目的探讨快速眼动(rapid eye movement,REM)睡眠对心血管疾病发病率的影响.方法利用前瞻性队列研究——美国“睡眠心脏健康研究”数据库(sleep heart health study,SHHS,注册号:NCT00005275),对纳入多导睡眠图监测记录的受试者基线睡眠...目的探讨快速眼动(rapid eye movement,REM)睡眠对心血管疾病发病率的影响.方法利用前瞻性队列研究——美国“睡眠心脏健康研究”数据库(sleep heart health study,SHHS,注册号:NCT00005275),对纳入多导睡眠图监测记录的受试者基线睡眠时间、睡眠效率及REM睡眠特征进行多元Cox回归模型分析.同时在睡眠呼吸障碍(sleep-disordered breathing,SDB)人群和非SDB人群中进行敏感性分析,来阐明REM睡眠对心血管疾病发病率的影响.结果本研究共纳入4902例受试者,随访11年后,其中有1152例受试者发生心血管疾病.经过多因素分析,发现随着REM睡眠时间延长(HR0.974,95%CI0.951~0.997,P=0.028)及REM睡眠构成比(percent of sleep time in REM sleep,REMP)增加(HR 0.990,95%CI0.980~1.000,P=0.047),心血管疾病发病率减低,差异有统计学意义.敏感性分析结果显示,在SDB人群中,这种相关性更加明显,即REM睡眠时间(HR 0.967,95%CI0.937~0.997,P=0.034)和REMP(HR0.986,95%CI0.974~0.999,P=0.039)越高,心血管疾病发生风险越低.结论在社区人群中,REM睡眠与心血管疾病发病率可能存在相关性,其中尤以SDB人群为甚.展开更多
Two japonica rice (Oryza saliva L.) cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain (as high as a three-fold difference), were compared for selenium (Se) accumulation in t...Two japonica rice (Oryza saliva L.) cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain (as high as a three-fold difference), were compared for selenium (Se) accumulation in their shoots when their growth media was supplied with different forms of Se. Results indicated that when treated with 0.25μmol L-1 Na2SeO3, Xiushui 48 accumulation of Se in the shoots was significantly more rapid (P≤0.05) than S. Andrea, probably because of greater Se uptake and transport in Xiushui 48. Xiushui 48 rice seedlings had a higher shoot-Se accumulation rate and absorbed selenocysteine (Se-Cys) more rapidly than S. Andrea seedlings. However, when treated with Se as 0.25 f33mol L-1 selenomethionine (Se-Met), the S. Andrea seedlings' accumulation rate was significantly greater (P≤0.05) than that of Xiushui 48. Possibly, the high Se accumulation rate of Xiushui 48 seedling shoots compared to S. Andrea shoots was the result of a higher capacity of Xiushui 48 to transform selenite to organic Se compounds and a higher selenite uptake rate.展开更多
The profile distribution of β-gulcosidase activity in twelve typical paddy soil profiles with high productivity in the Taihu Lake region of China were investigated. Activities of β-gulcosidase in the plow layers wer...The profile distribution of β-gulcosidase activity in twelve typical paddy soil profiles with high productivity in the Taihu Lake region of China were investigated. Activities of β-gulcosidase in the plow layers were in the range of 52.68-137.02 μg PNP g-1 soil h-1 with a mean of 89.22 μg PNP g-1 soil h-1. However, most plow layers ranged from 70 to 110 μg PNP g-1 soil h-1. The profile distribution of β-gulcosidase activity in the 12 soil profiles decreased rapidly with soil depth, with activity at the 60 cm depth only about 10% of that in the surface layers (0-15 cm or 0-20 cm). In these soil profiles, β-gulcosidase activity was significantly positively correlated with soil organic carbon and arylsulphatase activity. Meanwhile, a significantly negative correlation was shown between β-gulcosidase activity and soil pH.展开更多
An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and ...An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and S cycling in a paddy soil from the Taihu Lake region, China, under waterlogged and aerobic conditions. Compared with air-dried soil, waterlogging resulted in a significant decrease (P (?) 0.05) of fluorescein diacetate (FDA) andβ-D-glucosidase activities, and this effect was enhanced with increasing waterlogging time. Waterlogging also significantly inhibited (P (?)0.05) arylsulfatase as well as alkaline and acid phosphatase activities, but did not decrease the activities with the increase in waterlogging time. Short-term waterlogging did not affect urease activity, but prolonged waterlogging decreased it markedly. In contrast, the aerobic incubation (W1 and W2 treatments) significantly increased (P(?) 0.05) FDA, alkaline phosphatase, andβ-D-glucosidase activities. With aerobic treatments the activities of FDA and alkaline phosphatase increased with incubation time, whereasβ-D-glucosidase activity decreased. A significant difference (P (?) 0.05) was usually observed between the W1 and W2 treatments for the activities of FDA as well as alkaline and acid phosphatase; however,β-D-glucosidase and urease were usually not significant (P(?) 0.05). No activity differences were observed between waterlogging and aerobic incubation for arylsulfatase and urease.展开更多
Experimental and theoretical analysis were made on the natural humic acid removal and the membrane fouling of ultrafiltration （UF） with in-line coagulation. The results showed dissolved organic carbon （DOC） and UV...Experimental and theoretical analysis were made on the natural humic acid removal and the membrane fouling of ultrafiltration （UF） with in-line coagulation. The results showed dissolved organic carbon （DOC） and UV254 removals by the UF with in-line coagulation at pH 7 were increased from 28% to 53% and 40% to 78% in comparison with direct UF treatment respectively. At the same time, the analysis of high performance liquid chromatography showed that UF with coagulation had significant improvement of removal of humic acid with molecular weights less than 6000 Da in particular. Compared to direct UF, the in-line coagulation UF also kept more constant permeate flux and very slight increase oftransmembrane pressure during a filtration circle. Two typical membrane fouling models were used by inducing two coefficients Kc and Kp corresponding to cake filtration model and pore narrowing model respectively. It was found that membrane fouling by pore-narrowing effect was effectively alleviated and that by cake-filtration was much decreased by in-line coagulation. Under the condition of coagulation prior to ultrafiltration at pH 7, the cake layer formed on the membrane surface became thicker, but the membrane filtration resistance was lower than that at pH 5 with the extension of operation time.展开更多
文摘目的探讨快速眼动(rapid eye movement,REM)睡眠对心血管疾病发病率的影响.方法利用前瞻性队列研究——美国“睡眠心脏健康研究”数据库(sleep heart health study,SHHS,注册号:NCT00005275),对纳入多导睡眠图监测记录的受试者基线睡眠时间、睡眠效率及REM睡眠特征进行多元Cox回归模型分析.同时在睡眠呼吸障碍(sleep-disordered breathing,SDB)人群和非SDB人群中进行敏感性分析,来阐明REM睡眠对心血管疾病发病率的影响.结果本研究共纳入4902例受试者,随访11年后,其中有1152例受试者发生心血管疾病.经过多因素分析,发现随着REM睡眠时间延长(HR0.974,95%CI0.951~0.997,P=0.028)及REM睡眠构成比(percent of sleep time in REM sleep,REMP)增加(HR 0.990,95%CI0.980~1.000,P=0.047),心血管疾病发病率减低,差异有统计学意义.敏感性分析结果显示,在SDB人群中,这种相关性更加明显,即REM睡眠时间(HR 0.967,95%CI0.937~0.997,P=0.034)和REMP(HR0.986,95%CI0.974~0.999,P=0.039)越高,心血管疾病发生风险越低.结论在社区人群中,REM睡眠与心血管疾病发病率可能存在相关性,其中尤以SDB人群为甚.
基金Project supported by the National Natural Science Foundation of China (No. 40371063)the National Key Basic Research Support Foundation of China (No. G1999011808).
文摘Two japonica rice (Oryza saliva L.) cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain (as high as a three-fold difference), were compared for selenium (Se) accumulation in their shoots when their growth media was supplied with different forms of Se. Results indicated that when treated with 0.25μmol L-1 Na2SeO3, Xiushui 48 accumulation of Se in the shoots was significantly more rapid (P≤0.05) than S. Andrea, probably because of greater Se uptake and transport in Xiushui 48. Xiushui 48 rice seedlings had a higher shoot-Se accumulation rate and absorbed selenocysteine (Se-Cys) more rapidly than S. Andrea seedlings. However, when treated with Se as 0.25 f33mol L-1 selenomethionine (Se-Met), the S. Andrea seedlings' accumulation rate was significantly greater (P≤0.05) than that of Xiushui 48. Possibly, the high Se accumulation rate of Xiushui 48 seedling shoots compared to S. Andrea shoots was the result of a higher capacity of Xiushui 48 to transform selenite to organic Se compounds and a higher selenite uptake rate.
基金Project supported by the National Natural Science Foundation of China (No. 40371066)the National Key Basic Research Support Foundation of China (No.G1999011808).
文摘The profile distribution of β-gulcosidase activity in twelve typical paddy soil profiles with high productivity in the Taihu Lake region of China were investigated. Activities of β-gulcosidase in the plow layers were in the range of 52.68-137.02 μg PNP g-1 soil h-1 with a mean of 89.22 μg PNP g-1 soil h-1. However, most plow layers ranged from 70 to 110 μg PNP g-1 soil h-1. The profile distribution of β-gulcosidase activity in the 12 soil profiles decreased rapidly with soil depth, with activity at the 60 cm depth only about 10% of that in the surface layers (0-15 cm or 0-20 cm). In these soil profiles, β-gulcosidase activity was significantly positively correlated with soil organic carbon and arylsulphatase activity. Meanwhile, a significantly negative correlation was shown between β-gulcosidase activity and soil pH.
基金supported by State Key Laboratory of Petroleum Resources and Prospecting (Grant No. 2009009)Basic Scientific Research Special Fund of Central Colleges (Grant No. 2010ZY28)National Major Projects (Grant No.2008ZX05023-005 and 2008ZX05035-002)
基金Project supported by the National Basic Research Program of China (No. G1999011808) and the National Natural Science Foundation of China (No. 40371066).
文摘An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and S cycling in a paddy soil from the Taihu Lake region, China, under waterlogged and aerobic conditions. Compared with air-dried soil, waterlogging resulted in a significant decrease (P (?) 0.05) of fluorescein diacetate (FDA) andβ-D-glucosidase activities, and this effect was enhanced with increasing waterlogging time. Waterlogging also significantly inhibited (P (?)0.05) arylsulfatase as well as alkaline and acid phosphatase activities, but did not decrease the activities with the increase in waterlogging time. Short-term waterlogging did not affect urease activity, but prolonged waterlogging decreased it markedly. In contrast, the aerobic incubation (W1 and W2 treatments) significantly increased (P(?) 0.05) FDA, alkaline phosphatase, andβ-D-glucosidase activities. With aerobic treatments the activities of FDA and alkaline phosphatase increased with incubation time, whereasβ-D-glucosidase activity decreased. A significant difference (P (?) 0.05) was usually observed between the W1 and W2 treatments for the activities of FDA as well as alkaline and acid phosphatase; however,β-D-glucosidase and urease were usually not significant (P(?) 0.05). No activity differences were observed between waterlogging and aerobic incubation for arylsulfatase and urease.
基金The National Natural Science Foundation of China (No. 50138020)
文摘Experimental and theoretical analysis were made on the natural humic acid removal and the membrane fouling of ultrafiltration （UF） with in-line coagulation. The results showed dissolved organic carbon （DOC） and UV254 removals by the UF with in-line coagulation at pH 7 were increased from 28% to 53% and 40% to 78% in comparison with direct UF treatment respectively. At the same time, the analysis of high performance liquid chromatography showed that UF with coagulation had significant improvement of removal of humic acid with molecular weights less than 6000 Da in particular. Compared to direct UF, the in-line coagulation UF also kept more constant permeate flux and very slight increase oftransmembrane pressure during a filtration circle. Two typical membrane fouling models were used by inducing two coefficients Kc and Kp corresponding to cake filtration model and pore narrowing model respectively. It was found that membrane fouling by pore-narrowing effect was effectively alleviated and that by cake-filtration was much decreased by in-line coagulation. Under the condition of coagulation prior to ultrafiltration at pH 7, the cake layer formed on the membrane surface became thicker, but the membrane filtration resistance was lower than that at pH 5 with the extension of operation time.
