Continuous-flow electrosynthesis of urea and oxalic acid by CO_(2)-nitrate reduction and glycerol oxidation

Urea and oxalic acid are critical component in various chemical manufacturing industries.However,achieving simultaneous generation of urea and oxalic acid in a continuous-flow electrolyzer is a challenge.Herein,we report a continuous-flow electrolyzer equipped with 9-square centime-ter-effective area gas diffusion electrodes(GDE)which can simultaneously catalyze the glycerol oxidation reaction in the anode region and the reduction reaction of CO_(2) and nitrate in the cathode region,producing oxalic acid and urea at both the anode and cathode,respectively.The current density at low cell voltage(0.9 V)remained above 18.7 mA cm^(-2) for 10 consecutive electrolysis cycles(120 h in total),and the Faraday efficiency of oxalic acid(67.1%) and urea(70.9%)did not decay.Experimental and theoretical studies show that in terms of the formation of C-N bond at the cathode,Pd-sites can provide protons for the hydrogenation process of CO_(2) and NO_(3)^(-),Cu-sites can promote the generation of *COOH and Bi-sites can stabilize *COOH.In addition,in terms of glycerol oxidation,the introduction of Cu and Bi into Pd metallene promotes the oxidation of hydroxyl groups and the cleavage of C-C bond in glycerol molecules,respectively.

Exploration of Earth-Abundant Transition Metals(Fe,Co,Ni)Doped on W_(18)O_(49)System as Electrocatalysts for Urea Productiont

The conversion of inert N_(2)and CO_(2)into urea by electrocatalytic technology not only reduces the cost of urea synthesis in future,but also alleviatesthe environmental pollution problem caused by carbon emission in traditional industrial production.However,facing downside factors such as strong competitive reactions and unclear reaction mechanism,the design of high-performance urea catalysts is imminent.This study demonstrates that W_(18)O_(49)system doped heteronuclear metals(TM=Fe,Co,Ni)can effectively solve the problem of competitive adsorption between N_(2)and CO_(2)and realize the co-adsorption of N_(2)and CO_(2)at diverse sites.Their theoretical limiting voltages for urea production on TM-W_(18)O_(49)(TM=Fe,Co,Ni)systems are-0.46 V,-0.42 V and-0.52 V,respectively.The results are all lower than that of the contrastive voltage in pristine W_(18)O_(49)system(-0.91 V),further indicating the rationality and necessity of single-atom doped strategy for the co-reduction of two molecules.Specially,Co-W_(18)O_(49)can theoretically inhibit the side reactions of NRR,CO_(2)RR,and HER,which deserve future experimental exploration in future.The study suggests that doping heteronuclear metal into transition metal oxides is a feasible scheme to solve competitive adsorption and improve catalytic performance.

Preparation of High-Purity Linolenic Acid from Oil of Lithospermum Erythrorhizon by Urea Inclusion and Column Chromatography

Aim To separate high purity linolenic acid from the oil of Lithospermumerythrorhizon growing in the Northeast of China. Methods Urea inclusion and column chromatographywere used. Results Unsaturated fatty acid was separated, with a purity of 99.30 wt% of linolenicacid. Conclusion The experiment shows excellent reproducibility and high feasibility for industrialproduction.

Open-celled porous NiAl intermetallics prepared by replication of carbamide space-holders

Open-celled porous NiAl intermetallics with adjustable pore characteristics and mechanical properties were successfully prepared by using spherical carbamide as space-holders via combustion synthesis.Examinations of macroscopic and microscopic morphologies as well as the quasi-static compressive test for the resultant materials were carried out.Depending on the volume fraction and particle size of the carbamide,the porosity and pore size of the porous NiAl intermetallics can be controlled freely in a range of 57.57%-84.58% and 0.4-2.0 mm,respectively.Furthermore,quasi-static compressive tests indicate that the mechanical behavior of the present porous materials is in good agreement with the Gibson-Ashby model.

Effect of Transplanting Density on Rice Yield,Nitrogen Uptake and ^(15)N-fertilizer Fate

[Objective] The aim of this study was investigated the rice yield, nitrogen uptake and ^15-fertilizer fate at different transplanting density to provide scientific ba- sis for improving the yield of rice and applying reasonably fertilizer. [Method] A field experiment was carried out to study the effect of different transplanting density on rice yield, nitrogen （N） absorption, sources of N uptake by rice and the N balance in the plant-soil systems by using ^15-labelled urea. [Result] There were no significant differences in rice yields and total N uptakes by rice between treatments 30 cm × 30 cm and 40 cm × 40 cm, but the yield of rice and total N absorption in the two treatments were remarkably higher than those in 50 cm × 50 cm treatment. The amounts of total N uptake by rice were in the range of 112.3-162.7 kg/hm2 in the three transplanting densities. The result showed that about 1/3 of the total N uptake by rice was supplied by application fertilizer and the other 2/3 was obtained from the soil N pool. The ^15N-labelled urea absorbed by rice, residual in soil and lost accounted for 16.3%-26.1%, 17.0%-20.9% and 53.0%-66.7% of the total fertilizer, respectively. A great deal of ^15N-labelled urea was lost during the rice growing season. [Conclusion] Considering the rice yield and environmental protection, the transplanting density of 30 cm×30 cm was recommended in the hilly area of Sichuan basin in the southwest China.

Study on Release Properties of Slow Release Urea Coated by Industrial Lignin

This study aimed to investigate the release properties of slow release ure- a coated by industrial lignin and the influences of temperature, pH and post-ripening period on the release of nutrients in coated urea. According to the experimental results, the release of nutrients in coated fertilizers showed an S-shaped curve; on the 28th d, the nutrient release rate reached 73.77%; the differential solubility was 1.83%, and the theoretical release period was 50.25 d. The release of nutrients was significantly influenced by temperature. As the incubation temperature rose from 25 to 40 ℃, preliminary solubility increased from 8.03% to 16.24%; differential solubility increased from 1.83% to 1.88%; theoretical release period was reduced from 51.25 d to 45.55 d. The release of nutrients was promoted by H＋ and OH-. After they were placed at room temperature within 30 d, coated fertilizers exhibited the optimal release properties.

Nitrogen recovery and nitrate leaching of controlled release nitrogen fertilizer in irrigated paddy soil

Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRNF) on reco very and nitrate leaching on paddy soils. During two early rice cropping seasons (2002 and 2003), a single basal application of CRNF at 90 kg N ha-1 increased grain yields by 7.7%to 11.6%compared with two applications of urea. Estimated by the difference method fertilizer N recovery of CRNF (mean 76.3%) was 38.9 pe rcentage point higher than that of urea (mean 37.4%); estimated by 15N isotope method (mean 49.6%) CRNF (mean 67.1%) was 35.9 percentage point higher than ur ea (mean 31.2%). NO3--N leaching losses were 9.19 and 6.70 kg ha-1 for urea and CRNF, respectively. NO3--N leaching during the early rice cropping season was 27.1 %lower from CRNF than from two applications of urea. These losses repr esent 10.2%and 7.4%of applied urea-N and CRNF-N. Results from this study ind icate that CRNF improves N recovery and reduces NO3--N leaching and increases rice yield.

Effects of Urea Ammonium Chloride of Different Fertilization Patterns on Maize Yield and Yield Components

[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.

A Comparative Study of Nitrogen Loss after Application of Biochar Coated Urea and Common Urea in Vegetable Soil at Chaihe Catchment of Dianchi Lake

[Objective] This study aimed to provide the basis for scientific and rea- sonable application of nitrogen fertilizer and control Of agricultural non-point source pollution in vegetable-growing area at Chaihe catchment of Dianchi Lake. [Method] A pot experiment was carried out to compare the loss of nitrogen via ammonia volatilization and nitrogen leaching after application of biochar coated urea （BCU） and common urea （Urea） with different nitrogen rates （0 mg N/kg soil, 400 mg N/kg soil, 320 mg N/kg soil and 280 mg N/kg soil）. [Result] The results indicated that the amount of nitrogen loss was proportional to nitrogen applied rate. Leaching nitrogen was higher than ammonia volatilization. Compare with Urea treatments, ammonia volatilization and nitrogen leaching losses were significantly lower in BCU treatments at the same nitrogen application rate. At the nitrogen application rate of 320 and 280 mg N/kg soil, nitrogen loss, ammonia volatilization and leaching nitrogen was 43.5%-45.5%, 3.7%-21.7% and 49.8%-52.1% lower in BCU treatments than in Ure- a treatments, respectively. [Conclusion] The application of BCU could minimize nitro- gen loss by reducing nitrate leaching loss. It can be concluded that the low nitrogen application rate combined with BCU have a practical influence on controlling the risk of nitrogen pollution in Dianchi Lake.

Effects of Different Diuretics on Water Drinking Amount, Urination Volume and Related Blood Indices of Sheep Fed with Cottonseed

[Objective] This study aimed to investigate the effects of three kinds of diuretics on the water drinking amount and urination volume of sheep fed with cottonseed hulls. [Method] The method of self-control was adopted. Five two-year-old male Kazak sheep about 40 kg which never had intake of the feeds containing gossypol were selected. The experiment was divided into five periods, namely the control period, a period with the supplement of 300 mg/d of hydrochlorothiazide, a period with the supplement of 200 mg/d of hydrochlorothiazide, a period with the supplement of 350 mg of GY-01 and a period with the supplement of 200 mg of GY-01. The sheep were fed with the concentrate and the cottonseed hulls in the control period, and corresponding diuretics were supplemented in the rest four periods. The water drinking amount, urination volume and the contents of the hormone and ion in the blood were determined in each period. [Result] After 350 mg GY-01 was supplemented, the water drinking amount of each sheep had an increase of 60.14% compared with that of the sheep in the control period and the urination volume was 2.67 times of that of the latter, and the differences were both significant （P0.01）. The antidiuretic hormone declined by 32.59% compared with that of the sheep in the control period, with the significant difference （P 0.05）. The adrenocorticotropic hormone content increased by 81.93% compared with that of the sheep in the control period and the difference was significant （P0.01）. An increase of 28.04% （P 0.05） and 39.39% （P 0.01） was found in the contents of serum potassium and phosphorus respectively compared with that of sheep in the control period. [Conclusion] The diet with supplement of GY-01 can increase the urination volume of livestock fed with the cottonseed hulls, and the most appropriate supplement amount is 200 mg GY-01.

Adiponectin Gene Variation -4522C/T Is Associated with Type 2 Diabetic Obesity and Insulin Resistance in Chinese

The authors investigated the possible association of -4522C/T variation of adiponectin gene with coronary heart disease （CHD） and type 2 diabetes mellitus （T2DM）. Genotyping of SNP --4522C/T in 304 patients with CHD, 389 patients with T2DM, and 405 age and sex-matched healthy control subjects was carried out by means of PCR-RFLP approach. No significant difference in the genotype or allele frequencies was found, either between patients with CHD and control subjects, or between patients with T2DM and control subjects. However, in the subgroup analysis, an association of the TAr genotype and T allele with type 2 diabetes combined with obesity （BMI ≥ 25 kg/m2） was found （P = 0.014 and P = 0.034, respectively）. Also the homeostasis model assessment of insulin resistance （HOMA-IR） in T2DM patients with T/T genotype was significantly higher than that in T2DM patients carrying C allele （P = 0.0069）. The authors＇ findings for the first time demonstrated that SNP --4522 in the adiponectin gene was associated with T2DM that combined with obesity and higher insulin resistance index in patients with T2DM. This indicated that the variation might associate with an increased susceptibility to type 2 diabetic obesity and insulin resistance. But -4522C/T polymorphism did not contribute to the susceptibility of CHD.

The Prevention and Treatment of Polysaccharide from the Rhizomorph of Armillaria mellea on Diabetic Cataract in Rat

[Objective] To investigate the prevention and control effect of polysaccharide from the rhizomorph of Armillaria mellea by distilled water elution （AMP-1） on diabetic cataract in rats.[Methods] Streptozotocin （STZ）,combined with freund＇s adjuvant （CFA）,was used to induce diabetic cataract in rat,to observe the onset of lenticular turbidity by slit lamp and compare the turbid degree of eyes lens among different groups.The super oxide dismutase （SOD）,glutathione peroxidase （GSH-px） and malondialdehyde （MDA） in serum and eyes lens were measured by colorimetric method.[Results] The slit lamp examination results showed that AMP-1 obviously delayed the onset of diabetic cataract and reduced turbid degree of eyes lens.Compared with model group,AMP-1 at various doses should significantly reduce the level of MDA ascended in serum of rats.Medium-and high-dose groups could increase the levels of SOD and GSH-Px in serum,and the dose of AMP-1 was closely related to the effect.[Conclusion] AMP-1 played a prominent role in prevention and treatment of diabetic cataract in rats.

Study on the Nitrogen Release Law of Bamboo Charcoal-coated Urea and Its Biological Utilization Effects

[Objective] The study about the nitrogen releasing law of bamboo-charcoal coated urea and the biologic utilization effect was to find the coated urea with high efficiency,low price and simple production technology.[Method]Two kinds of bamboo-charcoal coated urea(BCCU)with different coating thickness were made by using bamboo-charcoal and macromolecule polymer as coating material.The experiments of soil eluviate,ammonia volatilization in corn field and potted plant of corn were conducted to study the nitrogen releasing law and the biologic utilization effect of self-made BCCU.[Result]The BCCU showed some slow-release capability and their accumulated nitrogen releasing rates in 29 d were 9.93%-16.27% lower than that of normal urea.Compared with the normal urea,the volatilization rate of ammonia in BCCU reduced to 16.66%-31.8%,the biomass of corn and nitrogen utilization rate increased by 12.8%-24.1% and 10.5%-16.99%,respectively.[Conclusion]Bamboo-charcoal in coated urea not only had some slow-release capability,but also had some adsorbability,which would reduce the eluviation and volatilization of nitrogen and protect environment from N pollution.

Reduced secretion of epidermal growth factor in duodenal ulcer patients with Helicobacter pylori infection

AIM To investigate the concentration changes of epidermal growth factor (EGF) in duodenal ulcer patients with H. pylori infection.

Experimental Study on Prevention and Treatment of Rat Passive Hermann Nephritis (PHN) with Ligustrazine

Objective: To explore the effects of ligustrazine on proteinuria, serumcreati-nine, urinary thromboxane A_2(TxA_2), metabolism of prostacyclinI_2(PGI_2)―6-keto-PGF_(1α), and renal pathological changes of SD rats with passive Hermannnephritis (PHN). Methods: The PHN model was induced by intravenous injection of rabbit anti-ratrenal tubular epithelial antigen (Tub―Ag) an-tiserum to SD rats. I. P. administration ofligustrazine to rats was given every 2 d for 1 to 5 weeks. The proteinuria, creatinine, TxA_2 and6-keto-PGF_(1α) were measured by sulfosaticylic acid, picric acid, and direct radioimmunoassayrespectively. The renal pathological changes were observed under light microscope, electronicmicroscope and by direct immunofluorescence staining rabbit and rat IgG. Results: The PHN ratstreated with ligustrazine had significantly less proteinuria, serum creatinine, urinary TxA_2 andpathological changes of kidney, and more urinary 6-keto-PGF_(1α) than those without administrationof ligustrazine. Conclusion: Ligustrazine decreases proteinuria, urinary TxA_2, and renal tissueinjury and increases urinary 6-keto-PGF_(1α). These data indicate that ligustrazine may modulatethe balance of TxA_2 and PG I_2 in rat PHN model and can be used for preventing and treatingmembranous glomerulonephritis.

Abnormal Change in Body Weight and Non-Fasting Blood Glucose Levels of Mouse Strain C57BL/6J in Generating Type 2 Diabetes Model

The commercially available inbred obesity-prone C57BL/6J （B6） and outbred stock ICR mice （3-week old） purchased from a breeder of Beijing were weaned onto high-fat diet （HFD）, HFD-3% fructose water （HFDF） and standard rodent chow, respectively. After exposure to the diets for six weeks, HFD and HFDF fed mice were injected intraperitoneally with streptozotocin （STZ, 100mg/kg body weight） and kept on the same diet for next four weeks. Body weight was recorded weekly. Non-fasting blood glucose levels of HFD and HFDF fed mice were measured before and after STZ injections. The body weight of HFD-fed and HFDF-fed B6 mice were significantly lower than that of the control, but body weight of HFD-fed and HFDF-fed ICR mice were significantly higher than that of the control. After injection of STZ, blood glucose levels were above the stardardized criterion （11 mmol/L） for the diabetes mouse model in both HFD and HFDF fed ICR mice, but reverse in B6 mice. The type 2 diabetes model was generated successfully in ICR but not in B6 mice, regardless of whether fructose was supplied. The current results indicated that ICR mouse is still a useful and economical strain for HFD-induced/STZ-treated type 2 diabetes model, and that some variation may occur in the genetic composition among B6 mice bred by different breeders.

糖尿病肾损害的评价指标

目的探讨联合检测血清胱抑素C(CysC)及尿微量白蛋白/肌酐(A/C)在评估糖尿病早期肾损害中的诊断价值。方法选取2008年6月至2011年12月间包头一附院收治的220例2型糖尿病(DM2)患者,根据尿白蛋白排泄率(UAER)分为三组:DM组,DN1组、DN2组,同时选择同期我院健康体检者75例作为正常对照组(NC组),同时检测血CysC及尿A/C,对检测结果行统计学分析。结果与NC组比较,其余实验组血CysC及尿A/C均升高,有统计学差异(P<0.05),且DN2组血CysC及尿A/C明显高于DN1组(P<0.05),各组血CysC及尿A/C联合检测时阳性率升高,且两项指标间存在显著正相关;结论除目前公认的评价糖尿病早期肾损害的指标尿A/C外,血CysC也可作为评价糖尿病早期肾损害的敏感指标,且联合检测具有更高的临床价值。

一批肥料国家标准将于2018年7月1日起实施

2018年1月24日,国家质量监督检验检疫总局和国家标准化管理委员会全文公开2017年第32号中国国家标准公告。其中涉及12项制修订肥料行业推荐性国家标准和2项施肥相关农机标准,自2018年7月1日起施行。《尿素》新标准最主要的变化是调整总氮、缩二脲等指标。农业用（肥料）尿素优等品的总氮质量分数须不低于46%,水分不高于0.5%;合格品的总氮质量分数不低于45%;

Fate of ^(15)N-Labeled Urea Under a Winter Wheat-Summer Maize Rotation on the North China Plain

A field experiment was conducted to investigate the fate of ^15N-labeled urea and its residual effect under the winter wheat （Triticum aestivum L.） and summer maize （Zea mays L.） rotation system on the North China Plain. Compared to a conventional application rate of 360 kg N ha^-1 （N360）, a reduced rate of 120 kg N ha^-1 （N120） led to a significant increase （P 〈 0.05） in wheat yield and no significant differences were found for maize. However, in the 0-100 cm soil profile at harvest, compared with N360, N120 led to significant decreases （P 〈 0.05） of percent residual N and percent unaccounted-for N, which possibly reflected losses from the managed system. Of the residual fertilizer N in the soil profile, 25.6%-44.7% and 20.7%-38.2% for N120 and N360, respectively, were in the organic N pool, whereas 0.3%-3.0% and 11.2%-24.4%, correspondingly, were in the nitrate pool, indicating a higher potential for leaching loss associated with application at the conventional rate. Recovery of residual N in the soil profile by succeeding crops was less than 7.5% of the applied N. For N120, total soil N balance was negative; however, there was still considerable mineral N （NH4^＋-N and NO3^--N） in the soil profile after harvest. Therefore, N120 could be considered ngronomically acceptable in the short run, but for long-term sustainability, the N rate should be recommended based on a soil mineral N test and a plant tissue nitrate test to maintain the soil fertility.