Soil C /N ratio is an important influencing factor in soil nitrogen cycling. Two-year old apple trees( Borkh. cv. ‘Fuji'/Malus hupehensis) were used to understand the effect of soil C/N ratio [6. 52( CK),10,15,20...Soil C /N ratio is an important influencing factor in soil nitrogen cycling. Two-year old apple trees( Borkh. cv. ‘Fuji'/Malus hupehensis) were used to understand the effect of soil C/N ratio [6. 52( CK),10,15,20,25,30,35 and 40]on apple growth and nitrogen utilization and loss by using15N trace technique. The results showed that,with the increasing of soil C/N ratio,apple shoot length and fresh weight increased at first,and then decreased; the higher apple shoot length and fresh weight appeared in C/N = 15,20 and 25 treatments,and there were no significant differences among these three treatments,but significantly higher than the other treatments. Statistical analysis revealed that there was significant difference in nitrogen utilization rate between the different treatments,the highest N utilization rate was occurred in soil C/N = 25 treatment which value was 22. 87%,and there was no significant difference between soil C/N = 25 and C/N = 20 treatments,but both the two treatments were significantly higher than the other treatments; Soil C/N = 40 had the lowest N utilization rate which value was 15. 43%,and this value was less than CK( 16. 65%). The proportion of plant absorption nitrogen from fertilizer was much higher when the value of soil C/N ratio in the range of 15- 25,but the percentage of plant absorption nitrogen from soil was much higher when the soil C/N ratio was too low( < 15) or high( < 25). Amount of residual nitrogen in soil increased gradually with the soil C/N ratio increasing,the amount of residual nitrogen in C/N = 40 treatment was 1. 32 times than that in CK. With the increasing of soil C/N ratio,fertilizer nitrogen loss decreased at first,and then increased,fertilizer nitrogen loss was the minimum in C/N = 25 treatments( 49. 87%) and the maximum were occurred in CK( 61. 54%). Therefore,regarding the apple growth and nitrogen balance situation,the value of soil C/N ratio in the range of 15- 25 would be favorable for apple growth and could increase effectively nitrogen fixed by soil,reduce nitrogen loss,and improve the nitrogen utilization ratio.展开更多
Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS) through demyelination and neurodegeneration. Several lines of evidence support a role for oxidative and nitrative str...Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS) through demyelination and neurodegeneration. Several lines of evidence support a role for oxidative and nitrative stress (OS and NS) in pathogenesis of multiple sclerosis. The mechanism of influence of OS and NS on blood-brainbarrier (BBB) has critical importance for evaluating antioxidant therapies. As far as we know, markers of oxidative and nitrative stress in MS patients have been investigated independently for their relationship with the state of the blood-brain-barrier. Blood plasma samples of 58 patients with relapse-remitting MS (RRMS) with normal (Group A, n = 48, 36.2 ± 10.5 years) and damaged BBB (Group B, n = 10, 38.2 ± 11.2 years) and of 44 healthy controls (39.2 ± 14.9 years) were analyzed. TAS (total antioxidant plasma status), lipoperoxides, protein carbonyls, 3-nitrotyrosine and uric acid were evaluated in each group. Our results confirmed decreased TAS (Group A: 1.35 ± 0.55 mmol/l, P e level of lipoperoxidation positively correlated with the state of BBB (P of protein’s carbonyls (A: 0.48 ± 0.11 nmol/mg protein, P nmol/l, P ed damage to plasma proteins, what was confirmed by their positive mutual correlation (P The level of uric acid was physiological and correlated negatively with protein’s carbonyls (P 0.05) while there was no significant relationship with 3-nitotyrosine. The results suggest the role of this antioxidant in the protection of the proteins against OS what was confirmed by its positive correlation with TAS展开更多
In this paper, the effect of Ba(NO 3) 2 on the efficiency of sulfur fixation of calcium oxide during coal combustion was studied. The results showed that addition of barium nitrate to the CaO can enhance the sulfur ...In this paper, the effect of Ba(NO 3) 2 on the efficiency of sulfur fixation of calcium oxide during coal combustion was studied. The results showed that addition of barium nitrate to the CaO can enhance the sulfur removal rate of CaO significantly. The X \|ray diffraction spectrum of residual ash of coal added some sulfur fixative expressed that Ba\+\{2+\} can form a compound of Ba\|Al\|Si\|O which encloses the CaSO\-4 to prevent it's decomposition, so Ba\+\{2+\} can improve the action of sulfur fixation of CaO. The combustion character of the original coal and original coal added sulfur fixative was researched with thermal\|gravity analyzer and the results expressed that adding some sulfur fixative to the coal will make the combustion character of coal change little.展开更多
Objective To study the preventive effect of rosiglitazone glial activation,oxidative/nitrative stress and spatial memory deficits induced by intracerebroventricular(ICV)injection of streptozotocin(STZ)in rats.Methods ...Objective To study the preventive effect of rosiglitazone glial activation,oxidative/nitrative stress and spatial memory deficits induced by intracerebroventricular(ICV)injection of streptozotocin(STZ)in rats.Methods 24 male Wistar rats were randomly divided into sham operated group,model group and rosiglitazone group.The model of Alzheimer's was induced by injection with ICV 10% STZ bilaterally,on day 1 and 3(3 mg·kg-1).The rats were treated with rosiglitazone(2 mg·kg-1,p.o.)for a consecutive 21 days,once a day,beginning 7 days prior to STZ injection.The learning and memory behavior was assessed using Morris water maze task and Y-maze 21 d after ICV STZ injection.Malondialdehyde(MDA),superoxide dismutase(SOD),glutathione(GSH)levels and nitrotyrosine immunoreactivity in brain were estimated as parameters of oxidative/nitrative stress.Brain acetyl cholinesterase(AchE)activity was measured by EllMann's method and activated microglia and astrocytes were detected by immunohistochemistry.Results ICV STZ injection resulted in a severe deficit in spatial learning and memory associated with increased MDA level(+69.5%)and nitrotyrosine immunoreactivity(+23.7%),decreased SOD activity(-29.2%)and GSH(-25.1%)in brain.It also showed the activated microglia and astrocytes in the cortex and hippocampal CA1 region and a significant decrease in acetylcholinesterase activity(-40.2%).Compared with model group,chronic administration of rosiglitazone significantly shorten the escape latency time from the third day in place navigation test,increase the number of passing through primary flat place in spatial probe test in Morris water maze test,and decrease the error times in Y-maze test(P<0.05 or P<0.01).In addition,it also prevented the glial changes,decreased the elevated MDA and nitrite levels and restored the depleted GSH and acetylcholinesterase activity in cortex(P<0.05),but had no effect on SOD activity in cortex.Conclusions Rosiglitazone has a neuroprotective role against streptozotocin-induced cognitive impairment and associated oxidative/nitrative stress.展开更多
Background Trans-arachidonic acids （TAAs）, newly discovered markers of nitrative stress and the major products of nitrogen dioxide （NO2）-mediated isomerization of arachidonic acid （AA）, represent a new mechanism...Background Trans-arachidonic acids （TAAs）, newly discovered markers of nitrative stress and the major products of nitrogen dioxide （NO2）-mediated isomerization of arachidonic acid （AA）, represent a new mechanism of NO2-induced toxicity. It has been reported that TAAs were generated in oxygen-induced microvascular degeneration model and TAAs were also generated in a diabetic retinopathy （DR） model. In this study, we examined high glucose-induced nitrative stress damage and TAAs levels and explored the possible mechanisms for DR caused by reactive nitrogen species. Methods Diabetic rats were induced by intraperitoneal injection of streptozotocin （BTZ） at 60 mg/kg. Bovine retinal capillary endothelial cells （BRECs） were selectively cultured and incubated with normal or high glucose. The serum TAAs and AA in diabetic rats were measured by the gas chromatography and mass spectrometry （GC/MS） method. The ratio of peak area of TAAs to AA with selected ion of 79 was estimated by a group t-test. Thrombospondin-1 （TSP-1） in the rat retinas and BRECs extracts were examined by Western blotting. The phosphorylation of extracellular signal-regulated kinase 1/2 （ERK1/2） protein was examined by Western blotting in BRECs incubated with high glucose. Results The TAAs to AA ratio （TAAs/AA） was significantly increased in the serum at 8, 12 and 16 weeks after BTZ injection （P 〈0.05）, with no noticeable change found at 2 or 4 weeks （P 〉0.05）. Expression of TSP-1 in the retina of diabetic rats was progressively elevated according to the duration of diabetes. TSP-1 expression was increased in BRECs incubated with high glucose all 48 hours. Moreover, high glucose also increased ERK1/2 expression, which peaked at 30 minutes and then decreased in the following 48 hours. Conclusion An elevation of TAAs/AA is associated with high glucose-induced nitrative stress, which probably involves upregulation of TSP-1 through activating ERK1/2.展开更多
The magneto-structural correlation between a Mn(II) ion, coordinated in an octahe-dral environment, and two nitronyl nitroxide radical ligands in trans- and cis-metal-radical com-plexes is investigated by the broken s...The magneto-structural correlation between a Mn(II) ion, coordinated in an octahe-dral environment, and two nitronyl nitroxide radical ligands in trans- and cis-metal-radical com-plexes is investigated by the broken symmetry (BS) approach within density functional theory (DFT). The dependences of coupling constants J on three structural parameters: (i) bond angle θ (Mn-O-N (nitroxide)); (ii) rotating angle ψ, defined by the nitronyl nitroxide radical plane rotating around the axial Mn-O (nitroxide); (iii) bond distance R (Mn-O (nitroxide)) are directly calculated. Our calculations showed that both trans- and cis-Mn(II)-radical complexes behave a stronger antiferromagnetic interaction, consistent with experiments. In view of molecular orbital theory, the direct exchanges, including σ-type and π-type exchanges, are responsible for the magnetic ex-change pathways. There is a preferable linear correlation between the calculated coupling con-stants J and the overlap integral squares Sa2b between the local magnetic orbitals at the various rotating angle ψ at the fixed bond angle θ and bond distance R, in both trans- and cis-Mn(II)- radical complexes.展开更多
Xinjiang Company of Shanxi Fengxi Fertilizer Industry(Group)Ltd.has started construction of the 100000 t/a ammonium calcium nitrate pro-duction line.It is scheduled for startup the end of this year.After the completio...Xinjiang Company of Shanxi Fengxi Fertilizer Industry(Group)Ltd.has started construction of the 100000 t/a ammonium calcium nitrate pro-duction line.It is scheduled for startup the end of this year.After the completion,Shanxi Fengxi will become the biggest ammonium calcium ni-trate producer in China.展开更多
The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t h...The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t hermo-dynamic parameters(the activation enthalpy,the active entropy and the activation free energy),the rate constant,three kinetic parameters(the activation energy,the pre-exponential constant and the reaction order)are obtained.The influence of temperature on the t itled reaction and the synthetic con dition of the complex have been discu ssed.展开更多
基金Special Fund for Agro-scientific Research in the Public Interest(201103003)the Earmarked Fund for China Agriculture ResearchSystem(CARS-28)
文摘Soil C /N ratio is an important influencing factor in soil nitrogen cycling. Two-year old apple trees( Borkh. cv. ‘Fuji'/Malus hupehensis) were used to understand the effect of soil C/N ratio [6. 52( CK),10,15,20,25,30,35 and 40]on apple growth and nitrogen utilization and loss by using15N trace technique. The results showed that,with the increasing of soil C/N ratio,apple shoot length and fresh weight increased at first,and then decreased; the higher apple shoot length and fresh weight appeared in C/N = 15,20 and 25 treatments,and there were no significant differences among these three treatments,but significantly higher than the other treatments. Statistical analysis revealed that there was significant difference in nitrogen utilization rate between the different treatments,the highest N utilization rate was occurred in soil C/N = 25 treatment which value was 22. 87%,and there was no significant difference between soil C/N = 25 and C/N = 20 treatments,but both the two treatments were significantly higher than the other treatments; Soil C/N = 40 had the lowest N utilization rate which value was 15. 43%,and this value was less than CK( 16. 65%). The proportion of plant absorption nitrogen from fertilizer was much higher when the value of soil C/N ratio in the range of 15- 25,but the percentage of plant absorption nitrogen from soil was much higher when the soil C/N ratio was too low( < 15) or high( < 25). Amount of residual nitrogen in soil increased gradually with the soil C/N ratio increasing,the amount of residual nitrogen in C/N = 40 treatment was 1. 32 times than that in CK. With the increasing of soil C/N ratio,fertilizer nitrogen loss decreased at first,and then increased,fertilizer nitrogen loss was the minimum in C/N = 25 treatments( 49. 87%) and the maximum were occurred in CK( 61. 54%). Therefore,regarding the apple growth and nitrogen balance situation,the value of soil C/N ratio in the range of 15- 25 would be favorable for apple growth and could increase effectively nitrogen fixed by soil,reduce nitrogen loss,and improve the nitrogen utilization ratio.
文摘Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS) through demyelination and neurodegeneration. Several lines of evidence support a role for oxidative and nitrative stress (OS and NS) in pathogenesis of multiple sclerosis. The mechanism of influence of OS and NS on blood-brainbarrier (BBB) has critical importance for evaluating antioxidant therapies. As far as we know, markers of oxidative and nitrative stress in MS patients have been investigated independently for their relationship with the state of the blood-brain-barrier. Blood plasma samples of 58 patients with relapse-remitting MS (RRMS) with normal (Group A, n = 48, 36.2 ± 10.5 years) and damaged BBB (Group B, n = 10, 38.2 ± 11.2 years) and of 44 healthy controls (39.2 ± 14.9 years) were analyzed. TAS (total antioxidant plasma status), lipoperoxides, protein carbonyls, 3-nitrotyrosine and uric acid were evaluated in each group. Our results confirmed decreased TAS (Group A: 1.35 ± 0.55 mmol/l, P e level of lipoperoxidation positively correlated with the state of BBB (P of protein’s carbonyls (A: 0.48 ± 0.11 nmol/mg protein, P nmol/l, P ed damage to plasma proteins, what was confirmed by their positive mutual correlation (P The level of uric acid was physiological and correlated negatively with protein’s carbonyls (P 0.05) while there was no significant relationship with 3-nitotyrosine. The results suggest the role of this antioxidant in the protection of the proteins against OS what was confirmed by its positive correlation with TAS
文摘In this paper, the effect of Ba(NO 3) 2 on the efficiency of sulfur fixation of calcium oxide during coal combustion was studied. The results showed that addition of barium nitrate to the CaO can enhance the sulfur removal rate of CaO significantly. The X \|ray diffraction spectrum of residual ash of coal added some sulfur fixative expressed that Ba\+\{2+\} can form a compound of Ba\|Al\|Si\|O which encloses the CaSO\-4 to prevent it's decomposition, so Ba\+\{2+\} can improve the action of sulfur fixation of CaO. The combustion character of the original coal and original coal added sulfur fixative was researched with thermal\|gravity analyzer and the results expressed that adding some sulfur fixative to the coal will make the combustion character of coal change little.
文摘Objective To study the preventive effect of rosiglitazone glial activation,oxidative/nitrative stress and spatial memory deficits induced by intracerebroventricular(ICV)injection of streptozotocin(STZ)in rats.Methods 24 male Wistar rats were randomly divided into sham operated group,model group and rosiglitazone group.The model of Alzheimer's was induced by injection with ICV 10% STZ bilaterally,on day 1 and 3(3 mg·kg-1).The rats were treated with rosiglitazone(2 mg·kg-1,p.o.)for a consecutive 21 days,once a day,beginning 7 days prior to STZ injection.The learning and memory behavior was assessed using Morris water maze task and Y-maze 21 d after ICV STZ injection.Malondialdehyde(MDA),superoxide dismutase(SOD),glutathione(GSH)levels and nitrotyrosine immunoreactivity in brain were estimated as parameters of oxidative/nitrative stress.Brain acetyl cholinesterase(AchE)activity was measured by EllMann's method and activated microglia and astrocytes were detected by immunohistochemistry.Results ICV STZ injection resulted in a severe deficit in spatial learning and memory associated with increased MDA level(+69.5%)and nitrotyrosine immunoreactivity(+23.7%),decreased SOD activity(-29.2%)and GSH(-25.1%)in brain.It also showed the activated microglia and astrocytes in the cortex and hippocampal CA1 region and a significant decrease in acetylcholinesterase activity(-40.2%).Compared with model group,chronic administration of rosiglitazone significantly shorten the escape latency time from the third day in place navigation test,increase the number of passing through primary flat place in spatial probe test in Morris water maze test,and decrease the error times in Y-maze test(P<0.05 or P<0.01).In addition,it also prevented the glial changes,decreased the elevated MDA and nitrite levels and restored the depleted GSH and acetylcholinesterase activity in cortex(P<0.05),but had no effect on SOD activity in cortex.Conclusions Rosiglitazone has a neuroprotective role against streptozotocin-induced cognitive impairment and associated oxidative/nitrative stress.
基金The study was supported by grants from the Young Scientists Fund of the National Natural Science Foundation of China （No. 81000384） and Administration of Traditional Chinese Medicine of Shanghai （No. 2010QL039A）.
文摘Background Trans-arachidonic acids （TAAs）, newly discovered markers of nitrative stress and the major products of nitrogen dioxide （NO2）-mediated isomerization of arachidonic acid （AA）, represent a new mechanism of NO2-induced toxicity. It has been reported that TAAs were generated in oxygen-induced microvascular degeneration model and TAAs were also generated in a diabetic retinopathy （DR） model. In this study, we examined high glucose-induced nitrative stress damage and TAAs levels and explored the possible mechanisms for DR caused by reactive nitrogen species. Methods Diabetic rats were induced by intraperitoneal injection of streptozotocin （BTZ） at 60 mg/kg. Bovine retinal capillary endothelial cells （BRECs） were selectively cultured and incubated with normal or high glucose. The serum TAAs and AA in diabetic rats were measured by the gas chromatography and mass spectrometry （GC/MS） method. The ratio of peak area of TAAs to AA with selected ion of 79 was estimated by a group t-test. Thrombospondin-1 （TSP-1） in the rat retinas and BRECs extracts were examined by Western blotting. The phosphorylation of extracellular signal-regulated kinase 1/2 （ERK1/2） protein was examined by Western blotting in BRECs incubated with high glucose. Results The TAAs to AA ratio （TAAs/AA） was significantly increased in the serum at 8, 12 and 16 weeks after BTZ injection （P 〈0.05）, with no noticeable change found at 2 or 4 weeks （P 〉0.05）. Expression of TSP-1 in the retina of diabetic rats was progressively elevated according to the duration of diabetes. TSP-1 expression was increased in BRECs incubated with high glucose all 48 hours. Moreover, high glucose also increased ERK1/2 expression, which peaked at 30 minutes and then decreased in the following 48 hours. Conclusion An elevation of TAAs/AA is associated with high glucose-induced nitrative stress, which probably involves upregulation of TSP-1 through activating ERK1/2.
基金supported by the National Natural Science Foundation of China(Grant Nos.20273005,20490210,NSFC/RGC 20318001)the Doctoral Program Foundation of the Ministry of Education(Grant No.20030001066).
文摘The magneto-structural correlation between a Mn(II) ion, coordinated in an octahe-dral environment, and two nitronyl nitroxide radical ligands in trans- and cis-metal-radical com-plexes is investigated by the broken symmetry (BS) approach within density functional theory (DFT). The dependences of coupling constants J on three structural parameters: (i) bond angle θ (Mn-O-N (nitroxide)); (ii) rotating angle ψ, defined by the nitronyl nitroxide radical plane rotating around the axial Mn-O (nitroxide); (iii) bond distance R (Mn-O (nitroxide)) are directly calculated. Our calculations showed that both trans- and cis-Mn(II)-radical complexes behave a stronger antiferromagnetic interaction, consistent with experiments. In view of molecular orbital theory, the direct exchanges, including σ-type and π-type exchanges, are responsible for the magnetic ex-change pathways. There is a preferable linear correlation between the calculated coupling con-stants J and the overlap integral squares Sa2b between the local magnetic orbitals at the various rotating angle ψ at the fixed bond angle θ and bond distance R, in both trans- and cis-Mn(II)- radical complexes.
文摘Xinjiang Company of Shanxi Fengxi Fertilizer Industry(Group)Ltd.has started construction of the 100000 t/a ammonium calcium nitrate pro-duction line.It is scheduled for startup the end of this year.After the completion,Shanxi Fengxi will become the biggest ammonium calcium ni-trate producer in China.
文摘The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t hermo-dynamic parameters(the activation enthalpy,the active entropy and the activation free energy),the rate constant,three kinetic parameters(the activation energy,the pre-exponential constant and the reaction order)are obtained.The influence of temperature on the t itled reaction and the synthetic con dition of the complex have been discu ssed.
