The 4.20 Lushan Ms7.0 earthquake occurred on the southwest segment of the Longmenshan fault on 20 April 2013. Some meaningful information on the prepa- ration and occurrence of this earthquake was found based on the d...The 4.20 Lushan Ms7.0 earthquake occurred on the southwest segment of the Longmenshan fault on 20 April 2013. Some meaningful information on the prepa- ration and occurrence of this earthquake was found based on the dynamic variation of gravity (DVG). To examine the great progress of the Lushan earthquake, we obtained the density variation (DENV) derived from the DVG using the compact gravity inversion method in this article. The inversion results reveal three main findings: (1) the DENV in the crust in the Jinshajiang fault area changed from positive in 2010-2011 to negative in 2011-2012. (2) The DENV in the Xianshuihe fault area decreased continuously from 2010 to 2012. (3) The DENV of the uppermost mantle of South China decreased in 2010-2011 and increased in 2011-2012. We propose that the flow/expansion of the middle-lower crust beneath the Bayan Har block and Moho subsidence on the southwest margin of the Chuan-Dian block may have been the major causes of the Lushan earthquake.展开更多
Nuclear magnetic resonance-visible mobile lipid, at 1.28 parts per million (ppm), is thought to be due to mobile lipid droplets formed in cells and has been considered unique for neural progenitor cells. However, th...Nuclear magnetic resonance-visible mobile lipid, at 1.28 parts per million (ppm), is thought to be due to mobile lipid droplets formed in cells and has been considered unique for neural progenitor cells. However, this idea remains controversial. The present study examined the 1.28 ppm biomarker in other stem cells and non-stem cells, and explored the relationship between 1.28 ppm biomarker and mobile lipid droplets. 1H nuclear magnetic resonance spectroscopy of EC109 cells, mesenchymal stem cells (MSCs) and adipogenic cells differentiated from MSCs was performed. Results show that 1.28 ppm biomarker was observed in human MSCs, but was absent from EC109 cells. Following adipogenic differentiation induced for 2 weeks, the 1.28 ppm biomarker climbed remarkably, with mobile lipid droplet generation, suggesting that the 1.28 ppm biomarker is not specific for neural progenitor cells because it is also observed in MSCs and adipogenic-induced differentiated cells. Moreover, it is possible to monitor MSCs differentiation following cell transplantation, using 1.28 ppm biomarker changes.展开更多
Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window...Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window admittance technique. For comparison, three bathymetry models are used: general bathymetric charts of the oceans, SIO V15.1,and BAT_VGG. The results show that BAT_VGG is more suitable for calculating T e than the other two models. T e along the Louisville Ridge was re-evaluated. The southeast of the ridge has a medium Te of 10–20 km, while Te increases dramatically seaward of the Tonga-Kermadec trench as a result of the collision of the Pacific and IndoAustralian plates.展开更多
In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and ...In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and a gravity anomaly model from the Scripps Institute of Oceanography. Characteristics of the isostatic anomaly and the earthquake dynamic environment of this region are analyzed,and the results show that there are obvious differences in the isostatic state between each block in the region. Tectonic movements are very intense in regions with high positive or negative isostatic gravity anomalies, and a number of sub-plates in this area are driven by external tectonic action, such as plate subduction and thrusting, of the Pacific, Indo-Australian and Eurasian plates. From the distribution of the isostatic gravity anomaly, the tectonic action of anti-isostatic movement obviously is the main source of power. Based on isostatic gravity and spatial distribution of earthquakes in the region, it is obvious that further contraction of the Indo-Australian Plate will result in the southwestern part of the Solomon Plate becoming part of the Owen Stanley thrust belt, and the northern part will enter the lower part of the Bismarck Plate. The eastern part of the Solomon Plate will enter the front of the Pacific Plate, resulting in northward and eastward migration of significant earthquakes along the Solomon Plate.展开更多
This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical chara...This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical characteristics are very complex. The analysis is carried out in terms of the ratio of elevation and Bouguer gravity anomaly, the normalized full gradient of a section of the Bouguer gravity anomaly (Gh) and the crustal density structure reveal that (1) the ratio of highs and lows of elevation and Bouguer gravity anomaly is large between Zhengyiguan fault (F4) and Helandonglu fault (F6), which can be explained due to crustal inhomogeneities related to the uplift of the Qinghai-Tibet block in the northeast; (2) the main active faults correspond to the Gh contour strip or cut the local region, and generally show strong deformation characteristics, for example the Bayanwulashan mountain front fault (F1) or the southeast boundary of Alxa block is in accord with the western change belt of Gh, a belt about 10 km wide that extends to about 30 km; (3) Yinchuan- Pingluo fault (FS) is the seismogenic structure of the Pin- gluo M earthquake, and its focal depth is about 15 km; (4) the Moho depth trend and Bouguer gravity anomaly vari- ation indicates that the regional gravity field is strongly correlated with the Moho discontinuity.展开更多
Numerous geophysical studies have revealed the lithospheric structure of the Qiangtang and the Songpan-Ganzi terranes in the eastern Tibetan Plateau.However,crust-mantle evolution and crustal response to the Indian li...Numerous geophysical studies have revealed the lithospheric structure of the Qiangtang and the Songpan-Ganzi terranes in the eastern Tibetan Plateau.However,crust-mantle evolution and crustal response to the Indian lithospheric subduction are still controversial.Answering these questions requires additional information regarding crustal structure.In this study,the 2-D normalized full gradient(NFG)of the Bouguer gravity anomaly was used to investigate anomalous sources and interpret the crustal structure underneath the Qiangtang and Songpan-Ganzi terranes.The NFG-derived structures with loworder harmonic numbers(N=33 and N=43)showed that an anomalous source beneath the southern Qiangtang terrane had a characteristic northeastward-dipping shape,suggesting the northeastward motion of the crustal material induced by underthrusting Indian lithospheric mantle.The NFG images with harmonic number N=53 showed a large-scale anomalous source in the lower crust of the transformational zone from the Qiangtang terrane to the Songpan-Ganzi terrane,consistent with thickening crust and resistance of lower crustal flow.The anomalous source demonstrated by the NFG results with harmonic number N=71,located in the upper crust underneath the Ganzi-Yushu fault,suggested a seismogenic body of the 2010 M6.9 Yushu event.展开更多
This study investigates data-processing methods and examines the precipitation effect on gravity measurements at the Dali gravity network, established in 2005. High-quality gravity data were collected during four meas...This study investigates data-processing methods and examines the precipitation effect on gravity measurements at the Dali gravity network, established in 2005. High-quality gravity data were collected during four measurement campaigns. To use the gravity data validly, some geophysical corrections must be considered carefully. We first discuss data-processing methods using weighted least- squares adjustment with the constraint of the absolute gravity datum. Results indicate that the gravity precision can be improved if all absolute gravity data are used as constraints and if calibration functions of relative gravi- meters are modeled within the observation function. Using this data-processing scheme, the mean point gravity pre- cision is better than 12 μgal. After determining the best data-processing scheme, we then process the gravity data obtained in the four measurement campaigns, and obtain gravity changes in three time periods. Results show that the gravity has a remarkable change of more than 50 pgal in the first time period from Apr-May of 2005 to Aug-Sept of 2007. To interpret the large gravity change, a mean water mass change (0.6 m in height) is assumed in the ETOPO1 topographic model. Calculations of the precipitation effect on gravity show that it can reach the same order of the observed gravity change. It is regarded as a main source of the remarkable gravity change in the Dali gravity network, suggesting that the precipitation effect on gravity mea- surements must be considered carefully.展开更多
In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical ex...In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical exploration profiles tend to bend curved roads for easy observation,however,it must be projected onto a straight line when data processing and analyzing.After projection,we don’t know the true position of the obtained crustal structure.Nonetheless,when the results used as an initial constraint condition for other geophysical inversion,such as gravity inversion,we need to know the true position of the data rather than the distance to the starting point.We solved this problem by profile vectorization and reprojection.The method can be used for extraction data of various geophysical exploration profiles,such as seismic reflection profiles,gravity profiles.展开更多
Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a ...Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a unique network of gravity tidal stations all over the Chinese mainland,we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models.The results show that the average efficiencies of the ocean tidal loading correction for O_(1),K_(1),M_(2) are 77%,7 s3%and 59%,respectively.The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations,but relative worse at stations far from ocean.展开更多
γδ-T cells play an indispensable role in host defense against different viruses, including influenza A virus. However, whether these cells have cytotoxic activity against influenza virus-infected lung alveolar epith...γδ-T cells play an indispensable role in host defense against different viruses, including influenza A virus. However, whether these cells have cytotoxic activity against influenza virus-infected lung alveolar epithelial cells and subsequently contribute to virus clearance remains unknown. Using influenza virus-infected A549 cells, human lung alveolar epithelial cells, we investigated the cytotoxic activity of aminobisphosphonate pamidronate (PAM)-expanded human Vγ9Vδ2-T cells and their underlying mechanisms. We found that PAM could selectively activate and expand human Vγ9Vδ2-T cells. PAM-expanded human Vγ9Vδ2-T cells efficiently killed influenza virus-infected lung alveolar epithelial cells and inhibited virus replication. The cytotoxic activity of PAM-expanded Vγ9Vδ2-T cells was dependent on cell-to-cell contact and required NKG2D activation. Perforin-granzyme B, tumor-necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas-Fas ligand (FasL) pathways were involved in their cytotoxicity. Our study suggests that targeting γδ2-T cells by PAM can potentially offer an alternative option for the treatment of influenza virus.展开更多
Preterm and small-for-gestational-age (SGA) neonates are vulnerable groups that are susceptible to various microbial infections. Vγ9Vδ2-T cells are critical components of the host immune system and have been demon...Preterm and small-for-gestational-age (SGA) neonates are vulnerable groups that are susceptible to various microbial infections. Vγ9Vδ2-T cells are critical components of the host immune system and have been demonstrated to play an important role in the defense against viral infection in adults. However, the characteristics of Vγ9Vδ2-T cells in children, especially the preterm and SGA populations, are poorly understood. Here, we examined the frequency and antiviral function of Vγ9Vδ2-T cells in neonates, including preterm, SGA and full-term babies. When compared to adults, neonates had a significantly lower percentage of Vγ9Vδ2-T cells in the blood. Upon influenza virus stimulation, neonatalVγ9Vδ2-T cells, especially from preterm and SGA babies, showed markedly decreased and delayed antiviral cytokine responses than those of adults. In addition, the antiviral responses of neonatal Vγ9Vδ2-T cells were positively correlated with gestational age and birth weight. Finally, a weaker expansion ofVγ9Vδ2-T cells by isopentenyl pyrophosphate (IPP) was shown in neonates than the expansion in adults. Our data suggest that the depressed antiviral activity and decreased frequency of Vγ9Vδ2-T cells may likely account for the high susceptibility to microbial infection in neonates, particularly in preterm and SGA babies. Improving Vγ9Vδ2-T -cell function of neonates may provide a new way to defend against virus infection.展开更多
The widespread use of TiO2 nanoparticles (NPs) makes inevitable their release into the soil. Phosphate is also widespread within soil, and is likely copresent with TiO2 NPs. However, the influence of phosphate on depo...The widespread use of TiO2 nanoparticles (NPs) makes inevitable their release into the soil. Phosphate is also widespread within soil, and is likely copresent with TiO2 NPs. However, the influence of phosphate on deposition/release— and thereby on transport— of TiO2 NPs in soil is yet to be elucidated. In this study we conducted saturated column experiments to systematically examine the transport of TiO2 NPs in soil amended with phosphate at different ionic strengths (ISs) (1, 10, 100 mmol/L NaCl) and pHs (4 and 9). Results show that the deposition of TiO2 NPs decreased with decreasing IS, increasing pH, and when soil absorbed phosphate. These observations are qualitatively in agreement with Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy calculations, because the repulsive energy barrier is larger and secondary minimum depth is smaller at a lower IS, higher pH, and in the presence of phosphate. Accordingly, both primary- and secondary-minimum deposition were inhibited. Interestingly, although the deposition was less at higher pH and in the presence of phosphate, the subsequent spontaneous detachment and detachment by reduction of solution IS in these cases were greater. In addition, the presence of phosphate in the solution can cause a small quantity of attached TiO2 NPs to detach, even without perturbations of physical and chemical conditions. Our study was the first to investigate the influence of phosphate on detachment of TiO2 NPs and the results have important implication for accurate prediction of fate and transport of TiO2 NPs in subsurface environments.展开更多
The neonates, particularly small-for-gestational-age (SGA) ones, are susceptible to various microbial infections. Natural killer (NK) cells are critical components of host innate immunity system and the main sourc...The neonates, particularly small-for-gestational-age (SGA) ones, are susceptible to various microbial infections. Natural killer (NK) cells are critical components of host innate immunity system and the main source of the inflammatory cytokines, which provide critical protection during the early phase of viral infections before the development of an appropriate adaptive immune response. However, little is known about the antiviral effects of NK cells in neonates especially the SGA population. Herein, a prospective descriptive study was performed to determine the differences of NK cell immunity among adults, appropriate-for gestational-age (AGA) and SGA neonates. Adults have much higher NK cell number in peripheral blood than that in cord blood from neonates. In response to influenza virus stimulation, neonatal NK cells, especially SGA baby cells, expressed significantly lower antiviral cytokines including perforin, interferon (IFN)-7 and tumor-necrosis factor (TNF)-α responses than adult NK cells. In addition, the antiviral cytokine responses of NK cells were positively correlated with neonatal birth weight. Our data suggested that the depressed antiviral activity and less frequency of NK cells are likely to be responsible for the high susceptibility to microbial infection in neonates, at least in part. Improving the function of innate immunity may provide a new way to defend virus infection.展开更多
基金supported by the National Natural Science Foundation of China (41304060)the National Key Basic Research Program of China (973 Program, 2013CB733305)Scientific Investigation of April 20, 2013 M7.0 Lushan, Sichuan Earthquake
文摘The 4.20 Lushan Ms7.0 earthquake occurred on the southwest segment of the Longmenshan fault on 20 April 2013. Some meaningful information on the prepa- ration and occurrence of this earthquake was found based on the dynamic variation of gravity (DVG). To examine the great progress of the Lushan earthquake, we obtained the density variation (DENV) derived from the DVG using the compact gravity inversion method in this article. The inversion results reveal three main findings: (1) the DENV in the crust in the Jinshajiang fault area changed from positive in 2010-2011 to negative in 2011-2012. (2) The DENV in the Xianshuihe fault area decreased continuously from 2010 to 2012. (3) The DENV of the uppermost mantle of South China decreased in 2010-2011 and increased in 2011-2012. We propose that the flow/expansion of the middle-lower crust beneath the Bayan Har block and Moho subsidence on the southwest margin of the Chuan-Dian block may have been the major causes of the Lushan earthquake.
基金the Key Program of National Natural Science Foundation of China,No.30930027the Natural Science Foundation of Guangdong Province,No.8151503102000032
文摘Nuclear magnetic resonance-visible mobile lipid, at 1.28 parts per million (ppm), is thought to be due to mobile lipid droplets formed in cells and has been considered unique for neural progenitor cells. However, this idea remains controversial. The present study examined the 1.28 ppm biomarker in other stem cells and non-stem cells, and explored the relationship between 1.28 ppm biomarker and mobile lipid droplets. 1H nuclear magnetic resonance spectroscopy of EC109 cells, mesenchymal stem cells (MSCs) and adipogenic cells differentiated from MSCs was performed. Results show that 1.28 ppm biomarker was observed in human MSCs, but was absent from EC109 cells. Following adipogenic differentiation induced for 2 weeks, the 1.28 ppm biomarker climbed remarkably, with mobile lipid droplet generation, suggesting that the 1.28 ppm biomarker is not specific for neural progenitor cells because it is also observed in MSCs and adipogenic-induced differentiated cells. Moreover, it is possible to monitor MSCs differentiation following cell transplantation, using 1.28 ppm biomarker changes.
基金supported financially by the Key Foundation of the Institute of Seismology,China Earthquake Administration (No. IS201506205)the National Natural Science Foundation of China (Nos. 41504017, 41204019, 41304003)
文摘Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window admittance technique. For comparison, three bathymetry models are used: general bathymetric charts of the oceans, SIO V15.1,and BAT_VGG. The results show that BAT_VGG is more suitable for calculating T e than the other two models. T e along the Louisville Ridge was re-evaluated. The southeast of the ridge has a medium Te of 10–20 km, while Te increases dramatically seaward of the Tonga-Kermadec trench as a result of the collision of the Pacific and IndoAustralian plates.
基金supported by the Science for Earthquake Resilience(XH17022)
文摘In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and a gravity anomaly model from the Scripps Institute of Oceanography. Characteristics of the isostatic anomaly and the earthquake dynamic environment of this region are analyzed,and the results show that there are obvious differences in the isostatic state between each block in the region. Tectonic movements are very intense in regions with high positive or negative isostatic gravity anomalies, and a number of sub-plates in this area are driven by external tectonic action, such as plate subduction and thrusting, of the Pacific, Indo-Australian and Eurasian plates. From the distribution of the isostatic gravity anomaly, the tectonic action of anti-isostatic movement obviously is the main source of power. Based on isostatic gravity and spatial distribution of earthquakes in the region, it is obvious that further contraction of the Indo-Australian Plate will result in the southwestern part of the Solomon Plate becoming part of the Owen Stanley thrust belt, and the northern part will enter the lower part of the Bismarck Plate. The eastern part of the Solomon Plate will enter the front of the Pacific Plate, resulting in northward and eastward migration of significant earthquakes along the Solomon Plate.
基金supported by the Key Projects of China Seismic Array(201308011)Earthquake Science(201508006)the China Earthquake Administration,Institute of Seismology Foundation(201326126)
文摘This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical characteristics are very complex. The analysis is carried out in terms of the ratio of elevation and Bouguer gravity anomaly, the normalized full gradient of a section of the Bouguer gravity anomaly (Gh) and the crustal density structure reveal that (1) the ratio of highs and lows of elevation and Bouguer gravity anomaly is large between Zhengyiguan fault (F4) and Helandonglu fault (F6), which can be explained due to crustal inhomogeneities related to the uplift of the Qinghai-Tibet block in the northeast; (2) the main active faults correspond to the Gh contour strip or cut the local region, and generally show strong deformation characteristics, for example the Bayanwulashan mountain front fault (F1) or the southeast boundary of Alxa block is in accord with the western change belt of Gh, a belt about 10 km wide that extends to about 30 km; (3) Yinchuan- Pingluo fault (FS) is the seismogenic structure of the Pin- gluo M earthquake, and its focal depth is about 15 km; (4) the Moho depth trend and Bouguer gravity anomaly vari- ation indicates that the regional gravity field is strongly correlated with the Moho discontinuity.
基金financially supported by the National Natural Science Foundation of China(Grant No.42074090)
文摘Numerous geophysical studies have revealed the lithospheric structure of the Qiangtang and the Songpan-Ganzi terranes in the eastern Tibetan Plateau.However,crust-mantle evolution and crustal response to the Indian lithospheric subduction are still controversial.Answering these questions requires additional information regarding crustal structure.In this study,the 2-D normalized full gradient(NFG)of the Bouguer gravity anomaly was used to investigate anomalous sources and interpret the crustal structure underneath the Qiangtang and Songpan-Ganzi terranes.The NFG-derived structures with loworder harmonic numbers(N=33 and N=43)showed that an anomalous source beneath the southern Qiangtang terrane had a characteristic northeastward-dipping shape,suggesting the northeastward motion of the crustal material induced by underthrusting Indian lithospheric mantle.The NFG images with harmonic number N=53 showed a large-scale anomalous source in the lower crust of the transformational zone from the Qiangtang terrane to the Songpan-Ganzi terrane,consistent with thickening crust and resistance of lower crustal flow.The anomalous source demonstrated by the NFG results with harmonic number N=71,located in the upper crust underneath the Ganzi-Yushu fault,suggested a seismogenic body of the 2010 M6.9 Yushu event.
基金financially supported by the CAS/CAFEA International Partnership Program for creative research teams (No. KZZD-EW-TZ-19)the National Natural Science Foundation of China (Nos. 41331066 and 41174063)
文摘This study investigates data-processing methods and examines the precipitation effect on gravity measurements at the Dali gravity network, established in 2005. High-quality gravity data were collected during four measurement campaigns. To use the gravity data validly, some geophysical corrections must be considered carefully. We first discuss data-processing methods using weighted least- squares adjustment with the constraint of the absolute gravity datum. Results indicate that the gravity precision can be improved if all absolute gravity data are used as constraints and if calibration functions of relative gravi- meters are modeled within the observation function. Using this data-processing scheme, the mean point gravity pre- cision is better than 12 μgal. After determining the best data-processing scheme, we then process the gravity data obtained in the four measurement campaigns, and obtain gravity changes in three time periods. Results show that the gravity has a remarkable change of more than 50 pgal in the first time period from Apr-May of 2005 to Aug-Sept of 2007. To interpret the large gravity change, a mean water mass change (0.6 m in height) is assumed in the ETOPO1 topographic model. Calculations of the precipitation effect on gravity show that it can reach the same order of the observed gravity change. It is regarded as a main source of the remarkable gravity change in the Dali gravity network, suggesting that the precipitation effect on gravity mea- surements must be considered carefully.
基金the support from Science for Earthquake Resilience of the China Earthquake Administration(XH17022)the National Natural Science Foundation of China(Grant No.U1939204,No.41204014)+1 种基金the Scientific Research Fund of Institute of Seismology and Institute of Crustal Dynamics,China Earthquake Administration(Grant No.IS20146141)National Key Research and Development Plan(Grant No.2017YFC1500204).
文摘In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical exploration profiles tend to bend curved roads for easy observation,however,it must be projected onto a straight line when data processing and analyzing.After projection,we don’t know the true position of the obtained crustal structure.Nonetheless,when the results used as an initial constraint condition for other geophysical inversion,such as gravity inversion,we need to know the true position of the data rather than the distance to the starting point.We solved this problem by profile vectorization and reprojection.The method can be used for extraction data of various geophysical exploration profiles,such as seismic reflection profiles,gravity profiles.
基金funded by The National Natural Science Foundation of China(No.41774015,41704135 and U1939204)National Key Research and Development Project of China(No.2018YFE0206100,2017YFC1500204)。
文摘Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a unique network of gravity tidal stations all over the Chinese mainland,we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models.The results show that the average efficiencies of the ocean tidal loading correction for O_(1),K_(1),M_(2) are 77%,7 s3%and 59%,respectively.The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations,but relative worse at stations far from ocean.
基金This work was supported in part by the National Natural Science Foundation of China (No. 30973235), Science and Technology Project of the Sichuan Science and Technology Department (2010SZ0110), General Research Fund, Research Grants Council of Hung Kong (HKU 781211M) and the Area of Excellence Scheme of the University Grants Committee, Hung Kong SAR, China (AoE/M-12/06).
文摘γδ-T cells play an indispensable role in host defense against different viruses, including influenza A virus. However, whether these cells have cytotoxic activity against influenza virus-infected lung alveolar epithelial cells and subsequently contribute to virus clearance remains unknown. Using influenza virus-infected A549 cells, human lung alveolar epithelial cells, we investigated the cytotoxic activity of aminobisphosphonate pamidronate (PAM)-expanded human Vγ9Vδ2-T cells and their underlying mechanisms. We found that PAM could selectively activate and expand human Vγ9Vδ2-T cells. PAM-expanded human Vγ9Vδ2-T cells efficiently killed influenza virus-infected lung alveolar epithelial cells and inhibited virus replication. The cytotoxic activity of PAM-expanded Vγ9Vδ2-T cells was dependent on cell-to-cell contact and required NKG2D activation. Perforin-granzyme B, tumor-necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas-Fas ligand (FasL) pathways were involved in their cytotoxicity. Our study suggests that targeting γδ2-T cells by PAM can potentially offer an alternative option for the treatment of influenza virus.
基金ACKNOWLEDGEMENTS This work was supported by the National Natural Science Foundation of China (No. 30973235 and 81170606), the Science and Technology project of the Sichuan Science and Technology Department (2010SZ0110), the General Research Fund from the Research Grants Council of Hong Kong (HKU 781211M) and the Area of Excellence Scheme of the University Grants Committee, Hong Kong SAR, China (AoE/M- 12/06).
文摘Preterm and small-for-gestational-age (SGA) neonates are vulnerable groups that are susceptible to various microbial infections. Vγ9Vδ2-T cells are critical components of the host immune system and have been demonstrated to play an important role in the defense against viral infection in adults. However, the characteristics of Vγ9Vδ2-T cells in children, especially the preterm and SGA populations, are poorly understood. Here, we examined the frequency and antiviral function of Vγ9Vδ2-T cells in neonates, including preterm, SGA and full-term babies. When compared to adults, neonates had a significantly lower percentage of Vγ9Vδ2-T cells in the blood. Upon influenza virus stimulation, neonatalVγ9Vδ2-T cells, especially from preterm and SGA babies, showed markedly decreased and delayed antiviral cytokine responses than those of adults. In addition, the antiviral responses of neonatal Vγ9Vδ2-T cells were positively correlated with gestational age and birth weight. Finally, a weaker expansion ofVγ9Vδ2-T cells by isopentenyl pyrophosphate (IPP) was shown in neonates than the expansion in adults. Our data suggest that the depressed antiviral activity and decreased frequency of Vγ9Vδ2-T cells may likely account for the high susceptibility to microbial infection in neonates, particularly in preterm and SGA babies. Improving Vγ9Vδ2-T -cell function of neonates may provide a new way to defend against virus infection.
基金the National Natural Science Foundation of China(Grant Nos.41671222 ,41271009)National Key Research and Development Program of China(No.2017YFD0800301).
文摘The widespread use of TiO2 nanoparticles (NPs) makes inevitable their release into the soil. Phosphate is also widespread within soil, and is likely copresent with TiO2 NPs. However, the influence of phosphate on deposition/release— and thereby on transport— of TiO2 NPs in soil is yet to be elucidated. In this study we conducted saturated column experiments to systematically examine the transport of TiO2 NPs in soil amended with phosphate at different ionic strengths (ISs) (1, 10, 100 mmol/L NaCl) and pHs (4 and 9). Results show that the deposition of TiO2 NPs decreased with decreasing IS, increasing pH, and when soil absorbed phosphate. These observations are qualitatively in agreement with Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy calculations, because the repulsive energy barrier is larger and secondary minimum depth is smaller at a lower IS, higher pH, and in the presence of phosphate. Accordingly, both primary- and secondary-minimum deposition were inhibited. Interestingly, although the deposition was less at higher pH and in the presence of phosphate, the subsequent spontaneous detachment and detachment by reduction of solution IS in these cases were greater. In addition, the presence of phosphate in the solution can cause a small quantity of attached TiO2 NPs to detach, even without perturbations of physical and chemical conditions. Our study was the first to investigate the influence of phosphate on detachment of TiO2 NPs and the results have important implication for accurate prediction of fate and transport of TiO2 NPs in subsurface environments.
文摘The neonates, particularly small-for-gestational-age (SGA) ones, are susceptible to various microbial infections. Natural killer (NK) cells are critical components of host innate immunity system and the main source of the inflammatory cytokines, which provide critical protection during the early phase of viral infections before the development of an appropriate adaptive immune response. However, little is known about the antiviral effects of NK cells in neonates especially the SGA population. Herein, a prospective descriptive study was performed to determine the differences of NK cell immunity among adults, appropriate-for gestational-age (AGA) and SGA neonates. Adults have much higher NK cell number in peripheral blood than that in cord blood from neonates. In response to influenza virus stimulation, neonatal NK cells, especially SGA baby cells, expressed significantly lower antiviral cytokines including perforin, interferon (IFN)-7 and tumor-necrosis factor (TNF)-α responses than adult NK cells. In addition, the antiviral cytokine responses of NK cells were positively correlated with neonatal birth weight. Our data suggested that the depressed antiviral activity and less frequency of NK cells are likely to be responsible for the high susceptibility to microbial infection in neonates, at least in part. Improving the function of innate immunity may provide a new way to defend virus infection.