Search Results (17)

The driving mechanism of new qualitative productivity forces for coordinated development, which constitutes an inherent requirement of high-quality development, requires creative factor allocation through spatial flows, and the same is true for new maritime qualitative productivity forces. In this study, we constructed an evaluation indicator system to assess the impact of spatial flows of marine new qualitative productivity force factors on economic coordinated development in China’s coastal regions. Using panel data from 11 coastal provinces (2003–2022), we quantified new qualitative productivity force factor spatial flows and marine economic coordinated development levels, visualized their spatial–temporal patterns, and empirically examined their interaction mechanisms. The key findings include the following: (1) From 2013 to 2022, marine new qualitative productivity force factor spatial flows in coastal China transitioned from clustered “block-style” to scattered “multi-point” distribution patterns, with marine economic coordination exhibiting steady growth alongside pronounced spatial polarization. (2) Marine new qualitative productivity force factor spatial flows demonstrate significant positive direct effects on local marine economic coordination. (3) The notable spatial spillover effects of marine new qualitative productivity force factor spatial flows enhance coordinated development in neighboring regions. (4) Heterogeneous impacts emerge across marine new qualitative productivity force factor dimensions, where the spatial flows of new-type marine objects of labor and means of labor exert particularly significant influences. These findings provide policy insights for optimizing the spatial allocation of marine new qualitative productivity force factors to advance China’s marine economic coordination. Full article

Typhoons can significantly alter ocean hydrodynamic processes through their powerful external forces, greatly affecting marine biogeochemistry and ocean productivity. However, the specific impacts of typhoons with different tracks on coastal dynamics, including frontal activities and phytoplankton lateral transport, are not well understood. This study captured two distinct types of typhoons, namely Merbok (2017) and Nuri (2020), which landed from the right and left sides of the Pearl River Estuary (PRE), respectively, utilizing satellite remote sensing data to study their impacts on frontal dynamics and marine productivity. We found that after both typhoons, the southwest monsoon amplified geostrophic currents significantly (increased ~14% after Nuri (2020) and 48% after Merbok (2020)). These stronger currents transported warmer offshore seawater from the South China Sea to the PRE and intensified the frontal activities in nearshore PRE (increased ~47% after Nuri (2020) and ~2.5 times after Merbok (2020)). The ocean fronts limited the transport of high-chlorophyll and eutrophic water from the PRE to the offshore waters due to the barrier effect of the front. This resulted in a sharp drop in chlorophyll concentrations in the offshore-adjacent waters of PER after Typhoon Nuri (2020) (~37%). By contrast, despite the intensified geostrophic current induced by the summer monsoon following Typhoon Merbok (2020), its stronger offshore force, driven by the intense offshore wind stress (characteristic of the left-side typhoon), caused the nearshore front to move offshore. The displacement of fronts lifted the restriction of the front barrier and led more high-chlorophyll (increased ~4 times) and eutrophic water to be transported offshore, thereby stimulating offshore algal blooms. Our findings elucidate the mechanisms by which different track typhoons influence chlorophyll distribution through changes in frontal dynamics, offering new perspectives on the coastal ecological impacts of typhoons and further studies for typhoon impact modeling or longshore management. Full article

The development of marine new quality productive forces and the enhancement of marine economic resilience are critical strategies for cultivating new drivers and advantages for high-quality and sustainable development in the marine sector. In order to deeply explore the relationship between these two constructs, this study selected panel data from 11 coastal provinces from 2007 to 2021 to construct an indicator system for MNQPFs and marine economic resilience, conducted scientific calculations and analysis, and, finally, used a two-way fixed effect model for empirical analysis and the instrumental variable method for robustness testing. The key findings are as follows: (1) The level of marine new quality productive forces (MNQPFs) in coastal areas demonstrates considerable spatial variability. The spatial distribution of MNQPF levels in the Bohai Sea and South China Sea regions is similar, whereas the levels in the Yellow Sea and East China Sea region demonstrate better balance. (2) A regional analysis of marine economic resilience indicates that the Bohai Sea region demonstrates a weak development trend and the South China Sea region demonstrates an unbalanced development trend, while the Yellow Sea and East China Sea region demonstrates a favorable development trend. (3) MNQPFs significantly improve marine economic resilience, including both its resistance and evolution abilities; the positive impact of marine new quality productive forces on the marine economic resilience’s recovery ability exhibits a time lag effect. (4) Heterogeneous results demonstrate that the positive impact of MNQPFs on marine economic resilience varies according to the level of marine economic development in different coastal areas, with a more significant promoting effect in less developed areas. Therefore, adaptively accelerating the development of marine new quality productive forces according to local conditions by effectively utilizing the unique resource endowments of each coastal area is essential for continuously strengthening marine economic resilience. This study can enrich research in the field of marine economics and provide references for marine economic development in coastal areas. Full article

Exploring the development laws of new quality productivity and leveraging its role in empowering marine economy high-quality development (MEHQ) is of great significance for promoting the construction of a maritime power in China, achieving the goals of Chinese-style modernization and solidifying the country’s advantages in marine economic development. This paper systematically reviews the mechanisms and effects of new quality productivity (NQP) in empowering MEHQ. Using panel data from 17 cities along the Bohai Sea from 2010 to 2022, we comprehensively measure the combined levels of NQP and MEHQ. Employing various statistical analysis methods, including benchmark regression models, multiple mediation effect models, and spatial Durbin models, we empirically test the mechanisms and spatial spillover effects of NQP in empowering MEHQ. The results indicate that NQP has a significant positive driving effect on MEHQ, and this conclusion remains valid after a series of robustness tests. The empowering effect of NQP on MEHQ mainly occurs through three pathways: marine technological innovation, optimization of marine industrial structure, and improvement of marine resource allocation efficiency. There is a positive correlation between NQP and MEHQ, with significant agglomeration phenomena, reflecting the non-uniform characteristics of spatial distribution. NQP not only empowers MEHQ but also exhibits significant spatial spillover effects, promoting MEHQ in adjacent regions and releasing growth dividends. Full article

The digital economy has emerged as a transformative force, creating new opportunities for sustainable development, especially within the marine fisheries sector. This study examines the impact of the digital economy on the green total factor productivity (GTFP) of fisheries in China’s coastal regions from 2011 to 2022. Using panel data from 11 coastal provinces, we employ the Slack-Based Measure (SBM) model and the Global Malmquist–Luenberger (GML) index to assess GTFP and analyze the effects of digital economic development. Our findings indicate the following: (1) the digital economy significantly enhances fishery GTFP, improving both resource efficiency and environmental sustainability; (2) the impact varies across regions, reflecting notable regional heterogeneity in digital infrastructure and adoption; and (3) a threshold effect exists, whereby the influence of the digital economy on GTFP varies depending on the level of digital economic development. This research underscores the dual role of digital technologies in boosting fisheries’ economic productivity while promoting greener, more sustainable practices. This study provides valuable insights for policymakers aiming to integrate digital transformation into the sustainable development of marine fisheries. Full article

New productive forces are the new impetus for the high-quality development of the marine economy. To accurately measure the development level of marine new productive forces, this study constructs an evaluation index system from four aspects: development impetus, development structure, development mode, and development achievements. This study determines the combination weights of indicators based on relative entropy. Kernel density estimation, spatial Markov chain and Dagum Gini coefficient are used to analyze the spatiotemporal evolution, regional disparities and sources of marine new productive forces in coastal provinces of China. Finally, the decision-making trial and evaluation laboratory together with interpretative structural modeling (DEMATEL-ISM) is used to analyze the key influencing factors of marine new productive forces. Results show that the marine new productive forces have been increasing year by year, but the overall level is relatively low. There is a phenomenon of “club convergence” in the development level of marine new productive forces, and the state transfer occurs between adjacent types. The overall variation in marine new productive forces is showing a downward trend, with disparities arising mainly from inter-regional variation and hypervariable densities. The key influencing factors include investment in marine R&D, the openness of foreign investment, the openness of foreign trade, and investment in pollution control. The study conclusion provides support for designing a development path for marine new productive forces that conforms to regional characteristics. Full article

In order to realize the multi-level utilization of marine shellfish resources and to develop the potential biological activity of processing by-products of Atrina pectinata, gelatin was extracted from the mantle and the potential whitening effect of its enzymatic peptides was explored. Taking tyrosinase inhibitory activity as the evaluation index, the enzyme hydrolysate process was optimized by response-surface methodology, and the optimal enzyme hydrolysate conditions were as follows: pH 5.82, 238 min enzyme hydrolysate time, and temperature of 54.5 °C. Under these conditions, the tyrosinase inhibition activity of Atrina pectinata mantle gelatin peptide (APGP) was 88.6% (IC₅₀ of 3.268 ± 0.048 mg/mL). The peptides obtained from the identification were separated by ultrafiltration and LC–MS/MS, and then four new peptides were screened by molecular docking, among which the peptide Tyr-Tyr-Pro (YYP) had the strongest inhibitory effect on tyrosinase with an IC₅₀ value of 1.764 ± 0.025 mM. The molecular-docking results indicated that hydrogen bonding is the main driving force for the interaction of the peptide YYP with tyrosinase. From the Lineweaver–Burk analysis, it could be concluded that YYP is inhibitory to tyrosinase and exhibits a mixed mechanism of inhibition. These results suggest that YYP could be widely used as a tyrosinase inhibitor in whitening foods and pharmaceuticals. Full article

Copiotrophic bacteria that respond rapidly to nutrient availability, particularly high concentrations of carbon sources, play indispensable roles in marine carbon cycling. However, the molecular and metabolic mechanisms governing their response to carbon concentration gradients are not well understood. Here, we focused on a new member of the family Roseobacteraceae isolated from coastal marine biofilms and explored the growth strategy at different carbon concentrations. When cultured in a carbon-rich medium, the bacterium grew to significantly higher cell densities than Ruegeria pomeroyi DSS-3, although there was no difference when cultured in media with reduced carbon. Genomic analysis showed that the bacterium utilized various pathways involved in biofilm formation, amino acid metabolism, and energy production via the oxidation of inorganic sulfur compounds. Transcriptomic analysis indicated that 28.4% of genes were regulated by carbon concentration, with increased carbon concentration inducing the expression of key enzymes in the EMP, ED, PP, and TCA cycles, genes responsible for the transformation of amino acids into TCA intermediates, as well as the sox genes for thiosulfate oxidation. Metabolomics showed that amino acid metabolism was enhanced and preferred in the presence of a high carbon concentration. Mutation of the sox genes decreased cell proton motive force when grown with amino acids and thiosulfate. In conclusion, we propose that copiotrophy in this Roseobacteraceae bacterium can be supported by amino acid metabolism and thiosulfate oxidation. Full article

Industrial engineering applications often require manufacturing large components in composite materials to obtain light structures; however, moulds are expensive, especially when manufacturing a limited batch of parts. On the one hand, when traditional approaches are carried out, moulds are milled from large slabs or laminated with composite materials on a model of the part to produce. In this case, the realisation of a mould leads to adding time-consuming operations to the manufacturing process. On the other hand, if a fully additively manufactured approach is chosen, the manufacturing time increases exponentially and does not match the market’s requirements. This research proposes a methodology to improve the production efficiency of large moulds using a hybrid technology by combining additive manufacturing and milling tools. A block of soft material such as foam is milled, and then the printing head of an additive manufacturing machine deposits several layers of plastic material or modelling clay using conformal three-dimensional paths. Finally, the mill can polish the surface, thus obtaining a mould of large dimensions quickly, with reduced cost and without needing trained personnel and handcraft polishing. A software tool has been developed to modify the G-code read by an additive manufacturing machine to obtain material deposition over the soft mould. The authors forced conventional machining instructions to match those of an AM machine. Thus, additive deposition of new material uses 3D conformal trajectories typical of CNC machines. Consequently, communication between two very different instruments using the same language is possible. At first, the code was tested on a modified Fused Filament Fabrication machine whose firmware has been adapted to manage a milling tool and a printing head. Then, the software was tested on a large machine suitable for producing moulds for the large parts typical of marine and aerospace engineering. The research demonstrates that AM technologies can integrate conventional machinery to support the composite materials industry when large parts are required. Full article

Natural products have various and complicated structures, which is still a challenge for elucidating these compounds, especially for those lacking two-dimensional nuclear magnetic resonance (2D NMR) correlations mainly caused by high C/H ratios or proton-deficient and multiple heteroatoms through the conventional structural analytical methods. We reported a novel module-assembly calculation method named Dooerafa, which included constructing the meta-structures by a grafting method based on the crucial and the limited 2D NMR correlations, ring-contraction strategy based on mechanic force field and quantum chemical theory, and self-assemble calculation in Python programming for shaping up the structural candidates along with DFT-GIAO calculation. This new method, verified by a known alkaloid spiroreticulatine with the structure determined by X-ray diffraction, was performed for the structural elucidation of aaptourinamine isolated from marine sponge Aaptos suberitoides, showing us a brand new scaffold of imidazo [4,5,1-ij]pyrrolo [3,2-f]quinolin-7(8H)-one, which has a biosynthetic relationship with the bioactive and structurally unique aaptamine alkaloid. Full article

This article reviews the state of the knowledge and technology in the field of friction-loss measurements in internal combustion piston engines. The dependencies that describe the loss of energy in combustion engines and injection apparatus are presented. Currently, very little can be found in the literature on the study of frictional forces in injection apparatus, but mainly in the piston–cylinder group, so this work significantly fills that gap. The aim of this article is to construct a device and to develop a method for assessing the technical state of injector nozzles to minimize friction losses in internal combustion engines at the stages of evaluation, design, production and operation. This article presents a stand for determining the maximum friction forces due to gravity loading by water-jet control. This article also presents test results on the maximum friction force between a needle and a body of injector nozzles in piston combustion engines on a designed and purpose-built stand outside of the combustion engine. Various designs and injector nozzles are made from various types of alloy steel for marine and automotive piston internal combustion engines fueled with distillation or residual fuels, and are tested. The research concerned conventional elements for the injection apparatus as well as electronically controlled subsystems. Precision pairs of injection equipment are selected for the tests: new ones are employed after the storage period and operated in natural conditions. The elements dismantled from the internal combustion engines are tested in the presence of fuel or calibration oil of similar properties. The maximum static frictional forces under the hydrostatic loading are measured, alongside the parameters for the dynamic movement of the nozzle needles from bodies of the injector nozzle as time, speed, acceleration and dynamic force. The influence of the angular position of the needle in relation to the bodies of the precision pairs conventional internal combustion engines, the diametral clearance between the nozzle body and needle, and the surface conditions on the values of the maximum friction force are also presented. Errors in shape and position result in the uniqueness of the friction force at the mutual angular position of the needle in relation to the nozzle body, and the decrease in diametral clearance and deterioration of the surface state increase the friction losses. A model was elaborated of the influence of various factors on the value of the maximum friction force. Full article

The bioactive natural product seriniquinone was discovered as a potential melanoma drug, which was produced by the as-yet-undescribed marine bacterium of the rare genus Serinicoccus. As part of a long-term research program aimed at the discovery of new agents for the treatment of cancer, seriniquinone revealed remarkable in vitro activity against a diversity of cancer cell lines in the US National Cancer Institute 60-cell line screening. Target deconvolution studies defined the seriniquinones as a new class of melanoma-selective agents that act in part by targeting dermcidin (DCD). The targeted DCD peptide has been recently examined and defined as a “pro-survival peptide” in cancer cells. While DCD was first isolated from human skin and thought to be only an antimicrobial peptide, currently DCD has been also identified as a peptide associated with the survival of cancer cells, through what is believed to be a disulfide-based conjugation with proteins that would normally induce apoptosis. However, the significantly enhanced potency of seriniquinone was of particular interest against the melanoma cell lines assessed in the NCI 60-cell line panel. This observed selectivity provided a driving force that resulted in a multidimensional program for the discovery of a usable drug with a new anticancer target and, therefore, a novel mode of action. Here, we provided an overview of the discovery and development efforts to date. Full article

Fungi comprise the second most species-rich organism group after that of insects. Recent estimates hypothesized that the currently reported fungal species range from 3.5 to 5.1 million types worldwide. Fungi can grow in a wide range of habitats, from the desert to the depths of the sea. Most develop in terrestrial environments, but several species live only in aquatic habitats, and some live in symbiotic relationships with plants, animals, or other fungi. Fungi have been proved to be a rich source of biologically active natural products, some of which are clinically important drugs such as the β-lactam antibiotics, penicillin and cephalosporin, the immunosuppressant, cyclosporine, and the cholesterol-lowering drugs, compactin and lovastatin. Given the estimates of fungal biodiversity, it is easy to perceive that only a small fraction of fungi worldwide have ever been investigated regarding the production of biologically valuable compounds. Traditionally, fungi are classified primarily based on the structures associated with sexual reproduction. Thus, the genus Neosartorya (Family Trichocomaceae) is the telemorphic (sexual state) of the Aspergillus section known as Fumigati, which produces both a sexual state with ascospores and an asexual state with conidiospores, while the Aspergillus species produces only conidiospores. However, according to the Melbourne Code of nomenclature, only the genus name Aspergillus is to be used for both sexual and asexual states. Consequently, the genus name Neosartorya was no longer to be used after 1 January 2013. Nevertheless, the genus name Neosartorya is still used for the fungi that had already been taxonomically classified before the new rule was in force. Another aspect is that despite the small number of species (23 species) in the genus Neosartorya, and although less than half of them have been investigated chemically, the chemical diversity of this genus is impressive. Many chemical classes of compounds, some of which have unique scaffolds, such as indole alkaloids, peptides, meroterpenes, and polyketides, have been reported from its terrestrial, marine-derived, and endophytic species. Though the biological and pharmacological activities of a small fraction of the isolated metabolites have been investigated due to the available assay systems, they exhibited relevant biological and pharmacological activities, such as anticancer, antibacterial, antiplasmodial, lipid-lowering, and enzyme-inhibitory activities. Full article

Several oil spill simulation models exist in the literature, which are used worldwide to simulate the evolution of an oil slick created from marine traffic, petroleum production, or other sources. These models may range from simple parametric calculations to advanced, new-generation, operational, three-dimensional numerical models, coupled to meteorological, hydrodynamic, and wave models, forecasting in high-resolution and with high precision the transport and fate of oil. This study presents a review of the transport and oil weathering processes and their parameterization and critically examines eighteen state-of-the-art oil spill models in terms of their capacity (a) to simulate these processes, (b) to consider oil released from surface or submerged sources, (c) to assimilate real-time field data for model initiation and forcing, and (d) to assess uncertainty in the produced predictions. Based on our review, the most common oil weathering processes involved are spreading, advection, diffusion, evaporation, emulsification, and dispersion. The majority of existing oil spill models do not consider significant physical processes, such as oil dissolution, photo-oxidation, biodegradation, and vertical mixing. Moreover, timely response to oil spills is lacking in the new generation of oil spill models. Further improvements in oil spill modeling should emphasize more comprehensive parametrization of oil dissolution, biodegradation, entrainment, and prediction of oil particles size distribution following wave action and well blow outs. Full article

Near-surface winds around the mountainous Caribbean islands contribute to orographic lifting and thermal diurnal rainfall that requires mesoscale analysis. Here, a new perspective is presented via high-resolution satellite and reanalysis products. Singular value decomposition is applied to 5 km cold-cloud duration satellite data to understand the leading mode of seasonal hydro-climate variability and its regional controls. The spatial loadings reflect wet islands in a dry marine climate, while temporal amplitude is modulated by the large-scale zonal circulation. When summer-time trade winds weaken, daytime confluence around Caribbean islands enlarges, gathering and lifting more moisture. In addition to the static geographic forcing, transient easterly waves impart the majority of marine rainfall between June and September. Higher resolution products capture the thermal orographic effect and reveal upward trends in island rainfall and soil moisture over the satellite era, while lower resolution products miss this effect. The climate of mountainous Caribbean islands is trending toward increased runoff and soil moisture. Full article