Dalian Ocean University

The rapid development of nanotechnology has been facilitating the transformations of traditional food and agriculture sectors, particularly the invention of smart and active packaging, nanosensors, nanopesticides and nanofertilizers. Numerous novel nanomaterials have been developed for improving food quality and safety, crop growth, and monitoring environmental conditions. In this review the most recent trends in nanotechnology are discussed and the most challenging tasks and promising opportunities in the food and agriculture sectors from selected recent studies are addressed. The toxicological fundamentals and risk assessment of nanomaterials in these new food and agriculture products are also discussed. We highlighted the potential application of bio-synthesized and bio-inspired nanomaterial for sustainable development. However, fundamental questions with regard to high performance, low toxic nanomaterials need to be addressed to fuel active development and application of nanotechnology. Regulation and legislation are also paramount to regulating the manufacturing, processing, application, as well as disposal of nanomaterials. Efforts are still needed to strengthen public awareness and acceptance of the novel nano-enabled food and agriculture products. We conclude that nanotechnology offers a plethora of opportunities, by providing a novel and sustainable alternative in the food and agriculture sectors.

Songlin Chen and colleagues sequenced the whole genomes of a male (ZZ) and a female (ZW) Chinese half-smooth tongue sole, Cynoglossus semilaevis. Their analysis provides insights into the structure and evolution of the sex chromosomes and adaptation to the benthic lifestyle of this flatfish. Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.

Organic sulfides in fuels have become one of the main sources of serious pollution. The desulfurization of fuels has become a frontier scientific topic demanding prompt solutions. Research shows that the emergence of ionic liquid analogues—deep eutectic solvents (DESs)—has provided a new opportunity for the deep extraction desulfurization of fuels because of their cheap and easily obtained raw materials, higher extraction desulfurization efficiencies, and simple and environmentally friendly synthesis process. In this study, some DESs were designed and synthesized. Choline chloride (ChCl), tetramethyl ammonium chloride (TMAC), and tetrabutyl ammonium chloride (TBAC) were chosen as typical hydrogen bond acceptors (HBA), and malonic acid (MA), glycerol (Gl), tetraethylene glycerol (TEG), ethylene glycol (EG), polyethylene glycol (PEG), and propionate (Pr) were chosen as hydrogen bond donors (HBD), from which a series of deep eutectic solvents were synthesized. Research shows that the above DESs can be used for the desulfurization of fuels successfully. Tetrabutyl ammonium chloride-based DESs possess the highest extraction efficiency. In optimal conditions, the extraction efficiency of TBAC/PEG can reach as high as 82.83% for one cycle, which is much higher than the traditional and functionalized ionic liquids (ILs). After five cycles, the extraction efficiency can reach up to 99.48%. In addition, sulfur content in fuels can be reduced to less than 8.5 ppm and deep desulfurization was realized. Finally, the extraction mechanism was investigated systematically with quantitative 1H NMR and FT-IR. The hydrogen bonds formed between DESs and benzothiophene (BT) account for the higher desulfurization efficiency. This study will provide new green solvents for the extraction desulfurization process of fuels.

Solar desalination is an effective way of converting solar energy to heat for seawater purification. The structure of absorbers and salt resistance are two crucial parameters for water transport and desalination stability. Here, we designed a vertically aligned Janus MXene aerogel (VA-MXA) with hydrophobic upper layer and hydrophilic bottom layer. Compared with irregular porous channels, such regulatable and well-ordered vertical array structure gives competitive advantage in the capillary water transport, light absorption, and vapor escape. MXene, which possesses a theoretical light-to-heat conversion efficiency of 100%, combined with the Janus structure, can efficiently convert light to heat and prevent the photothermal layer from “direct bulk water contact” with the hydrophobic upper layer, thus decreasing heat loss, while the hydrophilic bottom layer submerged in water can quickly pump water upward through the vertically aligned channels with low transport resistance and, meanwhile, enable effective inhibition of salt crystallization due to rapid dissolution with continuously pumping water. With a vertically aligned and Janus structure by flexible design, the Janus VA-MXA exhibited a high conversion efficiency (87%) and stable water yield for 15 days (∼1.46 kg·m–2·h–1) under 1 sun. About 6 L·m–2 of freshwater was output daily from seawater.

Abstract The family of transition metal carbides, nitrides, and carbonitrides (collectively called MXenes) has been a thriving field since the first invention of Ti 3 C 2 T x (MXene) in 2011. MXene is a new type of nanometer 2D sheet material, which exhibits great application potentials in various fields due to its multiple advantages such as high specific surface area, good electrical conductivity, and high mechanical strength. Electrocatalysis is regarded as the core of future clean energy conversion technologies, and MXene‐based materials provide inspiration for the design and preparation of electrocatalysts with high activity, high selectivity, and long loading life time. The applications of MXene‐based materials in electrocatalysis, including hydrogen evolution reaction, nitrogen reduction reaction, oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, and methanol oxidation reaction are summarized in this review. As a crucial session regarding experiments, the current safer and more environmentally friendly preparation methods of MXene are also discussed. Focusing on the materials design and enhancement methods, the key challenges and opportunities for MXene‐based materials as a next‐generation platform in both fundamental research and practical electrocatalysis applications are presented. This account serves to promote future efforts toward the development of MXenes and related materials in the electrocatalysis applications.

Similar to other industries, aquaculture constantly requires new techniques to increase production yields. Modern technologies and different scientific fields, such as biotechnology and microbiology, provide important tools that could lead to a higher quality and a greater quantity of products. New feeding practices in farming typically play an important role in aquaculture, and the addition of various additives to a balanced feed formula to achieve better growth is a common practice of many fish and shrimp feed manufacturers and farmers. As ‘bio-friendly agents’, immunostimulants, such as biological factors, probiotics and vitamins, can be introduced into the culture environment to control and kill pathogenic bacteria, as well as to promote growth of the cultured organisms. In addition, immunostimulants are non-pathogenic and non-toxic and do not produce undesirable side effects when administered to aquatic organisms. In this review, we summarize previous studies performed with both traditional immunostimulants and the most promising new generation of immunostimulants, such as polysaccharides, nutrients, oligosaccharides, herbs, microorganisms, prebiotics and different biological factors. This review primarily focuses on their protective efficacies and on what is known concerning their effects on the immune systems of aquatic organisms when delivered in vivo.

Remote data integrity checking is of crucial importance in cloud storage. It can make the clients verify whether their outsourced data is kept intact without downloading the whole data. In some application scenarios, the clients have to store their data on multicloud servers. At the same time, the integrity checking protocol must be efficient in order to save the verifier's cost. From the two points, we propose a novel remote data integrity checking model: ID-DPDP (identity-based distributed provable data possession) in multicloud storage. The formal system model and security model are given. Based on the bilinear pairings, a concrete ID-DPDP protocol is designed. The proposed ID-DPDP protocol is provably secure under the hardness assumption of the standard CDH (computational Diffie-Hellman) problem. In addition to the structural advantage of elimination of certificate management, our ID-DPDP protocol is also efficient and flexible. Based on the client's authorization, the proposed ID-DPDP protocol can realize private verification, delegated verification, and public verification.

A process for the effective extraction and fractionation of phlorotannins from Fucus vesiculosus with high antioxidant potentials was investigated. The antioxidant activity of F. vesiculosus extract/fractions was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, reducing power, and ferrous ion-chelating assays. Among the crude extract and different polarity fractions, the phlorotannin-enriched ethyl acetate fraction possessed the highest DPPH scavenging activity and reducing power. This fraction was further fractionated by Sephadex LH-20 column chromatography or ultrafiltration. The antioxidant properties were evaluated by both the above chemical antioxidant tests and a mononuclear cell-based bioassay. Sephadex subfractions LH-2 and LH-3 with high total phlorotannin content exhibited strong DPPH quenching activity, comparable to those of ascorbic acid and butylated hydroxytoluene and significantly higher than that of α-tocopherol. Polyphenols in F. vesiculosus were found to consist mainly of high molecular weight phlorotannin polymers. There were no clear relationships between the degree of polymerization, molecular size, and antioxidant activity. All the subfractions separated by Sephadex LH-20 column chromatography and ultrafiltration showed a high ability to scavenge reactive oxygen species generated by mononuclear cells. Further characterization of the phlorotannin compounds was performed on six Sephadex subfractions. Several phlorotannin oligomers were tentatively identified on the basis of HPLC-ESI-MS(n) analyses.

In-situ synchrotron X-ray computed microtomography with sub-micrometer voxel size was used to study the decomposition of gas hydrates in a sedimentary matrix. Xenon-hydrate was used instead of methane hydrate to enhance the absorption contrast. The microstructural features of the decomposition process were elucidated indicating that the decomposition starts at the hydrate-gas interface; it does not proceed at the contacts with quartz grains. Melt water accumulates at retreating hydrate surface. The decomposition is not homogeneous and the decomposition rates depend on the distance of the hydrate surface to the gas phase indicating a diffusion-limitation of the gas transport through the water phase. Gas is found to be metastably enriched in the water phase with a concentration decreasing away from the hydrate-water interface. The initial decomposition process facilitates redistribution of fluid phases in the pore space and local reformation of gas hydrates. The observations allow also rationalizing earlier conjectures from experiments with low spatial resolutions and suggest that the hydrate-sediment assemblies remain intact until the hydrate spacers between sediment grains finally collapse; possible effects on mechanical stability and permeability are discussed. The resulting time resolved characteristics of gas hydrate decomposition and the influence of melt water on the reaction rate are of importance for a suggested gas recovery from marine sediments by depressurization.

Abstract A series of triaxial compression tests were conducted in order to investigate the mechanical behavior of gas‐saturated methane hydrate‐bearing sediments, and a comparison was made between gas‐saturated and water‐saturated specimens. Measurements on gas‐saturated specimens indicate that (1) the larger the methane hydrate saturation, the larger the failure strength and the more apparent the shear dilation behavior; (2) failure strength and stiffness increase with increasing effective confining stress and pore pressure applied during compression, though the specimen becomes less dilative under higher effective confining stress; (3) lower temperatures lead to an increase of the stiffness and failure strength; (4) stiffness of specimens formed under lower pore pressure is higher than that of specimens formed under higher pore pressure but at the same effective stress; (5) stiffness and failure strength of gas‐saturated specimens are higher than those of water‐saturated specimens; (6) gas‐saturated specimens show more apparent strain‐softening behavior and larger volumetric strain than that of water‐saturated specimens.

Aquaculture effluent is often associated with increased organic carbon, suspended solids, phosphates, nitrogenous species (nitrates, nitrites, and ammonia), chemical oxygen demand and biological oxygen demand. This is regarded as a global threat to aquatic ecosystems due to its influence on surrounding waters as well as groundwater. The threat of aquaculture effluent is not confined to the aquatic ecosystems as high levels of phosphorus and nitrogen may become poisonous to plants and change their protein synthesis, enzyme activities, photosynthesis, oxidative stress response, membrane permeability, and respiratory processes. Other forms of water pollution such as the presence of heavy metals as well as pathogenic microbes are issues of concern since they can be transferred through the food chain. Bacillus species have demonstrated great ability in the maintenance of water quality in aquaculture which is simple and cost-effective. This review highlights that Bacillus modulates a wide range of water quality parameters including physical (transparency and total dissolved solids) and chemical (pH, conductivity, chemical oxygen demand, dissolved oxygen, biological oxygen demand, alkalinity, phosphates, nitrogenous species, hardness) water quality parameters, heavy metals, oil spillage as well as maintenance of microbial balance; hence reduction in pathogenic microbes. The efficiency of Bacillus in modulating water quality is greatly dependent on factors such as mode of application, dissolved oxygen, pH, temperature, source of nutrients, strain type, and metal ions. This review further highlights aquaculture activities that lead to pollution and the possible mechanisms used by Bacillus for improving water quality. It is recommended that a range of optimum conditions be established to increase the efficiency of Bacillus in modulating water quality. A better understanding of Bacillus to the genetic level and the development of new genetic tools is also recommended since the ability of microorganisms to modulate water quality is related to their genetic make-up.

Since microplastics (MPs) bring the potential risks to human health when plastics are ingested, more needs to be known about the presence and abundance of human ingestion of MPs. To address these issues, we reviewed 108 publications in Web of Science concerning abundances, sources, and analytical methods of MPs in human daily intake including fish, salt, drinking water, beverages, package food, and other food. The results demonstrate that aquatic food products (fish and bivalves) present a wide range of 0-10.5 items/g for bivalves and 0-20 items/individual for fish. Salt data in literatures present a concentration of 0-13,629 particles/kg. Drinking water is also a pathway of MPs exposure to human, presenting a concentration range from 0 to 61 particles/L for tap water and 0 to 6292 MPs/L for bottled water. Besides, MPs have been found in beverages, package food, sugar, honey, vegetables, and fruits. Therefore, human intake of MPs via ingestion is a nonnegligible exposure route.

Novel hierarchical activated carbon nanofiber (ACF) webs with tuned structure have been fabricated by incorporating carbon black (CB) into an electrospun polymer solution, followed by heat treatment. The as-made electrospun ACF webs show superior capacities as electrode materials in capacitive deionization (CDI) for desalination due to their advantageous hierarchical structures.

Recently, cloud computing rapidly expands as an alternative to conventional computing due to it can provide a flexible, dynamic and resilient infrastructure for both academic and business environments. In public cloud environment, the client moves its data to public cloud server (PCS) and cannot control its remote data. Thus, information security is an important problem in public cloud storage, such as data confidentiality, integrity, and availability. In some cases, the client has no ability to check its remote data possession, such as the client is in prison because of committing crime, on the ocean-going vessel, in the battlefield because of the war, and so on. It has to delegate the remote data possession checking task to some proxy. In this paper, we study proxy provable data possession (PPDP). In public clouds, PPDP is a matter of crucial importance when the client cannot perform the remote data possession checking. We study the PPDP system model, the security model, and the design method. Based on the bilinear pairing technique, we design an efficient PPDP protocol. Through security analysis and performance analysis, our protocol is provable secure and efficient.

Direct utilization of solar energy for photocatalytic removal of ammonia from water is a topic of strong interest. However, most of the photocatalysts with effective performance are solely metal-based semiconductors. Here, we report for the first time that a new type of atomic single layer graphitic-C(3)N(4) (SL g-C(3)N(4)), a metal-free photocatalyst, has an excellent photocatalytic activity for total ammonia nitrogen (TAN) removal from water. The results demonstrated that over 80% of TAN (initial concentration 1.50 mg · L(-1)) could be removed in 6 h under Xe lamp irradiation (195 mW · cm(-2)). Furthermore, the SL g-C(3)N(4) exhibited a higher photocatalytic activity in alkaline solution than that in neutral or acidic solutions. The investigation suggested that both photogenerated holes and hydroxyl radicals were involved the TAN photocatalytic oxidation process and that the major oxidation product was NO3(-)-N. In addition, SL g-C(3)N(4) exhibited good photocatalytic stability in aqueous solution. This work highlights the appealing application of an inexpensive metal-free photocatalyst in aqueous ammonia treatment.

Due to increasing safety concerns regarding human consumption of fish products, an increasing number of medicinal chemicals are prohibited from use in aquaculture. As a result, Chinese herbal medicines are being increasingly used, coining the use of the term “green medicine.” Research shows that Chinese herbal medicines have many beneficial effects on fish, including growth promotion, enhancement of disease resistance, and improvement in meat quality. Many effective ingredients have been discovered in Chinese herbal medicines, which function to promote feed intake, improve meat flavor, and increase digestive enzyme activity. They also regulate and participate in processes that improve the specific and non-specific immunity of fish; however, the composition of Chinese herbal medicines is very complex and it is often difficult to identify the effective ingredients. This article reviews the latest research and application progress in Chinese herbal medicines regarding growth and feed utilization, immunity and disease resistance, and the meat quality of cultured fish. It also discusses research on the chemical constituents of classical Chinese medicinal herbs and problems with the application of Chinese herbal medicines in fish culture. This article concludes by proposing that future studies on Chinese herbal medicines should focus on how to cheaply refine and extract the effective ingredients in classical Chinese medicinal herbs, as well as how to use them efficiently in aquaculture.

BACKGROUND: Treatment options for metastatic castrate-resistant prostate cancer (mCRPC) are limited and typically are centered on docetaxel-based chemotherapy. We previously reported that elevated miR-375 levels were significantly associated with poor overall survival of mCRPC patients. In this study, we evaluated if miR-375 induced chemo-resistance to docetaxel through regulating target genes associated with drug resistance. METHODS: We first compared miR-375 expression level between prostate cancer tissues and normal prostate tissues using data from The Cancer Genome Atlas (TCGA). To examine the role of miR-375 in docetaxel resistance, we transfected miR-375 using a pre-miRNA lentiviral vector and examined the effects of exogenously overexpressed miR-375 on cell growth in two prostate cancer cell lines, DU145 and PC-3. To determine the effect of overexpressed miR-375 on tumor growth and chemo-resistance in vivo, we injected prostate cancer cells overexpressing miR-375 into nude mice subcutaneously and evaluated tumor growth rate during docetaxel treatment. Lastly, we utilized qRT-PCR and Western blot assay to examine two miR-375 target genes, SEC23A and YAP1, for their expression changes after miR-375 transfection. RESULTS: By examining 495 tumor tissues and 52 normal tissues from TCGA data, we found that compared to normal prostate, miR-375 was significantly overexpressed in prostate cancer tissues (8.45-fold increase, p value = 1.98E-23). Docetaxel treatment induced higher expression of miR-375 with 5.83- and 3.02-fold increases in DU145 and PC-3 cells, respectively. Interestingly, miR-375 appeared to play a dual role in prostate cancer proliferation. While miR-375 overexpression caused cell growth inhibition and cell apoptosis, elevated miR-375 also significantly reduced cell sensitivity to docetaxel treatment in vitro, as evidenced by decreased apoptotic cells. In vivo xenograft mouse study showed that tumors with increased miR-375 expression were more tolerant to docetaxel treatment, demonstrated by greater tumor weight and less apoptotic cells in miR-375 transfected group when compared to empty vector control group. In addition, we examined expression levels of the two miR-375 target genes (SEC23A and YAP1) and observed significant reduction in the expression at both protein and mRNA levels in miR-375 transfected prostate cancer cell lines. TCGA dataset analysis further confirmed the negative correlations between miR-375 and the two target genes (r = -0.62 and -0.56 for SEC23A and YAP1, respectively; p < 0.0001). CONCLUSIONS: miR-375 is involved in development of chemo-resistance to docetaxel through regulating SEC23A and YAP1 expression. Our results suggest that miR-375 or its target genes, SEC23A or YAP1, might serve as potential predictive biomarkers to docetaxel-based chemotherapy and/or therapeutic targets to overcome chemo-resistance in mCRPC stage.

Temperature is one of the most prominent abiotic factors affecting ectotherms. Most fish species, as ectotherms, have extraordinary ability to deal with a wide range of temperature changes. While the molecular mechanism underlying temperature adaptation has long been of interest, it is still largely unexplored with fish. Understanding of the fundamental mechanisms conferring tolerance to temperature fluctuations is a topic of increasing interest as temperature may continue to rise as a result of global climate change. Catfish have a wide natural habitat and possess great plasticity in dealing with environmental variations in temperature. However, no studies have been conducted at the transcriptomic level to determine heat stress-induced gene expression. In the present study, we conducted an RNA-Seq analysis to identify heat stress-induced genes in catfish at the transcriptome level. Expression analysis identified a total of 2,260 differentially expressed genes with a cutoff of twofold change. qRT-PCR validation suggested the high reliability of the RNA-Seq results. Gene ontology, enrichment, and pathway analyses were conducted to gain insight into physiological and gene pathways. Specifically, genes involved in oxygen transport, protein folding and degradation, and metabolic process were highly induced, while general protein synthesis was dramatically repressed in response to the lethal temperature stress. This is the first RNA-Seq-based expression study in catfish in response to heat stress. The candidate genes identified should be valuable for further targeted studies on heat tolerance, thereby assisting the development of heat-tolerant catfish lines for aquaculture.

A newly discovered iridescent virus that causes severe disease and high mortality in farmed Litopenaeus vannamei in Zhejiang, China, has been verified and temporarily specified as shrimp hemocyte iridescent virus (SHIV). Histopathological examination revealed basophilic inclusions and pyknosis in hematopoietic tissue and hemocytes in gills, hepatopancreas, periopods and muscle. Using viral metagenomics sequencing, we obtained partial sequences annotated as potential iridoviridae. Phylogenetic analyses using amino acid sequences of major capsid protein (MCP) and ATPase revealed that it is a new iridescent virus but does not belong to the five known genera of Iridoviridae. Transmission electron microscopy showed that the virus exhibited a typical icosahedral structure with a mean diameter of 158.6 ± 12.5 nm (n = 30)(v-v) and 143.6 ± 10.8 nm (n = 30)(f-f), and an 85.8 ± 6.0 nm (n = 30) nucleoid. Challenge tests of L. vannamei via intermuscular injection, per os and reverse gavage all exhibited 100% cumulative mortality rates. The in situ hybridization showed that hemopoietic tissue, gills, and hepatopancreatic sinus were the positively reacting tissues. Additionally, a specific nested PCR assay was developed. PCR results revealed that L. vannamei, Fenneropenaeus chinensis, and Macrobrachium rosenbergii were SHIV-positive, indicating a new threat existing in the shrimp farming industry in China.

A series of acidic deep eutectic solvents were designed and synthesized, which could be used for the successful oxidation/extraction desulfurization of fuels.