed that the used resins could be regenerated completely by a 50% (v/v) ethanol aqueous solution.

Pristine l-proline was non-covalently loaded on the graphene oxide (GO) sheet in a simple route by mixing them in aqueous solution. Technologies of characterization well suggested that l-proline was efficiently loaded on the two sides and edge of the GO sheet through hydrogen-bonding or/and ionic interaction, giving the excellent l-proline/GO hybrid catalyst for the direct asymmetric aldol reaction. The unique multilayered structure of the GO carrier with sufficient interlayer space favored reagents’ diffusion toward l-proline chiral moiety and therefore resulted in the high catalytic efficiency of the heterogeneous l-proline. Excellent yield (96%) with high enantiomeric excess (79% ee) was obtained in the direct aldol reaction of 2-nitrobenzaldehyde with acetone catalyzed by l-proline/GO hybrid, which was comparable to that observed in the reactions promoted by l-proline itself. Furthermore, the l-proline/GO hybrid used as a heterogeneous catalyst could be easily recovered and recycled for seven times without significant loss of the reactivity.

The direct asymmetric aldol reaction of aromatic aldehydes with acetone catalyzed by L-proline was accelerated by the addition of diols or diphenols. The use of additives decrease the amount of L-proline needed and allowed the use of solvent free conditions. Catechol with two adjacent hydroxy groups on aromatic ring was the most efficient additive. Under the optimized conditions, 5 mol% L-proline with 1 mol% catechol gave excellent chiral selectivity (80% ee value) with > 90% yield, which was higher than that obtained using 30 mol% L-proline without an additive. Computations indicated that the additive promoted the reaction by an intermolecular hydrogen bond between the hydrogen of the hydroxyl group and the oxygen of the carbonyl group, which activated the carbonyl group of the aldehyde. Catechol with two adjacent hydroxyl groups on the aromatic ring can form two hydrogen bonds with the oxygen of the carbonyl group on the corresponding aldehyde. Therefore, the combination of L-proline and catechol was very efficient in catalyzing the direct asymmetric aldol reaction and gave a high yield in a short time.

High-throughput screening of GSK compound collection led to the discovery of a novel series of thiadiazole amides as potent and S1P3-sparing sphingosine-1-phosphate 1 (S1P1) receptor agonists. Synthesis, structure and activity relationship, selectivity, and some developability properties are described.

Novel chiral dimeric salen Mn(III) complexes bridged with N,N-dialkylimidazolium ionic liquids (ILs) at the C-5 position of the salicylaldehyde moieties were designed and synthesized. The ILs-bridged complexes presented excellent enantioselectivity and catalytic activity in the oxidative kinetic resolution of α-methyl benzyl alcohol, using diacetoxyiodobenzene as oxidant. The complexes combined the high catalytic efficiency of the active centers and the special solubility of the ILs, thus exhibiting notable efficacy of oxidative kinetic resolution and facile recovery from the reaction system by changing the solvent.

Chiral oxovanadium (IV) Schiff base complex covalently grafted with ionic liquid (IL: 1-(3-aminopropyl)-3-methylimidazolium tetrafluoroborate) has been reported first time. The IL-functionalized complex was found to be an efficient catalyst in the enantioselective oxidation of methyl aryl sulfides to sulfoxides with hydrogen peroxide as an oxidant. Especially, the IL-functionalized complex could be recovered conveniently by simple precipitation with addition of hexane and reused at least six cycles without loss of activity and enantioselectivity.

Cu/Cu2O nanowires were synthesized using anodic aluminum oxide templates in an aqueous acidic electrolyte using alternating current electrochemical deposition. The features of the final product were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (SEM). The results indicated that the diameter of the nanowires is about 50 nm, which is in accord with the size of the pores in the anodic aluminum oxide templates. The crystalline structure of the Cu and Cu2O nanowires exhibit preferred orientations of Cu (111) and Cu2O (200), respectively. The experimental results showed that contents of Cu and Cu2O in the final product are controlled by changing the pH value of the electrolyte. Pure Cu nanowires were obtained at lower pH values of 1–3, while pure Cu2O nanowires formed at a higher pH value of 5. When the pH = 4, the nanowires produced were a composite of Cu and Cu2O. The growth of Cu2O nanowires in acidic electrolyte is ascribed to a local increase in pH at the base of the pores in the template and a phenomenological model for this process is proposed and discussed.

Three kinds of mesoporous alumina (denoted as meso -Al 2 O 3 - x ( x = a, b, c)) supports with different surface basicity were synthesized by different structure-direct agent and different assembly pathway, respectively. The surface basicity of the meso -Al 2 O 3 - x and the commercial γ-Al 2 O 3 was measured by means of CO 2 -TPD and IR spectroscopy. The profiles of CO 2 -TPD and IR spectra indicated that the mesoporous alumina owned more abundant surface basic sites than that of γ-Al 2 O 3 . Au nanoparticles deposited on the above supports via the method of homogeneous deposition precipitation (HDP) using urea as the precipitation agent. The supported Au catalysts were characterized by N 2 adsorption–desorption isotherms, TEM, XPS and testing the catalytic performances in the epoxidation of styrene. The dispersion and average size of the gold particles are dependent of the number of surface basic sites on the supports. Transmission electron microscopy (TEM) observations show a homogeneous distribution of gold particles lower than 4 nm on meso -Al 2 O 3 -b and meso -Al 2 O 3 -c, which owned more basic sites on the surface. XPS spectra reveal that only metallic state of Au is presented on the supports, which is independent of surface properties. The different Al 2 O 3 supported Au catalysts were employed as highly active/selective and reusable catalysts for the epoxidation of styrene by anhydrous t -butyl hydroperoxide (TBHP). Au nanoparticles as well as the surface basic sites of the support are responsible for the epoxidation.