Institutional Repository of Yantai Institute of Coastal Zone Research, CAS
Not a member yet
13079 research outputs found
Sort by
Characteristics and models of anthropogenic disturbances on islands from perspective of coastline: Extensive cases from Indian Ocean and mediterranean sea
No full textThe negative impacts of anthropogenic disturbances on the ecology of small island states or regions are important topics mentioned by United Nations' Sustainable Development Goals. This study used the coastline as an indicator to analyze four parameters (the annual variation rate of the artificial coastline length, the index of coastline utilization degree, the index of coastline type diversity, and the standard deviation ellipse of the latter two indicators) to study the changing characteristics of coastal development and utilization of over 13,000 islands, revealing the spatiotemporal evolution characteristics and patterns of human disturbance in island coastal zones. The results indicated that:(1) The spatial-temporal patterns of coastline length and structure undergone significant changes. The length of artificial coastline increased, while natural coastline decreased. The most pronounced change in the artificial coastline was the proliferation of aquaculture embankments, and the most drastic changes occurred in the coastal areas of Southeast Asia.(2) The intensity of coastal development and utilization, as well as the diversity of coastline types, showed an upward trend on the islands. (3) The centroid of coastline utilization degree and type diversity both shifted southeastward by 59.53 km and 931.05 km, respectively. (4) The anthropogenic disturbance patterns on the islands primarily included land reclamation and occupation of original wetland systems. Our study revealed the spatiotemporal characteristics and multiple scenario patterns of anthropogenic disturbance on islands at a large spatial scale from 1990 to 2020, and we quantitatively analyzed the relationship between anthropogenic disturbance factors and changes in the coastline of islands. Islands are currently facing significant pressures from development and conservation. This work is of great significance for the study of sustainable development and management of islands experiencing highintensity human activities
Quantum phase synchronization via exciton-vibrational energy dissipation sustains long-lived coherence in photosynthetic antennas
No full textThe lifetime of electronic coherences found in photosynthetic antennas is known to be too short to match the energy transfer time, rendering the coherent energy transfer mechanism inactive. Exciton-vibrational coherence time in excitonic dimers which consist of two chromophores coupled by excitation transfer interaction, can however be much longer. Uncovering the mechanism for sustained coherences in a noisy biological environment is challenging, requiring the use of simpler model systems as proxies. Here, via two-dimensional electronic spectroscopy experiments, we present compelling evidence for longer exciton-vibrational coherence time in the allophycocyanin trimer, containing excitonic dimers, compared to isolated pigments. This is attributed to the quantum phase synchronization of the resonant vibrational collective modes of the dimer, where the anti-symmetric modes, coupled to excitonic states with fast dephasing, are dissipated. The decoupled symmetric counterparts are subject to slower energy dissipation. The resonant modes have a predicted nearly 50% reduction in the vibrational amplitudes, and almost zero amplitude in the corresponding dynamical Stokes shift spectrum compared to the isolated pigments. Our findings provide insights into the mechanisms for protecting coherences against the noisy environment.
Photosynthesis in biological systems occurs in a noisy environment that reduces the lifetime of coherences in the excitation energy transfer. Here the author demonstrate that long-lasting coherences are protected by quantum phase synchronization, realized in dimers by exciton-vibrational coupling where energy dissipation occurs predominantly in resonant anti-symmetric collective modes
Colorimetric and fluorescent independent dual "signal on" biosensor for accurate detection of ochratoxin A based on aptamer-triggered biocatalytic reactions
No full textOchratoxin A (OTA) is a hazardous food contaminant with significant health risks. Dual -channel OTA detection is noted for its cross-reference capability and high accuracy. Still, challenges in addressing in -system corrections and "signal off" related false positives and limited signal gains remain. Herein, we developed a dual -channel "signal on" aptasensor with one recognition process and two independent signal outputs for OTA analysis. The OTA aptamer binds to magnetic beads (MBs) and partially hybridizes with a complementary -trigger (cDNATrigger) sequence. Adding OTA disrupts the duplex sequence, leading to G-quadruplex (G4) formation and enrichment on the MBs, which then interacts with hemin to catalyze a color signal. Concurrently, the freed cDNA-Trigger catalyzes an enzyme -free DNA circuit, producing a fluorescence signal. The magnetic enrichment and signal amplification strategies make the proposed assay demonstrate excellent sensitivity toward OTA, with limits of detection (LOD) of 0.017 pM in the fluorescence channel and 48.1 pM in the colorimetric channel. Both channels have effectively detected OTA in grape juice and baijiu, demonstrating their applicability and reliability. Moreover, given the widespread use of smartphones globally, a mini -program with a self -correction function was designed to facilitate on -site colorimetric channel monitoring, making OTA detection more accessible and user-friendly
Effects of temperature on fertility in hybrid hermaphroditic <i>Argopecten</i> scallops
No full textTemperature is a critical factor affecting the growth, development and reproduction of aquatic organisms. The interspecific F1 hybrids between hermaphroditic bay scallops (Argopecten irradians) and Peruvian scallops (Argopecten purpuratus) exhibited significant heterosis in yield, but sterility in most hybrids hindered large scale interspecific hybridization and speciation. We first explored the physiological effect of temperature on the fertility of hybrid hermaphroditic Argopecten scallops with F1 hybrids treated at 6 different temperatures (18 degrees C, 20 degrees C, 22 degrees C, 24 degrees C, 26 degrees C, and 28 degrees C). The results showed that the final mortality rates from 18 degrees C to 22 degrees C were significantly lower than those from 24 degrees C to 28 degrees C. With the decrease of the temperature, the size, gonadal index, ATP content, and expression of most genes related to fertility regulation gradually decreased in F1 hybrids treated at 22 degrees C, 20 degrees C and 18 degrees C, and the apoptosis rate of oocytes gradually increased, but the activity of SOD (superoxide dismutase) and CAT (catalase) first increased and then decreased. The fertility of hybrids treated at 22 degrees C, 20 degrees C and 18 degrees C gradually decreased with the decrease of the temperature. According to gene expression, temperature may regulate the fertility of Argopecten F1 hybrids by affecting apoptosis, meiosis, ATP production and damage repair to inhibit the genesis and maturation of germ cells. Our findings suggest that temperature can affect the hybrid fertility of hermaphroditic Argopecten scallops and provide the basis for further research on the mechanism of temperature on sterility
Identifying the key factors influencing spatial and temporal variations of regional coastal fishing activities
No full textFishing is one of the most pervasive human activities for harvesting natural resources. Accurate understanding of the dynamic variations of regional fishing activities and their influence mechanisms is crucial for marine conservation and fisheries management. Previous studies have described the spatio-temporal distribution of fishing operations. However, there is still a need for a comprehensive interpretation of why and how these variations occur, especially in regional coastal waters. In this study, taking the Bohai Sea and its adjacent waters as an example, the correlation between regional fishing activities and multiple factors, including the marine environment, geographical position, socio-economic conditions, and marine management policies, was investigated from the perspective of human geography. Automatic Identification System (AIS) data for fishing vessels were used, combining remote sensing, geographic information system (GIS), and statistical models. The results indicated that the spatio-temporal variations of regional coastal fishing activities were driven by complex interactions among these factors. Overall, the average explanatory power of socio-economic and geographical position factors on fishing activities was higher than that of marine environmental factors. The importance of the marine environment and geographical position for fishing activities varied throughout different seasons. The sensitivity of fishing activities to geographical position was relatively high, with the explained deviance exceeding 62% of the total explained deviance. Intensive fishing was primarily observed within a particular range of the sea surface temperature frontal gradient (0.20-0.60 degrees C/km) or sea surface chlorophyll-a frontal gradient (1.06-1.25). The spatial distribution of fishing activities is effectively constrained by implemented marine management policies. This study sheds new light on the key factors influencing regional fishing activities in coastal waters and highlights the complexity of their interaction effects. These findings can provide a theoretical basis for the restoration of fishery resources and marine fishing management
Reproductive biology of <i>Hemitripterus villosus</i> in the Bohai Strait, China
No full textTo understand the reproductive biology of Hemitripterus villosus in the Bohai Strait, and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species, a year-round detail study was conducted for the first time. In total, 263 individuals were randomly sampled off the coasts of the Bohai Strait. Results show that and the overall female-to-male ratio (1.35:1) did not differ significantly from the 1:1 sex ratio. The length and weight relationship for females and males were regressed, depicting an isometric growth for both sexes. Four reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were identified. The monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to December. The average diameter of eggs ranged from 2.10 to 3.57 mm. The length at first sexual maturity was 224.87 mm for females and 241.26 mm for males. Significant positive relationships between absolute fecundity and fish size, and also gonadal weight were observed. H. villosus from the Bohai Strait exhibited smaller body size, smaller egg diameter, lower gonadosomatic index, lower absolute fecundity, and higher population extinction risk than the other populations' studied previously. Our findings contribute to understanding the status of this isolated westernmost population, and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait
Seasonal distribution of caffeine in the Bohai Sea, Yellow Sea, and estuaries of Yantai City, China
No full textWe employed a validated method to assess the seasonal variation and distribution of caffeine in the Bohai and Yellow Seas, as well as in Yantai urban estuaries and offshore region in northern China. Caffeine concentrations were highest during the summer in the Yellow Sea (1436.4 ng/L) and lowest in the Yantai urban offshore region during the spring and autumn and in the Yantai urban estuarine area and Bohai Sea during the winter (0.1 ng/L). There was significant variation in maximum caffeine levels among seasons across all regions examined, reaching a difference of 5980.5 times at the same sampling site between summer and winter. The caffeine concentration in the Yantai offshore region was significantly higher than in the Bohai and Yellow Seas. This study is the first investigation of seasonal fluctuations in the pollution levels of neurotoxic substances in the northern seas of China
Improvement of the Antioxidant and Antitumor Activities of Benzimidazole-Chitosan Quaternary Ammonium Salt on Drug Delivery Nanogels
No full textThe present study focused on the design and preparation of acid-responsive benzimidazole-chitosan quaternary ammonium salt (BIMIXHAC) nanogels for a controlled, slow-release of Doxorubicin HCl (DOX.HCl). The BIMIXHAC was crosslinked with sodium tripolyphosphate (TPP) using the ion crosslinking method. The method resulted in nanogels with low polydispersity index, small particle size, and positive zeta potential values, indicating the good stability of the nanogels. Compared to hydroxypropyl trimethyl ammonium chloride chitosan-Doxorubicin HCl-sodium tripolyphosphate (HACC-D-TPP) nanogel, the benzimidazole-chitosan quaternary ammonium salt-Doxorubicin HCl-sodium tripolyphosphate (BIMIXHAC-D-TPP) nanogel show higher drug encapsulation efficiency and loading capacity (BIMIXHAC-D-TPP 93.17 +/- 0.27% and 31.17 +/- 0.09%), with acid-responsive release profiles and accelerated release in vitro. The hydroxypropyl trimethyl ammonium chloride chitosan-sodium tripolyphosphate (HACC-TPP), and benzimidazole-chitosan quaternary ammonium salt-sodium tripolyphosphate (BIMIXHAC-TPP) nanogels demonstrated favorable antioxidant capability. The assay of cell viability, measured by the MTT assay, revealed that nanogels led to a significant reduction in the cell viability of two cancer cells: the human lung adenocarcinoma epithelial cell line (A549) and the human breast cancer cell line (MCF-7). Furthermore, the BIMIXHAC-D-TPP nanogel was 2.96 times less toxic than DOX.HCl to the mouse fibroblast cell line (L929). It was indicated that the BIMIXHAC-based nanogel with enhanced antioxidant and antitumor activities and acidic-responsive release could serve as a potential nanocarrier
A honeycomb-like micro-needle sensor with gold nanoparticles embedded for the determination of hexavalent chromium in seawater
No full textAs one of the most toxic heavy metals, hexavalent chromium (Cr(VI)) is a typical environmental pollutant that directly affects human health. In this work, a novel micro-needle sensor with honeycomb-like structure and embedded gold nanoparticles was proposed for the stable and sensitive determination of Cr(VI). The honeycomblike structure provided larger specific surface area to support more gold nanoparticles which exhibited excellent catalytic activity towards the electrochemical reduction of Cr(VI) to Cr(III). In addition, gold nanoparticles were embedded into the holes of the honeycomb-like structure, which can effectively prevent them from falling off from the electrode surface due to the protection of the holes. Combining the honeycomb-like structure of microneedle electrode with the excellent catalytic activity of gold nanoparticles, the fabricated sensor exhibited outstanding stability and sensitivity for the cathodic stripping determination of Cr(VI). A linear range of Cr(VI) from 0.5 to 300 mu mol/L was obtained, with the detection limit of 0.15 mu mol/L. The recovery of the sensor for the determination of hexavalent chromium in seawater samples was also investigated. Moreover, the sensor might be further adapted for the determination of other heavy metals with different nanoparticles embedded
Source identification of sedimentary organic carbon in coastal wetlands of the western Bohai Sea
No full textCoastal wetlands play a vital role in mitigating climate change, yet the characteristics of buried organic carbon (OC) and carbon cycling are limited due to difficulties in assessing the composition of OC from different sources (allochthonous vs. autochthonous). In this study, we analyzed the total organic carbon (TOC) to total nitrogen (TN) ratio (C/N), stable carbon isotope (delta 13C) composition, and n-alkane content to distinguish different sources of OC in the surface sediments of the coastal wetlands on the western coast of the Bohai Sea. The coupling of the C/N ratio with delta 13C and n-alkane biomarkers has been proved to be an effective tool for revealing OC sources. The three end-member Bayesian mixing model based on coupling C/N ratios with delta 13C showed that the sedimentary OC was dominated by the contribution of terrestrial particulate organic matter (POM), followed by freshwater algae and marine phytoplankton, with relative contributions of 47 +/- 21 %, 41 +/- 18 % and 12 +/- 17 %, respectively. The relative contributions of terrestrial plants, aquatic macrophytes and marine phytoplankton assessed by n-alkanes were 56 +/- 8 %, 35 +/- 9 % and 9 +/- 5 % in the study area, respectively. The relatively high salinity levels and strong hydrodynamic conditions of the Beidagang Reservoir led to higher terrestrial plants source and lower aquatic macrophytes source than these of Qilihai Reservoir based on the assessment of n-al- kanes. Both methods showed that sedimentary OC was mainly derived from terrestrial sources (plant -domi- nated), suggesting that vegetation plays a crucial role in storing carbon in coastal wetlands, thus, the coastal vegetation management needs to be strengthened in the future. Our findings provide insights into the origins and dynamics of OC in coastal wetlands on the western coast of the Bohai Sea and a significant scientific basis for future monitoring of the blue carbon budget balance in coastal wetlands