Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to pred...Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly scale.We obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite images.Then the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic variables.Results showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and November.Secondly,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in January.When monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation accuracy.The overall best performance was observed when all monthly synthetic variables were incorporated into the models.Thirdly,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of 0.56.Except for band 12 in December,the importance of the remaining bands did not exhibit significant differences.This research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images.展开更多
In this study,we mainly focus on probing expression profile and detailed functions of long non-coding RNA TFAP2A antisense RNA 1(TFAP2A-AS1)in non-small cell lung cancer(NSCLC).Moreover,the mechanisms played by TFAP2A...In this study,we mainly focus on probing expression profile and detailed functions of long non-coding RNA TFAP2A antisense RNA 1(TFAP2A-AS1)in non-small cell lung cancer(NSCLC).Moreover,the mechanisms played by TFAP2A-AS1 were unraveled comprehensively.Herein,a notable overexpressed TFAP2A-AS1 in NSCLC was observed by TCGA and our own cohort.An increased TFAP2A-AS1 level displayed a negative correlation with the overall survival of patients with NSCLC.Loss-of-function approaches illustrated that the absence of TFAP2A-AS1 weakened NSCLC cell proliferation,colony formation,migration and invasion in vitro.Also,interference of TFAP2A-AS1 caused in vivo tumor growth suppression.Mechanistically,TFAP2A-AS1 could negative regulate microRNA-584-3p(miR-584-3p)as a competitive endogenous RNA.Furthermore,cyclin-dependent kinase 4(CDK4),a direct target of miR-584-3p,was positively controlled by TFAP2A-AS1 in a miR-5184-3p-dependent manner.Rescue function experiments corroborated that the anticancer activities of TFAP2A-AS1 deficient on the oncogenicity of NSCLC cells were reversed by downregulating miR-584-3p or overexpressing CDK4.To sum up,TFAP2A-AS1 exhibits cancerpromoting roles in NSCLC through the adjustment of miR-584-3p/CDK4 axis.展开更多
Objective As there is currently no clear recommendation for third-line chemotherapy for small cell lung cancer （SCLC）, its efficacy is unknown. To date, there have rarely been reports of Chinese patients with SCLC w...Objective As there is currently no clear recommendation for third-line chemotherapy for small cell lung cancer （SCLC）, its efficacy is unknown. To date, there have rarely been reports of Chinese patients with SCLC who received third-line chemotherapy. Therefore, we investigated the efficacy, safety, and prognostic factors of Chinese patients with SCLC treated with third-line chemotherapy. Methods A retrospective analysis of patients with SCLC who received third-line chemotherapy was performed. Results Between 2007 and 2013, 62 patients [62 men （75.6%）, 20 women （24.4%）; median age at the time of diagnosis, 55 years] received third-line chemotherapy at our center. Of these patients, 44 had limited-stage disease and 38 had extensive-stage disease. On third-line chemotherapy, 55 （67.1%） patients had an Eastern Cooperative Oncology Group performance status （ECOG PS） of 0-1, objective response rate of 15.9%, and median overall survival after third-line chemotherapy （OS-3） and median progres- sion-free survival after third-line chemotherapy （PFS-3） of 5.6 months and 3.0 months, respectively. On univariate analysis, PFS-3 was significantly related with ECOG PS （P = 0.005）, response to second-line chemotherapy （P = 0.002）, response to third-line chemotherapy （P 〈 0.001）, and PFS after second-line chemotherapy （P = 0.026）. OS-3 was significantly related with ECOG PS （P 〈 0.001）, response to third-line chemotherapy （P = 0.033）, PFS after first-line therapy （P = 0.044）, and PFS after second-line therapy （PFS-2） （P = 0.007）. On multivariate analysis, ECOG PS （P = 0.008） and response to third-line chemotherapy （P = 0.046） were independent prognostic factors for PFS-3, while ECOG PS （P = 0.007） and PFS-2 （P 〈 0.001） were independent prognostic factors for OS-3. Conclusion Few patients with SCLC receive third-line chemotherapy. Our findings suggest that patients with an ECOG PS 0-1 and PFS-2 for 〉3 months will be benefit from third-line chemotherapy, which should be actively offered to them.展开更多
Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to det...Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributions to soil HMs. Furthermore, the source contribution rates and environmental data of each sampling point were simultaneously incorporated into a stepwise linear regression model to identify the crucial indicators for predicting soil HM spatial distributions. Results showed that 88% of Cu, 72% of Cr, and 72% of Ni came from natural sources;50% of Zn, 49% of Pb, and 59% of Cd were mainly caused by agricultural activities;and 44% of As and 56% of Hg originated from industrial activities. When three-type(natural, agricultural, and industrial) source contribution rates and environmental data were simultaneously incorporated into the stepwise linear regression model, the fitting accuracy was significantly improved and the model could explain 31%–86% of the total variance in soil HM concentrations. This study introduced three-type source contributions of each sampling point based on APCS-MLR analysis as new covariates to improve soil HM estimation precision, thus providing a new approach for predicting the spatial distribution of HMs using small sample sizes at the county scale.展开更多
Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke wi...Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke with internal carotid artery occlusion as the main clinical feature and discusses its treatment strategy.Treatment remedies:clinical diagnosis was carried out based on the present medical history,physical examination and craniocerebral CT(computed tomography).Neurological function was improved by intravenous thrombolysis,cerebrovascular angiography was used to clarify cerebrovascular occlusion,cerebral blood supply was identified by CT perfusion,and neurological function recovery was followed up.After intravenous thrombolysis,the patient’s consciousness turned clear and the right limb muscle strength recovery was not obvious,but the patient did not receive bridging therapy.Cerebral angiography showed about 90%stenosis at the beginning of the left internal carotid artery,and the blood flow terminated at the C7 segment.Cerebral CT perfusion imaging showed decreased perfusion in the left cerebral hemisphere,but the patient did not receive carotid endarterectomy and vascular bypass treatment.Post treatment evaluating:follow-up showed that NIHSS(National Institute of Health stroke scale)score was significantly decreased and limb function was significantly restored.Conclusion:early intravenous thrombolytic therapy can help reduce the area of ischemic penumbra and improve long-term prognosis.Severe vascular stenosis can stimulate vascular compensation,significantly reduce the range of ischemia when thrombus occurs,and effectively reduce the disability rate without bridging therapy.Whether vascular stenosis and occlusion are treated by vascular bypass,etc.,individualized plans should be made according to vascular compensation.展开更多
Deep synthesis technology is an emerging artificial intelligence technology.There have been a large number of audio and video contents based on deep synthesis technology spreading in the Internet.In this paper,we take...Deep synthesis technology is an emerging artificial intelligence technology.There have been a large number of audio and video contents based on deep synthesis technology spreading in the Internet.In this paper,we take the deep synthetic videos on YouTube platform as the research object,and investigate the factors influencing the propagation effect of deep synthetic videos by establishing an ordered probit model.It is found that the effect of deep synthesized video transmission of YouTube platform is mainly influenced by factors such as the video type,video duration,influence of publishers and forms of fraud.In addition,the comparative analysis of ordinary video and in-depth synthesized video reveals that both the video transmission effect are significantly affected by the video type,video duration and the influence of publishers.展开更多
The new near-αTNW700 titanium alloy is a potential candidate material for high performance ultrasonic/hypersonic aircrafts,which is designed for short-term service at 700℃.This study systematically investigated the ...The new near-αTNW700 titanium alloy is a potential candidate material for high performance ultrasonic/hypersonic aircrafts,which is designed for short-term service at 700℃.This study systematically investigated the superplastic deformation microstructure evolution and mechanism of TNW700 alloy at different strain rates and true strains at 925℃.Results show that TNW700 alloy exhibits excellent superplastic behavior in a constant strain rate range of 0.0005-0.005 s^(-1) with elongation above 400%.The peak stress decreases with decreasing strain rate,which is related to the increase ofβ-phase volume fraction caused by the increase of thermal exposure time.In addition,significant strain hardening is observed in early-middle stage of superplastic deformation,and flow softening is followed in middle-late stage.To rationalize these complex flow behaviors,electron backscatter diffraction(EBSD)and high resolution transmission electron microscopy(HRTEM)were used to characterize the microstructure.Strain hardening is correlated to the synergistic effect ofβgrain growth,dislocation accumulation,silicide precipitate,and solid solution strengthening ofαphase.Continuous dynamic recrystallization(CDRX)induced the fragmentation of primaryαgrains in middle-late stage of superplastic deformation,and the refinement ofαgrains,the increase ofβphase volume fraction and dynamic dislocation recovery are main causes of high strain softening.In addition,EBSD and TEM observations confirmed texture randomization,fine equiaxed primaryαgrains and intragranular dislocation movement,indicating that grain boundary sliding(GBS)accommodated by dislocation sliding/climb is the dominant superplastic deformation mechanism of TNW700 alloy.展开更多
Plasmon-generated hot electrons show great potential for driving chemical reactions.The utilization efficiency of hot electrons is highly dependent on the interaction of the electronic states at the interfaces between...Plasmon-generated hot electrons show great potential for driving chemical reactions.The utilization efficiency of hot electrons is highly dependent on the interaction of the electronic states at the interfaces between plasmonic nanoparticles and other materials/molecules.Strong interaction can produce new hybridized electron states,which permit direct hot-electron transfer,a more efficient transfer mechanism.However,Au usually has very weak interaction with most molecules because of its inertness,which makes direct hot-electron transfer impossible.Herein,the improvement of the hot-electron transfer efficiency from Au to N_(2)is demonstrated by introducing a Ru bridging layer.Both the N_(2)fixation rate and Faradic efficiency(FE)are enhanced by the excitation of plasmons.The enhancement of the N_(2)fixation rate is found to arise from plasmon-generated hot electrons.Theoretical calculations show that the strong interaction of the Ru electronic states with the N_(2)molecular orbitals produces new hybridized electronic states,and the Ru d electrons also strongly couple with the Au sp electrons.Such a bridging role of Ru makes direct hot-electron transfer from Au to N_(2)possible,improving the FE of nitrogen fixation.Our findings demonstrate a new approach to increasing the utilization efficiency of plasmonic hot electrons for chemical reactions and will be helpful to the design of plasmonic catalysts in the future.展开更多
基金National Key Research and Development Program of China(2022YFB3903302 and 2021YFC1809104)。
文摘Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly scale.We obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite images.Then the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic variables.Results showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and November.Secondly,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in January.When monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation accuracy.The overall best performance was observed when all monthly synthetic variables were incorporated into the models.Thirdly,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of 0.56.Except for band 12 in December,the importance of the remaining bands did not exhibit significant differences.This research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images.
文摘In this study,we mainly focus on probing expression profile and detailed functions of long non-coding RNA TFAP2A antisense RNA 1(TFAP2A-AS1)in non-small cell lung cancer(NSCLC).Moreover,the mechanisms played by TFAP2A-AS1 were unraveled comprehensively.Herein,a notable overexpressed TFAP2A-AS1 in NSCLC was observed by TCGA and our own cohort.An increased TFAP2A-AS1 level displayed a negative correlation with the overall survival of patients with NSCLC.Loss-of-function approaches illustrated that the absence of TFAP2A-AS1 weakened NSCLC cell proliferation,colony formation,migration and invasion in vitro.Also,interference of TFAP2A-AS1 caused in vivo tumor growth suppression.Mechanistically,TFAP2A-AS1 could negative regulate microRNA-584-3p(miR-584-3p)as a competitive endogenous RNA.Furthermore,cyclin-dependent kinase 4(CDK4),a direct target of miR-584-3p,was positively controlled by TFAP2A-AS1 in a miR-5184-3p-dependent manner.Rescue function experiments corroborated that the anticancer activities of TFAP2A-AS1 deficient on the oncogenicity of NSCLC cells were reversed by downregulating miR-584-3p or overexpressing CDK4.To sum up,TFAP2A-AS1 exhibits cancerpromoting roles in NSCLC through the adjustment of miR-584-3p/CDK4 axis.
基金Supported by grants from the Jilin Health and Family Planning Commission Scientific Research Project(No.2014Z014)the "12th Five" Project of National Key Subject of New Drug Innovation(No.2013ZX09104001)
文摘Objective As there is currently no clear recommendation for third-line chemotherapy for small cell lung cancer （SCLC）, its efficacy is unknown. To date, there have rarely been reports of Chinese patients with SCLC who received third-line chemotherapy. Therefore, we investigated the efficacy, safety, and prognostic factors of Chinese patients with SCLC treated with third-line chemotherapy. Methods A retrospective analysis of patients with SCLC who received third-line chemotherapy was performed. Results Between 2007 and 2013, 62 patients [62 men （75.6%）, 20 women （24.4%）; median age at the time of diagnosis, 55 years] received third-line chemotherapy at our center. Of these patients, 44 had limited-stage disease and 38 had extensive-stage disease. On third-line chemotherapy, 55 （67.1%） patients had an Eastern Cooperative Oncology Group performance status （ECOG PS） of 0-1, objective response rate of 15.9%, and median overall survival after third-line chemotherapy （OS-3） and median progres- sion-free survival after third-line chemotherapy （PFS-3） of 5.6 months and 3.0 months, respectively. On univariate analysis, PFS-3 was significantly related with ECOG PS （P = 0.005）, response to second-line chemotherapy （P = 0.002）, response to third-line chemotherapy （P 〈 0.001）, and PFS after second-line chemotherapy （P = 0.026）. OS-3 was significantly related with ECOG PS （P 〈 0.001）, response to third-line chemotherapy （P = 0.033）, PFS after first-line therapy （P = 0.044）, and PFS after second-line therapy （PFS-2） （P = 0.007）. On multivariate analysis, ECOG PS （P = 0.008） and response to third-line chemotherapy （P = 0.046） were independent prognostic factors for PFS-3, while ECOG PS （P = 0.007） and PFS-2 （P 〈 0.001） were independent prognostic factors for OS-3. Conclusion Few patients with SCLC receive third-line chemotherapy. Our findings suggest that patients with an ECOG PS 0-1 and PFS-2 for 〉3 months will be benefit from third-line chemotherapy, which should be actively offered to them.
基金supported by the special project of the National Key Research and Development Program of China(Nos.2021YFC1809104 and 2018YFC1800104)。
文摘Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributions to soil HMs. Furthermore, the source contribution rates and environmental data of each sampling point were simultaneously incorporated into a stepwise linear regression model to identify the crucial indicators for predicting soil HM spatial distributions. Results showed that 88% of Cu, 72% of Cr, and 72% of Ni came from natural sources;50% of Zn, 49% of Pb, and 59% of Cd were mainly caused by agricultural activities;and 44% of As and 56% of Hg originated from industrial activities. When three-type(natural, agricultural, and industrial) source contribution rates and environmental data were simultaneously incorporated into the stepwise linear regression model, the fitting accuracy was significantly improved and the model could explain 31%–86% of the total variance in soil HM concentrations. This study introduced three-type source contributions of each sampling point based on APCS-MLR analysis as new covariates to improve soil HM estimation precision, thus providing a new approach for predicting the spatial distribution of HMs using small sample sizes at the county scale.
文摘Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke with internal carotid artery occlusion as the main clinical feature and discusses its treatment strategy.Treatment remedies:clinical diagnosis was carried out based on the present medical history,physical examination and craniocerebral CT(computed tomography).Neurological function was improved by intravenous thrombolysis,cerebrovascular angiography was used to clarify cerebrovascular occlusion,cerebral blood supply was identified by CT perfusion,and neurological function recovery was followed up.After intravenous thrombolysis,the patient’s consciousness turned clear and the right limb muscle strength recovery was not obvious,but the patient did not receive bridging therapy.Cerebral angiography showed about 90%stenosis at the beginning of the left internal carotid artery,and the blood flow terminated at the C7 segment.Cerebral CT perfusion imaging showed decreased perfusion in the left cerebral hemisphere,but the patient did not receive carotid endarterectomy and vascular bypass treatment.Post treatment evaluating:follow-up showed that NIHSS(National Institute of Health stroke scale)score was significantly decreased and limb function was significantly restored.Conclusion:early intravenous thrombolytic therapy can help reduce the area of ischemic penumbra and improve long-term prognosis.Severe vascular stenosis can stimulate vascular compensation,significantly reduce the range of ischemia when thrombus occurs,and effectively reduce the disability rate without bridging therapy.Whether vascular stenosis and occlusion are treated by vascular bypass,etc.,individualized plans should be made according to vascular compensation.
文摘Deep synthesis technology is an emerging artificial intelligence technology.There have been a large number of audio and video contents based on deep synthesis technology spreading in the Internet.In this paper,we take the deep synthetic videos on YouTube platform as the research object,and investigate the factors influencing the propagation effect of deep synthetic videos by establishing an ordered probit model.It is found that the effect of deep synthesized video transmission of YouTube platform is mainly influenced by factors such as the video type,video duration,influence of publishers and forms of fraud.In addition,the comparative analysis of ordinary video and in-depth synthesized video reveals that both the video transmission effect are significantly affected by the video type,video duration and the influence of publishers.
基金the support to this research work from the Aeronautical Science Foundation of China(No.201936051001)the Academic Excellence Foundation of BUAA for PhD Students。
文摘The new near-αTNW700 titanium alloy is a potential candidate material for high performance ultrasonic/hypersonic aircrafts,which is designed for short-term service at 700℃.This study systematically investigated the superplastic deformation microstructure evolution and mechanism of TNW700 alloy at different strain rates and true strains at 925℃.Results show that TNW700 alloy exhibits excellent superplastic behavior in a constant strain rate range of 0.0005-0.005 s^(-1) with elongation above 400%.The peak stress decreases with decreasing strain rate,which is related to the increase ofβ-phase volume fraction caused by the increase of thermal exposure time.In addition,significant strain hardening is observed in early-middle stage of superplastic deformation,and flow softening is followed in middle-late stage.To rationalize these complex flow behaviors,electron backscatter diffraction(EBSD)and high resolution transmission electron microscopy(HRTEM)were used to characterize the microstructure.Strain hardening is correlated to the synergistic effect ofβgrain growth,dislocation accumulation,silicide precipitate,and solid solution strengthening ofαphase.Continuous dynamic recrystallization(CDRX)induced the fragmentation of primaryαgrains in middle-late stage of superplastic deformation,and the refinement ofαgrains,the increase ofβphase volume fraction and dynamic dislocation recovery are main causes of high strain softening.In addition,EBSD and TEM observations confirmed texture randomization,fine equiaxed primaryαgrains and intragranular dislocation movement,indicating that grain boundary sliding(GBS)accommodated by dislocation sliding/climb is the dominant superplastic deformation mechanism of TNW700 alloy.
基金This work was supported by Fundamental Research Funds for Central Universities(No.GK202201003)Funded Projects for the Academic Leaders and Academic Backbones of Shaanxi Normal University(No.18QNGG008)Shaanxi Sanqin Scholars Innovation Team,and Free Exploring Research Project for PhD Students of Shaanxi Normal University(No.2020TS106).
文摘Plasmon-generated hot electrons show great potential for driving chemical reactions.The utilization efficiency of hot electrons is highly dependent on the interaction of the electronic states at the interfaces between plasmonic nanoparticles and other materials/molecules.Strong interaction can produce new hybridized electron states,which permit direct hot-electron transfer,a more efficient transfer mechanism.However,Au usually has very weak interaction with most molecules because of its inertness,which makes direct hot-electron transfer impossible.Herein,the improvement of the hot-electron transfer efficiency from Au to N_(2)is demonstrated by introducing a Ru bridging layer.Both the N_(2)fixation rate and Faradic efficiency(FE)are enhanced by the excitation of plasmons.The enhancement of the N_(2)fixation rate is found to arise from plasmon-generated hot electrons.Theoretical calculations show that the strong interaction of the Ru electronic states with the N_(2)molecular orbitals produces new hybridized electronic states,and the Ru d electrons also strongly couple with the Au sp electrons.Such a bridging role of Ru makes direct hot-electron transfer from Au to N_(2)possible,improving the FE of nitrogen fixation.Our findings demonstrate a new approach to increasing the utilization efficiency of plasmonic hot electrons for chemical reactions and will be helpful to the design of plasmonic catalysts in the future.
