The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variabl...The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variables as well as their interactions remain unclear,especially in areas undergoing long-term forest restoration.In this study,Ca and Mg concentrations in the forest floor and topsoil from 239 forest plots across the Loess Plateau were measured,and the effects of forest types,climate,soil properties,stand characteristics and nitrogen deposition were explored.The results showed significantly higher Ca concentrations in the forest floor(20.68±8.04 mg/g)than in the topsoil(13.28±12.83 mg/g),whereas Mg exhibited the inverse pattern(3.64±1.09 and 10.11±2.51 mg/g,respectively).The effect of forest types was only significant on forest floor Ca,and Ca concentrations were higher in broadleaf and mixed forests than in coniferous forests.Overall,Ca and Mg concentrations in forest floor and topsoil increased with latitudes while decreased with elevations,and the significance of the trends varied among forest types.Forest floor Ca and Mg were mainly influenced by environmental variables aboveground,i.e.,basal area(BA)and mean annual precipitation(MAP),respectively;topsoil Ca and Mg were more affected by soil properties(soil C/N and pH,respectively).Those suggested a depletion of Ca belowground was associated with forest growth and enriched soil nitrogen,and the leaching of mobile Mg was correlated with rainfall and soil acidification.Besides,the impact of environmental variables on Ca-Mg balance(Ca/Mg ratio)belowground was primarily through the regulation of Ca.Elucidating the influence of environmental variables will improve our ability to predict future changes in base cations and thus forest soil health in the greening vegetated Loess Plateau.展开更多
AIM:To investigate the possibility of shortening the duration of peginterferon(Peg-IFN)plus ribavirin(RBV) combination therapy by incorporating interferon-β (IFN-β)induction therapy. METHODS:A one treatment arm,coho...AIM:To investigate the possibility of shortening the duration of peginterferon(Peg-IFN)plus ribavirin(RBV) combination therapy by incorporating interferon-β (IFN-β)induction therapy. METHODS:A one treatment arm,cohort prospective study was conducted on seventy one patients.The patients were Japanese adults with genotype 1b chronic hepatitis C,HCV-RNA levels of≥5.0 Log IU/mL or 100 KIU/mL,and platelet counts of≥90 000/μL.The treatment regimen consisted of a 2 wk course of twicedaily administration of IFN-βfollowed by 24 wk PegIFN plus RBV combination therapy.We prolonged the duration of the Peg-IFN plus RBV therapy to 48 wk if the patient requested it. RESULTS:The patients,including 44%males,were characterized by an median age of 63 years(range: 32-78 years),an median platelet count of 13.9(range: 9.1-30.6)×10 4 /μL,62%IFN-na?ve,and median HCV- RNA of 6.1(range:5.1-7.2)Log IU/mL.The sustained virologic response(SVR)rates were 34%(Peg-IFN:1-24 wk,n=61,95%confidence interval(CI): 24%-47%)and 55%(Peg-IFN:20-24 wk,n=31,95% CI:38%-71%,P<0.001;vs Peg-IFN:1-19 wk).TheSVR rate when the administration was discontinued early was 13%(Peg-IFN:1-19 wk,n=30,95%CI: 5%-30%),and that when the administration was prolonged was 50%(Peg-IFN:25-48 wk,n=10,95% CI:24%-76%,P<0.05;vs Peg-IFN:1-19 wk).In the patients who received 20-24 wk of Peg-IFN plus RBV,only the higher platelet count(≥130 000/μL) was significantly correlated with the SVR(odds ratio: 11.680,95%CI:2.3064-79.474,P=0.0024).In 45% (14/31)of the patients with a higher platelet count (≥130000/μL)before therapy,the HCV-RNA level decreased to below 3.3 Log IU/mL at the completion of IFN-β,and their SVR rate was 93%(13/14)after 20-24 wk administration of Peg-IFN plus RBV. CONCLUSION:These results suggest the possibilities of shortening the duration of Peg-IFN plus RBV combination therapy by actively reducing HCV-RNA levels using the IFN-βinduction regimen.展开更多
The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their mol...The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their molecular masses, isoelectric points (pI), pH-optima and other properties were analyzed by native proteinase gels.It was shown that the 65 kDa ATP-BPase is specifically induced by heat shock and not detectable in control cells.Its N-terminal 1-9 amino acid sequence was determined by Edman degradation, but no homologies to other proteins in the protein data bases were found. 30 and 31 kDa proteinases can be cleaved from the 45, 55 and 65 kDa proteinases to which they are linked. A possible relationship of the heat-induced 65 kDa ATP-BPase with the ATP-dependent proteinases (ATP-DPases) in prokaryotes and eukaryotes is discussed.展开更多
The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results sho...The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results showed that N^+ beam-induced mutation of maize pollens can result in the change of their DNA bases. The mutation is not properly random and its frequency increases with a rise in 30 keV N+ beam doses. It is conformed with A-G transformation, which is one of the most important factors in DNA bases induced by N+ beam.展开更多
AIM： To evaluate the daily high-dose induction therapy with interferon-α2b （IFN-α2b） in combination with ribavirin for the treatment of patients who failed with interferon monotherapy and had a relapse, based on ...AIM： To evaluate the daily high-dose induction therapy with interferon-α2b （IFN-α2b） in combination with ribavirin for the treatment of patients who failed with interferon monotherapy and had a relapse, based on the assumption that the viral burden would decline faster, thus increasing the likelihood of higher response rates in this difficult-totreat patient group. METHODS： Seventy patients were enrolled in this study. Treatment was started with 10 NU IFN-α2b daily for 3 wk, followed by IFN-α2b 5 NU/TIW in combination with ribavirin （1 000-1 200 mg/d） for 21 wk. In case of a negative HCV RNA PCR, treatment was continued until wk 48 （IFN-α2b 3MU/TIW＋1000-1200 mg ribavirin/daily）. RESULTS： The dose of IFN-α2b or ribavirin was reduced in 16% of patients because of hematologic side effects, and treatment was discontinued in 7% of patients. An early viral response （EVR） was achieved in 60% of patients. Fifty percent of all patients achieved an end-oftreatment response （EOT） and d0% obtained a sustained viral response （SVR）. Patients with no response had a significantly lower response rate than those with a former relapse （SVR 30% vs 53%; P=0.049）. Furthermore, lower response rates were observed in patients infected with genotype la/b than in patients with non-1-genotype （SVR 28% vs7d%; P=0.001）. As a significant predictive factor for a sustained response, a rapid initial decline of HCV RNA could be identified. No patient achieving a negative HCV-RNA PCR at wk 18 or later eventually eliminated the virus. CONCLUSION： Daily high-dose induction therapy with interferon-α2b is well tolerated and effective for the treatment of non-responders and relapsers, when interferon monotherapy fails. A fast decline of viral load during the first 12 wk is strongly associated with a sustained viral response.展开更多
Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to o...Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.展开更多
The young thalli of Porphyra yezoensis and P.haitanensis are induced by N-Methy-N’-Nitro-N-Nitrosoguanidine (NG), a strong mutagen to induce the mutant of chromatophore. It is showed that no mutants have been investi...The young thalli of Porphyra yezoensis and P.haitanensis are induced by N-Methy-N’-Nitro-N-Nitrosoguanidine (NG), a strong mutagen to induce the mutant of chromatophore. It is showed that no mutants have been investigated in all control groups, while in the induced groups, it is easy to find mutant cells or mutant cell masses in the thallus. The pigmentation mutants may be the result of NG inducement. The mutant rate increases obviously with the mutagen concentration or by prolonging the induction time. Within the scope of experiment, the inducement effects of Porphyra yezoensis are raised from 11.2% to 28.7%, and those of P. haitanensis from 10.1% to 20.2%. According to our experiments, the amount of mutant cells in the same area does not increase with the induction intensity The amount of mutant cells in every group of inducement of both species of Porphyraμ changes very little with the fixed fields check method. The lowest dose (25g/mL) of this experiment has a high mutant rate. The mutant rate shows the percentage of mutant cells in all the survived cells, while the amount of mutant cells reflects the effect of μinducement. Thus the optimum induction concentration of NG is 25 g/mL, and the optimum induction time is 30 minutes.展开更多
This paper discusses a comparative study of two modeling methods based on multimodel approach. The first is based on C-means clustering algorithm and the second is based on K-means clustering algorithm. The two method...This paper discusses a comparative study of two modeling methods based on multimodel approach. The first is based on C-means clustering algorithm and the second is based on K-means clustering algorithm. The two methods are experimentally applied to an induction motor. The multimodel modeling consists in representing the IM through a finite number of local models. This number of models has to be initially fixed, for which a subtractive clustering is necessary. Then both C-means and K-means clustering are exploited to determine the clusters. These clusters will be then exploited on the basis of structural and parametric identification to determine the local models that are combined, finally, to form the multimodel. The experimental study is based on MATLAB/SIMULINK environment and a DSpace scheme with DS1104 controller board. Experimental results approve that the multimodel based on K-means clustering algorithm is the most efficient.展开更多
基金supported by the National Natural Science Foundation of China(42401054)Natural Science Foundation of Hebei Province(D2024205019)Science and Technology Project of Hebei Education Department(BJ2025014).
文摘The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variables as well as their interactions remain unclear,especially in areas undergoing long-term forest restoration.In this study,Ca and Mg concentrations in the forest floor and topsoil from 239 forest plots across the Loess Plateau were measured,and the effects of forest types,climate,soil properties,stand characteristics and nitrogen deposition were explored.The results showed significantly higher Ca concentrations in the forest floor(20.68±8.04 mg/g)than in the topsoil(13.28±12.83 mg/g),whereas Mg exhibited the inverse pattern(3.64±1.09 and 10.11±2.51 mg/g,respectively).The effect of forest types was only significant on forest floor Ca,and Ca concentrations were higher in broadleaf and mixed forests than in coniferous forests.Overall,Ca and Mg concentrations in forest floor and topsoil increased with latitudes while decreased with elevations,and the significance of the trends varied among forest types.Forest floor Ca and Mg were mainly influenced by environmental variables aboveground,i.e.,basal area(BA)and mean annual precipitation(MAP),respectively;topsoil Ca and Mg were more affected by soil properties(soil C/N and pH,respectively).Those suggested a depletion of Ca belowground was associated with forest growth and enriched soil nitrogen,and the leaching of mobile Mg was correlated with rainfall and soil acidification.Besides,the impact of environmental variables on Ca-Mg balance(Ca/Mg ratio)belowground was primarily through the regulation of Ca.Elucidating the influence of environmental variables will improve our ability to predict future changes in base cations and thus forest soil health in the greening vegetated Loess Plateau.
文摘AIM:To investigate the possibility of shortening the duration of peginterferon(Peg-IFN)plus ribavirin(RBV) combination therapy by incorporating interferon-β (IFN-β)induction therapy. METHODS:A one treatment arm,cohort prospective study was conducted on seventy one patients.The patients were Japanese adults with genotype 1b chronic hepatitis C,HCV-RNA levels of≥5.0 Log IU/mL or 100 KIU/mL,and platelet counts of≥90 000/μL.The treatment regimen consisted of a 2 wk course of twicedaily administration of IFN-βfollowed by 24 wk PegIFN plus RBV combination therapy.We prolonged the duration of the Peg-IFN plus RBV therapy to 48 wk if the patient requested it. RESULTS:The patients,including 44%males,were characterized by an median age of 63 years(range: 32-78 years),an median platelet count of 13.9(range: 9.1-30.6)×10 4 /μL,62%IFN-na?ve,and median HCV- RNA of 6.1(range:5.1-7.2)Log IU/mL.The sustained virologic response(SVR)rates were 34%(Peg-IFN:1-24 wk,n=61,95%confidence interval(CI): 24%-47%)and 55%(Peg-IFN:20-24 wk,n=31,95% CI:38%-71%,P<0.001;vs Peg-IFN:1-19 wk).TheSVR rate when the administration was discontinued early was 13%(Peg-IFN:1-19 wk,n=30,95%CI: 5%-30%),and that when the administration was prolonged was 50%(Peg-IFN:25-48 wk,n=10,95% CI:24%-76%,P<0.05;vs Peg-IFN:1-19 wk).In the patients who received 20-24 wk of Peg-IFN plus RBV,only the higher platelet count(≥130 000/μL) was significantly correlated with the SVR(odds ratio: 11.680,95%CI:2.3064-79.474,P=0.0024).In 45% (14/31)of the patients with a higher platelet count (≥130000/μL)before therapy,the HCV-RNA level decreased to below 3.3 Log IU/mL at the completion of IFN-β,and their SVR rate was 93%(13/14)after 20-24 wk administration of Peg-IFN plus RBV. CONCLUSION:These results suggest the possibilities of shortening the duration of Peg-IFN plus RBV combination therapy by actively reducing HCV-RNA levels using the IFN-βinduction regimen.
文摘The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their molecular masses, isoelectric points (pI), pH-optima and other properties were analyzed by native proteinase gels.It was shown that the 65 kDa ATP-BPase is specifically induced by heat shock and not detectable in control cells.Its N-terminal 1-9 amino acid sequence was determined by Edman degradation, but no homologies to other proteins in the protein data bases were found. 30 and 31 kDa proteinases can be cleaved from the 45, 55 and 65 kDa proteinases to which they are linked. A possible relationship of the heat-induced 65 kDa ATP-BPase with the ATP-dependent proteinases (ATP-DPases) in prokaryotes and eukaryotes is discussed.
文摘The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results showed that N^+ beam-induced mutation of maize pollens can result in the change of their DNA bases. The mutation is not properly random and its frequency increases with a rise in 30 keV N+ beam doses. It is conformed with A-G transformation, which is one of the most important factors in DNA bases induced by N+ beam.
文摘AIM： To evaluate the daily high-dose induction therapy with interferon-α2b （IFN-α2b） in combination with ribavirin for the treatment of patients who failed with interferon monotherapy and had a relapse, based on the assumption that the viral burden would decline faster, thus increasing the likelihood of higher response rates in this difficult-totreat patient group. METHODS： Seventy patients were enrolled in this study. Treatment was started with 10 NU IFN-α2b daily for 3 wk, followed by IFN-α2b 5 NU/TIW in combination with ribavirin （1 000-1 200 mg/d） for 21 wk. In case of a negative HCV RNA PCR, treatment was continued until wk 48 （IFN-α2b 3MU/TIW＋1000-1200 mg ribavirin/daily）. RESULTS： The dose of IFN-α2b or ribavirin was reduced in 16% of patients because of hematologic side effects, and treatment was discontinued in 7% of patients. An early viral response （EVR） was achieved in 60% of patients. Fifty percent of all patients achieved an end-oftreatment response （EOT） and d0% obtained a sustained viral response （SVR）. Patients with no response had a significantly lower response rate than those with a former relapse （SVR 30% vs 53%; P=0.049）. Furthermore, lower response rates were observed in patients infected with genotype la/b than in patients with non-1-genotype （SVR 28% vs7d%; P=0.001）. As a significant predictive factor for a sustained response, a rapid initial decline of HCV RNA could be identified. No patient achieving a negative HCV-RNA PCR at wk 18 or later eventually eliminated the virus. CONCLUSION： Daily high-dose induction therapy with interferon-α2b is well tolerated and effective for the treatment of non-responders and relapsers, when interferon monotherapy fails. A fast decline of viral load during the first 12 wk is strongly associated with a sustained viral response.
基金This work was supported by the National Nature Science Foundation of China! No.19605005
文摘Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.
基金Supported by NSFCC39770593 EMBLC+1 种基金 CAS and Applied Fundamental Project of Jiangsu Province (BJ95182). National Key Fundamental Research Program (G1999012009).
文摘The young thalli of Porphyra yezoensis and P.haitanensis are induced by N-Methy-N’-Nitro-N-Nitrosoguanidine (NG), a strong mutagen to induce the mutant of chromatophore. It is showed that no mutants have been investigated in all control groups, while in the induced groups, it is easy to find mutant cells or mutant cell masses in the thallus. The pigmentation mutants may be the result of NG inducement. The mutant rate increases obviously with the mutagen concentration or by prolonging the induction time. Within the scope of experiment, the inducement effects of Porphyra yezoensis are raised from 11.2% to 28.7%, and those of P. haitanensis from 10.1% to 20.2%. According to our experiments, the amount of mutant cells in the same area does not increase with the induction intensity The amount of mutant cells in every group of inducement of both species of Porphyraμ changes very little with the fixed fields check method. The lowest dose (25g/mL) of this experiment has a high mutant rate. The mutant rate shows the percentage of mutant cells in all the survived cells, while the amount of mutant cells reflects the effect of μinducement. Thus the optimum induction concentration of NG is 25 g/mL, and the optimum induction time is 30 minutes.
文摘This paper discusses a comparative study of two modeling methods based on multimodel approach. The first is based on C-means clustering algorithm and the second is based on K-means clustering algorithm. The two methods are experimentally applied to an induction motor. The multimodel modeling consists in representing the IM through a finite number of local models. This number of models has to be initially fixed, for which a subtractive clustering is necessary. Then both C-means and K-means clustering are exploited to determine the clusters. These clusters will be then exploited on the basis of structural and parametric identification to determine the local models that are combined, finally, to form the multimodel. The experimental study is based on MATLAB/SIMULINK environment and a DSpace scheme with DS1104 controller board. Experimental results approve that the multimodel based on K-means clustering algorithm is the most efficient.
