[Effect of Stimulated N Deposition on N2O Emission from a Stipa krylovii Steppe in Inner Mongolia, China].

With fast development of industry, agriculture and society, very high N deposition occurs in China. N deposition has exceeded 3 g · (m² · a)⁻¹ in some areas of temperate steppes, which is a significant part of the Eurasia grassland, but may possibly be sensitive to N deposition. To study the effect of N deposition on N cycling in typical temperate steppe, N2O emissions were measured in a Stipa krylovii steppe in Inner Mongolia for a whole year. A field control experiment of simulated N deposition (by NaNO3 addition) was also carried out at 6 dose levels, CK (control), N2 [2 g · (m² · a)⁻¹], N5 [5 g · (m² · a)⁻¹], N10 [10 g · (m² · a)⁻¹], N25 [25 g · (m² · a)⁻¹], and N50 [50 g · (m² · a)⁻¹]. The results showed that the natural N2O-N emission flux was 0.10 g · (m² · a)⁻¹, accounting for about 3% of the total N deposition, and much depended on soil water content and soil temperature under ambient N deposition. In addition, enhanced N deposition might significantly increase N2O emission, especially at very high N doses (N25 and N50 treatments). The annual N2 0 emission flux showed a linear relationship with the N addition. Greater attention should therefore be paid to the relatively high N2O emission in the typical temperate steppe in China.

[The effects of aranidipine on ambulatory blood pressures in patients with mild to moderate essential hypertension].

OBJECTIVE: To evaluate the effect of aranidipine enteric-coated capsules on 24 h blood pressure and blood pressure variability (BPV) in patients with mild to moderate essential hypertension. METHODS: This was an open clinical trial with 2 weeks of placebo run-in period. A total of 74 patients with blood pressure (140-180/95-110 mm Hg (1 mm Hg = 0.133 kPa) were treated by aranidipine (5 mg/d) for 4 weeks.If clinical sitting blood pressure < 140/90 mm Hg at 4th week, aranidipine at 5 mg/d would be continued for another 8 weeks.If not, the dosage would be increased to 10 mg/d.If blood pressure <140/90 mm Hg at 8th week, aranidipine at 5 mg/d or 10 mg/d would be given constantly.If not, the dosage would be increased to 20 mg/d and given for another 4 weeks. All patients performed 24 h ambulatory blood pressure monitoring (ABPM) before and after the treatment with BPV evaluated by the average 24 h per unit time blood pressure standard deviation and morning blood pressure surge (MBPS). RESULTS: (1) After 12 weeks' treatment with aranidipine, the mean 24 h blood pressure was reduced significantly compared with the baseline [(14 ± 13)/(11 ± 9) mm Hg, both P < 0.05] with trough/peak (T/P) ratio of SBP and DBP in responders of 75.31% and 78.15%, respectively.(2) After 12 weeks' treatment, standard deviations of 24 h, daytime SBP/DBP and nighttime SBP/DBP were reduced significantly[(25 ± 3)/(14 ± 4) mm Hg vs (11 ± 3)/(8 ± 2) mm Hg, (24 ± 5)/(14 ± 4) mm Hg vs (11 ± 3)/(8 ± 2) mm Hg, (10 ± 3)/(8 ± 4) mm Hg vs (8 ± 3)/(6 ± 3) mm Hg], respectively with all P < 0.05.Significant decrease was shown in MBPS compared to the baseline [(27 ± 11) mm Hg vs (19 ± 9) mm Hg, P < 0.05]. (3) The incidence of adverse events was 13.4%, including mild dizziness, flushing and palpitation. CONCLUSION: Administration of aranidipine enteric-coated capsules can control 24 h blood pressure effectively and reduce BPV significantly in patients with mild to moderate essential hypertension with good safety profile.

[Efficacy and safety of aranidipine in Chinese patients with mild-to-moderate essential hypertension].

OBJECTIVE: To assess the efficacy and safety of aranidipine versus retard-released felodipine in Chinese patients with mild-to-moderate essential hypertension. METHODS: This was a multicenter, randomized, double-blind, placebo and active antihypertensive drug parallel-controlled study. After 2 weeks of placebo run-in period, 315 patients at 6 centers with diastolic blood pressure (DBP) between 95 to 109 mm Hg (1 mm Hg = 0.133 kPa) while systolic blood pressure (SBP) below 180 mm Hg were randomized to receive aranidipine 5-20 mg/d (n = 126) or retard-released felodipine 5-10 mg/d (n = 126) for 12 weeks. Others (n = 63) received placebo for 4 weeks. Their blood pressures were evaluated at baseline and the end of Weeks 4, 8 and 12. RESULTS: After a 12-week treatment, SBP decreased from 148.8 ± 10.7 mm Hg to (132.8 ± 11.2) mm Hg while DBP dropped from ( 98.4 ± 2.8) mm Hg to (83.9 ± 7.5) mm Hg. There were significant differences with the baseline values (P < 0.0001). After a 4-week treatment, the reductions of SBP in aranidipine and retard-released felodipine groups were (12.1 ± 11.0) mm Hg and (12.2 ± 11.2) mm Hg while the reductions of DBP in two groups (11.8 ± 6.9) mm Hg and (12.1 ± 7.9) mm Hg respectively. The reductions of SBP and DBP in two groups were (2.3 ± 8.4) mm Hg and (4.0 ± 5.1) mm Hg and they were significantly superior to that in placebo group (P < 0.0001). But no significant difference existed between aranidipine and retard-released felodipine groups. Also no significant differences were found between these two antihypertensive therapy groups at the end of Weeks 4, 8 and 12 in the reduction of blood pressure, total response rate and blood pressure control rate. But 20 mg daily aranidipine was significantly superior to 10 mg daily retard-released felodipine in the control rates of SBP and DBP. Adverse events occurred at 24.22% and 29.92% in aranidipine and retard-released felodipine groups respectively (P = 0.305). CONCLUSION: Administration of aranidipine 5-20 mg/d can effectively control blood pressure and is not inferior to retard-released felodipine 5-10 mg/d. The efficacy of 20 mg/d aranidipine is superior to that of retard-released felodipine 5-10 mg/d. And the effectiveness and safety of aranidipine are similar to those of retard-released felodipine.