Measurements of carbon dioxide(CO2),methane(CH4),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and cl...Measurements of carbon dioxide(CO2),methane(CH4),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and climate systems.In this study,for the first time,we present CO2,CH4,and CO column measurements carried out by a Bruker EM27/SUN Fourier-transform infrared spectrometer(FTIR)at Golmud(36.42°E,94.91°N,2808 m)in August 2021.The mean and standard deviation of the column-average dry-air mixing ratio of CO2,CH4,and CO(XCO2,XCH4,and XCO)are 409.3±0.4 ppm,1905.5±19.4 ppb,and 103.1±7.7 ppb,respectively.The differences between the FTIR co-located TROPOMI/S5P satellite measurements at Golmud are 0.68±0.64%(13.1±12.2 ppb)for XCH4and 9.81±3.48%(–10.7±3.8 ppb)for XCO,which are within their retrieval uncertainties.High correlations for both XCH4and XCO are observed between the FTIR and S5P satellite measurements.Using the FLEXPART model and satellite measurements,we find that enhanced CH4and CO columns in Golmud are affected by anthropogenic emissions transported from North India.This study provides an insight into the variations of the CO2,CH4,and CO columns in the Qinghai-Tibetan Plateau.展开更多
Studies arising from literature reviews are important as they facilitate specific understanding about the use of the Sentinel-5P satellite developed by the European Space Agency (ESA) to detect the concentration level...Studies arising from literature reviews are important as they facilitate specific understanding about the use of the Sentinel-5P satellite developed by the European Space Agency (ESA) to detect the concentration levels of atmospheric pollutants on a global scale. The objective of this literature review is to analyze the application of the geospatial optics of the Sentinel-5P satellite;coupled with the Tropospheric Monitoring Instrument (TROPOMI) in the detection of NO2 and CO over the period beginning in May 2018 and lasting through May 2024. This was accomplished using manuscripts published in the ScienceDirect databases. The study employed the rigorous Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method, using the specific search term ‘sentinel TROPOMI satellite’, which yielded 555 results published between 2018 and 2024. Subsequently, 274 manuscripts were selected, and 85 were classified for analysis after a concise review. The Content Analysis Method (CAM) was used to understand the absolute frequency, with the use of the MAXQDA software (version 24.2.0) in this analysis. The purpose of using TROPOMI in the 85 manuscripts analyzed is significant. The manuscripts studied focused on air quality monitoring (30.1%), COVID-19 impact detection (24.3%), assessment of pollution sources (23.3%), support for decision makers (13.6%) and the development of methods and tools (8.7%). In this context, 38.5% of the examined studies focused on Asia, followed Europe (29.2%), North and South America (25.1%) and Africa (7.3%). TROPOMI data makes it possible to contribute to creating future government public policies on both the local and global scale.展开更多
目的:探讨微小RNA-296-5p、S期激酶相关蛋白2(S-phase kinase-associated protein 2,Skp2)、核糖体蛋白L6(ribosomal protein L6,RPL6)与前列腺癌病理特征的关系及对手术预后的影响。方法:选取2018年1月至2023年1月120例前列腺患者,均...目的:探讨微小RNA-296-5p、S期激酶相关蛋白2(S-phase kinase-associated protein 2,Skp2)、核糖体蛋白L6(ribosomal protein L6,RPL6)与前列腺癌病理特征的关系及对手术预后的影响。方法:选取2018年1月至2023年1月120例前列腺患者,均行腹腔镜前列腺癌术治疗,对比不同病理特征患者miR-296-5p、Skp2、RPL6 mRNA表达水平,分析各指标与病理特征的关系。根据术后1年是否生化复发分为复发组(n=21)与未复发组(n=97),比较2组临床资料、miR-296-5p、Skp2、RPL6mRNA表达水平,分析miR-296-5p、Skp2、RPL6对手术预后的影响及预测价值。结果:不同病理分期、Gleason评分、术前血清前列腺特异性抗原(prostate specific antigen,PSA)水平、淋巴结转移患者miR-296-5p、Skp2、RPL6 mRNA表达水平比较,差异有统计学意义(F=12.927、22.416、10.088、34.239、20.180、12.208,t=4.649、-5.770、-5.713、4.716、-5.647、-6.884,均P=0.000);miR-296-5p与Gleason评分、病理分期、术前血清前列腺特异性抗原(prostate specific antigen,PSA)水平、淋巴结转移呈负相关(r=-0.578、-0.539、-0.517、-0.556,均P<0.001),Skp2、RPL6 mRNA与Gleason评分、病理分期、术前血清PSA水平、淋巴结转移呈正相关(r=0.531、0.507、0.476、0.493、0.494、0.473、0.420、0.505,均P<0.001);复发组淋巴结转移、病理分期、切缘阳性率、Gleason评分、高于未复发组,术后辅助治疗率低于未复发组(P<0.05);复发组miR-296-5p表达水平低于未复发组,Skp2、RPL6mRNA表达水平高于未复发组(P<0.05);校正前,logistic回归分析,病理分期、Gleason评分、淋巴结转移、切缘阳性、术后辅助治疗、miR-296-5p、Skp2、RPL6 mRNA是前列腺癌患者术后生化复发的影响因素(P<0.05),校正后,miR-296-5p、Skp2、RPL6mRNA仍是前列腺癌患者术后生化复发的影响因素(P<0.05);miR-296-5p、Skp2、RPL6联合预测前列腺术后生化复发的AUC为0.902(95%CI=0.833~0.949),大于各指标单独预测(P<0.05)。结论:前列腺癌患者miR-296-5p、Skp2、RPL6表达水平与病理特征、术后复发密切相关,三者联合预测前列腺术后生化复发具有较高的参考价值。展开更多
The replacement of liquid electrolyte with solid electrolyte can significantly improve the safety and power/energy density of lithium batteries.70Li2S–30P2S5 is one of the most promising solid electrolytes w...The replacement of liquid electrolyte with solid electrolyte can significantly improve the safety and power/energy density of lithium batteries.70Li2S–30P2S5 is one of the most promising solid electrolytes with high conductivity for solid–state batteries.In this work,the ionic conductivity and stability toward moisture and lithium metal of 70Li2S–30P2S5 were enhanced by introducing the different amounts of Li2O additives.65Li2S–30P2S5–1%Li2O delivered the highest conductivity,while 65Li2S–30P2S5–5%Li2O showed the best moisture stability and improved lithium compatibility.Solid-state batteries using 65Li2S–30P2S5–5%Li2O electrolyte and high-voltage LiNi0.6Mn0.2Co0.2O2 cathode exhibited low initial discharge capacity(100 mAh·g-1)and Coulombic efficiency(69%).Li3InCl6 electrolytes were introduced both in the cathode mixture to replace sulfide electrolyte and in the interface layer to improve the cathode compatibility for the solid-state batteries,showing enhanced discharge capacity(175 mAh·g-1)and improved initial Coulombic efficiency(86%).Moreover,it also exhibited good performance at-20℃.展开更多
We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation r...We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.展开更多
BACKGROUND: Numerous current studies have suggested that human telomerase reverse transcriptase (hTERT) gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the...BACKGROUND: Numerous current studies have suggested that human telomerase reverse transcriptase (hTERT) gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the mechanism of action remains unknown. OBJECTIVE: To evaluate the neuroprotective effects and possible mechanism of action of hTERT gene transfection in human embryonic cortical neurons treated with beta-amyloid fragment 25-35 (AI325-35). DESIGN, TIME AND SETTING: The randomized, controlled and molecular biological studies were performed at the Department of Anatomy and Brain Research, Zhongshan School of Medicine, Sun Yat-sen University, China, from September 2005 to June 2008. MATERIALS: AdEasy-1 Expression System was gifted by Professor Guoquan Gao from Sun Yat-Sen University, China. Human cortical neurons were derived from 12-20 week old aborted fetuses, obtained from the Guangzhou Maternal and Child Health Hospital, China. Mouse anti-Odk5 and mouse anti-p16 monoclonal antibodies (Lab Vision, USA), and mouse anti-hTERT monoclonal antibody (Epitomics, USA), were used in this study. METHODS: (1) Recombinant adenovirus vectors, encoding hTERT (Ad-hTERT) and green fluorescent protein (Ad-GFP), were constructed using the AdEasy-1 Expression System. Human embryonic cortical neurons in the Ad-hTERT group were transfected with Ad-hTERT for 1-21 days. Likewise, human embryonic cortical neurons in the Ad-GFP group were transfected with Ad-GFP for 1-21 days. Human embryonic cortical neurons in the control group were cultured as normal. (2) Human embryonic cortical neurons in the Ad-hTERT group were treated with 10 pmol/L Aβ25-35 for 24 hours. Normal human embryonic cortical neurons treated with 10 pmol/Lβ25.35 for 24 hours served as a model group. Human embryonic cortical neurons in the Ad-GFP and control groups were not treated with Aβ25-35. MAIN OUTCOME MEASURES: Expression of hTERT in human embryonic cortical neurons was evaluated by immunocytochemical staining and Western blot assay. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol (TRAP) ELISA kit. Neural activity in human embryonic cortical neurons was examined by MTT assay; apoptosis was measured using TUNEL assay; and Cdk5 and p16 protein expressions were measured by Western blot. RESULTS: Expression of hTERT protein was significantly increased and peaked at day 3 post-transfection in the Ad-hTERT group. No hTERT expression was detected in the Ad-GFP and control groups. Telomerase activity was significantly greater in the Ad-hTERT group compared with the Ad-GFP and control groups (P 〈 0.01). Compared with the control group, cell activity was significantly decreased (P 〈 0.05), and cell apoptotic rate, Cdk5 and p16 expression were significantly increased (P 〈 0.01) in the model group. Compared with the model group, cell activity was increased in the Ad-hTERT group, and peaked at day 3 post-transfection (P 〈 0.05). Neuroprotective effects also peaked at day 3 post-transfection; and the apoptotic rate, Cdk5 and p16 expression significantly decreased (P 〈 0.01). CONCLUSION: Expression of hTERT in human embryonic cortical neurons can relieve Aβ25-35-induced neuronal apoptosis. The possible mechanism by which hTERT produces these neuroprotective effects may be associated with inhibition of Cdk5 and p16 expression.展开更多
目的探讨雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)、p70S6激酶(p70S6kinase,p70S6K)及Lgr5蛋白在胃癌组织中的表达及相关性。方法采用免疫组织化学法检测132例胃癌患者手术切除的胃癌组织、癌旁组织标本和30例慢性非萎缩性...目的探讨雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)、p70S6激酶(p70S6kinase,p70S6K)及Lgr5蛋白在胃癌组织中的表达及相关性。方法采用免疫组织化学法检测132例胃癌患者手术切除的胃癌组织、癌旁组织标本和30例慢性非萎缩性胃炎患者胃镜下活检正常胃黏膜组织标本中mTOR、p70S6K和Lgr5蛋白表达,分析胃癌患者mTOR、p70S6K及Lgr5蛋白阳性表达率与临床病理特征的关系,对胃癌组织中Lgr5蛋白表达与mTOR、p70S6K蛋白表达的相关性进行分析。结果胃癌组织mTOR、p70S6K和Lgr5蛋白阳性表达率分别为65.15%、61.36%、70.45%,癌旁组织分别为24.24%、22.73%、34.09%,均高于正常胃黏膜组织(10.00%、13.33%、6.67%),且胃癌组织mTOR、p70S6K和Lgr5蛋白阳性表达率高于癌旁组织,差异均有统计学意义(P0.05),肿瘤直径≥5cm胃癌患者mTOR、p70S6K和Lgr5蛋白阳性表达率(72.73%、74.03%、80.52%)高于肿瘤直径<5cm者(54.55%、43.64%、56.36%),TNM分期Ⅰ+Ⅱ期者(50.98%、45.10%、54.92%)低于Ⅲ+Ⅳ期者(74.07%、72.84%、80.52%),组织学分级G_1+G_2期者(53.70%,50.00%,55.56%)低于G_3+G_4期者(73.08%、69.23%,80.77%),淋巴结转移N_0者(42.22%、44.44%、46.67%)低于N_1+N_2+N_3者(77.01%、70.11%、82.76%),侵犯程度T_1+T_2期者(42.11%、42.11%、44.74%)低于T_3+T_4期者(74.47%、69.15%、80.85%),差异均有统计学意义(P<0.01);胃癌组织中Lgr5蛋白表达与mTOR、p70S6K蛋白表达呈正相关(r=0.579,P=0.004 6;r=0.502,P=0.007 1)。结论mTOR、p70S6K和Lgr5蛋白表达与胃癌肿瘤浸润程度、淋巴结转移、TNM分期、组织学分级密切相关,可作为评估胃癌患者预后的指标。展开更多
We present an experimental determination on the Lande g-factors for the 5 s^2 ^1 S0 and 5 s5 p ^3P0 states in ultra-cold atomic systems, which is important for evaluating the Zeeman shift of the clock transition in th...We present an experimental determination on the Lande g-factors for the 5 s^2 ^1 S0 and 5 s5 p ^3P0 states in ultra-cold atomic systems, which is important for evaluating the Zeeman shift of the clock transition in the ^87Sr optical lattice clock. The Zeeman shift of the 5 s5 p ^3 P0-5 s^2 ^1 S0 forbidden transition is measured with the π-polarized and σ^±-polarized interrogations at different magnetic field strengths. Moreover, in the g-factor measurement with the σ^±-transition spectra, it is unnecessary to calibrate the external magnetic field. By this means, the ground state 5 s^2 ^1 S0 g-factor for the ^87Sr atom is-1.306(52) ×10^-4, which is the first experimental determination to the best of our knowledge, and the result matches very well with the theoretical estimation. The differential g-factorδg between the 5 s5 p^3 P0 state and the 5 s^2 ^1 S0 state of the ^87Sr atoms is measured in the experiment as well,which are-7.67(36) ×10^-5 with π-transition spectra and-7.72(43) X 10^-5 with σ^±-transition spectra, in good agreement with the previous report [Phys. Rev. A 76(2007) 022510]. This work can also be used for determining the differential g-factor of the clock states for the optical clocks based on other atoms.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42205140,41975035)the National Key Research and Development Program of China(2021YFB3901000).
摘要Measurements of carbon dioxide(CO2),methane(CH4),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and climate systems.In this study,for the first time,we present CO2,CH4,and CO column measurements carried out by a Bruker EM27/SUN Fourier-transform infrared spectrometer(FTIR)at Golmud(36.42°E,94.91°N,2808 m)in August 2021.The mean and standard deviation of the column-average dry-air mixing ratio of CO2,CH4,and CO(XCO2,XCH4,and XCO)are 409.3±0.4 ppm,1905.5±19.4 ppb,and 103.1±7.7 ppb,respectively.The differences between the FTIR co-located TROPOMI/S5P satellite measurements at Golmud are 0.68±0.64%(13.1±12.2 ppb)for XCH4and 9.81±3.48%(–10.7±3.8 ppb)for XCO,which are within their retrieval uncertainties.High correlations for both XCH4and XCO are observed between the FTIR and S5P satellite measurements.Using the FLEXPART model and satellite measurements,we find that enhanced CH4and CO columns in Golmud are affected by anthropogenic emissions transported from North India.This study provides an insight into the variations of the CO2,CH4,and CO columns in the Qinghai-Tibetan Plateau.
基金the Center for Studies and Research on Urban Mobility(NEPMOUR+S/ATITUS)Fundação Meridionalthe National Council for Scientific and Technological Development(CNPq),Brazil and the Atlantic International Research Center(AIR Center)for granting a doctoral scholarship via the Foundation for Science and Technology in Portugal.
摘要Studies arising from literature reviews are important as they facilitate specific understanding about the use of the Sentinel-5P satellite developed by the European Space Agency (ESA) to detect the concentration levels of atmospheric pollutants on a global scale. The objective of this literature review is to analyze the application of the geospatial optics of the Sentinel-5P satellite;coupled with the Tropospheric Monitoring Instrument (TROPOMI) in the detection of NO2 and CO over the period beginning in May 2018 and lasting through May 2024. This was accomplished using manuscripts published in the ScienceDirect databases. The study employed the rigorous Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method, using the specific search term ‘sentinel TROPOMI satellite’, which yielded 555 results published between 2018 and 2024. Subsequently, 274 manuscripts were selected, and 85 were classified for analysis after a concise review. The Content Analysis Method (CAM) was used to understand the absolute frequency, with the use of the MAXQDA software (version 24.2.0) in this analysis. The purpose of using TROPOMI in the 85 manuscripts analyzed is significant. The manuscripts studied focused on air quality monitoring (30.1%), COVID-19 impact detection (24.3%), assessment of pollution sources (23.3%), support for decision makers (13.6%) and the development of methods and tools (8.7%). In this context, 38.5% of the examined studies focused on Asia, followed Europe (29.2%), North and South America (25.1%) and Africa (7.3%). TROPOMI data makes it possible to contribute to creating future government public policies on both the local and global scale.
摘要目的:探讨微小RNA-296-5p、S期激酶相关蛋白2(S-phase kinase-associated protein 2,Skp2)、核糖体蛋白L6(ribosomal protein L6,RPL6)与前列腺癌病理特征的关系及对手术预后的影响。方法:选取2018年1月至2023年1月120例前列腺患者,均行腹腔镜前列腺癌术治疗,对比不同病理特征患者miR-296-5p、Skp2、RPL6 mRNA表达水平,分析各指标与病理特征的关系。根据术后1年是否生化复发分为复发组(n=21)与未复发组(n=97),比较2组临床资料、miR-296-5p、Skp2、RPL6mRNA表达水平,分析miR-296-5p、Skp2、RPL6对手术预后的影响及预测价值。结果:不同病理分期、Gleason评分、术前血清前列腺特异性抗原(prostate specific antigen,PSA)水平、淋巴结转移患者miR-296-5p、Skp2、RPL6 mRNA表达水平比较,差异有统计学意义(F=12.927、22.416、10.088、34.239、20.180、12.208,t=4.649、-5.770、-5.713、4.716、-5.647、-6.884,均P=0.000);miR-296-5p与Gleason评分、病理分期、术前血清前列腺特异性抗原(prostate specific antigen,PSA)水平、淋巴结转移呈负相关(r=-0.578、-0.539、-0.517、-0.556,均P<0.001),Skp2、RPL6 mRNA与Gleason评分、病理分期、术前血清PSA水平、淋巴结转移呈正相关(r=0.531、0.507、0.476、0.493、0.494、0.473、0.420、0.505,均P<0.001);复发组淋巴结转移、病理分期、切缘阳性率、Gleason评分、高于未复发组,术后辅助治疗率低于未复发组(P<0.05);复发组miR-296-5p表达水平低于未复发组,Skp2、RPL6mRNA表达水平高于未复发组(P<0.05);校正前,logistic回归分析,病理分期、Gleason评分、淋巴结转移、切缘阳性、术后辅助治疗、miR-296-5p、Skp2、RPL6 mRNA是前列腺癌患者术后生化复发的影响因素(P<0.05),校正后,miR-296-5p、Skp2、RPL6mRNA仍是前列腺癌患者术后生化复发的影响因素(P<0.05);miR-296-5p、Skp2、RPL6联合预测前列腺术后生化复发的AUC为0.902(95%CI=0.833~0.949),大于各指标单独预测(P<0.05)。结论:前列腺癌患者miR-296-5p、Skp2、RPL6表达水平与病理特征、术后复发密切相关,三者联合预测前列腺术后生化复发具有较高的参考价值。
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51821005,21975087,U1966214 and 51902116)the Certificate of China Postdoctoral Science Foundation Grant(No.2019M652634)We gratefully acknowledge the Analytical and Testing Center of HUST for allowing us to use its facilities.
摘要The replacement of liquid electrolyte with solid electrolyte can significantly improve the safety and power/energy density of lithium batteries.70Li2S–30P2S5 is one of the most promising solid electrolytes with high conductivity for solid–state batteries.In this work,the ionic conductivity and stability toward moisture and lithium metal of 70Li2S–30P2S5 were enhanced by introducing the different amounts of Li2O additives.65Li2S–30P2S5–1%Li2O delivered the highest conductivity,while 65Li2S–30P2S5–5%Li2O showed the best moisture stability and improved lithium compatibility.Solid-state batteries using 65Li2S–30P2S5–5%Li2O electrolyte and high-voltage LiNi0.6Mn0.2Co0.2O2 cathode exhibited low initial discharge capacity(100 mAh·g-1)and Coulombic efficiency(69%).Li3InCl6 electrolytes were introduced both in the cathode mixture to replace sulfide electrolyte and in the interface layer to improve the cathode compatibility for the solid-state batteries,showing enhanced discharge capacity(175 mAh·g-1)and improved initial Coulombic efficiency(86%).Moreover,it also exhibited good performance at-20℃.
基金supported by the National Natural Science Foundation of China,Nos.82271327(to ZW),82072535(to ZW),81873768(to ZW),and 82001253(to TL).
摘要We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.
基金the National Key Basic Research Program of China,No. 2006cb500700the National Natural Science Foundation of China,No.30470904the Natural Science and Technology Foundation of Guangdong Province,No. 04009356, 2008B030301320
摘要BACKGROUND: Numerous current studies have suggested that human telomerase reverse transcriptase (hTERT) gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the mechanism of action remains unknown. OBJECTIVE: To evaluate the neuroprotective effects and possible mechanism of action of hTERT gene transfection in human embryonic cortical neurons treated with beta-amyloid fragment 25-35 (AI325-35). DESIGN, TIME AND SETTING: The randomized, controlled and molecular biological studies were performed at the Department of Anatomy and Brain Research, Zhongshan School of Medicine, Sun Yat-sen University, China, from September 2005 to June 2008. MATERIALS: AdEasy-1 Expression System was gifted by Professor Guoquan Gao from Sun Yat-Sen University, China. Human cortical neurons were derived from 12-20 week old aborted fetuses, obtained from the Guangzhou Maternal and Child Health Hospital, China. Mouse anti-Odk5 and mouse anti-p16 monoclonal antibodies (Lab Vision, USA), and mouse anti-hTERT monoclonal antibody (Epitomics, USA), were used in this study. METHODS: (1) Recombinant adenovirus vectors, encoding hTERT (Ad-hTERT) and green fluorescent protein (Ad-GFP), were constructed using the AdEasy-1 Expression System. Human embryonic cortical neurons in the Ad-hTERT group were transfected with Ad-hTERT for 1-21 days. Likewise, human embryonic cortical neurons in the Ad-GFP group were transfected with Ad-GFP for 1-21 days. Human embryonic cortical neurons in the control group were cultured as normal. (2) Human embryonic cortical neurons in the Ad-hTERT group were treated with 10 pmol/L Aβ25-35 for 24 hours. Normal human embryonic cortical neurons treated with 10 pmol/Lβ25.35 for 24 hours served as a model group. Human embryonic cortical neurons in the Ad-GFP and control groups were not treated with Aβ25-35. MAIN OUTCOME MEASURES: Expression of hTERT in human embryonic cortical neurons was evaluated by immunocytochemical staining and Western blot assay. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol (TRAP) ELISA kit. Neural activity in human embryonic cortical neurons was examined by MTT assay; apoptosis was measured using TUNEL assay; and Cdk5 and p16 protein expressions were measured by Western blot. RESULTS: Expression of hTERT protein was significantly increased and peaked at day 3 post-transfection in the Ad-hTERT group. No hTERT expression was detected in the Ad-GFP and control groups. Telomerase activity was significantly greater in the Ad-hTERT group compared with the Ad-GFP and control groups (P 〈 0.01). Compared with the control group, cell activity was significantly decreased (P 〈 0.05), and cell apoptotic rate, Cdk5 and p16 expression were significantly increased (P 〈 0.01) in the model group. Compared with the model group, cell activity was increased in the Ad-hTERT group, and peaked at day 3 post-transfection (P 〈 0.05). Neuroprotective effects also peaked at day 3 post-transfection; and the apoptotic rate, Cdk5 and p16 expression significantly decreased (P 〈 0.01). CONCLUSION: Expression of hTERT in human embryonic cortical neurons can relieve Aβ25-35-induced neuronal apoptosis. The possible mechanism by which hTERT produces these neuroprotective effects may be associated with inhibition of Cdk5 and p16 expression.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61127901,11404025 and 91536106the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDB21030700+1 种基金the Key Research Project of Frontier Science of Chinese Academy of Sciences under Grant No QYZDB-SSW-JSC004the China Postdoctoral Science Foundation under Grant No 2014M560061
摘要We present an experimental determination on the Lande g-factors for the 5 s^2 ^1 S0 and 5 s5 p ^3P0 states in ultra-cold atomic systems, which is important for evaluating the Zeeman shift of the clock transition in the ^87Sr optical lattice clock. The Zeeman shift of the 5 s5 p ^3 P0-5 s^2 ^1 S0 forbidden transition is measured with the π-polarized and σ^±-polarized interrogations at different magnetic field strengths. Moreover, in the g-factor measurement with the σ^±-transition spectra, it is unnecessary to calibrate the external magnetic field. By this means, the ground state 5 s^2 ^1 S0 g-factor for the ^87Sr atom is-1.306(52) ×10^-4, which is the first experimental determination to the best of our knowledge, and the result matches very well with the theoretical estimation. The differential g-factorδg between the 5 s5 p^3 P0 state and the 5 s^2 ^1 S0 state of the ^87Sr atoms is measured in the experiment as well,which are-7.67(36) ×10^-5 with π-transition spectra and-7.72(43) X 10^-5 with σ^±-transition spectra, in good agreement with the previous report [Phys. Rev. A 76(2007) 022510]. This work can also be used for determining the differential g-factor of the clock states for the optical clocks based on other atoms.