在稻田土壤上对水稻的高量施用氮肥常常造成硝态氮(NO3--N)淋溶损失和肥料氮利用率低下的问题。本研究采用土壤渗漏器、微区和田间小区试验,研究了15N标记控释氮肥在稻田土壤上的氮素利用率和硝态氮的淋溶损失。在两年早稻种植期间,一...在稻田土壤上对水稻的高量施用氮肥常常造成硝态氮(NO3--N)淋溶损失和肥料氮利用率低下的问题。本研究采用土壤渗漏器、微区和田间小区试验,研究了15N标记控释氮肥在稻田土壤上的氮素利用率和硝态氮的淋溶损失。在两年早稻种植期间,一次性全量作基肥施用控释氮肥与尿素分二次施用的相比,两年的早稻产量分别平均提高7.7%和11.6%。在N90 kg hm-2用量下,由差值法测得的肥料氮利用率,按平均计,控释氮肥的N利用率(平均76.3%)比尿素分次施用的(平均37.4%)高出38.9%1。5N同位素法测得的控释氮肥的N利用率(平均67.1%)比尿素分次施用的(平均31.2%)高出35.9%。在早稻种植季节,施用尿素和控释氮肥的NO3--N淋失量分别为9.19 kg hm-2和6.7 kg hm-2,占施尿素N和控释氮肥氮的10.2%和7.4%。控释氮肥的氮淋失量比尿素分2次施用的降低27.1%。本研究结果表明,在稻田土壤上施用控释氮肥能减少氮的淋失量,提高氮素利用率和水稻产量。展开更多
Objective:To observe the change in the number of antibodies of preneoplastic hepatocellular carcinoma(HCC) using early treatment by Compound Phyllanthus Urinaria L.(CPUL) on patients with preneoplastic hepatitis B vir...Objective:To observe the change in the number of antibodies of preneoplastic hepatocellular carcinoma(HCC) using early treatment by Compound Phyllanthus Urinaria L.(CPUL) on patients with preneoplastic hepatitis B virus(HBV)-associated HCC.Methods:A total of 102 cirrhosis patients with regenerative or dysplastic nodules whose sera were tested positive for at least one of these six proteins(five up-regulated genes URG4,URG7,URG11,URG12 and URG19,and one down-regulated gene DRG2) were assigned randomly to two groups using continual random codes by SPSS software.Fifty-two patients were in the treatment group and 50 patients were in the control group.CPUL was used in the treatment group for 3 years,while the control group did not receive any treatment.The changes in HBV-DNA level,number of antibodies,and hepatocarcinogenesis occurred were observed.Patients who did not develop HCC were followed up for another 2 years.Results:HBV-DNA levels decreased >2log in 22.2%(10/45) of patients in the treatment group in contrast to only 5.0%(2/40) of patients in the control group(P=0.0228).The number of antibodies that were tested positive in the treatment group(1.08± 1.01)was significantly lower compared with the control group(2.11 ±1.12) after 24 months of drug treatment(P<0.01).Both the positive rates of anti-URG11(33/52) and anti-URG19(31/52) were over 60%at baseline in the two groups,and were decreased to 48.1%(25/52) and 46.2%(24/52) respectively at 36 months of drug treatment,while the rates increased to 68.0%(34/50) and 66.0%(33/50) respectively(P=0.0417,P=0.0436) in the control group.The positive rate of anti-DRG2 was increased to 55.8%(29/52) at 36 months of drug treatment,while in the control group was decreased to 36.0%(18/50,P=0.0452).Among the 102 patients who developed HCC,2 were in the treatment group and 9 were in the control group,meaning that a significant difference between the two groups(P=0.0212).In11 patients who developed HCC,anti-URG11 and anti-URG19 were always positive,while anti-DRG2 was negative.Pat展开更多
文摘在稻田土壤上对水稻的高量施用氮肥常常造成硝态氮(NO3--N)淋溶损失和肥料氮利用率低下的问题。本研究采用土壤渗漏器、微区和田间小区试验,研究了15N标记控释氮肥在稻田土壤上的氮素利用率和硝态氮的淋溶损失。在两年早稻种植期间,一次性全量作基肥施用控释氮肥与尿素分二次施用的相比,两年的早稻产量分别平均提高7.7%和11.6%。在N90 kg hm-2用量下,由差值法测得的肥料氮利用率,按平均计,控释氮肥的N利用率(平均76.3%)比尿素分次施用的(平均37.4%)高出38.9%1。5N同位素法测得的控释氮肥的N利用率(平均67.1%)比尿素分次施用的(平均31.2%)高出35.9%。在早稻种植季节,施用尿素和控释氮肥的NO3--N淋失量分别为9.19 kg hm-2和6.7 kg hm-2,占施尿素N和控释氮肥氮的10.2%和7.4%。控释氮肥的氮淋失量比尿素分2次施用的降低27.1%。本研究结果表明,在稻田土壤上施用控释氮肥能减少氮的淋失量,提高氮素利用率和水稻产量。
基金Supported by the National Natural Science Foundation of China(No.30371790 and No.30873245)the National Student Abroad Returned Foundation of China(No.006LHR11)the Technology Foundation of Shenzhen,China(No.200304145)
文摘Objective:To observe the change in the number of antibodies of preneoplastic hepatocellular carcinoma(HCC) using early treatment by Compound Phyllanthus Urinaria L.(CPUL) on patients with preneoplastic hepatitis B virus(HBV)-associated HCC.Methods:A total of 102 cirrhosis patients with regenerative or dysplastic nodules whose sera were tested positive for at least one of these six proteins(five up-regulated genes URG4,URG7,URG11,URG12 and URG19,and one down-regulated gene DRG2) were assigned randomly to two groups using continual random codes by SPSS software.Fifty-two patients were in the treatment group and 50 patients were in the control group.CPUL was used in the treatment group for 3 years,while the control group did not receive any treatment.The changes in HBV-DNA level,number of antibodies,and hepatocarcinogenesis occurred were observed.Patients who did not develop HCC were followed up for another 2 years.Results:HBV-DNA levels decreased >2log in 22.2%(10/45) of patients in the treatment group in contrast to only 5.0%(2/40) of patients in the control group(P=0.0228).The number of antibodies that were tested positive in the treatment group(1.08± 1.01)was significantly lower compared with the control group(2.11 ±1.12) after 24 months of drug treatment(P<0.01).Both the positive rates of anti-URG11(33/52) and anti-URG19(31/52) were over 60%at baseline in the two groups,and were decreased to 48.1%(25/52) and 46.2%(24/52) respectively at 36 months of drug treatment,while the rates increased to 68.0%(34/50) and 66.0%(33/50) respectively(P=0.0417,P=0.0436) in the control group.The positive rate of anti-DRG2 was increased to 55.8%(29/52) at 36 months of drug treatment,while in the control group was decreased to 36.0%(18/50,P=0.0452).Among the 102 patients who developed HCC,2 were in the treatment group and 9 were in the control group,meaning that a significant difference between the two groups(P=0.0212).In11 patients who developed HCC,anti-URG11 and anti-URG19 were always positive,while anti-DRG2 was negative.Pat
