The geological conditions of offshore shallow water delta oil reservoirs were complex, with limited well data and large well spacing. Taking A Oilfield in the Bohai Sea Area, China as an example, the target sand body ...The geological conditions of offshore shallow water delta oil reservoirs were complex, with limited well data and large well spacing. Taking A Oilfield in the Bohai Sea Area, China as an example, the target sand body was formed in a shallow water delta sedimentary environment, with well-developed underwater distributary channels and frequent branching and diversion. The reservoir was strong non-uniformity and uneven plane water cut pressure. To this end, based on the existing work of predecessors, combined with seismic, logging, and production dynamics data, and based on the genesis mechanism of shallow water delta reservoirs, the boundary of composite river channels was identified through seismic facies, and logging facies were used to subdivide them into single river levels within the composite river channels. Then, seismic waveform characteristics were applied to track and characterize the plane distribution of single river channels, guiding the efficient development of offshore shallow water delta oil fields and achieving increased storage and production in Bohai Oilfield, China.展开更多
AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mic...AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM(150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin, and superoxide dismutase(SOD). Inflammatory cytokines, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor-α(TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen(PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis wasmeasured by TUNEL assay.Furthermore,apoptosis proteins Caspases-3,6,8,and 9 were detected by Western blot.SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-αpathways.RESULTS:DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice.DHM could significantly decrease serum ALT,AST,IL-1β,IL-6 and TNF-αand increase serum albumin,SOD and liver SOD compared to the control group after CCl4 treatment(P<0.05).PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control(348.9±56.0 vs 107.1±31.4,P<0.01).TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(365.4±99.4 vs 90.5±13.8,P<0.01).Caspase activity detection showed that DHM could reduce the activities of Caspases-8,3,6 and 9 compared to the control(P<0.05).The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-αexpression.However,DHM could not affect TNF-αexpression after SP600125 treatment.Furthermore,DHM could significantly improve the survival rate of acute liver failure(ALF)mice(73.3%vs 20.0%,P<0.0001),and SP600125 could inhibit the effect of DHM.CONCLUSION:These findings demonstrate that DHM alleviates CCl4-induced liver injury,suggesting that DHM is a promising candidate for reversing liver injury and ALF.展开更多
Ca^(2+) channel blockers have been shown to protect neurons from ischemia, and aerobic exercise has significant protective effects on a variety of chronic diseases. The present study injected huwentoxin-I(HWTX-I), a s...Ca^(2+) channel blockers have been shown to protect neurons from ischemia, and aerobic exercise has significant protective effects on a variety of chronic diseases. The present study injected huwentoxin-I(HWTX-I), a spider peptide toxin that blocks Ca^(2+) channels, into the caudal vein of a chronic cerebral ischemia mouse model, once every 2 days, for a total of 15 injections. During this time, a subgroup of mice was subjected to treadmill exercise for 5 weeks. Results showed amelioration of cortical injury and improved neurological function in mice with chronic cerebral ischemia in the HWTX-I + aerobic exercise group. The combined effects of HWTX-I and exercise were superior to HWTX-I or aerobic exercise alone. HWTX-I effectively activated the Notch signal transduction pathway in brain tissue. Aerobic exercise up-regulated synaptophysin m RNA expression. These results demonstrated that aerobic exercise, in combination with HWTX-I, effectively relieved neuronal injury induced by chronic cerebral ischemia via the Notch signaling pathway and promoting synaptic regeneration.展开更多
Objective: Tumor microenvironment, especially the host immune system, plays a pivotal role in tumor initiation and progression. Profiling of immune signature within tumor might uncover biomarkers for targeted therapie...Objective: Tumor microenvironment, especially the host immune system, plays a pivotal role in tumor initiation and progression. Profiling of immune signature within tumor might uncover biomarkers for targeted therapies and clinical outcomes. However, systematic analysis of immune-related genes in gastric cancer(GC) has not been reported.Methods: Expressions of a total of 718 immune-related genes were generated in 372 stomach adenocarcinoma(STAD) patients from The Cancer Genome Atlas(TCGA) database using RNA-sequencing data. Integrated bioinformatics analyses were performed to identify prognostic factors as well.Results: Survival analyses revealed 73 genes, which were significantly associated with patient’s overall survival(OS). Taken together with clinicopathological parameters, we established a predictive model, containing 10 immune-related genes, which were NRP1, C6, CXCR4, LBP, PNMA1, TLR5, ITGA6, MICB, PBK and TNFRSF18,with powerful efficiency in distinguishing satisfactory or poor survival of STAD patients. Moreover, the top 3 ranked prognostic genes, NRP1, TGFβ2 and MFGE8, were also significantly associated with patient’s OS by an independent validation achieved from Kaplan-Meier plotter database.Conclusions: We profiled prognostic immune signature and established prognostic predictive model for GC,which could reflect immune disorders within tumor microenvironment, and also may provide novel predictive and therapeutic targets for GC patients in the near future.展开更多
Because ambient seismic noise provides estimated Green's function (EGF) between two sites with high accuracy, Rayleigh wave propagation along the path connecting the two sites is well resolved. Therefore, earthqua...Because ambient seismic noise provides estimated Green's function (EGF) between two sites with high accuracy, Rayleigh wave propagation along the path connecting the two sites is well resolved. Therefore, earthquakes which are close to one seismic station can be well located with calibration extracting from EGF. We test two algorithms in locating the 1998 Zhangbei earthquake, one algorithm is waveform-based, and the other is traveltime-based. We first compute EGF between station ZHB (a station about 40 km away from the epicenter) and five IC/IRIS stations. With the waveform-based approach, we calculate 1D synthetic single-force Green's functions between ZHB and other four stations, and obtain traveltime corrections by correlating synthetic Green's functions with EGFs in period band of 10-30 s. Then we locate the earthquake by minimizing the differential travel times between observed earthquake waveform and the 1D synthetic earthquake waveforms computed with focal mechanism provided by Global CMT after traveltime correction from EGFs. This waveform-based approach yields a location which error is about 13 km away from the location observed with InSAR. With the traveltime-based approach, we begin with measuring group velocity from EGFs as well as group arrival time on observed earthquake waveforms, and then locate the earthquake by minimizing the difference between observed group arrival time and arrival time measured on EGFs. This traveltime-based approach yields accuracy of 3 km, Therefore it is feasible to achieve GT5 (ground truth location with accuracy 5 km) with ambient seismic noises. The less accuracy of the waveform-based approach was mainly caused by uncertainty of focal mechanism.展开更多
An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord in...An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord injury by dropping a weight onto the spinal cord at T7–8. Superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells were transplanted into the injured spinal cord via the subarachnoid space. An outer magnetic field was used to successfully guide the labeled cells to the lesion site. Prussian blue staining showed that more bone marrow mesenchymal stem cells reached the lesion site in these rats than in those without magnetic guidance or superparamagnetic iron oxide labeling, and immunofluorescence revealed a greater number of complete axons at the lesion site. Moreover, the Basso, Beattie and Bresnahan(BBB) locomotor rating scale scores were the highest in rats with superparamagnetic labeling and magnetic guidance. Our data confirm that superparamagnetic iron oxide nanoparticles effectively label bone marrow mesenchymal stem cells and impart sufficient magnetism to respond to the external magnetic field guides. More importantly, superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells can be dynamically and non-invasively tracked in vivo using magnetic resonance imaging. Superparamagnetic iron oxide labeling of bone marrow mesenchymal stem cells coupled with magnetic guidance offers a promising avenue for the clinical treatment of spinal cord injury.展开更多
In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesenchymal stem cells can survive,migrate,integrate and help to restore the function and behaviors of spinal cord injury models...In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesenchymal stem cells can survive,migrate,integrate and help to restore the function and behaviors of spinal cord injury models,and that they may serve as a suitable approach to treating spinal cord injury.However,it is very difficult to track transplanted cells in vivo.In this study,we injected superparamagnetic iron oxide-labeled neuronal-like cells into the subarachnoid space in a rabbit model of spinal cord injury.At 7 days after cell transplantation,a small number of dot-shaped low signal intensity shadows were observed in the spinal cord injury region,and at 14 days,the number of these shadows increased on T2-weighted imaging.Perl’s Prussian blue staining detected dot-shaped low signal intensity shadows in the spinal cord injury region,indicative of superparamagnetic iron oxide nanoparticle-labeled cells.These findings suggest that transplanted neuronal-like cells derived from bone marrow mesenchymal stem cells can migrate to the spinal cord injury region and can be tracked by magnetic resonance in vivo.Magnetic resonance imaging represents an efficient noninvasive technique for visually tracking transplanted cells in vivo.展开更多
1.Introduction On 23 June 2020,the third geostationary Earth orbit satellite(GEO-3),the last satellite of the China's BeiDou Navigation Satellite System(BDS)-3 space segment construction project,was successfully l...1.Introduction On 23 June 2020,the third geostationary Earth orbit satellite(GEO-3),the last satellite of the China's BeiDou Navigation Satellite System(BDS)-3 space segment construction project,was successfully launched,marking the completion of the BDS global constellation deployment and indicating the successful completion of the BDS“three-step”development strategy.The positioning,navigation,and timing(PNT)service and special-feature services provided by the BDS have been widely used in key infrastructures of the national economy and defense security;they have also promoted a transformation of the production method and upgraded industrial infrastructure in China.展开更多
AIM: To investigate the relationship between 90-kuD ribosomal S6 kinase (p90RSK) and collagen type □expression during the development of hepatic fibrosis in vivo and in vitro.METHODS: Rat hepatic fibrosis was induced...AIM: To investigate the relationship between 90-kuD ribosomal S6 kinase (p90RSK) and collagen type □expression during the development of hepatic fibrosis in vivo and in vitro.METHODS: Rat hepatic fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. The protein expression and cell location of p90RSK and their relationship with collagen type □were determined by co-immunofluoresence and confocal microscopy. Subsequently, RNAi strategy was employed to silence p90RSK mRNA expression in HSC-T6, an activated hepatic stellate cell (HSC) line. The expression of collagen type □in HSC-T6 cells was assessed by Western blotting and real-time polymerase chain reaction. Furthermore, HSCs were transfected with expression vectors or RNAi constructs of p90RSK to increase or decrease the p90RSK expression, then collagen type □promoter activity in the transfected HSCs was examined by reporter assay. Lastly HSC-T6 cells transfected with p90RSK siRNA was treated with or without platelet-derived growth factor (PDGF)-BB at a final concentration of 20 μg/L and the cell growth was determined by MTS conversion.RESULTS: In fibrotic liver tissues, p90RSK was overexpressed in activated HSCs and had a significant positive correlation with collagen type □levels.In HSC-T6 cells transfected with RNAi targeted to p90RSK, the expression of collagen type □was down-regulated (61.8% in mRNA, P < 0.01, 89.1% in protein, P < 0.01). However, collagen type □promoter activity was not increased with over-expression of p90RSK and not decreased with low expression either, compared with controls in the same cell line (P = 0.076). Furthermore, p90RSK siRNA exerted the inhibition of HSC proliferation, and also abolished the effect of PDGF on the HSC proliferation.CONCLUSION: p90RSK is over-expressed in activated HSCs and involved in regulating the abnormal expression of collagen type □through initiating the proliferation of HSCs.展开更多
We constructed a compact high-power RF pulse generator based on a gyro-magnetic nonlinear transmission line(GNLTL) to produce a high-voltage pulse with a sub-nanosecond rise time and a relatively high repetition rate,...We constructed a compact high-power RF pulse generator based on a gyro-magnetic nonlinear transmission line(GNLTL) to produce a high-voltage pulse with a sub-nanosecond rise time and a relatively high repetition rate, which shows great potential for application in the high-power ultrawideband electromagnetic effect, etc. The influence of incident pulse parameters(rise time and voltage amplitude) and line length on the sharpening characteristics of the GNLTL were investigated experimentally to optimize the rising rate of the modulated pulse front. Based on the GNLTL equivalent circuit model consisting of an LC ladder network, the rise time, the voltage conversion coefficient and the rising rate properties of a modulated pulse were also numerically analyzed in a wider range. The results show that a?>?90 k V RF pulse with a rise time of 350 ps and a repetition rate of 1 kHz in burst mode is produced by the GNLTL at an axial biasing magnetic field of 22 kA m^-1 and a line length of 30 cm under the condition of a 70 kV incident pulse. Applying a faster and higher incident pulse is conducive to improving the sharpening effect of the GNLTL. Furthermore, within a certain range, increasing the line length of the GNLTL not only reduces the rise time, but increases the voltage conversion coefficient and the rising rate of a modulated pulse. Furthermore, considering the energy loss of ferrite rings, there is an optimal line length to obtain the fastest rising rate of a modulated pulse front edge.展开更多
The Yellowstone volcano is one of the largest active volcanoes in the world,and its potential hazards demand detailed seismological and geodetic studies.Previous studies with travel time tomography and receiver functi...The Yellowstone volcano is one of the largest active volcanoes in the world,and its potential hazards demand detailed seismological and geodetic studies.Previous studies with travel time tomography and receiver functions have revealed a low-velocity layer in the crust beneath the Yellowstone volcano,suggesting the presence of a magma chamber at depth.We use ambient seismic noise from regional seismic stations to retrieve short-period surface waves and then study the shallow shear velocity structure of the Yellowstone region by surface wave dispersion analysis.We first obtained a crustal model of the area outside of the Yellowstone volcano and then constructed an absolute shear wave velocity structure in combination with receiver function results for the crust beneath the Yellowstone volcano.The velocity model shows a low-velocity layer with shear velocity at around1.3 km/s,suggesting that a large-scale magma chamber exists at shallow levels within the crust of the Yellowstone volcanic region.展开更多
K416B Ni-based superalloy with high W content has good high temperature properties and low cost,which has a great development potential.To investigate the room temperature tensile property and the deformation feature ...K416B Ni-based superalloy with high W content has good high temperature properties and low cost,which has a great development potential.To investigate the room temperature tensile property and the deformation feature of K416B superalloy,tensile testing at room temperature was carried out,and optical microscopy (OM),scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the deformation and damage mechanisms.Results show that the main room temperature tensile deformation features of the K416B nickel-based superalloy are dislocations slipping in the matrix and shearing into γ’ phase.The <110> super-dislocations shearing into γ’ phase can form the anti-phase boundary two coupled (a/2)<110> partial-dislocations or decompose into the configuration of two (a/3)<112> partial dislocations plus stacking fault.In the later stage of tensile testing,the slip-lines with different orientations are activated in the grain,causing the stress concentration in the regions of block carbide or the porosity,and cracks initiate and propagate along these regions.展开更多
文摘The geological conditions of offshore shallow water delta oil reservoirs were complex, with limited well data and large well spacing. Taking A Oilfield in the Bohai Sea Area, China as an example, the target sand body was formed in a shallow water delta sedimentary environment, with well-developed underwater distributary channels and frequent branching and diversion. The reservoir was strong non-uniformity and uneven plane water cut pressure. To this end, based on the existing work of predecessors, combined with seismic, logging, and production dynamics data, and based on the genesis mechanism of shallow water delta reservoirs, the boundary of composite river channels was identified through seismic facies, and logging facies were used to subdivide them into single river levels within the composite river channels. Then, seismic waveform characteristics were applied to track and characterize the plane distribution of single river channels, guiding the efficient development of offshore shallow water delta oil fields and achieving increased storage and production in Bohai Oilfield, China.
基金Supported by Initial Fund of Guangdong Medical College,No.XB1338the Medical Research Fund of Guangdong Province,No.B2014306the Research Fund of Guangdong Medical College,No.M2013024
文摘AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM(150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin, and superoxide dismutase(SOD). Inflammatory cytokines, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor-α(TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen(PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis wasmeasured by TUNEL assay.Furthermore,apoptosis proteins Caspases-3,6,8,and 9 were detected by Western blot.SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-αpathways.RESULTS:DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice.DHM could significantly decrease serum ALT,AST,IL-1β,IL-6 and TNF-αand increase serum albumin,SOD and liver SOD compared to the control group after CCl4 treatment(P<0.05).PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control(348.9±56.0 vs 107.1±31.4,P<0.01).TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(365.4±99.4 vs 90.5±13.8,P<0.01).Caspase activity detection showed that DHM could reduce the activities of Caspases-8,3,6 and 9 compared to the control(P<0.05).The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-αexpression.However,DHM could not affect TNF-αexpression after SP600125 treatment.Furthermore,DHM could significantly improve the survival rate of acute liver failure(ALF)mice(73.3%vs 20.0%,P<0.0001),and SP600125 could inhibit the effect of DHM.CONCLUSION:These findings demonstrate that DHM alleviates CCl4-induced liver injury,suggesting that DHM is a promising candidate for reversing liver injury and ALF.
基金supprted by the National Natural Science Foundation of China(51672089,51672099)Specical Funding on Applied Science and Technology in Guangdong(2017B020238005)the State Key Laboratory of Advanced Technology for Material Synthesis and Processing(Wuhan University of Technology)(2015-KF-7)~~
基金supported by a grant from the Science and Technology Plans of Jiangxi Province Education Department of China,No.GJJ14705a grant from the Science and Technology Plans of Health and Family Planning Commission of Jiangxi Province of China,No.20175563
文摘Ca^(2+) channel blockers have been shown to protect neurons from ischemia, and aerobic exercise has significant protective effects on a variety of chronic diseases. The present study injected huwentoxin-I(HWTX-I), a spider peptide toxin that blocks Ca^(2+) channels, into the caudal vein of a chronic cerebral ischemia mouse model, once every 2 days, for a total of 15 injections. During this time, a subgroup of mice was subjected to treadmill exercise for 5 weeks. Results showed amelioration of cortical injury and improved neurological function in mice with chronic cerebral ischemia in the HWTX-I + aerobic exercise group. The combined effects of HWTX-I and exercise were superior to HWTX-I or aerobic exercise alone. HWTX-I effectively activated the Notch signal transduction pathway in brain tissue. Aerobic exercise up-regulated synaptophysin m RNA expression. These results demonstrated that aerobic exercise, in combination with HWTX-I, effectively relieved neuronal injury induced by chronic cerebral ischemia via the Notch signaling pathway and promoting synaptic regeneration.
基金financially supported by the Scientific Research Foundation of Shanxi Province Healthy Commission (No. 2017068)the Doctor Scientific Research Foundation of Shanxi cancer hospital (No. 2017A03)the Natural Science Foundation of Shanxi Province (No. 201801D221259)
文摘Objective: Tumor microenvironment, especially the host immune system, plays a pivotal role in tumor initiation and progression. Profiling of immune signature within tumor might uncover biomarkers for targeted therapies and clinical outcomes. However, systematic analysis of immune-related genes in gastric cancer(GC) has not been reported.Methods: Expressions of a total of 718 immune-related genes were generated in 372 stomach adenocarcinoma(STAD) patients from The Cancer Genome Atlas(TCGA) database using RNA-sequencing data. Integrated bioinformatics analyses were performed to identify prognostic factors as well.Results: Survival analyses revealed 73 genes, which were significantly associated with patient’s overall survival(OS). Taken together with clinicopathological parameters, we established a predictive model, containing 10 immune-related genes, which were NRP1, C6, CXCR4, LBP, PNMA1, TLR5, ITGA6, MICB, PBK and TNFRSF18,with powerful efficiency in distinguishing satisfactory or poor survival of STAD patients. Moreover, the top 3 ranked prognostic genes, NRP1, TGFβ2 and MFGE8, were also significantly associated with patient’s OS by an independent validation achieved from Kaplan-Meier plotter database.Conclusions: We profiled prognostic immune signature and established prognostic predictive model for GC,which could reflect immune disorders within tumor microenvironment, and also may provide novel predictive and therapeutic targets for GC patients in the near future.
基金supported by Chinese Acadmy of Sciences Fund(No.KCZX-YW-116-1)Joint Seismological Science Fundation of China (Nos.20080878 and 200708035)
文摘Because ambient seismic noise provides estimated Green's function (EGF) between two sites with high accuracy, Rayleigh wave propagation along the path connecting the two sites is well resolved. Therefore, earthquakes which are close to one seismic station can be well located with calibration extracting from EGF. We test two algorithms in locating the 1998 Zhangbei earthquake, one algorithm is waveform-based, and the other is traveltime-based. We first compute EGF between station ZHB (a station about 40 km away from the epicenter) and five IC/IRIS stations. With the waveform-based approach, we calculate 1D synthetic single-force Green's functions between ZHB and other four stations, and obtain traveltime corrections by correlating synthetic Green's functions with EGFs in period band of 10-30 s. Then we locate the earthquake by minimizing the differential travel times between observed earthquake waveform and the 1D synthetic earthquake waveforms computed with focal mechanism provided by Global CMT after traveltime correction from EGFs. This waveform-based approach yields a location which error is about 13 km away from the location observed with InSAR. With the traveltime-based approach, we begin with measuring group velocity from EGFs as well as group arrival time on observed earthquake waveforms, and then locate the earthquake by minimizing the difference between observed group arrival time and arrival time measured on EGFs. This traveltime-based approach yields accuracy of 3 km, Therefore it is feasible to achieve GT5 (ground truth location with accuracy 5 km) with ambient seismic noises. The less accuracy of the waveform-based approach was mainly caused by uncertainty of focal mechanism.
基金supported by the National Natural Science Foundation of China,No.81371628the Postdoctoral Science Foundation of China,No.2014T70233,2013M541206the Innovation Foundation of Shanxi Medical University First Hospital of China
文摘An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord injury by dropping a weight onto the spinal cord at T7–8. Superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells were transplanted into the injured spinal cord via the subarachnoid space. An outer magnetic field was used to successfully guide the labeled cells to the lesion site. Prussian blue staining showed that more bone marrow mesenchymal stem cells reached the lesion site in these rats than in those without magnetic guidance or superparamagnetic iron oxide labeling, and immunofluorescence revealed a greater number of complete axons at the lesion site. Moreover, the Basso, Beattie and Bresnahan(BBB) locomotor rating scale scores were the highest in rats with superparamagnetic labeling and magnetic guidance. Our data confirm that superparamagnetic iron oxide nanoparticles effectively label bone marrow mesenchymal stem cells and impart sufficient magnetism to respond to the external magnetic field guides. More importantly, superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells can be dynamically and non-invasively tracked in vivo using magnetic resonance imaging. Superparamagnetic iron oxide labeling of bone marrow mesenchymal stem cells coupled with magnetic guidance offers a promising avenue for the clinical treatment of spinal cord injury.
基金supported by a grant from Science and Technology Research Projects of Shanxi Province,No.20120321028-02a grant from the Scientific and Technical Foundation of Shanxi Provincial Health Department,No.201201067+1 种基金a grant from University Research and Development Projects of Shanxi Province,No.20131101grant from the National Natural Science Foundation of China,No.81371628
文摘In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesenchymal stem cells can survive,migrate,integrate and help to restore the function and behaviors of spinal cord injury models,and that they may serve as a suitable approach to treating spinal cord injury.However,it is very difficult to track transplanted cells in vivo.In this study,we injected superparamagnetic iron oxide-labeled neuronal-like cells into the subarachnoid space in a rabbit model of spinal cord injury.At 7 days after cell transplantation,a small number of dot-shaped low signal intensity shadows were observed in the spinal cord injury region,and at 14 days,the number of these shadows increased on T2-weighted imaging.Perl’s Prussian blue staining detected dot-shaped low signal intensity shadows in the spinal cord injury region,indicative of superparamagnetic iron oxide nanoparticle-labeled cells.These findings suggest that transplanted neuronal-like cells derived from bone marrow mesenchymal stem cells can migrate to the spinal cord injury region and can be tracked by magnetic resonance in vivo.Magnetic resonance imaging represents an efficient noninvasive technique for visually tracking transplanted cells in vivo.
文摘1.Introduction On 23 June 2020,the third geostationary Earth orbit satellite(GEO-3),the last satellite of the China's BeiDou Navigation Satellite System(BDS)-3 space segment construction project,was successfully launched,marking the completion of the BDS global constellation deployment and indicating the successful completion of the BDS“three-step”development strategy.The positioning,navigation,and timing(PNT)service and special-feature services provided by the BDS have been widely used in key infrastructures of the national economy and defense security;they have also promoted a transformation of the production method and upgraded industrial infrastructure in China.
基金Supported by Jinling Hospital Medical Research Fund, No. 2005029
文摘AIM: To investigate the relationship between 90-kuD ribosomal S6 kinase (p90RSK) and collagen type □expression during the development of hepatic fibrosis in vivo and in vitro.METHODS: Rat hepatic fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. The protein expression and cell location of p90RSK and their relationship with collagen type □were determined by co-immunofluoresence and confocal microscopy. Subsequently, RNAi strategy was employed to silence p90RSK mRNA expression in HSC-T6, an activated hepatic stellate cell (HSC) line. The expression of collagen type □in HSC-T6 cells was assessed by Western blotting and real-time polymerase chain reaction. Furthermore, HSCs were transfected with expression vectors or RNAi constructs of p90RSK to increase or decrease the p90RSK expression, then collagen type □promoter activity in the transfected HSCs was examined by reporter assay. Lastly HSC-T6 cells transfected with p90RSK siRNA was treated with or without platelet-derived growth factor (PDGF)-BB at a final concentration of 20 μg/L and the cell growth was determined by MTS conversion.RESULTS: In fibrotic liver tissues, p90RSK was overexpressed in activated HSCs and had a significant positive correlation with collagen type □levels.In HSC-T6 cells transfected with RNAi targeted to p90RSK, the expression of collagen type □was down-regulated (61.8% in mRNA, P < 0.01, 89.1% in protein, P < 0.01). However, collagen type □promoter activity was not increased with over-expression of p90RSK and not decreased with low expression either, compared with controls in the same cell line (P = 0.076). Furthermore, p90RSK siRNA exerted the inhibition of HSC proliferation, and also abolished the effect of PDGF on the HSC proliferation.CONCLUSION: p90RSK is over-expressed in activated HSCs and involved in regulating the abnormal expression of collagen type □through initiating the proliferation of HSCs.
基金supported by the China Postdoctoral Science Foundation (No. 2018M6335598)
文摘We constructed a compact high-power RF pulse generator based on a gyro-magnetic nonlinear transmission line(GNLTL) to produce a high-voltage pulse with a sub-nanosecond rise time and a relatively high repetition rate, which shows great potential for application in the high-power ultrawideband electromagnetic effect, etc. The influence of incident pulse parameters(rise time and voltage amplitude) and line length on the sharpening characteristics of the GNLTL were investigated experimentally to optimize the rising rate of the modulated pulse front. Based on the GNLTL equivalent circuit model consisting of an LC ladder network, the rise time, the voltage conversion coefficient and the rising rate properties of a modulated pulse were also numerically analyzed in a wider range. The results show that a?>?90 k V RF pulse with a rise time of 350 ps and a repetition rate of 1 kHz in burst mode is produced by the GNLTL at an axial biasing magnetic field of 22 kA m^-1 and a line length of 30 cm under the condition of a 70 kV incident pulse. Applying a faster and higher incident pulse is conducive to improving the sharpening effect of the GNLTL. Furthermore, within a certain range, increasing the line length of the GNLTL not only reduces the rise time, but increases the voltage conversion coefficient and the rising rate of a modulated pulse. Furthermore, considering the energy loss of ferrite rings, there is an optimal line length to obtain the fastest rising rate of a modulated pulse front edge.
基金supported by China Postdoctoral Science Foundation 2012M510043,2013T60166,NSFC 41074032 and CAS KZCX2-EW-121
文摘The Yellowstone volcano is one of the largest active volcanoes in the world,and its potential hazards demand detailed seismological and geodetic studies.Previous studies with travel time tomography and receiver functions have revealed a low-velocity layer in the crust beneath the Yellowstone volcano,suggesting the presence of a magma chamber at depth.We use ambient seismic noise from regional seismic stations to retrieve short-period surface waves and then study the shallow shear velocity structure of the Yellowstone region by surface wave dispersion analysis.We first obtained a crustal model of the area outside of the Yellowstone volcano and then constructed an absolute shear wave velocity structure in combination with receiver function results for the crust beneath the Yellowstone volcano.The velocity model shows a low-velocity layer with shear velocity at around1.3 km/s,suggesting that a large-scale magma chamber exists at shallow levels within the crust of the Yellowstone volcanic region.
基金financially supported by the National Basic Research Program of China(Nos.2010CB631200 and 2010CB631206)the National Natural Science Foundation of China(No.51701212,No.50931004,No.51571196,No.51601192 and No.51671188)+4 种基金the State Key Laboratory of Solidification Processing in NWPU(SKLSP201747)Liaoning Provincial Natural Science Foundation of China(No.2019-MS-336)the Key Regional Project of Science and Technology Service Network Program,Chinese Academy of Sciences(No.KFJ-STS-QYZX-079)the Youth Innovation Promotion Association Project,Chinese Academy of Sciences(2020)the National Science and Technology Major Project(J2019-VI-0018-0133)。
文摘K416B Ni-based superalloy with high W content has good high temperature properties and low cost,which has a great development potential.To investigate the room temperature tensile property and the deformation feature of K416B superalloy,tensile testing at room temperature was carried out,and optical microscopy (OM),scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the deformation and damage mechanisms.Results show that the main room temperature tensile deformation features of the K416B nickel-based superalloy are dislocations slipping in the matrix and shearing into γ’ phase.The <110> super-dislocations shearing into γ’ phase can form the anti-phase boundary two coupled (a/2)<110> partial-dislocations or decompose into the configuration of two (a/3)<112> partial dislocations plus stacking fault.In the later stage of tensile testing,the slip-lines with different orientations are activated in the grain,causing the stress concentration in the regions of block carbide or the porosity,and cracks initiate and propagate along these regions.
基金supported by the National Natural Science Foundation of China(51672089)the Science and Technology Planning Project of Guangdong Province(2015B020215011)the State Key Laboratory of Advanced Technology for Material Synthesis and Processing(Wuhan University of Technology)(2015-KF-7)~~
