A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla wer...A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla were recorded over the entire year. The community composition was dominated by coastal warm-water species belonging to typical subtropical inner bay communities. The prosperous stage of settlement lasted from April to September, and the adhesion strength of the fouling organisms was the highest in summer. Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species of fouling organism, and other dominant species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Stylochus ijimai, Spirobranchus kraussii, Crassostrea angulata, Perna viridis, Jassa falcata, Stenothoe valida, Sphaerozius nitidus, and Biflustra grandicella. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environmental factors. Temperature was the most important environmental factor determining the geographic distribution of fouling organisms. The temperature characteristics of species essentially reflect the differences in the fouling community composition in various climate zones. The species number, settlement stage, and settlement rate of fouling organisms are closely related to water temperature. Local natural environmental conditions（salinity, water currents, light, etc.） as well as human activity（such as aquaculture production） are all important factors affecting the settlement of fouling organisms.展开更多
Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 poly...Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 polychaetes, 16 mollusks, 23 crustaceans, three echinoderms, two cnidarians, one nemertean, one priapulid, two sipunculids, and one echiuran were identified. The average density and biomass of total macrobenthos were 984 ind./m2 and 1207.1 g/ma of wet weight, respectively. The predominant species in the study area were Scoloplos armiger, Eudorella pacifica, Ophiura sarsii, Heteromastus filiformis, Ennucula tenuis, and Harpiniopsis vadiculus by abundance, while the predominant species in this area was Echinarachnius parma by biomass. Hierarchical cluster analysis （Bray-Curtis similarity measure） revealed that two impor- tant benthic assemblages in the study area were CommunityA and Community B. CommunityA was stable and Community B was unstable, as shown by the Abundance/Biomass Comparisons （ABC） approach. The macrobenthic community structure in the shelf of the Bering Sea was characterized by its high abundance and biomass, high productivity but great heterogeneity.展开更多
The low-density imaging performance of a zone plate-based nano-resolution hard x-ray computed tomography(CT)system can be significantly improved by incorporating a grating-based Lau interferometer. Due to the diffract...The low-density imaging performance of a zone plate-based nano-resolution hard x-ray computed tomography(CT)system can be significantly improved by incorporating a grating-based Lau interferometer. Due to the diffraction, however,the acquired nano-resolution phase signal may suffer splitting problem, which impedes the direct reconstruction of phase contrast CT(nPCT) images. To overcome, a new model-driven nPCT image reconstruction algorithm is developed in this study. In it, the diffraction procedure is mathematically modeled into a matrix B, from which the projections without signal splitting can be generated invertedly. Furthermore, a penalized weighted least-square model with total variation(PWLSTV) is employed to denoise these projections, from which nPCT images with high accuracy are directly reconstructed.Numerical experiments demonstrate that this new algorithm is able to work with phase projections having any splitting distances. Moreover, results also reveal that nPCT images of higher signal-to-noise-ratio(SNR) could be reconstructed from projections having larger splitting distances. In summary, a novel model-driven nPCT image reconstruction algorithm with high accuracy and robustness is verified for the Lau interferometer-based hard x-ray nano-resolution phase contrast imaging.展开更多
Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species o...Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species of macrozoobenthos belonging to nine phyla, which were dominated by polychaetes （66）, crustaceans （30）, and mollusks （25）, followed by echinoderms （9） and others （ten others, including four cnidarians, one oligochaete, one sipuncula, one priapulida, two bryozoans, and one urochordata）. The dominant species were Aphelochaeta pacifica, Heteromastus filiformis, Nephtys ciliata, Nephtys caeca, Scoletoma fragilis, Golfingia margaritacea, Nuculana pernula, Macoma calcarea, Ennucula tenuis, Macoma inquinata, Musculus discors, Echinarachnius parma, and Ophiura sarsii, so there were more cold-eurythermal boreal immigrants than trulyArctic species （endemics）. The average density and biomass （mean ± SD across all stations） of the total macrozoobenthos were （916 ± 907） ind/m2 and （902.9 ± 1227.7） g/m2 （wet weight）, respectively. Relatively high density and biomass were observed in the samples from the northeastern and southern Chukchi Sea. The spatial variation of benthic communities in the study sea area was relatively large; this spatial heteroge- neity has led to high diversity and a patchy distribution pattern in the community structure. Compared to the 1st CHINARE （July-August, 1999）, this investigation revealed different degrees of decreases in the average taxa numbers and the average density, abundance, and biodiversity in the area over the recent decade, which might be associated with global warming, human activities, and sea ice variations.展开更多
Background: Acetylshikonin, a major constituent isolated from Arnebia euchroma, is a potential candidate for anti-colorectal cancer drugs. However, the potential activity and underlying mechanism of Acetylshikonin aga...Background: Acetylshikonin, a major constituent isolated from Arnebia euchroma, is a potential candidate for anti-colorectal cancer drugs. However, the potential activity and underlying mechanism of Acetylshikonin against colorectal cancer remain unclear. Methods: In this study, Acetylshikonin was isolated from the active CHCl3 extract of Arnebia euchroma using activity-guided screening, and elucidated by the extensive spectroscopic analysis and comparison with literature data. Human colorectal cancer cells HT29, DLD-1, HCT116 or Caco-2 were exposed to different concentrations of Acetylshikonin (6.25 - 100 μg/mL) for 24 or 48 h. Cell viability, cell apoptosis and cell cycle distribution were detected. The activity of Acetylshikonin and potential mechanism of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway were evaluated in vitro and vivo. Results: We found that Acetylshikonin exhibited remarkable anti-proliferative activity in a dose-dependent manner against HT29 cells with the IC50 values of 60.82 μg/ml and 30.78 μg/ml at 24, 48 h, respectively. Moreover, Acetylshikonin induced cell cycle arrest at G0/G1 phase and early apoptosis through inhibition of PI3K/Akt/mTOR pathway. Furthermore, the assays of cell inhibition, early apoptosis and G0/G1 phase distribution showed that suppression of the PI3K/Akt pathway using LY294002 enhanced the anti-cancer effect of Acetylshikonin. Similarly, Acetylshikonin also decreased the growth of tumour in colorectal cancer xenografts in mice through PI3K/Akt/mTOR pathway. Conclusions: To sum up, these new findings provided a framework for further exploration of Acetylshikonin which possessed the potential antitumor activity by inhibiting PI3K/Akt/mTOR pathway.展开更多
The size-fractionated biomass and primary production of phytoplankton, and the influence of environmental factors on it were studied in the Dongsha natural gas hydrate zone of the northern South China Sea in May 2013....The size-fractionated biomass and primary production of phytoplankton, and the influence of environmental factors on it were studied in the Dongsha natural gas hydrate zone of the northern South China Sea in May 2013.Low nutrient, low chlorophyll a（Chl a） and primary productivity characteristics were found in these waters. The phenomena of subsurface Chl a maximum layers（SCMLs） and primary production maximum layers（SPMLs）were observed in the Dongsha waters. There were significant differences in the size-fractionated biomass and primary production that showed picophytoplankton〉nanophytoplankton〉microphytoplankton in terms of biomass and degree of contribution to production. Vertical biomass distribution indicated there were considerable differences among different phytoplankton within the euphotic zone（Zeu） in spring. For example,microphytoplankton was distributed evenly in the euphotic layer and nanophytoplankton was mainly distributed in the subsurface or in the middle of the euphotic layer, while picophytoplankton was mainly distributed in the middle or bottom of the euphotic layer. Smaller cell size and larger relative surface area allow picophytoplankton to benefit from nutrient competition and to hold a dominant position in the tropical oligotrophic waters of low latitudes. There was a positive correlation between size-fractionated biomass and temperature with pH and a negative correlation between size-fractionated biomass and silicate with phosphate. There was a positive correlation between size-fractionated primary production and temperature and a negative correlation between size-fractionated biomass and salinity with phosphate. Phosphate was an important factor influencing the size structure of phytoplankton. Meanwhile, irradiation and the euphotic layer were more important in regulating the vertical distribution of size-fractionated phytoplankton in the Dongsha natural gas hydrate zone.展开更多
-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-...-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula.展开更多
F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM...F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM)基础上融入注意力机制(Attention),提出了一种基于BiLSTM-Attention的F_(10.7)预报模型.在加拿大DRAO数据集上其平均绝对误差(MAE)为5.38,平均绝对百分比误差(MAPE)控制在5%以内,相关系数(R)高达0.987,与其他RNN模型相比拥有优越的预测性能.针对中国廊坊L&S望远镜观测的F_(10.7)数据集,提出了一种转换平均校准(Conversion Average Calibration,CAC)方法进行数据预处理,处理后的数据与DRAO数据集具有较高的相关性.基于该数据集对比分析了RNN系列模型的预报效果,实验结果表明,BiLSTM-Attention和BiLSTM两种模型在预测F_(10.7)指数方面具有较好的优势,表现出较好的预测性能和稳定性.展开更多
基金The National Natural Science Foundation of China under contract Nos 41176102 and 41306116
文摘A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla were recorded over the entire year. The community composition was dominated by coastal warm-water species belonging to typical subtropical inner bay communities. The prosperous stage of settlement lasted from April to September, and the adhesion strength of the fouling organisms was the highest in summer. Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species of fouling organism, and other dominant species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Stylochus ijimai, Spirobranchus kraussii, Crassostrea angulata, Perna viridis, Jassa falcata, Stenothoe valida, Sphaerozius nitidus, and Biflustra grandicella. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environmental factors. Temperature was the most important environmental factor determining the geographic distribution of fouling organisms. The temperature characteristics of species essentially reflect the differences in the fouling community composition in various climate zones. The species number, settlement stage, and settlement rate of fouling organisms are closely related to water temperature. Local natural environmental conditions（salinity, water currents, light, etc.） as well as human activity（such as aquaculture production） are all important factors affecting the settlement of fouling organisms.
基金The China Action Plan of the International Polar Yearthe Public Science and Technology Research Funds Projects of Ocean under contract No.201105022-2+1 种基金the National Natural Science Foundation of China under contract Nos 41306115 and 41306116the Polar Science Strategic Research Foundation of China under contract No.20140309
文摘Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 polychaetes, 16 mollusks, 23 crustaceans, three echinoderms, two cnidarians, one nemertean, one priapulid, two sipunculids, and one echiuran were identified. The average density and biomass of total macrobenthos were 984 ind./m2 and 1207.1 g/ma of wet weight, respectively. The predominant species in the study area were Scoloplos armiger, Eudorella pacifica, Ophiura sarsii, Heteromastus filiformis, Ennucula tenuis, and Harpiniopsis vadiculus by abundance, while the predominant species in this area was Echinarachnius parma by biomass. Hierarchical cluster analysis （Bray-Curtis similarity measure） revealed that two impor- tant benthic assemblages in the study area were CommunityA and Community B. CommunityA was stable and Community B was unstable, as shown by the Abundance/Biomass Comparisons （ABC） approach. The macrobenthic community structure in the shelf of the Bering Sea was characterized by its high abundance and biomass, high productivity but great heterogeneity.
基金Project supported by the National Natural Science Foundation of China(Grant No.12027812)the Guangdong Basic and Applied Basic Research Foundation of Guangdong Province,China(Grant No.2021A1515111031)。
文摘The low-density imaging performance of a zone plate-based nano-resolution hard x-ray computed tomography(CT)system can be significantly improved by incorporating a grating-based Lau interferometer. Due to the diffraction, however,the acquired nano-resolution phase signal may suffer splitting problem, which impedes the direct reconstruction of phase contrast CT(nPCT) images. To overcome, a new model-driven nPCT image reconstruction algorithm is developed in this study. In it, the diffraction procedure is mathematically modeled into a matrix B, from which the projections without signal splitting can be generated invertedly. Furthermore, a penalized weighted least-square model with total variation(PWLSTV) is employed to denoise these projections, from which nPCT images with high accuracy are directly reconstructed.Numerical experiments demonstrate that this new algorithm is able to work with phase projections having any splitting distances. Moreover, results also reveal that nPCT images of higher signal-to-noise-ratio(SNR) could be reconstructed from projections having larger splitting distances. In summary, a novel model-driven nPCT image reconstruction algorithm with high accuracy and robustness is verified for the Lau interferometer-based hard x-ray nano-resolution phase contrast imaging.
基金The National Natural Science Foundation of China under contract Nos 41306116 and 41306115the Basic Research Funds of the Third Institute of Oceanography,State Oceanic Administration under contract No.HSK 2013006+2 种基金the Projects of Chinese Polar Scientific Research under contract No.CHINARE2012-2015the Marine Nonprofit Industry Special Research Project Fund under contract No.201105022-2the Polar Science Strategic Research Foundation of China under contract No.20140309
文摘Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species of macrozoobenthos belonging to nine phyla, which were dominated by polychaetes （66）, crustaceans （30）, and mollusks （25）, followed by echinoderms （9） and others （ten others, including four cnidarians, one oligochaete, one sipuncula, one priapulida, two bryozoans, and one urochordata）. The dominant species were Aphelochaeta pacifica, Heteromastus filiformis, Nephtys ciliata, Nephtys caeca, Scoletoma fragilis, Golfingia margaritacea, Nuculana pernula, Macoma calcarea, Ennucula tenuis, Macoma inquinata, Musculus discors, Echinarachnius parma, and Ophiura sarsii, so there were more cold-eurythermal boreal immigrants than trulyArctic species （endemics）. The average density and biomass （mean ± SD across all stations） of the total macrozoobenthos were （916 ± 907） ind/m2 and （902.9 ± 1227.7） g/m2 （wet weight）, respectively. Relatively high density and biomass were observed in the samples from the northeastern and southern Chukchi Sea. The spatial variation of benthic communities in the study sea area was relatively large; this spatial heteroge- neity has led to high diversity and a patchy distribution pattern in the community structure. Compared to the 1st CHINARE （July-August, 1999）, this investigation revealed different degrees of decreases in the average taxa numbers and the average density, abundance, and biodiversity in the area over the recent decade, which might be associated with global warming, human activities, and sea ice variations.
文摘Background: Acetylshikonin, a major constituent isolated from Arnebia euchroma, is a potential candidate for anti-colorectal cancer drugs. However, the potential activity and underlying mechanism of Acetylshikonin against colorectal cancer remain unclear. Methods: In this study, Acetylshikonin was isolated from the active CHCl3 extract of Arnebia euchroma using activity-guided screening, and elucidated by the extensive spectroscopic analysis and comparison with literature data. Human colorectal cancer cells HT29, DLD-1, HCT116 or Caco-2 were exposed to different concentrations of Acetylshikonin (6.25 - 100 μg/mL) for 24 or 48 h. Cell viability, cell apoptosis and cell cycle distribution were detected. The activity of Acetylshikonin and potential mechanism of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway were evaluated in vitro and vivo. Results: We found that Acetylshikonin exhibited remarkable anti-proliferative activity in a dose-dependent manner against HT29 cells with the IC50 values of 60.82 μg/ml and 30.78 μg/ml at 24, 48 h, respectively. Moreover, Acetylshikonin induced cell cycle arrest at G0/G1 phase and early apoptosis through inhibition of PI3K/Akt/mTOR pathway. Furthermore, the assays of cell inhibition, early apoptosis and G0/G1 phase distribution showed that suppression of the PI3K/Akt pathway using LY294002 enhanced the anti-cancer effect of Acetylshikonin. Similarly, Acetylshikonin also decreased the growth of tumour in colorectal cancer xenografts in mice through PI3K/Akt/mTOR pathway. Conclusions: To sum up, these new findings provided a framework for further exploration of Acetylshikonin which possessed the potential antitumor activity by inhibiting PI3K/Akt/mTOR pathway.
基金The National Natural Science Foundation of China under contract No.41506136the National Special Project on Gas Hydrate under contract Nos GZH201100311 and DD20160217the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2015005
文摘The size-fractionated biomass and primary production of phytoplankton, and the influence of environmental factors on it were studied in the Dongsha natural gas hydrate zone of the northern South China Sea in May 2013.Low nutrient, low chlorophyll a（Chl a） and primary productivity characteristics were found in these waters. The phenomena of subsurface Chl a maximum layers（SCMLs） and primary production maximum layers（SPMLs）were observed in the Dongsha waters. There were significant differences in the size-fractionated biomass and primary production that showed picophytoplankton〉nanophytoplankton〉microphytoplankton in terms of biomass and degree of contribution to production. Vertical biomass distribution indicated there were considerable differences among different phytoplankton within the euphotic zone（Zeu） in spring. For example,microphytoplankton was distributed evenly in the euphotic layer and nanophytoplankton was mainly distributed in the subsurface or in the middle of the euphotic layer, while picophytoplankton was mainly distributed in the middle or bottom of the euphotic layer. Smaller cell size and larger relative surface area allow picophytoplankton to benefit from nutrient competition and to hold a dominant position in the tropical oligotrophic waters of low latitudes. There was a positive correlation between size-fractionated biomass and temperature with pH and a negative correlation between size-fractionated biomass and silicate with phosphate. There was a positive correlation between size-fractionated primary production and temperature and a negative correlation between size-fractionated biomass and salinity with phosphate. Phosphate was an important factor influencing the size structure of phytoplankton. Meanwhile, irradiation and the euphotic layer were more important in regulating the vertical distribution of size-fractionated phytoplankton in the Dongsha natural gas hydrate zone.
文摘-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula.
文摘F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM)基础上融入注意力机制(Attention),提出了一种基于BiLSTM-Attention的F_(10.7)预报模型.在加拿大DRAO数据集上其平均绝对误差(MAE)为5.38,平均绝对百分比误差(MAPE)控制在5%以内,相关系数(R)高达0.987,与其他RNN模型相比拥有优越的预测性能.针对中国廊坊L&S望远镜观测的F_(10.7)数据集,提出了一种转换平均校准(Conversion Average Calibration,CAC)方法进行数据预处理,处理后的数据与DRAO数据集具有较高的相关性.基于该数据集对比分析了RNN系列模型的预报效果,实验结果表明,BiLSTM-Attention和BiLSTM两种模型在预测F_(10.7)指数方面具有较好的优势,表现出较好的预测性能和稳定性.
