OBJECTIVETo study the absorption, translocation and accumulation of N, P and K on Achyranthes bidentata.

METHODThe contents of N, P and K were determined by mean of sulfuric acid-hydrogen peroxide assimilating method, vanadium-ammonium molybdate colorimetric method and flame photometric method, respectively.

RESULTThe contents of N, P and K in the plant were decreasing during the growth period. The absorption rates of the three nutrients by A. Bidentata showed double-peak curves in the whole growth period, maximum absorption rate appeared in the middle ten days of October. About 8.59 kg of N, 1.36 kg of P and 7.40 kg of K were needed to produce each 100 kg root.

CONCLUSIONThe key nutrients absorption period is in the first ten days of September and in the middle ten days of October.

Achyranthes ; metabolism ; Biological Transport ; Nitrogen ; metabolism ; Phosphorus ; metabolism ; Potassium ; metabolism

Field experiments were conducted in farmers' rice fields in 2001 and 2002 to study the effects of nitrogen (N) management strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers' fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer's routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China.
Crops, Agricultural ; metabolism ; Fertilizers ; Nitrogen ; metabolism ; Oryza ; metabolism

OBJECTIVEThe aim of the present study is to investigate the effect of low temperature vernalization on metabolism change of carbon and nitrogen of Isatis indigotica.

METHODThe Yunnan and Beijing I. indigotica seedlings with six leaves were vernalized at 4 degrees C for 25 days, and the metabolism indicators of carbon and nitrogen were measured.

RESULTThere appeared a dramatic increase in the soluble sugar content, reducing sugar content and soluble protein content in response to the low temperature, after termination of vernalization it reached the maximum, however, starch and total nitrogen concentration decreased significantly, after termination of vernalization it reached the minimum.

CONCLUSIONThe high C/N value can promote the low temperature vernalization of I. indigotica.

Carbon ; metabolism ; Cold Temperature ; Isatis ; metabolism ; Nitrogen ; metabolism

OBJECTIVEThe goal of this study was to analyze protein requirements in healthy adults through a meta-analysis of nitrogen balance studies.

METHODSA comprehensive search for nitrogen balance studies of healthy adults published up to October 2012 was performed, each study were reviewed, and data were abstracted. The studies were first evaluated for heterogeneity. The average protein requirements were analyzed by using the individual data of each included studies. Study site climate, age, sex, and dietary protein source were compared.

RESULTSData for 348 subjects were gathered from 28 nitrogen balance studies. The natural logarithm of requirement for 348 individuals had a normal distribution with a mean of 4.66. The estimated average requirement was the exponentiation of the mean of the log requirement, 105.64 mg N/kg•d. No significant differences between adult age, source of dietary protein were observed. But there was significant difference between sex and the climate of the study site (P<0.05).

CONCLUSIONThe estimated average requirement and recommended nutrient intake of the healthy adult population was 105.64 mg N/kg•d (0.66 g high quality protein/kg•d) and 132.05 mg N/kg•d (0.83 g high quality protein/kg•d), respectively.

Adult ; Dietary Proteins ; Female ; Humans ; Male ; Nitrogen ; metabolism ; Nutritional Requirements

OBJECTIVEThe accumulation of dry matter, nitrogen, phosphorus and potassium in Prunella vulgaris and their relationships under field condition were studied, in order to provide a basis for the rational fertilization.

METHODThrough the dynamic sampling of P. vulgaris in different growing stages, and the dry weight of plant, the amount of dry matter and the content of N, P and K within each organ of the plant were measured.

RESULTThe dry weight of P. vulgaris linearly increased with the increase of nitrogen, phosphorus and potassium accumulation, there existed a significant correlation at whole growth period. The maximum stage accumulation rate of dry matter from mid-April to the beginning of May, reached 63.71%. The amount of dry matter was mainly distribution in leaves from late March to mid-April. The distribution ratio in stem was the highest from beginning of May to late May. Until mid-June, the distribution ratio of dry matter in spicas was higher than that in other organs. The absorption amounts of N, P and K were lower before mid-April, and the nutrient element was concentrated in plant leaves. From late April to beginning of May, the N, P and K accumulation reached maximum of total absorptive capacity, which accounted for 72.35%, 59.82%, 87.41%, respectively, and the mineral elements were concentrated distribution of plant stems. When transferred to reproductive stage, both accumulation amount and distribution rate of nutrient elements in spicas increased rapidly, which reached the maximum until mid-June. From elongation stages to quaring period was the period of maximal accumulation of dry matter and showed the maximal efficiency of N, P and K nutrition.

CONCLUSIONThe time from elongation stages to quaring period is the most crucial period in the growth development stage of P. vulgaris, and should be paid more attention to the supply of mineral nutrition and moisture of plant to promote spicas formation and dry matter accumulation in this stage. The average N, P2O5 and K2O absorption amount per 100 kg dry matter of spicas were 1.62, 0.36, 2.88 kg respectively, and the ratio of N-P2O5,-K2O was 1 : 0.22: 1.77.

Absorption ; Nitrogen ; metabolism ; Phosphorus ; metabolism ; Potassium ; metabolism ; Prunella ; growth & development ; metabolism ; Seasons

OBJECTIVETo study the absorption characteristics of nitrogen (N) , phosphorus (P) , and potassium (K) of Pinellia ternate from Sichuan under the cultivated condition.

METHODThe samples of P. ternate S-29 and S-33 from Sichuan were regularly collected randomly, the contents of nitrogen, phosphorus and potassium of each part (aerial and underground parts) were determined, and their distribution and accumulation characters of nitrogen, phosphorus, potassium were also studied.

RESULTThe absorption rate of aerial and underground parts of P. ternate were different in nitrogen, phosphorus, and potassium at different growing stages. Among them, the potassium uptake was the highest, while the phosphorus uptake was the lowest. Totally, the uptakes of nitrogen, phosphorus and potassium of P. ternate from Sichuan during "sprout tumble" stage were comparatively higher than that not at "sprout tumble" stage. A significant correlation was observed between the phosphorus and potassium uptake of the aerial and underground parts, respectively (P < 0.05). And there was also significant positive correlation between the nitrogen and phosphorus uptake at underground parts (P < 0.05). During the growth stage of P. ternate, for producing 100 kg air-dried P. ternate, 5.02-5.64 kg N, 2.44-2.56 kg P205, 11.62-13.49 kg K20 were needed to be absorbed.

CONCLUSIONP. ternate from Sichuan should be given enough base fertilizer in field cultivation, and then be supplied with phosphorus and potassium by combining foliar spray with field application during the middle ten days of June and last ten days of August. The ratios of potassium should be properly improved. There was promoting effect in the phosphorus and nitrogen assimilations of the underground parts of P. ternate from Sichuan.

China ; Nitrogen ; metabolism ; Phosphorus ; metabolism ; Pinellia ; growth & development ; metabolism ; Potassium ; metabolism

OBJECTIVEUnder various drought conditions and nitrogen application, the content of vindoline, catharanthine, vincristine and vinblastine in the leaf of Catharanthus roseus were illustrated to improve the content of alkaloid theoretically.

METHODSix groups were set in the experiment, which included: CK (natural control), CN (natural control + nitrogen), LK (low drought), LN (low drought + nitrogen), HK (high drought), HN (high drought + nitrogen) to discuss the change characteristics of total nitrogen, the activity of alkaline POD and TDC, the content of four alkaloids under the different conditions were measured.

RESULTUnder LK condition, the activity of POD, TDC were enhanced. In the early stage of stress (0-21 d), vindoline, catharanthine, vincristine and vinblastine accumulated, and reduced in the later stage (28-35 d). For all groups, adding exogenous nitrogen could improve the total content of nitrogen, vindoline and vinblastine, meanwhile the activity of POD and TDC were enhanced as well. The LN, HN treatments were beneficial to accumulating catharanthine and vinblastine.

CONCLUSIONDrought stress or additional nitrogen have an influence on both of the activities of POD and TDC, and the four alkaloids were affected as well. Thereinto, the LN condition was the most effective treatment for accumulating the four alkaloids (vindoline, catharanthine, vincristine and vinblastine), which were regulated by improve nitrogen content and enzymatic activity.

Catharanthus ; metabolism ; Nitrogen ; metabolism ; Peroxidase ; metabolism ; Stress, Physiological ; Vinblastine ; analogs & derivatives ; metabolism ; Vinca Alkaloids ; metabolism ; Vincristine ; metabolism ; Water ; metabolism

The performance of internal-loop air-lift nitrifying bioreactor was good with strong tolerance to influent ammonia concentration (78.49 mmol/L), high volume converting rate (163.18 mmol/L.d) and obvious working stability (ammonia removal > 94.42%). During operation of internal-loop air-lift bioreactor, the nitrifying activated sludge was granulated. The nitrifying granular activated sludge began to appear on day 45. Its average diameter was 0.83 mm, settling velocity was 55.53 m/h and specific ammonia removal rate was 0.95 mmol (NH4(+)-N)/g (VS).d. The nitrifying granular activated sludge had the activity for anaerobic ammonia oxidation with ammonia oxidation rate of 0.23 mmol (NH4(+)-N)/g(VS).d and nitrite reduction rate of 0.24 mmol (NO2(-)-N)/g(VS).d.
Ammonia ; metabolism ; Anaerobiosis ; Bioreactors ; Nitrites ; metabolism ; Nitrogen ; metabolism ; Oxidation-Reduction ; Sewage ; analysis

Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries were investigated. Nine hundred Miichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted feces decreased significantly in fries fed the diet supplementation with 1000 x 10(-6) fructooligosaccharides and 200 x 10(-6) carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccharides. Supplementation with both did not have significant effects on the concentration of phosphorus in feces of Miichthys miiuy fries.
Administration, Oral ; Animals ; Dietary Supplements ; Feces ; Fishes ; metabolism ; Nitrogen ; metabolism ; Oligosaccharides ; administration & dosage ; Phosphorus ; metabolism

Urea clearance index (KT/Vurea) and creatinine clearance weekly (Ccr) are main indexes to evaluate dialysis adequacy. In order to discuss whether they are suitable to evaluate peritoneal dialysis adequacy, we applied trans-peritoneum transport kinetic model and explored the transport characteristics of fluid and various solutes. We found that: (1) There was no specific relationship among the removal of solutes with different molecular weights; (2) There was significant difference between urea removal and fluid and sodium removal. Our results suggest that urea and creatinine removal do not represent other solutes and fluid removal. KT/Vurea and Ccr may thus not suit to be used alone to evaluate peritoneal dialysis adequacy.
Biomarkers ; metabolism ; Blood Urea Nitrogen ; Creatinine ; metabolism ; Humans ; Peritoneal Dialysis, Continuous Ambulatory ; Urea ; metabolism