Dietary Plant Sterols Supplementation Increases In Vivo Nitrite and Nitrate Production in Healthy Adults: A Randomized,Controlled Study

A randomized, double‐blinded, placebo‐controlled and crossover study was conducted to simultaneously measure the effects, 3 h after consumption and after 4‐wk daily exposure to plant sterols‐enriched food product, on in vivo nitrite and nitrate production in healthy adults. Eighteen healthy participants (67% female, 35.3 [mean] ± 9.5 [SD] years, mean body mass index 22.8 kg/m²) received 2 soy milk (20 g) treatments daily: placebo and one containing 2.0 g free plant sterols equivalent of their palmityl esters (β‐sitosterol, 55%; campesterol, 29%; and stigmasterol, 23%). Nitrite and nitrate concentrations were measured in the blood plasma and urine, using stable isotope‐labeled gas chromatography‐mass spectrometry. L‐arginine and asymmetric dimethylarginine concentrations in blood serum were measured using commercially available enzyme immunoassays. Nitrite and nitrate concentrations in blood plasma (nitrite 5.83 ± 0.50 vs. 4.52 ± 0.27; nitrate 15.78 ± 0.96 vs. 13.43 ± 0.81 μmol/L) and urine (nitrite 1.12 ± 0.22 vs. 0.92 ± 0.36, nitrate 12.23 ± 1.15 vs. 9.71 ± 2.04 μmol/L) were significantly elevated after 4‐wk plant sterols supplementation Placebo and 3‐h treatments did not affect the blood plasma and urinary concentrations of nitrite and nitrate. Circulating levels of L‐arginine and asymmetric dimethylarginine were unchanged in the placebo and treatment arms. Total plant sterols, β‐Sitosterol, campesterol, and stigmasterol concentrations were significantly elevated after 4‐wk treatments compared to the placebo and 3‐h treatments. Blood plasma nitrite and nitrate concentrations correlated significantly with the plasma total and specific plant sterol concentrations. Our results suggest that dietary plant sterols, in the combination used, can upregulate nitrite, and nitrate production in vivo.     

偏钒酸钾-硝酸铊纳米复合粉体的制备及其光催化降解苏丹红Ⅱ号的研究

采用硝酸铊、偏钒酸钾、亚硫酸钠、二氧化锰为反应原料,经过水热法合成出了偏钒酸钾-硝酸铊纳米复合粉体,活化该复合粉体后考察其对苏丹红Ⅱ号的降解能力,并对粉体进行SEM、XRD、XPS表征。实验结果表明,偏钒酸钾掺杂量为2.5%(质量分数)的复合粉体具有最强的催化活性,25 mg的偏钒酸钾-硝酸铊纳米复合粉体可对200 m L浓度为1×10~(-3)mol/L的苏丹红溶液有效降解。     

Catalytic ozonation of ethyl benzene using modified pumice with magnesium nitrate from polluted air

This paper reports a novel technology developed for a Catalytic Ozonation Process (COP) to treat polluted air streams containing ethyl benzene. Raw pumice was modified with magnesium nitrate, and then used as a catalyst in the COP. The best removal efficiency of ethyl benzene for single ozonation and single modified pumice was 58–80%, respectively at 50 ppm of this pollutant, while the maximum removal efficiency of ethyl benzene was 90% for COP (6 L/min of flow rate of inlet air, 15 g of the adsorbent, and 50 ppm of ethyl benzene). The saturation and breaking point of the catalyst in low concentrations occurred after 12 h, which was later than single ozonation. According to the results obtained, pumice modified with magnesium can be used as a cost effective, efficient and suitable catalyst to treat polluted air containing volatile organic compounds in the oil refining industries.     

高纯硝酸锶的工艺研究

从反应原理出发,以工业碳酸锶或其次品为原料,经过工业硝酸酸化、利用同离子效应除去大部分钡、再次沉淀去除钡和铁及其他杂质,然后蒸发浓缩、结晶去除钙等碱土金属和碱金属、过滤烘干,制得高纯硝酸锶。通过正交实验,找出了合适的除钡工艺参数、除铁工艺参数,并确定了结晶的工艺参数及所得成品的烘干温度。通过以上方式制得的产品纯度高、质量好,对实际生产具有很好的指导意义。     

小苗膜下移栽对烤烟硝酸还原酶、转化酶活性及致香物质的影响

为了更好地应用小苗膜下移栽技术,进行了小苗膜下移栽与常规地膜覆盖膜上移栽对比试验,对其生理效应进行了研究。结果表明,与常规移栽相比,采用小苗膜下移栽方式的根系阳离子交换量（CEC）分别在团棵期、旺长期、成熟期提高1.37、1.50、1.51倍,差异均达到显著水平;叶片硝酸还原酶（NR）活性分别在团棵期、旺长期、成熟期提高1.4、1.31、1.49倍;叶片蔗糖转化酶（INV）活性分别在团棵期、旺长期、成熟期提高1.2、1.4、1.4倍;烟株干物质积累,根部干重在团棵期、旺长期、成熟期分别提高2.7、1.4、1.2倍,在团棵期差异达到显著水平;叶片干质量在团棵期、旺长期、成熟期分别高于对照1.3、1.1、1.3倍,现蕾期差异达到显著水平;烟叶中性致香物质含量显著提高,尤其对香气质量产生重大影响的类胡萝卜素类降解产物总量提高1.51倍,类西柏烷类的茄酮含量提高1.47倍;烟叶化学成分品质指标更接近优质烟叶指标的要求。     

浅谈木粉在膨化硝铵炸药中的物理敏化作用

文章通过分析和生产实践,提出木粉作为膨化硝铵炸药的一种组分,具有物理敏化的重要作用。木粉可改善膨化硝铵炸药管道效应作用,并提出加强炸药管道效应的研究以及建立炸药管道效应检测标准的建议。     

Dissociation of outer membrane for Escherichia coli cell caused by cerium nitrate

The biological effect of cerium nitrate on the outer membrane(OM) of Escherichia coli(E.coli) cell was studied,and the antim-icrobial mechanism of rare earth elements was explored.The antimicrobial effect of cerium nitrate on E.coli cell was valued by plate count method,and the morphology change of E.coli cell was observed with scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The results showed that the E.coli cell suspension was flocculated when the concentration of Ce(NO3)3?6H2O...     

硝酸锰对PMN-PZT热释电陶瓷性能的影响

研究了硝酸锰溶液掺杂对富锆铌镁酸铅-锆钛酸铅(PMN-PZT)热释电陶瓷材料的相组成、微观结构、介电性能、热释电性能等方面的影响,并对实验结果作出物理机理的解释。实验结果表明,以液态硝酸锰的形式进行锰掺杂使锰的加入更容易,有效改善了固态锰掺杂时析出损失和混合不均等问题;适量的硝酸锰溶液掺杂有助于陶瓷晶粒的生长,能有效地降低PMN-PZT陶瓷材料的相对介电常数(rε)和介电损耗(tanδ),并增加其热释电系数(p);在x(Mn)=3.0%时,制备出综合热释电性能良好的PMN-PZT热释电陶瓷,即室温时rε=197,tanδ=0.15%,p=3.5×10-8C/cm2℃,探测优值FD=8.7×10-5Pa-1/2,低温铁电相-高温铁电相(FRL-FRH)相变温度时rε=300,tanδ=0.45%,pmax=35×10-8C/cm2℃,FD=40.5×10-5Pa-1/2,符合制作热释电红外探测器的要求。