In the DF1-1 Gas Field in the Yinggehai Basin, South China Sea, the velocity-depth plot and velocity spectra show significant variations from a linear trend, exhibiting a distinct reversal phenomenon. Velocity paramet...In the DF1-1 Gas Field in the Yinggehai Basin, South China Sea, the velocity-depth plot and velocity spectra show significant variations from a linear trend, exhibiting a distinct reversal phenomenon. Velocity parameters derived from velocity spectral analysis of the seismic data and sonic logs indicate that the interval velocity reverses below 2,100 m (2.2 s two-way time (TWT)) in the DF1-1 Gas Field. Some direct hydrocarbon indicators (DHIs) models developed for the shallow strata cannot be simply applied to the moderately to deeply buried strata for direct exploration target recognition because the velocity reversal has caused the middle-deep gas reservoirs to exhibit a moderate or weak seismic amplitude. The hydrocarbon indicator method of “Differential Interformational Velocity Analysis (DIVA)” with the aid of other hydrocarbon indicating techniques was employed to effectively identify DHIs in the middle-deep strata under velocity inversion. The result has shown that the DIVA technique can be effectively used as a DHI in both the shallow and the middle-deep strata in the study area with the shallow strata characterized by Type I DIVA anomaly and the middle-deep strata characterized by the Type II DIVA anomaly.展开更多
HIERARCHY is a guiding structure in human society.People both climb and topple down social ladders as they struggle to gain a foothold in school,at work or in the public eye. What if this instinct could be altered? Sc...HIERARCHY is a guiding structure in human society.People both climb and topple down social ladders as they struggle to gain a foothold in school,at work or in the public eye. What if this instinct could be altered? Scientists in Shanghai have figured out how to do just that. Experimenting on mice,a research team with the Institute of展开更多
We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein...We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final(S)-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.展开更多
Treatment of petroleum spills and organic solvent pollution in general is an important issue; several techniques are under development to remove oil from water. The use of absorbents is one of the most common techniqu...Treatment of petroleum spills and organic solvent pollution in general is an important issue; several techniques are under development to remove oil from water. The use of absorbents is one of the most common techniques to tackle this problem. These absorbents can be classified based on their characteristics of recyclability into irreversible and reversible ones. In this review, we discuss the application of several materials as oil absorbents, according to their classification and characteristics such as hydrophobicity, surface area and oil absorption capacity. Also, the fabrication methods for some materials are presented and analyzed.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
The precursors of La0.7Sr0.3-xCaxCo0.9Fe0.1O3-δ(LSCCF, x=0.05, 0.10, 0.15, 0.20) as the cathode materials for intermediate temperature solid oxide fuel cell (ITSOFC) were prepared by reverse titration co-precipitatio...The precursors of La0.7Sr0.3-xCaxCo0.9Fe0.1O3-δ(LSCCF, x=0.05, 0.10, 0.15, 0.20) as the cathode materials for intermediate temperature solid oxide fuel cell (ITSOFC) were prepared by reverse titration co-precipitation method with metal-nitrates as starting materials and mixed alkali (NaOH and Na2CO3) as a precipitating agent. The formation process of LSCCF from the precursors was monitored by TG-DSC, and the crystal structure and particles morphology of the precursors which were calcined at 600, 800, 1000 ℃ for 3 h were characterized using XRD, SEM technologies. Compared with the solid state reaction of constituent oxides, when the pH value of the precipitating solution was in the range of 9.1~9.5, the LSCCF powders from the precursors caclined at 800 ℃ for 3 h had high purity, homogeneous and single perovskite phase. The electrical conductivity of the LSCCF samples sintered at 1200 ℃ for 3 h, which was measured as a function of temperatures from 100 to 800 ℃ by DC four-probe method in air, decreased with x from 0.05 to 0.20. The value of electrical conductivity was almost equal because of Ca2+, Sr2+ co-dopant resulting in the 'mix effect' while x=0.10 or 0.15. The electrical conductivity of all doped samples was higher than 100 S·cm-1 at intermediate temperatures from 500 to 800 ℃, and there was good compatibility between the LSCCF cathode and Ce0.8Sm0.2O2 electrolyte.展开更多
Introduction: Coverage of defects of the distal lower extremity and foot remains a challenging reconstructive prcedure. Free tissue transfer remains the standard for the management of these defects. However, there are...Introduction: Coverage of defects of the distal lower extremity and foot remains a challenging reconstructive prcedure. Free tissue transfer remains the standard for the management of these defects. However, there are some disadvantages like;longer operative times, bulky contour, and the need for highly skilled expertise. The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipo-fascial flap that is used for coverage of defects that involve the distal third of the leg, ankle, and foot. A significant advantage of this flap is a constant blood supply that does not require sacrifice of a major artery. Methods: Twenty RSSAF flaps were harvested for reconstruction of different traumatic soft tissue defects of the lower third of leg, ankle and foot. Follow up for 6 months postoperative. Results: Twenty Patients;twelve males and eight females underwent reconstruction of different soft tissue defects over the foot and ankle using RSSAF. The overall complications occurred in 6 flaps;4 minor and 2 major complications. The remaining 14 flaps passed an uneventful follow up. Conclusions: The reverse superficial sural artery flap RSSAF can be used as a reliable alternative to free tissue transfer in reconstruction of defects over the lower third of leg, ankle, and foot. Venous congestion is the major threat to the flap but its incidence can be minimized by wide pedicle, less kink of the flap, and keep the venae comitants around the artery.展开更多
In the different stages of the development of the old-age service, the responsibility and function of the government will be different. In the new period, the government should redefine its role in advancing the socia...In the different stages of the development of the old-age service, the responsibility and function of the government will be different. In the new period, the government should redefine its role in advancing the socialization of the old-age service. The level of socialization of old-age services is not high, the lack of vitality of the pension market, the imperfect system and other problems arise because the government is not clear. The government should deal with the relationship between the main body of the market and avoid the 'double failure' of the government and the market. The government should play a guiding role in the policy, laws and regulations and other aspects of good service work for the social services of the elderly to provide a good development environment.展开更多
In order to realize the parametric design of the conjugate cam weft insertion mechanism,according to the necessary parameters of weft insertion process,ideal kinematic curves of the weft insertion mechanism were given...In order to realize the parametric design of the conjugate cam weft insertion mechanism,according to the necessary parameters of weft insertion process,ideal kinematic curves of the weft insertion mechanism were given,and the mathematical model of reverse solution for this mechanism was established.The parameters of this mechanism were obtained by reverse solution on the basis of the given ideal kinematic curves and kinematic requirements.The parametric design platform which was integrated with the functions of parametric reverse solution,motion simulation,three-dimensional modeling and virtual assembly was developed based on VB.NET and Unigraphics(UG) NX.After entering the technological parameters of weft insertion process and essential structural parameters by users,three-dimensional drawing of the main parts such as the conjugate cam and shaft,can be obtained by this platform,also the processing data of the cam can be calculated.This platform provides a rapid approach for parametric design of weft insertion mechanism.展开更多
A novel class of molecules with structure N-(3-arylpropyl)-9,10-dihydro-9-oxoacridine-4-carboxamides (20- 29) were designed by generating a pharmacophore for potent MDR reversal activity using phase drug design so...A novel class of molecules with structure N-(3-arylpropyl)-9,10-dihydro-9-oxoacridine-4-carboxamides (20- 29) were designed by generating a pharmacophore for potent MDR reversal activity using phase drug design software. The designed molecules were synthesized by a novel synthesis route and evaluated for their inhibitory effects on the transport activity of P-glycoprotein (P-gp) by standard Hoechst 33342 assay method. Based on the pIC50 values of ten title compounds screened, three compounds exhibited better activity as compared to Verapamil used as standard.展开更多
基金supported by the National Natural Science Foundation of China (No.40702024)the Project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China (No.2009022014)Open Research Foundation of Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences),Ministry of Education (No.TPR-2009-33)
文摘In the DF1-1 Gas Field in the Yinggehai Basin, South China Sea, the velocity-depth plot and velocity spectra show significant variations from a linear trend, exhibiting a distinct reversal phenomenon. Velocity parameters derived from velocity spectral analysis of the seismic data and sonic logs indicate that the interval velocity reverses below 2,100 m (2.2 s two-way time (TWT)) in the DF1-1 Gas Field. Some direct hydrocarbon indicators (DHIs) models developed for the shallow strata cannot be simply applied to the moderately to deeply buried strata for direct exploration target recognition because the velocity reversal has caused the middle-deep gas reservoirs to exhibit a moderate or weak seismic amplitude. The hydrocarbon indicator method of “Differential Interformational Velocity Analysis (DIVA)” with the aid of other hydrocarbon indicating techniques was employed to effectively identify DHIs in the middle-deep strata under velocity inversion. The result has shown that the DIVA technique can be effectively used as a DHI in both the shallow and the middle-deep strata in the study area with the shallow strata characterized by Type I DIVA anomaly and the middle-deep strata characterized by the Type II DIVA anomaly.
文摘HIERARCHY is a guiding structure in human society.People both climb and topple down social ladders as they struggle to gain a foothold in school,at work or in the public eye. What if this instinct could be altered? Scientists in Shanghai have figured out how to do just that. Experimenting on mice,a research team with the Institute of
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA11030404),the Key Project from Chinese Academy of Sciences(KGZD-EW-606)the National Natural Science Foundation of China(21302199)Guangzhou Science and Technology Plan Projects(201510010012)
文摘We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final(S)-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.
基金the Universidad Autónoma de Nuevo León (Monterrey city, Mexico) for financial support (Project Paicyt-2015)
文摘Treatment of petroleum spills and organic solvent pollution in general is an important issue; several techniques are under development to remove oil from water. The use of absorbents is one of the most common techniques to tackle this problem. These absorbents can be classified based on their characteristics of recyclability into irreversible and reversible ones. In this review, we discuss the application of several materials as oil absorbents, according to their classification and characteristics such as hydrophobicity, surface area and oil absorption capacity. Also, the fabrication methods for some materials are presented and analyzed.
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
文摘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the National High-Tech Development Plan (2006AA05Z417)the Natural Science Foundation of Lia-oning Province (20062145)the Education department of Liaoning Province (05L073)
文摘The precursors of La0.7Sr0.3-xCaxCo0.9Fe0.1O3-δ(LSCCF, x=0.05, 0.10, 0.15, 0.20) as the cathode materials for intermediate temperature solid oxide fuel cell (ITSOFC) were prepared by reverse titration co-precipitation method with metal-nitrates as starting materials and mixed alkali (NaOH and Na2CO3) as a precipitating agent. The formation process of LSCCF from the precursors was monitored by TG-DSC, and the crystal structure and particles morphology of the precursors which were calcined at 600, 800, 1000 ℃ for 3 h were characterized using XRD, SEM technologies. Compared with the solid state reaction of constituent oxides, when the pH value of the precipitating solution was in the range of 9.1~9.5, the LSCCF powders from the precursors caclined at 800 ℃ for 3 h had high purity, homogeneous and single perovskite phase. The electrical conductivity of the LSCCF samples sintered at 1200 ℃ for 3 h, which was measured as a function of temperatures from 100 to 800 ℃ by DC four-probe method in air, decreased with x from 0.05 to 0.20. The value of electrical conductivity was almost equal because of Ca2+, Sr2+ co-dopant resulting in the 'mix effect' while x=0.10 or 0.15. The electrical conductivity of all doped samples was higher than 100 S·cm-1 at intermediate temperatures from 500 to 800 ℃, and there was good compatibility between the LSCCF cathode and Ce0.8Sm0.2O2 electrolyte.
文摘Introduction: Coverage of defects of the distal lower extremity and foot remains a challenging reconstructive prcedure. Free tissue transfer remains the standard for the management of these defects. However, there are some disadvantages like;longer operative times, bulky contour, and the need for highly skilled expertise. The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipo-fascial flap that is used for coverage of defects that involve the distal third of the leg, ankle, and foot. A significant advantage of this flap is a constant blood supply that does not require sacrifice of a major artery. Methods: Twenty RSSAF flaps were harvested for reconstruction of different traumatic soft tissue defects of the lower third of leg, ankle and foot. Follow up for 6 months postoperative. Results: Twenty Patients;twelve males and eight females underwent reconstruction of different soft tissue defects over the foot and ankle using RSSAF. The overall complications occurred in 6 flaps;4 minor and 2 major complications. The remaining 14 flaps passed an uneventful follow up. Conclusions: The reverse superficial sural artery flap RSSAF can be used as a reliable alternative to free tissue transfer in reconstruction of defects over the lower third of leg, ankle, and foot. Venous congestion is the major threat to the flap but its incidence can be minimized by wide pedicle, less kink of the flap, and keep the venae comitants around the artery.
文摘In the different stages of the development of the old-age service, the responsibility and function of the government will be different. In the new period, the government should redefine its role in advancing the socialization of the old-age service. The level of socialization of old-age services is not high, the lack of vitality of the pension market, the imperfect system and other problems arise because the government is not clear. The government should deal with the relationship between the main body of the market and avoid the 'double failure' of the government and the market. The government should play a guiding role in the policy, laws and regulations and other aspects of good service work for the social services of the elderly to provide a good development environment.
基金National Natural Science Foundation of China (No.50875243)Natural Science Foundation of Zhejiang Province,China (No.Y1110100)
文摘In order to realize the parametric design of the conjugate cam weft insertion mechanism,according to the necessary parameters of weft insertion process,ideal kinematic curves of the weft insertion mechanism were given,and the mathematical model of reverse solution for this mechanism was established.The parameters of this mechanism were obtained by reverse solution on the basis of the given ideal kinematic curves and kinematic requirements.The parametric design platform which was integrated with the functions of parametric reverse solution,motion simulation,three-dimensional modeling and virtual assembly was developed based on VB.NET and Unigraphics(UG) NX.After entering the technological parameters of weft insertion process and essential structural parameters by users,three-dimensional drawing of the main parts such as the conjugate cam and shaft,can be obtained by this platform,also the processing data of the cam can be calculated.This platform provides a rapid approach for parametric design of weft insertion mechanism.
文摘A novel class of molecules with structure N-(3-arylpropyl)-9,10-dihydro-9-oxoacridine-4-carboxamides (20- 29) were designed by generating a pharmacophore for potent MDR reversal activity using phase drug design software. The designed molecules were synthesized by a novel synthesis route and evaluated for their inhibitory effects on the transport activity of P-glycoprotein (P-gp) by standard Hoechst 33342 assay method. Based on the pIC50 values of ten title compounds screened, three compounds exhibited better activity as compared to Verapamil used as standard.