To satisfy practical requirements of high real-time accuracy and low computational complexity of synthetic aperture radar (SAR) image ship small target detection, this paper proposes a small ship target detection meth...To satisfy practical requirements of high real-time accuracy and low computational complexity of synthetic aperture radar (SAR) image ship small target detection, this paper proposes a small ship target detection method based on the improved You Only Look Once Version 3 (YOLOv3). The main contributions of this study are threefold. First, the feature extraction network of the original YOLOV3 algorithm is replaced with the VGG16 network convolution layer. Second, general convolution is transformed into depthwise separable convolution, thereby reducing the computational cost of the algorithm. Third, a residual network structure is introduced into the feature extraction network to reuse the shallow target feature information, which enhances the detailed features of the target and ensures the improvement in accuracy of small target detection performance. To evaluate the performance of the proposed method, many experiments are conducted on public SAR image datasets. For ship targets with complex backgrounds and small ship targets in the SAR image, the effectiveness of the proposed algorithm is verified. Results show that the accuracy and recall rate improved by 5.31% and 2.77%, respectively, compared with the original YOLOV3. Furthermore, the proposed model not only significantly reduces the computational effort, but also improves the detection accuracy of ship small target.展开更多
With the rapid development of technology,people's living standards have been greatly improved,and more and more people have started to care more about the theory and health preservation function of TCM.Gastrodia e...With the rapid development of technology,people's living standards have been greatly improved,and more and more people have started to care more about the theory and health preservation function of TCM.Gastrodia elata,as a precious Chinese herbal medicine,is harmless to human health.Due to the high economic benefits and real benefits for farmers,the G.elata industry has developed rapidly.Zhaotong is the hometown of G.elata f.glauca in China,but the current situation of the G.elata industry lags behind other producing areas.Through field survey and literature review,this paper comprehensively analyzed the development status of the G.elata industry in Zhaotong City.Combined with the natural conditions,policy conditions,and socio-economic conditions of the G.elata industry in Zhaotong City to find countermeasures and recommendations to promote the further development of the G.elata industry in Zhaotong and provide recommendations for the sustainable development of G.elata industry.展开更多
Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/o...Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/or involves chemical additions with limited lifespan,residue formation or other adverse side effects.Microbial electrochemistry has evolved very fast in the past years–this field relates to the study of electrochemical interactions between microorganisms and solid-state electron donors or acceptors.Current can be supplied in such so-called bioelectrochemical systems(BESs)at low voltage to provide or extract electrons in a very precise manner.A plethora of metabolisms can be linked to electrical current now,from metals reductions to denitrification and dechlorination.In this perspective,we provide an overview of the emerging applications of BES and derived technologies towards the bioremediation field and outline how this approach can be game changing.展开更多
Background:Clinical opportunistic screening is a cost-effective cancer screening modality.This study aimed to establish an easyto-use diagnostic model serving as a risk stratification tool for identification of indivi...Background:Clinical opportunistic screening is a cost-effective cancer screening modality.This study aimed to establish an easyto-use diagnostic model serving as a risk stratification tool for identification of individuals with malignant gastric lesions for opportunistic screening.Methods:We developed a questionnaire-based diagnostic model using a joint dataset including two clinical cohorts from northern and southern China.The cohorts consisted of 17,360 outpatients who had undergone upper gastrointestinal endoscopic examination in endoscopic clinics.The final model was derived based on unconditional logistic regression,and predictors were selected according to the Akaike information criterion.External validation was carried out with 32,614 participants from a community-based randomized controlled trial.Results:This questionnaire-based diagnostic model for malignant gastric lesions had eight predictors,including advanced age,male gender,family history of gastric cancer,low body mass index,unexplained weight loss,consumption of leftover food,consumption of preserved food,and epigastric pain.This model showed high discriminative power in the development set with an area under the receiver operating characteristic curve(AUC)of 0.791(95%confidence interval[CI]:0.750-0.831).External validation of the model in the general population generated an AUC of 0.696(95%CI:0.570-0.822).This model showed an ideal ability for enriching prevalent malignant gastric lesions when applied to various scenarios.Conclusion:This easy-to-use questionnaire-based model for diagnosis of prevalent malignant gastric lesions may serve as an effective prescreening tool in clinical opportunistic screening for gastric cancer.展开更多
Soil salinization and water scarcity are main restrictive factors for irrigated agriculture development in arid regions.Knowing dynamics of soil water and salt content is an important antecedent in remediating saliniz...Soil salinization and water scarcity are main restrictive factors for irrigated agriculture development in arid regions.Knowing dynamics of soil water and salt content is an important antecedent in remediating salinized soils and optimizing irrigation management.Previous studies mostly used remote sensing technologies to individually monitor water or salt content dynamics in agricultural areas.Their ability to asses different levels of crop water and salt management has been less explored.Therefore,how to extract effective diagnostic features from remote sensing images derived spectral information is crucial for accurately estimating soil water and salt content.In this study,Linear spectral unmixing method(LSU)was used to obtain the contribution of soil water and salt to each band spectrum(abundance),and endmember spectra from Sentinel-2 images.Calculating spectral indices and selecting optimal spectal combination were individually based on soil water and salt endmember spectra.The estimation models were constructed using six machine learning algorithms:BP Neural Network(BPNN),Support Vector Regression(SVR),Partial Least Squares Regression(PLSR),Random Forest Regression(RFR),Gradient Boost Regression Tree(GBRT),and eXtreme Gradient Boosting tree(XGBoost).The results showed that the spectral indices calculated from endmember spectra were able to effectively characterize the response of crop spectral properties to soil water and salt,which circumvent spectral ambiguity induced by water-salt mixing.NDRE spectral index was a reliable indicator for estimating water and salt content,with determination coefficients(R2)being 0.55 and 0.57,respectively.Compared to other models,LSU-XGBoost model achieved the best performance.This model properly reflected the process of soil water-salt dynamics in farmland during crop growth period.This study provided new methods and ideas for soil water-salt estimation in dry irrigated agricultural areas,and provided decision support for gover-nance of salinized land and optimal management of irrigation.展开更多
The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the inter...The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the interplay of climate,soil and vegetation type.Here,we synthesized currently available soil carbon data to show that mean organic carbon density in the topsoil(0-10 cm)in TP grassland(3.12±0.52 kg C m^(-2))is less than half of that in Arctic tundra(6.70±1.94 kg C m^(-2)).Such difference is primarily attributed to their difference in radiocarbon-inferred soil carbon turnover times(547 years for TP grassland versus 1609 years for Arctic tundra)rather than to their marginal difference in topsoil carbon inputs.Our findings highlight the importance of improving regional-specific soil carbon turnover and its controlling mechanisms across permafrost affected zones in ecosystem models to fully represent carbon-climate feedback.展开更多
T-2 toxin,an omnipresent environmental contaminant,poses a serious risk to the health of humans and animals due to its pronounced cardiotoxicity.This study aimed to elucidate the molecular mechanism of cardiac tissue ...T-2 toxin,an omnipresent environmental contaminant,poses a serious risk to the health of humans and animals due to its pronounced cardiotoxicity.This study aimed to elucidate the molecular mechanism of cardiac tissue damage by T-2 toxin.Twenty-four male Sprague-Dawley rats were orally administered T-2 toxin through gavage for 12 weeks at the dose of 0,10,and 100 nanograms per gram body weight per day(ng/(g·day)),respectively.Morphological,pathological,and ultrastructural alterations in cardiac tissue were meticulously examined.Non-targeted metabolomics analysis was employed to analyze alterations in cardiac metabolites.The expression of the Sirt3/FoxO3α/MnSOD signaling pathway and the level of oxidative stress markers were detected.The results showed that exposure to T-2 toxin elicited myocardial tissue disorders,interstitial hemorrhage,capillary dilation,and fibrotic damage.Mitochondria were markedly impaired,including swelling,fusion,matrix degradation,and membrane damage.Metabonomics analysis unveiled that T-2 toxin could cause alterations in cardiacmetabolic profiles as well as in the Sirt3/FoxO3α/MnSOD signaling pathway.T-2 toxin could inhibit the expressions of the signaling pathway and elevate the level of oxidative stress.In conclusion,the T-2 toxin probably induces cardiac fibrotic impairment by affecting amino acid and choline metabolism as well as up-regulating oxidative stress mediated by the Sirt3/FoxO3α/MnSOD signaling pathway.This study is expected to provide targets for preventing and treating T-2 toxin-induced cardiac fibrotic injury.展开更多
文摘To satisfy practical requirements of high real-time accuracy and low computational complexity of synthetic aperture radar (SAR) image ship small target detection, this paper proposes a small ship target detection method based on the improved You Only Look Once Version 3 (YOLOv3). The main contributions of this study are threefold. First, the feature extraction network of the original YOLOV3 algorithm is replaced with the VGG16 network convolution layer. Second, general convolution is transformed into depthwise separable convolution, thereby reducing the computational cost of the algorithm. Third, a residual network structure is introduced into the feature extraction network to reuse the shallow target feature information, which enhances the detailed features of the target and ensures the improvement in accuracy of small target detection performance. To evaluate the performance of the proposed method, many experiments are conducted on public SAR image datasets. For ship targets with complex backgrounds and small ship targets in the SAR image, the effectiveness of the proposed algorithm is verified. Results show that the accuracy and recall rate improved by 5.31% and 2.77%, respectively, compared with the original YOLOV3. Furthermore, the proposed model not only significantly reduces the computational effort, but also improves the detection accuracy of ship small target.
文摘With the rapid development of technology,people's living standards have been greatly improved,and more and more people have started to care more about the theory and health preservation function of TCM.Gastrodia elata,as a precious Chinese herbal medicine,is harmless to human health.Due to the high economic benefits and real benefits for farmers,the G.elata industry has developed rapidly.Zhaotong is the hometown of G.elata f.glauca in China,but the current situation of the G.elata industry lags behind other producing areas.Through field survey and literature review,this paper comprehensively analyzed the development status of the G.elata industry in Zhaotong City.Combined with the natural conditions,policy conditions,and socio-economic conditions of the G.elata industry in Zhaotong City to find countermeasures and recommendations to promote the further development of the G.elata industry in Zhaotong and provide recommendations for the sustainable development of G.elata industry.
基金funded through the European Union’s Horizon 2020 project ELECTRA under grant agreement No.826244National Natural Science Foundation of China(NSFC)(No.31861133001,31861133002,31861133003)+3 种基金Serra Hunter Fellow(UdG-AG-575)the funding from the ICREA Academia awarthe Catalan Government with code 2017-SGR-1552supported by the Ghent University special research fund under grant No.BOF19/GOA/026.
文摘Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/or involves chemical additions with limited lifespan,residue formation or other adverse side effects.Microbial electrochemistry has evolved very fast in the past years–this field relates to the study of electrochemical interactions between microorganisms and solid-state electron donors or acceptors.Current can be supplied in such so-called bioelectrochemical systems(BESs)at low voltage to provide or extract electrons in a very precise manner.A plethora of metabolisms can be linked to electrical current now,from metals reductions to denitrification and dechlorination.In this perspective,we provide an overview of the emerging applications of BES and derived technologies towards the bioremediation field and outline how this approach can be game changing.
基金supported by grants from the National Science and Technology Fundamental Resources Investigation Program of China(No.2019FY101102)the National Natural Science Foundation of China(No.82073626)+1 种基金the National Key Research and Development Program of China(No.2021YFC2500405)the Sanming Project of Shenzhen(No.SZSM201612061).
文摘Background:Clinical opportunistic screening is a cost-effective cancer screening modality.This study aimed to establish an easyto-use diagnostic model serving as a risk stratification tool for identification of individuals with malignant gastric lesions for opportunistic screening.Methods:We developed a questionnaire-based diagnostic model using a joint dataset including two clinical cohorts from northern and southern China.The cohorts consisted of 17,360 outpatients who had undergone upper gastrointestinal endoscopic examination in endoscopic clinics.The final model was derived based on unconditional logistic regression,and predictors were selected according to the Akaike information criterion.External validation was carried out with 32,614 participants from a community-based randomized controlled trial.Results:This questionnaire-based diagnostic model for malignant gastric lesions had eight predictors,including advanced age,male gender,family history of gastric cancer,low body mass index,unexplained weight loss,consumption of leftover food,consumption of preserved food,and epigastric pain.This model showed high discriminative power in the development set with an area under the receiver operating characteristic curve(AUC)of 0.791(95%confidence interval[CI]:0.750-0.831).External validation of the model in the general population generated an AUC of 0.696(95%CI:0.570-0.822).This model showed an ideal ability for enriching prevalent malignant gastric lesions when applied to various scenarios.Conclusion:This easy-to-use questionnaire-based model for diagnosis of prevalent malignant gastric lesions may serve as an effective prescreening tool in clinical opportunistic screening for gastric cancer.
基金the National Natural Science Foundation of China for the project(No.52279047).
文摘Soil salinization and water scarcity are main restrictive factors for irrigated agriculture development in arid regions.Knowing dynamics of soil water and salt content is an important antecedent in remediating salinized soils and optimizing irrigation management.Previous studies mostly used remote sensing technologies to individually monitor water or salt content dynamics in agricultural areas.Their ability to asses different levels of crop water and salt management has been less explored.Therefore,how to extract effective diagnostic features from remote sensing images derived spectral information is crucial for accurately estimating soil water and salt content.In this study,Linear spectral unmixing method(LSU)was used to obtain the contribution of soil water and salt to each band spectrum(abundance),and endmember spectra from Sentinel-2 images.Calculating spectral indices and selecting optimal spectal combination were individually based on soil water and salt endmember spectra.The estimation models were constructed using six machine learning algorithms:BP Neural Network(BPNN),Support Vector Regression(SVR),Partial Least Squares Regression(PLSR),Random Forest Regression(RFR),Gradient Boost Regression Tree(GBRT),and eXtreme Gradient Boosting tree(XGBoost).The results showed that the spectral indices calculated from endmember spectra were able to effectively characterize the response of crop spectral properties to soil water and salt,which circumvent spectral ambiguity induced by water-salt mixing.NDRE spectral index was a reliable indicator for estimating water and salt content,with determination coefficients(R2)being 0.55 and 0.57,respectively.Compared to other models,LSU-XGBoost model achieved the best performance.This model properly reflected the process of soil water-salt dynamics in farmland during crop growth period.This study provided new methods and ideas for soil water-salt estimation in dry irrigated agricultural areas,and provided decision support for gover-nance of salinized land and optimal management of irrigation.
基金This work was supported by Preliminary Research on Three Poles Environment and Climate Change(2019YFC1509103)the National Natural Science Foundation of China(41861134036 and 41922004)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0606)the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA19070303 and XDA20050101).
文摘The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the interplay of climate,soil and vegetation type.Here,we synthesized currently available soil carbon data to show that mean organic carbon density in the topsoil(0-10 cm)in TP grassland(3.12±0.52 kg C m^(-2))is less than half of that in Arctic tundra(6.70±1.94 kg C m^(-2)).Such difference is primarily attributed to their difference in radiocarbon-inferred soil carbon turnover times(547 years for TP grassland versus 1609 years for Arctic tundra)rather than to their marginal difference in topsoil carbon inputs.Our findings highlight the importance of improving regional-specific soil carbon turnover and its controlling mechanisms across permafrost affected zones in ecosystem models to fully represent carbon-climate feedback.
基金supported by the National Natural Science Foundation of China(No.81872567).
文摘T-2 toxin,an omnipresent environmental contaminant,poses a serious risk to the health of humans and animals due to its pronounced cardiotoxicity.This study aimed to elucidate the molecular mechanism of cardiac tissue damage by T-2 toxin.Twenty-four male Sprague-Dawley rats were orally administered T-2 toxin through gavage for 12 weeks at the dose of 0,10,and 100 nanograms per gram body weight per day(ng/(g·day)),respectively.Morphological,pathological,and ultrastructural alterations in cardiac tissue were meticulously examined.Non-targeted metabolomics analysis was employed to analyze alterations in cardiac metabolites.The expression of the Sirt3/FoxO3α/MnSOD signaling pathway and the level of oxidative stress markers were detected.The results showed that exposure to T-2 toxin elicited myocardial tissue disorders,interstitial hemorrhage,capillary dilation,and fibrotic damage.Mitochondria were markedly impaired,including swelling,fusion,matrix degradation,and membrane damage.Metabonomics analysis unveiled that T-2 toxin could cause alterations in cardiacmetabolic profiles as well as in the Sirt3/FoxO3α/MnSOD signaling pathway.T-2 toxin could inhibit the expressions of the signaling pathway and elevate the level of oxidative stress.In conclusion,the T-2 toxin probably induces cardiac fibrotic impairment by affecting amino acid and choline metabolism as well as up-regulating oxidative stress mediated by the Sirt3/FoxO3α/MnSOD signaling pathway.This study is expected to provide targets for preventing and treating T-2 toxin-induced cardiac fibrotic injury.
